Study On Transmission Efficiency And Temperature Rise Of Two-step Movable Tooth Drive

Double-stage movable tooth transmission is simple and compact and has small size,large transmission ratio,high efficiency and large bearing capacity.It is very suitable for oil drilling and robots fields.This paper focuses on the study of two-stage movable tooth transmission from the aspects of elastohydrodynamic lubrication,efficiency,heat transfer,temperature rise and prototype development.According to the theory of elastohydrodynamic lubrication and Dowson-Higginson formula,the minimum oil film thickness of the two-stage movable tooth transmission is calculated,and the lubrication state is determined according to the film thickness ratio,and the influence of parameters on the minimum oil film thickness is analyzed.The results show that the film lubrication occurs between the movable tooth and the raceways,increasing the center distance between the movable tooth and the wave generator and the radius of the movable tooth can effectively increase the minimum oil film thickness.The surface precision can be improved by polishing and other processing methods for improving the lubrication state.The force and torque in the transmission system are analyzed,the hertzian contact stress,relative sliding speed and friction factor are calculated,and the meshing efficiency of the low-speed stage drive is solved.Bearing efficiency is solved by considering friction and heat.The transmission efficiency is obtained by combining the transmission loss and bearing loss.The heat generated by friction between the movable teeth and the profile wheel is investigated.The thermal analysis model of the movable tooth and the profile wheel is established.The heat conduction equation and the thermal stress equation are deduced,MATLAB software is used to calculate the temperature rise,and analyze the influence of parameters on the temperature rise.The results show that,in order to reduce the temperature rise,the eccentricity distance and the radius of the movable tooth should be appropriately increased,the center distance between the movable tooth and the wave generator,the center radius of the first movable tooth,the input torque of the driving shaftand the input speed of the driving shaft should be appropriately reduced.NX10.0 software is used to simulate the two-stage movable tooth drive,and the solid prototype is processed,assembled and adjusted.The prototype runs smoothly and without noise.On the basis of the structure,the design and development of the two-stage movable tooth extraction drive prototype and the two-stage cycloidal movable tooth driving prototype are presented.The results show that the three kinds of double-stage transmission structures can achieve constant transmission ratio reduction and run well.