In the process of transmission of hydraulic system, pressure loss, volume loss and mechanical loss will inevitably occur. These lost energy Z will eventually be converted into heat energy, which is shown as the temperature rise of the hydraulic system. The system temperature is too high mainly due to the following reasons:
1. High temperature caused by high pressure leakage of the system
When the hydraulic pump is worn, internal leakage will increase. The high temperature generated by high-pressure leakage will be brought back to the oil tank by the oil, and the oil temperature in the tank will rise randomly. The hot oil will be sucked into the hydraulic pump again to make the oil rise again until the heat is balanced. A good way to deal with high temperature Z is to repair the hydraulic pump in time to reduce the internal leakage of the system.
2. High temperature caused by high pressure overflow of the system
Long term high-pressure overflow will produce high temperature, which will convert hydraulic energy into heat energy. If a constant pressure variable displacement pump is used, the pressure set by the constant pressure valve should be lower than the pressure set by the overflow valve. The overflow valve acts as a safety valve and is not allowed to overflow under high pressure.
3. High temperature caused by high pressure throttling of the system
Throttling is a common method in hydraulic system, but high-pressure throttling will produce high temperature, especially high-pressure throttling with large flow. Therefore, it is not allowed to close the orifice at will. Attention should be paid to the operation of regulating throttle valve. IV. The influence of ambient temperature on the system temperature The oil temperature of the hydraulic system is generally 40~60 ℃, and Z should not exceed 80 ℃. However, in some places, the temperature is too high, such as the ambient temperature reaching 50 ℃, which will bring serious challenges to the hydraulic system, especially when working outdoors, it is directly affected by solar radiation, which will be more detrimental to the system heat dissipation.
The hydraulic system is widely used. The operation of large machinery, such as CNC machine tools, requires the use of hydraulic systems, which play an executive role in the entire operation process of these large machinery. Therefore, the normal operation of hydraulic systems plays a very important role in the operation of large machinery, such as CNC machine tools. In the normal operation of large machinery, high temperature often occurs. In fact, if the temperature is too high, it will bring certain potential safety hazards to the hydraulic system. How to keep the hydraulic system at high temperature?
1、 Change the hydraulic oil regularly. The hydraulic system is used in high temperature and high dust environment. With the increase of time, the hydraulic putty gradually ages and deteriorates. It is necessary to replace the hydraulic oil regularly to prevent directional leakage.
2、 Replace the seals regularly. The oil system works under high temperature for a long time. Seals age easily. Aging seals shall be updated in time.
3、 Since all actuators of the system are energized, the insulation between them and the pump station depends on the insulated flange pipe joint. The original design used asbestos board. Although asbestos board plays a role in heat preservation, its strength is not enough and it is not oil resistant. It is easy to burst, causing leakage and fire.
4、 The sealing groove and seal larger than the theoretical design size shall be adopted for the hydraulic cylinder with short distance and large cylinder.
5、 Strengthen the management of hydraulic system. Each pipe joint of the hydraulic system shall be inspected regularly by a specially assigned person, and the two joint surfaces with leakage shall be replaced in time to prevent accidents.
