Mold motor and air conditioner provided with mold motor

Abstract

The purpose of the present invention is to provide a highly safe mold motor and an air conditioner including the same. This mold motor includes a printed circuit board in which a plurality of windings wound around each of a plurality of teeth via an insulator, a plurality of pins to which the ends of the corresponding one of the windings are connected, and a plurality of through holes into which the corresponding one of the pins are inserted are formed. In the printed circuit board, a pin inserted into each through hole or a winding connected to a pin is connected to an electrode of the printed circuit board by solder. The through holes include a first through hole (426a) and a second through hole (426b), and the pins include a first pin (460a) inserted into the first through hole and a second pin (460b) inserted into the second through hole. The difference between the maximum width of the first through hole and the maximum width of a first portion (460aa) disposed inside the first through hole of the first pin is greater than the difference between the maximum width of the second through hole and the maximum width of a second portion (460ba) disposed inside the second through hole of the second pin.

Description

Molded motor and air conditioner equipped with molded motor

[0001] The present invention relates to a molded motor and an air conditioner equipped with a molded motor.

[0002] Conventionally, molded motors such as those disclosed in Patent Document 1 (JP 2016-27781 A) and air conditioners equipped with such molded motors are known.

[0003] From a safety standpoint, when using molded motors, measures are taken to prevent fire accidents, such as using flame-retardant materials for the components that make up the motor, covering the motor with non-flammable materials, and employing protection systems outside the motor (for example, current / temperature fuses or systems that cut off the power supply based on temperature protection detection).

[0004] Although the above measures provide safety, there is also a need to improve the safety of the motor itself in terms of preventing fires.

[0005] A molded motor according to a first aspect includes a stator core, an insulator, a plurality of windings, a plurality of pins, and a printed circuit board. The stator core has a plurality of teeth arranged in a circumferential direction. The insulators are arranged at ends of the plurality of teeth. A plurality of windings are wound around each of the plurality of teeth via the insulator. The plurality of pins are attached to the insulator in a circumferential direction. An end of a corresponding one of the windings is connected to each of the plurality of pins. The printed circuit board is formed with a plurality of through holes through which a corresponding one of the pins is inserted. On the printed circuit board, the pins inserted in each through hole or the windings connected to the pins inserted in each through hole are connected via solder to electrodes arranged in or around each through hole. The stator core with the windings wound around the plurality of teeth via the insulator and the printed circuit board are molded with resin. The through holes include a first through hole and a second through hole. The pins include a first pin inserted into the first through hole and a second pin inserted into the second through hole, and the difference between the maximum width of the first through hole and the maximum width of a first portion of the first pin disposed inside the first through hole is greater than the difference between the maximum width of the second through hole and the maximum width of a second portion of the second pin disposed inside the second through hole.

[0006] In the molded motor of the first aspect, when abnormally high heat occurs due to a rare short in the winding, etc., the solder connecting the winding and the electrode melts due to the high heat and is pulled into the stator side through the gap between the first through hole and the first part of the first pin, bringing the winding and the electrode into an electrically non-conductive state and stopping the motor, thereby providing a high level of safety.

[0007] The resin (casing resin) used to mold the stator core and printed circuit board of a molded motor is generally a thermosetting resin that is highly heat-resistant and does not melt even when the temperature rises slightly. Therefore, even if the solder melts in the event of an abnormally high temperature caused by a layer short in the winding, the solder does not immediately leak out of the thermosetting resin. If there is no space for the solder to move inside the casing resin, there is a risk that the winding and the electrodes will not be electrically disconnected. In contrast, in this molded motor, the large gap between the first through hole and the first portion of the first pin allows the molten solder to be drawn into the stator through this gap, electrically disconnecting the winding and the electrodes and allowing the motor to stop, resulting in high safety.

[0008] Increasing the maximum width of all through holes and the maximum width of the part of the pin that is positioned inside the through hole makes it easier to stop the molded motor when abnormally high heat occurs, but in this case, problems may arise such as the printed circuit board becoming more likely to come off the pin when it is attached to the pin during the manufacturing process of the molded motor.

[0009] In contrast, in the molded motor of the first aspect, the through hole and pin also include the second through hole and second pin, so that it is possible to realize a molded motor that is easy to manufacture while increasing the safety of the molded motor.

[0010] A molded motor according to a second aspect is the molded motor according to the first aspect, wherein the maximum width of the first through hole is greater than the maximum width of the second through hole.

[0011] In the molded motor of the second aspect, a structure can be easily realized in which the difference between the maximum width of the first through hole and the maximum width of the first portion of the first pin is greater than the difference between the maximum width of the second through hole and the maximum width of the second portion of the second pin.

[0012] A molded motor according to a third aspect is the molded motor according to the first or second aspect, wherein the maximum width of the first portion of the first pin is smaller than the maximum width of the second portion of the second pin.

[0013] In the molded motor of the third aspect, a structure can be easily realized in which the difference between the maximum width of the first through hole and the maximum width of the first portion of the first pin is greater than the difference between the maximum width of the second through hole and the maximum width of the second portion of the second pin.

[0014] A molded motor according to a fourth aspect is the molded motor according to any one of the first to third aspects, wherein the pins connected to the windings of each phase include a first pin.

[0015] In the molded motor of the fourth aspect, even if abnormally high heat occurs in any phase of the motor, the windings and electrodes can be electrically disconnected at an early stage, thereby stopping the molded motor, thereby providing a high level of safety.

[0016] A molded motor according to a fifth aspect is the molded motor according to any one of the first to fourth aspects, wherein in-phase windings are wound around two circumferentially consecutive teeth, and an end of one of the in-phase windings wound around the two consecutive teeth is connected to a first pin and an end of the other winding is connected to a second pin.

[0017] In the molded motor according to the fifth aspect, a molded motor with high safety can be realized.

[0018] A molded motor according to a sixth aspect is the molded motor according to any one of the first to fifth aspects, wherein the first through hole is a through hole.

