Free f cam
A special case of this cam is constant lead, where the position of the follower is linear with rotation, as in a lead screw.
The purpose and detail of implementation influence whether this application is called a cam or a screw thread, but in some cases, the nomenclature may be ambiguous.
Displacement diagrams are traditionally presented as graphs with non-negative values.
A simple displacement diagram illustrates the follower motion at a constant velocity rise followed by a similar return with a dwell in between as depicted in figure 2.
Cams used for function generation may have grooves that require several revolutions to cover the complete function, and in this case, the function generally needs to be invertible so that the groove does not self intersect, and the function output value must differ enough at corresponding rotations that there is sufficient material separating the adjacent groove segments.
A face cam of this type generally has only one slot for a follower on each face.
In some applications, a single element, such as a gear, a barrel cam, or other rotating element with a flat face, may do duty as a face cam in addition to other purposes.
However, the most common type is in the valve actuators in internal combustion engines.
Here, the cam profile is commonly symmetric and at rotational speeds generally met with, very high acceleration forces develop.