US 6,358,178 B1Granted

Planetary gearing for a geared neutral traction drive

AssigneeGeneral Motors Corporation

InventorScott Henry Wittkopp

Life of this patent

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Abstract

A powertrain having an engine and a continuously variable transmission provides a continuously variable drive ratio between the engine and the transmission output. The transmission includes a continuously variable unit (CVU) and a planetary gear arrangement. The CVU is of the traction type. The planetary gear arrangement has a compound planetary gear set, two simple planetary gear sets, and two torque transmitting mechanisms. The compound gear set is disposed adjacent the CVU and has members connected with the input and the output of the CVU. The two simple planetary gear sets are disposed axially between the compound planetary gear set and transmission output shaft. The sun gear member of the compound planetary gear set is rotatably supported on a single shaft that passes axially therethrough and transmits power from the engine to the carrier assembly member of the compound planetary gear set and one input member of the CVU. The sun gear members of the simple planetary gear sets are interconnected and rotatably supported on a single shaft that passes axially therethrough and delivers power from the ring gear member of the compound planetary gear set and the carrier assembly member of one simple planetary gear set to one of the torque transmitting mechanisms. The torque transmitting mechanisms are supplied with pressurized fluid through a common support element.

Claims6

Dependent claims

A continuously variable transmission comprising:

an input member;
an output member;
a continuously variable unit positioned coaxial with and connected to said input member;
a compound planetary gear set, positioned axially adjacent said continuously variable unit, including a sun gear member, a carrier assembly member, and a ring gear member, a shaft portion of said input member passing coaxially through and rotatably supporting said sun gear member, said shaft portion being the sole rotating member passing through said sun gear member and being drivingly connected with said carrier assembly member;
a first simple planetary gear set, positioned axially adjacent said compound planetary gear set, including a sun gear member, a ring gear member, and a carrier assembly member;
a second simple planetary gear set, positioned coaxially between said first simple planetary gear set and said output member, including a sun gear member, a ring gear member, and a carrier assembly member, said sun gear member being drivingly connected with said sun gear member of said first simple planetary gear set;
and
an intermediate shaft passing coaxially through and rotatably supporting both said sun gear members of said first and second simple planetary gear sets, said intermediate shaft being the sole rotating member passing through said sun gears and being continuously drivingly connected with said ring gear member of said compound gear set and said carrier assembly member of said first simple planetary gear set and transmitting rotation therefrom to a selectively engageable torque transmitting mechanism connectable between said intermediate shaft and said output member.

5 more elements

A continuously variable transmission comprising:

input means including input shaft means for transmitting power to said continuously variable transmission;
output means including output shaft means for transmitting power from said continuously variable transmission;
a continuously variable unit having axially spaced input members and centrally disposed output members, said input shaft means passing concentrically through said continuously variable unit and being drivingly connected to a first of said input members;
a compound planetary gear set disposed adjacent said continuously variable unit and having a first sun gear member drivingly connected with said output members of said continuously variable unit, a first carrier assembly member drivingly connected with a second of said input members, and a ring gear member, said input shaft means having a portion thereof passing concentrically through said first sun gear member and being drivingly connected with said first carrier member and being the only rotatable member passing through said first sun gear;
a first simple planetary gear set disposed adjacent said compound planetary gear set and having a second sun gear member, a second carrier assembly member continuously drivingly connected with said first ring gear member, and a second ring gear member drivingly connected with said first carrier assembly member;
a second simple planetary gear set disposed between said first simple planetary gear set and said output means and having a third sun gear member continuously drivingly connected with said second sun gear, a third ring gear member continuously drivingly connected with said output means, and a third carrier assembly member;
and
an intermediate shaft means for transmitting power from said first ring gear member and said second carrier assembly member to a first torque transmitting mechanism that is selectively connectable with said output means, said intermediate shaft means passing concentrically through said second and third sun gear members and being the sole rotatable member passing therethrough.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/611,981Filed 7 Jul 2000
Granted: 19 Mar 2002
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

F16H 37/086
At least one power path being a continuously variable transmission, i.e. CVT: cVT using two coaxial friction members cooperating with at least one…
F16H 37/084
With arrangements for dividing torque between two or more intermediate shafts, i.e. with two or more internal power paths: at least one power path…
F16H 2037/0886
Power-split transmissions with summing differentials, with the input of the CVT connected or connectable to the input shaft: with switching means,…
F16H
Gearing