MORE IN Machine Component Design
RGPV Mechanical Engineering (Semester 5)
Machine Component Design
December 2015
Total marks: --
Total time: --
INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1(a) State the causes of stress concentration in brief.
2 M
1(b) Define the terms:
i) Notch sensitivity
2 M
1(c) Draw Goodman's diagram. State its significance.
3 M
Solve any one question from Q.1(d) & Q.1(e)
1(d) Explain :
i) S-N curve
ii) Soderberg equation
7 M
1(e) A round, steel tension member, 1.5m long, is subjected to a maximum load of 4000kg.
i) What should be its diameter if the total elongation is not to exceed 3 mm?
ii) Choose a steel that would be suitable on the basis of yield strength if the load is gradually applied and repeated(not reversed).
7 M

2(a) Compare Rectangular sunk key, Square sunk key and parallel sunk key.
2 M
2(b) State the functions of shaft, axle and spindle.
2 M
2(c) How the strength of a steel material for shafting is estimated in ASME design code for shaft?
3 M
Solve any one question from Q.2(d) & Q.2(e)
2(d) A shaft carries a 900 N Pulley in the center of two ball bearings which are 1800 mm apart. The pulley is keyed to the shaft and receives 40kW of power at 150rpm. The power is transmitted from the shaft through a flexible coupling just outside the right bearing. The belt derive is horizontal and the sum of the belt tension is 8000N. Calculate the diameter of the shaft if permissible stress in bending is 90 N/mm2 and in shear it is 45 N/mm2.
7 M
2(e) Explain the steps for designing a shaft under dynamic load considering suitable example.
7 M

3(a) State about various types of springs.
2 M
3(b) Define Spring Buckling.
2 M
3 M
Solve any one question from Q.3(d) & Q.3(e)
3(d) Design a helical spring for a safety valve. The valve must below off at a pressure of 1.2 MPa and should lift by 3mm for 5% increase in pressure. The valve diameter is 55 mm. The max allowable shear stress is 400 MN/m2and the modulus of rigidity is 82.7×103MN/m2, Take the spring index as 9.
7 M
3(e) Design a valve spring of a petrol engine for the following operating conditions:
Spring load when valve is open=450N
Spring load when valve is closed=250N
Max. Inside diameter of spring=25mm
Length of spring when valve is open =40mm
Length of spring when valve is closed=50mm
Max. strength=400MPa
7 M

4(a) State the classification of breaks.
2 M
4(b) State the classifications of clutches with their applications.
2 M
4(c) Discuss uniform pressure an uniform wear theories for breaks and clutches.
3 M
Solve any one question from Q.4(d) & Q.4(e)
4(d) Discuss the design steps for disk brakes with formula used.
7 M
4(e) Design a cone clutch to transmit a power of 50kW at a rated speed of 700 rpm. Also determine:
i) The axial force capacity
ii) The axial force necessary to transmit the torque
7 M

5(a) Write Reynold's equation for journal bearing. State its significance.
2 M
5(b) State brief about factors affecting bearing life.
2 M
5(c) Explain brief about boundary lubrication in journal bearing.
3 M
Solve any one question from Q.5(d) & Q.5(e)
5(d) Derive Petroff's equation for the co-efficient of friction in a lightly loaded bearing.
7 M
5(e) Design the journal bearing for a centrifugal pump from the following data: