GB1181929A - Improvements relating to Planetary Change-Speed Gearing - Google Patents

Abstract

1,181,929. Change-speed gear. DAIMLERBENZ A.G. 1 Feb.. 1968 [3 Feb., 1967], No. 5172/68. Heading F2D. A planet gear for a motor vehicle providing four forward and reverse ratios comprises two planet trains I, II, the first of which has one element 14 clutched at K 1 to an input shaft 13 during all forward ratios whilst a second element 12 is clutched at K 2 to the input shaft 13 during direct-drive and reverse ratios, and the second sun-ring train II has an output element 18 fast with the output from the first train, a second reaction element 20 and a third element 19 fast with another element 14 of the first train. In Figs. 1-6 the carrier 18 of the second train is the output element, the ring gear 20 is held by a brake B 1 and the sun gear 19 is fast with the forward ratio input element 14 of the first train and is thus driven by the input shaft 13 when the clutch K 1 is engaged. In Fig. 1 the first train I comprises two sun-ring planet trains 10, 11 having interconnected suns 12 which may be held by a brake By or clutched to the input 13 by clutch K 2 . The carrier 15 of the train 10 and ring gear 16 of the train 11 are fast with the output 18 whilst the ring gear 14 of train 10 is clutched at K 1 to the input during forward ratios and the carrier 17 of train 11 may be held by a brake B 2 . First ratio, using the second train II alone, is obtained by engaging the clutch K 1 and brake B 1 . For second ratio the clutch K 1 and brake B 2 are engaged to compound the trains 10, 11. Third ratio uses the train 10 alone and is obtained by engaging the clutch K 1 and brake B 3 . For direct drive the first train I is locked-up by engaging both clutches K 1 , K 2 . Reverse is provided by engaging the clutch K 2 and brake B 1 to compound all three trains. Engagement of the clutches K 1 , K 2 and brakes B 1 , B 2 , B 3 in the order stated above produces the ratios specified above in all embodiments. In Fig. 2 (not shown), the first train I comprises two sun-rings, trains (21, 22) having interconnected carriers (26) held by the brake (B 2 ) for second ratio. The ring gear (24) of the train (21) and sun gear (25) of train (22) are held by the brake (B 3 ) for third ratio and clutched at (K 2 ) to the input for direct-drive and reverse. The sun (23) of tne train (21) is clutched to the input at (K 1 ) during forward ratios and the ring gear (16) of the train (22) is fast with the output 18. In Figs. 3 and 4 (not shown), the first train I comprises intermeshed planets (29, 30) on a carrier (28) which is held by a brake (B 2 ) for second ratio and the planets (29, 30) mesh an output ring gear (32) and sun gears (31) clutched at (K 1 ) to the input shaft during forward ratios. The planets mesh a second sun gear (Fig. 3) or ring gear (Fig. 4) which is clutched at (K 2 ) to the input for direct drive and reverse ratios or held by a brake (B 3 ) for third ratio. In Fig. 5 (not shown) the first train I comprises intermeshed planets on an output carrier (40) which planets mesh ring gears (37, 39) respectively clutched at (K 1 ) to input during forward ratios and held by a brake (B 2 ) for second ratio. A second sun gear (38) meshes the planets and is clutched at (K 2 ) to input during direct-drive and reverse ratios and is held by a brake (B 3 ) for third ratio. In Fig. 6 (not shown), the first train I has output carried stepped planets (35) meshing a sun gear (41) that is held by a brake (B 2 ) for second ratio, a ring gear (37) that is clutched at (K 1 ) to input during forward ratios and a second sun gear (38) which is clutched at (K 2 ) to input during direct-drive and reverse and is held by a brake (B 3 ) for third ratio. In Figs. 7-12 (not shown), the first train I is identical to the first trains of Figs. 1-6 but in each ease the second sun-ring train II has an output ring gear (42), a planet carrier 43 which is held by the brake (B 1 ) for first ratio and a sun gear 44 connected to the element of the first train that is held by the brake (B 2 ) during second ratio. Figs. 13 and 14 (not shown), are similar to Figs. 12 and 9 and have identical connections between the gear elements but the second train II is arranged between the clutches (K 1 , K 2 ) and the first train I.