The oil pump in an internal combustion engine is usually a gear type (gear pump), driven by the crankshaft or camshaft, or a rotor type (rotary pump).
A mechanically-driven device for distributing or pumping oil around a 4 stroke engine & into a 2 stroke engine
coerce: to cause to do through pressure or necessity, by physical, moral or intellectual means :"She forced him to take a job in the city"; "He squeezed her for information"
The continuous physical force exerted on or against an object by something in contact with it
The use of persuasion, influence, or intimidation to make someone do something
a force that compels; "the public brought pressure to bear on the government"
The force exerted per unit area
the force applied to a unit area of surface; measured in pascals (SI unit) or in dynes (cgs unit); "the compressed gas exerts an increased pressure"
The sucker-rod pump, a beam-pumping unit. There were several more further to the right. The red-coded fixtures in the ground are oil out; the blue ones are water in. Water, separated from the oil, is forced back into the ground to provide the pressure to force the oil and water out of the ground. The oil and water is carried to a nearby separator complex. The oil is pumped into a pipeline and the water is sent back to be forced back into the ground.