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Dokumentenidentifikation EP0639305 07.11.1996
EP-Veröffentlichungsnummer 0639305
Titel VORRICHTUNG ZUR ERMITTLUNG DER ROTORSTELLUNG FÜR EINEN BÜRSTENLOSEN MOTOR
Anmelder Samsung Electronics Co., Ltd., Kyungki, KR;
Jung, Yeong Chun, Seoul, KR
Erfinder JUNG, Yeong Chun, Yangchun-gu, Seoul 158-097, KR
Vertreter Kahler, Käck & Fiener, 86899 Landsberg
DE-Aktenzeichen 69305162
Vertragsstaaten DE, IT
Sprache des Dokument En
EP-Anmeldetag 04.05.1993
EP-Aktenzeichen 939104303
WO-Anmeldetag 04.05.1993
PCT-Aktenzeichen KR9300036
WO-Veröffentlichungsnummer 9322820
WO-Veröffentlichungsdatum 11.11.1993
EP-Offenlegungsdatum 22.02.1995
EP date of grant 02.10.1996
Veröffentlichungstag im Patentblatt 07.11.1996
IPC-Hauptklasse H02K 29/10

Beschreibung[en]
Technical Field

The present invention is related to a rotor position detecting apparatus for a brushless motor, and particularly to a rotor position detecting apparatus for a compressor which is embodied by a brushless motor.

Background Art

In a refrigerator, an air conditioner or similar appliance, a compressor, which is used for changing the state of a fluid, for example refrigerant, is generally embodied by an A.C. induction motor. Furthermore, the compressor used in the appliance is tightly closed with housings welded together in order to prevent a decrease in the pressure therein. Within the housing, a motor is connected to a piston (in a reciprocating compressor). A connector, which is mounted in the body of the housing, has several terminals electrically connected to each of the phase windings of the motor. When the phase voltages are applied to the terminals, the axis of the motor starts to rotate, thereby causing the piston connected to the axis to reciprocate within a cylinder. In the manner described above, refrigerant is drawn into the cylinder and is then compressed. The closed compressor is required to normally operate under the temperature condition of a maximum 130°C and several tens of Psi, and to endure oil and refrigerant.

Compared with an A.C. motor, a brushless motor has a low noise level and low power consumption, and may be operated at continuously varying rotating rate. Considering the advantages, a closed compressor embodied by a brushless motor has been continuously developed. The brushless motor is activated by D.C. currents, out of phase from each other, flowing into each of the phase windings. Accordingly, a means for detecting the polarity of the rotor is essential to the brushless motor. A pair of light emitting and receiving elements are typically used for detecting the polarity of the rotor.

However, there is a problem in that it is impossible to place the elements in the housing of the closed compressor, which operates under the condition of high temperature and high pressure, because the elements are normally made of semiconducting material. Furthermore, there is another problem in that the compressor seal is easily damaged because the signal wires of the elements are drawn out of the housing. Considering these problems, there has been developed a system using a winding induced voltage, instead of detecting by the elements. However, the system has a problem in that a means for detecting the winding induced voltage, a filter means and a means for starting the compressor are additionally required, and also it is not applicable to the brushless motor.

Rotor position detecting apparatuses using a photoelectric conversion system and optical fibers for transmitting and receiving light signals are known in the prior art from GB-A-2 221 031, EP-A-0 285 053 and FR-A-2 562 298.

Disclosure of Invention

It is an object of the present invention to provide a rotor position detecting apparatus constructed with simple configuration without damaging the sealing of a closed compressor embodied by a brushless motor.

According to the present invention, there is provided a rotor position detecting apparatus for an electric motor, wherein said motor includes a stator, a rotor and a closed, sealed housing, said apparatus further comprising:

  • a plurality of light reflecting members attached to the surface of the rotor of the motor around the rotor axis;
  • a plurality of light non-reflecting members attached to the surface of the rotor alternating with said light reflecting members;
  • a pair of optical fibers for transmitting and receiving a light signal, one end of the pair of optical fibers positioned to face the surface of the rotor,
  • said pair of optical fibers being divided into two sections, one being internal of the housing and the other being external of the housing,
  • a pair of light emitting and photoelectric converting elements respectively positioned to face the other end of said pair of transmitting and receiving optical fibers; and,
  • a connector mounted to the body of the housing, said connector comprising a plurality of terminals connected to phase windings of the stator, a hole for guiding said pair of transmitting and receiving optical fibers, and a transparent window which allows said internal section of said pair of optical fibers to face said external section of said pair of optical fibers whilst physically separating said two sections of said pair of optical fibers.

