scholarly journals Visualization research on the influence of an ultrasonic degassing system on the operation of a hydraulic gear pump

2018 ◽  
Vol 211 ◽  
pp. 03005 ◽  
Author(s):  
Piotr Antoniak ◽  
Jarosław Stryczek ◽  
Michał Banaś ◽  
Oleksandr Lyhovskyi ◽  
Ihor Gryshko ◽  
...  
Keyword(s):  
High Speed ◽  
Theoretical Description ◽  
Working Fluid ◽  
Operating Parameters ◽  
Gear Pump ◽  
Hydraulic Systems ◽  
Chemical Methods ◽  
Physical Methods ◽  
Working Medium ◽  
Gear Pumps

Gear pumps make a group of the most popular hydraulic energy generators. Research and development works concerning those units have been going on for decades, and thanks to them gear pumps feature very good operating parameters. However, even well-designed gear pumps will not work properly if the physical properties of the working fluid are incorrect. One of such properties is compressibility of the fluid, which largely depends on the amount of gas dissolved in the medium. For this reason, the aim is to reduce the amount of gas dissolved in the working medium. It can be done using both chemical and physical methods. Because chemical methods can affect the chemical composition of the working fluid, it is the physical methods that are usually used in hydraulic systems. This paper presents preliminary visualization research into the influence of an ultrasonic degassing system on the operation of a hydraulic gear pump. Apart from that, operation of such a system and its theoretical impact on the work of the gear pump is discussed Experimental study, using a high-speed camera, was carried out in order to verify the theoretical description.

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 The Influence of Radial and Axial Gaps on Volumetric Efficiency of External Gear Pumps

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4468
Author(s):  
Paulina Szwemin ◽  
Wieslaw Fiebig
Keyword(s):  
Fluid Flow ◽  
Volumetric Efficiency ◽  
Operating Parameters ◽  
Gear Pump ◽  
Cfd Model ◽  
External Gear Pumps ◽  
Flow Phenomena ◽  
Gear Pumps ◽  
The Impact ◽  
External Gear Pump

The design of gear pumps and motors is focused on more efficient units which are possible to achieve using advanced numerical simulation techniques. The flow that appears inside the gear pump is very complex, despite the simple design of the pump itself. The identification of fluid flow phenomena in areas inside the pump, considering the entire range of operating parameters, is a major challenge. This paper presents the results of simulation studies of leakages in axial and radial gaps in an external gear pump carried out for different gap shapes and sizes, as well as various operating parameters. To investigate the processes that affect pump efficiency and visualize the fluid flow phenomena during the pump’s operation, a CFD model was built. It allows for a detailed analysis of the impact of the gears’ eccentricity on leakages and pressure build-up on the circumference. Performed simulations made it possible to indicate the relationship between leakages resulting from the axial and radial gap, which has not been presented so far. To verify the CFD model, experimental investigations on the volumetric efficiency of the external gear pump were carried out. Good convergence of results was obtained; therefore, the presented CFD model is a universal tool in the study of flow inside external gear pumps.

scholarly journals PRINCIPLES OF CONSTRUCTION OF THE GENERALIZED MATHEMATICAL MODEL OF THE HYDRAULIC EXTINGUISHER OF OSCILLATIONS OF THE PASSENGER CAR

2021 ◽  
Vol 1 (38) ◽  
pp. 173-184
Author(s):  
I. Shcherbyna
Keyword(s):  
Mathematical Model ◽  
Operating Conditions ◽  
Working Fluid ◽  
Operating Parameters ◽  
Hydraulic Systems ◽  
Passenger Cars ◽  
Passenger Car ◽  
Periodic Movement ◽  
Depth Analysis ◽  
The Impact

The study of the processes associated with the use of working fluids in the elements of hydraulic drives was preceded by studies of the unsteady periodic movement of the working fluid in the pipelines of hydraulic systems. Such processes take place in hydraulic drives and their elements, and are associated with the compressibility of the working fluid. The stability of the operation of hydraulic valves, which are supplied to hydraulic systems in order to maintain, within the required limits, pressures or flow rates, is also largely predetermined by non-stationary hydro mechanical processes occurring in the pipelines of these systems, channels and chambers of hydraulic devices. The peculiarities of the working processes of passive vibration dampers of passenger cars include the interaction of the working fluid with moving parts and its flow through the channels and through the calibrated holes with local artificial resistance. For in-depth analysis of changes in operating parameters, it is necessary to use a mathematical model that should reflect the processes that occur during the operation of the hydraulic device. In the presented article the generalized mathematical model of the hydraulic damper of fluctuations of the passenger car of the НЦ-1100 type is developed. This model takes into account the special operating conditions of the hydraulic shock absorber, which allows you to study the impact of operating parameters on the performance of the device.

