US3836216A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure balanced seal assembly
Assignee: Avco Corp
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Filing: 1973-04-02
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Granted: 1974-09-17
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Expires: 1993-04-02
Abstract
Abstract A pressure balanced seal assembly comprising a nonrotatable split carbon ring in sealing engagement with a rotatable shaft. A steel pressure balance ring has a pair of tabs which connect with the free ends of the split carbon ring. The outer periphery of the pressure balance ring is connected to a low pressure discharge so that pressure which acts to urge the carbon ring into the shaft also urges the pressure balance ring outward, thus urging the carbon ring toward an expanded position. This causes the carbon ring to be urged inward against the shaft with a substantially uniform force irrespective of the pressure acting on the carbon ring.
Inventors
- 👤 A Junker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:05
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/26; F16J15/30; F01; F01D; F01D11/00; F01D11/003; F16C; F16C27/00; F16C27/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
186 words
A seal assembly for first and second elements rotatable with respect to one another and having an annular gap therebetween, said seal assembly comprising: a ringlike sealing element positioned across said gap and nonrotatable with respect to said first element and abutting said second element, said sealing element being exposed to a pressure urging said sealing element against said second element; a pressure balance ring adjacent said sealing element and having a first surface facing said sealing element and a second surface facing away from said sealing element, said pressure balance ring having means for connecting with said sealing element so that displacement of said pressure balance ring away from said sealing element urges said sealing element away from said second element; and means for maintaining a pressure on the second surface of said pressure balance ring that is substantially lower than the pressure acting to urge said sealing element against said second element whereby said pressure balance ring is urged away from said sealing element to maintain a substantially uniform force urging said sealing element against said second element irrespective of variations in said pressure.
Claim 2
Dependent Claim
186 words
A seal assembly for first and second elements rotatable with respect to one another and having an annular gap therebetween, said seal assembly comprising: a ringlike sealing element positioned across said gap and nonrotatable with respect to said first element and abutting said second element, said sealing element being exposed to a pressure urging said sealing element against said second element; a pressure balance ring adjacent said sealing element and having a first surface facing said sealing element and a second surface facing away from said sealing element, said pressure balance ring having means for connecting with said sealing element so that displacement of said pressure balance ring away from said sealing element urges said sealing element away from said second element; and means for maintaining a pressure on the second surface of said pressure balance ring that is substantially lower than the pressure acting to urge said sealing element against said second element whereby said pressure balance ring is urged away from said sealing element to maintain a substantially uniform force urging said sealing element against said second element irrespective of variations in said pressure.
Claim 3
Dependent Claim
62 words
A seal assembly as in claim 1 wherein said pressure maintaining means comprises an annular element having an annular recess into which the second surface of said pressure balance ring extends, said element having at least one port extending to a low pressure source thereby to maintain a pressure differential across said pressure balance ring urging it away from said sealing element.
Claim 4
Dependent Claim
50 words
A seal assembly as in claim 1 wherein said sealing element is a split ring and said pressure balance ring is a split ring positioned around the periphery of said sealing ring whereby expansion of said pressure balance ring radially outward urges said sealing element away from said second element.
Claim 5
Dependent Claim
37 words
A seal assembly as in claim 3 wherein said connection means on said pressure balance ring comprises a pair of tabs at the free end thereof projecting into recesses adjacent the free end of said sealing ring.
Claim 6
Dependent Claim
37 words
A seal assembly as in claim 4 wherein said pressure balance ring has a series of recesses formed on its inner facing side in between a series of lands which abut the periphery of said sealing ring.
Claim 7
Dependent Claim
32 words
A seal assembly as in claim 5 wherein said pressure balance ring is formed from a flexible material and sized to compress said sealing ring against said second element under static conditions.
Claim 8
Dependent Claim
46 words
A seal assembly as in claim 5 further comprising a pin fixed to said first element and received in recesses adjacent the free end of said pressure balance ring thereby preventing said pressure balance ring and said sealing ring from rotating relative to said second element.
Claim 9
Dependent Claim
38 words
A seal assembly as in claim 7 wherein said first element comprises an annular housing including a radial wall having an opening anD said second element comprises a shaft extending through said opening and rotatable in said housing.
Claim 10
Dependent Claim
60 words
A seal assembly as in claim 8 wherein said pressure maintaining means comprises an additional radial wall adjacent said first-mentioned radial wall to form a recess in said housing, said housing having at least one port connected to a low pressure source exterior of said housing, said recess being formed to receive the second surface of said pressure balance ring.
Claim 11
Dependent Claim
47 words
A seal assembly as in claim 9 further comprising: a bearing assembly for journaling said shaft relative to said housing on one side of said radial wall; and means for forming a pressure chamber on the opposite side of said radial wall thereby providing said pressure force.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |