An "auger" is, either a drilling bit (for woodworking, especially), or a helicoilda device for conveying liquids, powders or granular -even coarse granular) material. Hence, for instance, a snowplow is usually equipped with an auger ("tornillo sin fin") to eject the snow away from the path being open across the snow (and even as a drill for opening holes in ice (in which case it is also sort of a drill bit, though a VERY wide one and usually quite long, too).

This latter is also called an "Archimedes screw" (tornillo de Arquímedes).

In ceramics (brickmaking), the clay wet mass is pushed through a die, via an "auger press".

However, while the context here is quite scarce, I am quite confident that they are referring to gears. In that case, this is a "worm", part of a "worm drive", which consists of a "worm" ("tornillo sin fin") and a "worm wheel" (corona)