INTERNAL LOBE PUMP DESIGN

1997 ◽  
Vol 21 (2) ◽  
pp. 109-121 ◽  
Author(s):  
G. Mimmi ◽  
P. Pennacchi
Keyword(s):  
Flow Rate ◽  
Design Parameters ◽  
Specific Flow ◽  
Pump Design ◽  
Positive Displacement ◽  
Performance Indexes ◽  
Rotor Profile ◽  
Main Components ◽  
Definition Of ◽  
Lobe Pump

The subject of this paper is the theoretical analysis of the internal lobe pump which is a particular type of positive displacement rotary pump. The main components of the pump are the rotors: usually the outer one is characterised by lobes with circular shape, while the inner rotor profile is determined as conjugate to the other. For this reason the first topic presented here is the definition of the geometry of the rotors starting from the design parameters. The choice of these parameters is subject to some limitations in order to avoid inner rotor undercutting and to limit the pressure angle between the rotors. Now we will consider the design optimisation. The first step is the determination of the instantaneous flow rate as a function of the design parameters. This allows us to calculate two performance indexes commonly used for the study of positive displacement pumps: the flow rate irregularity and the specific flow rate. These indexes are used to optimise the design of the pump and to obtain the sets of optimum design parameters. Finally further considerations are presented regarding the calculation and the use of other performance indexes, the specific slipping and the rotor curvature, which are particularly suitable for giving more elements for the analysis of this case.

Involute Gear Pumps Versus Lobe Pumps: A Comparison

1997 ◽  
Vol 119 (4) ◽  
pp. 458-465 ◽  
Author(s):  
G. C. Mimmi ◽  
P. E. Pennacchi
Keyword(s):  
Optimum Design ◽  
Flow Rate ◽  
Design Parameters ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Positive Displacement ◽  
Involute Gear ◽  
Performance Indexes ◽  
Rotary Pumps ◽  
Gear Pumps

In previous studies we have considered several types of positive displacement rotary pumps and deeply analyzed the generation of the flow rate and the design limits. This has been done in order to evaluate the main performance indexes; one of which, the flow rate irregularity, is related to the possibility that the pump becomes a source of vibration and noise. A second index is the specific flow rate, related to the delivery capacity of the pump. In this paper, following our previous researches, we analyzed internal involute gear pumps and internal lobe pumps, that have similar operations but different performances. The design parameters and the way to optimize the performances are proposed for both cases. Finally a comparison is made between the two types of pumps with optimum design parameters.

Involute Gear Pumps Versus Lobe Pumps: A Comparison

1996 ◽  
Author(s):  
Giovanni C. Mimmi ◽  
Paolo E. Pennacchi ◽  
Carlo G. Savi
Keyword(s):  
Optimum Design ◽  
Flow Rate ◽  
Design Parameters ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Positive Displacement ◽  
Involute Gear ◽  
Performance Indexes ◽  
Rotary Pumps ◽  
Gear Pumps

Abstract In previous studies we have considered several types of positive displacement rotary pumps and deeply analyzed the generation of the flow rate and the design limits. This has been done in order to evaluate the main performance indexes: one of these, the flow rate irregularity, is related to the possibility that the pump becomes a source of vibration and noise. A second index is the specific flow rate, related to the delivery capacity of the pump. In this paper, following our previous researches, we analyze internal involute gear pumps and internal lobe pumps, that have similar way to operate but different performances. The design parameters and the way to optimize the performances are summarized for both cases. Finally a comparison between the two types of pumps is proposed, along with some optimum design cases.

Rotor Design and Optimization in Internal Lobe Pumps

1997 ◽  
Vol 50 (11S) ◽  
pp. S133-S141 ◽  
Author(s):  
Giovanni Mimmi ◽  
Paolo Pennacchi
Keyword(s):  
Flow Rate ◽  
Performance Comparison ◽  
Definite Function ◽  
Pump Design ◽  
Design And Optimization ◽  
Performance Indexes ◽  
New Type ◽  
Improved Performance ◽  
Lobe Pump ◽  
Rotor Curvature

