What Is a Flat Belt?

Belt drive is also called "belt drive". A type of mechanical transmission. It consists of one or several belts tightly sleeved on two wheels (called "pulleys"). The two wheels are respectively mounted on the driving shaft and the driven shaft. Use the friction between the belt and the two wheels to transfer motion and power.

The belt drive is a tensioned (endless) belt, which is placed on the pulleys of the two drive shafts. It relies on the belt and the pulley

The belt drive is composed of a driving wheel 1, a driven wheel 2, and an endless belt tensioned on two pulleys; due to the tension, a pressing force is generated at the contact portion of the belt and the pulley. When the driving wheel runs, the belt is driven by friction, and the belt drives the driven wheel to run. In this way, the power of the driving shaft is transmitted to the driven shaft.

Belt drive is widely used in machinery. Compared with mesh drive (gear, worm gear drive), belt drive has the following characteristics:

(1) Simple structure, low manufacturing cost, convenient installation and maintenance.

(2) The belt is full of elasticity, which can mitigate shock and vibration, so it runs smoothly and has low noise during work.

(3) It is suitable for transmission with a large center distance, but from the other side, the transmission profile is large and poor in compactness.

(4) The elastic sliding of the belt on the pulley changes with the change of the load, so the transmission ratio is not accurate. But when overloaded, slipping can occur. Therefore, damage to other transmission members can be prevented. But it is usually not used as an overload protection device.

(5) The belt must be tensioned, so that the shaft and bearing are subjected to a large force.

(6) Belts and pulleys can generate heat and generate electricity through friction, so they should not be used in areas where there is a danger of explosion.

(7) The efficiency and durability of the belt drive are low. Compared with the flat belt drive, the V-belt has the advantages of a larger transmission ratio i, a smaller center distance A, a compact transmission profile, and a smaller belt sliding and tensioning force. ^[3]

Because the belt drive works by friction, it can effectively alleviate the impact of the load and run smoothly without noise. Manufacturing and installation accuracy is not as strict as the requirements of meshing transmission; similar to friction wheel transmission at work, it will cause the belt to slip when overloaded, so it can prevent the damage of other parts and increase the belt length within a reasonable range to accommodate a larger center distance Working conditions (center distance can be up to 15 meters).

However, the belt drive that operates by friction has the same disadvantages as the friction wheel drive: 1) elastic sliding and slipping, which reduces efficiency and cannot maintain an accurate transmission ratio; 2) when transmitting the same large circumferential force, the contour size The pressure on the shaft is greater than the meshing transmission force; 3) The life of the belt is short, generally only 2000 to 3000 hours.

Troubleshooting of belt drive: The main failure of belt drive is slipping. The reasons for slipping are: too loose belt, oil on the belt or pulley, serious belt wear or elongation. When the belt is too loose, it should be readjusted according to the tightness required in the manual. If the belt or pulley is slippery due to oil stains, it should be removed in time. If the belt is severely worn or stretched, it should be replaced with a new belt.