fluid drive on older combines and oliver lugamatic

wilson ind · Mar 9, 2014

questions on Thomas speed control. YES B&D I have the Manuel.On combine forum some talked of free wheeling, what about the Oliver lugamatic? I have a unit from a M-M combine I plan on using to make a doodle bug of sorts. Any one with experience with either oliver Lugamatic or Masey or M-M combines please discuss this unit . E mail is open as well as this forum. I have been told by one combine owner the unit was not efficient as to amount of power used in the operation of the unit. Should the unit be used more at engine speed or can it be used after gearbox with reverse? Can the thing even be run either direction?

Bob · Mar 9, 2014

They were simply a hydraulic gear pump inside a drum/reservoir, in series with the drive mechanism. NO motor, just a pump and a restictor mechanism.

To go FAST, you moved a lever that operated a valve that closed off the output of the pump, effectively locking it up, so the pump body/drum turned along with the input shaft (less a tiny amount of slip).

To slow down, the valve was opened to a degree that allowed enough oil flow out of the pump discharge back to the reservoir to let the pump "slip" a certain amount, to get the desired output speed.

There was (of course) no feedback mechanism, and they "slipped" more at a given lever setting as the oil warmed up, requiring the operator to fiddle with the control to maintain exact speed.

The drums were deeply finned to aid in cooling the oil as much as possible.

Bottom line is the were VERY crude and inefficient, and inaccurate in speed control, compared to a modern hydrostatic unit.

Are you aware of their inner workings?

Tramway Guy · Mar 9, 2014

Oliver Lugmatic on the 995 was an Allison torque converter, quite a bit different from the combine drives. No doubt the converter on the Oliver was purchased as a package from GM as a package with the 3-71 engine.
I think the combine drives were basically a variable fill fluid coupling, incapable of multiplying torque as a TC can, as fluid couplings lack a stator.

oliver fan · Mar 9, 2014

I can't answer any of your questions, but I would like to add a little information.

Certain Oliver tractors had, as an option, the Thomas variable drive unit. This was in the 1940's and 50's model 60, 66 and 77 standard and industrial tractors.

Several years ago I was in contact with a man in ND that had a 60 industrial with one, and I sent him a copy of the information I had. I didn't stay in touch with him to know what he did with the tractor.

Oliver also used that unit in their model 40 self propelled combines.

Jimmie D. Phelps · Mar 9, 2014

The reason they used them in a Massey-Harris 21A was that the machine had just a three speed trans. When cutting grain you have various thickness of grain. Without the fluid drive you just had to change gears and were either to fast or two slow and sometimes even 1st was too fast. With the fluid drive you could go from 0 to max gear speed or anywhere in between. You could keep a even flow into the Machine. It worked great and did not rob power.

gordey · Mar 9, 2014

We have a super 77 industrial with the Vari-Drive.

Bob · Mar 9, 2014

Our family had a 21A, and I still have the drive from it.

I remember my Uncle saying it ran quite warm, so they must have used/wasted a certain amount of power, but, obviously being able to slow ground speed down enough to let the combine have a chance to feed properly without slipping the clutch must have been quite a thing!

Jimmie D. Phelps · Mar 9, 2014

Harvesting in ripe wheat when it"s 95 out everything on the combine runs quite warm, including ME the operator. On picture of me standing by combine you can see the hyda. lever above my right shoulder.

David from Kansas · Mar 10, 2014

Drove one of those MM combines for a neighbor back in the 50's. Only thing I can remember was the sound when you moved that lever; squealed like a pig under a gate.

wilson ind · Mar 10, 2014

Thank you I only have a skematig of inner workings it does sound a bit crude by todays standards.

fluid drive on older combines and oliver lugamatic

wilson ind

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Bob

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Tramway Guy

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oliver fan

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Jimmie D. Phelps

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gordey

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Bob

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Jimmie D. Phelps

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David from Kansas

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wilson ind

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