JP5131304B2 - Motor, ventilation fan, heat exchange unit - Google Patents

Description

  The present invention relates to a motor including a drive circuit board and a device having a fan driven by the motor.

  In recent years, application of brushless DC motors (hereinafter referred to as BLDCM), which are energy-saving motors, to devices is progressing due to an increase in environmental awareness. However, BLDCM requires electronic components including a new electronic circuit such as a drive circuit and an inverter that are not necessary for induction motors that have been applied to many devices in the past, and this electronic circuit and electronic components are built-in. In order to obtain a BLDCM, a BLDCM housing that can incorporate a substrate on which a drive circuit is mounted is attached to a motor, or is molded with resin including the drive circuit to form an outer frame of the BLDCM. .

Conventionally, the switching unit is a switching element and a PN junction diode using a silicon (Si) semiconductor or a Schottky barrier using a Si semiconductor as a flywheel diode (hereinafter referred to as FRD) that prevents a through current during switching. A BLDCM including a substrate on which an inverter composed of a diode (hereinafter referred to as SBD) is inserted and mounted is known (see, for example, Patent Document 1).
Thus, in the BLDCM having a configuration in which the inverter is not separately provided outside the motor but built in the case, there is a problem that an electrolytic corrosion phenomenon occurs in a bearing serving as a bearing of the motor shaft.

  Therefore, a special structure in which a conductive paint is applied to the motor frame in order to suppress the electrolytic corrosion phenomenon of the bearing is also disclosed (see, for example, Patent Document 2).

JP 2002-223581 (see columns 0012, 0047, 0103 and FIG. 30) JP 2009-118628 A (refer to claim 1, FIG. 1)

  In the conventional configuration, since the inverter-equipped board is built in the motor, the inverter and the bearing are placed close to each other, and a voltage is induced between the inner and outer rings of the bearing by the electromagnetic field generated from the inverter, and the voltage level is the bearing. When the withstand voltage is exceeded, there has been a problem that an electric corrosion phenomenon occurs in which a discharge occurs between the inner and outer rings and the ball inside the bearing to damage the bearing. In addition, Si-SBD has a problem that it has a low voltage tolerance and is easily damaged by a reverse voltage during switching.

  In addition, when a structure in which a conductive layer is provided inside the motor, there is a problem that the material cost and processing cost of the motor increase. The configuration in which the conductive layer is provided on the surface of the motor frame is effective in suppressing the potential between the two bearings provided on both sides of the rotor, but has no effect on the induced voltage of the bearing alone.

  The present invention has been made in order to solve the above-described problems. An electromagnetic field generated from an inverter is reduced by using a wide band gap semiconductor as a diode for preventing reverse current of the inverter to reduce a surge current generated when switching the inverter. An object of the present invention is to provide a highly reliable heat exchange unit and a ventilation fan having a highly reliable motor that suppresses the electric corrosion phenomenon of the bearing caused by the motor and a fan driven by the motor.

In order to solve the conventional problems, the motor of the present invention is arranged in an annular shape, has a stator around which an insulating member is attached to an iron core and a coil is wound, and a shaft, and is provided on the inner periphery of the stator. A rotor that rotates in rotation, a switching element and an inverter having a Schottky barrier diode made of a wide band gap semiconductor that prevents reverse current during switching, and a substrate that generates an alternating current supplied to the coil and supports the shaft And a second bearing that is provided closer to the substrate than the first bearing and supports the shaft, and the substrate is substantially perpendicular to the rotation axis direction of the shaft. And the inverter is mounted on the surface of the substrate opposite to the surface facing the second bearing, Motor plate, characterized in that it is molded with a resin for fixing the stator.

  In the motor of the present invention, since a reverse current at the time of switching is prevented by a Schottky barrier diode made of a wide band gap semiconductor, it is possible to reduce the surge current at the time of switching and suppress the electrolytic corrosion phenomenon that occurs in the bearing.

1 is a circuit diagram of a motor drive circuit according to a first embodiment of the present invention. Sectional drawing of the motor of Embodiment 1 of this invention. Sectional drawing of the bearing of the motor of Embodiment 1 of this invention. The graph of the surge current-time of the inverter main circuit of Embodiment 1 of this invention. Sectional drawing of another motor of Embodiment 1 of this invention. Sectional drawing of the ventilation fan of Embodiment 2 of this invention. The block diagram of the air conditioning apparatus of Embodiment 3 of this invention. The top view of the outdoor heat exchange unit of Embodiment 3 of this invention. The perspective view of the indoor heat exchange unit of Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a circuit diagram of a motor built-in drive circuit 1 built in the motor according to the first embodiment of the present invention. AC power is supplied to the motor built-in drive circuit 1 from a commercial AC power source 2 provided outside the motor. The AC voltage supplied from the commercial AC power supply 2 is converted into a DC voltage by the rectifier circuit 3. The DC voltage converted by the rectifier circuit 3 is converted to an AC voltage having a variable frequency by the inverter main circuit 4 and applied to the BLDCM 5. The BLDCM 5 is driven by variable frequency AC power supplied from the inverter main circuit 4. The rectifier circuit 3 includes a chopper circuit that boosts the voltage applied from the commercial AC power supply 2 and a smoothing capacitor that smoothes the rectified DC voltage.

