Tribological Design of Machine Elements, Proceedings of the 15th Leeds-Lyon Symposium on Tribology held at Bodington Hall, The University of Leeds

1989 ◽  
Keyword(s):  
Machine Elements ◽  
The University

Optimized Cage Design for Increasing the Life of Solid Lubricated Roller Bearings

2012 ◽  
Author(s):  
Matthias Marquart ◽  
Bernd Sauer
Keyword(s):  
High Temperatures ◽  
High Vacuum ◽  
Roller Bearing ◽  
Solid Lubrication ◽  
Parameter Study ◽  
Outer Race ◽  
Roller Bearings ◽  
Weak Points ◽  
Machine Elements ◽  
The University

Roller bearings rank among the most used machine elements. Depending on the applications a lifetime of thousands of hours (e.g. machine tools: 15000h) can be realized as long as standard lubrications can be used. Nevertheless some applications only provide special environments, like high temperatures or vacuum, where oil or grease cannot be used. In these areas solid lubrication might be a choice. However solid lubricated roller bearing cannot offer similar lifetimes nor is a universally valid lifetime prediction available for such systems. Currently the friction work of a tribologically stressed surface offers a possibility for estimating the life. For doing so the paper gives an introduction. Further a test rig designed to examine roller bearings under high temperatures up to 300°C and high vacuum will be presented. In various experiments the influence of roller bearing cage design on its possible lifetime could be proven, especially if the cage has been used as a lubricant depot. On this basis a multibody simulation (mbs) model was built to get an understanding of the inner dynamics of roller bearings and its parts, e.g. rolling bodies and cage. While the geometry was built in commercial software the calculation of contacts, e.g. rolling body to raceway, and loads as well as friction is done in user written subroutines developed at the Institute of Machine Elements, Gears, and Transmissions at the University of Kaiserslautern. This model allows for an investigation of the effects resulting due to a parameter study of the geometry of the different parts a common roller bearing consists of: inner race, outer race, rolling bodies and cage. By using this tool the weak points in cage design could be determined as well as options for increasing the functionality of a cage as lubricant depot were shown. Combining experimental with simulated results, a new cage design for solid lubricated roller bearings could be developed. This new cage design increases the lifetime of the used test bearings from 2.5 million revolutions to more than 40 million revolutions. A further benefit of the new cage design is the ability to run at much higher rotational speeds than bearing systems that are available on the market nowadays.

Regular Student Feedback Concerning Education Quality - Good Practice To Follow

2014 ◽  
Vol 1 (1) ◽  
pp. 425-430
Author(s):  
Valentina Haralanova ◽  
Samir Khoshaba
Keyword(s):  
Higher Education ◽  
Good Practice ◽  
Student Feedback ◽  
Education Quality ◽  
European Universities ◽  
Engineering Department ◽  
Higher Education Quality ◽  
Machine Elements ◽  
The University ◽  
Survey Questionnaires

AbstractThis paper presents some of the experience of two European Universities concerning regular student feedback in the area of higher education quality, which is implemented at the end of every course of a particular subject. It also presents a comparison between survey questionnaires at Linnaeus University, Sweden in Machine Design courses, at the Mechanical Engineering Department, where such feedback has been applied during the last fifteen years, and the existing experience in the same field at the Department of Machine Sciences, Machine Elements, and Engineering Graphics at the University of Ruse, Bulgaria. Conclusions are made on the necessity of providing students with regular opportunity to take part in quality management in higher education.

Couplings and Clutches

2020 ◽  
Author(s):  
Boris Obsieger
Keyword(s):  
Problem Solving ◽  
Mechanical Engineering ◽  
Electrical Engineering ◽  
Engineering Practice ◽  
Practical Application ◽  
Calculation Methods ◽  
Naval Architecture ◽  
Lecture Notes ◽  
Machine Elements ◽  
The University

Textbook in machine elements at two universities. *** Published in two languages and several variants. *** Provides students of mechanical engineering, naval architecture and electrical engineering required literature, as well as a suitable problem-solving basis for experts in engineering practice. *** This book is divided into seven chapters which deal with ( 1-st) rigid couplings, (2-nd) compensating couplings, (3-rd) flexible couplings, (4-th) friction clutches, (5-th) electromagnetic friction clutches, (6-th) hydrodynamic couplings and (7-th) special types of couplings. *** A practical application is supported by detailed descriptions of designs variants, principles of operation and calculation methods, as well as through 227 figures, 74 tables and calculation examples of flexible couplings and friction clutches. *** This textbook is the result of continual improvements on the lecture notes Couplings and clutches, starting from 2001. The book has been reviewed by prominent experts from several universities, and upon their recommendations the Croatian edition of this book was adopted as a textbook of the University of Rijeka in 2005 and then translated into English. Both variants are adopted as university textbooks of the Juraj Dobrila University of Pula in 2020/2021.*** Finally, it must be emphasized that the purpose of this textbook, although amply illustrated and comprehensive, is not one of replacing lectures, but of helping students acquire knowledge that will serve them in building their future careers. *** More at "https://university-books.eu/obsieger/couplings".

