CAM Follower-I

• A Cam is mechanical member used to impart desired motion to a follower by direct contact.
• Cam- follower mechanism belong to higher pair mechanism.
• It is used in automated machines, IC engines, machine tools, printing control mechanisms, textile weaving industries etc.
• A driver member is known as cam.
• A driven member is known as follower.
• A frame is one which supports the cam and guides the follower.

Classification of cams

1. According to Shape

1.1 Wedge and Flat Cams

A wedge cam has a translational motion and follower can either translate or oscillate.

1.2 Radial or Disc Cams

A cam in which the follower moves radially from the centre of rotation of the cam is known as radial or disc or plate cam.

1.3 Cylindrical Cams

A cylinder has a circumferential contour cut in the surface and the cam rotates about its axis. The follower motion is either oscillating or reciprocating type. These cams are also called drum or barrel cams.

1.4 Spiral Cam

A spiral cam is face cam in which a groove is cut in the form of a spiral. It is used in computers.

1.5 Globoidal Cams

It has two types of surface i.e. convex and concave. It is used when moderate speed and angle of oscillation of the follower is large.

Classification of Follower

1. According to shape

1.1 Knife edge follower

The contacting end of the follower has a sharp knife edge. Its use is limited as it produces excessive wear of the contacting surface.

1.2 Roller Follower

It consists of a cylindrical roller which rolls on cam surface. At low speeds, the follower has pure rolling but at high speeds some sliding also occurs. The roller followers are extensively used where more space is available such as gas and oil engines.

1.3 Flat face follower

The follower face is perfectly flat. It experiences a side thrust due to the friction between contact surfaces of follower and cam.

1.4 Spherical face follower

The contacting end of the follower is of spherical shape which overcomes the drawback of side thrust as experiences by flat face follower.

2. According to Movement

2.1 Reciprocating Follower

In this type, as cam rotates the follower reciprocates or translate in the guides.

2.2 Oscillating Follower

The follower is pivoted at a suitable point on frame and the rotary motion of cam is converted into predetermined oscillatory motion of the follower.

3. According to location of line of movement

3.1 Radial Follower

The follower is known as a radial follower as a radial follower if the line of movement of the follower passes through the centre of the rotating of the cam.

3.2 Offset Follower

If line of movement of the follower is offset from the center of the cam shaft, the follower is known as offset follower.

PART-2

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