The Standard Stock Range of Drive Wheels for Short Pitch (5mm to 2″ pitch) Roller Chains whether British or American Standard are mainly produced in three main design types:-
A SPROCKET. Usually in Carbon Steel with a boss one side, with tooth sizes from 8 to 40, although the range has been extended to include other popular tooth sizes up to 114.
A PLATE WHEEL. Usually in Carbon Steel without boss with a tooth size range 8 to 50 inclusive and there on after varing tooth sizes up to 125 depending on Pitch size.
A CHAIN WHEEL. Usually in Cast Iron with a boss one side and Spoked like a wheel on a cart, with tooth size of 38, 45, 57, 76, 95 & 114.
Short Pitch Chains have Rollers that have been Tempered to improve chain loading and wear. When driven at high speed you should always use drive wheels with a High Carbon content (Min C45/EN8) so as to slow down the wear on the teeth and to ensure more even wear over both drive wheels and in particular when the drive ratio is more than 1:1.
However drive wheels for their Longer Pitch conveyoring cousins (1 1/2″ to 12″ Pitch) as these chains can be supplied with or without Tempered Rollers. Then chains WITHOUT, you should use Cast Iron or Mild Steel wheels and for chains WITH then you should use Carbon Steel C45/EN8 both generally are of the boss one side type, although a popular alternative design is with a Double Central boss.
Prolonging the Life of your Wheels by up to 50%
As all the short as well as some of the Longer pitch Roller chains are produced with a Harden Steel Roller to improve chain loading and wear, you can improve the life of your drive wheel by up to 50% by using a Carbon Steel wheel En8 mininum and either Flame or Induction Harden the teeth. This has become common practice for large ratio drives, when the teeth on the smaller wheel maybe in contact with the Tempered Rollers many times more than the larger wheel, and Heavy Duty applications such as quarries, and earth moving equipment etc.
(Tip: When selecting a Heat Treatment supplier we would always recommend selecting a supplier who provides a Certificate of Hardness in support of their work)
How to Identify a Roller Chain Drive Wheel
As most European manufactuers have now adopted the Italian Squared Off Tooth Form with metric nominal dimensions, it is possible to find conformity from one manufacturer to another for the British Standard short Pitch drive wheels. However this does not apply for drive wheels for the American Short Pitch Series and the Imperial and Metric Long Pitch Roller Chains, these can vary widely from one manufacturer to another. Therefore the easiest and safest way to identify a wheel and in particular a worn one, is to identify the chain it is driving.
So in the first instant see if there are any identifying references on the side plate of the chain, as some manufacturers do provide the ISO chain reference number or there own reference along side their Brand name. Then if not, please follow this procedure.
This is particularly adviseable if the Drive Wheel is badly worn as only when you have fully identified the chain will you be sure whether the chain is a Short Pitch or Long Pitch and whether it is Imperial or Metric and if its a British or American Series Chain.
Having either obtained a chain reference or obtained the appropriate dimensions of the chain and the number of teeth. You will need to establish the characteristics of the Drive wheel, and as they can vary in any number of ways, we would then recommend all of the following:
- Shaft Size (including the keyway size & Type)
- Wheel Design Type
- All Dimensions
- Any Characteristics which are critical to the application