JP2012249470A - Electric motor for fan drive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inverter integrated type electric motor for fan drive which reduces the size and the cost by forming a structure that protects switching elements and coils from overheating together and enables heat radiation of the switching elements which does not cause the size increase of the electric motor.SOLUTION: An electric motor for fan drive includes: a rotor 31; a stator 32 rotatably driving the rotor 31; and a printed wiring board 40 on which a power module 41 is mounted. The power module 41 has: an inverter main circuit having switching elements and diode elements which are formed by wide band gap semiconductors; and an overheating protection circuit having a temperature detection element and controlling the switching elements on the basis of the detection temperature of the temperature detection element. A heat radiation surface 41a provided at the opposite side of a mounting surface of the power module 41 is in direct or indirect contact with coils 35 of the stator 32.

Description

  The present invention relates to a fan driving motor used in a refrigerator, an air conditioner, and the like.

  In a fan driving motor, a configuration including an inverter device that converts a DC voltage into an AC voltage is the mainstream, and in recent years, the motor is being built in an inverter device. As this kind of electric motor, there is an electric motor in which a motor main body having a rotor and a stator and a printed wiring board including an inverter main circuit are housed and integrated in a case (see, for example, Patent Document 1).

Japanese Patent No. 2960754 (page 4, FIG. 1)

  In an inverter-integrated electric motor such as Patent Document 1, since the inside of the electric motor becomes high temperature due to heat generated by a switching element and an armature winding (hereinafter referred to as a winding) constituting the inverter main circuit, a countermeasure for heat radiation is an issue. Has been. As a heat dissipation measure, a method of attaching a heat sink to a heat dissipation surface of a power module having a switching element is generally used. However, this method has a problem that the heat sink must be enlarged in consideration of the heat-resistant temperature of an IGBT (Insulated Gate Bipolar Transistor) that forms the switching element, and the motor becomes large. Further, in Patent Document 1, a plurality of electronic circuits are made into one chip to secure a heat dissipation space, and a heat dissipation plate is arranged in the space to improve heat dissipation, but further improvement is desired. .

  By the way, the switching element which comprises an inverter main circuit is easy to be destroyed by overcurrent or overheating. For this reason, it is general that an overheat protection function for protecting the switching element is incorporated in a power module having the switching element and configured as one package.

  In addition, the motor for driving the fan is usually provided with not only an overheat protection function for protecting the switching element but also an overheat protection function for protecting the winding. The overheat protection device that performs overheat protection of the winding opens the contact when the specified temperature is exceeded, temporarily interrupts the current flowing through the winding, and stops the temperature rise of the winding itself. I am trying.

  Thus, overheating protection is required for each of the switching element and the winding in the fan driving electric motor, and an overheating protection device is provided for each of them. For this reason, there existed a problem of causing the enlargement and cost increase.

  The present invention has been made in order to solve the above-described problems, and it is possible to reduce the size and cost as a configuration in which both the switching element and the winding are collectively protected against overheating, and the size of the motor is increased. An object of the present invention is to obtain an inverter-integrated fan driving motor capable of dissipating heat from a switching element without accompanying.

  A fan driving electric motor according to the present invention includes a rotor, a stator that rotationally drives the rotor, and a printed wiring board on which the power module is mounted. The power module includes a switching element and a diode formed of a wide band gap semiconductor. An inverter main circuit having an element, and an overheat protection circuit having a temperature detection element and controlling the switching element based on a detection temperature of the temperature detection element, and mounting the power module on the printed circuit board; The heat dissipating surface provided on the opposite side is brought into direct or indirect contact with the stator winding.

  According to the present invention, the overheat protection circuit in the power module can perform not only the switching element but also the overheat protection of the winding, and the overheat protection device dedicated to the winding can be made unnecessary. By dissipating heat to the stator side, a heat sink can be eliminated. As a result, downsizing and cost reduction are possible.

1 is a schematic exploded perspective view showing a configuration of a fan drive motor according to Embodiment 1 of the present invention. It is a figure which shows the structure of the inverter apparatus incorporated in the electric motor for a fan drive which concerns on Embodiment 1 of this invention. It is an enlarged view which shows the attachment structure of the stator of FIG. 1, a power module, a printed wiring board, and a lower case part. It is the figure which looked at FIG. 3 from the arrow A direction. It is a general | schematic disassembled perspective view which shows the structure of the electric motor for a fan drive which concerns on Embodiment 2 of this invention. It is an enlarged view which shows the attachment structure of the stator of FIG. 5, a heat radiating plate, a power module, and a printed wiring board. It is sectional drawing which cut | disconnected the part shown in FIG. 6 in the circumferential direction in the power module part. It is sectional drawing which shows the structure which provided the compound further in FIG. It is a general | schematic disassembled perspective view of the stator and heat sink plate part of the electric motor for fan drive which concerns on Embodiment 3 of this invention. It is a general | schematic disassembled perspective view of the electric motor for a fan drive which concerns on Embodiment 4 of this invention. It is an enlarged view which shows the attachment structure of the stator of FIG. 10, an attachment plate, and a printed wiring board. It is a schematic exploded perspective view which shows the structure of the electric motor for a fan drive which concerns on Embodiment 5 of this invention. It is a cross-sectional view in the power module part of FIG.

