Diesel engines Flashcards
Who invented the diesel engine?
Rudolf diesel
What are the applications for a diesel engine within the RN?
- Diesel generator
- Air compressors
- Fire pumps
- Main engines and motor boats
What is the prime mover of a diesel generator?
Diesel engine
What is the free end of an engine?
The opposite end of the engine to the flywheel.
What is the drive end of an engine?
The end of the engine connected to the flywheel.
Name all components on this diagram.
- Rocker arm
- Fuel injector
- Valve
- Pushrod
- Piston rings
- Gudgeon pin
- Piston
- Connecting rod
- Camshaft
- Crankshaft
- Flywheel
- Oil sump
What is the purpose of the rocker arm?
Transfers motion from the pushrod to activate the valve.
What is the purpose of the fuel injector?
It injects atomised fuel into the cylinders.
What is the purpose of the inlet valve?
It allows air into the cylinder from the inlet port when open.
What is the purpose of the exhaust valve?
It allows the exhaust gases to exit the cylinder through the exhaust port, when open.
What is the purpose of the pushrod?
It transfers motion from the camshaft to the rocker arm to open the valves.
What is the purpose of a compression piston rings?
They provide a sliding seal between the outer surface of the piston and the inner surface of the cylinder.
What is the purpose of oil control piston rings?
They keep oil in the sump from leaking into the combustion chamber, where it would be burned and lost.
What is the purpose of a gudgeon pin?
The gudgeon pin connects the piston to the small end bearing of the connecting rod.
What is the purpose of the piston?
To receive pressure forces from the combustion process and to transfer them via the connecting rod to the crankshaft.
What is the secondary purpose of a piston?
To allow compression of air.
What is the purpose of the connecting rod?
To connect the piston to the crankshaft.
What is the purpose of the camshaft?
It controls opening and closing of the valves and they rotate at half engine speed.
What is the purpose of the crankshaft?
To convert the reciprocating motion of the pistons into rotary motion.
What is the purpose of a flywheel?
To promote smooth running during the non power strokes of an engine and to help the engine over these idle strokes.
What is the purpose of a sump?
It acts as a reservoir for the engines oil.
Describe the induction stroke.
The intake valve begins to open while the piston moves down from Top dead centre (T.D.C) to bottom dead centre (B.D.C) the increase in volume causes a depression in the piston and thus air is sucked in.
Describe the compression stroke.
The intake valve is shut. The piston moves up to T.D.C from B.D.C compressing the air at a ratio ranging from 16:1 - 20:1. Just before the piston reaches T.D.C atomised fuel is injected into the combustion area. The temperature above the piston will typically be 800 degrees celcius.
Describe the power stroke.
Both valves remain shut, the heat from the compressed air ignites the atomised fuel forcing the piston down from T.DC to B.D.C.