ME MD

 

	Important Question For GTU Exam
1	Give classification of gears.
2	Explain interference and undercutting in involute gear tooth profile.
3	A pair of spur gears consists of a 20 teeth pinion meshing with a 120 teeth gear. The module is 4 mm. calculate (i) the center distance, (ii) the pitch circle diameter of the pinion and gear, (iii) the addendum and dedendum, (iv) the tooth thickness, (v) the bottom clearance, and (vi) the gear ratio.
4	Explain different types of gear tooth failures
5	Explain the following terms used in helical gears : (a) Helix angle; (b) Normal pitch; (c) Axial pitch; (d) Normal Pressure angle
6	A pair of bevel gear with 200 pressure angle consists of a 20 teeth pinion meshing with a 30 teeth gear. The module is 4 mm, while the face width is 20 mm. The material for pinion and gear is steel 50C4 (σut=750 N/mm2 ). The surface hardness of gear is 400 BHN. The pinion rotates at 500 rpm and receives 2.5 kW power from the electric motor. The service factor is 1.5. Determine the factor of safety against bending failure and against pitting failure
7	Design the bevel gear pair for the following specification using Carl Barth velocity factor and wear consideration: Power transmitted : 40 kW Input speed : 360 rpm Reduction ratio : 3 Shaft angle : 900 Application : Agitator
8	Explain the role of pressure angle in the gears.
9	Explain the Law of gearing.
10	A Helical cast steel gear with 30˚ helix anle has to transmit 35kW at 1500rpm. If the gear has 24 teeth, determine the necessary module, pitch diameter and face width for 20˚ full depth. The static stress for cast steel may be taken as 56MPa. The width of face may be taken as 3 times the normal pitch. What would be the end thrust on the gear? The tooth factor for 20˚ full depth involute gear may be taken as 0.154-0.912/TE, Where TE represents the equivalent number of teeth.
11	Why dissimilar materials are used for worm and worm wheel?.
12	What is the minimum number of teeth on spur gear? Why?
13	A worm drive transmits 15 kW at 2000 rpm to a machine carriage at 75 rpm. The worm is triple threaded and has 65 mm pitch diameter. The worm gear has 90 teeth of 6 mm module. The tooth form is to be 200 full depth involute. The coefficient of friction between the mating teeth may be taken as 0.10. Calculate: 1. Tangential force acting on the worm 2. Axial thrust and separating force on worm 3. Efficiency of the worm drive.
14	Define Piston Head and Piston Skirt.
15	What are the design requirements of piston?
16	The following data is given for the piston of a four-stroke diesel engine: cylinder bore = 250 mm, material for piston rings = grey cast iron, allowable tensile strength = 100 N/mm2, allowable radial pressure on cylinder wall = 0.03 MPa, thickness of piston head = 42 mm, number of piston rings = 4. Calculate, 1. Radial width of the piston rings. 2. Axial thickness of the piston rings. 3. Gap between the free ends of the piston ring before assembly. 4. Gap between the free ends of the piston ring after assembly. 5. Width of the top land. 6. Width of the ring grooves. 7. Thickness of piston barrel.
17	Define Dry Cylinder liner and Wet Cylinder liner.
18	Explain Design of Cylinder
19	The bore of a cylinder of the four-stroke diesel engine is 150 mm. the maximum gas pressure inside the cylinder is limited to 3.5 MPa. The 07 2 cylinder head is made of grey cast iron FG 200 (Sut = 200 N/mm2 ) and the factor of safety is 5. Determine the thickness of the cylinder head. Stud are used to fix the cylinder head to the cylinder and obtain a leakage proof joint. They are made of steel FeE (Syt = 250 N/mm2 ) and the factor of safety is 5. Calculate (i) number of studs, (ii) nominal diameter of studs, (iii) pitch of studs.
20	Classification of Pulleys
21	A Cast Iron Pulley transmits 20 kW at 300 r.p.m. The Diameter of Pulley is 550 mm and has four straight arms of elliptical cross-section in which the major axis is twice the minor axis. Find the dimensions of the arm if the allowable bending stress is 15 Mpa. Mention the plane in which the major axis of the arm should lie.
22	Explain with neat sketch 6X7, 6X19 and 6X37 wire ropes.
23	What are the functions of I.C.Engine piston ?. List the elements involved in the I.C.Engine piston.
24	Why the cylinder liners are being used in I.C.Engine?. What are the desirable properties of the materials for the cylinder liners.
25	The following data is given for the piston of a four-stroke diesel engine: Cylinder bore : 250 mm Material of piston rings : Gray C.I. Allowable tensile stress : 100 N / mm2 Allowable radial pressure on cylinder wall : 0.03 MPa Thickness of piston head : 42 mm No. of piston rings : 4 Calculate: i) Radial width of the piston rings ii) Axial thickness of the piston rings iii) Gap between the free ends of the piston rings before and after the assembly iv) Width of the top land v) Width of the ring grooves vi)Thickness of the piston barrel
26	The following data is given for a 3600 hydrodynamic bearings: Radial load :- 3.1 kN, Journal diameter:- 50 mm, Bearing length : 50 mm, Journal speed : 1440 rpm Radial clearance : 50 microns, Viscosity of lubricant : 25 cP, Density of lubricant : 860 kg / m3 ,Sp. Heat of lubricant : 1.76 kJ / kg 0C. Assuming that the total heat generated in the bearing is carried by the total oil flow in the bearing. Calculate: i) Sommerfield Number ii) Minimum oil-film thickness iii) The coefficient of friction iv) The power lost in friction v) The total flow rate of lubricant in liter/minute vi) Side leakage.
