Patent US3741679A successfully refreshed from Google Patents.
US3741679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal pump
Assignee: Subscription Television Inc
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Filing: 1971-09-17
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Granted: 1973-06-26
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Expires: 1991-09-17
Abstract
Abstract A centrifugal pump is provided with an improved impeller sealing arrangement which substantially reduces the likelihood of seal failure or leakage of the pump. The drive shaft of the impeller is sealed on one side of the pump housing by a mechanical seal carried in a non-pressurized reservoir of liquid, and a reduced pressure area is created by the pump impeller on an opposite side of the pump housing so that any tendency to leak will be from the reservoir to the pumped fluid. The mechanical seal which may be of a single or double face type is disposed within a reservoir containing an aqueous mixture of ethylene glycol which is under atmospheric pressure so that the normal direction of flow is from the reservoir through the seal faces and into the low pressure region. The above described pump may be provided with either straight centrifugal or self priming inlet housing sections and may be provided with a bearing pedestal or the pump shaft may be directly connected to the output shaft of an electric motor or other driving device.
Inventors
- 👤 D Johnston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:41
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/08; F04D29/10; F04D29/12; F04D29/126; F04D29/16; F04D29/165; F04D29/167; F16; F16J; F16J15/00; F16J15/16; F16J15/164; F16J15/40; Y; Y10; Y10S; Y10S277/00; Y10S277/91
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
231 words
A centrifugal pump comprising: a housing provided with an interior pumping chamber having a liquid inlet passage and a liquid outlet passage; impeller means mounted for rotation within said chamber for receiving liquid from said inlet passage and pumping it to said outlet passage, said impeller means including an impeller disc having one side thereof facing said inlet passage and a plurality of vanes carried by said one side and extending from adjacent the axis to the periphery thereof; drive shaft means connected to said impeller means and extending from the other side of said disc outwardly through a wall of said housing; mechanical seal means for said drive shaft means including two relatively-rotatably-engaged parts, one carried by said housing wall and the other by said drive shaft means; means defining a seal chamber exterior of said housing adapted to receive and hold a liquid at about atmospheric pressure in contact with the interengagement between said parts for cooling and cleaning said seal means; and means for maintaining a pressure less than atmospheric on the pumping chamber side of said seal means to induce a flow of liquid from said seal chamber between said parts into said pumping chamber, comprising at least one aperture extending through said impeller disc at a position close to the axis thereof and behind and closely adjacent to the trailing surface of one of said vanes.
Claim 2
Dependent Claim
231 words
A centrifugal pump comprising: a housing provided with an interior pumping chamber having a liquid inlet passage and a liquid outlet passage; impeller means mounted for rotation within said chamber for receiving liquid from said inlet passage and pumping it to said outlet passage, said impeller means including an impeller disc having one side thereof facing said inlet passage and a plurality of vanes carried by said one side and extending from adjacent the axis to the periphery thereof; drive shaft means connected to said impeller means and extending from the other side of said disc outwardly through a wall of said housing; mechanical seal means for said drive shaft means including two relatively-rotatably-engaged parts, one carried by said housing wall and the other by said drive shaft means; means defining a seal chamber exterior of said housing adapted to receive and hold a liquid at about atmospheric pressure in contact with the interengagement between said parts for cooling and cleaning said seal means; and means for maintaining a pressure less than atmospheric on the pumping chamber side of said seal means to induce a flow of liquid from said seal chamber between said parts into said pumping chamber, comprising at least one aperture extending through said impeller disc at a position close to the axis thereof and behind and closely adjacent to the trailing surface of one of said vanes.
Claim 3
Dependent Claim
34 words
The structure defined in claim 1 including first annular sealing means between the housing and the side of the impeller means opposite the inlet passage for sealing the mechanical seal means from discharge pressure.
Claim 4
Dependent Claim
54 words
The structure defined in claim 2 including second annular sealing means between the housing and the other side of the impeller means for sealing the inlet passage from discharge pressure, the diameters of said first and second annular sealing means being such as to substantially axially balance the hydraulic pressures on said impeller means.
Claim 5
Dependent Claim
16 words
The pump as claimed in claim 1 wherein said seal chamber reservoir contains an aqueous solution.
Claim 6
Dependent Claim
14 words
The pump as claimed in claim 4 wherein said aqueous solution includes ethylene glycol.
Claim 7
Dependent Claim
39 words
The pump claimed in claim 1 wherein said inlet pasSage is generally circular in cross section and said aperture is formed nearer to the axis of rotation of said impeller means than is the periphery of said suction passage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |