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A novel thermoelastohydrodynamic (TEHD) lubrication model has been developed for slipper pair in axial piston pump. The model considers the interaction between elastohydrodynamic behavior and viscosity temperature effect. Deformation of the slipper is discussed as well as the distribution of oil film thickness, pressure and temperature. Effects of working conditions and slipper structure parameters on TEHD lubrication performance, such as film thickness, pressure, temperature, and leakage flow rate are investigated. The predicted temperature and film thickness show good agreement with measurements, while the pressure shows a reasonable distribution comparing with previous studies. The influence of load pressure and shaft rotational speed on the TEHD lubrication characteristics are illustrated which shows the elastohydrodynamic pressure should be balanced against the oil film temperature and pressure in optimized design of slipper structure parameters. Finally, the structure parameters of slipper, such as the slipper radius ratio and orifice length-diameter ratio, were optimized to improve the TEHD lubrication performance of slipper pair. [ABSTRACT FROM AUTHOR]

• A method of combining surface texturing with longitudinal or transverse micro-vibration is proposed for further improving the tribological performance of mechanical components. • The feasibility of tribology enhancement is verified by numerical and experimental study. • The friction coefficient slightly increases with the increase of vibration frequency and significantly diminishes with the increase of vibration velocity amplitude. • The friction reduction mechanism is mainly attributed to the improvement of lubrication condition. A method of combining surface texturing with longitudinal or transverse micro-vibration was proposed to further enhance the tribological performance of mechanical components. The influences of vibration parameters and micro-dimple geometrical parameter on the tribological performance were studied to verify the feasibility of tribology enhancement by numerical and experimental methods. Results show that the friction coefficients can be significantly reduced by superimposing longitudinal or transverse vibration on the textured surfaces under different lubrication conditions. The friction coefficient slightly increases with the increase of vibration frequency and significantly diminishes with the increase of vibration velocity amplitude. The improvement of lubrication condition is the main mechanism of friction reduction. Since the vibrations can enhance the average load capacity of the textured surface and drag out the lubricant reserved in the micro-dimples, in turn, enlarge the thickness of lubricant film. These results provide a novel perspective to reduce friction and save energy in mechanical systems and metal processing. [ABSTRACT FROM AUTHOR]

• The effects of micro-dimple geometric parameters and operating conditions on the tribological performance of textured surface have been comprehensively investigated. • An effective and efficient optimization method of geometric parameter is established by combining single factor analysis and orthogonal analysis. • The friction reduction effect of textured surface is verified by numerical simulation and experimental study. • Results can provide theoretical guidance for the optimization of texture geometric parameters under different application conditions. Aiming at establishing an effective and efficient optimization method of texture parameters to further enhance the tribological performance of mechanical equipment, numerical simulation and experimental studies were undertaken to assess the tribological performance of textured surface. Pressure distributions and velocity distributions of the lubricant flow were analyzed by three-dimensional computational fluid dynamic simulation to comprehensively understand the effects of geometric parameters and operating conditions. It is found that the tribological performance of the textured surface is significantly affected by the micro-dimple geometric parameters, and the optimum texturing geometric parameters are highly dependent on the operating conditions. The comparative tribological experiments of untextured and textured specimens were conducted, and the specimen with area density of 28.26% achieves a maximum friction reduction rate of 26.61% under the tested conditions. The numerical simulation and experimental results were cross-checked and consistent with each other to verify that the textured surface can achieve a remarkable friction reduction effect. The friction reduction mechanism is mainly attributed to the improvement of carrying capacity, lubricant reservation, contact area reduction and secondary lubrication. Results can provide theoretical guidance for the optimization of texture geometric parameters under different application conditions. Image, graphical abstract [ABSTRACT FROM AUTHOR]