In the mechanical design standard, what is the minimum diameter of type A single groove pulley? What are the causes of belt breakage?

1, the linear speed of V-belt should not exceed 25m? Seconds, the linear speed of flat belt is generally 10 ~ 20m? Seconds, which can be reduced under special circumstances. The belt line speed can be calculated by the following formula:

V = π dn/60× 1000 (m？ Seconds)

Where v is the linear speed of the belt, (m? Seconds)

D- pulley diameter, (mm)

N- pulley speed, (rpm)

2. The number of times the flat belt passes through the small pulley C per second should not exceed 3 ~ 5 times, and the V-belt should not exceed 20 times.

C=V/L (times? Seconds)? Where l-belt length (m)

3. The wrap angle of the small triangle pulley should not be less than 120? (flat belt 150? ), otherwise the diameter difference between the two pulleys should be reduced, or the center distance should be increased, or the pinch pulley should be installed.

4. The diameter of the small pulley should not be too small to avoid excessive bending of the belt and shorten its service life.

For flat belt drive, the diameter of small pulley is generally 25 ~ 30 times larger than the thickness of cloth-sandwiched adhesive tape.

The minimum diameter d of the flat pulley can be calculated by the following formula:

D minimum value =C? √N/n 1 (mm)

Where c is the calculation coefficient and c =1150 ~1400.

N-transmission power (kW)

N 1- pulley revolutions (rpm)

For V-belt drive, the diameter of small V-belt pulley should not be less than the following value, otherwise the wrap angle is not enough, and the belt is easy to slip and damage.