Working principle of automobile steering booster pump

Although most cars use electric power steering system at present, some cars still use hydraulic power steering system. The purpose of using power steering system is to reduce the driver's steering force. By improving the corresponding steering characteristics, the steering operation is lighter, but the response during steering is still completed by the driver. Power steering pump is the power source of power steering system, and hydraulic oil is the medium of energy conversion (hydraulic energy is converted into mechanical energy). When the engine is working, the steering booster pump is driven by the crankshaft pulley through the belt and plays an auxiliary role. The hydraulic booster system is shown in the following figure. Hydraulic power steering system consists of steering pump, high-pressure oil pipe, oil return pipe, steering gear, oil control valve and power cylinder. The mechanical part consists of steering knuckle, tie rod and longitudinal rod. Because the booster pump is driven by V-belt, in order to ensure that the system has a certain pressure, as long as the engine is started, the booster system will work whether we turn or not. Due to cost and material problems, hydraulic power system is more widely used in economical cars. The function of the booster pump is to generate high pressure in the steering system, and the high pressure oil pipe is responsible for transmitting the pressure from the booster pump to the oil quantity regulating valve in the steering gear. The oil regulating valve is installed on the steering gear housing, and there is a pinion at the end to match the rack in the steering gear. The power cylinder is installed in the steering gear and usually contains hydraulic oil. The middle of the cylinder is separated by a piston, including two small cylinders with upper and lower volumes. There are three types of boosters: rack-and-pinion type, circulating ball type and worm direct-selling type. Rack-and-pinion type is most used in automobiles, which can be said to be 100%. Because cars don't need very large torque transmission, small trucks use circular ball type. Structure and working principle of power-assisted pump The key components of power-assisted steering pump are blades, stator, rotor, safety valve (pressure valve) seal, bearing front cover and rear cover, as shown in the following figure. When the engine is working, the rotating speed of the outer end of the rotor is synchronized with the rotating speed of the engine, thus driving the rotor to rotate. The blades are mounted on the stator. When the rotor rotates, the blades will expand due to centrifugal force to seal the shell, thus forming a closed space. Because in the process of rotor operation, the closed space has experienced a spatial change from big to bottom and from small to big, so the pressure acting on the upper and lower power cylinders will cause a pressure difference.