Effect of Design Changes in Railway Catenary-Pantograph Systems on Power Collection at High Speed

1968 ◽  
Vol 90 (4) ◽  
pp. 680-689
Author(s):  
R. T. Gray ◽  
S. Levy ◽  
J. A. Bain ◽  
E. J. Leclerc
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Operating Conditions ◽  
Department Of Transportation ◽  
High Speeds ◽  
Design Changes ◽  
Force Variation ◽  
Suitable System ◽  
The U.S

Using a GE-635 computer program developed for the U.S. Department of Transportation, a study has been made of the effect of changes in the catenary-pantograph system on the quality of power collection at high speeds. The study explored the effect of: (a) Sag between towers, (b) pantograph spacing, (c) stiffness of the tower support, (d) damping and stiffness of the pantograph, (e) stiffness of the contact spring, (f) dropper stiffness, (g) dropper spacing. It was found that all of these have a significant effect on the constancy of the contact force between catenary and pantograph. By proper choice of system constants, the contact force variation can be substantially reduced. A basis is provided for selecting suitable system constants for a given range of operating conditions.

Computer Evaluation of Controlled Pantographs for Current Collection From Simple Catenary Overhead Equipment at High Speed

1983 ◽  
Vol 105 (4) ◽  
pp. 287-294 ◽  
Author(s):  
T. Vinayagalingam
Keyword(s):  
Contact Force ◽  
High Speed ◽  
Overhead Line ◽  
Combined System ◽  
Current Collection ◽  
Constant Height ◽  
Force Profile ◽  
Force Variation ◽  
Computer Simulation Technique

A digital computer simulation technique is used to study the effects of changing pantograph characteristics upon the quality of current collection from simple catenary overhead equipment at high speed. In particular, the likely benefits to be derived by the use of controlled pantographs are assessed. Pantograph performance is judged on the basis of contact force variation and displacement responses of pantograph and contact wire. These studies have shown that the dynamic displacements of the combined system are determined primarily by the overhead line parameters rather than by the pantograph. At higher speeds droppers in the vicinity of the pantograph slacken and this is seen to influence significantly the contact force profile. On a “constant height” overhead line, the proposed “frame compensated” and “panhead inertia compensated” pantographs do not show any marked improvement in the quality of current collection.

Анализ параметров ультразвуковых сигналов при высокоскоростном контроле рельсов

2021 ◽  
Vol 3 ◽  
pp. 3-16
Author(s):  
А.А. Марков ◽  
Е.А. Максимова
Keyword(s):  
High Speed ◽  
Flaw Detection ◽  
Scanning Speed ◽  
Integral Parameter ◽  
Destructive Testing ◽  
Detection Systems ◽  
High Speeds ◽  
Bolt Holes ◽  
Non Destructive

The results of studies of changes in the parameters of ultrasonic (US) signals with an increase in the speed of rail testing are presented. Signals from rail bolt holes were selected as test reflectors. It is shown that the holes closest to the rail joint are not fully sounded, and the signals from them cannot be used as test reflectors. For a full assessment of the decrease in the quality of non-destructive testing of rails with an increase in the scanning speed, it is proposed to use the integral parameter of the analyzed reflector. A noticeable decrease in this parameter at high speeds requires a trade-off when choosing between productivity and quality rail testing. The proposed technique can be used to assess the efficiency of operating and newly created flaw detection systems. The necessity of improving the methods of sounding the first bolt holes of joints and correcting regulatory documents for high-speed testing of rails is substantiated.

Prevention of Material Deterioration in ECM of Sintered Carbide with Iron Ions

2017 ◽  
Vol 11 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Akihiro Goto ◽  
◽  
Atsushi Nakata ◽  
Sicong Wang ◽  
Nagao Saito ◽  
...  
Keyword(s):  
High Speed ◽  
Electrochemical Machining ◽  
High Speed Machining ◽  
Conductive Liquid ◽  
Sintered Carbide ◽  
High Speeds ◽  
Quality Degradation ◽  
Fe Ions ◽  
Electrical Source

This study focuses on electrochemical machining as a method of processing sintered carbide at high speeds. Previous studies have suggested the possibility of using electrochemical machining to achieve high-speed machining of sintered carbide. However, there has been strong resistance in industry against bringing sintered carbide into contact with a conductive liquid. This is because the material quality of sintered carbide is degraded by the elution of Co when it is brought into contact with a conductive liquid.In previous reports, the authors have shown that it is possible to control two modes of Co elution occurring during electrochemical machining: the elution from sintered carbide when it comes into contact with an electrolyte, and the selective elution of Co due to difference in the speeds of WC dissolution and elution of Co when sintered carbide is connected to an electrical source for processing. It was shown that it is possible to control the elution Co in sintered carbide when it comes into contact with an electrolyte by adding Co ions to the electrolyte to increase the concentration of Co ion, and that it is possible to prevent the excessive elution of Co by using a bipolar electrical source for machining. Although we showed that it is possible to carry out electrochemical machining of sintered carbide without degrading its quality, adding of large amounts of Co ions to the electrolyte entails a high cost. In this report, therefore, we describe the addition of Fe ions instead of Co ions to perform electrochemical machining of sintered carbide without quality degradation.