The inverter main circuit 4 is a three-phase bridge inverter circuit, and the switching part of the inverter main circuit 4 is composed of six IGBTs (insulated gate bipolar transistors) 6a to 6f serving as inverter main elements and six flywheel diodes (FRD). Schottky barrier diodes (SiC-SBD) 7a to 7f using carbide (SiC) are provided. The SiC-SBDs 7a to 7f, which are FRDs, are reverse current prevention means for suppressing the counter electromotive force generated when the IGBTs 6a to 6f turn the current from ON to OFF.
In the first embodiment, the IGBTs 6a to 6f and the SiC-SBDs 7a to 7f are IC modules in which each chip is mounted on the same lead frame and molded with epoxy resin and packaged. The IGBTs 6a to 6f may be IGBTs using SiC or GaN instead of IGBTs using silicon (Si-IGBT), and MOSFETs (Metal-Oxide-Semiconductor Field-) using Si, SiC, or GaN instead of IGBTs. Other switching elements such as Effect Transistor may be used.

Two voltage-dividing resistors 8a and 8b connected in series are provided between the rectifier circuit 3 and the inverter main circuit 4, and the high-voltage DC voltage is reduced by the voltage-dividing circuit using the voltage-dividing resistors 8a and 8b. A DC voltage detector 8 is provided for sampling and holding the electrical signal.
The BLDCM 5 includes a rotor and a stator, and the rotor is rotated by AC power supplied from the inverter main circuit 4. In the vicinity of the rotor, a magnetic pole position detection sensor 9 is provided as a rotor detection means for detecting the rotation angle and position of the rotor, and an electrical signal from the magnetic pole position detection sensor 9 is processed to obtain rotor position information. A rotor position detecting unit 10 for converting to the above is provided.
The rotor position information detected by the rotor position detector 10 is output to the output voltage calculator 11. This output voltage calculation unit 11 is an optimum inverter main circuit 4 to be added to the BLDCM 5 based on the command of the target rotational speed N given from the outside of the motor built-in drive circuit 1 or information on the operating conditions of the device and the rotor position information. The output voltage is calculated. The output voltage calculation unit 11 outputs the calculated output voltage to a PWM (Pulse Width Modulation) signal generation unit 12.
The PWM signal generation unit 12 outputs a PWM signal having the output voltage given from the output voltage calculation unit 11 to the main element drive circuit 4a that drives each of the IGBTs 6a to 6f of the inverter main circuit 4, and the inverter main circuit 4 Each of the IGBTs 6a to 6f is switched by the main element drive circuit 4a.

  In the first embodiment, the inverter main circuit 4 is a three-phase bridge, but another inverter circuit such as a single phase may be used.

  Here, the wide band gap semiconductor will be described. A wide band gap semiconductor is a generic term for semiconductors having a larger band gap than Si, and SiC used in the SiC-SBDs 7a to 7f is one of the wide band gap semiconductors, in addition to gallium nitride (GaN), There are diamonds. Furthermore, wide band gap semiconductors, particularly SiC, have higher heat resistance temperature, dielectric breakdown strength, and thermal conductivity than Si. In the first embodiment, SiC is used for the FRD of the inverter circuit, but other wide band gap semiconductors may be used instead of SiC.

  FIG. 2 is a sectional view of the motor according to the first embodiment, and the configuration of the motor will be described with reference to FIG. The motor includes a stator 13 arranged in an annular shape and a rotor 14 inserted into the stator 13. The stator 13 includes an iron core 15 formed by laminating a plurality of electromagnetic steel plates, insulating members 16a and 16b provided on both end surfaces of the iron core 15 in the rotation axis direction of the rotor 14, and the insulating members 16a and 16b. And a coil 17 wound in a slot provided with. A shaft 18 is inserted and fixed to the rotor 14 so as to coincide with the central axis thereof, and the rotation axis of the rotor 14 and the rotation axis of the shaft 18 coincide with each other.

  Two bearings 19 a and 19 b that serve as bearings for the shaft 18 are provided before and after the rotor 14 of the shaft 18. A shaft 18 protrudes from the bearing 19 a, and a bearing 19 b is provided on the opposite side of the bearing 19 a through the rotor 14. The bearings 19a and 19b are fitted and fixed in recesses provided in the brackets 20a and 20b, respectively. A thermosetting unsaturated polyester resin 21 is provided on the radially outer side of the stator 13 from the bracket 20a to the bracket 20b, and the bracket 21a, the bracket 20b, and the stator 13 are integrally fixed by the resin 21. It is fixed.

Next, the arrangement and configuration of the motor drive circuit board 22 which is a printed board having the motor built-in drive circuit 1 described with reference to FIG. 1 will be described. The motor drive circuit board 22 has a substantially ring shape, and the shaft 18 is inserted through an opening provided at the center thereof.
The motor drive circuit board 22 is fixed by a fixed piece or resin 21 extending from the insulating member 16a, and is substantially perpendicular to the rotational axis direction of the shaft 18 so as not to contact the rotor 14 and the stator 13 through a gap. Is provided. The motor drive circuit board 22 is disposed between the rotor 14 and the bearing 19 a in the direction of the rotation axis of the shaft 18. That is, the linear distance from the motor drive circuit board 22, particularly the module having the inverter main circuit 4 among the boards, is arranged at a position closer to the bearing 19a and the bracket 20a than to the bearing 19b and the bracket 20b. In addition, it is good also as a structure arrange | positioned between the rotor 14 and the bearing 19b in the axial direction of the shaft 18.
The motor driving circuit board 22 and the coil 17 of the stator 13 are electrically connected by terminal pins (not shown), and the AC power of variable frequency generated by the inverter main circuit 4 is supplied to the stator 13 to be supplied to the coil 17. Generates a magnetic field and the rotor 14 rotates.

