A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

A laundry treating apparatus is provided. The laundry treating apparatus includes a cabinet, a drum accommodated in the cabinet, a tub accommodating the drum, and a dynamic absorber provided to absorb oscillation of the cabinet. The dynamic absorber includes a support plate coupled to the cabinet, a first moving mass movably provided on the support plate to absorb oscillation transmitted to the cabinet, and a second moving mass movably provided on the support plate to absorb oscillation transmitted to the cabinet. To absorb the oscillation, a time point at which the second moving mass starts relative motion with respect to the support plate is different from that at which the first moving mass starts relative motion with respect to the support plate.

A coupling device according to an embodiment is a coupling device for connecting a first shaft and a second shaft that includes a primary inner ring member mounted on the first shaft, a primary outer ring member disposed on an outer circumferential side of the primary inner ring member, a primary elastic member for connecting the primary inner ring member and the primary outer ring member, a secondary inner ring member mounted on the second shaft, a secondary outer ring member disposed on an outer circumferential side of the secondary inner ring member, a secondary elastic member for connecting the secondary inner ring member and the secondary outer ring member, and a weight attaching plate interposed between the primary outer ring member and the secondary outer ring member, the weight attaching plate including a weight attaching portion capable of attaching and detaching an additional weight to and from the outer circumferential side of the primary outer ring member and the outer circumferential side of the secondary outer ring member.

A joint mechanism comprises at least one body, at least one first roller and at least one second roller mutually positioned on said body and is configured to move any one of said first roller and second roller towards the other so as to allow a beam used particularly in vibration isolation mechanisms to translate along at least one first axis. The body has at least one first part and at least one second part essentially adjacent to each other and said first part and said second part are engaged by means of at least one first flexible element in a manner such that they allow at least partial movement with respect to each other, so as to allow said beam to be rotated at least partially around at least one rotating point in the direction of at least one second axis.

A vibration damper is proposed with two damper halves which enclose a passage opening in the assembled state and, in the installed position, bear against a component which is guided through the passage opening. The damper halves have corresponding latching means which permit an attachment of the vibration damper to the component. Each damper half has in each case one collar, which collars, in the assembled state of the vibration damper, are arranged at opposite ends of the vibration damper. The vibration damper can be mounted simply, even retrospectively. Moreover, the vibration damper can also be released again without damage.

A “TUNABLE VISCOELASTIC NEUTRALIZER WITH OSCILLATING MASS ON SHAFT FOR CONTROL OF VIBRATIONS IN PIPES IN GENERAL” is a dynamic viscoelastic vibration neutralizer for industrial pipes, consisting of a metallic housing (CAR), to which the shaft supports (SE1 and SE2) are fixed, by means of the use of the screws (PF1, PF2, PF3, PF4, PF5 and PF6), the supports of the viscoelastic pieces (SM1 and SM2) and the supports of the housing itself (SC1, SC2, SC3 and SC4), which allow the junction of the device with the system to be controlled; an oscillating mass (MAS), fixed in the center of a metallic shaft (EIX), which is supported by the shaft supports (SE1 and SE2); and two sets of viscoelastic pieces (MV-1 and MV-2), which are fixed by one of their ends to the supports of the viscoelastic pieces (SM1 and SM2) and by the other to the oscillating mass (MAS).

A directional vibration control apparatus, which includes a tunable vibration absorber (TVA) for a vibratory compactor machine is provided. The TVA includes a frame mounting structure that is configured to mechanically interface with a frame of the vibratory compactor to provide a fixed attachment of the TVA to the frame of the vibratory compactor, a TVA carrier that extends from the frame mounting structure into an interior portion of a drum of the vibratory compactor machine, a resilient element that includes a first portion that is fixedly attached relative to the TVA carrier and a second portion that includes a degree of freedom of movement relative to the TVA carrier, and a mass that is attached to the second portion of the resilient element and that includes the degree of freedom of movement relative to the TVA carrier.

A device for damping vibrations in a structure including a first (or inner) element rotatably mounted around a rotational axis and a second (or outer) element rotatably mounted around said rotational axis. A radius (R1) of a circle portion delimitating the first element with respect to the rotational axis, being smaller than a radius (r2) of a circle portion delimitating the second element with respect to the rotational axis.

In one embodiment, a method for cooling an engine damper, including converting a gas to a liquid, and cooling an engine damper by passing the liquid through a tube portion located between fan air flow and the engine damper.

A power transmission device includes an inertia ring, a plate, a plurality of first bolts, a torque transmission member, and a plurality of second bolts. The inertia ring has an annular shape. The inertia ring includes a plurality of through holes. The plurality of through holes are disposed at intervals in a circumferential direction. The plate is disposed on a first side with respect to the inertia ring in an axial direction. The plurality of first bolts are screwed into the plurality of through holes from the first side to fasten the plate to the inertia ring. The torque transmission member is disposed on a second side with respect to the inertia ring in the axial direction. The plurality of second bolts are screwed into the plurality of through holes from the second side to fasten the torque transmission member to the inertia ring.