JP5490182B2 - Electric motor, air conditioner incorporating the electric motor, and method for manufacturing the electric motor - Google Patents

Description

  The present invention relates to an electric motor, an air conditioner incorporating the electric motor, and a method for manufacturing the electric motor.

  In recent years, electric motors are increasingly used in a system driven by an inverter of a pulse width modulation (Pulse Width Modulation) method (hereinafter referred to as a PWM method as appropriate). In such a PWM inverter-driven electric motor, the neutral point potential of the winding does not become zero, so that a potential difference (hereinafter referred to as a shaft voltage) occurs between the outer ring and the inner ring of the bearing. This shaft voltage contains high-frequency components due to switching of the inverter. When the shaft voltage reaches the breakdown voltage of the oil film inside the bearing, a current (hereinafter referred to as shaft current) flows inside the bearing, and the electric corrosion occurs inside the bearing. Will occur. When electrolytic corrosion progresses, a wave-like wear phenomenon occurs in the bearing inner ring, the bearing outer ring, or the bearing rolling element, and abnormal noise resulting from this wear phenomenon is one of the main causes of problems in the motor.

  In conventional motors, the current flowing inside the bearing is reduced by electrically connecting the bearing inner ring and the outer ring, and the occurrence of wave wear in the bearing inner ring, bearing outer ring or bearing rolling element is suppressed, resulting in the wave wear phenomenon. The occurrence of abnormal noise is suppressed (for example, see Patent Document 1 below).

JP-A-9-291944

  However, since the electric motor shown in Patent Document 1 uses a configuration in which a movable part that operates with rotation and a non-movable part are in contact with each other when electrically connecting a bearing inner ring and an outer ring. During use, there is a problem that the bearing inner ring and the outer ring are not electrically connected due to wear, and the shaft current suppression effect is reduced.

  The present invention has been made in view of the above, and includes an electric motor capable of suppressing electric corrosion of a bearing even during long-term use, an air conditioner incorporating the electric motor, and a method for manufacturing the electric motor. The purpose is to provide.

  In order to solve the above-described problems and achieve the object, an electric motor according to the present invention includes a stator having an annular stator core, and is disposed inside the stator and rotates opposite to the stator core. A rotor having a permanent magnet disposed on the outer peripheral side of the shaft; a first bearing that rotatably supports one end of the rotating shaft; and a second bearing that rotatably supports the other end of the rotating shaft. A drive circuit board on which a circuit that rotationally drives the rotor is mounted between the stator and the first bearing in the axial direction of the rotary shaft, and is disposed substantially perpendicular to the axial direction; The rotating shaft is disposed between the first bearing and the permanent magnet in the axial direction of the rotating shaft, and is disposed so as to cover the rotating shaft without contacting the rotating shaft. A first conductor ring electrically connected to the outer ring of the bearing; It is arranged between the second bearing and the permanent magnet in the axial direction of the rotating shaft, and is arranged so as to cover the periphery of the rotating shaft without coming into contact with the rotating shaft. A mold in which a second conductor ring electrically connected to an outer ring, the stator core and the drive circuit board are integrally formed, and a recess is formed therein so as to accommodate the rotor. And a conductive bracket that is fitted into the inner peripheral portion of the mold resin so as to close the opening of the recess, and the outer ring of the second bearing is fitted inside. .

  According to the present invention, there is an effect that the electrolytic corrosion of the bearing can be suppressed even during long-term use.

1 is a side cross-sectional view of an electric motor 100 according to Embodiment 1. FIG. FIG. 2 is a diagram schematically showing the main part of the electric motor 100. FIG. 3 is a diagram showing a cross section of the rotary shaft 10 and the board-side conductor ring 16-1, or a cross section of the rotary shaft 10 and the non-board-side conductor ring 16b-1. FIG. 4 is a perspective view showing the conductor ring assembly. FIG. 5 is a diagram illustrating a manufacturing process of the electric motor 100 according to the second embodiment. FIG. 6 is a configuration diagram of an air conditioner 300 according to the third embodiment.

