Research into the lubrication of a rotary lip seal using ferrofluid

2021 ◽  
pp. 135065012110537
Author(s):  
Marcin Szczęch
Keyword(s):  
Magnetic Fluid ◽  
Operating Pressure ◽  
Test Results ◽  
Friction Zone ◽  
Lip Seal ◽  
Term Operation ◽  
Lip Seals ◽  
The Magnetic Field ◽  
Lubrication Conditions

The paper presents the results of research into a hybrid seal which is a combination of standard rotary lip seals and a magnetic fluid seal. To maintain the magnetic fluid in the friction zone region, either a specially shaped pole piece was used or the shaft was modified accordingly. The research study concerns the allowable operating pressure and lubrication conditions in short-term and durability tests after which shaft wear was also assessed. Magnetic fluids with different rheological and magnetic properties were considered. The test results showed that the long-term operation of a hybrid seal is possible. The requirements, however, are the appropriate value of the magnetic field and dynamic viscosity of the magnetic fluid.

Research on the Improvement of OCT Used in Power System

2013 ◽  
Vol 385-386 ◽  
pp. 995-998
Author(s):  
Hong Peng He ◽  
Jun Liu
Keyword(s):  
Power System ◽  
Solenoid Coil ◽  
Broad Application ◽  
Term Operation ◽  
Current Transducer ◽  
Operation Stability ◽  
The Magnetic Field ◽  
Application Prospects ◽  
Optical Structure

Smart grid puts forward higher requirements for measurement equipments, so optical current transducer (OCT) used in power system possess broad application prospects. In this paper, magnetism gathering technology is applied in the design of OCTs optical structure and the magnetism gathering optical structure based on solenoid coil is proposed. Compared with traditional bulk optical structure, this structure simplifies the optical structure significantly. Results of simulation and field operation indicate that this structure can not only enhance the magnetic field created by the measured current significantly, but also improve the long-term operation stability of OCT.

scholarly journals Method to Evaluate the Resistance–Capacitance Voltage Divider and Uncertainty Analysis

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7744
Author(s):  
Yi Luo ◽  
Bin Guo ◽  
Bin Qian ◽  
Lijuan Xu ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Uncertainty Analysis ◽  
Measurement Errors ◽  
Measurement Accuracy ◽  
Dielectric Breakdown ◽  
Voltage Divider ◽  
Test Results ◽  
Term Operation ◽  
Economic Significance ◽  
Capacitance Voltage

The resistance and capacitance parameters of a resistance–capacitance divider may change due to factors such as long-term operation, internal insulation flashover, and dielectric breakdown, which will affect the measurement characteristics of the resistance–capacitance divider. Since it is difficult to separate the voltage divider, and because improper disassembly will damage the insulation of the equipment, measuring the resistance and capacitance parameters of a voltage divider non-destructively has always been a problem. In this paper, an indirect method for evaluating the resistance and capacitance parameters is proposed, and the uncertainty of measurement of this method is determined. Simulation and actual test results show that this method can be used to estimate the resistance–capacitance parameters and has a good level of measurement accuracy. Besides, through the uncertainty analysis, it is concluded that the proposed method can overcome measurement errors within a certain range and has high practicability. Finally, a very practical application scenario of the proposed method is given, showing that the proposed method has good economic significance.

scholarly journals КОЭФФИЦИЕНТЫ ДЕГРАДАЦИИ ПРОЧНОСТИ СИЛОВЫХ ЭЛЕМЕНТОВ КУПОЛА ПАРАШЮТА ПОСЛЕ ДЛИТЕЛЬНОЙ ЭКСПЛУАТАЦИИ ИЛИ ХРАНЕНИЯ

2019 ◽  
pp. 62-71
Author(s):  
Петр Александрович Фомичев ◽  
Игорь Михайлович Сила
Keyword(s):  
Service Life ◽  
Breaking Load ◽  
Strength Characteristics ◽  
Test Results ◽  
Structural Elements ◽  
Term Operation ◽  
Lower Confidence ◽  
Strength Tests ◽  
Normal Law

The technique of processing the test results to the destruction of samples cut from slings and dome fabric after prolonged use or storage of the parachute is described. The normal law of load distribution before failure is adopted.It is proposed to find the minimum breaking load as the lower confidence limit depending on the number of tested samples and a confidence probability of 0.99.The results of strength tests of samples from the parachutes of the landing D-5 series 2 of 1983, the spare Z-5 of 1984, and the rescue S-5K series 2 of 1989 are presented.A total of 301 samples were tested, including 54 samples from slings D-5, 48 samples from slings Z-5 and S-5K, samples from fabrics of domes on the base and weft. Samples from slings were cut out at the edge of the dome, in the middle, at the arc buckles.Fabric samples were cut radially from the top to the edge of the dome. The dependence of the strength characteristics on the location of the samples along the length of the slings or the dome panel has not been established.There are no gross errors in the tests according to the Grubbs criterion.The strength degradation coefficients of the slings and fabrics of the domes are determined as the ratio of the breaking load after long-term operation or storage to the initial values adopted during the design.The proximity of the degradation coefficients of slings and dome fabrics was noted. Based on the set of test results in order to obtain the minimum values of the degradation coefficients, a linear dependence on the life of the parachute is established.This period should be counted from the year the parachute was made.The dependence of the minimum degradation coefficients (maximum degradation) on the service life makes it possible to assess the drop in the strength characteristics of the structural elements with increasing service life. This dependence allows you to predict the maximum allowable landing speed when deciding on the extension of the life of the parachute.

