Our common power steering has three kinds of mechanical hydraulic power, electronic hydraulic power, electric power.

Mechanical hydraulic power

Mechanical hydraulic booster is a mode of power we are the most common, it was born in 1902, invented by Englishman Frederick W. Lanchester, and commercial application of the earliest to wait half a century later, in 1951, Chrysler to mature hydraulic steering booster system application in the imperial cars. Because the technology is mature and reliable, and the cost is low, it can be widely popularized.

Hydraulic pump, oil pipe, pressure fluid control valve, V type transmission belt, oil tank and so on are the main components of the mechanical hydraulic power assist system. The power output of the engine is converted into a hydraulic pump pressure, and an auxiliary force is applied to the steering system.

Electronic hydraulic power

Because the mechanical hydraulic power needs to consume a large engine power, so the people in the mechanical hydraulic power on the basis of improvement, developed a more energy saving electronic hydraulic power steering system. The system of steering pump no longer direct driven by the engine, but by the motor to drive the and before the foundation of added electric control system, the steering assisting force size not only with steering angle related, and the speed. Mechanical structure on the increase of the hydraulic reaction device and liquid flow distribution valve, the new electronic control system, including the speed sensor, solenoid valve, steering ECU, etc..

Electric power assisted

EPS is the English Power Steering Electric abbreviation, that is, electric power steering system. Electric power steering system is the development direction of automobile steering system. The system by the electric power machine directly provides power steering, eliminating the need for hydraulic power steering system necessary for the power steering pump, hose, hydraulic oil, transmission belt and installed in the engine on the belt pulley, saving energy, and protect the environment. In addition, it also has the characteristics of simple adjustment, flexible assembly and can provide power steering in a variety of situations. It is with these advantages, electric power steering system as a new steering technology, will challenge everyone is very well known, has a history of more than 50 years of history of the hydraulic steering system.

According to the different installation position of the booster motor, EPS system can be divided into 3 types of steering shaft power, gear booster, rack power. The steering shaft booster EPS motor is fixed on one side of the steering shaft, and is connected with the steering shaft through a speed reducing mechanism. The gear motor and the gear wheel are connected with the small gear, and the direct drive gear is driven by the EPS. Rack and pinion power EPS of the motor and the reduction mechanism will provide a direct drive rack to provide power.

Driver in the manipulation of the steering wheel steering, torque sensor to the steering wheel and steering torque size, the voltage signal transmitted to the electronic control unit, electronic control unit according to the torque sensor to detect the torque voltage signal, rotation direction and speed signals and, to a motor controller issued a directive, causes motor output appropriate size and direction of the steering torque, thereby generating auxiliary power. When the automobile does not turn, the electronic control unit does not issue commands to the motor controller, and the motor does not work.