Brief Description of the Drawings

The present invention will now be described in detail with reference to the accompanying drawings: in which,

  • Fig. 1 is a plane view of a compressor, to which an apparatus of the present invention is applied, from which the upper cover thereof has been removed;
  • Fig. 2 is a circuit diagram for explaining a rotor position detecting apparatus according to the present invention; and,
  • Figs. 3A to 3D are cross-sectional views of a connector for a phase voltage supply and optical fibers, in which 3A is a cross- sectional view of a connector, 3B is a cross-sectional exploded view of a connector, 3C is a cross-sectional view of a connector wherein the optical fibers are connected, and 3D is a right side view of a connector.

Best Mode for Carrying out the Invention

As a preferred embodiment employing a rotor position detecting apparatus according to the present invention, a closed compressor will now be described in detail.

Referring to Fig. 1, the numeral 1 denotes a housing for tightly closing the compressor. Stator 2 with windings 21, is annularly fixed to the housing 1, and a rotor 3 is rotatably secured as surrounded by the stator 2. In the preferred embodiment, it will be explained that the compressor is embodied by a bipolar two-phase brushless motor, but the number of poles and phase windings of the motor may be increased as appropriate. A control system for driving the brushless motor has already been disclosed in U.S patent No. 4,472,664 by the inventor of the present invention. Therefore, a further description will be omitted in the specification. Two light reflecting members 31 are attached to the upper surface of the rotor 3 in two 90° arc quadrants opposite each other around the rotor axis. Two light non-reflecting members 32 are also attached to the upper surface of the rotor 3 in alternating 90° arc quadrants with the light reflecting members 31. For example, the two light reflecting members 31 may be attached to the N-poles of the rotor 3, and the two light non-reflecting members 32 may be attached to the S-poles thereof. It is also possible to arrange the light reflecting and non-reflecting members 31 and 32 in other configurations. For example, the two light reflecting members 31 may be attached to the S-poles of the rotor 3, and the two light non-reflecting members 32 may be attached to the N-poles thereof. The number of the light reflecting and non-reflecting members 31 and 32 may be properly increased according to the number of poles and phase windings of the rotor 3. The light reflecting and non-reflecting members 31 and 32 may be also attached to the cylindrical surface of the rotor 3. One end of a pair of optical fibers 41 and 42 for transmitting and receiving light respectively are positioned 0 to face the upper surface of the rotor 3, to which the light reflecting and non-reflecting members 31 and 32 are attached. The numeral 7 denotes a connector which has terminals 71 electrically connected to the phase windings 21 and the ground line. The connector 7 also has a hole for guiding the pair of 5 optical fibers 41 and 42 through the middle portion thereof. The pair of optical fibers 41 and 42 may be drawn out of the housing 1 through the hole, and the other end of the pair of optical fibers 41 and 42 is positioned to face a pair of light emitting and photoelectric elements 8 and 5. However, when the pair of optical fibers 41 and 42 is directly drawn out of the housing 1, the compressor cannot be satisfactorily sealed. Accordingly, it is desirable for the internal optical fibers of the housing 1 to face the external optical fibers of the housing 1 through the medium of a transparent window. Further details will be described later referring to Figs. 3A to 3D.

Referring to Figs. 3A to 3D, sealing members 72 are provided in the spaces between terminals 71 and connector 7 to prevent any decrease in pressure in the compressor. The guide holes 74 and 75 are formed in the middle portion of the connector 7. The diameter of hole 75 facing the interior of housing 1 is smaller than that of hole 74 facing exterior of housing 1. The other end of the internal pair of optical fibers 41 and 42 is fitted into the hole 75. The transparent window 76 is inserted into the hole 74. A connecting member 77, which subsequently is tightly fitted into the hole 74, has a hole 78 for guiding the one end of the external pair of optical fibers 411 and 421. The other end of the pair of external optical fibers 411 and 421 is positioned to face the pair of light emitting and photoelectric elements 8 and 5. By arranging the apparatus in the manner described above, any decrease in the pressure in the compressor can be effectively prevented. Next, a motor drive control portion 6 is provided in the exterior of the housing 1. The motor drive control portion 6 supplies the phase voltages to the terminals 71 connected with the phase windings 21.