  Embodiments of an electric motor according to the present invention, an air conditioner incorporating the electric motor, and a method for manufacturing the electric motor will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a side cross-sectional view of electric motor 100 according to the present embodiment, and FIG. 2 is a diagram schematically showing main parts of electric motor 100. 3 is a cross-sectional view of the rotary shaft 10 and the board-side conductor ring 16a-1, or a cross-section of the rotary shaft 10 and the non-board-side conductor ring 16b-1, and FIG. 4 shows a conductor ring assembly. It is a perspective view. An electric motor 100 shown in FIG. 1 includes, as main components, a stator 6, a drive circuit board 4, a rotor 14, a board-side bearing 15a (first bearing), and an anti-board-side bearing 15b (second board). Bearing), substrate side conductor ring 16a-1 (first conductor ring), anti-substrate conductor ring 16b-1 (second conductor ring), mold resin 2, and conductive bracket 20. Configured. The electric motor 100 is a brushless DC motor driven by an inverter, for example. In FIG. 1, the left half of the configuration of the electric motor 100 centering on the rotating shaft 10 is shown, but the same applies to the right half.

  The stator assembly 3 is an assembly of the stator 6 and the drive circuit board 4 among the components of the electric motor 100. The rotor assembly 15 is an assembly of the rotor 14, the board-side bearing 15 a, and the non-board-side bearing 15 b among the components of the electric motor 100.

  The mold stator 1 is formed in a substantially cylindrical shape with the rotating shaft 10 as the center, and includes a stator assembly 3 and a mold resin 2. The stator assembly 3 is integrally formed with the mold resin 2. The stator assembly 3 includes a drive circuit board 4 and the like. However, since the drive circuit board 4 and the like have a weak structure, low pressure molding is desirable. To form the drive circuit board 4 and the like integrally, for example, a thermosetting resin (mold resin 2) such as unsaturated polyester resin is used. ) Is used.

  The drive circuit board 4 and the stator 6 are mechanically coupled by the mold resin 2 and are integrally formed. The mold resin 2 constitutes the outline of the electric motor 100, and constitutes the bearing housing portion 2b on the substrate side surface (upper side in FIG. 1) of the mold stator 1. The bearing housing portion 2b surrounds and supports the outer ring 15a-1 of the board side bearing 15a.

  The mold resin 2 accommodates the rotor assembly 15 into the mold stator 1 through an opening provided on the surface (lower side in FIG. 1) opposite to the load (fan or the like) side surface of the mold resin 2. For example, a mortar-shaped recess 19 that is formed is provided. The opening is a portion where the conductive bracket 20 is provided in FIG. The conductive bracket 20 is manufactured, for example, by pressing a conductive metal.

  The stator 6 includes a winding 7, a stator core 8, and an insulator 9. The stator core 8 is manufactured by punching a magnetic steel sheet having a thickness of, for example, about 0.1 to 0.7 mm into a strip shape, and laminating by caulking, welding, adhesion, or the like. The stator core 8 is annular and includes a plurality of teeth (not shown) on the inner peripheral side, and an insulator 9 is applied to the teeth. The insulator 9 is molded integrally with or separately from the stator core 8 using a thermoplastic resin such as PBT (polybutylene terephthalate). Concentrated windings 7 are wound around the teeth to which the insulator 9 is applied. A plurality of concentrated windings 7 are connected to form, for example, a three-phase single Y-connection winding. However, distributed winding may be used.

  The drive circuit board 4 is built in the mold stator 1 in the vicinity of the board-side bearing 15a held by the bearing housing portion 2b. Specifically, the drive circuit board 4 is disposed between the board-side bearing 15a and the stator 6 in the axial direction of the rotary shaft 10, and is disposed substantially perpendicular to the axial direction. A power conversion circuit (not shown) for driving the electric motor 100 is mounted on the drive circuit board 4, and the power conversion circuit includes an inverter circuit and the like. The inverter circuit converts AC power for rotationally driving the rotor 14 from a DC power source. The voltage from the inverter circuit is applied to the winding 7 via a terminal (not shown) that electrically connects the drive circuit board 4 and the winding 7. In addition to the inverter circuit, the drive circuit board 4 includes, for example, a Hall element that detects the rotation speed or the rotation position of the rotor 14 based on a change in magnetic flux density generated by the position detection magnet 11, and the drive circuit board 4. Although connection leads and the like for electrically connecting an external circuit (not shown) of the electric motor 100 are mounted, these are not shown in FIG.

