Ordinary outer wheel mechanism. Slot number z 3 4 5 and pin number n1~ 61~ 41~ 31~ 2 Reference: Mechanical Principles of Northwestern Polytechnical University, 7th Edition p242.

Grooved wheel drive is a kind of one-way intermittent motion mechanism, which consists of a driving turntable with a cylindrical pin, a grooved wheel and a frame, also known as Maltese mechanism. It is often used to convert the continuous rotation of the driving part into the unidirectional periodic intermittent rotation of the driven part.

Geneva mechanism can be divided into outer Geneva mechanism and inner Geneva mechanism. They are all used for intermittent transmission between parallel shafts, but the pulley of the former rotates in the opposite direction to the dial, while the latter rotates in the same direction. Outer wheel mechanism is widely used.

Generally, grooves on pulleys are evenly distributed for transmitting motion between parallel shafts. This pulley mechanism is called ordinary pulley mechanism. Some special pulley mechanisms are also used in some machines. As shown in Figure 4, for multi-pin grooved wheel mechanisms with different arm lengths, the radial dimensions of radial grooves are different, and the circular pins are unevenly distributed on the dial. In this way, in a cycle of the sheave, several movement requirements with different movement time and stop time can be realized.