Bearing fits and tolerances with tolerance class

1 tolerance level of choice
      And bearing with the shaft or bearing bore tolerance level and precision of the bearing. And P0-level precision bearing with the shaft, the tolerance level is generally IT6, bearing hole is generally IT7. The rotating accuracy and smooth running applications with higher requirements (such as electric motors, etc.) should be selected axis IT5, bearing hole is IT6.

2 the tolerance zone selection
      Equivalent radial load P is divided into "light", "normal" and "heavy" load, such as several cases, with the bearing dynamic load rating C of the relationship:
Light load normal load P ≤ 0.06C 0.06C <P ≤ 0.12C heavy loads 0.12C <P
1) shaft tolerance
       Install radial bearings and angular contact bearings with reference to the corresponding shaft tolerance tolerance zone tables. For most applications, the shaft rotation and radial load direction unchanged, ie the bearing inner ring rotates relative to the loading direction of the occasion, the general should choose transition or interference fit. Stationary shaft and radial load direction unchanged, ie the bearing inner ring is stationary relative to the loading direction of the occasion, you can choose the transition or a small gap with (too much clearance is not allowed).

2) shell hole tolerance zone
      Install radial bearings and angular contact bearings with reference to the corresponding shell hole tolerance zone tolerance table. Select the attention to the load direction oscillating or rotating outer ring, you should avoid clearance fit. Equivalent radial load also affects the size of the outer ring with the selection.

3) the choice of bearing structure
      Roll bearings seat unless there are special needs, and more generally with the overall structure, split bearing only in the assembly have difficulty, or the advantages of easy assembly on a main consideration when used, but it can not be applied to a tight fit or a more precise fit, for example, than the K7 K7 and tighter fit, and if the tolerance class IT6 or more sophisticated bore are not using split bearing.