How does oil pass through an external gear type pump?

In an external gear type pump, oil passes through the pump primarily as the gears rotate. The design of these pumps allows for the movement of fluid through the spaces created between the gear teeth as they intermesh. When the gears turn, they create a vacuum at the inlet side of the pump, which draws oil into the pump from an external source. As the gears continue to rotate, the oil is trapped between the teeth and is carried around the outer circumference of the gears, eventually being pushed out through the outlet port.

The movement through the rotating gear teeth and outside the housing is key because it directly leverages the gear mechanism to transport the fluid efficiently. This operation also allows for a smooth transfer and consistent flow of oil, which is essential in applications requiring reliable lubrication or pressure generation.

The other choices reflect processes or mechanisms that do not pertain to how oil is physically moved through an external gear type pump. A filtration system does play a crucial role in maintaining fluid cleanliness but does not influence the fundamental operation of how oil is pumped. Similarly, indicating that oil would pass only through the inlet port neglects the important role of the intermeshing gears. Vaporization is also not a relevant mechanism in this context, as oil must remain in its liquid