Hydrostatic transaxle

A hydrostatic transmission assembly for a zero turn radius mower, comprising:

• a first and a second hydrostatic transmission module;
• a first and a second axle drive unit;
• and
• a first and a second coaxial axle, said first axle being operably couple to said first axle drive unit, said second axle being operably coupled to said second axle drive unit, said first axle extending through said first drive unit and said second axle extending through said second drive unit;
• said second drive unit;
• said first and said second axle drive unit each comprising a rotatable fluid motor, a housing, and a rotating fluid pump, each said fluid pump being of variable displacement, each said motor being rotated at a plurality of speeds and in a forward and a reverse direction in response to changes in pump displacement of said pump.

A hydrostatic transmission assembly comprising:

• a hydrostatic transmission module including a transmission housing, a rotating fluid pump, and a rotatable fluid motor, said fluid pump being of variable displacement;
• an axle drive unit comprising a housing and a drive means having an input and an output disposed in said axle drive housing;
• a plurality of axles including a first axle extending through said drive unit housing;
• and
• a transaxle frame whereby said hydrostatic transmission module and said axle drive unit are affixed to said transaxle frame.

A hydrostatic transmission assembly for a zero turn radius mower comprising:

• a first and a second hydrostatic transmission modules each comprising a transmission housing, a rotating fluid pump and a rotatable fluid motor, each said pump being of variable displacement, each said motor being rotated at various speeds and in forward and reverse directions in response to changes in pump displacement;
• a first and a second axle drive unit each comprising a drive unit housing and a speed reduction gear train, said axle drive unit having an input and an output, said first hydrostatic transmission module motor being operably coupled to said first axle drive unit input, said second hydrostatic transmission module motor being operably coupled to said second axle drive unit input;
• and
• a first and a second coaxial axle, said first axle being operably coupled to said first axle drive unit output, said second axle being operably coupled to said second axle drive unit output, said first and second axles respectively extending through said first and second axle drive unit housings.