1. Vane hydraulic motor Due to the action of the pressure oil, the unbalanced force causes the rotor to generate torque. The output torque of the vane hydraulic motor is related to the displacement of the hydraulic motor and the pressure difference between the inlet and outlet of the hydraulic motor, and its speed is determined by the flow rate input to the hydraulic motor. Since the hydraulic motor is generally required to be able to rotate forward and reverse, the vanes of the vane hydraulic motor should be placed radially. In order to keep the pressure oil flowing at the root of the blade, a one-way valve should be set on the passage between the return and pressure oil chambers leading to the root of the blade. The inner surface of the stator is in close contact to ensure a good seal, so a preload spring should be set at the root of the blade. The vane type hydraulic motor is small in size, small in moment of inertia, and sensitive in action. Therefore, vane hydraulic motors are generally used in occasions with high rotational speed, small torque and sensitive action requirements.

In the hydraulic system, if the pressure somewhere is lower than the air separation pressure at the working temperature of the oil, the air in the oil will be separated to form a large number of bubbles; when the pressure is further reduced to the saturated vapor pressure at the working temperature of the oil , the oil will rapidly vaporize and produce a large number of air bubbles. These bubbles are mixed in the oil to generate cavities, which make the oil filled in the pipeline or hydraulic components into a discontinuous state. This phenomenon is generally called cavitation.

Since the vibration and noise of the hydraulic system are inevitable, and in recent years, with the development of hydraulic technology in the direction of high speed, high pressure and high power, the noise of the hydraulic system has become increasingly serious, and has become a factor hindering the further development of hydraulic technology. If it exceeds 70dB, it will become noise, which makes people feel extremely uncomfortable, and even makes people restless. As pollution, noise has been paid more and more attention by people. Therefore, it has positive and far-reaching significance to study and analyze the mechanism of hydraulic noise and vibration, thereby reducing and reducing vibration and noise, and improving the performance of hydraulic system.

The cylinder barrel is the main component of the oil cylinder, mining single pillar, hydraulic support, gun barrel and other products. The quality of its processing directly affects the life and reliability of the entire product. The cylinder has high processing requirements, and its inner surface roughness is required to be Ra0.4 ~ 0.8µm, and the requirements for coaxiality and wear resistance are strict. The basic feature of the cylinder barrel is deep hole machining, which has always troubled the processing personnel. The rolling process, because the surface layer has residual compressive stress on the surface, helps to seal the tiny cracks on the surface and hinders the expansion of erosion. Thereby, the corrosion resistance of the surface can be improved, and the generation or expansion of fatigue cracks can be delayed, thereby improving the fatigue strength of the cylinder. Through rolling forming, a layer of cold work hardening layer is formed on the rolling surface, which reduces the elastic and plastic deformation of the contact surface of the grinding pair, thereby improving the wear resistance of the inner wall of the cylinder and avoiding burns caused by grinding. After rolling, the reduction of surface roughness value can improve the fit properties. As the control hub of the hydraulic system, the hydraulic valve moves frequently, and has very high requirements on the precision, sealing and reliability of each component device. Most foreign companies use rolling to improve the precision coordination.

The hydraulic system schematic diagram is a difficult point for many people to start the hydraulic industry. It takes a lot of work to fully understand a schematic diagram. 1. Study the relevant books that you can find within your ability. For many people who study hydraulic technology courses, the content of the books they use is relatively old and classic, so they need to be supplemented with materials.

​As a transmission technology, hydraulic system has its outstanding advantages: 1. It can generate a lot of force and is easy to control. The hydraulic oil with very high pressure (20~30MPa) can be easily obtained with a pump, and a large force can be generated after the pressure oil is fed into the hydraulic cylinder. For example, if the cylinder diameter is 30CM an