scholarly journals Design Multistage External Gear Pumps for Dry Sump Systems: Methodology and Application

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Davide Guerra ◽  
Marco Polastri ◽  
Mattia Battarra ◽  
Alessio Suman ◽  
Emiliano Mucchi ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Gear Tooth ◽  
Design Procedure ◽  
Journal Bearings ◽  
Gear Pump ◽  
Operational Parameters ◽  
Systems Methodology ◽  
External Gear Pumps ◽  
Calculation Step ◽  
Gear Pumps

Thanks to their manufacturing simplicity, robustness, and consolidated design knowledge, external gear pumps are widely adopted in the automotive fields. With the purpose of leading the design procedure of these positive displacement machines, within this work, the authors integrate in a comprehensive tool the salient equations adopted for the design of the major gear pump features. The presented procedure is devoted to the design of multistage external gear pumps characterized by a singular floating driving shaft supported by fluid-dynamic journal bearings. Focusing the attention on the procedure flexibility, it has been structured in three iterative calculation phases. The core section of the methodology concerns the geometrical design of the involute gear tooth profile. It is oriented to ensure a proper volumetric displacement while complying with the space requirement and the tooth manufacturing limitations. Thus, through the analytical pressure loads estimation combined with the operational parameters, the second calculation step provides the design of the driving shaft and the relevant dimensions of the journal bearings. Finally, by means of a power loss approach, the third macrosection of the procedure leads to estimating the clearances between gear tip and housing. The potentials of the methodology are exposed by describing its applications to a case study of multistage gear pump employed in the dry sump lubrication system of an automotive heavy-duty engine. Each calculation step application is outlined with reference to the proposed analytical formulation and the results of the parameters calibration are presented. Within this context, the procedure is assessed by means of a CFD analysis. The results highlight the accuracy of the methodology on the estimation of the required delivery flow rate. Aside from being accurate, flexible, and reliable, the procedure stands out for being an innovative tool within the multistage gear pump framework.

scholarly journals Experimental and Numerical Study on the Flow Ripple of Circular-arc Gear Pumps Considering the Center Distance Deviation

2021 ◽  
Author(s):  
Xiaoling Wei ◽  
Yongbao Feng ◽  
Zhenxin He ◽  
Ke Liu
Keyword(s):  
Pressure Pulsation ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Gear Tooth ◽  
Tooth Profile ◽  
Gear Pump ◽  
Circular Arc ◽  
Gear Pumps ◽  
Distance Deviation ◽  
Center Distance

Abstract Novel circular-arc gear pumps effectively solve the problems of oil trapping and flow pulsation experienced with traditional gear pumps. However, the center distance deviation associated with assembly and installation during gear pump processing has an important influence on the outlet pressure pulsation characteristics of circular-arc gear pumps. First, the circular-arc tooth profile equation, conjugate curve equation and meshing line equation were derived to design the circular-arc gear meshing and center distance deviation functions. Second, the circular-arc gear tooth profile was accurately obtained. Then, a pressure pulsation characteristic simulation model for the novel circular-arc gear pumps considering the center distance deviation was established. The results show that with the increase of center distance deviation, the outlet flow rate of the arc gear pump increases first and then decreases greatly. Moreover, the center distance deviation has little effect on the independent tooth cavity pressure. Finally, the proposed fluid dynamic model is used to simulate a commercial circular-arc gear pump, which was tested within this research for modeling validation purposes. The comparisons highlight the validity of the proposed simulation approach.

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.

A Design Procedure for Multistage External Gear Pumps

2020 ◽  
Author(s):  
Davide Guerra ◽  
Marco Polastri ◽  
Mattia Battarra ◽  
Alessio Suman ◽  
Emiliano Mucchi ◽  
...  
Keyword(s):  
Design Procedure ◽  
Target Delivery ◽  
Multi Stage ◽  
External Gear Pumps ◽  
Geometrical Features ◽  
Fluid Properties ◽  
Gear Pumps ◽  
Working Parameters

Abstract In this work, the authors present a robust and integrated procedure for the design of multi-stage gear pumps to be used in dry sump system applications. Based on the target delivery flow rate, rotational speed and fluid properties, the developed iterative method enables to directly obtain the geometrical features and the working parameters of the pump components, such as gearpair specifics, shaft and journal bearing dimensions, clearance values. The methodology is then applied to a case study in order to highlight its features and detail the achievable outcomes. Quality of the results is assessed by means of a CFD analysis, demonstrating the capability to obtain the expected volumetric efficiency.

