Explain the importance of reliability in DOM.
[3 marks]Why the section of the arms in pulley is usually elliptical? In which plan the major axis of arm section is placed & why?
[4 marks]Design a cast iron protective type flange coupling to transmit 15 KW at 900 r.p.m. from an electric motor to a compressor. The service factor may be assumed as 1.35. The following permissible stresses may be used : Shear stress for shaft , bolt & key material = 40 MPA Crushing stress for bolt & key = 80 MPA. Shear stress for cast iron = 8 MPA
[7 marks]Explain the importance of Ergonomics with examples.
[3 marks]Explain step by step design procedure of flat belt pulley with neat sketch.
[ marks]A Differential band brake, as shown in fig. 1.1 has drawn diameter of mm & angle of contact 240 °. The brake is 5mm thick & 100 mm wide. The coefficient of friction between the band and the drum is 0.3. If the band is subjected to a stress of 50 MPa , Find : 1. The least force required at the end of 600 mm lever , and 2. The torque applied to the brake drum shaft.
[7 marks]Write all design steps for cast iron pulley to transmit power P.
[7 marks]Explain with the help of sketch how the co-efficient of friction varies with bearing characteristics number of different state of lubrication
[3 marks]What is condition for self –locking in differential band brake? Give Advantages & Disadvantages of differential band brake.
[4 marks]Design a journal bearing for a centrifugal pump from the following data: Load on the journal = 20,000N, Speed of the journal =900rpm, type of oil is SAE10, For which absolute viscosity at 55°C=0.017kg/m-s, ambient temperature of oil=15.5°C, Maximum bearing pressure for the pump=1.5N/mm2. Calculate also mass of lubricant oil required for artificial cooling, if rise of temperature of oil be limited to 10°C. Heat dissipation coefficient=1232W/m2/°C
[7 marks]Differentiate coupling & clutch.
[3 marks]Explain the Hydrodynamic lubrication in journal bearing with appropriate figure.1
[4 marks]Apair of straight teeth spur gear , having 20° involutes full depth teeth is to transmit 12 KW at 300 r.p.m of the pinion. The speed ratio is 3:1. The allowable static stresses for gear of cast iron & pinion of steel are 60 MPA & 105 MPA respectively. Assume the following: Number of teeth of pinion = 16 ; Face width = 14 times module ; Velocity factor(Cv) = y = 4.5 The tooth form factor y can be taken as 4.5+v 0.912 y = 0.154− no of teetℎ Determine the module, face width & pitch diameters of gears.
What are the desirable properties of shoe friction material used for lining of brake shoe?
[3 marks]Briefly discuss the stresses in wire rope with examples.
[4 marks]Derive the Lewis equation for design of spur gear.
[7 marks]Define Gear Terminology. Explain any two of them.
[3 marks]What is Brake? Enlist Brakes. Differentiate Self –Energizing & Self – locking brake.
[4 marks]A Cantilever Beam mad eof cold drawn carbon steel of circular cross section as shown in fig.1.2 is subjected to a load which varies from –Fto -3F. Determine the maximum load that this member can withstand for an identified life using a F.S = 2 . the stress concentration factor is 1.42. & notch sensitivity is 0.9 . Ultimate stress -= 550 MPA Yield stress= 470 MPA , Endurance limit = 275 MPA , Size factor = 0.85 & Surface finish factor =0.89 .
[7 marks]What is Antifriction Bearing? Classify journal bearing.
[3 marks]What do you mean by Stress –concentration & Notch –Sensitivity?
[4 marks]Write the complete design procedure for crane hoisting mechanism.
[7 marks]What is Split Muff coupling? Give Application & Advantages of it. .
[3 marks]What is meant by Endurance strength of a material? Explain the influence of various factors on endurance limit of a ductile material.
[4 marks]Amachine component is subjected to flexural stress which fluctuates between + 300MN/m2 & - 150 MN/m2. Determine the value of minimum ultimate strength according to 1. Gerber relation. 2. Soderberg relation. Take Yield strength = 0.55 Ultimate strength; Endurance strength = 0.5 Ultimate strength; & factor of safety = 2. Fig 1.1 Fig 1.2
[7 marks]