CAM & FOLLOWER Prepared by B.BALAMURALI AP/MECH SNS COLLEGE OF ENGINEERING, COIMBATORE- 641 107.   DEPARTMENT OF MECHANICAL ENGINEERING   CAM & FOLLOWER Prepared by B.BALAMURALI AP/MECH ME 6401- KOM / TOPIC-10

RECAP What is Inversion of mechanism. Give some applications of inversion of double slider crank mechanism. ME 6401- KOM / TOPIC-10

CAM & FOLLOWER It is a rotating mechanical member used for transmitting desired motion to a follower by direct contact. A cam may be reciprocating , rotating or oscillating whereas the follower may be reciprocating or oscillating. It is one of the most convenient means of producing movements of an irregular or complex character not easily obtained by linkages. The cam and follower have a line contact and hence constitute a higher pair. ME 6401- KOM / TOPIC-10

CLASSIFICATIONS OF CAMS RADIAL / DISC / PLATE cams WEDGE / FLAT cams CYLINDRICAL / BARREL cams CONICAL cams GLOBOIDAL cams END / FACE cams ME 6401- KOM / TOPIC-10

RADIAL / DISC / PLATE CAMS The follower reciprocates in a plane perpendicular to the axis of cam. ME 6401- KOM / TOPIC-10

It has a wedge shape which imparts translatory motion to the follower. WEDGE / FLAT CAMS It has a wedge shape which imparts translatory motion to the follower. ME 6401- KOM / TOPIC-10

CYLINDRICAL / BARREL CAMS A cylinder which has a circumferential counter cut in the surface, rotates about its axis. Follower rides on the groove cut on the periphery of the cylinder. ME 6401- KOM / TOPIC-10

CONICAL CAMS If the cylindrical surface in the cylindrical cam is replaced by a conical surface. ME 6401- KOM / TOPIC-10

GLOBOIDAL CAMS It is similar to the cylindrical cams but they have either a convex or concave surface. ME 6401- KOM / TOPIC-10

END / FACE CAMS The end cam has a rotating portion of a cylinder, a cone, or a sphere, which oscillates a follower having its axis perpendicular to the cam axis. ME 6401- KOM / TOPIC-10

CLASSIFICATION OF FOLLOWERS According to the follower shape/surface in contact. According to the motion of the follower According to the path of motion of the follower. ME 6401- KOM / TOPIC-10

ACCORDING TO THE FOLLOWER SHAPE/SURFACE IN CONTACT Knife edge follower - When contacting end of the follower has a sharp knife edge. Roller follower – When contacting end of the follower is a roller. Flat faced / Mushroom follower - When contacting end of the follower is perfectly flat faced. Spherical faced follower - When contacting end of the follower is of spherical shape. ME 6401- KOM / TOPIC-10

ACCORDING TO THE FOLLOWER SHAPE/SURFACE IN CONTACT ME 6401- KOM / TOPIC-10

ACCORDING TO THE MOTION OF THE FOLLOWER Reciprocating/Translating follower – When the follower reciprocates in guides as the cam rotates uniformly. Oscillating/Rolling follower – When the uniform rotary motion of the cam is converted into predetermined oscillatory motion of the follower. ME 6401- KOM / TOPIC-10

ACCORDING TO THE MOTION OF THE FOLLOWER ME 6401- KOM / TOPIC-10

ACCORDING TO THE PATH OF MOTION OF THE FOLLOWER Radial/In-line follower – When the motion of the follower is along an axis passing through the centre of the cam. Offset follower - When the motion of the follower is along an axis away (offset) from the axis of the cam centre. ME 6401- KOM / TOPIC-10

ACCORDING TO THE PATH OF MOTION OF THE FOLLOWER ME 6401- KOM / TOPIC-10

RADIAL CAM NOMENCLATURE ME 6401- KOM / TOPIC-10

RADIAL CAM NOMENCLATURE CAM PROFILE – The working surface of cam which comes into contact with follower. BASE CIRCLE – It is the smallest circle that can be drawn tangential to cam profile from the centre of rotation of cam. TRACE POINT – It is the theoretical reference point on the follower which is used to generate pitch curve. PITCH CURVE – The locus or path of trace point is called pitch curve. PRIME CIRCLE – The smallest circle that can be drawn tangent to the pitch curve . ME 6401- KOM / TOPIC-10

RADIAL CAM NOMENCLATURE PRESSURE ANGLE – The angle b/w the line of action of the follower and corresponding normal to the pitch curve through trace point. PITCH POINT – It is a point on pitch curve at which the pressure angle is max. PITCH CIRCLE - It is the circle passing through the pitch point & concentric with base circle. LIFT / STROKE OF FOLLOWER - The maximum distance through which the follower moves. ME 6401- KOM / TOPIC-10

TYPES OF FOLLOWER MOTION Uniform Velocity Simple Harmonic Motion Uniform Acceleration and Retardation Motion Cyloidal Motion ME 6401- KOM / TOPIC-10

FORMULA ME 6401- KOM / TOPIC-10

WORKTIME ME 6401- KOM / TOPIC-10

WORKTIME ME 6401- KOM / TOPIC-10

ME 6401- KOM / TOPIC-10