Chain tension and arrangements chain drives

Correct chain tension is crucial for smooth operation and a long service life of the chain drive. It is essentially adjusted via the preload and the slack in the loose strand.

Adjust preload

Slack in loose strand is determined by the shaft distance.

Depending on the incline of the chain drive, the following reference values apply:

Incline of chain drive	Slack A - C (in % of the shaft distance)
< 45° to horizontal	2 - 6 %
> 45° to horizontal	1 - 3 %
> 60° or reversing	Chain tensioners or tension rollers required

Note: Chain preload is not always necessary.

When is the chain preload required?

Preload is common in clocked and reversing operation , to prevent chain accumulation on the drive sprocket
In other applications, a slight mechanical preload is often sufficient so that the chain is under light tension everywhere.

Reference values for the preload

Maximum: 5% of operating tension
As low as possible, as higher preload leads to additional wear (chain elongation)
Individually depending on parameters such as:
- Chain type
- Moving mass
- Acceleration and delay
- Alignment of chain drive

Tip: The preload should always be adjusted gradually from lower to higher until proper operation is ensured.

Length compensation for wear

Due to wear-related chain elongation, a length compensation is required to ensure the function of the chain drive.

Tensioning and guiding

The correct tension and guidance of the chain is vital for smooth operation. This is the only way to reliably prevent unwanted wear, malfunctions and failures.