SKF Needle roller bearing components

Inner rings

Inner rings are available in two series:

• IR series
  • With or without a lubrication hole
  • With or without a machining allowance
• LR series

IR series inner rings

• Are the standard SKF inner rings for needle roller bearings
• Are hardened and ground
• Have a precision ground raceway surface with a lead-in chamfer on both sides
  The chamfers facilitate assembly and protect the seal lips from damage during the mounting process.
• Are available in some sizes with a lubrication hole (designation suffix IS1)
  Inner rings with additional lubrication holes are available on request.
• Are available on request with a pre-ground raceway and a machining allowance (designation suffix VGS)
  They can be finish ground after mounting on a shaft in applications where extremely tight geometrical tolerances are required.

LR series inner rings

• Are hardened, and the bore and raceway diameter are ground
• Side faces are turned and the edges are smoothed
• Can be used to provide a cost-effective bearing arrangement for applications where the larger run-out and width tolerances are less important

Both inner ring series

• Are also available in different widths
• Permit greater axial displacement of the shaft, relative to the housing, when they are wider than standard
  • Provide an excellent counterface for the lips of contact seals
• Should be located on both sides to prevent axial movement (regardless of whether the ring has an interference or loose fit)
  • One side can be located against a shoulder
  • The other side can be located by either a snap ring, a distance ring or a nut

Needle rollers

• Are made of carbon chromium steel
• Have a hardness of 58 to 65 HRC
• Have a precision ground surface

For assistance in designing full complement bearing arrangements or to calculate performance data for these bearing arrangements, contact the SKF application engineering service.