The Rim-Face Dial Indicator method

The Rim-Face dial indicator method

• Introduction
• What if only one shaft can be rotated?
• Accuracy issues
• Setup problems
• Axial end-float
• Rim-Face Measurement Procedure
• Compensate for bar sag
• Alternative method
• Determine the alignment corrections
• Performing the calculations
• Computing the offset
• Computing the angularity
• Computing feet movements
• Shim calculations
• Move calculations
• Example calculations
• The graphical method
• Summary

The Reverse-Dial Method

The Reverse Dial method

• Introduction
• Reverse dial procedure
• Compensate for bar sag
• Performing the calculations
• Computing the offset
• Computing the angularity
• Computing feet movements
• Shim and move calculations
• An example
• Example:
• The graphical method
• Summary
• Alternative method

Laser Alignment

Laser alignment systems

• Introduction
• The basic components in a laser alignment system
• Benefits of laser alignment systems over dial indicators
• How do laser alignment systems work?
• Using a Prism – Return Beam Method
• Beam Splitter – Single Beam Method
• Twin Emitter/Detector Pairs – Dual Beam Method
• Using a horizontal beam and a vertical detector

Using the laser alignment system

• Performing the laser alignment
• Pre-alignment
• Preparing the coupling
• Attaching the brackets
• Attach the brackets
• Check the optics
• Mount the laser heads
• Aim the heads
• Zeroing the beam
• Check for repeatability
• Rough alignment (“roughing-in”)
• Correcting gross angularity
• Correcting gross parallel offset
• Dealing with gross misalignment
• Rough alignment with a laser system
• Dealing with distance and angularity
• Cones and circles and distance
• Enter the machine dimensions
• How accurate should the dimensions be?
• Entering the coupling diameter

Performing laser alignment measurements

• Performing the measurements
• The 3:00-12:00-9:00 method
• Swept measurements
• Getting the results
• Aligning spacer shafts or jackshafts
• What if you can’t rotate one shaft?
• What if the shaft can’t be rotated easily?
• What if you can’t rotate either shaft?
• Limitations of laser systems
• Backlash
• Vibration
• Heat, steam, sunlight, water vapor
• General comment about commercial systems

Moving the Machine

Moving the machine

• Introduction
• Perform the vertical move first
• Gross misalignment
• Using a laser alignment system
• Moving the machine vertically – shimming

Base bound and bolt bound

• Base bound
• Machine the feet
• Moving the machine horizontally
• Using a dial indicator to measure the horizontal move
• Using shims to measure horizontal machine moves
• Bolt bound
• Turn-down the bolts
• Open the bolt holes of the machine feet
• Moving the stationary machine
• Drill new holes

Dynamic and Thermal Movement

Dynamic and Thermal Movement

• Introduction
• Which machines will be affected?
• Thermal effects
• Manufacturer’s supplied offsets
• Sources of heat
• Internal or system sources of heat
• External sources of heat
• Mechanical effects
• Pipe strain
• Oil wedges
• Jacking fluid
• Catenary sag
• Foundation changes

• Why is misalignment so important?
• Bearing damage
• Seal damage
• Coupling damage
• Vibration
• Energy consumption
• Product quality
• Downtime and production capacity
• Detecting misalignment

What is misalignment?

• What is misalignment?
• A closer look at misalignment
• Shaft fatigue
• Even bent shafts have rotational centerlines
• Offset and angular misalignment
• Alignment conventions
• Specifying misalignment
• Using feet corrections to specify misalignment
• Using Total Indicator Readings to specify the misalignment
• Using offset and angularity to specify alignment targets
• Angularity targets
• Visualizing tolerance
• Tolerances and speed
• Spacer couplings (jack shafts) conventions and tolerances
• Published tolerances
• Dynamic movement

Pre-Alignment checks and soft foot

• Pre-alignment tasks

Determining the alignment state

• Determining the alignment state
• Using a straightedge or feeler gauge
• Using dial indicators
• The Rim and Face method
• The Reverse Dial method
• Reverse dial method
• Dial indicator limitations

Laser alignment systems

• Laser alignment systems
• Moving the machine
• Moving the machine vertically – shimming
• Moving the machine laterally
• Summary

Shaft Alignment Mathematics – A Primer

Offset, angularity and alignment mathematics

• Introduction
• Equal triangles
• Triangles and alignment
• A triangle from two offsets
• Dealing with negative numbers

Understanding Dial Indicators

Dial indicators

• Introduction
• What can go wrong?
• Zero the dial
• Bar sag
• Total Indicator Readings (TIR)
• Hysteresis
• Clock positions
• Backlash
• Why do we rotate both shafts?

Using dial indicators for shaft alignment

• Using dial indicators for shaft alignment
• Rim measurements
• Face measurements
• Axial end-play and float
• Repeat all tests
• Validity rule

Pre-Alignment Checks and Corrections

Pre-alignment Checks

• Introduction
• Plan and review maintenance history
• Why is the machine not aligned?
• Installing a new machine
• Decide on the required tolerance and coupling gap
• Pipe strain
• Mechanical looseness
• Bent shafts and coupling runout
• General preparations on site: Safety
• General preparations on site: Clean up
• General preparations on site: Shims
• General preparations on site: Jacking bolts

Soft Foot Checks and Corrections

Detecting and Correcting Soft Foot

• Introduction
• Different types of soft foot
• Rocking soft foot
• Short foot – parallel air gap
• Even foot
• High foot
• Bent foot
• Squishy foot
• Induced soft foot

Why is soft foot important?

• Why is soft foot important?
• Shaft fatigue
• Bearing distortion
• Impact on the alignment task

Testing for soft foot

• Testing for soft foot
• Taking soft foot measurements
• Recording results
• Using dial indicators to measure soft foot

Correcting soft foot

• Correcting rocking soft foot
• Short cut number one: The Casanova method
• Short cut number two: The 80% Rule
• Using feeler gauges
• Using a “stair” of shims
• More complex shim patterns
• Detecting and correcting induced soft foot
• Mysterious soft foot
• Summary