Cam 4mf8

Aim : seminar on any topic of 4th semester Name: hadolikar s.l Branch: ME Ro.no.1027

Subject: theory of machines Topic : cam & followers

Concept & definition of cam followers

A cam is rotating a machine element which gives reciprocating or oscillating motion to the another element know as follower.

The cam & follower has a point or line constitute a higher pair.

According to surface

1 . Knife edged follower

According to motion of the follower

According to the path of motion of the followers

Offset follower

1 radial cam

2 cylindrical cam 3 wedge cam

Cylindrical cam

Wedge cam

1 .The most well known use of cams is in car engines. The Cam operated valve system can be found in modern car engines and incorporates a number of cams; the valves are opened by cams, fourand six-lobed cams govern the spark distribution and many car petrol oil pumps are cam driven.

2 . These are used in wall clock

3 . These are used in feed mechanism In automatic lathe machine

4. These are used in paper cutting machine.

5 . It is use in textile machine

Cam terminology The cam terminology used for drawing cam profile & displacement diagram .  First we know the .  Base circle: It is the smallest circle can be drawn to the cam profile.  Trance point: It is the reference point of the follower & is used to generate a pitch curve . 

Pressure angle : It represent include the angle at any point on the pitch curve between line or motion of the follower & normal to that point on the cam profile .  Pitch point : It is the point on the pitch curve having maximum pressure angle  Pitch circle : It is a circle drawn from the center of the cam through the pitch point.  Prime circle : it is the smallest circle can be drawn from center of the cam & tangent to pitch curve . 

Cam angle : it is the angle of rotation of the cam for a definite displacement of the followers  Cam profile : it is the actual working surface of the cam with which the surface of the follower is always in it transmit the required motion to the follower. 

Types of motion of the follower 1.

Uniform velocity or uniform motion.

2.

simple harmonic motion.

3.

uniform acceleration & retardation.

1. Uniform

velocity or uniform motion.

simple harmonic motion

uniform acceleration & retardation

 Prob

1: draw the profile of disc cam to given uniform velocity motion to the knife edged follower during outstroke of 60mm during 1st half revolution. The follower again turns to its original position with velocity during next half of three revolution . The minimum radius of the cam is 50mm & diameter of the cam shaft is 35mm. The axis of follower es through the axis of the cam.

Given data: out stroke of follower (s)=60mm Minimum radius of the cam =50mm diameter of

the cam shaft = 35mm

Angle of outstroke=180 angle of return stroke=180