GB964179A - Marine drive transmission - Google Patents

Abstract

964,179. Propeller driving arrangements. ROLLS-ROYCE Ltd. Aug. 1, 1962 [Aug. 8, 1961], No. 28670/61. Heading B7V. [Also in Division F1] In a marine power unit drive transmission including four engines, each adapted to drive a power input shaft, the four power input shafts being arranged in two pairs, each pair is drivingly connected to a respective secondary shaft by way of a respective primary differential gear, the two secondary shafts are drivingly connected to a common output shaft by way of a secondary differential gear, and the four engines are staggered to reduce the overall width of the transmission. In a drive transmission, particularly suitable for a whaler, shafts 9 and 10, Fig. 1, of variable speed engines 5 and 6 are connected to a primary spur gear differential gear 20, the shaft 9 being connected thereto by way of gears 17, 18, 19 and a shaft 16 coaxial with the shaft 10. The differential gear 20 has an output gear 22 which meshes with a gear 23 on a secondary shaft 24. Shafts 11 and 12 of variable speed engines 7 and 8 are connected to a primary spur gear differential gear 26 having an output gear 27 meshing with a gear 28 on a secondary shaft 29. The axes of the input shafts 9 to 12 are located in the same horizontal plane. Shafts 24 and 29 are connected to a secondary spur gear differential gear 31 having an output gear 32 meshing with a gear 33 freely rotatable on a shaft 34, which gear 33 meshes with a gear 35 freely rotatable on a shaft 36. The shafts 34 and 36 are geared to a shaft 46 connected to an output shaft 47 through reduction gearing 48 to 52. Preferably the output shaft lies in plane symmetrically placed between the two pairs of input shafts, and the axes of the shafts are parallel. The gears 33 and 35 are each associated with a dog clutch sleeve 37 or 38, Fig. 2, splined to the shaft 34 or 36. A member 42 pivoted at 43 engages one of the sleeves 37, 38 with an associated member on the gear 33 or 35 to provide forward or reverse drive to the output shaft 47. Each of the input shafts 9 to 12 has associated therewith a unit 13 containing a free wheel or a selfengaging dog clutch, so that one or more of the shafts 9 to 12 may be held against contrarotation whilst power is transmitted to the output shaft by the remaining input shafts. Additionally, the unit 13 contains a scooptype fluid coupling which allows each engine to be started whilst it is disconnected from its start. If one engine fails, the remaining engines can still transmit drive to the output shaft.