Experimental Investigation of Flowrate Irregularity in Rotary Gear Pumps

1992 ◽  
Author(s):  
G. Mimmi
Keyword(s):  
Experimental Investigation ◽  
Flow Rate ◽  
Experimental Tests ◽  
Periodic Variation ◽  
Experimental Results ◽  
Gear Pump ◽  
Gear Pumps ◽  
Hot Film ◽  
Instantaneous Flow Rate ◽  
External Gear Pump

Abstract In a previous paper the author proposed a method to reduce the periodic variation in flow rate for an external gear pump. To verify the experimental results, a series of experimental tests on a expressly realized gear pump, was carried out. The pump was equipped with relieving grooves milled into the side plates. The tests were done on a closed piping specifically realized and equipped for measuring the instantaneous flow rate of the fluid through a wedge-shaped hot film probe.

scholarly journals Flow Characteristic and Trapping Characteristics of Cycloid Rotor Pump

2015 ◽  
Vol 9 (1) ◽  
pp. 449-454 ◽  
Author(s):  
Ren Zhenxing ◽  
Liu Chunyan ◽  
Li Yulong
Keyword(s):  
Flow Rate ◽  
Flow Characteristics ◽  
Position Angle ◽  
Gear Pump ◽  
Rotary Pump ◽  
Uniformity Coefficient ◽  
Discharge Pressure ◽  
Instantaneous Flow Rate ◽  
External Gear Pump ◽  
Better Than

To accurately calculate the flow rate of cycloid rotary pump as well as to correctly understand its trapped oil phenomenon, firstly the instantaneous flow rate formula of cycloid rotary pump was established based on the method of swept area, and then it was compared with the two present approximate formulas by an example. Secondly, based on the established flow rate formula and the created trapped oil model in the present literature, the trapped oil pressure of a single cavity near the minimum volume position was simulated. It was pointed that for cycloid rotary pump as an example, the flow non-uniform coefficient was 6.45%, and in contrast, the flow non-uniformity coefficient of external gear pump was 21.2%. Relative to the accurate results, the two present approximate errors of flow rates were 1.93% and 2.90%; and the present approximate error of flow non-uniform coefficient was 7.13%; when the minimum position angle was added by 0.5° or 1° or 2°, relative to discharge pressure of the pump, the corresponding maximum peak of trapped oil pressure increased by 1.6% or 6.0% or 21.7%. The results indicate that the flow characteristics of cycloid rotary pump are better than the external gear pump, the two present approximate errors of flow rate are little but the present approximate error of flow non-uniform coefficient is higher. Also, there is a trapped oil phenomenon in cycloid rotary pump which is not obvious.

Computer Prediction of Cyclic Excitation Sources for an External Gear Pump

1985 ◽  
Vol 199 (3) ◽  
pp. 175-180 ◽  
Author(s):  
K Foster ◽  
R Taylor ◽  
I M Bidhendi
Keyword(s):  
Computer Program ◽  
Gear Pump ◽  
Computer Prediction ◽  
Pressure Distributions ◽  
External Gear Pumps ◽  
Theoretical Predictions ◽  
Gear Pumps ◽  
External Gear Pump

A description is given of a computer program for investigating the performance of the external gear pumps under varying conditions with the special emphasis on the examination of pressure distributions within the pump, i.e. excitation forces for the vibration of the pump case and the variation in flow generated by the pump. Measurements are presented for the variation with time of tooth space pressure and the results are compared with the theoretical predictions from the computer program.

Analytical and Experimental Investigation of Flow-Reversible Heat Exchangers Using Temperature-Entropy Bond Graphs

1984 ◽  
Vol 106 (2) ◽  
pp. 170-175 ◽  
Author(s):  
Rahmatallah Shoureshi ◽  
Kevin M. McLaughlin
Keyword(s):  
Experimental Investigation ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Compressible Flows ◽  
Rate Of Change ◽  
Experimental Results ◽  
Bond Graphs ◽  
Rate Oscillation ◽  
Flow Heat

Modeling of heat exchangers using true bond graphs with temperature and rate of change of entropy as power variables is presented. Techniques used for modeling of irreversabilities and compressible flows are shown. The results of two and three lump models are compared with experimental results, with the agreement between those low order models and the experimental results being good. This paper shows how well a three lump model (6th order) can predict the dynamics of an actual reversal of flow. Heat exchanger response to mass flow rate oscillation is presented.

