how does a hydraulic motor work


Hydraulic motor pump is a kind of pumping equipment that uses hydraulic pressure as the driving force, hydraulic pump open hydraulic system of a power component, equivalent to the engine, the service life of the hydraulic pump is relatively long, but also need to be determined according to external factors, hydraulic pump is classified, can be divided into variable pump and quantitative pump. Hydraulic motor pump is also a frequent product manufactured by Hanjiu, and has gained a large number of repeat customers due to its excellent quality.


First, the working principle of hydraulic pump


Hydraulic pump is a kind of hydraulic component that provides pressurized liquid for hydraulic transmission, and is a kind of pump. Its function is to convert the mechanical energy of power engines (such as electric motors and internal combustion engines) into pressure energy of liquids. The cam is driven by an electric motor to rotate. When the cam pushes the plunger upward, the sealing volume formed by the plunger and the cylinder block is reduced, and the oil is squeezed out of the sealing volume and discharged to the place where it is needed through the check valve. When the cam rotates to the descending part of the curve, the spring forces the plunger downward, forming a certain vacuum degree, and the oil in the tank enters the sealing volume under the action of atmospheric pressure. The wheel makes the plunger continuously lift and lower, the sealing volume periodically decreases and increases, and the pump continuously absorbs and drains oil.


Second, performance parameters


The hydraulic pump is the power component of the hydraulic system, its function is to provide pressure oil to the hydraulic system, from the perspective of energy conversion, it will be the mechanical energy output of the prime mover (such as the engine) into the pressure energy of the liquid that is easy to transport. The hydraulic motor is an actuator that converts the pressure energy of the input liquid into the mechanical energy of the output shaft rotation to drag the load to do work. According to the structural form, hydraulic pumps and hydraulic motors can be specifically divided into gear type, vane type, plunger type and other types.


1. Hydraulic pump pressure

The working pressure of the hydraulic pump refers to the pressure at which the pump (or motor) outputs (or inputs) the oil when it is actually working, which is determined by the external load.

Rated pressure refers to the highest pressure that can operate continuously according to test standards under normal working conditions. Its size is limited by life, and if it works beyond the rated pressure, the service life of the pump (or motor) will be shorter than the life of the design. When the working pressure is greater than the rated pressure, it is called overload.


2. Rotational speed

The operating speed refers to the actual rotation speed of the pump (or motor) while working.

Rated speed refers to the highest speed that can operate normally for a long time under rated pressure. If the pump works beyond the rated speed, it will cause insufficient oil absorption, vibration and loud noise, and the parts will suffer cavitation damage and reduce the life.

The minimum stable speed refers to the minimum speed allowed for normal operation of the motor. At this speed, the motor does not creep.


3. Displacement, flow rate

Displacement refers to the volume of liquid discharged (or input) obtained by the change in the geometry of the sealing cavity per revolution of the pump (or motor), and the commonly used unit is ml/r (milliliters / revolution). The displacement can be adjusted to become a variable displacement pump (or variable motor), and the displacement can not be changed to become a quantitative pump (or quantitative motor).


The actual flow rate refers to the flow at the outlet (or inlet) when the pump (or motor) is working. Due to the internal leakage of the pump itself, its actual flow rate is less than the theoretical flow. Since the motor itself also has internal leakage, it is necessary to achieve the specified speed.


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