Patent ID: 7431123
Filing Date: 2008-10-07
Classification: A01D,B60K,B62D,F16H

Abstract:
1. An integral hydrostatic transaxle apparatus for driving and steering a vehicle, comprising: a housing; a pair of axles disposed in said housing; a pair of planetary gear units disposed in said housing for differentially connecting said axles with each other wherein said planetary gear units include a driving input part and a steering input part; a first hydrostatic transmission disposed in said housing and operably connected to said driving input part of said planetary gear units for steplessly driving said pair of axles, said first hydrostatic transmission including a first hydraulic pump, a first hydraulic motor and a first center section fluidly connecting said first pump and said first motor; a second hydrostatic transmission disposed in said housing and operably connected to said steering input part of said planetary gear units for accelerating one of said pair of axles and decelerating the other of said pair of axles, said second hydrostatic transmission including a second hydraulic pump, a second hydraulic motor and a second center section fluidly connecting said second pump and said second motor, wherein said housing comprises a first part and a second part joined together along a joint surface and defining a contiguous interior space, wherein said first and second hydrostatic transmissions, said pair of planetary gear units, and said pair of axles are disposed in the interior space; and a pair of first and second transmission shafts disposed in parallel to said pair of axles so as to be supported in said housing, wherein said first transmission shaft includes a first connection portion for connecting said driving input part of said planetary gear units to said first hydraulic motor, wherein said second transmission shaft includes a second connection portion for connecting said steering input part of said planetary gear units to said second hydraulic motor, and wherein said second connecting portion includes a pair of gear trains, each of which is interposed between each of said driven gears and said steering input part of said planetary gear units, wherein each of said gear trains is partly disposed relatively rotatably on said first transmission shaft.