Design & Study on CBZb2-Based External Gear Pump Optimum Clearance

2009 ◽  
Vol 628-629 ◽  
pp. 203-208
Author(s):  
Q. Wei ◽  
B.D. Jing ◽  
D.H. Bao ◽  
L.J. Yang
Keyword(s):  
Theoretical Calculations ◽  
Fluid Motion ◽  
Frictional Resistance ◽  
Friction Loss ◽  
Main Element ◽  
Gear Pump ◽  
Hydraulic Pump ◽  
Loss Analysis ◽  
Output Efficiency ◽  
And Performance

Hydraulic components are widely used in mechanical industry. To comply with the requirements of modern products for high quality and performance, hydraulic components are required to improve their own efficiency and controlling capability. The hydraulic pump, as a main element for energy conversion, exerts tremendous influence on the overall output efficiency of a product. The first is the energy loss analysis of a hydraulic pump, which is aimed to enable the pump to achieve a higher efficiency. Theoretical calculations may deviate to some extent from the experimental data as the equation of fluid motion is calculated based upon the ideal fluid; moreover, the leakage at the tooth meshing though at little amount, the friction loss between the shaft and its bearings, and the friction loss due to the meshing of gears were not considered during modeling. To determine the optimum clearance, it is necessary to take into account the workmanship factors, thermal expansion and contraction, frictional resistance, working conditions and any other factors as a whole. This was followed by obtaining the optimum clearance at the minimal power loss from the energy efficient perspective. These above-mentioned conclusions have some instructional significance over the design of the hydraulic pump.

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.

scholarly journals Control and Performance Analysis of a Digital Direct Hydraulic Cylinder Drive

2020 ◽  
Author(s):  
Niels H Pedersen ◽  
Per Johansen ◽  
Lasse Schmidt ◽  
Rudolf Scheidl ◽  
Torben O. Andersen
Keyword(s):  
Motor Unit ◽  
System Analysis ◽  
Hydraulic Cylinder ◽  
Controller Synthesis ◽  
Successful Implementation ◽  
Discrete Elements ◽  
Hydraulic Pump ◽  
And Performance ◽  
Feedback Control Strategy ◽  
Novel Concept

This paper concerns control of a digital direct hydraulic cylinder drive (D-DHCD) and is a novel concept with the potential to become the future solution for energy efficient hydraulic drives. The concept relies on direct control of a differential cylinder by a single hydraulic pump/motor unit connected to each cylinder inlet/outlet. The pump/motor unit in this research uses the digital displacement technology and comprises of numerous individually digital controlled pressure chambers, such that the ratio of active (motoring, pumping or idling) chambers determines the machine power throughput. This feature reduces energy losses to a minimum, since the inactive (idling) chambers has very low losses. A single DDM may provide individually load control for several cylinders without excessive throttling due to various load sizes. Successful implementation of the concept relies on proper control of the DDM, which demands a dynamical model that allows for system analysis and controller synthesis. This is a challenging task, due to the highly non-smooth machine behavior, comprising both non-linear continuous and discrete elements. This paper presents the first feedback control strategy for a D-DHCD concept, based on a discrete dynamical approximation and investigates the control performance in a mathematical simulation model representing the physical system.

scholarly journals Nanocrystalline Cellulose and Polyvinyl Alcohol Coating Application to Cardboard Packaging Papers and Investigation of the Effects on Paper Properties

2020 ◽  
Vol 26 (3) ◽  
pp. 317-322
Author(s):  
Semiha YENİDOĞAN
Keyword(s):  
Frictional Resistance ◽  
Light Sensitivity ◽  
Absorption Capacity ◽  
Nanocrystalline Cellulose ◽  
Surface Appearance ◽  
Paper Properties ◽  
Coating Application ◽  
And Performance ◽  
Water Absorbability ◽  
The Impact

In the packaging sector of the printing industry, different coating applications are tried and investigated in order to increase the surface appearance and performance characteristics of paper and cardboard. The printability, water and ink absorption capacity, frictional resistance, light sensitivity of the visual graphical design that are going to be printed on the packaging papers are some of them. In this study, different types of cardboards that are used as a packaging material were chosen and coated with nanocrystalline cellulose (NCC)/PVA at different rates (%). In order to determine effective and economical usage conditions, the coating solutions, at three different concentrations as 3 wt.%, 5 wt. %, 7 wt.%, were prepared. The coating was applied on the test papers, which were at the same weights (350 g/m2) and had different surface properties as matte glossy, bright glossy, American Bristol. NCC/PVA existence on the coated paper surface was confirmed with Fourier Transform Infrared Spectroscopy (ATR-FTIR). The impact of the coating, which was prepared at different concentrations, on the packaging materials was studied with respect to thickness, stiffness, water absorbability, contact angle and surface tension.

scholarly journals FLOW RESISTANCE DUE TO INTENSE BEDLOAD TRANSPORT

1984 ◽  
Vol 1 (19) ◽  
pp. 89
Author(s):  
Daniel M. Hanes
Keyword(s):  
Flow Resistance ◽  
Fluid Motion ◽  
Fixed Bed ◽  
Fluid Flows ◽  
Frictional Resistance ◽  
Bedload Transport ◽  
Local Pressure ◽  
Gradient Forces ◽  
Granular Fluid ◽  
Lift Off

When water flows over a stationary bed the fluid motion is retarded by both skin the friction and local pressure gradient forces related to the roughness of the bed. If the bed itself is composed of discreet movable grains, the boundary is less clearly defined and the dynamics poorly understood (see Gust and Southard, 1983). Owen (1964) proposed that saltating grains (grains which lift off the bed, move through the fluid, and fall back to the bed without colliding with other grains) have the effect of increasing the frictional resistance of the bottom. At higher flow stages, Hanes and Bowen (1984) have suggested a model for bedload transport which is based upon the dynamics of collisional grain flows following Bagnold (1954, 1956). In such a collision dominated flow, it appears that the resistance of the bed to the overlying flow can be less than the resistance of a fixed bed to the same overlying flow. This result is consistent with the dynamics of rapid granular-fluid flows, as will be discussed below.

scholarly journals Calibrations and Performance of the Airborne Cloud Extinction Probe

2014 ◽  
Vol 31 (2) ◽  
pp. 326-345 ◽  
Author(s):  
Alexei Korolev ◽  
Alex Shashkov ◽  
Howard Barker
Keyword(s):  
Crystal Surface ◽  
Theoretical Calculations ◽  
Light Attenuation ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Cloud Droplets ◽  
Fine Crystal ◽  
A New Technique ◽  
And Performance ◽  
Scattering Phase Function

Abstract A new airborne instrument that measures extinction coefficient β in clouds and precipitation has been designed by Environment Canada. The cloud extinction probe (CEP) utilizes the transmissometric method, which is based on direct measurement of light attenuation between the transmitter and receiver. Transmissometers are known to be susceptible to forward scattering, which becomes increasingly significant as the particle size increases. A new technique for calibrating transmissometers was developed here in order to determine the response function of the probe. Laboratory calibrations show that CEP-derived β may be underestimated by a factor of 2 for circular particles with diameters greater than 100 μm. Results for spherical particles are in good agreement with theoretical predictions. For nonspherical particles, however, estimates of β can deviate significantly from those derived for spheres that have the same projected area. For in situ observations of ice particles, CEP measurements often deviate significantly from theoretical calculations, whereas for small cloud droplets agreement is good. It is hypothesized that CEP-derived estimates of β for ice clouds depend much on variations in the scattering phase function that arise from details in ice crystal surface roughness and fine crystal structure. This would complicate greatly the estimation of β from transmissometers for ice-bearing clouds.

