Use and maintenance of low speed and high torque hydraulic motor

In the construction machinery, mining machinery, construction machinery, often use low-speed high-torque hydraulic motor to drive walking or lifting mechanism. Low-speed high-torque hydraulic motor is a small number of axial plunger, mostly radial plunger, radial piston hydraulic motor can be part of the balance or even all of its role in the rotor to withstand the high and low pressure chamber hydraulic force, The size and quality of these motors are large, so it is characterized by a large transmission torque and a high power at low speed. In this way, it is often not necessary or with a very simple reduction device can be connected with the working mechanism, thus simplifying the machine.

At present, the industrial and mining enterprises to use the radial plunger low-speed high-torque hydraulic motor varieties and types of many, according to its working principle and structure can be divided into crankshaft connecting rod, static balance and internal curve multi-acting several. The internal curve multi-acting hydraulic motor has the advantages of large transmission torque, small torque ripple, low quality, compact structure and high starting efficiency. Therefore, it is the most widely used low-speed high-torque hydraulic motor. Replica watches Therefore, this article within the curve of multi-acting hydraulic motor as the focus, to discuss the use of low-speed high-torque hydraulic motor and maintenance.

1. Note the use of hydraulic motor
First low-speed high-torque hydraulic motor in normal use, the first should ensure that it has enough back to the oil back pressure. The back pressure should be the minimum output pressure that ensures the steady operation of the hydraulic motor at no load. Usually with the increase in speed, the corresponding increase in the back pressure value of the oil back to the oil. Second, the hydraulic motor due to wear or seal aging caused by poor sealing and leakage increased, or mechanical frictional resistance is too large, resulting in hydraulic motor flow instability, torque fluctuations, leading to the emergence of crawling phenomenon. Do not work for a long time at the lowest stable speed. Because, when the low speed into the motor flow less, the proportion of large leakage, causing volumetric efficiency reduction, leading to crawling. In general, the maximum steady speed of the multi-acting hydraulic motor can reach 0.1r / min ~ lr / min. Again, for the continuous operation of the hydraulic motor, in order to avoid the motor shell in the continuous operation of the high temperature caused by friction wear gap is too large, resulting in large internal leakage, the pressure inside the shell increases, the leakage to the shell, causing Reduced volumetric efficiency, it must be cooled and rinsed. The flushing fluid can take away the impurities inside the motor and have a cooling effect on the radial seal. The flushing circuit should be independent of the system circuit.
2. Hydraulic motor daily maintenance of several requirements
2.1 back to the oil pressure
For the smooth operation of the motor, requiring a certain back to the oil back pressure, the internal curve motor should be more or so will lead to the roller from the stator rail surface and impact, vibration, noise, serious damage. The pressure value of the hydraulic motor is proportional to the inlet and outlet pressure difference. When the inlet pressure is constant, when the back pressure increases, the pressure difference between the inlet and the outlet of the hydraulic motor is reduced. Therefore, Resulting in hydraulic motor rotation powerless. Under normal circumstances its back to the oil back pressure should be 0.3MPa ~ 1.0MPa.
2.2 Drain line The drain line is not normally connected to the system. For a motor with a flushing system, the drain line can act as a flushing backflow tubing. When the motor shaft is installed horizontally, the drain line should be connected to the drain port at the top of the housing (Figure 2). If the motor shaft is installed in the vertical direction, the drain pipe should be connected to the optional drain port of the upper cover of the motor (Figure 2). If necessary, increase the appropriate back pressure on the drain line and the back pressure can not be too large. Will cause the shaft seal damage caused by leakage, back pressure should be controlled below 0.5MPa, the work of the instantaneous peak should be less than 0.8MPa, by measuring the motor shell pressure can be known), so that the motor is always filled with oil. And can reduce the motor running noise.
2.3 Regularly add grease because the internal curve of multi-acting hydraulic motor speed is low, the load is large, the internal rolling bearing is difficult to form a lubricating oil film, it should be regularly fat-lubricated, the cycle is generally 2000h ~ 3000h.
2.4 Motor installation and replacement Replace the motor as far as possible so that the motor output shaft less or with