Which gear set uses two interconnected planetary gear sets sharing a common carrier capable of producing four forward ratios (including one overdrive) and one reverse?

Which gear set uses two interconnected planetary gear sets sharing a common carrier capable of producing four forward ratios (including one overdrive) and one reverse?

• A. ZF
• B. Ravigneaux
• C. Lepelletier
• D. Simpson

Answer: (B)

The gear arrangement described is a two-planet, two-sun compound train with a single common carrier. In this Ravigneaux setup, two sun gears of different sizes are mounted on the same carrier, and planet gears mesh with both sun gears as well as with the ring gear, forming two interconnected planetary sets that share the carrier. Because the two suns rotate together on the same carrier and the clutches can lock or drive different elements, you can generate multiple speed states. This configuration yields four forward gear ratios, one of which is overdrive, plus a reverse when the direction of rotation is reversed by engaging the appropriate elements. The distinctive feature here is the shared carrier with two sun gears of different sizes enabling several gear ratios in a compact package. Other options refer to different compound-set concepts or to a manufacturer rather than this specific arrangement, so they don’t describe the same two-interconnected-planetary-with-a-common-carrier design.

The gear arrangement described is a two-planet, two-sun compound train with a single common carrier. In this Ravigneaux setup, two sun gears of different sizes are mounted on the same carrier, and planet gears mesh with both sun gears as well as with the ring gear, forming two interconnected planetary sets that share the carrier. Because the two suns rotate together on the same carrier and the clutches can lock or drive different elements, you can generate multiple speed states. This configuration yields four forward gear ratios, one of which is overdrive, plus a reverse when the direction of rotation is reversed by engaging the appropriate elements. The distinctive feature here is the shared carrier with two sun gears of different sizes enabling several gear ratios in a compact package. Other options refer to different compound-set concepts or to a manufacturer rather than this specific arrangement, so they don’t describe the same two-interconnected-planetary-with-a-common-carrier design.