Types of Splines

There are 4 types of splines: Involute, Parallel key, helical, and ball. Learn about their characteristics. And, if you’re not sure what they are, you can always request a quotation. These splines are commonly used for building special machinery, repair jobs, and other applications. The CZPT Manufacturing Company manufactures these shafts. It is a specialty manufacturer and we welcome your business.

Involute splines

The involute spline provides a more rigid and durable structure, and is available in a variety of diameters and spline counts. Generally, steel, carbon steel, or titanium are used as raw materials. Other materials, such as carbon fiber, may be suitable. However, titanium can be difficult to produce, so some manufacturers make splines using other constituents.
When splines are used in shafts, they prevent parts from separating during operation. These features make them an ideal choice for securing mechanical assemblies. Splines with inward-curving grooves do not have sharp corners and are therefore less likely to break or separate while they are in operation. These properties help them to withstand high-speed operations, such as braking, accelerating, and reversing.
A male spline is fitted with an externally-oriented face, and a female spline is inserted through the center. The teeth of the male spline typically have chamfered tips to provide clearance with the transition area. The radii and width of the teeth of a male spline are typically larger than those of a female spline. These specifications are specified in ANSI or DIN design manuals.
The effective tooth thickness of a spline depends on the involute profile error and the lead error. Also, the spacing of the spline teeth and keyways can affect the effective tooth thickness. Involute splines in a splined shaft are designed so that at least 25 percent of the spline teeth engage during coupling, which results in a uniform distribution of load and wear on the spline.

Parallel key splines

A parallel splined shaft has a helix of equal-sized grooves around its circumference. These grooves are generally parallel or involute. Splines minimize stress concentrations in stationary joints and allow linear and rotary motion. Splines may be cut or cold-rolled. Cold-rolled splines have more strength than cut spines and are often used in applications that require high strength, accuracy, and a smooth surface.
A parallel key splined shaft features grooves and keys that are parallel to the axis of the shaft. This design is best suited for applications where load bearing is a primary concern and a smooth motion is needed. A parallel key splined shaft can be made from alloy steels, which are iron-based alloys that may also contain chromium, nickel, molybdenum, copper, or other alloying materials.
A splined shaft can be used to transmit torque and provide anti-rotation when operating as a linear guide. These shafts have square profiles that match up with grooves in a mating piece and transmit torque and rotation. They can also be easily changed in length, and are commonly used in aerospace. Its reliability and fatigue life make it an excellent choice for many applications.
The main difference between a parallel key splined shaft and a keyed shaft is that the former offers more flexibility. They lack slots, which reduce torque-transmitting capacity. Splines offer equal load distribution along the gear teeth, which translates into a longer fatigue life for the shaft. In agricultural applications, shaft life is essential. Agricultural equipment, for example, requires the ability to function at high speeds for extended periods of time.

Involute helical splines

Involute splines are a common design for splined shafts. They are the most commonly used type of splined shaft and feature equal spacing among their teeth. The teeth of this design are also shorter than those of the parallel spline shaft, reducing stress concentration. These splines can be used to transmit power to floating or permanently fixed gears, and reduce stress concentrations in the stationary joint. Involute splines are the most common type of splined shaft, and are widely used for a variety of applications in automotive, machine tools, and more.
Involute helical spline shafts are ideal for applications involving axial motion and rotation. They allow for face coupling engagement and disengagement. This design also allows for a larger diameter than a parallel spline shaft. The result is a highly efficient gearbox. Besides being durable, splines can also be used for other applications involving torque and energy transfer.
A new statistical model can be used to determine the number of teeth that engage for a given load. These splines are characterized by a tight fit at the major diameters, thereby transferring concentricity from the shaft to the female spline. A male spline has chamfered tips for clearance with the transition area. ANSI and DIN design manuals specify the different classes of fit.
The design of involute helical splines is similar to that of gears, and their ridges or teeth are matched with the corresponding grooves in a mating piece. It enables torque and rotation to be transferred to a mate piece while maintaining alignment of the 2 components. Different types of splines are used in different applications. Different splines can have different levels of tooth height.

Involute ball splines

When splines are used, they allow the shaft and hub to engage evenly over the shaft’s entire circumference. Because the teeth are evenly spaced, the load that they can transfer is uniform and their position is always the same regardless of shaft length. Whether the shaft is used to transmit torque or to transmit power, splines are a great choice. They provide maximum strength and allow for linear or rotary motion.
There are 3 basic types of splines: helical, crown, and ball. Crown splines feature equally spaced grooves. Crown splines feature involute sides and parallel sides. Helical splines use involute teeth and are often used in small diameter shafts. Ball splines contain a ball bearing inside the splined shaft to facilitate rotary motion and minimize stress concentration in stationary joints.
The 2 types of splines are classified under the ANSI classes of fit. Fillet root splines have teeth that mesh along the longitudinal axis of rotation. Flat root splines have similar teeth, but are intended to optimize strength for short-term use. Both types of splines are important for ensuring the shaft aligns properly and is not misaligned.
The friction coefficient of the hub is a complex process. When the hub is off-center, the center moves in predictable but irregular motion. Moreover, when the shaft is centered, the center may oscillate between being centered and being off-center. To compensate for this, the torque must be adequate to keep the shaft in its axis during all rotation angles. While straight-sided splines provide similar centering, they have lower misalignment load factors.

Keyed shafts

Essentially, splined shafts have teeth or ridges that fit together to transfer torque. Because splines are not as tall as involute gears, they offer uniform torque transfer. Additionally, they provide the opportunity for torque and rotational changes and improve wear resistance. In addition to their durability, splined shafts are popular in the aerospace industry and provide increased reliability and fatigue life.
Keyed shafts are available in different materials, lengths, and diameters. When used in high-power drive applications, they offer higher torque and rotational speeds. The higher torque they produce helps them deliver power to the gearbox. However, they are not as durable as splined shafts, which is why the latter is usually preferred in these applications. And while they’re more expensive, they’re equally effective when it comes to torque delivery.
Parallel keyed shafts have separate profiles and ridges and are used in applications requiring accuracy and precision. Keyed shafts with rolled splines are 35% stronger than cut splines and are used where precision is essential. These splines also have a smooth finish, which can make them a good choice for precision applications. They also work well with gears and other mechanical systems that require accurate torque transfer.
Carbon steel is another material used for splined shafts. Carbon steel is known for its malleability, and its shallow carbon content helps create reliable motion. However, if you’re looking for something more durable, consider ferrous steel. This type contains metals such as nickel, chromium, and molybdenum. And it’s important to remember that carbon steel is not the only material to consider.

Standard Length Splined Shafts

Standard Length Splined Shafts are made from Mild Steel and are perfect for most repair jobs, custom machinery building, and many other applications. All stock splined shafts are 2-3/4 inches in length, and full splines are available in any length, with additional materials and working lengths available upon request and quotation. CZPT Manufacturing Company is proud to offer these standard length shafts.

Disc brake mounting interfaces that are splined

There are 2 common disc brake mounting interfaces, splined and center lock. Disc brakes with splined interfaces are more common. They are usually easier to install. The center lock system requires a tool to remove the locking ring on the disc hub. Six-bolt rotors are easier to install and require only 6 bolts. The center lock system is commonly used with performance road bikes.
Post mount disc brakes require a post mount adapter, while flat mount disc brakes do not. Post mount adapters are more common and are used for carbon mountain bikes, while flat mount interfaces are becoming the norm on road and gravel bikes. All disc brake adapters are adjustable for rotor size, though. Road bikes usually use 160mm rotors while mountain bikes use rotors that are 180mm or 200mm.