Active Control of a High-Speed Pantograph

1997 ◽  
Vol 119 (1) ◽  
pp. 1-4 ◽  
Author(s):  
D. N. O’Connor ◽  
S. D. Eppinger ◽  
W. P. Seering ◽  
D. N. Wormley
Keyword(s):  
Dynamic Model ◽  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
High Speed Train ◽  
Single Measurement ◽  
Force Variation ◽  
Catenary System ◽  
And Performance ◽  
And Control

The design and performance of an active controller for a pantograph which collects current for a high-speed train are considered. A dynamic model of the pantograph/catenary system is described and control objectives are established. A design which incorporates a frame-actuated controller and requires only a single measurement is described. Over an array of train speeds, the contact force variation with the actively controlled pantograph is 50 percent less than for the equivalent passive pantograph system.

Active Control of Fuzzy for High-Speed Pantograph

2012 ◽  
Vol 251 ◽  
pp. 158-163 ◽  
Author(s):  
Gang Yang ◽  
Zhong Mei Dai ◽  
Fu Li ◽  
Zheng Zhi Luo
Keyword(s):  
Active Control ◽  
Contact Force ◽  
High Speed ◽  
Fuzzy Controller ◽  
Current Collection ◽  
Maximum Value ◽  
Dynamic Performances ◽  
Catenary System ◽  
The Impact

The regular current collection is very important for high-speed train， and can be obviously improved by the use of active control. In order to study the impact of the fuzzy active control on pantograph-catenary system, the model ohe simulation model is created with the software of simulink. Finally the influences of fuzzy active control on dynamic performances and quality of current collection of the pantograph-catenary system are analyzed. It seems that, the performances of the system with or without active control is established, the fuzzy controller is constructed, and tf the pantograph- catenary system can be improved obviously under the fuzzy active control, the maximum value of the contact force is reduced to 50 percent, the minimum is increased to 80 percent, and the fluctuation extent of the contact force is reduced to 70 percent.

Angular Contact Ball Bearings: Track Position at High Speeds

1969 ◽  
Vol 184 (1) ◽  
pp. 351-370
Author(s):  
K. C. Falcon ◽  
C. Andrew
Keyword(s):  
High Speed ◽  
Contact Angles ◽  
Operating Conditions ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Test Rig ◽  
Outer Race ◽  
High Speeds ◽  
Surface Displacements ◽  
Lubricant Flow

The track position of the balls on the outer race of an angular contact bearing of the series and size used on the main shaft of aero gas turbine engines was measured in a test rig. The test rig was capable of simulating the operating conditions of the bearing with respect to axial load, inner race speed and high lubricant flow rates. The contact angle, defined by the track position, was deduced from the measurement of sub-surface displacements in the race using a number of small transducers embedded therein. The resulting contact angles were compared with values predicted from a number of unconfirmed theories in current use. At conditions of high speed and low load the correlation is poor; an over-estimation of the cage speed, arising from the false assumption that gross ball slip does not occur, gives rise to an over-estimation of the changes of contact angles from their nominal values.

scholarly journals DETERMINATION OF DYNAMIC LOADS IN TRANSMISSIONS TRACKED FOREST MACHINE WHILE OVERCOMING OBSTACLES

2017 ◽  
Vol 7 (1) ◽  
pp. 185-196
Author(s):  
Клубничкин ◽  
Vladislav Klubnichkin ◽  
Клубничкин ◽  
Evgeniy Klubnichkin ◽  
Бухтояров ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Dynamic Loads ◽  
Pilot Studies ◽  
Torque Transmission ◽  
Characteristic Species ◽  
Final Drive

The theoretical analysis of dynamic phenomena in transmission tracked forest machine is much more difficult in the absence of experimental data on the effects of the input characteristic of the machine. The most characteristic species in the transmission effects that arise under real operating conditions allow to evaluate the results of experimental studies, they also provide an opportunity to assess the quality of theoretical studies. To determine the loading of the transmission in the experiment involves the measurement of a number of kinematic and power parameters characterizing the speed and stress state of the transmission. In the course of the research used a special measuring equipment made in Germany includes the high-speed digital telemetry system for strain "TEL1-PCM-HS" company KMT. This article describes how to determine the dynamic load transmission elements tracked forest machine LZ-5 in overcoming individual barriers in experimental studies (tests). The paper presents a program of pilot studies tracked forest machine. Presented curves change the time settings on the final drives and cardan shaft, depending on the speed of the engine and drive sprockets in overcoming obstacles GLZM with different gears. histograms were constructed on the distribution of the torque transmission shafts for various modes of overcoming obstacles in order to analyze the influence of operational factors on the magnitude of dynamic loads. The article presents the distribution curve of the moments on the driven shaft final drive to overcome obstacles tracked forest machine with a pack assortments in the volume of 12m3. It was noted that there are no less than 20 times the dynamic point values, which exceed the estimated time for the overcoming of obstacles. From the studies that the transmission level of at least dynamic forces having height obstacles.

