| The existing robot precision reducer mainly includes harmonic reducer,RV reducer,Spinea reducer and so on.Most of these high-precision gear reducers are monopolized by foreign manufacturers,Although domestic manufacturers can produce the same type of reducer,there is still a certain gap between domestic reducers and foreign products.In order to develop a high-precision reducer with completely independent intellectual property rights,more in-depth research on precision reducers is required.This paper takes NN type small tooth difference reducer as the research object,through structural design,tooth profile design,and combined with the theoretical basis of deformation coordination design,a new rigid-flexible compound small tooth difference reducer is designed,and the finite element and multi-body dynamic analysis software were used to analyze the static and dynamic characteristics of the gear reducer transmission pair.The main contents are as follows:(1)Designing a new type of small-tooth-difference reducer based on the CSF-25 harmonic reducer’s volume,rated load,torsional stiffness and other indicators.Firstly,several different low-tooth differential transmission structures are analyzed,and the traditional NN small-tooth differential transmission structure is improved,compared with the traditional structure,the new transmission structure changes from a double-row gear to a single-row gear in the axial direction,and the axial size of the transmission pair is significantly reduced;At the same time,the compound cycloid tooth profile is designed to replace the involute tooth profile,and the compound cycloid gear is modified according to the accuracy requirements of the cycloid gear.(2)The AnsysAIM software was used to establish the finite element analysis model of single-tooth meshing of compound cycloid gears.By establishing the meshing model of cycloid teeth with different profile parameters,the influence of cycloid profile parameters on meshing characteristics of cycloid teeth was obtained,and the cycloid profile parameters were determined.Then the finite element analysis model of multi-tooth meshing of cycloid gear and involute gear is established to obtain the meshing characteristics of stress distribution and torsional stiffness of the gear under the condition of multi-tooth meshing.(3)Adams is used to establish a rigid virtual prototype of cycloid and involute gear profile transmission pair,and the dynamic characteristics are analyzed.The angular velocity,meshing force,output torque and other dynamic characteristics of the two profile output gears are compared.The simulation results show that the output angular velocity and output torque of cycloid profile gear pair fluctuate less,but the meshing force is higher than that of involute gear.(4)The rigid and flexible composite gear pair was designed with metal rubber as the flexible part by means of deformation coordination design.Taking into account the manufacturing and assembly error,temperature variation and other factors of the reducer parts,the ring gap of the rigid-flex composite gear and the dynamic center distance of the gear pair are calculated.The elastic modulus of metal rubber is calculated according to the torsional stiffness of CSF-25 harmonic reducer.(5)A virtual prototype of rigid and flexible composite transmission pair was established by Adams,and its dynamic characteristics were compared with those of rigid transmission pair.The results show that the output angular velocity,meshing force and output torque of the rigid and flexible composite transmission pair are obviously decreased;Then change the center distance of the rigid-flex compound gear pair to explore the effect of the center distance on the dynamic characteristics of the rigid-flex compound gear.The simulation results show that as the center distance increases,the angular velocity fluctuation of the output gear decreases,the meshing force increases slightly,the vibration acceleration of gear Z2 decreases,and the vibration acceleration of gear Z3 increases. |
PDF Full Text Request