[0019] In the molded motor of the sixth aspect, the inner surface of the through hole is copper plated, so that the molten solder tends to move more quickly to the stator side than in a case where the through hole is not copper plated.

[0020] A molded motor according to a seventh aspect is the molded motor according to any one of the first to sixth aspects, wherein the insulator is made of a thermoplastic resin.

[0021] In molded motors, the stator and printed circuit board are covered with mold resin, so even if the melted solder moves to the stator side during abnormally high heat, there may not be enough space for the solder to flow into.

[0022] In contrast, in the molded motor of the seventh aspect, the insulator is melted by the molten solder, and the molten solder can flow into the space where the insulator was located. Therefore, in the molded motor of the seventh aspect, it is easy to put the windings and the electrodes of the printed circuit board into an electrically non-conductive state in the event of abnormally high heat generation, thereby achieving a high level of safety.

[0023] A molded motor according to an eighth aspect is the molded motor according to any one of the first to seventh aspects, wherein the solder is Sn—Ag—Cu based.

[0024] In the molded motor of the eighth aspect, Sn-Ag-Cu solder, which has a relatively low melting point, is used, so that in the event of abnormally high heat, it is easy to establish an electrical disconnection between the windings and the electrodes of the printed circuit board, thereby achieving a high level of safety.

[0025] An air conditioning apparatus according to a ninth aspect comprises a utilization unit including a fan having a molded motor according to any one of the first to eighth aspects, and a heat source unit connected to the utilization unit by piping.

[0026] 6 is a schematic configuration diagram of an air conditioning apparatus according to one embodiment. FIG. 7 is a schematic perspective view of a utilization unit of the air conditioning apparatus of FIG. 1. FIG. 8 is a longitudinal sectional view of the utilization unit of FIG. 2. FIG. 9 is a perspective view of a motor used to drive a fan of the utilization unit of FIG. 2. FIG. 10 is a schematic longitudinal sectional view of the motor of FIG. 4. FIG. 11 is a schematic right side view showing the structure of a stator according to one embodiment of the motor of FIG. 4, depicting a state in which the molded resin and a printed circuit board have been removed. FIG. 12 is a schematic right side view depicting a state in which a printed circuit board has been attached to the stator of FIG. 6, depicting a state in which the molded resin has been removed. FIG. 13 is a schematic right side view of the motor of FIG. 4. FIG. 14 is a wiring diagram of the motor of FIG. 4. FIG. 15 is a diagram for explaining movement of melted solder in the motor of FIG. 4, depicting an enlarged longitudinal sectional view of a portion of the motor configuration. FIG. 16 is a diagram for explaining an example of a configuration for making the gap between the first through hole and the first pin larger than the gap between the second through hole and the second pin in the motor of FIG. 4. FIG. 17 is a diagram for explaining another example of a configuration for making the gap between the first through hole and the first pin larger than the gap between the second through hole and the second pin in the motor of FIG. 4. 5A and 5B are diagrams for explaining another example of a configuration for making the gap between the first through hole and the first pin larger than the gap between the second through hole and the second pin in the motor of Fig. 4. Fig. 5A and 5B are diagrams for illustrating an example of an arrangement of the first through hole and the second through hole in the motor of Fig. 4.

[0027] Hereinafter, a molded motor and an air conditioner using the molded motor according to the present disclosure will be described with reference to the drawings.

[0028] (1) Configuration of the Air Conditioner Fig. 1 is a schematic diagram of an air conditioner 100. The air conditioner 100 operates using a vapor compression refrigeration cycle to cool and heat the interior of a building, etc. However, the air conditioner 100 may also be a device dedicated to cooling.

[0029] The air conditioning apparatus 100 comprises a utilization unit 10 and a heat source unit 20 (see FIG. 1). The utilization unit 10 and the heat source unit 20 are connected via a liquid refrigerant connection pipe 102 and a gas refrigerant connection pipe 104 (see FIG. 1). The refrigerant circuit 110 of the air conditioning apparatus 100, which operates a vapor compression refrigeration cycle, is formed by connecting the utilization unit 10 and the heat source unit 20 via the refrigerant connection pipes 102, 104. The refrigerant circuit 110 is filled with refrigerant.

[0030] The utilization unit 10 is installed indoors (space to be air-conditioned) and mainly includes a utilization heat exchanger 12 and a utilization fan 14 (see FIG. 1).

[0031] The utilization heat exchanger 12 functions as a refrigerant evaporator during cooling operation to cool the indoor air, and functions as a refrigerant radiator during heating operation to heat the indoor air.

[0032] The utilization fan 14 draws indoor air into the utilization unit 10, exchanges heat with the refrigerant in the utilization heat exchanger 12, and then supplies the air to the room as supply air. The utilization fan 14 has a motor 40 whose frequency (number of rotations) can be changed by an inverter.

[0033] The heat source unit 20 is installed in the heat source and constitutes part of the refrigerant circuit 110. The heat source unit 20 has a compressor 122, a four-way switching valve 124, a heat source heat exchanger 126, an expansion valve 128, a liquid side shut-off valve 130, a gas side shut-off valve 132, and an accumulator 134 (see FIG. 1). The heat source unit 20 also has a heat source fan 136 (see FIG. 1). Each component of the heat source unit 20 is a part of the heat source machine of a widely used air conditioner, and therefore detailed description thereof will be omitted.

[0034] (2) Operation of the Air Conditioning Apparatus The air conditioning apparatus 100 performs cooling operation and heating operation.

[0035] During cooling operation, the four-way selector valve 124 is switched to the cooling cycle state (the state indicated by the solid line in FIG. 1 ), and the high-pressure gas refrigerant discharged from the compressor 122 is sent to the heat-source heat exchanger 126. The refrigerant sent to the heat-source heat exchanger 126 exchanges heat with heat-source air supplied by the heat-source fan 136, releasing heat and becoming high-pressure liquid refrigerant. The high-pressure liquid refrigerant is decompressed in the expansion valve 128, then passes through the liquid refrigerant connection pipe 102 and is sent to the utilization heat exchanger 12, where it exchanges heat with indoor air supplied by the utilization fan 14 and evaporates. During this process, the indoor air is cooled, and the cooled air is supplied to the utilization facility, thereby cooling the room. The low-pressure gas refrigerant evaporated in the utilization heat exchanger 12 passes through the gas refrigerant connection pipe 104 and the four-way selector valve 124 and is drawn into the compressor 12.

