A number of factors affect ball bearing speed limitation such as temperature, load, vibration, radial play, retainer, lubricant, ball material and closures. The speeds quoted in our technical drawings are only approximate and valid for bearings used on a horizontal shaft with a metal cage, standard tolerance grade and radial play, medium loading, rotating inner ring and suitable lubricant (see below). Vertical shaft applications will require a maximum speed reduction of approximately 20 percent due to reduced cage guidance and less effective lubricant retention.

Temperature excesses and higher loads will also require slower speeds. Bearings fitted with contact seals cannot achieve the same speeds due to increased friction between seal lip and bearing inner ring. The choice of lubricant may also have a significant effect on the speed rating. The maximum rpm at which a lubricant can effectively operate varies from type to type.

The following adjustment factors are approximate and are based on bearings with a metal crown or ribbon cage. The maximum speed of a bearing can be increased by the use of a nylon or phenolic cage provided a suitable lubricant is used. The use of ceramic balls will increase bearing speed by up to 40 percent but ceramic balls also reduce the load capacity of a bearing as the harder ceramic balls cause an increase in stress on the bearing rings.

Speed Reduction Table:

 

Rotating Inner Ring

Rotating Outer Ring

Open/ZZ

2RS

Open/ZZ

2RS

Petroleum Oil

Nil Reduction

40% Reduction

20% Reduction

40% Reduction

Synthetic Oil

Nil Reduction

40% Reduction

20% Reduction

40% Reduction

Silicon Oil

30% Reduction

40% Reduction

50% Reduction

50% Reduction

Standard Grease

30% Reduction

40% Reduction

50% Reduction

50% Reduction

High Speed Grease

Nil Reduction

40% Reduction

20% Reduction

40% Reduction

Silicon Grease

30% Reduction

40% Reduction

50% Reduction

50% Reduction

Our determination to remain specialised gives us a high level of product knowledge, providing bearing and lubrication solutions to existing or potential customers, whether individuals or large corporations. We don’t just sell bearings, we help to solve your problems. - Chris Johnson, managing director of SMB Bearings.