US 5,195,754 AGranted

Laterally translating seal carrier for a drilling mud motor sealed bearing assembly

AssigneeKalsi Engineering, Inc.

InventorLannie Dietle

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Abstract

A sealing and lubrication assembly for rotating shafts intended for operation in an abrasive environment and wherein the rotary shaft may have lateral translation or excursion during its rotation. A housing receives the rotary shaft in bearing supporting relation and defines a lubricant chamber about the shaft. A seal carrier is movably positioned about the rotary shaft and has non-rotatable articulating or laterally translating relation with the housing. A high pressure rotary shaft seal is supported by the seal carrier and maintains bearing and sealing engagement with the rotary shaft during its lateral translation or excursion. The seal carrier is hydraulic force balanced and thus is not subject to pressure induced loads that might otherwise interfere with its articulation or lateral translation.

Claims29

Dependent claims

A high pressure rotary shaft sealing mechanism for a rotary shaft of equipment capable of operating in a high pressure fluid environment and having a sealing surface that is subject to lateral excursion during rotation thereof, said rotary shaft sealing mechanism comprising:

(a) a housing having said rotary shaft located therein and projecting therefrom;
(b) a pilot being located within said housing;
(c) a laterally translating seal carrier being disposed within said housing and about said rotary shaft and having at least a portion thereof capable of lateral translation responsive to lateral excursion of said sealing surface of said rotary shaft;
(d) a first sealing element establishing sealing engagement between said pilot and said laterally translating seal carrier and establishing a first pressure responsive sealing area of said seal carrier;
and
(e) a second sealing element establishing sealing engagement between said laterally translating seal carrier and said sealing surface of said rotary shaft and defining a second pressure responsive area of said seal carrier being substantially equal with said first pressure responsive area, whereby opposed pressure induced hydraulic forces acting axially and oppositely on said first and second pressure responsive areas of said laterally translating seal carrier are substantially balanced and thus said laterally translating seal carrier in substantially free floating and is thus readily movable by shaft induced forces and is capable of simultaneous lateral excursion along with said sealing surface of said rotary shaft to maintain optimum sealing engagement between said second sealing element and said sealing surface of said rotary shaft during all aspects of rotation and lateral excursion thereof.

3 more elements

A high pressure sealing and lubrication assembly for a rotary shaft intended for operation in an abrasive environmental medium having an environmental pressure, wherein said rotary shaft is supported by bearings for rotation and defines a sealing surface thereabout that is subject to lateral translation during rotation of said rotary shaft, said sealing and lubrication assembly comprising:

(a) a housing rotatably receiving said rotary shaft therein and forming a lubricant chamber about said rotary shaft adapted to receive a liquid lubricant;
(b) a pilot being located within said housing;
(c) a seal carrier being disposed about said rotary shaft and having non-rotatable laterally translating movable relation with said housing, said seal carrier having a seal retainer and having a seal support defining a minimal extrusion gap with said rotary shaft;
(d) a static sealing element establishing sealed relation with said pilot and said seal carrier and defining a first pressure responsive area exposed to said lubricant chamber;
(e) a rotary shaft seal establishing sealed relation between said seal carrier and said rotary shaft, said rotary shaft seal establishing a second pressure responsive are substantially equal to and opposing said first pressure responsive area for substantially balancing pressure induced axial force acting on said seal carrier, whereby said rotary shaft seal remains free for lateral translation by said rotary shaft at all ranges of environmental pressure, thus permitting said rotary shaft seal to maintain said sealing engagement with said rotary shaft during all aspects of shaft rotation and lateral translation.

2 more elements

In a mud motor for deep earth boring in the drilling of wells for petroleum products and having a housing a rotary shaft extending from the housing for driving connection with a rotary drill bit, and having a lubricant chamber between said housing said rotary shaft, the improvement comprising:

(a) a pilot being located within said housing;
(b) a laterally translating seal carrier being disposed within said housing and about said rotary shaft;
(c) a first sealing element establishing a sealed relation between said pilot and said laterally translating seal carrier and defining a first axial pressure responsive area of said laterally translating seal carrier;
and
(d) a second sealing element establishing a sealed relation between said laterally translating seal carrier and said rotary shaft, said second sealing element defining a second axial pressure responsive area of said laterally translating seal carrier being substantially equal and axially opposite said first pressure responsive area, whereby opposing axially directed hydraulically induced forces acting on said laterally translating seal carrier and being developed by the pressure of lubricant within said lubricant chamber and the pressure of drilling fluid in which said mud motor is immersed are substantially balanced and said laterally translating seal carrier is thus free for lateral translation by forces imparted thereto by said rotary shaft and said second sealing element is enabled to maintain optimum sealing engagement with said rotary shaft.

2 more elements

Dependencies are inferred from the claim text.