| 摘要 |
971,873. Change-speed gear. HOBBS TRANSMISSION Ltd. Jan. 19, 1962 [Jan. 24, 1961], No. 2761/61. Heading F2D. A five forward and one reverse ratio planetary gear comprises a first input clutch A, engaged for all the forward ratios to drive a shaft 10 and a sun-gear 13, the latter meshing the planet pinion 24 of a three-gear planet cluster 22 . . . 24 rotating in a carrier 18. The larger pinion 27 of a two-gear cluster 27, 30 also meshes the planet pinion 24 while the smaller pinion 30 thereof meshes a sun-gear 31 fast with an output shaft 32. To establish the first ratio, with the input clutch A engaged, a brake 37 is engaged to station a ring gear 21 meshed by the planet pinion 22 of the three-gear cluster. The planet cage 18 then rotates slowly backwards. To establish the second ratio, the brake 37 is disengaged and a brake 36 is instead engaged, to hold the cage 18 stationary. To establish the third -ratio, the brake 36 is disengaged, thus freeing the cage 18, and a brake 35 is engaged to hold a sun-gear 16 meshing the planet pinion 22 of the three-gear cluster; the cage now rotates slowly forward. Fourth is established by disengaging the brake 35, and engaging a brake 34 to station a smaller sun-gear 14, so that the cage 18 rotates forwardly at an increased speed. Fifth (direct drive) is established by disengaging the brake 34, and engaging a second input clutch B, locking-up the gear. For reverse, the clutch A is disengaged, but the clutch B is engaged to drive the sun-gear 14, and the brake 37 is engaged to station the ring gear 21. As modifications, the three-gear planet cluster 22 . . . 24 may be provided with additional pinions meshing with sun gears and/or ring gears to provide more ratios. In another construction, Fig. 2 (not shown), the cage is carried by the output shaft, and the brakes 36, 37 are fast with ring gears meshing the pinions of the two-gear cluster 27, 30. Reference has been directed by the Comptroller to Specification 738,590. |
