HST Engine braking

B

bczoom

Guest
OK, I saw this on another forum where we discuss the Kubota RTV (which has a HST transmission)

The poster is looking for a description on how HST engine braking works. I've got the concept down but having difficulty putting into words that make sense.

Here's the post. Can anyone provide me/us a good description?

It was asked, does the engine do the braking on the RTV coming to a stop. Or is it really the hydro-transmission. I know we all call it a engine brake. But, really, what will be the right answer to tell 'em folks who ask.

I explained to them how the " Jake" brake, or engine brake works on our Peterbuilts. Or compression release engine brakes. They still look at me with doubt. And the statement then comes in to the effect of, " ok, well how does it work on the hydro-transmisson. " Confused [*-)]

The questions has been asked from several local folks, and then, read it on another site .......
Edit/Delete Message
 

Mark777

Member
bczoom,

Having never really torn down an HST, I believe the source for braking comes from fluid back pressure applied to the valve body, and through the "Swawhplate" - which slows down, or stops all forward/reverse momentum.

Actually in the instance of forward-reverse and stopping power it's all provided by the pump pressures and the engine doesn't really do anything but provide constant fluid power through the pump.

IMHO: This is an excellent link that simplifies how the braking process works -

www.fluidpowersafety.com ---then click on Safety Alerts (at bottom of page). Choose SA-030 "Does your Hydrostatically-Propelled vehicle have brakes?", on the following page.

It's one of the best explanations I've read in a very long time. It includes several animated images that helps too.

Mark
 
Last edited:
B

bczoom

Guest
Thanks Mark!!!

Like you said, they give a great description.
 
Top