ROTATION BODY AND COMPRESSOR

摘要

PROBLEM TO BE SOLVED: To provide a rotation body that can suppress resonance by the pendulum motion of a mass body accommodated in a rolling guide part and reduce noise based on a collision between the mass body and the inner surface of the rolling guide part. SOLUTION: A pulley body 42 is formed with a recessed part 45 for accommodating a spherical mass ball 48. The mass ball 48 is spaced by a prescribed distance from the rotational center axis of the pulley body and put in pendulum motion around an axis parallel with the rotational center axis by rolling along a rolling guide face 46 of the recessed part 45. The rolling guide face 46 is provided with a recessed part 46A whose cross section on a plane including the center axis of the pendulum motion is formed in circular arc shape (with an equal radius to the mass ball 48). The mass ball 48 is put in pendulum motion in the state of being partially put inside the recessed part 46A. The movement of the mass ball 48 in the axial direction is thereby regulated.