| 摘要 |
The present invention relates to a multistage transmission comprising: a center shaft arranged in a frame such that the center shaft does not rotate; an input member arranged coaxially with the center shaft such that the input member is rotatable; a hub arranged coaxially with the center shaft such that the hub is rotatable; a planetary gear assembly which is coupled to the input member and mounted on the hub, and which is arranged coaxially with the center shaft such that the planetary gear assembly is rotatable, and which has at least two pairs of planetary gears which are arranged in parallel to each other, wherein each of the planetary gears has a sun gear, a ring gear, a carrier and a satellite gear, and wherein the ring gears and the carriers of said two adjacent pairs of planetary gears cross each other and are coupled together so as to be prevented from rotating; a clutch assembly which is involved in the operation of each of the sun gears which is selectively coupled to and separated from the ring gear, the carrier, the satellite gear, the sun gear adjacent thereto and/or the center shaft; and a transmission shaft which is arranged coaxially with the center shaft to select a rotating direction with respect to the center shaft, and which is involved in the operation of the clutch assembly. The multistage transmission of the present invention provides gear ratios such as stage 3, stage 6, stage 9, stage 12, stage 18 and so on between the input member and the hub in accordance with the rotating direction of the transmission shaft. |
