Method for calculating strength of end face spline

Abstract

The application discloses a kind of end face spline strength calculation methods, including following steps, include six steps.First, confirm material selection, clear end face spline parameter and external load parameter;Second, calculate minimum locking force by formula;Then, calculate tooth surface contact area, contact force, contact stress, and bending moment, section coefficient, root bending stress in turn;Then, calculate the comprehensive influence coefficient K obtained by multiplying working condition coefficient and comprehensive engagement coefficient;Determine allowable stress again, allowable contact stress is the product of safety factor and tensile strength, and allowable bending stress is the product of safety factor and yield strength;Finally, tooth surface contact stress and root bending stress are compared with corresponding allowable stress respectively, to determine whether it meets the strength requirement.Can ensure accuracy and universality, while quickly solving end face spline to each strength, and judging whether end face spline parameter design is qualified.

Description

TECHNICAL FIELD

[0001] The application relates to bearing detection, in particular to a calculation processing method for the strength of an end face spline of a wheel hub bearing. BACKGROUND

[0002] The end face spline is one of commonly used connection types in a universal coupling and other transmission mechanisms due to its unique structure and transmission characteristics. For example, in a constant velocity drive shaft assembly of an automobile, the end face spline can be used to transmit torque between a bell housing and a wheel hub bearing. The current domestic standard, such as GB / T 17855-1999 spline load capacity calculation method, details the load capacity calculation process, criteria and corresponding examples of a cylindrical involute spline and a cylindrical rectangular tooth spline, but does not describe how to convert and apply the end face spline load calculation and how to determine the criteria. Some literature proposes a simplified calculation model, which cannot be applied to the selection of different working conditions in actual engineering applications. SUMMARY

[0003] In view of the deficiencies of the prior art, the application provides an end face spline strength calculation method, which can ensure accuracy and universality, quickly solve the strength of the end face spline and determine whether the end face spline parameter design is qualified.

[0004] To achieve the above-mentioned purpose, the application provides an end face spline strength calculation method, which comprises the following steps: step one, confirming material selection, obtaining the tensile strength and yield strength of the corresponding material according to the material selection, determining the inner diameter D i , outer diameter D e , tooth number z, tooth profile angle gamma, tooth root fillet r1 and tooth crest fillet r2, and determining the external load parameters, including external torque M, locking force F a , load type, working condition coefficient, safety coefficient and comprehensive engagement coefficient;

[0005] Step two, calculating the minimum locking force, using the following formula,

[0006]

[0007] Step three, calculating the tooth surface contact stress and tooth root bending stress; first, calculating the tooth surface contact area S,

[0008]

[0009] calculating the tooth surface contact force F,

[0010]

[0011] calculating the tooth surface contact stress sigma H ,

[0012]

[0013] Calculate the bending moment M b ,

[0014]

[0015] Calculate the section coefficient W,

[0016]

[0017] Calculate the root bending stress σ b ,

[0018]

[0019] Step four, the comprehensive influence coefficient K is calculated; the comprehensive influence coefficient K is the product of the working condition coefficient and the comprehensive meshing coefficient;

[0020] Step five, the allowable stress is calculated; the allowable stress includes the allowable contact stress and the allowable bending stress; the allowable contact stress is the product of the safety factor and the tensile strength; the allowable bending stress is the product of the safety factor and the yield strength;

[0021] Step six, the judgment is made; the tooth surface contact stress and the allowable contact stress are compared, and the tooth root bending stress and the allowable bending stress are compared; if it is lower than the allowable contact stress or the allowable bending stress, the strength requirement is met.

[0022] The beneficial effect of such arrangement is that: in the calculation, the tooth surface contact stress calculation adopts actual meshing high calculation, the root bending stress calculation is based on the end face spline as a cantilever beam, the allowable stress calculation involves a comprehensive influence coefficient K, and the comprehensive influence coefficient is calculated for different working conditions, which belongs to the prior art and will not be described here. In the application of the calculation method, VBA language and Excel form programming can be used to form a user interface and an execution control. The user interface includes an input box and an output box matched with the execution control. The input box provides a related parameter input form. The execution control contains algorithms for calculating the minimum locking force and calculating the tooth surface contact stress and the root bending stress. The calculation process is as follows: input the material parameters of the end face spline; input the basic parameters of the end face spline; input the external load parameters; calculate the minimum locking force and determine whether the input locking force meets the requirements; if not, directly adjust the locking force; if the locking force meets the requirements, the next step is divided into two modules; one is a tooth surface contact stress calculation module, and the other is a tooth root bending stress calculation module. The tooth surface contact stress calculation module steps are to calculate the tooth surface contact area, the tooth surface contact force, and the tooth surface contact stress; the tooth root bending stress calculation module steps are to calculate the bending moment, the section coefficient, and the tooth root bending stress. The next step is to calculate the comprehensive influence coefficient K, calculate the allowable stress, and determine whether the strength meets the requirements. If not, modify the end face spline parameters. Thus, the computer performs the cooperation calculation, the structure is derived more intuitively and accurately, and the efficiency is effectively improved. The units involved in the formula are input torque M (Nm), locking force F a (KN), outer diameter D e (mm), inner diameter D i (mm), tooth root fillet r1 (mm), tooth crest fillet r2 (mm). And by using this method, the tooth surface contact stress and the tooth root bending stress can be accurately analyzed, and the error caused by directly applying the cylindrical spline formula can be avoided. The problems of complex calculation process, easy to make mistakes and low efficiency are overcome, and the universality is improved, which is suitable for the application of end face spline under different working conditions. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is the flowchart of the embodiment of the present application;

