Patent ID: 7798260

Claim:
A track vehicle comprising: a frame and a cab on the frame operable to support an operator; left and right motors each rotating an output shaft at a first speed; a separate speed reduction system operably coupled to each output shaft; left and right drive shafts rotatable on the frame being driven by the respective speed reduction system at a second speed that is slower than the first speed; left and right drive sprockets mounted for rotation with the respective left and right drive shafts; left and right track carriages pivotally mounted adjacent first ends thereof to pivot about the left and right drive shafts, respectively, and positioned at outer sides of the frame, thereby supporting the cab; and left and right tracks mounted for movement about the track carriages in response to rotation of the respective left and right drive shafts, wherein the left and right tracks are driven by the left and right drive sprockets to move the track vehicle along a ground surface; wherein the speed reduction systems include left and right relatively small diameter chain sprockets mounted to the output shafts of the respective left and right motors, left and right relatively large diameter chain sprockets mounted to the respective left and right drive shafts, and left and right chains coupling the respective left small and large chain sprockets and the right small and large chain sprockets such that the drive shafts rotate at slower speed and higher torque than the motor output shafts, all portions of the speed reduction systems being within the frame and between the left and right track carriages.