GB677179A - Improvements in hydraulic torque converters - Google Patents

Abstract

677,179. Hydraulic torque converters. AKTIEBOLAGET LJUNGSTROMS ANGTURBIN. March 15, 1950 [March 15, 1949], No. 6485/50. Class 69 (ii). In a hydraulic torque converter consisting of at least one pump blade ring 1, at least two turbine blade rings 2, 4 and one or more guide or reaction blade rings 3 and of which one is located between the first two turbine rings 2, 4, the blades of at least the first blade ring reaction member 3 are arranged to have a ratio of inlet edge radius to the maximum distance from the outlet edge of the blade to a tangent to the inlet edge thereof greater than the corresponding ratio of the blades of the turbine blade rings ; the blade length of at least the first blade ring of the reaction member 3 may be greater at the outlet edge than at the inlet edge. The cross-section of the duct between the outlet of the second-stage turbine 4 and the inlet to the pump 1 in the direction of'liquid flow firstly increases, reaching a maximum approximately halfway round the duct, and subsequently decreases ; similar variations are provided in the duct between the first-stage turbine 2 and the reaction member 3. The dotted lines indicate the duct crosssections of prior converters. The shortening of the inlet edges of the reaction blades results in a decrease of the angle between the inlet directions of liquid flow on starting and at the point where the primary and secondary torques are equal whilst the large inlet edge radius of the reaction blades give rise to a decrease of converter maximum efficiency, whereas the efficiency between the turbine and impeller at both low and high speeds is increased so improving the acceleration characteristics. The invention can also be applied to single- and three-stage converters.