[0036] During heating operation, the four-way selector valve 124 is switched to the heating cycle state (the state indicated by the dashed line in FIG. 1 ), and the high-pressure gas refrigerant discharged from the compressor 122 passes through the gas refrigerant connection pipe 104 and is sent to the utilization heat exchanger 12. The refrigerant sent to the utilization heat exchanger 12 exchanges heat with the indoor air supplied by the utilization fan 14, dissipating heat and becoming high-pressure liquid refrigerant. At this time, the indoor air is heated, and the heated air is supplied to the utilization unit, thereby heating the room. The high-pressure liquid refrigerant passes through the liquid refrigerant connection pipe 102 and is sent to the heat source unit 20, where it is decompressed by the expansion valve 128 and sent to the heat-source heat exchanger 126. The refrigerant sent to the heat-source heat exchanger 126 exchanges heat with the heat-source air supplied by the heat-source fan 136 and evaporates. The low-pressure gas refrigerant evaporated in the heat-source heat exchanger 126 passes through the four-way selector valve 124 and is drawn into the compressor 122.

[0037] (3) Utilization Unit The utilization unit 10 will be described in detail with reference to FIGS. 2 and 3. FIG.

[0038] For convenience of explanation, terms such as front (front face), rear (rear face), top, bottom, right, left, etc. are used in describing the utilization unit 10. These terms correspond to the directions indicated by arrows in the drawings.

[0039] In this embodiment, the utilization unit 10 is a wall-mounted unit whose rear surface is attached to a wall as shown in Figures 2 and 3. The directions shown in the description refer to the direction when the utilization unit 10 is hung on a wall and viewed from the front toward the wall.

[0040] The utilization unit 10 mainly includes a housing 16, a utilization heat exchanger 12, a utilization fan 14, and a flap 18 (see FIGS. 2 and 3). The utilization heat exchanger 12 and the utilization fan 14 are housed in the housing 16.

[0041] An intake port B2 for taking in indoor air is formed on the top surface of the housing 16 (see FIGS. 2 and 3). An air outlet B1 is formed in the front lower part of the housing 16. A flap 18 is disposed at the air outlet B1 (see FIGS. 2 and 3).

[0042] A refrigerant flows inside the heat transfer tubes of the utilization heat exchanger 12, and exchanges heat with the air flowing around the heat transfer tubes.

[0043] The utilization fan 14 is a cylindrical crossflow fan having an impeller 15 that extends elongatedly in both the left and right directions. A motor 40 that rotates the impeller 15 of the utilization fan 14 is disposed on one end side (the right side in this embodiment) of the utilization fan 14. As the impeller 15 rotates, indoor air is drawn in through the intake port B2. The air drawn in through the intake port B2 is supplied to the utilization heat exchanger 12. The air that has exchanged heat with the refrigerant in the utilization heat exchanger 12 passes through the impeller 15 and is blown out from the outlet B1 into the room (the space to be air-conditioned). The flap 18 adjusts the direction of the air blown out from the outlet B1.

[0044] (4) Motor (4-1) Overall Configuration The motor 40 mainly includes a rotor 46, a stator 45, a printed circuit board (wiring board) 425, and a power supply harness 470 (see FIGS. 4 and 5). The stator 45 mainly includes a stator core 452, insulators 454a and 454b, a winding 456, and pins 460.

[0045] The stator core 452 has a plurality of teeth Tu1 to 4, Tv1 to 4, and Tw1 to 4 (see FIG. 6). In the following, when describing each of the teeth Tu1 to 4, Tv1 to 4, and Tw1 to 4 in common, or when describing the teeth Tu1 to 4, Tv1 to 4, and Tw1 to 4 collectively, the teeth Tu1 to 4, Tv1 to 4, and Tw1 to 4 may be referred to as teeth T. In this embodiment, the stator core 452 has a total of 12 teeth T, but the number of teeth T is not limited to 12 and may be designed as appropriate. The plurality of teeth T are arranged in a row in the circumferential direction.

[0046] Insulators 454a, 454b are disposed at both ends (left and right ends in this case) of each tooth T (see FIG. 5). The insulators 454a, 454b are preferably made of a thermoplastic resin. The reason why the insulators 454a, 454b are preferably made of a thermoplastic resin will be described later.

[0047] The motor 40 is a concentrated winding motor. A winding (coil) 456 is wound around each tooth T of a stator core 452 via insulators 454a and 454b (see FIG. 6).

[0048] A plurality of pins 460 are attached to the insulator 454a (in this embodiment, the insulator disposed on the right side of the stator core 452) and lined up in the circumferential direction (see FIG. 6). Specifically, the same number of pins 460 as the number of teeth T of the stator core 452 are attached to the insulator 454a and lined up in the circumferential direction, and each pin 460 corresponds to one tooth T. An end of a corresponding one of the windings 456 (the winding 456 wound around the corresponding tooth T) is connected to each of the plurality of pins 460 (see FIG. 5).

[0049] A printed circuit board (wiring board) 425 is disposed on the right side of the insulator 454a. A plurality of through holes 426 are formed in the printed circuit board 425 and arranged in the circumferential direction (see FIG. 7 ). Although not limited thereto, the through holes 426 are preferably through holes (the inner walls of the through holes 426 are conductively plated (copper plated)). A corresponding pin 460 is inserted into each through hole 426 (the pins 460 are not shown in FIG. 7 ). The pins 460 inserted into each through hole 426 or the windings 456 connected to the pins 460 inserted into each through hole 426 are connected by solder 427 to electrodes arranged in each through hole 426 (if the through holes 426 are through holes) or to electrodes (lands) 428 arranged around each through hole 426 (see FIG. 7 ).

[0050] The solder 427 used is Sn—Ag—Cu based or Sn—Cu based lead-free solder. A harness lead-out member 429 to which a harness 470 that supplies three-phase power is connected is fixed to the printed circuit board 425 (see FIGS. 4 and 7).

[0051] The stator core 452, around which the winding 456 is wound via the insulators 454a and 454b, the pin 460 attached to the insulator 454a, and the printed circuit board 425 are integrated by a molded resin 430. The molded resin 430 is a thermosetting resin with excellent heat resistance. While not limited to a specific material, the molded resin may be, for example, an epoxy resin. The molded resin 430 covers the periphery of the printed circuit board 425. The resin 430 also fills the space between the insulator 454a and the printed circuit board 425.

[0052] The rotor 46 has magnets 46b located radially outward of the windings 456. The magnets 46b are arranged on the cylindrical outer periphery of the rotor 46, and a motor rotating shaft 49 is fixed to the inner periphery of the rotor 46 (see FIG. 5). As shown in FIG. 8, the rotor 46 has multiple magnets 46b arranged in the circumferential direction. Adjacent magnets 46b in the circumferential direction have opposite polarities.

[0053] The magnet 46b is preferably a resin magnet, which is made by dispersing and mixing, for example, ferrite magnetic powder or rare earth magnetic powder such as NAFeB in a resin binder.

[0054] The windings 456 of the stator 45 are located inside the cylindrical outer periphery of the rotor 46. When current flows through the windings 456 of the stator 45, a magnetic field is generated, causing the rotor 46, which has magnets 46b, to rotate. As a result, the motor shaft 49 rotates, causing the impeller 15 fixed to the motor shaft 49 to rotate. Bearings 48 are disposed between the inner periphery of the stator 45 and the motor shaft 49. The motor shaft 49 and rotor 46 are supported by the stator 45 via these bearings 48.

[0055] (4-2) Connection of Windings Twelve teeth T are arranged in the circumferential direction around the stator core 452. Specifically, the teeth Tu1, Tu2, Tw1, Tw2, Tv3, Tv4, Tu3, Tu4, Tw3, Tw4, Tv1, Tv2 are arranged in this order counterclockwise in the drawing.

[0056] These 12 teeth T are divided into six tooth pairs, each consisting of a pair of teeth adjacent to each other in the circumferential direction. Specifically, the teeth Tu1 and Tu2 form the tooth pair Tua, the teeth Tw1 and Tw2 form the tooth pair Twa, the teeth Tv3 and Tv4 form the tooth pair Tvb, the teeth Tu3 and Tu4 form the tooth pair Tub, the teeth Tw3 and Tw4 form the tooth pair Twb, and the teeth Tv1 and Tv2 form the tooth pair Tva.

[0057] Although not limited thereto, one continuous winding 456 is wound around the tooth pair Tua (Tu1). One continuous winding 456 is also wound around each of the tooth pairs Tub, Tva, Tvb, Twa, and Twb.

[0058] The winding 456 wound around each of the teeth Tu1, Tu2, Tu3, and Tu4 corresponds to the U-phase of three-phase AC. Here, the windings 456 wound around each of the teeth Tu1, Tu2, Tu3, and Tu4 are referred to as Lu1, Lu2, Lu3, and Lu4. The winding 456 wound around each of the teeth Tv1, Tv2, Tv3, and Tv4 corresponds to the V-phase of three-phase AC. The windings 456 wound around each of the teeth Tv1, Tv2, Tv3, and Tv4 are referred to as Lv1, Lv2, Lv3, and Lv4. The winding 456 wound around each of the teeth Tw1, Tw2, Tw3, and Tw4 corresponds to the W-phase of three-phase AC. The windings 456 wound around the teeth Tw1, Tw2, Tw3, and Tw4 are referred to as Lw1, Lw2, Lw3, and Lw4, respectively.

[0059] The windings Lu1 to 4, Lv1 to 4, and Lw1 to 4 are connected as shown in Fig. 9. The detailed connection state is the same as that in Patent Document 1 (JP 2016-27781 A).

[0060] (4-3) Configuration of Printed Circuit Board and Pins The configuration of the through-hole 426 of the printed circuit board 425 and the pin 460 arranged in the through-hole 426 for improving safety will be described.

[0061] First, a conventional molded motor will be described.

[0062] In conventional molded motors, the maximum width of the through holes in the printed circuit board (for example, the diameter of the through holes in the case of circular holes) is the same, and the maximum width of the pins placed in the through holes is also the same (substantially the same).

[0063] Note that the dimension of the portion of the pin that is placed inside the through hole refers to the maximum width of the pin when only the pin is placed inside the through hole (when only a pin without a winding wound around it is placed inside the through hole). For example, when the pin is cylindrical, the maximum width of the pin is the diameter of the pin. When the pin is rectangular, the maximum width of the pin is the length of the diagonal of a cross section of the pin cut in a direction perpendicular to the longitudinal direction. When the pin with a winding wound around it is placed inside the through hole, the dimension of the portion of the pin that is placed inside the through hole refers to the maximum width of the pin with a winding wound around it.

[0064] Because conventional molded motors have this configuration, the dimensions of the gap between the through hole and the portion of the pin that is placed inside the through hole are the same (substantially the same) for all of the through holes in the printed circuit board. In conventional molded motors, the gap between the through hole and the portion of the pin that is placed inside the through hole is designed to be narrow, around 0.2 mm to 0.3 mm, for example, to prevent the pin from falling out of the through hole in the printed circuit board, or to reduce the amount of solder used to connect the pin or the pin with the winding wound around it to the electrode (through hole or land) on the printed circuit board.