Embodiment 1 FIG.
FIG. 1 is a schematic exploded perspective view showing a configuration of a fan driving electric motor according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing a configuration of an inverter device built in the motor for driving the fan shown in FIG. In FIG. 1 and each figure to be described later, the same reference numerals denote the same or corresponding parts, which are common throughout the entire specification. Furthermore, the forms of the constituent elements appearing in the entire specification are merely examples and are not limited to these descriptions. Further, in the following drawings including FIG. 1, the size relationship of each component may be different from the actual one. Prior to the description of the overall configuration of the fan drive motor shown in FIG. 1, an inverter device built in the fan drive motor will be described with reference to FIG.

  The inverter device 10 is a device that converts a DC voltage supplied from, for example, a DC power supply 16 on the air conditioner side, on which the fan driving motor 20 is mounted, into an AC voltage and supplies the AC voltage to a stator 32 (described later) of the fan driving motor 20. The inverter main circuit 11 and the microcomputer 15 are provided. A circuit that rectifies and smoothes commercial AC voltage and supplies a DC voltage to the inverter device 10 and a control circuit that issues a drive command to the microcomputer 15 are mounted on the control device in the air conditioner. The control device and the inverter device 10 are Connected by communication wiring and power supply wiring.

  The inverter main circuit 11 includes a plurality of switching elements 11a to 11f, a plurality of diode elements 12a to 12f, a drive circuit 13, and an overheat protection circuit 14. The inverter main circuit 11 is incorporated in one package to constitute a power module 41 (see FIG. 1). The drive circuit 13 may be included not in the power module 41 but on the microcomputer 15 side.

  The switching elements 11a to 11f and the diode elements 12a to 12f are each composed of a wide band gap semiconductor. A wide band gap semiconductor is a general term for semiconductor elements having a larger band gap than silicon (Si) elements, and examples include silicon carbide (SiC) elements, gallium nitride (GaN), diamond elements, and the like. It is done. A wide band gap semiconductor has a feature that it has a high heat-resistant temperature (about 400 ° C.) and can operate at a high temperature.

  The drive circuit 13 generates an operation signal (PWM signal, gate signal) based on a control signal sent from the microcomputer 15 and outputs the operation signal to each switching element 11a to 11f, and performs a switching operation of each switching element 11a to 11f.

  The overheat protection circuit 14 includes a temperature detection element (not shown). When an overheat state is detected based on the temperature detected by the temperature detection element, the overheat protection circuit 14 outputs a signal indicating the detection result to the microcomputer 15 to switch the switching elements 11a to 11a. 11f is controlled. Specifically, for example, all the switching elements are stopped. This example is characterized in that the overheat protection circuit 14 performs not only the switching elements 11a to 11f but also the overheat protection of the winding 35 of the stator 32 described later, and details thereof will be described later.

  The microcomputer 15 controls the drive circuit 13 by outputting a control signal to the drive circuit 13 in accordance with a control signal from the control device in the air conditioner or a signal from the overheat protection circuit 14.

Next, the configuration of the fan drive motor 20 will be described with reference to FIG.
The fan drive motor 20 includes a motor main body 30, a printed wiring board 40 on which a power module 41 is mounted, and a metal upper case 50a and lower case 50b for housing them, and is generally substantially circular. It is columnar. A plurality of mounting holes 21 are provided in the outer peripheral portions of the lower case 50b, the printed wiring board 40, and the stator 32. Screws 22 are inserted into the mounting holes 21 and screw holes provided in the upper case 50a (see FIG. The whole is integrated by screwing into (not shown).

  Each of the upper case 50a, the lower case 50b, and the printed wiring board 40 is provided with an opening 23 through which the rotation shaft 31a of the rotor 31 of the electric motor main body 30 passes, and the upper case 50a and the lower case 50b are opened. A fan (not shown) is connected to the end of the rotating shaft 31 a protruding from the hole 23.

Next, each component part which comprises the electric motor 20 for fan drive is demonstrated sequentially.
The electric motor main body 30 includes a rotor 31 and a stator 32 that is disposed on the outer periphery of the rotor 31 and rotationally drives the rotor 31. The stator 32 has a configuration in which a winding 35 is wound around a plurality of teeth 34 protruding from the inner periphery of a cylindrical stator core 33 made of a laminated iron core via an insulating layer (not shown). . The number of teeth 34 is normally 6 to 20, but FIG. 1 shows nine examples.

  In the electric motor main body 30 configured as described above, the rotor 31 rotates by causing a current to flow through the winding 35 of the stator 32 to generate a rotating magnetic field, and the fan attached to the rotating shaft 31a of the rotor 31 rotates. Perform air circulation.

  The printed wiring board 40 is formed in a disc shape, and a power module 41 is mounted on the printed wiring board 40. In addition to the power module 41, a plurality of electronic components are mounted on the printed wiring board 40, but are not shown. Wiring for supplying a DC voltage to the printed wiring board 40 is connected to the printed wiring board 40 from outside the lower case 50b through wiring holes (not shown) provided in the lower case 50b.

  In the power module 41, the surface opposite to the mounting surface on the printed circuit board 40 is a heat radiating surface 41a that radiates the heat generated by the power module 41. In the assembled state, the heat radiating surface 41a and the winding 35 Are in contact with each other. In this example, the heat dissipating surface 41 is intentionally brought into contact with the winding 35 in order to protect the winding 35 from overheating using the overheating protection circuit 14 inside the power module 41.

  The power module 41 receives heat from the winding 35 when the winding 35 comes into contact with the heat radiation surface 41 a of the power module 41. However, in this example, the switching elements 11a to 11f and the diode elements 12a to 12f in the power module 41 can be operated at a temperature higher than the protection temperature (about 150 ° C. to 200 ° C.) of the winding 35. Therefore, there is no problem in the operation of the power module 41 even if the heat from the winding 35 is received.

  As the operating temperature of the overheat protection function by the overheat protection circuit 14, when the wide band gap semiconductor is an SiC element (the SiC element itself can be operated at a high temperature up to 350 ° C.), the overheat protection of the winding 35 is given priority. The protection temperature of the wire 35 is 150 ° C. to 200 ° C. That is, for example, when the temperature exceeds 150 ° C., the switching operation of each of the switching elements 11a to 11f is stopped. In addition, the specific processing content of the overheat protection function in the overheat protection circuit 14 is not particularly limited, and the overheat protection may be achieved in stages according to the detected temperature.

  Next, a specific mounting structure between the printed wiring board 40 on which the power module 41 is mounted and the stator 32 having the winding 35 will be described in detail.

FIG. 3 is an enlarged view showing the attachment structure of the stator, power module, printed wiring board, and lower case part of FIG. 1, and shows a cross section of these parts cut in the radial direction. FIG. 4 is a view of FIG. 3 as viewed from the direction of the arrow A.
The stator 32 of the motor 20 for driving the fan is usually a binding string 36 (not shown in FIG. 1) so that the height of the winding end 35a protruding from the axial end surface of the stator iron core 33 is uniform. It is tied up using. Here, the power module 41 is attached to the stator 32 using the binding string 36.

  Specifically, first, the printed wiring board 40 completed by mounting a plurality of electronic components including the power module 41 is opposed to the stator 32, and the heat radiation surface 41a of the power module 41 is brought into contact with the winding end 35a. In this state, the binding string 36 wound around the stator iron core 33 is wound around the printed wiring board 40 and the power module 41 by a plurality of turns so as to stick to each other. At this time, the binding string 36 is passed through the gap between the printed wiring board 40 and the power module 41 so that the power module 41 can be stably attached to the winding end 35a.

  The binding string 36 is not limited to the same material as the string used to make the height of the winding 35 uniform overall, and may be a string made of a different material. In the first embodiment, from the viewpoint of improving workability, it is assumed that the string used to make the height of the winding 35 uniform is used for fixing the power module 41 and the winding 35 as they are. However, the power module 41 and the winding 35 may be fixed separately with a string made of the same material.

  Next, the lower case 50b is attached to the printed wiring board 40 through the attachment member 37 through the attachment holes 51 (see FIG. 1) provided in the lower case 50b and the attachment holes 42 (see FIG. 1) provided in the printed wiring board 40. Since the lower case 50b is composed of a metal member, a gap is provided between the lower case 50b and the printed wiring board 40 to be attached from the viewpoint of ensuring insulation with the printed wiring board 40.

