GB1230410A - - Google Patents

Abstract

1,230,410. Hydro-mechanical variable-ratio epicyclic gear. T. TSURUYA. 23 Aug., 1968, No. 40428/68. Heading F2D. An automatic variable-ratio split-torque transmission, for motor vehicles or construction equipment, comprises a sun-ring train having a carrier 43 fast with the transmission output shaft 44, a sun 42 driven from the transmission input shaft 1 through a shaft 10, and a ring 39 driven from the input shaft 1 through a torque converter 3-5, a hollow shaft 7 and a planetary three-speed gear. The latter provides Low, Intermediate and "1/1" drives therethrough and comprises planets 18 carried by a double ring 28 and meshing a ring 19 and a sun 17 fast on the shaft 7, planets 27 carried by a sun 34 and meshing the double ring 28 and a sun 26 also fast on the shaft 7, and planets 36 carried by the ring 39 and meshing the sun 34 and the double ring 28. One-way brakes 20, 29 respectively acting on the rings 19, 28 to provide Intermediate and Low are rendered effective by brake-bands 22, 33. The torque converter reactor 5 reacts on a one-way brake 8. The torque converter pump 3 drives an oil pump 12 which together with an output shaft oil pump (not shown) is used to provide a gear control pressure differential. Operation.-In Low, with the band 33 applied, initially, under high load, the output shaft 44 and the carrier 43 are held and, in consequence, the converter turbine is rotated reversely against converter fluid friction. As output load is decreased and the output shaft rotates forwardly, the turbine rotation changes to forward. In shift from Low to Intermediate, on application of the band 22, the one-way brake 29 releases. It is stated that on release of the band 22 the planetary three-speed gear rotates solid at 1/1 ratio. In addition to "normal" engine braking, a brake band 40 may be applied to the ring 39 for increased engine braking; further, this band may also be applied for short-distance startermotor vehicle propulsion.