Dial indicator shaft alignment procedure

Dial Indicator Shaft Alignment Procedure:

Shaft alignment using a dial indicator is a precise method for ensuring that two connected shafts are properly aligned to avoid excessive wear, vibration, and energy loss. Here’s a step-by-step procedure for shaft alignment using a dial indicator.

Training manual of shaft alignment

1. Preparation:

- Safety First: Ensure the machinery is de-energized and locked out to prevent accidental startup.

- Clean the Shaft: Clean both the shaft surfaces to remove dirt, debris, or oil that may affect accuracy.

- Check for Obvious Defects: Inspect the shafts, couplings, and other machine parts for any visible damage or wear that could affect alignment.

2. Set Up the Dial Indicator:

- Mount the Indicator: Secure the dial indicator on the stationary shaft (usually the motor or driven machine) using a magnetic base or clamp.

- Position the Indicator: Place the dial indicator plunger against the rotating shaft (usually the pump or driver) at a point near the coupling, ensuring good contact between the plunger and shaft surface.

Shaft alignment pdf document

- Zero the Dial: Set the dial indicator to zero at the starting point, typically the 12 o’clock position.

3. Measure Misalignment:

- Rotate the Shafts: Slowly rotate both shafts together in the same direction (clockwise or counterclockwise) by 90-degree increments (12, 3, 6, and 9 o’clock positions). Take readings at each position.

- Radial Misalignment: Measure at the top, bottom, and sides of the shafts to determine if the centerlines of the shafts are offset.

- Angular Misalignment: Measure the difference in readings at opposite positions (12 vs. 6 o’clock or 3 vs. 9 o’clock). This indicates whether the shafts are tilted relative to each other.

Laser shaft alignment handbook

4. Interpret the Readings:

- Radial Offset: If the dial indicator shows a consistent gap between the shafts at different positions, this indicates radial (parallel) misalignment. The difference in readings across the top, bottom, and sides will give an indication of the amount of offset.

- Angular Misalignment: A difference in the readings between opposite positions (e.g., 12 and 6 o’clock) indicates angular misalignment. The larger the difference, the greater the angular deviation.

5. Make Adjustments:

- Vertical Adjustment:

- Shim the Equipment: To correct vertical misalignment, add or remove shims under the feet of the machine (usually the motor or the driven machine) based on the dial readings.

Shaft alignment handbook

- Check Level: After adjusting, recheck the alignment by taking new readings at all positions.

- Horizontal Adjustment:

- Move the Equipment: Loosen the mounting bolts and gently shift the machine horizontally (left or right) to correct any lateral offset based on the dial indicator readings.

- Re-tighten Bolts: Once aligned, tighten the mounting bolts and recheck the alignment readings to ensure nothing has shifted during the adjustment.

6. Re-check Alignment:

- Repeat Measurement: After adjustments are made, rotate the shafts again and take new dial indicator readings at all positions (12, 3, 6, 9 o’clock).

Pump-motor shaft alignment pdf document

- Fine-tune Alignment: If the readings still show misalignment, repeat the adjustment steps until the dial indicator shows minimal deviation, ideally within the machine manufacturer’s specified tolerance (usually ±0.002 inches or 0.05 mm).

7. Lockdown and Final Check:

- Tighten Fasteners: Once proper alignment is achieved, tighten all mounting bolts securely.

- Recheck Alignment: Perform a final check of the dial indicator readings to confirm that alignment hasn’t shifted during tightening.

Rotating equipment shaft alignment pdf document

8. Remove the Dial Indicator:

- Dismount the Indicator: Remove the dial indicator setup and ensure the machinery is clean and free of loose tools.

- Test Run: Power up the machine and perform a test run to confirm smooth operation without excessive vibration or noise.

For more information follow Mechanical World