Disc brake mounting interfaces that are helical splined

A helical splined disc brake mounting interface is designed with a splined connection between the hub and brake disc. This splined connection allows for a relatively large amount of radial and rotational displacement between the disc and hub. A loosely splined interface can cause a rattling noise due to the movement of the disc in relation to the hub.
The splines on the brake disc and hub are connected via an air gap. The air gap helps reduce heat conduction from the brake disc to the hub. The present invention addresses problems of noise, heat, and retraction of brake discs at the release of the brake. It also addresses issues with skewing and dragging. If you’re unsure whether this type of mounting interface is right for you, consult your mechanic.
Disc brake mounting interfaces that are helix-splined may be used in conjunction with other components of a wheel. They are particularly useful in disc brake mounting interfaces for hub-to-hub assemblies. The spacer elements, which are preferably located circumferentially, provide substantially the same function no matter how the brake disc rotates. Preferably, 3 spacer elements are located around the brake disc. Each of these spacer elements has equal clearance between the splines of the brake disc and the hub.
Spacer elements 6 include a helical spring portion 6.1 and extensions in tangential directions that terminate in hooks 6.4. These hooks abut against the brake disc 1 in both directions. The helical spring portion 5.1 and 6.1 have stiffness enough to absorb radial impacts. The spacer elements are arranged around the circumference of the intermeshing zone.
A helical splined disc mount includes a stabilizing element formed as a helical spring. The helical spring extends to the disc’s splines and teeth. The ends of the extension extend in opposite directions, while brackets at each end engage with the disc’s splines and teeth. This stabilizing element is positioned axially over the disc’s width.
Helical splined disc brake mounting interfaces are popular in bicycles and road bicycles. They’re a reliable, durable way to mount your brakes. Splines are widely used in aerospace, and have a higher fatigue life and reliability. The interfaces between the splined disc brake and BB spindle are made from aluminum and acetate.
As the splined hub mounts the disc in a helical fashion, the spring wire and disc 2 will be positioned in close contact. As the spring wire contacts the disc, it creates friction forces that are evenly distributed throughout the disc. This allows for a wide range of axial motion. Disc brake mounting interfaces that are helical splined have higher strength and stiffness than their counterparts.
Disc brake mounting interfaces that are helically splined can have a wide range of splined surfaces. The splined surfaces are the most common type of disc brake mounting interfaces. They are typically made of stainless steel or aluminum and can be used for a variety of applications. However, a splined disc mount will not support a disc with an oversized brake caliper.

The Different Types of Splines in a Splined Shaft

A splined shaft is a machine component with internal and external splines. The splines are formed in 4 different ways: Involute, Parallel, Serrated, and Ball. You can learn more about each type of spline in this article. When choosing a splined shaft, be sure to choose the right 1 for your application. Read on to learn about the different types of splines and how they affect the shaft’s performance.

Involute splines

Involute splines in a splined shaft are used to secure and extend mechanical assemblies. They are smooth, inwardly curving grooves that resist separation during operation. A shaft with involute splines is often longer than the shaft itself. This feature allows for more axial movement. This is beneficial for many applications, especially in a gearbox.
The involute spline is a shaped spline, similar to a parallel spline. It is angled and consists of teeth that create a spiral pattern that enables linear and rotatory motion. It is distinguished from other splines by the serrations on its flanks. It also has a flat top. It is a good option for couplers and other applications where angular movement is necessary.
Involute splines are also called involute teeth because of their shape. They are flat on the top and curved on the sides. These teeth can be either internal or external. As a result, involute splines provide greater surface contact, which helps reduce stress and fatigue. Regardless of the shape, involute splines are generally easy to machine and fit.
Involute splines are a type of splines that are used in splined shafts. These splines have different names, depending on their diameters. An example set of designations is for a 32-tooth male spline, a 2,500-tooth module, and a 30 degree pressure angle. An example of a female spline, a fillet root spline, is used to describe the diameter of the splined shaft.
The effective tooth thickness of splines is dependent on the number of keyways and the type of spline. Involute splines in splined shafts should be designed to engage 25 to 50 percent of the spline teeth during the coupling. Involute splines should be able to withstand the load without cracking.

Parallel splines

Parallel splines are formed on a splined shaft by putting 1 or more teeth into another. The male spline is positioned at the center of the female spline. The teeth of the male spline are also parallel to the shaft axis, but a common misalignment causes the splines to roll and tilt. This is common in many industrial applications, and there are a number of ways to improve the performance of splines.
Typically, parallel splines are used to reduce friction in a rotating part. The splines on a splined shaft are narrower on the end face than the interior, which makes them more prone to wear. This type of spline is used in a variety of industries, such as machinery, and it also allows for greater efficiency when transmitting torque.
Involute splines on a splined shaft are the most common. They have equally spaced teeth, and are therefore less likely to crack due to fatigue. They also tend to be easy to cut and fit. However, they are not the best type of spline. It is important to understand the difference between parallel and involute splines before deciding on which spline to use.
The difference between splined and involute splines is the size of the grooves. Involute splines are generally larger than parallel splines. These types of splines provide more torque to the gear teeth and reduce stress during operation. They are also more durable and have a longer life span. And because they are used on farm machinery, they are essential in this type of application.

Serrated splines

A Serrated Splined Shaft has several advantages. This type of shaft is highly adjustable. Its large number of teeth allows large torques, and its shorter tooth width allows for greater adjustment. These features make this type of shaft an ideal choice for applications where accuracy is critical. Listed below are some of the benefits of this type of shaft. These benefits are just a few of the advantages. Learn more about this type of shaft.
The process of hobbing is inexpensive and highly accurate. It is useful for external spline shafts, but is not suitable for internal splines. This type of process forms synchronized shapes on the shaft, reducing the manufacturing cycle and stabilizing the relative phase between spline and thread. It uses a grinding wheel to shape the shaft. CZPT Manufacturing has a large inventory of Serrated Splined Shafts.
The teeth of a Serrated Splined Shaft are designed to engage with the hub over the entire circumference of the shaft. The teeth of the shaft are spaced uniformly around the spline, creating a multiple-tooth point of contact over the entire length of the shaft. The results of these analyses are usually satisfactory. But there are some limitations. To begin with, the splines of the Serrated Splined Shaft should be chosen carefully. If the application requires large-scale analysis, it may be necessary to modify the design.
The splines of the Serrated Splined Shaft are also used for other purposes. They can be used to transmit torque to another device. They also act as an anti-rotational device and function as a linear guide. Both the design and the type of splines determine the function of the Splined Shaft. In the automobile industry, they are used in vehicles, aerospace, earth-moving machinery, and many other industries.

