INA aligning needle roller bearings compensation of misalignment
Due to the spherical outer ring and the concave support ring, aligning needle roller bearings can compensate static shaft misalignments of up to 3°.
The INA aligning needle roller bearings must not be used to support swivel or wobble type motion. During adjustment motion between the outer cup and the ring, a breakaway torque occurs.
In order that adjustment motion can take place, the tolerances for the housing bore according to the table must be observed.
Raceways for INA bearings without inner ring
In the case of bearings without an inner ring, the rolling element raceway on the shaft must be hardened and ground.
The surface hardness of the raceway must be 670 HV + 170 HV and the hardness depth Eht or Rht must be sufficiently large.
Tolerances for the shaft raceway/housing bore
| Housing material | Shaft tolerance for bearings without inner ring | Bore tolerance |
|---|---|---|
| Steel or cast iron | h6 | N6 |
| Light metal | R6 |
Tolerances for the shaft raceway/housing bore
| Surface quality | Raceway for bearings without inner ring | Housing bore |
|---|---|---|
| Roughness max. | Ra0,1 (Rz0,4) | Ra0,8(Rz4) |
| Roughness max. | 25% of h6 | IT 5/2 |
| Parallelism max. | 50% of h6 | IT 5/2 |
Minimum radial load
In order to ensure operation without slippage, the INA bearings must be subjected to a minimum radial load Fr min. This applies in particular to high speed bearings since, if the radial load is insufficient or not present, damaging sliding motion may occur between the rolling elements and raceways.
In continuous operation, therefore, a minimum radial load of magnitude Cr/P < 50 is necessary.