(1) The chain speed and the driven sprocket angular speed change periodically, resulting in additional dynamic loads.The greater the acceleration of the chain, the greater the dynamic load will be.The acceleration of the chain is
visible,SprocketThe higher the rotational speed, the larger the chain pitch, and the smaller the number of sprocket teeth, the dynamic load will increase.
(2) The speed of the chain in the vertical direction also changes periodically, causing the chain to vibrate laterally, which is one of the reasons why the chain drive generates dynamic load.
(3) The moment the chain link enters the sprocket, the chain link and theSprocketThe gear teeth mesh at a certain relative speed, and the chain and gear teeth will be impacted, and additional dynamic load will be generated.As shown in Figure 6.11, according to the principle of relative motion, the sprocket is regarded as stationary, and the chain link enters the gear teeth with an angular velocity -w and generates an impact.This phenomenon is exacerbated with the increase of the speed of the sprocket and the increase of the chain pitch.Make the transmission produce vibration and noise.
(4) If the chain is not well tensioned and the chain is slack, in the case of starting, braking, reversing, load changes, etc., inertial impact will be generated, causing the chain drive to generate a large dynamic load.
Due to the dynamic load effect of chain drives, chain drives are not suitable for high speeds.