Research on Floating Moment Balancing Mechanism of a Gear Pump's Asymmetric Floating Plate with a V-Shaped Groove

2013 ◽  
Vol 415 ◽  
pp. 555-558
Author(s):  
An Lin Wang ◽  
Xiao Lu Zhang ◽  
Xue Wen Shan ◽  
Wei Liu
Keyword(s):  
Flow Field ◽  
Structural Characteristics ◽  
Evaluation Criteria ◽  
Internal Flow ◽  
Experimental Tests ◽  
Gear Pump ◽  
Balance Performance ◽  
Floating Plate ◽  
Gear Pumps ◽  
Groove Structure

Symmetrical floating plate of the high pressure and large displacement gear pump in rated conditions is inability to achieve the floating moment balance. To solve this problem, a new balancing mechanism is presented in this paper, which is asymmetric with a V-shaped groove structure on its driven side, called asymmetric balancing mechanism. Compared with traditional symmetric balancing mechanism, the floating plate with asymmetric balancing mechanism the can the coupling problem between the gear shaft and gear inner flow field through its own asymmetrical structure, so that the gear pumps internal flow field was the symmetrical distribution. According to the structural characteristics of the floating plates, Parameterized moment model based on discrete feature points was established. Theoretical analysis and experimental tests show the result , when suffered floating moment as evaluation criteria, in rated conditions, compared with the traditional symmetrical balancing mechanism one, that the balance performance of the floating plate with V-shaped groove asymmetric balancing mechanism improve by 41.42%.

Vibroacoustic Measurements and Simulations Applied to External Gear Pumps. An Integrated Simplified Approach

2016 ◽  
Vol 41 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Eleonora Carletti ◽  
Giuseppe Miccoli ◽  
Francesca Pedrielli ◽  
Giorgio Parise
Keyword(s):  
Complex Dynamics ◽  
Gear Tooth ◽  
Fluid Pressure ◽  
Sound Intensity ◽  
Integrated Approach ◽  
Gear Pump ◽  
Simplified Approach ◽  
Noise Field ◽  
Gear Pumps ◽  
External Gear Pump

Abstract This paper describes the development phases of a numerical-experimental integrated approach aimed at obtaining sufficiently accurate predictions of the noise field emitted by an external gear pump by means of some vibration measurements on its external casing. Harmonic response methods and vibroacoustic analyses were considered as the main tools of this methodology. FFT acceleration spectra were experimentally acquired only in some positions of a 8.5 cc/rev external gear pump casing for some working conditions and considered as external excitation boundary conditions for a FE quite simplified vibroacoustic model. The emitted noise field was computed considering the pump as a ‘black box’, without taking into account the complex dynamics of the gear tooth meshing process and the consequent fluid pressure and load distribution. Sound power tests, based on sound intensity measurements, as well as sound pressure measurements in some positions around the pump casing were performed for validation purposes. The comparisons between numerical and experimental results confirmed the potentiality of this approach in offering a good compromise between noise prediction accuracy and reduction of experimental and modelling requirements.

Design of Rotor for Internal Gear Pump Using Cycloid and Circular-Arc Curves

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
T. H. Choi ◽  
M. S. Kim ◽  
G. S. Lee ◽  
S. Y. Jung ◽  
J. H. Bae ◽  
...  
Keyword(s):  
Flow Rate ◽  
Superior Performance ◽  
Correction Coefficient ◽  
Gear Pump ◽  
Circular Arc ◽  
Limit Value ◽  
Outer Rotor ◽  
Gear Pumps ◽  
Internal Fluid Flow ◽  
Internal Gear

In the case of internal gear pumps, the eccentricity of the outer rotor, which resembles a circular lobe, must be limited to a certain value in order to avoid the formation of cusps and loops; furthermore, the tip width of the inner rotor, which has a hypocycloid curve and an epicycloid curve, should not be allowed to exceed the limit value. In this study, we suggest that the tip width of the inner rotor be controlled by inserting a circular-arc curve between the hypocycloid and epicycloid curves. We also suggest that the outer rotor be designed using the closed-form equation for the inner rotor and the width correction coefficient. Thus, it is possible to design a gerotor for which there is no upper limit on the eccentricity, as in this case, undercut is prevented and there is no restriction on the tip width. We also develop an automated program for rotor design and calculation of the flow rate and flow rate irregularity. We demonstrate the superior performance of the gerotor developed in this study by analyzing the internal fluid flow using a commercial computational fluid dynamics (CFD)-code.

