Patent ID: 7530915

Claim:
An apparatus that receives a mechanically driven input power at variable speeds and transmits that power to an output shaft at a desired speed, the apparatus comprising: a housing that rotatingly receives the input power; a variable displacement hydraulic unit connected to the housing and mounted within the housing; a fixed displacement hydraulic unit within the housing, the variable displacement hydraulic unit in fluidic communication with the fixed displacement hydraulic unit; and a differential located within the housing and having a ring gear, a plurality of planetary gears in mesh relationship with the ring gear and a sun gear in mesh relationship with the plurality of planetary gears, the ring gear connected to the housing, the sun gear connected to the fixed displacement hydraulic unit, said differential connected to said housing independently of said variable displacement hydraulic unit, the output shaft connected to the plurality of planetary gears, said output shaft providing structural rigidity to said apparatus by substantially extending co-axially through the apparatus.