Patent ID: 8277350

Claim:
A hybrid system for regulating the delivery of power to a drive shaft and providing at least two power-split modes, said hybrid system comprising: an engine; a transmission; and a hybrid control system capable of computing and setting power requirement for said hybrid system, allocating power resources for said hybrid system and setting engine operating power state; said transmission comprising: a power splitting device; and an output power path selecting device capable of providing at least two speed ratios; said power splitting device having: an input shaft operatively coupled with said engine; a compound planetary gear system having a fixed configuration and a fixed set of coaxially rotatable members, each of said coaxially rotatable members being capable of rotating at a different speed, the compound planetary gear system has kinematic characteristics that are uniquely defined by two characteristic parameters; said compound planetary gear system consisting essentially of: a first planetary gear set is a complete simple planetary gear set consisting of three coaxially rotatable members; and a second planetary gear set is an incomplete planetary gear set consisting of two coaxially rotatable members; said first and second planetary gear sets sharing a common member; a member of said first planetary gear set being jointed with a member of said second planetary gear set to form said common member; said compound planetary gear system formed by said first and second planetary gear sets constituting a four-shaft compound planetary gear system having a first, a second, a third and a fourth coaxial rotatable members that corresponds respectively to a first, a second, a third and a fourth branch of a four-branch speed monograph said output power path selecting device including: an output shaft operatively coupled with drive shaft; a first pair of constant meshing gears having a first drive gear and a first driven gear, the teeth ratio of the first drive and driven gears defining the first speed ratio; a second pair of constant meshing gears having a second drive gear and a second driven gear, the teeth ratio of said second dive and driven gears defining the second speed ratio; a first clutch; a second clutch; said output shaft being selectively connected through at least one of said, clutches to two different coaxially rotatable members of said compound planetary gear system respectively with different speed ratios, the ratio of said two speed ratios being a function of said characteristic parameters of said compound planetary gear system.