GB1112321A - Improvements in or relating to power transmission mechanism - Google Patents

Abstract

1,112,321. Change, speed gear; friction clutches. AUTOMOTIVE PRODUCTS. GO. Ltd. 5 Jan.. 1967 [6 Jan.. 1966]; No.656/66. Headings, F2C, F2D and F2L. In a bevel planet gear for a motor vehicle wherein stepped bevel planets 22;23on a carrier 24 mesh with two bevel pinions 15, 19 which are selectively connected by first and second friction clutches 28, 55 with an input shaft 12, the first clutch 28 is a conventional clutch having a driven disc 33 clamped between a driving flywheel 27 and a presser plate 31 by a diaphragm spring 26 whilst the driving element 54 of the second clutch is driven from the presser plate 31 of the first clutch through a plate 48 and sleeve 16. Gear arrangement.-As shown, the planets 22, 23 mesh an output bevel pinion 25 and a reaction bevel pinion 26 in addition to the pinions 15, 19. For forward ratios, the clutch 28 is engaged to connect the. pinion 15 to the input shaft 12. For low ratio a band brake 61, holds the carrier 24. Second and third ratios are provided by selectively engaging band brakes 62, 63 to hold the pinions 26, 19, respectively. For direct-drive the clutch 55 is. engaged in addition to the clutch 28 to drive both pinions 15, 19 and lock-up the bevel train. For reverse ratio the clutch 28 is released and the clutch 55 engaged to drive the pinion 19 whilst the carrier 24 is held by the brake 61. In, Fig. 3 (not shown) output carried stepped bevel planets (83, 84) mesh bevel pinions (86, 87) which are selectively connected to an input shaft (71) by first andsecond friction clutches (75, 79). The pinions (86, 87) are on the same side of the carrier (85). The planets (83, 84) also mesh reaction bevel pinions (88, 91) which are selectively; held by a, disc brake (94) and aband brake (93) respectively. Low ratio is provided by engaging the clutch (75) to. connect the pinion (86) to the input shaft and by engaging the brake; (93) to hold the pinion (91) For second ratio the brake (93) is released and the brake (94) engaged to hold the pinion (88) whilst the clutch (75) remains engaged. Third ratio is provided by releasing the clutch (75) and engaging the clutch (79) to connect the pinion (87) to the input shaft and by engaging the brake (93) to hold the pinion (91) The brake (93) is released andthe brake (94) engagedto hold the pinion (88) whilst the clutch (79) remains engaged for fourth ratio. Direct drive is provided by engaging both clutches (75, 79) to lock-up the planet train. Forreverse the clutch (75) is engaged to drive the pinion (86) whilst the pinion (87) is held by a brake (92). Clutches and brakes.-The presser plate 31 of the clutch 28 is connected by tangential straps (32) (Fig. 2; not shown) with the flywheel 27 and radial projections (49) on the plate 48 engage recesses 51 in the presserplate to provide a driving connection from the flywheel 27through the presser plate 31 plate 48 and sleeve 16 to thedriving element 54 of the second clutch. The driving element 54 carries clutch discs 57 engageable with discs 58 on a drum 56 fast with the pinion 19. The clutch 55 is engaged by supplying pressure liquid to a servo-piston 59. The clutch 28 is, disengaged: by supplying pressure liquid to a non-rotatable servo cylinder 39 which acts through a thrust bearing 43 on the inner ends of fingers 44 of, the diaphragm spring. Pressure liquid is selectively supplied to the, clutches and brakes by a manually controlled forward-neutral-reverse valve (not shown) and. a valve, (not shown) automatically controlled in response to speed and/or load. Gradual, engagement of the clutch 28 is obtained by providing a restriction in the exhaust line from the servo 39 or by providing a valve in the exhaust line which is controlled by engine speed or a separate manual control.