MULTI-SPEED TRANSMISSION

摘要

A family of transmission gearing arrangements produces nine forward speed ratios and one reverse speed ratio. Each arrangement includes a two state shift element. In a first state, the shift element passively holds a shaft against rotation in one direction while permitting rotation in the opposite direction. In a second state, the shift element holds the shaft against rotation in both directions. The shift element may be implemented as a combination of a one-way-brake and a dog clutch. Each arrangement also includes a gearing arrangement that produces three speed relationships between an input and an intermediate shaft, including an underdrive relationship, a reverse speed relationship, and holding the intermediate shaft against rotation.

主权项

1. A transmission comprising:
an input; an output; first, second, and third shafts; a first gearing arrangement configured to fixedly impose a linear speed relationship among the first shaft, the second shaft, the output, and the third shaft; a second gearing arrangement configured to alternately i) hold the first shaft against rotation, ii) establish an underdrive relationship between the input and the first shaft, and iii) establish a reverse speed relationship between the input and the first shaft; a first shift element comprising a passive one-way-clutch between a transmission housing and the second shaft and a dog clutch configured to selectively couple the second shaft to the transmission housing; a second shift element configured to selectively coupled the input to the second shaft; and a third shift element configured to selectively couple the input to the third shaft.