Coupling assembly with double shear channel

A coupling assembly (11) for transmitting torque between a first part (14) and a second part (16), which parts (14, 16) are rotatable relative to one another, said coupling assembly (11) comprising said first and second parts (14, 16) and a friction coupling means (12) having first friction plates (15) non-rotatably connected to the first part (14) of the coupling assembly and having second friction plates (17) non-rotatably connected to the second part (16) of the coupling assembly, and further comprising pressure generating means (13) comprising a pump body member (20) and an axially-displaceable piston (19) for loading the friction coupling means (12), and a pressure chamber (21) formed by the pump body member (20) and by the piston (19) and filled with a highly viscous fluid, wherein the pump body member (20) is non-rotatably connected to the first part (14) of the coupling assembly (11) and wherein at least one conveying plate (22) is provided in the pressure chamber (21), which conveying plate (22) is non-rotatably connected to the second part (16) of the coupling assembly (11), and wherein a shear channel-control member subcombination (23) is provided in the pressure chamber (21), which member (23) cooperates with at least one conveying plate (22), characterised in that the shear channel-control member subcombination (23) forms two circumferential grooves (35, 36) which are of limited length and which are each covered by one of the two radial surfaces of the conveying plate (22) and thus form two shear channels (37, 38), and that the conveying plate (22) comprises through passages (54) which connect the two shear channels (37, 38) to one another, and that there is an open connection between the one end of said shear channels and a reservoir (26) and between the other end of said shear channels and the pressure chamber (21).

A coupling assembly (111) for transmitting torque between a first part (114) and a second part (116), which parts (114, 116) are rotatable relative to one another, said coupling assembling (111) comprising said first and second parts (114, 116) and friction coupling means (112) having first friction plates (115) non-rotatably connected to the first part (114) of the coupling assembly (111) and having second friction plates (117) non-rotatably connected to the second part (116) of the coupling assembly (111), and further comprising a pressure generating device (113) comprising a pump body member (120) and an axially-displaceable piston (119) for loading the friction coupling means (112), and a pressure chamber (121) formed by the pump body member (120) and by the piston (119) and filled with a highly viscous fluid, wherein the pump body member (120) is non-rotatably connected to the first part (114) of the coupling assembly (111) and wherein at least one conveying plate (122) is provided in the pressure chamber (121), which conveying plate (122) is non-rotatably connected to the second part (116) of the coupling assembly (111), and wherein a shear channel-control member subcombination (123) is provided in the pressure chamber (121), which member (123) cooperates with at least one conveying plate (22), characterised in that the shear channel-control member subcombination (123) forms a circumferential groves (135) which is of limited arcuate length and which is covered by one of the two radial surfaces of the conveying plate (122) to form a first shear channel (137), and in the shear channel-control member subcombination (123) there is provided a circumferential slot (136) which is of limited arcuate length and which is covered by the other one of the two radial surfaces of the conveying plate (122) on the one hand and by a second conveying plate (129) on the other hand, which is also non-rotatably connected to the second part (116) of the coupling assembly (111) to form a second shear channel (138), that the first conveying plate (122) comprises through-passages (154) which connect the shear channels (137, 138) to one another, and that there is an open connection between the one end of said shear channels and a reservoir (126) and between the other end of said shear channels and the pressure chamber (121).