How Condition Monitoring Supports Precision Maintenance

1 www.lifetime-reliability.com

Condition Monitoring that Supports Precision Maintenance

SIRFRt CM & Lube Forum 2010 Conference

Mike Sondalini Lifetime Reliability Solutions

www.lifetime-reliability.com

http://www.lifetime-reliability.com/







Precision Maintenance of Machinery is …

1. Accurate Fits and Tolerance at Operating Temperature

2. Impeccably Clean, Contaminant-Free Lubricant Life-long

3. Distortion-Free Equipment for its Entire Lifetime

4. Forces and Loads into Rigid Mounts and Supports

5. Laser Accurate Alignment of Shafts at Operating Temperature

6. High Quality Balanced Rotating Parts

7. Total Machine Vibration Low

8. Correct Torques and Tensions in all Components

9. Correct Tools in Precise Condition to do the Task to Standard

10. Only In-specification Parts

11. Failure Cause Removal during Maintenance

12. Proof Test for Precision Work and Equipment

13. A quality assurance system to make all the above happen





Typical Standards for a Precision Maintenance Program

1. Accurate Fits and Tolerance – ISO Shaft/Hole Tolerance Tables, International Tolerance Grade

2. Clean, Contaminant-Free Lubricant – ISO 4406, ISO 11500

3. Distortion-Free Equipment – Shaft Alignment Handbook – Piotrowski

4. Shafts, bearings, couplings Running True to Centre – Shaft Alignment Handbook

5. Forces and Loads into Supports – Shaft Alignment Handbook

6. Accurate Alignment of Shafts – Shaft Alignment Handbook

7. High Quality Balancing of Rotating Parts – ISO 1940

8. Machine Vibration – ISO 10816

9. Correct Torques and Tensions – ISO/ASME Bolt, Stud and Nut Standards

10.Correct Tools in Correct Condition – ‘As-New Specification’

11.Only In-specification Parts – OEM Specifications, Metallurgical Specifications

12.Failure Cause Removal During Maintenance – Creative Disassembly; ‘5 Why’

13.Proof Test for Precision Work and Equipment – Measurement, Start-up Condition Monitor

14.A system to use the standards successfully – 3T Accuracy Controlled Procedures





Vibration:

Balancing:

Alignment: Fastener Torque:

Deformation:

Lubricant Cleanliness:

Reaching High Reliability is Easy…

Fits and Tolerance:





The answers to these questions let you

check your machinery’s true condition.

First find out...

How round does it need to be? How flat does it need to be? How straight does it need to be? How clean does it need to be? How tight does it need to be? How right does it need to be?





Form Tolerance Manufacturers Use





ISO Hole Tolerances - minimum hole size as basic diameter

- denoted by Capital letter (say, H)

40 H8

Basic Size

Fundamental Deviation

IT grade

Tolerance Zone

ϕ40 Shaft Hole

H

8 IT grade

Fundamental

Deviation





Hole Fundamental Deviation

40 H8 H8

40.039

40.000

Fundamental

Deviation





ISO Shaft Tolerances

- minimum shaft size as basic diameter

- denoted by lower case letter (say, h)

40 h9

Basic size

Fundamental Deviation

IT grade

Tolerance zone Shaft ϕ40 Hole

h

9 IT grade

Fundamental

Deviation





Shaft Fundamental Deviation

40 h9 h9

40.000

39.938

Fundamental

Deviation





Case Study: Shaft Reliability Control Check

Condition Requirements from the

manufacturer or appropriate

engineering specifications

Thanks to CBC Bearings and Rod Bennett

for the information and example

150mm Spherical Roller Bearing Mounted

on a Shaft Tapered Sleeve





Is the 150mm Shaft In Tolerance?

Shaft Tolerances for Bearing Adapter Sleeves





Is the 150mm Shaft Round?





Is the 150mm Shaft Cylindrical?





Is the 150mm Shaft Tapered?

149.99 149.96 149.98





Roller Bearing Flexing from Unsupported Ring

The bearing is not fully

supported along the shaft

and both the ring and taper

sleeve will flex back and

forth every time a roller

passes over the cavity





Roller Bearing Excessive Clearance

will greatly reduce bearing life

may occur because of wrong installation

setup, improper fits at the seatings,

excessive wear (contamination)

the ideal clearance for most bearings is nil

clearance at operating conditions

may lead to scalloping at the load zone

may lead to wear of the cage in cylindrical

rollers and catastrophic failure

Internal Clearance and Bearing Life





Impacts of Out-of-Roundness

What it should be..

