A torque transmission device includes a first element, a second element, and a third element which are able to rotate about an axis of rotation; a first spring which is arranged between the first element and the third element; a second spring which is arranged between the second element and the third element; a first supporting seat positioned at a first end of the first spring; and a second supporting seat positioned at a first end of the second spring. The third element includes a torque transfer element directly transferring torque between the first spring and the second spring.

In an aspect, a spring assembly is provided for an isolator, and includes first and second helical compression springs, a retainer and a spring housing. The first helical compression spring has a central aperture and has a first end and a second end. The second helical compression spring having a central aperture and having a first end and a second end, wherein the second spring is coaxial with and nested within the first spring. The retainer has a base and a post that extends from the base into the central aperture at the first end of the second helical spring. The spring housing that has an interior space in which the first and second springs are positioned, and further includes a base-engaging aperture that holds the base of the retainer. The spring housing includes a drive wall that is engaged with the first ends of the first and second springs.

A spring assembly includes a first coil spring and a second coil spring. The second coil spring includes a first winding portion and a second winding portion. The first winding portion includes a plurality of windings from a first winding to at least a second winding. The second winding portion is a portion except for the first winding portion. An outer diameter of each of the plurality of windings of the first winding portion is smaller than an outer diameter of each of at least one winding of the second winding portion. Each of the plurality of windings of the first winding portion includes the substantially same outer diameter.

A damper disc assembly includes first and second input plates, an output unit, a high stiffness damper unit, and first and second low stiffness damper units. The output unit includes an input-side member and an output-side member disposed rotatably relative to each other. The high stiffness damper unit elastically couples the input-side member and the first and second input plates in a rotational direction and is actuated in a high torsion angular range of torsional characteristics. The first and second low stiffness damper units elastically couple the input-side member and the output-side member and are actuated in a low torsion angular range of the torsional characteristics. The second low stiffness damper unit is actuated later than actuation of the first low stiffness damper unit.

A lock-up device includes a drive plate, a driven plate, first torsion springs, second torsion springs, a spring holder and a rotation restricting unit. The rotation restricting unit is configured to restrict and bring the first torsion spring in each group and the second torsion spring in each group to a deactivated state by at least either of engagement of the spring holder with the driven plate or engagement of the drive plate with the spring holder.

A torque transmission device for a motor vehicle, having a torque input element, a torque output element, and at least one pair of elastic members mounted between the torque input and output elements and counteracting rotation of input and output elements with respect to one another. The elastic members are arranged serially by means of a phasing member so that the elastic members deform in phase with one another. The stiffness K1 of the elastic member mounted between the torque input element and the phasing member is less than the stiffness K2 of the elastic member mounted between the phasing member and the torque output element, the ratio K2/K1 being equal to at least 2. One elastic member of the at least one pair of elastic members includes two coaxial helical springs mounted one inside the other.

A torque transmission apparatus including a first rotor, a second rotor, an elastic body deployed in a torque transmission path between the first rotor and the second rotor to absorb torque fluctuation between the first and second rotors, and a pair of seat members. The pair of seat members include holding portions for holding ends of the elastic body at one end surfaces and contact surfaces at the other end surfaces, and the contact surfaces are formed into convex curved surfaces so as to rollaby contact concave curved lateral end surfaces of a housing of the first rotor and concave curved lateral end surfaces of projecting portions of the second rotor.

Torque is applied to an inner member of a torsional coupling. The first stage (low torque) has a bonded part in series with a set of compression style coil springs. The torsional stiffness of the bonded part is approximately 25% of the resulting torsional stiffness provided by the coil springs. In the second stage (high torque), tangs on the inner member engage with a sprocket plate, transferring torque to the coil springs. The coil springs are held in place by a unique geometry on the sprocket plate and spring holders, which prevent metal-to-metal contact between the coil springs and upper and lower housing portions of the torsional coupling. Surface effect damping occurs at very high torques when the rubber molded around the tangs on the inner member rub on bumps formed on the lower housing portion. A thrust bearing reacts axial forces and eliminates metal-to-metal contact.

A torsional vibration damper (70) with a damping device which has an input (67) and an output (72) which is operatively connected to a driven side (73). The output is connected to a mass damper system (1) and also to a mass arrangement (100). One of the two subassembliesi.e., mass damper system (1) and mass arrangement (100)which are connected to the output (72) of the damping device (70) engages at the respective other subassembly comprising mass damper system or mass arrangement which is in turn connected to the output by a connection arrangement (77).

According to the present invention, in a rotational fluctuation reducing apparatus, a serial connection formed, via an intermediate retainer 36, between a low-rigidity first coil spring 32 and a high-rigidity second coil spring 34 is disposed between the first retainer 16 and the second retainer 18 which form a pair, which are spaced apart from each other in the circumferential direction, and which are made of resin material. The first coil spring 32 and the intermediate retainer 36 are disposed in a bottomed recess 40 of the first retainer 16. During deformation, the intermediate retainer 36 is caused to slide at a radially outer portion of the bottomed recess 40 of the first retainer 16. The second coil spring 34 is contained in a bottomed recess 42 of the second retainer 18. Damping control is performed, in a low-torque range, under low torsional rigidity resulting from the serial connection of the first coil spring 32 and the second coil spring 34, and is performed, in a normal torque range, under high torsional rigidity provided solely by the second coil spring 34. The present invention achieves reduction in abnormal noise due to switching taking place through resin-metal contact and low noise during the idling.