Patent ID: 8220603
Filing Date: 2012-07-17
Classification: F16F

Abstract:
1. A rotary damper, comprising a casing, an intermediate rotor mounted on the casing so as to be rotatable about an axis of rotation (x), and a braking element, functionally interposed between the casing and the intermediate rotor to brake the rotation of the intermediate rotor with respect to the casing, and additionally comprising a terminal rotor mounted on the intermediate rotor so as to be rotatable about said axis of rotation, wherein the intermediate rotor and the terminal rotor delimit between them a lateral support surface and a lateral shaft surface which is rotatable within the lateral support surface, a plurality of rolling elements being interposed between these surfaces, said lateral shaft and support surface and said rolling elements being positioned in such a way that, in a first direction of rotation (A) of the lateral shaft surface with respect to the lateral support surface, the terminal rotor can rotate freely with respect to the intermediate rotor, and, in a second and opposite direction of rotation (B) of the lateral shaft surface with respect to the lateral support surface, the terminal rotor is coupled rigidly to the intermediate rotor, wherein a plurality of recesses are formed on the lateral shaft surface, each recess accommodating a corresponding rolling element, said lateral support surface forming a circular track for the rolling elements, and each recess being shaped so as to create, in the second direction of rotation, a centrifugal displacement of the corresponding rolling element such that the rolling element is locked between the recess and the lateral support surface; wherein each recess comprises an aperture side which is flush with the circumferential part of the lateral shaft surface, an abutting side, formed so as to face in the first direction of rotation (A) and designed to drive the corresponding rolling element in this first direction of rotation (A), and a wedge side, formed so as to face in the second direction of rotation (B) and designed to guide the corresponding rolling element in the centrifugal direction in the second direction of rotation (B); and wherein said casing comprises a pivot portion formed on the base of the casing, said pivot portion projecting axially from said base, wherein said intermediate rotor comprises a disc portion, and a shaft portion and a collar portion extending coaxially from the disc portion the shaft portion and the collar portion forming an annular cavity delimited therebetween, said intermediate rotor having a central hole formed in the disc portion, through which the intermediate rotor is rotatable mounted on the pivot portion of the casing, wherein said terminal rotor has a central through hole formed therein, through which the terminal rotor is rotatably mounted on the shaft portion of the intermediate rotor, and wherein said lateral support surface is formed by a radially inner surface of the collar portion of the intermediate rotor, and said lateral shaft surface is formed by a radially outer surface of the terminal rotor.