Analysis of Oil Injection Cooling Characteristics of High Pitch Line Velocity Gear Pairs

The higher the linear speed of the gear is, the more significant the friction heat generation phenomenon will be, which is not conducive to the improvement of gear life and efficiency. Thus, it is necessary to conduct an analysis of the oil injection cooling characteristics of the gear pair under the high pitch line velocity and explore optimal cooling parameters. Based on the Hertz contact theory and gear meshing characteristics, the average contact stress, relative sliding velocity, and friction coefficient of the tooth surface were solved. Based on the heat generation theory, the average heat flux density of the tooth surface at the high pitch line velocity was obtained. Furthermore, the heat flux density of the tooth surface was used as a boundary condition, and a simulation model for the oil injection cooling characteristics of high speed gears with a pitch line velocity of 120 m/s was established. The effects of the injection speed, injection angle, and gear baffle configuration on the cooling characteristics were explored. The results show that increasing the injection speed can improve the cooling effect of the tooth surface to a certain extent. When the injection angle is 60° and the axial injection angle is 20° higher, a lower tooth surface temperature can be obtained. The axial baffle configuration has a better cooling effect on the tooth surface compared to other baffle configurations.