Views: 2 Author: Site Editor Publish Time: 2023-11-30 Origin: Site
First the oil is mixed with water
1. The way in which water enters the oil
(1) The oil tank cover is due to the alternations of cold and hot, and the water in the air condenses into water drops and falls into the oil.
(2) The seal of the cooler or heat exchanger is damaged or the cooling pipe is broken so that the water leaks into the oil.
(3) The wet air entering the system through the hydraulic cylinder piston rod seal is not tight and condenses into water droplets.
(4) When using oil, the moisture of the person and the water absorbed by the oil when exposed to the wet environment and the hydrophilic cooperation with water.
2. The danger of mixing water into the oil
(1) After a certain amount of water is mixed into the oil, the hydraulic oil will be emulsified into a white turbid state. If the anti-emulsification ability of the hydraulic oil itself is poor, after a period of time, the water can not be separated from the oil, so that the oil is always in a white turbid state. This white emulsified oil enters the hydraulic system, which not only rusts the hydraulic components inside, but also reduces their lubrication performance, aggravates the wear of parts, and reduces the efficiency of the system.
(2) After the iron series metal in the hydraulic system rusts, the peeling rust flows in the hydraulic system pipes and hydraulic components, and spreads and spreads down, which will lead to the internal rust of the entire system, producing more peeling rust and oxides.
(3) Water will also interact with some additives in the oil to produce pollutants such as precipitation and gum, accelerating the deterioration of the oil.
(4) The interaction between water and sulfur and chlorine in the oil produces sulfuric acid and hydrochloric acid, which intensifies the abrasive wear of the components, accelerates the oxidation and deterioration of the oil, and even produces a lot of sludge.
(5) These water pollutants and oxidation products then become a catalyst for further oxidation, which eventually leads to blockage or jamming of hydraulic components, causing a series of failures such as hydraulic system failure, distribution pipe blockage, cooler efficiency reduction, and oil filter blockage.
(6) In addition, at low temperatures, water condenses into tiny ice particles, which are also easy to block the gaps and dead openings of the control elements.
Second, the oil is mixed with various impurity particles
Solid pollutants in oil mainly exist in the form of particles. Some of these impurities are residual during the processing and assembly of components, some are generated during the working process of hydraulic components, and some are caused by the intrusion of external impurities, and the harm is:
1. Various particulate impurities in the oil can cause harm to the pump and motor. When impurity particles enter the gear end face of the gear pump or gear motor and between the two end cover side plates, the tooth tip and the housing, or when impurity particles enter the blade and blade groove of the vane pump or blade motor, the rotor end face and the oil distribution disc, the stator and the rotor (blade top), or when impurity particles enter the plunger and plunger cylinder hole of the plunger pump or plunger motor, When the rotor and the oil distribution plate, the sliding shoe and the tilt plate, the sliding pair of the variable mechanism, it may cause the stuck fault. Even if it does not cause a stuck fault, it will aggravate the wear. Impurity particles may also clog the oil inlet filter in front of the pump, causing cavitation in the pump or causing a variety of concurrent failures.
2. Various particulate impurities in the oil will cause harm to the hydraulic cylinder. Particle impurities will cause strain and wear between piston and cylinder block, piston rod and cylinder head hole and sealing element, increase oil discharge, volumetric efficiency and effective thrust (pull) reduce, if particle impurities jam piston or piston rod, will cause cylinder no action.
3. Pollution particles in the oil can cause harm to various valve components. Pollution particles may cause the slide valve to jam or throttle 121 blockage, resulting in valve failure, even if there is no jam or blockage fault, pollution particles will also cause premature wear of valve components moving pairs, increase the matching gap, and deteriorate the performance.
4. The pollutants multiply bacteria, aggravate the aging of the oil, make the oil black and smelly, and further produce pollution.
Such a vicious circle may have the following consequences:
(1) Pollutants clog the oil filter, causing the oil pump to empty, producing vibration and noise.
(2) Pollutants increase the friction of the cylinder or motor, resulting in crawling.
(3) pollutants cause the servo valve and other components with poor anti-pollution ability to completely lose function.
(4) Pollutants block the pressure gauge channel, so that the pressure can not be correctly transmitted and reacted.
Three, oil into the air
The air in the oil mainly comes from the loose pipe joint, the loose component joint surface, the tubing exposed to the oil surface and the sealing failure, and the oil exposed to the atmosphere will dissolve the air. In addition, when the amount of oil in the tank is small, it accelerates the circulation of hydraulic oil, making it difficult to remove bubbles, and at the same time, the "eating oil" depth of the oil pump suction pipe is not enough to make air easy to enter.
The air mixed with the hydraulic system is usually suspended in the hydraulic oil with a diameter of 0.05 ~ 0.50mm bubble state, which has a serious impact on the bulk elastic modulus of the hydraulic oil in the hydraulic system and the viscosity of the hydraulic oil. As the pressure of the hydraulic system rises, some of it is mixed into the air-soluble hydraulic oil, and the rest still exists in the gas phase. When the amount of air mixed increases, the volume elastic coefficient of the hydraulic oil decreases sharply, the pressure wave propagation speed in the hydraulic oil slows down, and the dynamic viscosity of the oil increases linearly. The air suspended in the oil is combined with the hydraulic oil into a mixed liquid. The stability of the oil is determined by the size of the bubble, which has a significant impact on the hydraulic system. There may be vibration, noise, pressure fluctuation, instability of hydraulic components, crawling and reversing impact of moving parts, inaccurate positioning or action disorders, and other failures, while also increasing power consumption. The oxidation of the oil is accelerated and the lubrication performance of the oil is reduced.
Zhongshan Wanda Machinery Automation Technology Co., LTD/Zhongshan Paktat Machinery Manufacture Co., Ltd.is one of China's hydraulic press professional production enterprises, the company has large floor boring and milling machine, heavy lathe, milling planer and other key equipment, advanced process equipment, can design and produce 2-12000 tons of various types of hydraulic press.
