A dynamic damper for suppressing vibration generated by a gear attached to a rotation shaft, the dynamic damper, includes: a mass body that is disposed inside a rotation shaft having a hollow shape and extends along a shaft center of the rotation shaft; and an elastic body that couples the mass body to the rotation shaft. Further, a flow path for lubricating liquid to flow is provided between an inner peripheral surface of the rotation shaft and the mass body, and the flow path is formed by the inner peripheral surface of the rotation shaft at an axial position where the elastic body is disposed.

A dynamic damper includes: a mass body that is disposed inside a rotation shaft and extends along a shaft center of the rotation shaft; and an elastic body interposed between the mass body and the rotation shaft. Further, the mass body is allowed to vibrate to a linear motion state, the elastic body includes: first and second contact surfaces, when the gear generates vibration so as to fall from a radial direction of the rotation shaft to an axial direction side of the rotation shaft, compressive stress acts on the elastic body by the mass body vibrating so as to push the first contact surface in response to the vibration, and when the gear generates vibration along the axial direction, compressive stress acts on the elastic body by the mass body coming in the linear motion state and vibrating so as to push the second contact surface.

A dynamic damper includes: a mass body that is disposed inside a rotation shaft and extends along a shaft center of the rotation shaft; and an elastic body interposed between the mass body and the rotation shaft. Further, the mass body is allowed to vibrate to a linear motion state, the elastic body includes: first and second contact surfaces, when the gear generates vibration so as to fall from a radial direction of the rotation shaft to an axial direction side of the rotation shaft, compressive stress acts on the elastic body by the mass body vibrating so as to push the first contact surface in response to the vibration, and when the gear generates vibration along the axial direction, compressive stress acts on the elastic body by the mass body coming in the linear motion state and vibrating so as to push the second contact surface.

Provided is a torque-transmission joint 15a that is able to reduce the thrust force that is transmitted between the output shaft 12a of an electric motor 8 and a worm shaft 6a without generating noise. A shock-absorbing member 18a that is made using an elastic material is assembled between a driving-side transmission member 16a that is supported by the output shaft 12a and a driven-side member 17a that is supported by the worm shaft 6a. Held sections 33a, 33b of the shock-absorbing member 18a are located between the side surfaces in the circumferential direction of driving-side arm sections 21a of the driving-side transmission member 16a and side surfaces in the circumferential direction of driven-side arm sections 23a of the driven-side transmission member 17a. A damper section 26 is integrally provided with the shock-absorbing member 18a, and that damper section 26 is elastically held between the tip-end surface of the output shaft 12a and the base-end surface of the worm shaft 16a.

Torsional vibration dampers are disclosed that have a hub defining a plurality of fastener-receiving openings and an inertia member concentric about and spaced a radial distance apart from a shaft-receiving member of the hub and having a plurality of receptacles defining a bore oriented axially. Each receptacle aligns with one of the plurality of fastener-receiving openings, and receives one of a plurality of elastomeric rings with a fastener seated therein and received in the fastener-receiving openings to operatively connect the inertia member to the hub through compression of the elastomeric rings. The height of each elastomeric ring is greater than the axial width of the receptacles, and compression of the elastomeric rings deforms each radially into a first gap between the hub and the inertia member and a second gap between the inertia member and the fastener, thereby axially locking the inertia member to the hub for rotation together.

The invention provides a motor for generating rotary power, the motor comprising: a stator for receiving electrical power; a rotor arranged coaxially with respect to the stator and having one or more magnets arranged thereon so that in response to the stator receiving the electrical power, the rotor is caused to rotate; the rotor comprising a rotor housing having an inner wall, the magnets being arranged around the housing, and wherein the inner wall has plural tortuous paths for the flow of coolant extending along the length of the rotor housing. Preferably, the motor has an output shaft arranged at least partially axially within the rotor housing; the inner wall being shaped for engagement with and so as to drive the output shaft.

A vehicle-mounted electric oil-free air compressor, including a motor, a box body, a piston, and a flywheel shaft. The motor is fixed on the box body, a cylinder cover is at the top of the box body, a main shaft of the motor includes a coupling driving end, the flywheel shaft is driven by an elastic body to rotate. The piston includes a primary intake valve piece and a primary exhaust valve piece, the box body is provided with a secondary cavity, a secondary exhaust valve piece is provided at a vent hole on one side of the cavity, and the primary exhaust valve piece is also a secondary intake valve piece of the compressor, increasing the exhaust pressure. When the piston reciprocates, the stress is balanced and the vibration is small, and with the assistance of a high-efficiency flywheel, the operation of the air compressor is stable.

A shock-absorbing member comprises held sections located at a plurality of locations in a circumferential direction and comprising paired held sections and non-paired held sections, and is constructed to have a non-circular cylindrical shape in cross-section. Portions where outer-diameter side end sections of held sections that are adjacent to each other in the circumferential direction are made continuous by way of outer-diameter side cover sections, and portions where inner-diameter side end sections of held sections that are adjacent to each other in the circumferential direction are made continuous directly or by way of inner-diameter side cover sections, in an alternating sequence in the circumferential direction. Drive-side arm sections are placed between the non-paired held sections, driven-side arm sections are placed between the paired held sections, and the outer circumferential surfaces of the drive-side arm sections are covered by the outer-diameter side cover sections.

A sealing structure with a torsional damper and an oil seal includes a damper pulley serving as a torsional damper and an oil seal. The damper pulley has an annular hub pocket that is recessed in the outer side direction and extends in the circumferential direction along a boss part of a hub. The oil seal includes a side lip that extends toward the outer side. An outer circumferential surface of the hub pocket increases in a diameter toward the outer side, the side lip of the oil seal does not enter inside the hub pocket, and an annular gap is formed between an outer side end of the side lip and an inner side end of the outer circumferential surface of the hub pocket.

A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins. The first hub is mounted for concurrent rotation with the input shaft. The second hub is mounted for concurrent rotation with the rotor shaft. The first side coupling assembly has a first side coupling body and a first side elastomeric insert. The first side coupling body includes an inboard body portion having a first series of pockets and an outboard body portion having a second series of pockets. The first side elastomeric insert has a first and second plurality of lobes. The pockets of the first and second series of pockets are tangentially offset relative to each other and each receive respective first and second plurality of lobes therein.