scholarly journals Calculation of Unloading Area of Internal Gear Pump and Optimization

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Shanxin Guo ◽  
Dagui Chen
Keyword(s):  
Calculation Method ◽  
Gear Tooth ◽  
Expansion Method ◽  
Low Noise ◽  
Gear Pump ◽  
Pump Design ◽  
Calculation Results ◽  
Gear Pumps ◽  
Optimization Schemes ◽  
Internal Gear

In order to obtain the calculation method of the unloading area of the internal gear pump during oil trapping, a pair of internal gears including an external gear and an internal gear was used as the research object to simulate the oil trapping process. The geometric relationship during the meshing process was established, and the unloading area expression was obtained by using the geometric pattern expansion method with the variable f as the independent variable. Guided by a mathematical model, two improved optimization schemes were proposed for the internal gear tooth profile, and the unloading area expressions sud, suda, and sudb were obtained. Taking the meshing gear pair with module 3 and number of teeth 13/19 as examples, the simulation results were very consistent with the existing literature. The reliability of the model and the feasibility of the optimization scheme are obtained based on the theoretical analysis and calculation results. This calculation method of unloading area can be applied to the same type of gear pump design in the future, providing a reference for the design of high pressure and low noise gear pumps.

Application of Non-Circular Planetary Gear Mechanism in the Gear Pump

2012 ◽  
Vol 591-593 ◽  
pp. 2139-2142
Author(s):  
Hong Ding
Keyword(s):  
Pressure Fluctuations ◽  
Hydraulic Drive ◽  
Planetary Gear ◽  
Low Noise ◽  
Gear Transmission ◽  
Gear Pump ◽  
Flow Ripple ◽  
Large Pressure ◽  
Gear Pumps ◽  
Gear Mechanism

Gear pump is the most commonly used hydraulic component in hydraulic drive system.Volumetric efficiency of the traditional gear pump is low, big flow ripple causes large pressure fluctuations, makes pipes and valves vibration, noisy. The imbalance pressure on gear pump’s gears, shafts and bearings and the large radial load limits its pressure increased. Planetary gear transmission compared with ordinary gear transmission, it has many unique advantages. So the writer on the basis of the combination of proposed non-circular planetary gear pumps and gear pump works discussed the structure and working principle of the pump. The non-circular planetary gear pump with many advantages such as big flow, uniform flow, low noise and so on. It can be widely used in various hydraulic transmission systems.

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.

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.

Numerical analysis of the lubricating gap between the gear shaft and the journal bearing in water hydraulic internal gear pumps

2017 ◽  
Vol 232 (12) ◽  
pp. 2297-2314 ◽  
Author(s):  
Ruilong Du ◽  
Yinglong Chen ◽  
Hua Zhou
Keyword(s):  
Journal Bearing ◽  
Radial Force ◽  
Gear Pump ◽  
Film Pressure ◽  
Proposed Model ◽  
Gear Pumps ◽  
Water Hydraulic ◽  
Film Characteristics ◽  
Internal Gear ◽  
Shaft Journal

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 and the journal bearing in water hydraulic internal gear pumps. The model consists of two parts: the gear part that addresses the radial force on the gear shaft and the film part that addresses the film characteristics of the gear shaft/journal bearing interface. The radial force is obtained by summing the fluid pressure around the gear circumference and the meshing force of the gear pair. The film characteristics are analysed by an elastohydrodynamic model that involves the evaluation of the film geometry, the film pressure, and the elastic deformation of the gear shaft/journal bearing interface. The radial force evaluated by the gear part is balanced by the film pressure evaluated by the film part. The gear part is validated by experiments on an oil internal gear pump from the aspect of the outlet pressure ripple, and the film part is validated by comparison with the results from other research groups. The proposed model allows the evaluation of radial micro-motion as well as the eccentric positions of the gear shaft. In addition, the influence of film deformation is further discussed, suggesting that the maximum film deformation should be maintained under 1.3 times the minimum film height. The proposed model can be used as a tool for design optimization of the water-lubricated journal bearing in water hydraulic internal gear pumps.

