J
John Larkin
Guest
On Tue, 05 Apr 2011 21:57:53 -0700, TheQuickBrownFox
<thequickbrownfox@overthelazydog.org> wrote:
air injection into the cylinders, and have no external starters.
John
<thequickbrownfox@overthelazydog.org> wrote:
I meant _big_ diesels, thousands of HP. They usually start by directOn Tue, 05 Apr 2011 20:03:56 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:
On Tue, 05 Apr 2011 17:53:28 -0700, TheQuickBrownFox
thequickbrownfox@overthelazydog.org> wrote:
On Tue, 05 Apr 2011 17:06:56 -0400, "Michael A. Terrell"
mike.terrell@earthlink.net> wrote:
John Larkin wrote:
Aren't some big diesels started with compressed air?
An electric powered compressor is used to turn them over, in place of
a small 'pony motor'.
You couldn't be more incorrect.
Compressed air, built up into a surge tank, gets fed into an AIR MOTOR,
which is what turns the flywheel of da big rig engine.
Wrong, as always. Big diesels, like marine engines and big generators,
are started by injecting air directly into the cylinders.
http://en.wikipedia.org/wiki/Air-start_system
I've seen this done on ships. They start almost instantly. Vrooom!
Why add external starter motors when all those huge pistons are
already on the crankshaft?
John
Busses, tractors ('18 wheelers'), etc. That class of 'big' diesel.
Instead of the starter motor WE see on OUR engines, THEY have an air
motor, mounted right on the flywheel perimeter, yielding the most torque
on the crank possible externally applied. They have BIG flywheels.
Direct cylinder injection (of pressurized air) is used to ASSIST or
give that primary kick, when it is on these engines, and it only usually
involves 1 or 2 cylinders, The air motor is what cranks the shaft and it
is in the same location and the same form factor that an electric starter
motor would be.
air injection into the cylinders, and have no external starters.
John