Theoretical calculations and performance results of a PZT thin film actuator

2003 ◽  
Vol 50 (10) ◽  
pp. 1240-1246 ◽  
Author(s):  
M. Hoffmann ◽  
H. Kuppers ◽  
T. Schneller ◽  
U. Bottger ◽  
U. Schnakenberg ◽  
...  
Keyword(s):  
Thin Film ◽  
Theoretical Calculations ◽  
Pzt Thin Film ◽  
And Performance ◽  
Performance Results

scholarly journals Methodology based on best practice rules to design a new-born trochoidal gear pump

2017 ◽  
Vol 232 (6) ◽  
pp. 1057-1068 ◽  
Author(s):  
PJ Gamez-Montero ◽  
R Castilla ◽  
E Codina
Keyword(s):  
Design Process ◽  
Best Practice ◽  
Research Work ◽  
Gear Pump ◽  
Selection Effects ◽  
Hydraulic Pump ◽  
Pump Design ◽  
Know How ◽  
New Born ◽  
Pump Construction

The trochoidal gear pump, also known as gerotor, owing to its remarkable advantages compared to other hydraulic pumps is chosen for many engineering applications. As each application is unique, the designer ought to be knowledgeable of the required specifications as a first task but need not be an expert in the hydraulic pump design. The review of the existing research reveals significant gaps to develop a new-born project and the work presented in this paper, drawn on existing research work and the authors’ own experience and know-how, aims to overcome them. The objective of the paper is then to provide a summary of the best practice rules to design a trochoidal gear pump from scratch achieving a thorough understanding. In the conceptual stage, making decisions come according to a predetermined set of four parameters known by the designer that will lead to the complete development of the trochoidal gear set. Afterwards, in the design process, the most important characteristics of the pump such as the porting, the pump construction, and the limitations are presented based on the significant explanations, with regard to each feature, selection, effects, and good practices. As a result, the methodology presented compiles the process of engineering in designing a new trochoidal gear pump as a catalogue of guidelines aiming to overcome a vague design due to a lack of knowledge. This collection of best practice rules intends to guide the designer to take good decisions early in the design process that limit design change later in the final stage—the prototype.

Compliances Calculation and Performance Analysis of the Novel Half Hybrid Flexure Hinge

2013 ◽  
Vol 303-306 ◽  
pp. 1714-1720 ◽  
Author(s):  
Qing Ling Liu
Keyword(s):  
Finite Element ◽  
Performance Analysis ◽  
Theoretical Calculations ◽  
Finite Element Simulations ◽  
Flexure Hinge ◽  
The Novel ◽  
Compact Structure ◽  
And Performance ◽  
The Right ◽  
Better Than

A novel flexure hinge named right circular corner filleted half hybrid flexure hinge was advanced. Based on the Castigliano second theorem, the compliance formulas of the novel flexure hinge were formulated. The theoretical calculations and the finite element simulations were performed simultaneously, the similar results were obtained which indicated the correctness of the compliance formulas. The influence of the geometric parameters of the novel flexure hinge on its performance was analysed. Compared with right circular corner filleted double hybrid flexure hinge, the compliance and sensitivity to the load of the novel half hybrid flexure hinge were better than that of the right circular corner filleted double hybrid flexure hinge. All of the above analysis results indicated the novel flexure hinge are more suitable for application in the compact structure and large displacement.

Analysis on Pre-Stressed Friction Loss in Bending Channel under Contact Pressure Non-Uniform Distribution Hypothesis

2011 ◽  
Vol 255-260 ◽  
pp. 49-53 ◽  
Author(s):  
Hai Qian Cheng ◽  
Qing Hua Cheng ◽  
Kai Yin Zhang
Keyword(s):  
Uniform Distribution ◽  
Contact Pressure ◽  
Frictional Resistance ◽  
Friction Loss ◽  
Positive Pressure ◽  
Distribution Law ◽  
Contact Conditions ◽  
Friction Resistance ◽  
Loss Formula ◽  
Distribution Assumption

The pre-stressed friction loss formula in bending channel recommended by Bridge Rules was based on the uniform distribution hypothesis of contact pressure. From some conflicts in application of the formula, the non-uniform distribution law of the contact pressure was revealed. On the basis of elastic contact analysis, two types of non-uniform distribution hypothesis were proposed, including cosine and second-degree parabola distribution. Then the contact positive pressure expressions were derived respectively and the frictional resistance was calculated to compare with the calculated value under the uniform distribution. The results indicate that the friction resistance under any non-uniform distribution of positive pressure is less than under the uniform distribution. So the uniform distribution assumption of contact pressure does not cause Bridge Specifications formula underestimate friction loss. It is necessary to do further research on the applicability of Coulomb’s law under the contact conditions in the curved channel.

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