| Between 2015 and 2021,the domestic industrial robot demand for reducers has increased from 263,000 to 931,100,and harmonic reducer is the key component of joint for industrial robot.At present,one third of the domestic market of harmonic reducers for robots is still occupie d by Japanese company Harmonic Drive,although domestic companies such as leaderdrive are rising,the comprehensive performance of domestic harmonic reducers is still slightly insufficient.This paper intends to start from the aspect of tooth profile affecting the comprehensive performance of harmonic reducer,and takes the S tooth profile with relatively stable meshing backlash as the research object.With Matlab and Workbench software as the auxiliary tools,the plane tooth profile design,spatial tooth profile design and meshing characteristics analysis of S tooth profile are carried out.Finally,the simulation analysis shows that the spatial tooth profile design of the flexspline is necessary and can improve the transmission accuracy and life of harmonic gear,this paper mainly completed the following work :Firstly,convex set integral geometry is introduced to describe the neutral layer curve of the flexspline,the angle relationship between the neutral layer curve equation of the flexspline and the components of harmonic gear drive is derived in the form of support funct ion as cosine curve.The main components of harmonic reducer are selected and designed,and the flex spline and flexible bearing which are prone to failure are checked.Secondly,the S tooth profile under ideal motion state is designed by the motion trajectory of the wave generator,and the plane tooth profile modification of the S tooth profile is carried out by considering the tooth profile deflection of the flexspline tooth in the motion process.In order to verify the effect of plane modification,a series of meshing characteristics of the S tooth profile after plane modification are analyzed,including the trajectory analysis of the flexspline tooth relative to the circular spline tooth groove,the assembly state analysis of the flexspline and the circular spline,and the change of the backlash value during the tooth profile movement.Then,the spatial tooth profile design of the plane modified S tooth profile is carried out by using the linear deformation assumption of the flexspline generating line and the simulation results.Considering that the circular spline is more difficult to realize the spatial tooth profile processing than the flexspline,it is finally decided to complete the spatial tooth profile design by changing the flexspline tooth profile.Both methods need to divide the flexspline into two sections from the main section.After obtaining the initial wall thickness adjustment of each section,the final wall thickness adjustment of the tooth profile trajectory without interference can be obta ined by continuously reducing the adjustment value.The meshing characteristics of typical section of the flexspline after spatial tooth profile design are analyzed.Finally,the finite element model of the harmonic reducer with two kinds of spatial tooth profile design and plane tooth profile design is established.The stress and deformation of the overall and the flexspline of the reducer with the above two design methods are analyzed.The stress and radial deformation of the flexspilne and the contact pressure of the tooth profile of the reducer with two kinds of spatial tooth profile design are analyzed.The necessity of spatial tooth profile design is verified and the comprehensive performance of the flexspline based on simulation design is relatively good. |
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