US4357550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brushless D.C. motor
Assignee: Papst Licensing GmbH and Co KG
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Filing: 1980-01-14
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Granted: 1982-11-02
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Expires: 2000-01-14
Abstract
Abstract The invention relates to a collectorless D.C. motor with a horizontal air gap, particularly a low-speed motor for the direct drive of recording and/or reproducing devices. As per invention, the rotor axle is supported within an axial bore of the motor housing, with the motor housing made of plastic. The stator winding and the magnetic return structure are fixedly arranged on the motor housing which is also provided with bores for attaching the motor on installing it into the device. Obviating of machining sequences, simplification of assembly and direct support of the rotor axle in the motor housing all contribute to a reduction in manufacturing cost.
Inventors
- 👤 Siegfried Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:15
CPC Classifications
H; H02; H02K; H02K29/00; H02K29/06; H02K29/08; H02K5/00; H02K5/04; H02K5/08; H02K5/16; H02K5/167; H02K5/1675; H02K7/00; H02K7/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
In a commutatorless D.C. motor with a plane air gap and a rotor shaft, particularly for use as a direct drive of signal-processing recording and/or reproducing devices, an improvement comprising a plastic motor housing having a bore extending perpendicular to the plane of the air gap, said rotor shaft being received in said bore, said bore being shaped so as to form at least two bearing surfaces supporting the rotor shaft and to further form spaces between the rotor shaft and the housing, said spaces containing lubricant; and a thrust bearing located at a lower end of the bore and supporting a lower end of the rotor shaft.
Claim 2
Dependent Claim
108 words
In a commutatorless D.C. motor with a plane air gap and a rotor shaft, particularly for use as a direct drive of signal-processing recording and/or reproducing devices, an improvement comprising a plastic motor housing having a bore extending perpendicular to the plane of the air gap, said rotor shaft being received in said bore, said bore being shaped so as to form at least two bearing surfaces supporting the rotor shaft and to further form spaces between the rotor shaft and the housing, said spaces containing lubricant; and a thrust bearing located at a lower end of the bore and supporting a lower end of the rotor shaft.
Claim 3
Dependent Claim
24 words
The improvement defined by claim 1, further including a magnetic return structure fixed to the plastic housing on at least a lower face thereof.
Claim 4
Dependent Claim
32 words
The improvement defined by claim 2, wherein the magnetic return structure has a cross-section which varies circumferentially in accordance with pole spacing in the motor, whereby a momentum of reluctance is generated.
Claim 5
Dependent Claim
12 words
The improvement defined by claim 1, wherein the bearing surfaces are cylindrical.
Claim 6
Dependent Claim
18 words
The improvement defined by claim 4, wherein at least two of the bearing surfaces are unequal in diameter.
Claim 7
Dependent Claim
12 words
The improvement defined by claim 1, wherein the thrust bearing is adjustable.
Claim 8
Dependent Claim
43 words
The improvement defined by claim 1, further including an element contacting the rotor shaft when the rotor shaft is received within the bore, whereby electrostatic charges accumulated on a rotor attached to the rotor shaft may be discharged to ground through the element.
Claim 9
Dependent Claim
16 words
The improvement defined by claim 1, wherein the rotor shaft has a convexly curved lower end.
Claim 10
Dependent Claim
43 words
The improvement defined by claim 8, further including at least one element contacting the rotor shaft at its lower end, whereby electrostatic charges accumulated on a rotor attached to the rotor shaft may be discharged to ground through said at least one element.
Claim 11
Dependent Claim
30 words
The improvement defined by claim 1, wherein the bearing surfaces have deformable projections which deform when the rotor shaft has been received within the bore, whereby bearing play is minimized.
References Cited (Backward Citations)
US3354332A
Cited
US3678314A
Cited
US4079277A
Cited
US3932069A
Cited
US4072874A
Cited
US4208784A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |