pulley

The belt pulley is a kind of hub parts, generally the relative size is relatively large, and the manufacturing process is mainly casting and forging. Generally, the larger size is designed by casting method, the material is generally cast iron (good casting performance), and cast steel is rarely used (poor casting performance of steel); Generally, the smaller size can be designed as forging, and the material is steel. Pulley is mainly used for long-distance transmission of power, such as small diesel power output, agricultural vehicles, tractors, automobiles, mining machinery, mechanical processing equipment, textile machinery, packaging machinery, lathe, forging machine, some small horsepower motorcycle power transmission, agricultural machinery power transmission, air compressor, reducer, reducer, generator, gin and so on.
The advantages of belt pulley drive are: the belt pulley transmits kinetic energy to ease the impact of load; The belt pulley drives smoothly with low noise and vibration; The structure of belt pulley drive is simple and easy to adjust; The manufacturing and installation accuracy of pulley drive is not as strict as meshing drive; The belt pulley drive has the function of overload protection; The adjustment range of the center distance between the two shafts of the belt pulley drive is large. The disadvantages of belt drive are: the belt pulley drive has elastic sliding and slipping, the transmission efficiency is low and the accurate transmission ratio can not be maintained; When the belt pulley transmission transmits the same large circumferential force, the profile size and shaft pressure are larger than the meshing transmission; The service life of the pulley drive belt is short. All kinds of mechanical equipment pulley diameter and other dimensions are matched according to the deceleration ratio, and designed according to the working speed and motor speed. Working speed / motor speed = diameter of driving pulley / diameter of driven pulley * 0.98 (sliding coefficient). If steel pulley is used, the linear speed shall not be higher than 40m / S; if cast iron pulley is used, the linear speed shall not be higher than 35m / s. conversion ratio between motor speed and pulley diameter: speed ratio = output speed: input speed = pitch circle diameter of load pulley: pitch circle diameter of motor pulley. The diameter of pitch circle is the same as the reference diameter, the diameter is -2h= the diameter of the pitch circle, h is the groove depth of the reference line, the V-belt h of different models is different, Y Z a B C D E, and the groove depth of the reference line is h = 1.622.753.54.8 8.19.6 respectively. The diameter of the pulley pitch circle is the theoretical diameter of the pulley joint line position, which is a bit like the diameter of the gear indexing circle. PD is generally used for the outer circle, OD is generally used for the outer circle. The conversion formula of different groove type pitch circle and outer circle is different. Generally, we can easily measure the outer circle of the pulley. According to the formula, the pitch circle is calculated.Spz:od=pd+4; SPA:OD=PD+5.5; SPB:OD=PD+7; SPC:OD=PD+9.6。 The small outer diameter of pulley a or spa is 80mm, if it is less than this size, especially in high speed, the belt is prone to delamination and cracks at the bottom. SPZ belt, small wheel not less than 63mm can. At the same time, pay attention to the installation method and tension of belt, too small and easy to slip, too large and easy to damage the belt and bearing.