A crosslinked fluororesin-coated rotor manufacturing method is a method for manufacturing an annular outer rotor of an internal gear pump including the outer rotor, and an inner rotor, a side surfaces of the outer rotor being coated with a crosslinked fluororesin, an inner peripheral surface of the outer rotor not being coated with the crosslinked fluororesin, the method including: using an outer masking jig for covering the inner peripheral surface in a state where the side surfaces of the outer rotor are exposed; coating the outer rotor with an uncrosslinked fluororesin in a state where the outer masking jig is mounted to the outer rotor; and then irradiating the fluororesin with radiation in a state where the outer masking jig is removed from the outer rotor, to crosslink the fluororesin.

A crosslinked fluororesin-coated pump rotor manufacturing method is a method for manufacturing a pump rotor having flat rotor side surfaces and provided with a coating layer of a crosslinked fluororesin on each rotor side surface, the method including: screen-printing a dispersion liquid obtained by dispersing particles of a fluororesin in a solvent, on the rotor side surface by using a screen plate having an opening having a shape in which the opening does not protrude from an outer peripheral edge of the rotor side surface; then heating the pump rotor to a temperature equal to or higher than a melting point of the fluororesin to bake the fluororesin on the rotor side surface; and then irradiating the fluororesin with radiation to crosslink the fluororesin.

A pump includes a casing defining an interior volume. The pump casing includes at least one balancing plate that can be part of a wall of the pump casing with each balancing plate including a protruding portion having two recesses. Each recess is configured to accept one end of a fluid driver. The balancing plate aligns the fluid displacement members with respect to each other such that the fluid displacement members can pump the fluid when rotated. The balancing plates can include cooling grooves connecting the respective recesses. The cooling grooves ensure that some of the liquid being transferred in the internal volume is directed to bearings disposed in the recesses as the fluid drivers rotate.

A mud motor includes a rotor and a stator. Drilling fluid received by cavities of the mud motor drives the rotor to rotate within the stator. The rotor includes one or more rotor lobes extending helically and defining a rotor pitch. The stator includes two or more stator lobes extending helically and defining a stator pitch. The rotor and the stator together define a tapered profile of the mud motor that varies proceeding from a top end of the mud motor to a bottom end of the mud motor. At least one of the rotor pitch or the stator pitch vary as proceeding from the top end of the mud motor to the bottom end of the mud motor.

A pump device includes a rotating body, a pump housing including a suction port and a discharge port, and a relief valve. In the pump device, a fluid is sucked from the suction port and discharged from the discharge port by rotation of the rotating body. The relief valve includes a valve body and a biasing member. The discharge port includes an one end in a direction in which the discharge port extends. The one end is shallower than a middle portion of the discharge port. The pump housing includes a relief flow path through which the fluid flows when the relief valve opens. The relief flow path is provided so as to be open to a groove bottom surface of the one end of the discharge port.

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.

A hydraulic gerotor pump for an automatic transmission may comprise a housing and a gear set rotatably disposed within the housing. The gear set may comprise an inner gear and an outer gear having radially opposed intermeshing teeth that together define a plurality of circumferentially disposed variable volume pumping chambers therebetween. The housing may be made of a first aluminum-based material, and the inner gear and the outer gear of the gear set may be made of a second aluminum-based material. The linear coefficient of thermal expansion of the first aluminum-based material may be substantially the same as that of the second aluminum-based material.

Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides structural and/or operational advantages in the rotary machine.

A gear pump includes gears received within a housing defining an inlet, an outlet and end plates. The gears have shaft portions on each of two sides of each of the two gears. The shaft portions are mounted in journal bearings. The journal bearings each have a gear side face adjacent one of the two gears. A remote face is on a remote side of the journal bearing remote from each of the two gears. There is a plurality of heat pipes in at least one of the journal bearings. The heat pipes move heat from the gear face of the at least one of the journal bearings to the remote face. The plurality of heat pipes is enclosed by the housing, and extend generally in an axial direction from an end adjacent the gear face to an end adjacent the remote face. A fuel supply system is also disclosed.

Provided is a hydraulic orbital machine and a method of adjusting a hydraulic orbital machine comprising a first and a second lobed disk which rotate eccentrically about a rotation axis and within respective rotors; the machine is characterized by the fact that it has adjustment means designed to mutually angularly offset the angles at which, when the machine is at a standstill, the chambers defined between the lobed disks and the stator have minimum volume.