In the apparatus described above, the light generated by the light emitting element 8 is transmitted by the optical fibers 41 and 411, and it reaches the upper surface of the rotor 3, to which the light reflecting and non-reflecting members 31 and 32 are attached. The light thus reached is reflected, and then transmitted through the optical fibers 42 and 421 only when the light reflecting members 31 pass under the end the optical fibers 41 and 42. The transmitted light is converted into a corresponding electric signal through the photoelectric converting element 5, and is provided to the motor drive control portion 6. Based on whether the electrical signal from the photoelectric converting element 5 is received or not, the motor drive control portion 6 detects the kind of pole of the rotor 3, thereby providing the phase windings 21 with voltages having different phases from each other.

The light emitting element 8 may be preferably embodied by a light emitting diode, the photoelectric converting element 5 may be preferably embodied by a photo transistor.

Industrial Applicability

As described above, a rotor position detecting apparatus according to the present invention may be preferably applicable to a brushless motor, particularly to a closed compressor embodied by a brushless motor in a refrigerator or an air conditioner, thereby increasing not only the rotor position detecting ability but also the effectiveness of the seal of the closed compressor.


Anspruch[de]
  1. Eine Vorrichtung zur Ermittlung der Rotorstellung für einen Elektromotor, bei der der Motor einen Stator (2), einen Rotor (3) und ein geschlossenes, abgedichtetes Gehäuse (1) einschließt, wobei die Vorrichtung weiterhin aufweist:
    • eine Vielzahl von lichtreflektierenden Elementen (31), die an der Oberfläche des Rotors (3) des Motors um die Rotorachse herum befestigt sind;
    • eine Vielzahl von Licht-reflexionsfreien Elementen (32), die an der Oberfläche des Rotors abwechselnd zu den lichtreflektierenden Elementen befestigt sind;
    • ein Lichtleitfaserpaar (41, 42) zum Senden und Empfangen eines Lichtsignals, wobei ein Ende des Lichtleitfaserpaars der Oberfläche des Rotors gegenüberliegend angeordnet ist, und wobei das Lichtleitfaserpaar in zwei Abschnitte unterteilt ist, wobei einer innerhalb des Gehäuses (1) und der andere außerhalb des Gehäuses (1) ist;
    • ein Paar von lichtemittierenden bzw. photoelektrisch umwandelnden Elementen (5, 8), das dem anderen Ende des sendenden bzw. empfangenden Lichtleitfaserpaares (41, 42) gegenüberliegend angeordnet ist; und
    • einen Verbinder (7), der am Aufbau des Gehäuses (1) montiert ist, wobei der Verbinder (7) eine Vielzahl von mit den Phasenwicklungen (21) des Stators (2) verbundene Anschlußpunkte (71), ein Loch (75) zum Führen des sendenden und empfangenden Lichtleitfaserpaares (41, 42) und ein transparentes Fenster (76) aufweist, welches dem inneren Abschnitt des Lichtleitfaserpaares ermöglicht dem äußeren Abschnitt des Lichtleitfaserpaares gegenüberzustehen, während es die zwei Abschnitte des Lichtleitfaserpaares physisch trennt.
  2. Eine Vorrichtung zur Ermittlung der Rotorstellung gemäß Anspruch 1, bei der die Vielzahl von lichtreflektierenden und Licht-reflexionsfreien Elementen (31, 32) an der Oberseite des Rotors (3) befestigt ist.
  3. Eine Vorrichtung zur Ermittlung der Rotorstellung gemäß Anspruch 1, bei der die Vielzahl von lichtreflektierenden und Licht-reflexionsfreien Elementen (31, 32) an der zylindrischen Oberfläche des Rotors (3) befestigt ist.
  4. Eine Vorrichtung zur Ermittlung der Rotorstellung gemäß irgendeinem der Ansprüche 1-3, bei der der Motor ein bürstenloser Motor ist und der Motor ein Teil eines geschlossenen Kompressors ist.
Anspruch[en]
  1. A rotor position detecting apparatus for an electric motor, wherein said motor includes a stator (2), a rotor (3) and a closed, sealed housing (1), said apparatus further comprising:
    • a plurality of light reflecting member (31) attached to the surface of the rotor (3) of the motor around the rotor axis;
    • a plurality of light non-reflecting member (32) attached to the surface of the rotor alternating with said light reflecting members;
