When the car runs in a straight line, the steering control valve connects the working fluid pumped out by the steering pump with the oil tank, and the steering pump is in the unloading state. When the car needs to turn right, the steering control valve connects the working fluid pumped by the steering oil pump with the R chamber, connects the L chamber with the oil tank, and deflects the left and right wheels to the right through the transmission structure to achieve right turning.
The role of the steering gear amplifies the torque imposed by the driver on the steering wheel, reduces the speed, and then transmits it to the steering transmission mechanism. As the steering gear is a mechanism with a large transmission ratio, its transmission efficiency is generally low. The ratio of output power and input power of the steering gear is called the transmission efficiency of the steering gear The transmission efficiency obtained when the power is input by the steering column and output by the steering rocker arm is called positive efficiency, while the efficiency obtained when the transmission direction is opposite to this is called the reverse efficiency. In order to reduce the physical consumption of the driver when operating the steering wheel, it is important to improve the transmission efficiency of the steering gear as much as possible, especially its positive efficiency.
The main function of the steering gear is to increase the force transmitted from the steering wheel to the pitman shaft and change the direction of force transmission. In order to improve the safety of driving, modern cars generally use segmented steering shafts, which are connected with universal joints in the middle. This can not only improve driving safety but also be conducive to the layout, deformation and maintenance of the whole vehicle, as well as the serialized production of the steering gear.