Abstract: An example apparatus includes an outer rotor having a first axial face and a second axial face opposite the first axial face, wherein the first axial face comprises a circumferential contour defining a plurality of lobe faces, and wherein the second axial face comprises a transformed circumferential contour defining a corresponding plurality of lobe faces, where the transformed circumferential contour comprises at least one of a scale transformation of the circumferential contour or a rotational transformation of the circumferential contour; and an inner rotor configured to rotate eccentrically within the outer rotor, thereby forming a gerotor element for a fluid pump.

Abstract: In a general aspect, fluid flow in a gerotor system is enhanced. In some cases, a gerotor apparatus includes inner and outer gears. The outer gear includes inward-facing teeth and an inner surface that defines an inner profile of the outer gear. The inner gear includes outward-facing teeth and an outer surface that defines an outer profile of the inner gear. The inner gear and the outer gear reside in contact such that the inner profile of the outer gear seals against the outer profile of the inner gear at multiple distinct points. One or more cutouts are defined by the inner surface of the outer gear between a neighboring pair of the inward-facing teeth, by the outer surface of the inner gear between a neighboring pair of the outward-facing teeth, or both.

Abstract: In a general aspect, fluid flow in a gerotor system is enhanced. In some cases, a gerotor apparatus includes inner and outer gears. The outer gear includes inward-facing teeth and an inner surface that defines an inner profile of the outer gear. The inner gear includes outward-facing teeth and an outer surface that defines an outer profile of the inner gear. The inner gear and the outer gear reside in contact such that the inner profile of the outer gear seals against the outer profile of the inner gear at multiple distinct points. One or more cutouts are defined by the inner surface of the outer gear between a neighboring pair of the inward-facing teeth, by the outer surface of the inner gear between a neighboring pair of the outward-facing teeth, or both.