STUPIDSID
Solve any one question fromQ.1(a,b) and Q.2(a,b)
1(a)
Define the following terms & explain the significance.
i) Pressure angle
ii) Contact ratio.
i) Pressure angle
ii) Contact ratio.
2 M
1(b)
A pair of involute spur gears with 20° pressure angle mesh externally and give a speed reduction 3:1, The module is 3mm and addendum is 1.1 module. If the pinion rotates at 120 rpm, determine
i) Minimum number of teeth on each wheel.
ii) Contact ratio.
i) Minimum number of teeth on each wheel.
ii) Contact ratio.
8 M
2(a)
Define the following term & explain the significance
i) Normal circular pitch
ii) Helix angle.
iii) Centre distance in spiral gears
iv) Lead angle of worm.
i) Normal circular pitch
ii) Helix angle.
iii) Centre distance in spiral gears
iv) Lead angle of worm.
4 M
2(b)
Derive an expression for efficiency of spiral gears.
6 M
Solve any one question fromQ.3 and Q.4
3
A drive is made up of two spiral gears of same hand, same diameter & of normal pitch 14 mm. The centre distance between the axes of shaft is approximately 150mm. The speed ratio 1.6 & the angle between shaft axes is 75°. Assuming coefficient of friction o.0.105 determine.
i) Spiral angle on each wheel.
ii) Number of teeth on each wheel.
iii) Efficiency of drive
iv) Maximum efficiency.
i) Spiral angle on each wheel.
ii) Number of teeth on each wheel.
iii) Efficiency of drive
iv) Maximum efficiency.
10 M
4
The annulus A in epicyclic gear train rotates at 300 rpm about the axis of fixed sun gear which has 80 teeth. A three armed spider is driven at 180rpm. Determine the number of teeth required on planet P. Refer Fig.1
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10 M
Solve any one question fromQ.5(a,b) and Q.6
5(a)
Explain the advantages and disadvantages of stepped regulation stepless regulation drives in context of automotive application
4 M
5(b)
Explain the following
i) Disc variator
ii) Cone variator
iii) Continous variable Transmission
iv) Infinitely variable Transmission
i) Disc variator
ii) Cone variator
iii) Continous variable Transmission
iv) Infinitely variable Transmission
12 M
6
A rotor of the turbine of a ship has a mass of 2500 kg rotates at a speed of 32000 rpm. Counter clockwise as seen from stern. The rotor has radius of gyration of 0.4.m. Determine the gyroscopic couple and its effect when
a) Ship steers to the left in a curve of 80m radius at a speed of 7.75 m/s
b) Shp pitches 5 degrees above and below the means position and the bow is descending with its maximum velocity. The pitching motion is SHM with a periodic time of 40 seconds
c) Ship rolls and at instant, its angular velocity is 0.4 rad/ s clock wise when viewed from stern. Also find the maximum angular acceleration during pitching.
a) Ship steers to the left in a curve of 80m radius at a speed of 7.75 m/s
b) Shp pitches 5 degrees above and below the means position and the bow is descending with its maximum velocity. The pitching motion is SHM with a periodic time of 40 seconds
c) Ship rolls and at instant, its angular velocity is 0.4 rad/ s clock wise when viewed from stern. Also find the maximum angular acceleration during pitching.
16 M
Solve any one question fromQ.7(a,b) and Q.8(a,b)
7(a)
Explain the following terms
i) Precision points
ii) Function generation
iii) Body guidance
iv) Chebysheve spacing
i) Precision points
ii) Function generation
iii) Body guidance
iv) Chebysheve spacing
8 M
7(b)
Design a slider crank mechanism to coordinate three positions of the input and output links for the following data by inversion method.
θ12=30° S12=40mm
θ13=60° S13 = 96mm.Eccentricity = 20 mm
θ12=30° S12=40mm
θ13=60° S13 = 96mm.Eccentricity = 20 mm
8 M
8(a)
Design a four link mechanism to coordinate three positions of input and output links for the following angular displacements by inversion method.
θ12 = 35° φ12=50°
θ13=80° φ13=80°
θ12 = 35° φ12=50°
θ13=80° φ13=80°
8 M
8(b)
Design a slider crank mechanism to coordinate three positions of crank and slider for the following data by relative pole method.
θ12=40° S12=180mm
θ13=120° S13= 300mm Take eccentricity of slider as 20mm.
θ12=40° S12=180mm
θ13=120° S13= 300mm Take eccentricity of slider as 20mm.
8 M
Solve any one question fromQ.9(a,b) Q.10
9(a)
Derive an expression for displacement, velocity and acceleration of a flat faced follower when it makes contact with a circular arc cam at
i) Circular Flank
ii) Nose
i) Circular Flank
ii) Nose
14 M
9(b)
Explain advanced cam curves.
4 M
10
A cam is to give the following motion of a knief edge follower
To raise the follower through 30 mm with uniform acceleration deceleration during 120° rotation of cam
Dwell for text 30 °
To lower the follower with SHM during next 90° rotation of cam
Dwell for rest of cam rotation
Use following data to draw the cam profile
Minimum radius of cam 30 mm
Speed 800 rpm counter clockwise
Follower axis inline. Also draw displacement, velocity and acceleration diagrams for the motion of follower in one complete rotation given to the cam, indicating the main values.
To raise the follower through 30 mm with uniform acceleration deceleration during 120° rotation of cam
Dwell for text 30 °
To lower the follower with SHM during next 90° rotation of cam
Dwell for rest of cam rotation
Use following data to draw the cam profile
Minimum radius of cam 30 mm
Speed 800 rpm counter clockwise
Follower axis inline. Also draw displacement, velocity and acceleration diagrams for the motion of follower in one complete rotation given to the cam, indicating the main values.
18 M
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