P08AU44 Theory of Machines–I B.E Model Question Paper : pescemandya.org

Name of the College : P.E.S College of Engineering
University : Visvesvaraya Technological University
Department : Automobile Engineering
Subject Code/Name : P08AU44/Theory of Machines–I
Year : July 2010
Degree : B.E
Sem : IV
Website : pescemandya.org
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/pescemandya.org/4669-qp.pdf

PES Theory of Machines–I Question Paper

Fourth Semester B.E. Degree Examination, July 2010
Model Question Paper :
Theory of Machines – I ( P08AU44)
Time : 3 Hrs Max. Marks : 100
Note : Answer any FIVE full questions selecting at least two questions from each part.

Related : P.E.S College Engineering P08AU64 CAD/CAM/CAE B.E Model Question Paper : www.pdfquestion.in/4677.html

PART – A

1 a. Define a kinematic chain. Describe various forms of kinematic chain with examples. (05 Marks)
b. Explain the Grubler’s mobility equation for a planar mechanism. Determine the mobility of a cam with an oscillating follower fitted with a roller. (05 Marks)
c. Sketch and explain the kinematic chain with three lower pairs. (05 Marks)
d. Sketch and explain the elliptical trammel mechanism. (05 Marks)

2. Sketch and explain the following mechanisms :
a. Geneva wheel (06 Marks)
b. Ratchet and Pawl mechanism (06 Marks)
c. Ackermann steering mechanism (08 Marks)

3. a. State and prove kennedy’s theorem. (05 Marks)
b. In a slider crank mechanism the lengths of crank and connecting rod are 125 mm and 500 mm respectively. The center of gravity G of the connecting rod is 275 mm from the slider. The crank speed is 600 rpm C.W. The crank makes 45 deg, from IDC cw. For the position shown locate all the instantaneous centres and find velocity of slider, point G and angular velocity of connecting rod. (15 Marks)

4. The stroke of a steam engine is 400 mm and the length of the connecting rod is 600 mm. The crank rotates at 300 rpm clockwise direction and the crank is inclined at 30° with the inner dead center. The center of gravity of the connecting rod is 240 mm away from the crank end. Determine the following
a. Velocity and acceleration of the piston.
b. Angular velocity and angular acceleration of the connecting rod.
c. Velocity and acceleration at the center of gravity of the connecting rod. (20 Marks)

PART – B

5. a. The thickness of an involute gear tooth is 4.98 mm at a radius of 50.8 mm and a pressure angle of 20°. Calculate the tooth thickness on the base circle. (05 Marks)

b. The following data refer to the two mating involute gears of 20° pressure angle: Number of

teeth on pinion is 30, gear ratio is 2, module is 12 mm and the speed of the pinion is 600 rpm. The line of contact on each side of the pitch is half the maximum possible length. Find the height of addendum for each gear wheel and the length of arc of contact. Also find the maximum velocity of sliding during approach and recess. (15 Marks)

6. a. Sketch and describe a bevel gear differential used in automobiles. (06 Marks)

b. A fixed annular gear A and a smaller concentric rotating gear B are connected by a compound gear CD. The gear C meshes with gear A and D with B. The compound gears revolved in a pin on the arm R, which revolves about the axis of A and B. The number of teeth on gears A, B and D are 150, 40 and 100 respectively. Determine the number of teeth on gear

C, if the gears A and C have twice the module of gears B and D. How many revolutions will B make for one complete revolution of the arm R? (14 Marks)

7. a. Derive the condition for maximum power to be transmitted by a flat belt drive and hence obtain the expression for the corresponding maximum velocity of the belt. (06 Marks)

b. A rope drive is required to transmit 230kW from a pulley of one metre diameter running at 450 RPM. The safe pull in each rope is 800 N and the mass of the rope is 0.46 kg per metre length. The angle of lap and the groove angles are 160° and 45° respectively. If the coefficient of friction between the rope and pulley surface is 0.3, calculate the number of ropes required. (14 Marks)

8. A cam with a base circle radius of 35 mm is rotating at a uniform speed of 100 rpm in anticlockwise direction. Draw the profile for the disc cam with reciprocating knife edge follower on the center line of the cam shaft for the following follower motion.
a. Follower to move upward 30 mm with simple harmonic motion in 0.1 sec.
b. Follower to dwell in next 0.15 sec.
c. Follower to move upward to another 30 mm with simple harmonic motion in 0.15 sec.

d. Follower to return to its starting position with uniform acceleration and retardation in the remaining period of one complete revolution of the cam shaft. However, the acceleration period is twice the retardation period.
Determine the maximum velocity and acceleration of the follower during its outward stoke. (20 Marks)