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Gear pump

About: Gear pump is a research topic. Over the lifetime, 7490 publications have been published within this topic receiving 38837 citations. The topic is also known as: Gear pump.


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Patent
27 Mar 1984
TL;DR: In this article, the hydraulic pump mechanism is operated by rotational movement of the pedal drive shaft and the hydraulic drive mechanism is driven by the fluid pump by the pump system and is coupled to one of the wheels of the bicycle for providing a rotational force to such wheel.
Abstract: A hydraulically driven bicycle frame with two axle members coupled to the bicycle frame and front and rear wheels mounted on such axles for rotation about the axis of the respective axle and a pair of pedals mounted on a pedal drive shaft coupled to the bicycle frame for rotation for applying manual power for operating the hydraulic system of the bicycle. The hydraulically driven bicycle has a hydraulic pump mechanism and a hydraulic drive mechanism. The hydraulic pump mechanism is operated by rotational movement of the pedal drive shaft. The hydraulic pump mechanism includes a pump housing having two sectional pump housing members that form a pump chamber between them. The two sectional pump housing members are capable of relative movement with respect to each other so that the pump chamber is capable of being varied in size for varying the flow of fluid through the pump mechanism. The hydraulic drive mechanism is driven by the fluid pump by the pump system and is coupled to one of the wheels of the bicycle for providing a rotational force to such wheel. The hydraulic drive mechanism includes a drive housing having two sectional drive housing members which form a drive chamber between them. The two sectional drive members are capable of relative movement with respect to each other so that the drive chamber is capable of being varied in size for varying the flow of fluid through the hydraulic drive mechanism. The hydraulic pump mechanism and the hydraulic drive mechanism are interconnected by fluid circulating tubes so that a closed hydraulic system is constructed on the bicycle.

38 citations

Patent
24 Nov 1978
TL;DR: In this paper, the axially inwardly extended driven and driving shafts are journalled in common holes or bores, respectively, to ensure the correct axial alignment between them.
Abstract: A gear pump or motor wherein at least two pump or gear units are arranged in coaxial relationship and have their axially inwardly extended driven and driving shafts journalled in a common intermediate casing, the driving shafts being splined together with an internally splined sleeve. The inlet port opened in the intermediate casing is communicated through low-pressure passages with the pump chambers of the respective pump or motor units (and with the assembly chamber or pocket formed to accommodate the opposing ends of the axially inwardly extended driving shafts). The diameter of the inlet port is made larger than the size of the sleeve for interconnecting the driving shafts so that the sleeve may be inserted through the inlet opening into the assembly chamber or pocket and interconnect the driving shafts. Thus, in assembly the interconnection between the driving shafts may be much facilitated. Furthermore, the correct axial alignment between them may be ensured because the axially inwardly extended driven and driving shafts are journalled in common holes or bores, respectively.

38 citations

Patent
05 Dec 1983
TL;DR: In this article, a gear pump assisted screw conveyor extrusion system utilizing a cartridge heating device disposed axially within the screw and having the drives for the gear pump and the screw correlated in speed to create relatively little pressure in the thermoplastic material being extruded such that relatively little mechanical working thereof occurs.
Abstract: A gear pump assisted screw conveyor extrusion system utilizing a cartridge heating device disposed axially within the screw and having the drives for the gear pump and the screw correlated in speed to create relatively little pressure in the thermoplastic material being extruded such that relatively little mechanical working thereof occurs. The thermoplastic material is melted in the screw conveyor primarily by heat transfer from the cartridge heater and the gear pump is utilized for conveying the melted material under pressure to a subsequent work station. A relatively deep material-conveying spiral channel is provided in the screw for maximized extrusion output per revolution of the screw and minimized mechanical energy generation by the screw. A motionless mixer may be employed intermediate the screw and the work station to homogenize the melted material for reducing temperature gradients therein. The system advantageously is capable of extruding material at a substantially greater rate and a lower material temperature and with substantially increased power economy than conventional systems utilizing a high pressure, externally heated screw conveyor portion.

38 citations

Journal ArticleDOI
TL;DR: In this paper, the instantaneous pressure of the meshing action in the external gear pumps and motors is investigated to improve the system performance of hydraulically assisted mechatronic systems, and the approach can also be applied to determine the backlash area to avoid large pressure variations between two meshing volumes.
Abstract: To improve the system performance of hydraulically assisted mechatronic systems, the research investigates the instantaneous pressure of the meshing action in the external gear pumps and motors. The undesired large pressure overshoots or spikes could be excited by virtue of the sudden volumetric change of meshing pockets. In practice, the spikes cause the gear machines to be noisy, inefficient, and have fatigue problems. The study employs the optimization theorem to analyze the nonlinear dynamical equations to define the instantaneous flow area overlapped by the wear-plate profiles and control volumes. The approach can also be applied to determine the backlash area to avoid large pressure variations between two meshing volumes. System noise may consequently be reduced and the mechanical efficiency is improved in gear machines. However, the volumetric efficiency may be compromised. Thus, all these issues have to be considered to achieve the optimal design.

38 citations

Journal ArticleDOI
TL;DR: In this article, the flow characteristics of external spur gear pumps using a flowrate formula derived in closed form were investigated and the effect of design parameters such as tooth number, module, pressure angle and addendum coefficient on pump flowrate behavior were discussed.

37 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202320
202251
202154
2020137
2019198
2018276