Theoretical Analysis and Design of a Variable Delivery External Gear Pump for Low and Medium Pressure Applications

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Srinath Tankasala ◽  
Andrea Vacca
Keyword(s):  
High Pressures ◽  
Optimization Approach ◽  
Gear Pump ◽  
Flow Variation ◽  
Analysis And Design ◽  
Target Pressure ◽  
Electric Actuation ◽  
Variation Mechanism ◽  
Instantaneous Flow Rate ◽  
External Gear Pump

This paper describes a unique design concept that is capable of electronically controlling the flow delivered by an external gear pump (EGP). The principle used for varying the flow relies on the variable timing concept which has been previously demonstrated by the author's research team for EGP's operating at high pressures (HPs) (p > 100 bar). This principle permits to vary the flow within a certain range, without introducing additional sources of power loss. In this paper, the above concept has been applied to formulate a design for a variable delivery EGP for low pressure (LP) applications (p < 30 bar), suitable for direct electric actuation. Specific design principles for the gear and the flow variation mechanisms are introduced to limit the force required by the electric actuation, and for maximizing the flow variation range. Also, the low target pressure allows the variable timing principle to be realized with an asymmetric solution, with only one variable timing element present at one side of the gears. A detailed analysis concerning the relationship between the electrically commanded position of the flow varying element and the theoretical flow delivered by the pump is also presented. This analysis is used to formulate analytical expressions for the instantaneous flow rate and the flow nonuniformity of the pump. The paper details the design principle of the proposed variable flow pump and describes the multi-objective optimization approach used for sizing the gears and flow variation mechanism. The paper also discusses the experimental activity performed on a prototype of the proposed unit, able to achieve a flow variation of 31%.

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.

A Solution for an Electronically-Controlled Variable Delivery External Gear Pump

2017 ◽  
Author(s):  
Srinath Tankasala ◽  
Andrea Vacca
Keyword(s):  
Cost Effective ◽  
Spur Gear ◽  
Gear Pump ◽  
Electronic Control ◽  
Pump Design ◽  
Flow Variation ◽  
Electronic Control System ◽  
Gear Pumps ◽  
Pressure Compensation ◽  
External Gear Pump

This paper describes an innovative design concept to enable electronic control of the flow delivered by external spur gear pumps. The basic principle used to obtain flow variation relies on a variable timing concept previously demonstrated by the author’s research team. This principle permits to vary the flow within a certain range, without introducing additional sources of power loss. Previous work proved the applicability of the proposed concept in a pressure compensated design of an external gear pump for high pressure applications. This concept took advantage of the pressure differential acting on the “slider”, which is an internal element performing the flow regulation. In this paper, a solution that permits to achieve balance of the pressure forces acting on the slider is proposed. This solution reduces the actuation forces, thus enabling direct flow control actuation through an electronic control system. The proposed solution is cost effective, it consists of a limited number of parts, and it is suitable for pumps without pressure compensation, i.e. for low or intermediate pressures. The paper details the aspects of the pump design, which was performed by using a multi-objective algorithm that maximizes the flow operating range and at the same time the pump. The optimum design could achieve a flow variation of about 32% in simulation and this was also demonstrated in actual experiments on a prototype realized at the author’s Research Center. The proposed design can impact several of the current applications of external gear pumps, introducing the additional “flow on demand” capability.

scholarly journals Parameterization, Modeling, and Validation in Real Conditions of an External Gear Pump

2021 ◽  
Vol 13 (6) ◽  
pp. 3089
Author(s):  
Miquel Torrent ◽  
Pedro Javier Gamez-Montero ◽  
Esteban Codina
Keyword(s):  
Working Conditions ◽  
Test Bench ◽  
Fluid Dynamic ◽  
Graph Model ◽  
Field Tests ◽  
Black Box ◽  
Gear Pump ◽  
Volumetric Behavior ◽  
External Gear Pump ◽  
Standard Tests

This article presents a methodology for predicting the fluid dynamic behavior of a gear pump over its operating range. Complete pump parameterization was carried out through standard tests, and these parameters were used to create a bond graph model to simulate the behavior of the unit. This model was experimentally validated under working conditions in field tests. To carry this out, the pump was used to drive the auxiliary movements of a drilling machine, and the experimental data were compared with a simulation of the volumetric behavior under the same conditions. This paper aims to describe a method for characterizing any hydrostatic pump as a “black box” model predicting its behavior in any operating condition. The novelty of this method is based on the correspondence between the variation of the parameters and the internal changes of the unit when working in real conditions, that is, outside a test bench.

The Research on Pure Water Hydraulic External Gear Pump

2010 ◽  
Vol 44-47 ◽  
pp. 1767-1772
Author(s):  
De Xin Zhao ◽  
Rui Bo Yuan ◽  
Jing Luo
Keyword(s):  
Surface Treatment ◽  
Structural Design ◽  
Treatment Process ◽  
Pure Water ◽  
Spare Part ◽  
Gear Pump ◽  
Calculation Of Parameters ◽  
Water Hydraulic ◽  
Engineering Materials ◽  
External Gear Pump

This article describes the structure of pure water hydraulic external gear pump, structural design and calculation of parameters,analysises the mai spare part material of pure water hydraulic external gear pump and determines the type of the new engineering materials. Besides the surface treatment process of pump are discussed. Pure water hydraulic external gear pump is simulated by FLUENT, obtaining the parameters of the influence of the pump's performance.

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.

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