The Reduction of Gear Pump Pressure Ripple

1987 ◽  
Vol 201 (2) ◽  
pp. 99-106 ◽  
Author(s):  
K A Edge ◽  
B R Lipscombe
Keyword(s):  
Hydraulic System ◽  
Pressure Fluctuations ◽  
Gear Pump ◽  
Noise Levels ◽  
Flow Ripple ◽  
Flow Fluctuation ◽  
Accurate Knowledge ◽  
Airborne Noise ◽  
Pressure Ripple ◽  
Pump Pressure

Pressure fluctuations in a hydraulic system may be substantially reduced by cancelling the flow ripple produced by the pump. This paper describes a secondary flow ripple generating mechanism which introduces an equal and opposite flow fluctuation to that generated by the pump. Tests have shown that the mechanism can virtually cancel four harmonics of pressure ripple but success is dependent on an accurate knowledge of the pump flow fluctuation characteristic. This is best determined experimentally. Similar improvements can be achieved using a mechanism in a motor. This has the additional benefit of reducing torque fluctuations. The reduction in gear pump pressure ripple achieved with the mechanism has been shown to reduce overall airborne noise levels from a hydraulic system by as much as 10 dB, although the airborne noise radiated from the pump casing was not affected.

scholarly journals Measurement of small vessel machinery vibration induced acoustic signature levels

2019 ◽  
Vol 16 (2) ◽  
pp. 87-98 ◽  
Author(s):  
GVV Pavan Kumar ◽  
V V S Prasad ◽  
B H Nagesh
Keyword(s):  
Pressure Fluctuations ◽  
Response Spectra ◽  
Underwater Sound ◽  
Underwater Noise ◽  
Noise Levels ◽  
Small Vessels ◽  
Performance Point ◽  
Engine Room ◽  
Airborne Noise ◽  
Main Engine

Ship vibrations, airborne and underwater noise levels have always been a challenging topic from a performance point of view in ship design, building and operation. The measurement shall help in monitoring the self-noise and the technical state of their machinery mechanism. The vibration levels on the main engine and auxiliary Genset foundation, airborne noise levels of the engine room and underwater self-noise levels of a small mechanized fishing trawler was measured at the jetty in idling condition.  The vibration levels on the foundation measured the average value of 0.207 mm/s for the main engine and 1.36 mm/s for auxiliary Genset. The airborne noise levels measured 99 dB (A) in the engine room. The peak underwater sound pressure levels measured 162 dB re 1µPa. The response spectra indicate the peak vibration and noise levels in the lower frequency region <1.2 kHz. The machinery excitation forces transferred to the hull surface as pressure fluctuations which generated the airborne and underwater noise levels. Though the measurement limited to jetty conditions, detailed analysis can be useful for detection, classification, and tracking of small vessels.

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.

Measurement of the longitudinal transmission characteristics of fluid-filled hoses

1997 ◽  
Vol 211 (3) ◽  
pp. 219-228 ◽  
Author(s):  
J E Drew ◽  
D K Longmore ◽  
D N Johnston
Keyword(s):  
Dynamic Properties ◽  
Pressure Fluctuations ◽  
Structural Vibration ◽  
Impedance Matrix ◽  
Hydraulic Circuit ◽  
Transmission Characteristics ◽  
Flow Ripple ◽  
Power Steering ◽  
Axial Tension ◽  
Pressure Ripple

Flexible hoses used within a hydraulic circuit can reduce the levels of both pressure fluctuations and structural vibration. An important application is in automotive power steering where tubular inserts and restrictors are often used inside a hose to enhance the reduction of pressure ripple. The performance of a hose assembly in the frequency domain is usually specified by an impedance matrix relating pressure and flow ripple at the ends. However, these quantities are coupled to fluctuating axial tension and motion of the hose walls and it is desirable to have a 4 × 4 impedance matrix relating the complex amplitudes of all these quantities. A convenient method of experimentally measuring this matrix is presented. As well as allowing investigation of the main structural and fluid transmission from the hose assembly to the subsequent pipework, the 4 × 4 impedance matrix provides a way of obtaining the dynamic properties of hose walls under realistic conditions for use in further studies.

