KOM- இயந்திர இயங்கியல் 113302 / ME 2203

ME 2203 KINEMATICS OF MACHINERY
QUESTION BANK
1. List the classifications of cam followers based on shape.
2. Define rubbing velocity.
3. State Kennedy’ s theorem.
4. Define Corioli's component of acceleration.
5. State the expressions for maximum velocity and acceleration of a follower moves with
Cycloidal motion.
6. What is prime circle of a cam? What is the radial distance between the prime circle and
base circle for a cam with knife edge follower?
7. Define pitch curve of the cam.
8. Explain tangential and normal component of acceleration.
9. Construct a tangent cam and mention the important terminologies on it.
10. Define transmission angle of a four bar linkage. What is the effect of transmission angle
on mechanical advantage?
11. What are the properties of instant centers?
12. How is the number of instant centers in a mechanism calculated?
13. Give the difference between the fixed and permanent instant centres.
14. Write a note on the location of instant centres.
15. Explain the terminologies in cams a) prime circle b) lift c)pitch curve d) Base circle
16. Give the difference between the radial and tangential cam.
17. Sketch the different types of followers.
18. Draw the displacement diagram[ free hand sketching] for a SHM follower: outstroke 180 0, return 1800 lift 40 mm.
19. Sketch the velocity and acceleration diagram [ free hand sketching] for uniform velocity follower assuming 40 mm lift , 1200 deg outstroke, 600 dwell, 90 0 return stroke and 90 0 dwell.
20. Explain the term pressure angle with respect to cams.

16 marks
1. (i) Find the number of instantaneous centers for a six link mechanism. State the use of instantaneous centre method in kinematic analysis. (4)
(ii) Crank of a slider crank mechanism rotates clockwise at a constant speed of 300 rpm, crank and connecting rod are of lengths 150 mm and 600 respectively. Determine the following; at a crank angle of 45° from inner dead centre position (1) Linear velocity and acceleration of the midpoint of connecting rod (2) Angular velocity and angular acceleration of the connecting rod. (12)
2. (i) Explain the following terms : (1) Prime circle (2) Pressure Angle related to cams. (4)
(ii) Draw the profile of a disc cam to give uniform motion and uniform velocity during outstroke of 25 mm to a knife edge follower during first half revolution. Return of cam is also of similar uniform motion with uniform velocity during remaining half revolution. Minimum radius of the cam is 25 mm. Assume that the axis of knife edge follower passes through cam axis.
3. i) Briefly explain the features of mushroom followers. (4)
(ii) Draw the profile of a cam to give following motion to a flat faced reciprocating follower. (1) Follower to have a stroke of 20 mm during 120° of cam rotation. (2) Follower to dwell for 30° of cam rotation (3) Follower to return to initial position during 120° of cam rotation. (4) Follower to dwell for remaining 90° of cam rotation. The base circle radius is 40 mm and the follower axis coincides with cam axis of rotation. (12)
4. (i) Compare instantaneous center method and velocity polygon method for velocity
analysis of mechanisms. (4)
(ii) A four bar linkage has following dimensions: Crank AO2 = 150 mm; Link AB = 450 mm;
Link BO4 = 300 mm; Link O2O4 = 200 mm. Link O2O4 is fixed. Find the angular acceleration of links AB and BO4 when the crank is rotating with a constant angular velocity of 200 rad/s counter clockwise and also positioned of 45° to horizontal. (12)
5. Draw the profile of a cam to give following motion to a reciprocating follower with a flat face:
(i) Follower to have a stroke of 20 mm during 120° of cam rotation. (ii) Follower to dwell for 30° of cam rotation. (iii) Follower to return to its initial position during 120° of cam rotation. (iv) Follower to dwell for remaining 90° of cam rotation. Minimum radius of cam = 25 mm. Out stroke and return stroke of the follower are simple harmonic.
6.A cam with a minimum radius of 25 mm, rotating in clockwise direction with a uniform
speed of 100 rpm is to be designed to give the motion for a roller follower as follows. (i) To raise through 50 mm during 120° rotation of cam with SHM. (ii) Fully raised through next 30°. (iii) To lower during next 60° with UAUR. (iv) Dwell for the remaining period. Draw the profile of the cam when the line of stroke of the follower is offset by 15 mm from the axis of the camshaft.

7. Draw the profile of disc cam to give uniform acceleration and retardation out stroke of 25
to a knife edge follower during first half of revolution. Return of cam also takes place with
uniform motion during remaining half of cam revolution. Assume minimum radius of cam as 25 mm.

8. The driving crank AD of the quick-return mechanism, as shown in figure, revolves at a uniform speed of 200 r.p.m. Find the velocity and acceleration of the tool-box R, in the position shown, when the crank makes an angle of 60°with the vertical line of centers PA. What is the acceleration of sliding of the block at B along the slotted lever PQ?Refer the picture in the top.