The reciprocating rectilinear motion mechanism consists of a disk pinned at its center at...

The reciprocating rectilinear motion mechanism consists of a disk pinned at its center at A that rotates with a constant angular velocity ωAB, a slotted arm CD that is pinned at C, and a bar that can oscillate within the guides at E and F. As the disk rotates, the peg at B moves within the slotted arm, causing it to rock back and forth. As the arm rocks, it provides a slow advance and a quick return to the reciprocating bar due to the change in distance between C and B.

Determine the angular velocity and angular acceleration of the slotted arm CD as functions of θ, δ = R/h, d, and ωAB. After doing so, plot the velocity and acceleration of the bar as a function of the disk angle θ for one full cycle of the disk’s motion and for ωAB = 90 rpm, d = 0.12 m, and

(a) δ = R/h = 0.1

(b) δ = R/h = 0.3

(c) δ = R/h = 0.6

(d) δ = R/h = 0.9

Explain why this mechanism is often referred to as a quick return mechanism.

Figure P6.115