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Showing papers on "Gear pump published in 2018"


Journal ArticleDOI
TL;DR: The visualization research method has been presented, which has been used for the study of the flow processes and phenomena in the external gear pump, and resulted in a considerable reduction of the intensity of the cavitation phenomena.

29 citations


Journal ArticleDOI
TL;DR: The presented outcomes demonstrate the ability of the proposed algorithm in accurately detect the presence of cavitation phenomena and to determine its intensity in pump real time operation, suggesting it may be a powerful tool for early detection of pumps incipient faults.

28 citations


Journal ArticleDOI
TL;DR: A clear interpretation of the displacing action and the transient features of the delivery flow was never addressed in past literature, and an analysis on the kinematic flow ripple is given, showing how such design concept can reduce or even eliminate the k Cinematic flow pulsations.

25 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigated cavitation in external gear machines by means of a dedicated experimental campaign, in which four different pump prototypes have been designed and manufactured to perform this research, one specifically built up to not be affected by cavitation.

21 citations


Journal ArticleDOI
TL;DR: In this article, a certain aircraft gear pump as the research object, aim at the typical failure forms, gear contact fatigue, of gear pump, proposes the prediction method based on the virtual simulation.

20 citations


Journal ArticleDOI
TL;DR: The technique of modelling external gear pumps that operate with non-Newtonian fluids is described, in particular, how the displacing action of the unit can be modelled using a lumped parameter approach which involves dividing fluid domain into several control volumes and internal flow connections.

17 citations


Journal ArticleDOI
01 Mar 2018
TL;DR: The trochoidal gear pump, also known as the gerotor pump, is chosen for many engineering applications as mentioned in this paper, owing to its remarkable advantages compared to other hydraulic pumps, and it is suitable for many applications.
Abstract: The trochoidal gear pump, also known as gerotor, owing to its remarkable advantages compared to other hydraulic pumps is chosen for many engineering applications. As each application is unique, the...

13 citations


Journal ArticleDOI
TL;DR: In this article, a dynamic sealing method for micro-hydraulic systems, using magnetorheological (MR) fluids, is proposed to minimize backflow under particular conditions, which occurs at the transition from attached to detached plug flow.
Abstract: One obstacle in developing micropumps is their extremely low efficiency, compared to their macroscale counterparts. Thus the authors explore a dynamic sealing method for microhydraulic systems, using magnetorheological (MR) fluids: To minimize backflow under particular conditions, they identify the optimal combination of parameters, which occurs at the transition from attached to detached plug flow. This leads to a design space for gear pumps that can achieve high efficiency and accuracy, using current mechanical architectures and tolerances. Also, the optimal magnetic field intensity is investigated for different working conditions, and a metric for effectiveness is proposed.

13 citations



Journal ArticleDOI
TL;DR: In this article, a gear pump with double circular arc helical gear as motion pair is proposed to solve the problems of the general involute external gear pump, based on the comparison and analysis of their meshin...
Abstract: Aiming at the problems of the general involute external gear pump, a gear pump with double circular arc helical gear as motion pair is proposed. Based on the comparison and analysis of their meshin...

9 citations


Journal ArticleDOI
TL;DR: In this article, a dynamic sealing method for external gear pumps to reduce the volumetric losses through the clearance between the tips of gears and the housing by using magneto-rheological (MR) fluids is presented.
Abstract: Micropumps are microfluidic components which are widely used in applications such as chemical analysis, biological sensing and micro-robots. However, one obstacle in developing micropumps is the extremely low efficiency relative to their macro-scale counterparts. This paper presents a dynamic sealing method for external gear pumps to reduce the volumetric losses through the clearance between the tips of gears and the housing by using magneto-rheological (MR) fluids. By mitigating these losses, we are able to achieve high efficiency and high volumetric accuracy with current mechanical architectures and manufacturing tolerances. Static and dynamic sealing using MR fluids are investigated theoretically and experimentally. Two Mason numbers $Mn\left(p\right)$ and $Mn\left(\Omega\right)$ which are defined in terms of pressure gradient of the flow and velocity of the moving boundary respectively are used to characterize and evaluate the sealing performance. A range of magnetic field intensities is explored to determine optimal sealing effectiveness, where effectiveness is evaluated using the ratio of volumetric loss and friction factor. Finally, we quantify the effectiveness of this dynamic sealing method under different working conditions for gear pumps.

