Seven principles that should be followed in bearing selection of lubricating grease.

The seven principles that should be followed in selecting lubricating grease for bearings are:

1. Environmental conditions: when the bearing works under the conditions of dampness, corrosive gas, low temperature, dust and strong radiation, the lubricating oil is easy to be contaminated and deteriorated, so the lubricating oil with strong resistance to water, wear, corrosion, cold and radiation should be selected. In serious places with running water splashing, emulsion spraying, moist air or dust dust, lubricating oil should not be selected, but grease should be chosen.

2. Bearing accuracy: when the friction surface of the bearing is rough, it is generally suitable for oil with high viscosity in order to withstand the local pressure caused by poor contact, while when the precision of the friction surface is high, the lubricating grease with low viscosity should be selected. to reduce unnecessary energy loss and temperature rise.

3. Working temperature: working temperature affects the viscosity change and lubrication effect of lubricating oil. Therefore, when the working temperature is low, the lubricating grease with low viscosity should be selected; when the working temperature is very high, the lubricating grease with high viscosity or appropriate additives should be selected. Above, you can generally consider the use of solid lubricant. When the ambient temperature is different, the viscosity of the selected lubricating grease should also change. For example, when lubricating the same bearing, in the north or winter of our country, the grease with lower viscosity should be chosen than that in the south or summer. When the working temperature often changes, the lubricating grease with excellent viscosity-temperature characteristics should also be selected, that is, the viscosity of the lubricating grease does not change much with the increase or decrease of the working temperature, so as to ensure that the thickness of the oil film is stable in a certain range.

4, movement speed: the higher the rotational speed, the more we should choose the lubricating grease with low viscosity, so as to avoid the increase of motion resistance and generate too much heat; on the contrary, in the case of low speed, the lubricating grease with higher viscosity should be used to improve the bearing capacity.

5. The nature of movement: there are shock, vibration, frequent load change, speed change and starting in the movement. Stopping, reversing frequently, and reciprocating or intermittent exercise are not conducive to the formation of oil film, so lubricating grease with higher viscosity should be selected. Sometimes grease or even solid lubricant is preferred to ensure reliable lubrication.

6. Working load: the greater the load on the rolling bearing, the higher the viscosity of the lubricating oil, and it should have better oiliness and extreme pressure, so as to prevent the lubricating oil from extruding from the friction pair or producing direct contact between metals. The smaller the radial clearance of the rolling bearing is, the higher the machining precision of the friction surface is and the lower the viscosity of the lubricating grease should be.

7, bearing hardness: when the friction surface hardness of the bearing motion is low, the lubricating grease with high viscosity should be selected, and the amount of oil should be sufficient; on the contrary, the viscosity of the lubricating grease can be reduced.