Hydraulic pumps and hydraulic motors are indispensable hydraulic components on every excavator. The structure and working principle are also very similar. Some non-professionals sometimes confuse these two domestic excavator accessories. Some people say that the hydraulic pump and the hydraulic motor are like a pair of lovers, each attacking the other; some people say that the hydraulic pump and the hydraulic motor are like a generator and an electric motor. Is this description correct? What is the difference between the two? Chuanna Hydraulics, a domestic supplier of excavator parts, also took this to deal with such questions for us:

Hydraulic pump

Similarities between hydraulic motors and hydraulic pumps:

(1) In principle, hydraulic motors and hydraulic pumps are reversible. If they are driven by a motor, the output is hydraulic energy (pressure and flow), which is a hydraulic pump; if pressure oil is input, the output is mechanical energy (turn Torque and speed), it becomes a hydraulic motor.

(2) From the structural point of view, the two are similar.

(3) In terms of operating principle, both of them use the modification of the sealed working volume for oil absorption and oil discharge. Regarding the hydraulic pump, oil is sucked when the working volume increases, and high-pressure oil is discharged when the working volume decreases. Regarding hydraulic motors, high-pressure oil enters when the working volume increases, and low-pressure oil is discharged when the working volume decreases.

The difference between hydraulic motor and hydraulic pump:

(1) The hydraulic pump is the power equipment, and the hydraulic motor is the actuator. A hydraulic pump is a conversion device that converts the mechanical energy of a motor into hydraulic energy. It outputs flow and pressure, and the expected volume power is high; a hydraulic motor is a device that converts the pressure energy of a liquid into mechanical energy, and outputs torque and speed, with high expected mechanical power.

(2) The steering of the output shaft of the hydraulic motor must be able to rotate forward and backward, so its structure is symmetrical; and some hydraulic pumps (such as gear pumps, vane pumps, etc.) have clear rules for steering and can only roll in one direction. The direction of rotation cannot be changed at will.

(3) In addition to the oil inlet and outlet ports, hydraulic motors have separate oil leak ports; hydraulic pumps generally only have oil inlet and outlet ports (except the axial piston pump), and the leaking oil inside is connected to the oil inlet port. .

(4) The volume power of hydraulic motors is lower than that of hydraulic pumps.

(5) Generally, the working speed of hydraulic pumps is relatively high, while the output speed of hydraulic motors is relatively low. In addition, the oil suction port of the gear pump is large and the oil discharge port is small, while the suction and discharge ports of the gear hydraulic motor are the same size. Domestic excavator accessories

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