Experimental Study on Critical Design of Electro-Hydrostatic Actuators Small in Size and Light in Weight

2020 ◽  
Vol 32 (5) ◽  
pp. 911-922
Author(s):  
Mitsuo Komagata ◽  
Tianyi Ko ◽  
Ko Yamamoto ◽  
Yoshihiko Nakamura ◽  
◽  
...  
Keyword(s):  
Experimental Study ◽  
Theoretical Investigation ◽  
High Reliability ◽  
Viscous Friction ◽  
Human Environment ◽  
Critical Design ◽  
Involute Gear ◽  
Actuation Systems ◽  
Current Systems

Actuation systems for robots and other machines used in critical applications is an area that requires further research. In such applications, a machine works in a human environment and physically interacts with humans. Reliability and backdrivability are still insufficient in current systems. An electro-hydrostatic actuator has the potential advantage of high reliability by nature and high backdrivability in mechanical simplexity when it is designed to be small and light. This study provides a theoretical investigation of the methods for evaluating internal leaks and other mechanical losses, such as Coulomb and viscous friction, and experimentally evaluates two types (trochoid and involute gear) of prototyped hydraulic pumps.

Study of Fault Self-Recovery and Seal Improvement for Centrifugal Compressor

2010 ◽  
Author(s):  
Weimin Wang ◽  
Jinji Gao ◽  
Yan Li ◽  
Shuangxi Li
Keyword(s):  
Experimental Study ◽  
Centrifugal Compressor ◽  
Thrust Bearing ◽  
Mechanical Performance ◽  
High Reliability ◽  
Relevant Information ◽  
Axial Displacement ◽  
Oil Film ◽  
Dry Gas Seal ◽  
Low Leakage

For centrifugal compressor, discharge or suction pressure variations due to process fluctuations or balance drum seal degradation can result in rotor thrust increasing which may jeopardize thrust bearing and compressor’s reliability. Also, the leakage flow through balance drum seal can seriously affect the efficiency of compressor. Summarizing the characteristic of axial displacement fault about centrifugal compressor and analyzing the mechanical performance of tilt pads thrust bearing, theory of axial displacement fault self-recovery is presented and realized through experimental study. The method presented in this paper monitors the stiffness of oil film and identifies the reason of axial displacement increasing. Also the low leakage feature of Dry-Gas-Seal (DGS), high reliability of labyrinth, and the feasibility of upgrading existing structure are taken into account at the same time to design a combined labyrinth-dry gas seal system on the balancing drum. Based on the combined seal system, a Fault Self-Recovering (FSR) mechanism for the fault of rotor axial displacement is introduced to assure the minimum oil film thickness was ensured in real time. The modern Computational Fluid Dynamics (CFD) and experimental study were used to validate this concept. The result and relevant information indicate that the method can realize axial displacement fault self-recovering effectively and the combined sealing system could improve the efficiency of the centrifugal compressor about four percent.

Design and Experimental Study a Logging Instrument with Dual Channel and Two-Way Hydraulic Control Valve

2011 ◽  
Vol 341-342 ◽  
pp. 848-853 ◽  
Author(s):  
Min Qiang Dai ◽  
Sheng Dun Zhao ◽  
Xiao Mei Yuan
Keyword(s):  
Experimental Study ◽  
High Reliability ◽  
Control Valve ◽  
Process Equipment ◽  
Hydraulic Control ◽  
Work Requirements ◽  
Experimental Platform ◽  
Dual Channel ◽  
Actual Service ◽  
Working Principle

The paper introduces the working principle of a logging instrument, and according to the working principle and instrument’s function of two-way hydraulic control valve. Facing to the key problems of process equipment in the actual service and workflow, the structure of value was designed and optimized. At the same time, the logging instrument with a dual-channel and two-way hydraulic control valve is designed and processed. Meanwhile, we build an experimental platform and make the experiment according to principle of the instrument. The results show that the design of this dual-channel and two-way hydraulic control valve logging instrument met the work requirements, and it has high reliability in oil exploration, which could be promoted and used in logging areas.

Experimental Study of Flow Rate and its Ripple of a Cosine Gear Pump

2012 ◽  
Vol 220-223 ◽  
pp. 661-664
Author(s):  
Hua Rong Hu ◽  
Jian Wang
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Gear Pump ◽  
Testing Platform ◽  
Flow Ripple ◽  
Involute Gear ◽  
Small Flow ◽  
Design And Application

According to the standard,The testing platform of the cosine gear pump is designed and the theory proves to be correct through experiment. Namely the cosine gear pump has an advantage of big flow rate and small flow ripple in comparison with involute gear pump under the same parameters. The results may provide a basis for the cosine gear pump in the design and application.

scholarly journals The wave-making resistance of ships: a theoretical and practical analysis

1909 ◽  
Vol 82 (554) ◽  
pp. 276-300 ◽  
Keyword(s):  
Experimental Study ◽  
Theoretical Investigation ◽  
Frictional Coefficient ◽  
Frictional Resistance ◽  
Total Resistance ◽  
Forward Motion ◽  
Practical Analysis ◽  
Hydrodynamical Theory

