| 摘要 |
Annular sealing apparatus comprising a resilient sleeve 2 deformable between a closed sealing configuration FIG 1 and an open non-sealing configuration FIG 2. Pump 1 is controllable to effect deformation by alteration of pressure exerted on the sleeve. The sealing sleeve may be a waisted annular band / hyperboloid. The pump may be arranged to provide suction to deform the sleeve to the open position or increase pressure to increase the sealing force in the closed position. An end 8 of the sleeve may be axially movable to accommodate deformation of the sleeve. There may be a pressure sensor 14 in communication with a control system 16. The pump may be connected to a cavity 7 between the sleeve and a housing 5. An accumulator may be provided to compensate for variations in volume of the cavity. The sleeve may be polymeric, elastomeric or rubber and may mitigate wear. |
