Lab Manual | To plot slider displacement, velocity & acceleration against crank rotation for Single slider crank Mechanisms

To plot slider displacement, velocity & acceleration against crank rotation for Single slider crank Mechanisms.

APPARATUS USED:- Single slider crank mechanism.

THEORY:-

1. Definition of Single slider cranks mechanism.

2. Working of Single slider crank mechanism.

A slider crank mechanism converts the reciprocating motion of a slider into a roatary motion of crank or vice-versa.

Velocity :- Fig. shows a slider –crank mechanism in which OA is the crank moving with uniform angular velocity in the clockwise direction. At point B, a slider moves on the fixed guide G. AB is the coupler joining A and B. it is required to find the velocity of the slider at B.

Velocity vector equation :

Velocity of B rel. to O = Vel. of B rel. to A + Vel. of A rel. to O

Vbo = Vba + Vao

Vbg = Vao + Vba

gb = oa + ab

Accelration :- Acc. Of B rel. to O = Acc. Of B rel. to A + Acc. Of A rel. to O

g1b1 = o1a1 + _a1ba + bab1

PROCEDURE:-

a) Bring the wheel & the slider to the respective reference marks.

b) For a given angle of rotation of the crank, note down the displacement of the slides.

c) Plot a graph between slider displacement & the crank rotation.

d) Assume that the crank is rotating with a uniform angular speed of one rad/sec.

e) Convert the crank rotation angle into time & plot the slider displacement versus time.

f) By graphical differentiation, determine the velocity time graph .

g) By graphical differentiation twice, determine the acceleration time graph.

h) Calculate the values of velocity & acceleration.

OBSERVATION TABLE :-

Crank Radius, r =

Length of Connecting rod, l =

PRECAUTIONS:-

1 Displacement of slider should be measured at equal intervals of crank angle rotation.

2 Smooth curves should be drawn while plotting.

VIVA-QUESTIONS :-

· What do you mean by I.C.R. ?

· What is the formulae for calculating I.C.R for all mechanisms ?

· How will you find I.C.R. of velocity for 4 bar chain mechanisms and single slider crank mechanism?

· How will you find graphically & analytically the methods of velocity & acc. Analysis of 4-bar chain mechanism and single slider crank mechanism. ?