français vers anglais Technique / Génie Ingénierie : industriel Heavy industrial plant

This term occurs in a parts list and drawing legend for a large piece of industrial plant — it's a rotary screen machine, though I don't believe the term is specific to this type of equipment in either FR or EN. Possibly Belgian FR (though I have encountered it before used in FR-FR). And preferably EN-GB.

It clearly isn't a 'tread', and although it is similar in idea to a 'race' as used in say a ball- or roller-bearing, I find it difficult to believe that same term would apply here. Basically, the machine consists of a massive drum or barrel that is supported using 'rings', around the periphery of each of which there is this metal 'thingy' that is cradled on smaller rollers or wheels and allow the thing to be rotated on a horizontal axis; it's a bit like the metal 'tyre' fitted to railway wheels. Obviously it is some kind of 'running surface' and subject to wear, hence why it is made separately (by forging, apparently).
Anyon know if there is a specific term for this, or failing that, suggest a plausible possiiblity?

Thanks a lot in advance!