Seal/bearing assembly
AssigneeA. W. Chesterton Company
InventorThomas W. Ramsay
Life of this patent
Estimating the term…
Abstract
For fitment into the stuffing box of a centrifugal pump. A spiral-groove is cut on the outer surface of the rotor of a pair of tapered bearing surfaces. The groove is 0.02 mm deep, 2 mm wide, and its circumferential length is 50 cm. Barrier-liquid is fed to an entry-mouth of the spiral-groove, and groove generates a pressure in the stuffing box high enough to overcome process pressure. The barrier-liquid may be water. The interface between the bearing surfaces is sealed from the process-fluid and from the outside.
Claims49
Apparatus for a rotating shaft, comprising a stator component, and a rotor component adapted for rotation about the axis of rotation of the shaft, wherein:
- the rotor and the stator components are formed with complementary tapered bearing-surfaces coaxially disposed about the axis;
- the bearing-surfaces of the rotor and stator components are so arranged as to sweep each other in a hydro-dynamic-bearing relationship, over an area termed the bearing area, upon rotation of the rotor;
- one of the bearing-surfaces is formed with a continuous spiral groove, which extends in a spiral configuration along and around the bearing-surface, over the bearing area;
- the spiral-groove comprises several turns extending over the bearing-surface, the arrangement thereof being such as to leave lands between adjacent turns of the spiral-groove;
- the apparatus is so structured that the spiral-groove has an entry-mouth and an exit-mouth;
- apparatus is so structured as to define an entry-chamber and an exit-chamber, being chambers which are in fluid-conveying-communication with the entry-mouth and the exit-mouth respectively;
- the apparatus includes a means for receiving a barrier-liquid from a source of barrier-liquid, and for conveying the barrier-liquid to the entry-chamber;
- the apparatus is so structured that the fit of the bearing-surfaces ensures the establishment and the continuance, during rotation, of a hydro-dynamic film between the bearing-surfaces.
Seal assembly apparatus for a rotating shaft having an impeller and mounted for rotation within a housing comprising a stator component and a rotor component adapted for rotation about the axis of rotation of the shaft, characterized in that the apparatus includes the following features, in combination:
- the stator and rotor components are annularly and coaxially disposed about the shaft axially adjacent to the impeller and have complementary axially tapered surfaces for fitting together in a male-female configuration, the rotor being secured for rotation with the shaft and the stator being secured to the housing;
- one of the complementary surfaces is formed with a continuous spiral groove which extends in a spiral configuration around the surface, the spiral groove having open entry and exit mouths at opposite axial ends, and the complementary surfaces are configured for positively pumping a barrier fluid for sealing toward the impeller fully across the surface upon rotation of the rotor;
- and a means for receiving a barrier fluid from a source of barrier fluid, and for reliably conveying the barrier fluid to the open entry mouth of the spiral groove.
Dependencies are inferred from the claim text.