US4428719A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brushless motor fan
Assignee: Hitachi Ltd
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Filing: 1981-05-06
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Granted: 1984-01-31
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Expires: 2001-05-06
Abstract
Abstract Provided is a brushless-motor fan unit having a centrifugal fan and a scroll casing enclosing the centrifugal fan therein. The rotor of the brushless-motor is carried by the centrifugal fan. Further, the motor shaft carrying the centrifugal fan is supported at its front and rear ends by the scroll casing. With this construction, the motor housing can be eliminated so as to obtain a compact centrifugal type motor fan unit in a small thickness as a whole.
Inventors
- 👤 Toshio Hayashibara
- 👤 Kunihiro Noto
- 👤 Yoshinori Fukasaku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:04
CPC Classifications
F; F04; F04D; F04D25/00; F04D25/02; F04D25/06; F04D25/0606
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
188 words
In a brushless motor fan unit of centrifugal type, comprising: a scroll casing having an inlet port, a scroll space and a compartment located on a side of said scroll space opposite said inlet port; a brushless motor accommodated in compartment and including a rotor, a stator concentric with said rotor and a shaft concentric with said rotor and having a front and a rear end; a centrifugal fan supported in said scroll space by said shaft and driven by said rotor, said centrifugal fan having a rear end part onto which a conical hub is concentrically attached, having an apex directing toward said inlet port; and a power unit for energizing said brushless motor, wherein the improvement comprises front means, positioned at said inlet port, for supporting said front end of said shaft and rear means, positioned in said compartment, for supporting said rear end of said shaft, said rotor being directly attached to a side of said rear end part that is opposite the side to which said conical hub is attached, concentrically therewith, and said stator being attached to said scroll casing with said compartment.
Claim 2
Dependent Claim
188 words
In a brushless motor fan unit of centrifugal type, comprising: a scroll casing having an inlet port, a scroll space and a compartment located on a side of said scroll space opposite said inlet port; a brushless motor accommodated in compartment and including a rotor, a stator concentric with said rotor and a shaft concentric with said rotor and having a front and a rear end; a centrifugal fan supported in said scroll space by said shaft and driven by said rotor, said centrifugal fan having a rear end part onto which a conical hub is concentrically attached, having an apex directing toward said inlet port; and a power unit for energizing said brushless motor, wherein the improvement comprises front means, positioned at said inlet port, for supporting said front end of said shaft and rear means, positioned in said compartment, for supporting said rear end of said shaft, said rotor being directly attached to a side of said rear end part that is opposite the side to which said conical hub is attached, concentrically therewith, and said stator being attached to said scroll casing with said compartment.
Claim 3
Dependent Claim
20 words
A brushless-motor fan unit as set forth in claim 1, wherein said front and rear means rotatably support said shaft.
Claim 4
Dependent Claim
18 words
A brushless-motor fan unit as set forth in claim 2, wherein said rotor is surrounded by said stator.
Claim 5
Dependent Claim
17 words
A brushless motor fan unit as set forth in claim 1, wherein said rotor surrounds said stator.
Claim 6
Dependent Claim
37 words
A brushless-motor fan unit as set forth in claim 3 or 4, wherein said power unit includes a speed control device having rotor position sensors, control circuits and power transistors feeding an electrical power to said stator.
Claim 7
Dependent Claim
24 words
A brushless-motor fan unit as set forth in claim 5, wherein said rotor position sensors and said control circuits are disposed in said compartment.
Claim 8
Dependent Claim
22 words
A brushless-motor fan unit as set forth in claim 5, wherein said speed control device as a whole disposed in said compartment.
Claim 9
Dependent Claim
31 words
A brushless motor fan unit as set forth in claim 1, wherein said conical hub defines therein ventilating holes through which a cooling-air circulation is established by way of said compartment.
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) | 1987-01-30 | 1987-08-01 | 1988-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-30 | 1991-08-01 | 1992-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-30 | 1995-08-01 | 1996-01-31 | $7700.00 | Window Closed / Lapsed |