English to Portuguese Tech/Engineering Mechanics / Mech Engineering

Power is applied to the rotor and transmitted to the idler gear with which it meshes.
The space between the outside diameter of the idler and the inside diameter of the rotor is sealed by the crescent.
When the pump is started, there is an increase in volume as the teeth come out of mesh.
This creates a partial vacuum, drawing the liquid into the pump through the suction port.

Minha dúvida é com relação ao uso do idler sozinho, pois em idler gear usei engrenagem intermediária. Grata!