Abstract: To overcome the shortages of the rotating valve plate hydraulic transformer in pressure ratio, flow pulsation and noise, a novel hydraulic transformer with small flow pulsation and noise is presented. The characteristics of the modern hydraulic transformer are analysed. A novel hydraulic transformer with a rotating swash plate and double cylinders are investigated. Small flow pulsation and noise are achieved by increasing the piston number and the initial position control of the swash plate angle. The characteristics of the swash plate angle and the moment of resistance when rotating the swash plate were investigated. The pressure ratio was tested by a prototype. The initial position of the swash plate should be set in the position where the middle of the port A and the top dead centre are superposed. When the rotary angle of the swash plate is below 100°, the uniformity coefficient of the output flow reduces about 40% in the novel hydraulic transformer. However, when the rotary angle of the swash plate continues to become larger, the uniformity coefficient will become same. The measured results indicated that the novel configuration can realise a wider pressure ratio range.

Key words: Control angle, Hydraulic transformer, Noise, Pressure ratio, Uniformity coefficient, annular magnetic field control, fine grinding wheel, grits uniform distribution, ultra-precision grinding