Forecasting method for transmission intermediate shaft limit bearing capacity

Abstract

The invention belongs to the technical field of automobiles, and particularly relates to a forecasting method for transmission intermediate shaft limit bearing capacity. According to the invention, the method includes defining material nonlinearity and contact nonlinearity of parts; defining boundary conditions on a bearing outer ring; loading the gear meshing force to the gear meshing node; trulyreproducing the stress state of the intermediate shaft; obtaining a high-precision intermediate shaft gear engagement node rotation angle and intermediate shaft transmission torque relation curve; onthe basis, the curve slope ratio is adopted to accurately forecast the fracture limit bearing torque of the intermediate shaft, the simulation replacement test of the fracture limit bearing torque ofthe intermediate shaft is realized, the product development cost is reduced, and the problem of obtaining the limit bearing capacity of the intermediate shaft of the transmission at present is solved.

Description

technical field [0001] The invention belongs to the technical field of automobiles, in particular to a method for forecasting the ultimate bearing capacity of a transmission intermediate shaft. Background technique [0002] In the process of product design, two technical means are usually used to obtain the ultimate bearing capacity of the intermediate shaft of the transmission. The first is the test technology method, which relies on the physical prototype, the test period is long, and it lags behind product development, so it cannot fully meet the needs of product development; the ultimate bearing capacity test is a destructive test, and the sample will be scrapped after the test, and the test cost is high ; and in most cases, the ultimate bearing torque of the intermediate shaft is higher than the ultimate bearing torque of the transmission housing, and the transmission housing has broken before the intermediate shaft breaks, so it is difficult to directly obtain the ulti...

AI Technical Summary

Problems solved by technology

The first is the test technology method, which relies on the physical prototype, the test period is long, and it lags behind product development, so it cannot fully meet the needs of product development; the ultimate bearing capacity test is a destructive test, and the sample will be scrapped after the test, and the test cost is high ; and in most cases, the ultimate bearing torque of the intermediate shaft is higher than the ultimate bearing torque of the transmission housing, and the transmission housing has broken before the intermediate shaft breaks, so it is difficult to directly obtain the ultimate bearing torque of the intermediate shaft by means of tests

The second is simulation technology, which has the following problems: ① There are many forms of stress, such as Mises stress, maximum principal stress, maximum shear stress, etc.; stress has many states, such as stretching, bending, torsion, etc.; There are many types of strength, such as tensile strength, compressive strength, bending strength, etc., which stress and which material strength are used to calculate the ultimate load-bearing torque, the engineer has a lot of subjectivity, so that the calculation result of the limit load-bearing torque Variations, low precision, can not meet the needs of product development

② Safety factor evaluation overcomes the shortcomings of stress evaluation to a certain extent. It considers the influence of stress form, stress state and material strength corresponding to different stress states, and avoids the subjectivity of engineers. However, it is found in practical applications that the calculated ultimate bearing torque is far from It is lower than the actual test value, which is more conservative, so that the transmission intermediate shaft has a large backup coefficient of strength, heavy quality, and high cost, which seriously affects product competitiveness.

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