Abstract Moving towards high power density, high dynamic responsibility, and high reliability, the electro-hydrostatic actuators (EHA) have put forward great demand on the piston pumps. As a typical pump control system, EHA pumps need to maintain high efficiency in a wide range of rotational speed and pressure to implement the function of position servo. High speed and wide speed range bring great challenge to the cylinder block/valve plate interface, which has to fulfill simultaneously a bearing and sealing function. Cermet coatings are beneficial to improve the friction and wear performance of the sliding surfaces. In this study, a dedicated frictional test apparatus of cylinder block/valve plate interface has been built which could accurately simulate the working conditions of EHA pumps in a wide operational condition. Equations of the friction coefficient are established based on the combination of experiments and friction theory. When pairing with the tin-bronze cylinder block, friction coefficients of TiAlN coated and nitrided valve plate are calculated by these equations. Additionally, the wear status of these two friction pairs are evaluated by a 3D measuring laser microscope. In the wide speed range of 500–10000 rpm, the decrease percentage of friction coefficient and the wear rate for TiAlN coated valve plate are 52.55%∼64.9% and 12-14% of the nitrided one, respectively.

中文翻译：

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TiAlN涂层阀板摩擦学特性的实验研究

摘要 朝着高功率密度、高动态响应和高可靠性的方向发展，电液静力执行器（EHA）对柱塞泵提出了很高的要求。EHA泵作为典型的泵控制系统，需要在较宽的转速和压力范围内保持高效率，以实现位置伺服功能。高转速和宽转速范围给气缸体/阀板接口带来了巨大挑战，它必须同时完成轴承和密封功能。金属陶瓷涂层有利于提高滑动面的摩擦磨损性能。在这项研究中，建立了一个专用的缸体/阀板界面摩擦试验装置，可以准确地模拟 EHA 泵在广泛运行条件下的工作条件。摩擦系数方程是在实验和摩擦理论相结合的基础上建立的。当与锡青铜气缸体配对时，TiAlN 涂层和氮化阀板的摩擦系数由这些方程计算。此外，这两个摩擦副的磨损状态通过 3D 测量激光显微镜进行评估。在 500-10000 rpm 的较宽转速范围内，TiAlN 涂层阀板的摩擦系数降低百分比和磨损率分别为氮化阀板的 52.55%~64.9% 和 12-14%。这两个摩擦副的磨损状态通过 3D 测量激光显微镜进行评估。在 500-10000 rpm 的较宽转速范围内，TiAlN 涂层阀板的摩擦系数降低百分比和磨损率分别为氮化阀板的 52.55%~64.9% 和 12-14%。这两个摩擦副的磨损状态通过 3D 测量激光显微镜进行评估。在 500-10000 rpm 的较宽转速范围内，TiAlN 涂层阀板的摩擦系数降低百分比和磨损率分别为氮化阀板的 52.55%~64.9% 和 12-14%。