shaft-ledge gen.

[Mentality]

Подскажите пожалуйста, что может означать "shaft-ledge" контекст ниже.
Заранее спасибо.
Looking from the cover opening inside the oscillator, identify as reference casing wall that side
of oscillator with the shaft-ledge against the gears – is possible to see the gear’s key end
whereas on the other side of the gear the key is covered by the gear spacer item 16;

[Mike Ulixon]

ledge 1) выступ; борт; бурт; край; реборда...