The topic of this paper is the design of internal lobe pumps and their optimization which is based on specific performance indexes. Internal lobe pumps can be classified as different types depending on the shape of the lobe of the outer rotor. First, the design of internal lobe pumps with elliptical, sinusoidal, and polycircular lobe profiles is considered. The latter is a new type of lobe profile with special shape whose curvature follows a definite function. Then we introduce the performance indexes used for the comparison. Some of these indexes, such as the flow rate irregularity, are commonly used for performance comparison, while others, such as the specific slipping and the rotor curvature, are particularly suitable in this case. The comparisons are made with the circular type that had been analyzed by the authors in previous papers (see eg, Mimmi, Pannacchi, and Savi (1996), Internal Lobe Pump Design, Mechanics in design - Proc CSME Forum ’96, SA Meguid (ed), Toronto, Ontario, Canada). It is not easy to univocally state the superiority of one type with respect to the others, however, it is possible to notice that elliptical and polycircular types are comparable to the circular ones in terms of flow rate irregularity, but have improved performance in terms of specific slipping and rotor curvature.

Development of an Integrated System for the Automated Design of a Gerotor Oil Pump

2006 ◽  
Vol 129 (10) ◽  
pp. 1099-1105 ◽  
Author(s):  
Y. J. Chang ◽  
J. H. Kim ◽  
C. H. Jeon ◽  
Chul Kim ◽  
S. Y. Jung
Keyword(s):  
Flow Rate ◽  
Integrated System ◽  
Design Parameters ◽  
Specific Flow ◽  
Automotive Engine ◽  
Lubricant Oil ◽  
Oil Pump ◽  
Machine Element ◽  
Gerotor Pump ◽  
Main Components

A gerotor pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, construction, and other various applications. In particular, the pump is an essential machine element that feeds lubricant oil in an automotive engine. The main components of the pump are the two rotors. Usually, the outer one is characterized by lobes with a circular shape, while the inner rotor profile is determined as a conjugate to the other. In this study, the design optimization has been carried out to determine the design parameters that maximize the specific flow rate and minimize the flow rate irregularity. The integrated system, which is composed of three main modules, has been developed through AutoLISP, Visual Basic language, and the CAD method, and considers various design parameters. An optimally designed model for a general type of gerotor pump has been generated and experimentally verified for its pump performances. Results obtained using the system enable the designer and manufacturer of the oil pump to be more efficient in this field.

Flow Rate Regularity in Rotary Trochoidal-Lobe Pumps

1994 ◽  
Author(s):  
G. Mimmi ◽  
P. Pennacchi
Keyword(s):  
Flow Rate ◽  
Distinctive Feature ◽  
Pump Design ◽  
Instantaneous Flow ◽  
Positive Displacement ◽  
Involute Gear ◽  
Gear Pumps ◽  
Points Of View ◽  
Lobe Pump ◽  
Instantaneous Flow Rate

Abstract This paper analyses a particular type of rotary positive-displacement pumps with lobes having epitrochoidal flanks, whose distinctive feature is that of providing a strictly constant geometric instantaneous flow rate. The pump design is analysed from geometric and kinematical points of view. Then the behavior of this type of lobe pump is compared with that of involute gear pumps.

Development of an Automated Design System for Oil Pumps with Multiple Profiles (Circle, Ellipse and Involute)

2009 ◽  
Vol 620-622 ◽  
pp. 37-40 ◽  
Author(s):  
Chul Kim ◽  
Beom Cheol Hwang ◽  
Hyun Ki Moon ◽  
Hyun Woo Lee ◽  
Myung Jun Song
Keyword(s):  
Flow Rate ◽  
Essential Element ◽  
Integrated System ◽  
Design System ◽  
Automotive Engine ◽  
Automotive Engines ◽  
Lubricant Oil ◽  
Rotor Profile ◽  
Main Components ◽  
Lobe Pump

An internal lobe pump is suitable for oil hydraulics of machine tools, automotive engines, compressors, constructions and other other applications. In particular, this type of pump is an essential element of an automotive engine to feed lubricant oil. We perform a theoretical analysis of the internal lobe pump whose main components are rotors. Usually, the outer is characterized by a lobe with elliptical and involute shapes, while the inner rotor profile is determined as the conjugate to the other rotor. Our integrated system, which is composed of three main modules, was developed through AutoLISP using AutoCAD. It generates a new lobe profile, and automatically calculates the flow rate and flow rate irregularity according to the lobe profile generated. Results obtained from the analysis enable the designer and manufacturer of oil pumps to be more efficient.

