When the hydraulic oil is in use, if the temperature is too high, the viscosity of the hydraulic oil will decrease, and the lubricity will decrease, which will accelerate the wear of the oil pump and hydraulic components during operation, which is likely to cause leakage. If the temperature is low, the viscosity of the hydraulic oil will increase, which will cause the movement flexibility of the hydraulic components to decrease. In severe cases, the movement components may be unable to move and affect normal operation.
Generally, it is better to control the temperature of hydraulic oil in the range of 20℃-60℃.
The effect of high temperature:
The volume of the hydraulic oil is expanded, and the pressure of the hydraulic oil enclosed in the cavity rises, causing danger. The performance of rubber seals in hydraulic systems deteriorates, which can swell and soften rubber, accelerate rubber aging, and even seal failure.
Air bubbles are more likely to be generated. Air bubbles destroy the lubricating oil film, cause sintering or increase wear on the friction surface, and accelerate the oxidative deterioration of hydraulic oil, which affects the accuracy and sensitivity of hydraulic components, and cannot meet the requirements of the hydraulic system in severe cases. It often causes the corrosion of steel and other non-ferrous metals in hydraulic oil to intensify, causing damage to the surface of the parts and producing corrosives at the same time.
The lubricating film formed on the metal surface of the friction part is chemically decomposed, and the lubricating film is destroyed.
The oxidation of hydraulic oil is intensified, and some ketones, acids, gums, asphaltenes and other substances are gradually generated in the hydraulic oil, which contaminates the hydraulic oil and shortens the service life of the hydraulic oil. When the hydraulic oil is oxidized to a certain degree, the hydraulic oil fails and cannot be used.
The viscosity of the hydraulic oil becomes smaller, the viscosity is too low, the leakage of the hydraulic system increases, the efficiency decreases, and the hydraulic system even fails to work normally.
The effect of low temperature:
1. Low temperature increases the viscosity of hydraulic oil. If the viscosity is too high, the self-priming ability of the oil pump will decrease, the pressure loss of the hydraulic system will increase, and the power loss will increase. It is generally believed that when the viscosity is greater than or equal to 1000mm2/s, the hydraulic system cannot work normally, and when the viscosity is greater than or equal to 2000mm2/s, the hydraulic system cannot be started normally. ,,,,,,
2. The low temperature causes the water in the hydraulic oil to solidify, and the solidified water adheres to the surface of the hydraulic valve parts, oil filter, etc., which may cause the hydraulic valve to jam, the oil filter to block, and the hydraulic system can not work normally. ,,,,,
3. The low temperature causes the rubber sealing material in the hydraulic system to shrink, harden, etc., which reduces the sealing performance and even causes the seal to fail. To
4. The low temperature causes the hydraulic oil to shrink, especially the hydraulic oil in the closed cavity, which causes the pressure to drop and even produces negative pressure.