Static And Dynamic Analysis Of Flexspline And Flexible Bearing Under The Cam With Typical Profile

The harmonic reducer has been widely applied in the field of space agency and industrial robots because of its small volume, high transmission accuracy, large reduction ratio and many other advantages. Although the reducer with a short cup-shaped flexspline is small in volume and has compact structure, the decreased size of its cylinder will lead to the sharp rise in stress. This thesis takes a short type of harmonic reducer as the research objects, studies include the flexspline and the flexible bearing key parts, which is easy to break. Recently, the research for the flexspline and the flexible bearing under the action of typical cam profile is not very sufficient. The study in this paper can provide a certain reference value for the selection of cam profile and parameter, and for the law study of the flexspline and the flexible bearing under the typical profile cam and the typical working conditions.Firstly, a complete model with gear teeth and a simplified model without gear teeth of the flexspline are established based on the finite element method. Comparison is made between the two models in the difference in stress and deformation law. According to different wave generator types, the flexspline under the action of two forces and four forces is analyzed respectively. In addition, the static contact analysis is made when the elliptical cam and the dual eccentric circular arc cam wave generator assembles into the flexspline respectively. The deformation and the stress distribution laws are researched, and the influence of the cam’s key structural parameters is studied as well.Secondly, the static contact analysis is carried out to the flexible bearing considering different working conditions. The effect of two kind of concentrated force with different direction on the bearing’s stress distribution is analyzed under the condition of general bearing. Besides, the deformation and the stress distribution laws are analyzed when the elliptical cam and the dual eccentric circular arc cam assemble into the flexible bearing respectively, and the influence of the cam’s key structural parameters on the flexible bearing is also studied.Thirdly, Lanczos Block algorithm is used to analyze the free mode and the pre-stress mode of the flexspline. Based on the static analysis model, the transient dynamic analysis of the flexspline is carried out based on LS-DYNA. Considering two typical working conditions in which the flexspline is fixed or driven, the movement rule and the stress variation characteristic of the flexspline are studied under the action of two types of wave generator respectively, including the elliptical cam and the dual eccentric circular arc cam generator.Finally, on the basis of the static analysis model of the flexible bearing, the cage is also modeled, and the free mode of the flexible bearing is analyzed by MPC algorithm. Then, the transient dynamic analysis of the flexible bearing is conducted through LS-DYNA. Under the same working condition, the dynamic characteristics of the flexible bearing is studied when the inner race has not deformed and has deformed to ellipse or dual eccentric circular arc respectively, then the comparison of the movement rule and the stress variation characteristic between those analysis is made.