Patent ID: 7127889

Claim:
A hydraulic drive apparatus, comprising: a transmission housing having a center section mounted therein; a first hydraulic motor located in the transmission housing and comprising a first rotatable cylinder block disposed on the center section and having a plurality of pistons disposed therein; a second hydraulic motor located in the transmission housing and comprising a second rotatable cylinder block disposed on the center section and having a plurality of pistons disposed therein; a first motor shaft engaged to and driven by the first hydraulic motor and a second motor shaft engaged to and driven by the second hydraulic motor; a first axle housing mounted on one end of the transmission housing, and a first output axle located in the first axle housing and drivingly connected to the first hydraulic motor shaft; a second axle housing mounted on an opposite end of the transmission housing, and a second output axle located in the second axle housing and drivingly connected to the second hydraulic motor shaft; and a first swash plate assembly, comprising a first plate member movable with respect to a first internal surface of the transmission housing; a first thrust bearing mounted to a first surface of the first plate member and engaged to the pistons of the first hydraulic motor; a first actuator engaged to a second surface of the first plate member opposite to the first surface and movable between a plurality of positions; and a first control arm engaged to the first actuator, wherein a portion of the first control arm extends outside the transmission housing.