Journal ArticleDOI
02 May 2018
TL;DR: In this paper, the authors presented and analyzed the hydrostatic transmission of power and motion in agricultural machinery and the most important elements of this group of systems and the possibilities of their application in agricultural technology are given.
Abstract: The paper presents and analyzes the hydrostatic transmission of power and motion. The most important elements of this group of systems and the possibilities of their application in agricultural technology are given. Particular attention is paid to the positive-displacement pumps that have the widest application in agricultural machinery: gear pumps with external and internal gears, vane pumps, piston-axial pumps with inclined swash plate and piston-axial pumps with inclined cylinder block. Two hydrostatic power transmission and control systems are also presented. The first is a very simple mechanical- hydraulic system of automatic leveling of self-propelled berry fruits harvester. In contrast, the other hydrostatic system is very sophisticated. It is implemented as a very complex combination of hydrostatic and mechanical power transmission subsystems, with the accompanying control digital electronic system, and is intended for the wheat harvester propulsion and steering.

Journal ArticleDOI
13 Nov 2018-Aviation
TL;DR: In this paper, some peculiarities of transition lubrication regimes for textured surfaces in lubricated contact have been discussed for high precision sliding units, such as valve slides of oil and hydraulic systems, faces of gear pump gears, ring-to-cylinder interface of aircraft reciprocating engines etc.
Abstract: Textured surfaces with partially regular micro relief (PRMR) are reported to be an effective means to control lublication. It was found they are good wear debris trap and suppliers of lubricant directly to the actual friction area. Their tribological properties depend on the clearance between mating surfaces, relative slip speed, direction of motion. These parameters change the lubrication regime, and vice versa changing geometry of PRMR it is possible to predict and control lubrication regime for given conditions. Application of micro textured surface is prospective for high precision sliding units – valve slides of oil and hydraulic systems, faces of gear pump gears, ring-to-cylinder interface of aircraft reciprocating engines etc. providing high service life. On other side, changing texture parameters it is possible to stop the leakage of fluid through the gap, what may be efficiently utilized in aircraft non-contacting mechanical (hydrodynamic and hydrostatic) seals of gas compressors and gear mechanisms. This paper discloses some peculiarities of transition lubrication regimes for textured surfaces in lubricated contact.

Journal ArticleDOI
TL;DR: A new lumped parameter model compatible 2D morphological approach is proposed based on the mapping of gear profile function from real coordinate space to a binary-valued matrix in the integer coordinate space, reducing the control area calculation problem from polygon segmentation and numerical integration to pixel counting, relaxing the computational difficulty in design evaluations.
Abstract: During the working cycle of an external gear pump, hydraulic oil trapped between the pair of meshing gear and pinon teeth may exert high-pressure pulses due to periodic volumetric compression and expansion of the trapped volume. The pressure pulses cause excessive alternating radial loads on the gear shafts, partially responsible for the noise and vibration in the unit. To reduce the trapped pressure pulsation, a relief chamber that connected to the trapped volume to absorb the pressure pulsation is designed in place of the traditional relief grooves to avoid the reconciliation between cross port leakage and pressure pulsation reduction. A new lumped parameter model compatible 2D morphological approach is proposed based on the mapping of gear profile function from real coordinate space to a binary-valued matrix in the integer coordinate space, reducing the control area calculation problem from polygon segmentation and numerical integration to pixel counting, relaxing the computational difficulty in design evaluations. Initial results show that the proposed method can trace and calculate the area of the trapped region, and the relief chamber is capable of effectively attenuating the peak magnitude of trapped pressure pulses by 95%.

Proceedings ArticleDOI
01 Nov 2018
TL;DR: The improved involute external gear pump is developed, developed using highly rigid ceramics-casing to reduce the increase of the internal leakage and the viscous friction loss.
Abstract: In this research, we suggest a method to reduce the loss of the pump aiming to develop small and high-pressure pump for EHA. To reduce the loss of the pump, we focused on the internal leakage loss and the viscous friction loss. We formulated each loss and found that it is effective for loss reduction to make gaps inside the pump narrower and increase the discharge amount per 1 rad making the radius of the gear small. Based on the above, we developed the improved involute external gear pump. Compared with conventional trochoid pump, the internal leakage loss of developed pump is reduced by 22.4% at 10MPa and the viscous friction loss is reduced by 85.6% at 10MPa. Also, there is a problem that internal leakage increases when the internal pressure becomes high. This problem is caused by the deformation of the pump-casing under high pressure. We developed highly rigid ceramics-casing to reduce the increase of the internal leakage. Compared with the pump using aluminum-casing, the pump using ceramics-casing reduced 56.2% in internal leakage loss when the internal pressure increased from 3MPa to 6MPa.

