Rajasthan Technical University 2009 B.Tech Mechanical Engineering Design of Machine Elements-I - Question Paper
Rajasthan tech. University
B.tech four sem (Main/back)
Year 2009
Design of Machine Elements-I
Total Mo. of Questions : 10) rnftl No. ofVges 4
B.Tech. I Vth Semester (Maia/paek) E**eisetion - 2009 Mechanical rjjlnrrriti
DesfgnfMachfrfe Elements-I 4E20&
Time : 3 Hoars Maximum Marks : 80
Total Mo. of Questions : 10) rnftl No. ofVges 4
Min. Passing Marks : 24
Instructions to Candidates:
Attempt overall Five Questions sele&hig one question from each unit. AH questions carry equal marks. (Schert&tic diagrams must be shown wherever necessary. Any data you feel missing mty suitably be assumed and slated dearly. Units of quantities used/calculated mu.\t be stated clearly.)
Until
1. a) What are the factors that affectjthe selection of material for engineering put?**? 'Explain. '' '-
b) What are the desirable mechanical properties of metals? Explain.
c) On what basis steels are designated? Explain with the help of examples.
d) What is the effect of adding impurities on cast iron? Explain. (4+4+4+4)
4E2049 / 5,000 (1) [Contd....
Unit -IV
7. A shaft is supported by two bearings placed lm apart. A 600 mm diameter J pulley is mounted at a distance of 300 mm to tfib ifyjBHtfleft hand bearing and
this drives a pulley directly below it with the help of belt having maximum tension of 2.25 kN. Another pulley 400 mm diameter is placed 200 mm to the left of right hand bearing and is driver? with the help of electric motor and belt which is placed horizontally to the right. Angle of contact is 180 &fj is 0.24. Determine suitable diameter of shaft, assuming safe stress as 63MPa in tension and 42 MPa in shear for the shaft-matgljal. (16)
8. a) Explain oldham coupling- and
sketch.
b) The shaft and the flange of a marine engine are to be designed for flange coupling, in which the flange is forced on the end of the shaft. The following particulars are to be considered indesign -Power of the engine = 3MW Speed of the engine = 100 rpm Permissible shear stress in bolt & phaft = 60 MPa No. of bolts used - 8
Pitch circle diameter of bolts = 1.6 x dia. of shaft Find
i) Diameter of shaft
ii) Diameter of bolts
iii) Thickness of flange and
Total Mo. of Questions : 10) rnftl No. ofVges 4
iv) Diameter of flange. (6+10)
Unit-V
9. a) A mild steel bracket as shown in figure 1 is subjected to a pull of 5 kN acting at an angle of 30" to the vertical. The bracket has a rectangular section whose thickness is Y% of*15 width. Determine the section of bracket if the permissible stress in the material is limited to 55 MPa
Unit -IV
7. A shaft is supported by two bearings placed lm apart. A 600 mm diameter J pulley is mounted at a distance of 300 mm to tfib ifyjBHtfleft hand bearing and
this drives a pulley directly below it with the help of belt having maximum tension of 2.25 kN. Another pulley 400 mm diameter is placed 200 mm to the left of right hand bearing and is driver? with the help of electric motor and belt which is placed horizontally to the right. Angle of contact is 180 &fj is 0.24. Determine suitable diameter of shaft, assuming safe stress as 63MPa in tension and 42 MPa in shear for the shaft-matgljal. (16)
8. a) Explain oldham coupling- and
sketch.
b) The shaft and the flange of a marine engine are to be designed for flange coupling, in which the flange is forced on the end of the shaft. The following particulars are to be considered indesign -Power of the engine = 3MW Speed of the engine = 100 rpm Permissible shear stress in bolt & phaft = 60 MPa No. of bolts used - 8
Pitch circle diameter of bolts = 1.6 x dia. of shaft Find
i) Diameter of shaft
ii) Diameter of bolts
iii) Thickness of flange and
Total Mo. of Questions : 10) rnftl No. ofVges 4
iv) Diameter of flange. (6+10)
Unit-V
9. a) A mild steel bracket as shown in figure 1 is subjected to a pull of 5 kN acting at an angle of 30" to the vertical. The bracket has a rectangular section whose thickness is Y% of*15 width. Determine the section of bracket if the permissible stress in the material is limited to 55 MPa
b) A shaft is transmitting 100 kW at 180 rpm. If the allowable stress in the material is 60 MPa, find the suitable diameter for the shaft. The shaft is not to twist more than 1 in a length of 3 meters. Take modulus of rigidity G as 80 GPa. (10+6)
10. a) A simply supported beam carries a concentrated load of 2kN at its centre. Calculate maximum deflection of beam and its location.
 |
|
Figure - 2 |
Cross section is circular with diameter as 5 mm and modulus of elasticity E is 200 GPa.
b) Determine the size of the bolts and the thickness of the arm for the bracket as shown in figure 3. It carries a load of 40 kN at an angle of 60" to the vertical. The material for the bracket and the bolt is same & safe stresses arc 70, 50 & 105 MPa in tension sear & compression respectively. (6+10)
4E2049
|
Attachment: |
| Earning: Approval pending. |
