Cams topics include: Cams and its classifications, tangent cams and circular arc cams. A machine cam is a component that rotates or moves back and forth to create a motion in a follower. The cam's contacting surface shape is determined by the follower's profile and the prescribed motion. The follower is usually flat or circular.  Cams are often found in engines, industrial printers, manufacturing machines, and other mechanical equipment. They can be found in different materials, sizes, and styles. Some common types of cams include: Barrel cam, Face cam, Disc cam, Heart cam.  Cams can be... Show more

Cams topics include: Cams and its classifications, tangent cams and circular arc cams.

A machine cam is a component that rotates or moves back and forth to create a motion in a follower. The cam's contacting surface shape is determined by the follower's profile and the prescribed motion. The follower is usually flat or circular. 

Cams are often found in engines, industrial printers, manufacturing machines, and other mechanical equipment. They can be found in different materials, sizes, and styles.

Some common types of cams include: Barrel cam, Face cam, Disc cam, Heart cam. 

Cams can be classified into two main types:
Oscillating cams: These cams are typically used in reciprocating engines, such as those found in automobiles and motorcycles. They are typically shaped like a lobe and are mounted on a shaft that rotates as the engine runs. 

Cams can also be classified based on their physical shape. Some types of cams include:
Disk or plate cam: Has an irregular contour to impart a specific motion to the follower
Knife edge follower: Based on surface in contact
Roller follower: Based on surface in contact 

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Machine Dynamics Practice Test: Cams

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25 Questions

1. Cam angle is defined as the angle

moved by the cam from the instant the follower begins to rise, till it reaches its highest positionduring which the follower returns to its initial positionthrough which, the cam rotates during the period in which the follower remains in the highest positionof rotation of the cam for a definite displacement of the follower

2. In the given figure, the cam has contact with _______

Base circleStraight flankShaftNose

3. If φ is the angle of action of cam on the circular flank, and r₁ is the base circle of the cam, then the minimum acceleration of the follower is given by the equation.

ω2(R+r1)cos φω2(R-r1)cos φω2(R-r1)ω2(R+r1)sin φ

4. The retardation of a flat faced follower when it has contact at the apex of the nose of a circular arc cam, is given by

ω2×OQsinθω2×OQtanθω2×OQcosθω2×OQ

5. The size of cam is independent of the base circle.

MaybeFalseDon't KnowTrue

6. Tangent cam with reciprocating follower is an example of cams with specified contours.

TrueDon't KnowFalseMaybe

7. The size of a cam depends upon

prime circlebase circlepitch circlepitch curve

8. For a follower Simple Harmonic Motion having a small period of dwell at the beginning of motion, the jerk is 0.

FalseDon't KnowTrueMaybe

9. The displacement of a flat faced follower when it has contact with the flank of a circular arc cam, is given by

(R-r1)(1-cosθ)(R-r1)(1-sinθ)R(1-sinθ)R(1-cosθ)

10. Cylindrical cams can be classified as

none of thesetangentreciprocatingcircular

11. For high speed engines, the cam follower should move with

uniform acceleration and retardationuniform velocitycycloidal motionsimple harmonic motion

12. The given figure is a velocity time diagram for which of the follower motion?

Simple harmonicUniform velocityUniform acceleration and retardationUniform acceleration

13. For S.H.M. cam, the acceleration of the follower at the ends of the stroke and aimed stroke respectively, is

zero and minimumzero and maximumminimum and maximummaximum and zero

14. If φ is the angle of action of cam on the circular flank, and r₁ is the base circle of the cam, then the maximum velocity of the follower is given by the equation.

ω(R-r1)sin φω(R+r1)sin φω(R+r1)cos φω(R-r1)cos φ

15. The angle between the direction of the follower motion and a normal to the pitch curve is called

pitch anglebase angleprime anglepressure angle

16. If φ is the angle of action of cam on the circular flank, and r₁ is the base circle of the cam, then the maximum acceleration of the follower is given by the equation.

ω2(R+r1)sin φω2(R+r1)cos φω2(R-r1)ω2(R-r1)cos φ

17. From the given figure below, at what value of theta(angle of ascent) the acceleration will be maximum?

30Constant acceleration060

18. Angle of action of cam is defined as the angle

through which the cam rotates during the period in which the follower remains in the highest positionof rotation of the cam for a definite displacement of the followermoved by the cam from the instant the follower begins to rise, till it reaches its highest positionmoved by the cam from beginning of ascent to the termination of descent

19. Tangent cams are symmetric about __________

Radial line of cam shaftAlong the rollerTangent line of cam shaftCentre line of cam shaft

20. The cam follower generally used in aircraft engines is

knife edge followerroller followerflat faced followerspherical faced follower

21. From the given data, calculate the acceleration of follower in m/s² at the beginning of the lift for a symmetrical tangent cam operating a roller follower.
Least radius of the cam is 30 mm; Roller radius is 17.5 mm. The angle of ascent is 75° and the total lift is 17.5 mm. The speed of the cam shaft is 600 r.p.m.

187.6183.2190.1185.5

22. When the flanks of the cam are straight and tangential to the base circle and nose circle, then the cam is known as a ____________

Radial camTangent camRoller camReciprocating cam

23. If θ is the angle turned by the cam from the beginning of the roller displacement, how the velocity changes with the change in theta?

Increases with negative change in thetaIncreases with increase in thetaDecreases with increase in thetaIndependent of theta

24. The linear velocity of the reciprocating roller follower when it has contact with the straight flanks of the tangent cam, is given by

ω(r1-r2)sinθω(r1-r2)cosθω(r1+r2)cosθcosec2θωr1+r2)sinθsec2θ

25. In the given figure, the cam has contact with _______

NoseArmShaftStraight flank