Proceedings ArticleDOI
20 Nov 2018
TL;DR: 3D CFD results not only can be used to support the main assumptions done on the lumped parameter model, but also permit to gain further insight on the operation of the CCHGP unit, particularly with respect to the flow features of the meshing process.
Abstract: The concept of continuous-contact helical gear pumps (CCHGP) has been proposed and successfully commercialized in the recent past. Thanks to the continuous-contact rotor profile design and to the helical gear structure, this design eliminates the kinematic flow oscillation. This has important implications on the fluid borne noise generation, which is considered as one of the major sources of noise emissions and mechanical vibrations for positive displacement machines. Although the commercial success of the CCHGP concept, there is very little published studies about the underling physics at the basis of the functioning of this type of design. This is mostly due to the complexity of the fluid domain that characterize the functioning of CCHGP units. In this paper, a transient 3D CFD study is conducted for a reference CCHGP unit for high-pressure (up to 200 bar) fluid power applications. The results of the 3D CFD simulation are compared with those given by a lumped-parameter model developed at the Maha Fluid Power Research Center of Purdue University (USA), which was previously validated against experimental results. The results show how with a proper discretization of the fluid domain the CFD simulation approach can be used for the case of helical CCHGP units. Both models provide a good description of the main features of operation of the unit. The lumped parameter model is quicker, thus suitable for fast optimization studies. However, the CFD results not only can be used to support the main assumptions done on the lumped parameter model, they also permit to gain further insight on the operation of the CCHGP unit, particularly with respect to the flow features of the meshing process.

Journal ArticleDOI
01 Apr 2018
TL;DR: In this paper, a self-circulating oil bearing system has been proposed for middle-pressure and high-pressure gear pumps, where the temperature failure problem of bearings is now of considerable concern.
Abstract: For middle-pressure and high pressure gear pumps, the temperature failure problem of bearings is now of considerable concern due to their heavy loads. A self-circulating oil bearing system has been...

Journal ArticleDOI
TL;DR: It is found that the pump is best suited for bending of these type of actuators in the development of prosthetic hand because of its ability to reduce the weight of the devices.



Journal ArticleDOI
01 Jun 2018
TL;DR: In this article, a numerical model for analysing the lubricating gap between the gear shaft and the bearing is presented. But the model is limited to water hydraulics and it is not suitable for hydraulic systems.
Abstract: Water hydraulics has drawn considerable attention in recent years for its environmental friendliness. This paper presents a numerical model for analysing the lubricating gap between the gear shaft ...

Patent
04 May 2018
TL;DR: In this article, an indoor wall grinding device, penumatic telescopic rod, including a motor, an end cap, a controller, and a cover plate, the cutter installation department, cutter ofpolishing, the brush cleaner, dust extraction, dust guiding pipe, grinding device installs the box, first slide rail, the dust collection box, second slide rail.
Abstract: The utility model discloses an indoor wall grinding device, penumatic telescopic rod, including a motor, an end cap, a controller, and a cover plate, the cutter installation department, the cutter ofpolishing, the brush cleaner, dust extraction, dust guiding pipe, grinding device installs the box, first slide rail, the dust collection box, the second slide rail, the air pump, the pneumatic cylinder, hydraulic pressure elevating gear installs the box, the pneumatic cylinder support frame, a reversing valve, the gear pump, the engine, and a control panel, an unidirectional valve, oil return oilfilter and oil tank, it rotates to utilize the motor to drive the gear pump, it can be at vertical motion to utilize the pneumatic cylinder messenger to polish the cutter, utilize the spout, a sliderail, the cutter is polished with walking wheel messenger to the pulley can be at transverse movement, with each instruments operation of control panel control, this device easy operation, control accurately, it is inhaleed the lung by the worker aloft to avoid the dust to waft, and body health is influenced, the polluted environment, the efficiency of polish is improved.

