In the late 1850s Low speed high torque hydraulic motor It is developed from one stator and rotor part of the oil pump, which is composed of an internal gear ring and a matching gear or rotor.
-、 Hydraulic motor Weak rotation
The hydraulic motor is an actuator built on Hydraulic transmission The tail end of is to convert hydraulic energy into mechanical kinetic energy to make the platform rotate. This motor is a hydraulic motor with axial plunger point contact and medium speed.
1. Phenomenon
During operation, the running speed of the platform is lower than 6r/min
2. Reason description
The structure and working principle of the hydraulic motor and the axial piston pump are basically the same. Axial plunger pump is powered by oil suction and pressure, that is, it converts mechanical kinetic energy into liquid pressure energy. The hydraulic motor receives high pressure oil and discharges low pressure oil, which is to convert the liquid pressure energy into mechanical kinetic energy. It can be seen that the hydraulic motor is actually equivalent to the combination of several single cylinder piston cylinders, that is, several one-way cylinders are distributed circumferentially, and the outer edge of the plunger is against the swashplate. When the oil pump supplies pressure oil to the oil cylinder, the plunger extends under the action of the pressure oil and drops on the swashplate, so a torque is generated. The oil pump supplies pressure oil to the hydraulic motor continuously, and the hydraulic motor continues to run, and the rear transmission gear is meshed with the fixed inner gear ring of the frame through the gear transmission box to pull the platform to rotate. It can be seen from the above that the structure and working principle of the hydraulic motor are basically the same as the basic principle of the hydraulic mooring cylinder mentioned above. If the hydraulic motor has a slow running equipment fault, its analysis, diagnosis and removal methods are similar to those of the hydraulic cylinder and the axial piston pump of the working device, so I will not comment on them here. Please refer to the above contents for analysis, diagnosis and removal of hydraulic motor faults.
2、 Hydraulic motor "crawling"
1. Phenomenon
The platform stops and moves during operation, that is, the operation is discontinuous. Slow speed and insufficient strength.
2. Reason description
The hydraulic motor is an energy conversion device, that is, the input liquid pressure energy converts the output of mechanical energy. If the working efficiency of the pressure motor is not considered, the input of energy should be equivalent to the output. It can be seen that the weak rotation of the hydraulic motor must be the input of the hydraulic horse
The energy reached is reduced, and when the energy is difficult to overcome the rotating resistance of the platform, it will stop. According to the hydraulic transmission principle, the hydraulic motor rotates by hydraulic pressure. The hydraulic motor stops when the control valve is connected to the pressure oil circuit, which must be because the working pressure of the oil fed into the plunger cylinder of the hydraulic motor cannot solve the friction resistance of the platform operation. When the accumulated energy is enough to solve the friction resistance, the hydraulic motor will make the friction resistance be solved and jump to rotate, the oil pressure in the system will drop sharply, and the motor will be intermittent again, so that the platform will "crawl" if repeated, or the friction resistance that blocks the rotation of the hydraulic motor will be too large to cause "crawl". As for the reduction of flow and working pressure of hydraulic fluid that can be fed into the boom, please refer to the cause description and diagnosis of slow boom cylinder lifting.
In a word, the "creeping" of the hydraulic motor makes the oil pressure in the system unstable. The unstable oil pressure is mostly caused by the air in the system. The main reason for the air entering the system is the same as the previous part. The reason why the hydraulic motor has too much rotating resistance leads to the low mechanical efficiency of the motor itself. For example, the friction resistance between the plunger and the mating friction pair is too large, the friction resistance between the swashplate and the plunger is too large, the friction resistance caused by abnormal bearings is too large, or the mechanical transmission efficiency of the transmission case is low. Or the mechanical friction resistance of the rotary table of the platform is too large.
3. Diagnosis and resolution
If the oil cylinder of the hydraulic working device is also "crawling", the problem lies in the main oil path of the hydraulic system. Diagnosis should be made according to the diagnostic method described in the previous section of the boom oil cylinder lifting slowly, focusing on the cavitation, finding out the cause and diagnosing the symptoms
solve. If the boom hydraulic cylinder of the working device works normally, the "creeping" problem of the hydraulic motor should be at the tail end of the hydraulic motor and transmission, that is, the mechanical transmission box and the platform turntable.
(1) Check the hydraulic motor safety valve and adjust the safety valve at the lower part of the hydraulic motor control valve. Screw off the safety valve nut, and turn the regulating screw plug with an Allen wrench. The pressure changes 2.345MPa every turn. Therefore, the pressure gauge test should be 9.8MPa. If it is less than 9.8MPa, it indicates that the "creeping" problem is mostly caused by the low set pressure of the hydraulic motor.
(2) Check the hydraulic motor and mechanical transmission parts. If the set pressure of the hydraulic motor safety valve is 9.8MPs, it means that the "creeping" is that the mechanical friction resistance between the hydraulic motor and the rotary platform is too large. Touch the shell of the hydraulic motor with your hand. If it feels hot, it indicates that the friction force of the hydraulic motor is too large. It is confirmed that this is the cause of the "crawling" problem and should be solved. If the temperature of the hydraulic motor is normal, the temperature condition of the hand model transmission box and rotary table can be used, or the lubrication condition can be observed. as
There are areas with high temperature in the handle, and the lubrication is not very good, which indicates that most of the problems are caused by "crawling", that is, the friction resistance is too large, which should be solved.