    • a pair of optical fibers (41,42) for transmitting and receiving a light signal, one end of the pair of optical fibers positioned to face the surface of the rotor, said pair of optical fibers being divided into two sections, one being internal of the housing (1) and the other being external of the housing (1),
    • a pair of light emitting and photoelectric converting elements (5,8) respectively positioned to face the other end of said pair of transmitting and receiving optical fibers (41,42); and,
    • a connector (7) mounted to the body of the housing (1), said connector (7) comprsing a plurality of terminals (71) connected to phase windings (21) of the stator (2), a hole (75) for guiding said pair of transmitting and receiving optical fibers (41,42), and a transparent window (76) which allows said internal section of said pair of optical fibers to face said external section of said pair of optical fibers whilst physically separating said two sections of said pair of optical fibers.
  2. A rotor position detecting apparatus, as set forth in Claim 1, wherein said plurality of light reflecting and non-reflecting members (31,32) are attached to the upper surface of said rotor (3).
  3. A rotor position detecting apparatus, as set forth in Claim 1, wherein said plurality of light reflecting and non-reflecting members (31,32) are attached to the cylindrical surface of said rotor (3).
  4. A rotor position detecting apparatus, as set forth in any of Claims 1-3, wherein said motor is a brushless motor, and said motor is a part of a closed compressor.
Anspruch[fr]
  1. Appareil de détection de la position d'un rotor pour un moteur électrique, dans lequel ledit moteur inclut un stator (2), un rotor (3) et un logement fermé et hermétique (1), ledit appareil comprenant également :
    • plusieurs éléments réfléchissant la lumière (31) fixés à la surface du rotor (3) du moteur autour de l'axe de rotor ;
    • plusieurs éléments ne réfléchissant pas la lumière (32) fixés à la surface du rotor de manière alternative par rapport auxdits éléments réfléchissant la lumière ;
    • une paire de fibres optiques (41, 42) destinées à transmettre et à recevoir un signal lumineux, une extrémité de la paire de fibres optiques étant placée de manière à faire face à la surface du rotor, ladite paire de fibres optiques étant divisée en deux sections, l'une étant interne au logement (1) et l'autre étant externe au logement (1) ;
    • une paire d'éléments photoélectriques destinés à émettre et à convertir de la lumière (5, 8) placés respectivement de manière à faire face à l'autre extrémité de ladite paire de fibres optiques transmettant et recevant la lumière (41, 42) ; et
    • un connecteur (7) monté sur le corps du logement (1), ledit connecteur (7) comprenant plusieurs terminaux (71) reliés aux enrouleurs de phase (21) du stator (2), un trou (75) destiné à guider ladite paire de fibres optiques transmettant et recevant la lumière (41, 42) et une fenêtre transparente (76) qui permet à ladite section interne de ladite paire de fibres optiques de faire face à ladite section externe de ladite paire de fibres optiques tout en séparant physiquement lesdites deux sections de ladite paire de fibres optiques.
  2. Appareil de détection de la position d'un rotor selon la revendication 1, dans lequel lesdits plusieurs éléments réfléchissant et ne réfléchissant pas la lumière (31, 32) sont fixés à la surface supérieure dudit rotor (3).
  3. Appareil de détection de la position d'un rotor selon la revendication 1, dans lequel lesdits plusieurs éléments réfléchissant et ne réfléchissant pas la lumière (31, 32) sont fixés à la surface cylindrique dudit rotor (3).
  4. Appareil de détection de la position d'un rotor selon l'une des revendications 1 à 3, dans lequel ledit moteur est un moteur sans collecteur et ledit moteur est une partie d'un compresseur fermé.






IPC
A Täglicher Lebensbedarf
B Arbeitsverfahren; Transportieren
C Chemie; Hüttenwesen
D Textilien; Papier
E Bauwesen; Erdbohren; Bergbau
F Maschinenbau; Beleuchtung; Heizung; Waffen; Sprengen
G Physik
H Elektrotechnik

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