Introduction of hydraulic motor common sense
Issuing time:2020-12-01 08:42Author:宁波中意液压马达
Hydraulic transmission refers to a transmission method that uses liquid as the working medium for energy transmission and control. As one of the four transmission methods that are commensurate with mechanical transmission, electric transmission and pneumatic transmission, hydraulic transmission is characterized by its large power-to-weight ratio and easy The advantages of overload protection, flexible adjustment, fast response, and high control precision have become an important symbol in the development of the national manufacturing industry.
In recent years, in the context of the rapid development of domestic and foreign manufacturing industries, market users have continuously increased their demand for various hydraulic products, and at the same time they have become more and more stringent in their performance and functions.
In the hydraulic transmission system, the hydraulic motor is a power executive element that converts hydraulic energy into rotating mechanical energy. The performance of its working characteristics directly determines the performance of the entire hydraulic transmission system. It is one of the most critical basic components in the hydraulic transmission system. One.
According to the output speed, hydraulic motors can be divided into two categories: high speed and low speed: those with an output speed higher than 500r/min are high-speed hydraulic motors. Their main characteristics are high speed, small moment of inertia, easy to start and brake, speed control and The commutation sensitivity is high, and the output torque of high-speed hydraulic motors is usually not large; those with an output speed lower than 500r/min belong to low-speed hydraulic motors. The main characteristics of low-speed hydraulic motors are large torque, large displacement, large power-to-weight ratio, and speed It is low, so it can be directly connected with the transmission mechanism without a reduction gear, which greatly simplifies the transmission mechanism.
Hydraulic motors can be divided into gear type, cycloid type, vane type, radial plunger type, axial plunger type, etc. according to the structure type.
Gear hydraulic motors include external gear motors and internal gear motors. Gear motors have the advantages of small size, light weight, and convenient maintenance. At the same time, gear motors also have large pressure and flow pulsation, volumetric efficiency and low input pressure, and output rotation. Shortcomings such as small moment and large noise.
The working principle of the cycloidal motor is similar to that of the internal gear motor. It adopts the structure of the cycloidal gear mesh instead of the internal gear. Although it has the disadvantages of large pressure and flow pulsation, low volumetric efficiency and low input pressure, it has all the current hydraulic pressures. Among the power components, the smallest volume and the simplest structure under the same displacement have outstanding advantages, and it has become the indispensable hydraulic motor with the largest number of products at present, and has good development and application prospects.
The vane motor has the advantages of small size, uniform flow, smooth operation, low noise, sensitive action, and high input speed. At the same time, the vane motor also has a large leakage, poor low-speed stability, low working pressure, and low oil pressure. Disadvantages such as higher cleanliness requirements.
The radial piston motor is generally a low-speed and high-torque hydraulic motor. The connecting rod type radial piston motor is composed of a housing, a crankshaft, a distribution shaft, a connecting rod, a plunger, and an eccentric. The advantages are simple structure, reliable operation, The output torque is large and the pressure is high. The disadvantages are that the volume is relatively large, the weight is large, and the low-speed stability of the torsional pulsation is poor; the inner curve plunger motor has a stable output, a large power-to-weight ratio, a high working pressure, and a large output torque. With outstanding advantages such as good low-speed stability, it has become an ideal product for low-speed high-torque hydraulic motors and has an unshakable position in high-power and high-quality transmission.
Axial plunger motors are generally high-speed motors. The main features are high speed, small moment of inertia, easy to start and brake, and high sensitivity for speed regulation and commutation. In fact, the difference in the structure of hydraulic motors mainly lies in the difference in the structure of the key friction pair. The machining accuracy and material technology of the friction pair directly determine the output characteristics of the hydraulic motor. Compared with international high-end hydraulic motor products, the performance indicators of domestic hydraulic motors generally have a significant gap. The problem of "stuck neck" is precisely the processing accuracy and material technology, which will also become the basic direction of our long-term efforts.