  The motor drive circuit board 22 includes a pre-drive IC 23 in which the output voltage calculation unit 11 and the PWM signal generation unit 12 are packaged, and a main circuit module 24 in which the inverter main circuit 4 and the main element drive circuit 4a are packaged. As implemented. The main circuit module 24 uses SiC for the SiC-SBDs 7a to 7b housed therein, and SiC has a higher dielectric breakdown strength, thermal conductivity, heat-resistant temperature, allowable heat-resistant density, and electric power than Si. Since the loss and the amount of heat released thereby are small, it is possible to reduce the thickness and size of the element and the IC module packaged with the element, and further reduce the necessity of providing a heat dissipation plate and heat dissipation resin. Therefore, in the first embodiment, the pre-drive IC 23 and the bearing 19a and the bracket 20a are combined with the thin main circuit module 24 as compared with the conventional module even if a hybrid IC is used without using a monolithic IC. It is surface-mounted on the surface of the motor drive circuit board 22 on the opposite side and on the rotor 14 side. Further, a plurality of magnetic pole position detection sensors 9 are provided on the surface of the motor drive circuit board 22 on the rotor 14 side, and the rotation of the magnet provided in the rotor 14 is detected and output to the rotor position detection unit 10. Yes.

  The motor drive circuit board 22 is soldered to terminal pins that are electrically connected to the coil 17. The motor drive circuit board 22 is supplied with a high-voltage DC voltage VDC of 100 V or higher boosted by a chopper circuit (not shown), a control power supply VCC of less than 100 V, and a command voltage VSP. The magnetic pole position detection sensor 9 detects the magnetic pole arrangement of the magnet, and the pre-drive IC 23 controls the energization of the main circuit module 24 based on the output signal of the sensor. In the first embodiment, SiC having a dielectric breakdown electric field about 10 times larger than that of Si is used for the shot barrier diode. Therefore, the high-voltage DC voltage VDC can be set to 600 V or higher and applied to the inverter main circuit 4. The high-voltage direct-current voltage VDC can be made higher than that of an inverter using conventional Si. Since the current value flowing from the inverter main circuit 4 to the coil 17 of the BLDCM 5 can be lowered, the winding of the coil 17 can be made thinner and the amount of winding used can be reduced.

  In FIG. 2, the pre-drive IC 23 and the main circuit module 24 are illustrated, but the output voltage calculation unit 11, the PWM signal generation unit 12, the main element drive circuit 4a, and the inverter main circuit 4 are separately provided. You may mount on a motor drive circuit board, and you may mount what was packaged together. Further, the DC voltage detection unit 8 and the rotor position detection unit 10 are also mounted on the motor drive circuit board 22. Further, when the DC voltage detection unit 8 and the rotor position detection unit 10 are also mounted on the same surface as the pre-drive IC 23 and the main circuit module 24, the rotor position detection unit 10 and the output voltage calculation unit pass through the motor drive circuit board 22. 11 and the DC voltage detection unit 8 and the PWM signal generation unit 12 need not be wired.

  In the first embodiment, a connector (not shown) for connecting the motor drive circuit board 22 and the external commercial AC power source 2 is provided. The connector is connected to the rectifier circuit 3. In the first embodiment, the connector is connected to the rotor side surface of the motor drive circuit board 22. However, the connector is connected to the bearing side opposite to the rotor side surface. It is good also as composition to do.

  FIG. 3 is a sectional view of the bearings 19a and 19b of the first embodiment. A plurality of balls 29 are arranged in a ring-shaped inner ring 27 and an outer ring 28 provided outside the ring-shaped inner ring 27. The shaft 18 is inserted into the central opening of the inner ring 27 and rotates in it. Shields 30 are provided above and below the balls 29 to prevent foreign substances from entering, and the balls 29 are provided with nylon cages 31 for holding the balls 29 at equal intervals. . Note that an insulating lubricant is applied to the inside of the bearing.

  The inner ring 27, the outer ring 28, the ball 29, and the shield 30 are each made of metal, and the voltage induced in the electromagnetic field generated by the surge current during switching of the inverter is between the shield 30 and the inner ring 27 and between the ball 29 and the inner ring 27. When the insulation of the oil film of the lubricating oil between the ball 29 and the outer ring 28 becomes larger, the oil pierces through the oil film of the lubricating oil and an electric corrosion phenomenon occurs in the bearing. At that time, a current loop may occur between the inner ring 27, the outer ring 28, the ball 29, and the shield 30, and in such a configuration, even if the bearings 19a and 19b are formed of an insulating mold, the bearing alone It is easy for electric corrosion to occur.

