Jim Warman Posted May 22, 2010 Share Posted May 22, 2010 Furbling around the 'net, I stumbled across a few examples of engines using turbo-compound technology. Basically, these engines have a power recovery turbine or "blowdown" turbine fitted to the exhaust. These turbines recover energy that would normally be lost in the blowdown phase of the exhaust stroke (usually that part of the exhaust stroke before valve overlap) - the technology applies to both gas and diesel engines. Currently, Detroit Diesel and Scania both have engines with blowdown turbines connected to the crankshaft. Caterpillar is researching a combined power recovery turbine/turbocharger unit. The recovered power drives a motor/generator and can be used to power additional traction motors. Other manufacturers are also working on this technology. Part of what makes this so interesting is that turbo compound motors were first developed in the years following WW2 (that's 60 year old technology, boys and girls) and used quite extensively in aircraft. Diesel, gas - radial, inline. Many motors benefitted from the additional power made available with this technology. About 20% of enmgine output can be recovered - in the case of the Pratt & Whitney R-4360 (admittedly, that's 4362 cubic inches - not quite 72 liters), recovered power could be as high as 600 HP. Underhood real estate on modern vehicles is at a premium, even so, as we see advances in automotive applications, there is a very real chance that we may see this sort of technology applied to those vehicles we work on - if not in my lifetime, perhaps in yours. What might we see next? An electric crawler tractor? This gets good around 1:40.... Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted May 23, 2010 Share Posted May 23, 2010 That is really interesting jim. I work for cat and had no idea they were developing an electric drive dozer. On the ag side of our market, Agco has supposedly developed an electric drive ro-gator(self propelled sprayer). The current machines are hydrostatic drive with four hydraulic wheel motors. We have been told that it will probably never make in the u.s. market. Why not?????? the electric drive would be way better than our current system. The current system has a lot of parasitic loss that produces a significant amount of heat. Besides that I hate hydraulic oil, I would much rather work with wiring than oil. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted May 23, 2010 Share Posted May 23, 2010 Looks like there is some training in your future eh? Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted May 23, 2010 Author Share Posted May 23, 2010 In retrospect, I am nearly surprised that it took this long for them to visit the concept (or revisit as the case may be). We've had diesel-electrics for a long, long time.... railway locomotives, large earthmoving equipment (shovels, draglines, bucketwheel excavators). Some of the "new" stuff we see is actually old stuff that the available technology just couldn't support. Today, we have either improved technology and/or greater need. This is an exciting time to be involved in this industry. Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted May 25, 2010 Share Posted May 25, 2010 Could be...... I dontk work in the heavy shop so I wont have to learn the dozers. Would still be interesting to see how it all works though. I am curious to see what comes in the future. They are trying to come up with fuel economy standards for Medium and Heavy duty trucks now. I think is a good thing as long as they can meet the standards with out sacrificing reliability and durability in the engines. The future is looking to be very interesting. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted May 25, 2010 Author Share Posted May 25, 2010 "reliability and durability".... I read that with mixed emotions. 'Back in the day', we would see things that were "overbuilt". You could cook the piss out of the engine in the old mans Roadmaster, nail a curb hard with a front wheel or commit some other grievous error.... and nobody would be the wiser. Today, everything is "purpose built". You can run an engine hot, but overheating it will be devastating. Touch a curb and things will bend... Do anything outside the design envelope and it will cost you dearly. Some people will see this "do NOT drive it to destruction" edict as a lack of reliability. Personally, as long as you do not abuse a vehicle, I see them lasting longer than they ever did in years gone by. Quote Link to comment Share on other sites More sharing options...
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