Reduction of axial piston pump pressure ripple

2000 ◽  
Vol 214 (1) ◽  
pp. 53-64 ◽  
Author(s):  
K A Harrison ◽  
K A Edge
Keyword(s):  
Piston Pump ◽  
Hydraulic Systems ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Speed Flow ◽  
Wide Range ◽  
Pump Delivery ◽  
Pressure Ripple ◽  
Pump Pressure ◽  
Axial Piston

The reduction in source flow ripple in hydraulic systems is the most effective method of reducing pump-generated pressure ripple and system noise. This paper describes reductions in axial-piston pump delivery flow ripple achieved using a novel timing mechanism which is inherently speed, flow and pressure sensing. Fixed-speed tests have shown that the mechanism can significantly reduce axial-piston pump delivery flow ripple over a wide range of delivery pressures and pump displacements. Furthermore, the reduction in pressure ripple achieved with the mechanism has been shown to contribute towards reductions in overall air-borne noise levels of up to 6 dB in a simple system. A simulation model has been produced to predict the behaviour of the prototype mechanism. The model has been compared with the measured delivery flow ripple and achieves good agreement.

Study on the Spring-Piston External Mesh Gear Pump with Low Flow Fluctuation

2011 ◽  
Vol 201-203 ◽  
pp. 2200-2205
Author(s):  
Jian Zhuo Zhang ◽  
Kang Kang Li ◽  
Meng Gao ◽  
Tian Zi Zhu
Keyword(s):  
Flow Rate ◽  
Fourier Transformation ◽  
Hydraulic System ◽  
Low Flow ◽  
Gear Pump ◽  
Input Flow ◽  
Matlab Software ◽  
Flow Fluctuation ◽  
Piston System ◽  
External Mesh

The cycle function of input flow rate was obtained by Fourier transformation of the instantaneous input flow rate of external mesh gear pump. The model of hydraulic system consisting of gear pump, spring, piston and load was established, the differential functions of the model were established too. The influence of dynamic compensating characteristics in the system caused by both pistons with different area and stiffness of spring was analyzed with MATLAB software and the change of fluctuating flow in the same system was obtained. The simulation result shows that the flow fluctuation of external mesh gear pump could be reduced by using the spring-piston system.

The Quantification of Internal Noise Levels and Wall Pressure Spectra in Industrial Gas Pipelines

1991 ◽  
Author(s):  
M. P. Norton ◽  
A. Pruiti
Keyword(s):  
Prediction Models ◽  
Transmission Loss ◽  
Pressure Fluctuations ◽  
Internal Noise ◽  
Wall Pressure ◽  
Gas Pipelines ◽  
Noise Levels ◽  
Empirical Prediction ◽  
Wall Pressure Fluctuations ◽  
Semi Empirical

Abstract This paper addresses the issue of quantifying the internal noise levels/wall pressure fluctuations in industrial gas pipelines. This quantification of internal noise levels/wall pressure fluctuations allows for external noise radiation from pipelines to be specified in absolute levels via appropriate noise prediction models. Semi-empirical prediction models based upon (i) estimated vibration levels and radiation ratios, (ii) semi-empirical transmission loss models, and (iii) statistical energy analysis models have already been reported on by Norton and Pruiti 1,3 and are not reported on here.

Reinforcement Learning for Active Noise Control in a Hydraulic System

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Eric R. Anderson ◽  
Brian L. Steward
Keyword(s):  
Reinforcement Learning ◽  
Hydraulic System ◽  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Operating Point ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Active Noise ◽  
Pressure Ripple

Abstract Hydraulic pressure ripple in a pump, as a result of converting rotational power to fluid power, continues to be a problem faced when developing hydraulic systems due to the resulting noise generated. In this paper, we present simulation results from leveraging an actor-critic reinforcement learning method as the control method for active noise control in a hydraulic system. The results demonstrate greater than 96%, 81%, and 61% pressure ripple reduction for the first, second, and third harmonics, respectively, in a single operating point test, along with the advantage of feed forward like control for high bandwidth response during dynamic changes in the operating point. It also demonstrates the disadvantage of long convergence times while the controller is effectively learning the optimal control policy. Additionally, this work demonstrates the ancillary benefit of the elimination of the injection of white noise for the purpose of system identification in the current state of the art.

