How much do you know about hydraulic motors? Be sure to learn these basics!

I. Hydraulic motor torque and speed

The working pressure of the motor p: the actual pressure of the hydraulic oil at the motor inlet

The working pressure difference of the motorΔp: The difference between the inlet pressure and the outlet pressure of the motor. That is Δp=p-pout, usually set pout=0

Then Δp=p .

The actual flow of the motor: the flow at the motor inlet.

Considering the leakage, the theoretical flow of the motor: qt= q· ηV

Where: ηV——volume efficiency of motor

The output speed of the motor is equal to the ratio of the theoretical flow qt to the displacement V (displacement per revolution), i.e.

n= qt/V= q· ηV /V

The actual output torque of the motor should consider the influence of mechanical efficiency, that is,

T=Tt· ηm

If the outlet pressure of the motor is zero, the inlet working pressure is p, and the displacement is V, then the motor The theoretical output torque of

Second, high-speed hydraulic motor

Generally speaking, a motor with a rated speed higher than 500r/min is a high-speed motor, and a motor with a rated speed lower than The 500r/min motor is a low-speed motor.

Basic forms of high-speed hydraulic motors: gear, vane, and axial piston type

Main features: high speed, small moment of inertia, easy to start, brake, speed regulation and reversing .

 Usually the output torque of high-speed motors is not large, and the minimum stable speed is high, which can only meet the High-speed and low-torque conditions.

How a plunger motor works

When the pressure oil is input to the hydraulic motor, the plunger in the pressure chamber is pushed out and pressed on the inclined On the disc, the swash plate produces a reaction force on the plunger, which can be decomposed into an axial component force and a component force perpendicular to the axial direction. Among them, the component force perpendicular to the axial direction produces the torque that rotates the cylinder.

Third, low speed and high torque hydraulic motor

• Low-speed and high-torque hydraulic motors are relative to high-speed motors. The structure is mostly radial plunger type.

• Features: Low minimum speed, about 5-10r/min, large output torque, can Up to tens of thousands of N·m; large radial size and large moment of inertia.

• Usually, it can be directly connected with the working mechanism, without the need for a reduction device, which greatly simplifies the transmission structure .

• There are three basic forms of low-speed and high-torque hydraulic motors: crank-link motor, static balance Motors and multi-acting internal curve motors.

Crank connecting rod low speed high torque hydraulic motor


Previous page

Next page


Should you say "Dragon Boat Festival" or "Happy Dragon Boat Festival"

Dragon Boat Festival This festival has a festival tradition of avoiding pestilence and health care and remembering the ancestors. It is necessary to wear sachets and collect herbs... In addition to zongzi, there are other delicacies. So, let's take a look at the interesting knowledge and customs of the Dragon Boat Festival?