Cam Quiestions- Slides.pdf

7/28/2019 Cam Quiestions- Slides.pdf

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Q. If a cam when rolling in a clockwisedirection imparts the following motion onthe follower:0 to 90 Rise with Simple

Harmonic motion for 60mm90 to 130 Remain at this Displacement

(Dwell)130 to 310 Fall with UniformAcceleration and Retardationthrough 60mm310 to 360 Remain at this Displacement

(Dwell)The minimum cam radius is 40mm.Construct the profile of the cam and findthe maximum velocity and accelerationduring ascent and descent if speed of thecam is 200 rpm.

Ans : Vmax= 1256.63 mm/sec (ascent)Vmax=799.8 mm/sec (descent)amax =52.61x 103 mm/s2 (ascent)


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amax =10.66x 103 mm/s2 (descent)

Q. Draw the profile of a cam to raise avalve with SHM through 40 mm in 1/4thof revolution and keep it fully openthrough 1/10th revolution and to lowerit with uniform acceleration andretardation in 1/6th revolutions. Thevalve remains closed during the rest ofthe revolutions The diameter of theroller is 20 mm and min. radius of thecam is to be 30 mm. The axis of thevalve rod passes through axis of thecam shaft. The cam shaft rotates at360 rpm. clockwise .Determinemaximum velocity and max.acceleration of the follower during outstroke and return stroke.

Ans: Vmax= 1507.6mm/sec (ascent)Vmax=2879.30mm/sec (descent)


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amax = 113642.88 mm/s2 (ascent)amax = 207245.16 mm/s2 (descent)

Q. The following data relates to a camwhich operates a roller follower whichmoves with cycloidal motion during ascentand returns with uniform acceleration anddeceleration , acceleration being the halfthe deceleration.

Min. radius of cam = 30mmRoller radius = 10 mmLift of follower = 45mmOffset of follower axis = 12 mm to rightAngle of ascent = 700Angle of descent = 1200Angle of dwell between angle of ascent

and descent = 450Speed of cam = 200 rpm.

Draw the cam profile and determinemaximum velocity, maximum accelerationduring lift and maximum velocity ,theacceleration and retardation during return.


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Ans: Vmax = 1542.86 mm/sec (ascent)Vmax = 900 mm/sec (descent)amax = 101516.4 mm/s2 (ascent)f1 = 13500.063 mm/s2 f2 = 27000 mm/s2

Q. The following data relates to a camprofile, in which the follower moves with

SHM during the lift and returning it withuniform acceleration and deceleration,

acceleration being half thedecelerationMin. radius of cam = 30 mmRoller radius = 10 mmLift of follower = 45 mmOffset of follower axis = 12mm towardsrightAngle of ascent = 700Angle of descent = 1200Angle of dwell betn ascent and descent =450Speed of cam = 200 rpmDraw the cam profile and determine max.velocity , max. acceleration during lift


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Ans. Vmax = 1211.52 mm/sec amax = 35235.62 mm /s2

A roller follower of 10 mm radius isoperated by a uniformly rotating cam.The follower is raised through adistance of 25 mm in 1200 rotation ofcam, remains at rest for the next 300and is lowered during further 1200 ofrotation of cam. The rising of thefollower takes place with a cycloidalmotion and the lowering with uniformacceleration deceleration. However,the uniform acceleration is 2/3 ofuniform deceleration. Least radius ofcam is 25 mm which rotates at 300rpm .Design the cam profile and


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determine the values of maximumvelocity and max. acceleration duringaccent and the values of maximumvelocity and uniform acceleration anddeceleration during decent.

Ans. Vmax= 750 mm/sec(ascent) Vmax=750 mm/sec (descent)

amax =35310 mm/s2 (ascent) a = 18.75 m/s2 a' = 28.13 m/s2

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Cam Quiestions- Slides.pdf