GB731022A - Epicyclic gear box, especially for motor vehicles - Google Patents

Abstract

731,022. Change-speed gear. PAVESI, F. June 4, 1953 [June 5, 1952], No. 15387/53. Class 80 (2). A planetary gear giving a direct and a reduced drive comprises planet pinions 2, in a carrier 3, meshing an internally toothed annulus 6 connected to a main driving shaft 7 and a sun gear 1 carrying non-rotatably but axially slidably a coned friction member 16, movable in one direction to engage a coned surface on the annulus for direct drive and in the other to engage a stationary coned brake member 17 for reduced drive, the coned friction member 16 being moved in one direction by a single helicoidal spring 24 and in the other by a single fluid pressure operated piston 25 in a cylinder 26. The driven planet carrier 3 is fast on a shaft 10 carrying a sun gear 28 meshing planets 35 which in turn mesh double planets 39 meshing an internally toothed annulus 40 and a sun gear 41 of larger diameter than the sun gear 28. The interengaging planets are mounted in a carrier 32 connected to a final driven shaft 13, the carrier rotatably supporting the annulus 40 which can. be held stationary by a positive detent. The sun gear 41 is rotatable on the shaft 10 and can either be clutched thereto for direct drive by a multi-disc clutch 53 engaged against spring force when pressure fluid is admitted to a cylinder 55 and piston 54, via ducts 56, or held stationary for reduced drive by applying a hydraulically operated brake band 46 to a drum 44 secured for rotation with the sun gear. With the clutch 53 and brake 46 disengaged, reverse is obtained by applying the previously mentioned positive detent to the annulus 40. As a modification, the annulus 40 may be split into two parts of which the second meshes the planets 35 and may be held stationary for an additional reduced ratio.