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.

scholarly journals STUDY OF EFFECT OF SOLID CONTAMINANTS IN THE LUBRICANT ON BALL BEARINGS VIBRATION

2012 ◽  
pp. 28-31
Author(s):  
ONKAR L. MAHAJAN ◽  
ABHAY A. UTPAT
Keyword(s):  
Experimental Tests ◽  
Solid Particles ◽  
Particle Sizes ◽  
Ball Bearings ◽  
Bearing Failure ◽  
Mean Square ◽  
Rolling Bearings ◽  
Vibration Signals ◽  
Deep Groove ◽  
Concentration Levels

In deep groove ball bearings contamination of lubricant grease by solid particles is one of the main reason for early bearing failure. To deal with such problem, it is fundamental not only the use of reliable techniques concerning detection of solid contamination but also the investigation of the effects of certain contaminant characteristics on bearing performance. Nowadays the techniques such as vibration measurements are being increasingly used for on-time monitoring of machinery performance. The present work investigates the effect of lubricant contamination by solid particles on the dynamic behavior of rolling bearings, in order to determine the trends in the amounts of vibration affected by contamination in the Grease and by the bearing wear itself. Experimental tests are performed with Deep-groove ball bearings. The Dolomite powder in three concentration levels and different particle sizes was used to contaminate the grease. Vibration signals were analyzed in terms of Root Mean Square (RMS) values and also in terms of defect frequencies.

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.

Galling 50 , a Stochastic Measure of Galling Resistance

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Scott R. Hummel ◽  
Jeffrey Helm
Keyword(s):  
Stainless Steels ◽  
Test Methods ◽  
Reduction Technique ◽  
Test Results ◽  
Sigmoidal Function ◽  
Test Conditions ◽  
Stochastic Measure ◽  
Overall Performance ◽  
Data Reduction Technique ◽  
Applied Stresses

A new parameter called the Galling50 value is proposed to provide a statistically relevant measure of galling resistance. The Galling50 value represents the stress value where galling is expected to occur in 50% of the specimens tested. Galling50 is determined from the analysis of a series of tests that measure the probability of galling at different applied stresses. A method for graphically representing experimental galling data is presented. A sigmoidal function is used to mathematically represent the overall performance of the galling results. Similar to previous test methods, the proposed method provides a single parameter for reporting galling resistance results, making it suitable for comparison between different materials and test conditions. Test results for type 303, 304, and 316 stainless steels are given as an example of the testing and data reduction technique.

Study on the Characteristics of Elastic Wave Velocities of Rockmass under Different Test Methods

2012 ◽  
Vol 170-173 ◽  
pp. 449-452 ◽  
Author(s):  
Wu Xiu Ding ◽  
Hong Yi Wang ◽  
Bing Xie
Keyword(s):  
Elastic Wave ◽  
Influence Factors ◽  
Field Tests ◽  
Test Methods ◽  
Test Results ◽  
Penetration Test ◽  
Wave Velocities ◽  
Test Conditions ◽  
Study Results ◽  
Main Influence

There are many methods of testing elastic wave velocities of engineering rockmass such as the elastic wave penetration test between adits, elastic wave test on the adit wall and the borehole sonic method etc, but the test results vary with different test methods. It is important to understand and apply appropriately the test results. Based on the field tests, the characteristics of elastic wave velocities under different test methods are studied. The research indicates that the main influence factors of different test methods on wave velocities include the rockmass occurrence environments and the test conditions. For the elastic wave penetration test between adits, the rockmass occurrence environments are basically unchanged, and the influences of the test conditions are little, so the wave velocity obtained by this method is more scientific. The study results are important for the reasonable evaluation of engineering rockmass.

Analisa Pengujian Repeatability Timbangan Elektronik dengan Metode Syarat Teknis Timbangan Non Otomatis dan Metode NMI Australia

2019 ◽  
Vol 4 (2) ◽  
pp. 176-183
Author(s):  
Ponco Wali
Keyword(s):  
Research Method ◽  
Test Methods ◽  
Test Results ◽  
Repeat Testing ◽  
Testing Method ◽  
Technical Requirements

Testing repeat electronic scales with non-automatic scales technical requirements so far is fairly long if not using a calculator or computer. The aim of this research is to compare the repeatability testing method of electronic scales using methods according to the technical requirements of non-automatic scales and the Australian NMI method, both of which refer to OIML R76 in determining the validity or cancellation of electronic scales repeatability testing. This research method is done through repeat testing on 3 samples of electronic scales, then on each electronic scale 2 test methods are performed. The conclusion is that the electronic scales repeatability testing uses the non-automatic scales technical requirements method and the Australian NMI method has some differences although both refer to OIML R76. These differences include several points, namely the charge used, the method of adding additions, the formula for determining electronic scales, and different test results. The Australian NMI method is deemed to make it easier and more time efficient compared to the non-automatic weighing technical requirements method.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

scholarly journals Methodology for Selecting the Operating Conditions of a Vibration Generator Used in the Hot-Dip Galvanizing Process

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2042
Author(s):  
Wojciech Kacalak ◽  
Igor Maciejewski ◽  
Dariusz Lipiński ◽  
Błażej Bałasz
Keyword(s):  
Simulation Model ◽  
Asynchronous Motor ◽  
Experimental Tests ◽  
Suspension System ◽  
Operating Conditions ◽  
Test Results ◽  
Forced Simulation

A simulation model and the results of experimental tests of a vibration generator in applications for the hot-dip galvanizing process are presented. The parameters of the work of the asynchronous motor forcing the system vibrations were determined, as well as the degree of unbalance enabling the vibrations of galvanized elements weighing up to 500 kg to be forced. Simulation and experimental tests of the designed and then constructed vibration generator were carried out at different intensities of the unbalanced rotating mass of the motor. Based on the obtained test results, the generator operating conditions were determined at which the highest values of the amplitude of vibrations transmitted through the suspension system to the galvanized elements were obtained.

scholarly journals Evaluation of Bleeding Resistance in Chip Seal and Asphalt Emulsion Residue Rheology

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong
Keyword(s):  
Influence Factors ◽  
Application Rate ◽  
Test Methods ◽  
Test Results ◽  
Asphalt Emulsion ◽  
Aggregate Gradation ◽  
Factors Affecting ◽  
Promising Tool ◽  
Chip Seal ◽  
Asphalt Emulsions

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.

Shock Test and Acceleration Analysis Methods of Marine Diesel Engines to Underwater Explosions

2013 ◽  
Vol 345 ◽  
pp. 64-67
Author(s):  
Jian Hua Zhao ◽  
Rui Bo Zhang ◽  
De Bin Zhu ◽  
Hong Bin Gao
Keyword(s):  
Diesel Engine ◽  
Low Frequency ◽  
Vibration Signal ◽  
Test Methods ◽  
Shock Acceleration ◽  
Test Results ◽  
Shock Test ◽  
Marine Diesel ◽  
Reduction Methods ◽  
Acceleration Analysis

Shock test of marine diesel engine is the important content for ship anti-shock research. Plentiful shock tests of equipments have been carried out abroad, but there is no detailed test methods of diesel engine. According to simulation results, 8-channel acceleration test points are determined. Because diesel engine is working, the measured shock acceleration is interfered by vibration signal. Orthogonal wavelet decomposition and wavelet noise reduction methods are used to separate shock component from test results. The seperated shock component consists of two parts. One is the low-frequency part caused by the shock from diesel foundation and then attenuation through the isolator, the other is the high-frequency part caused by the secondary shock of the retainer.

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