ITMC Mechanical Systems & Equipment Maintenance 2 — Questions and Answers
Question 1: Which type of bearing is best suited for handling both radial and axial (thrust) loads simultaneously?
- Deep groove ball bearing
- Cylindrical roller bearing
- Angular contact ball bearing (Correct answer)
- Needle roller bearing
Correct answer: Angular contact ball bearing
Angular contact ball bearings are designed to handle combined radial and axial loads due to their contact angle geometry.
Question 2: When a V-belt drive shows signs of slipping under load, the FIRST corrective action should be:
- Replace the belt immediately
- Adjust center distance to increase belt tension (Correct answer)
- Apply belt dressing compound
- Increase the drive pulley diameter
Correct answer: Adjust center distance to increase belt tension
Adjusting the center distance to restore proper tension is the first step before considering replacement or other measures.
Question 3: A pump cavitates when the fluid pressure at the inlet falls below the liquid's:
- Atmospheric pressure
- Vapor pressure (Correct answer)
- Discharge pressure
- Static head pressure
Correct answer: Vapor pressure
Cavitation occurs when inlet pressure drops below the fluid's vapor pressure, causing vapor bubbles to form and collapse.
Question 4: What is the primary purpose of a mechanical seal in a centrifugal pump?
- To reduce impeller vibration
- To prevent fluid leakage along the shaft (Correct answer)
- To balance axial thrust on the shaft
- To reduce bearing temperature
Correct answer: To prevent fluid leakage along the shaft
Mechanical seals prevent process fluid from leaking out along the rotating pump shaft.
Question 5: Which gear type produces the LEAST amount of noise during operation?
- Spur gear
- Bevel gear
- Worm gear
- Helical gear (Correct answer)
Correct answer: Helical gear
Helical gears have angled teeth that engage gradually, resulting in quieter and smoother operation than spur gears.
Question 6: An infrared thermometer shows a motor bearing running at 210°F (99°C) when the ambient temperature is 75°F (24°C). This indicates:
- Normal bearing operation
- Possible lubrication failure or overloading (Correct answer)
- Correct bearing pre-load
- Normal thermal expansion
Correct answer: Possible lubrication failure or overloading
A bearing temperature rise greater than 70°F above ambient typically signals lubrication failure, overloading, or misalignment.
Question 7: What does a high vibration reading in the axial direction on a rotating machine most commonly indicate?
- Unbalance
- Looseness
- Misalignment (Correct answer)
- Bearing defect
Correct answer: Misalignment
Axial vibration is the signature direction for angular or parallel misalignment in coupled rotating machinery.
ITMC Mechanical Systems & Equipment Maintenance 2
Which type of bearing is best suited for handling both radial and axial (thrust) loads simultaneously?