1. The most common motion form in cam mechanism is that the cam rotates at a uniform speed and the follower moves back and forth. When the cam rotates, the follower moves in a four-stage motion cycle of "up-stop-down-stop".

Second, the definition and use of cam mechanism:

1. Cam mechanism consists of cam, follower and frame.

The cam is the driving part, and the motion law of the driven part is determined by the contour of the cam.

Cam mechanism is a kind of high pair mechanism widely used in mechanical engineering.

Cam mechanism is often used in low-speed, light-load automaton or its control mechanism.

2. When the cam rotates, according to the contour of the cam, the valve of the follower can be forced to move downward to open the valve (closed by the force of the spring), so that the valve can be opened or closed at a predetermined time to complete the valve distribution action of the internal combustion engine.

3. The cam mechanism can convert the constant-speed continuous rotation of the driving cam into the reciprocating linear motion of the driven cam or swing around a certain point, and accurately realize the required motion law by relying on the cam profile curve.

Third, the advantages and disadvantages of cam mechanism:

1, which has the advantages that as long as the cam profile curve is designed correctly, the follower can realize any given motion law, and the structure is simple, compact and reliable.

2. Disadvantages: the cam and the follower are in point or line contact, which is not easy to lubricate and easy to wear.