Provided is a gear pump device that enables improvement in volumetric efficiency and manufacturability, and also makes it possible to ensure sealing property and to reduce drive torque. According to the present invention, a sealing mechanism is provided with an annular rubber member, an outer member, and an inner member, wherein: the inner member has, at an end of an outer peripheral wall on the side of an inner gear in the axial direction, a notch which is recessed radially inward of the inner gear so as to form, together with an axial one end face of the inner gear, a depressed part; and the outer member has an insertion part which is disposed within the depressed part and which abuts against the axial one end face of the inner gear so as to constitute a part of a sealing surface on the other side.

One or more techniques and/or systems are disclosed for a gear pump for low speed transfers of viscous liquid slurries promotes growth of suspended particles, such as sugar crystals, by avoiding crushing of the particles. The pump includes a rotor gear in mesh with an eccentrically mounted idler gear supported on a boss of a pump head that includes a crescent seal extending into an opening resulting from the eccentricity of the idler gear relative to the rotor gear. The idler gear contains a radially extending land on each tooth profile, symmetrically oriented on adjacently spaced pairs of teeth. The lands, configured to minimize crushing of crystals passing through the pump, engage mating rotor teeth for sealing between inlet and outlet ports of the pump. To promote crystal growth, the lands cover only 10% to 30% of profile surface area of each tooth. To minimize gear tooth wear, the lands are axially staggered between successive adjacent pairs of teeth.

A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

A compressor may include first and second scrolls, an axial biasing chamber, and a control valve. The second scroll includes an outer port and an inner port. The outer and inner ports may be open to respective intermediate-pressure compression pockets. The control valve may be in fluid communication with the inner port, the outer port, and the axial biasing chamber. Movement of the control valve into the first position allows fluid communication between the inner port and the axial biasing chamber. Movement of the control valve into the second position allows fluid communication between the outer port and the axial biasing chamber.

A microfluidic pumping system configured to prevent backflow from an outlet of the system toward an inlet of the system. The microfluidic pumping system comprising a gear housing that has an inlet and an outlet and that houses a drive gear, an idler gear and a drive shaft. The system further includes a front end plate that is coupled to a first surface of the gear housing and a rear end plate that is coupled to a second, different surface of the gear housing. Also coupled to the gear housing is a first and second Halbach magnet arrays that is disposed between the front end plate and the rear end plate. The first and second Halbach magnet arrays include one or more solenoids and the first Halbach magnet array is disposed proximate to the drive gear and the second Halbach magnet array is disposed proximate to the idler gear.

A gear pump for low speed transfers of viscous liquid slurries promotes growth of suspended particles, such as sugar crystals, by avoiding crushing of the particles. The pump includes a rotor gear in mesh with an eccentrically mounted idler gear supported on a boss of a pump head that includes a crescent seal extending into an opening resulting from the eccentricity of the idler gear relative to the rotor gear. The idler gear contains a radially extending land on each tooth profile, symmetrically oriented on adjacently spaced pairs of teeth. The lands, configured to minimize crushing of crystals passing through the pump, engage mating rotor teeth for sealing between inlet and outlet ports of the pump. To promote crystal growth, the lands cover only 10% to 30% of profile surface area of each tooth. To minimize gear tooth wear, the lands are axially staggered between successive adjacent pairs of teeth.

A crescent internal gear pump includes a front cover, an end cover, a ring gear and a pinion gear disposed within a gear housing in an eccentric, intermeshing relationship. The housing is disposed intermediate the front cover and the end cover. A crescent is disposed radially intermediate the ring gear and the pinion gear. The crescent partially extends into a correspondingly shaped slot in the end cover. The gear housing, the ring gear, and the pinion gear can have substantially the same thickness. A shim can be disposed intermediate the end cover and the gear housing for establishing a desired clearance therebetween.

A stepping motor-driven system includes a stepping motor, an output device, and a belt and pulley system operably coupling the stepping motor with the output device to impart rotation therebetween. The belt and pulley system includes an input pinion engaged with the stepping motor, an output pinion engaged with the output device, and a timing belt. The timing belt is disposed about the input and output pinions, inhibits elongation, and defines a plurality of spaced-apart grooves on an inwardly-facing surface thereof that are wider than the teeth of the pinions and are configured to receive the teeth of the pinions in meshed engagement therewith. As a result, a gap is defined within each groove. The gaps permit backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor, thereby inhibiting loss of control.

A stepping motor-driven system includes a stepping motor, an output device, and a belt and pulley system operably coupling the stepping motor with the output device to impart rotation therebetween. The belt and pulley system includes an input pinion engaged with the stepping motor, an output pinion engaged with the output device, and a timing belt. The timing belt is disposed about the input and output pinions, inhibits elongation, and defines a plurality of spaced-apart grooves on an inwardly-facing surface thereof that are wider than the teeth of the pinions and are configured to receive the teeth of the pinions in meshed engagement therewith. As a result, a gap is defined within each groove. The gaps permit backlash of the timing belt in response to changes in a rotational speed input to the belt and pulley system from the stepping motor, thereby inhibiting loss of control.

A sealing assembly for a progressive cavity pump and a progressive cavity pump assembly having a retaining sleeve, a ring, and an elastic diaphragm terminating in a first end of the diaphragm in a first opening, and in a second end of the diaphragm, opposite the first end, in a second opening larger than the first opening. The second opening is held in contact with the retaining sleeve by the ring, and the first opening is configured to grip a rotor of the progressive cavity pump, and the ring is configured to hold the second opening fixed with respect to a stator of the progressive cavity pump.