Anna University Chennai 2007-3rd Sem B.E Mechanical Engineering ./B.Tech , ME 232 — KINEMATICS OF MACHINES - Question Paper

instantaneous centres. (5)
(ii) State the reasons for velocity and acceleration analysis. (3)
(iii) Derive the analytical expressions to determine the angular position
of the coupler and the angular position of the output link of a four
bar crank–rocker mechanism in terms of the link lengths and input
angular position. (8)
13. (a) (i) Sketch a cam–roller follower arrangement indicating important
cam terminologies and discuss them in detail. (8)
(ii) Sketch and briefly compare the displacement, velocity and
acceleration diagrams for uniform velocity, uniform acceleration
and retardation, simple harmonic motion and cycloidal motion, used
in cam mechanisms. (8)
Or
(b) A disc cam used for moving a knife edge follower with simple harmonic motion during lift and uniform acceleration and retardation motion during return rotates in clockwise direction at 300 rpm. The line of motion of the follower has an offset 10 mm to the right of camshaft axis. The minimum radius of the cam is 30 mm. The lift of the follower
is 40 mm. The cam rotation angles are : Lift 60?, dwell 90?, return 120? and remaining angle for dwell. Draw the cam profile and determine the maximum velocity and acceleration during the lift and return.
14. (a) 2 gear wheels mesh externally to provide a velocity ratio of three to 1. The involute teeth has six mm module and 20? pressure angle. Addendum is equal to 1 module. The pinion rotates at 90 rpm. Determine :
(i) Number of teeth on pinion to avoid interference and the corresponding number on the wheel (ii) the length of path and arc of contact (iii) contact ratio and (iv) the maximum velocity of sliding.
Or
(b) In a reverted epicyclic gear train, the arm A carries 2 gears and and a compound gear . The gear meshes with gear and the gear meshes with gear . The numbers of teeth on , and are 80, 48 and 72 respectively. obtain the speed and direction of gear when gear is fixed and arm A makes 400 rpm counter clockwise.
15. (a) (i) Prove or disprove the subsequent statement :
‘‘Angle of friction is equal to angle of repose’’. (6)
(ii) A bolt is having V–threads. The pitch of the threads is five mm and
the V–angle is 55?. The mean diameter of the bolt is 20 mm. The
bolt is tightened by screwing a nut. The mean radius of the bearing
surface of the nut is 25 mm. The load on the bolt is 5000 N. The
coefficient of friction for nut and bolt is 0.1 whereas for nut and
bearing surface is 0.16. Determine the force needed at the end of a
spanner 0.6 m long. (10)
Or
(b) (i) Briefly discuss the subsequent :
Slip of the belt and creep of the belt. (5)
(ii) An open belt drive connects 2 pulleys of 1.2 m and 0.5 diameters
on parallel shafts four m apart. The maximum tension in the belt is
1800 N. The coefficient of friction is 0.3. The driven pulley of
diameter 1.2 m runs at 250 rpm. compute the length of the belt
required, the power transmitted, and the torque on every of the two
shafts. (11)

Earning:   Approval pending.