Mechanical Analysis Of Flexible Bearings In Harmonic Drive

Harmonic gear transmission relies on the wave deformation of the flexspline to realize the movement and power transmission.Compared with other transmission technologies,it has many irreplaceable advantages.It has been widely used in many fields such as aerospace,robots and precision instruments.As flexible bearings are key components of harmonic reducers,their performance has an important impact on the life and accuracy of harmonic reducers.Focused on the wrap angle between the flexible bearing and flexspline,the internal load distribution on balls of flexible bearing,the deformation of flexspline tooth ring under the action of discrete balls,and the analysis of the taper deformation of the flexspline,a series of theoretical and numerical verification research are done.As an example of tooth ring calculation model under the action of wave generator,radial contact force and internal force of the tooth ring under the action of an elliptic wave generator is given.A method for calculating the contact forces between discrete balls and outer raceway is established by using the existing theoretical formulae and superposition principle.The influence of the number of balls in the bearing and different circumferential positions of balls to the contact force are discussed.In order to analyze the radial load distribution of the flexspline,a finite element contact model between the flexible bearing and the flexspline is established.The contact between the deformed outer raceway of the bearing and the flexspline is defined to investigate the radial forces on the flexspline to reach the specified displacement,contact status and the contact stress on the outer raceway of the flexible bearing.A finite element contact model between flexible bearing and cup-shaped flexspline is built with parametric language.Contact forces on the balls and contact state of the flexible bearing,and the tapered deformation of the outer raceway and theflexspline are analyzed under action of a solid element flexible bearing with applied radial displacement on an ellipse isometric line.