Patent ID: 9458912
Filing Date: 2016-10-04
CPC Classification: F16H

Claim Text:
1. A multi-stage transmission for a vehicle, comprising: an input shaft; an output shaft; a first planetary gear device, a second planetary gear device, a third planetary gear device, and a fourth planetary gear device disposed between the input shaft and the output shaft to transmit rotary force, each of the first, second, third, and fourth planetary gear devices having a first, second, and third rotary element; and at least six shifting elements, each shifting element connected to at least one of the first, second, and third rotary elements of the first, second, third, and fourth planetary gear devices; wherein the first rotary element of the first planetary gear device is installed to be fixable by a first shifting element of the at least six shifting elements, the second rotary element of the first planetary gear device is permanently connected to the third rotary element of the third planetary gear device and the third rotary element of the fourth planetary gear device, and the third rotary element of the first planetary gear device is selectively connected to the first rotary element of the second planetary gear device and the second rotary element of the third planetary gear device; wherein the first rotary element of the second planetary gear device is installed to be fixable by a second shifting element of the at least six shifting elements, the second rotary element of the second planetary gear device is permanently connected to the input shaft and selectively connected to the second rotary element of the third planetary gear device, and the third rotary element of the second planetary gear device is permanently connected to the first rotary element of the third planetary gear device; wherein the first rotary element of the third planetary gear device is permanently connected to the first rotary element of the fourth planetary gear device; and wherein the first rotary element of the fourth planetary gear device is installed to be fixable by a third shifting element of the at least six shifting elements, and the second rotary element of the fourth planetary gear device is permanently connected to the output shaft.