Ball splines

The invention relates to a ball-spinned shaft. The shaft comprises a plurality of balls that are arranged in a series and are operatively coupled to a load path section. The balls are capable of rolling endlessly along the path. This invention also relates to a ball bearing. Here, a ball bearing is 1 of the many types of gears. The following discussion describes the features of a ball bearing.
A ball-splined shaft assembly comprises a shaft with at least 1 ball-spline groove and a plurality of circumferential step grooves. The shaft is held in a first holding means that extends longitudinally and is rotatably held by a second holding means. Both the shaft and the first holding means are driven relative to 1 another by a first driving means. It is possible to manufacture a ball-splined shaft in a variety of ways.
A ball-splined shaft features a nut with recirculating balls. The ball-splined nut rides in these grooves to provide linear motion while preventing rotation. A splined shaft with a nut that has recirculating balls can also provide rotary motion. A ball splined shaft also has higher load capacities than a ball bushing. For these reasons, ball splines are an excellent choice for many applications.
In this invention, a pair of ball-spinned shafts are housed in a box under a carrier device 40. Each of the 2 shafts extends along a longitudinal line of arm 50. One end of each shaft is supported rotatably by a slide block 56. The slide block also has a support arm 58 that supports the center arm 50 in a cantilever fashion.

Sector no-go gage

A no-go gauge is a tool that checks the splined shaft for oversize. It is an effective way to determine the oversize condition of a splined shaft without removing the shaft. It measures external splines and serrations. The no-go gage is available in sizes ranging from 19mm to 130mm with a 25mm profile length.
The sector no-go gage has 2 groups of diametrally opposed teeth. The space between them is manufactured to a maximum space width and the tooth thickness must be within a predetermined tolerance. This gage would be out of tolerance if the splines were measured with a pin. The dimensions of this splined shaft can be found in the respective ANSI or DIN standards.
The go-no-go gage is useful for final inspection of thread pitch diameter. It is also useful for splined shafts and threaded nuts. The thread of a screw must match the contour of the go-no-go gage head to avoid a no-go condition. There is no substitute for a quality machine. It is an essential tool for any splined shaft and fastener manufacturer.
The NO-GO gage can detect changes in tooth thickness. It can be calibrated under ISO17025 standards and has many advantages over a non-go gage. It also gives a visual reference of the thickness of a splined shaft. When the teeth match, the shaft is considered ready for installation. It is a critical process. In some cases, it is impossible to determine the precise length of the shaft spline.
The 45-degree pressure angle is most commonly used for axles and torque-delivering members. This pressure angle is the most economical in terms of tool life, but the splines will not roll neatly like a 30 degree angle. The 45-degree spline is more likely to fall off larger than the other two. Oftentimes, it will also have a crowned look. The 37.5 degree pressure angle is a compromise between the other 2 pressure angles. It is often used when the splined shaft material is harder than usual.

How to Calculate Stiffness, Centering Force, Wear and Fatigue Failure of Spline Couplings

There are various types of spline couplings. These couplings have several important properties. These properties are: Stiffness, Involute splines, Misalignment, Wear and fatigue failure. To understand how these characteristics relate to spline couplings, read this article. It will give you the necessary knowledge to determine which type of coupling best suits your needs. Keeping in mind that spline couplings are usually spherical in shape, they are made of steel.

Involute splines

An effective side interference condition minimizes gear misalignment. When 2 splines are coupled with no spline misalignment, the maximum tensile root stress shifts to the left by 5 mm. A linear lead variation, which results from multiple connections along the length of the spline contact, increases the effective clearance or interference by a given percentage. This type of misalignment is undesirable for coupling high-speed equipment.
Involute splines are often used in gearboxes. These splines transmit high torque, and are better able to distribute load among multiple teeth throughout the coupling circumference. The involute profile and lead errors are related to the spacing between spline teeth and keyways. For coupling applications, industry practices use splines with 25 to 50-percent of spline teeth engaged. This load distribution is more uniform than that of conventional single-key couplings.
To determine the optimal tooth engagement for an involved spline coupling, Xiangzhen Xue and colleagues used a computer model to simulate the stress applied to the splines. The results from this study showed that a “permissible” Ruiz parameter should be used in coupling. By predicting the amount of wear and tear on a crowned spline, the researchers could accurately predict how much damage the components will sustain during the coupling process.
There are several ways to determine the optimal pressure angle for an involute spline. Involute splines are commonly measured using a pressure angle of 30 degrees. Similar to gears, involute splines are typically tested through a measurement over pins. This involves inserting specific-sized wires between gear teeth and measuring the distance between them. This method can tell whether the gear has a proper tooth profile.
The spline system shown in Figure 1 illustrates a vibration model. This simulation allows the user to understand how involute splines are used in coupling. The vibration model shows 4 concentrated mass blocks that represent the prime mover, the internal spline, and the load. It is important to note that the meshing deformation function represents the forces acting on these 3 components.

Stiffness of coupling

The calculation of stiffness of a spline coupling involves the measurement of its tooth engagement. In the following, we analyze the stiffness of a spline coupling with various types of teeth using 2 different methods. Direct inversion and blockwise inversion both reduce CPU time for stiffness calculation. However, they require evaluation submatrices. Here, we discuss the differences between these 2 methods.
The analytical model for spline couplings is derived in the second section. In the third section, the calculation process is explained in detail. We then validate this model against the FE method. Finally, we discuss the influence of stiffness nonlinearity on the rotor dynamics. Finally, we discuss the advantages and disadvantages of each method. We present a simple yet effective method for estimating the lateral stiffness of spline couplings.
The numerical calculation of the spline coupling is based on the semi-analytical spline load distribution model. This method involves refined contact grids and updating the compliance matrix at each iteration. Hence, it consumes significant computational time. Further, it is difficult to apply this method to the dynamic analysis of a rotor. This method has its own limitations and should be used only when the spline coupling is fully investigated.
The meshing force is the force generated by a misaligned spline coupling. It is related to the spline thickness and the transmitting torque of the rotor. The meshing force is also related to the dynamic vibration displacement. The result obtained from the meshing force analysis is given in Figures 7, 8, and 9.
The analysis presented in this paper aims to investigate the stiffness of spline couplings with a misaligned spline. Although the results of previous studies were accurate, some issues remained. For example, the misalignment of the spline may cause contact damages. The aim of this article is to investigate the problems associated with misaligned spline couplings and propose an analytical approach for estimating the contact pressure in a spline connection. We also compare our results to those obtained by pure numerical approaches.

Misalignment

To determine the centering force, the effective pressure angle must be known. Using the effective pressure angle, the centering force is calculated based on the maximum axial and radial loads and updated Dudley misalignment factors. The centering force is the maximum axial force that can be transmitted by friction. Several published misalignment factors are also included in the calculation. A new method is presented in this paper that considers the cam effect in the normal force.
In this new method, the stiffness along the spline joint can be integrated to obtain a global stiffness that is applicable to torsional vibration analysis. The stiffness of bearings can also be calculated at given levels of misalignment, allowing for accurate estimation of bearing dimensions. It is advisable to check the stiffness of bearings at all times to ensure that they are properly sized and aligned.
A misalignment in a spline coupling can result in wear or even failure. This is caused by an incorrectly aligned pitch profile. This problem is often overlooked, as the teeth are in contact throughout the involute profile. This causes the load to not be evenly distributed along the contact line. Consequently, it is important to consider the effect of misalignment on the contact force on the teeth of the spline coupling.
The centre of the male spline in Figure 2 is superposed on the female spline. The alignment meshing distances are also identical. Hence, the meshing force curves will change according to the dynamic vibration displacement. It is necessary to know the parameters of a spline coupling before implementing it. In this paper, the model for misalignment is presented for spline couplings and the related parameters.
Using a self-made spline coupling test rig, the effects of misalignment on a spline coupling are studied. In contrast to the typical spline coupling, misalignment in a spline coupling causes fretting wear at a specific position on the tooth surface. This is a leading cause of failure in these types of couplings.

Wear and fatigue failure

The failure of a spline coupling due to wear and fatigue is determined by the first occurrence of tooth wear and shaft misalignment. Standard design methods do not account for wear damage and assess the fatigue life with big approximations. Experimental investigations have been conducted to assess wear and fatigue damage in spline couplings. The tests were conducted on a dedicated test rig and special device connected to a standard fatigue machine. The working parameters such as torque, misalignment angle, and axial distance have been varied in order to measure fatigue damage. Over dimensioning has also been assessed.
During fatigue and wear, mechanical sliding takes place between the external and internal splines and results in catastrophic failure. The lack of literature on the wear and fatigue of spline couplings in aero-engines may be due to the lack of data on the coupling’s application. Wear and fatigue failure in splines depends on a number of factors, including the material pair, geometry, and lubrication conditions.
The analysis of spline couplings shows that over-dimensioning is common and leads to different damages in the system. Some of the major damages are wear, fretting, corrosion, and teeth fatigue. Noise problems have also been observed in industrial settings. However, it is difficult to evaluate the contact behavior of spline couplings, and numerical simulations are often hampered by the use of specific codes and the boundary element method.
The failure of a spline gear coupling was caused by fatigue, and the fracture initiated at the bottom corner radius of the keyway. The keyway and splines had been overloaded beyond their yield strength, and significant yielding was observed in the spline gear teeth. A fracture ring of non-standard alloy steel exhibited a sharp corner radius, which was a significant stress raiser.
Several components were studied to determine their life span. These components include the spline shaft, the sealing bolt, and the graphite ring. Each of these components has its own set of design parameters. However, there are similarities in the distributions of these components. Wear and fatigue failure of spline couplings can be attributed to a combination of the 3 factors. A failure mode is often defined as a non-linear distribution of stresses and strains.

How to Calculate Stiffness, Centering Force, Wear and Fatigue Failure of Spline Couplings

There are various types of spline couplings. These couplings have several important properties. These properties are: Stiffness, Involute splines, Misalignment, Wear and fatigue failure. To understand how these characteristics relate to spline couplings, read this article. It will give you the necessary knowledge to determine which type of coupling best suits your needs. Keeping in mind that spline couplings are usually spherical in shape, they are made of steel.

Involute splines

An effective side interference condition minimizes gear misalignment. When 2 splines are coupled with no spline misalignment, the maximum tensile root stress shifts to the left by 5 mm. A linear lead variation, which results from multiple connections along the length of the spline contact, increases the effective clearance or interference by a given percentage. This type of misalignment is undesirable for coupling high-speed equipment.
Involute splines are often used in gearboxes. These splines transmit high torque, and are better able to distribute load among multiple teeth throughout the coupling circumference. The involute profile and lead errors are related to the spacing between spline teeth and keyways. For coupling applications, industry practices use splines with 25 to 50-percent of spline teeth engaged. This load distribution is more uniform than that of conventional single-key couplings.
To determine the optimal tooth engagement for an involved spline coupling, Xiangzhen Xue and colleagues used a computer model to simulate the stress applied to the splines. The results from this study showed that a “permissible” Ruiz parameter should be used in coupling. By predicting the amount of wear and tear on a crowned spline, the researchers could accurately predict how much damage the components will sustain during the coupling process.
There are several ways to determine the optimal pressure angle for an involute spline. Involute splines are commonly measured using a pressure angle of 30 degrees. Similar to gears, involute splines are typically tested through a measurement over pins. This involves inserting specific-sized wires between gear teeth and measuring the distance between them. This method can tell whether the gear has a proper tooth profile.
The spline system shown in Figure 1 illustrates a vibration model. This simulation allows the user to understand how involute splines are used in coupling. The vibration model shows 4 concentrated mass blocks that represent the prime mover, the internal spline, and the load. It is important to note that the meshing deformation function represents the forces acting on these 3 components.

Stiffness of coupling

The calculation of stiffness of a spline coupling involves the measurement of its tooth engagement. In the following, we analyze the stiffness of a spline coupling with various types of teeth using 2 different methods. Direct inversion and blockwise inversion both reduce CPU time for stiffness calculation. However, they require evaluation submatrices. Here, we discuss the differences between these 2 methods.
The analytical model for spline couplings is derived in the second section. In the third section, the calculation process is explained in detail. We then validate this model against the FE method. Finally, we discuss the influence of stiffness nonlinearity on the rotor dynamics. Finally, we discuss the advantages and disadvantages of each method. We present a simple yet effective method for estimating the lateral stiffness of spline couplings.
The numerical calculation of the spline coupling is based on the semi-analytical spline load distribution model. This method involves refined contact grids and updating the compliance matrix at each iteration. Hence, it consumes significant computational time. Further, it is difficult to apply this method to the dynamic analysis of a rotor. This method has its own limitations and should be used only when the spline coupling is fully investigated.
The meshing force is the force generated by a misaligned spline coupling. It is related to the spline thickness and the transmitting torque of the rotor. The meshing force is also related to the dynamic vibration displacement. The result obtained from the meshing force analysis is given in Figures 7, 8, and 9.
The analysis presented in this paper aims to investigate the stiffness of spline couplings with a misaligned spline. Although the results of previous studies were accurate, some issues remained. For example, the misalignment of the spline may cause contact damages. The aim of this article is to investigate the problems associated with misaligned spline couplings and propose an analytical approach for estimating the contact pressure in a spline connection. We also compare our results to those obtained by pure numerical approaches.

Misalignment

To determine the centering force, the effective pressure angle must be known. Using the effective pressure angle, the centering force is calculated based on the maximum axial and radial loads and updated Dudley misalignment factors. The centering force is the maximum axial force that can be transmitted by friction. Several published misalignment factors are also included in the calculation. A new method is presented in this paper that considers the cam effect in the normal force.
In this new method, the stiffness along the spline joint can be integrated to obtain a global stiffness that is applicable to torsional vibration analysis. The stiffness of bearings can also be calculated at given levels of misalignment, allowing for accurate estimation of bearing dimensions. It is advisable to check the stiffness of bearings at all times to ensure that they are properly sized and aligned.
A misalignment in a spline coupling can result in wear or even failure. This is caused by an incorrectly aligned pitch profile. This problem is often overlooked, as the teeth are in contact throughout the involute profile. This causes the load to not be evenly distributed along the contact line. Consequently, it is important to consider the effect of misalignment on the contact force on the teeth of the spline coupling.
The centre of the male spline in Figure 2 is superposed on the female spline. The alignment meshing distances are also identical. Hence, the meshing force curves will change according to the dynamic vibration displacement. It is necessary to know the parameters of a spline coupling before implementing it. In this paper, the model for misalignment is presented for spline couplings and the related parameters.
Using a self-made spline coupling test rig, the effects of misalignment on a spline coupling are studied. In contrast to the typical spline coupling, misalignment in a spline coupling causes fretting wear at a specific position on the tooth surface. This is a leading cause of failure in these types of couplings.

