Ifhydraulic cylinderIf the hydraulic system is likened to the human torso, then hydraulic oil is equivalent to human blood. In a hydraulic system, hydraulic oil plays a role in energy transmission, system lubrication, corrosion prevention, rust prevention, and cooling. The effective operation of a hydraulic system is closely related to the type and viscosity of the hydraulic oil used.hydraulic cylinderWhat type of hydraulic oil is most suitable for the system? Understanding hydraulic oil performance and making the correct selection is essential.

1. Hydraulic oil designation, composition and properties:

HL General-purpose machine tool oil, a refined mineral lubricating oil with rust prevention and antioxidant properties.

HM Anti-wear hydraulic oil, a refined mineral lubricating oil with rust prevention, antioxidant, and anti-wear properties.

HV Low-temperature hydraulic oil, a refined mineral lubricating oil with rust prevention, antioxidant, and anti-wear properties, with added viscosity improvers.

HG Hydraulic guide rail oil, a refined mineral lubricating oil with rust prevention, antioxidant, anti-wear, and anti-stick-slip properties.

HS Synthetic hydrocarbon low-temperature hydraulic oil, a synthetic hydrocarbon oil with rust prevention, antioxidant, and anti-wear properties.

3. Selection of hydraulic oil viscosity

A goodhydraulic cylinderalso requires the selection of hydraulic oil with appropriate viscosity. High-temperature and high-pressure systems should use hydraulic oil with higher viscosity to obtain better lubricity. Conversely, low-temperature and low-pressure systems should use hydraulic oil with lower viscosity to reduce energy consumption. Generally speaking, using excessively high viscosity is beneficial for lubricity, but it increases system resistance and pressure loss, resulting in increased power loss, increased oil temperature, unstable hydraulic action, noise, etc.; excessively high viscosity can also make it difficult for the pump to absorb oil during low-temperature startup, or even cause interruption of oil supply during low-temperature startup, resulting in equipment failure. Conversely,hydraulic cylinder manufacturerdesign. When the viscosity of the hydraulic system is too low, it will increase the internal and external leakage of the hydraulic equipment, and the hydraulic system working pressure will be unstable or decrease. In severe cases, it will lead to abnormal wear of the pump.

2. Selection of hydraulic oil type

1. Select according to the operating ambient temperature. For machinery operating at high ambient temperatures or near heat sources, oils with high viscosity-temperature characteristics (i.e., the change in oil viscosity with temperature) or fire-resistant oils should be prioritized. In harsh operating conditions, to ensure system safety and reliability, oils with good viscosity-temperature characteristics, thermal stability, lubricity, and corrosion resistance should be selected.

2. According tohydraulic cylindersystem operating pressure selection. Different operating pressures have different requirements for hydraulic oil quality. As the system operating pressure increases, the anti-wear, antioxidant, anti-foaming, anti-emulsification, and hydrolysis stability of the hydraulic oil should also be improved. At the same time, in order to prevent leakage caused by increased pressure, the viscosity of the hydraulic oil should also be increased accordingly; conversely, low-viscosity hydraulic oil should be selected.

3. According to the choice of sealing material.hydraulic cylinderThe sealing material of the device is compatible with the oil used in the system; otherwise, the seals may experience expansion, contraction, corrosion, or dissolution, resulting in reduced system performance. For example, HM anti-wear hydraulic oil has poor compatibility with natural rubber, butyl rubber, ethylene rubber, and silicone rubber, which should be taken seriously in actual use.