Not to get all mechanically nerdy on you, but the "worm" is the helical drive piece on the input shaft, the "worm gear" is round brass part on the output shaft you are referring to as a "spur gear." Again, being very technical, a "spur gear" has a very different tooth geometry than a "worm gear." and is not used with a worm drive.
Gears are round things with teeth around the edge, the "worm" in a "worm drive" is--technically--not a gear.
Especially in the Leroy-Somers boxes, I completely agree the worm does not wear at any significant rate. It's made of steel. The brass gear (by whatever name) is the part that wears.
If I confused anybody by being overly jargon-ish in my writing, the part I was referring to was the round gear made of brass with teeth in the edges connected to the output shaft of the gearbox. NOT the helical part off to the side that is driven by the motor.
Back Creek, Annapolis, MD
---In amelyachtowners@..., <divanz620@...> wrote :
'That gear you show is the spur gear. The worm gear is the one attached to the motor shaft. In my experience (as per your photo) it's the spur gear that wears not the worm.