The outline for 2-pier alignment is really meant for new installations where the rollers are fitted with spherical roller bearings. Once a rotary dryer, cooler, granulator, let’s just call them units, is installed subsequent alignment is deceptively simple. In short the steps would be:
- Grind the rollers and tyres
- Set zero skew on all the rollers
- Shim for contact
- And if necessary float the unit
If the rollers were to be fitted with sleeve bearings, alignment would entail nothing more than floating the rollers, provided the bases were correctly sloped and no shimming is required. For spherical roller bearings monitoring the axial force on the roller rather than measuring its position solves the problem.
- Establish the center line
- Measure elevations
- Measure diameters
- Measure existing offsets
- Calculate the required offsets
- Reposition the rollers as necessary
- Re-align the pinion if necessary
The listed steps are the prime objectives in any "cold offset" traditional alignment for a new installation. For an existing installation the initial consideration is to correctly position the shell in the seals at both the discharge and feed ends. This involves relatively coarse roller adjustments that can be made without precise measurement.
Consideration should be given the gear to pinion mesh at the same time in effort to optimize it.
