Hydrostatic Transaxles on everyday riding lawn mowers

[Carscw]

I have a full understanding of hydraulics as a have built and operated many sand dredges. I have rebuilt pumps and motors while being broke down in the middle of the chattahoochee river.

I understand how a Chevy 350 hydromatic transmission works.

I do not understand how a mower hydrostatic transmission works with heavy duty grease.

I guess I will sit down and read up on it.

(( cowboy up and get over it ))

 

[Carscw]

I guess you mean me. When talking about hydrostatic drives, I assume you mean drives or units which include a variable pressure pump, some sort of controlled pressure pistons, a relief valve system, a fluid which is used to transfer the energy and hoses connecting this unit to one or more hydraulic motors and/or cylinders, depending on the size, to do work. The pressure pump is powered is powered by either an electric motor or fuel driven engine. Today's tractors, as well as many other pieces of equipment can now use this type of propulsion system, because the technology is available to put all these parts into a unit just a little larger than the old 6-speed geared transmission. In my opinion, that is the reason it can be called a hydrostatic transmission or trans axle. It has all the components, except hoses, of what you are talking about. Some company's (Simplicity, Wheel Horse, etc) even run their power steering and PTO cylinders off the same pump with hoss. Both the same in different size packages.

I never doubted that you knew about how this all works.
Was not question your knowledge on this subject
I am just trying to understand it all.

(( cowboy up and get over it ))

 

[Rivets]

Never seen one yet with grease in it. Ones I work on have everything from SAE 30 motor oil, multi viscosity oil, hydraulic fluid, or synthetic lube.

 

[4950cycle]

Point taken Rivets, I guess I have never found one of these yet in riding lawn mowers I've worked on. Never saw anything inside the couple 5 and 6 speed transaxles I've worked on that depends on anything hydrolic to operate. You could put them together bone dry and in my opinion they would work fine barring lubrication. Guess I just havn't ran into one of these hydrostatic transaxles yet. But I thought all these modern day (20 yrs. and newer) Riding lawn mower drive systems were called hydrostatic whether you select your ratio or automatic ? Thank you for the input though.

 

[lawn mower fanatic]

I moved your thread to the General Mower Discussion Forum. :smile:

 

[exotion]

A thought occured to me today. The word static is sometimes used as a synonym to mimic or copy.

So hydrostatic probably meens it is mimicking a hydro transmission. Maybe the way it shifts? The way it feels? Or something like that

 

[Fish]

Much of the problem is just terminology. Transaxle, on the older units were a combo of transmission and differential. The real old differential was separate on the real old
models, and the transmission was up in the tractor frame, the differential was a box mounted on the axle, and a chain connected them.

Then MTD came out with their vari-drive, so the gears {1-7} was accomplished by the two belts and the vari-pulley, like a 10 speed bicycle, and their rear end
is just a differential, with a forward/reverse feature.

Snapper type rear ends came about too, but their gears 1-6 and reverse were accomplished by the drive wheel on that plate on the crankshaft..........

Hydro Trannys, well some are just hydro units attached to a differential, here is a little Hydrogear diddy.....

Hydro-Gear ZT-2800 ZT-3100 Product Presentation (english) - YouTube