preload springs for ball bearings

Preloading of bearings is a process of applying an axial load to either the inner or outer ring of the bearing so that radial play is taken up and running components are in contact. This is seen as good practice as it reduces noise, vibration and ultimately extends bearing life.

There are essentially two methods to preload a bearing. Firstly, a solid preload such as a threaded plug 
or circlip, or secondly by a spring, i.e. a disc spring. The disadvantage of a solid preload is that it cannot compensate for tolerance build up or thermal movement of the surrounding components and so running torque may be affected.

The disc spring, as well as applying a constant load around the bearing ring, overcomes the disadvantages of using a solid preload. Where a very light preload is required the disc spring has radial slots to reduce the axial force applied.

See links below for size details

• Standard disc springs Diameter 9.8 to 358mm
• Slotted disc springs Diameter 9.8 to 94.5mm