Multi-speed transmission
AssigneeFord Global Technologies, LLC
InventorRobert Scott Lippert
Life of this patent
Estimating the term…
Abstract
A transmission gearing arrangement has four simple planetary gear sets and five or six shift elements. A ring gear is fixedly held against rotation. A sun gear and a carrier are fixedly coupled to the input shaft. One embodiment has two brakes and three clutches and produces seven forward speeds by selective engagement of various combinations of two of the shift elements. Other embodiments have two brakes and four clutches and produce nine forward speeds by selective engagement of various combinations of two of the shift elements. Each embodiment may optionally include a passive one way brake that simplifies the control of certain shifts.
Claims22
A transmission comprising:
- an input;
- an output;
- first, second, third, and fourth shafts;
- a first gearing arrangement configured to fixedly impose a linear speed relationship among the input, the first shaft, and the second shaft;
- a second gearing arrangement configured to fixedly impose a proportional speed relationship between the second shaft and the third shaft;
- a third gearing arrangement configured to fixedly impose a linear speed relationship among the third shaft, the output, and the fourth shaft;
- and
- a fourth gearing arrangement configured to selectively impose a linear speed relationship among the first shaft, the input, and the output.
A transmission comprising:
- a first gearset imposing a fixed linear speed relationship among an input, a first shaft, and a second shaft;
- a second gearset imposing an underdrive relationship between the second shaft and a third shaft;
- a third gearset imposing a fixed linear speed relationship among the third shaft, an output, and a fourth shaft;
- and
- a gearset imposing a selective linear speed relationship among the first shaft, the input, and the output.
Dependencies are inferred from the claim text.