Categories: Third Year Second Semester (3-2)

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

5 A crane hook made from a 50mm diameter bar as shown in below figure. Find the

maximum tensile stress and specify its location.

.

[16M]

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

[16M]

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

5 A crane hook made from a 50mm diameter bar as shown in below figure. Find the

maximum tensile stress and specify its location.

.

[16M]

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

[16M]

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

[16M]

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

5 A crane hook made from a 50mm diameter bar as shown in below figure. Find the

maximum tensile stress and specify its location.

.

[16M]

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

[16M]

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

[16M]

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

maximum tensile stress and specify its location.

.

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

[16M]

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is the significance of bearing Number? [4M]

b) Define Bending Stiffness? [2M]

c) Enumerate the different types of materials used for the cylinder liners. [4M]

d) Write short note on classifications and different types of anti friction bearings. [4M]

e) Sketch the cross section of a V belt and label its important parts. [4M]

f) What is the function of connecting rod of IC engine? [4M]

PART -B

2 a) A 100 mm long and 60 mm diameter journal bearing supports a load of 2500 N at

600 rpm. If the room temperature is 20

o

C, what should be the viscosity of oil to limit

the bearing surface temperature to 60

o

C? Diametral clearance = 0.06 mm. Energy

dissipation coefficient based on the projected area of the bearing = 210 W/m

2o

C

[8M]

b) A 250?250 mm bearing carries a load of 108 KN. The bearing rotates at 1500 rpm.

The clearance ratio is 670. For full journal bearing the power lost in friction is

14.36 KW. Find the viscosity of the oil.

[8M]

3 The following data is given for a connecting rod:

Engine speed =1500 rpm

Length of connecting rod=320 mm

Length of stroke=140 mm

Density of the material=7830 Kg/m

3

Thickness of web flanges= 6 mm

The cross section of the connecting rod is I section.

Upper and bottom flange dimensions are = 4mm

Web dimensions are = 3mm

Calculate the whipping stress in connecting rod.

[16M]

4 a)Explain different materials used for piston

b)The following data is given for the piston of a four stroke diesel engine.

The following data is given for the piston of a four stroke diesel engine.

Cylinder bore = 120 mm

Maximum gas pressure = 6 MPa

Allowable bearing pressure for skirt = 0.45 MPa

Ratio of side thrust on liner to maximum gas load on piston=0.1

Width of top land =20 mm

Width of ring grooves = 3 mm

Total number of piston rings = 4

Axial thickness of piston rings = 3.5 mm

Calculate (i)length of skirt (ii) length of piston

1 of 2

[6M]

[10M]

R13

SET – 3

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

maximum tensile stress and specify its location.

.

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is the significance of bearing Number? [4M]

b) Define Bending Stiffness? [2M]

c) Enumerate the different types of materials used for the cylinder liners. [4M]

d) Write short note on classifications and different types of anti friction bearings. [4M]

e) Sketch the cross section of a V belt and label its important parts. [4M]

f) What is the function of connecting rod of IC engine? [4M]

PART -B

2 a) A 100 mm long and 60 mm diameter journal bearing supports a load of 2500 N at

600 rpm. If the room temperature is 20

o

C, what should be the viscosity of oil to limit

the bearing surface temperature to 60

o

C? Diametral clearance = 0.06 mm. Energy

dissipation coefficient based on the projected area of the bearing = 210 W/m

2o

C

[8M]

b) A 250?250 mm bearing carries a load of 108 KN. The bearing rotates at 1500 rpm.

The clearance ratio is 670. For full journal bearing the power lost in friction is

14.36 KW. Find the viscosity of the oil.

[8M]

3 The following data is given for a connecting rod:

Engine speed =1500 rpm

Length of connecting rod=320 mm

Length of stroke=140 mm

Density of the material=7830 Kg/m

3

Thickness of web flanges= 6 mm

The cross section of the connecting rod is I section.

Upper and bottom flange dimensions are = 4mm

Web dimensions are = 3mm

Calculate the whipping stress in connecting rod.

[16M]

4 a)Explain different materials used for piston

b)The following data is given for the piston of a four stroke diesel engine.

The following data is given for the piston of a four stroke diesel engine.

Cylinder bore = 120 mm

Maximum gas pressure = 6 MPa

Allowable bearing pressure for skirt = 0.45 MPa

Ratio of side thrust on liner to maximum gas load on piston=0.1

Width of top land =20 mm

Width of ring grooves = 3 mm

Total number of piston rings = 4

Axial thickness of piston rings = 3.5 mm

Calculate (i)length of skirt (ii) length of piston

1 of 2

[6M]

[10M]

R13

SET – 3

Code No: RT32033

5 The curved beam in Fig:1 has a circular cross section 50 mm in diameter. The inside

diameter of the curved beam is 40 mm. Determine the stress at B for P=20 KN.

Fig:1

[16M]

6 A pair of helical gears with 30

0

helix angle is used to transmit 15 KW at10000 rpm

of the pinion. The velocity ratio is 4:1. Both gears are to be made of hardened steel

of static strength 100MPa. The gears are 20

0

stub and the pinion is to have 24 teeth.

The face width may be taken as14 times the module. Find the module and face

width from the stand point of strength and check the gears for wear.

[16M]

7 a) Explain various materials used for machine tool beds. [8M]

b) Write various steps involved in design of lathe bed. [8M]

*****

2 of 2

R13

SET – 3

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

maximum tensile stress and specify its location.

.

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is the significance of bearing Number? [4M]

b) Define Bending Stiffness? [2M]

c) Enumerate the different types of materials used for the cylinder liners. [4M]

d) Write short note on classifications and different types of anti friction bearings. [4M]

e) Sketch the cross section of a V belt and label its important parts. [4M]

f) What is the function of connecting rod of IC engine? [4M]

PART -B

2 a) A 100 mm long and 60 mm diameter journal bearing supports a load of 2500 N at

600 rpm. If the room temperature is 20

o

C, what should be the viscosity of oil to limit

the bearing surface temperature to 60

o

C? Diametral clearance = 0.06 mm. Energy

dissipation coefficient based on the projected area of the bearing = 210 W/m

2o

C

[8M]

b) A 250?250 mm bearing carries a load of 108 KN. The bearing rotates at 1500 rpm.

The clearance ratio is 670. For full journal bearing the power lost in friction is

14.36 KW. Find the viscosity of the oil.

[8M]

3 The following data is given for a connecting rod:

Engine speed =1500 rpm

Length of connecting rod=320 mm

Length of stroke=140 mm

Density of the material=7830 Kg/m

3

Thickness of web flanges= 6 mm

The cross section of the connecting rod is I section.

Upper and bottom flange dimensions are = 4mm

Web dimensions are = 3mm

Calculate the whipping stress in connecting rod.

[16M]

4 a)Explain different materials used for piston

b)The following data is given for the piston of a four stroke diesel engine.

The following data is given for the piston of a four stroke diesel engine.

Cylinder bore = 120 mm

Maximum gas pressure = 6 MPa

Allowable bearing pressure for skirt = 0.45 MPa

Ratio of side thrust on liner to maximum gas load on piston=0.1

Width of top land =20 mm

Width of ring grooves = 3 mm

Total number of piston rings = 4

Axial thickness of piston rings = 3.5 mm

Calculate (i)length of skirt (ii) length of piston

1 of 2

[6M]

[10M]

R13

SET – 3

Code No: RT32033

5 The curved beam in Fig:1 has a circular cross section 50 mm in diameter. The inside

diameter of the curved beam is 40 mm. Determine the stress at B for P=20 KN.

Fig:1

[16M]

6 A pair of helical gears with 30

0

helix angle is used to transmit 15 KW at10000 rpm

of the pinion. The velocity ratio is 4:1. Both gears are to be made of hardened steel

of static strength 100MPa. The gears are 20

0

stub and the pinion is to have 24 teeth.

The face width may be taken as14 times the module. Find the module and face

width from the stand point of strength and check the gears for wear.

[16M]

7 a) Explain various materials used for machine tool beds. [8M]

b) Write various steps involved in design of lathe bed. [8M]

*****

2 of 2

R13

SET – 3

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is a Gear? Classify. [4M]

b) Why trapezoidal cross ? section is more appropriate for crane hook? [2M]

c) Enumerate materials used for the bearings. [4M]

d) What is the function of the piston ring. Explain the materials used for the piston

rings.

[4M]

e) What are the methods and materials used for manufacture of crank shaft? [4M]

f) Why are square threads preferable over V-threads for power transmission? [4M]

PART -B

2 a) What are the various terms used the journal bearings analysis and design. Give their

definitions in brief.

[8M]

b) Explain with reference to the neat sketch the importance of the bearing characteristic

curve.

[8M]

3 Design a cast iron piston for a four stroke IC engine for the following specifications

Cylinder bore=120 mm

Stroke length=150 mm

Maximum gas pressure=5 MPa

Brake mean effective pressure=0.7 MPa

Fuel consumption=0.25 Kg/KW/hr

Speed=2400 rpm

Assume any other data necessary for the design

[16M]

4 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine.

[8M]

5 A curved beam with a rectangular cross section strikes a 90

0

arc and is loaded and

supported as shown in Fig.2. The thickness of the beam is 50mm. Determine the

hoop stress

??

? along line A-A at the inside and outside radii and at the centroid of

the beam.

Fig.2

1 of 2

R13

SET – 4

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II (Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Differentiate between journal and roller bearings. [4M]

b) What are the engineering applications of curved beams? [2M]

c) What is the function of the piston and materials used for piston? [4M]

d) Write advantages of belt drives over rope drives. [4M]

e) Write short notes on gear drives giving their merits and demerits. [4M]

f) Discuss the various types of cylinder liners. [4M]

PART -B

2 a) What are rolling contact bearings? Discuss their advantages over sliding contact

bearings.

[6M]

b) A ball bearing subjected to a radial load of 5KN is expected to have a life of 8000

hours at 1450 rpm with a reliability of 99 percent. Calculate the dynamic load capacity

of the bearing so that it can be selected from manufactures catalogue based on a

reliability of 90 percent.

[10M]

3 The following data is given for the piston of a four stroke diesel engine.

Cylinder bore=100 mm

Material of piston rings=grey cast iron

Allowable tensile stress=90 MPa

Allowable radial pressure on the cylinder wall=0.035MPa

Thickness of the piston head=16 mm

Number of piston rings=4

Calculate (i) Radial width of piston rings (ii) Axial thickness of the piston rings (iii) Gap between the free ends of the piston ring before assembly (iv) Gap between

the free ends of the piston ring after assembly (v) Width of the top land (vi) Width of

ring grooves (vii) Thickness of piston barrel and (viii) Thickness of barrel at top end

[16M]

4 The following data is given for the cap and bolts of the big end of the connecting rod.

Engine speed=1500rpm

length of the connecting rod =320mm

length of stroke=140mm

mass of reciprocating parts=1.75kg

length of crank pin=54mm

diameter of the crank pin=38mm

permissible tensile stress for the bolts=120MPa

permissible bending stress for cap=120MPa

Calculate the nominal diameter of the bolts and thickness of the cap for the big end.

1 of 2

[16M]

R13

SET – 1

Code No: RT32033

maximum tensile stress and specify its location.

.

