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.

Manufacturing and study on influence of changes in center distance in circle arc-involute-circle arc gear pump operating at high pressure and high speed

2016 ◽  
Vol 230 (18) ◽  
pp. 3285-3297 ◽  
Author(s):  
Minghui Hao ◽  
Yang Zhou ◽  
Shuanghui Hao
Keyword(s):  
High Pressure ◽  
High Speed ◽  
End Milling ◽  
Radial Force ◽  
Numerical Control ◽  
Gear Pump ◽  
Circular Arc ◽  
Ball End Milling ◽  
Gear Pumps ◽  
Center Distance

This study examined the effect of changes in center distance on a circular-arc gear pump that operates at high pressure and high speed. In principal these types of gear pumps have no trapped-oil and flow ripples. The effect of changes in center distance caused by assembly, machining, radial force and oil film force on the performance of circular-arc gear pumps was studied. The results show that the flow rate, axial force and torque increased linearly with an increase in variables [Formula: see text]. Computer aided manufacturing for ball end milling has been developed to simulate the process of numerical control of the rotors of circular-arc gear pumps. Two methods for assessing interference are provided. The trajectories of the centers of ball end milling for rough and finish machining are simulated.

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.

Load Capacity of a New W-N Gear With Basic Rack of Combined Circular and Involute Profile

1985 ◽  
Vol 107 (4) ◽  
pp. 565-572 ◽  
Author(s):  
Y. Ariga ◽  
S. Nagata
Keyword(s):  
Laboratory Test ◽  
Gear Tooth ◽  
Load Capacity ◽  
Helix Angle ◽  
Tooth Profile ◽  
Circular Arc ◽  
K Factor ◽  
Involute Curve ◽  
Gear Profile ◽  
Center Distance

A new W-N gear tooth profile is developed. The gear developed has an addendum of circular arc and a dedendum of involute curve. This particular tooth profile is believed to solve the problem of conventional W-N gear profile—that is, the profile is sensitive to center distance variations. No pitting on the gear was observed even after 1 × 107 revolutions cycle during the laboratory test using a pair of gear having specified values of Mn (normal module) = 4, β (helix angle) = 30 deg, and Lloyd’s K factor at 8 MPa.

Improving the Characteristics of Gear Pumps: Part A — Discharge

2003 ◽  
Author(s):  
Ahmed M. M. El-Bahloul ◽  
Yasser Z. R. Ali
Keyword(s):  
Correction Factor ◽  
Helix Angle ◽  
Tooth Profile ◽  
Radius Of Curvature ◽  
Circular Arc ◽  
Pressure Angle ◽  
Face Width ◽  
Angle Change ◽  
Number Of Teeth ◽  
Gear Pumps

The main objective of this paper is to study the effect of gear geometry on the discharge of gear pumps. We have used gears of circular-arc tooth profile as gear pumps and have compared between these types of gearing and spur, helical gear pumps according to discharge. The chosen module change from 2 to 16 mm, number of teeth change from 8 to 20 teeth, pressure angle change from 10 to 30 deg, face width change from 20 to 120 mm, correction factor change from −1 to 1, helix angle change from 5 to 30 deg, and radii of curvature equal 1.4, 1.5, 2, 2.5, 2.75, and 3m are considered. The authors deduced that the tooth rack profile with radius of curvature equal 2.5, 2.75, 3m for all addendum circular arc tooth and convex-concave tooth profile, and derived equations representing the tooth profile, and calculated the points of intersections between curves of tooth profile. We drive the formulas for the volume of oil between adjacent teeth. Computer program has been prepared to calculate the discharge from the derived formulae with all variables for different types of gear pumps. Curves showing the change of discharge with module, number of teeth, pressure angle, face width, correction factor, helix angle, and radius of curvature are presented. The results show that: 1) The discharge increases with increasing module, number of teeth, positive correction factor, face width and radius of curvature of the tooth. 2) The discharge increases with increasing pressure angle to a certain value and then decreases with increasing pressure angle. 3) The discharge decreases with increasing helix angle. 4) The convex-concave circular-arc gears gives discharge higher than that of alla ddendum circular arc, spur, and helical gear pumps respectively. 5) A curve fitting of the results are done and the following formulae derived for the discharge of involute and circular arc gear pumps respectively: Q=A1bm2z0.895e0.065xe0.0033αe−0.0079βQ=A2bm2z0.91ρ10.669e−0.0047β

Study on Design Method of the Double Arc Gear Hobs

2013 ◽  
Vol 823 ◽  
pp. 257-260
Author(s):  
Jie Wu ◽  
Jia Quan Wang
Keyword(s):  
Design Method ◽  
Gear Tooth ◽  
Tooth Profile ◽  
Tooth Surface ◽  
Engineering Practice ◽  
Approximate Design ◽  
Circular Arc ◽  
Running Performance ◽  
Engagement Theory ◽  
Gear Rack