  The attachment member 37 can be made of a material such as metal or resin. If the attachment member 37 is made of metal, it is fixed by screws, and if it is made of resin, it is fixed by fitting. Since the printed wiring board 40 vibrates due to the vibration from the rotor 31, the mounting member 37 takes into account the board weight corresponding to the thickness of the printed wiring board 40 (here, about 1.0 mm to 3.0 mm). Select one with fracture strength.

  As described above, according to the first embodiment, the switching elements 11a to 11f and the diode elements 12a to 12f in the power module 41 are formed of the wide band gap semiconductor, so that the heat radiation surface 41a of the power module 41 is formed. It is possible to have a structure in contact with the winding 35, and the overheating protection of the winding 35 can be performed by the overheating protection circuit 14 in the power module 41. As a result, the overheat protection device that has been necessary for overheating protection of the conventional winding can be made unnecessary, and downsizing and cost reduction are possible. Therefore, it is possible to reduce the size and cost of the air conditioner including the fan driving electric motor 20.

  Further, since the heat radiation surface 41a of the power module 41 is in contact with the winding 35, the heat on the power module 41 side can be radiated to the winding 35 side. Therefore, the heat sink conventionally provided in the power module 41 can be dispensed with, and from this point, the size and cost can be reduced.

Embodiment 2. FIG.
In the first embodiment, the structure in which the power module 41 and the winding 35 are attached by the binding string 36 has been described. However, in the second embodiment, the power module 41 and the winding 35 are provided between the printed wiring board 40 and the stator 32. A heat radiating plate for radiating the heat is provided, and the heat radiating plate is attached as a mounting plate. Except for the mounting structure portion using the heat radiating plate, the second embodiment is the same as the first embodiment, and hereinafter, the second embodiment will be described focusing on the portions different from the first embodiment.

  FIG. 5 is a schematic exploded perspective view showing the configuration of the fan drive motor according to Embodiment 2 of the present invention. In addition, illustration of the upper case 50a is abbreviate | omitted in FIG. FIG. 6 is an enlarged view showing a mounting structure of the stator, the heat radiating plate, the power module, and the printed wiring board of FIG. FIG. 7 is a cross-sectional view of the portion shown in FIG. 6 cut in the circumferential direction at the power module portion.

  The heat radiating plate 60 has a disk shape, and the size thereof is formed to be approximately the same as the axial end surface of the stator 32, and in contact with all the winding end portions 35a in the attached state. It is formed so that heat from 35a is transmitted. Further, the heat radiating plate 60 is provided with a screw hole 61 for mounting the power module 41 and a through hole through which the screw 22 passes.

  For the heat radiating plate 60, a member having thermal conductivity and heat radiating properties such as metal or ceramic having high thermal conductivity is used. In the case of a metal, aluminum mainly having high thermal conductivity and relatively inexpensive is used, but copper having higher thermal conductivity than aluminum and iron cheaper than aluminum may be used. The thickness of the heat radiation plate 60 is preferably set to 0.1 to 1.0 mm, for example, in consideration of workability and heat dissipation. In order to improve heat dissipation, a plurality of heat dissipation plates 60 may be stacked. In this case, the maximum thickness is 3.0 mm. The thickness up to this thickness is effective in reducing the size and cost of the fan driving motor 20.

  When the power module 41 is attached to the stator 32 using the heat radiating plate 60, first, the printed wiring board 40 and the heat radiating plate 60 that are completed by mounting a plurality of electronic components including the power module 41 are attached. Specifically, the heat radiating surface 41 a of the power module 41 is brought into contact with the heat radiating plate 60. In this state, the screw holes 41b provided in the power module 41 and the screws provided in the heat dissipation plate 60 are passed through the mounting opening 43 provided in the printed wiring board 40 at a location facing the resin molded portion of the power module 41. A screw 63 is screwed into the hole 60a, and both are fixed. The screw 63 has a length that does not penetrate the heat radiating plate 60 so that the tip of the screw 63 does not contact the winding 35 when the screw 63 is attached and the winding 35 is not damaged. Between the power module 41 and the heat radiating plate 60, a compound 64 such as silicon grease or a heat radiating sheet may be sandwiched between the power module 41 and the heat radiating plate 60 to promote heat dissipation.

  Next, the heat dissipation plate 60 to which the printed wiring board 40 is fixed is attached to the stator core 33. Specifically, first, the heat radiating plate 60 is brought into contact with the plurality of winding end portions 35a. At this time, it is desirable to align the power module 41 and the winding end 35a so as to oppose each other via the heat radiation plate 60 so that the detection accuracy of the winding temperature in the power module 41 is increased.

