Search

Interfacial issues have always been the top priority of tribology which directly affect tribological performance of friction materials and output characteristics of Ultrasonic Motors (USMs). Therefore, from the perspective of bionics, a series of surface textures with different parameters were designed to regulate friction interface. The tribological properties of textured friction materials were systematically analyzed. The results found that tribological performance was affected by positive and negative aspects. Consequently, there is an optimal parameter in the case of the best tribological behavior. The optimal parameter was obtained by virtue of orthogonal experimental design and matrix analysis based on mathematical statistics. Additionally, the energy conversion efficiency of USMs with textured friction materials compared to untextured samples increased by 29%. • The surface textures were used to increase the energy conversion efficiency of USMs. • The tribological properties of textured friction materials were systematically analyzed. • The reason for the improvement of the output characteristics of the USMs was revealed. • PTFE composites with surface textured show a high potential for using as tribo-materials for USMs. [ABSTRACT FROM AUTHOR]

Two ways to enhance conversion efficiency of the ultrasonic motor (USM) were developed. According to mechanical and tribological properties, an advanced polyimide (PI) friction material was fabricated. In comparison to conventional polytetraflfluoroethylene (PTFE) friction material, the novel PI friction material enhanced efficiency from 29% to 44%, an improvement of 51.7%. The results indicated high friction coefficient and high elastic modulus were essential for improving efficiency. Inspired by the unique topography, the micro-dimples were introduced into PI friction material which improved the efficiency from 44% to 53%, an increment of 20.5%. The optimum parameter was diameter of 200 μm and area density of 7%. The effect of surface texture on tribological behavior and output characteristic of the USM was comprehensively explored. • The advanced PI friction material and the surface texture enhance efficiency from 29% to 53%, an increase of 82.8%. • High friction coefficient and high elastic modulus are the main reason for improving the conversion efficiency of the USM. • The surface texture enhance the efficiency of the USM because of increased tangential frictional force. [ABSTRACT FROM AUTHOR]