Talking about Some Factors Affecting the Limit Speed of Rolling Bearings
Many people still know about the bearing speed. The so-called TIMKEN bearing limit speed refers to the bearing speed, which decreases as the bearing diameter series and width series increase. The speed of each rolling bearing has a certain limit. When the bearing rotates, as the speed increases, the temperature rise generated by the frictional heat inside the bearing also increases. The speed limit is an empirical allowable value for continuous operation without seizing or overheating. Therefore, the limiting speed (rpm) of various bearings varies with bearing structure, size, cage structure, material, bearing load, lubrication method, and cooling conditions including the periphery of the bearing.
Here are some factors related to the limit speed of rolling bearings:
1. Lubrication method: Bearings lubricated by oil and gas or oil mist can continuously supply a small amount of new lubricating oil to the bearing, effectively ensuring the thickness of the bearing lubricating oil film. Moreover, the jet lubrication method can quickly take away the heat generated by the bearing operation due to the large amount of oil supply, and increase the limit speed of the bearing.
2. Bearing load: The limit speed of the rolling bearing can reach a higher speed under certain load and lubrication conditions, depending on the bearing type, size, direction, lubrication method, clearance, cage structure, cooling conditions, load (size, type , Direction) and so on. Improving bearing accuracy and proper adjustment of bearing clearance can increase the limiting speed of deep groove ball bearings.
3. Pre-tightening force: If the pre-tightening force of the bearing is too large when the bearing is installed, the contact stress between the rolling elements and the raceway surface will increase when the bearing is running, and the heat generation will also increase, which will further increase the internal pre-tightening force of the bearing. Large, make the bearing more prone to wear and reduce the limit speed.
4. Drive mode: The limit speed of the bearing will vary with the drive mode of the spindle. For example, when the electric spindle is driven, the internal heat generation of the spindle is large. If the outer cylinder is used for cooling at the same time, the temperature difference between the inner and outer rings of the bearing will change. Large, increase the internal load of the bearing and reduce the speed; when the outer cylinder is used for cooling, due to the different tolerances of the bearing seat, the thermal expansion of the bearing and the bearing seat is different, the outer ring fit is changed from a clearance fit to an interference fit, and the internal pre-tightening force Increasing will cause the rotation speed to change.
5. The size of the bearing clearance: when the clearance after the bearing is installed is a small negative value, the rated life is relatively long, and the carrying capacity and limit speed are also very high at this time, but because the actual clearance has to be subtracted The small negative clearance is difficult to control due to the deformation caused by the interference and the temperature difference, and once the clearance is too negative, the rated life will be significantly reduced. Therefore, at present, the positive clearance close to 0 is generally selected.
6. Bearing combination: When the bearing is combined, due to the large amount of oil supply, the heat generated by the bearing can be quickly taken away, and the limit speed can be further improved.
Many people still know about the bearing speed. The so-called bearing limit speed refers to the bearing speed, which decreases as the bearing diameter series and width series increase. The speed of each rolling bearing has a certain limit. When the bearing rotates, as the speed increases, the temperature rise generated by the frictional heat inside the bearing also increases. The speed limit is an empirical allowable value for continuous operation without seizing or overheating. Therefore, the limiting speed (rpm) of various bearings varies with bearing structure, size, cage structure, material, bearing load, lubrication method, and cooling conditions including the periphery of the bearing.