loading

Best Wholesale Bearing Suppliers With Custom Service, JNSN Bearing Supplier Yours Ideal Partner

Eight selection principles for special lubricating oil for motor bearings

by:JNSN     2022-03-13
From the failure examples of oil-lubricated motor rolling bearings, it can be seen that most of the failures are caused by insufficient viscosity of the lubricating oil. The lower the viscosity of the lubricating oil, the worse the bearing capacity of the oil film, the easy to rupture the oil film, and the direct contact between the metal materials on the relative moving surfaces inside the rolling bearing, resulting in increased friction, increased wear, significantly shortened service life of the rolling bearing, or bearing failure. Burn, breakage accident. However, if the viscosity of the lubricating oil is too high, the frictional resistance will increase, the heat generated by stirring the lubricant will increase, and the energy consumption of the system will increase. On the other hand, for rolling bearings operating under special conditions such as high speed, high load and high temperature, there may be special requirements for anti-rust, anti-oxidation, anti-wear and improving the adsorption capacity of lubricating oil. Therefore, the selection of lubricating oil is mainly the determination of the viscosity grade of the lubricating oil and the determination of the type of additives used or the selection of different lubricating oil products with certain additives. The general selection principle of lubricating oil is as follows. One: Working temperature Working temperature affects the viscosity change and lubricating effect of lubricating oil. Therefore, when the working temperature is low, lubricating oil with lower viscosity should be used; when the working temperature is high, lubricating oil with high viscosity or appropriate additives should be selected. Depending on the ambient temperature, the viscosity of the selected lubricating oil should also change. For example, when lubricating the same bearing in winter, the lubricating oil with lower viscosity should be selected than in the south or in summer. When the working temperature changes frequently, lubricating oil with excellent viscosity-temperature characteristics should also be selected, that is, the viscosity of the lubricating oil used 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 within a certain range. Two: The higher the speed of motion, the more lubricating oil with lower viscosity should be used to avoid the increase of motion resistance and excessive heat generation; on the contrary, in the case of low speed, the lubricating oil with higher viscosity should be used to improve the bearing capacity. ability. Three: Motion nature There are shocks, vibrations, frequent load changes, speed changes, and starting in motion. Parking, frequent reversal, and reciprocating or intermittent motion are not conducive to the formation of oil film, so lubricating oil with higher viscosity should be used. Greases, or even solid lubricants, are sometimes preferred to ensure reliable lubrication. Four: The larger the load that the rolling bearing bears, the higher the viscosity of the lubricating oil should be selected, and it should have good oiliness and extreme pressure, so as to prevent the lubricating oil from being squeezed out of the friction pair, or causing direct metal-to-metal contact . Five: Structural features The smaller the radial clearance of the rolling bearing, the higher the machining accuracy of the friction surface, and the lower the viscosity of the lubricating oil. Six: Environmental conditions When the bearing works under the conditions of humidity, corrosive gas, low temperature, dust and strong radiation, the lubricating oil is easily polluted and deteriorated. At this time, water resistance, wear resistance, corrosion resistance, cold resistance and radiation resistance should be selected. Strong lubricant. In places with serious water splashes, emulsion sprays, humid air or dust and debris, it is generally not appropriate to use lubricating oil, but lubricating grease. Seven: Bearing accuracy When the bearing motion friction surface is rough, the oil with high viscosity is generally used to withstand the local large pressure due to poor contact. When the motion friction surface accuracy is high, low viscosity lubricating oil should be used to reduce the pressure. Small unnecessary energy loss and temperature rise. Eight: Bearing hardness When the bearing motion friction surface hardness is low, lubricating oil with high viscosity should be selected, and the amount of oil should be sufficient; otherwise, the viscosity of the lubricating oil can be reduced. In order to give full play to the effect of the lubricant, be sure to select a lubrication method and a high-quality lubricant suitable for the conditions of use. When the motor is assembled, the grease injected into the bearing housing must be clean. The grease is not clean and is mixed with impurities, especially hard impurities, which can easily cause abnormal wear of the bearing and cause bearing failure. The filling amount of lubricating grease should be appropriate. If the amount added is too small, the bearing will be heated due to intermittent lack of oil and dry grinding, which will cause bearing failure; . The filling of motor grease should be injected according to the design amount, and it should be distributed reasonably in the bearing chamber space. The bearing chamber space is composed of the bearing chamber and the inner and outer bearing caps. The grease should be distributed as far as possible in the bearing chamber and on the surface that can be enveloped by the bearing, and the space to be filled is determined according to the rotational speed. During the operation of the motor, it is necessary to prevent the grease from deteriorating and losing, causing bearing failure, and should regularly and quantitatively replenish the special grease for the bearing, and the oil return pan should be designed. It is strictly forbidden to mix different grades of grease to prevent the grease from deteriorating, losing its lubricating performance and causing bearing failure.
Custom message
Chat Online
Chat Online
Leave Your Message inputting...
Sign in with: