Classified by cam shape, disc cam: This cam is a disc-shaped part that rotates around a fixed axis. Its diameter varies, and when the follower rotates around the fixed axis, it can push the follower to move in a plane perpendicular to the camshaft. It is a relatively basic type of cam, with a simple structure and wide application.

　　 Moving cam: When the rotating axis of a disc cam is located at a distance, it evolves into a moving cam (or wedge cam). The cam is plate-shaped and moves linearly relative to the frame. Cylindrical cam: If the moving cam is rolled into a cylinder, it becomes a cylindrical cam. In this cam mechanism, the relative motion between the cams is spatial motion, so it belongs to a spatial cam mechanism.

　　 Different motion requirements lead to different profile curves for the cam. In one working cycle, the cam completes movements such as lifting, returning, and dwelling according to the design expectations. The cam generally rotates uniformly, and the follower moves according to the cam curve. In each stage, we focus on the lifting and return curves of the cam, as this part corresponds to the "movement" of the follower at the beginning and end of the state and process. We call this the cam work cycle diagram, where the displacement curve describes the functional relationship between the follower displacement and the cam rotation angle, which is a more intuitive description tool for the working principle of the cam. For the convenience of subsequent discussions, it is necessary to be familiar with the following basic concepts, especially the base circle, pressure angle, and stroke.

　　 Base circle, that is, the circle formed by the small radius r of the cam, generally denoted as (Note: The base circle radius of the roller follower disc cam is the short distance from the cam rotation center to the theoretical profile of the cam) Pressure angle, the angle of cam rotation during the movement of the follower from the starting point to the end point. Dwell angle, the angle of cam rotation when the follower is stationary at the end point. Return angle, the angle of cam rotation during the movement of the follower from the end point to the starting point. Dwell angle near the starting point, the angle of cam rotation when the follower is stationary at the starting point. Stroke is the displacement/distance of the follower from the starting point to the end point.

　　 The motion law of a cam generally refers to the motion law of the follower, which is consistent with the law of the cam curve, that is, during the movement of the follower, its displacement, velocity, and acceleration change with time, and the trajectory is usually a straight line or an arc. According to whether the follower needs to stop and where it stops within a cycle, the displacement curve of the follower can be divided into four basic types, and the basic types can be further combined into other forms.

　　 In the cam displacement curve, we focus on the "lifting" and "return" motion law "curves", hoping to understand some motion states of the follower during the process or at the starting point, which are usually defined and described using parameters such as acceleration. For the same motion law, the actual profile of the cam using different follower designs is the same. This section ends here. See you next time! Please follow and like if you enjoy!