Hydraulic torque converter for automotive vehicle

1. A hydraulic torque converter for an automotive vehicle, comprising:

an impeller (I) coaxial with an axis A and provided with impeller vanes ( 1 ), each defined by an inner side edge ( 11 ), an outer side edge ( 12 ), a trailing edge ( 13 ) and a leading edge ( 14 );

a turbine (T) coaxial with the axis A and provided with turbine vanes ( 2 ), each defined by an inner side edge ( 21 ), an outer side edge ( 22 ), a trailing edge ( 23 ) and a leading edge ( 24 ); and

a reactor (R) coaxial with the axis A and provided with reactor vanes ( 3 ), each defined by an inner side edge ( 31 ), an outer side edge ( 32 ), a trailing edge ( 33 ) and a leading edge ( 34 );

the turbine vanes ( 2 ) defining, during rotation thereof, a turbine envelope ( 52 ), the envelope ( 52 ) comprising a turbine inner side surface ( 62 ), a turbine trailing surface ( 82 ) and a turbine leading surface ( 92 ), defined by the inner side edges ( 21 ), the trailing edges ( 23 ) and the leading edges ( 24 ) respectively of the turbine vanes ( 2 ) during the rotation;

the impeller ( 1 ) vanes defining, during rotation thereof, an impeller envelope ( 51 ), the envelope ( 51 ) comprising an impeller inner side surface ( 61 ), an impeller trailing surface ( 81 ) and an impeller leading surface ( 91 ), defined by the inner side edges ( 11 ), the trailing edges ( 13 ) and the leading edges ( 14 ) respectively of the impeller vanes ( 1 ) during the rotation;

the reactor vanes ( 3 ) defining, during rotation thereof, a reactor envelope ( 53 ), the envelope ( 53 ) comprising a reactor inner side surface ( 63 ), a reactor trailing surface ( 83 ) and a reactor leading surface ( 93 ), defined by the inner side edges ( 31 ), the trailing edges ( 33 ) and leading edges ( 34 ) respectively of the reactor vanes ( 3 ) during the rotation;

the side surfaces of the turbine, impeller and reactor together defining an envelope of an inner core;

the impeller trailing surface ( 81 ) being separated by an outer axial distance d 1 from the turbine leading surface ( 92 ), the turbine trailing surface ( 82 ) being separated by an inner axial distance d 2 from the reactor leading surface ( 93 ), the outer and inner axial distances respectively corresponding to the minimum axial distance between the surfaces concerned at the facing points which are closest to each other;

the ratio of the distances d 2 /d 1 being equal to or lower than 1.4;

the reactor comprising at least one vane the leading edge of which defines the reactor leading surface during rotation thereof, the at least one vane being qualified as an “elongated” reactor vane.

2. The hydraulic torque converter according to claim 1 , wherein the ratio of the distances d 2 /d 1 is equal to or lower than 1.1.

3. The hydraulic torque converter according to claim 1 , wherein the ratio of the distances d 2 /d 1 is equal to or greater than 0.6.

4. The hydraulic torque converter according to claim 1 , wherein the ratio of the distances d 2 /d 1 is equal to or greater than 0.9.

5. The hydraulic torque converter according to claim 1 , wherein the converter comprises a plurality of “elongated” reactor vanes.

6. The hydraulic torque converter according to claim 5 , wherein the plurality of “elongated” reactor vanes are distributed in a regular manner at the periphery of the reactor.

7. The hydraulic torque converter according to claim 5 , wherein each alternate reactor vane is the “elongated” vane.

8. The hydraulic torque converter according to claim 5 , wherein all of the reactor vanes are “elongated”.

9. An automatic transmission for an automotive vehicle, comprising a hydraulic torque converter in accordance with claim 5 .

10. An automatic transmission for an automotive vehicle, comprising a hydraulic torque converter in accordance with claim 1 .