Compact multi-speed automatic transmission with load sharing and anti-phase gear assembly

A transmission, comprising:

• an input shaft;
• an output shaft;
• a first planetary gear assembly selectively in mechanical communication with said input and output shafts, said first planetary gear assembly including:
• a first gearset having gear components with helical gear teeth comprising a first sun gear, a first ring gear and a first planet gear rotatably supported on a carrier component and meshed with at least one of said first sun gear and said first ring gear;
• a second gearset having gear components with helical gear teeth comprising a second sun gear fixed for rotation with said first sun gear, a second ring gear and a second planet gear rotatably supported on said carrier component and meshed with at least one of said second sun gear and said second ring gear, said gear components of said second gearset having an equal number of helical teeth with an equivalent helix angle and tooth pitch as said gear components of said first gearset, and wherein said gear components of said second gearset arranged to have opposite helix inclination and are circumferentially indexed by one-half tooth pitch relative to corresponding gear components of said first gearset;
• and
• a second planetary gear assembly in mechanical communication with said first planetary gear assembly and said output shaft, said second planetary gear assembly including a third gearset having gear components with helical gear teeth comprising a third sun gear selectively rotatable with a component of said first planetary gear assembly, a third ring gear and a third planet gear rotatably supported on a second carrier component and meshed with at least one of said third sun gear and said third ring gear and a fourth gearset having gear components with helical gear teeth comprising a fourth sun gear fixed for rotation with said third sun gear, a fourth ring gear and a fourth planet gear rotatably supported on said second carrier component and meshed with at least one of said fourth sun gear and said fourth ring gear, said gear components of said fourth gearset having an equal number of helical teeth with an equivalent helix angle and tooth pitch as said gear components of said third gearset, and wherein said gear components of said fourth gearset are arranged to have opposite helix inclination and are circumferentially indexed by one-half tooth pitch relative to corresponding gear components of said third gearset.