  A plurality (two in this case) of mounting work openings 43a are formed on the outer peripheral portion of the printed wiring board 40 at concentric intervals, and screw holes of the heat radiating plate 60 are formed through the mounting work openings 43a. The heat radiating plate 60 is fixed to the stator core 33 by screwing the screw 62 to 61 and screwing the tip of the screw 62 into a screw hole (not shown) provided in the stator core 33. In this fixed state, the power module 41 abuts indirectly on the winding end 35 a via the heat radiating plate 60. Further, the screw 62 is set such that the length of the shaft portion takes into account the protruding height of the winding end portion 35a from the end surface of the stator core and the thickness of the printed wiring board 40, and is generally about 1 cm to 10 cm. . The distance between the end surface of the stator core 33 and the heat radiating plate 60 is adjusted by the tightening amount of the screw 62, and both are fixed in a substantially parallel state. The attachment of the lower case 50b is the same as that in the first embodiment.

  The order of attachment is arbitrary, and the power module 41 mounted on the printed wiring board 40 may be attached to the heat dissipation plate 60 after the heat dissipation plate 60 is attached to the stator core 33.

  By using the heat radiating plate 60 as described above, the heat of the power module 41 can be radiated and the heat radiating plate 60 is configured to come into contact with all the winding end portions 35a. The heat of the heat spreads over the entire heat radiating plate, so that the winding itself can radiate heat.

  In the above mounting structure, the power module 41 is indirectly in contact with the winding end 35a via the heat dissipation plate 60 as described above, and the overheat protection circuit 14 determines the temperature of the heat dissipation plate 60 to the temperature of the winding 35. Consider overheating protection. The overheat protection function is the same as in the first embodiment. Strictly speaking, the temperature of the heat radiating plate 60 is not the same as the winding temperature. However, since the heat radiating plate 60 is in contact with all the winding end portions 35a and receives heat from them, it is substantially equal to the winding temperature. Can be considered. Therefore, the overheat protection circuit 14 can detect the temperature with a small error from the actual temperature of the winding 35.

  The heat dissipation plate 60 is not limited to the configuration in contact with all the winding end portions 35a. For example, the heat dissipation plate 60 may have a configuration in contact with two or three winding end portions 35a. However, as described above, a configuration in which all the winding end portions 35a are in contact with each other is preferable from the viewpoint of reducing temperature detection errors.

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained, and the heat radiation plate 60 is provided between the power module 41 and the winding end 35a. The heat dissipation of the module 41 and the winding 35 can be enhanced.

  Moreover, since the contact area with the coil | winding 35 was enlarged as the structure which all the coil | winding edge parts 35a contact the heat sink plate 60, the heat | fever of all the coil | winding edge parts 35a can be transmitted to the heat radiating plate 60. As a result, the heat dissipation of the winding 35 can be improved, and the temperature of the heat radiating plate 60 can be brought close to the winding temperature as compared with the case where it is in contact with some of the winding ends 35a. 14 can reduce the detection error of the winding temperature. As a result, it is possible to prevent inconvenience that the overheat protection does not operate even though the protection temperature is actually exceeded, and a highly accurate overheat protection function can be realized.

  Further, since the power module 41 and the winding end portion 35a are opposed to each other via the heat dissipation plate 60, for example, the power module 41 is overheated as compared with the case where the power module 41 is positioned facing the region between the winding end portions 35a. The detection accuracy in the protection circuit 14 can be increased.

Embodiment 3 FIG.
In the third embodiment, a recess for accommodating the tip of the winding end 35a is provided on the surface of the heat radiation plate 60 of the second embodiment so that the contact area between the winding 35 and the heat radiation plate 60 is increased. is there. The rest of the configuration is the same as that of the second embodiment, and hereinafter, the third embodiment will be described focusing on the differences from the second embodiment.

FIG. 9 is a schematic exploded perspective view of the stator and the heat radiating plate portion of the fan drive motor according to Embodiment 3 of the present invention.
The heat dissipation plate 60 of the third embodiment has the same number of recesses 65 as the winding end 35a at a position facing the winding end 35a. The recess 65 is formed by press working at the time of manufacturing the heat radiating plate. Note that the total volume of all the recesses 65 is about 50% or less of the entire volume of the heat dissipation plate 60 from the viewpoint of strength. The method of attaching the heat radiating plate 60 is the same as that of the second embodiment.

  With this configuration, the same operational effects as in the second embodiment can be obtained, and the contact area between the heat radiation plate 60 and the winding 35 can be increased by providing the heat radiation plate 60 with the recess 65. The heat of the winding 35 can be further transmitted to the heat radiating plate 60 as compared with the second embodiment. Therefore, the heat dissipation can be further improved, and the temperature of the heat dissipation plate 60 can be made closer to the winding temperature. As a result, the temperature difference between the detected temperature in the overheat protection circuit 14 and the actual winding temperature, that is, the detection error can be reduced, and the inconvenience associated with the error can be suppressed.

