Analysis And Optimization Of The Structure Of The Short-tube Flexspline Double-arc Harmonic Reducer

Harmonic gear transmission is a brand-new transmission method that emerged during the 1950s due to the rapid development of aerospace industry.The har monic reducer is mainly composed of three core components:wave generato r,flexible wheel and rigid wheel.Because of its simple structure,small size,light weight,large transmission ratio and other advantages,it is widely used in various fields.In practical applications,ordinary harmonic reducers often cannot meet the in stallation space requirements of aerospace and other fields due to their large axial dimensions,while short-tube harmonic reducers have smaller axial dimensions than ordinary harmonic reducers.It occupies smaller space and lighter weight,so it has broad er application prospects in robotics,aerospace and other fields.In the research of this subject,firstly,the research on the transmission of the short-tube flexspline harmonic reducer was carried out.Through the comparison and analysis of the axial size between it and the ordinary harmonic reducer,it was found that the smaller the axial size,the smaller the The larger the opening angle is,it is not conducive to the increase of the meshing area between the flexspline and the rigid gear teeth.In addition,it will further cause the problem of increased concentrated stress at the connection between the bottom of the flexspline and the barrel body,and the use of short-tube flexspline is proposed.The design method of the double-arc tooth profile,and the structure of the connection between the bottom of the cylinder and the cylinder body is changed,and a new type of short cylinder flexspline is designed.First of all,this paper conducts a theoretical analysis on the deformation of the flexspline,improves the key structure of the flexspline,and optimizes the existing cylindrical flexspline to remove the original long cylindrical flexspline barrel and change it to a double round The arc structure optimizes the structural parameters of its key positions to ensure the reliability of the flexspline.Secondly,in order to make the teeth of the rigid wheel and the flexible wheel achieve complete conjugate in the true sense,this paper appl ies the double-arc tooth profile to the flexible wheel tooth profile.Ac cording to the current double-arc tooth profile standard,the design of the tooth profile of the flexspline is completed,and mathematical methods such as coordinate changes are used t o achieve the derivation and solution of the tooth profile of the rigid gear.Thirdly,the overall structural design of the harmonic reducer,first determine the structural form and geometric parameters of the flexspline according to actual needs,and then determine the structural form and geometric parameters of the rigid whe el and wave generator on this basis,and use Solidworks to complete the model construction.assembly.The stress calculation and stability analysis of the flexspline cylinder body stress theoretically prove the rationality of the flexspline structure design.Finally,with the support of the relevant functions of the finite element analysis software ANSYS Workbence,the finite element analysis was carried out for the original long tube flexspline and the improved new flexspline.The stress of the flexspline was taken as the objective function.Further optimize the structural parameters to ensure that the structure can achieve the best results.Finally,a set of optimal solutions for the geometric parameters of the flexspline structure are obtained:the double arc radius of the flexspline is R₂=2.5mm,the wall thickness of the flexspline isδ=0.4mm,and the ring gear width b_R=12mm.Through theoretical analysis and calculation and finite ele ment simulation,it is concluded that in the harmonic gear transmission,the number of meshing teeth increases by 12%,which proves that the double-circular-arc tooth-shaped harmonic reducer is compared with the involute tooth-shaped harmonic reducer.The device has good meshing performance.Through comparative analysis,the maximum stress value of the new flexspline is 15%lower than that of the long-tube flexspline.The maximum stress value of the long-tube flexspline occurs at the connection between the gear ring and the barrel,and the maximum stress value of the new flexspline The point is offset to the double-arc structure.As a result,the stress at th e teeth of the new flexspline is greatly reduced,and the flexibility of the flexspline is higher,th e transmission is more stable,and the service life is longer,thereby improving the overall working performance of the harmonic reducer.