1874

Rotary vane pump

• Put a rotor
• in a chamber
• with vanes
• extending
• from the rotor
• and pressing
• the chamber wall
• to move a liquid,
• creating an
• expanding chamber
• to pull liquid in,
• and a contracting
• chamber to squeeze
• liquid out.

Positive displacement pump

• A constant flow machine
• produces the same flow
• at a given speed regardless
• of the discharge pressure—in theory.
• Because it relies on moving seals,
• an increase of discharge pressure
• can slightly decrease the flow
• as fluid leaks around the seals—in practice.

Eccentricity

• If the center of the rotor
• is not at the center of the chamber
• and the vanes are pushed by springs against the chamber wall
• unequal partitions—intake and discharge—improve efficiency.
• I think the same advantage cannot be claimed
• for people with eccentric behaviors—must be
• there are other reasons we love them.