COUPLING & ALIGNMENT
Zero-Stress Coupling Logic & Foundation Settlement
FOUNDATION SETTLEMENT RISK
Since 2014, the powerhouse foundation has likely shifted. For a 1.3 MW unit spinning at 750/1000 RPM, the margin for error is microscopic.
A vertical shift of only 0.10mm creates a permanent bending force (Cyclic Loading) that will eventually shear the shaft or melt a bearing.
TYPE A: OFFSET
Parallel mismatch: Generator centerline is higher/lower than turbine centerline.
TYPE B: ANGULAR
Gap/Zazor mismatch: Coupling faces are not parallel (open at top or side).
RIM & FACE PROCEDURE
- Mount dial indicators to read Rim (Radial) and Face (Axial).
- Rotate both shafts together in 90° increments (12:00, 3:00, 6:00, 9:00).
- Record Total Indicator Reading (TIR). Pass threshold: ≤ 0.05 mm.
COUPLING BOLT INTEGRITY
Vibration is constant. Mechanical washers are insufficient. Apply Loctite 243 (Blue) to threads during final torquing.
A low-frequency "Growl" or "Hum" coming from the coupling guard indicates misalignment.