How can a child tie a rope when throwing a ball?

There are two ways to trap the ball rope: one is to loosen the front end of the ball rope; Unfold into a larger rope loop; 1 Put the ball directly into the rope loop (suitable for experts; 2 Wrap the rope twice, and then put it into the bearing (for beginners).

Bearing is an important part of modern mechanical equipment. Its main function is to support the mechanical rotating body, reduce the friction coefficient during its movement and ensure its rotation accuracy.

According to the different friction properties of moving elements, bearings can be divided into rolling bearings and sliding bearings. Among them, rolling bearing has been standardized and serialized, but compared with sliding bearing, its radial size, vibration and noise are larger and its price is higher.

Rolling bearings are generally composed of outer ring, inner ring, rolling body and cage. According to the shape of rolling elements, rolling bearings are divided into two categories: ball bearings and roller bearings. When other parts move relatively on the shaft, it is used to reduce the friction coefficient in the process of power transmission and keep the center position of the shaft fixed.

Bearing is an important part of modern mechanical equipment. Its main function is to support the mechanical rotating body, so as to reduce the friction coefficient of mechanical load in the transmission process of equipment. According to the different friction properties of moving elements, bearings can be divided into rolling bearings and sliding bearings.