Review of Gear Pump Development at NRL

2020 ◽  
Author(s):  
Logan T. Williams
Keyword(s):  
System Development ◽  
Design Guidelines ◽  
Lessons Learned ◽  
Naval Research ◽  
Gear Pump ◽  
Pump Design ◽  
External Gear Pumps ◽  
Gear Pumps ◽  
Original Goal ◽  
Small Form Factor

Abstract Research into hydraulic quadrupeds at the US Naval Research Laboratory (NRL) has created the demand for in-house development of miniaturized hydraulic components, including pumps. As part of this effort to develop a miniaturized hydraulic powertrain, external gear pumps were examined, designed, and iterated upon to create an efficient pump package with a small form factor (1.5 × 1.6 × 1.8 inches). The evolution of the pump design has touched every component of the pump and has resulted in many practical design guidelines, novel pump components, and improved pump analysis tools. The original goal of developing the capability for integrated hydraulic powertrain components, such as embedding the pump into the quadruped’s hydraulic manifold, was to enable further compaction and streamlined system development. An additional result of the project was the accumulation of gear pump design fundamentals and lessons learned that can benefit any pump designer.

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.

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.

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.

scholarly journals About the Influence of Eco-Friendly Fluids on the Performance of an External Gear Pump

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 799
Author(s):  
Gabriele Muzzioli ◽  
Luca Montorsi ◽  
Andrea Polito ◽  
Andrea Lucchi ◽  
Alessandro Sassi ◽  
...  
Keyword(s):  
Olive Oil ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Volumetric Efficiency ◽  
Green Economy ◽  
Gear Pump ◽  
Research Activity ◽  
Industrial Oil ◽  
Fluid Properties ◽  
Gear Pumps

This paper wants to investigate the effects of eco-friendly fluids on the thermo-fluid-dynamic performance of external gear pumps in order to provide a first response to the increasingly urgent demands of the green economy. A computational fluid dynamics (CFD) approach based on the overset mesh technique was developed for the simulation of the full 3D geometry of an industrial pump, including all the characteristic leakages between components. A sensibility analysis of the numerical model with respect to different fluid properties was performed on a commonly used mineral oil, showing the key role of the fluid compressibility on the prediction of the pump volumetric efficiency. Moreover, the influence of temperature internal variations on both fluid density and viscosity were included. The BIOHYDRAN TMP 46 eco-friendly industrial oil and olive oil were further considered in this work, and the results of the simulations were compared for the three fluid configurations. A slightly lower volumetric efficiency was derived for the olive oil application against the other two conditions, but suggestive improvements were produced in terms of pressure and temperature distributions. Therefore, based on the obtained results, this paper encourages research activity towards the use of eco-friendly fluids in the hydraulic field.

A Numerical Procedure to Design the Optimal Axial Balance of Pressure Compensated Gear Machines

2014 ◽  
Author(s):  
Divya Thiagarajan ◽  
Andrea Vacca
Keyword(s):  
Numerical Procedure ◽  
Operating Conditions ◽  
Force Balance ◽  
Gear Pump ◽  
Power Losses ◽  
Outlet Port ◽  
External Gear Pumps ◽  
Gear Pumps ◽  
Force Components ◽  
External Gear Pump

This paper presents an innovative numerical procedure to determine the optimal balancing area of lateral bushes in external gear pumps or motors. In pressure compensated designs of external gear machines, the lateral bushes perform the important functions of sealing the tooth space volumes while they transfer fluid from the inlet to the outlet port. In normal operating conditions, a lubricating gap exists between the lateral bush and the gear permitting to minimize losses due to shear stress and leakage. These conditions are found by determining proper balancing areas at the side of the bushes not facing the gears, in which the pressure of the high pressure port is properly established. This problem is also known as “axial balance” of external gear machines. To determine the optimal axial balance which minimizes the power losses associated with the lubricating gap in all operating conditions, all the static and hydrodynamic forces acting on the lateral bushes have to be considered. This delicate aspect of external gear units design is usually addressed through empirical procedures; while in this paper an automatic numerical procedure is presented. The proposed method is based on the solution of the force balance of the lateral bushes, taking into account all force components, including the hydrodynamic terms due to the relative inclination between bushes and gears and material deformation. After detailing the procedure, the paper describes its potentials by showing the advantages arising from the optimization of the axial balance of a particular external gear pump for fluid power applications.

scholarly journals Acoustic tests of type KPF1 high-pressure external gear pumps

2020 ◽  
pp. 1-10
Author(s):  
Piotr Osiński ◽  
Janusz Rutański ◽  
Paweł Bury ◽  
Rafał Cieślicki
Keyword(s):  
High Pressure ◽  
Sound Pressure ◽  
Power Level ◽  
Acoustic Power ◽  
Gear Pump ◽  
Reverberation Chamber ◽  
Sound Power Level ◽  
External Gear Pumps ◽  
Gear Pumps ◽  
Pressure Unit

This article presents the results of testing the sound pressure level and sound power level of the experimental 3PW-KPF1-24-40-2-776 high-pressure gear pump. Acoustic tests were conducted in an reverberation chamber. The results of the acoustic power tests indicate good acoustic parameters of the tested high-pressure unit.

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