Abstract: A family of two speed transmissions has a plurality of members that can be utilized in drive trains to provide varying gear ratios. The transmission family members include step pinion planetary gear sets. In one embodiment, there is a single step pinion planetary gear set with two sun gears configured selectively as the transmission input, two ring gears, one of which is rigidly attached to ground and the other is configured to act as the transmission output. In another embodiment, there is removed one of the ring gears and there is added a planetary reduction gear set comprised of a sun gear, a ring gear rigidly attached to ground and a planetary carrier configured to act as the transmission output. In another embodiment, there is provided a transmission comprising a plurality of helical gear sets and a planetary gear set for speed reduction.

Abstract: A family of two speed transmissions has a plurality of members that can be utilized in drive trains to provide varying gear ratios. The transmission family members include step pinion planetary gear sets. In one embodiment, there is a single step pinion planetary gear set with two sun gears configured selectively as the transmission input, two ring gears, one of which is rigidly attached to ground and the other is configured to act as the transmission output. In another embodiment, there is removed one of the ring gears and there is added a planetary reduction gear set comprised of a sun gear, a ring gear rigidly attached to ground and a planetary carrier configured to act as the transmission output. In another embodiment, there is provided a transmission comprising a plurality of helical gear sets and a planetary gear set for speed reduction.