The theoretical investigation of the total resistance to the forward motion of a ship is usually simplified by regarding it as the sum of certain independent terms such as the frictional, wave-makings and eddy-making resistances. The experimental study of frictional resistance leads to a formula of the type. R s =ƒSV m , (1) where S is the wetted surface, V the speed,ƒ a frictional coefficient, and m an index whose value is about 1.83. After deducting from the total resistance the frictional part calculated from a suitable formula of this kind, the remainder is called the residuary resistance. Of this the wave-making resistance is the most important part; the present paper is limited to the study of wave-making resistance, and chiefly its variation with the speed of the ship. The hydrodynamical theory as it stands at present may be stated briefly.

scholarly journals The diurnal variation of terrestrial magnetism

1914 ◽  
Vol 89 (612) ◽  
pp. 379-392 ◽  
Keyword(s):  
Experimental Study ◽  
Diurnal Variation ◽  
Observational Data ◽  
Theoretical Investigation ◽  
Small Degree ◽  
Law And Order ◽  
Terrestrial Magnetism ◽  
The Earth ◽  
Reasonable Proportion ◽  
The Subject

The diurnal variation of terrestrial magnetism has been the subject of experimental study for many years, and at a considerable number of observatories scattered all over the earth. But the co-ordination of the results, and the theoretical investigation of the physical cause or causes of the phenomena, have not made progress which seems to bear a reasonable proportion to the vast amount of observational data that has accumulated. As far as I know, Dr. Arthur Schuster’s memoirs constitute the most inspiring and systematic attempt to reduce this matter to scientific law and order. Although I have found it convenient to depart from the method pursued by Schuster, this change of procedure was in no small degree suggested by various remarks in his memoirs.

scholarly journals A REVIEW OF EXPERIMENTAL STUDY OF PV SYSTEM AND PEDAL POWER WITH GRID

2020 ◽  
Vol 3 (4) ◽  
pp. 31-34
Author(s):  
Priyanka Verma ◽  
A.K. Sharma
Keyword(s):  
Experimental Study ◽  
Energy Conversion ◽  
High Reliability ◽  
Photovoltaic Effect ◽  
Electrical Energy ◽  
Pv System ◽  
Short Time ◽  
Design And Application

Through the photovoltaic effect the energy contained in the sunlight can be converted directly into electrical energy. This method of energy conversion presents some advantages, such as: Its modular characteristic offers large flexibility in the design and application of this kind of energy generator. Short time of installation and operation. High reliability, and low maintenance.

scholarly journals Current systems biology approaches in hazard assessment of nanoparticles

2015 ◽  
Author(s):  
Friederike Ehrhart ◽  
Chris Evelo ◽  
Egon Willighagen
Keyword(s):  
Systems Biology ◽  
Hazard Assessment ◽  
Low Dose ◽  
Bulk Material ◽  
Common Knowledge ◽  
Biological Systems ◽  
Consumer Products ◽  
Human Environment ◽  
Current Systems ◽  
Nano Size

The amount of nanoparticles (NPs) in human environment is increasing. The main sources are the increased introduction in consumer products and air pollution (diesel exhaust). It is meanwhile common knowledge that NPs behave differently as bulk material because of their nano-size. This leads in general to a higher reactivity and some other changed properties, e.g. solubility, surface potential, conductivity, and, to different effects on biological systems. The main impacts of NPs on a cellular and organism level are meanwhile well known: release of toxic ions, increased oxidative stress, and inflammation. Beside these, there is increasing evidence that NPs, especially in low dose/long exposure scenarios, affect biological systems in a broader way, interact with drugs, and exacerbate the effects of diseases. To investigate these effects systems biology approaches are the method of choice. This review summarizes the state of the art of nanoparticle effects on cells and organisms and demonstrate the add value of systems biology investigations to NP hazard assessment.

Improvement of PEFC Cell Performance With a Movable Rib

2011 ◽  
Author(s):  
Hirofumi Tanigawa ◽  
Ryoji Hakataya ◽  
Takaharu Tsuruta
Keyword(s):  
Water Management ◽  
Experimental Study ◽  
High Performance ◽  
High Reliability ◽  
Cell Performance ◽  
Water Behavior ◽  
Control Water ◽  
Better Than

Water management is very important in the development of the PEFC with high performance and high reliability. We found that the moisturizing effect in the straight-type channel is marked as compared with the serpentine-type channels, and the draining performance in the serpentine-type channel is better than that in the straight-type channel. Then, we have developed the movable rib which can change the position of the rib manually. Experimental study shows that the movable rib can control water behavior and can improve the cell performance.

The Simulation and Experimental Study of Metal Cutting Based on Cold Air Technology

2011 ◽  
Vol 189-193 ◽  
pp. 242-247
Author(s):  
Qiong Lin ◽  
Zhen Xiang Zhang ◽  
Qiu Cheng Wang
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Metal Cutting ◽  
High Reliability ◽  
Fem Simulation ◽  
Green Manufacturing ◽  
Cold Air ◽  
Novel Approach ◽  
Green Manufacturing Technology

Metal Cutting based on cold air technology is a green manufacturing technology which has the potential of great application prospect. In order to study the influence of cold air technology on metal cutting characteristics, the experiment and FEM simulation of both 0Cr18Ni9 stainless steel and 45 steel were performed under three cutting conditions. The results are analyzed to reveal that with cold air technology the temperature of cutting area can be effectively reduced and the tool life, surface roughness and the shape of chip can be significantly improved. The study on metal cutting with cold air technology based on simulation has a relatively high reliability, which provides a novel approach for the research on metal cutting with cold air technology.

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