Wear and fatigue failure

The failure of a spline coupling due to wear and fatigue is determined by the first occurrence of tooth wear and shaft misalignment. Standard design methods do not account for wear damage and assess the fatigue life with big approximations. Experimental investigations have been conducted to assess wear and fatigue damage in spline couplings. The tests were conducted on a dedicated test rig and special device connected to a standard fatigue machine. The working parameters such as torque, misalignment angle, and axial distance have been varied in order to measure fatigue damage. Over dimensioning has also been assessed.
During fatigue and wear, mechanical sliding takes place between the external and internal splines and results in catastrophic failure. The lack of literature on the wear and fatigue of spline couplings in aero-engines may be due to the lack of data on the coupling’s application. Wear and fatigue failure in splines depends on a number of factors, including the material pair, geometry, and lubrication conditions.
The analysis of spline couplings shows that over-dimensioning is common and leads to different damages in the system. Some of the major damages are wear, fretting, corrosion, and teeth fatigue. Noise problems have also been observed in industrial settings. However, it is difficult to evaluate the contact behavior of spline couplings, and numerical simulations are often hampered by the use of specific codes and the boundary element method.
The failure of a spline gear coupling was caused by fatigue, and the fracture initiated at the bottom corner radius of the keyway. The keyway and splines had been overloaded beyond their yield strength, and significant yielding was observed in the spline gear teeth. A fracture ring of non-standard alloy steel exhibited a sharp corner radius, which was a significant stress raiser.
Several components were studied to determine their life span. These components include the spline shaft, the sealing bolt, and the graphite ring. Each of these components has its own set of design parameters. However, there are similarities in the distributions of these components. Wear and fatigue failure of spline couplings can be attributed to a combination of the 3 factors. A failure mode is often defined as a non-linear distribution of stresses and strains.

Analytical Approaches to Estimating Contact Pressures in Spline Couplings

A spline coupling is a type of mechanical connection between 2 rotating shafts. It consists of 2 parts – a coupler and a coupling. Both parts have teeth which engage and transfer loads. However, spline couplings are typically over-dimensioned, which makes them susceptible to fatigue and static behavior. Wear phenomena can also cause the coupling to fail. For this reason, proper spline coupling design is essential for achieving optimum performance.

Modeling a spline coupling

Spline couplings are becoming increasingly popular in the aerospace industry, but they operate in a slightly misaligned state, causing both vibrations and damage to the contact surfaces. To solve this problem, this article offers analytical approaches for estimating the contact pressures in a spline coupling. Specifically, this article compares analytical approaches with pure numerical approaches to demonstrate the benefits of an analytical approach.
To model a spline coupling, first you create the knowledge base for the spline coupling. The knowledge base includes a large number of possible specification values, which are related to each other. If you modify 1 specification, it may lead to a warning for violating another. To make the design valid, you must create a spline coupling model that meets the specified specification values.
After you have modeled the geometry, you must enter the contact pressures of the 2 spline couplings. Then, you need to determine the position of the pitch circle of the spline. In Figure 2, the centre of the male coupling is superposed to that of the female spline. Then, you need to make sure that the alignment meshing distance of the 2 splines is the same.
Once you have the data you need to create a spline coupling model, you can begin by entering the specifications for the interface design. Once you have this data, you need to choose whether to optimize the internal spline or the external spline. You’ll also need to specify the tooth friction coefficient, which is used to determine the stresses in the spline coupling model 20. You should also enter the pilot clearance, which is the clearance between the tip 186 of a tooth 32 on 1 spline and the feature on the mating spline.
After you have entered the desired specifications for the external spline, you can enter the parameters for the internal spline. For example, you can enter the outer diameter limit 154 of the major snap 54 and the minor snap 56 of the internal spline. The values of these parameters are displayed in color-coded boxes on the Spline Inputs and Configuration GUI screen 80. Once the parameters are entered, you’ll be presented with a geometric representation of the spline coupling model 20.

Creating a spline coupling model 20

The spline coupling model 20 is created by a product model software program 10. The software validates the spline coupling model against a knowledge base of configuration-dependent specification constraints and relationships. This report is then input to the ANSYS stress analyzer program. It lists the spline coupling model 20’s geometric configurations and specification values for each feature. The spline coupling model 20 is automatically recreated every time the configuration or performance specifications of the spline coupling model 20 are modified.
The spline coupling model 20 can be configured using the product model software program 10. A user specifies the axial length of the spline stack, which may be zero, or a fixed length. The user also enters a radial mating face 148, if any, and selects a pilot clearance specification value of 14.5 degrees or 30 degrees.
A user can then use the mouse 110 to modify the spline coupling model 20. The spline coupling knowledge base contains a large number of possible specification values and the spline coupling design rule. If the user tries to change a spline coupling model, the model will show a warning about a violation of another specification. In some cases, the modification may invalidate the design.
In the spline coupling model 20, the user enters additional performance requirement specifications. The user chooses the locations where maximum torque is transferred for the internal and external splines 38 and 40. The maximum torque transfer location is determined by the attachment configuration of the hardware to the shafts. Once this is selected, the user can click “Next” to save the model. A preview of the spline coupling model 20 is displayed.
The model 20 is a representation of a spline coupling. The spline specifications are entered in the order and arrangement as specified on the spline coupling model 20 GUI screen. Once the spline coupling specifications are entered, the product model software program 10 will incorporate them into the spline coupling model 20. This is the last step in spline coupling model creation.

Analysing a spline coupling model 20

An analysis of a spline coupling model consists of inputting its configuration and performance specifications. These specifications may be generated from another computer program. The product model software program 10 then uses its internal knowledge base of configuration dependent specification relationships and constraints to create a valid three-dimensional parametric model 20. This model contains information describing the number and types of spline teeth 32, snaps 34, and shoulder 36.
When you are analysing a spline coupling, the software program 10 will include default values for various specifications. The spline coupling model 20 comprises an internal spline 38 and an external spline 40. Each of the splines includes its own set of parameters, such as its depth, width, length, and radii. The external spline 40 will also contain its own set of parameters, such as its orientation.
Upon selecting these parameters, the software program will perform various analyses on the spline coupling model 20. The software program 10 calculates the nominal and maximal tooth bearing stresses and fatigue life of a spline coupling. It will also determine the difference in torsional windup between an internal and an external spline. The output file from the analysis will be a report file containing model configuration and specification data. The output file may also be used by other computer programs for further analysis.
Once these parameters are set, the user enters the design criteria for the spline coupling model 20. In this step, the user specifies the locations of maximum torque transfer for both the external and internal spline 38. The maximum torque transfer location depends on the configuration of the hardware attached to the shafts. The user may enter up to 4 different performance requirement specifications for each spline.
The results of the analysis show that there are 2 phases of spline coupling. The first phase shows a large increase in stress and vibration. The second phase shows a decline in both stress and vibration levels. The third stage shows a constant meshing force between 300N and 320N. This behavior continues for a longer period of time, until the final stage engages with the surface.

