Why use variable displacement oil pump?

When the engine speed gradually increases, the pump oil volume and pressure of the oil pump will increase with the increase of the speed. After the pump oil volume and pressure meet the lubrication requirements, the continuous increase will consume more engine power. Therefore, the variable displacement oil pump is required. The use of variable displacement oil pump can generally reduce the fuel consumption of passenger car engine by 1% ~ 2%. Variable displacement oil pump adopts vane pump, which is composed of rotor, slide valve, vane, regulating oil chamber, oil pressure control solenoid valve, etc. The oil pressure control solenoid valve is installed on the main oil circuit and controlled by the computer.

When the engine operates at low speed, the computer controls the oil pressure control solenoid valve to reduce the oil pressure in the regulating oil chamber. At this time, the spring pushes the slide valve to move to the left, the volume of the oil inlet chamber is large, and the displacement of the oil pump is large to meet the needs of engine lubrication.

When the engine operates at high speed, the computer controls the oil pressure control solenoid valve to increase the oil pressure in the regulating oil chamber, the slide valve moves to the right, the volume of the oil inlet chamber is small, and the displacement of the oil pump is small, so as to avoid backflow and save energy consumption.