top of page

Understanding the Purpose of Hydraulic Oil

Forces and motions are transmitted by hydraulic systems. The idea behind the systems is the same, even if their goals may differ greatly. A force is applied to another component by means of hydraulic oil movement. Your brakes' functionality is one illustration of this. Your brake pads are compressed against the braking disc by hydraulic fluid. In this case, the hydraulic oil's operating pressure is somewhat high while the fluid displacement is comparatively modest.

A crane operator who has the ability to move his bucket in any direction using hydraulics is another example. The last part of the hydraulic system moves as a result of the force that the fluid transfers. In this case, the working pressure is relatively low, and the fluid's kinetic energy is quite large.


What is the purpose of hydraulic oil?

A hydraulic oil serves three purposes. Therefore, the transfer of forces comes first. Second, the oil is utilized to lubricate the moving parts by separating them from one another. Thirdly, another purpose of the oil is to release heat from the system.

Viscosity of hydraulic oil

There are several factors to consider while selecting a hydraulic oil. First, the oil's viscosity, or thickness. The best viscosity depends on a variety of contradictory characteristics. Low viscosity oil is needed for effective power transfer, quick system response, and low energy usage.

Proper hydraulic oil sealing and lubrication

To provide appropriate lubrication and sealing, the oil must, nonetheless, have a suitable viscosity. In addition, the hydraulic oil needs to be the proper viscosity. Additionally, from startup to ideal operation, it needs to be kept at a variety of temperatures.

ISO VG classification

The viscosities of most hydraulic oils range from ISO VG 15 to ISO VG 68. The standard for viscosity at 40 degrees Celsius is ISO VG. In gearbox and hydraulic oils, this viscosity categorization is always used to show the oil's thickness. The viscosity of most gearbox oils ranges from ISO VG 150 to ISO VG 460. The actual oil thickness may differ from the ISO VG value by -10% to +10%. It is common for the machine's maintenance guide to provide the ISO VG value. The kind and brand of hydraulic pump is frequently the deciding element when selecting viscosity.

The hydraulic oil's quality is not immediately indicated by this ISO VG rating. Estimating this using a different ISO standard is simpler. The ISO 6743/4 standard is this. This standard helps to clarify the differences between various oils.

DIN and ISO hydraulic oil specifications

The ISO HM and ISO HV are the two most often used categories for hydraulic oil. "Mineral oil with corrosion inhibitor, antioxidant, and anti-wear" is how ISO describes the HM standard. "Mineral oil with corrosion inhibitor, antioxidant and anti-wear, increased VI" is how the ISO HV is defined. The higher Viscosity Index of the ISO HV oil distinguishes these two lubricants from one another.

DIN specifications

The German DIN standard is also in use throughout Europe. There are several parallels between the DIN standard and the ISO standard. At DIN, the ISO HM can be converted to DIN HLP. The ISO HV has been converted to the DIN HVLP at DIN.

The enhanced viscosity index (HM versus HV) is the difference.

Benefits of using enhanced VI oils (HV):

  1. Enhanced machinery effectiveness

  2. Lower temperatures demand less pump energy.

  3. Under high load, the machine remains in the ideal viscosity working range for longer.

  4. reduced use of gasoline

  5. Enhanced robustness

30 views0 comments
bottom of page