Multi-speed transmission

摘要

A family of transmission gearing arrangements produces up to nine forward and one reverse speed ratios by selective engagement of three shift elements in various combinations. Each disclosed transmission includes four planetary gear sets and six elements. Two of the arrangements feature planetary gear sets that are separated radially and are particularly suited to applications that require reduced axial length.

主权项

1. A transmission comprising:
an input shaft, an output shaft, and second, third, and fourth shafts; a first gearing arrangement configured to selectively constrain the second shaft to rotate at a speed between speeds of the input shaft and of the fourth shaft; a second gearing arrangement configured to fixedly constrain the third shaft to rotate at a speed between speeds of the second shaft and of the fourth shaft; a third gearing arrangement configured to selectively constrain the output shaft to rotate at a speed between zero and a speed of the third shaft, and to selectively constrain the input shaft to rotate at a speed between speeds of the third shaft and of the output shaft; a first clutch configured to selectively couple the input shaft to the second shaft; a first brake configured to selectively hold the second shaft against rotation; and a second brake configured to selectively hold the fourth shaft against rotation.