I've been reading that hydrostatic transmissions have a
"dynamic braking" aspect that sort of foregoes the need for normal brakes, like in a car.I've seen this design in skidders, small and huge loaders,
lawnmowers and stuff like that. They seem to all have an additional "parking brake" as, for instance on my machine
a big rod that slides into the chain sprockets on either side and blocks them, when I lift the seat bar. You don't apply this sort of brake while you're moving. Recent machines have a similar setup but the parking brake
is retracted hydraulically and will re-engage automatically
on loss of pressure. For those of us with seatbar-operated
parking brakes, lifting the seat bar at the right moment
could be a very important safety manoeuver ! There was a
short mention to this effect in the operator's manual. Which brings me to my question : I'd be interested in hearing
from those who have experienced (and survived :-) the loss of
hydraulic pressure to a piston pump-driven drivetrain. How does the machine behave ? I know that normal braking is done by the transmission, the machine coming to rest if the controls are centered or, more
quickly, if reversed. I also notice that my machine will creep slightly forward in neutral if I'm on a hill. I'm wondering if this dynamic braking provided by the hydrostatic transmission also works after losing pressure (for instance after the engine stalls or a hose ruptures or something) ? Does a machine come to a halt by itself or is it in a free-wheeling condition ? Can you effect any kind of steering or is the game over ? Just wondering, Paul PS for really nice animations of pumps in action
see>Link
and>Link http://www.bru-hyd.com/getriebm.e.htm
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