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Theory of machine| part -1

Kinematics links - Every part of machine which have relative motion to another part.   → The link should be resistance body.   What is resistant body? →Under the action of force it can transfer motion and power. Kinematics links →1. Rigid links     2. Flexible links     3. Fluid links Rigid links - There is no deformation.   Ex - piston,connecting rod Flexible links - Deformation is allowed under permissible limits. Ex - Belt drive Fluid links - A fluid link is one that is deformed by having fluid in a closed vessel and the motion is transmitted through the fluid by pressure. Ex - Hydraulic press   Types of links - 1. Singular 2. Binary 3. Ternary 4. Quaternary links
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                         I.C ENGINE
Engine perform parameter,
                                        Parameters are used to measure performance of an engine:
           (1) Power  (2) Efficiency (3) Fuel consumption
1.power : (a) Indicated power (IP)
                 (b) Brake power (BP)
                 (c) Frictional power (FP)

 2.Efficiency(η) :
(a) Indicated tharmal efficiency
(b) Brake tharmal efficiency
(c) Mechanical efficiency
(d) Relative efficiency
(e) Volumetric efficiency

3.Fuel consumption :
(a) Indicated specific fuel
(b) brake specific fuel

           


In suction stroke; piston moves T.D.C to B.D.C.
 Crank moves (A to B) in rotary motion.
 Connecting rod moves reciprocating motion.
In comparison stroke ; Piston moves B.D.C to T.D.C.
Connecting rod moves (B to A)


Combustion: also known as power or ignition This is the start of the second revolution of the four stroke cycle. At this point the crankshaft has completed a full 360 degree revolution. While the piston is at T.D.C. (the end of the compression stroke) the compressed air-fuel mixture is ignited by a spark plug (in a gasoline engine) or by heat generated by high compression (diesel engines), forcefully returning the piston to B.D.C. This stroke produces mechanical work from the engine to turn the crankshaft.


Exhaust: also known as outlet. During the exhaust stroke, the piston once again returns from B.D.C. to T.D.C. while the exhaust valve is open. This action expels the spent air-fuel mixture through the exhaust valve.
 Form 1st law energy conversation we get, show in pic :
       

          
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