The Test Device Development Of Chain-Transmission Velocity Fluctuation And The Experimental Study Of Chain-Transmission Polygon-Effect

The speed, efficiency, automation, precision and reliability for mechanical Products are required higher and higher while vibration and noise lower and lower, weight lighter at present. As the important component Part of automobile and engineering machine transmission system, Chain Drives has been applied in some fields, such as framing, mining, lifting, transportation, metallurgy, architecture, Petroleum, chemical industry and other mechanical fields. Roller chain is the widest application in the chain drives. It consists of the chain, the drive sprocket and the driven sprocket. Roller sprockets have some special dentiform teeth. Depending upon the meshing which lies in between chain teeth and chain nodes, it can transfer the desired movement. Chain drives'operating characteristic has the most important influence for entire transmission system. The polygon-effect of chain-transmission, seriously affected the stability and noise of the chain transmission at high speed. Therefore, it is necessary that steady effect of the system of roller chain at high speed is increased and noise is lowed. This also now a difficult and hot point of the study of roller chain. Author summarizes the research of roller chain at high speed and research. The modern test and measurement instruments update greatly and it is possible to do the polygon-effect trial. The paper's main content is just about the research of the polygon-effect of chain-transmission based on Lab VIEW.This paper summarizes the development stage and present status of the polygon-effect of chain-transmission. This paper studies dynamic performance of chain system through kinematics, dynamics and sets up a driven wheels angular velocity asymmetry coefficient mathematical model, and then introduced the design of the chain transmission test. The design of the chain transmission test extends the experimental study means of chain drive. These studies are the base for the following test. The results are as follows:1. With the polygon-effect of chain-transmission test, we get the driven wheel angular velocity curve, when the driving wheel angular velocity is a constant, the driven wheel angular velocity changes periodically, and this curve similar to a cosine curve.2. When the rotational speed is too low, the driven wheel angular velocity waveform (frequency) will increase, the magnitude becomes larger. And when the speed is too high, the driven wheel angular velocity waveform (frequency) will be reduced, the magnitude becomes larger too. 3. With the test results of appendix 1 and appendix 2, we can see that when the tooth number of the driving wheel unchanged, with the increasing number of the driven gear, the driven wheel's angular velocity asymmetry coefficient becomes smaller. Therefore, in the chain drive design, in order to reduce the polygon-effect, more sprocket teeth should be chosen, but when the tooth number is too large, the driven wheel's angular velocity asymmetry coefficient did not change significantly. Therefore, in the chain drive design, the sprocket teeth number should not be too much.4. Through a large number of experiments, double-pitch precision roller chain can greatly match with the short pitch sprocket, and compared with the single pitch roller chains, chain drive change of the angular velocity is relatively stable, when using double-pitch precision roller chain. Therefore, in practical engineering applications, we can use double-pitch precision roller chain instead of single-pitch roller chain.