US Patent 7322896 Hybrid transmission

A hybrid transmission for a four-wheel drive hybrid vehicle. A simple planetary gearset as a front planetary gearset and a double-pinion planetary gearset as a rear planetary gearset are mounted in a rear section of a transmission housing. A pair of motor/generators are mounted in a front section of the transmission housing nearer to an engine. A first planet-pinion carrier is connected to a second planet-pinion carrier, and to an engine input shaft via an engine clutch. A tubular first ring gear is connected to a first output shaft for driving a front axle. A second ring gear is connected to a second output shaft for driving a rear axle. The second output shaft extends through a bore of the first output shaft. A first sun gear is connected to the first motor/generator. A second sun gear is connected to the second motor/generator.