Effects of oil channels and oil flow rate on cooling performance of closed circuit axial piston transmission

Abstract

Closed circuit axial piston transmission (CCAPT) has been implemented in the field of hydraulic transmission. As a result of frictional loss and leakage loss, the temperature rise is unavoidable, that can shorten the service life of crucial components. Based on the method of computational fluid dynamics and liquid-solid mathematical coupling, structure optimization of CCAPT is investigated in the paper to decrease temperature. The influence of the position of oil inlet and outlet channels, oil flow rate and the filling-oil channels type is analyzed, meanwhile the temperature distribution and flow streamline are monitored. The results indicate that the higher inlet velocity may give rise to a better cooling performance of CCAPT but there is an optimal upper limit of inlet velocity, which is 3.5 m/s in this study. Besides, cooling performance and reducing temperature are obvious when oil inlet and outlet channels are set close to both sides of CCAPT. In addition, axisymmetric filling-oil channels have a slightly better effect on cooling performance but the cooling performance is not obvious. The paper can provide design reference for reasonable selection of oil channels and oil flow rate.