MP1-Monitoring and Prognostics

Question 1

Why do machines fail, main causes?
D-I-Pr-Ra-Ma-EL

Answer 1

• At the drawing table: Bad design - Operation conditions-Environment
• During installation: Not Correct mounted - Doesn’t followed procedures during installation
• When buying gear: Price &Quality
• Bad communication: No repports - nothing on paper-
• Bad maintenance: No standards - which kind of maintenance
• End of life: When damaged, change the sparpart directly

Question 2

What are the maintenance strategies?

R-PR-PR-PO-PR

Answer 2

Question 3

Failure modes and criticality

What is Criticality and Failure Modes?

Answer 3

• The criticality determines the level of maintenance attention.
  (How important or critical is the component)
• The failure mode determines the type of maintenance strategy and the monitoring technology. What can goes wrong

Critical

Question 4

What are the Wear mechanisms

Ab-Ad-Fa-Co-Er

Answer 4

Question 5

Bearing Failure

Which factores determine the life of a bearing?
Q-S-A-M-L

Answer 5

Question 6

What are the bearing damage classification?

F-W-C-EL-PD-FR

Answer 6

Question 7

What kind of failures

Answer 7

• Abrasive wear: removal material
• Adhesive wear: welding
• Corrosion; sealing- micromovement - oxidation
• False Brinelling: Vibration Shiny
• Bearing currents: Current leakage or sparking
• Load:Static shock or Pumps, Fans and Compressors Handling damage
• Indents from debris: Overloading - Debts

Question 8

Belt Failure

What influences the belts life

Answer 8

1. Sheave diameter
   * 10% reduction in sheave diameter, 40% reduction in life
2. Temperature
   * Oxidation and softening of the rubber
   * 24000 hours design life is 70°

Question 9

Belt Failure

Which problems are when mounting the belt?

MA-RE-TE

Answer 9

Misalignment
* Improper tension
* Belt wear
* Belt resonance

Question 10

Gear Failure

Main Characteristics of the Gear in General

LS - LUB-LOA

Answer 10

Life-span
* Some high end gears for 20-year lifespan
* Life calculation and durability testing
Lubrication
Two reasons:
* To provide an oil film
* To remove heat
Loads
* Contact load generates stress distribution
* Gear design and materials to withstand stress

Question 11

Wat are the Gear Failures?

Answer 11

Gear tooth wear
* Surface fatigue (pitting)
* Plastic deformation
* Web crack
* Gear tooth fracture
* Adhesive (scuffing)

Question 12

Wat are the Gear Failures?

Answer 12

Surface fatigue (pitting)
High stress in contact zone
Localized fatigue
Normal life, moderate pitting
Progressive pitting
Spalling

Question 13

Couplings

Why do we use couplings

T-V-Ma-De

Answer 13

Why use couplings
1. Torque and rotation transmission within prescribed design limits
2. Vibration dampening (especially in reciprocating machinery)
3. Allow misalignment, however
* How much misalignment is
allowed before issues
occur?
* Forces on bearings
4. Tune torsional damping

Question 14

Couplings

What are the most commong types?

Answer 14

• Spline couplings
• Disc couplings
• Spider couplings

Question 15

Root Cause Methodology

What is a Root Cause Methodology?

Answer 15

Step-by-step method for examining a failed application
Five keys
Acting as a crime scene investigation

Question 16

How to apply the RCA in maintenance

Answer 16

• Create a Root Cause Failure Analysis database for tracking failures
• Gather equipment information and history
• Implement and track changes