Principle of selecting lubricating oil according to mechanical working conditions

load

When the load is high, lubricating oil with high viscosity, oiliness, and good extreme pressure should be selected. On the contrary, for low loads, lubricating oil with low viscosity should be selected. Intermittent or high impact mechanical motion can easily damage the oil film. Therefore, lubricating oil with high viscosity or good extreme pressure should be selected, or lubricating grease with low cone penetration (harder) made from this type of lubricating oil.

speed

High speed requires the use of lubricating oil with lower viscosity or lubricating grease made from lubricating oil with lower viscosity; On the contrary, use lubricating oil with higher viscosity or lubricating grease made from lubricating oil with higher viscosity. For the selection of grease for high-speed rolling bearings, in order to supplement the mechanical stability and channeling of all grease, as well as overcome the effect of centrifugal force, it is best to choose lubricating grease with a higher viscosity, such as No. 3 grease; For bearings with generally low rotational speeds, in order to reduce the torque of the bearing, especially the starting torque, low viscosity lubricating grease should be selected as much as possible.

temperature

Under high temperature conditions, lubricating oils with high viscosity, high flash point, good oiliness, and good oxidation stability should be selected, or lubricating greases with high drop points made from base oils and thickeners with good thermal stability (such as lithium soap, loaded calcium soap, loaded aluminum soap, etc.) should be used. Under low temperature conditions, lubricating oil with low viscosity and low pour point or lubricating grease with good low-temperature performance made from this oil should be selected. For friction parts with large temperature changes, lubricating oil with good viscosity and temperature performance or lubricating grease with a wide temperature range (such as universal lithium grease) should be selected.

damp

In humid working environments or working conditions with frequent contact with water, lubricating oil and grease with strong anti emulsification ability and good rust resistance should be selected, and sodium based grease should not be used.

Friction surface accuracy

Surface roughness requires the use of lubricating oil or grease with high viscosity or low cone penetration. On the contrary, lubricating oil or grease with lower viscosity or higher cone penetration should be selected.

Friction surface position

Lubricating oil is prone to loss on vertical guide rails and lead screws, and lubricating oil with high viscosity should be selected. Vertical bearings should use lubricating grease to reduce loss and maintain lubrication.

Lubrication method

In the circulating lubrication system, it is required that the oil change period is long and the heat dissipation is fast. The lubricating oil with low viscosity, good foam resistance and oxidation stability should be selected. In splash and oil mist lubrication systems, to reduce the oxidation effect of lubricating oil, lubricating oil with anti-oxidation and anti foaming additives should be selected. In centralized lubrication systems, for ease of transportation, low viscosity No.1 or No.1 lubricating grease should be selected.