The speed control of hydraulic Motor in the working process is generally controlled by speed control loop, and the speed control loop includes speed control loop and speed conversion loop. The following is a brief introduction to speed control loop.
Adjusting speed refers to adjusting the movement speed of the actuator. The method of changing the movement speed of the actuator can be found from its speed expression.
The speed of hydraulic cylinder: v=q/a; the speed of hydraulic motor: nm=q/vm
It can be seen that changing the flow q entering the actuator, or changing the geometric size of the actuator (the working area a of the hydraulic cylinder or the displacement vm of the hydraulic motor) can change its movement speed.
Changing the flow q entering the actuator can be achieved by combining a fixed-displacement pump with a throttling element; it can also be achieved directly by using a variable pump.
For hydraulic cylinders, it is difficult to change their working area a in structure, so speed regulation can only be achieved by changing the input flow; for hydraulic motors, speed regulation can be achieved by changing the input flow or by changing their displacement (using variable motors).
According to the above analysis, the following two basic speed control methods can be summarized:
1. Throttling speed control, using a quantitative pump to supply oil, using a throttling element to change the oil flow distribution of the parallel branch, and then changing the flow entering the actuator to achieve speed control.
2. Volume speed control, using the effective working volume (displacement) of the hydraulic pump or hydraulic motor to achieve speed control.
If the above two hydraulic press speed control methods are combined, the speed control method using a variable pump and a throttling element is called volume throttling speed control.
