2nd Engineer Marine Diesel Engineering: Clutches & Gearboxes

Play an AI-generated podcast conversation about this lesson

What is the purpose of clutches in marine vessels?

To allow a separation of driver and driven components, usually engine to gearbox, alternator, or cargo pump.

In multi-engine systems, what advantage do clutches provide?

They allow an engine to be disengaged for economy or maintenance, or reversing without stopping the engine.

What type of clutches are usually integral with the gearbox?

We normally expect clutches to be integral with the gearbox.

How are air-operated clutches usually activated?

Air-operated clutches are usually air activated. Signup and view all the answers

What supplies the application force for the friction pads or linings in air-operated clutches?

The compressed air in a reinforced neoprene rubber tube supplies the application force for the friction pads or linings. Signup and view all the answers

What is the purpose of the compressed Control Air in air-operated clutches?

The compressed Control Air is both filtered and dried. Signup and view all the answers

How does compressed air expand in a radial air-operated clutch?

The compressed air expands an actuating tube around the outside of the friction pads. Signup and view all the answers

Why are clutches important in marine engineering operations?

Clutches allow for disengagement of the engine for various purposes, such as economy, maintenance, or reversing without stopping the engine. Signup and view all the answers

What is the purpose of the radial air operated clutch?

To transmit torque by forcing pads into contact with the friction drum. Signup and view all the answers

How is slipping prevented in the clutch?

Slip is prevented by maintaining air pressure inside the clutch. Signup and view all the answers

What is the function of the springs in the clutch?

The springs are incorporated for disengagement of the clutch. Signup and view all the answers

How is air typically supplied to these clutches?

Air is often supplied via a Rotor Coupling or a Rotating Air Seal. Signup and view all the answers

What is the purpose of the emergency driving plate in case of internal air component failure?

To engage the clutch in the event of internal air component failure. Signup and view all the answers

Why is monitoring air pressure important in these clutches?

Monitoring air pressure is important to prevent slippage and overheating. Signup and view all the answers

What action does the expansion of the tube in the axial air operated clutches produce?

The expansion of the tube produces a sandwich action between the friction pads and disc. Signup and view all the answers

How does the open construction of the clutch aid in pad cooling?

The open construction allows air access for pad cooling. Signup and view all the answers

What is the importance of using a four point support in a gearbox?

To prevent the gearbox from following any foundation deflection. Signup and view all the answers

Where should oil be sprayed in a gear casing and why?

Oil must be sprayed into the gear teeth at the point where they mesh to produce the required oil film. Signup and view all the answers

How does applying oil to the teeth as they disengage help in reducing power losses and overheating in high speed gears?

It helps to reduce bulk temperature of the oil and prevent scuffing. Signup and view all the answers

What is a key characteristic of an epicyclic gearbox in terms of size and complexity?

It is small and compact but more complex compared to other arrangements. Signup and view all the answers

Why is the gear ratio in an epicyclic gearing system considered somewhat non-intuitive?

Because there are several ways in which an input rotation can be converted into an output rotation. Signup and view all the answers

What is the main function of Pneumaflex clutches in terms of torsional vibration?

Shift resonance between natural and exciting frequencies Signup and view all the answers

How does a plate-type clutch operate?

Through a friction grip between the pressure plate and clutch plate linings Signup and view all the answers

What does the rubber element in Pneumaflex clutches help to compensate for?

Centre mismatch, axial and angular misalignment Signup and view all the answers

What is the role of the rubber elements in Pneumaflex clutches in terms of noise?

Isolate structure-borne noise effectively Signup and view all the answers

How is a Pneumaflex clutch engaged?

Air supplied to clutch cylinder pushes friction cones against friction surface Signup and view all the answers

How is a Pneumaflex clutch disengaged?

Air is vented to release cylinder and piston assemblies Signup and view all the answers

What elements does a Pneumaflex clutch compensate for within a predetermined tolerance range?

Shaft centre mismatch, axial and angular misalignment Signup and view all the answers

What happens in a plate-type clutch when the pressure plate and clutch plate linings are in touch?

The engine is engaged to the gearbox and axle Signup and view all the answers

What is the term used to describe the failure of the lubrication film that results in wear near the pitch line?

Mild Scuffing or Galling Signup and view all the answers

What is the consequence of constant failure of the lubrication film that may lead to pressure welding or seizure between surfaces?

Advanced Scuffing or Galling Signup and view all the answers

What type of wear occurs when abrasive material enters between surfaces with the oil, resulting in abnormal wear?

Abrasion Signup and view all the answers

What is the term used to describe abnormal tooth surface loading that can result in chips or flakes breaking away due to overstressed sub-surface metal?

Flaking or Spalling Signup and view all the answers

What causes scoring on surfaces, where sharp projections break through the oil film and score the mating surface?

Scoring Signup and view all the answers

What should be checked if fracture of gear teeth is found?

Remaining teeth on both driver and driven, Condition of oil and filters, Bearing clearance Signup and view all the answers

What type of failure occurs when increased loading on the remaining surface causes further pitting until the working areas are destroyed?

Pitting Signup and view all the answers

What term refers to the sliding and yielding of the surface and subsurface metal that progresses towards the tooth tips of the driving wheel and the root of the driven wheel?

Sliding and yielding Signup and view all the answers