Hydraulic oil pumps and oil motors inevitably fail during use, and these faults can be classified into sudden and abrasive faults. Among them, the wear failure mostly occurs in the later stage of the system work, mainly due to the natural wear of the parts, and the damage caused to the system is mostly caused by the failure of the sealing material and the slowing of the moving speed of the actuator, which has little effect; Sudden faults often occur in the early stage of system operation and in the middle of system operation. They are mainly caused by the failure of the manager to use and maintain the operating requirements and procedures. The damage caused to the system is mostly represented by the oil pump cylinder. Malignant accidents such as burning damage, oil motor crawling, hydraulic component damage, and hydraulic circuit rupture have a great impact. The frequency of these faults is closely related to the quality of daily use, maintenance and maintenance. In order to maintain a good working condition and long service life for a long time, in addition to establishing and improving the necessary daily maintenance system to reduce the later wear and tear, it should also prevent the initial and medium-term bursts to the utmost extent. Sexual accident.
1 to ensure the normal state of the system oil
The problem of hydraulic oil has always been considered as the main culprit in the failure of the hydraulic system. Due to space limitations, it will not be repeated here. Only some typical problems will be explained.
1.1 oil viscosity should meet the requirements
For example, ZB type oil pump is recommended to use hydraulic oil with small viscosity change with oil temperature. The viscosity range is within 20~100cst. When the ambient temperature is above 15°C, it is recommended to use upper thick 40-2, 30 mechanical oil and 30th machine hydraulic. Oil, when the ambient temperature is below 25 °C, it is recommended to use YH-10 aviation hydraulic oil; domestic α-type and CB-4 gear pumps, YB-type vane pumps are recommended to use No. 20 mechanical oil.
1.2 Keep the oil clean and maintain a certain oil filter accuracy
1) The end face clearance of the axial piston pump can be automatically compensated, the gap is small, the oil film is thin, and the oil filter oil has the highest precision.
2) The oil level of the inclined disc type axial piston pump is 10~15μm.
3) Solid impurities cause wear and loss of capacity, resulting in clogging and jamming of through holes, variable mechanisms, parts, and the like.
4) Once the oil is contaminated, it should be replaced and rinsed with clean oil.
1.3 working oil temperature is appropriate
1) - as the hydraulic oil temperature should be 10 ~ 50 ℃, should be less than the maximum 65 ℃, it should be less than the local short 90 ℃.
2) low temperature should be light load or no-load start, until the oil temperature to normal and then resume normal operation. When the temperature is generally below 10 ℃, should be no-load operation to load more than 20min: if the temperature is above or below 0 ℃ 35 ℃, should be heated or cooled; or winter start when the oil temperature region above 15 ℃ raised side It can be loaded; not allowed to start below -15 ℃.
3) It is strictly forbidden to fill the cold oil into the hot component during work, or to fill the cold oil into the cold component, so as to avoid the temperature difference is too large, and the expansion or contraction is not enough to kill. In the winter or cold regions, if the electric heater is used to heat the oil in the fuel tank, the pump and the motor are still cold and easy to get stuck. Pay special attention when using it.
2 to ensure normal working conditions
2.1 normal inhalation conditions
Although the hydraulic oil pump is a positive displacement pump and has a certain self-priming capacity, there are many friction sealing surfaces in the mercury, and the self-priming ability is limited, especially the internal flow passage of the pump is complicated, and the general oil absorption height (the oil level of the oil tank to the pump center) is low. , about 12 ~ 50cm, and some mercury is expressly stipulated that self-priming is not allowed, such as ZB227 type, so the inhalation conditions should be considered to minimize the inhalation resistance:
1) The suction pipe must not be equipped with a filter, otherwise it will be supplied with a negative suction or auxiliary pump;
2) It is best to make the fuel tank above the pump suction port or use an auxiliary pump to supply oil. For example, the ZB type oil pump (except ZB227 type) is allowed to self-prime when it is rotated below the rated speed (1500r/min), but this will cause the capacity ratio to drop by about 5%, and it will inevitably affect its service life. This method of use is not recommended; most manufacturers recommend using an auxiliary pump for oil supply, and the pressure is about 0.7 MPa when living. When the CY type oil mercury is running at the rated speed, it is allowed to self-prime, the suction height is ≤500mm, and it is operated at the highest speed. When the oil suction pipe is small, the height of the flow column is allowed, and the oil absorption height is 300~500 mm. When it is larger, the pump must use auxiliary mercury to supply oil, and the oil supply pressure is ≤0.4Mpa. |
3) The suction pipe should be short and straight, and the pipe diameter should be slightly larger than the pump inlet.