Speed-Variable Switched Differential Pump System for Direct Operation of Hydraulic Cylinders

2015 ◽  
Author(s):  
Lasse Schmidt ◽  
Daniel B. Roemer ◽  
Henrik C. Pedersen ◽  
Torben O. Andersen
Keyword(s):  
Dynamic Properties ◽  
Main Idea ◽  
Chamber Pressure ◽  
Gear Pump ◽  
Hydraulic Systems ◽  
Direct Drive ◽  
Motion Direction ◽  
Pump System ◽  
Compression Flow ◽  
Gear Pumps

Efforts to overcome the inherent loss of energy due to throttling in valve driven hydraulic systems are many, and various approaches have been proposed by research communities as well as the industry. Recently, a so-called speed-variable differential pump was proposed for direct drive of hydraulic differential cylinders. The main idea was here to utilize an electric rotary drive, with the shaft interconnected to two antiparallel fixed displacement gear pumps, to actuate a differential cylinder. With the design carried out such that the area ratio of the cylinder matches the displacement ratio of the two gear pumps, the throttling losses are confined to cross port leakage in the cylinder and leakage of the pumps. However, it turns out that the volumetric pump losses and the pressure dynamics of the cylinder and connecting pipes may cause pressure increase- or decrease in the cylinder chambers, which may seriously influence the dynamics and hence the performance during operation. This paper presents an analysis of these properties, and a redesign of the hydraulic system concept is proposed. Here the area- and displacement ratios are deliberately mismatched, causing inherent pressure build-up or cavitation in the return chamber, depending on the direction of motion. In order to avoid cavitation, a third gear pump is introduced, which provides a flow in the relevant cylinder chamber in one direction of motion, while operating in idle mode in the opposite motion direction. Together with two 2/2 way proportional valves, this design allows to control the lower chamber pressure levels, throttling excess compression flow to tank. The resulting design introduces additional losses due to throttling of excess compression flow, but also improves the dynamic properties of the system significantly. The proposed features are verified by comparison with the original pump concept and a conventional valve concept. Furthermore, significant improvement in energy efficiency is demonstrated under certain load conditions.

A Gear Micropump without Bearings Production

2015 ◽  
Vol 775 ◽  
pp. 352-356 ◽  
Author(s):  
Leonid Rodionov ◽  
Pavel Rekadze ◽  
Jarosław Stryczek
Keyword(s):  
Composite Materials ◽  
Friction Coefficient ◽  
High Efficiency ◽  
Type A ◽  
High Accuracy ◽  
Fluid Power ◽  
Gear Pump ◽  
Working Medium ◽  
Gear Pumps ◽  
Compact Design

Progress in the field of microelectronics and micromechanics has created new opportunities for the development of fluid power microsystems and microhydraulics. Miniaturization of hydraulic elements allows replacing the classical hydraulics with microhydraulics, where due to size or weight the former cannot be applied. Gear pumps are common use due to their reliability, resistance to working medium impurities, high efficiency, small size in comparison with other pumps and simple and compact design. Therefore micropumps often associate with a gear pump type. A micropump entails microbearings production. This requirement leads to cost increasing due to requirements to high accuracy of manufacturing. The paper focuses on a method for micropumps production without bearings. The idea based on application of materials with satisfactory friction coefficient in pairs. Friction pairs analysis made from different polymer and composite materials was carried out. As a result a gear micropump was designed and produced.

scholarly journals Instruments of identification of hydraulic components potential failures

2018 ◽  
Vol 183 ◽  
pp. 03008 ◽  
Author(s):  
Joanna Fabiś-Domagała ◽  
Grzegorz Filo ◽  
Hassan Momeni ◽  
Mariusz Domagała
Keyword(s):  
Quality Management ◽  
Working Fluid ◽  
Gear Pump ◽  
Operation Condition ◽  
Gear Pumps

This paper presents an analysis of potential failures of hydraulic components on the example of a hydraulic gear pump with the use of instruments of quality management. The “five why” method was implemented to evaluate failures as well as the bases for the causes which have an influence on pumps failures. The causes are connected with operation condition of gear pumps and the quality of working fluid. In the next step, by using a systematic diagram, appropriate improvement actions for the identified causes were determined.

