A Research of Ti Doped DLC Housing on the Friction Loss in Small Wankel Rotary Engine

Ti掺杂DLC膜对小型转子发动机摩擦损失的影响

¹ School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China
² Navigation and Control Technology Institute of NORINCO Group, Beijing 100089, China

Received: 9 October 2018

Abstract

Ti doped DLC coating was deposited on ductile iron disk commonly used material in small Wankel rotary engine. The friction coefficient under the working condition of apex seal was investigated. The results show that the Ti doped DLC coating is of low friction coefficient. In addition, the surface hardness and the morphology were improved by Ti doped DLC coating. After that, the Ti doped DLC coating was deposited on the housing. A performance testing platform for small Wankel rotary engine was built. The effect of Ti doped DLC coating under motored and working conditions were measured. The results show that when the operation speed varies from 7 000 to 17 000 r/min, the friction loss between apex seal and Ti doped DLC coating ranges 15~38 W under motored condition. It is only 68% of the friction loss between apex seal and ductile iron. Under working condition, the coating increases 23~78 W of the engine output power, which can improve the output power of small Wankel rotary engine by 24%~43%.

摘要

在小型转子发动机常用的球墨铸铁材料上沉积Ti掺杂DLC膜。测量该膜在径向密封片工作状态下的摩擦学性能，试验结果表明Ti掺杂DLC膜具有较低的摩擦因数。Ti掺杂DLC膜会提高镀膜区域表面硬度和表面质量。在小型转子发动机气缸上沉积Ti掺杂DLC膜，搭建小型转子发动机性能测试平台，测量倒拖工况和工作状态下小型转子发动机摩擦损失功率和输出功率。结果表明，转速从7 000~17 000 r/min，在倒拖工况下，Ti掺杂DLC膜气缸与径向密封片摩擦损失功率为15~38 W，摩擦损失功率是球墨铸铁气缸的68%。在工作状态下，与球墨铸铁相比，Ti掺杂DLC膜能够提高23~78 W的输出功率，小型转子发动机输出功率提高了24%~43%。