FIG. 4 is a waveform diagram of the IGBT turn-on current of the inverter main circuit 4 according to the first embodiment. The horizontal axis indicates time t, the vertical axis indicates the magnitude of the surge current, and the IGBT of the inverter is t = t0. The case of switching is shown. 3 is a graph showing the reverse current when using SiC-SBD, which is shown by a solid line, and for comparison, the case where a PN junction diode of Si is used instead of SiC-SBD is shown by a broken line. It is shown.
In the first embodiment, as shown in FIG. 3, the SiC-SBD is used for the flywheel diode (FRD) of the reverse current prevention means at the time of switching, so that it is connected in series with the previous GBT when the Si-IGBT is turned on. Since the generation of the surge current due to the reverse recovery current of the FRD can be significantly reduced, the induced voltage induced in the loop formed by the inner and outer rings of the bearing 19a, the inner ball and the bracket 20a in the vicinity of the motor drive circuit board 22 Can be significantly reduced, and the induced voltage generated by the loop of the bearing 19a alone in the vicinity of the motor drive circuit board 22 can be reduced. Therefore, providing a loop that electrically short-circuits the induced voltage between a plurality of bearings as in the prior art is particularly effective for the problem of electric corrosion that cannot be countered. In addition, it is needless to say that a special short circuit structure as a motor is not required because the generation of surge current as a generation source is suppressed for the induced voltage between the plurality of bearings. In addition, since the short-circuit structure is a normal contact structure, there is no fear of a quality defect due to insufficient pressing pressure of the contact portion and a short-circuit failure due to aged deterioration of the contact portion.

Further, as described above, since the present invention uses SiC having a dielectric breakdown electric field larger than Si, the voltage value of the high-voltage DC voltage boosted by the chopper circuit is set higher than that of the inverter using Si for FRD. It is possible to reduce the value of the current flowing from the motor built-in drive circuit 1 to the BLDCM 5 by setting the high-voltage DC voltage high, and at the same time, the surge current generated during switching can be reduced. It is possible to suppress the electrolytic corrosion phenomenon of the bearing caused by the above.
Further, by suppressing the surge current, radiation noise in the FM / UHF / VHF band from the electric wiring connected to the motor can be reduced.

  In the present invention, in order to fundamentally prevent the cause of the surge current on the motor drive circuit board 22 side that induces a voltage in the bearing, it is also effective for the metal shield 30 and the bearings 19a and 19b of the cage 31. Has an effect.

  As shown in FIG. 2 of the first embodiment, the motor drive circuit board 22 is provided substantially perpendicular to the rotation axis of the shaft 18 and is held at a position held by the protrusion of the insulating member 16a of the stator 13. With the arrangement, the inverter main circuit 4 of the motor drive circuit board 22 is arranged in the vicinity of the bearing 19a, so that the effect of the present invention is particularly high.

  FIG. 5 shows a sectional view of another motor according to the first embodiment. In FIG. 2, only the stator 13 of the motor is shown molded with an unsaturated polyester resin 21. However, as shown in FIG. 5, the motor drive circuit board 22 is also molded with a resin 21a together with the stator 13. However, it goes without saying that the same effect can be obtained. Further, as shown in FIG. 5, when the bearing 19a is fixed with the resin 21a, the bracket 19a can be configured without the bracket for fixing the bearing 19a.

  Conventionally, when an inverter using Si for FRD is mounted on a substrate, a radiator material having a higher thermal conductivity than a resin such as a bracket or a heat sink is provided near the substrate in order to dissipate the heat generated by the inverter. Although it was necessary to provide separately, in the present invention, SiC that uses less energy loss at the time of switching than Si is used for the FRD, and the amount of heat generated in the inverter main circuit 4 is small. Even if the main circuit module 24 is molded with the resin 21a, the reliability of the inverter can be maintained by the amount of heat released from the resin 21a. Further, since power loss during switching is reduced, a highly efficient motor can be obtained.

  As described above, in the first embodiment, the wide band gap Schottky barrier diode is used as the reverse current prevention means at the time of switching of the switching element of the inverter main circuit 4. By reducing the electromagnetic wave generated from the inverter, the electrolytic corrosion phenomenon occurring in the bearings 19a and 19b serving as the bearings of the motor shaft 18 can be suppressed.

  Further, the motor drive circuit board 22 is arranged substantially perpendicular to the rotation axis direction of the shaft 18, and the inverter main circuit 4 is a motor on the opposite side to the surface facing the bearing 19a closer to the motor drive circuit board 22 than the bearing 19b. Since it is mounted on the surface of the drive circuit board 22, the galvanic phenomenon occurring in the bearing 19a can be suppressed by increasing the distance between the inverter main circuit 4 and the bearing 19a.

  Further, since a wide band gap semiconductor having a higher dielectric breakdown electric field strength and higher heat resistance temperature than Si is used as a reverse current prevention means of the inverter, a small and thin main circuit module 24 can be obtained. By mounting the main circuit module 24 on the same surface as the magnetic pole position detection sensor 9 together with the IC 23, the need to make a hole in the motor drive circuit board 22 is reduced, and wiring is efficiently connected on one side of the motor drive circuit board 22. be able to. Further, by disposing the main circuit module 24 in the gap between the motor drive circuit board 22 and the stator 13 or the rotor 14, a small motor having a small width in the axial direction of the shaft 18 can be obtained.

  Further, by using a wide band gap semiconductor having a dielectric breakdown electric field strength larger than that of Si, the main circuit module 24 can be made thinner than the conventional one using Si, and the thickness is made thinner than the magnetic pole position detection sensor 9. As a result, the distance between the magnetic pole position detection sensor 9 and the rotor 14 can be reduced.

  Further, as shown in FIG. 5, by molding the main circuit module 24 having the SiC-SBDs 7a to 7f inside with the resin 21a, the heat generated by the inverter can be radiated through the resin 21a. When the main circuit module 24 is surface-mounted on the motor drive circuit board 22, the main circuit module 24 can be firmly fixed on the board by molding with the resin 21a.

