1. MECHANISMS
Prof. kiran gore

2. How Mechanisms are made? Mechanism consist of following element
Mechanisms are used to obtain required motion in machines.
It is capable of transforming one type of input motion in to another.
How Mechanisms are made?
Mechanism consist of following element
Link or Element
Kinematic Pair
Kinematic Chain

3. What is a Link or Element?
A resistant body, which is a part of machine and has a motion relative to other connected part is known as an Element or Link.
Cylinder
Piston
Crank
Connecting Rod

4. What is resistant body ?
The body, which is capable of transmitting the forces with negligible deformation is called as resistant body.

5. Examples of Link or Element: Link1- Piston LInk2- Cylinder
Link 3- Crank
Link 4 Connecting Rod
Cylinder
Piston
Crank
Connecting Rod

6. What is a kinematics Pair?
When two element or link which are connected together in such way that the motion between them is constrained (in a definite direction) is known as kinematic Pair.
Kinematic Pair 2
1.Kinematic Pair –I
Crank & Frame
2.Kinematic Pair –II
Crank & Connecting Rod
3.Kinematic Pair- III
Connecting Rod & Piston
4.Kinematic Pair – IV
Piston & Cylinder 4 2 3 1

7. Kinematic chain
when the kinematic pair are connected in such manner that the last link is joined to the first link to transmit completely or successfully constrained motion, then it is called as kinematic chain

8. Ex. Kinematic chain

9. Mechanisms Example for Mechanism
If one of the links or element of a kinematic chain is fixed,
the arrangement can be used for transmitting or
transforming the motion, and it is called as Mechanism.
In short Mechanism is a kinematic chain with one link
fixed.
Example for Mechanism

10. Types of kinematic chain or Mechanism
Four bar chain or quadric cycle chain.
Single slider crank chain
Double slider crank chain

11. Four Bar Chain

12. Four Bar Chain Mechanism
It is simplest kinematics chain, consists of 4 links & forming 4 turning pair; A0, A, B, B0. Each link have different length.
If 1 link in 4 bar chain is fixed, then it is called as bar chain Mechanism & other 3 links moves relative to each other.

13. Four Bar Chain Mechanism
It is simplest kinematics chain, consists of 4 links & forming 4 turning pair; A0, A, B, B0. Each link have different length.
If 1st link in 4 bar chain is fixed, then it is called as 4 bar chain Mechanism & other 3 links moves relative to each other.

14. Slider Crank Chain
A single crank chain is a modification of the basic four-bar chain. It consists of one sliding pair and three turning pairs.
It is found in reciprocating steam engine mechanism.
This type of mechanism converts rotary motion into reciprocating motion and vice versa.
Links: Frame and cylinder, crank, connecting rod, crosshead or piston.

15. First Inversion of a single slider crank chain
Reciprocating engine and Air compressor
Links – 1- fixed
2- crank
3- connecting rod
4- slider

16. Slider Crank mechanism

17. Comparison between Mechanism & Machine

18. THANK YOU