It’s important to clarify a few points about the terminology used:
- Radial Tyre Type Clutch: This term is not typically used in diesel engine propulsion systems. Radial tire clutches are more commonly found in agricultural equipment and utilize the inflated shape of a tire to create clamping force.
- Air Operated Clutch: This is a more likely description for a compressed air-actuated clutch used in a diesel engine propulsion system.
Here’s a breakdown of a typical air-operated clutch operation in a diesel engine propulsion system for a medium-speed application:
Components:
- Compressed Air System: Provides pressurized air for clutch actuation.
- Air Actuator Cylinder: A piston cylinder connected to the clutch housing.
- Pressure Plate: Clamps the friction plates against the driven plate.
- Friction Plates: Multiple interleaved discs with high-friction material surfaces.
- Driven Plate: Connects to the propeller shaft and rotates with the engine flywheel when engaged.
- Control System: Regulates compressed air flow to the actuator for engagement and disengagement.
Operation:
- Engagement:
- The control system directs compressed air into the actuator cylinder.
- The pressurized air pushes the piston within the cylinder, extending the piston rod.
- The extending piston rod applies force to the pressure plate through levers or linkages.
- The pressure plate clamps the friction plates between itself and the driven plate.
- Friction between the plates transmits torque from the engine flywheel (connected to the pressure plate) to the driven plate and ultimately the propeller shaft.
- The engine and propeller become connected, propelling the vessel.
- Disengagement:
- When the control system vents compressed air from the actuator cylinder, the piston retracts due to spring pressure or compressed air from the opposite side of the cylinder (depending on the design).
- This allows the pressure plate to move away from the friction plates due to spring force.
- With the pressure plate disengaged, friction between the plates is eliminated, and the connection between the engine and propeller shaft is interrupted.
- The engine can continue to run without propelling the vessel (idling).
Additional Points:
- Spring-Engaged Design: Some clutches might be designed to be “spring-engaged, air-disengaged.” This means a strong spring holds the pressure plate and friction plates together by default. Compressed air is used to overcome the spring force and disengage the clutch. In case of air pressure loss, the spring automatically forces the clutch into the engaged position.
- Interlocks: Safety interlocks might be implemented. For example, the clutch might not engage until engine speed falls below a certain RPM or until lubrication oil pressure reaches a minimum level.
This description provides a general overview of an air-operated clutch in a diesel engine propulsion system. The specific design and control system might vary depending on the application and manufacturer.