Patent
Li Yang, Xu Huixi, Yin Yuan, Wang Fuli, Li Jixu 
05 Jun 2018
TL;DR: In this article, a high-precision buoyancy regulating device for an autonomous underwater robot, comprising of a water permeable shell and a sealing shell, is presented. But the design of the buoyancy regulator is not discussed.
Abstract: The invention relates to the field of autonomous underwater robots, in particular to a high-precision buoyancy regulating device for an autonomous underwater robot, comprising a water permeable shelland a sealing shell, wherein an outer oil bag is arranged in the water permeable shell, and the sealing shell is provided with an inner oil cylinder, a direct-current motor, a gear pump, the valve setA and the valve set B. The gear pump is driven to rotate through the direct-current motor; the oil outlet of the inner oil cylinder is connected with the oil inlet port of the gear pump; the oil outlet port of the gear pump is connected with the first port of the valve group A; the second port of the valve group A is connected with the oil port of the outer oil bag; the oil inlet of the outer oilsac is also connected with an oil inlet port of the valve group B; and the oil outlet port of the valve group B is connected with a connection pipeline between the inner oil cylinder and the gear pump, therein, a one-way valve and a solenoid valve A are arranged in parallel in the valve group A, and an electromagnetic valve B and a throttle valve are connected in series in the valve group B. Theinvention can independently adjust the buoyancy of the underwater robot, has small volume, low energy consumption, low noise and high reliability.

Patent
06 Mar 2018
TL;DR: In this article, a double-planet-row confluence continuously variable transmission (DPSV) is described. And the authors present a hydraulic control system for the DPSV, which consists of a cluttered control system, a lubricating cooling system and an oil supply system.
Abstract: The invention discloses a clutch hydraulic control system for a double-planet-row confluence hydro-mechanical continuously variable transmission. The clutch hydraulic control system comprises a clutchcontrol system, a lubricating cooling system and an oil supply system. The oil supply system comprises an oil tank. Oil in the oil tank passes through a rough filter and then passes through a low-pressure large-flow gear pump and a high-pressure small-flow gear pump after. The low-pressure large-flow gear pump communicates with a first hydraulic clutch, a second hydraulic clutch and a third hydraulic clutch. An oil outlet of the high-pressure small-flow gear pump communicates with a precise filter, and the precise filter communicates with a first proportional pressure reducing valve, a secondproportional pressure reducing valve and a third proportional pressure reducing valve. The three proportional pressure reducing valves communicate with spring reset oil cylinders. The three hydraulicclutches are connected into a control oil way through the three spring reset oil cylinders. By means of the clutch hydraulic control system for the double-planet-row confluence hydro-mechanical continuously variable transmission, the structure is simpler, the size is reduced, the cost is reduced, the oil pressure is stably controlled, hydraulic oil compensation can be conducted on oil leakage ofthe system, and reliability of the lubricating cooling system is high.

Journal ArticleDOI
TL;DR: An EDM method for manufacturing plastic micro gear pumps is proposed in this paper, where the mating gears formed on the foils are then re-positioned on the EDM machine, released from the foil, and placed in a second foil pre-machined by EDM for the pump housing, using an ejector pin fabricated by reshaping the tool electrode used to machine the two foils.

Patent
05 Jan 2018
TL;DR: In this paper, a single-action reciprocating hydraulic actuator is proposed, which consists of a hydraulic cylinder, an energy accumulator, a manual pump and a hydraulic power pack.
Abstract: The invention discloses a single-action reciprocating hydraulic actuator. The single-action reciprocating hydraulic actuator comprises a hydraulic cylinder, an energy accumulator, a manual pump and ahydraulic power pack, wherein the hydraulic power pack is composed of a fuel tank, a motor, a gear pump, a proportional overflow valve and two one-way valves which are arranged on a hydraulic manifoldblock; the hydraulic manifold block is fixed to the upper part of the hydraulic cylinder; an oil way outlet of the hydraulic manifold block is connected to a rod cavity of the hydraulic cylinder through a pipeline; the energy accumulator is arranged at the lower part of the hydraulic cylinder in a sleeving mode and communicates with a rodless cavity of the hydraulic cylinder; the rod cavity and the rodless cavity of the hydraulic cylinder communicate with an exhaust valve; and a pressure sensor and a displacement sensor are arranged in a system. The single-action reciprocating hydraulic actuator has the advantages that when an emergency occurs and the gear pump cannot work normally, the operation can be performed through the manual pump, and therefore safe operation of the actuator can berealized; and the hydraulic system is simple, the size of the hydraulic manifold block is small, the integration degree is high, the bubble amount of the hydraulic system is small, the safety and thereliability can be achieved, and the problems that when an existing actuator achieves the functions of single-direction output and reciprocating return stroke, the structure of the hydraulic system is complex, the pipeline is complex, the bubble amount is large, and the heating value is high can be solved.

