JP5656795B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner, and more particularly, to an air conditioner provided with a protection circuit for an electric motor that drives a fan of an indoor unit of the air conditioner.

  As a conventional air conditioner, for example, “a main body is provided with an inlet and an outlet, and a heat exchanger that exchanges heat between the air sucked from the inlet and a fan motor that is a driving mechanism is provided in the main body. A fan connected to each other, and the fan includes flanges on both sides provided with a boss and a plurality of blades provided between the flanges, and one end of the boss is connected to a rotation shaft of the fan motor, In an air conditioner in which a shaft protruding from a boss at the other end is supported by a sliding bearing, the boss is formed from a conductive member, the bosses at both ends are connected by a conductive means, and the sliding An air conditioner characterized in that a grounding means is connected to the bearing, and a grounding path is formed to reach the rotating shaft of the fan motor, the boss, the conduction means, the sliding bearing, and the grounding means. Machine " There are things to say. In such a case, it is possible to eliminate the need to newly install a grounding device including a grounding table, a brush, a support and the like inside the air conditioner, and accordingly, reduce the cost of the air conditioner. Can be made "(see Patent Document 1).

JP 2010-121807 (Claim 1 and paragraph [0009])

  However, in the conventional air conditioner (Patent Document 1), by forming a ground path that discharges electric charges generated on the rotating shaft of the motor in the order of the shaft of the motor, the crossflow fan, the sliding bearing, and the ground, The electric corrosion of the bearing was prevented. For this reason, the potential difference between the bearing inner ring and the bearing outer ring has not been eliminated. Further, in such a ground path, if the power supply voltage varies, the potential with respect to the ground also varies accordingly, so that the potential difference between the bearing inner ring and the bearing outer ring may increase. In addition, when external noise or lightning is superimposed on the ground wire, a surge occurs between the bearing inner ring and the bearing outer ring, and the potential difference between the bearing inner ring and the bearing outer ring may become extremely large transiently. .

  For this reason, discharge may occur between the bearing inner ring and the bearing outer ring due to a potential difference generated between the bearing inner ring and the bearing outer ring of the motor. Therefore, wavy wear may occur on the transfer surface of the bearing.

  In recent years, electric motors used for air conditioners and the like have been required to save energy. For this reason, high efficiency DC brushless motors occupy most of the motors used in air conditioners and the like. The DC brushless motor is driven by a PWM method (pulse width modulation). That is, the DC brushless motor is driven by inverter control. Therefore, a high frequency switching voltage is applied to the DC brushless motor by an inverter. For this reason as well, discharge may occur between the bearing inner ring and the bearing outer ring due to a potential difference generated between the bearing inner ring and the bearing outer ring of the DC brushless motor. Therefore, wavy wear may occur on the transfer surface of the bearing.

  As a result, electrolytic corrosion may occur on the transfer surface of the bearing, so that conventional air conditioners cannot prevent the occurrence of electrolytic corrosion.

  The present invention has been made to solve the above-described problems, and is to provide an air conditioner that can prevent the occurrence of electrolytic corrosion.

An air conditioner according to the present invention includes a shaft, a rotor fixed to the shaft, a stator portion that houses the rotor, a bearing inner ring that is fixed to the shaft and has the same potential as the shaft, and the bearing inner ring. A motor that has a bearing outer ring that is paired with the bracket, a bracket that is interposed between the stator portion and the bearing outer ring, supports the bearing outer ring, and has the same potential as the bearing outer ring, and one side of the electric motor is A conductive fan connected to the shaft, a conductive fan provided on the other side of the fan and rotating as the fan rotates, and a conductive fan rotatably supporting the fan shaft. and sliding bearing, and the bearing mount of the conductive supporting said sliding bearing, electrically connected with said bearing inner ring and the bearing outer race via the bracket, the bearing And a wheel and the bearing outer ring in a conductive state, and a short circuit for the ground to a non-conducting state, the bearing inner ring, the fan, the fan shaft, said sliding bearing and said bearing mount, electrical The short circuit is configured to electrically connect the bearing mount and the bracket to bring the bearing inner ring and the bearing outer ring into a conductive state .

  The present invention has an effect of providing a long-life and highly reliable air conditioner by preventing the occurrence of electrolytic corrosion.

It is the schematic which shows the air conditioner in Embodiment 1 of this invention. It is a disassembled perspective view of the indoor unit of the air conditioner in Embodiment 1 of this invention. It is a figure which shows the structure which prevents the electric corrosion of the electric motor of the conventional air conditioner. It is a block diagram of the electric motor ASSY in Embodiment 1 of this invention. It is sectional drawing of the electric motor ASSY in Embodiment 1 of this invention. It is a block diagram of the mold motor in Embodiment 1 of this invention. It is sectional drawing of the mold motor in Embodiment 1 of this invention. It is a figure which shows an example of the electrical model using the mold motor of the conventional air conditioner. It is a figure which shows the schematic of the indoor unit of the air conditioner incorporating the mold motor in Embodiment 1 of this invention, and an example of the 1st electrical wiring. It is a figure which shows an example of the electrical model using the crossflow fan in Embodiment 1 of this invention. It is a figure which shows the schematic of the indoor unit of the air conditioner incorporating the mold motor in Embodiment 2 of this invention, and an example of the 2nd electrical wiring. It is the wiring diagram expanded centering on the mold motor of the indoor unit of the air conditioner incorporating the mold motor in Embodiment 2 of this invention. It is a figure which shows an example of the electrical model using the brush in Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 FIG.
FIG. 1 is a schematic diagram showing an air conditioner according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioner includes an indoor unit 52 of an air conditioner, an outdoor unit 53 of an air conditioner, and the like. The indoor unit 52 of the air conditioner and the outdoor unit 53 of the air conditioner release indoor heat to the outside during cooling, and take in the outdoor heat into the room during heating.

  FIG. 2 is an exploded perspective view of the indoor unit of the air conditioner according to Embodiment 1 of the present invention. As shown in FIG. 2, the indoor unit 52 of the air conditioner includes a cross flow fan 9, an electric motor first mount 16, an electric motor second mount 17, an electric motor ASSY 18, an indoor unit base 20, a bearing mount 55, a sliding bearing 56, and It includes a cross flow fan shaft 57 and the like. The electric motor ASSY 18 is supported and fixed so as to be sandwiched between both the electric motor first mount 16 and the electric motor second mount 17. The integrated motor ASSY 18, the motor first mount 16, and the motor second mount 17 are attached to the indoor unit base 20. The mold motor is one of the components of the motor ASSY 18 and the cross flow fan 9 is attached to the shaft of the mold motor. A slide bearing 56 is attached to the shaft 57 of the cross flow fan. The sliding bearing 56 is attached to the bearing mount 55. In this way, the indoor unit 52 of the air conditioner is formed. Then, a heat exchanger, a board | substrate, etc. are attached. And the indoor unit 52 of the air conditioner blows a gas such as cold air or warm air that the heat exchanger exchanges heat into the room by rotating the cross flow fan or the like based on the control signal of the substrate, Cooling and heating the room.

The “cross flow fan 9” corresponds to the “fan” in the present invention.
In addition, the air conditioner demonstrated above shows an example, and is not limited to this. For example, an air conditioner indoor unit using a sirocco fan instead of the cross flow fan 9 may be used.

  Next, a structure for preventing electrolytic corrosion in a conventional air conditioner will be described, and after describing the structure of the electric motor, a structure for preventing electrolytic corrosion without depending on the structure of the electric motor will be described.

  First, FIG. 3 is a diagram showing a structure for preventing electric corrosion of a motor of a conventional air conditioner. As shown in FIG. 3, the conventional air conditioner includes a cross flow fan 9, an electric motor ASSY 18, a bearing mount 55, a sliding bearing 56, a cross flow fan shaft 57, an earth 65, and the like. Further, as shown in FIG. 3, the conventional air conditioner is provided with a ground 65 in order to prevent electric corrosion of the electric motor. Specifically, the ground path is formed by bringing the shaft of the motor, the cross flow fan 9, the sliding bearing 56, and the ground into conduction.

  Next, the structure of the electric motor will be described with reference to FIGS.

  FIG. 4 is a configuration diagram of the electric motor ASSY 18 according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view of electric motor ASSY 18 in the first embodiment of the present invention. FIG. 6 is a configuration diagram of the molded electric motor according to the first embodiment of the present invention. FIG. 7 is a cross-sectional view of the molded electric motor according to Embodiment 1 of the present invention.

  As shown in FIG. 4, the electric motor ASSY 18 is provided with a rubber mount 14 on the shaft side and a rubber mount 15 on the opposite shaft side. The rubber mounts 14 and 15 are parts formed from a ring-shaped rubber or the like. The rubber mounts 14 and 15 absorb vibrations of the mold motor. Therefore, the air conditioner can prevent internal vibration by incorporating a molded electric motor equipped with the rubber mounts 14 and 15. That is, the rubber mounts 14 and 15 have a vibration-proof function.

  As shown in FIG. 5, the motor ASSY 18 includes a winding 2, a mold resin 3, a rotor 4, a substrate 5, a first bracket 6, a second bracket 7, an insulating portion 8, a stator portion 10, a shaft 11, and a shaft side bearing. 12, an anti-shaft side bearing 13, a rubber mount 14, a rubber mount 15, a core 30, a bearing outer ring 34, a bearing inner ring 35, a bearing outer ring 36, a bearing inner ring 37, and the like.

  As shown in FIG. 6, the molded electric motor includes a bearing outer ring 34, a bearing inner ring 35, a bearing outer ring 36, and a bearing outer ring 36, which are respectively arranged inside the first bracket 6 and the second bracket 7 by the first bracket 6 and the second bracket 7. The bearing inner ring 37 is supported and fixed.

  As shown in FIG. 7, the molded motor is formed from components other than the rubber mounts 14 and 15 among the components of the motor ASSY 18. That is, the mold motor includes the winding 2, the mold resin 3, the rotor 4, the substrate 5, the first bracket 6, the second bracket 7, the insulating portion 8, the stator portion 10, the shaft 11, the shaft side bearing 12, and the opposite shaft side. The bearing 13, the core 30, the bearing outer ring 34, the bearing inner ring 35, the bearing outer ring 36, and the bearing inner ring 37 are provided.

  As shown in FIG. 7, the winding 2 is wound around the core 30 in which the steel plates are laminated with the insulating portion 8 interposed therebetween. Next, by attaching the insulating portion 8 to the substrate 5, the stator portion 10 including the core 30, the insulating portion 8, the winding 2, and the substrate 5 is formed. The substrate 5 is mounted with electronic components such as drive elements that drive the mold motor. Next, the stator mold is molded by enclosing the stator portion 10 and the first bracket 6 with the mold resin 3. Next, the rotor 4 is inserted into the stator mold through a gap, and the shaft-side bearing 12 is supported by the first bracket 6 and the anti-shaft-side bearing 13 is supported by the second bracket 7. The shaft-side bearing 12 is formed of a bearing outer ring 36 and a bearing inner ring 37, and a lubricant such as an iron ball or grease is provided between the bearing outer ring 36 and the bearing inner ring 37. The non-shaft side bearing 13 is formed of a bearing outer ring 34 and a bearing inner ring 35, and a lubricant such as an iron ball or grease is provided between the bearing outer ring 34 and the bearing inner ring 35. The shaft 11 is fixed to the bearing inner ring 37 and the bearing inner ring 35 together with the rotor 4, and the shaft 11 rotates according to the rotation of the rotor 4. In this way, a molded electric motor is formed.

In addition, the electric motor ASSY18 demonstrated above shows an example, and is not limited to this.
In addition, the mold motor demonstrated above shows an example, and is not limited to this.
The “mold motor” corresponds to the “motor” in the present invention.
The “first bracket 6” and the “second bracket 7” correspond to the “bracket” in the present invention.

  Next, after describing an electrical model of a conventional mold motor in FIG. 8, a structure for preventing electrolytic corrosion without depending on the structure of the motor ASSY 18 described above will be described with reference to FIGS.

  FIG. 8 is a diagram illustrating an example of an electrical model using a mold motor of a conventional air conditioner. As shown in FIG. 8, the molded motor has a capacitance as a stray capacitance between the components, and is electrically connected to each other.

  For example, a core-rotor capacity 23 exists between the rotor 4 and the core 30. Further, assuming that a portion including a circuit, a coil, and the like is an INV portion (inverter portion), an INV portion-core capacitance 22 exists between the INV portion 24 and the core 30.

  The rotor 4 and the shaft 11 are integrally formed and have the same potential. Other capacity 21 exists as another capacity between the rotor 4 and the INV section 24, that is, between the shaft 11 and the INV section 24.

  Between the core 30 and the second bracket 7, a core-second bracket capacitance 39 exists. Between the INV portion 24 and the second bracket 7, there is an INV portion-second bracket capacitance 26.

  The second bracket 7 and the bearing outer ring 34 have the same potential, and the shaft 11 and the bearing inner ring 35 have the same potential. Between the bearing outer ring 34 and the bearing inner ring 35, there is a floating capacity 27 between the bearing inner and outer rings. That is, a floating capacity 27 between the bearing inner and outer rings exists between the second bracket 7 and the shaft 11. The stray capacitance 27 between the bearing inner and outer rings is the capacitance of the non-shaft side bearing 13.

  Between the core 30 and the first bracket 6, there is a core-first bracket capacitance 43. Between the first bracket 6 and the INV portion 24, an INV portion-first bracket capacitance 40 exists.

  Between the first bracket 6 and the second bracket 7, there is a first bracket-second bracket capacitance 42.

  The first bracket 6 and the bearing outer ring 36 have the same potential, and the shaft 11 and the bearing inner ring 37 have the same potential. Between the bearing outer ring 36 and the bearing inner ring 36, a floating capacity 28 between the bearing inner and outer rings exists. That is, the bearing inner / outer ring stray capacitance 28 exists between the first bracket 6 and the shaft 11. The stray capacitance 28 between the bearing inner and outer rings is the electrostatic capacitance of the shaft side bearing 12.

  A case where the power of the INV unit 24 is applied to the winding 2 from the substrate 5 on which the driving element is mounted will be described on the premise of such an electrical configuration.

  When the power of the INV unit 24 is applied, the stray capacitance described above is synthesized. Next, a stray capacity 27 is generated between the bearing outer ring 34 and the bearing inner ring 35, and a stray capacity 28 is generated between the bearing outer ring 36 and the bearing inner ring 37. As a result, a potential difference is generated between the bearing outer rings 34 and 36 and the bearing inner rings 35 and 37, and a voltage is generated. In this state, when a potential difference equal to or greater than a predetermined value is reached, electric discharge occurs due to dielectric breakdown between the grease between the bearing outer rings 34 and 36 and the bearing inner rings 35 and 37. At this time, the energy of this discharge damages the transfer surface of the bearing. In this way, the phenomenon of electrolytic corrosion occurs. And by repeating such discharge, wavy wear occurs on the transfer surface. As a result, abnormal noise is generated in the molded motor, which causes a malfunction of the air conditioner itself.

  The stray capacitance described above varies depending on the structure of the molded motor. In other words, the mold motor has different stray capacitances depending on the structure based on the specifications of the mold motor.

  In FIG. 8, the stray capacity between the bearing outer rings 34 and 36 and the bearing inner rings 35 and 37 is the sum of the stray capacity between the inner and outer rings of the bearing and the stray capacity of the system in contact with the bearing inner and outer rings. When the structure of the motor is different, the floating capacity of each system of the bearing inner and outer rings changes. Therefore, electrolytic corrosion can be prevented by reducing these stray capacitances or by zeroing these stray capacitances. Here, the expression of the capacitance of the parallel plate conductor is shown in Expression (1).

  In formula (1), by reducing C, electrolytic corrosion can be prevented. Further, in the formula (1), by balancing C between the bearings, that is, by making the C between the bearings have the same capacity, it is possible to eliminate the potential difference and prevent electrolytic corrosion. Moreover, in Formula (1), it is possible to prevent electrolytic corrosion by zeroing C between the bearings, that is, by short-circuiting the bearings.

  In short, electrolytic corrosion is prevented by eliminating the potential difference between the bearing outer rings 34 and 36 and the bearing inner rings 35 and 37 and making them conductive. Thereby, the long-term reliability of the mold motor can be improved, and a long-life mold motor can be provided. And an air conditioner is provided with such a molded electric motor, so that a long-life and highly reliable air conditioner can be provided. In addition, by preventing electric corrosion, noise generation caused by electric corrosion can be prevented.

  In addition, the electrical model demonstrated above shows an example, and is not limited to this.

  Next, an example of an embodiment for preventing electrolytic corrosion as described above will be specifically described with reference to FIGS.

  FIG. 9 is a schematic diagram of an indoor unit of an air conditioner incorporating the molded electric motor according to Embodiment 1 of the present invention and a diagram illustrating an example of the first electrical wiring. As shown in FIG. 9, the first electrical wiring 63 includes a molded motor shaft 11, a first bracket 6, a second bracket 7, a cross flow fan 9, a cross flow fan shaft 57, a sliding bearing 56, and a bearing. The mount 55 is connected.

  The cross flow fan 9 is made conductive by, for example, mixing and molding a conductive resin coating or conductive resin powder. The shaft 57 of the cross flow fan is made of a metal, for example, to have conductivity. The sliding bearing 56 is made conductive, for example, by forming it with a conductive resin or metal. The bearing mount 55 is made conductive by containing a conductive material such as carbon, for example. The bearing mount 55, the first bracket 6, and the second bracket 7 are provided with conductivity in the indoor unit base 20 shown in FIG. 2 or through a conductive heat exchanger installed in front of the cross flow fan 9. The wiring is electrically connected by wiring. The first electrical wiring 63 formed in this way is prevented from being grounded to the ground. However, the indoor unit 52 of the air conditioner is grounded with respect to the ground. That is, the first electrical wiring 63 is electrically insulated from the ground, but the motor shaft 11, the cross flow fan 9, the cross flow fan shaft 57, the sliding bearing 56, and the bearing mount. 55, the first bracket 6 and the second bracket 7 are electrically connected.

  The “first electrical wiring 63” corresponds to the “short circuit” in the present invention. That is, the first electrical wiring 63 is a protection circuit for the motor.

In addition, the electrical wiring demonstrated above shows an example, and is not limited to this.
The material of the shaft 11 of the mold motor, the crossflow fan 9, the shaft 57 of the crossflow fan, the sliding bearing 56, the bearing mount 55, the first bracket 6 and the second bracket 7 is shown as an example. It is not limited to this.

  However, the motor shaft 11, the cross flow fan 9, the cross flow fan shaft 57, the sliding bearing 56, the bearing mount 55, the first bracket 6 and the second bracket 7 are made conductive.

  Next, on the premise of the electrical connection described above, the potential of each component of the molded motor will be described with reference to FIG.

  FIG. 10 is a diagram illustrating an example of an electrical model using the crossflow fan according to Embodiment 1 of the present invention.

  In the electrical model of FIG. 10, items not particularly described are the same as those of the electrical model of FIG. 8, and the same functions and configurations are described using the same reference numerals.

  The first electrical wiring 63 described in FIG. 9 makes the potential of the shaft 11 and the potential of the bearing outer ring 36 of the shaft side bearing 12 the same as shown in FIG. The potential of the bearing outer ring 34 is the same. That is, the potential difference between the shaft 11 and the bearing outer ring 36 of the shaft side bearing 12 becomes zero, and the potential difference between the shaft 11 and the bearing outer ring 34 of the non-shaft side bearing 13 becomes zero. Specifically, as shown in FIG. 10, the shaft 11, the cross flow fan 9, the cross flow fan shaft 57, the slide bearing 56, the bearing mount 55, the first bracket 6, the second bracket 7, the bearing outer ring 34, the bearing The inner ring 35, the bearing outer ring 36, and the bearing inner ring 37 all have the same potential.

  That is, the stray capacitances 27 and 28 between the bearing inner and outer rings become zero. This means that C in the above-described formula (1) becomes zero. Thereby, generation | occurrence | production of an axial current can be suppressed. The first electrical wiring 63 is not grounded. Therefore, the direct influence by the ground can be prevented. For this reason, even if lightning, noise, or the like is superimposed on the power supply voltage, the generation of the shaft current can be prevented, and the generation of the shaft current due to other unstable power supply can be prevented.

  In this way, electrolytic corrosion can be prevented. Thereby, the long-term reliability of the electric motor can be improved, and a long-life electric motor can be provided. And by providing such an electric motor in an air conditioner, a long-life and highly reliable air conditioner can be provided. Further, by preventing electric corrosion, noise generation caused by electric corrosion can also be prevented.

  In other words, the shaft 11 of the molded motor and the first bracket 6 that is conductive and the second bracket 7 that is conductive are electrically connected by using components of an air conditioner, and the like is formed. Since the first electrical wiring 63 is not grounded, no voltage is generated between the inner and outer rings of the bearing, and the shaft current does not flow. As a result, even if the structure of the mold motor is changed, the configuration that prevents the axial current from flowing is independent of the structure of the mold motor, and therefore, electrolytic corrosion can be prevented. Thereby, the freedom degree of design of an air conditioner can be increased. That is, it is possible to prevent electrolytic corrosion while maintaining quality without deteriorating efficiency and performance.

  Further, since it is not necessary to consider the influence of the power supply, it is not necessary to provide a configuration for reducing the noise level of the power supply. Therefore, the cost of the air conditioner can be reduced. Furthermore, since electric corrosion can be prevented, generation of noise due to electric corrosion can be prevented. As a result, a long-life and highly reliable mold motor and an air conditioner equipped with the mold motor can be provided.

  The first electrical wiring 63 is not grounded. That is, since the first electrical wiring 63 is in a non-conductive state with respect to the ground, the first electrical wiring 63 itself is in an insulated state with respect to the ground. Therefore, normally, even if noise or lightning is superimposed on the ground connected to the indoor unit base 20, it is in a non-conductive state with respect to the ground and is in an insulated state with respect to the indoor unit base 20. 1 electrical wiring 63 is not affected by this. Accordingly, it is possible to avoid the deterioration of electrolytic corrosion caused by the ground connection due to the ground connection.

  As described above, in the first embodiment, the shaft 11, the rotor 4 fixed to the shaft 11, the stator portion 10 that houses the rotor 4, and the shaft 11 are fixed and have the same potential as the shaft 11. The bearing inner rings 35 and 37, the bearing outer rings 34 and 36 paired with the bearing inner rings 35 and 37, and the stator 10 and the bearing outer rings 34 and 36 are interposed between the stator 10 and the bearing outer rings 34 and 36 to support the bearing outer rings 34 and 36. The molded motor having the first bracket 6 and the second bracket 7 having the same potential as the outer rings 34 and 36, the bearing inner rings 35 and 37, and the bearing outer rings 34 and 36 are connected via the first bracket 6 and the second bracket 7. Are electrically connected to each other, and the bearing inner rings 35 and 37 and the bearing outer rings 34 and 36 are connected to each other, and the first electric wiring 63 is set to a non-conductive state with respect to the ground. Can preventThereby, the long-term reliability of the electric motor can be improved, and a long-life electric motor can be provided. And by providing such an electric motor in an air conditioner, a long-life and highly reliable air conditioner can be provided. Further, by preventing electric corrosion, noise generation caused by electric corrosion can also be prevented.

  In the first embodiment, the cross flow fan 9, the cross flow fan shaft 57 that transmits the rotation of the cross flow fan 9, the slide bearing 56 that supports the rotation of the cross flow fan shaft 57, and the slide bearing are provided. The shaft 11 of the mold motor, the cross flow fan 9, the shaft 57 of the cross flow fan, the sliding bearing 56, the bearing mount 55, the first bracket 6 and the second bracket 7 are provided. The first electric wiring 63 is formed of a mold motor shaft 11, a cross flow fan 9, a cross flow fan shaft 57, a sliding bearing 56, a bearing mount 55, and a first bracket 6. The second bracket 7 is electrically connected to the bearing inner rings 35, 37. Since such a bearing outer ring 34, 36 in the conductive state, it is possible to prevent electrolytic corrosion. Thereby, the long-term reliability of the electric motor can be improved, and a long-life electric motor can be provided. And by providing such an electric motor in an air conditioner, a long-life and highly reliable air conditioner can be provided. Further, by preventing electric corrosion, noise generation caused by electric corrosion can also be prevented.

Embodiment 2. FIG.
FIG. 11 is a schematic diagram of an indoor unit of an air conditioner incorporating a molded motor according to Embodiment 2 of the present invention and a diagram illustrating an example of the second electrical wiring.

  In the second embodiment, items that are not particularly described are the same as those in the first embodiment, and the same functions and configurations are described using the same reference numerals.

  The difference from the first embodiment is that the shaft 11, the first bracket 6, and the second bracket 7 of the molded motor are short-circuited by using the conductive brush 61.

  As shown in FIG. 11, the second electrical wiring 64 is formed by bringing the conductive brush 61 into contact with the shaft 11 of the mold motor without using the cross flow fan 9, thereby causing the shaft 11 of the mold motor, The first bracket 6 and the second bracket 7 are electrically connected. Note that the shape, material, and the like of the conductive brush 61 are not particularly limited as long as they are conductive.

  Specific wiring will be described with reference to FIG.

  FIG. 12 is an enlarged wiring diagram centering on the mold motor of the indoor unit 52 of the air conditioner incorporating the mold motor according to the second embodiment of the present invention. As shown in FIG. 12, the shaft 11, the conductive brush 61, the first bracket 6, and the second bracket 7 of the mold motor are electrically connected by the second electrical wiring 64. The second electrical wiring 64 formed in this way is prevented from being grounded to the ground. However, the indoor unit 52 of the air conditioner is grounded with respect to the ground. That is, the second electrical wiring 64 is electrically insulated from the ground, while the electric shaft 11, the conductive brush 61, the first bracket 6, and the second bracket 7 are electrically connected. Make it conductive.

  The “second electrical wiring 64” corresponds to the “short circuit” in the present invention. That is, the second electrical wiring 64 is a motor protection circuit.

In addition, the conductive brush 61 demonstrated above shows an example, and is not limited to this. For example, a short circuit using a connection terminal or the like instead of the conductive brush 61 may be used.
In addition, the electrical wiring demonstrated above shows an example, and is not limited to this.

  Next, on the premise of the electrical connection described above, the potential of each component of the molded motor will be described with reference to FIG.

  FIG. 13 is a diagram illustrating an example of an electrical model using a brush according to Embodiment 2 of the present invention.

  In the electrical model of FIG. 13, items that are not particularly described are the same as those of the electrical model of FIG. 8, and the same functions and configurations are described using the same reference numerals.

  11 and 12, the potential of the shaft 11 and the potential of the bearing outer ring 36 of the shaft side bearing 12 shown in FIG. 13 are the same, and the potential of the shaft 11 and the non-shaft side bearing shown in FIG. The potential of the thirteen bearing outer rings 34 is the same. That is, the potential difference between the shaft 11 and the bearing outer ring 36 of the shaft side bearing 12 becomes zero, and the potential difference between the shaft 11 and the bearing outer ring 34 of the non-shaft side bearing 13 becomes zero. Specifically, as shown in FIG. 13, the shaft 11, the conductive brush 61, the first bracket 6, the second bracket 7, the bearing outer ring 34, the bearing inner ring 35, the bearing outer ring 36, and the bearing inner ring 37 are all at the same potential. It becomes.

  That is, the stray capacitances 27 and 28 between the bearing inner and outer rings become zero. This means that C in the above-described formula (1) becomes zero. Thereby, generation | occurrence | production of an axial current can be suppressed. The second electrical wiring 64 is not grounded. Therefore, the direct influence by the ground can be prevented. For this reason, even if lightning, noise, or the like is superimposed on the power supply voltage, the generation of the shaft current can be prevented, and the generation of the shaft current due to other unstable power supply can be prevented.

  In this way, electrolytic corrosion can be prevented. Thereby, the long-term reliability of the mold motor can be improved, and a long-life mold motor can be provided. And an air conditioner provided with such a molded electric motor can provide a long-life and highly reliable air conditioner. Further, by preventing electric corrosion, noise generation caused by electric corrosion can also be prevented.

  In other words, the shaft 11 of the molded motor and the first bracket 6 that is conductive and the second bracket 7 that is conductive are electrically connected by using components of an air conditioner, and the like is formed. Since the second electrical wiring 64 is not grounded, no voltage is generated between the inner and outer rings of the bearing, and the shaft current does not flow. As a result, even if the structure of the mold motor is changed, the configuration that prevents the axial current from flowing is independent of the structure of the mold motor, and therefore, electrolytic corrosion can be prevented. Thereby, the freedom degree of design of an air conditioner can be increased. That is, it is possible to prevent electrolytic corrosion while maintaining quality without deteriorating efficiency and performance. Further, since it is not necessary to consider the influence of the power supply, it is not necessary to provide a configuration for reducing the noise level of the power supply. Therefore, the cost of the air conditioner can be reduced. Furthermore, since electric corrosion can be prevented, generation of noise due to electric corrosion can be prevented. As a result, a long-life and highly reliable mold motor and an air conditioner equipped with the mold motor can be provided.

  The first electrical wiring 63 is not grounded. That is, since the first electrical wiring 63 is in a non-conductive state with respect to the ground, the first electrical wiring 63 itself is in an insulated state with respect to the ground. Therefore, normally, even if noise or lightning is superimposed on the ground connected to the indoor unit base 20, it is in a non-conductive state with respect to the ground and is in an insulated state with respect to the indoor unit base 20. 1 electrical wiring 63 is not affected by this. Accordingly, it is possible to avoid the deterioration of electrolytic corrosion caused by the ground connection due to the ground connection.

  As described above, in the second embodiment, the molded motor includes the conductive brush 61, and the second electrical wiring 64 includes the molded motor shaft 11, the first bracket 6, the second bracket 7, In addition, since the conductive brush 61 is electrically connected to bring the bearing inner rings 35 and 37 and the bearing outer rings 34 and 36 into a conductive state, electrolytic corrosion can be prevented. Thereby, the long-term reliability of the mold motor can be improved, and a long-life mold motor can be provided. And an air conditioner provided with such a molded electric motor can provide a long-life and highly reliable air conditioner. Further, by preventing electric corrosion, noise generation caused by electric corrosion can also be prevented.

  In the first and second embodiments, the first electrical wiring 63 and the second electrical wiring 64 are formed outside the mold motor, so that they do not depend on the structure of the mold motor. Electric corrosion can be prevented.

  2 Winding, 3 Mold resin, 4 Rotor, 5 Substrate, 6 First bracket, 7 Second bracket, 8 Insulating part, 9 Cross flow fan, 10 Stator part, 11 Shaft, 12 Shaft side bearing, 13 Anti-shaft side Bearing, 14, 15 Rubber mount, 16 Motor first mount, 17 Motor second mount, 18 Motor ASSY, 19 Motor mount ASSY, 20 Indoor unit base, 21 Other capacity, 22 INV part-core capacity, 23 Core-rotor Capacity, 24 INV section, 26 INV section-second bracket capacity, 27 floating capacity between bearing inner and outer rings, 30 core, 34, 36 bearing outer ring, 35, 37 bearing inner ring, 39 core-second bracket capacity, 40 INV section-first bracket capacity, 42 first bracket-second bracket capacity, 43 Capacity between core and first bracket, 52 Air conditioner indoor unit, 53 Air conditioner outdoor unit, 55 Bearing mount, 56 Slide bearing, 57 Cross flow fan shaft, 61 Conductive brush, 63 First electrical Wiring, 64 second electrical wiring, 65 ground.

Claims (3)

A shaft, a rotor fixed to the shaft, a stator portion that houses the rotor, a bearing inner ring that is fixed to the shaft and has the same potential as the shaft, a bearing outer ring that is paired with the bearing inner ring, An electric motor having a bracket interposed between a stator portion and the bearing outer ring, supporting the bearing outer ring and having the same potential as the bearing outer ring;
A fan having one side connected to the shaft of the electric motor and having conductivity;
A shaft of a conductive fan provided on the other side of the fan and rotating with the rotation of the fan;
A conductive sliding bearing that rotatably supports the shaft of the fan;
A conductive bearing mount for supporting the sliding bearing;
A short circuit for electrically connecting the bearing inner ring and the bearing outer ring via the bracket to bring the bearing inner ring and the bearing outer ring into a conductive state and a non-conductive state with respect to the ground;
Have
The bearing inner ring, the fan, the shaft of the fan, the sliding bearing and the bearing mount are electrically connected,
The air conditioner characterized in that the short circuit makes the bearing inner ring and the bearing outer ring conductive by electrically connecting the bearing mount and the bracket . A shaft, a rotor fixed to the shaft, a stator portion that houses the rotor, a bearing inner ring that is fixed to the shaft and has the same potential as the shaft, a bearing outer ring that is paired with the bearing inner ring, An electric motor having a bracket interposed between a stator portion and the bearing outer ring, supporting the bearing outer ring and having the same potential as the bearing outer ring;
A short circuit for electrically connecting the bearing inner ring and the bearing outer ring via the bracket to bring the bearing inner ring and the bearing outer ring into a conductive state and a non-conductive state with respect to the ground;
Have
The bearing inner ring, the bearing outer ring, and the bracket are arranged in an insulated state on the shaft side and the non-shaft side, respectively.
The short-circuit circuit electrically connects the bracket on the shaft side and the bracket on the opposite shaft side, and is electrically connected to the bracket on the opposite shaft side, and is in contact with the shaft that is rotationally driven. The air conditioner is characterized in that the bearing inner ring and the bearing outer ring are brought into conduction by electrically connecting the shaft and the bracket via the conductive brush. The air conditioner according to claim 1 or 2 , wherein the short circuit is formed outside the electric motor.

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