1) Classification of bearing hydraulic oil
According to the use requirements, it is divided into: anti-wear, low setting, anti combustion, cleaning, anti silver, CNC, hydraulic transmission oil, etc.
By performance: mineral oil and synthetic oil.
According to the working principle, it is divided into liquid pressure energy for liquid transmission and liquid kinetic energy for hydraulic transmission.
2) Advantages and disadvantages of hydraulic system
Classification, specification, quality requirements and precautions of oil for hydraulic system.
HL common hydraulic oil
HM antiwear hydraulic oil
Hg hydraulic guide oil
HV, HS low temperature hydraulic oil
Water based solution
3) Main properties of hydraulic oil
1 Viscosity and viscosity temperature
2 low temperature performance
3 oxidation stability
4 rust and corrosion resistance
5 abrasion resistance
6 Shear Stability
7 demulsibility and hydrolytic stability
8 foaming and air release
9 cleanliness and filtration performance
10 adaptability of hydraulic pressure to non-metallic materials and metal materials such as sealing materials and coatings
4) Selection of hydraulic oil
1. The ambient temperature of indoor and fixed equipment changes little
2. Large temperature difference of hydraulic equipment and environment in open air, cold area and severe cold area
3 underground and water hydraulic equipment and humid environment
4 equipment near high temperature heat source and open fire
Hydraulic oil type selection
Environment / working condition Pressure < 7mp2 Below 50 ℃ Pressure 7-14 MP2 Below 50 ℃ Pressure 7-14 MP2 Below 50-80 ℃ Pressure > 14mp2 Below 100-80 ℃
Indoor fixed equipment HL HM HM HM
Open air, cold area and severe cold area Hm or HS Hm or HS Hm or HS Hm or HS
Underground and aboveground HL HL or HM HL or HM HM
Near high temperature heat source or open fire HFAE/HFAS HFB、HFC HFDR HFDR
Hydraulic oil shall be selected for various hydraulic pumps
Pump type Viscosity (40 ℃) mm2 / S Applicable hydraulic oil Type and viscosity
Vane pump Below 7mp2 30-50 40-75 HM32、46、68
7mp2up 50-70 55-90 HM46、68、100
Screw pump 30-50 40-0 HL32、46、68
Gear pump 30-70 95-165 HL high voltage HM32、46、68、100
Radial Piston Pump 30-50 65-240 HL high voltage HM32、46、68、100、150
Axial piston pump forty 70-150 HL high voltage HM32、46、68、100、150
Note: 15 ℃ – 40 ℃ and 40 ℃ – 80 ℃ refer to the temperature of the hydraulic system.
A potential pollution B invasion pollution C regeneration pollution
6) Consequences of contamination on hydraulic parts
A. the working performance of the hydraulic system decreases and the action is out of balance
B. the surface of hydraulic components is worn, scratched, bitten, internal and external leakage of hydraulic cylinder, insufficient thrust, unstable action, resulting in sound and vibration
C. after the deterioration of hydraulic oil, brown colloidal suspension will be generated, which will block the orifice and cause component action failure
Judgment and treatment of hydraulic oil pollution
Appearance color smell state Treatment measures
The color is transparent without change normal good Use as usual
Transparent but pale normal Mixed with other oils Check viscosity symbol It can be used continuously
Turn milky white normal Mix air and water Water removal or oil change
Turn dark brown stink oxidative deterioration Change all oil
Transparent with small black spots normal Mixed impurities Filter oil quality
Transparent with flash normal Metal powder entering filter
High service temperature of hydraulic oil
Hydraulic fluid type Continuous working state ℃ High temperature ℃
water 38-50 sixty-five
Mineral hydraulic oil 50-65 120-140
Water in oil emulsion 50-65 sixty-five
Water glycol 50-65 seventy
phosphate 65-82 one hundred and fifty
7) Analysis and treatment of faults caused by hydraulic oil
Classification of fault causes of hydraulic system
Cause of failure Ratio%
Improper use and management of hydraulic oil seventy
Mechanical wear ten
Lack of understanding of equipment performance ten
Overload operation five
8) Mechanical failure caused by hydraulic oil
1 viscosity is too low, pump noise, insufficient displacement, internal leakage and unstable pressure valve.
2. The viscosity is too high, the oil absorption is poor, the cavitation and filter resistance are large, the pipeline resistance is large, the pressure loss is large, and the action of the control valve is slow.
3. Poor anti emulsification, rust and accelerated deterioration and aging of hydraulic oil.
4 deterioration and aging, oil sludge, corrosion of metal materials and increased wear.
5 anti foam properties, bubble cavitation, noise, slow action.
9) Brief introduction of foreign famous brand hydraulic oil
① Mineral oil modulation
(1) Mobil DTE extraordinary series hydraulic oil (ashless)
The mineral oil is used as the base oil. The modulation is strict. The copper alloy in the hydraulic components highlights the anti-corrosion protection, high temperature and thermal oxidation stability, reduces oil sludge, has unique anti-wear and anti emulsification, and can still operate with a small amount of water.
A large amount of water can be separated from water quickly. The additive will not react and precipitate with water, and is very soluble with a variety of metal working fluids. Available for all piston vane and gear pumps.
Can be divided into: Mobil DTE extraordinary 22, 32, 46, 68100.