Embodiment 4 FIG.
The fourth embodiment shows another attachment form of the power module 41 to the winding 35, and a structure for attachment using an attachment plate will be described. Except for the attachment structure portion using the attachment plate, the second embodiment is the same as the first embodiment, and hereinafter, the fourth embodiment will be described focusing on the portions different from the first embodiment.

  FIG. 10 is a schematic exploded perspective view of a fan drive motor according to Embodiment 4 of the present invention. In addition, illustration of the upper case 50a is abbreviate | omitted in FIG. FIG. 11 is an enlarged view showing the mounting structure of the stator, the mounting plate and the printed wiring board of FIG.

  In the fourth embodiment, the power module 41 is attached to the stator 32 using a metal attachment plate 70. The attachment plate 70 has a shape in which a strip-shaped metal plate is formed in a substantially U-shaped cross section and both ends of the U-shaped portion 71 are bent outward. A through hole 73 through which a screw 74 is inserted is formed in each bent portion 72 at both ends of the U-shaped portion 71. Further, a plurality (two in this case) of screw holes 70a are provided on the back surface of the U-shaped portion 71 of the mounting plate 70 for mounting the power module. The mounting plate 70 is formed to a size that covers one winding end 35a, and generally has a vertical, horizontal, and height of, for example, about 5 to 50 cm. The mounting plate 70 is formed of the same material as the heat dissipation plate 60 of the second embodiment.

  Further, the printed wiring board 40 is formed with an attachment opening 44 for work when attaching the attachment plate 70 to the stator core 33 and attaching the power module 41 to the attachment plate 70. Here, the opening 44 for attachment work is sized so that both of these two attachment works can be performed, but it may be configured separately for each attachment work.

  When the power module 41 is attached to the stator 32 using the attachment plate 70 configured as described above, first, the power module 41 mounted on the printed wiring board 40 is mounted on the back surface of the U-shaped portion 71 of the attachment plate 70. It is made to contact | abut to the thermal radiation surface 41a. Then, the screw 63 is screwed into the screw holes 41 b and 60 a provided in the power module 41 and the mounting plate 70 through the mounting work opening 44, and the power module 41 is fixed to the mounting plate 70. The screw 63 has a length that does not penetrate the mounting plate 70 so that the tip of the screw 63 does not contact the winding 35 when the screw 63 is attached and the winding 35 is not damaged.

  Then, the printed wiring board 40 to which the attachment plate 70 has been attached is disposed so as to face the stator 32 so that the attachment plate 70 covers the winding end 35a. Then, the screw 74 is passed through the through hole 73 of the mounting plate 70 through the mounting work opening 44 and screwed into the screw hole 33 c provided in the stator core 33, and the mounting plate 70 to which the power module is already mounted is fixed to the stator core 33. To do. In this fixed state, both sides of the U-shaped portion 71 of the mounting plate 70 abut on the winding end 35 a and the heat radiation surface 41 a of the power module 41. The order of attachment is arbitrary, and after attaching the attachment plate 70 to the stator core 33, the power module 41 mounted on the printed wiring board 40 may be attached to the attachment plate.

  Although not shown in FIGS. 10 and 11, spacers are provided in portions other than the connection portion by the mounting plate 70 so that the printed wiring board 40 and the end face of the stator 32 are fixed in a substantially parallel state. For example, the gap between the printed wiring board 40 and the end face of the stator 32 is made uniform.

  In the above mounting structure, the power module 41 is indirectly in contact with the winding end 35 a via the mounting plate 70, and the overheat protection circuit 14 regards the temperature of the mounting plate 70 as the temperature of the winding 35. Provide overheat protection. The overheat protection function is the same as in the first embodiment. Strictly speaking, the temperature of the mounting plate 70 is not the same as the winding temperature, but the mounting plate 70 is made of metal so that the heat of the winding 35 can be easily transferred, and is large enough to cover one winding end 35a. Since it is not larger than necessary, the temperature can be made equal to the temperature of the winding 35. Therefore, the overheat protection circuit 14 in the power module 41 can detect the temperature with a small error from the actual temperature of the winding 35.

  As described above, according to the fourth embodiment, the same operational effects as those of the first embodiment can be obtained, and since the attachment is performed by screwing, the attachment work is simpler than the attachment method using the binding string 36. Can be In the second embodiment, the structure in which the power module 41 is attached to the stator 32 without using the binding string 36 is shown. However, the attachment plate 70 of the fourth embodiment is the disk-like shape of the second embodiment. Since it is smaller than the heat radiating plate 60, the amount of the metal material to be used can be reduced and the cost can be reduced. Moreover, since it is small, handling is easy and attachment work is also easy.

