US 5,690,578 AGranted

Ravigneaux planetary gear transmission

AssigneeGeneral Motors Corporation

InventorArthur Hall, III

Life of this patent

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Abstract

A planetary gear transmission has a single sun gear, two ring gears and a carrier assembly having a first pinion gear meshing with the sun gear and one ring, and a second pinion gear meshing with the first pinion gear and the second ring gear. The carrier assembly is continuously connected with a transmission output shaft. Input drive to the planetary gearing is provided through two selectively operable rotating clutches which are connectable with the sun gear and one ring gear, respectively. The sun gear and both ring gears are provided with selectively operable brakes for establishing reaction members within the planetary gear arrangement. In another embodiment of the planetary transmission, a second input drive path is provided through a third selectively operable rotating clutch which is connectable with the other ring gear. Selective control of the clutches and brakes permits the establishment of four forward drive ratios and a reverse ratio when two rotating input clutches are used and an additional plurality of ratios when the second input path and third input clutch are used.

Claims6

Dependent claims

A power transmission comprising:

a sun gear;
a first ring gear;
a second ring gear;
a carrier assembly having a first pinion meshing with said sun gear and said first ring gear, and a second pinion meshing with said first pinion and said second ring gear;
an input shaft;
an output shaft continuously drivingly connected with said carrier assembly;
a selectively engageable first clutch selectively connecting said input shaft with said first ring gear;
a selectively engageable second clutch selectively connecting said input shaft with said sun gear;
a first selectively engageable brake for selectively connecting said sun gear to a housing of the transmission;
a second selectively engageable brake for selectively connecting one of said first and second ring gears to the housing;
and
a third selectively engageable brake for selectively connecting the other of said first ring gear and second ring gear to said housing, said second clutch and said second brake being engaged to establish a reverse ratio between said input and output shafts, said first clutch and said first brake being engaged to establish a first forward ratio, said first clutch and said second brake being engaged to establish a second forward ratio, said third brake and said first clutch being engaged to establish a third forward ratio, and said first clutch and said second clutch being selectively engaged to establish a fourth forward ratio between said input and output shafts.

9 more elements

A power transmission comprising:

a sun gear;
a first ring gear;
a second ring gear;
a carrier assembly having a first pinion meshing with said sun gear and one of said first and second ring gears, and a second pinion meshing with said first pinion and another said first and second ring gears;
an input shaft;
an output shaft continuously drivingly connected with said carrier assembly;
a selectively engageable first clutch selectively connecting said input shaft with said first ring gear;
a selectively engageable second clutch selectively connecting said input shaft with said sun gear;
a first selectively engageable brake for selectively connecting said sun gear to a housing of the transmission;
a second selectively engageable brake for selectively connecting one of said first and second ring gears to the housing;
and
a third selectively engageable brake for selectively connecting the other of said first ring gear and second ring gear to said housing, said second clutch and said second brake being engaged to establish a reverse ratio between said input and output shafts, said first clutch and said first brake being engaged to establish a first forward ratio, said first clutch and said second brake being engaged to establish a second forward ratio, said third brake and said first clutch being engaged to establish a third forward ratio, and said first clutch and said second clutch being selectively engaged to establish a fourth forward ratio between said input and output shafts.

9 more elements

Dependencies are inferred from the claim text.