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The rotating speed of a bearing is normally affected by friction heat generated in the bearing. If the heat exceeds a certain amount, seizure or other failures may occur in a bearing, thus causing rotation to be discontinued.
Limiting speed of bearing refers to the rotating speed at which the bearing can be rotated continuously without excessive increase in temperature. And in case of a sealed bearing with contact type seal, the rotating speed is limited by two more factors; those are running speed of seal contact surface and heat-resistance characteristics of packed grease.
Limiting speed of bearing varies depending on the bearing type, dimensions, accuracy, lubrication method, the properties and amount of lubricant, the type and material of cage, and load conditions.
The lubrication based limiting speed for each bearing is listed in the bearing specification tables (grease or oil bath). When bearing rotating speed is close to or higher than the limiting speed specified in this catalogue, consult ZXB.
The limiting speed specified in the bearing specification tables is applied when bearings of standard design are rotated under normal load conditions (C/P¡Ý13, Fa/Fr¡Ü approx. 0.25).