Misalignment of a spline coupling

A study aimed to investigate the position of the resultant contact force in a spline coupling engaging teeth under a steady torque and rotating misalignment. The study used numerical methods based on Finite Element Method (FEM) models. It produced numerical results for nominal conditions and parallel offset misalignment. The study considered 2 levels of misalignment – 0.02 mm and 0.08 mm – with different loading levels.
The results showed that the misalignment between the splines and rotors causes a change in the meshing force of the spline-rotor coupling system. Its dynamics is governed by the meshing force of splines. The meshing force of a misaligned spline coupling is related to the rotor-spline coupling system parameters, the transmitting torque, and the dynamic vibration displacement.
Despite the lack of precise measurements, the misalignment of splines is a common problem. This problem is compounded by the fact that splines usually feature backlash. This backlash is the result of the misaligned spline. The authors analyzed several splines, varying pitch diameters, and length/diameter ratios.
A spline coupling is a two-dimensional mechanical system, which has positive backlash. The spline coupling is comprised of a hub and shaft, and has tip-to-root clearances that are larger than the backlash. A form-clearance is sufficient to prevent tip-to-root fillet contact. The torque on the splines is transmitted via friction.
When a spline coupling is misaligned, a torque-biased thrust force is generated. In such a situation, the force can exceed the torque, causing the component to lose its alignment. The two-way transmission of torque and thrust is modeled analytically in the present study. The analytical approach provides solutions that can be integrated into the design process. So, the next time you are faced with a misaligned spline coupling problem, make sure to use an analytical approach!
In this study, the spline coupling is analyzed under nominal conditions without a parallel offset misalignment. The stiffness values obtained are the percentage difference between the nominal pitch diameter and load application diameter. Moreover, the maximum percentage difference in the measured pitch diameter is 1.60% under a torque of 5000 N*m. The other parameter, the pitch angle, is taken into consideration in the calculation.

How to Calculate Stiffness, Centering Force, Wear and Fatigue Failure of Spline Couplings

There are various types of spline couplings. These couplings have several important properties. These properties are: Stiffness, Involute splines, Misalignment, Wear and fatigue failure. To understand how these characteristics relate to spline couplings, read this article. It will give you the necessary knowledge to determine which type of coupling best suits your needs. Keeping in mind that spline couplings are usually spherical in shape, they are made of steel.

Involute splines

An effective side interference condition minimizes gear misalignment. When 2 splines are coupled with no spline misalignment, the maximum tensile root stress shifts to the left by 5 mm. A linear lead variation, which results from multiple connections along the length of the spline contact, increases the effective clearance or interference by a given percentage. This type of misalignment is undesirable for coupling high-speed equipment.
Involute splines are often used in gearboxes. These splines transmit high torque, and are better able to distribute load among multiple teeth throughout the coupling circumference. The involute profile and lead errors are related to the spacing between spline teeth and keyways. For coupling applications, industry practices use splines with 25 to 50-percent of spline teeth engaged. This load distribution is more uniform than that of conventional single-key couplings.
To determine the optimal tooth engagement for an involved spline coupling, Xiangzhen Xue and colleagues used a computer model to simulate the stress applied to the splines. The results from this study showed that a “permissible” Ruiz parameter should be used in coupling. By predicting the amount of wear and tear on a crowned spline, the researchers could accurately predict how much damage the components will sustain during the coupling process.
There are several ways to determine the optimal pressure angle for an involute spline. Involute splines are commonly measured using a pressure angle of 30 degrees. Similar to gears, involute splines are typically tested through a measurement over pins. This involves inserting specific-sized wires between gear teeth and measuring the distance between them. This method can tell whether the gear has a proper tooth profile.
The spline system shown in Figure 1 illustrates a vibration model. This simulation allows the user to understand how involute splines are used in coupling. The vibration model shows 4 concentrated mass blocks that represent the prime mover, the internal spline, and the load. It is important to note that the meshing deformation function represents the forces acting on these 3 components.

Stiffness of coupling

The calculation of stiffness of a spline coupling involves the measurement of its tooth engagement. In the following, we analyze the stiffness of a spline coupling with various types of teeth using 2 different methods. Direct inversion and blockwise inversion both reduce CPU time for stiffness calculation. However, they require evaluation submatrices. Here, we discuss the differences between these 2 methods.
The analytical model for spline couplings is derived in the second section. In the third section, the calculation process is explained in detail. We then validate this model against the FE method. Finally, we discuss the influence of stiffness nonlinearity on the rotor dynamics. Finally, we discuss the advantages and disadvantages of each method. We present a simple yet effective method for estimating the lateral stiffness of spline couplings.
The numerical calculation of the spline coupling is based on the semi-analytical spline load distribution model. This method involves refined contact grids and updating the compliance matrix at each iteration. Hence, it consumes significant computational time. Further, it is difficult to apply this method to the dynamic analysis of a rotor. This method has its own limitations and should be used only when the spline coupling is fully investigated.
The meshing force is the force generated by a misaligned spline coupling. It is related to the spline thickness and the transmitting torque of the rotor. The meshing force is also related to the dynamic vibration displacement. The result obtained from the meshing force analysis is given in Figures 7, 8, and 9.
The analysis presented in this paper aims to investigate the stiffness of spline couplings with a misaligned spline. Although the results of previous studies were accurate, some issues remained. For example, the misalignment of the spline may cause contact damages. The aim of this article is to investigate the problems associated with misaligned spline couplings and propose an analytical approach for estimating the contact pressure in a spline connection. We also compare our results to those obtained by pure numerical approaches.

Misalignment

To determine the centering force, the effective pressure angle must be known. Using the effective pressure angle, the centering force is calculated based on the maximum axial and radial loads and updated Dudley misalignment factors. The centering force is the maximum axial force that can be transmitted by friction. Several published misalignment factors are also included in the calculation. A new method is presented in this paper that considers the cam effect in the normal force.
In this new method, the stiffness along the spline joint can be integrated to obtain a global stiffness that is applicable to torsional vibration analysis. The stiffness of bearings can also be calculated at given levels of misalignment, allowing for accurate estimation of bearing dimensions. It is advisable to check the stiffness of bearings at all times to ensure that they are properly sized and aligned.
A misalignment in a spline coupling can result in wear or even failure. This is caused by an incorrectly aligned pitch profile. This problem is often overlooked, as the teeth are in contact throughout the involute profile. This causes the load to not be evenly distributed along the contact line. Consequently, it is important to consider the effect of misalignment on the contact force on the teeth of the spline coupling.
The centre of the male spline in Figure 2 is superposed on the female spline. The alignment meshing distances are also identical. Hence, the meshing force curves will change according to the dynamic vibration displacement. It is necessary to know the parameters of a spline coupling before implementing it. In this paper, the model for misalignment is presented for spline couplings and the related parameters.
Using a self-made spline coupling test rig, the effects of misalignment on a spline coupling are studied. In contrast to the typical spline coupling, misalignment in a spline coupling causes fretting wear at a specific position on the tooth surface. This is a leading cause of failure in these types of couplings.

Wear and fatigue failure

The failure of a spline coupling due to wear and fatigue is determined by the first occurrence of tooth wear and shaft misalignment. Standard design methods do not account for wear damage and assess the fatigue life with big approximations. Experimental investigations have been conducted to assess wear and fatigue damage in spline couplings. The tests were conducted on a dedicated test rig and special device connected to a standard fatigue machine. The working parameters such as torque, misalignment angle, and axial distance have been varied in order to measure fatigue damage. Over dimensioning has also been assessed.
During fatigue and wear, mechanical sliding takes place between the external and internal splines and results in catastrophic failure. The lack of literature on the wear and fatigue of spline couplings in aero-engines may be due to the lack of data on the coupling’s application. Wear and fatigue failure in splines depends on a number of factors, including the material pair, geometry, and lubrication conditions.
The analysis of spline couplings shows that over-dimensioning is common and leads to different damages in the system. Some of the major damages are wear, fretting, corrosion, and teeth fatigue. Noise problems have also been observed in industrial settings. However, it is difficult to evaluate the contact behavior of spline couplings, and numerical simulations are often hampered by the use of specific codes and the boundary element method.
The failure of a spline gear coupling was caused by fatigue, and the fracture initiated at the bottom corner radius of the keyway. The keyway and splines had been overloaded beyond their yield strength, and significant yielding was observed in the spline gear teeth. A fracture ring of non-standard alloy steel exhibited a sharp corner radius, which was a significant stress raiser.
Several components were studied to determine their life span. These components include the spline shaft, the sealing bolt, and the graphite ring. Each of these components has its own set of design parameters. However, there are similarities in the distributions of these components. Wear and fatigue failure of spline couplings can be attributed to a combination of the 3 factors. A failure mode is often defined as a non-linear distribution of stresses and strains.