[0065] In contrast, in the motor 40 of the present disclosure, the through hole 426 is divided into a first through hole 426a and a second through hole 426b. In the motor 40 of the present disclosure, the difference between the maximum width of the first through hole 426a and the maximum width of a first portion 460aa of the pin 460 (referred to as first pin 460a) that is inserted therethrough is designed to be larger than the difference between the maximum width of the second through hole 426b and the maximum width of a second portion 460ba of the pin 460 (referred to as second pin 460b) that is inserted therethrough. For example, the difference between the maximum width of the second through hole 426b and the maximum width of the second portion 460ba of the second pin 460b arranged inside the second through hole 426b is approximately 0 mm to 0.8 mm, and the difference between the maximum width of the first through hole 426a and the maximum width of the first portion 460aa of the first pin 460a arranged inside the first through hole 426a is approximately 1.0 to 1.5 mm.

[0066] The reason for adopting such a configuration is as follows.

[0067] In the motor 40, for example, a layer short circuit may occur in the winding 456 for some reason, which may result in abnormally high temperatures. If such an abnormality occurs, it is preferable for the motor 40 to be stopped early for safety reasons. To achieve this safety measure, it is conceivable to provide a protection system external to the motor 40. However, instead of or in addition to this, it is preferable for the motor 40 itself to be provided with a function for stopping the motor 40 in the event of abnormally high temperatures.

[0068] Therefore, in the motor 40 of the present disclosure, a configuration is adopted in which electrical continuity in the motor 40 is cut off in the event of abnormally high heat, as a method for stopping the motor 40 in the event of abnormally high heat. Specifically, the motor 40 adopts a configuration in which the abnormally high heat melts the components that make up the electrical path, thereby cutting off electrical continuity. More specifically, because the copper foil of the printed circuit board 425 and the material of the windings 456 that make up the electrical path have relatively high melting temperatures, the motor 40 of the present disclosure adopts a configuration in which the abnormally high heat in the windings 456 is transferred to the solder 427 via the windings 456 and pins 460, and electrical continuity is cut off at the portion of the solder 427 that has a lower melting temperature than the copper foil of the printed circuit board 425 and the material of the windings 456. A more detailed description will be given below.

[0069] Even in conventional molded motors, solder can melt in the event of abnormally high temperatures. However, in molded motors, the stator and printed circuit board are covered with molded resin, so even if the solder melts, there is no space for the molten solder to move (the solder does not move even when melted), so electrical continuity may not be severed. As mentioned above, there is a gap between the through-hole and the pin portion located inside the through-hole, but in conventional molded motors, the gap is so narrow that it is difficult for the solder to move through this gap.

[0070] Therefore, in the motor 40 of the present disclosure, a portion of the through hole 426 is designated as the first through hole 426a, and the difference between the maximum width of the first through hole 426a and the maximum width of the first portion 460aa of the first pin 460a arranged inside the first through hole 426a is increased, thereby allowing the molten solder 427 to move in the gap between the first through hole 426a and the first pin 460a, making it easier to cut off electrical continuity in the motor 40 in the event of abnormally high temperatures.

[0071] In particular, in the configuration of the present disclosure, the molten solder 427 is likely to reliably move toward the stator 45 side for the following reasons.

[0072] The surface tension of the molten solder 427 decreases as the temperature of the solder 427 increases. Therefore, the surface tension of the solder 427 is low on the stator 45 side where abnormal heat generation is occurring, and is high on the printed circuit board 425 away from the stator 45. When the surface tension becomes uneven in this way, the Marangoni effect causes the molten solder 427 to flow, and the molten solder 427 is drawn toward the high-temperature stator 45 where abnormal heat generation is occurring. As a result, in the motor 40 of the present disclosure, electrical continuity is likely to be cut off early in the event of abnormally high heat.

[0073] In order to facilitate the movement of the solder 427 toward the stator 45, it is preferable that the through holes 426 (particularly the first through holes 426a) are through holes with conductive plating on the inner walls, rather than non-through holes with no conductive plating on the inner walls.

[0074] Furthermore, it is preferable to select a material for the pin 460 that allows the solder 427 to flow easily over its surface. Alternatively, it is preferable to plate the surface of the pin 460 so that the solder 427 can flow easily over its surface. With this configuration, the solder 427 can move easily toward the stator 45.

[0075] Furthermore, in order to achieve early disconnection of electrical conductivity at abnormally high temperatures, it is preferable to use Sn-Ag-Cu solder (melting point 217°C), which has a lower melting temperature, for solder 427 rather than Sn-Cu solder (melting point 227-228°C).

[0076] Furthermore, since the stator 45 and printed circuit board 425 of the motor 40 are covered with thermosetting mold resin 430, which provides little space for the solder 427 to move, it is preferable that the insulator 454a be made of a thermoplastic resin. Because the insulator 454a is made of a thermoplastic resin, when the molten solder 427 flows toward the stator 45, the heat of the solder 427 melts the insulator 454a, and the solder 427 penetrates into the insulator 454a, as shown in FIG. 10 (the solder 427 is depicted by hatching with dots in FIG. 10 ). As a result, space for the solder 427 to move is secured in the event of abnormally high temperatures, and electrical continuity in the motor 40 can be quickly cut off in the event of abnormally high temperatures.

[0077] Furthermore, if there is little space for the molten solder 427 to move, the gas generated by melting the resin at an abnormally high temperature will become high pressure, and the pressure may cause the gas and molten solder 427 to spray out of the molded resin 430. In contrast, the configuration of motor 40 of the present disclosure melts insulator 454a to ensure space for the solder 427 to flow in, thereby preventing such problems from occurring.

[0078] From the viewpoint of quickly cutting off electrical continuity in motor 40 in the event of abnormally high heat, it is preferable to increase the maximum width of all through holes 426 and the maximum width of the portion of pin 460 disposed inside through hole 426. In other words, it is preferable to make all through holes 426 the first through holes 426a of the present disclosure.

[0079] However, with this configuration, there is a possibility that problems may occur, such as the printed circuit board 425 easily becoming detached from the pin 460 when the printed circuit board 425 is attached to the pin 460 during the manufacturing process. Therefore, in the motor 40 of the present disclosure, the through hole 426 is provided with a first through hole 426a having a large gap between it and the pin 460 and a second through hole 426b having a small gap between it and the pin 460.

