Ans.
Links -
link AD frame (Fixed)
link AB (Crank)
link BC (Coupling Rod)
link CD (Crank)
Pairs -
Turning Pair = AD (Frame) & AB (Crank)
Turning Pair = AD (Frame) & CD (Crank)
Turning Pair = AB (Crank) & BC (Connecting Rod)
Turning Pair = CD (Crank) & BC (Connecting Rod)
Construction:
This mechanism is an inversion four bar kinematic chain . This has four turning pairs.
It is consists of frame AD which is fixed, on which two cranks AC & BD are fitted on it .The cranks are free to rotate about points A and D. Both the cranks have same lengths. Two cranks are connected to each other by means of coupling rod, which connects the other ends B and C of both cranks. At the connections B and C there is turning pair.
Working –
When link AB starts rotating about fixed point A. The rotary motion of wheel is transmitted to next wheel by means of coupling rod BC. As a result the other wheel also starts rotating in same direction and same speed, because both cranks have same radius of rotation.
Application –
The mechanism is used to connect driving & driven shaft of locomotive. Here both driving & driven wheels always rotate in same direction.