Energy efficiency modeling and validation of a novel swash plate-rotating type hydraulic transformer

This paper reports a mathematical model and an experimental validation for the efficiency of a new type of hydraulic transformer, which utilizes a new structure of rotating swash plate. Such a type allows the valve plate being fixed without relative movement to the 3 pressure ports, reducing the throttling loss. An efficiency model is derived accounting for the leakage loss, friction loss and churning loss inside the hydraulic transformer. An experimental test rig is built up to validate the theoretical work. It can be seen that the simulated results are consistent with the test data. So the proposed efficiency model is verified to be correct. Results also show that the highest total efficiency of the new type of hydraulic transformer can reach 70%, and the high-efficiency zone of the transformer appears when the transformation ratio is between 0.5 and 1.75, which is evidently larger than the previous designs. The present work indicates the good potentials of the swash plate-rotating type of hydraulic transformer.