When the steering wheel turning (turn left) When the steering wheel turns left, the turning bring the match of spline, cause the steering shaft also turns left. Because the valve sleeve is connected with valve cartridge by using of spring laminations, the valve cartridge compact the spring laminations, bring about the turning angle difference between the valve sleeve and valve cartridge, which make all holes in the valve sleeve are all connected with slots of valve cartridge.
In such case, the manual pump oil port of valve sleeve is connects with steering cylinder oil port (at left steering side) in the direction of valve cartridge through the valve cartridge, and the steering cylinder oil port (at the right steering side) of valve sleeve is connected with valve outlet port of valve sleeve. The oil enters into the manual pump from oil pump through steering gear inlet port and returns to the valve sleeve.
After the oil is circulated, it flows into steering cylinder from valve cartridge slot through the oil port of steering cylinder inside the valve sleeve, meanwhile, the oil come from steering cylinder is compressed back to oil tank through valve sleeve oil hole and valve cartridge slot. Under the above situation, the hydraulic oil inside the oil pump rotates the manual pump, which is similar to an oil motor, to reduce the manipulation force of steering wheel. When the steering wheel stops rotation, the rebound force of spring lamination make the rotation angle difference between the valve sleeve and valve cartridge to change. The case of “Steering wheel doesn’t turn” abovementioned is same.
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