Patent
23 Feb 2018
TL;DR: In this paper, the utility model discloses a high-efficient, high-power diesel oil, marine fuel oil microemulsified device, which includes: first control valve, a mass flow meter, first measuring pump are installed to diesel oil or marine fueloil storage tank, its delivery line, second control valve and second measuring pump were installed to soft water storage tank.
Abstract: The utility model discloses a high -efficient, high -power diesel oil, marine fuel oil microemulsified device, it includes: first control valve, a mass flow meter, first measuring pump are installed to diesel oil or marine fuel oil storage tank, its delivery line, second control valve, the 2nd mass flow meter, second measuring pump are installed to soft water storage tank, its delivery line, output termination in the 3rd mass flow meter of first measuring pump, second measuring pump, the 3rd mass flow meter's output termination in basket filter, basket filter's output termination in high speedshearing dispersion isotropic symmetry, output termination in the static mixer of high speed shearing dispersion isotropic symmetry, static mixer's output termination passes through the gear pump andinserts the product tank in ultrasonic wave emulsification cast resonant wedge whistle sub -assembly, the output of ultrasonic wave emulsification cast resonant wedge whistle sub -assembly. The device production efficiency is high, 9550 kilocalorie kg of calorific value >, and it is with low costs, the oil -water ratio is up to 70: 30, the characteristics that have energy -conservation, environmental protection, comprehensive use of resources.

Proceedings ArticleDOI
20 Nov 2018
TL;DR: The validation results prove that similarity is useful to represent a pump’s characteristic over a wide operating range and the prediction of the volume flow rate and the power consumption at a changed viscosity show good accuracy.
Abstract: Gear pumps are used in numerous different applications and industrial sectors. However, when selecting a suitable gear pump for a specified application, manufacturers are often confronted with a lack of comparable measurement data for the desired combination of operating conditions and pumping fluid. Consequently, an estimation of the volume flow rate and the power consumption of a pump under the operating conditions of the application is necessary. In this context, this paper discusses the application of similarity on external gear pumps and presents its validation by means of measured pump characteristics. Seven gear pumps of different displacement volume are measured at different operating conditions varying pressure, rotational speed and the viscosity of the pumping fluid. The validation results prove that similarity is useful to represent a pump’s characteristic over a wide operating range. The prediction of the volume flow rate and the power consumption at a changed viscosity show good accuracy. However, the scaling of the pump characteristic based on the displacement volume show contradictory results.

Patent
25 Jan 2018
TL;DR: In this paper, a method for controlling the torque of an engine when a DPF is regenerated according to the present disclosure comprises the steps of: detecting outputs of a gear pump and a main hydraulic pump as parameters for correcting a PDF regeneration condition; increasing the flow rate of the gear pump or main hydraulic pumps; controlling an engine so as to reach a predetermined target engine torque value.
Abstract: A method for controlling the torque of an engine when a DPF is regenerated according to the present disclosure comprises the steps of: detecting outputs of a gear pump and a main hydraulic pump as parameters for correcting a DPF regeneration condition; increasing the flow rate of the gear pump or main hydraulic pump; controlling the torque of an engine so as to reach a predetermined target engine torque value as the flow rate of the gear pump or main hydraulic pump is increased; starting DPF regeneration when the torque of the engine reaches the predetermined target engine torque value; allowing the number of revolutions of the engine to be increased on the basis of the target engine torque value during the DPF regeneration; and performing the DPF regeneration until the temperature of exhaust gas reaches a predetermined target DPF regeneration temperature.

Patent
10 Jan 2018
TL;DR: In this article, a hot water tank, hot water discharge, and cold water inlet are connected by a feed passage, an outlet passage, and a bypass line including a pump between feed and outlet passage.
Abstract: The installation is for connection between a hot water tank 10, hot water discharge 26, and a cold water inlet 28. The installation comprises a feed passage 12 to connect between the tank and inlet, an outlet passage 14 to connect between the tank and discharge, and a bypass line 16 including a pump 22 between the feed and outlet passage. An electric heater 32 is provided at a three-way junction between the hot water discharge, bypass line and outlet passage. A non-return valve 44 may be provided to prevent reverse flow of water along the bypass. Alternatively the pump may be a positive displacement pump, such as a gear pump, to inhibit reverse flow. A programmable controller ideally uses readings from multiple temperature sensors 50,52,54,56 to control operation of the pump, heater and valves so that water supplied to the discharge is at a desired temperature. The controller may also operate the installation to combat Legionella. Ideally the bypass line includes a heat exchanger to supply thermal energy from a low-grade heat source such as a solar or district system. A calorifer 60 may be provided to supply heat from the installation to a central heating system.