[0080] (4-3-1) Design of Printed Circuit Board and Pins How to make the gap between the first through hole 426a and the first pin 460a different from the gap between the second through hole 426b and the second pin 460b will be described.

[0081] In one aspect, as shown in Figures 11A and 11B, the dimensions of the first pin 460a and the second pin 460b are the same, and the maximum width D1 of the first through hole 426a (diameter D1 if the through hole 426a is circular as in Figures 11A and 11B) is made larger than the maximum width D2 of the second through hole 426b (diameter D2 if the through hole 426b is circular as in Figures 11A and 11B), thereby ensuring that the gap between the first through hole 426a and the first portion 460aa of the first pin 460a is larger than the gap between the second through hole 426b and the second portion 460ba of the second pin 460b.

[0082] The first portion 460aa of the first pin 460a, which is disposed inside the first through-hole 426a, and the second portion 460ba of the second pin 460b, which is disposed inside the second through-hole 426b, may have a winding 456 wound thereon, as shown in FIG. 11A, or may not have a winding 456 wound thereon, as shown in FIG. 11B.

[0083] In another aspect, as shown in FIG. 11C , the dimensions of the first through hole 426a and the second through hole 426b are the same, and the maximum width A1 of the first pin 460a (particularly of the first portion 460aa) (if the first pin 460a is cylindrical as in FIG. 11C , the diameter A1 of the cylinder) is made smaller than the maximum width A2 of the second pin 460b (particularly of the second portion 460ba) (if the second pin 460b is cylindrical as in FIG. 11C , the diameter A2 of the cylinder). This makes it possible to ensure that the gap between the first through hole 426a and the first portion 460aa of the first pin 460a is larger than the gap between the second through hole 426b and the second portion 460ba of the second pin 460b. 11C illustrates a state in which the winding 456 is not wound around the first pin 460a and the second pin 460b, but the present invention is not limited to this, and the winding 456 may be wound around the pin 460 in the first portion 460aa and the second portion 460ba. Even when the winding 456 is wound around the pin 460, by making the maximum width A1 of the first pin 460a smaller than the maximum width A2 of the second pin 460b, the gap between the first through hole 426a and the first pin 460a can be made larger than the gap between the second through hole 426b and the second pin 460b.

[0084] Although not shown in the figures, in yet another aspect, for example, the dimensions of the pin 460 and the dimensions of the through hole 426 are all the same, and the winding 456 is not wound around the first portion 460aa of the first pin 460a, and the winding 456 is wound around the second portion 460ba of the second pin 460b, thereby ensuring that the gap between the first through hole 426a and the first portion 460aa of the first pin 460a is larger than the gap between the second through hole 426b and the second portion 460ba of the second pin 460b.

[0085] In addition, the configurations described here for making the gap between the first through hole 426a and the first part 460aa of the first pin 460a larger than the gap between the second through hole 426b and the second part 460ba of the second pin 460b may be combined as appropriate.

[0086] (4-3-2) Arrangement of First Through Holes and Second Through Holes The arrangement of the first through holes 426a and the second through holes 426b will be described below.

[0087] The plurality of through holes 426 includes at least one first through hole 426a and at least one second through hole 426b.

[0088] From the viewpoint of ease of assembly in the manufacturing process, it is preferable that at least three second through holes 426b be included in the through hole 426. By providing the second through holes 426b in three locations, the printed circuit board 425 attached to the pin 460 is less likely to come off the pin 460.

[0089] Furthermore, it is preferable that the pins 460 connected to the U-phase, V-phase, and W-phase windings 456 include at least one first pin 460a. In other words, it is preferable that at least one first through hole 426a be included for each of the U-phase, V-phase, and W-phase. The reason why such a configuration is preferable is as follows.

[0090] It is not known whether abnormally high heat caused by a layer short or the like will occur in the U-phase, V-phase, or W-phase. Furthermore, because the windings of each phase are not directly connected to the windings of the other phases, even if abnormally high heat occurs due to a layer short in the U-phase, for example, this heat is unlikely to be transmitted to the pins 460 to which the V-phase and W-phase windings 456 are connected via the V-phase and W-phase windings 456. In contrast, by providing first through-holes 426a in each of the U-phase, V-phase, and W-phase in three-phase AC (by providing first pins 460a in each of the U-phase, V-phase, and W-phase in three-phase AC), even if abnormally high heat occurs in any phase, the heat is transmitted to first pins 460a via the metal portion, melting solder 427 relatively quickly and enabling electrical continuity in motor 40 to be quickly cut off.

[0091] More preferably, one end of each of the circumferentially adjacent windings 456 of the same phase is connected to the first pin 460a, and the other end of each of the circumferentially adjacent windings 456 of the same phase is connected to the second pin 460b.

[0092] More specifically, of the windings Lu1 and Lu2 wound around the tooth pair Tua (teeth Tu1 and Tu2), one winding is connected to the pin 460 which is the first pin 460a, and the other winding is connected to the pin 460 which is the second pin 460b. The same applies to the tooth pairs Tub, Tva, Tvb, Twa, and Twb.

