The Movement Form Analysis Of The Roller Toroidal Worm Drive

As a kind of excellent toroidal worm drive,compared with the traditional cylindrical worm drive,roller enveloping worm gear has the characteristics of simultaneous participation in the number of meshing teeth,high transmission efficiency and large carrying capacity.It has a broad application prospects in the future of the machinery industry.In this paper,the single roller enveloping worm drive is used as the research object,and the meshing theory,three-dimensional modeling,moving performance and meshing efficiency of the transmission are studied deeply.The main contents include:The composition and structure of the single roller enveloping worm gear are introduced,and the principle of the meshing transmission is clarified.Based on the gear meshing theory and differential equation,the coordinate system of the worm drive,the worm tooth surface equation,the worm gear tooth surface equation,the instantaneous contact line equation,the instantaneous velocity equation and the roll rotation angular velocity equation are deduced to construct a single roller theoretical system of enveloping worm gear.The kinematic performance of the worm pair is studied,and the distribution of the contact line and the instantaneous velocity distribution on the roller are analyzed.From the column top to the roller root,at each contact point on the worm wheel contact line,the movement speed gradually decreases.Based on the theoretical analysis,a method of calculating and determining the angular velocity of the roller is proposed,which provides a reference for the future theoretical research.The initial parameters of the roller enveloping worm are selected and the geometrical parameters of the worm are calculated numerically.The three-dimensional solid model of worm and worm wheel is established by MATLAB engineering software and Pro/E three dimensional modeling software.The relationship between the meshing efficiency η and the friction coefficient f,the gear ratio i12 and the roller radius R is analyzed.The results show that the friction coefficient has the greatest influence on the meshing efficiency,and the gear ratio is the second.The radius has little effect on the meshing efficiency.Therefore,the roller should be kept in contact with the worm gear in a good lubrication state,to avoid excessive engagement efficiency loss caused by excessive friction.