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 rotary, self-priming, positive displacement pump is described. The pump may include a pump housing including an inlet and an outlet, a pump chamber including an upper wall, a lateral wall, and a floor, first and second rotary impellers in the pump chamber, and a pair of gears each secured to the first and second rotary impellers, and a pressure relief feature operable to relieve pressure developing in a relatively high pressure zone of the pump chamber. The gears mesh with each other to ensure that the vanes do not contact one another during rotation. The pressure relief feature may comprise one or more channels formed in the pump housing and/or the first and second rotary impellers. The channels connect the high pressure zone with another zone to redistribute pressure. The channels may include one continuous channel or alternatively, a plurality of unconnected channels.

In accordance with one embodiment, the gear pump comprises a first gear meshed with a second gear as well as a housing, in which the gears are supported. The housing includes a first void, which at least partly adjoins a first side surface of the first gear, and a second void, which at least partly adjoins a second side surface of the first gear. The gear pump further comprises a fluid intake channel configured to direct fluid towards the gears, wherein at least one deflector is arranged within the fluid intake such that an incident fluid flow is diverted towards the first void as well as to the second void.

In an oil pump, an inner rotor and an outer rotor rotate to discharge the oil through a discharge port. The discharge port has an outer extension portion located on a radially inner side with respect to a root circle of the outer rotor and on a radially outer side of a tip circle of the outer rotor and an inner extension portion located on the radially inner side with respect to the tip circle of the outer rotor and on the radially outer side with respect to a root circle of the inner rotor. An inter-tooth chamber facing a partitioning portion that partitions the suction port from the discharge port comes into communication with the outer extension portion and the inner extension portion. Then, a tip seal portion defining the inter-tooth chamber intersects an outer edge of an opening of the discharge port.

An embodiment of a gear pump arrangement includes a first gear defining a first set of teeth; and a second gear defining a second set of teeth, the first set of teeth and the second set of teeth being in meshed communication such that fluid is pumped in response to rotation of the first gear and the second gear, at least one of the first set of teeth and the second set of teeth having at least one gear tooth passageway through each tooth thereby fluidically connecting opposing faces of the tooth.

One embodiment of a pump may include an idler gear having a plurality of idler gear teeth extending radially outward, wherein at least one of the idler gear teeth may be formed with an idler gear cavity therein. The pump may include a drive gear having a plurality of drive gear teeth extending radially outward that may be intermeshed with the idler gear teeth during use. The drive gear may be formed with a recess at on axial end thereof, and the axial position of the recess may correspond to the axial position of the idler gear cavity. In one embodiment of a pump, each idler gear tooth may be formed with an identical idler gear cavity at the same relative position on each idler gear tooth.

A fluid system includes a variable-speed and/or a variable-torque pump to pump a fluid, at least one proportional control valve assembly, an actuator that is operated by the fluid to control a load, and a controller that establishes a speed and/or torque of the pump and a position of the at least one proportional control valve assembly. The pump includes at least one fluid driver that provides fluid to the actuator, which can be, e.g., a fluid-actuated cylinder, a fluid-driven motor or another type of fluid-driven actuator that controls a load. Each fluid driver includes a prime mover and a fluid displacement assembly. The fluid displacement assembly can be driven by the prime mover such that fluid is transferred from the inlet port to the outlet port of the pump.

A gear pump is provided with: a casing including a suction port configured to suck fluid, and a discharge port configured to expel the pressurized fluid; a gear including a wheel portion with gear teeth and an axially elongated shaft portion, the gear being so housed in the casing as to transport the fluid from the suction port to the discharge port; and a floating bearing rotatably supporting the shaft portion and being movable axially, the floating bearing including a sealing face in contact with the wheel portion, a receiver face axially opposed to the sealing face; and a communication path having an opening on the sealing face and communicating the opening with a third pressurization chamber defined by a third receiver face of the receiver face and the casing.

A rotary, self-priming, positive displacement pump is described. The pump may include a pump housing including an inlet and an outlet, a pump chamber including an upper wall, a lateral wall, and a floor, first and second rotary impellers in the pump chamber, and a pair of gears each secured to the first and second rotary impellers, and a pressure relief feature operable to relieve pressure developing in a relatively high pressure zone of the pump chamber. The gears mesh with each other to ensure that the vanes do not contact one another during rotation. The pressure relief feature may comprise one or more channels formed in the pump housing and/or the first and second rotary impellers. The channels connect the high pressure zone with another zone to redistribute pressure. The channels may include one continuous channel or alternatively, a plurality of unconnected channels.

A gear pump assembly includes a drive gear having a plurality of circumferentially spaced teeth, and a driven gear likewise having a plurality of circumferentially spaced teeth positioned for intermeshing engagement between the drive and driven gears via the teeth. A bleed mechanism directs carryover fluid from a discharge side of a bearing dam to an inlet side of the bearing dam in order to supply the carryover fluid to a carryover volume disposed between mating drive gear teeth and driven gear teeth. The bleed mechanism including a passage communicating with at least one of (i) a gear face of the drive gear, (ii) a gear face of the driven gear; or (iii) a bottom of a gear tooth profile adjacent a root region between adjacent gear teeth.