Hydrodynamic transmission for vehicles

Abstract

A transmission for locomotives, earthmoving vehicles or analogous conveyances has two closely adjacent parallel adjustable starting torque converters, one in the forward and the other in the reverse drive train, a common first gear train which connects the primary shafts of the starting converters with each other and with the input shaft, a second gear train which connects the secondary shafts of the starting converters with each other and with the output shaft, a cruising converter which is coaxial with the starting converter of the forward drive train and has a discrete secondary shaft coaxial with the secondary shaft of the respective starting converter and connected with the output shaft by a third gear train, a hydraulic brake whose rotor is driven by the secondary shaft of the starting converter of the reverse drive train and is effective only when the output shaft rotates in the forward direction, a first control unit which engages the brake and causes evacuation of working fluid from the working circuit of the cruising converter when the RPM of the output shaft is excessive, and a second control unit which reduces the transmission of power by the starting converter of the forward gear train when the RPM of the outut shaft exceeds a rated value by 20-40 percent. The brake and the converters are mounted in the casing of the transmission at the four corners of an imaginary square. At least the starting converters have stationary housing, turbine wheels which are designed for centrifugal flow of working fluid therethrough, and annuli of adjustable guide vanes which are designed for centripetal flow of working fluid therethrough.