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US 6,595,887 B2Granted
Combined hydrostatic and gear transmissions employing independent sumps
AssigneeHydro-Thoma Limited
InventorChristian Helmut Thoma
Life of this patent
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AssigneeHydro-Thoma Limited
InventorChristian Helmut Thoma
Estimating the term…
A hydrostatic power transmitting device in combination with a speed reducing apparatus together disposed within a common housing having an interior space divided by partitioning device into a first region in which the hydrostatic unit is disposed and a second region in which said speed reducer is accommodated. First and second regions are segregated from each other by the partitioning device being in the form of a flexible non-porous barrier. The elastically deformable partitioning device can therefore adjust its shape to take up any change in the amount of hydrostatic transmitting fluid in the first region due to temperature changes of the fluid and facilitates the regulation in depth of lubricant held by the second region. Thereby an initially low level of lubricant in the second region lessens the adverse effect of power-retarding drag losses, especially during cold weather winter operation, and a rising level of lubricant ensures good lubrication when temperatures are elevated and viscosity is low. Preferably the second region is sealed from the environment, and the above atmospheric positive pressure in the second chamber aided or induced by the expanding volume of fluid in the first region provides a net increase of pressure experienced by low-pressure side of the closed-loop circuit of the hydrostatic transmission.
A hydrostatic and gear transmission comprising a housing structure formed with internal hydrostatic and gear chambers, the hydrostatic chamber containing a hydrostatic transmission and substantially full to capacity with hydrostatic fluid, the gear chamber containing a gear train and holding lubricating fluid for said gear train, a tube disposed in said housing structure and interconnecting said hydrostatic and gear chambers, said tube providing a path for hydrostatic fluid to enter said gear chamber and wherein such fluid movement induces an increase in the level of pressure of said hydrostatic fluid within said hydrostatic chamber.
A hydrostatic and gear transmission comprising a housing structure formed with internal hydrostatic and gear chambers, the hydrostatic chamber containing a hydrostatic transmission said substantially full to capacity with hydrostatic fluid, the gear chamber containing a gear train and holding lubricating fluid for said gear train, a hole disposed in said housing structure and interconnecting said hydrostatic and gear chambers, said hole proving a path for hydrostatic fluid to enter said gear chamber and wherein such fluid movement induces an increase in the level of pressure of said hydrostatic fluid within said hydrostatic chamber.
A hydrostatic and gear transmission comprising a housing structure formed with internal hydrostatic and gear chambers, the hydrostatic chamber containing a hydrostatic transmission and substantially full to capacity with hydrostatic fluid, the gear chamber containing a gear train and holding lubricating fluid for said gear train, a mechanical differential in said housing structure and drivingly connected to said gear train, a pair of axle shafts rotatably supported in said housing structure drivingly connected to said mechanical differential and extending outwardly from said housing, a hole disposed in said housing structure and interconnecting said hydrostatic and gear chambers, said hole proving a path for hydrostatic fluid to enter said gear chamber and wherein such fluid movement induces an increase in the level of pressure of said hydrostatic fluid within said hydrostatic chamber.
Dependencies are inferred from the claim text.