Mud-lubricated bearing assembly with mechanical seal
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
F16C-033/74
F16C-003/00
F16C-017/10
F16C-017/04
E21B-004/00
출원번호
US-0252507
(2016-08-31)
등록번호
US-RE46746
(2018-03-06)
발명자
/ 주소
Marchand, Nicholas Ryan
Prill, Jonathan Ryan
출원인 / 주소
NATIONAL OILWELL VARCO, L.P.
대리인 / 주소
Conley Rose, P.C.
인용정보
피인용 횟수 :
0인용 특허 :
13
초록▼
In a mud-lubricated bearing assembly for a downhole motor, a mechanical seal is provided between the mandrel and the lower end of the bearing housing to prevent discharge of drilling fluid (mud) from the bearing assembly into the wellbore annulus. The mechanical seal is effected by mating wear-resis
In a mud-lubricated bearing assembly for a downhole motor, a mechanical seal is provided between the mandrel and the lower end of the bearing housing to prevent discharge of drilling fluid (mud) from the bearing assembly into the wellbore annulus. The mechanical seal is effected by mating wear-resistant annular contact surfaces provided on the mandrel and the bearing housing, with biasing means preferably being provided to keep the contact surfaces in sealing engagement during both on-bottom and off-bottom operational modes. The diverted drilling fluid passing through the bearings is redirected into the bore of the mandrel via ports through the mandrel wall to rejoin the main flow to the drill bit, such that substantially all of the drilling fluid flows through the bit.
대표청구항▼
1. A mud-lubricated bearing assembly comprising: a generally cylindrical housing;an elongate mandrel having a longitudinal bore, saidwherein the mandrel beingis coaxially disposed within the housing and beingis rotatable relative to the housing;a thrust bearing configured to transfer axial on-bottom
1. A mud-lubricated bearing assembly comprising: a generally cylindrical housing;an elongate mandrel having a longitudinal bore, saidwherein the mandrel beingis coaxially disposed within the housing and beingis rotatable relative to the housing;a thrust bearing configured to transfer axial on-bottom loads and off-bottom loads from the mandrel to the housing;a radial bearing disposed within thean annular space between the mandrel and the housing and, where in the radial bearing is configured to maintain coaxial alignment of the mandrel and the housing;an annular lower seal ring coaxially and non-rotatably secured to a lower region of the mandrel, saidwherein the lower seal ring havingincludes an annular upper seal surface in a plane perpendicularly transverse to the longitudinal axis of the mandrel; andan annular upper seal ring mounted to a lower region of the housing such that, wherein the upper seal ring is non-rotatable relative to the housing and axially movable relative to the housing within a defined range of travel, saidand wherein the upper seal ring havingincludes an annular lower seal surface matingly engageable with the upper seal surface of the lower seal ring;wherein the mandrel includes one or more fluid ports configured to allow fluid flow into the mandrel bore of the mandrel from anthe annular space between the mandrel and the housing. 2. AThe bearing assembly as inof claim 1, further comprising biasing means for maintaining said upper and lower seal surfaces in mating engagement. 3. AThe bearing assembly as inof claim 2, wherein the biasing means comprises a spring. 4. AThe bearing assembly as inof claim 2, wherein the spring is disposed above the upper seal ring in the annular space between the mandrel and the housing. 5. AThe bearing assembly as inof claim 1, further comprising a seal assembly for sealing between the upper seal ring and the housing. 6. AThe bearing assembly as inof claim 5, wherein the seal assembly comprises an O-ring disposed within an annular seal groove in an outer surface of the upper seal ring. 7. AThe bearing assembly as inof claim 1, wherein non-rotatability of the lower seal ring relative to the mandrel is provided by an interference fit between the lower seal ring and the mandrel. 8. AThe bearing assembly as inof claim 1, wherein non-rotatable axial movability of the upper seal ring relative to the housing is provided by a plurality of axially-oriented splines on the upper seal ring that slidably engages a plurality of mating grooves on the housing. 9. AThe bearing assembly as inof claim 1, wherein the upper seal surface on the lower seal ring and the lower seal surface of the upper seal ring are wear-resistant. 10. AThe bearing assembly as inof claim 9, wherein the upper and lower seal surfaces are provided with wear resistance by hard facing. 11. AThe bearing assembly as inof claim 1, wherein the upper seal surface on the lower seal ring and the lower seal surface of the upper seal ring are polished. 12. AThe bearing assembly as inof claim 1, further comprising means for providing a pressure drop across the bearing assembly. 13. AThe bearing assembly as inof claim 12, wherein the means for providing a pressure drop comprises a flow-restricting nozzle disposed in a lower region of the mandrel bore. 14. The bearing assembly of claim 1, wherein the upper seal ring is axially movable relative to the housing within a defined range of travel. 15. The beating assembly of claim 1, wherein the annular upper seal surface of the lower seal ring is disposed in a plane perpendicularly transverse to the longitudinal axis of the mandrel. 16. A mud-lubricated bearing assembly comprising: an outer housing;an elongate mandrel coaxially disposed within the outer housing, wherein the mandrel includes a longitudinal bore and is configured to rotate relative to the outer housing;a thrust bearing disposed in an annular space between the mandrel and the outer housing, wherein the thrust bearing is configured to transfer axial on-bottom loads and off-bottom loads from the mandrel to the housing;a radial bearing disposed within an annular space, where in the radial bearing is configured to maintain coaxial alignment of the mandrel and the outer housing;a first seal ring disposed about the mandrel, wherein the first seal ring is non-rotatably coupled to the mandrel and includes an annular seal surface; anda second seal ring disposed about the mandrel, wherein the second seal ring is non-rotatably coupled to the outer housing and includes an annular seal surface that, matingly engages the annular seal surface of the first seal ring:wherein the mandrel includes a fluid port extending radially from the annular space to the bore of the mandrel. 17. The bearing assembly of claim 16, wherein the second seal ring is axially moveable relative to the outer housing. 18. The bearing assembly of claim 17, wherein the second seal ring is axially moveable relative to the outer housing within a defined range of travel. 19. The bearing assembly of claim 16, wherein the first seal ring is positioned axially below the second seal ring. 20. The bearing assembly of claim 16, further comprising biasing means disposed in the annular space, wherein the second seal ring is axially positioned between the biasing means and the first seal ring, and wherein the biasing means is configured to urge the annular seal surface of the second seal ring into engagement with the annular seal surface of the first seal ring. 21. The bearing assembly of claim 16, further comprising an annular seal assembly radially positioned between the second seal ring and the housing. 22. The bearing assembly of claim 16, wherein the first seal ring is non-rotatably coupled to the mandrel with an interference fit. 23. The bearing assembly of claim 16, wherein the second seal ring is coupled to the outer housing with a plurality of axially-oriented splines on the second seal ring that slidably engage a plurality of mating grooves on the outer housing.
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Crase Gary M. (Cypress CA), Adjustable stacked bearing assembly.
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