  A hole for inserting the rotor assembly 15 (rotating shaft 10) is provided at the center of the drive circuit board 4.

  The rotor 14 has a rotating shaft 10, an annular rotor insulating portion 12 provided on the outer peripheral portion of the rotating shaft 10, and is provided on the outer peripheral side of the rotor insulating portion 12 so as to face the stator core 8. The rotor magnet 13 is a permanent magnet that is disposed, and a position detection magnet 11 that is provided between the rotor magnet 13 and the drive circuit board 4 in the axial direction of the rotary shaft 10. . The rotor 14 is rotatable about the rotating shaft 10, obtains a rotating force by the rotating magnetic field from the stator 6, transmits torque to the rotating shaft 10, and loads (not shown) provided on the rotating shaft 10 (for example, The fan built in the indoor unit and / or outdoor unit of the air conditioner is driven.

  The rotor insulating portion 12 is provided to insulate the rotating shaft 10 and the rotor magnet 13 and insulate the rotating shaft 10 and the stator core 8 from each other. The rotor magnet 13, the rotating shaft 10, and the position detecting magnet 11 are integrally formed by a rotor insulating portion 12 injected by, for example, a vertical molding machine. For the rotor insulating portion 12, for example, a thermoplastic resin such as PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) is used, and those in which a glass filler is blended with these resins are also suitable. A dielectric layer is formed on the rotor insulating portion 12.

  As the rotor magnet 13, a resin magnet formed by mixing a magnetic material with a thermoplastic resin, a rare earth magnet (neodymium, samarium iron), a ferrite sintered magnet, or the like is used.

  In the axial direction of the rotary shaft 10, a substrate side bearing 15a is attached to the load side (upper side in FIG. 1) of the rotary shaft 10 to which a fan or the like is attached, and the rotary shaft on the opposite side (lower side in FIG. 1) 10 is attached with a non-substrate-side bearing 15b. The rotating shaft 10 is rotatably supported by the substrate side bearing 15a and the non-substrate side bearing 15b.

  The board-side bearing 15a is a ball bearing, and is disposed between the inner and outer rings, an inner ring 15a-3 that rotates integrally with the rotary shaft 10, an outer ring 15a-1 that is fitted into the inner peripheral surface of the bearing housing portion 2b. And a plurality of rolling elements 15a-2.

  The non-board-side bearing 15b is a ball bearing, and is disposed between the inner and outer rings, an inner ring 15b-3 that rotates integrally with the rotary shaft 10, an outer ring 15b-1 that is fitted on the inner peripheral surface of the conductive bracket 20, and the outer ring 15b. And a plurality of rolling elements 15b-2. The conductive bracket 20 is in electrical contact with the outer ring 15b-1.