Influence of Different Design Parameters on the Theoretical Flow Ripple in Balanced Vane Pumps

2019 ◽  
Author(s):  
Mattia Battarra ◽  
Emiliano Mucchi
Keyword(s):  
Fluid Dynamics ◽  
Flow Rate ◽  
Theoretical Approach ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Pump Design ◽  
Flow Ripple ◽  
Ring Shape ◽  
Tip Radius ◽  
Excessive Noise

Abstract The present study focuses the attention on the correlation between the cam ring design and the kinematic flow ripple in balanced vane pumps. In particular, the work addresses the influence of the main pump design parameters on the oscillations of the flow rate produced by the volume variation of both undervane pockets and displaced chambers, which is considered as one of the main sources of excessive noise and vibration. The pump operating principle is firstly defined and the design philosophy is presented, together with the theoretical approach used to determine both then vane motion and resulting flow ripple. The proposed methodology is evaluated by means of a parametric study involving design parameters such as vane thickness and tip radius. The analysis suggests that these geometrical parameters, together with the cam ring shape, affect the pump dynamic behavior due to their correlation with the fluid-dynamics of the machine.

Optimisation of air-jet vortex generators with respect to system design parameters

1999 ◽  
Vol 103 (1028) ◽  
pp. 475-480 ◽  
Author(s):  
T. P. Bray ◽  
K. P. Garry
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Vortex Generator ◽  
Design Parameters ◽  
Air Jet ◽  
System Input ◽  
System Requirements ◽  
Jet Nozzle ◽  
Definition Of

Abstract A simple technique is proposed that allows the definition of the geometry and characteristics of an air-jet vortex generator to be defined, using the system requirements in practical design. Typically, the aircraft designer is concerned with the mass flow-rate and air pressure requirements of any pneumatic system for inclusion to an airframe. These parameters are not congruent with those for air-jet vortex generator aerodynamic design, and therefore, some tool is required to bridge the gap. Such a tool is proposed, based on empirical methods for the prediction of air-jet vortex generator behaviour. The technique allows the comparison of the vortex strength, and the system inputs (the jet mass flow-rate and the air-jet plenum pressure) for the air-jet, for a range of jet nozzle diameters and jet velocity ratios. Through this comparison, the optimum air-jet design can be reached for a given system input.

scholarly journals A NOVEL DESIGN OF THE ROOTS BLOWER

2019 ◽  
Vol 57 (2) ◽  
pp. 249 ◽  
Author(s):  
Tran Ngoc Tien ◽  
Nguyen Hong Thai
Keyword(s):  
Flow Rate ◽  
Volumetric Efficiency ◽  
Specific Flow Rate ◽  
Specific Flow ◽  
Rotor Profile ◽  
Profile Design ◽  
Novel Design

This paper reports a novel curve developed from non - circular gearing theory, which can be applied in rotor profile design of the two - lobe Roots blower. The formulas for calculating the volumetric efficiency and specific flow rate of the blower have also been established. To evaluate this type of the Roots blower, the volumetric efficiency and specific flow rate are being compared with those parameters of the two traditional designs and one recent variant.

A More Accurate Definition of Mechanical and Volumetric Efficiencies for Digital Displacement® Pumps

2019 ◽  
Author(s):  
Christopher Williamson ◽  
Noah Manring
Keyword(s):  
Output Power ◽  
Fluid Pressure ◽  
Check Valve ◽  
Operating Conditions ◽  
Design Parameters ◽  
Total Efficiency ◽  
Pump Design ◽  
Input And Output ◽  
Definition Of ◽  
Compressibility Effects

Abstract The apparent volumetric displacement of digital displacement pumps and motors is reduced with increasing fluid pressure. So-called pump shrinkage has been documented in previous publications, where fluid compressibility effects were assumed to affect input and output power equally. In this paper, the authors derive the torque and flow rate of an ideal digital displacement pump. It is shown that the output power shrinks slightly more than the input. The difference between input and output shrinkage is counted as a power loss according to the accepted definition of total efficiency. New equations are presented for calculating mechanical and volumetric efficiencies which are up to 2% more accurate than the previous method (which assumes equal shrinkage) and up to 5% more accurate than conventional equations (which assume no shrinkage). Compressibility effects may be even more significant depending on pump design parameters, fluid properties, flow control algorithms and operating conditions. Calculations of partial pump efficiencies require a derived displacement volume to be known. The derived displacement volume of digital displacement pumps is considered for the first time in this paper. The contributions of this work are instructive for understanding the unique characteristics of digital displacement pumps as well as check-valve type pumps in general.

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