A damper device includes a first rotary element, a second rotary element, and a third rotary element being each rotatable about a rotary center, a first elastic member elastically expanding and contracting in response to a relative rotation of the first rotary element and the second rotary element, a first stopper being provided at the first rotary element and the second rotary element, the first stopper restricting the relative rotation of the first rotary element and the second rotary element by a contact thereof, a second elastic member elastically expanding and contracting in response to a relative rotation of the second rotary element and the third rotary element, and a second stopper being provided at the first rotary element and the third rotary element, the second stopper restricting the relative rotation of the first rotary element and the third rotary element by a contact thereof.

A disk assembly of a torque converter bypass clutch includes a disk defining a circular spring cavity and a plurality of arc springs circumferentially arranged in the cavity with gaps defined between adjacent ones of the arc springs. Each of the springs includes an end cap fitted on an end of the spring. Spring connectors are each disposed in one of the gaps and include an end received within a corresponding one of the end caps.

An arcuate spring having a plurality of coils which are configured and dimensioned to provide an arcuate shape to the spring and being substantially free of internal stresses which would tend to urge the coils into linear alignment. The spring is designed to function under load conditions while maintaining its natural arcuate shape. The spring is can be heated by use of an induction heating process.

A damper device according to an embodiment includes first to third rotating elements rotatable about a rotational center; a first elastic element located between the first and third rotational elements and compressed by relative rotation of the first rotational element to the third rotational element in one rotational direction; a second elastic element located between the second and third rotational elements and compressed by relative rotation of the third rotational element to the second rotational element in the one rotational direction, a support member intervenient between the third rotational element and the first elastic element to support the first elastic element; and a restrictor provided with the third rotational element to rotatably support the support member in a plane orthogonal to the rotational center, to restrict the support member from rotating beyond a certain angle and from moving away from the third rotational element in rotational directions.

A damper device includes: a pressing plate; a rotation plate disposed to oppose the pressing plate; an elastic member elastically linking the pressing and rotation plates, and in which bending is generated when relative twist of the pressing and rotation plates is generated; and seats provided on both end surfaces of the elastic member The seat has a projected surface, the pressing plate has a recessed surface corresponding to the projected surface, the seats and the pressing plate come into surface-contact with each other in a case where the relative twist is not generated, one seat and the pressing plate come into surface-contact with each other, and a void is formed between the other seat and the pressing plate, in a case where the relative twist is generated, and the void increases as an angle of the relative twist increases.

A disk assembly of a torque converter bypass clutch includes a disk defining a circular spring cavity and a plurality of arc springs circumferentially arranged in the cavity with gaps defined between adjacent ones of the arc springs. Each of the springs includes an end cap fitted on an end of the spring. Spring connectors are each disposed in one of the gaps and include an end received within a corresponding one of the end caps.

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.

An isolator includes a driver that is connectable with a shaft of a device, a rotary drive member that is engageable with an endless drive member; and a first isolation spring and a second isolation spring. The first and second isolation springs are positioned such that during rotation of the driver in a first direction torque is transferred from the driver to the first rotary drive member through the first isolation spring and not through the second isolation spring, and such that during rotation of the first rotary drive member in the first direction torque is transferred from the first rotary drive member to the driver through the second isolation spring and not through the first isolation spring.

A damper device includes a first rotary element, a second rotary element, and a third rotary element being each rotatable about a rotary center, a first elastic member elastically expanding and contracting in response to a relative rotation of the first rotary element and the second rotary element, a first stopper being provided at the first rotary element and the second rotary element, the first stopper restricting the relative rotation of the first rotary element and the second rotary element by a contact thereof, a second elastic member elastically expanding and contracting in response to a relative rotation of the second rotary element and the third rotary element, and a second stopper being provided at the first rotary element and the third rotary element, the second stopper restricting the relative rotation of the first rotary element and the third rotary element by a contact thereof.

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.