  The board-side conductor ring 16 a-1 is arranged between the board-side bearing 15 a and the rotor magnet 13 in the axial direction of the rotary shaft 10, and is arranged so as to penetrate a hole provided in the drive circuit board 4. Yes. The board-side conductor ring 16a-1 has a ring shape and is formed from a conductive member. The board-side conductor ring 16a-1 is disposed coaxially with the rotary shaft 10 so as to cover the periphery of the rotary shaft 10 without contacting the rotor 14 including the rotary shaft 10 and the board-side bearing 15a (FIG. 3). A capacitance is formed between the rotary shaft 10 and the rotary shaft 10. FIG. 3 shows a cross-sectional configuration of the rotary shaft 10 and the substrate-side conductor ring 16a-1 or the rotary shaft 10 and the non-substrate-side conductor ring 16b-1 by a plane perpendicular to the rotary shaft 10. As shown in FIG. 3, a gap 21 is formed between the rotating shaft 10 and the board-side conductor ring 16a-1 (or the non-board-side conductor ring 16b-1), and the board-side conductor ring 16a-1 is formed. (Or the non-substrate-side conductor ring 16b-1) and the rotating shaft 10 are not in contact with each other. The board-side conductor ring 16a-1 is press-fitted and held on the inner peripheral side of the ring-like board-side conductor ring holding portion 16a-2. The board-side conductor ring holding part 16a-2 has a shorter length in the axial direction than the board-side conductor ring 16a-1, for example. The board side conductor ring 16a-1 and the board side conductor ring holding part 16a-2 constitute a board side conductor ring assembly 16a (first conductor ring assembly) (FIG. 4). In FIG. 4, the board-side conductor ring assembly 16 a composed of the board-side conductor ring 16 a-1 and the board-side conductor ring holding part 16 a-2, or the non-board-side conductor ring 16 b-1 and the anti-board-side conductor ring. The non-board | substrate side conductor ring assembly 16b (2nd conductor ring assembly) comprised from the holding | maintenance part 16b-2 is shown. The board-side conductor ring assembly 16 a is fixed to the mold stator 1 by being press-fitted into the recess 19. That is, the board-side conductor ring 16a-1 is supported by the mold stator 1 via the board-side conductor ring holding portion 16a-2.

  The board | substrate side conductor ring holding | maintenance part 16a-2 can be formed with an electroconductive member, for example. In this case, the board-side conductor ring holding portion 16a-2 and the outer ring 15a-1 are electrically connected via the board-side lead wire 16a-3. Thereby, the board | substrate side conductor ring 16a-1 is electrically connected with the outer ring | wheel 15a-1 via the board | substrate side conductor ring holding | maintenance part 16a-2 and the board | substrate side lead wire 16a-3. When the board-side conductor ring holding portion 16a-2 is formed of an insulating member, as shown in FIG. 2, the board-side conductor ring 16a-1 and the outer ring 15a-1 are connected to the board-side lead wire 16a-3. Can be connected directly. In addition, in FIG. 2, description of the board | substrate side conductor ring holding part 16a-2 and the non-board | substrate side conductor ring holding part 16b-2 is abbreviate | omitted. FIG. 2 schematically shows the configuration of the main part when both the board-side conductor ring holding part 16a-2 and the non-board-side conductor ring holding part 16b-2 are formed of an insulating member. The same components as those in FIG. 1 are denoted by the same reference numerals.

  The non-substrate-side conductor ring 16 b-1 is disposed between the anti-substrate-side bearing 15 b and the rotor magnet 13 in the axial direction of the rotation shaft 10. The non-substrate-side conductor ring 16b-1 has a ring shape and is formed from a conductive member. The non-substrate-side conductor ring 16b-1 is disposed coaxially with the rotary shaft 10 so as to cover the periphery of the rotary shaft 10 without contacting the rotor 14 including the rotary shaft 10 and the anti-substrate-side bearing 15b (see FIG. 3) Capacitance is formed between the rotating shaft 10 and the rotating shaft 10. The non-substrate-side conductor ring 16b-1 is press-fitted and held on the inner peripheral side of the ring-shaped anti-substrate-side conductor ring holding portion 16b-2. For example, the length in the axial direction of the non-board-side conductor ring holding portion 16b-2 is shorter than that of the non-board-side conductor ring 16b-1. The non-board side conductor ring 16b-1 constitutes the anti-board side conductor ring assembly 16b together with the anti-board side conductor ring holding portion 16b-2 (FIG. 4). The non-board-side conductor ring assembly 16 b is fixed to the mold stator 1 by being press-fitted into the recess 19. That is, the non-substrate-side conductor ring 16b-1 is supported by the mold stator 1 via the anti-substrate-side conductor ring holding portion 16b-2. As shown in FIG. 1, the outer diameter of the non-substrate-side conductor ring holding portion 16 b-2 is larger than the outer diameter of the substrate-side conductor ring holding portion 16 a-2 depending on the shape of the recess 19.

  The non-substrate-side conductor ring holding portion 16b-2 can be formed of, for example, a conductive member. In this case, the non-board-side conductor ring 16b-1 is electrically connected to the outer ring 15b-1 via the non-board-side conductor ring holding portion 16b-2 and the conductive bracket 20. That is, when the conductive bracket 20 is assembled to the inner peripheral portion 2 a of the mold resin 2, the non-substrate-side conductor ring holding portion 16 b-2 comes into contact with the outer peripheral side contact portion 20 a of the conductive bracket 20. Electrically connected (FIG. 1). When the non-substrate-side conductor ring holding portion 16b-2 is formed of an insulating member, as shown in FIG. 2, the anti-substrate-side conductor ring 16b-1 and the outer ring 15b-1 are connected to the anti-substrate-side lead wire. 16b-3 may be directly connected, or the non-substrate-side conductor ring 16b-1 and the conductive bracket 20 may be directly connected by the anti-substrate-side lead wire 16b-3. In either case, the non-substrate-side conductor ring 16b-1 and the outer ring 15b-1 are electrically connected.

  When the rotor assembly 15 is inserted into the recess 19 from the opening of the mold stator 1, the board-side bearing 15a attached to the rotary shaft 10 is incorporated into the bearing housing portion 2b. One end of the rotating shaft 10 passes through the bearing housing portion 2b, and the above-described fan or the like is attached to the rotating shaft 10. On the other hand, an anti-board side bearing 15b is attached to the other end of the rotating shaft 10, and when the conductive bracket 20 is press-fitted into the inner peripheral portion 2a of the mold resin 2 and is fitted so as to close the opening, A non-substrate-side bearing 15 b is incorporated inside the conductive bracket 20.

  The operation will be described below. When a voltage is induced between the inner and outer rings of the board-side bearing 15a and the non-board-side bearing 15b (hereinafter also simply referred to as “bearings”) with the switching of the inverter, the rotating shaft 10 and the board-side conductor ring 16a-1 A non-substrate-side conductor ring 16b-1 (hereinafter, also simply referred to as “conductor ring”) is in a conductive state in terms of high frequency. This is because the rotating shaft 10 and the conductor ring are arranged close to each other, whereby a capacitance is formed between the rotating shaft 10 and the conductor ring, and the high frequency component of the voltage induced between the bearing inner and outer rings. This is because the impedance between the rotating shaft 10 and the conductor ring is low (conductive state). As a result, the shaft current flowing between the bearing inner and outer rings flows between the rotating shaft 10 and the conductor ring, so that the shaft current is reduced. Therefore, the occurrence of wavy wear in the inner ring, outer ring, or rolling element is suppressed, and the occurrence of abnormal noise due to the wavy wear phenomenon is suppressed.

  As described above, the electric motor 100 according to the present embodiment includes the stator 6 having the annular stator core 8, the inner side of the stator 6, and the rotating shaft 10 facing the stator core 8. A rotor 14 having permanent magnets (rotor magnets 13) arranged on the outer peripheral side, a first bearing (substrate-side bearing 15a) that rotatably supports one end of the rotating shaft 10, and the other of the rotating shaft 10. In the axial direction between the second bearing (anti-substrate-side bearing 15b) that rotatably supports the end and the stator 6 and the first bearing (substrate-side bearing 15a) in the axial direction of the rotary shaft 10. A drive circuit board 4 that is arranged substantially perpendicular to the circuit board and on which a circuit for rotating the rotor 14 is mounted, a first bearing (substrate-side bearing 15a) and a permanent magnet (rotor magnet) in the axial direction of the rotary shaft 10. 13) and rotate without contacting the rotating shaft 10. A first conductor ring (substrate-side conductor ring 16a-1) disposed so as to cover the periphery of the shaft 10 and electrically connected to the outer ring 15a-1 of the first bearing (substrate-side bearing 15a); The rotary shaft 10 is disposed between the second bearing (the non-substrate-side bearing 15b) and the permanent magnet (rotor magnet 13) in the axial direction of the rotary shaft 10, and covers the periphery of the rotary shaft 10 without contacting the rotary shaft 10. A second conductor ring (anti-substrate-side conductor ring 16b-1) electrically connected to the outer ring 15b-1 of the second bearing (anti-substrate-side bearing 15b), and a stator core 8 and the drive circuit board 4 are integrally molded, and the mold resin 2 provided with a recess 19 formed so as to accommodate the rotor 14 therein, and the mold resin 2 so as to close the opening of the recess 19 Is fitted into the inner periphery of the And the conductive bracket 20 in which the outer ring of the bearing (anti-substrate side bearing 15b) is fitted inside, so that when the voltage is induced between the inner and outer rings of the bearing due to the switching of the inverter, this voltage is Between the inner and outer rings of the bearing with respect to the high-frequency components contained, the rotating shaft 10 and the conductor rings (the board-side conductor ring 16a-1 and the non-board-side conductor ring 16b-1) are brought into conduction, and the bearing inner and outer rings flow. Since the shaft current that has been flowing flows through the rotating shaft 10 and the conductor ring, the shaft current is reduced.

  Since the electric motor 100 according to the present embodiment is not configured such that the movable part and the non-movable part are in contact with each other as in the conventional technique described in Patent Document 1, a problem due to wear does not occur. Even during long-term use, electric corrosion of the bearing can be suppressed.

  In the present embodiment, since the dielectric layer (rotor insulating portion 12) is provided between the stator core 8 and the rotating shaft 10, the rotating shaft 10 and the rotor magnet 13 are insulated. In addition, the rotating shaft 10 and the stator core 8 can be insulated. Therefore, the radial impedance of the rotor 14 is increased, and the axial current flowing from the rotor 14 to the stator 6 can be reduced.

  Further, as shown in FIG. 1, the dielectric layer (rotor insulating portion 12) can be provided between the rotating shaft 10 and the rotor magnet 13, for example. As a result, the rotary shaft 10 and the rotor magnet 13 can be insulated, the impedance in the radial direction of the rotor 14 is increased, and the axial current flowing from the rotor 14 to the stator 6 can be reduced. is there.

  Further, since the mold resin 2 is a thermoplastic resin, low-pressure molding is possible, and the drive circuit board 4 and the like that are weak in strength can be easily integrally molded.

Embodiment 2.
FIG. 5 is a diagram illustrating a manufacturing process of the electric motor 100 according to the present embodiment. The configuration of the electric motor 100 is as described in the first embodiment. Hereinafter, a method for manufacturing the electric motor 100 will be described with reference to FIG.
(1) The stator 6 and the drive circuit board 4 are manufactured (step S1).
(2) The drive circuit board 4 is assembled to the stator 6 to manufacture the stator assembly 3 (step S2).
(3) The stator assembly 3 is integrally formed with a thermosetting resin (mold resin 2) to manufacture the mold stator 1 (step S3).
(4) After the board-side bearing 15a is inserted into the bearing housing portion 2b of the mold stator 1, the board-side conductor ring assembly 16a is press-fitted into the recess 19 (step S4).
(5) The rotor 14 is manufactured (step S5).
(6) The rotor 14 is accommodated in the recess 19 of the mold stator 1 (step S6). At this time, the rotating shaft 10 is inserted through the board-side conductor ring 16a-1, and the rotating shaft 10 is press-fitted into the inner ring of the board-side bearing 15a.
(7) The non-substrate-side conductor ring assembly 16b is press-fitted into the recess 19, and at this time, the rotary shaft 10 is inserted into the anti-substrate-side conductor ring 16b-1 and the rotary shaft 10 is press-fitted into the anti-substrate-side bearing 15b ( Step S7).
(8) The conductive bracket 20 is press-fitted into the recess 19 of the mold stator 1 to close the opening of the recess 19 (step S8). Thereby, the electric motor 100 is manufactured.

