Research on the hydraulic transformer with new distribution pairs

A new distribution pairs of the hydraulic transformer (HT) has been proposed to extend its output pressure range. A common pressure rail (CPR) test-rig was built to test the performance of the HT. The simulation and the test were carried out to explore the output pressure, the displacement and the speed stability of the HT. The research results have shown as follows. Firstly, the designed HT can realize regulating the pressure, and its output pressure is determined by the control angle of the port plate and affected by the load. The ratio of the load pressure (p _B) to the supply pressure (p _A) of the HT varies from 0 to 1.2. Secondly, the HT is a hydraulic component of variable displacement, and the displacement of the every port of the HT depends on the control angle and is not affected by loads. Finally, the speed stability of the HT becomes better with the control angle rising, and the movement zone exists while the control angle is lower than 15°. The high pulsation of the driving torque of the HT results in the poor speed stability. The research will contribute to the improvement of the HT performance in the future. Supported by the National Excellent Young Scientists Fund (Grant No. 50425518) and the National Natural Science Foundation of China (Grant No. 50305032).