Proceedings of The Modern Language Association of America

PMLA ◽  
1935 ◽  
Vol 50 (4) ◽  
pp. 1343-1343
Keyword(s):  
Modern Language Association ◽  
Modern Language ◽  
Local Committee ◽  
Tuesday Morning ◽  
University Of Cincinnati ◽  
The University ◽  
Plaza Hotel

The fifty-second meeting of the Modern Language Associationof America was held, on the invitation of the University of Cincinnati, at Cincinnati, Ohio, Monday, Tuesday, and Wednesday, December 30 and 31, 1935, and January 1, 1936. The Association headquarters were in the Netherland Plaza Hotel, where all meetings were held except those of Tuesday morning and afternoon. These took place at the University of Cincinnati. Registration cards at headquarters were signed by about 900, though a considerably larger number of members were in attendance. The Local Committee estimated the attendance at not less than 1400. This Committee consisted of Professor Frank W. Chandler, Chairman; Professor Edwin H. Zeydel; Professor Phillip Ogden; Mr. John J. Rowe (for the Directors); and Mr. Joseph S. Graydon (for the Alumni).

Spectrophotometric reductions with an IBM 1620

1966 ◽  
Vol 24 ◽  
pp. 116-117
Author(s):  
P.-I. Eriksson
Keyword(s):  
Astronomical Data ◽  
Spectrophotometric Data ◽  
Electronic Computers ◽  
The University ◽  
Near Future

Nowadays more and more of the reductions of astronomical data are made with electronic computers. As we in Uppsala have an IBM 1620 at the University, we have taken it to our help with reductions of spectrophotometric data. Here I will briefly explain how we use it now and how we want to use it in the near future.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

Production of New and Revised A.A.V.S.O. Charts

1979 ◽  
Vol 46 ◽  
pp. 368
Author(s):  
Clinton B. Ford
Keyword(s):  
Variable Star ◽  
Standard Form ◽  
Original Data ◽  
University Of Pennsylvania ◽  
Standard Format ◽  
Additional Information ◽  
The Gift ◽  
The University

A “new charts program” for the Americal Association of Variable Star Observers was instigated in 1966 via the gift to the Association of the complete variable star observing records, charts, photographs, etc. of the late Prof. Charles P. Olivier of the University of Pennsylvania (USA). Adequate material covering about 60 variables, not previously charted by the AAVSO, was included in this original data, and was suitably charted in reproducible standard format.Since 1966, much additional information has been assembled from other sources, three Catalogs have been issued which list the new or revised charts produced, and which specify how copies of same may be obtained. The latest such Catalog is dated June 1978, and lists 670 different charts covering a total of 611 variables none of which was charted in reproducible standard form previous to 1966.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Some Biological Applications of High Voltage Electron Microscopy

1974 ◽  
Vol 32 ◽  
pp. 298-299
Author(s):  
Hans Ris
Keyword(s):  
High Voltage ◽  
Chromosome Structure ◽  
Nerve Fibers ◽  
Good Resolution ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
University Of Wisconsin ◽  
High Voltage Electron ◽  
One Year ◽  
The University

The High Voltage Electron Microscope Laboratory at the University of Wisconsin has been in operation a little over one year. I would like to give a progress report about our experience with this new technique. The achievement of good resolution with thick specimens has been mainly exploited so far. A cold stage which will allow us to look at frozen specimens and a hydration stage are now being installed in our microscope. This will soon make it possible to study undehydrated specimens, a particularly exciting application of the high voltage microscope.Some of the problems studied at the Madison facility are: Structure of kinetoplast and flagella in trypanosomes (J. Paulin, U. of Georgia); growth cones of nerve fibers (R. Hannah, U. of Georgia Medical School); spiny dendrites in cerebellum of mouse (Scott and Guillery, Anatomy, U. of Wis.); spindle of baker's yeast (Joan Peterson, Madison) spindle of Haemanthus (A. Bajer, U. of Oregon, Eugene) chromosome structure (Hans Ris, U. of Wisconsin, Madison). Dr. Paulin and Dr. Hanna are reporting their work separately at this meeting and I shall therefore not discuss it here.

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