[0093] As described above, the windings Lu1 and Lu2 are directly connected (the windings 456 wound around the teeth Tu1 and Tu2 are one winding), the windings Lu3 and Lu3 are directly connected (the windings 456 wound around the teeth Tu3 and Tu4 are one winding), and the windings Lv1 and Lv2 are directly connected (the windings 456 wound around the teeth Tv1 and Tv2 are one winding). ), windings Lv3 and Lv4 are directly connected (the winding 456 wound around teeth Tv3 and teeth Tv3 is a single winding), windings Lw1 and Lw2 are directly connected (the winding 456 wound around teeth Tw1 and teeth Tw2 is a single winding), and windings Lw3 and Lw4 are directly connected (the winding 456 wound around teeth Tw3 and teeth Tw4 is a single winding). Therefore, the pin 460 to which one of the windings Lu1 and Lu2 is connected is referred to as the first pin 460a (the pin inserted into the first through hole 426a), the pin 460 to which one of the windings Lu3 and Lu4 is connected is referred to as the first pin 460a, the pin 460 to which one of the windings Lv1 and Lv2 is connected is referred to as the first pin 460a, the pin 460 to which one of the windings Lv3 and Lv4 is connected is referred to as the first pin 460a, and the pin 460 to which one of the windings Lw1 and Lw2 is connected is referred to as the first pin 460a. By designating pin 460 as first pin 460a and designating pin 460 to which one of windings Lw3 and Lw4 is connected as first pin 460a, even if a layer short occurs in any of windings Lu1 to Lu4, windings Lv1 to Lv4, or windings Lw1 to Lw4, causing abnormally high heat, the heat can be transferred to first pin 460a via winding 456, melting solder 427 relatively quickly, and quickly cutting off electrical continuity in motor 40.

[0094] Although there is no particular limitation to the specific arrangement, for example, as shown in FIG. 12, first through holes 426a and second through holes 426b are alternately arranged.

[0095] (5) Features (5-1) The motor 40 includes a stator core 452, an insulator 454a, a plurality of windings 456, a plurality of pins 460, and a printed circuit board 425. The stator core 452 has a plurality of teeth T arranged side by side in the circumferential direction. The insulators 454a are arranged at ends of the plurality of teeth T. The plurality of windings 456 are wound around each of the plurality of teeth T via the insulators 454a. The plurality of pins 460 are attached to the insulator 454a and arranged side by side in the circumferential direction. An end of a corresponding one of the windings 456 is connected to each of the plurality of pins 460. The printed circuit board 425 is formed with a plurality of through holes 426 through which a corresponding one of the pins 460 is inserted. In the printed circuit board 425, pins 460 inserted through each through hole 426 or windings 456 connected to the pins 460 inserted through each through hole 426 are connected via solder 427 to electrodes arranged in or around each through hole 426. The stator core 452, in which the windings 456 are wound around the multiple teeth T via insulators 454a, and the printed circuit board 425 are molded with molding resin 430. The through holes 426 include a first through hole 426a and a second through hole 426b. The pins 460 include a first pin 460a inserted through the first through hole 426a and a second pin 460b inserted through the second through hole 426b. The difference between the maximum width of the first through hole 426a and the maximum width of the first portion 460aa positioned inside the first through hole 426a of the first pin 460a is greater than the difference between the maximum width of the second through hole 426b and the maximum width of the second portion 460ba positioned inside the second through hole 426b of the second pin 460b.

[0096] With this configuration, when abnormally high heat occurs due to a rare short in the winding 456 or the like, the solder 427 connecting the winding 456 to the electrode (the through-hole serving as the first through-hole 426a or the land 428 of the printed circuit board 425) melts due to the high heat and is pulled toward the stator 45 through the gap between the first through-hole 426a and the first part 460aa of the first pin 460a, bringing the winding 456 and the electrode into an electrically non-conductive state, thereby stopping the motor 40 and providing a high level of safety.

[0097] Increasing the maximum width of all through holes 426 and the maximum width of the portion of pin 460 located inside through hole 426 can make it easier to stop motor 40 when abnormally high heat occurs. However, in this case, there is a possibility that problems will occur, such as printed circuit board 425 becoming more likely to come off pin 460 when printed circuit board 425 is attached to pin 460 during the manufacturing process of motor 40.

[0098] In contrast, in the present motor 40, the through hole 426 and the pin 460 also include the second through hole 426b and the second pin 460b, so that the safety of the motor 40 can be improved and the motor 40 can be easily manufactured.

[0099] (5-2) For example, in the motor 40, the maximum width D1 of the first through-hole 426a is larger than the maximum width D2 of the second through-hole 426b.

[0100] With this configuration, it is easy to realize a structure in which the difference between the maximum width D1 of the first through hole 426a and the maximum width A of the first portion 460aa of the first pin 460a is greater than the difference between the maximum width D2 of the second through hole 426b and the maximum width A of the second portion 460ba of the second pin 460b.

[0101] Furthermore, instead of or in addition to the configuration in which the maximum width D1 of the first through hole 426a is larger than the maximum width D2 of the second through hole 426b, the maximum width A1 of the first portion 460aa of the first pin 460a may be smaller than the maximum width A2 of the second portion 460ba of the second pin 460b.

[0102] By configuring in this manner, even if the dimensions of all the through holes 426 are the same, a structure can be realized in which the difference between the maximum width D of the first through hole 426a and the maximum width A1 of the first portion 460aa of the first pin 460a is greater than the difference between the maximum width D of the second through hole 426b and the maximum width of the second portion 460ba of the second pin 460b.

[0103] (5-3) Preferably, the pins 460 connected to the windings 456 of each phase include a first pin 460a. Specifically, if the electricity supplied to the motor 40 is three-phase AC, the pins 460 connected to the windings 456 of each of the U-phase, V-phase, and W-phase preferably include a first pin 460a.

[0104] In other words, it is preferable that at least one first through hole 426 a be provided for each phase. Specifically, if the electricity supplied to the motor 40 is three-phase AC, it is preferable that at least one first through hole 426 a be provided for each of the U phase, V phase, and W phase.

[0105] By configuring in this manner, even if abnormally high heat occurs in any phase of motor 40, motor 40 can be stopped at an early stage by electrically disconnecting winding 456 from electrodes of printed circuit board 425 (through holes such as first through holes 426a and lands 428 of printed circuit board 425), thereby providing a high level of safety.

[0106] (5-4) In the motor 40 of this embodiment, the same-phase winding 456 is wound around two circumferentially consecutive teeth T. Specifically, the U-phase winding 456 is wound around the circumferentially consecutive teeth Tu1, Tu2, the U-phase winding 456 is wound around the circumferentially consecutive teeth Tu3, Tu4, the V-phase winding 456 is wound around the circumferentially consecutive teeth Tv1, Tv2, the V-phase winding 456 is wound around the circumferentially consecutive teeth Tv3, Tv4, the W-phase winding 456 is wound around the circumferentially consecutive teeth Tw1, Tw2, and the W-phase winding 456 is wound around the circumferentially consecutive teeth Tw3, Tw4. Of the two in-phase windings 456 wound around two consecutive teeth T, it is preferable that the end of one winding 456 is connected to the first pin 460a and the end of the other winding 456 is connected to the second pin 460b.

