Shafts and hubs
Roundness
The roundness of the shaft should be within tolerance IT7-IT8. For example, the portion of shaft supporting the SH-bushing should be round and straight within this specified tolerances. The same tolerances are also valid for the hub.
Surface roughness
The surface roughness of the shaft should be max 3,2 Ra.
Hollow shafts
The maximum allowable inside diameter for a hollow shaft (fig 1) application can be obtained as follows:
dhmax = d v((Rp0,2 – 2(Py D)/d)/(Rp0,2))
where
| dhmax | = | maximum allowable inside diameter for the shaft [mm] |
| d | = | bore diameter of the inner sleeve [mm] |
| Rp0,2 | = | yield limit of the shaft material [N/mm2] |
| Py | = | surface pressure against hub [N/mm2] |
| D | = | diameter of the outer sleeve [mm] |
fig 1
Details of tolerances for shafts and hubs are given in the table.