US3882335A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cooling apparatus for the rotor of an electric machine which uses a heat pipe
Assignee: Siemens AG
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Filing: 1973-04-18
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Granted: 1975-05-06
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Expires: 1993-04-18
Abstract
Abstract An improved cooling apparatus for the rotor of an electric motor in which a hollow center portion of the rotor has placed within it working fluid to cause the rotor to act as a heat pipe. The improvement comprises a fan placed over the end of the rotor shaft. The fan has a hollow portion in its hub which acts as an extension of the heat pipe thereby allowing the cooling vanes of the fan and the hub, which forms a part of inner heat pipe surface, to be made of one piece thereby allowing a more efficient heat transfer from the heat pipe to the cooling vanes.
Inventors
- 👤 Paul Fries
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:11
CPC Classifications
F; F28; F28D; F28D15/00; F28D15/02; F28D15/04; H; H02; H02K; H02K9/00; H02K9/22; H02K9/225
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
188 words
Apparatus for improved cooling in an electric machine in which the rotor shaft is hollow and contains a small amount of working fluid so that it acts as a heat pipe comprising: a. a fan having a plurality of essentially rectangular radial vanes, said fan having a hub shaped to fit over the end of the hollow shaft and said fan inclusive its vanes and its hub being formed in a single piece of highly conductive material and said hub having a hollow portion of a diameter equal to that of the hollow shaft to form an extension of the heat pipe, whereby the working fluid will be evaporated in the shaft portion of the heat pipe and will travel to the fan portion of the heat pipe where it will be condensed with heat being removed by the conductive effect of said hub and vanes and the air flowing thereover due to rotation of the fan, b. at least two trapezoidal guide baffles between two different pairs of vanes of said fan; and c. a hood, having a shape matching that of the fan, enclosing said fan.
Claim 2
Dependent Claim
188 words
Apparatus for improved cooling in an electric machine in which the rotor shaft is hollow and contains a small amount of working fluid so that it acts as a heat pipe comprising: a. a fan having a plurality of essentially rectangular radial vanes, said fan having a hub shaped to fit over the end of the hollow shaft and said fan inclusive its vanes and its hub being formed in a single piece of highly conductive material and said hub having a hollow portion of a diameter equal to that of the hollow shaft to form an extension of the heat pipe, whereby the working fluid will be evaporated in the shaft portion of the heat pipe and will travel to the fan portion of the heat pipe where it will be condensed with heat being removed by the conductive effect of said hub and vanes and the air flowing thereover due to rotation of the fan, b. at least two trapezoidal guide baffles between two different pairs of vanes of said fan; and c. a hood, having a shape matching that of the fan, enclosing said fan.
Claim 3
Dependent Claim
13 words
The invention according to claim 1 wherein said guide baffles are diametrically opposed.
Claim 4
Dependent Claim
26 words
The invention according to claim 1, wherein said fan has a threaded portion in its hub and is screwed onto the end of said hollow shaft.
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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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |