*3.4. Influence of Gear Rotation Speed on Picking Rate*

The jujube branch picking mechanism makes collisions among jujube branches as well as collisions between jujube branches and the wall surface through the dialing of the teeth, which form a granular force. At the same time, with the appearance of tumbling, collision, entanglement, and throwing, the picking rate changes. When the gear rotation speed was 100 r/min, the collision and force between the jujube branch and the gear may be small, and the entanglement and throwing phenomenon may be rarer (Figure 10a). When the gear rotation speed increases to 120 r/min, the force of the gear on the jujube branch increases, and collisions and throws become more frequent (Figure 10b). When the rotation speed reaches 150 r/min, the force of the shifting tooth is further strengthened, and the number of jujube branches that are shifted away increases (Figure 10c).

**Figure 10.** Influence of the gear rotation speed on the movement of jujube branches. (**a**) Gear rotation speed is 100 r/min. (**b**) Gear rotation speed is 120 r/min. (**c**) Gear rotation speed is 150 r/min.

It can be found from Figure 11 that with the increase in gear rotation speed, the collision effect between particles becomes stronger and the particle pickup rate decreases.

**Figure 11.** Relationship between gear speed and picking rate.

Numerical simulation values and test results show that the increase in the rotation speed of the gear makes the interaction between the particles more serious and reduces the picking rate of jujube branches. Compared with the size of the jujube branch and the total number of feeds, the speed of the gear shift affects the particle contact force and tumbling force less than the size of the jujube branch and more than the total number of feeds.
