| 摘要 |
In power transmissions having power transmitting structures available for selective coupling to a plurality of power transmitting paths, increased kinematic degrees of freedom result when an input transmitter allows having a reaction element grounded in a reference frame, usually the transmission casing, inserted topologically inside a power transmitting structure or path. The reaction element may be selectively coupled to at least one power transmitting path to ground or restrain selected gearing elements of a geartrain. Interior placement of the reaction element allows that gearing elements or power transmitting paths normally blocked from access to the transmission case or a reference frame may be selectively coupled to either a power transmitting structure or to a braking or restraining structure, substantially increasing the number of possible ratio states. Resultant embodiments include combinational incrementally variable transmissions (CIVT's), which have a minimum number of gearset linkages and where n free or independent gearing elements can have at least 2 kinematic states, yielding at least 2n-1 possible distinct ratio states. Clutching to achieve these ratio states may be combinational and independent. CIVT's allow using fewer component gearsets than needed previously to form inexpensive, high multi-speed, wide ratio transmissions that do not require final ratio reduction for automotive applications. Embodiments shown include an eight speed planetary power shift transaxle transmission that uses two singly linked simple planetary gearsets and one optional input transmitter planetary gearset; a five speed transmission using a single planetary gearset; and an eighteen speed transmission using three singly linked simple planetary gearsets.
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