Sheave, the noun of the workpiece, generally refers to the component of the sheave mechanism, which together with the crank and the frame equipped with the round pin constitute the stepping motion sheave mechanism, which is mainly used in intermittent transmission. The sheave mechanism has the advantages of simple structure, easy processing, reliable operation, accurate control of the turning angle, and high mechanical efficiency. Compared with a ratchet mechanism, a sheave mechanism moves more smoothly when entering and disengaging.
According to the position of the groove, the plane sheave is divided into an outer sheave and an inner sheave:
Outer sheave: The radial opening of the sheave is outward from the center of the circle, and the driving part and the driven sheave turn in the opposite direction.
Inner sheave: The radial opening of the sheave is from the center of the circle inward, and the driving part and the driven sheave turn in the same direction.
The fewer the number of grooves of the outer sheave mechanism, the worse the dynamic performance. The dynamic performance of the inner sheave mechanism is better than that of the outer sheave mechanism.