| 摘要 |
<p>Contactless sealing between low speed, (5-1500 rpm), rotary shaft (302) and wall (304) is achieved in dusty environments by enabling build-up of powdery material on facing surfaces of seal (300). Labyrinthine annular passage (L, shown with exaggerated clearances) between shaft (302) and wall (304) has minimum initial clearance of not less than 0.4 mm, however entrained powder entering passage (L) deposits in layers on facing surfaces thereof to reduce cross-section of passage (L) and fluid flow therethrough. L-section setting rings may be inserted in passage (L) at assembly to maintain correct clearances. They will deteriorate rapidly during running-in of seal (300) but may contribute to build-up of powder layers.</p> |
