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AssigneeGeneral Motors Corporation
InventorsMadhusudan Raghavan, Norman Kenneth Bucknor, Patrick Benedict Usoro
Estimating the term…
The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and one fixed interconnection. Also, one planetary gear member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members and with the transmission housing, and are operated in combinations of three to establish at least seven forward speed ratios and one reverse speed ratio.
A family of transmissions wherein each family member comprises:
A family of transmissions having a plurality of family members wherein each family member comprises:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Backward citations are indexed for grants only.
Composed of a number of gear trains without drive passing from one train to another: with intermeshing orbital gears
Gearings having three or more central gears: composed of a number of gear trains without drive passing from one train to another
Characterised by the number of forward speeds: the gear ratios comprising seven forward speeds
Characterised by the number of forward speeds: the gear ratios comprising eight forward speeds
Term end not estimated
1. Field of the Invention
The present invention relates to a family of power transmissions having three planetary gear sets that are controlled by six torque-transmitting devices to provide at least seven forward speed ratios and one reverse speed ratio.
2. Background Art
FIG. 1a is a schematic representation of a powertrain including a planetary transmission incorporating a family member of the present invention;
FIG. 1b is a truth table and chart depicting some of the operating characteristics of the powertrain shown in FIG. 1a;
FIG. 2a is a schematic representation of a powertrain having a planetary transmission incorporating another family member of the present invention;
Referring to the drawings, wherein like characters represent the same or corresponding parts throughout the several views, there is shown in FIG. 1a a powertrain 10 having a conventional engine and torque converter 12, a planetary transmission 14, and a conventional final drive mechanism 16.
The planetary transmission 14 includes an input shaft 17 continuously connected with the engine and torque converter 12, a planetary gear arrangement 18, and an output shaft 19 continuously connected with the final drive mechanism 16. The planetary gear arrangement 18 includes three planetary gear sets 20, 30 and 40.
The planetary gear set 20 includes a sun gear member 22, a ring gear member 24, and a planet carrier assembly 26. The planet carrier assembly 26 includes a plurality of pinion gears 27 rotatably mounted on a carrier member 29 and disposed in meshing relationship with both the sun gear member 22 and the ring gear member 24.