Factors Affecting the Maximum Speed of Rolling Bearings:
Lubrication Method
Bearings lubricated with oil-air or oil-mist lubrication can continuously supply a small amount of fresh lubricant to the bearing, effectively maintaining a thick lubricant film. Furthermore, jet lubrication, due to its large oil supply, can quickly dissipate heat generated by the bearing during operation, thereby increasing the maximum speed of the bearing.
Bearing Load
The maximum speed of a rolling bearing is the maximum speed achieved under certain load and lubrication conditions. It is closely related to the bearing type, size, orientation, lubrication method, clearance, cage structure, cooling conditions, and load (size, type, and direction). Improving bearing accuracy and appropriately adjusting bearing clearance can increase the maximum speed of deep groove ball bearings.
Preload
Excessive preload during bearing installation will increase the contact stress between the rolling elements and raceway surfaces during operation, resulting in increased heat generation. This in turn further increases the internal preload of the bearing, making the bearing more susceptible to wear and reducing the maximum speed. Drive Type
The bearing's limiting speed varies depending on the spindle drive method. For example, when using an electric spindle, the spindle generates significant internal heat. If external cooling is also used, the temperature difference between the inner and outer rings of the bearing increases, increasing the internal load on the bearing and reducing the limiting speed. When using external cooling, due to different tolerances of the bearing seat and the different thermal expansion rates of the bearing and seat, the outer ring fit changes from a clearance fit to an interference fit, increasing the internal preload and causing a change in the limiting speed.
Bearing Load
When the bearing's clearance after installation is slightly negative, the rated life is longest, and the load capacity and limiting speed are also the highest. However, because the actual clearance must subtract the interference fit and deformation caused by temperature differences, this slight negative clearance is difficult to control. If the clearance becomes too negative, the rated life will be significantly reduced. Therefore, a positive clearance close to zero is generally selected.
Bearing Combination
When bearings are combined, the large amount of oil supplied can quickly dissipate the heat generated by the bearings, further increasing the limiting speed.