27	Design the bevel gear pair for the following specification using Carl Barth velocity factor and wear consideration: Power transmitted : 40 kW Input speed : 360 rpm Reduction ratio : 3 Shaft angle : 900 Application : Agitator
28	Find the range ratio, geometric progression ratio and spindle speeds for the following data: Nmin = 100 r.p.m., Nmax = 1800 r.p.m. and number of speed steps = 8. Also, draw all possible structure diagrams.
29	List the major advantages of using geometric progression of for speed regulation in a gear box.
30	Differentiate between Hydrodynamic and Hydrostatic bearings.
31	Explain the significance of L/D ratio and minimum oil-film thickness in hydrodynamic bearings.
32	A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure of 1.4 N/mm2 . The speed of the journal is 900 r.p.m. and the ratio of journal diameter to the diametral clearance is 1000. The bearing is lubricated with oil whose absolute viscosity at the operating temperature of 75 °C may be taken as 0.011 kg/m-s. The room temperature is 35 °C. Find : 1. The amount of artificial cooling required, and 2. The mass of the lubricating oil required, if the difference between the outlet and inlet temperature of the oil is 10°C. Take specific heat of the oil as 1850 J / kg / °C.
33	Discuss advantages of rolling contact bearings over sliding contact bearings.
34	Derive the equation for equivalent dynamic load for bearing under cyclic loads.
35	With neat sketch explain the ‘inertia bending forces’ acting on connecting rod of an Internal Combustion (IC) engine.
36	Describe the design procedure of a crank shaft of an Internal Combustion (IC) engine.
37	Select a single row deep groove ball bearing for a radial load of 4000 N and an axial load of 5000 N, operating at a speed of 1600 r.p.m. for an average life of 5 years (300 days/year) at 10 hours per day. Assume uniform and steady load.
38	Explain with neat sketches : Construction and designation of steel wire ropes.
39	A crane hook having an approximate trapezoidal section is shown in Figure 1. The hook is made of plain carbon steel 45C8 (yield strength = 380 MPa) and the f.o.s. is 3.5. Determine the load carrying capacity of the hook.
40	A crane is lifting a load of 25 kN through a wire rope and a hook. The weight of hook, etc. is 15 kN. The rope drum diameter may be taken as 3 times the diameter of the rope. The load is to be lifted with an 04 3 acceleration of 1 m/s2 . Calculate the diameter of the wire rope. Take f.o.s. of 6 and Young’s modulus for the wire rope 80 kN/mm2 . The ultimate stress may be taken as 1800 Mpa. The cross-sectional area of the wire rope may be taken as 0.38 times the square of the wire rope diameter.
41	Draw layout diagram of gear box, ray diagram and speed chart for a multi-speed gear box of a radial drilling machine required to give eight steps. The power from motor to the input shaft of gear box is transmitted by a V-belt drive with a speed reduction of 1:6. The minimum and maximum spindle speeds are 70 rpm and 1800 rpm respectively.
42	Explain the rang ratio in gear box design.
43	Explain in brief about mountings of bearings
44	Differentiate between Arithmetic, Geometric and Harmonic Progressions in case of design of gear box.
45	An elevator at the construction site is required to raise building materials weighing 5.5 KN. A maximum velocity of 1 m/s is attained in one second while raising the materials. The lift of material is 25 m. The drum diameter is 40 times the rope diameter. Find the number of 6 X 19 wire ropes required if 12 mm diameter ropes are used. Assume: diameter of wire dw= 0.063 d, area of rope Ar= 0.38 d2 , mass of rope = 0.0036 d2 kg/m, Er = 84000 N/m2 , breaking strength = 385 d2 , factor of safety = 5. d is diameter of rope.
46	What is material handling? What are the essentials of good material handling system?
47	Give selection criteria of bearings in a particular application
48	Explain interference and undercutting in involute gear tooth profile
49	What is the minimum number of teeth on spur gear? Why?
50	What is the criterion for design of push rod?
51	Name the materials used for engine cylinder and engine piston.
52	Why is the area of inlet valve port more than that of an exhaust valve?
53	What are the design requirements of piston?
54	Discuss stresses in wire rope with usual formulae.
55	Give Classification and application of various Material handling equipment.
56	How are the gears classified?. Explain the role of pressure angle in the gears.
57	Explain different types of gear tooth failures
58	Derive the “ Petroff’s equation with assumptions made there in
59	Classify the rolling contact bearings. And explain how they are designated according to ISI code of practice
60	What are the functions of I.C.Engine piston ?. List the elements involved in the I.C.Engine piston
61	Design the following components of EOT cranes for the following requirements: Application : class – II Load to be lifted : 8 tones Hoisting speed : 4 m / min Maximum lift of the load : 12 m (i) Select through design procedure a suitable wire rope (ii) Sheave in a snatch block assembly of crane.