| 摘要 |
<p>A transmission comprises an input member; a driven member; a torque converter driven by the input member; a first planetary gear assembly including a first sun gear, a plurality of first planet gears, and a first ring gear which is connected to the torque converter to be driven thereby; a clutch selectively engageable for transmitting torque applied to the input member directly to the first planetary ring gear; a second planetary gear assembly including a second sun gear which is constrained to rotate with the first sun gear of the first planetary gear assembly, a second planet gear arrangement, and a second ring gear; a common planet carrier having rotatingly mounted thereupon the first planet gears and the second planet gear arrangement, the common planet carrier driving the driven member; first brake means selectively actuable for stopping rotation of the second ring gear so that the first planetary gear assembly and the second planetary gear arrangement operate in a split-torque relationship transmitting torque applied to the first ring gear from the input member to the driven member through the common planet carrier; second brake means selectively actuable for stopping rotation of the first and second sun gears so that torque applied to the first gear ring is transmitted to the driven member through the common planet carrier; and a second clutch selectively engageable for drivingly connecting the input member directly with the common planet carrier and driven member so that the driven member is driven at a speed of rotation equal to the speed of rotation of the input member. This provides the basic component for a transmission for a vehicle utilizing four planetary gear sets to provide seven output ratios in the highly efficient mechanical range with almost identical step ratios throughout a broad range of output speeds. The torque converter is provided for operation primarily in the first range but also available in any one of the speed ratios, while a fifth planetary arrangement provides a reverse drive.</p> |
