Hydro-mechanical transmission
AssigneeSouthwest Research Institute
InventorGary Lee Stecklein
Life of this patent
Estimating the term…
Abstract
A hydro-mechanical transmission system. The system includes an engine having a drive shaft that extends into and supplies power to a gear box having a first and second planetary gear set, wherein the first and second planetary gear set includes a sun with a first ring gear fixed and a carrier coupled to the drive shaft through a double clutch, a hydraulic pump driven by the engine and hydraulically coupled to a hydraulic motor, a low pressure accumulator coupled to the motor and the pump, a high pressure accumulator coupled to the motor and the pump, wherein the hydraulic motor couples to the suns of both planetary gear sets, wherein the engine drives the carrier of the second planetary gear set with the ring of the second planetary gear set coupled to the drive shaft through a double clutch.
Claims25
A hydro-mechanical transmission system, comprising:
- an engine having a drive shaft that extends into and supplies power to a gear box having a first and second planetary gear set, wherein the first and second planetary gear sets include coupled suns with a first ring gear fixed and the first gear carrier coupled to the drive shaft through a double clutch,
- a hydraulic pump driven by the engine and hydraulically coupled to a hydraulic motor,
- a low pressure accumulator coupled to the motor and the pump,
- a high pressure accumulator coupled to the motor and the pump,
- wherein the hydraulic motor is coupled to the suns of both the first and second gears of the planetary gear sets, wherein the engine drives the carrier of the second planetary gear set with the ring of the second planetary gear set coupled to the drive shaft through a double clutch.
A method for manufacturing a hydro-mechanical transmission system, comprising:
- providing an engine having a drive shaft that extends into and supplies power to a gear box having a first and second planetary gear set, wherein the first and second planetary gear sets include coupled suns with a first ring gear fixed and the first gear carrier coupled to the drive shaft through a double clutch, providing a hydraulic pump driven by the engine and hydraulically coupled to a hydraulic motor, providing a low pressure accumulator coupled to the motor and the pump, providing a high pressure accumulator coupled to the motor and the pump, wherein the hydraulic motor is coupled to the suns of both the first and second gears of the planetary gear sets, wherein the engine drives the carrier of the second planetary gear set with the ring of the second planetary gear set coupled to the drive shaft through a double clutch.
A method for powering a vehicle, comprising:
- using a hydro-mechanical transmission system to power the wheels of a vehicle, wherein the hydro-mechanical transmission system comprises
- an engine having a drive shaft that extends into and supplies power to a gear box having a first and second planetary gear set, wherein the first and second planetary gear set includes coupled suns with a first ring gear fixed and a carrier coupled to the drive shaft through a double clutch,
- a hydraulic pump driven by the engine and hydraulically coupled to a hydraulic motor,
- a low pressure accumulator coupled to the motor and the pump,
- a high pressure accumulator coupled to the motor and the pump,
- wherein the hydraulic motor is coupled to the suns of both the first and second gears of the planetary gear sets, wherein the engine drives the carrier of the second planetary gear set with the ring of the second planetary gear set coupled to the drive shaft through a double clutch.
A method for powering a vehicle, comprising:
- employing hydro-mechanical transmission system that comprises a hydraulic motor that is coupled to the suns of both the first and second gears of the planetary gear sets to power a drive shaft without use of power from an engine until reaching a synchronous shift condition with a first ring gear fixed and a carrier coupled to the drive shaft through a double clutch, wherein the engine is coupled to the carrier of the second planetary gear set with the ring of the second planetary gear set coupled to the drive shaft through a double clutch, wherein a hydraulic pump coupled to the engine goes from zero displacement to a displacement sufficient to start the engine and return the pump to zero displacement;
- then engaging the engine to power the drive shaft that is coupled to the carrier of the second planetary gear set, wherein the hydraulic motor speed then goes to zero.
Dependencies are inferred from the claim text.