The development trend of hydraulic technology, taking construction machinery as an example, is mainly to high pressure, high speed, miniaturization, mechatronics integration, as well as improve product cleanliness, control system pollution and other directions. As most of the construction machinery is field work, the hydraulic system is often affected by dust, high and low temperature, vibration, snow and other attacks, resulting in hydraulic oil pollution, causing failure. According to statistics at home and abroad, more than 70% of the faults in hydraulic and lubrication systems are caused by the pollution of the working medium (hydraulic oil). The product standard of mineral and synthetic hydrocarbon hydraulic oil in China is gb11118.1-94, including the technical specifications of HL, HM, HG, HV and HS. With the gradual improvement of modernization and the development of control technology, hydraulic transmission system has been widely used in various industries because of its own advantages. The working medium of hydraulic system is hydraulic oil, which is called the "blood" of hydraulic system, and its quality will directly affect the normal operation of the whole system. The correct daily use and maintenance management of hydraulic fluid are the key measures to ensure the long-term operation of hydraulic fluid.
No. 68 anti-wear hydraulic oil selection principle:
1. Generally, HL oil is selected for indoor fixed equipment with the pressure of hydraulic system < 7.0MPa and temperature below 50℃; Choose HL or HM oil for system pressure 7.0-14.0mpa and temperature below 50℃, and choose HM oil for temperature between 50 and 80℃. System pressure > 14.0MPa choose HM or high pressure anti-wear hydraulic oil.
2. Choose HV or HS oil for cold or cold areas in the open air.
3, for the equipment near the high temperature heat source, choose anti-combustion hydraulic oil.
4, higher requirements for the monthly environmental protection equipment (such as food machinery, medical machinery), choose the environment can accept hydraulic oil.
5, for the requirements of long life, poor environmental conditions of the hydraulic oil equipment to choose hydraulic oil excellent products; For the requirements of the use of short cycle, ease the working conditions of the hydraulic equipment to choose a first-class hydraulic oil.
6, hydraulic and guide rail lubrication share a system, should choose hydraulic guide rail oil.
7. The open-loop CNC machine tool using electro-hydraulic pulse motor USES the hydraulic oil of CNC machine tool, and the closed-loop system of electro-hydraulic servo mechanism USES the clean hydraulic oil.
8. Silver resistant hydraulic oil is selected for the hydraulic system with silver components.
Introduction to no.68 anti-wear hydraulic oil model:
L-hl hydraulic oil: anti-oxygen and anti-rust hydraulic oil.
L-hm hydraulic oil: anti-wear hydraulic oil improves anti-wear performance on the basis of HL.
L-hg hydraulic oil: hydraulic guide oil, modeling and slippage improvement based on HM.
L-hv hydraulic oil: low temperature hydraulic oil, improved low temperature performance on the basis of HM.
L-hs hydraulic oil: low temperature hydraulic oil with lower pour point than HV.
High pressure anti-wear hydraulic oil: enhanced anti-wear property on the basis of HM hydraulic oil, passed the high pressure pump bench test.
No. 68 anti-wear hydraulic oil performance features:
Excellent oxidation stability, hydrolysis stability and thermal stability, to resist the influence of air, water and high temperature, high pressure and other factors, so that it is not easy to aging, prolong the service life.
Second, good anti-emulsification, can be quickly separated from the water in the mixed oil, so as to avoid the formation of emulsion, causing the metal corrosion of the hydraulic system and reducing the performance.
Three, suitable viscosity and good viscosity temperature performance, to ensure that the hydraulic components in the working pressure and working temperature changes under the condition of good lubrication, cooling and sealing.
Four, good extreme pressure wear resistance, to ensure the oil pump, hydraulic motor, control valve and cylinder friction pair under high pressure, high speed harsh conditions get normal lubrication, reduce wear.
One. Good foam resistance and air release value, so as to ensure the foam generated under the condition of intense mechanical agitation during operation;
Can disappear quickly; And it can release the air mixed with oil in a short time to achieve accurate, sensitive and smooth transmission of static pressure.
Seven, good rust resistance, to prevent the metal surface rust.
Reference for main parameters of no.68 anti-wear hydraulic oil:
泡沫性（泡沫倾向/泡沫稳定性）/ml/ml( )/ml/ml 不大于
氧化安定性（酸值2.0mg KOH/g）/h 不小于
Precautions for use of no.68 anti-wear hydraulic oil:
1. Keep the hydraulic oil clean to prevent metal scrap, fiber and other impurities from entering the oil.
2, mailbox before adding oil, should be thoroughly cleaned, and the injection of new oil must be filtered (filter precision is generally 5-10 microns) otherwise the performance of the hydraulic system and hydraulic pump life will be greatly affected.
3. Check oil quality and oil level regularly.
4. Ensure that the temperature rise of the oil in the mailbox does not exceed the allowable range of the hydraulic oil, and all working requirements shall not exceed 60℃, otherwise the cooling system of the hydraulic oil shall be checked. When the oil temperature is too low, preheat the oil and make the oil temperature gradually rise (the required temperature reaches more than 30℃), and then run the machine
5, hydraulic oil in the use of the main detection of oil appearance, viscosity change, color change, acid value change, moisture, impurities, corrosion and other items, regular testing these items can find problems in advance, take appropriate measures to avoid failure.