Working of a Cam Controlled System
Introduction
A cam controlled system is a mechanical arrangement in which a cam converts rotary motion into a desired reciprocating or oscillating motion of a follower. It is widely used to automate mechanical operations where precise motion control is required.
Components of a Cam Controlled System
- Cam: A specially shaped rotating element that drives the follower.
- Follower: A component that follows the contour of the cam and moves accordingly.
- Camshaft: The shaft on which the cam is mounted.
- Frame/Base: Supports the system.
- Spring (optional): Returns the follower to its initial position if needed.
Working Principle
- The cam is mounted on a rotating shaft.
- As the cam rotates, its specially shaped profile pushes the follower.
- The follower moves according to the shape of the cam — either up and down (reciprocating) or back and forth (oscillating).
- When the cam lobe moves away, the follower returns to its original position, often aided by a spring.
Example: Cam Operated Reciprocating Pump
Description
In a cam-operated reciprocating pump, the cam controls the motion of the pump’s piston (acting as the follower). This system converts rotary motion of the camshaft into reciprocating motion of the piston, which pumps fluid.
Working
- The camshaft is rotated by an external power source (like an electric motor).
- As the cam rotates, its lobe pushes the follower (connected to the piston rod) upwards.
- This upward movement raises the piston, causing fluid to be drawn into the pump cylinder (suction stroke).
- When the cam lobe rotates away, the spring or gravity pushes the follower back, moving the piston down.
- The downward stroke forces the fluid out of the pump (delivery stroke).
- This repetitive motion of the piston pumps the fluid continuously.
Advantages of Cam Controlled System
- Precise control over follower motion.
- Can produce complex motion patterns by designing different cam profiles.
- Durable and reliable with simple construction.
- Common in automotive (valve timing mechanisms), textile machines, and printing presses.
Neat Sketch Description
- A rotating cam mounted on a shaft.
- A follower in contact with the cam profile.
- A spring pushing the follower back.
- The follower connected to a piston inside a pump cylinder.
- Arrows showing rotation of cam and reciprocation of piston.
Summary
A cam controlled system is an efficient way to transform rotary motion into a controlled reciprocating or oscillating motion. The cam profile determines the motion characteristics of the follower, enabling its wide use in various mechanical systems, including pumps, internal combustion engines, and automated machinery.