Hitachi | hydraulic pump flow regulation super difficult ? Count a few twists can be !

Hitachi | hydraulic pump flow regulation super difficult ? Count a few twists can be !
As a representative of Japanese imported machines, Hitachi excavator has won the favor of domestic machine friends with its strong performance and durability, so the ownership of Hitachi excavator in the Chinese market can be said to be considerable. 
 
However, no matter which series of Hitachi excavators is, when the excavator is in a variety of construction environments for tens of thousands of hours, it is faced with the problem of adjusting the hydraulic pump. Today, we will take you to understand the hydraulic pump flow adjustment method of Hitachi excavator.

principle of operation
The hydraulic pump provides pressure oil to drive hydraulic components such as motors or cylinders. The main pump is composed of pump 1 and pump 2. The output shaft is connected to the cylinder body of each pump through the plunger of the hydraulic pump. When the output shaft rotates with the cylinder body, the plunger moves in the cylinder body, absorbs and discharges the hydraulic oil.
In order to control the main pump flow, the inclination angle of the cylinder is changed, so that the piston stroke increases or decreases according to the inclination angle. The inclination angle of the cylinder is changed by the up and down movement of the servo piston, so that the main pump flow increases or decreases.

Adjustment method of Hitachi ZX200-3 hydraulic pump
1.The adjustment method of the maximum flow of the hydraulic pump : 
 
Loosen the regulator lock nut 1, and adjust the screw 2, clockwise adjustment to increase the flow, counterclockwise adjustment to reduce the flow. When adjusting the maximum flow, the adjustment screw 2 should not be more than 2 circles.

2.The minimum flow adjustment method of hydraulic pump : 
 
Loosen the regulator locking nut 3, and adjust the screw 4, clockwise adjustment to reduce the flow, counterclockwise adjustment to increase the flow. When the minimum flow is adjusted, it is required that the rotation adjustment screw 4 should not be greater than 2 turns.

3.Hydraulic pump torque adjustment method : 
 
Loosen the regulator lock nut 7, and adjust the screw 8, clockwise adjustment will increase the torque, counterclockwise adjustment will reduce the torque. The locking nut 9 is also loosened and the screw 10 is adjusted. The clockwise adjustment torque increases and the counterclockwise adjustment torque decreases.

At this time, attention should be paid to : first, the adjustment screw rotation should not be greater than 1 lap ; the second is to observe the change of engine power while rotating the adjustment screw, and tighten the locking nut 9 after appropriate adjustment.

Through the introduction of the above article, the hydraulic pump adjustment process of Hitachi excavator is completely presented in front of everyone, but it is not an easy thing to adjust the hydraulic pump. If there is no maintenance experience or skills, we must operate carefully.