The Different Types of Splines in a Splined Shaft

A splined shaft is a machine component with internal and external splines. The splines are formed in 4 different ways: Involute, Parallel, Serrated, and Ball. You can learn more about each type of spline in this article. When choosing a splined shaft, be sure to choose the right 1 for your application. Read on to learn about the different types of splines and how they affect the shaft’s performance.

Involute splines

Involute splines in a splined shaft are used to secure and extend mechanical assemblies. They are smooth, inwardly curving grooves that resist separation during operation. A shaft with involute splines is often longer than the shaft itself. This feature allows for more axial movement. This is beneficial for many applications, especially in a gearbox.
The involute spline is a shaped spline, similar to a parallel spline. It is angled and consists of teeth that create a spiral pattern that enables linear and rotatory motion. It is distinguished from other splines by the serrations on its flanks. It also has a flat top. It is a good option for couplers and other applications where angular movement is necessary.
Involute splines are also called involute teeth because of their shape. They are flat on the top and curved on the sides. These teeth can be either internal or external. As a result, involute splines provide greater surface contact, which helps reduce stress and fatigue. Regardless of the shape, involute splines are generally easy to machine and fit.
Involute splines are a type of splines that are used in splined shafts. These splines have different names, depending on their diameters. An example set of designations is for a 32-tooth male spline, a 2,500-tooth module, and a 30 degree pressure angle. An example of a female spline, a fillet root spline, is used to describe the diameter of the splined shaft.
The effective tooth thickness of splines is dependent on the number of keyways and the type of spline. Involute splines in splined shafts should be designed to engage 25 to 50 percent of the spline teeth during the coupling. Involute splines should be able to withstand the load without cracking.

Parallel splines

Parallel splines are formed on a splined shaft by putting 1 or more teeth into another. The male spline is positioned at the center of the female spline. The teeth of the male spline are also parallel to the shaft axis, but a common misalignment causes the splines to roll and tilt. This is common in many industrial applications, and there are a number of ways to improve the performance of splines.
Typically, parallel splines are used to reduce friction in a rotating part. The splines on a splined shaft are narrower on the end face than the interior, which makes them more prone to wear. This type of spline is used in a variety of industries, such as machinery, and it also allows for greater efficiency when transmitting torque.
Involute splines on a splined shaft are the most common. They have equally spaced teeth, and are therefore less likely to crack due to fatigue. They also tend to be easy to cut and fit. However, they are not the best type of spline. It is important to understand the difference between parallel and involute splines before deciding on which spline to use.
The difference between splined and involute splines is the size of the grooves. Involute splines are generally larger than parallel splines. These types of splines provide more torque to the gear teeth and reduce stress during operation. They are also more durable and have a longer life span. And because they are used on farm machinery, they are essential in this type of application.

Serrated splines

A Serrated Splined Shaft has several advantages. This type of shaft is highly adjustable. Its large number of teeth allows large torques, and its shorter tooth width allows for greater adjustment. These features make this type of shaft an ideal choice for applications where accuracy is critical. Listed below are some of the benefits of this type of shaft. These benefits are just a few of the advantages. Learn more about this type of shaft.
The process of hobbing is inexpensive and highly accurate. It is useful for external spline shafts, but is not suitable for internal splines. This type of process forms synchronized shapes on the shaft, reducing the manufacturing cycle and stabilizing the relative phase between spline and thread. It uses a grinding wheel to shape the shaft. CZPT Manufacturing has a large inventory of Serrated Splined Shafts.
The teeth of a Serrated Splined Shaft are designed to engage with the hub over the entire circumference of the shaft. The teeth of the shaft are spaced uniformly around the spline, creating a multiple-tooth point of contact over the entire length of the shaft. The results of these analyses are usually satisfactory. But there are some limitations. To begin with, the splines of the Serrated Splined Shaft should be chosen carefully. If the application requires large-scale analysis, it may be necessary to modify the design.
The splines of the Serrated Splined Shaft are also used for other purposes. They can be used to transmit torque to another device. They also act as an anti-rotational device and function as a linear guide. Both the design and the type of splines determine the function of the Splined Shaft. In the automobile industry, they are used in vehicles, aerospace, earth-moving machinery, and many other industries.

Ball splines

The invention relates to a ball-spinned shaft. The shaft comprises a plurality of balls that are arranged in a series and are operatively coupled to a load path section. The balls are capable of rolling endlessly along the path. This invention also relates to a ball bearing. Here, a ball bearing is 1 of the many types of gears. The following discussion describes the features of a ball bearing.
A ball-splined shaft assembly comprises a shaft with at least 1 ball-spline groove and a plurality of circumferential step grooves. The shaft is held in a first holding means that extends longitudinally and is rotatably held by a second holding means. Both the shaft and the first holding means are driven relative to 1 another by a first driving means. It is possible to manufacture a ball-splined shaft in a variety of ways.
A ball-splined shaft features a nut with recirculating balls. The ball-splined nut rides in these grooves to provide linear motion while preventing rotation. A splined shaft with a nut that has recirculating balls can also provide rotary motion. A ball splined shaft also has higher load capacities than a ball bushing. For these reasons, ball splines are an excellent choice for many applications.
In this invention, a pair of ball-spinned shafts are housed in a box under a carrier device 40. Each of the 2 shafts extends along a longitudinal line of arm 50. One end of each shaft is supported rotatably by a slide block 56. The slide block also has a support arm 58 that supports the center arm 50 in a cantilever fashion.

Sector no-go gage

A no-go gauge is a tool that checks the splined shaft for oversize. It is an effective way to determine the oversize condition of a splined shaft without removing the shaft. It measures external splines and serrations. The no-go gage is available in sizes ranging from 19mm to 130mm with a 25mm profile length.
The sector no-go gage has 2 groups of diametrally opposed teeth. The space between them is manufactured to a maximum space width and the tooth thickness must be within a predetermined tolerance. This gage would be out of tolerance if the splines were measured with a pin. The dimensions of this splined shaft can be found in the respective ANSI or DIN standards.
The go-no-go gage is useful for final inspection of thread pitch diameter. It is also useful for splined shafts and threaded nuts. The thread of a screw must match the contour of the go-no-go gage head to avoid a no-go condition. There is no substitute for a quality machine. It is an essential tool for any splined shaft and fastener manufacturer.
The NO-GO gage can detect changes in tooth thickness. It can be calibrated under ISO17025 standards and has many advantages over a non-go gage. It also gives a visual reference of the thickness of a splined shaft. When the teeth match, the shaft is considered ready for installation. It is a critical process. In some cases, it is impossible to determine the precise length of the shaft spline.
The 45-degree pressure angle is most commonly used for axles and torque-delivering members. This pressure angle is the most economical in terms of tool life, but the splines will not roll neatly like a 30 degree angle. The 45-degree spline is more likely to fall off larger than the other two. Oftentimes, it will also have a crowned look. The 37.5 degree pressure angle is a compromise between the other 2 pressure angles. It is often used when the splined shaft material is harder than usual.

