| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotary damper capable of inhibiting communication between one chamber and the other chamber via an outer circumference of a shaft and suppressing wear and frictional force in a packing. <P>SOLUTION: The rotary damper includes: an annular recessed part 11 provided in a casing 2 and facing both of a pressure chamber and an outer circumference of a shaft 1; a side seal 9 housed in the annular recessed part and forming a back pressure chamber P1 between itself and a packing 7; and a discharge passage communicating the back pressure chamber to the one chamber and the other chamber. The side seal receives the pressure of a chamber at a higher pressure in the one chamber and the other chamber and communicates the chamber in the higher pressure to the back pressure chamber, and is pressed by the pressure of the back pressure chamber to tightly adhere to a circumferential side face of the annular recessed part and to an axial end face 1c of a diameter-enlarged part 1b, thereby sealing a gap between the casing and the shaft, blocking communication between the one chamber and the other chamber via the outer circumference of the shaft. The discharge passage releases the pressure of the back pressure chamber to a chamber with a lower pressure in the one chamber and the other chamber and suppresses pressure retention in the back pressure chamber. <P>COPYRIGHT: (C)2013,JPO&INPIT |