1500RPM = 25

impacts/second

3000RPM = 50

impacts/second

Spalling





Temperature and Bearing Life

20oC 20oC Inner Ring Unrestrained

Temperature Growth

ΔT

Inner Ring

100 oC*

50 oC Housing

50

11

0

70

40 oC

Steel Coefficient of Expansion = 12.5 x 10-6 / oC

Ring Diameter Temperature Rise Ring Expansion Radial Expansion

mm ΔT C degrees µm µm

70 20 17.5 8.75

70 40 35 17.5

70 60 52.5 26.25





...what about the rest of the machine...





How to Make Machines Highly Reliable?

Set Machine Quality Standards that deliver

reliability so that you can measure if a part’s

condition will indeed produce reliability





Importance of Setting Condition Standards





…DO NOT USE

STANDARDS THAT

ACTUALLY CAUSE

FAILURES

Challenge Yourself to IT5 Standard

ANSI API

ANSI pump base allowed flatness = 0.127mm/m… this standard causes soft-foot

API 610 flatness = 0.05mm/m… this standard makes you remove soft-foot





Set Quality Standards that Create Reliability

FAILURE FOCUSED By this stage the bearing is well on the way to failure and certain downtime





Job Plans with No Quality Control

JOB PLAN TO INSTALL CONVEYOR PULLEY PLUMMER BLOCK

1. Prepare for Job in Dirt-Free Work Area

2. Safe Isolation and Handover

3. Check Parts and Materials are Correct

4. Access Plummer Blocks and Bearings

5. Check Shaft Condition and Tolerance

6. Measure Bearing Internal Clearance

7. Measure Plummer Base Plate Accuracy

8. Locate Bearings on Shaft

9. Mount Bearings on Shaft

10. Position Plummer Blocks and Place Pulley

11. Complete Plummer Block and Seals Assembly

12. Align Plummer Blocks

13. Lubricate Bearing and Seals

14. Align Plummer Blocks and Bolt Down

15. Commission and Test

16. Clean-up and Hand Back





Develop Job Plans with Measurable Quality Specifications

JOB PLAN TO INSTALL CONVEYOR PULLEY PLUMMER BLOCK

1. Work Area Prepared to site Dirt-Free standard

2. Safe Isolation and Handover Delivered from Operator

3. Check Parts and Materials are Correct to BOM

4. Plummer Blocks and Bearings Access Installed

5. Shaft Condition and Tolerance Checked against OEM values

6. Bearing Internal Clearance Measured against OEM values

7. Plummer Base Plate Measured against OEM values

8. Bearings on Shaft Located to OEM values

9. Bearings on Shaft Mounted to OEM standards

10. Plummer Blocks and Pulley Positioned to OEM standards

11. Complete Plummer Block and Seals Assembly Positioned to OEM standards

12. Plummer Blocks Aligned to OEM standards

13. Bearing and Seals Lubricated to OEM standards

14. Plummer Blocks Aligned and Bolted Down to OEM standards

15. Commission and Test that operating specification is met

16. Clean-up and Hand Back to Site Workplace Cleanliness Standards





Failure Detection Zone Failure Cause Elimination Zone

Condition Monitoring that Drives Reliability

Failure Monitoring (feedback control) Health Monitoring (feed forward control)





“Chop Out The Roots of Failure”

X

X

X Get rid of the cause of

vibration! Get rid of the cause of

poor connections!

Get rid of the cause of oil

contamination!

“Chop Out

the Roots” “Chop Out

the Roots”





Is it round, is it flat, is it straight, is it clean, is it tight, is it right?

Vibration:

Balancing:

Alignment:

Fastener Torque:

Deformation:

Lubricant Cleanliness:

Fits and Tolerance:





Set Quality Conditions that Create Machinery Health and Cause Equipment Reliability

Health Monitoring (feed forward control)

Failure Monitoring (feedback control)

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Inspect

for

Failure

Built for

Reliability

Inspect

for

Health

Inspect

for

Health

Built for

Reliability

Inspect

for

Health

Inspect

for

Health

Inspect

for

Health

Pe

rfo

rma

nce

Built for

Reliability




Documents

How Condition Monitoring Supports Precision Maintenance