1. Air intrusion. When the air intrudes into the hydraulic system, it has a large volume in the low-pressure area. When it enters the high-pressure area, it is compressed, and the volume suddenly decreases. When it enters the low-pressure area, the volume suddenly increases, resulting in a sudden change in the bubble volume, that is, "explosion" phenomenon, resulting in noise. Solution: Generally, the hydraulic cylinder is equipped with an exhaust device special-purpose Low speed cycloidal hydraulic motor Exhaust. In addition, a common method is to exhaust the actuator several times during the fast full stroke after startup. 2. The quality of the hydraulic pump or motor is poor. The quality of the hydraulic pump is poor, the accuracy does not fully meet the technical requirements, the pressure and flow fluctuations are large, the oil trapping phenomenon has not been eliminated well, and poor sealing and poor bearing quality are the main reasons for the noise. In use, due to wear of hydraulic pump parts, excessive clearance, insufficient flow the north sea manufactor The force is easy to fluctuate and will also produce noise.

1. The hydraulic system is characterized by high energy density. For motors with the same power, hydraulic motors are much smaller and lighter than motors. And it is easy to apply to mobile devices. 2. The hydraulic motor has convenient speed regulation, which can be adjusted infinitely from 0 to the maximum speed according to the adjustment of the hydraulic valve. The motor itself does not need special design and has low cost. This is much cheaper than motor+reducer, or variable frequency motor and servo motor. 3. The hydraulic motor is totally enclosed and can be safely used in dusty, wet (even underwater) and flammable environments, which is much more reliable than explosion-proof (flameproof) motors. 4. The hydraulic system has strong anti overload capacity, and it is protected by the overflow valve, allowing long (relatively) frequent overloads. It is easy to recover under overload conditions, without damaging the equipment or restarting the equipment. These unparalleled advantages of motors have made hydraulic motors and hydraulic technology rapidly spread and popularized all over the world in the past 20 years. People increasingly feel the importance of hydraulic motors in practice.

The ignition time of internal combustion engines can be compared with this. It can be seen from the working principle of the cycloidal hydraulic motor that the oil sleeve and the rotor rotate synchronously, and the accuracy refers to the accuracy of the oil distribution link matching with the rotor to rotate the oil inlet, seal and discharge. There are many factors special-purpose Low speed cycloidal hydraulic motor It will affect the oil distribution accuracy, such as the asymmetry of the rotor spline and cycloid tooth shape, the relative position accuracy of the stator sleeve needle hole and bolt hole, and the relative position asymmetry of the pin hole and spline on the output shaft and its internal spline, Low speed cycloidal hydraulic motor manufactor The relative position accuracy of the longitudinal oil groove and the relative wedge groove of the coupling, and the asymmetry of splines at both ends of the coupling. As long as the above factors are controlled within the tolerance range, they will not have a great impact on the oil distribution accuracy, because all processing errors will not be offset.

1. Generally, the motor shall be able to run forward and backward. Therefore, the hydraulic motor is usually required to have structural symmetry in the design. 2. The actual working pressure difference of the hydraulic motor depends on the load torque. When the moment of inertia of the driven load is large and the speed is high, rapid braking or reverse rotation is required, high hydraulic impact will be generated. Therefore, the system should be equipped with necessary safety valves and buffer valves. 3. Under normal working conditions, the inlet and outlet pressure of the hydraulic motor is higher than the atmospheric pressure, so there is no suction performance problem like the hydraulic pump. However, if the hydraulic motor can work under pump conditions, its oil inlet should have a minimum pressure limit to avoid cavitation. 4. Some hydraulic motors must have sufficient back pressure at the oil return port to ensure normal operation. The higher the speed, the greater the back pressure, which indicates that the utilization rate of oil source pressure is not high and the system loss is increased. 5. Because the internal leakage of the motor is inevitable, there will be slow sliding when the hydraulic motor oil outlet is closed for braking. Therefore, when long-term accurate braking is required, a separate anti-skid brake shall be set.

Its basic types are gear type, screw type, vane type and axial plunger type. Its main characteristics are high speed, small moment of inertia, convenient starting and braking, adjustment (speed adjustment and special-purpose Low speed cycloidal hydraulic motor Reversing) High sensitivity. As the output torque of high-speed hydraulic motor is generally small, it is also called high-speed small torque hydraulic motor. Its basic type is radial plunger type, in addition, there are axial plunger, vane type, gear type and other structural types. Low speed hydraulic motors are mainly characterized by large displacement, large volume and low speed (sometimes Low speed cycloidal hydraulic motor manufactor It can rotate a few revolutions per minute or even a few revolutions per minute), so it can be directly connected to the working mechanism; It does not need a speed reducer, greatly simplifying the transmission mechanism. Usually, the output torque of low-speed hydraulic motor is large, so it is also called low-speed high torque hydraulic motor.