An anti-resonance apparatus of a propeller shaft may include a support provided in a tube and configured to be rotated with the tube, and including at least a guide pin arranged at equal angles around a longitudinal axis of the tube and formed in a radial direction of the support, at least a mass body slidably engaged to the at least a guide pin and guided by the at least a guide pin to be moved along a longitudinal axis of the at least a guide pin, and a return spring configured to provide an elastic force in a moving direction in which the at least a mass body is moved toward the support.

In a method for identifying an unbalance correction for flexible rotors (1), the rotor (1) is rotatably mounted in two bearing devices. An RPM sensor (4) records the speed of the rotor (1) and a radial movement of the rotor (1) is recorded, by means of position sensors (3) at measuring points (6), during an unbalance measurement run or a plurality of unbalance measurement runs for different rotor speeds. The measured values recorded are fed to an evaluation device (5), which determines the eccentricity measured values assigned to the measuring points (6) by means of expanding the influence coefficient method, and therefore unbalances are determined per plane and eccentricities are determined per measuring point for each measurement run.

A balancing system for a rotating member is presented. The rotating member includes a hollow portion and an axis of rotation which extends through the hollow portion. The balancing system includes a vessel that is insertable into the hollow portion of the rotating member. The vessel includes an outer shell which is shaped to conform to inner walls of the hollow portion. A plurality of solid balancing beads partially fill the vessel. When the vessel is inserted into hollow portion and the rotating member is rotating, the axis of rotation passes through the vessel and the balancing beads are centrifugally positioned within the vessel to compensate for imbalance in the rotating member.

A balance weight having one or more journals with a reduced mass portion disposed between a pair of journal portions that define circumferentially extending bearing surfaces. The reduced mass portion has a body, which defines a circumferentially extending bearing surface that is concentric with the bearing surfaces on the journal portions, and at least one stiffening structure that is configured to resist flexing of the journal portions relative to one another due to the transmission of bending loads through the balance shaft.

A vibration damping device is configured to reduce vibration that causes lateral flexing of an elongated member that extends along a centerline. The device includes a split sleeve co-extending with and disposed about the elongated member, and a spring that extends about the sleeve and exerts a force that biases the sleeve radially inward.

A balance weight having one or more journals with a reduced mass portion disposed between a pair of journal portions that define circumferentially extending bearing surfaces. The reduced mass portion has a body, which defines a circumferentially extending bearing surface that is concentric with the bearing surfaces on the journal portions, and at least one stiffening structure that is configured to resist flexing of the journal portions relative to one another due to the transmission of bending loads through the balance shaft.

A device for balancing a turbomachine rotor having a driver rotor and a driven rotor is provided. The device comprises a base that is coaxially fixable to the turbomachine rotor and configured to transfer torque from the driver rotor to the driven rotor. The device also comprises at least three balancing tools arranged on the base, each balancing tool (i) defining a respective balancing direction along a radial direction of the base and (ii) comprising: a weight moveable along the respective balancing direction, and a motor configured to move the weight along the respective balancing direction to balance the rotor.

A transmission shaft comprising: an input side for inputting torque; an output side for outputting torque; a rod extending in a longitudinal direction between the input side and the output side to transfer torque along the transmission shaft, the rod comprising a first end provided at the input side, a second end provided at the output side and a torsional compliant section extending therebetween providing the transmission shaft with a torsional stiffness. A casing extends around the torsional compliant section and is arranged to resist deflection of the rod without increasing the torsional stiffness of the transmission shaft.

A damped propshaft assembly with a hollow shaft and a tuned damper, which is received in the hollow shaft and includes a liner and a damping member. The liner's mass and stiffness are tuned to attenuate one or more of a bending mode vibration and a torsion mode vibration that occurs at a first predetermined frequency. The liner is not configured to substantially damp shell mode vibration that occurs at a frequency that is not equal to the first predetermined frequency. The damping member is coupled to the liner and is configured to primarily attenuate shell mode vibration in the hollow shaft at one or more desired frequencies. The tuned damper attenuates the at least one of the bending moment vibration and the torsion mode vibration at the first predetermined frequency and also attenuates shell mode vibration. A method for forming a damped propshaft assembly is also provided.

Friction shaft damper includes springy projections pressing against inside surface of a portion of rotor such as drive shaft with spring force. Central mass may be positioned inside surface of drive shaft by projections extending outwardly from central mass and slideably engaging inside surface of drive shaft. Enlarged section or chamber of shaft may surround and axially trap damper. Axially spaced apart sets of springy fingers may position mass inside shaft and radially inner ends of fingers may be secured to mass and radially outer ends of fingers may be positioned and free to slide along inside surface of shaft. Two axially spaced apart annular deflection limiters may be placed around mass with small clearances C between deflection limiters and inside surface of shaft. Damper may be a multi-lobed wave spring having multi-lobed rim attached to mass by struts. Damper may be multi-lobed wave spring with crests.