6 A V belt drive is required for a 15 KW, 1440 rpm electric motor, which drives a

centrifugal pump running at 360 rpm for a service of 24 hours per day. From space

considerations, the center distance should be approximately1m. Determine (i) Belt specifications (ii) Number of belts (iii) Correct center distance and (iv) Pulley diameters

7 A spur gear made of bronze drives a mild steel pinion with angular velocity ratio of 3.5. The

pressure angle is 14.5 degrees. It transmits 5 KW at 1800 rpm of pinion. Considering only

strength, design the smallest diameter gears and find also necessary face width. The number of

teeth should not be less than15 teeth on either gear. The elastic strength of bronze may be

taken 84 MPa and of steel as105 MPa. Lewis form factor for 14.5 degrees pressure angle may

be taken as

T

y

684 . 0

124 . 0 ? ?

Where T=No. of teeth.

[16M]

*****

2 of 2

R13

SET – 1

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) Define the term ?Bearing Life.?? [4M]

b) Draw the stress distribution over the depth of curved beam? [2M]

c) What is the function of the cylinder and materials used for cylinder? [4M]

d) Write advantages of rope drives over belt drives. [4M]

e) What is the function of connecting rod of IC engine? [4M]

f) Explain various engineering applications of sliding contact bearings? [4M]

PART -B

2 a) List the important physical characteristics of a good bearing material. [6M]

b) The main bearing of a steam engine is 100 mm and 175 mm long. The bearing

supports a load of 28 KN at 250 rpm. If the ratio of diametral clearance to the

diameter is 0.001 and absolute viscosity of the lubricating oil is 0.015 kg/m-s.

Find: i) the coefficient of friction and ii) heat generated at the bearing due to friction.

[10M]

3 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine. [8M]

4 A connecting rod is to be designed for a high speed, four stroke IC engine. The

following data are available.

Piston diameter=88mm; Mass of reciprocating parts=1.6kg; Length of the

connecting rod (centre to centre)=300mm; Stroke=125mm; RPM=2200 (when

developing 50kw); Possible over speed=3000rpm; compression ration = 6.8:1;

Probable explosion pressure=3.5MPa. Design and draw fully dimensioned drawing

of the connecting rod.

[16M]

5 Derive Winkler-Bach formula for the given curved beam from first principles. Also

sketch stress distribution across the depth of the section.

6 A100 mm wide and 10 mm thick belt transmits 5 KW between two parallel shafts.

The distance between the shaft centers is 1.5 m and the diameter of the smaller pulley

is 440 mm. The driving and driven shafts rotate at 60 rpm and 150 rpm respectively.

Find the stress in the belt, if the two pulleys are connected by i) open belt ii) a cross

belt. The coefficient of friction is 0.22

[16M]

7 A double threaded power screw, used for lifting the load, has a nominal diameter of

25 mm and a pitch of 6mm. The coefficient of friction of screw threads is 0.1.

Neglecting collar friction, calculate.

i) efficiency of the screw with the square threads ii) efficiency with Acme threads

[16M]

*****

1 of 1

R13

SET – 2

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is the significance of bearing Number? [4M]

b) Define Bending Stiffness? [2M]

c) Enumerate the different types of materials used for the cylinder liners. [4M]

d) Write short note on classifications and different types of anti friction bearings. [4M]

e) Sketch the cross section of a V belt and label its important parts. [4M]

f) What is the function of connecting rod of IC engine? [4M]

PART -B

2 a) A 100 mm long and 60 mm diameter journal bearing supports a load of 2500 N at

600 rpm. If the room temperature is 20

o

C, what should be the viscosity of oil to limit

the bearing surface temperature to 60

o

C? Diametral clearance = 0.06 mm. Energy

dissipation coefficient based on the projected area of the bearing = 210 W/m

2o

C

[8M]

b) A 250?250 mm bearing carries a load of 108 KN. The bearing rotates at 1500 rpm.

The clearance ratio is 670. For full journal bearing the power lost in friction is

14.36 KW. Find the viscosity of the oil.

[8M]

3 The following data is given for a connecting rod:

Engine speed =1500 rpm

Length of connecting rod=320 mm

Length of stroke=140 mm

Density of the material=7830 Kg/m

3

Thickness of web flanges= 6 mm

The cross section of the connecting rod is I section.

