US4829254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor with velocity indicating device
Assignee: Johnson Electric SA
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Filing: 1987-08-31
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Granted: 1989-05-09
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Expires: 2007-08-31
Abstract
Abstract A fractional horsepower permanent magnet direct-current motor has a velocity indicating device positioned around the commutator, between the brush gear and the armature. The device comprises a conductor in the form of a square wave copper strip which is printed on a flexible support and centered on a circle about the motor shaft, and a magnet assembly mounted on the armature. Magnet assembly comprises radially extending blades which are formed from plastics bonded magnetic material. The blades are magnetized so that adjacent blades have opposite polarity. As the magnet rotates with the shaft, the blades move relative to the conductor and so induce an electrical signal in the conductor. The signal can be monitored to indicate the motor speed as is generally known. The blades also act as a centrifugal fan, helping to cool the motor.
Inventors
- 👤 Roger F. Baines
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:29
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/42; G01P3/44; G01P3/46; G01P3/465; G01P3/48; G01P3/481; G01P3/487; H; H02; H02K; H02K23/00; H02K23/66; H02K7/00; H02K7/20
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
158 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein the magnet means comprises a plurality of radially extending fan blades, radially outer ends of circumferentially adjacent fan blades having opposite polarity.
Claim 2
Dependent Claim
158 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein the magnet means comprises a plurality of radially extending fan blades, radially outer ends of circumferentially adjacent fan blades having opposite polarity.
Claim 3
Dependent Claim
23 words
A motor as claimed in claim 1, wherein apertures are provided in the housing adjacent the radially outer ends of the fan blades.
Claim 4
Dependent Claim
27 words
A motor as claimed in claim 1, wherein said conductor is square wave-shaped and arranged in a circle centred on an axis of rotation of the rotor.
Claim 5
Dependent Claim
14 words
A motor as claimed in claim 3, wherein the conductor is square wave shaped.
Claim 6
Dependent Claim
18 words
A motor as claimed in claim 4, wherein the conductor is printed on an annular flexible plastics support.
Claim 7
Dependent Claim
208 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein said conductor is square wave-shaped and arranged in a circle centered on an axis of rotation of the rotor, wherein the conductor is printed on an annular flexible plastics support, and wherein said conductor is formed in a plurality of layers, each layer printed on a respective said annular support, said supports being integral with one another and folded together, the conductor paths in the layers being in register with each other.
Claim 8
Dependent Claim
208 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein said conductor is square wave-shaped and arranged in a circle centered on an axis of rotation of the rotor, wherein the conductor is printed on an annular flexible plastics support, and wherein said conductor is formed in a plurality of layers, each layer printed on a respective said annular support, said supports being integral with one another and folded together, the conductor paths in the layers being in register with each other.
Claim 9
Dependent Claim
21 words
A motor as claimed in claim 6, wherein said conductor is positioned on an end of a stator of the motor.
Claim 10
Dependent Claim
17 words
A motor as claimed in claim 7, wherein the motor is a permanent magnet direct current motor.
Claim 11
Dependent Claim
210 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein said conductor is wave-shaped and arranged in a circle centred on an axis of rotation of the rotor, wherein the conductor is a printed circuit, printed on an annular flexible plastics support, and wherein said conductor is formed in a plurality of layers, each layer printed on a respective said annular support, said supports being integral with one another and folded together, the conductor paths in the layers being in register with each other.
Claim 12
Dependent Claim
210 words
An electric motor having a housing, a rotor rotatably mounted in the housing and comprising a shaft, a wound armature and a commutator mounted fast on the shaft and electrically connected to a winding of the armature, and brush gear bearing on the commutator, wherein velocity detecting means is provided in the motor housing between the brush gear and the armature, the detecting means comprising magnet means mounted on the rotor between the armature and the brush gear for rotation along a path with the rotor, and conductor means mounted in the motor housing adjacent the path of rotation of the magnet means, the arrangement being such that rotation of the magnet means relative to the conductor means induces an electrical signal in the conductor means indicative of the speed of rotation of the rotor, wherein said conductor is wave-shaped and arranged in a circle centred on an axis of rotation of the rotor, wherein the conductor is a printed circuit, printed on an annular flexible plastics support, and wherein said conductor is formed in a plurality of layers, each layer printed on a respective said annular support, said supports being integral with one another and folded together, the conductor paths in the layers being in register with each other.
Claim 13
Dependent Claim
21 words
A motor as claimed in claim 9, wherein said conductor is positioned on an end of a stator of the motor.
Claim 14
Dependent Claim
17 words
A motor as claimed in claim 10, wherein the motor is a permanent magnet direct current motor.
Claim 15
Dependent Claim
24 words
A motor as claimed in claim 10, wherein the conductor is supported on an annular ferromagnetic ring positioned between the conductor and the stator.
Claim 16
Dependent Claim
30 words
A motor as claimed in claim 6, wherein the magnet means comprises a plurality of radially extending fan blades, radially outer ends of circumferentially adjacent fan blades having opposite polarity.
Claim 17
Dependent Claim
48 words
A motor as claimed in claim 1, wherein said conductor is formed in a plurality of layers, each layer printed on a respective said annular support, said supports being integral with one another and folded together, the conductor paths in the layers being in register with each other.
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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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |