Difference Between Hydraulic Motor And Hydraulic Pump

The main difference between hydraulic motor and hydraulic pump lies in their function, structure, application and output characteristics.

Function and application: Hydraulic pump is a conversion device that converts the mechanical energy of the motor into hydraulic energy. Its main function is to output flow and pressure. It is expected to have high volumetric efficiency and is usually used in situations where stable flow and pressure are required. Hydraulic motor is a conversion device that converts the pressure energy of the liquid into mechanical energy. It outputs torque and speed. It is expected to have high mechanical efficiency. It is mainly used in situations where pressure energy needs to be converted into mechanical energy, such as injection molding machinery, ships, hoists, etc.

Structural differences: Although hydraulic pumps and hydraulic motors have similar structural elements, such as closed and periodically variable volumes and corresponding oil distribution mechanisms, their working principles are different. Hydraulic pumps absorb oil when the working volume increases and discharge high-pressure oil when it decreases; hydraulic motors enter high-pressure oil when the working volume increases and discharge low-pressure oil when it decreases.

Output characteristics: Hydraulic pumps are energy devices. The direction of their output shafts is clearly specified and may only rotate in one direction. The hydraulic motor is an actuator, and the direction of its output shaft must be able to rotate forward and reverse, so its structure is symmetrical. In addition, in addition to the inlet and outlet ports, the hydraulic motor also has a separate leakage port, while the hydraulic pump generally only has an inlet and outlet port (except for the axial piston pump), and the internal leakage oil is connected to the inlet port.

Volumetric efficiency and speed: The volumetric efficiency of the hydraulic motor is lower than that of the hydraulic pump. Usually, the working speed of the hydraulic pump is relatively high, while the output speed of the hydraulic motor is relatively low. These differences make the hydraulic pump and hydraulic motor play different roles in the hydraulic system, and they cannot be directly reversed and universal.

In summary, the main differences between hydraulic motors and hydraulic pumps are their functions, structures, output characteristics and application occasions.