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There is not a general classification for cam and follower mechanical systems. However, the functional embodiments and functions of each sub-system have relatively few possibilities, which we can classify.
The general shape of the cam is generated by the relative motion of the cam and follower-profile. Planar: •The cam is a disc, plate, track, groove, conjugate, ramp, slot Spatial: •The cam is cylindrical, barrel, globoidal |
The modes of cam motion are: Rotating: •The cam swings back and forth - the cam oscillates •The cam rotates continuously •The cam moves progressively (rare) Translating: •The cam slides back and forth - the cam reciprocates •The cam moves progressively (rare) Stationary: •The cam is a fixed to a frame, and multiple tooling with followers move around the cam. Most common on rotating machinery - such as a bottle labeling, capping, or filling machine. •The cam is a fixed to a frame and a tool with a follower slides along the the cam - e.g. a Slot Cam. |
The shape of the Follower-Profile influences the shape of the cam. Roller shapes •Cylindrical Follower-Roller - commonly used •Barrel Follower-Roller (Crowned Followers) - commonly used •Logarithmic Follower-Roller - the actual logarithmic function is the intellectual property of each manufacturer. •Taper Follower-Rollers - occasionally used with barrel, globoidal cams Other shapes •Flat-faced Follower - not as common as cylindrical •Knife-edged Follower - not a practical shape, but here for completeness •Other general shapes. See Typical Cam-Profile Shapes |
The modes of Follower motion are: Rotating Followers: a lever: •Swing back and forth: an oscillating follower •Progressive motion, they index, in one direction Translating Followers: a slider: •Sliding back and forth: a reciprocating follower Stationary Followers: •A Stationary Follower moves the Cam. Not as common. Molding machines, wedge type cams. |
The constraint between the Cam-Profile and the Follower-Profiles influences whether the Cam-Profile is: Force Closed: The constraint is an external force •Gravity, Spring, Air-Cylinder, ... Form Closed (also called Body Closed): The constraint is another “body”: •Groove (Track), Rib, Slot, within which you constrain the Follower-Profile. •Conjugate Cams: these systems require manufacturing and production accuracy for two (or more) Follower-Profiles to be in contact with two or more Cam-Profiles. |
Non-progressive: The follower returns to the same position after each cycle by reversing its direction of motion at some point in the cycle. Progressive: (also called indexing motion, Indexing Cams The follower moves progressively to a new position at the end of each cycle. In most cases the follower is replaced by another follower at the end of a motion cycle. Equally spaced followers return to their original positions after a number of motion-cycle. Most indexing systems use several roller followers equally spaced around a follower wheel or 'turret'. |