6.1.2 Special Layouts
- Slack side on top (Figures 6.2 and 6.3)
If the shaft center distance is short, proper chain tension should be maintained by adjusting the shaft center distance. If the shaft center distance is long, do not allow the two sides of the chain to touch each other. Reduce slack span by installing an idler.
Figure 6.2 Short Center Distance
Figure 6.3 Long Center Distance
- High chain speed and fluctuating loads
In this case, the chain's characteristic frequency, impact period of the driven shaft, or polygonal action created by the chain/sprocket engagement, may create large chain vibrations. A guide shoe made of NBR rubber or UHMW polyethylene will help reduce vibrations.
- Vertical or near-vertical shaft centers
Install an automatic tensioner to eliminate excess chain slack. This is imperative if the driving shaft is on the bottom (Figure 6.4).
Figure 6.4 Vertical Drive