Alignment | Industrial Machine Alignment | Equipment Alignment | Part -2

Alignment , Industrial Machine Alignment, Equipment Alignment 

Alignment Procedure, Laser Alignment , Concept of Misalignment , Condition Monitoring, alignment methods, alignment Tolerance, Reverse indicator Method, Soft Foot, Fixing of Dial Gauge.

Scientific
Diagnosis Of Misalignment

1. Vibration Spectrum Analysis

2. Vibration Phase Analysis

3. Wear Particle Analysis

1. Vibration Spectrum Analysis

Angular – Axial vibration at  1X RPM

Offset  – Radial vibration at 2X or 3X RPM

Harmonics (3X-10X) generates as severity increases.

If the 2X amplitude more than 50% of 1X then coupling damage start.

If the 2X amplitude more than 150% of 1X then machine should be stopped for correction.

 

2. Vibration Phase Analysis

Angular – 180⁰ phase shift in the axial direction across the coupling.

Offset – 180⁰ phase shift in the radial direction across the coupling. 0⁰ to 180⁰ phase shift occur as the sensor moves from horizontal to the vertical direction of the same machine.

Skew – 180⁰ phase shift in the axial or radial direction   across the coupling.

3. Wear Particle Analysis

Curly cutting wear particle of  5:1  to  50:1 aspect ratio.

Types Of Couplings

Flexible : Pin bush, Tyre, Love joy,

                ESBI  Valkan tyre

Semi Flexible : Fluid

Rigid : Geared, Resilient

Flexible Coupling

Can flexible coupling take misalignment?

Flexible coupling can be used to take minor misalignment but it will generate heat and flexible members will fail prematurely

Alignment Methods

1. Rough Alignment

     (a) Using straight edge

    (b) Twin wire method

2. Precision Alignment

     (a) Face & Rim

    (b) Reverse indicator

1.) Rough Alignment

(a) Using  straight edge

(b) Using twin wire

(a) Face & Rim Method

Advantages:

1. Good for large dia. coupling hubs where the shafts are close together.

2. To be used where one of the shafts can not rotate during alignment.  

3. Easy to use.

Disadvantages:

1. Difficult to take face readings, if there is axial float in the shaft.

2. Requires removal of coupling spool.

3. More complex alignment calculation.

(b) Reverse Indicator Method

Advantages:

1. More accurate than face & rim method.

2. Readings are not affected by axial float.

3. Possible to keep the coupling spool.

Disadvantages:

1. Both shafts have to be rotated.

2. Should not be used on close coupled shafts.

3. Difficult to take readings on long shaft.

Which Method To Be Used?

If  L > D Reverse Indicator

Combination Method

Alignment Tolerance

Disadvantages Of Dial Indicator Method

Indicator Sag

Soft Foot

Tightening Of Holding Down Bolts

Fixing Of Dial Gauge

Rules For Good Alignment

Laser  Alignment

Laser

Light Amplified By Stimulated Emission Of Radiation

1. Laser was originally emitted by charge sent through a gas mixture of Helium & Neon.

  2. Now it emitted by a low power semi conductor diode with collimating lenses.

3. Modulated to avoid interference from other light source. 

4. It is collinear.

5. Single wave length of 670 nm.

6. Class II Laser is used for Laser Alignment System.

Laser  Alignment

Advantages:

1. Easy to use.

2. Use Reverse Indicator Method.

3. Machine does the calculations.

4. 0 – 20m max. working distance.

5. Selectable high resolution 0.1, 0.01, 0.001mm.

6. No indicator sag.

7. Soft foot measurement program.

8. Horizontal shaft alignment with mim 60⁰ rotation.

9. Vertical shaft alignment program.

10.Thermal or offset compensation.

11. Machine train alignment program.

12. Cardon shaft alignment.

13. Straightness, Flatness, Perpendicularly,

      Parallelism measurement.

14. Spindle alignment.

15. Static feet correction.

16. Continuous monitoring.

Face Readings

Graphical representation