CPM - Certified Plant Mechanic Mechanical Power Transmission Questions and Answers

Question 1

A plant mechanic is servicing a conveyor system that frequently jams due to oversized material.
To protect the expensive gearbox and motor from damage during these overload events, which of the following components is specifically designed to fail and be easily replaced?

Accepted Answer

Shear pin

Answer

Flexible coupling

Answer

Worm gear

Answer

Rigid coupling

Question 2

When selecting a gear set to transmit power between two parallel shafts, which gear type is known for smoother, quieter operation at high speeds compared to spur gears, due to more gradual tooth engagement?

Accepted Answer

Helical gear

Answer

Bevel gear

Answer

Worm gear

Answer

Rack and pinion

Question 3

Which of the following is the primary advantage of a synchronous (timing) belt drive over a standard V-belt drive for applications requiring precise shaft synchronization?

Accepted Answer

They eliminate slippage due to positive tooth engagement.

Answer

They are less expensive.

Answer

They allow for intentional slippage under high load.

Answer

They require less initial tension.

Question 4

A mechanic is installing a new V-belt drive. After initial installation and tensioning, what is the recommended best practice regarding belt tension?

Accepted Answer

Re-tension the belt after a brief run-in period of 24-48 hours.

Answer

The initial tension is sufficient for the life of the belt.

Answer

Over-tension the belt slightly to account for initial stretching.

Answer

Check the tension again only when slippage is audible.

Question 5

What is the primary function of a flexible shaft coupling in a power transmission system?

Accepted Answer

To accommodate for minor angular and parallel shaft misalignment.

Answer

To increase the torque transmitted between shafts.

Answer

To provide a solid, zero-backlash connection.

Answer

To act as a sacrificial component during overloads.

Question 6

In a heavy-duty, high-load, and high-shock application, such as a rock crusher, which type of bearing is generally more suitable for supporting the main rotating shaft due to its ability to handle shock loads and its long operational life under such conditions?

Accepted Answer

Journal bearing

Answer

Ball bearing

Answer

Needle roller bearing

Answer

Thrust bearing

A plant mechanic is servicing a conveyor system that frequently jams due to oversized material.To protect the expensive gearbox and motor from damage during these overload events, which of the following components is specifically designed to fail and be easily replaced?

A plant mechanic is servicing a conveyor system that frequently jams due to oversized material.
To protect the expensive gearbox and motor from damage during these overload events, which of the following components is specifically designed to fail and be easily replaced?