1. Scope and Purpose
This guide describes technical procedures for precision alignment between shafts of rotating machines, such as motor-pump sets, reducers and compressors. Correct alignment is essential to reduce vibrations, extend the life of bearings, mechanical seals and couplings, and minimize energy consumption. This procedure must be carried out during initial installation, after maintenance involving decoupling, or when abnormal vibrations are detected.
2. Safety Precautions
WARNING: Failure to comply with safety protocols may result in serious injury or death.
LOCKING AND TAGGING (LOTO): It is mandatory to isolate all energy sources (electric, pneumatic, hydraulic) before starting any intervention on the equipment. Use locking devices and identification tags in accordance with standards NR-10 and NR-12.
PERSONAL PROTECTIVE EQUIPMENT (PPE): Use protective gloves against cuts and abrasions, steel-toed boots, impact safety glasses and hearing protection, if necessary.
ENERGY RESIDUAL: Make sure that the shaft is completely stopped and that there is no risk of movement due to potential energy (e.g. suspended load or residual pressure in hydraulic systems).
3. Tools and Materials Required
| Tool | Specification | Quantity |
|---|
| Laser Alignment System | Accuracy of +/- 0.005mm | 1 |
| Dial Clocks | Resolution 0.01mm | 2 |
| Magnetic Base/Stand | Rigid base with fine adjustment | 2 |
| Blade Calibrator (Feeler) | 0.05 to 1.00 mm | 1 |
| Shim Set | Stainless Steel (various thicknesses) | 1 |
| Torque meter | Manufacturer torque range | 1 |
| Caliper | 0 - 150mm | 1 |
4. Pre-Maintenance Inspection Checklist
| Item | Verification | Criteria (Accept/Reject) | Notes |
|---|
| Fixing the Base | Check screw tightness | No backlash (rated torque) | |
| State of Feet | Check "soft foot" | < 0.05mm | |
| Cleaning | Support surface and axles | Rust/dirt free | |
| Coupling State | Visual inspection | No cracks or excessive wear | |
5. Step by Step Procedure
5.1. "Soft Foot" Check
Before aligning, ensure that all machine feet are in firm contact with the base.
- With the fixing screws tight, position the dial indicator on the foot to be checked.
- Loosen the fixing screw and observe the deflection of the watch.
- If the deflection is greater than 0.05 mm, add shims until the deflection is within tolerance.
- Common mistake: Performing alignment before correcting the soft foot will result in misalignment again when tightening the screws.
5.2. Alignment with Clock Dial (Edge and Face Method)
- Attach the supports to the axles.
- Reset the clocks at the 12 o'clock, 3 o'clock, 6 o'clock and 9 o'clock positions.
- Rotate both axes simultaneously.
- Calculate angular (face difference) and radial (edge difference) misalignment.
- Make corrections using shims on the engine feet and lateral displacement.
- Note: Always compensate for deflection of support rods if they are long.
5.3. Laser Alignment
- Mount the sensors on the axles according to the manufacturer's manual.
- Enter the dimensions (distances between sensors and coupling).
- Rotate the axes to the positions requested by the software.
- The system will automatically calculate the misalignment.
- Adjust the feet according to the software's recommendations.
Alignment Tolerance Table (General Reference)
| Speed (RPM) | Radial Misalignment (mm) | Angular Misalignment (mm/100mm) |
|---|
| 1500 | 0.10 | 0.08 |
| 3000 | 0.05 | 0.05 |
6. Post-Maintenance Verification Checklist
| Test | Expected Result | Real | Pass/Fail |
|---|
| Final Alignment | Within tolerance (RPM) | | |
| Soft Foot | < 0.05mm | | |
| Screw Torque | As per OEM manual | | |
| Initial Vibration | Acceptable levels (ISO 10816) | | |
7. Troubleshooting Guide
| Symptom | Probable Cause | Corrective Action |
|---|
| Excessive radial vibration | Radial misalignment or soft foot | Realign and correct feet |
| Excessive axial vibration | Angular misalignment | Correct angular misalignment |
| High temperature in the coupling | Extreme misalignment | Realign and check for damage to elements |
8. Recommended Maintenance Schedule
| Task | Frequency | Estimated Duration | Skill Level |
|---|
| Visual inspection | Monthly | 15 min | Operator/Technician |
| Laser check | Semiannual | 2-4 hours | Specialized Technician |
| Full alignment | As needed/failed | 4-8 hours | Specialized Technician |
9. Spare Parts Reference
| Part Description | Typical Specification | UNITEC category |
|---|
| Calibrated shims | Stainless Steel, 0.05 to 2.0mm | Mounting Accessories |
| Coupling elements | Rubber/Polymer | Couplings |
| Base screws | Grade 8.8 or higher | Fasteners |
To consult parts and technical specifications, access our catalog: https://www.unitecd.com/e-catalog/
10. References
- ABNT NBR ISO 10816: Mechanical vibrations - Assessment of machine vibration.
- NR-10: Safety in Electrical Installations and Services.
- NR-12: Workplace Safety in Machines and Equipment.
- Instruction manuals from manufacturers of couplings and rotating equipment.
