Design And Analysis Of Small Teeth Difference Planetary Gear Transmission For Electric Valve Actuators Based On Romax Designer

Involution planetary gear transmission with small teeth difference has been widely applied.It has many merits,such as small size,compact structure,high bearing capacity,large power transmission and high efficiency etc.As no uniform standard of calculation,now there are many method for structural design and analysis which combined a variety of design method and virtual technology.In this paper,designed and calculated the internal gear of the electric valve actuators with small teeth difference planetary transmission,and its static and dynamic analysis are based on Romax Designer.The main contents and conclusions are as follows:(1)Selected the appropriate tooth number difference,displacement factor and addendum coefficient.Designed and calculated parameters of two internal gear pairs.Tested contact ratio,clearance and interference of internal gear pairs.The contact ratio,clearance could meet the requirements,it doesn't have tooth-overlapping interference and fillet interference,but it has radial installation interference.Therefore,the planet gear can only be installed in the axial direction.(2)3D model of small teeth difference planetary transmission was built by Romax Designer.Located the planetary gears by setting up planet carrier.Used offset between the planet carrier and planetary gear shaft to act eccentric position between the planetary gear and internal gear.Laid a foundation for subsequent statics and dynamics analysis.(3)Through statics analysis of the transmission system,tested the strength of the shaft,bearing,gear,and predicted service hours of the bearing.Then security of the transmission system is sure.(4)Through the dynamics analysis of the transmission system,output transmission error and tooth contact analysis results.Applied a comprehensive lead modification combined crown modification and slope modification to the planetary gears.The results showed that after modification,transmission errors had decreased,and there was a marked decrease about tooth surface contact stress and normal load.