Research On Fiber Powder Filled Polymer Based Friction Materials Of Ultrasonic Motors

Ultrasonic motor is a new type of piezoelectric actuator, which has outstanding advantages of compact structure, low speed and large torque, fast response, high control accuracy, no electromagnetic interference, etc. In recent years, the field of aerospace, weapon equipment, precision positioning and other fields have an urgent need for different performance of ultrasonic motor. Ultrasonic motor using piezoelectric ceramics to the electric energy into the stator vibration, and then through the stator and the rotor of the friction drive vibration can be converted into kinetic energy. So friction material is the core part of ultrasonic motor, which directly determines the performance of ultrasonic motor.In order to meet the requirements, to obtain a kind of high stalling torque, low noload speed, good comprehensive indexes friction materials, the properties of the composite materials were studied by choosing the PTFE as matrix, glass fiber and carbon fiber as reinforcing fillers.First of all, the friction material of glass fiber powder filled PTFE based was prepared by cold pressing and sintering, and the influence of different content of glass fiber powder on the mechanical properties, tribological properties and electrical properties of the friction materials was studied by single factor method, the optimum content of glass fiber powder and the optimum particle size were determined. The effect of glass fiber powder on the properties of friction material was analyzed by means of scanning electron microscope.Then, the friction material of carbon fiber powder filled PTFE based was prepared by the same method, the influence of different content of carbon fiber powder on the mechanical properties, tribological properties and electrical properties of the friction materials was studied by the same method, the optimum content of carbon fiber powder and the optimum particle size were determined. The effect of carbon fiber powder on the properties of friction material was analyzed by means of scanning electron microscope.In order to reduce the glass fiber powder scratches on the stator surface, try adding carbon fiber powder and molybdenum disulfide and improve the contrast effect, choose the use of carbon fiber powder and glass fiber powder co- filled PTFE matrix. Through the experimental research on the best ratio of carbon fiber powder and glass fiber powder, the best formula of the friction material with high torque transfer torque, low no load speed and good comprehensive performance is obtained.