Patent ID: 7465245

Claim:
Continuously variable hydromechanical transmission for agricultural tractors, comprising: an input shaft ( 1 S) arranged to be coupled to a prime mover of the tractor and extending along a first direction (x 1 ) substantially aligned with the shaft of the prime mover and with a shaft (S 1 ) of a power take-off of the tractor; an output shaft (OS); a hydrostatic unit (HU) including a variable displacement pump (P) arranged to be driven by the prime mover shaft of the tractor and a motor (M) driven by the pump (P), wherein the pump and motor are positioned substantially in line along a second direction (x 2 ) spaced transversely downwards from said first direction (x 1 ); a torque splitter unit (TSU) of an epicyclic gearing, positioned substantially in line with the hydrostatic unit (HU) along said second direction (x 2 ) and including a first and a second input shaft (S 3 , S 4 ), coupled to the motor (M) of the hydrostatic unit (HU) and to the prime mover of the tractor respectively, and at least a first and a second output shaft (S 5 , S 6 ), the rotational speeds of said first and second output shafts (S 5 , S 6 ) varying, respectively, in a first and a second range (VD 1 -VD 2 , VC 1 -VC 2 ; VD 1 -VD 2 , VB 1 -VB 2 ) adjacent to each other, at high speed and low speed respectively, as the rotational speed of the first input shaft (S 3 ) varies between a maximum value (rpmA; rpmC) and a minimum value (−rpmA; −rpmC); a clutch unit (CU), positioned substantially in line with the hydrostatic unit (HU) and with the torque splitter unit (TSU) along said second direction (x 2 ) and arranged to couple the output shaft (OS) of the transmission selectively to the first or second output shaft (S 5 , S 6 ) of the torque splitter unit (TSU), in such a way as to provide a pair of forward operating ranges (“transport” and “work”), at high and low speed respectively; and a reversing unit (RU), positioned substantially in line with the hydrostatic unit (HU), the torque splitter unit (TSU) and the clutch unit (CU) along said second direction (x 2 ), and interposed between the clutch unit (CU) and the output shaft (OS) of the transmission, said unit being arranged to provide a reverse operating range (“reverse”).