Causes of high hydraulic oil temperature

There are many reasons why the hydraulic oil temperature is too high. Let's analyze several common factors below:

1. Improper oil selection
The brand, quality and viscosity grade of the oil do not meet the requirements, or the hydraulic oils of different brands are mixed, resulting in the low or high viscosity index of the hydraulic oil. If the viscosity of the oil is too high, the power loss increases and the oil temperature rises; If the viscosity is too low, the leakage will increase and the oil temperature will rise.

2. The construction site is seriously polluted and the environment is bad,
With the increase of the working time of the machine, impurities and dirt are easy to be mixed in the oil. The polluted hydraulic oil will enter into the fitting gap of the pump, the motor and the valve, which will scratch and damage the accuracy and roughness of the fitting surface, increase the leakage and increase the oil temperature.

3. Air in hydraulic system
The air mixed into the hydraulic oil will escape from the oil and form bubbles in the low-pressure area. When it moves to the high-pressure area, these bubbles will be broken by the high-pressure oil, and will be rapidly compressed to release a lot of heat, causing the oil temperature to rise.

4. The oil level in the hydraulic oil tank is too low
If the amount of oil in the hydraulic oil tank is too small, the hydraulic system will not have enough flow to take away the heat generated, resulting in an increase in oil temperature.

5. Poor operation of hydraulic oil cooling circulation system
Generally, water-cooled or air-cooled oil coolers are used to forcibly cool the oil temperature of the hydraulic system. The heat dissipation coefficient of water-cooled cooler will be reduced due to dirty fins or poor water circulation; Air cooled cooler will block the gap of the radiator of the cooler due to excessive oil contamination, which is difficult for the fan to dissipate heat, resulting in an increase in oil temperature.

6. Parts are seriously worn
Gear, pump body and side plate of gear pump, cylinder body and port plate of plunger pump and motor, cylinder hole and plunger, valve rod and valve body of reversing valve are all sealed by clearance. Wear of these components will cause increased internal leakage and oil temperature.

7. Blocked oil filter
When passing through the oil filter, abrasive particles, impurities and dust will be adsorbed on the filter element of the oil filter, resulting in an increase in oil absorption resistance and energy consumption, and an increase in oil temperature.

8. High ambient temperature
The ambient temperature is too high, and the oil temperature will be too high if it is used under high load for a long time.