| 摘要 |
PURPOSE:To eliminate an abrasion portion and to extend the life by bringing a rotary ring out of contact with a stationary ring while a rotary shaft is rotating and bring it into contact with the stationary ring while at halt so as to seal both of them closely. CONSTITUTION:When a pump shaft 1 is rotated and a centrifugal heavy bob unit 31 is moved outward (in an arrow A direction) by means of the centrifugal force, a movable member 25 is guided by a guide pin 30 in one body with a rotary ring 26 against the spring force of a spring 29, and is displaced upward so that the contact face 26a of the rotary ring 26 is brought out of contact with the contact face 20a of a stationary ring 20. On the other hand, while the pump shaft 1 is at halt, no centrifugal force is applied to the centrifugal heavy bob unit 31, thereby, the movable member 25 and rotary ring 26 are both pushed downward by means of the spring force of the spring 29, and the contact face 26a of the rotary ring 26 is brought into contact with the contact face 20a of the stationary ring 20 with an appropriate pressing force. |