  By adopting such a manufacturing process, the electric motor 100 according to the present embodiment can be efficiently manufactured.

Embodiment 3.
FIG. 6 is a configuration diagram of the air conditioner 300 according to the present embodiment. The air conditioner 300 includes an indoor unit 310 and an outdoor unit 320 connected to the indoor unit 310. The indoor unit 310 is equipped with an indoor unit blower (not shown), and the outdoor unit 320 is equipped with an outdoor unit blower 330.

  The outdoor unit blower 330 and the indoor unit blower each incorporate the electric motor 100 described in Embodiment 1 as a drive source. By mounting the electric motor 100 on the outdoor unit blower 330 and the indoor unit blower, which are main components of the air conditioner 300, the durability of the air conditioner 300 is improved, and the substrate side bearing 15a and the anti-substrate side bearing are provided. Noise due to electric corrosion generated from 15b can be reduced. Noise is a particular problem due to the electric corrosion of these bearings, and the indoor unit 310 of the air conditioner 300 is required to be quiet in order to be used in a living space for a long time, and the resistance to electric corrosion can be improved. This greatly contributes to product reliability. In addition to the air conditioner 300, the electric motor 100 can be used by being mounted on, for example, a ventilation fan, a home appliance, a machine tool, or the like.

  An electric motor according to an embodiment of the present invention, an air conditioner incorporating the electric motor, and a method for manufacturing the electric motor are examples of the contents of the present invention, and are combined with another known technique. Of course, it is possible to change and configure such as omitting a part without departing from the gist of the present invention.

  The present invention is useful as an electric motor, an air conditioner incorporating the electric motor, and a method for manufacturing the electric motor.

DESCRIPTION OF SYMBOLS 1 Mold stator 2 Mold resin 2b Bearing housing part 2a Inner peripheral part 3 Stator assembly 4 Drive circuit board 6 Stator 7 Winding 8 Stator core 9 Insulator 10 Rotating shaft 11 Position detection magnet 12 Rotor insulation part 13 Rotation Child magnet 14 Rotor 15 Rotor assembly 15a Board side bearing 15b Anti-board side bearings 15a-1, 15b-1 Outer rings 15a-2, 15b-2 Rolling elements 15a-3, 15b-3 Inner ring 16a Board side conductor ring assembly 16a -1 Substrate side conductor ring 16a-2 Substrate side conductor ring holding portion 16a-3 Substrate side lead wire 16b Anti-substrate side conductor ring assembly 16b-1 Anti-substrate side conductor ring 16b-2 Anti-substrate side conductor ring holding portion 16b-3 Non-board-side lead wire 19 Recess 20a Contact 20 Conductive bracket 21 Air gap 100 Electric motor 300 Air conditioner 310 Indoor unit 320 Outdoor unit 330 Blower for outdoor unit

Claims (17)

