Fluid transmission system with lock-up clutch

#1. Field of the Invention

#The present invention relates to an improvement in a fluid transmission system with a lock-up clutch, comprising a plurality damper springs accommodated in an annular arrangement in an annular spring-accommodating groove defined in a clutch piston of the lock-up clutch, a plurality of first transmitting claws provided on the clutch piston and each inserted between adjacent damper springs, and a plurality of second transmitting claws provided on a turbine impeller and each inserted between the adjacent damper springs in an opposed relation to the first transmitting claws.

#2. Description of the Related Art

#FIG. 1 is a vertical sectional side view of a torque converter with a lock-up clutch according to a first embodiment of the present invention;

#FIG. 2 is a sectional view taken along a line 2—2 in FIG. 1;

#FIG. 3 is a view of an outer side of a turbine impeller in the torque converter;

#The present invention will now be described by way of embodiments with reference to the accompanying drawings.

#Referring first to FIG. 1, a torque converter T as a fluid transmission system includes a pump impeller 2, a turbine impeller 3 opposed to the pump impeller 2, and a stator impeller 4 disposed between the inner peripheries of the pump impeller 2 and the turbine impeller 3. A circulation circuit 6 for transmitting a power by a working oil is defined among the three impellers 2, 3 and 4.

#A side cover 5 is integrally connected to the pump impeller 2 by welding to cover an outer surface of the turbine impeller 3. A starting ring gear 7 is welded to an outer peripheral surface of the side cover 5, and a drive plate 8 coupled to a crankshaft 1 is secured to the ring gear 7 by a bolt 9. A thrust needle bearing 36 is interposed between a hub 3h of the turbine impeller 3 and the side cover 5.