Upper and bottom flange dimensions are = 4mm

Web dimensions are = 3mm

Calculate the whipping stress in connecting rod.

[16M]

4 a)Explain different materials used for piston

b)The following data is given for the piston of a four stroke diesel engine.

The following data is given for the piston of a four stroke diesel engine.

Cylinder bore = 120 mm

Maximum gas pressure = 6 MPa

Allowable bearing pressure for skirt = 0.45 MPa

Ratio of side thrust on liner to maximum gas load on piston=0.1

Width of top land =20 mm

Width of ring grooves = 3 mm

Total number of piston rings = 4

Axial thickness of piston rings = 3.5 mm

Calculate (i)length of skirt (ii) length of piston

1 of 2

[6M]

[10M]

R13

SET – 3

Code No: RT32033

5 The curved beam in Fig:1 has a circular cross section 50 mm in diameter. The inside

diameter of the curved beam is 40 mm. Determine the stress at B for P=20 KN.

Fig:1

[16M]

6 A pair of helical gears with 30

0

helix angle is used to transmit 15 KW at10000 rpm

of the pinion. The velocity ratio is 4:1. Both gears are to be made of hardened steel

of static strength 100MPa. The gears are 20

0

stub and the pinion is to have 24 teeth.

The face width may be taken as14 times the module. Find the module and face

width from the stand point of strength and check the gears for wear.

[16M]

7 a) Explain various materials used for machine tool beds. [8M]

b) Write various steps involved in design of lathe bed. [8M]

*****

2 of 2

R13

SET – 3

Code No: RT32033

III B. Tech II Semester Regular/Supplementary Examinations, April – 2018

DESIGN OF MACHINE MEMBERS ? II

(Mechanical Engineering)Time: 3 hours Max. Marks: 70

Note: 1. Question Paper consists of two parts (Part-A and Part-B)2. Answering the question in Part-A is compulsory

3. Answer any THREE Questions from Part-B

*****

PART ?A

1 a) What is a Gear? Classify. [4M]

b) Why trapezoidal cross ? section is more appropriate for crane hook? [2M]

c) Enumerate materials used for the bearings. [4M]

d) What is the function of the piston ring. Explain the materials used for the piston

rings.

[4M]

e) What are the methods and materials used for manufacture of crank shaft? [4M]

f) Why are square threads preferable over V-threads for power transmission? [4M]

PART -B

2 a) What are the various terms used the journal bearings analysis and design. Give their

definitions in brief.

[8M]

b) Explain with reference to the neat sketch the importance of the bearing characteristic

curve.

[8M]

3 Design a cast iron piston for a four stroke IC engine for the following specifications

Cylinder bore=120 mm

Stroke length=150 mm

Maximum gas pressure=5 MPa

Brake mean effective pressure=0.7 MPa

Fuel consumption=0.25 Kg/KW/hr

Speed=2400 rpm

Assume any other data necessary for the design

[16M]

4 a) Explain the various types of cylinder liners. [8M]

b) Discuss the design of piston for an internal combustion engine.

[8M]

5 A curved beam with a rectangular cross section strikes a 90

0

arc and is loaded and

supported as shown in Fig.2. The thickness of the beam is 50mm. Determine the

hoop stress

??

? along line A-A at the inside and outside radii and at the centroid of

the beam.

Fig.2

1 of 2

R13

SET – 4

Code No: RT32033

6 It is required to select a v-belt drive to connect a 20 KW, 1440 rpm motor to a

compressor running at 480 rpm for 15 hours per day. Space is available for a center

distance approximately 1.2m. Determine

i)The specifications of the belt

ii)Diameter of the motor and compressor pulleys

iii)The correct center distance and the number of belts

[16M]

7 a) How the gears are classified and what are the various terms used in spur gear

technology?

[8M]

b) Discuss the design procedure of spur gears.

[8M]

*****

2 of 2

R13

SET – 4

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