The pour point is – 39 ℃ ~ – 24 ℃, the flash point is 210 ℃ – 230 ℃, and the index is 97.
(2) Mobil dte20 series anti-wear hydraulic oil
Mineral oil is the base oil, the vane pump test (vv-104c) is only 28mg, the wear (below 50mg is qualified) is excellent, anti emulsifying, a small amount of water operates normally, and a large amount of water can be separated quickly and anti-wear.
Suitable for ordinary, heavy-duty hydraulic system. (equivalent to China’s anti-wear hydraulic oil) shall not be used for silver parts.
Divided into Mobil DTE21 (10), 22 (22), 24 (32), 25 (46), 26 (68), 27 (100),
Pour point – 24 ℃ ~ – 15 ℃, flash point 166 ℃ – 212 ℃, index 98
(3) Mobil DTE layer 10m series anti-wear hydraulic oil
It is a kind of hydraulic oil with high viscosity index. It is used in industries operating at low temperature or rapidly changing temperature. Ships and mobile equipment shall not be used for silver parts.
Temperature adjustment range:
DTE 11M -38-54℃
DTE 13M -32-67℃
DTE 15M -26-79℃
DTE 16M -20-89℃
DTE 18M -13-105℃
DTE 19M -1-110℃
Viscosity index 142-115
(4) Mobil environmental protection hydraulic oil eac-224h (degradable)
It is a biodegradable and non-toxic oil. Excellent anti-wear and extremely strong oil film, suitable for hydraulic system under general or extreme working conditions, suitable for industry, vehicle and marine, including high-pressure servo valve system equipment
Pour point – 34 ℃, flash point 294 ℃, index 217.
(5) Mobil AW series anti-wear hydraulic oil
It is suitable for hydraulic systems without gears, blades or axial piston pumps and requiring anti-wear hydraulic oil.
Points: aw32, 46, 68100, pour point – 18 ℃ ~ – 15 ℃, index 95.
(6) shell delis s anti-wear hydraulic oil (ash free)
High quality mineral oil is a zinc free anti-wear agent, chlorine free formula, excellent anti-oxidation and excellent anti-wear. In the vane pump test, the weight loss of delis s part is less than 20mg, which is equivalent to 1 / 10 of ordinary qualified oil. Do not produce crawling phenomenon.
It is divided into S46, (46) and s68 (68).
Pour point – 30 ℃, flash point 218-222, index 98.
(7) shell delis t anti-wear hydraulic oil
High quality mineral oil viscosity index improver is suitable for those hydraulic and hydraulic systems with little temperature change. It is also suitable for the lubrication of ordinary load gear bearings. It has high shear stability, excellent wear resistance and good filtration.
In particular, the pollution of water and calcium can greatly reduce the performance of filter blockage, anti-corrosion, anti climbing, anti foaming, moisture and so on.
Points: T15 (15), T32 (32), T37 (37), T46 (46), T68 (67),
Pour point – 42 ℃ ~ – 30 ℃, flash point 160 ℃ – 260 ℃, index 159-152.
Shell delis, anti-wear hydraulic oil
Mineral oil with high viscosity index is known as “standard” lubricating oil in the industry. Thermal stability, oil sludge resistance. It can maintain oxygen resistance under the conditions of air, water and copper.
Excellent anti-wear, excellent filtration, users can use finer filters, low friction, anti stick slip, strong water separation and strong defoaming ability.
Points: 22, 32, 37, 46, 68100.
Pour point – 30 ℃ ~ – 24 ℃, flash point 255-288, index 100-99.
② Synthetic oil modulation
(1) Mobil shc500 series anti-wear hydraulic oil
It’s made of synthetic oil. Suitable for gear pump, piston pump or vane pump. Temperature: 120 ℃ – 130 ℃. High and low pressure hydraulic system and permanently sealed hydraulic system under harsh conditions.
Sub Mobil SHC 522 (15), 524 (32), 525 (46), 526 (68)
Pour point – 54 ℃, flash point 210 ℃ – 240 ℃, index 135-158
(2) Purple crown all-weather hydraulic oil (synthetic extreme)
It is a kind of clean, long-life, super thermal stability and oxidation stability. It can restore some unstable hydraulic systems to a good state and prolong their service life. Better low-temperature fluidity and reduce the temperature during operation.
Due to the use of xinlailik additive, it has ultra-high oil film strength, excellent anti-corrosion, anti-corrosion and excellent water separation, and water can be eliminated. Good compatibility and long service life of seals, conducive to environmental protection and reduce waste oil discharge.
ISO 32, index 130, flash point 235, pour point – 50 ℃
(3) high clean hydraulic oil (syndrau IC)
Refined synthetic oil plus advanced synlaic additives has an abnormal cleanliness, which is 250 times higher than that of other representative hydraulic oils. The service life is extended by 4-5 times. The tough oil film is wear-resistant, cooling, low noise and long life.
It also prolongs the service life of pumps, filters and seals. It is suitable for various hydraulic systems to be used under harsh conditions of high pressure and low temperature (- 40 ℃). It has the ability to clean the dirt and eliminate the dirt accumulation in the system.
Therefore, when applying it for the first time, pay attention to the pressure difference of the filter, wash and change the filter element frequently.
Divided into: 10, 15, 32, 46, 68100150
Pour point – 40 ℃ ~ – 37 ℃, flash point 193-232, index 102-101.