Embodiment 2. FIG.
In the second embodiment, the BLDCM in which the motor drive circuit board 22 is arranged in a space separated from the space in which the stator 13 and the rotor 14 are provided, and the ceiling embedded duct ventilation fan on which the motor driving circuit board 22 is mounted are illustrated in FIG. This will be described using a cross-sectional view. In the first embodiment, the motor drive circuit board 22 is arranged between the bearing 19a and the rotor 14 in the axial direction of the shaft 18. However, in the ventilation fan of the second embodiment, the motor drive circuit is arranged in the axial direction of the shaft 18. The substrate 22 is provided at a position farther from the rotor 14 than the bearing 19a. In addition, the same code | symbol is attached | subjected to the component same as the component used in Embodiment 1. FIG.

  In the second embodiment, the motor drive circuit board 22 is housed in a motor housing 33 of a sheet metal frame that is a non-combustible material. The interior of the motor casing 33 is partitioned into upper and lower spaces by a partition plate 32 made of resin or sheet metal, and the stator 13 and the rotor 14 are provided in the space below the partition plate 32, and the upper space is The motor drive circuit board 22 is provided substantially perpendicular to the axial direction of the shaft 18. The bearing 19 a is fixed by a partition plate 32, and the bearing 19 b is sandwiched and fixed by a protrusion provided on the motor housing 33. A centrifugal fan 34 is attached to the end of the shaft 18 that protrudes from an opening provided in the bearing 19 b and the motor housing 33. The centrifugal fan 34 is housed in a fan housing 35 made of sheet metal, and the fan housing 35 is fitted and attached to a ceiling wall 36. An opening is provided in the intake surface 35a of the fan housing 35 parallel to the surface of the ceiling wall 36, and air is sucked from the intake surface 35a by the rotating centrifugal fan 34. An intake grill 37 is attached to the intake surface 35a. A duct is connected to the side surface of the fan housing 35, and the intake air is exhausted through the duct.

  In the second embodiment, since the motor drive circuit board 22 is provided on the leeward side of the centrifugal fan 34, the main circuit module 24 can be cooled by the air sucked by the centrifugal fan 34. Accordingly, an opening may be provided in the partition plate 32 to cool the motor drive circuit board 22 with the wind generated by the rotation of the rotor 14, and an opening may be provided on the surface of the motor housing 35 that faces the centrifugal fan 34. It is good also as a structure which takes in the wind produced by rotation of the fan 34 to the motor housing | casing 33. FIG.

The magnetic pole position detection sensor 9 includes a Hall element using a compound semiconductor of indium antimony (InSb) and a circuit that converts a bias and Hall voltage to the Hall element into a pulse on a Si substrate in one surface-mount package. It is a mounted Hall IC. In the pre-drive IC 23, the DC voltage detection unit 8, the rotor position detection unit 10, the output voltage calculation unit 11, and the PWM signal generation unit 12 are realized on one silicon chip to control the main element drive circuit 4 a and the inverter main circuit 4. And is mounted on the surface of the motor drive circuit board 22 that faces the partition plate 32. The main circuit module 24 houses Si-IGBTs 6a to 6f, SiC-SBDs 7a to 7f, and a main element drive circuit 4a in a resin package, and faces the motor housing 33 on the surface of the motor drive circuit board 22. Insert mounted on the surface.
In the second embodiment, since the main circuit module 24 is a single in-line package in which metal leads protrude from one side of the package, the area of land and solder (not shown) for electrical connection with the motor drive circuit board 22 is reduced. Can be small. Therefore, the pre-drive IC 23 can be mounted immediately below the back surface of the motor drive circuit board 22, and the wiring between the pre-drive IC 23 and the main circuit module 24 can be shortened on the board. The IGBTs 6a to 6f may be IGBTs using SiC or GaN instead of IGBTs using Si, or other switching elements such as MOSFETs using Si, SiC, or GaN instead of IGBTs. Good.

  Terminal pins that penetrate the partition plate 32 are attached to the motor drive circuit board 22, and the motor drive circuit board 22 and the coil 17 of the stator 13 are electrically coupled via the terminal pins. The alternating current generated by the main circuit module 24 flows to the coil 17 through the terminal pin.

  The ventilation fan shown in FIG. 6 is connected to an operation unit that is provided outside to operate an operation condition, and information on the operation condition transmitted from the operation unit is input to the output voltage calculation unit 11. The output voltage calculation unit 11 calculates the output voltage of the inverter main circuit 4 applied to the BLDCM 5 based on the input information, and outputs the calculation result to the PWM signal generation unit 12.

6 shows a state in which the main circuit module 24 is inserted and mounted, the surface mounting may be performed by a single in-line package, and the pre-drive IC may be mounted on the same plane as the main circuit module 24.
In FIG. 6, the lead frame of the main circuit module 24 is bent and the package is provided sideways, but it may be mounted upright. By raising the package, the wiring area of the motor drive circuit board 22 can be used effectively.
FIG. 6 shows a smoothing electrolytic capacitor 3a that reduces voltage ripple among the components of the rectifier circuit 3, but the height of the electrolytic capacitor 3a is higher than that of the magnetic pole position detection sensor 9 and the main circuit module 24. If it is larger, the electrolytic capacitor 3a is provided on the surface of the motor drive circuit board 22 that faces the motor housing 33. Conversely, the height of the electrolytic capacitor 3a is equal to the magnetic pole position detection sensor 9 or the main circuit module 24. If smaller than this, the electrolytic capacitor 3 a may be mounted on the surface of the motor drive circuit board 22 that faces the partition plate 32. Particularly in the latter case, when the electrolytic capacitor 3a, the main circuit module 24, and the like are mounted on the same surface as the magnetic pole position detection sensor 9, the motor housing 35 can be reduced in size to form a small ventilation fan.

