Subject:
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Re: Scrapers
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Newsgroups:
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lugnet.technic
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Date:
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Mon, 12 Sep 2005 16:37:48 GMT
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Viewed:
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4076 times
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In lugnet.technic, Nathan Bell wrote:
> In lugnet.technic, Nathan Bell wrote:
> > In lugnet.technic, Ross Crawford wrote:
> > > In lugnet.technic, Nathan Bell wrote:
> > > > Does anyone know where I can find some good pictures/diagrams on how scrapers
> > > > work?
> > >
> > > I guess you can't really see the details in this pic:
> > > http://www.brickshelf.com/gallery/RoscoHead/construction/Micro/lil_scraper.jpg
> > > ;)
> > >
> > > There's a pretty good photo here:
> > > http://www.machinerytrader.com/listings/forsale/detail.asp?OHID=4976697&guid=22213E5C0EAA44BFA5CD2834E223FD2A
> > >
> > > And some others probably too if you poke around that site. The tub is raised and
> > > lowered using the vertical cylinders just behind the front wheels. Larger
> > > scrapers generally have 2 engines these days, one at each end. And as Mark said,
> > > most are generally engineered so as they can also be pushed by other equipment,
> > > including other scrapers, very helpful especially in slippery conditions, as a
> > > tracked vehicle pushing can get much more grip than a wheeled tractor.
> > >
> > > Unfortunately I don't know of any online diagrams, but it may be worth
> > > contacting a John Deere agent for datasheets and information. I've found they're
> > > usually happy to provide any info they have.
> > >
> > > ROSCO
> >
> > Thank you all for the pics. The one Rosco sent was the type I was looking for.
> > There are 2 types that I can see. One has a hollow tub in the middle and
> > collects the dirt. The other is basically the same thing but with
> > tread-mill-type blades in front of the tub. I already have the tread mill
> > created, but everything in between is what I need pics of. I took some
> > yesterday and might upload them to Brickshelf.
>
> I forgot to thank Mark Bellis and John Fors for their info yesterday.
>
> Which engine drives the rotating blades? Is one engine for hydraulics and one
> for driving the wheels? Or is one engine for the rear half and one for the
> front? Which engine performs which functions?
>
> This is what I have so far- not much at all. I have 10 engine pistons, and may
> put 6 in front and 4 in back.
>
> http://www.brickshelf.com/cgi-bin/gallery.cgi?f=145054
The front engine has an automatic gearbox to the front wheels. Less power is
needed in loose soils than in hard, compacted soils. I guess being such a big
machine, it has a proper control system, such that power to each axle is
controlled from each axle's engine with a combined traction control system.
The cut-away diagrams show the brakes, but looking at the picture I suspect
they're actually electric motors. The book says nothing about electric drive
though. The pictures show a large cylindrical blue unit over the front axle,
which could be a generator as the automatic gearbox arrow points somewhere else.
This is a kids' book! An electric drive system makes sense, since this machine
is 87 tons, less than a 130 ton diesel engine on rails, The drive to each wheel
can be controlled electrically for individual torque requirements buch more
simply than in a mechanical system, and also having wires between units is
easier and more reliable than thicker hydraulic pipes or direct mechanical drive
shafts.
I suspect the front engine has the power take-off for the hydraulics since it is
the more powerful one. A V16 is at the front with a tall radiator with 2 fans
arranged one above the other and a large exhaust stack. The front engine is
mostly in front of the front wheels. The rear engine isn't shown, but I suspect
a V8 or V12 - less powerful than the front engine but enough to drive the rear
wheels. There's no sign of an exhaust stack for that one.
I suggest a V6 in front and a V4 behind, since the front engine should be short
enough to sit in front of the wheels. The cab on this picture is to the left at
the front, over the front curve of the left wheel arch. There's an aircon unit
on top of it.
Mark
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Message has 1 Reply:
 | | Re: Scrapers
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| (...) Is it possible they have a hydraulic drive controlled by only one engine? When the scraper bends down in the middle, it shortens the distance between the front and rear wheels, and visa- versa. That would mean that the axles would be turning (...) (19 years ago, 13-Sep-05, to lugnet.technic)
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Message is in Reply To:
| | Re: Scrapers
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| (...) I forgot to thank Mark Bellis and John Fors for their info yesterday. Which engine drives the rotating blades? Is one engine for hydraulics and one for driving the wheels? Or is one engine for the rear half and one for the front? Which engine (...) (19 years ago, 12-Sep-05, to lugnet.technic)
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