高速重载圆柱齿轮弹流润滑数值分析

Numerical Study of Elastohydrodynamic Lubrication for High Speed and Heavy Duty Cylindrical Gear

为研究高速重载下齿轮的性能,采用复合直接迭代法,对航空发动机传动系统中高速、重载圆柱齿轮润滑状态进行仿真分析,研究不同功率、不同转速、不同滑油入口温度对齿轮啮合区压力、油膜厚度、油膜温度的影响。数值计算结果表明:随着齿轮传递功率的增加或是转速的降低,啮合区压力增加,油膜温度有所上升;当齿轮保持较高转速时,功率对油膜厚度的影响较小;转速与功率都会对油膜最高温升产生影响,其中功率对最高温升的影响更大;低功率情况下随着转速增加最高温升呈现先下降后增加的趋势,而高功率时增加转速则最高温升一直下降,固定转速时则温升随功率的增加而增加;低速重载工况下油膜厚度最薄,容易出现干摩擦;入口滑油温度的升高会使压力、膜厚、温升均有所下降,因此采用合适的滑油入口温度可以使齿轮接触区承受较低的载荷并拥有较厚的油膜。

In order to study the performance of gears under high speed and over load,the compound direct iteration method was used to simulate and analyze the lubrication state of high speed and heavy duty cylindrical gears in aeroengine transmission system.The effects of different power,different rotational speed and different lubricating oil inlet temperature on gear meshing zone pressure,oil film thickness and oil film temperature were studied.The results show that with the increase of gear transmission power or the decrease of rotational speed,the pressure in the meshing area increases and the oil film temperature increases.When the gear keeps a high speed,the power has little effect on the oil film thickness.Both rotational speed and power have an impact on the maximum temperature rise of the oil film,and power has a greater impact on the maximum temperature rise.At low power,the maximum temperature rise decreases first and then increases with the increase of rotational speed,while at high power,the maximum temperature rise decreases all the time with the increase of speed,and at fixed speed,the temperature rise increases with the increase of power.Under the condition of low speed and heavy duty,the oil film thickness is the thinnest and dry friction is easy to occur.The increase of inlet oil temperature will decrease the pressure,film thickness and temperature rise.Therefore,the appropriate lubricating oil inlet temperature can make the gear contact area bear lower load and have thicker oil film.