GB880062A - Improvements in or relating to hydro-mechanical power transmissions - Google Patents

Abstract

880,062. Hydro-mechanical variable-speed gear. SVENSKA ROTOR MASKINER A.B. Nov. 6, 1957 [Nov. 8, 1956], No. 34593/57. Class 80 (2). [Also in Group XXXIV] A hydro-mechanical variable speed gear for motor cars comprises a hydro-dynamic torque converter having an impeller 22, a one-piece turbine 24, 28 and a rotatable reactor 26, compounded planetary gearing between the turbine and the reactor being controlled by the selective fluid-pressure actuation of friction brakes 56, 60, 72 to cause, under certain circumstances, the turbine and the reactor to rotate in the same direction at different speeds or the turbine and the reactor to rotate in opposite directions, a forward-reverse axially slidable selector sleeve 84 connecting the gearing &c. to a final driven shaft 38. In the form shown, the forwardreverse selector sleeve 84 is splined on a flange 38a fast with the driven shaft, and is moved rightwards for forward drive from the position shown to engage internal teeth 88 with splines 90 on a member fast with a shaft 36 rotated by the turbine 24, 28. Leftward sliding of the selector sleeve 84 from the position shown for reverse drive engages the internal teeth 88 with planet pinions 76 meshing planet pinions 66 on a carrier 64 held stationary by application of the brake 72. Under these circumstances, with the brakes 56, 60 released and the brake 72 applied, a sun-gear 62, meshing the planets 66 and fast with a planet carrier 46 similarly fast with the reactor 26, rotates with the reactor and the driven shaft 38 rotates backwards. The turbine 24, 28 and the reactor 26 now rotate in opposite directions. With the forwardreverse selector sleeve 86 slidden rightwards into splined engagement with the shaft 36 and the brake 72 applied, the turbine 24, 28 drives the shaft 38 forwardly. Maintaining the forward-reverse sleeve 86 in its right-hand position, and releasing the brake 72 while applying the brake 60 to station the planet carrier 46 and the reactor 26, causes the torque converter to act in the normal manner, the turbine 24, 28 driving the shaft 38 forward in the usual way. By releasing the brake 60 and applying the brake 56 to station a ring gear 54 meshing planet pinions 48 supported in the carrier 46 and in turn meshing a sun gear 52 carried by the shaft 36 fast with the turbine 24, 28, the turbine and the reactor are caused to rotate in the same direction, but at different speeds, the reactor rotating at a lower speed than the turbine, and the driven shaft 38 rotating forwardly. By sliding the forward-reverse selector sleeve further rightwards, internal teeth 82 thereon in constant splined engagement with the flange 38a on the driven shaft are brought into engagement with teeth 10a on a disc secured to a non-rotary casing 10 to lock the driven shaft 38, as when parking the motor car. The application of the brake 56 &c. is controlled by automatic mechanism 83 responsive to input and output speeds, such as described in Specification 880,063. In a modified form, Fig. 4 (not shown), the sun gear 62 is replaced by a ring gear and the ring gear 78 is replaced by a sun gear.