1. The hazards of excessively high hydraulic oil temperature in variable vane pumps
① For variable vane pumps, the viscosity of the hydraulic oil, volumetric efficiency and hydraulic system efficiency are reduced, leakage increases, and even the mechanical equipment cannot work normally.
② The parts of the hydraulic system expand due to overheating, destroying the original normal matching clearance of the relative moving parts, resulting in increased friction resistance and easy jamming of the hydraulic valve. At the same time, the lubricating oil film becomes thinner and mechanical wear increases, resulting in pumps, valves, The precision mating surfaces of motors, etc. may fail or be scrapped due to premature wear.
③ Accelerate the aging and deterioration of rubber seals, shorten their service life, and even lose their sealing performance, causing serious leakage in the hydraulic system.
④Vaporization of oil and evaporation of water can easily cause cavitation in hydraulic components; oxidation of oil can form colloidal sediments, which can easily block the small holes in the oil filter and hydraulic valve, causing the hydraulic system to not work properly.
Therefore, excessively high hydraulic oil temperature will seriously affect the normal use of the machine, reduce the service life of hydraulic components, and increase the maintenance cost of construction machinery.
2. Causes and preventive measures of excessively high hydraulic oil temperature in variable vane pumps
(1) Improper oil selection for variable vane pump
The brand, quality and viscosity grade of the oil do not meet the requirements, or different brands of hydraulic oil are mixed, causing the viscosity index of the hydraulic oil to be too low or too high. If the oil viscosity is too high, the power loss will increase and the oil temperature will rise; if the viscosity is too low, the leakage will increase and the oil temperature will rise.
Preventive measures: The oil selected should be determined according to the manufacturer’s recommended grade and the working environment and temperature factors where the machine is located. For some machines with special requirements, special hydraulic oil should be used; when the maintenance of hydraulic components and systems is inconvenient, anti-wear hydraulic oil with good performance should be used.
Post time: Dec-05-2023