The internal groove cam with an internal follower is characterized by its compactness. It is useful in applications where space is limited and where, for various reasons (accessibility, safety, product handling, and feeding), it is necessary—if not essential—to place the primary motion generated by the cam-follower mechanism in a "protected" position.
The follower can either oscillate linearly or around a pivot; generally, rollers with a large diameter relative to the cam bore can be used. Unlike standard applications where the cam typically rotates at a constant speed and the follower moves according to a predefined motion law, this type of cam is stationary. In this configuration, it is the follower that combines the motion received from the drive axis with the motion generated by the cam profile.
The cam represented in the figure is of the cylindrical type, but it is possible to manufacture globoidal or flat cams depending on specific requirements and plant configurations. The internal cam profile can be of several types:
The choice of profile type is strictly linked to the application and, consequently, to the function the cam is required to perform. Several parameters influence the definition of the profile type, including operating speed, loads (dynamic, working, or impulsive loads related to system anomalies), required precision, movement quality during transfer phases, and lubrication.
The choice of cam material and the subsequent thermal or surface treatment is derived from the application type and the aforementioned parameters. Heat treatments range from nitriding to case hardening. From a dimensional standpoint, it is possible to manufacture cams with a central bore ranging from 160mm to 1500mm.