초록 ▼

A compound planetary gear set converts engine power into four forward-speeds and one reverse-speed, and the gear train provides eight forward-speeds and two reverse-speeds by utilizing the compound planetary gear set. The compound planetary gear set includes a first sun gear, first planetary gears e

A compound planetary gear set converts engine power into four forward-speeds and one reverse-speed, and the gear train provides eight forward-speeds and two reverse-speeds by utilizing the compound planetary gear set. The compound planetary gear set includes a first sun gear, first planetary gears engaged with the first sun gear, a first ring gear engaged with the first planetary gears, a second sun gear, second planetary gears engaged with the second sun gear and integrally formed with the first planetary gears, third planetary gears engaged with the second planetary gears, a second ring gear engaged with the third planetary gears, and a compound planet carrier for supporting the first to third planetary gears. The compound planetary gear set can be controlled by four frictional elements.

대표청구항 ▼

The invention claimed is: 1. A gear train comprising: an input shaft for receiving engine power; a single planetary gear part including a first sun gear coupled with the input shaft, a plurality of first planetary gears meshed with the first sun gear, and a first ring gear meshed with the first pla

The invention claimed is: 1. A gear train comprising: an input shaft for receiving engine power; a single planetary gear part including a first sun gear coupled with the input shaft, a plurality of first planetary gears meshed with the first sun gear, and a first ring gear meshed with the first planetary gears; a double planetary gear part including a second sun gear, a plurality of second planetary gears meshed with the second sun gear, formed integrally and in alignment with the first planetary gears and having diameters different from diameters of the first planetary gears, a plurality of third planetary gears meshed with the second planetary gears, and a second ring gear meshed with the third planetary gears while accommodating the third planetary gears therein; a planet carrier for rotatably supporting the first to third planetary gears; a first brake for selectively stopping the rotation of the first ring gear; a second brake for selectively stopping the rotation of the second ring gear; an output shaft selectively coupled with the planet carrier and/or the second sun gear; a first clutch for coupling/decoupling the planet carrier with/from the output shaft; and a second clutch for coupling/decoupling the second sun gear with/from the output shaft. 2. The gear train of claim 1, wherein a diameter of the first sun gear is smaller than that of the second sun gear, and the second planetary gears are integrally formed with the first planetary gears. 3. The gear train of claim 1, further comprising a first one-way clutch installed between the second ring gear and a transmission case for preventing the second ring gear from rotating in a negative direction. 4. The gear train of claim 3, further comprising a second one-way clutch installed between the planet carrier and the output shaft for preventing the output shaft from rotating slower than the planet carrier. 5. A gear train comprising: an input shaft for receiving engine power; a simple planetary gear set including an SP sun gear, a plurality of SP planetary gears meshed with the SP sun gear, an SP planetary ring gear meshed with the SP gears, and an SP carrier coupled with the input shaft and rotatably supporting the SP planetary gears; a compound planetary gear set including a first sun gear, a plurality of first planetary gears meshed with the first sun gear, a first ring gear meshed with the first planetary gears, a second sun gear, a plurality of second planetary gears meshed with the second sun gear, formed integrally and in alignment with the first planetary gears and having diameters different from diameters of the first planetary gears, a plurality of third planetary gears meshed with the second planetary gears, a second ring gear meshed with the third planetary gears, and a planet carrier for rotatably supporting the first to third planetary gears; an intermediate shaft for connecting the SP ring gear to the first sun gear; an output shaft selectively coupled with the planetary carrier and/or the second sun gear; an SP brake for selectively braking the SP sun gear; a first brake for selectively braking the first ring gear; a second brake for selectively braking the second ring gear; an SP clutch for coupling/decoupling the input shaft to/from the SP sun gear; a first clutch for coupling/decoupling the planet carrier to/from the output shaft; and a second clutch for coupling/decoupling the second sun gear to/from the output shaft. 6. The gear train of claim 5, wherein a diameter of the first sun gear is smaller than that of the second sun gear, and the second planetary gears are integrally formed with the first planetary gears. 7. The gear train of claim 5, further comprising an SP one-way clutch installed between the input shaft and the intermediate shaft for preventing the intermediate shaft from rotating slower than the input shaft. 8. The gear train of claim 7, further comprising a first one-way clutch installed between the second ring gear and a transmission case for preventing the second ring gear from rotating in a negative direction. 9. The gear train of claim 8, further comprising a second one-way clutch installed between the planet carrier and the output shaft for preventing the output shaft from rotating slower than the planet carrier. 10. The gear train of claim 5, further comprising an SP one-way clutch installed between the input shaft and the SP sun gear for preventing the SP sun gear from rotating slower than the input shaft. 11. The gear train of claim 10, further comprising a first one-way clutch installed between the second ring gear and a transmission case for preventing the second ring gear from rotating in a negative direction. 12. The gear train of claim 11, further comprising a second one-way clutch installed between the planet carrier and the output shaft for preventing the output shaft from rotating slower than the planet carrier. 13. A gear train comprising: an input shaft for receiving engine power; a simple planetary gear set including an SP sun gear, a plurality of SP planetary gears meshed with the SP sun gear, an SP ring gear meshed with the SP planetary gears, and an SP carrier connected to the input shaft for rotatably supporting the SP planetary gears; a first intermediate shaft connected to the SP ring gear; a transfer driving gear driven by the first intermediate shaft; a transfer driven gear engaged with the transfer driving gear; a second intermediate shaft disposed parallel to the first intermediate shaft and fixedly connected to the transfer driven gear; a compound planetary gear set including a first sun gear connected to the second intermediate shaft, a plurality of first planetary gears meshed with the first sun gear, a first ring gear meshed with the first planetary gears, a second sun gear, a plurality of second planetary gears meshed with the second sun gear, formed integrally and in alignment with the first planetary gears and having diameters different from diameters of the first planetary gears, a plurality of third planetary gears meshed with the second planetary gears, a second ring gear meshed with the third planetary gears, and a planet carrier for rotatably supporting the first to third planetary gears; an output shaft selectively coupled with the compound planet carrier and/or the second sun gear; an SP brake for selectively braking the SP sun gear; a first brake for selectively braking the first ring gear; a second brake for selectively braking the second ring gear; an SP clutch for coupling/decoupling the input shaft to/from the SP sun gear; a first clutch for coupling/decoupling the planet carrier to/from the output shaft; and a second clutch for coupling/decoupling the second sun gear to/from the output shaft. 14. The gear train of claim 13, wherein a diameter of the first sun gear is smaller than that of the second sun gear, and the second planetary gears are integrally formed with the first planetary gears.