Split power infinitely variable transmission architecture
AssigneeAllison Transmission, Inc.
InventorBrian Schoolcraft
Life of this patent
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Abstract
A transmission includes an input shaft, an output shaft, a variator, a plurality of clutches including a first clutch, a second clutch, a third clutch, a fourth clutch, and a variator bypass clutch, and a plurality of gearsets including a first gearset, a second gearset, a third gearset, and a fourth gearset. The transmission is operable in a plurality of operating modes, including at least mode in which the variator is utilized to provide a transmission ratio varying within a defined range and at least one mode in which the variator is bypassed to provide a fixed transmission ratio.
Claims20
A transmission operable in a plurality of operating modes, the transmission comprising:
- an input shaft configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission,
- a plurality of gearsets arranged between the input shaft and the output shaft and including a first planetary gearset coupled to the input shaft and a second planetary gearset coupled to the input shaft,
- a variable-ratio unit coupled to the second planetary gearset and configured to receive a power load, and
- a plurality of torque transmitting mechanisms including a first clutch and a variator bypass clutch, the first clutch engageable to couple the first planetary gearset to the second planetary gearset to define a first power path therebetween, and the variator bypass clutch engageable to bypass the variable-ratio unit so that power transmitted along the first power path is transmitted to the variator bypass clutch rather than the variable-ratio unit,
- wherein the power load received by the variable-ratio unit is reduced in at least one operating mode when (i) the first clutch is engaged and (ii) the variator bypass clutch is engaged.
A transmission operable in a plurality of operating modes, the transmission comprising:
- an input shaft configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission,
- a plurality of gearsets arranged between the input shaft and the output shaft and including a first planetary gearset coupled to the input shaft and a second planetary gearset coupled to the input shaft,
- a variable-ratio unit coupled to the second planetary gearset and configured to receive a power load, and
- a plurality of torque transmitting mechanisms including a first clutch and a second clutch, the first clutch engageable to couple the first planetary gearset to the second planetary gearset to define a first power path therebetween and the second clutch engageable to couple the first planetary gearset to the second planetary gearset to define a second power path therebetween,
- wherein the power load received by the variable-ratio unit is reduced in at least one operating mode when (i) the first clutch is engaged and (ii) the second clutch is engaged.
A transmission comprising:
- an input shaft configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission,
- a variable-ratio unit configured to receive a power load, and
- a plurality of torque-transmitting mechanisms engageable to define a plurality of power paths between the input shaft and the output shaft, including a first clutch, a second clutch, and a third clutch engageable in combination with one another to transmit power along a first power path, a second power path, and a third power path,
- wherein a first gearset included in the transmission is configured to (i) transmit power from the input shaft to the output shaft along the first power path when the first clutch is engaged, (ii) recirculate power from the input shaft back to the input shaft along the second power path when the second clutch is engaged, and (iii) recirculate power from the input shaft back to the input shaft along the third power path when the third clutch is engaged.
Dependencies are inferred from the claim text.