Tribometer designed for train wheel/rail studies Currently under construction at NRC's Western Laboratory in Vancouver is a tribometer which will be used to measure frictional characteristics both between train wheels and rails in the field and between pairs of discs in various laboratory simulation experiments. The instrument is required mainly for experimental determination of interfacial contact creepage and traction characteristics, including limiting adhesion, for non-Coulomb friction conditions. Such conditions are typical of the rail/wheel interface which has been contaminated by flange lubricating grease and other inadvertently introduced contaminants. These materials affect not only the mode and extent of wear of the wheels and rails but also the rail/wheel forces and, ultimately, the dynamic stability and curving ability of railway vehicles.
The laboratory version of the instrument will use only the measuring wheel. Attachment of another disc, driven by a variable speed motor and pressed into contact with the measuring wheel by a loading device will allow measurements to be made related not only to rail/wheel systems but to other rolling-sliding devices such as gears or traction drives also. It is hoped that a laboratory prototype of this
versatile tribometer will be operational by mid-1984 and Tribology lnternationa will be publishing further details and the first results after proving trials have taken place.
on a rigid heavy-gauge open fronted aluminium frame. The frame is designed to accept an extension to carry a lubrication transfer pump when necessary, although a four-gallon oil reservoir is also a standard extra fitting.
layout of controlled systems. As elsewhere, the use of the computer as an aid in the design, development and manufacture of components and systems is becoming increasingly common.
J. Kalousek, National Research Council, Division of Mechanical Engineering, 3904 West 4th Avenue, Vancouver, BC, V6R 1P5, Canada
In the field version of the tribometer (illustrated), one wheel will measure traction forces and the other (reference) wheel will monitor the 'free-rolling' velocity. The measuring wheel can be braked, misaligned in yaw by -+ 3 ° or tilted by +- 30 ° to generate spin. Full instrumentation will provide measurement of vertical and lateral loads, torque and spin moments acting on the measuring wheel and provide plots of various combinations of these parameters. Both the tribometer operation and data recording instrumentation will be controlled by a microcomputer.
Airless spray system All of the components requited for art airless spray lubrication System, with the exception of the nozzles, have been concentrated into one compact module in the PresSpray Breadboard. At the heart of every PresSpray system is the ejector which draws lubricant from either a reservoir or pump supply and ejects it to the nozzles at the correct velocity to form an efficient air-less spray. There are eighteen ejectors available to match production requirements precisely through a choice of six different capacity nozzles. All of the components are assembled
Indicum Limited, Unit 13, Thorpe Way, Overthorpe Industrial Estate, Banbury, Oxon OX16 8SP, UK
cad of high pressure hydraulics Increasing value is being placed on the knowledge of the dynamic behaviour of individual elements of high pressure hydraulic systems as well as on the
'Computer aided design in high pressure hydraulic systems' is a collection of case studies and research reports which has been published by MEP. It costs £18.00 in the UK, £23.00 elsewhere, Mechanical Engineering Publications Ltd, PO Box 24, Northgate Avenue, Bury St Edmunds, Suffolk IP32 6BW, UK
April 84 Vol 17 No 2