  Further, because of the small size, the mounting plate 70 can be set to a temperature substantially equal to the winding temperature, and the temperature difference between the detected temperature in the overheat protection circuit 14 of the power module 41 and the actual winding temperature can be reduced. As a result, it is possible to prevent inconvenience that the overheat protection does not operate even though the protection temperature is actually exceeded, and a highly accurate overheat protection function can be realized.

Embodiment 5 FIG.
In the first to fourth embodiments, the power module 41 is attached to the stator 32 so as to face the winding end 35a in the axial direction. However, in the fifth embodiment, the power module 41 is attached to the outer peripheral surface of the stator 32. It is a thing. Except this attachment structure part, it is the same as that of Embodiment 1, and it demonstrates below focusing on the part from which Embodiment 5 differs from Embodiment 1. FIG.

FIG. 12 is a schematic exploded perspective view showing the configuration of the fan drive motor according to the fifth embodiment of the present invention. 13 is a cross-sectional view of the power module portion of FIG.
Prior to the description of the configuration of the fan drive motor according to the fifth embodiment, the heat transfer path of the heat of the winding 35 will be described.
The winding 35 is wound around the stator core 33, and the heat of the winding 35 is transferred to the stator core 33, and the temperature of the stator core 33 rises as the temperature of the winding 35 rises. The winding 35 is made of a copper material and the iron core is made of a metal material such as iron. Since the amount of heat transferred from the winding 35 to the stator core 33 is large, the temperature of the winding 35 and the temperature of the stator core 33 are substantially the same. It is equivalent. Therefore, even when the power module 41 is in contact with the outer peripheral surface of the stator core 33, the overheat protection circuit 14 in the power module 41 monitors the temperature substantially the same as when the power module 41 is directly attached to the winding 35. Is possible.

Hereinafter, a specific attachment structure of the power module 41 to the outer peripheral surface of the stator core 33 will be described.
The mounting plate 70 is formed in a U-shaped cross-section by bending both ends of a strip-shaped plate material, has a length equivalent to the axial length of the stator 32, and through holes 82 are formed in both end portions 81. ing. The material of the mounting jig 80 may be rubber other than metal such as iron or aluminum. Even if rubber is used, the screw mounting part is made of metal.

  The stator iron core 33 has a planar mounting surface 33a extending in the axial direction on a part of the outer peripheral surface, and the power module 41 is mounted on the mounting surface 33a. Further, screw holes 33b for attaching the attachment plate 70 are provided on both end surfaces of the stator iron core 33 in the axial direction.

  When the power module 41 is attached to the outer peripheral surface of the stator 32 using the mounting jig 80 configured as described above, the resin molded portion of the power module 41 mounted on the printed wiring board 40 and the printed wiring board 40 The mounting jig 80 is passed between them, and the mounting jig 80 is pressed against the stator core 33 side so that the power module 41 is sandwiched between the mounting jig 80 and the mounting surface 33a of the stator core 33.

  Then, a screw 83 is inserted into each of the through holes 82 of the mounting jig 80 and screwed into a screw hole 33 b provided in the stator core 33, thereby fixing the mounting jig 80 to the stator core 33, and the power module 41. Insert and fix.

  Since the stator core 33 is provided with the flat mounting surface 33a in this manner, the contact between the heat radiation surface 41a of the power module 41 and the stator core 33 is in surface contact, so that the heat of the stator core 33 can be efficiently transferred to the power module. 41 can be transmitted. In addition, it is good also as a rounded shape except the location where the power module 41 of the stator core 33 is attached.

  In the above mounting structure, the heat radiating surface 41a of the power module 41 is in contact with the stator core 33, and the overheat protection circuit 14 in the power module 41 detects the temperature of the stator core 33 and uses the detected temperature as the winding temperature. Consider overheating protection. The operation of the overheat protection function is the same as in the first embodiment. As described above, the stator core 33 is equivalent to the winding temperature, and the overheat protection circuit 14 in the power module 41 can detect the temperature with a small error from the actual temperature of the winding 35.

  As described above, according to the fifth embodiment, the same operational effects as in the first embodiment can be obtained, and a flat mounting surface 33a is provided on the outer peripheral surface of the stator core 33, and the mounting surface 33a is provided. Since the heat radiation surface 41a of the power module 41 is in contact with the power module 41, the overheat protection in the power module 41 is maintained at substantially the same temperature as when the power module 41 is attached directly to the winding 35. It is possible to monitor with the circuit 14.

