27438962 Rr 321401 Principles of Machine Design
8
SET-1 RR Code.No: 26045 JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD III .B.TECH –II SEM SUPPLEMENTARY EXAMINATIONS JANUARY- 2010 PRINCIPLES OF MACHINE DESIGN (MECHATRONICS) Time: 3hours Max.Marks:80 Answer any FIVE questions All questions carry equal marks - - - 1. A shaft is subjected to a twisting moment of 5 kN-m and a bending moment of 2kN-m. If the material has S y = 330 MPa and F.S = 2, find the diameter of shaft using a) Maximum shear stress theory. b) Maximum energy of distortion theory. [8+8] 2.a) What are the usual methods of manufacturing of shafts? b) A 250mm diameter solid shaft is used to drive the propeller of marine vessel. It is necessary to reduce the weight of the shaft by 70%. What would be the dimension of a hallow shaft made of the same material as the solid shaft? [8+8] 3. A hydrodynamic full journal bearing is to carry a load of 25 kN at a speed of 3000rpm. The journal diameter is 150 mm and the length of bearing is 75 mm. SAE 30 oil is used with an average operating temperature of 55 0 C. If the radial clearance is 0.075 mm, calculate the power loss, the side leakage and the minimum film thickness. [16] 4. Design and give a dimensioned sketch of a rigid flange coupling for the following specifications: Diameter of shafts to be connected = 50 mm Number of machined bolts fitted to reamed holes = 4 Pitch circle diameter of bolts = 150 mm The material for the bolts and the shafts is the same and has an ultimate strength of 525 MN/m 2 with yield point in tension of 315 MN/m 2 . The size of the bolts should be such as to have the same capacity as the shaft in torsion. Assume that the bolts are “finger tight” and the shear stress in uniformly distributed in the shank of bolts under load. [16] 5. A thin-walled spherical pressure vessel of 1 m diameter is subjected to a cyclic water pressure which varies between 3 and 7 MPa. The vessel will be fabricated from annealed steel having σ u = 665 MN/m 2 , σ y = 325 MN/m 2 σ` e = 315 MN/m 2 . Find the required thickness of the shell to have a factor of safety of 1.6. [16]
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Transcript of 27438962 Rr 321401 Principles of Machine Design
SET-1RRCode.No: 26045
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD III .B.TECH –II SEM SUPPLEMENTARY EXAMINATIONS JANUARY- 2010
PRINCIPLES OF MACHINE DESIGN (MECHATRONICS)
Time: 3hours Max.Marks:80 Answer any FIVE questions
All questions carry equal marks - - -
1. A shaft is subjected to a twisting moment of 5 kN-m and a bending moment of
2kN-m. If the material has Sy = 330 MPa and F.S = 2, find the diameter of shaft using
a) Maximum shear stress theory. b) Maximum energy of distortion theory. [8+8] 2.a) What are the usual methods of manufacturing of shafts? b) A 250mm diameter solid shaft is used to drive the propeller of marine vessel. It is
necessary to reduce the weight of the shaft by 70%. What would be the dimension of a hallow shaft made of the same material as the solid shaft? [8+8]
3. A hydrodynamic full journal bearing is to carry a load of 25 kN at a speed of
3000rpm. The journal diameter is 150 mm and the length of bearing is 75 mm. SAE 30 oil is used with an average operating temperature of 55 0C. If the radial clearance is 0.075 mm, calculate the power loss, the side leakage and the minimum film thickness. [16]
4. Design and give a dimensioned sketch of a rigid flange coupling for the following
specifications: Diameter of shafts to be connected = 50 mm Number of machined bolts fitted to reamed holes = 4 Pitch circle diameter of bolts = 150 mm The material for the bolts and the shafts is the same and has an ultimate strength of
525 MN/m2 with yield point in tension of 315 MN/m2. The size of the bolts should be such as to have the same capacity as the shaft in torsion. Assume that the bolts are “finger tight” and the shear stress in uniformly distributed in the shank of bolts under load. [16]
5. A thin-walled spherical pressure vessel of 1 m diameter is subjected to a cyclic
water pressure which varies between 3 and 7 MPa. The vessel will be fabricated from annealed steel having σu = 665 MN/m2, σy = 325 MN/m2 σ`e = 315 MN/m2. Find the required thickness of the shell to have a factor of safety of 1.6. [16]
6. Design a piston, piston rings and gudgeon pin for a single acting four stroke engine
or the following given data: Cylinder bore = 100 mm Stroke = 125 mm Maximum gas pressure = 5 MPa BMEP = 0.6 MPa Fuel consumption = 0.15 kg/Break kW/h Speed = 2000 rpm. [16] 7. Design a V-belt drive to be used from an electric motor to the flywheel of a forging
press, given the following data. Motor power 100 kW Over load factor: 1.6 Speed of the motor: 740 rpm Speed of the fly wheel: 250 rpm Diameter of the flywheel pulley: 15000 rpm Center distance: 2000 mm approx. [16] 8. A 15 kW and 1200 rpm. Motor drives a compressor at 300 rpm through a pair of
