High-frequency hydraulic feed drive for non-circular workpiece cutting

The efficiency and the accuracy of non-circular workpiece are to a large extent dependent upon the dynamic responding speed and the stiffness. The high-frequency hydraulic feed drive presented is composed of a bellows tube actuator and a pressure wave generator. The bellows tube actuator works on the elastic deformation with pressurized oil introduced inside. The elastic formation is converted into the linear motion of the cutting tool carriage. Within the range of elasticity, the displacement of the deformation is linearly proportional to the value of pressure. Thus, by controlling the pressure wave form, the desired trajectory of the cutting tool can be obtained. To obtain high-frequency response for the hydraulic feed drive, a pressure valve is used to as the pressure wave generator. The dynamic characteristics and the stiffness are theoretically and experimentally investigated. A special experiment has been designed to test the performance of the hydraulic feed drive and it is demonstrated that for the non-circular workpiece cutting the hydraulic feed drive can keep the accuracy of the contour higher than 1 micrometer.