Connected between the flywheel and the continuously variable transmission of the Flybrid, mechanical KERS is an epicyclic gear system, the focus of this article.
Epicyclic gearing is a gear system that consists of one or more planet gears, rotating about a central sun gear. Typically, the planet gears are mounted on a movable arm or carrier which itself may rotate relative to the sun gear. Epicyclic gearing systems may also incorporate the use of Read more…
An engineer should not only have solid grounding in the fundamentals of his discipline but an interest in history too. A thorough understanding of the principles involved in product design is, I would have thought, an absolute necessity but an appreciation of all that has gone before is as equally valuable. So when other people are perhaps relaxing or enjoying the fruits of their labour I often prefer to saunter around some of the smaller transport museums in this land. On one occasion hidden behind a glass case I came Read more…
I guess you could say that the first decade of the 21st century, in the world of motor sport at least, were the years of the alternative fuels. Diesel (yes, we’re talking motor sports here), bio-ethanol, RME (rape methyl esters) and even CNG (compressed natural gas) have all been used during the decade for one kind of motor racing or another but there was one type of alternative fuel going back to the eighties and which didn’t quite make the headlines, for obvious reasons - and that was toluene. C7H8 to give it its Read more…
In previous articles on the subject of fasteners, we have dwelt very little on the subject of female threads, other than in the article talking of bespoke nuts. The other main situation where we will find female threads is where these have been machined into castings or into machined parts. Unless the rules forbid their use, it is likely that we will have chosen an aluminium block, or where we are designing bespoke parts, aluminium is a very popular material, either in its cast or wrought forms, owing to its low density. Where Read more…
In the previous RET Monitor article on the subject of exhaust insulation, we looked at plasma sprayed thermal barrier coatings for exhaust systems. In preceding articles, we have examined the reasons why thermal insulation of exhaust systems is necessary in certain applications, and advantageous in many others. An alternative to coating the exhaust system are the various types of thermally insulating wrappings, which may be in the form of a metallic ‘bag’ or ‘blanket’ or alternatively a refractory cloth, such as asbestos.
In a conventional multi-point port injected gasoline engine the fuel is introduced into the air stream in the form of a jet of liquid. Atomising into small droplets, these mix with the air, begin to vaporise and eventually get carried off past the intake valves and into the combustion chamber. In between, varying amounts of this fuel might condense on the wall, travel along it and eventually vaporise back into the air stream. However the presence of this fuel, often referred to as a ‘puddle’ can have a significant effect on Read more…
The most common type of engine dynamometer today used by engine builders the world over, must be the eddy current machine. But few will ever forget, of those who ever used them, the DPX water brake. Made by Froude in Worcester, England since shortly after the turn of the (20th) century, and once to be found gracing some out-of-the-way engine test facility at University, to many this would be their introduction to the subtle art of engine testing. Classed as a fluid friction device, resistance to the torque of the engine is offered by a combination of shaft bearing friction, Read more…
In the author’s article on the mitigation of stress concentration in critical areas of crankshafts last month (Crankshafts: Stress-concentration mitigation), we mentioned the 1943 paper by Matinaglia. Some of his findings are repeated in the books by C.F. Taylor, which, if you don’t have a copy of these, you would do well to avail yourself of. The paper by Matinaglia is worth reading but, having been published many decades ago in a trade journal, is not easy to get sight of.
In the case that you don’t have this article delivered to your inbox, I hope that the title has drawn you here either in the hope that you will find how to make your con rods smaller and lighter (in which case you may be disappointed) or because you disagree with the fundamental statement of the title.
Previous articles on the subject of con rods have talked about some of the material choices for these parts, and in the recent magazine Focus article on the subject of con rods, the author discussed the Read more…
There are a number of surface treatments which go under the generic term ‘phosphating’, but not all are used for the same purposes and equally not all will be potentially of use to us as engine designers or in specifying parts which will increase performance or reliability.
Phosphate is itself not a substance, but a negatively charged ion which may be found in solutions in a number of forms. The form which we might remember from chemistry (if we haven’t used selective recall to blank chemistry from our memory) is PO4, Read more…
