GB841963A - Transmission - Google Patents

Abstract

841,963. Change-speed gear. ROLLSROYCE Ltd. Oct. 10, 1958 [Oct. 11, 1957], No. 31814/57. Class 80 (2). [Also in Group XXXI] A locomotive power unit comprises at least two engines 10, 11, Fig. 1, each connected through a torque converter 12, 13 to a differential gear 18 driving a wheel 37 or wheels of the locomotive, means 15, 16 being provided to prevent reverse rotation of the output member of each torque converter when the engine associated with that converter is inoperative. The converter 12 drives a sun gear 17 while the converter 13 drives a sun gear 24 through a gear train 25 ... 27, the gears 17, 24 meshing with planet pinions on a carrier 19 driving a shaft 30 through a gear 29. The shaft 30 drives a pair of bevel gears 32, 33 either of which may be clutched to a wheel-driving shaft 34. Each engine is fitted with an all-speed governor 47, 48 connected to a single regulator 49. Fig. 4 shows a two-speed gear in which the shaft 30 is driven through a 2: 1 reduction gear 55, 56 from the planet carrier 19 until a metalto-metal friction clutch is engaged with a gear 29 to give a 1: 1 drive from the carrier to the shaft 30 and cause the drive from the gear 56 to be overridden by a unidirectional coupling 57. In an alternative construction, a double dog clutch connects the gears 29 and 56 alternately with the shaft 30. A fluid coupling may be used in place of the clutch 58. Each of the means 15, 16 consists of a helically splined sleeve 50 having a series of pawls 52a which run over a fixed set of dogs 53 until the drive is reversed when the pawls hold the sleeve stationary while the splines move it axially to bring dogs 52 into engagement with the dogs 53. Fig. 7 shows an alternative reverse gear in which two shafts are connected by gears 70 ... 72 to rotate in the same direction and are driven by either one of a pair of oppositely rotating gears 61, 65 through clutches 74, 75 with a common operating member 76. The gear 61 drives the gear 65 and is driven by a third gear (not shown) mounted on the shaft 30 and positioned above the gears 61 and 65. Four engines connected in pairs by differential gears may be employed, the two differential gears being connected by drives of different ratio to a third differential connected to the wheels through a reverse gear.