Fourth Paper: A New Design of Angular Contact Ball Race

1970 ◽  
Vol 185 (1) ◽  
pp. 382-393 ◽  
Author(s):  
D. J. Haines ◽  
M. J. Edmonds
Keyword(s):  
High Speed ◽  
Operating Conditions ◽  
Approximate Analysis ◽  
Full Extent ◽  
Operating Range ◽  
Contact Points ◽  
High Speeds ◽  
New Race ◽  
Outer Contact ◽  
Ball Motion

The work reported in the second and third papers revealed that under high speed operating conditions significant slide occurs at the contact points. The full extent of the present limitations became apparent in 1967 and led in that year to the new race design. In this design the balls contact the outer track at two points simultaneously instead of the conventional one point. An approximate analysis of race behaviour is presented which indicates that when the new bearing is driven from the inner track the ball motion is controlled at this track over most of the operating range. This fact and the retention of the inner, and the major outer contact positions, at points close to their static positions result in improvements in performance of up to 30 per cent at high speeds.

Application of Lund’s Stability Analysis Program in Design of Modern Turbomachinery

2003 ◽  
Vol 125 (4) ◽  
pp. 471-476 ◽  
Author(s):  
Pranabesh De Choudhury
Keyword(s):  
Stability Analysis ◽  
High Speed ◽  
Analytical Tool ◽  
Gas Pressure ◽  
Operating Conditions ◽  
Analysis Program ◽  
Gas Density ◽  
High Speeds ◽  
Design And Manufacture

The analytical tool developed by Lund has aided in the design and manufacture of modern turbomachinery operating at relatively high speeds, under severe operating conditions, with high gas pressure, and gas density. The purpose of this paper is to show, by means of selected problems, as a practicing engineer in the design of high speed turbomachinery, how the methods developed by Lund aided in the design and problem diagnostics of such turbomachinery.

PROBLEMS OF HIGH-SPEED RAIL FLAW DETECTION

2021 ◽  
pp. 16-25
Author(s):  
A. A. Markov ◽  
E. A. Maksimova
Keyword(s):  
Magnetic Flux ◽  
High Speed ◽  
Average Length ◽  
Flaw Detection ◽  
Scanning Speed ◽  
High Speeds ◽  
Acoustic Contact ◽  
Bolt Holes ◽  
Location Zone

The main factors that reduce the quality of non-destructive testing of rails during high-speed scanning are considered. The most significant factors are the quality and volume of obtaining primary information about the condition of the monitored rails. It is shown that, at high-speed (up to 120 km/h) control, the compression of the defect location zone is clearly manifested and the length of the areas with acoustic contact violations increases. Analysis of real flaw diagrams of diagnostic complexes shows that with an increase in the scanning speed, the length of the location zone even from such large reflectors in the rails, such as bolt holes, significantly decreases. The average length of the instability zone of the bottom signal over the welded joints of the rails also increases significantly. The compression of the location zones of the reflectors can be compensated by expanding the aperture of the ultrasonic transducers. Improving the quality of the acoustic contact requires further improvement of the design of the search system and the systems for supplying the contacting liquid to the transducers, depending on the scanning speed. The Magnetic Flux Leakage(MFL) method can effectively detect defects in the rail head up to 20 mm deep at high speeds. Mathematical modeling of the magnetic flux in the controlled rails is performed. This allows us to start creating a new rail magnetization system with an increased interpole distance for high speeds. The introduction of modern methods for processing a significant flow of flaw detection information using neural networks requires the formation of a large sample base of training signals from real defects in different sections of rails. This is a complex task in its own right. For the first time, the issues of checking the operability of flaw detection devices in real control conditions are raised. Testing of ultrasonic equipment at high speeds is proposed to be carried out with the help of special electronic-acoustic simulators of defects. They are installed on different surfaces of the rails on which the diagnostic complexes pass. Operational quality control of ultrasonic rail inspection can be evaluated by statistical analysis of signal parameters from structural elements (bolt holes). The choice between the monitoring performance and the required reliability of detecting rail defects must be made based on the results of real passes of diagnostic complexes at operating scanning speeds.

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