ROTARY DAMPER

PURPOSE: To provide a rotary damper in which its follow-up property is excellent at a high torque, and its directivity can take toward the magnitude of braking action. CONSTITUTION: A housing 1 in which a guide groove 2 is formed along an inner circumference and a step part 3 is formed at an opening end, and a first projection 12 engaged with the guide groove 2 are formed along an outer circumference, and also a second projection 13 is formed along the inner circumference, and a ring collar 11 moved in the shaft direction of the housing 1 and a flange 32 arranged in the center of the shaft direction are watertightly and rotatively attached on the step part 3 by an O-ring 51 and a cap 61. A rotary damper comprises a shaft 31 in which a spiral groove 34 engaged with the second projection 13 is formed along the outer circumference which is passed through the collar 11 and inserted in the housing 1, a coil spring 41 arranged between the bottom of the housing 1 and the collar 11, and by which the collar 11 is energized in the direction of the flange 32, and silicone oil 71 filled in a space consisting of the housing 1 and the flange 32.