Types and composition of automobile steering system

Characteristics and application of automobile steering system types and components Up to now, automobile steering system has gone through four stages: traditional mechanical steering system, hydraulic power steering system, electro-hydraulic power steering system and electric power steering system, and may develop into steer-by-wire system in the future. At present, the automobile steering system is in the transition stage from hydraulic power steering system, electro-hydraulic power steering system to electric power steering system. Mechanical steering system The mechanical steering system takes the driver's physical strength as the steering energy, and the components that transmit the force are all mechanical, mainly composed of steering control mechanism, steering gear and steering transmission mechanism. The traditional mechanical steering system is mainly composed of steering control mechanism, steering gear and steering transmission mechanism. Steering mechanism is the mechanism that the driver controls the steering gear, including the parts input from the steering wheel to the steering gear. The steering gear is a booster, which amplifies and outputs the torque from the steering wheel according to a certain transmission ratio. The steering mechanism is a mechanism that transmits the torque output by the steering gear to the steering wheel, including components from the steering rocker arm to the steering wheel. The traditional mechanical steering system has the advantages of simple structure, reliable operation and low production cost. However, with the improvement of vehicle speed and vehicle quality, steering control becomes more difficult and steering becomes more and more laborious. Hydraulic Power Steering System Hydraulic Power Steering System (HPS) is an additional hydraulic power steering system based on the traditional mechanical steering system, which generally consists of an oil pump, a power-assisted device and a control valve. It uses hydraulic pressure to promote the steering movement of traditional mechanical steering mechanism, reduces the labor intensity of drivers, and solves the contradiction between "light" and "sensitive" steering caused by the fixed transmission ratio of traditional mechanical steering system to some extent. However, the disadvantage is that the hydraulic booster pump will consume extra energy of the engine as long as the engine works, whether the car turns or not. Electric power steering system The electric power steering system (EPAS or EPS) is based on the traditional mechanical steering system, adding sensor devices, electronic control devices, steering assist mechanisms, etc. Through software modification, different steering assist characteristics of different vehicles and different working conditions can be realized, and at the same time, the hydraulic system is cancelled and the environmental protection performance is improved. However, due to the limited power and steering force of the motor, it is mostly used in small cars. Power steering system has the advantages of improving driver's driving comfort, reducing driving fatigue and improving driving safety, and is an indispensable part of modern cars.