2. Chain Dynamics
Number of Teeth in Sprocket
Figure 2.11 Elongation Versus the Number of Sprocket Teeth
In conveyor chains, in which the number of working teeth in sprockets is less than transmission chains, the stretch ratio is limited to 2 percent. Large pitch conveyor chains use a straight line in place of curve B in the sprocket tooth face. 2.2 CHAIN DRIVE IN ACTION Let’s study the case of an endless chain rotating on two sprockets (Figure 2.12).
Figure 2.12 An Endless Chain Rotating Around Two Sprockets
2.2.1 Chordal Action You will find that the position in which the chain and the sprockets engage fluctuates, and the chain vibrates along with this fluctuation. Even with the same chain, if you increase the number of teeth in the sprockets (change to larger diameter), vibration will be reduced. Decrease the number of teeth in the sprockets and vibration will increase. This is because there is a pitch length in chains, and they can only bend at the pitch point. In Figure 2.13, the height of engagement (the radius from the center of the sprocket) differs when the chain engages in a tangent position and when it engages in a chord.
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