spur gears having 200 stub teeth. The center to center distance between the shafts is 400 mm. The motor pinion is made of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day under light shock conditions, find from standpoint of strength,
a) Module b) Face width and
c) Number of teeth and pitch circle diameter of each gear. Check the gears thus designed from consideration of wear. The surface endurance limit may be taken as 700 MPa. [5+5+6]
--ooOoo--
SET-2RRCode.No: 26045
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD III .B.TECH –II SEM SUPPLEMENTARY EXAMINATIONS JANUARY- 2010
PRINCIPLES OF MACHINE DESIGN (MECHATRONICS)
Time: 3hours Max.Marks:80 Answer any FIVE questions
All questions carry equal marks - - -
1. A hydrodynamic full journal bearing is to carry a load of 25 kN at a speed of
3000rpm. The journal diameter is 150 mm and the length of bearing is 75 mm. SAE 30 oil is used with an average operating temperature of 55 0C. If the radial clearance is 0.075 mm, calculate the power loss, the side leakage and the minimum film thickness. [16]
2. Design and give a dimensioned sketch of a rigid flange coupling for the following
specifications: Diameter of shafts to be connected = 50 mm Number of machined bolts fitted to reamed holes = 4 Pitch circle diameter of bolts = 150 mm The material for the bolts and the shafts is the same and has an ultimate strength of
525 MN/m2 with yield point in tension of 315 MN/m2. The size of the bolts should be such as to have the same capacity as the shaft in torsion. Assume that the bolts are “finger tight” and the shear stress in uniformly distributed in the shank of bolts under load. [16]
3. A thin-walled spherical pressure vessel of 1 m diameter is subjected to a cyclic
water pressure which varies between 3 and 7 MPa. The vessel will be fabricated from annealed steel having σu = 665 MN/m2, σy = 325 MN/m2 σ`e = 315 MN/m2. Find the required thickness of the shell to have a factor of safety of 1.6. [16]
4. Design a piston, piston rings and gudgeon pin for a single acting four stroke engine
or the following given data: Cylinder bore = 100 mm Stroke = 125 mm Maximum gas pressure = 5 MPa BMEP = 0.6 MPa Fuel consumption = 0.15 kg/Break kW/h Speed = 2000 rpm. [16]
5. Design a V-belt drive to be used from an electric motor to the flywheel of a forging press, given the following data.
Motor power 100 kW Over load factor: 1.6 Speed of the motor: 740 rpm Speed of the fly wheel: 250 rpm Diameter of the flywheel pulley: 15000 rpm Center distance: 2000 mm approx. [16] 6. A 15 kW and 1200 rpm. Motor drives a compressor at 300 rpm through a pair of
spur gears having 200 stub teeth. The center to center distance between the shafts is 400 mm. The motor pinion is made of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day under light shock conditions, find from standpoint of strength,
a) Module b) Face width and
c) Number of teeth and pitch circle diameter of each gear. Check the gears thus designed from consideration of wear. The surface endurance limit may be taken as 700 MPa. [5+5+6]
7. A shaft is subjected to a twisting moment of 5 kN-m and a bending moment of
2kN-m. If the material has Sy = 330 MPa and F.S = 2, find the diameter of shaft using
a) Maximum shear stress theory. b) Maximum energy of distortion theory. [8+8] 8.a) What are the usual methods of manufacturing of shafts?
b) A 250mm diameter solid shaft is used to drive the propeller of marine vessel. It is necessary to reduce the weight of the shaft by 70%. What would be the dimension of a hallow shaft made of the same material as the solid shaft? [8+8]
--ooOoo--
SET-3RRCode.No: 26045
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD III .B.TECH –II SEM SUPPLEMENTARY EXAMINATIONS JANUARY- 2010
PRINCIPLES OF MACHINE DESIGN (MECHATRONICS)
Time: 3hours Max.Marks:80 Answer any FIVE questions
All questions carry equal marks - - -
1. A thin-walled spherical pressure vessel of 1 m diameter is subjected to a cyclic
water pressure which varies between 3 and 7 MPa. The vessel will be fabricated from annealed steel having σu = 665 MN/m2, σy = 325 MN/m2 σ`e = 315 MN/m2. Find the required thickness of the shell to have a factor of safety of 1.6. [16]
2. Design a piston, piston rings and gudgeon pin for a single acting four stroke engine
or the following given data: Cylinder bore = 100 mm Stroke = 125 mm Maximum gas pressure = 5 MPa BMEP = 0.6 MPa Fuel consumption = 0.15 kg/Break kW/h Speed = 2000 rpm. [16] 3. Design a V-belt drive to be used from an electric motor to the flywheel of a forging
press, given the following data. Motor power 100 kW Over load factor: 1.6 Speed of the motor: 740 rpm Speed of the fly wheel: 250 rpm Diameter of the flywheel pulley: 15000 rpm Center distance: 2000 mm approx. [16] 4. A 15 kW and 1200 rpm. Motor drives a compressor at 300 rpm through a pair of
spur gears having 200 stub teeth. The center to center distance between the shafts is 400 mm. The motor pinion is made of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day under light shock conditions, find from standpoint of strength,