  As described above, also in the second embodiment, SiC-SBD is used for the FRD of the inverter of the motor that drives BLDCM, which is generated in the bearing 19a adjacent to the motor drive circuit board 22 while preventing a surge current during switching. As in the first embodiment, it is possible to provide a highly reliable and low noise ventilation fan by suppressing the electric corrosion phenomenon.

  In the second embodiment, since the motor housing 33 is directly connected to the centrifugal fan 34 and the fan housing 35 of the ventilation fan, vibrations of the bearings 19a and 19b are generated in the centrifugal fan 34 and the fan housing 35 when electric corrosion occurs. Since it is transmitted directly, the user is remarkably uncomfortable, so the effect of noise reduction by improving the electric corrosion reliability by suppressing the surge current is particularly high.

  Further, the motor drive circuit board 22 is provided substantially perpendicular to the rotation axis direction of the shaft 18 and faces the motor housing 35 opposite to the surface facing the nearest bearing 19a of the two bearings 19a and 19b. By mounting the inverter (particularly the main circuit module 24) on the surface of the motor drive circuit board 22, the distance between the bearing 19a and the inverter can be increased, so that the electrolytic corrosion phenomenon occurring in the bearing 19a can be further suppressed.

Embodiment 3 FIG.
Although Embodiment 2 demonstrated the ventilation fan which mounted the motor with a built-in inverter, this Embodiment 3 demonstrates the outdoor heat exchange unit and the indoor heat exchange unit which built the inverter. FIG. 7 is a configuration diagram of an air conditioner including the outdoor heat exchange unit and the indoor heat exchange unit according to the third embodiment. The motor described in the third embodiment is the same as that described in the first embodiment.

  FIG. 7 shows a state in which an outdoor unit 38 which is an outdoor heat exchange unit and an indoor unit 39 which is an indoor heat exchange unit are connected by an internal / external connection pipe 40 including a refrigerant pipe through which refrigerant flows and an information transmission wire. . The user operates the operation unit 41 provided in the room to set the temperature, humidity, air volume, operation time, and the like of the indoor space. The operation unit 41 transmits the operating conditions set by the user to the outdoor unit 38 and the indoor unit 39.

FIG. 8 is a top view of the outdoor unit 38 that is an outdoor heat exchange unit (however, the motor 51 is a cross-sectional view). The outdoor unit 38 has a bottom plate 42a and an outer shell 42b. The inside is divided by an outdoor unit partition plate 43, and a blower chamber 44a is provided on one side and a machine chamber 44b is provided on the other side. The outer shell 42b includes a front panel 45 having a blow grill on the front side and a plurality of vent holes provided on the side surface, and a substantially L-shaped side panel 46 that forms the machine room 44b together with the outdoor unit partition plate 43. Has been. A compressor 47 is installed on the bottom plate 42a of the machine chamber 44b, and a substantially L-shaped outdoor heat exchanger in which a corner portion 48a is formed in an arc shape from the back side of the bottom plate 42a to the side surface side of the blower chamber 44a. 48 is installed. The compressor 47 and the outdoor heat exchanger 48 are connected by a refrigerant pipe 49. Further, the refrigerant pipe 49 is connected to the outdoor unit 38 and the indoor unit 39 through the inside / outside connection pipe 40, and the refrigerant circulates through the inside. A top plate (not shown) is provided on the front panel 45, the side panel 46, and the outdoor heat exchanger 48.
In the air blowing chamber 44a, a fitting portion having a screw hole provided at the upper end portion is fitted into the upper end portion of the outdoor heat exchanger 48, and a blower mounting plate 50 is provided from the bottom plate 42a to the top plate. The motor 51 is attached to the center in the vertical direction. The motor 51 is any of the motors described in the first embodiment. A propeller fan 52 is attached to the shaft of the motor 51, and the propeller fan 52 rotates to suck air into the outdoor unit 38.
The air sucked by the propeller fan 52 passes through the outdoor heat exchanger 48 and exchanges heat, enters the air blowing chamber 44 a, and is discharged from an opening provided in the front panel 45 in front of the propeller fan 52.
In the third embodiment, a four-way valve and a pressure reducing valve are provided in the refrigerant pipe 49 between the compressor 47 and the outdoor heat exchanger 48.

