Next Article in Journal
Case Study about the Energy Absorption Capacity of Metal Oxide Varistors with Thermal Coupling
Next Article in Special Issue
Analysis of the Design of a Poppet Valve by Transitory Simulation
Previous Article in Journal
Insights from Past Trends in Exergy Efficiency and Carbon Intensity of Electricity: Portugal, 1900–2014
Previous Article in Special Issue
The Determination of the Theoretical Stroke Volume of Hydrostatic Positive Displacement Pumps and Motors from Volumetric Measurements
Article Menu
Issue 3 (February-1) cover image

Export Article

Open AccessArticle
Energies 2019, 12(3), 535;

Theoretical Investigation into the Ripple Source of External Gear Pumps

1,2,* and 1,2
School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
Maha Fluid Power Research Center, Purdue University, Lafayette, IN 47905, USA
Author to whom correspondence should be addressed.
Received: 31 December 2018 / Revised: 3 February 2019 / Accepted: 4 February 2019 / Published: 8 February 2019
(This article belongs to the Special Issue Energy Efficiency and Controllability of Fluid Power Systems 2018)
PDF [14771 KB, uploaded 15 February 2019]


External gear pumps are among the most popular fluid power positive displacement pumps, however they often suffer of excessive flow pulsation transmitted to the downstream circuit. To meet the increasing demand of quiet operation for modern fluid power system, a better understanding of the ripple source of gear pumps is desirable. This paper presents a novel approach for the analysis of the ripple source of gear pumps based on decomposition into a kinematic component and a pressurization component. The pump ripple can be regarded as the superposition of the displacement solution and the pressurization solution. The displacement solution is driven by the kinematic flow, and it can be derived from the kinematic flow theory; instead, the pressurization solution can be approximated by overlapping the pressurization flow for a single displacement chamber. Furthermore, in this way the changes of these two components with modification of the delivery circuit are determined in both analytical and numerical ways. The result of this analysis provides a good interpretation of the pulsation simulated by a detailed lumped-parameter simulation model, thus showing its validity. The result also indicates that the response of two ripple sources to the change of the loading in the downstream hydraulic circuit is very different. These findings reveal the limitation of the traditional experimental method for determining the pump ripple, that new experimental methods which are more physics-based can be potentially formulated based on this work. View Full-Text
Keywords: flow power gear machines; external gear pumps; flow pulsation; noise and pulsations; hydraulics flow power gear machines; external gear pumps; flow pulsation; noise and pulsations; hydraulics

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Zhao, X.; Vacca, A. Theoretical Investigation into the Ripple Source of External Gear Pumps. Energies 2019, 12, 535.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top