The operation of radial lip seals in contaminated environments and the significance of the test rig design

2000 ◽  
Vol 214 (2) ◽  
pp. 167-178 ◽  
Author(s):  
K. W. Shore ◽  
F. R. Hall ◽  
J. M. Hampshire ◽  
G. D. Carnell
Keyword(s):  
Experimental Tests ◽  
Test Methods ◽  
Ball Bearings ◽  
Bearing Failure ◽  
Test Results ◽  
Data Logging ◽  
Test Rig ◽  
Lip Seal ◽  
Test Conditions ◽  
Lip Seals

The performance and basic rating life of rotating contact ball bearings have increased substantially over recent years, but the performance of radial lip seals, designed to protect these bearings against the ingress of contaminants, has not. In particular, the failure of the lip seals used to protect self-lubricating ball bearings has been identified as a major cause of bearing failure. To understand in detail the mechanisms of failure, these bearings and seals have to be assessed by performing carefully controlled experimental tests. As elastomeric lip seals are intrinsically sensitive to test conditions, their performance is often subject to statistical scatter. Therefore, the design of test rigs to carry out this research is vital so as to eliminate as many unwanted variables as possible. Typical test rigs and the usual tests previously carried out by the major bearing manufacturers are detailed, and the performance of both the test rigs and the seals are discussed. A new radial lip seal test rig, designed specifically for assessing seal performance is shown, and improved test methods and data logging are detailed. Typical lip seal test results are presented and analysed. The aim of this work is to characterize empirically lip seal behaviour under both contaminated and uncontaminated conditions, enabling a deeper understanding of lip seal performance to aid future improved lip seal designs to be formulated.

Second Generation Sodium Heat Pipe Receiver for a USAB V-160 Stirling Engine: Evaluation of On-Sun Test Results Using the Proposed IEA Guidelines and Analysis of Heat Pipe Damage

1997 ◽  
Vol 119 (4) ◽  
pp. 279-285 ◽  
Author(s):  
D. Laing ◽  
C. Tra¨bing
Keyword(s):  
Performance Evaluation ◽  
Heat Pipe ◽  
Second Generation ◽  
International Energy Agency ◽  
Test Results ◽  
Energy Agency ◽  
Term Operation ◽  
Sodium Heat Pipe ◽  
Absorber Surface

At the DLR a second generation sodium heat pipe receiver for the Schlaich Bergermann und Partner (SBP) 9-kWe dish/Stirling system has been developed and constructed. Long-term operation occurred from Oct. 1992 until Aug. 1993 at the Plataforma Solar de Almeria (PSA) in Spain, accumulating 950 operating hours. The performance of the SBP 9-kWe system with a sodium heat pipe receiver is evaluated according to the guidelines for dish/Stirling performance evaluation by Stine and Powel, as proposed to the International Energy Agency (IEA). Tests were stopped due to a leak in the receiver absorber surface. The analysis of this damage are reported.

scholarly journals Development of Small Vuilleumier Cooler for Space Use. Test Results of Long Term Operation.

1992 ◽  
Vol 27 (7) ◽  
pp. 563-570 ◽  
Author(s):  
Masakuni KAWADA ◽  
Shunsuke HOSOKAWA ◽  
Isao KUDO ◽  
Hideto YOSHIMURA
Keyword(s):  
Space Use ◽  
Test Results ◽  
Term Operation

Study on the Friction Characteristics of Different Lubrication Modes under Alternating Magnetic Field

2010 ◽  
Vol 455 ◽  
pp. 490-494 ◽  
Author(s):  
Hong Bin Liu ◽  
Ji Shun Li ◽  
Yu Jun Xue ◽  
Wei Ma
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Load Capacity ◽  
Expanded Graphite ◽  
Test Results ◽  
Friction Zone ◽  
Lubrication Performance ◽  
Lubricating Property ◽  
Alternating Magnetic Fields ◽  
Better Than

Magnetic fluid has many advantages when serving as lubricant. With an appropriate magnetic field this lubricant can prevent leakage and increase the load capacity of lubricant film. It can also be fixed at the friction zone by applying an external magnetic field. This paper aims to improve the lubrication performance of friction pairs under alternating magnetic fields. The test was conducted on a NG-x reciprocating friction tester. Test results using the magnetic fluid and those using expanded graphite were compared. The tribo-surfaces were obtained in real time. It is concluded that the magnetic fluid lubricant has better lubricating property than the nonmagnetic lubricant (expanded graphite) because it can cling on friction pairs uniformly, and the endurance magnetic fluid lubricant is better than that of nonmagnetic lubricant.

Test results of long term operation of the superfluid-cooled cryostat for a 1 GHz NMR spectrometer

2002 ◽  
Vol 12 (1) ◽  
pp. 1347-1350 ◽  
Author(s):  
S. Ito ◽  
T. Miki ◽  
M. Yoshikawa ◽  
A. Hamada ◽  
Y. Kawate ◽  
...  
Keyword(s):  
Test Results ◽  
Term Operation

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

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