Next, the operation of the outdoor unit 38 during the operation of the air conditioner will be described. It is assumed that the cooling operation for cooling the room and the heating operation for heating the room can be switched by switching a four-way valve provided in the refrigerant pipe 49. Here, the compressor 47 is compressed by the compressor 47 into the outdoor heat exchanger 48. A description will be given of the cooling operation in which the high temperature refrigerant flows.
When the user selects the cooling operation by the operation unit 41 and sets the operation information such as the indoor target temperature and the air volume, when the cooling operation starts, the high-temperature and high-pressure refrigerant compressed by the compressor 47 exchanges outdoor heat through the four-way valve. Flows to vessel 48. In the outdoor heat exchanger 48, heat is exchanged with air having a temperature lower than that of the refrigerant sucked by the propeller fan 52 to heat the air to become a low-temperature high-pressure refrigerant. The low-temperature and high-pressure refrigerant that has passed through the outdoor heat exchanger 48 is depressurized by a pressure reducing valve provided in the refrigerant pipe 49 and then flows into the indoor unit 39.
Since the air sucked into the propeller fan 52 is heated by the outdoor heat exchanger 48 and the temperature rises, the temperature of the blower chamber 44a rises. In particular, since the motor 51 is arranged leeward of the outdoor heat exchanger 48, the temperature of the motor 51 rises together with the built-in motor drive circuit board.

  The operation unit 41 outputs the set operation information to the output voltage calculation unit 11 mounted on the motor drive circuit board 22 built in the motor 51. The output voltage calculation unit 11 calculates the output voltage of the inverter main circuit 4 applied to the BLDCM 5 based on the information input from the operation unit 41 and the output value of the rotor position detection unit 10 and outputs the calculation result to the PWM signal generation unit 12. To do. Sensors that detect the indoor temperature and the outdoor temperature may be provided, and the output voltage calculation unit 11 may output a calculation result using the output values of these sensors to the PWM signal generation unit 12.

As described above, since the outdoor unit 38 of the third embodiment uses SiC-SBD for the FRD of the inverter built in the motor 51 that drives the propeller fan 52, the bearing unit is the same as in the first embodiment. It is possible to provide a highly reliable and low noise outdoor unit that suppresses the electric corrosion phenomenon and the accompanying noise.
Further, since the motor drive circuit board is built in the motor 51, it is not necessary to separately arrange an inverter for driving the motor in the machine room 44b, the machine room 44b can be widely used, and the piping of the refrigerant pipe 49 can be performed. It becomes easy.
Further, during the cooling operation, the high-temperature air heat-exchanged by the outdoor heat exchanger 48 hits the motor 51. However, since SiC has a heat-resistant temperature of 200 degrees or more, the reliability of the inverter can be maintained. Further, the compressor 47 operates as described above, and a refrigerant having a predetermined set temperature or higher (for example, 80 ° C. or higher) flows into the outdoor heat exchanger 48, the temperature of the blower chamber 44a becomes higher than expected, and an inverter built in the motor 51 Further, even if heat is generated, the reliability can be maintained without failure of the main element drive circuit unit at the heat resistant temperature of SiC.

  The outdoor heat exchange unit described above with reference to FIG. 8 can be used not only as an outdoor unit of an air conditioner, but also as an outdoor unit of a hot water heater that boils hot water with a radiator of a refrigeration cycle. By applying the present invention to the above, the same effects as described above are obtained.

Up to this point, the outdoor heat exchange unit including the outdoor heat exchanger has been described above. Next, the indoor heat exchange unit including the indoor heat exchanger will be described with reference to FIG.
FIG. 9 is a perspective view of the indoor unit of the air conditioner. The indoor unit 39 is attached to the wall of the room, and a housing 53 and a detachable front suction grill 54 constitute an outer shell. Further, the housing 53 forms an upper suction grill 55, a guide wall near the back surface, and a nozzle 56 for blowing out air from the opening below the front surface. Left and right vanes 57 that change the direction of the blown air in the left and right direction and upper and lower vanes 58 that change in the up and down direction are provided at the outlet of the nozzle 56.
A motor 59 is housed and fixed inside the housing 53. As the motor 59, the motor described in the first embodiment is used. An impeller 60 serving as a fan for blowing air is attached to the shaft of the motor 59 in parallel with the air outlet of the nozzle 56. And the indoor heat exchanger 61 is arrange | positioned so that the impeller 60 may be surrounded. The indoor heat exchanger 61 is connected to a refrigerant pipe 49 that is connected to the outdoor heat exchanger 48 of the outdoor unit 38. Between the indoor heat exchanger 61, the front suction grille 54, and the front suction grille 54, a filter 62 for removing dust and dust in the air to be sucked is provided.

Next, the operation of the outdoor unit 38 during the operation of the air conditioner will be described. It is assumed that the cooling operation for cooling the room and the heating operation for heating the room can be switched by switching the four-way valve provided in the refrigerant pipe 49. Here, the compressor 47 is compressed by the compressor 47 in the indoor heat exchanger 61. The heating operation during which the high-temperature refrigerant is introduced will be described.
When the user selects the heating operation with the operation unit 41 and sets the operation information such as the indoor target temperature and the air volume, when the heating operation starts, the high-temperature and high-pressure refrigerant compressed by the compressor 47 exchanges the indoor heat through the four-way valve. Flows into the vessel 61. In the indoor heat exchanger 61, the impeller 60 exchanges heat with air cooler than the refrigerant sucked from the front suction grille 54 and the opening of the front suction grille 54, and heats the air to become a low-temperature high-pressure refrigerant. The low-temperature and high-pressure refrigerant that has passed through the indoor heat exchanger 61 is depressurized by a pressure reducing valve provided in the refrigerant pipe 49 and then flows to the outdoor unit 38.
Since the air sucked into the impeller 60 is heated by the indoor heat exchanger 61 and the temperature rises, the temperature of the internal space of the indoor unit 39 including the housing rises. Therefore, together with the built-in motor drive circuit board, the motor 59 The temperature goes up.

