GB1085618A - Improvements in or relating to automatic power transmission systems providing changes of gear ratio - Google Patents

Abstract

1,085,618. Change-speed gear; friction clutches. AUTOMOTIVE PRODUCTS CO. Ltd. April 26, 1966 [May 4, 1965; Jan. 6, 1966], Nos. 6206/66 and 655/66. Headings F2C and F2D. In a change-speed planet gear for a motor vehicle wherein stepped bevel planets 14 mesh input bevel gears 17, 18 selectively connected to a driving shaft 11 by hydraulically operated friction clutches 24, 25, the clutch 24 comprises a housing 28 fast with the driving shaft 11 and surrounding a driven plate assembly 39 fast with the bevel gear 17 whilst the clutch 25 has driving plates 51 splined on a cylindrical extension 52 of the housing 28 and is surrounded by a driven housing 55 fast with the bevel gear 18. The clutch 24 is engaged by pressure liquid supplied to a chamber 41 to move left a piston 42 which acts through a diaphragm spring 43 on a presser plate 34. The clutch 25 is engaged by pressure liquid supplied to a chamber 59 to move left, against the bias of a return spring 67, a piston 61 acting directly on a presser plate 53. Gear arrangement.-As shown, the input bevel gears 17, 18 mesh the planet pinion 15 on opposite sides of the carrier 13 and are selectively clutched to the driving shaft 11 for forward and reverse ratios. The planet pinion 16 meshes an output bevel gear 21 and a reaction bevel gear 22. For low ratio the clutch 24 is engaged to drive the forward bevel gear 17 and the carrier 13 reacts on a one-way detent 73. On additional engagement of a brake 71 to hold the reaction bevel gear 22 the carrier rotates forwardly to increase the speed of the output gear 21 and provide second ratio. For third ratio the clutch 24 and a brake 72 are engaged, the latter holding the bevel gear 18 whereupon the carrier rotates forwardly with increased speed. Direct drive is provided by engaging both clutches 24, 25 whilst reverse is provided by engaging the clutch 25 and a brake 69 which holds the carrier 13. The driving shaft 11 may, as shown, be driven through a torque converter 75 or through a fluid coupling or centrifugal clutch. In Fig. 2 (not shown) the axis of the planet carrier (86) is inclined to the gear axis and the reverse brake (102) is used additionally for low ratio, the one-way detent being omitted. The forward drive clutch (81) is larger than the reverse drive clutch (92) and is additionally used as a starting clutch. In Fig. 3 (not shown) the input bevel pinions (127, 128) mesh different steps of the planets (131 and are both on the same side of the carrier (125) which is fast with the output shaft (126). Reaction bevel gears (133, 134) mesh the planets (131) on the other side of the carrier. For low and second ratios the clutch (138) is engaged to drive the input bevel gear (127) and brakes (136, 135) selectively hold the reaction gears (134, 133). For third and fourth ratios the clutch (139) is engaged to drive the input bevel gear (128) and the brakes (136, 135) are selectively engaged. Direct drive is provided by engaging both clutches (138, 139) and reverse is provided by engaging the clutch (138) to drive the input bevel gear (127) whilst the other input bevel gear (128) is held by a brake (137).