A sealing structure that allows for formation of a side lip, as well as a labyrinth structure between an oil seal and a torsional vibration damper, even when a reinforcing ring has a short inward flange part. The sealing body 120 includes a side lip 124 extending from near a distal end of an inward flange part 112 of the reinforcing ring 110 radially inward and further toward an air side (A) than a dust lip 122 to a position not as far as the outer circumferential surface of a tubular part 210. The tubular part 210 includes a small-diameter part 211 on which the dust lip 122 slides, and a large-diameter part 212 on the air side (A). The large-diameter part 212 has a tapered surface 212a formed on an outer circumferential surface thereof that reduces in diameter toward the air side (A). An annular gap S is formed between this tapered surface 212a and an inner circumferential surface of the side lip 124.

A power take off includes a housing, an input mechanism that is supported in the housing and is adapted to be rotatably driven by a source of rotational energy, and an output mechanism that is supported in the housing and is rotatably driven by the input mechanism, the output mechanism being adapted to rotatably drive a rotatably driven accessory. The power take off further includes a two piece damping assembly that minimizes the transmission of torque transients from the input mechanism to the output mechanism. The two piece damping assembly may be an input cluster gear assembly that includes a first gear portion and a second gear portion that are supported for rotational movement relative to one another. The two piece damping assembly may also be part of a clutch assembly for selectively the output mechanism to be rotatably driven by the input mechanism.

A sealing structure allows for formation of a side lip, as well as a labyrinth structure between an oil seal and a torsional vibration damper, even when a reinforcing ring has a short inward flange part. The sealing body 120 includes a side lip 124 extending from near a distal end of an inward flange part 112 radially inward and further toward an air side (A) than a dust lip 122 to a position not as far as the outer circumferential surface of a tubular part 210. An annular member 250 is further provided, which is fixed to the outer circumferential surface of the tubular part 210 further on the air side (A) than the side lip 124 and covering an outer circumferential surface of the side lip 124 such that there is a gap between the annular member 250 itself and the outer circumferential surface of the side lip 124.

Torsional vibration dampers having a dual spring-dashpot system are disclosed that result in a lightweight hub and a lightweight inertia ring, which is concentric about the hub. The hub has a two-piece construction: a central hub defining an innermost sleeve that defines a bore for receiving a shaft; and a monolithic, generally-annular spoke defining an outermost ring concentric about and spaced radially outward from the central hub portion. A first elastomer member, which acts as a primary spring to damp torsional vibrations, is positioned concentrically against an inner surface or an outer surface of the outermost ring of the hub with the inertia ring concentrically positioned against the first elastomer member. A second elastomer member is positioned between and operatively couples the central hub to the annular spoke, thereby attributing a flexibility to the hub.

A wheel/hub assembly includes an axle shaft, a wheel, and a hub supporting the wheel on the axle shaft. The wheel/hub assembly has a target resonant frequency of vibration. A tuned mass-spring damper is vibrationally coupled to the wheel/hub assembly, and has a counteracting resonant frequency of vibration that is predetermined with reference to the target resonant frequency of vibration.

A vibration absorber for securely fixing to the housing of a gearbox includes an absorber mass having a first group of segments that are rotationally symmetrical to one another with respect to a rotational axis and/or central axis of the gearbox. The segments can be rigidly connected to one another. The vibration absorber can further include connectors that are rigidly connected to two segments each.

A torsion absorber is provided for attachment to a cylindrical section of a shaft. The torsion absorber includes a flywheel and at least one tensioner. The at least one tensioner is configured to brace a first segment and a second segment of the flywheel against the cylindrical section of the shaft.

An integrated gear and torsional vibration damper assembly (10, 20, 30, 30) includes a gear (11, 21, 31, 41) having a toothed portion (11a, 21a, 31a, 41a) and a torsional vibration damper (12, 22, 32, 42) supported on the gear (11, 21, 31, 41) for limited rotational and dampened movement relative to each other. The gear (11) may include a hub portion (11b), and the torsional vibration damper (12) may be supported on the hub portion (11b) of the gear (11). Alternatively, the gear (21) may include a hub portion (21b), an intermediate ring (23) may be supported on the hub portion (21b) of the gear (21), and the torsional vibration damper (22) may be supported on the intermediate ring (23). Alternatively, the gear (31) may include a toothed portion (31a) and a hub portion (31b) that extends radially inwardly from the toothed portion (31a) and has an opening (31c) extending therethrough, and the torsional vibration damper (32) may extend through the opening (31c). Alternatively, the gear (41) may include an inner circumferential surface that engages and supports an outer circumferential surface of the torsional vibration damper (41).

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 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.