The difference between high-speed rolling bearings and ordinary rolling bearings

For each bearing, it has its own limit speed, which is mainly limited by the temperature rise caused by friction heating inside the bearing. When the speed exceeds a certain limit, the bearing will be burned and unable to continue rotating, or even get stuck. Therefore, we are rotating the appropriate bearing type based on the speed of the bearing, so we need to select the requirements for the bearing. In some applications, other factors are more important than the limit speed. For example, low-speed, reciprocating oscillation, etc.

The limit speed of a bearing refers to the boundary value of frictional heating and continuous rotation that does not cause burns. Therefore, the maximum speed of a bearing depends on factors such as the type, size and accuracy of the bearing, lubrication method, quality and quantity of lubricant, material and type of retainer, load conditions, etc.

Select bearing category based on rotational speed

1. The maximum speed and rotational accuracy of ball bearings are higher than those of roller bearings, so high speed should be given priority consideration for ball bearings.

2. When the inner diameter is the same, the smaller the outer diameter, the smaller the rolling element, and the smaller the centrifugal inertia force exerted by the rolling element on the foreign raceway, making it suitable for high-speed work. Therefore, on highways, bearings with the same diameter series and smaller outer diameters should be selected. If a bearing with a smaller outer diameter cannot meet the load capacity requirements, the same bearing can be installed or wide series bearings can be considered.

3. The material and structure of the cage have a significant impact on the bearing speed.

Factors affecting bearing speed

The factors that affect the ultimate speed of bearings include the magnitude of the applied load, stress direction, type and quantity of lubricant, manufacturing accuracy of bearings, bearing tolerance level, and bearing clearance.

A typical high-speed bearing refers to a bearing that reaches a speed of 60 meters per second. The high, medium, and low speeds of bearings are not determined by rotational speed, but by linear speed. A small bearing that can rotate for tens of thousands of revolutions is not considered a high-speed bearing, while a large bearing that can rotate for hundreds of revolutions is considered a high-speed bearing. In sliding bearings, liquid static pressure bearings, liquid dynamic pressure bearings, gas static pressure bearings, and gas dynamic pressure bearings are all suitable for high-speed rotation.