  The operation unit 41 outputs the set operation information to the output voltage calculation unit 11 mounted on the motor drive circuit board built in the motor 59. The output voltage calculation unit 11 calculates the output voltage of the inverter main circuit 4 applied to the BLDCM 5 based on the information input from the operation unit 41 and the output value of the rotor position detection unit 10 and outputs the calculation result to the PWM signal generation unit 12. To do. Sensors that detect the indoor temperature and the outdoor temperature may be provided, and the output voltage calculation unit 11 may output a calculation result using the output values of these sensors to the PWM signal generation unit 12.

  As described above, since the indoor unit 39 of the third embodiment uses SiC-SBD for the FRD of the inverter built in the motor 59 that drives the impeller 60, the bearing unit is the same as in the first embodiment. It is possible to provide a highly reliable and low noise indoor unit that suppresses the electric corrosion phenomenon and the noise associated therewith.

  Further, since the motor drive circuit board is built in the motor 59, it is not necessary to separately arrange an inverter for driving the motor inside the housing 53, and the internal space of the indoor unit 39 can be widely used. Construction of piping connecting the indoor heat exchanger 61 is facilitated.

  Further, during heating operation, the interior of the indoor unit 39 becomes hot due to the high-temperature air exchanged by the indoor heat exchanger 61. However, since SiC has a heat resistant temperature of 200 degrees or more, the reliability of the inverter can be maintained. . Further, the compressor 47 operates as described above, and a refrigerant having a predetermined temperature or higher (for example, 80 degrees or higher) flows into the indoor heat exchanger 61, the temperature inside the indoor unit 39 becomes higher than expected, and an inverter built in the motor 59 Even if heat is further generated, if the heat resistance temperature of SiC is sufficient, the reliability of the main element drive circuit unit can be sufficiently maintained without failure.

  The motor according to the present invention can be used for a motor that drives a fan built in an indoor unit / outdoor unit of an air conditioner, and a motor that drives a fan built in an outdoor unit of a water heater using a heat pump. .

1 Motor built-in drive circuit,
2 commercial AC power supply,
3 Rectifier circuit,
4 Inverter main circuit,
4a Main element drive circuit 5 BLDCM,
6a-6f IGBT,
7a-7f SiC-SBD,
8 DC voltage detector,
8a, 8b Voltage dividing resistance,
9 Magnetic pole position detection sensor,
10 rotor position detector,
11 Output voltage calculator,
12 PWM signal generator,
13 Stator,
14 rotor,
15 Iron core,
16a, 16b insulation member,
17 coils,
18 shaft,
19a, 19b bearings,
20a, 20b bracket,
21 resin,
22 Motor drive circuit board,
23 Pre-drive IC,
24 main circuit module,
27 Inner ring,
28 outer ring,
29 balls,
30 Shield,
31 cage,
32 partition plate,
33 motor housing,
34 Centrifugal fan,
35 fan housing,
36 ceiling wall,
37 Intake grill,
38 outdoor unit,
39 Indoor unit,
40 Internal and external connection piping,
41 operation unit,
42a bottom plate,
42b outline,
43 outdoor unit partition plate 44a blower chamber,
44b machine room,
45 Front panel,
46 side panels,
47 compressor,
48 outdoor heat exchanger,
49 Refrigerant piping,
50 mounting plate,
51 motor,
52 propeller fan,
53 housing,
54 Front suction grille,
55 Upper suction grille,
56 nozzles,
57 Left and right vanes,
58 Upper and lower vanes,
59 motor,
60 impeller,
61 Indoor heat exchanger,
62 filters,

Claims (6)

A stator that is arranged in a ring, an insulating member is attached to the iron core, and the coil is wound;
A rotor having a shaft, provided on the inner periphery of the stator and rotating;
A substrate on which an inverter having a Schottky barrier diode made of a wide bandgap semiconductor that prevents a reverse current during switching and a switching element is mounted to generate an alternating current supplied to the coil;
A first bearing that supports the shaft, and a second bearing that is provided closer to the substrate than the first bearing and supports the shaft ,
The substrate is provided substantially perpendicular to the rotation axis direction of the shaft,
The inverter is mounted on the surface of the substrate opposite to the surface facing the second bearing;
The motor, wherein the substrate is molded with a resin that fixes the stator. A sensor that is disposed in proximity to the rotor and detects the position of the rotor is mounted on the substrate,
The motor according to claim 1 , wherein the inverter is surface-mounted on the same surface of the substrate as the center. The motor according to claim 2 , wherein the switching element and the Schottky barrier diode of the inverter are packaged with a resin, and the resin is thinner than the sensor. Motor according to any one of claims 1 to 3, wherein the wide band gap semiconductor is silicon carbide, or gallium nitride and diamond. A motor according to any one of claims 1 to 4 ,
A fan attached to the shaft and rotating to inhale air;
A housing that houses the fan and has a duct that exhausts the air,
The ventilation fan characterized by the said board | substrate being arrange | positioned substantially perpendicular to the rotating shaft of the said shaft. A motor according to any one of claims 1 to 4 ,
A fan attached to the shaft and rotating to inhale air;
A high-temperature refrigerant compressed by a compressor flows, and the high-temperature refrigerant exchanges heat with the air to become a low-temperature refrigerant, and a heat exchanger,
The heat exchange unit, wherein the substrate is disposed substantially perpendicular to a rotation axis of the shaft.

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