The gear pump may have a casing, a main shaft and rotating means connected to one end of the main shaft and configured to rotate the main shaft. Housed by the casing, a toothed wheel and at least one other toothed element are intermeshed with the toothed wheel. The other end of the main shaft is connected to one of the toothed wheel and the casing. Rotating the main shaft relative to the rotating means rotates the toothed wheel and the at least one other toothed element relative to the casing, thereby generating the flow. The other one of the casing and the toothed wheel is configured to be rotated around an axis defined by the main shaft for varying a flow rate of the generated flow.

A fluid delivery system having at least one fluid storage device and a pump with at least one fluid driver with a flow-through shaft that has a through-passage. The pump includes a casing, and at least one fluid driver having a prime mover and at least one fluid displacement member. A shaft of the prime mover and/or a shaft of the fluid displacement member and/or a common shaft of the prime mover/fluid displacement member (depending on the configuration of the pump) is a flow-through shaft with a through-passage configuration that allows fluid communication between at least one port of the pump and the at least one fluid storage device.

A rotary pump, the rotational direction of which can preferably be switched, featuring: a housing including a pump space featuring an inlet into a low-pressure region of the pump space for a fluid to be pumped and an outlet from a high-pressure region of the pump space for the fluid to be pumped; at least one rotor which forms delivery cells in the pump space; a bearing; and a sealing stay which axially faces the at least one rotor and separates the low-pressure region from the high-pressure region in the rotational direction of the at least one rotor; and featuring at least one lubricant feed, in the sealing stay, which feeds a fluid, as a lubricant, from at least one of the delivery cells to the bearing.

Rotary positive displacement machines with 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 multi-stage embodiments, the rotor-stator geometry remains substantially constant along the axis of the rotary machine. In other multi-stage embodiments, the rotor-stator geometry varies along the axis of the rotary machine.

A method for delivering a gas/liquid mixture fluid via a screw spindle pump that has a housing forming at least one fluid inlet and one fluid outlet and in which a drive spindle and a running spindle, coupled in terms of rotation, are accommodated. The spindles, in each rotation position of the drive spindle, delimit together with the housing multiple pump chambers. The drive spindle is rotated by a drive in a drive direction, whereby a respective one of the pump chambers that is initially open toward the respective fluid inlet is closed off. The resulting closed-off pump chamber is moved axially toward the fluid outlet and, there, upon attainment of an opening rotation angle, is opened toward the fluid outlet. The drive spindle is driven so that, for a given pump geometry of the screw spindle pump, the pressure in the respective pump chamber prior to and/or upon attainment of the opening rotation angle is increased in relation to the suction pressure of the screw spindle pump, which prevails in the region of the respective fluid inlet, by at most 20% or by at most 10% of a difference in pressure between the suction pressure and the pressure in the region of the fluid outlet.

An oil pump is configured to include a rotor, a drive shaft that drives the rotor to rotate, a rotor chamber in which the rotor is contained, an inlet port and an outlet port each provided in the vicinity of the rotor chamber, and a pump cover. The pump cover is made of a resin. On a portion of an outer surface side of the pump cover corresponding to an inner portion, in which oil circulates, of the pump cover, a rib that has an erecting wall shape is provided.

Lobe pumps have rings which can be located at least partially in at least one of cover plates and rotors, if not both to provide at least thrust bearings to space the rotors from the cover plates. Some rotors may have voids in ears to make the rotor lighter in weight with the voids potentially capped, symmetrically disposed, arcuately shaped and/or have other desirable features. Some rotors may have ears extending beyond cutouts which may extend beyond hubs, if not beyond hub extensions as well which may receive cover spigots thereabout. Some rings may act as radial bearings as well when located in the cover spigots.

A positive displacement gear pump or gear hydraulic motor having at least a first rotor with first rotor teeth and a second rotor with second rotor teeth, the first rotor teeth meshing with the second rotor teeth. First rotor chambers are defined between first rotor teeth and second rotor chambers are defined between the second rotor teeth. As the rotors mesh, the first rotor chambers, second rotor chambers or both become enclosed or substantially enclosed to form what are referred to here as secondary chambers. Pressure variations in a secondary chamber are relieved by internal flow channels in the first rotor, second rotor or both, creating a fluid connection between the first rotor chambers and the second rotor chambers. The first rotor may be an internal gear rotor or both rotors may be external gear rotors.

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.

The gear pump may have a casing, a main shaft and rotating means connected to one end of the main shaft and configured to rotate the main shaft. Housed by the casing, a toothed wheel and at least one other toothed element are intermeshed with the toothed wheel. The other end of the main shaft is connected to one of the toothed wheel and the casing. Rotating the main shaft relative to the rotating means rotates the toothed wheel and the at least one other toothed element relative to the casing, thereby generating the flow. The other one of the casing and the toothed wheel is configured to be rotated around an axis defined by the main shaft for varying a flow rate of the generated flow.