Simulated Helical Gear Pump Analysis Using a New CFD Approach

2009 ◽  
Author(s):  
Aaron S. Heisler ◽  
John J. Moskwa ◽  
Frank J. Fronczak
Keyword(s):  
High Speed ◽  
System Development ◽  
Gear Tooth ◽  
Fluid Motion ◽  
Computation Time ◽  
Helix Angle ◽  
Helical Gear ◽  
Gear Pump ◽  
Helical Gears ◽  
Gear Pumps

The purpose of this paper is to focus on cavitation prediction at high-speeds in helical gear pumps for the purpose of hydrostatic dynamometer system development. Details of the fluid motion will be described through various stages of fluid transfer from the pump inlet to the outlet using various mesh densities. Using the results of these simulations, a discussion of design improvements for high-speed hydrostatic dynamometer operation is included. Conducting CFD simulations on external gear pumps is a difficult problem depending upon the complexity of the individual components. Simulating helical gears is especially taxing due to the complexity of the gear tooth profile. The additional detail in a helical gear pump model leads to an increase of the required mesh density and therefore increased computation time. A less computationally complex approach to simulating helical gears is to consider a helical gear as a series of thin spur gears rotated according to a predetermined helix angle. Details of this approach and results are discussed in this paper.

Causes of gear pump fails and methods for their elimination

2020 ◽  
pp. 98-107
Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev
Keyword(s):  
Adhesion Strength ◽  
Production Systems ◽  
Low Cost ◽  
High Strength ◽  
Strength Properties ◽  
Research Purpose ◽  
Working Fluid ◽  
Gear Pump ◽  
Repair Service ◽  
Recovery Method

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.

scholarly journals Psychoacoustic Evaluation of Hydraulic Pumps

2021 ◽  
Vol 13 (13) ◽  
pp. 7320
Author(s):  
Tobias Pietrzyk ◽  
Markus Georgi ◽  
Sabine Schlittmeier ◽  
Katharina Schmitz
Keyword(s):  
Sound Pressure ◽  
Paired Comparison ◽  
Hydraulic Drive ◽  
Operating Parameter ◽  
Gear Pump ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Listening Tests ◽  
Internal Gear ◽  
Axial Piston

In this study, sound measurements of an axial piston pump and an internal gear pump were performed and subjective pleasantness judgements were collected in listening tests (to analyze the subjective pleasantness), which could be seen as the inverse of the subjective annoyance of hydraulic drives. Pumps are the dominant sound source in hydraulic systems. The noise generation of displacement machines is subject of current research. However, in this research only the sound pressure level (SPL) was considered. Psychoacoustic metrics give new possibilities to analyze the sound of hydraulic drive technology and to improve the sound quality. For this purpose, instrumental measurements of the acoustic and psychoacoustic parameters are evaluated for both pump types. The recorded sounds are played back to the participants in listening tests. Participants evaluate them regarding the subjective pleasantness by means of paired comparison, which is an indirect scaling method. The dependence of the subjective pleasantness on speed and pressure was analyzed for both pump types. Different regression analyses were carried out to predict the subjectively perceived pleasantness or annoyance of the pumps. Results show that a lower speed is the decisive operating parameter for reducing both the SPL and the annoyance of a hydraulic pump.

Calculation of a closed hydraulic volumetric system

2021 ◽  
pp. 27-30
Author(s):  
Keyword(s):  
Power Plant ◽  
Wind Power ◽  
Hydraulic System ◽  
Working Fluid ◽  
Wind Power Plant ◽  
Hydraulic Systems ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Oil Pump ◽  
Selection Of

An algorithm is proposed for calculating a closed volumetric hydraulic pump-hydraulic motor system using the example of the hydraulic system of a wind power plant, based on the calculation of the hydraulic systems of mobile machines. The main characteristics of the system components, the selection of initial data for the calculation, working fluid and diameters of hydraulic lines are analyzed. Keywords: hydraulic system, energy, fluid, oil, pump, motor, renewable energy source, wind power plant, machine. [email protected]

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