Rotatable assemblies, machining bar assemblies and methods therefor

A rotatable assembly having one end adapted to be secured to a rotatable support for rotating the rotatable assembly about a rotational axis, the rotatable assembly comprising:

• a main body having a cavity;
• a damping mass arranged within the cavity and movable in radial directions, substantially perpendicular to the rotational axis, relative to the main body;
• a damping structure arranged to support the damping mass relative to the main body and arranged to damp vibrational movements of the damping mass relative to the main body in the radial directions;
• and
• at least one auxiliary supporting structure arranged to separate the damping mass and the main body, wherein each auxiliary supporting structure comprises layers of resilient material and layers of metallic material alternatingly arranged along the rotational axis or in the radial directions;
• wherein the damping structure comprises a plurality of spring elements;
• wherein each spring element has a flat appearance;
• wherein the spring elements comprise a material having a frequency dependent elastic modulus;
• and
• wherein the rotatable assembly is configured such that when a vibration frequency of the rotatable assembly is changed 5% from 4530 Hz, the elastic modulus of the spring elements will change to match the changed vibration frequency of the rotatable assembly.

A rotatable assembly having one end adapted to be secured to a rotatable support for rotating the rotatable assembly about a rotational axis, the rotatable assembly comprising:

• a main body having a cavity;
• a damping mass arranged within the cavity and movable in radial directions, substantially perpendicular to the rotational axis, relative to the main body;
• a damping structure arranged to support the damping mass relative to the main body and arranged to damp vibrational movements of the damping mass relative to the main body in the radial directions;
• and
• at least one auxiliary supporting structure arranged to separate the damping mass and the main body,
• wherein each auxiliary supporting structure comprises layers of resilient material and layers of metallic material alternatingly arranged along the rotational axis or in the radial directions,
• wherein the damping structure comprises a plurality of spring elements, and
• wherein each spring element has a flat appearance.