Lesson 4/Learning Event 1
At the outlet side of the pump, the gear teeth come back into mesh (engagement). With the teeth of both
gears in mesh, there is no longer room for oil between them. The oil is forced out from between the gear
teeth into the outlet (discharge) side of the pump.
FIGURE 58. ROTOR-TYPE PUMP.
The rotor-type pump uses an inner rotor with lobes that move in and out of mesh with an outer rotor.
The inner rotor is keyed to, and driven by, a shaft like the gear in the pump in the illustration. As the inner
rotor rotates, it carries the outer rotor with it in the same direction.