(1) environmental conditions: ambient temperature-based;
(2) Working conditions: pump type, work pressure, temperature, speed, oil and metal seals and coatings, adaptability, the cycle of operation of the system and work characteristics;
(3) the nature of the hydraulic oil: the oil's physical and chemical pointer, performance and features;
(4) economy: oil prices, life. ?
The selection of good and suitable for hydraulic oil, in the course of management and maintenance is very important, you should note the following.
① to prevent hydraulic oil pollution: pollutants greatest harm is caused by corrosion of the equipment, plug the filter and the throttle and accelerate the aging of oil and corrosion on components;
② to prevent air mixing: mixed with air to produce cavitation, noise, and hydraulic oil to premature deterioration, affect the use;
(3) to prevent water mixed: mixed with cooling water and steam to make the hydraulic system in metal corrosion, accelerated oil deterioration, and reduce the lubrication of the hydraulic oil;?
④ control the use of temperature of hydraulic oil: mineral oil hydraulic oil, working continuously for 50 to 65 ℃, the maximum temperature of 120 to 140 ℃. The temperature rise will accelerate the oxidative deterioration of the hydraulic oil, oxidation of the acid can cause corrosion of metal components.
1, choose the basis of construction machinery with the liquid oil
① hydraulic parts hydraulic components used in the hydraulic oil has a minimum configuration requirements, so the choice of hydraulic paste filling machine, you should pay attention to the compatibility of hydraulic types of material used in seals and coatings, or paints and hydraulic oil to ensure good lubrication of the movement, vice, so that the components meet the design life to meet the performance requirements.
Hydraulic pump is the most sensitive one of the components of the hydraulic oil viscosity and viscosity-temperature performance, therefore, often the requirements of the system pump hydraulic oil as an important basis for the choice of hydraulic oil (except for a servo valve system).
② system conditions on the executive body speed, the higher the system pressure and the accuracy requirements of the agency action, the higher the wear and load carrying capacity, such as the requirements of the hydraulic oil.
Possible by the system operating temperature, continuous operation time and the working environment and hygiene conditions, choose the oil should be noted that the oil viscosity, high temperature performance and thermal stability to reduce sludge formation and deposition.
③, the smaller the tank the size of the fuel tank of oil, anti-oxidation stability, extreme pressure abrasion resistance, the higher the air release and filtration requirements.
④, the ambient temperature for construction machinery in the underground, water, indoor, outdoor, cold areas, or in the temperature cold area, as well as near the presence of high temperature heat source or open flame such as ambient temperature characteristics, a reasonable selection of hydraulic oil. If no open flames near the operating temperature below 60 ℃, carrying lighter, you can use an ordinary hydraulic oil, if the equipment required to start in the low temperature, are required to use low pour hydraulic oil.
In summary, if the hydraulic oil quality standards system to perform high velocity fluid flow rate is also high, the hydraulic loss increases, but leakage is relatively reduced, it should choose the lower viscosity oil; contrary , when the oil flow rate is low, the amount of leakage is relatively increased, will be working bodies of the velocity of impact, it should choose the higher viscosity of oil. Normally, when work pressure is high, should use the high viscosity of the hydraulic oil, because to solve the leak problem should give priority to more than overcome the viscous resistance in hypertension; when working pressure is low, should use low viscosity oil. Ambient temperature is high, the higher viscosity of oil, to the contrary, the lower viscosity oil should be used.
⑤, hydraulic oil to finalize the preliminary selection of hydraulic oil, and pay attention to the verification of their supply, viscosity, and quality characteristics, scope of application, and compatibility of materials, systems and components, see the indicators whether to fully meet use requirements.
⑥, the economy should consider the price of the hydraulic pellet packing machine life, and the hydraulic system and maintain the safe operation of the cycle, focusing on the economic benefits of a good brand.