US4381867A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatically positionable mechanical shaft seal
Assignee: Nippon Pillar Packing Co Ltd
•
Filing: 1982-03-11
•
Granted: 1983-05-03
•
Expires: 2002-03-11
Abstract
Abstract A mechanical seal made in a unit construction in which a seal unit case is fitted into and held by the inner periphery of a seal housing in a non-rotatable but axially slidable manner, the seal housing houses a rotary ring disposed on a rotary shaft in a non-rotatable but axially slidable manner, and a stationary ring in contact with the rotary ring at the sealing end surfaces thereof is securely fixed to the seal housing. The mechanical seal can be automatically moved to a position where a first fluid and a second fluid are balanced in pressure in response to a difference in pressure between these two fluids.
Inventors
- 👤 Yoshiaki Ohgoshi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:25
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/003; F; F16; F16J; F16J15/00; F16J15/16; F16J15/34; F16J15/3464; F16J15/348; F16J15/3484
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
147 words
A mechanical shaft seal for intercepting a first fluid and a second fluid, comprising: a rotary ring disposed on a rotary shaft in a non-rotatable but axially slidable manner; a stationary ring; a seal unit case for housing said rotary ring and to which said stationary ring is secured; a seal housing, said seal unit case being fitted in airtight fashion to and held by the inner periphery of said seal housing in a non-rotatable manner but being automatically axially displaceable to a position on the shaft at which said first and second fluids are balanced in pressure; and, a spring-load retaining mechanism disposed between said seal unit case and said rotary ring for applying spring-load to said rotary ring to maintain contact between said rotary ring and said stationary ring, regardless of the axial displacement of said unit case and the rotation of said rotary ring.
Claim 2
Dependent Claim
147 words
A mechanical shaft seal for intercepting a first fluid and a second fluid, comprising: a rotary ring disposed on a rotary shaft in a non-rotatable but axially slidable manner; a stationary ring; a seal unit case for housing said rotary ring and to which said stationary ring is secured; a seal housing, said seal unit case being fitted in airtight fashion to and held by the inner periphery of said seal housing in a non-rotatable manner but being automatically axially displaceable to a position on the shaft at which said first and second fluids are balanced in pressure; and, a spring-load retaining mechanism disposed between said seal unit case and said rotary ring for applying spring-load to said rotary ring to maintain contact between said rotary ring and said stationary ring, regardless of the axial displacement of said unit case and the rotation of said rotary ring.
Claim 3
Dependent Claim
58 words
The mechanical shaft seal as recited in claim 1, wherein the seal unit case comprises front and rear walls and a cylindrical portion connecting said front wall to said rear wall, said front and rear walls being fitted in airtight fashion to the inner periphery of the seal housing by O-rings in a non-rotatable but axially slidable manner.
Claim 4
Dependent Claim
40 words
The mechanical shaft seal as recited in claim 2, wherein the stationary ring is securely fixed to the front wall of the seal unit case, and the rotary ring is housed in the cylindrical portion of the seal unit case.
Claim 5
Dependent Claim
73 words
The mechanical shaft seal as recited in claim 3, wherein the spring-load retaining mechanism comprises a fixed ring secured through the rear wall of the unit case; a movable ring opposite to said fixed ring disposed on the rotary shaft in a non-rotatable but axially slidable manner; first and second spring retainers respectively connected to the rotary ring and the movable ring; and, a spring disposed in the first and second spring retainers.
Claim 6
Dependent Claim
55 words
The mechanical shaft seal as recited in claim 4, wherein the first and second spring retainers are formed in an identical cylindrical shape, the abutting ends of the spring retainers being formed in a comb shape to be engaged with each other for permitting both said retainers to be axially moved within a predetermined range.
Claim 7
Dependent Claim
102 words
The mechanical shaft seal as recited in claim 5, wherein: the fixed ring has therein a communicating hole communicating with the second fluid side and the inside of the cylindrical portion of the seal case; the cylindrical portion of the seal case has therein a communicating hole communicating with the inside of the cylindrical portion and the outside thereof, at a position opposite to the sealing end surfaces of the stationary ring and the rotary ring; and, the seal unit case has in the rear wall a communicating hole communicating with the outside of the cylindrical portion and the second fluid side.
Claim 8
Dependent Claim
17 words
The mechanical shaft seal as recited in claim 1, mounted on the rotary shaft of a turbodrill.
Claim 9
Dependent Claim
38 words
The mechanical shaft seal as recited in claim 6, further comprising a guide rod passing through the front and rear walls of the seal unit case, said guide rod permitting the seal unit case only to axially moved.
Claim 10
Dependent Claim
68 words
The mechanical shaft seal as recited in claim 6, wherein the outer peripheries of the front and rear walls of the seal unit case have non-circular sections including linear portions, and the inner periphery of the seal housing, into which the outer peripheries of the front and rear walls are fitted, has a non-circular section corresponding to those of the outer peripheries of the front and rear walls.
Claim 11
Dependent Claim
58 words
The mechanical shaft seal as recited in claim 1, wherein the inner periphery of the rotary ring has a non-circular section including linear portions, and the outer periphery of the rotary shaft, on which the inner periphery of the rotary ring is put, has a non-circular section corresponding to that of the inner periphery of the rotary ring.
Claim 12
Dependent Claim
58 words
The mechanical shaft seal as recited in claim 4, wherein the inner periphery of the movable ring has a non-circular section including linear portions, and the outer periphery of the rotary shaft, on which the inner periphery of the movable ring is disposed, has a non-circular section corresponding to that of the inner periphery of the movable ring.
References Cited (Backward Citations)
US2122378A
Cited
US2354478A
Cited
US3035841A
Cited
US2949321A
Cited
US3180648A
Cited
US3090627A
Cited
DE1155644B
Cited
US3109659A
Cited
US3201135A
Cited
US3339930A
Cited
US3392984A
Cited
US3767212A
Cited
US3810637A
Cited
US3926442A
Cited
US4087100A
Cited
US4104169A
Cited
US4118040A
Cited
US4335888A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-02 | 1986-11-01 | 1987-05-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-02 | 1990-11-01 | 1991-05-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-02 | 1994-11-01 | 1995-05-03 | $7700.00 | Window Closed / Lapsed |