Apparatus utilizing rotary motion of a member as the motive force for a pump
AssigneeNL Industries, Inc.
InventorAndre L. Piazza
Life of this patent
Estimating the term…
Abstract
An arrangement for minimizing the pressure differential across shaft seals is characterized by a pump powered by the rotative force of a shaft to pump a fluid from a reservoir chamber into a chamber next-adjacent to each shaft seal. When the pressures in the chambers adjacent to the seals exceed a predetermined magnitude, a pressure relief arrangement is opened, thus venting the chambers and maintaining the differentials across the seals as minimal as possible.
Claims18
In apparatus of the type having a stationary member, a rotatable member disposed within the stationary member for rotary motion with respect thereto, an upper and a lower seal disposed at axially spaced locations between the rotatable and stationary members to define an interior region therebetween, a bearing to be isolated from regions above the upper seal and below the lower seal mounted to one of the members, the interior region being able to receive a fluid therewithin, wherein the improvement comprises:
- a pumping element disposed in a driven relationship with the rotatable member, the pumping element being disposed intermediate the bearing and the upper seal, a piston element being disposed intermediate the bearing and the lower seal, the pumping element and piston element cooperating to subdivide the interior region into an upper, a lower and a central portion;
- means for communicating the upper portion with the lower portion;
- a pressure relief arrangement between one of the upper or lower portion and the central portion for relieving the pressure generated in a fluid disposable within the former portion into the latter portion when the pressure in the former portion exceeds a predetermined biasing force;
- the pumping element being operable by the rotation of the rotatable member to pump a fluid disposed in the central portion into the upper and lower portions to maintain the pressure of the fluid in the upper and lower regions at a level greater than the pressure of a fluid in the region above the upper seal and in the region below the lower seal.
In apparatus of the type having a housing, a shaft mounted on a bearing for rotation with respect to the housing, a first and a second seal respectively disposed between the shaft and the housing on opposite sides of the bearing to define an interior region able to contain a lubricating fluid therein, the bearing and the first seal defining a first internal chamber, a member disposed between the bearing and the second seal to define a second chamber between the bearing and the member and a third chamber between the member and the second seal, wherein the improvement comprises an arrangement for minimizing pressure differences across the first and second seals, said arrangement comprising:
- means for communicating the first chamber and the third chamber;
- a pressure relief arrangement for venting the third chamber and reducing the pressure in the first chamber when the pressure of the fluid within the third chamber exceeds a predetermined biasing force;
- and
- a pump responsive to motive force imparted thereto by rotation of the shaft to pump fluid from the second chamber to the first and third chambers,
- the pressure relief arrangement being responsive to the force exerted by the fluid in the third chamber so that when the pressure therein exceeds a predetermined magnitude the relief arrangement opens to vent fluid from the third chamber to the second chamber to minimize pressure differences across the seals.
Dependencies are inferred from the claim text.