What are these wheels called in English?

If they were oriented to face you axle-on, they would be called dials, of course. As they're not, the best I can think of is digit wheel. I can't find an official definition page, but Alibaba has a category page for that term, and everything on it looks like what you're talking about...

I've always called them rotors. (The caption of the first picture at that link starts off with "A series of three rotors...") However, the aforementioned barrel, drum, wheel terms are more common than rotor in discussions of mechanical counters, where the term counter wheel often is used. Two other terms used are disc and ring; a wikipedia row counter article refers to knurled number rings in its "Pendant knitting counters" section and to number discs (or disks) in other sections. However, the disc terms are specific to flat counters with rotating discs, instead of to cylindrical parts as contained in those Veeder-Root-style mechanical counters.

Due to their cylindrical shape the wheels in a mechanical counter like this might be referred to as barrels or drums.

You can also find odometer wheel