Noise Control Decision Process for Marine Vessels

2014 ◽  
Author(s):  
Raymond W. Fischer ◽  
Louis M. Pettit
Keyword(s):  
Marine Mammals ◽  
Noise Control ◽  
Regulatory Body ◽  
Noise Levels ◽  
Radiated Noise ◽  
Underwater Radiated Noise ◽  
Sound Levels ◽  
Airborne Noise ◽  
Control Decision ◽  
Marine Vessels

There is a price to be paid to achieve compliance with the acoustic requirements imposed by regulatory agencies. Acoustic requirements typically appear in ship specifications as airborne and/or underwater radiated noise limits as the need to preclude hearing loss for crew members and the need to control sound levels experienced by marine mammals receive more recognition. Recent changes and additions to regulatory body requirements addressing compartment airborne noise and underwater radiated noise can be found in IMO Resolution MSC.337(91) Annex 1 and Annex 2 which state that IMO Resolution A.468(XII) “Code on Noise Levels Onboard Ships” shall take effect on 1 July 2014 for all SOLAS compliant vessels. Thus the airborne noise levels in compartments and at on-deck work stations onboard as-built ships seeking a SOLAS certificate will need to be measured, and must demonstrate compliance with noise limits stated in paragraph 4.2 of IMO Resolution A.468(XII). IMO “Guidelines for the Reduction of Underwater Noise from Commercial Shipping to Address Adverse Impacts on Marine Life” dated 7 April 2014 and agencies such as ICES and DNV have established guidance and/or criteria for control of underwater radiated noise from vessels, and these too are now commonly appearing in ship specifications. Specifications referencing such criteria typically require that compliance be demonstrated by at-sea testing of underwater radiated noise. Making the correct decisions during the ship design process will minimize costs for noise control and will provide a positive return on investment. The process of how best to comply with noise limits while minimizing costs through optimization of noise control treatments and design approaches is discussed.

A Fast and Effective Method for the Optimization of the Valve Plate of Swashplate Axial Piston Pumps

2021 ◽  
Author(s):  
Gianluca Marinaro ◽  
Emma Frosina ◽  
Kim Stelson ◽  
Adolfo Senatore
Keyword(s):  
Numerical Model ◽  
Dynamic Pressure ◽  
Valve Plate ◽  
Lumped Parameter Model ◽  
Piston Pump ◽  
Axial Piston Pump ◽  
Flow Ripple ◽  
Lumped Parameter ◽  
Pressure Ripple ◽  
Axial Piston

Abstract This research presents a lumped parameter numerical model aimed at designing and optimizing an axial piston pump. For the first time, it has been shown that a lumped parameter model can accurately model axial piston pump dynamics based on a comparison with CFD models and experimental results. Since the method is much more efficient than CFD, it can optimize the design. Both steady-state and dynamic behaviors have been analyzed. The model results have been compared with experimental data, showing a good capacity in predicting the pump performance, including pressure ripple. The swashplate dynamics have been investigated experimentally, measuring the dynamic pressure which controls the pump displacement; a comparison with the numerical model results confirmed the high accuracy. An optimization process has been conducted on the valve plate geometry to control fluid-born noise by flow ripple reduction. The NLPQL algorithm is used since it is suitable for this study. The objective function to minimize is the well-known function, the Non-Uniformity Grade, a parameter directly correlated with flow ripple. A prototype of the best design has been realized and tested, confirming a reduction in the pressure ripple. An endurance test was also conducted. As predicted from the numerical model, a significant reduction of cavitation erosion was observed.

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