Rotary positive displacement machines based on trochoidal geometry and including a helical rotor that undergoes planetary motion relative to a helical stator can be designed and configured so that the axial load or rotor pressure force is positive, negative, or neutral. In some embodiments, a change in axial load, caused by a change in differential pressure across the machine, can be used to trigger a change in a mechanical configuration of the machine.

Disclosed are a hydrostatic pressure support and a spherical pump having the same. The hydrostatic pressure support is arranged between each of two parallel sides of a slipper and a sliding groove, and includes a first liquid flow channel, a second liquid flow channel, and a pressure-bearing groove. An inlet of the first liquid flow channel is communicated with one of two working chambers of the spherical pump, and an inlet of the second liquid flow channel is communicated with the other of the two working chambers. An outlet of the first liquid flow channel and an outlet the second liquid flow channel are respectively communicated with the pressure-bearing grooves provided on the two parallel sides of the slipper.

A displacement device including an inner rotor and an outer rotor with meshing projections. Points on each rotor trace a hypotrochoidal path relative to the other. The tips of the outer rotor projections may contact the inner rotor at Top Dead Center (TDC) and Bottom Dead Center (BDC) to form higher and lower pressure regions. Various elements may shape other elements to form seals.

A rotary engine rotor (10) comprising three rotor flanks (12) arranged in a generally equilateral triangle shape, each rotor flank (12) having a leading edge (16) and a trailing edge (17), an elongate lip (21) being provided on the leading edge (16) of at least one of the rotor flanks (12), the elongate lip (21) extending the full axial length of the rotor flank (12). In another aspect, at least one rotor flank (12) comprises a cavity having a leading edge and a trailing edge, and at least a portion of the base of the cavity proximal to a trailing edge thereof is curved outwardly.

One example of a gerotor pump includes an inner rotor comprising multiple teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis. The gerotor pump also includes a hollow outer rotor including an outer surface and an inner surface having substantially identical contours, the inner surface configured to engage with the multiple teeth and to rotate about a second longitudinal gerotor pump axis. The pump includes a pump housing within which the inner rotor and the outer rotor are disposed, wherein the outer surface of the outer rotor defines gaps between the pump housing and the outer rotor.

A rotor is shown with an asymmetrical structure for a pump, wherein the rotor includes at least one cutting edge and at least one rounded edge, as well as the pump as such including one or more rotor(s). The rotor (1) has a first circular element (4) where a material-moving cavity (5) is provided in the first circular element (4).

The invention prevents a decrease in strength of a screw rotor including a hollow portion and improves cooling performance. There is provided a screw rotor having a helical tooth on an outer periphery, the helical tooth extending by a predetermined length in an axial direction, in which a radial cross section of the screw rotor includes a cross section of a tooth portion, a cross section of an axial portion, a cross section of a support portion connected to an axial side of a tooth bottom or a tooth tip in the cross section of the tooth portion and an outer diameter side of the axial portion, and a cross section of a hollow portion formed by the support portions adjacent to each other in a rotational direction and an axial side inner surface of the tooth bottom or the tooth tip, and an axial longitudinal cross section of the screw rotor is a cross section in which the axial portion, the support portion, the axial side of the tooth bottom or the tooth tip, and an axial end portion of the screw rotor are continuously connected to each other as an integral structure by a three-dimensional fabrication method or the like.

Disclosed are a hydrostatic pressure support and a spherical pump having the same. The hydrostatic pressure support is arranged between each of two parallel sides of a slipper and a sliding groove, and includes a first liquid flow channel, a second liquid flow channel, and a pressure-bearing groove. An inlet of the first liquid flow channel is communicated with one of two working chambers of the spherical pump, and an inlet of the second liquid flow channel is communicated with the other of the two working chambers. An outlet of the first liquid flow channel and an outlet the second liquid flow channel are respectively communicated with the pressure-bearing grooves provided on the two parallel sides of the slipper.

Improved solids handling in rotary positive displacement machines, where the machines are based on trochoidal geometry, can be achieved through the use of solids-handling features on the surface of the rotor and/or stator and/or by the use of modified seals mounted on the rotor or stator. In at least some embodiments the rotary machines comprise a helical rotor that undergoes planetary motion relative to a helical stator.

A vacuum pump screw rotor, comprising at least two helical displacer elements on a rotor shaft. The at least two displacer elements have different pitches, but the pitches of each displacer element are constant. Furthermore, the displacer elements each have a helical recess, each having a contour that remains the same over its entire length. Hereby, a suction-side displacer element has a recess having an asymmetric contour, and a pressure-side displacer element has a recess having a symmetrical contour.