1、 Brief description:
QJM radial ball plug type Low speed high torque hydraulic motor , won the second prize of research achievements of Zhejiang Scientific Research Conference. It can be formed with various hydraulic oil pumps, valves and hydraulic accessories Hydraulic transmission device Based on various countermeasures adopted in the design, it can meet the working conditions of various equipment. This type Hydraulic motor It has many advantages, such as light weight, small size, large range of speed change, stepwise variable, self opening and closing of mechanical equipment braking system, good low-speed stability, reliable operation, shock resistance, high efficiency, long service life, etc. At present, it has been widely used in functional departments such as engineering construction, lifting and transportation, metallurgical industry super heavy, crude oil, coal mining, shipbuilding, machine tools, light industry injection molding, geological exploration, etc. It can directly drive crawler walking, track wheel driving, various rotary lifting machinery and equipment, exploratory drilling, belt transportation, raw material mixing, ground segmentation, shipbuilding driving, plastic pre molding and other mechanisms.
2、 Main features:
1. The rolling element of this type of hydraulic motor is replaced by a steel ball Inner curve hydraulic motor More than 2 rollers and beams are used, so the structure is simple, the operation is reliable, and the volume and weight are significantly reduced.
2. The inertia of the motion pair is small, and the steel ball is firm and reliable, so this type of hydraulic motor can continue to operate under high speed rotation and impact load.
3. There are few friction pairs, the internal force of the oil distribution shaft and rotor is balanced, the ball plug pair transmits force with the help of the ball pad made of self-lubricating composite materials, and has the preconditions of static pressure balance and excellent lubrication. The soft plastic piston ring seal high-pressure oil that can compensate the damage by itself is adopted, so it has high mechanical equipment and capacity efficiency, and can operate smoothly at very low speed, The starting torque is relatively large.
4. Due to the characteristics of the structure, the back pressure of the return oil required by the hydraulic motor is low, generally 0.3~0.8MPa. The higher the speed, the greater the back pressure. 5. Because the oil distribution shaft is rigidly connected with the stator, the inlet and outlet oil pipes of this type of hydraulic motor are allowed to be connected by steel pipes.
6. This type of hydraulic motor has two-stage and three-stage variable displacement, so it has a relatively large range of speed changes.
7. Simple structure, convenient replacement, no special requirements for cleanliness, and the oil filtration precision can be selected according to the requirements of the supporting facilities hydraulic oil pump. 8. Except for the shell type and the supported type, the outlet shaft of the hydraulic motor can only bear the torque, and cannot bear the radial and axial external forces. 9. With a "T" type hydraulic motor, the center point has a through hole, and the transmission shaft can cross the hydraulic motor.
10. The hydraulic motor with "S" type is equipped with a mechanical equipment braking system that can be switched on and off automatically, and can complete reliable braking.
11. With "Se" and "SeZ" hydraulic motors, the starting and braking can be controlled manually or intelligently. The control working pressure is low, the braking torque is large, and the use is convenient and reliable.
3、 Structural principle of basic type axial rotation hydraulic motor:
The oil distribution shaft of QJM hydraulic motor is rigidly connected with the rear cover. The rotor body is supported radially by the oil distribution shaft, and supported by the stator spherical raceway and steel ball
The sub outlet shaft is an internal spline. It is specified that the rotating shaft of the operating mechanism is loose and matched with it, so the rotor body is variable and the oil distribution shaft is rigid, so it is allowed to use steel pipes to connect the oil inlet and outlet. The pressure oil is distributed through the channel (or speed change valve) in the oil distribution shaft to the oil distribution window of each high-pressure chamber and enters into each piston cylinder hole. Under the effect of pressure oil, the piston passes through the steel ball and exerts a positive pressure N on the stator, and the stator exerts a reaction force N 'of the same value on the steel ball. N 'can be divided into two components: radial force and tangential force. The radial force is balanced by oil pressure, and the tangential force F acts on the rotor body through the piston. Then the rotor body rotates around the oil distribution shaft with the help of force F. Since several pistons are under the effect of pressure oil at the same moment, a large torque can be formed. When the piston rotates with the rotor body to the end point of the stator surface, the piston moves back and forth to the shaft center with the help of the stator surface, and the running oil in the piston cylinder is discharged back to the low-pressure flow channel through the oil distribution rotating window. This cycle is to transform the pressure energy into mechanical energy, so that the hydraulic motor continues to rotate. Reverse rotation can be achieved by changing the oil flow direction of the two oil ports. Changing the flow into the hydraulic motor can change the rotation speed to achieve the effect of stepless speed change. Graded Variable hydraulic motor The change of displacement is realized by the change of the specific position of the variable speed valve in the hydraulic motor oil distribution shaft. The specific position of the variable speed valve can be adjusted by manual mechanism or pilot valve.
4、 How to select effective models:
The hydraulic motors with the same base model number have three pressure classes, with their rated pressures of 10, 16, and 2 OMPa, and peak pressures of 16, 25, and 31.5 MPa respectively. How can we effectively select a model and specification that is more suitable for the working conditions of the main engine?
First, it should be considered to improve the working efficiency of the transmission system. For the working conditions of the transmission system with low power, low rotation speed and large torque, the key factor affecting the total power of the transmission system is the capacity working efficiency. For the hydraulic devices with the same power of the transmission system, reducing the system pressure can significantly improve the capacity working efficiency, Therefore, the model with the rated pressure of 10MPa should be used at this time. At the same time, the specific pressure should be lower. When the power of the transmission system is lower and the rotation speed is lower, the lower the pressure is, the more beneficial it is. On the contrary, the mechanical efficiency is the key factor affecting the overall working efficiency of the transmission system under the working condition of high power and high rotation speed. Therefore, the model with rated pressure of 16 or 2 OMPa should be used. In addition: for the working conditions with low speed stability requirements, the larger the displacement of the hydraulic motor, the better the low speed stability. It is also related to pressure. The lower the pressure, the better the speed stability.