The Flow Pulsation Analysis of an External Gear Pump

2011 ◽  
Vol 236-238 ◽  
pp. 2327-2331
Author(s):  
Yan Zhi Li ◽  
Li Huan Gao ◽  
Xiao Yang Tang
Keyword(s):  
Pulse Amplitude ◽  
Gear Pump ◽  
Flow Pulsation ◽  
Flow Ripple ◽  
Pump Flow ◽  
External Gear Pumps ◽  
Tooth Width ◽  
Different Types ◽  
Gear Pumps ◽  
External Gear Pump

In this paper, the theoretical flow ripple of an external gear pump is studied for pumps of similar size using different numbers of teeth on the driving and driven gears. External gear pumps with three different types of tooth profiles are studied. Nondimensional flowrates and fluctuation coefficients of gear pumps are discussed. By using the formula, flowrates can be calculated accurately and efficiently. Results indicate that: in the case of the same displacement (except teeth number and tooth width, other parameters of the gear pump are the same) the gear pump flow pulsation decreases with the increasing of the teeth number. We also concluded that changing tooth profiles on the driving and driven gear can get different pulse amplitude of the flow ripple.

Experimental Validation of a Model for the Dynamic Analysis of Gear Pumps

2013 ◽  
Author(s):  
Emiliano Mucchi ◽  
Giorgio Dalpiaz
Keyword(s):  
Experimental Validation ◽  
Gear Pump ◽  
Test Plate ◽  
Operational Conditions ◽  
Experimental Apparatus ◽  
Gear Pumps ◽  
Force Components ◽  
Set Up ◽  
The Time Domain ◽  
External Gear Pump

This paper concerns the experimental validation of an elastodynamic model of an external gear pump for steering systems in vehicles. The elastodynamic model takes into account the most important phenomena involved in the operation of this kind of machines. Two main sources of noise and vibration can be considered: pressure and gear meshing. An experimental apparatus has been set up for the measurements of the case accelerations and force components in operational conditions. The model was validated by comparison between simulations and experimental results concerning forces and moments: it deals with the external and inertia components acting on the gears, estimated by the model, and the reactions and inertia components on the pump case and the test plate, obtained by measurements. The validation is carried out comparing the level of the time synchronous average in the time domain and the waterfall maps in the frequency domain, with particular attention to identify system resonances. The validation results are globally satisfactory.

scholarly journals The Influence of Radial and Axial Gaps on Volumetric Efficiency of External Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4468
Author(s):  
Paulina Szwemin ◽  
Wieslaw Fiebig
Keyword(s):  
Fluid Flow ◽  
Volumetric Efficiency ◽  
Operating Parameters ◽  
Gear Pump ◽  
Cfd Model ◽  
External Gear Pumps ◽  
Flow Phenomena ◽  
Gear Pumps ◽  
The Impact ◽  
External Gear Pump

The design of gear pumps and motors is focused on more efficient units which are possible to achieve using advanced numerical simulation techniques. The flow that appears inside the gear pump is very complex, despite the simple design of the pump itself. The identification of fluid flow phenomena in areas inside the pump, considering the entire range of operating parameters, is a major challenge. This paper presents the results of simulation studies of leakages in axial and radial gaps in an external gear pump carried out for different gap shapes and sizes, as well as various operating parameters. To investigate the processes that affect pump efficiency and visualize the fluid flow phenomena during the pump’s operation, a CFD model was built. It allows for a detailed analysis of the impact of the gears’ eccentricity on leakages and pressure build-up on the circumference. Performed simulations made it possible to indicate the relationship between leakages resulting from the axial and radial gap, which has not been presented so far. To verify the CFD model, experimental investigations on the volumetric efficiency of the external gear pump were carried out. Good convergence of results was obtained; therefore, the presented CFD model is a universal tool in the study of flow inside external gear pumps.

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