A stator having an annular stator core;
A rotor having a permanent magnet disposed inside the stator and disposed on the outer peripheral side of the rotating shaft facing the stator core;
A first bearing rotatably supporting one end of the rotating shaft;
A second bearing rotatably supporting the other end of the rotating shaft;
A drive circuit board on which a circuit that rotates and drives the rotor is disposed substantially perpendicular to the axial direction between the stator and the first bearing in the axial direction of the rotating shaft;
The first bearing is disposed between the first bearing and the permanent magnet in the axial direction of the rotating shaft, and is disposed so as to cover the periphery of the rotating shaft without contacting the rotating shaft. A first conductor ring electrically connected to the outer ring of
The second bearing is disposed between the second bearing and the permanent magnet in the axial direction of the rotating shaft, and is disposed so as to cover the periphery of the rotating shaft without contacting the rotating shaft. A second conductor ring electrically connected to the outer ring of
Molding resin in which the stator iron core and the drive circuit board are integrally formed, and a recess is formed inside the rotor so as to accommodate the rotor;
A conductive bracket that is fitted into the inner periphery of the mold resin so as to close the opening of the recess, and an outer ring of the second bearing is fitted inside,
An electric motor comprising:   The electric motor according to claim 1, wherein the first conductor ring is fixed to the mold resin via a first conductor ring holding portion.   The electric motor according to claim 2, wherein the first conductor ring holding portion is formed of a conductive member. The first conductor ring holding portion and the outer ring of the first bearing are connected via a first lead wire,
The first conductor ring is electrically connected to an outer ring of the first bearing through the first conductor ring holding portion and the first lead wire. The electric motor described.   The electric motor according to claim 2, wherein the first conductor ring holding portion is formed of an insulating member.   6. The electric motor according to claim 5, wherein the first conductor ring is electrically connected to an outer ring of the first bearing through a first lead wire.   The electric motor according to claim 2, wherein the second conductor ring is fixed to the mold resin via a second conductor ring holding portion.   The electric motor according to claim 7, wherein the second conductor ring holding portion is formed of a conductive member. The second conductor ring holding portion is in contact with the conductive bracket;
The said 2nd conductor ring is electrically connected with the outer ring | wheel of the said 2nd bearing via the said 2nd conductor ring holding | maintenance part and the said electroconductive bracket. Electric motor.   The electric motor according to claim 7, wherein the second conductor ring holding portion is formed of an insulating member. The second conductor ring and the conductive bracket are connected via a second lead wire,
11. The electric motor according to claim 10, wherein the second conductor ring is electrically connected to an outer ring of the second bearing through the second lead wire and the conductive bracket.   11. The electric motor according to claim 10, wherein the second conductor ring is electrically connected to the outer ring of the second bearing through a second lead wire.   The electric motor according to any one of claims 1 to 12, wherein a dielectric layer is provided between the stator core and the rotating shaft.   The electric motor according to claim 13, wherein the dielectric layer is provided between the rotating shaft and the permanent magnet.   The electric motor according to claim 1, wherein the mold resin is a thermoplastic resin.   An air conditioner comprising the electric motor according to any one of claims 1 to 15. A stator having an annular stator core, a rotor having a permanent magnet disposed inside the stator and disposed on the outer peripheral side of the rotating shaft so as to face the stator core, and one end of the rotating shaft A first bearing that rotatably supports the second shaft, a second bearing that rotatably supports the other end of the rotating shaft, and the stator and the first bearing in the axial direction of the rotating shaft. Between the first bearing and the permanent magnet in the axial direction of the rotary shaft, and a drive circuit board that is disposed substantially perpendicular to the axial direction and on which a circuit that rotationally drives the rotor is mounted. A first conductor ring that is disposed so as to cover the periphery of the rotation shaft without contacting the rotation shaft, and is electrically connected to the outer ring of the first bearing; and Arranged between the second bearing and the permanent magnet in the axial direction A second conductor ring that is disposed so as to cover the periphery of the rotation shaft without contacting the rotation shaft, and is electrically connected to the outer ring of the second bearing, the stator core, and The drive circuit board is integrally molded, and a mold resin provided with a recess formed to accommodate the rotor therein, and an inner periphery of the mold resin so as to close the opening of the recess And a conductive bracket with the outer ring of the second bearing fitted inside, and a method of manufacturing an electric motor comprising:
Assembling the drive circuit board to the stator to produce a stator assembly;
Producing the mold stator by integrally molding the stator assembly with the mold resin; and
After the first bearing is inserted into the bearing housing portion of the mold stator, a first conductor ring assembly comprising the first conductor ring and a first conductor ring holding portion that holds the first conductor ring is formed. Press-fitting into the recess;
Storing the rotor in the recess, passing the rotating shaft through the first conductor ring, and press-fitting the rotating shaft into the inner ring of the first bearing;
A second conductor ring assembly comprising a second conductor ring and a second conductor ring holding portion for holding the second conductor ring is inserted into the recess by inserting the rotary shaft through the second conductor ring. Press-fitting and press-fitting the rotary shaft into the second bearing;
Press-fitting the conductive bracket into the recess and closing the opening;
A method for manufacturing an electric motor, comprising:

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