What are High-Speed Bearings？

1. What are High-Speed Bearings?

High-speed bearings are rolling bearings where the product of the pitch circle diameter （Dpw） and rotational speed ( n ) ( Dpw × n ) exceeds ( 1× 10⁶  mm·r/min ). In practical applications, their ( Dpw × n ) values can reach up to ( 3× 10⁶ mm·r/min ).

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2. Bearings Suitable for High-Speed Operation

The following bearing types and their ( Dpw × n ) values under different l

ubrication methods are recommended:

Bearing Type	Oil Jet Lubrication	Oil Mist Lubrication	Oil-Air Lubrication
Deep Groove Ball Bearing	1.5 × 10⁶	1.05 × 10⁶	1.56 × 10⁶
Angular Contact Ball Bearing (15°)	1.5 × 10⁶	1.1 × 10⁶	1.56 × 10⁶
Cylindrical Roller Bearing	1.3 × 10⁶	0.85 × 10⁶	1.17 × 10⁶
Flexible Roller Bearing	1.5 × 10⁶	—	—
Precision Ceramic Ball Bearing	2 × 10⁶	—	2 × 10⁶

 

Key Considerations for Using High-Speed Bearings：

 

1. Centrifugal Force of Rolling Elements (Steel Balls)At high speeds, the centrifugal force of the rolling elements in the bearing increases, which can affect the lubrication and friction performance of the bearing. Therefore, it is necessary to accurately calculate the centrifugal force of the steel ball.
   

D: Steel Ball Diameter (mm)

nm: Ball Speed or Cage Speed (r/min)

dm: Center Distance (Half of the Sum of the Bearing's Outer and Inner Diameters) (mm)

 

For high-speed angular contact ball bearings, due to the influence of the centrifugal force generated by the high-speed rotation of the rolling elements, the contact angle on the outer ring (ao) will decrease, while the contact angle on the inner ring (ai) will increase.

 

       2.Gyroscopic Torque

         For bearings with a contact angle greater than zero, when the rolling element rotates around two intersecting axes (the axis of revolution and the axis of spin), it is subjected to an inertial torque. This inertial torque is referred to as gyroscopic torque.

Under the influence of gyroscopic torque, the steel ball tends to experience rotational motion within the axial plane about its own axis. This rotational motion is known as gyroscopic spin or gyroscopic self-rotation.

Gyroscopic spin represents a sliding motion of the steel ball relative to the raceway, which increases friction and heat generation. Under normal operating conditions, gyroscopic spin of the steel balls is not allowed in bearings.

To prevent the occurrence of gyroscopic spin, the following measures can be taken:

1. Reduce the gyroscopic torque through bearing structure design.
2. Increase the contact load by applying axial preload.
3. Increase the coefficient of friction in the contact zone.

These methods help to eliminate gyroscopic spin and improve the performance and lifespan of the bearing.

Calculation of Gyroscopic Torque（ball bearings）