Patent GB-924776-A (GB)
Title: Hydrodynamic working circuit
IPC: F16D57/04
Filed: 1962-02-22
Abstract: 924,776. Fluid-friction brakes. C. SCHULER-VOITH, M. VOITH, H. W. SCHWEPPENHAUSER, and C. KNAPP, [trading as VOITH-GETRIEBE KOMM.-GES.]. Feb. 22, 1962 [Feb. 24, 1961], No. 6974/62. Class 103 (1). [Also in Group XXIX] An hydrodynamic working circuit, such as a turbo converter, turbo coupling or turbo brake, comprises a control circuit passing through the working chamber of the working circuit and including a filling control device, and a cooling circuit passing through the working chamber and having a cooler, the cooling circuit and control circuit being connected at least partly in parallel in such manner that the filling control device and the cooler are in the parallel connected parts of the two circuits. As applied to a torque converter 60, Fig. 3, the cooler 71 is connected by pipes 68, 80 to the outer and inner peripheries 67, 66 of the working circuit, and the filling control device, which consists of a throttle valve 73, sump 74, throttle valve 75 and pump 76, is connected in parallel with the cooler. The converter is emptied by stopping the pump 76 and opening valve 73, and is filled by starting the pump and adjusting both valves 73, 75 to control the degree of filling. During initial filling, the low pressure in pipe 68 permits a spring 84 to open a by-pass valve 82 so that fluid from the sump 74 passes directly to the pump 76, the valve 82 closing as the pressure rises in the pipe 68. In normal operation, the pumping action of the impeller of the converter effects circulation of fluid through the cooler. In an embodiment consisting of an hydrodynamic brake 1, Fig. 1, the cooler 6 is connected by pipes 5, 7 to the outer and inner peripheries 2h, 2k of the brake, and the filling control device, which consists of an elevated tank 9 and valves 11, 12 are also connected to the inner and outer peripheries 2k, 2l of the brake by pipes 8, 10. The filling and emptying of the brake is controlled by the valves 11, 12, rapid filling being assisted by a valve 17 which connects the link 9 to a pipe 16 leading to an intermediate part of the working circuit when the pressure in the pipe 8 is sufficiently low to enable a spring 14 to open the valve. In another embodiment, a hydrodynamic brake 26 for the output shaft 33 of a turbo gear 25 is connected by pipes 47, 39 and 41, 46 to a cooler 40, the pipe 39 being connected by a pipe 36 to a pump in the sump of the turbo gear. The pump is connected by a pipe 37 to a valve 51 joined by pipes 52, 53 to the brake and by pipe 54 to the sump. When the brake is empty valve 51 and valves 38, 42 in the pipes leading to the cooler are in the position shown, the pump passing liquid through pipes 36, 39, the cooler 40 and pipes 41, 45 to the turbo gear. To brake the shaft 33, the valves 51 and 42 are operated so that the pump supplies liquid through pipes 37 and 52 to the brake and liquid from the cooler is supplied through pipes 41, 46, valve 38 maintaining pipe 47 closed until the pressure in the converter is sufficient to open valve 38 and permit circulation through the cooler. The valve 51 can be placed in positions intermediate its ends to control the degree of filling of the brake. The pipes 37, 52, 53 and 54 and the valve 51 may be replaced by a single pipe, the pump 35 then being of the reversible kind.