  DESCRIPTION OF SYMBOLS 10 Inverter device, 11 Inverter main circuit, 11a-11f Switching element, 12a-12f Diode element, 13 Drive circuit, 14 Overheat protection circuit, 15 Microcomputer, 16 DC power supply, 20 Fan drive motor, 21 Mounting hole, 22 Screw, 23 Opening, 30 Motor body, 31 Rotor, 31a Rotating shaft, 32 Stator, 33 Stator iron core, 33a Mounting surface, 33b Screw hole, 33c Screw hole, 34 Teeth part, 35 Winding, 35a Winding end, 36 Cable tie, 37 Mounting member, 40 Printed circuit board, 41 Power module, 41a Heat radiation surface, 41b Screw hole, 42 Mounting hole, 43 Working hole, 43a Working hole, 44 Working hole, 50a Upper case, 50b lower case, 51 mounting hole, 60 heat dissipation Rate, 60a screw hole, 61 screw hole, 62 screw, 63 screw, 64 compound, 65 dent, 70 plate, 70a screw hole, 71 U-shaped part, 72 bent part, 73 through hole, 74 screw, 80 mounting jig , 81 both ends, 82 through holes, 83 screws.

Claims (13)

A rotor,
A stator for rotationally driving the rotor;
And a printed circuit board on which the power module is mounted,
The power module is
An inverter main circuit having a switching element and a diode element formed of a wide band gap semiconductor;
An overheat protection circuit that includes a temperature detection element and controls the switching element based on a detection temperature of the temperature detection element;
An electric motor for driving a fan, wherein a heat radiating surface provided on a side opposite to a mounting surface of the power module on the printed wiring board is brought into direct or indirect contact with a winding of the stator.   By passing a binding string between the connection terminal of the power module and the printed wiring board and winding the binding string around the yoke portion of the stator, the power module directly contacts the heat radiation surface with the winding. The electric motor for driving a fan according to claim 1, wherein the electric motor is driven and fixed to the stator in a contact state.   The plurality of winding ends of the winding protruding from the axial end surface of the stator iron core of the stator are bound and bound with a string, and the string is used as the binding string as it is. Fan drive motor.   Between the stator and the printed wiring board, one surface is in contact with a plurality of winding end portions protruding from the axial end surface of the stator core of the stator, and the other surface is a heat dissipation surface of the power module. The electric motor for driving a fan according to claim 1, further comprising a heat dissipating plate in contact with the electric fan.   5. The fan driving motor according to claim 4, wherein any one of the plurality of winding end portions and the power module are opposed to each other through the heat radiating plate.   6. The fan driving motor according to claim 4, wherein a plurality of recesses for receiving tip portions of the plurality of winding end portions are provided on the one surface of the heat radiating plate. 7.   The power module is screwed to the heat dissipation plate by screwing a power module fixing screw to the heat dissipation plate from the mounting surface side of the power module, and the power module fixing screw attaches the heat dissipation plate to the heat dissipation plate. The motor for driving a fan according to any one of claims 4 to 6, wherein the motor is adjusted so as not to penetrate and protrude from the surface.   The heat dissipating plate has a plurality of screw holes on the outer periphery, and a heat dissipating plate fixing screw screwed into the screw hole is screwed into a screw hole provided in the stator iron core so that the heat dissipating plate is fixed to the stator iron core. The motor for driving a fan according to any one of claims 4 to 7, wherein the motor for driving the fan is attached to the fan.   The space between the heat radiating plate and the stator iron core is adjusted by the tightening amount of the screw for the heat radiating plate, and both are fixed in a substantially parallel state. The fan driving motor according to any one of the preceding claims.   A mounting plate for fixing the power module mounted on the printed wiring board and the stator; the mounting plate having thermal conductivity; and one surface of the stator core in the axial direction of the stator The power module is attached to the stator core so as to cover and abut one of a plurality of winding end portions protruding from the end surface of the mounting plate, and the heat module is in contact with the other surface of the mounting plate. The electric motor for driving a fan according to claim 1, wherein the electric motor is mounted.   2. The motor for driving a fan according to claim 1, wherein the power module is mounted in a state where the heat radiating surface is in contact with a flat mounting surface provided on an outer peripheral surface of the stator iron core.   The power module is attached to the stator iron core by fixing an attachment jig passed through a gap between the resin molded portion of the power module and the printed wiring board to the stator iron core of the stator. The electric motor for a fan drive according to claim 11.   The fan driving motor according to any one of claims 1 to 12, wherein the wide band gap semiconductor is one of SiC, GaN, and diamond.

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