Roll-Ring Self-Adjusting Chain Tensioner, 30 / 1/2 x 5/16"

Roll-Ring is a self-adjusting chain tensioner for roller chain drives. It is a toothed polymer ring that sits between the two strands of the chain. The ring is pre-stressed, so it presses the strands apart and takes up slack, and it also damps chain movement.

Roll-Ring needs no brackets, sprockets, bolts or tools and does not need adjusting after fitting. It works on horizontal, vertical and diagonal drives and in reverse.

Where this product is used

• Printing machinery
• Confectionery production lines
• Airport baggage conveyor drives
• Brewery cleaning and filling lines
• Roller conveyors
• Vibratory drives in blasting equipment

Features

• Toothed polymer ring that tensions the chain and damps chain movement
• Self-adjusting, with no manual take-up
• Self-lubricating and maintenance-free in service
• No brackets, bolts, sprockets or tools, and fitted in seconds
• Works on horizontal, vertical and diagonal drives and in reverse
• For ISO 05B-1 to 20B-1 chain (DIN 8187) and ANSI 35 to 100 chain
• 17 sizes by chain and tooth count (26, 30, 34 and 36 teeth)
• Operating temperature -20 to +70 °C (the 20B size is -20 to +60 °C)

Key specifications

Sizes and ratings

Fitting and use

Fit the Roll-Ring between the two chain strands. Its teeth engage the chain and it deforms to an oval shape to take up slack. Opposing movement of the load strand and the slack strand holds it in position.

Maximum static force is the force of the ring at 20 °C at maximum adjustment, without the extra dynamic force that rises with chain speed. Maximum chain speed is the limit for that size, and the limit of the chain itself still applies.

The ring gives its greatest tension at low chain speeds and keeps reserve tension and damping at speed. Other Roll-Ring series are made for hot and for cold conditions.

Check the tensioner on the drive, as application-specific conditions can vary.

Choosing the right option

Start with the chain: its ISO or ANSI number and whether it is simplex or duplex. Then measure the largest working gap between the two chain strands, from pin centre to pin centre, and the space between the sprockets. The gap between the strands must be below the reference diameter of the Roll-Ring, and there must be enough room between the sprockets for it.

Position the tensioner with at least one chain pitch between it and the smaller sprocket. If several sizes fit, choose the one with the most teeth. For duplex chain, fit a Roll-Ring in each strand.