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.

Friction torque characteristics of an internal gear pump

2011 ◽  
Vol 225 (6) ◽  
pp. 1523-1534 ◽  
Author(s):  
Y Inaguma
Keyword(s):  
Mathematical Model ◽  
Friction Torque ◽  
Operating Conditions ◽  
Gear Pump ◽  
Operating Pressure ◽  
New Model ◽  
Pump Speed ◽  
Gear Pumps ◽  
Internal Gear ◽  
Three Components

This paper describes the influence of pump operating conditions, such as operating pressures, pump speeds, and oil temperatures, on the friction torque characteristics of internal gear pumps for automobiles. Additionally, it presents a new mathematical model reflecting the influence of the oil temperature on the friction torque. In an internal gear pump, the friction torque was affected by oil temperature as well as operating pressure and pump speed. When the operating pressure was high, the influence of oil temperature on friction torque at a pump speed of less than 1000 r/min was contrary to that at a pump speed of greater than 1000 r/min. It was considered that the friction torque is fundamentally composed of three components: the component dependent on the operating pressure, dependent on the pump speed, and independent of both the operating pressure and the pump speed. However, the component dependent on the operating pressure was affected significantly by not only the pump speed but also the oil temperature. In addition, another factor besides the viscosity of the oil existed in the component dependent on the pump speed. A mathematical model for the friction torque characteristic of the internal gear pump was newly established by adding factors including the oil temperature to the Wilson’s model. The new model was able to represent with accuracy the experimental friction torque characteristic in the internal gear pump under various pump operating conditions.

A New Continuous Contact Low-Noise Gear Pump

1983 ◽  
Vol 105 (4) ◽  
pp. 736-741 ◽  
Author(s):  
K. Mitome ◽  
K. Seki
Keyword(s):  
Point Contact ◽  
Practical Method ◽  
Spur Gear ◽  
Helical Gear ◽  
Low Noise ◽  
Tooth Profile ◽  
Gear Pump ◽  
Excellent Performance ◽  
Continuous Contact ◽  
Gear Pumps

Developed is a new low-noise gear pump which has no trapping and whose gears are in continuous one-point contact in the plane of rotation. First this paper studies a practical method to design the tooth profile of a spur gear for a given path of contact. A new tooth profile is obtained by giving a closed path of contact like a figure 8. Basic dimensions are determined and limites of them are obtained. Both theoretical and approximate displacements are expressed in terms of the basic dimensions. Secondly, a helical gear pump is studied. The helical gear can be discussed in the same way as the spur gear by new basic dimensions. Finally some test gear pumps are made and tested. Test prove that this gear pump has excellent performance and durability.

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.

scholarly journals Simulation Research on Trapped Oil Pressure of Involute Internal Gear Pump

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shanxin Guo ◽  
Xiangfeng Guan
Keyword(s):  
High Performance ◽  
Gear Pump ◽  
Outer Contour ◽  
Simulation Research ◽  
Scanning Method ◽  
Gear Pumps ◽  
Instantaneous Flow Rate ◽  
Internal Gear ◽  
Meshing Process ◽  
Internal Meshing

The main structure of an internal gear pump consisted of an internal gear pair, including an internal gear and an external gear. The internal gear pump had oil trapping phenomenon like other hydraulic gear pumps. In order to solve the oil trapping phenomenon of involute gear pump with internal meshing tooth profile, in this paper, the mathematical equation of gear outer contour is established according to the principle of generation method, and the variation law of the trapped oil area in meshing process is deduced by theoretical instantaneous flow rate obtained by scanning method. Then, the minimum trapped oil volume and unloading area are solved by the graphic method. Finally, based on fluid mechanics and dynamics, the trapped oil pressure model is obtained. The change of the trapped oil area and trapped oil pressure in a meshing cycle is simulated by MATLAB. The results show that the trapped oil area changes in a parabola, and the trapped pressure fluctuates in mountains and valleys. When the trapped area is the smallest, the trapped oil pressure reaches the peak at the corresponding corner. The research results can provide guidance for the development of high-performance internal gear pumps.

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