Shaft seal with lip lifting in response to shaft rotation and gas pressure
AssigneeGMN Georg Muller Nurnberg GmbH
InventorsHeinz Wehrfritz, Michael Brunke
Life of this patent
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Abstract
Apparatus for effecting a seal between a rotary shaft and its enclosure includes a sealing element having an elastic lip portion coupled to the shaft for rotation therewith and a sealing portion associated with the enclosure, the elastic lip portion forming a contact seal with the sealing portion when the shaft is stationary or rotating slowly. The elastic lip portion tends to lift from the sealing portion to form a non-contact seal upon a predeterminable increase in the rate of shaft rotation. Compressed gas is introduced into a region between the rotary elastic lip portion and the sealing portion to form a gas cushion therebetween to facilitate lifting of the elastic lip portion.
Claims9
Apparatus for effecting a seal between a first rotary machine component and a second machine component comprising:
- a sealing element coupled to said first machine component for rotation therewith, said sealing element including an elastic lip portion having a first sealing surface;
- a sealing portion associated with said second machine component, said sealing portion having a second sealing surface adapted to form a seal with said first sealing surface;
- said first sealing surface of said elastic lip portion forming a contact seal with said second sealing surface over a region of mutual engagement when said first machine component is stationary or rotating slowly with respect to said second machine component, said first sealing surface of said elastic lip portion tending to lift from said second sealing surface to form a non-contact seal upon a predeterminable increase in the rate at which said first machine component rotates with respect to said second machine component;
- and
- means for introducing compressed gas into a region between said rotary elastic lip portion and said second sealing surface to form a gas cushion therebetween to facilitate lifting of said first sealing surface from said second sealing surface.
Method for effecting a seal between a first rotary machine component and a second machine component including a sealing element coupled to said first machine component for rotation therewith, said sealing element including an elastic lip portion having a first sealing surface, a sealing portion associated with said second machine component, said sealing portion having a second sealing surface adapted to form a seal with said first sealing surface;
- said first sealing surface of said elastic lip portion forming a contact seal with said second sealing surface over a region of mutual engagement when said first machine component is stationary or rotating slowly with respect to said second machine component, said first sealing surface of said elastic lip portion tending to lift from said second sealing surface to form a non-contact seal upon a predeterminable increase in the rate at which the first machine component rotates with respect to the second machine component, comprising the step of:
- introducing compressed gas into a region between said rotary elastic lip portion and said second sealing surface to form a gas cushion therebetween to facilitate lifting of said first sealing surface from said second sealing surface.
Dependencies are inferred from the claim text.