Important RGPV Question

ME- 702(D), Advance Machine Design

VII Sem, ME

Unit- I: Design of Belt, Rope and Chain Drives

Q.1 Find out the expression for maximum tension in belt. (RGPV Dec 2020)

Q.2 Derive the expression for the length of crossed belt drive. (RGPV Dec 2020)

Q.3 What are the advantages and disadvantages of flat belt drive? (RGPV May 2019)

Q.4 Discuss the construction of wire ropes with the help of a neat sketch. (RGPV May 2019)

Q.5 Design a chain drive to actuate a compressor from 15 kW electric motor running at 1000 rpm, the compressor speed being 350 rpm. The minimum centre distance is 500 mm. The compressor operates 16 hours per day. The chain tension may be adjusted by shifting the motor on slides. (RGPV May 2019)

Q.6 A V-belt is driven on a flat pulley and a V-pulley. The drive transmits 20 kW from a 250mm diameter V-pulley operating at 1800 rpm to a 900mm diameter flat pulley. The centre distance is Im, the angle of groove 40 deg and mu = 0.2 density of belting is 1110kg / (m ^ 3) and allowable stress MPa for belt materialbe the number of belts required if C-size V-belts having 230m * m ^ 2 cross-sectional area are used. (RGPV May 2019)

Q.7 What do you mean by slip in a belt drive? Differentiate between open belt and crossed belt drive. List out the applications of belt drives. (RGPV May 2019)

Following are the details on a crossed belt drive

Diameter of the driver 200mm

Diameter of the follower 400mm

Center distance of the drive 2m

Speed of the drive : 400rpm

Angle of contact 197.3

Determine the length of the belt required.

Q.8 Compare belt drive, chain drive and rope drive for power transmission. (RGPV Jun 2020)

Q.9 Derive an expression for power rating of a V-belt drive. (RGPV Jun 2020)

Q.10 Following are the details of a crossed belt drive(RGPV Jun 2020)

Diameter of the driver : 200mm

Diameter of the follower : 400mm

Center distance of the drive : 2m

Speed of the drive : 400rpm

Angle of contact : 197.3°

Determine the length of the belt required. 

Q.11 What do you mean by slip in a belt drive? Differentiate between open belt and crossed belt drive. List out the applications of belt drives. (RGPV Jun 2020)

Unit- II: Spur and Helical Gears

Q.1 What do you understand by Formative spur gear’ in helical gears? (RGPV Dec 2020)

Q.2 Explain the construction of involute profile. (RGPV Dec 2020)

Q.3 A pair of parallel helical gears consists of 18 teeth pinion meshing with a 63 teeth gear. The helix angle is 23 degree while the normal pressure angle is 20 degree. Calculate axial pitch. (RGPV Dec 2020)

Q.4 In which gear self-locking is possible? Give the condition for self-locking. (RGPV Dec 2020)

Q.5 Write down the steps involve in designing Spur Gear. (RGPV Dec 2020)

Q.6 What are the modes of failure for helical gears. (RGPV Dec 2020)

Q.7 A pair of parallel helical gears consists of an 18 teeth pinion meshing with a 45 teeth gear. 7.5 kW power at 2000 rpm is applied to the pinion through it’s shaft. The normal module is 6 mm while the normal pressure angle is 20 deg The helix angle is 23 deg Determine the tangential, radial and axial components of the resultant tooth force between the meshing teeth. Draw also free body diagram of forces. (RGPV May 2019)

Q.8 What are the advantages of cycloidal teeth gears and involute teeth gear? (RGPV Jun 2020) 

Unit- III: Bevel Gears

Q.1 Derive Lewis equation for bevel gears. (RGPV Dec 2020)

Q.2 Write down the general steps involved in design of bevel gear. (RGPV Dec 2020)

Q.3 What are the forces involved in bevel gear while in operation explain. (RGPV Dec 2020)

Q.4 It is required to design a pair of bevel gears, which are mounted on shafts intersecting at right angles. The pinion receives 20 kW power through its shaft and rotates at 720 rpm. The number of teeth on pinion and gear are 30 and 45 respectively. The pressure angle is 20° full depth teeth form the gears are made of plain carbon steel with permissible bending stress as 200 MPa. The gears are case hardened and the surface hardness is 300 BHN. Take service factor = 1.25. (RGPV Dec 2020)

Q.5 A pair of bevel gears, with 20° pressure angle, consists of a 20 teeth pinion meshing with a 30 teeth gear. The module is 4mm, while the face width is 20mm. The material for the pinion and gear is steel 50C4 (Sut = 750 N/mm2). The gear teeth are lapped and ground (Class – 3) and the surface hardness is 400 BHN. The pinion rotates at 500 rpm and receives 2.5 kW power from the electric motor. The starting torque of the motor is 150% of the rated torque. Determine the factor of safety against bending failure and against pitting failure. (RGPV Jun 2020) 

Unit- IV: Design of I.C. Engine Components

Q.1 Write down the General design considerations in IC engines. (RGPV Dec 2020)

Q.2  Design a connecting rod for a petrol engine from the following data: (RGPV Dec 2020)

Diameter of piston = 110 mm;

Mass of reciprocating parts = 2 kg;

Length of connecting rod = 325 mm;

Stroke = 150 mm;

 Speed = 1500 rpm

with possible over speed of 1850 rpm; Compression ratio = 4:1; Factor of safety = 4; Maximum explosion pressure = 5.5 MPa Select suitable material and permissible stresses for its.

Q.3 Design a plain carbon steel centre crankshaft for a single acting four stroke, single cylinder engine for the following data: Piston diameter = 250 mm; Stroke = 400 mm;

Maximum combustion pressure = 2.5 MPa; Weight of the flywheel = 5 kg; Total belt pull = 100 N; Length of connecting rod = 950 mm. The flywheel is used as a pulley. When the crank has turned through 300 from top dead centre, the pressure on the piston is 1 MPa and the torque on the crank is maximum. Any other data required for the design may be assumed. (RGPV Dec 2020)

Q.4 A crank shaft of the center-crank type is to be designed for a diesel engine developing 7.5 kW on brake at 1200 r.p.m. The crank shaft is of the forged type and has to carry two y wheels of 500 N each on either side of the main bearing. The plane of rotation of each wheel is 100mm from the center line of adjacent main bearing. The maximum load on connecting rod is 35kN. The length of stroke of piston is 160mm and the length of connecting rod 320mm. Maximum torque will be experienced in the crank shaft when the crank turns 300 from the inner dead center position. The maximum permissible stress in crank pin, web and shaft should not exceed 60N / m * m ^ 2 the safe limit for the bearing stress for the crank pin and the main bearings is 800N / m * m ^ 2 Design the crank shaft. (RGPV May 2019)

Q.5 Design a cast iron trunk type stroke engine developing running at 600 rpm, The other piston for a single acting four 75 kW per cylinder when avilable data is as follows: (RGPV May 2019)

Maximum gas pressure

4.8 N/mm²

Indicated mean effective pressure

= 0.65 N/mm²

Mechanical efficiency 95%

Radius of crank 110mm

Fuel consumption = 0.3kg/BPMxx

Calorific value of fuel (higher) = 44x103kJ/kg

Difference of temperatures at the centre and edges of the piston head = 200 C

Allowable stress for the material of the piston

= 33.5 MPa

Allowable stress for the material of the piston rings and gudgeon pin 80 MPa

Allowable bearing pressure on the piston barrel = 0.4 N/mm²

Allowable bearing pressure on the gudgeon pin= 17 N/mm².

Q.6 State the function of the following in an internal combustion engine: (RGPV Jun 2020)

i) Ribs

ii) Piston Skirt

iii) Piston Rings 

Unit -V: Design of Miscellaneous Components

Q.1 Write short notes on knuckle and cotter joints. (RGPV Dec 2020)

Q.2 Compare the stress distribution in a thin and thick walled pressure vessel. (RGPV Jun 2020)

Extra Questions

Q.1 What is the use of Lagrange multipliers? What is their practical significance. (RGPV May 2019)

Q.2 Find the maxima and minima, if any of the functions(RGPV May 2019)

i) f(x) = 4x ^ 3 – 18x ^ 2 + 27x – 7

ii) f(x) = (x ^ 4) / (x – 1) * (x – 3) ^ 3

Q.3 Why are two universal joints often used when there is angular misalignment between two shafts? (RGPV Jun 2020)

Q.4 What do you understand by simplex, duplex and triplex chains? (RGPV Jun 2020)

— Best of Luck for Exam —