Criteria S.I. Engine (Petrol or Spark Ignition Engine) C.I. Engine (Diesel or Compression Ignition Engine) Working Cycle Works on Otto Cycle or Constant Volume Cycle. Works on Diesel Cycle. Mixture During Suction Stroke Takes a mixture of air and petrol during the suction stroke. Takes only air during the suction stroke. Fuel Used Uses petrol as fuel. Uses diesel as fuel. Compression Ratio Has a compression ratio that varies from 6 to 10. Has a compression ratio that varies from 16 to 20. Engine Weight and Cost S.I. engines are lighter and cheaper. C.I. engines are heavier and costlier. Initial Cost Initial cost is lower compared to C.I. engines. Initial cost is high due to high compression ratio. Starting Starting is easy. Starting is difficult, especially in cold conditions. ...
Q-9.Kinematic Chain:- A kinematic chain is a combination of kinematic links in space that are so connected that the relative motion of the links is completely or successfully constrained, and the last link is connected to the first link.
Example:- Four bar chain
Slider Crank
Relationship which is good for Kinematie Chain
(No of links ) L = 2P ( no of Pair )- 4
&
( No of joint ) J = 3/2L - 2
Kinematic Chains and Their Constraints
A kinematic chain consists of a series of kinematic links connected in such a way that the relative motion between the links is either completely constrained, partially constrained, or unconstrained. This chain can be classified based on the relationship between the number of links (l) and the number of pairs (p).
1. Locked Chain (Structure)
Condition:- ( l > 2p - 4 )
Description:- The chain is locked, meaning no relative motion is possible between the links.
Example:- Three-bar chain.
2. Constrained Kinematic Chain
Condition:- ( l = 2p - 4 )
Description:- The chain has one degree of freedom, meaning it is a constrained kinematic chain.
Example:- Four-bar chain.
3.Unconstrained Chain
Condition:- ( l < 2p - 4 )
Description:- The chain is unconstrained, meaning the relative motion between the links is not completely constrained.
Example:- Five-bar chain.
Types of Kinematic chain :- 3 types
1. Four bar chain
2. Slider Crank chain
3. Double slider Crank chain