Analysis of churning losses distribution of hydraulic pump in engineering vehicles using MPS method

Abstract

The power losses of the hydraulic pump in engineering vehicle include mechanical losses, churning losses, and volume losses. The proportion of churning losses to power losses increases markedly, with the continuous improvement of the rotating speed of the hydraulic pump. The churning losses of the hydraulic pump are calculated by moving particle semi-implicit (MPS) method. It indicates that the inclination angle, speed, and oil content will significantly influence the churning losses. The churning torque and power losses of each rotating part increase with the pump speed. The churning losses of the cylinder block are the largest, followed by the retainer and slippers. The churning losses of pistons and shaft are small. With the decrease of oil volume, the churning losses decrease. With the decrease of the inclined angle of the swashplate, the total churning losses decreases. When the oil content is 70% of the full oil, the churning losses of the hydraulic pump is reduced by 57.4%. It provides guidance for the design of the hydraulic pump of high-power density for engineering vehicles and a new numerical calculation method for churning losses of the hydraulic pump.