Analytical Approaches to Estimating Contact Pressures in Spline Couplings

A spline coupling is a type of mechanical connection between 2 rotating shafts. It consists of 2 parts – a coupler and a coupling. Both parts have teeth which engage and transfer loads. However, spline couplings are typically over-dimensioned, which makes them susceptible to fatigue and static behavior. Wear phenomena can also cause the coupling to fail. For this reason, proper spline coupling design is essential for achieving optimum performance.

Modeling a spline coupling

Spline couplings are becoming increasingly popular in the aerospace industry, but they operate in a slightly misaligned state, causing both vibrations and damage to the contact surfaces. To solve this problem, this article offers analytical approaches for estimating the contact pressures in a spline coupling. Specifically, this article compares analytical approaches with pure numerical approaches to demonstrate the benefits of an analytical approach.
To model a spline coupling, first you create the knowledge base for the spline coupling. The knowledge base includes a large number of possible specification values, which are related to each other. If you modify 1 specification, it may lead to a warning for violating another. To make the design valid, you must create a spline coupling model that meets the specified specification values.
After you have modeled the geometry, you must enter the contact pressures of the 2 spline couplings. Then, you need to determine the position of the pitch circle of the spline. In Figure 2, the centre of the male coupling is superposed to that of the female spline. Then, you need to make sure that the alignment meshing distance of the 2 splines is the same.
Once you have the data you need to create a spline coupling model, you can begin by entering the specifications for the interface design. Once you have this data, you need to choose whether to optimize the internal spline or the external spline. You’ll also need to specify the tooth friction coefficient, which is used to determine the stresses in the spline coupling model 20. You should also enter the pilot clearance, which is the clearance between the tip 186 of a tooth 32 on 1 spline and the feature on the mating spline.
After you have entered the desired specifications for the external spline, you can enter the parameters for the internal spline. For example, you can enter the outer diameter limit 154 of the major snap 54 and the minor snap 56 of the internal spline. The values of these parameters are displayed in color-coded boxes on the Spline Inputs and Configuration GUI screen 80. Once the parameters are entered, you’ll be presented with a geometric representation of the spline coupling model 20.

Creating a spline coupling model 20

The spline coupling model 20 is created by a product model software program 10. The software validates the spline coupling model against a knowledge base of configuration-dependent specification constraints and relationships. This report is then input to the ANSYS stress analyzer program. It lists the spline coupling model 20’s geometric configurations and specification values for each feature. The spline coupling model 20 is automatically recreated every time the configuration or performance specifications of the spline coupling model 20 are modified.
The spline coupling model 20 can be configured using the product model software program 10. A user specifies the axial length of the spline stack, which may be zero, or a fixed length. The user also enters a radial mating face 148, if any, and selects a pilot clearance specification value of 14.5 degrees or 30 degrees.
A user can then use the mouse 110 to modify the spline coupling model 20. The spline coupling knowledge base contains a large number of possible specification values and the spline coupling design rule. If the user tries to change a spline coupling model, the model will show a warning about a violation of another specification. In some cases, the modification may invalidate the design.
In the spline coupling model 20, the user enters additional performance requirement specifications. The user chooses the locations where maximum torque is transferred for the internal and external splines 38 and 40. The maximum torque transfer location is determined by the attachment configuration of the hardware to the shafts. Once this is selected, the user can click “Next” to save the model. A preview of the spline coupling model 20 is displayed.
The model 20 is a representation of a spline coupling. The spline specifications are entered in the order and arrangement as specified on the spline coupling model 20 GUI screen. Once the spline coupling specifications are entered, the product model software program 10 will incorporate them into the spline coupling model 20. This is the last step in spline coupling model creation.

Analysing a spline coupling model 20

An analysis of a spline coupling model consists of inputting its configuration and performance specifications. These specifications may be generated from another computer program. The product model software program 10 then uses its internal knowledge base of configuration dependent specification relationships and constraints to create a valid three-dimensional parametric model 20. This model contains information describing the number and types of spline teeth 32, snaps 34, and shoulder 36.
When you are analysing a spline coupling, the software program 10 will include default values for various specifications. The spline coupling model 20 comprises an internal spline 38 and an external spline 40. Each of the splines includes its own set of parameters, such as its depth, width, length, and radii. The external spline 40 will also contain its own set of parameters, such as its orientation.
Upon selecting these parameters, the software program will perform various analyses on the spline coupling model 20. The software program 10 calculates the nominal and maximal tooth bearing stresses and fatigue life of a spline coupling. It will also determine the difference in torsional windup between an internal and an external spline. The output file from the analysis will be a report file containing model configuration and specification data. The output file may also be used by other computer programs for further analysis.
Once these parameters are set, the user enters the design criteria for the spline coupling model 20. In this step, the user specifies the locations of maximum torque transfer for both the external and internal spline 38. The maximum torque transfer location depends on the configuration of the hardware attached to the shafts. The user may enter up to 4 different performance requirement specifications for each spline.
The results of the analysis show that there are 2 phases of spline coupling. The first phase shows a large increase in stress and vibration. The second phase shows a decline in both stress and vibration levels. The third stage shows a constant meshing force between 300N and 320N. This behavior continues for a longer period of time, until the final stage engages with the surface.

Misalignment of a spline coupling

A study aimed to investigate the position of the resultant contact force in a spline coupling engaging teeth under a steady torque and rotating misalignment. The study used numerical methods based on Finite Element Method (FEM) models. It produced numerical results for nominal conditions and parallel offset misalignment. The study considered 2 levels of misalignment – 0.02 mm and 0.08 mm – with different loading levels.
The results showed that the misalignment between the splines and rotors causes a change in the meshing force of the spline-rotor coupling system. Its dynamics is governed by the meshing force of splines. The meshing force of a misaligned spline coupling is related to the rotor-spline coupling system parameters, the transmitting torque, and the dynamic vibration displacement.
Despite the lack of precise measurements, the misalignment of splines is a common problem. This problem is compounded by the fact that splines usually feature backlash. This backlash is the result of the misaligned spline. The authors analyzed several splines, varying pitch diameters, and length/diameter ratios.
A spline coupling is a two-dimensional mechanical system, which has positive backlash. The spline coupling is comprised of a hub and shaft, and has tip-to-root clearances that are larger than the backlash. A form-clearance is sufficient to prevent tip-to-root fillet contact. The torque on the splines is transmitted via friction.
When a spline coupling is misaligned, a torque-biased thrust force is generated. In such a situation, the force can exceed the torque, causing the component to lose its alignment. The two-way transmission of torque and thrust is modeled analytically in the present study. The analytical approach provides solutions that can be integrated into the design process. So, the next time you are faced with a misaligned spline coupling problem, make sure to use an analytical approach!
In this study, the spline coupling is analyzed under nominal conditions without a parallel offset misalignment. The stiffness values obtained are the percentage difference between the nominal pitch diameter and load application diameter. Moreover, the maximum percentage difference in the measured pitch diameter is 1.60% under a torque of 5000 N*m. The other parameter, the pitch angle, is taken into consideration in the calculation.