Multi-speed transmission

摘要

A family of transmission gearing arrangements each establish at least one reverse gear ratio and between nine and fifteen forward gear ratios. A shiftable gearing arrangement establishes a variety of speed ratio between the input and a first shaft. In some embodiments, a fixed speed ratio is established upstream or downstream of the shiftable gearing arrangement. In reverse and low gear ratios, a low clutch couples the first shaft to the output. In the high gear ratios, a combining planetary gear set establishes a linear speed relationship between the first shaft, a second shaft rotating at a speed proportional to the input, and the output.

主权项

1. A transmission comprising:
an input; an output; a first gearing arrangement configured to impose a plurality of selective proportional speed relationships between the input and a first shaft; and a second gearing arrangement configured to i) impose a linear speed relationship among the first shaft, a second shaft, and the output, ii) selectively couple the first shaft to the output, and iii) impose a proportional speed relationship between the input and the second shaft.