[0107] With this configuration, a highly safe motor 40 can be realized.

[0108] (5-5) Preferably, the first penetrating hole 426a is a through-hole.

[0109] Here, since the inner surface of the through hole 426 is copper plated, the molten solder 427 tends to move more quickly toward the stator 45 than if the inner surface were not copper plated.

[0110] (5-6) Preferably, the insulator 454a is made of a thermoplastic resin.

[0111] In the motor 40, the stator 45 and the printed circuit board 425 are covered with the molded resin 430, so even if the melted solder 427 moves to the stator 45 side in the event of abnormally high heat, there may not be enough space for the solder 427 to flow into.

[0112] In contrast, in this configuration, the insulator 454a is melted by the molten solder 427, and the molten solder 427 can flow into the space where the insulator 454a was located. Therefore, with this configuration, when abnormally high heat is generated, it is easy to put the winding 456 and the electrodes of the printed circuit board 425 (the through-holes serving as the first through-holes 426a and the lands 428 of the printed circuit board 425) into an electrically non-conductive state, thereby achieving high safety.

[0113] (5-7) Preferably, the solder 427 is Sn—Ag—Cu based.

[0114] By using Sn-Ag-Cu solder 427, which has a lower melting point than Sn-Cu solder 427, it is easier to quickly bring winding 456 and the electrodes of printed circuit board 425 into an electrically non-conductive state in the event of abnormally high heat generation, compared to when Sn-Cu solder 427 is used, thereby achieving high safety.

[0115] (6) Modifications (6-1) Modification A In the above embodiment, an example has been described in which the winding 456 is wound around the pin 460, but the method of connecting the pin 460 and the winding 456 is not limited to this. For example, the pin 460 may be provided with clamping portions that clamp the winding 456, and the pin 460 and the winding 456 may be electrically connected by clamping an end of the winding 456 between the clamping portions.

[0116] <Additional Note> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the present disclosure as defined in the claims.

[0117] REFERENCE SIGNS LIST 10 Utilization unit 14 Utilization fan (fan) 20 Heat source unit 40 Motor (molded motor) 45 Stator 100 Air conditioning device 102 Liquid refrigerant communication pipe (piping) 104 Gas refrigerant communication pipe (piping) 425 Printed circuit board 426 Through hole 426a First through hole 426b Second through hole 427 Solder 430 Molded resin 452 Stator core 454a Insulator 456 Winding 460 Pin 460a First pin 460aa First portion 460b Second pin 460ba Second portion A Maximum width (maximum width of first portion, maximum width of second portion) A1 Maximum width (maximum width of first portion) A2 Maximum width (maximum width of second portion) D Maximum width (maximum width of first through hole, maximum width of second through hole) D1 Maximum width (maximum width of first through hole) D2 Maximum width (maximum width of second through hole) Lu1 to Lu4 Windings Lv1 to Lv4 Windings Lw1 to Lw4 Windings T Teeth Tu1 to Tu4 Teeth Tv1 to Tv4 Teeth Tw1 to Tw4 Teeth

[0118] JP 2016-27781 A

Claims

1. A stator core (452) having a plurality of teeth (Tu1-4, Tv1-4, Tw1-4) arranged side by side in the circumferential direction; insulators (454a) arranged on the ends of the plurality of teeth; a plurality of windings (456) wound around each of the plurality of teeth via the insulator; a plurality of pins (460) arranged side by side on the insulator in the circumferential direction and each having an end of a corresponding one of the windings connected thereto; and a printed circuit board (425) having a plurality of through holes (426) formed therein through which a corresponding one of the pins is inserted, and the pins inserted in each of the through holes or the windings connected to the pins inserted in each of the through holes are connected via solder (427) to electrodes arranged in or around each of the through holes, a molded motor (40) in which the stator core, in which the windings are wound around the plurality of teeth via the insulators, and the printed circuit board are molded with resin (430); the through holes include a first through hole (426a) and a second through hole (426b); the pins include a first pin (460a) inserted into the first through hole and a second pin (460b) inserted into the second through hole; and a difference between a maximum width (D1, D) of the first through hole and a maximum width (A, A1) of a first portion (460aa) of the first pin disposed inside the first through hole is greater than a difference between a maximum width (D2, D) of the second through hole and a maximum width (A, A2) of a second portion (460ba) of the second pin disposed inside the second through hole.

2. The molded motor according to claim 1, wherein the maximum width (D1) of the first through hole is greater than the maximum width (D2) of the second through hole.

3. A molded motor according to claim 1 or 2, wherein the maximum width (A1) of the first portion of the first pin is smaller than the maximum width (A2) of the second portion of the second pin.

4. A molded motor according to any one of claims 1 to 3, wherein the pins connected to the windings of each phase include the first pin.

5. A molded motor as claimed in any one of claims 1 to 4, wherein the windings of the same phase are wound around two circumferentially consecutive teeth, and the end of one of the two windings of the same phase wound around two consecutive teeth is connected to the first pin, and the end of the other of the two windings of the same phase wound around two consecutive teeth is connected to the second pin.

6. A molded motor according to any one of claims 1 to 5, wherein the first through hole is a through hole.

7. A molded motor according to any one of claims 1 to 6, wherein the insulator is made of a thermoplastic resin.

8. A molded motor according to any one of claims 1 to 7, wherein the solder is a Sn-Ag-Cu system.

9. An air conditioning device (100) comprising: a utilization unit (10) including a fan (14) having a molded motor according to any one of claims 1 to 8; and a heat source unit (20) connected to the utilization unit by piping (102, 104).

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