GB735922A - Hydraulic torque transmission - Google Patents

Abstract

735,922. Variable-speed gearing. STANDARD MOTOR CO., Ltd. March 9, 1954 [May 7, 1953], No. 12716/53. Class 80 (2). Three separate gear-type pumps 11, 12, 13 coupled to the spindles 54 of three planet pinions 29 are mounted in a casing 14 rotatable with a driving shaft 21. The three planet pinions 29 are in mesh respectively with three sun gears 24, 25, 26, the first of which is fast on the driven shaft 22 while the others are fast on sleeves 27, 28 rotatable on the driven shaft. These sleeves 27, 28 also carry gears meshing with double gears 31 and 39, 40 respectively on. a lay-shaft 32 which in turn mesh with gears 33, 35 connected to the driven shaft 22 through free-wheel devices 34, 36. The three pumps 11, 12, 13 are fed through inlet passages 18 from reservoirs 16, 17 in the casing 14 and deliver to a common central chamber 20 from which an outlet 44 is controlled by a balanced piston relief valve 45 loaded by a spring 51. The spring 51 is acted upon through a rod 50 by a centrifugal device 49 responsive to the speed of the driving shaft and casing 14 to increase its loading and close the relief outlet 44. With the engine idling and the driven shaft stationary the planets 29 rotate planet-fashion around the sungears 24, 25, 26. As the speed of the engine and casing 14 is increased the valve 45 tends to close to increase the pressure in chamber 20 and torque is thereby transmitted from all three pumps to the driven shaft. As the engine speed is further increased the pump driving the lowest speed train 26, 39, 40, 35 is slowed down relative to the casing and shaft 22 over-runs this train through free-wheel 36. On further increase of engine speed the next pump slows down and the associated train 25, 30, 31, 33 is also over-run. Finally the remaining pump associated with the sun 24 is stopped and a direct drive results.