Thermal Expansion of the Shaft - Axial Displacement
Extreme Bearings are supplied with spacer rings in order to provide axial location. These can be omitted for a "free end" axial front.
Extreme Bearing is Made to Adapt Thermal Expansion of the Shaft
The seats of an Extreme Bearing are machined to a tolerance in order to provide a loose fit. The bearing seats in the housings are sufficiently wide to allow the bearing axial displacement and likewise to accommodate for thermal expansion of the shaft due to high temperatures.
Room for Axial Displacement
Suitable for expansion and contraction of the shaft. The Extreme Bearing blocks can absorb expansion of the shaft because there is an adjustment or locating ring in the bearing housing.
Fixed and Floating Bearing Location
Extreme Bearing units are suitable for fixed and floating bearing location. The locating ring can be removed from a bearing block of a pair placed opposite each other so that bearing axial displacement is possible.
Allow for Thermal Expansion and Contraction
There is a total clearance available for thermal expansion that is equal to the thickness of the location ring. The expansion and contraction of material must be considered in order to maintain the clearance that is required to operate the bearing well. In the diagram, the clearance for contraction by cooling is indicated by C and the clearance for expansion by heating is indicated by B.
Clearance Values
| Shaft Ø (mm) | C - Max. Cooling Shrinkage (mm) | B - Max. Heating Expansion (mm) |
|---|---|---|
| 20 | 3.5 | 3.5 |
| 25 | 3.5 | 3.5 |
| 30 | 3.5 | 3.5 |
| 35 | 3.5 | 3.5 |
| 40-100 | 3.5-5.0 | 3.5-5.0 |
Design Benefits
- Prevents Binding - Allows shaft to expand/contract freely
- Accommodates Temperature Changes - From -25°C to 95°C+
- Fixed + Floating Configurations - One fixed, one floating bearing recommended
- Adjustable Location - Spacer rings provide precise positioning
Proper consideration of thermal expansion is critical for long bearing life and reliable operation.