In a complete hydraulic system, it consists of power components, actuators, control components, auxiliary components and an additional hydraulic oil. The control circuit of the hydraulic system is a circuit that controls the speed of movement of actuators such as hydraulic cylinders or hydraulic motors by adjusting the flow of hydraulic oil (that is, hydraulic medium) .According to the function of the control circuit, it can be divided into speed control circuits and Synchronous loop.

Control circuit of hydraulic system

         First: speed control loop:

         Used to control the movement speed of a single actuator, you can use a throttle or speed control valve to control the flow, as shown in the figure, the throttle valve plays this role. The throttle valve controls the flow of the hydraulic pump into the hydraulic cylinder (excess flow flows back to the oil tank through the overflow valve), thereby controlling the movement speed of the hydraulic cylinder. This form is called throttle speed regulation. It can also be adjusted by changing the output flow of the hydraulic pump, which is called volume speed regulation.

Hydraulic pump, hydraulic motor repair

Second: Synchronous loop:

        A circuit that controls the synchronous operation of two or more actuators, for example, the method of rigidly connecting the two actuators to ensure synchronization; use a throttle valve or a speed control valve to adjust the flow of the two actuators to make them equal, In order to ensure synchronization; the pipelines of the hydraulic cylinders are connected in series to ensure that the flow into the two hydraulic cylinders is the same, thereby synchronizing the two hydraulic cylinders.

          In the maintenance of hydraulic pumps, it is necessary to understand the various control circuits of each hydraulic system at all times. Only when the hydraulic system is disassembled or tested can the hydraulic system be adjusted to avoid damage to the hydraulic system due to problems with the control circuit. Nowadays, the most frequently used is the speed control circuit, which is simple, convenient and practical, and is very popular with customers.