English
Le français
Türkçe
When the foot height changes, what really changes is the centre height of the motor shaft (dimension H). With a coupling drive, the two shafts must be brought onto the same axis again; with a belt drive, the pulleys must stay in the same plane and the distance between them must be rechecked. In addition, the base, the fixing bolts and the protective guards are reviewed.
How big can the difference be?
On IEC frames, the shaft height equals the frame number. When the same power falls into a different frame, the difference becomes significant:
| Existing frame | New frame | Change in shaft centre |
|---|---|---|
| 112M (H 112 mm) | 132S (H 132 mm) | Rises by 20 mm |
| 132M (H 132 mm) | 160M (H 160 mm) | Rises by 28 mm |
| 100L (H 100 mm) | 90L (H 90 mm) | Drops by 10 mm |
With a coupling drive
If the motor shaft sits higher than the machine shaft, the coupling runs at an angle, and vibration and bearing load increase. If the motor has dropped, full-surface calibrated shims matching the foot size can be placed underneath; if it has risen, the motor base must be machined or the machine side raised on a sub-base. The final adjustment should be verified with an alignment measurement.
With a belt drive
- Are the pulleys in the same plane? The axial position of the shaft end may also change on the new frame; if the pulleys are offset, the belt runs crooked.
- Has the centre distance changed? Belt length or tensioning travel may not be enough.
- On a slide-rail base, is the motor still within the adjustment range in its new position?
Small items that get overlooked
When moving to a taller frame, foot thickness and hole diameter may also change; the existing bolts may turn out too short or too thin. Belt and coupling guards may no longer cover the new shaft height; a guard must never be left open. As the terminal box also rises, the cable length should be checked.
You can compare the H and foot dimensions of each frame on the technical drawings page, review the values of, for example, the 5.5 kW 1500 rpm 132S aluminium model, and find other models in the right frame in the shop.