Mounting dimensions mean the necessary dimensions to mount bearings on shafts or housings, which include the fillet radius or shoulder diameters.
Standard values are shown in "Table 14-2 Shaft/housing fillet radius and shoulder height of radial bearings". (The mounting related dimensions of each bearing are given in the bearing specification table.) The grinding undercut dimensions for ground shafts are given in "Table 14-3 Grinding undercut dimensions for ground shafts".
For thrust bearings, the mounting dimensions should be carefully determined such that bearing race will be perpendicular to the support and the supporting area will be wide enough. For thrust ball bearings, the shaft shoulder diameter da should be larger than pitch diameter of ball set, while the shoulder diameter of housing Da should be smaller than the pitch diameter of ball set. (Fig. 14-6 Thrust ball bearings)
For thrust roller bearings, the housing/shaft diameter Da/da should cover the lengths of both rollers. (Fig. 14-7 Spherical thrust roller bearings)
Table 14-2 Shaft/housing fillet radius and shoulder height of radial bearings
| Chamfer dimension of inner ring or outer ringr(min) | Shaft and housing | ||
|---|---|---|---|
| Fillet radius ra(max) | Shoulder heighth(min) | ||
| General1) cases | Special2) cases | ||
| 0.05 | 0.05 | 0.3 | 0.3 |
| 0.08 | 0.08 | 0.3 | 0.3 |
| 0.1 | 0.1 | 0.4 | 0.4 |
| 0.15 | 0.15 | 0.6 | 0.6 |
| 0.2 | 0.2 | 0.8 | 0.8 |
| 0.3 | 0.3 | 1.25 | 1 |
| 0.5 | 0.5 | 1.75 | 1.5 |
| 0.6 | 0.6 | 2.25 | 2 |
| 0.8 | 0.8 | 2.75 | 2.5 |
| 1 | 1 | 2.75 | 2.5 |
| 1.1 | 1 | 3.5 | 3.25 |
| 1.5 | 1.5 | 4.25 | 4 |
| 2 | 2 | 5 | 4.5 |
| 2.1 | 2 | 6 | 5.5 |
| 2.5 | 2 | 6 | 5.5 |
| 3 | 2.5 | 7 | 6.5 |
| 4 | 3 | 9 | 8 |
| 5 | 4 | 11 | 10 |
| 6 | 5 | 14 | 12 |
| 7.5 | 6 | 18 | 16 |
| 9.5 | 8 | 22 | 20 |
| 12 | 10 | 27 | 24 |
| 15 | 12 | 32 | 29 |
| 19 | 15 | 42 | 38 |
[Notes]
- Shoulder heights greater than those specified in the Table are required to accommodate heavy axial loads.
- Used when an axial load is small.
These values are not recommended for tapered roller bearings, angular contact ball bearings, or spherical roller bearings.
[Remark]
Fillet radius can be applied to thrust bearings.
Table 14-3 Grinding undercut dimensions for ground shafts
| Chamfer dimension of inner ring r(min) | Grinding undercut dimensions | ||
|---|---|---|---|
| t | rg | b | |
| 1 | 0.2 | 1.3 | 2 |
| 1.1 | 0.3 | 1.5 | 2.4 |
| 1.5 | 0.4 | 2 | 3.2 |
| 2 | 0.5 | 2.5 | 4 |
| 2.1 | 0.5 | 2.5 | 4 |
| 3 | 0.5 | 3 | 4.7 |
| 4 | 0.5 | 4 | 5.9 |
| 5 | 0.6 | 5 | 7.4 |
| 6 | 0.6 | 6 | 8.6 |
| 7.5 | 0.6 | 7 | 10 |
Fig. 14-6 Thrust ball bearings
Fig. 14-7 Spherical thrust roller bearings
