Regie Nationale Des Usines Renault

Claude Chevalier

Jean M Bouvet

Jean P Parthuisot

Jean-Marie Bouvet

Gino Zammarchi

This hydrodynamic torque converter for the automatic transmission of motor vehicles which provide several gear ratios comprises means for bridging the input and output shafts of the converter. The hydraulic fluid supplied through the hollow transmission shaft penetrates into the converter inner space via a gaged orifice; the outlet of the control chamber of the converter is closed by a solenoid valve in one position thereof; the pressure in the converter inner space is the same as in the control chamber, and spring means are provided for urging the control piston to its release position when the assembly operates as a torque converter. In the other valve position the pressure prevailing in the converter inner space having its outlet closed is applied to the control piston against the force of the spring means. The pressure in the control chamber is low and thus the friction lining carried by the control piston produces the desired bridging action.

Hydrodynamic torque converter with bridging means

The device consists of a comparison unit 35 comparing the respective speeds 31a and 32a of the input shaft 2 and the output shaft 7 of the converter with a pre-set value so as to supply a 'bridging' control command to an electrohydraulic transducer 14; and a timing unit 34 eliminating the 'bridging' by signal 34a during the changeover from one transmission ratio to another in accordance with the data supplied by the unit 20 and transmitting with a delay the changeover control command to the transmission control elements 13a and 13b.

Electronic device controlling the bridging or locking of a hydrodynamic

The control device comprises a moving slide 25 acted on by a return spring 27 and capable of uncovering an orifice 31 allowing hydraulic fluid to be fed to a release chamber 32 moving the control piston 17 removing the 'bridging' between the input impeller 2 and the output turbine 10 of the converter 1. The 'bridging' is actuated by an electrohydraulic transducer 43 controlled by an electronic device 49 in accordance with the input and output speeds sensed by sensors 46 and 48. 'Bridging' of the converter 1 is thus achieved for all the transmission ratios as well as 'debridging' on each change from one ratio to another.

Growing community of inventors

Jouars-Pontchartrain, France

Claude Chevalier