| CPC F16F 9/12 (2013.01) [F16F 2222/12 (2013.01); F16F 2232/02 (2013.01); F16F 2236/106 (2013.01)] | 5 Claims |
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1. A rotary damper comprising:
a housing of which an inside is filled with a viscous fluid;
a cap which closes an opening of the housing; and
a rotor which exposes a shaft to an outside from the cap and is accommodated in the housing and rotatably supported with respect to the housing,
wherein the rotary damper imparts a resistance to rotation of the rotor by a torque generated by a shear resistance of the viscous fluid,
the housing includes a bearing portion which is formed at a center of a bottom surface facing a side surface of the rotor and rotatably supports a shaft center of the shaft, a plurality of walls which are erected concentrically centered on the bearing portion, include notches which are formed at point-symmetrical peripheral positions centered on the bearing portion and distributed and arranged at peripheral positions evenly dividing circumferences centered on the bearing portion between adjacent walls, and have a height forming a predetermined gap with the side surface of the rotor, a peripheral wall which is formed around an outermost wall of the plurality of walls and has a height abutting on a side surface of the cap, and a fitting portion which is formed around the peripheral wall and fitted to the cap,
the rotor includes a supported portion which is formed at a center of the side surface facing the bottom surface of the housing and rotatably supported by the bearing portion, a plurality of walls which are erected concentrically centered on the supported portion at a pitch deviated from a standing pitch of the walls of the housing by a half pitch, includes notches formed in walls surrounded by an outermost wall at point-symmetrical peripheral positions centered on the supported portion and distributed and arranged at peripheral positions evenly dividing circumferences centered on the supported portion between adjacent walls, and have a height forming a predetermined gap with the bottom surface of the housing, a peripheral wall formed in a polygonal shape which is erected around the outermost wall of the plurality of walls and has a height forming a predetermined gap with the bottom surface of the housing, and a plurality of discharge holes which are formed at equal intervals with equal arc lengths in a circumferential direction centered on the supported portion and open the side surface of the rotor on an inner peripheral side of the peripheral wall, and
the cap has a lid portion which covers a side surface of the rotor opposite to the side surface on which the plurality of walls are formed, and a peripheral edge portion which is formed around the lid portion and is fitted to the fitting portion of the housing.
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