The working temperature of hydraulic cylinder oil is generally in the range of 30 ° C to 80 ° C. too high oil temperature will have a series of bad effects on the system, such as decreased viscosity, increased leakage, decreased volumetric efficiency, instability of hydraulic speed, change of clearance between motion amplitudes with different thermal expansion coefficients, possible jamming, etc., which will deteriorate the oil, aging seals, loss of sealing performance, etc.

The reasons for the rise of the oil temperature of the hydraulic cylinder are various, such as the volume of the oil tank is too small, the heat dissipation area is not enough, the oil storage volume of the oil tank is too small, the ambient temperature is high, and the cooler function fails; There is no unloading circuit in the system, and the oil pump is still overflowing under high pressure when it stops working; The pipe is too thin and long, too much bending, too large pressure loss, low machining accuracy of components, excessive friction and heating relative to moving parts, etc.

From the perspective of use and maintenance, the following issues should be noted:

1. Always maintain the correct oil level in the oil tank, so that the oil has sufficient circulating cooling oil;

2. Always keep sufficient water in the cooler and smooth pipelines;

3. When the system is not working, the oil pump needs to be unloaded;

4. Correctly select the viscosity of hydraulic cylinder oil.