Machine Design 1 - December 2016
MU Mechanical Engineering (Semester 6)
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) What are the three different modes of failure of mechanical component? 5 marks
1(b) What is self locking and overhauling in screw jack? 5 marks
1(c) What are the assumptions made in design of weld joint? 5 marks
1(d) What are the different types coupling? 5 marks
1(e) What are the different types of spring? What are their different materials? 5 marks
2(a) A knuckle joint subject t an axial pull of 80 KN. Select suitable material and design and draw the joint. 5 marks
2(b) What is cotter? Why taper is provided on the cotter? 5 marks
3(a) A C-clamp is subjected to clamping force of 4 KN. Maximum distance between jaws is 30 mm. Distance between screw axis and frame axis is 100mm
i) Select appropriate materials and stresses for screw, nut and frame.
ii) Design screw and nut.
iii) Cehck screw for buckling failure.
Determine dimensions of cross section of frame. 5 marks
3(b) Discuss on various types threads used for power screw. 5 marks
4(a) Design a flexible coupling of pin bush type construction for connecting a reducing gear shaft to stone crusher shaft. The unit is driven by 30 KW, 720 rpm motor through 5:1 reduction. Choose suitable material and their design stresses for the parts of coupling. 5 marks
4(b) A steel plate subjected to force 5N and fixed to a channel by means of three identical bolts, as shown.The bolts are made of plain carbon steel 45C8 and the factor of safety is 3. Find the size of the bolts
!mage. 5 marks
5(a) Design the hollow shaft from the strength and rigidity consideration with the following data
i) Power to be transmited=60KW at 1440 r.p.m
ii) Ration of inner to outer diameter = 0.5
iii) Overhang = 250mm
iv) Bending load =20 KN
v) Permissible angle of twist =0.5° select suitable material. 5 marks
5(b) What is stress concentration? What are the various causes of stress concentration? Discuss the various methods to reduce the effect of stress concentration. 5 marks
6(a) A helical compression spring is subjected to a load varying from zero to maximum of 9KN, with corresponding deflection of 90 mm. Considering average service and spring steel having ultimate tensile strength σ=2000/d0.16 N/mm2, where d is diameter of spring wire in mm and G=80000 N/mm2.Determine
i) Wire diameter and coil diameter.
ii) Total numbers of coil
iii) Free length, pitch and helix angle.
iv) Check for solid stress. 5 marks
6(b) Explain neeping of the leaf spring with neat sketch. 5 marks
6(c) Discuss the materials and practical applications for the various types of springs. 5 marks