Lubrication Characteristics Of Planet Gear Axial Sliding Bearings In High-Speed Planetary Transmissions Of Vehicles

To improve the speed of the planet wheel bearing is one of the main restricting factors to improve the vehicle planetary transmission power density. To reduce the planet wheel axial bearing wear, and meet the requirement of high speed working condition, this paper introduced dynamic pressure lubrication mechanism on the basis of the traditional smooth surface supporting, carried on the groove hydrodynamic pressure lubrication design, and introduce dynamic pressure lubrication mechanism to produce fluid dynamic pressure bearing capacity when the relative movement occurs between planetary gear and axial bearing, so as to realize the non-contact to reduce wear, and increase the cooling performance.Based on Reynolds equation, groove edge angle and the bottom of the slot angle as two trough type parameters are introduced to establish the film thickness distribution function with groove sections which are triangle, rectangle and circular arc. Considering the fluid density and fluid viscosity is affected by factors such as fluid temperature and pressure, the numerical model of hydrodynamic pressure lubrication with the axial bearing is established. The finite volume method is adopted to solve discretely the equation, and study the lubricating properties of slot.Study on the law of axial bearing hydrodynamic pressure lubrication characteristics along with the speed, and find that the oil film bearing, lubricating oil flow and oil temperature rise with the increase of the rotational speed linearly, and the change is very obvious. Through related data, hydrodynamic pressure lubrication performance of the rectangular groove, triangular groove, circular arc groove is compared respectively, and the result shows that, the oil film bearing capacity and oil temperature rise of the triangle groove is the largest, the rectangular groove is minimum, and lubricating oil flow is opposite under the same condition.Study on the law of axial bearing hydrodynamic pressure lubrication characteristics along with the groove edge angle, and find that the oil film bearing capacity decreases after increasing with the increase of groove edge angle, and the oil film bearing capacity reaches the maximum when the edge of the groove angle at between-0.05 rad and-0.04 rad; lubricating oil flow increases after decreasing with the increase of groove edge angle, and the lubricating oil flow reaches the minimum when the edge of the groove angle at between 0.05 rad and 0.06 rad; lubricating oil flow decreases after increasing with the increase of groove edge angle, and the lubricating oil flow reaches the maximum when the edge of the groove angle at 0.06 rad around.Study on the law of axial bearing hydrodynamic pressure lubrication characteristics to the groove bottom angle, and find that the oil film bearing capacity increases with the absolute value increase of groove bottom angle, and the oil film bearing capacity reaches the minimum when the edge of the groove bottom angle at 0 rad; lubricating oil flow decreases with the increase of groove bottom angle; lubricating oil temperature rise increases with the increase of groove bottom angle.