In the late 1850s, the original Low speed high torque hydraulic motor It is transformed from one stator and rotor part of the oil pump, which is composed of one internal transmission gear and one matching transmission gear or rotor.

1、 Low speed High torque hydraulic motor Rotation fatigue

Hydraulic motor It is the executive agency, located in Hydraulic transmission At the tail end of, hydraulic energy is converted into mechanical kinetic energy to make the system rotate. This motor adopts a hydraulic motor with axial plunger point contact at medium speed.

1. Question

The system rotation speed is less than 6r/min2 during operation. Reason description

The structure and working principle of the hydraulic motor and the axial piston pump are basically the same. The axial piston pump is driven by oil suction and pressure, that is, it converts mechanical kinetic energy into liquid pressure energy. The hydraulic motor is fed with high pressure oil and discharged with low pressure oil, which will convert the liquid pressure energy into mechanical kinetic energy. It can be seen that the hydraulic motor is essentially equivalent to the combination of many single cylinder piston cylinders, that is, many one-way cylinders are evenly distributed in the circumference, and the outer edge of the plunger is pushed against the swashplate. When the oil pump supplies pressure oil to the oil cylinder, the plunger protrudes under the action of the pressure oil and lowers on the swashplate, thus forming a torque. The oil pump continuously supplies pressure oil to the hydraulic motor, and the hydraulic motor rotates continuously. With the help of the gear transmission box, the transmission gear meshes with the internal transmission gear fixed on the frame to drive the system to rotate.

It is known from the above that the structure of the hydraulic motor and the working principle of T. are basically the same as the working principle of the aforementioned hydraulic cylinder. If the problem of slow rotation of the hydraulic motor occurs, the analysis, inspection and solution methods are similar to the hydraulic cylinder and axial plunger pump of T. Please refer to the above contents when analyzing, checking and solving the problems of hydraulic motor., Low speed high torque hydraulic motor "crawling" mode

1. Question

When the system rotates, it stops and moves, that is, the rotation discontinuity. The speed is slow and the energy is insufficient. 2. Reason description

The low-speed high torque hydraulic motor is an energy conversion device, that is, the input liquid pressure energy is converted into mechanical kinetic energy output. If the working efficiency of the pressure motor wood body is not fully considered, the input of kinetic energy should be equivalent to the output. From this point of view, the sluggish rotation of the hydraulic motor must be the reduction of the kinetic energy input into the hydraulic motor. When the kinetic energy is difficult to overcome the resistance of the system rotation, the rotation stop occurs.

According to the basic principle of hydraulic transmission, the hydraulic motor operates by hydraulic pressure. When the hydraulic motor stops when the control valve is connected to the pressure oil circuit, it must be that the hydraulic oil pressure fed into the plunger cylinder of the hydraulic motor cannot overcome the resistance of the service platform. When the accumulated force is enough to overcome the resistance, the hydraulic motor will make the overcome resistance jump and run, the hydraulic oil pressure in the system will drop sharply, and the motor will be interrupted again. This will cause the service platform to "crawl" or prevent the hydraulic motor from running with too much resistance to "crawl". So that the total flow and pressure of the hydraulic fluid can be reduced. Please refer to the cause description and detection of the boom cylinder lifting delay.

In a word, the "creeping" of the hydraulic motor makes the hydraulic oil pressure in the system unstable. The unstable hydraulic oil pressure is mostly caused by air in the system. The reason for air infiltration in the system is the same as that in the first part.

The mechanical efficiency of the hydraulic motor is low due to the excessive resistance of the motor. For example, the resistance between the plunger and the matched friction pair is too large, the resistance between the swashplate and the plunger is too large, the friction resistance is too large due to poor rolling bearings, or the transmission efficiency of the gearbox is low. Or it is caused by the excessive friction resistance of the disk mechanical equipment of the service platform.

3、 Detection and elimination

If the oil cylinder of the hydraulic working device is still "crawling", the problem lies in the main oil circuit of the hydraulic system. The detection should be carried out according to the detection method described in the first part of the boom oil cylinder lifting delay. The key is to check the cavitation, find out the cause and eliminate it pertinently.

If the boom hydraulic cylinder of the working device works well, the problem of "creeping" of the hydraulic motor should be at the tail end of the hydraulic motor and transmission, that is, part of the mechanical equipment gearbox and service platform wheel.

(1) Inspection of safety valve of hydraulic motor

Adjust the safety valve below the hydraulic motor control valve. Unscrew the safety valve screw cap, turn the adjusting screw plug with an internal hexagonal wrench, and change the pressure of 2.345MPa for each circle of operation. Therefore, the barometer 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 gear transmission. If the set pressure of the safety valve of the hydraulic motor is 9.8MPs, it means that the "creeping" is caused by excessive friction resistance of some mechanical equipment from the hydraulic motor to the rotary service platform.

Touch the hydraulic motor housing with your hand. If you feel hot, it indicates that the friction force of the hydraulic motor is too large, which indicates that it is the cause of "crawling" and should be eliminated.

If the temperature of the hydraulic motor is OK, you can use the temperature condition of the manual gearbox and wheel disc, or check the lubrication condition. If there is a place with high temperature and poor lubrication, it means that most of the problems are caused by "crawling", that is, excessive friction resistance should be eliminated.