Predictions of friction and flash temperature in marine gears based on a 3D line contact mixed lubrication model considering measured surface roughness

Abstract

Wear and scuffing failures often occur in marine transmission gears due to high friction and flash temperature at the interface between the meshing-teeth. In this paper, a numerical solution procedure was developed for the predictions of transient friction and flash temperature in the marine timing gears during one meshing circle based on the 3D line contact mixed lubrication simulation, which had been verified by comparing the flash temperature with those from Blok’s theory. The effect of machined surface roughness on the mixed lubrication characteristics is studied. The obtained results for several typical gear pairs indicate that gear pair 4–6 exhibits the largest friction and the highest interfacial temperature increase due to severe rough surface asperity contacts, while the polished gear surfaces yield the smallest friction and the lowest interfacial temperature. In addition, the influences of the operating conditions and the gear design parameters on the friction-temperature behaviors are discussed. It is observed that the conditions of heavy load and low rotational velocity usually lead to significantly increased friction and temperature. In the meantime, by optimizing the gear design parameters, such as the modulus and the pressure angle, the performance of interfacial friction and temperature can be significantly improved.

摘要

船舶传动齿轮由于啮合过程中齿面摩擦大、温度高, 经常发生磨损和胶合故障。本文基于线接 触的三维混合润滑模型, 建立了一种预测船用定时齿轮在一个啮合周期内的瞬态摩擦温度特性的数值 解法, 并与Blok 理论进行了对比, 验证了该方法的正确性。研究了表面粗糙度对润滑特性的影响, 对 几种典型齿轮副进行研究, 结果表明, 由于较严重的表面粗糙接触, 齿轮副4-6 的摩擦因数最大, 界 面温度最高, 而抛光齿轮表面的摩擦因数最小, 界面温度最低。此外, 讨论了工况和结构对摩擦温度 状态的影响, 研究表明在重载、低速的工况会导致摩擦因数较大以及温度较高的问题。同时, 通过对 齿轮模数和压力角等结构设计参数的优化, 可以显著提高齿轮的界面摩擦和温度性能。