Monday 24 October 2011

Engine Basics - The Basic Frame Work Of Engines..


ENGINEs
Engines are everywhere, It makes our lives simpler and faster everyday. It makes our complex tasks into simpler  & easier one. Our world comes to halt if there are no engines. It helps humans in innumerable ways, and at last made the mankind to reach the sky even to the space.

                   To say about an engine it is a device that converts one form of energy to another form. Mainly the engines function by employing the thermal energy or heat energy to useful mechanical work.
                   These engines can be broadly classified into two types,
1. External combustion engines [EC Engines]
2. Internal combustion engines [IC Engines]




In external combustion engines the combustion takes place outside the engine whereas in internal combustion engines the combustion takes place inside the engine.  External combustion engines are not efficient and the loss of thermal energy is high, so internal combustion engines are highly employed even though they are highly complex  machines.

Classification of engines







Internal combustion engine -cutaway


 IC Engines.


BASIC ENGINE COMPONENTS


SPARK IGNITION ENGINE 
Components
  • Cylinder 
  • Engine Block
  • Piston
  • Inlet Manifold
  • Exhaust Manifold
  • Inlet & Exhaust valves
  • Connecting Rod
  • Crankshaft
  • Piston Rings
  • Gudgeon Pin
  • Camshaft
  • Cams
  • Fly Wheel  
MULTI CYLINDER ENGINE

Displaying the components & four stroke cycle.





COMPONENTS - A CLOSER LOOK.

Engine Block:


The engine block is the main supporting frame for the various components of the engine. The block of a multi cylinder engine is cast as a single unit called as cylinder block. It forms the main frame work for the engine allowing different components of the engine to be placed. 


Cylinder:


It is a Cylindrical space which allows the piston to move in a specific motion. The cylinder is supported by a engine block. An engine block can act directly as a cylinder or liners can be used in the block which acts as cylinder.


Piston:

It is a cylindrical component fitted into the cylinder perfectly and provides a gas tight space with the piston rings and lubricant. It is the first component in transmitting the engine power.


Inlet Manifold:


The pipe which connects to the intake system to the inlet valve of the engine through which air or air-fuel mixture is drawn into the cylinder.

Exhaust manifold:


The pipe which connects the exhaust system to exhaust valve of the engine through which the exhaust gases are expelled out from the engine.


Spark Plug:


It is a component to initiate the combustion process in a spark-ignition engine or petrol engine which is placed above the cylinder head.


Piston Rings


Piston rings are fitted around the slots of the piston which provides a tight seal between the piston and the cylinder preventing the leakage of combustion gases.


Gudgeon Pin:
It forms the link between the small end of the connecting rod and the piston.


Connecting Rod:
It interconnects the piston and the crankshaft. The two ends of the connecting rod are called as small end and the big end . small end is connected to the piston by gudgeon pin and the big end is connected to the crankshaft by crankpin.


Crankshaft:


It converts the motion of the piston into a rotary motion at the output shaft. The crankshaft is enclosed in a crankcase.


Camshaft:
The camshaft controls the opening and closing of the valves. The associated parts are push rods, rocker arms, valve springs and tappets. the camshaft is driven by the crankshaft through timing gears.


Inlet and Exhaust Valves:


The valves are present above the cylinder head as mushroom shaped poppet type. Generally Two types of valves are present. 1.The inlet valve 2.The exhaust valve. Through the inlet valve the charge is taken into the engine, the burnt exhaust gases after combustion escapes through the exhaust valve.


Cams:


It is the integral part of the camshaft which is designed to open the valves at correct timing intervals.


Fly Wheel:


To make the angular velocity of the shaft without fluctuation and to maintain a correct balance of engine mechanism fly wheels are employed. it is attached to the output shaft.. ....

Video animation about the complete assembly of  components into a complete engine ....