This article find that one of the effecting the double circular arc gear s running performance is the double circular arc gear tooth profile precision, through analysis to the running-in properties of double arc gear. The problems about tooth profile precision of gear hobs caused by the current profiling theory and approximate design method of gear hobs are analyzed. In the design of circular arc gear hob, use the space engagement theory, can eliminating the tooth error. Acquiring the equation of hobs basic of worm tooth surface by analytical and calculation that the establishment of basic gear rack and worm of hob meshing. The hob not only eliminate the tooth profile error in manufacturing, but also improve the running performance of double circular arc gear, and provides the theory evidence for engineering practice.

Helical Gears With Circular Arc Teeth: Simulation of Conditions of Meshing and Bearing Contact

1985 ◽  
Vol 107 (4) ◽  
pp. 556-564 ◽  
Author(s):  
F. L. Litvin ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Circular Arc ◽  
Helical Gears ◽  
Numerical Examples ◽  
Technological Method ◽  
Bearing Contact ◽  
Paper Cover ◽  
Tooth Surfaces ◽  
Center Distance

Methods proposed in this paper cover: (a) generation of conjugate gear tooth surfaces with localized bearing contact; (b) derivation of equations of gear tooth surfaces; (c) simulation of conditions of meshing and bearing contact; (d) investigation of the sensitivity of gears to the errors of manufacturing and assembly (to the change of center distance and misalignment); and (e) improvement of bearing contact with the corrections of tool settings. Using this technological method we may compensate for the dislocation of the bearing contact induced by errors of manufacturing and assembly. The application of the proposed methods is illustrated by numerical examples. The derivation of the equations is given in the Appendix.

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.

Design of Asymmetric Double Circular Arc Gear for Large-Scale High-Pressure Gear Pumps

2011 ◽  
Vol 181-182 ◽  
pp. 361-365 ◽  
Author(s):  
Yuan Wei Liu ◽  
Jia Fan
Keyword(s):  
High Pressure ◽  
Large Scale ◽  
Large Displacement ◽  
Gear Pump ◽  
Constant Flow ◽  
Circular Arc ◽  
Bright Future ◽  
Gear Pumps

In this paper, an asymmetric double circular arc gear which is suitable for large-scale high-pressure gear pumps is introduced. While demonstrated its superiority, the displacement formula of the double circular arc gear pump is derived and the gear parameters are identified. The asymmetric double circular arc gear can meet the needs of large displacement and high pressure. There are advantages such as constant flow, no pulse, and no topping, which make this kind of gear has a bright future.

Improving the Characteristics of Gear Pumps: Part B — Pressure

2003 ◽  
Author(s):  
Ahmed M. M. El-Bahloul ◽  
Yasser Z. R. Ali
Keyword(s):  
Correction Factor ◽  
Helix Angle ◽  
Tooth Profile ◽  
Radius Of Curvature ◽  
Circular Arc ◽  
Pressure Angle ◽  
Face Width ◽  
Angle Change ◽  
Number Of Teeth ◽  
Gear Pumps

The main objective of this paper is to study the effect of gear geometry on the oil pressure of gear pumps. We have used gears of circular-arc tooth profile as gear pumps and have compared between these types of gearing and spur, helical gear pumps according to pressure. The chosen module change from 2 to 16 mm, number of teeth change from 8 to 20 teeth, pressure angle change from 10 to 30 deg, face width change from 20 to 120 mm, correction factor change from −1 to 1, helix angle change from 5 to 30 deg and radii of curvatures equal 1.4, 1.5, 2, 2.5, 2.75, and 3m are considered. The authors deduced that the tooth rack profile with radius or curvature equal 2.5, 2.75, 3m for all- addendum circular arc tooth and convex-concave tooth profile, and derived equations of pressure difference for spur, helical, and circular- are gear pumps. Computer program has been prepared to calculate the pressure from the derived formulae with all variables for different types of gear pumps. Curves showing the change of pressure with module, number of teeth, pressure angle, face width, correction factor, helix angle, and radius of curvature are presented. The results show that: 1) Pressure increases with increasing helix angle. 2) Pressure decreases with increasing face width, number of teeth, positive correction factor, module, pressure angle and radius of curvature of the tooth. 3) The all- addendum circular-arc gears generates pressure higher than helical, convex-concave and spur gear pumps. 4) A curve fitting is done for all variables with pressure and the following formulae derived for the pressure: P=A3b−0.943z−1.175m−2.1β0.175e−0.61xe−0.0048αP=A4b−1z−1.34m−2β0.119ρ1−0.393 These formulae represent simple tool for the designer to calculate the pressure of involute and circular arc gear pumps.

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