The Scotch yoke (also known as slotted link mechanism[1]) is a reciprocating motion mechanism, converting the linear motion of a slider into rotational motion, or vice versa.
The piston or other reciprocating part is directly coupled to a sliding yoke with a slot that engages a pin on the rotating part.
The term "inversion of mechanism" refers to the practice of fixing one link at a time in a kinematic chain to get different mechanisms. In the four bar linkage mechanism, it is expected that the number of inversions will equal the total number of links in the kinematic chain.
It's like obtaining different variations of a mechanism.
In purely rotational motion, allpoints on the object move incircles around the axis ofrotation (“O”). The radius ofthe circle is R. All points on astraight line drawn through theaxis move through the sameangle in the same time.
Imagine a straight line going through the object and see if it rotates.