[0024] Fig. 2 is the system interface diagram of the embodiment of the present application without input data;

[0025] Fig. 3 is the system interface diagram of the embodiment of the present application with input data. DETAILED DESCRIPTION

[0026] The implementation of the end face spline strength calculation method of the present application is as follows Figs. 1 to 3The user interface and execution control are formed by using VBA language and Excel form programming, the user interface includes an input box and an output box matched with the execution control, the input box provides a related parameter input form; the algorithm for calculating the minimum locking force and the algorithm for calculating the tooth surface contact stress and the tooth root bending stress are calculated, and the calculation process is as follows:

[0027] 1. Input the material parameters of the end face spline;

[0028] 2. Input the basic parameters of the end face spline;

[0029] 2. Input the external load parameters;

[0030] 3. Calculate the minimum locking force, and determine whether the input locking force meets the requirement;

[0031] 4. Calculate the tooth surface contact stress and the tooth root bending stress;

[0032] 5. Calculate the comprehensive influence coefficient K;

[0033] 6. Calculate the allowable stress;

[0034] 7. Determine whether the strength meets the requirement;

[0035] 8. Output the tooth surface contact stress and the tooth root bending stress;

[0036] The above scheme uses Excel form programming combined with VBA language, can realize the integration of calculation, the calculation result is more convenient, and manual operation is not needed. Moreover, it has universality, can improve the calculation efficiency and accuracy without simplifying the calculation process, and the operation required is simple, only the corresponding parameters need to be input.

[0037] Specifically, when the system operates, the following steps are based on, step one, confirming material selection, according to material selection, obtaining the corresponding material tensile strength, yield strength, determining the end face spline inner diameter D i , outer diameter D e , tooth number z, tooth surface angle γ, tooth root fillet r1 and tooth crest circle angle r2, determining the external load parameters, including external torque M, locking force F a , load type, working condition coefficient, safety coefficient and comprehensive engagement coefficient;

[0038] Step two, calculate the minimum locking force, use the following formula to calculate,

[0039]

[0040] Step three, calculate the tooth surface contact stress and the tooth root bending stress; first, calculate the tooth surface contact area S,

[0041]

[0042] calculating the tooth surface contact force F,

[0043]

[0044] calculating the tooth surface contact stress σ H ,

[0045]

[0046] calculating the bending moment M b ,

[0047]

[0048] calculating the section modulus W,

[0049]

[0050] calculating the root bending stress σ b ,

[0051]

[0052] Step four, calculating the comprehensive influence coefficient K; the comprehensive influence coefficient K is the product of the working condition coefficient and the comprehensive meshing coefficient;

[0053] Step five, calculating the allowable stress; the allowable stress includes the allowable contact stress and the allowable bending stress; the allowable contact stress is the product of the safety factor and the tensile strength; the allowable bending stress is the product of the safety factor and the yield strength;

[0054] Step six, judging, comparing the tooth surface contact stress and the allowable contact stress, and comparing the root bending stress and the allowable bending stress, if lower than the allowable contact stress or the allowable bending stress, the strength requirement is met.

[0055] The above example is only one of the preferred specific examples of the present application, and the usual changes and replacements made by those skilled in the art within the scope of the technical solutions of the present application are all included in the protection scope of the present application.

Claims

1. A method of calculating the strength of an end face spline, characterized by: Comprising the following steps: Step one, confirm material selection, according to material selection to obtain the corresponding material tensile strength, yield strength, determine the end face spline inner diameter D i , outer diameter D e , number of teeth z, tooth surface angle γ, tooth root fillet r1 and tooth crest circle angle r2, determine the external load parameters, including external torque M, locking force F a , load type, working condition coefficient, safety factor and comprehensive engagement coefficient; Step two, calculate the minimum locking force, using the following formula to calculate, Step three, calculate the tooth surface contact stress and tooth root bending stress; first calculate the tooth surface contact area S, Calculate the tooth surface contact force F, Computing the tooth surface contact stress σ H , Compute the bending moment M b , Calculate the cross section coefficient W, Calculating the root bending stress σ b , Step four, the comprehensive influence coefficient K calculation; comprehensive influence coefficient K is the product of the working condition coefficient and the comprehensive meshing coefficient; Step five, calculate the allowable stress; the allowable stress includes the allowable contact stress and the allowable bending stress; the allowable contact stress is the product of the safety factor and the tensile strength; the allowable bending stress is the product of the safety factor and the yield strength; Step six, judgment, compare the tooth surface contact stress and the allowable contact stress, compare the tooth root bending stress and the allowable bending stress, lower than the allowable contact stress or the allowable bending stress, then meet the strength requirements.

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