Bearing Mounting
Metric Series Radial Ball and Roller Bearing Standards
- For metric series radial ball and roller bearings, the American Bearing Manufacturers Association (ABMA) and American National Standards (ANSI) provided guidance on bearing shaft and housing fits.
- ANSI/ABMA Standard 7 establishes the general selection of shaft and housing fits for metric radial ball and roller bearings.
- These recommendations will serve well for the majority of applications, but some applications may require further review by the bearing manufacturer to evaluate requirements and provide system integration recommendations.
- Application requirements that might necessitate deviation from ABMA Standard 7 recommendations:
- Thermal variation
- Positioning accuracy
- Torque sensitive
- Stiffness sensitive
- Housing and shaft materials and design
- Heavy application loads
Applicable Definitions:
When discussing Bearing Mounting, the following definitions apply:
Interference: The intentional interference fit between the bearing and the components it is mounted on, such as the shaft or the housing. In an interference fit, the bearing’s inner and outer races are slightly larger than the shaft or housing diameters, respectively. This ensures a tight and secure fit without any looseness or movement of the bearing during operation. The interference fit helps transmit forces effectively between the bearing and the components it supports.
Clearance: Bearing mounting clearance refers to the gap or space between the inner race (the part of the bearing that attaches to the shaft) and the outer race (the part that attaches to the housing or structure) when the bearing is installed. This clearance allows for thermal expansion and contraction of the bearing components due to temperature changes during operation. Proper clearance helps prevent excessive heat buildup and potential binding of the bearing, ensuring smooth rotation and reduced wear.
Tolerance References for Clearance and Interference