a) Module b) Face width and
c) Number of teeth and pitch circle diameter of each gear. Check the gears thus designed from consideration of wear. The surface endurance limit may be taken as 700 MPa. [5+5+6]
5. A shaft is subjected to a twisting moment of 5 kN-m and a bending moment of 2kN-m. If the material has Sy = 330 MPa and F.S = 2, find the diameter of shaft using
a) Maximum shear stress theory. b) Maximum energy of distortion theory. [8+8] 6.a) What are the usual methods of manufacturing of shafts? b) A 250mm diameter solid shaft is used to drive the propeller of marine vessel. It is
necessary to reduce the weight of the shaft by 70%. What would be the dimension of a hallow shaft made of the same material as the solid shaft? [8+8]
7. A hydrodynamic full journal bearing is to carry a load of 25 kN at a speed of
3000rpm. The journal diameter is 150 mm and the length of bearing is 75 mm. SAE 30 oil is used with an average operating temperature of 55 0C. If the radial clearance is 0.075 mm, calculate the power loss, the side leakage and the minimum film thickness. [16]
8. Design and give a dimensioned sketch of a rigid flange coupling for the following
specifications: Diameter of shafts to be connected = 50 mm Number of machined bolts fitted to reamed holes = 4 Pitch circle diameter of bolts = 150 mm The material for the bolts and the shafts is the same and has an ultimate strength of
525 MN/m2 with yield point in tension of 315 MN/m2. The size of the bolts should be such as to have the same capacity as the shaft in torsion. Assume that the bolts are “finger tight” and the shear stress in uniformly distributed in the shank of bolts under load. [16]
--ooOoo--
SET-4RRCode.No: 26045
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD III .B.TECH –II SEM SUPPLEMENTARY EXAMINATIONS JANUARY- 2010
PRINCIPLES OF MACHINE DESIGN (MECHATRONICS)
Time: 3hours Max.Marks:80 Answer any FIVE questions
All questions carry equal marks - - -
1. Design a V-belt drive to be used from an electric motor to the flywheel of a forging
press, given the following data. Motor power 100 kW Over load factor: 1.6 Speed of the motor: 740 rpm Speed of the fly wheel: 250 rpm Diameter of the flywheel pulley: 15000 rpm Center distance: 2000 mm approx. [16] 2. A 15 kW and 1200 rpm. Motor drives a compressor at 300 rpm through a pair of
spur gears having 200 stub teeth. The center to center distance between the shafts is 400 mm. The motor pinion is made of forged steel having an allowable static stress as 210 MPa, while the gear is made of cast steel having allowable static stress as 140 MPa. Assuming that the drive operates 8 to 10 hours per day under light shock conditions, find from standpoint of strength,
a) Module b) Face width and
c) Number of teeth and pitch circle diameter of each gear. Check the gears thus designed from consideration of wear. The surface endurance limit may be taken as 700 MPa. [5+5+6]
3. A shaft is subjected to a twisting moment of 5 kN-m and a bending moment of
2kN-m. If the material has Sy = 330 MPa and F.S = 2, find the diameter of shaft using
a) Maximum shear stress theory. b) Maximum energy of distortion theory. [8+8] 4.a) What are the usual methods of manufacturing of shafts? b) A 250mm diameter solid shaft is used to drive the propeller of marine vessel. It is
necessary to reduce the weight of the shaft by 70%. What would be the dimension of a hallow shaft made of the same material as the solid shaft? [8+8]
5. A hydrodynamic full journal bearing is to carry a load of 25 kN at a speed of
3000rpm. The journal diameter is 150 mm and the length of bearing is 75 mm. SAE 30 oil is used with an average operating temperature of 55 0C. If the radial clearance is 0.075 mm, calculate the power loss, the side leakage and the minimum film thickness. [16]
6. Design and give a dimensioned sketch of a rigid flange coupling for the following
specifications: Diameter of shafts to be connected = 50 mm Number of machined bolts fitted to reamed holes = 4 Pitch circle diameter of bolts = 150 mm The material for the bolts and the shafts is the same and has an ultimate strength of
525 MN/m2 with yield point in tension of 315 MN/m2. The size of the bolts should be such as to have the same capacity as the shaft in torsion. Assume that the bolts are “finger tight” and the shear stress in uniformly distributed in the shank of bolts under load. [16]
7. A thin-walled spherical pressure vessel of 1 m diameter is subjected to a cyclic
water pressure which varies between 3 and 7 MPa. The vessel will be fabricated from annealed steel having σu = 665 MN/m2, σy = 325 MN/m2 σ`e = 315 MN/m2. Find the required thickness of the shell to have a factor of safety of 1.6. [16]
8. Design a piston, piston rings and gudgeon pin for a single acting four stroke engine
or the following given data: Cylinder bore = 100 mm Stroke = 125 mm Maximum gas pressure = 5 MPa BMEP = 0.6 MPa Fuel consumption = 0.15 kg/Break kW/h Speed = 2000 rpm. [16]
--ooOoo--
