| 摘要 |
PCT No. PCT/GB91/01330 Sec. 371 Date Apr. 1, 1992 Sec. 102(e) Date Apr. 1, 1992 PCT Filed Aug. 5, 1991 PCT Pub. No. WO92/03670 PCT Pub. Date Mar. 5, 1992.A planetary gear unit made up of a number of inter-connected co-axial three element planetary gear trains (12, 13) each including a sun (15, 19) a planet carrier (17, 21) and an annulus (14, 18). One (12) of the planetary gear trains is a dominant train with a first element (14) connected to an input member (10) of the unit and a second element (17) connected to an output member (11) of the unit. The remaining train or trains (13) of the unit are connected to the third element (15) of the dominant train to vary, by the use of associated clutches (C1, C2, C3, C4) acting between elements of the trains and ground, the direction and speed of rotation of the third element (15), thus providing a number of overall gear ratios from the unit. |
