Hydraulic motor Advantages over motor
1. High power density: 45KW motor weighs 400-500KG, and 45KW hydraulic motor weighs only 45KG. In some occasions requiring compact volume, such as winch of crane, only hydraulic motor can be used;
2. Good control performance: hydraulic control allows the hydraulic motor to complete the stepless speed change process faster: this is much better than the motor.
Common faults often occurred in the application of hydraulic motor and their solutions:
1. Motor oil leakage
(1) Oil leakage at the shaft end: because the oil seal and output shaft are in constant friction during normal use of the motor, it is easy to wear the contact surface between the oil seal and the shaft. If it exceeds a certain degree, the oil seal will lose its sealing performance, resulting in oil leakage. At this time, replace the oil seal. If the output shaft is severely worn, replace the output shaft at the same time
(2) Oil leakage at the cover: the "O" ring under the cover is crushed or aged, and the sealing performance is lost. The probability of this situation is very low. If it occurs, it is only necessary to replace the "O" ring
"O" ring is OK.
(3) Motor gap oil leakage: the "O" ring between the motor housing and the front side plate, or between the front side plate and the stator body, or between the stator body and the rear side plate is aged or crushed. In this case, only replace the "O" ring
2. The motor runs weakly
(1) The stator body is loose: because all parts of the motor are in friction with each other during the operation of the motor, if the hydraulic oil in the system is too poor, the loss of parts in the motor will often be accelerated. When the needle column loss in the stator body exceeds a certain degree, the gap inside the stator body pair will become larger, and the normal oil sealing effect cannot be achieved, which is easy to cause excessive internal leakage of the motor. It shows that the motor operates normally without load, but the noise is slightly larger than normal, and it is often weak or slow under load. At this time, the needle column should be replaced as soon as possible.
(2) Loss between the output shaft and the housing: the main reason for this common fault is that the hydraulic oil has poor purity and contains impurities, which causes grooves to be worn out in the housing, leading to greater internal leakage of the motor, which leads to motor weakness. The solution is to replace the shell or the whole pair.
3. Large leakage outside the motor
(1) The plane assembly clearance of the stator body is increased: the plane clearance of the BMR series motor stator body should be approximately kept within 0.03m-0.04mm (slightly different according to the displacement). With the increase of the use frequency and the friction and grinding of impurities and pollutants in the daily oil, when the clearance exceeds 0.04mm, the leakage of the motor may increase significantly, It also affects the output torque of the motor. In addition, in view of the fact that customers usually block the external oil drain port when using BMR series motors, when the external pressure exceeds 1MPa, it may bring great pressure to the oil seal, which may lead to oil leakage of the oil seal. Treatment method: grind the plane of stator body, so that the assembly clearance between it and cycloid wheel is controlled within the standard range.
(2) The assembly clearance between the output shaft and the housing is too large: with the increase of the use frequency and the friction and grinding of impurities and pollutants in the daily oil, when the assembly clearance between the output shaft and the housing is large and standard, the leakage of the motor may increase significantly (more obvious than that described in Cause 1). Solution: Replace the output shaft with a new one to match the housing.
(3) The "O" ring with too large diameter is used: when the user disassembles and cleans it by himself, if the "O" ring with too thick diameter is used, the plane of the parts may not fit properly, and there is a large gap, which will increase the leakage of the motor. Such things are usually rare. The solution is to replace the "O" ring that meets the specifications
(4) The fastening screws are not tightened: if the fastening screws are not tightened, the plane of the parts will not fit properly, and there will be large gaps, which will lead to large leakage of the motor. The solution is to tighten the screws within the specified torque range.
4. The motor does not rotate or creeps
(1) The assembly clearance of the stator body matching plane is too small: as mentioned before, the plane clearance of the BMR series motor stator body should be kept within 0.03m-0.04m. If the relatively large metal particles in the system oil penetrate into the motor, it will cause the roughening of the inner wall cavity of the motor and the surface of the main shaft, resulting in deformation of the assembly clearance and even some gaps below 0.03, The cycloid wheel may bite the front side plate or the rear side plate. At this time, it will be found that the motor runs unevenly or repeatedly. In serious cases, the motor will bite directly, causing no rotation. Treatment: grind the plane of the cycloid wheel to control the plane clearance between it and the stator body within the standard range. If it is serious, remove and replace the output shaft or housing.
