Motor

Abstract

To provide a motor capable of suppressing or preventing intrusion of a refrigerant used in an air conditioner.SOLUTION: A motor is configured to drive a fan in an air conditioner, the motor including: a stator around which a coil is wound; a rotor that has a shaft and is provided rotatably with respect to the stator; a board that includes an electronic component that drives and controls the stator and the rotor; a body case including a first housing region that houses the stator and houses the rotor with the shaft that is partly exposed to the outside, and a second housing region that houses the board; and a first partition wall that divides the first housing region from the second housing region.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a motor that drives a fan in an air conditioner. [Background technology]

[0002] 2. Description of the Related Art Conventionally, sealed structures for motors provided in engine compartments of automobiles (Patent Documents 1 and 2) and waterproof motors (Patent Document 3) are known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-187076 A [Patent Document 2] JP 2003-348785 A [Patent Document 3] JP 2019-140897 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional motors with sealed structures are very expensive and not adopted as motors for driving fans of air conditioners. Or, since the sealed structure of conventional motors is intended to prevent the intrusion of dust, moisture, etc., when the sealed structure is applied to a motor for driving a fan of a heat exchanger in an air conditioner that uses a refrigerant, it is difficult to prevent the refrigerant from infiltrating into the inside. When a flammable refrigerant is used in an air conditioner, it is not preferable to expose the control circuit to the refrigerant, since there is a possibility that the refrigerant will leak due to a malfunction and ignite when an electronic component malfunctions. Furthermore, since it is necessary to provide lead wires that are connected to the control circuit and drawn out to the outside, there are many gaps that lead to the outside. In addition, the ball bearing that rotatably fixes the rotor to the stator also has gaps that lead to the outside. Therefore, it is easy to allow the refrigerant to infiltrate.

[0005] Therefore, an object of the present disclosure is to provide an inexpensive motor that can suppress or prevent infiltration of flammable refrigerant used in air conditioners into a control circuit unit. [Means for solving the problem]

[0006] The motor of the present disclosure is a motor that drives a fan in an air conditioner, and comprises a stator having a coil wound thereon, a rotor having a shaft and arranged to rotate freely relative to the stator, a substrate on which electronic components for driving and controlling the stator and the rotor are arranged, a main body case having a first accommodating area that accommodates the stator and the rotor so that part of the shaft is exposed to the outside, and a second accommodating area that accommodates the substrate, and a first partition wall that separates the first accommodating area from the second accommodating area.

[0007] In the present disclosure, in the main body case, the stator and the rotor are accommodated in the first accommodation area, and the board on which the electronic components are provided is accommodated in the second accommodation area. The first compartment wall separates the first accommodation area from the second accommodation area. As a result, the second accommodation area of ​​the main body case is isolated from the first accommodation area by the first compartment wall. Therefore, even if a flammable refrigerant enters the first accommodation area through a portion where the lead wire connected to the control circuit is drawn out from the main body case to the outside, and a gap between the main body case and the ball bearing that rotatably fixes the shaft of the rotor, the refrigerant is less likely to enter the second accommodation area from the first accommodation area. Therefore, it is possible to suppress or prevent the board accommodated in the second accommodation area from being exposed to the refrigerant. Therefore, it is possible to reduce the risk that the electronic components of the board become an ignition source and the refrigerant will ignite, thereby improving safety. In addition, by adopting the above configuration, a special seal structure is not required in the portion where the lead wire connected to the control circuit is drawn out from the main body case to the outside, and in the gap between the main body case and the ball bearing that rotatably fixes the shaft of the rotor. Furthermore, it is possible to use many of the same parts as the motor that drives the fan in the conventional air conditioner, so that a motor with improved safety can be obtained at low cost.

[0008] In the above disclosure, the motor may further include a second partition wall that separates the second accommodation area from the outside and is connected to the first partition wall.

[0009] According to the above configuration, the second partition wall that separates the second housing area from the outside can be provided independently of the wall portion that configures the main body case. In this case, the second partition wall can be connected to the first partition wall later, making it easier to place the board in the second housing area.

[0010] In the above disclosure, the second partition wall may be connected to the first partition wall by press fitting.

[0011] According to the above configuration, fixing tools such as screws are not required.

[0012] In the above disclosure, the second housing area may be filled with a drip-proof material.

[0013] According to the above configuration, even if the refrigerant should enter the second accommodation area, the refrigerant can be absorbed by the drip-proof material.

[0014] In the above disclosure, the motor may further include wiring that electrically connects the electronic component to the rotor or the stator, and the first partition wall may have a hole through which the wiring is inserted.

[0015] According to the above configuration, the electronic component on the board arranged in the second housing area and the rotor or stator arranged in the first housing area can be connected by wiring through the hole.

[0016] In the above disclosure, the motor may further include a seal portion that seals a gap between the wiring and the hole.

[0017] According to the above configuration, even if the coolant enters the first accommodating region, the seal portion can suppress or prevent the coolant from the first accommodating region from entering the second accommodating region. Effect of the Invention

[0018] According to the present disclosure, it is possible to provide an inexpensive motor that is capable of suppressing or preventing intrusion of flammable refrigerant used in air conditioners into a control circuit unit. [Brief description of the drawings]

[0019] [Figure 1] 1 is a diagram showing the overall configuration of an air conditioner according to one embodiment; [Diagram 2] FIG. [Diagram 3] 3 is a cross-sectional view of the motor shown in FIG. 2 taken along line III-III. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, a motor according to an embodiment of the present disclosure will be described with reference to the drawings. The motor described below is merely one embodiment of the present disclosure. Therefore, the present disclosure is not limited to the following embodiment, and additions, deletions, and modifications are possible without departing from the spirit of the present disclosure.

[0021] FIG. 1 is a diagram showing the overall configuration of an air conditioner 1 according to one embodiment. As shown in FIG. 1, the air conditioner 1 includes an outdoor heat exchanger 2 that exhausts heat to the outside during cooling operation, an indoor heat exchanger 3 that absorbs heat from outdoor air, and a circulation path 4 that includes these heat exchangers 2 and 3. Fans 7 and 8 driven by motors 5a and 5b are provided near the outdoor heat exchanger 2 and the indoor heat exchanger 3, respectively. In the following description, the motor 5 includes the motors 5a and 5b. An airflow generated by the rotational driving of the fan 7 flows through the outdoor heat exchanger 2, and an airflow generated by the rotational driving of the fan 8 flows through the indoor heat exchanger 3.

[0022] For convenience, the following description uses the expressions "upstream" and "downstream," which refer to the "upstream" and "downstream" of the flow of the refrigerant that flows through the circulation path 4 when the air conditioner 1 is in cooling operation. The arrows along the circulation path 4 shown in Fig. 1 indicate the direction in which the refrigerant flows from "upstream" to "downstream" during cooling operation. The flow of the refrigerant during heating operation is opposite to the flow of the refrigerant during cooling operation, as shown by the dashed line.

[0023] 1, a refrigerant pipe 4a constituting part of the circulation path 4 is provided inside the indoor heat exchanger 3, and a refrigerant pipe 4b is extended from its downstream end and connected to an indoor unit liquid side connection part 10 (the connection part on the downstream side during cooling operation). Another refrigerant pipe 4c is extended from this indoor unit liquid side connection part 10, and its downstream end is connected to the upstream end of a refrigerant pipe 4d via a two-way valve 11, and its downstream end is connected to a first port of a four-way valve 12. A refrigerant pipe 4e is extended from a second port of the four-way valve 12 that communicates with the first port during cooling operation, and its downstream end is connected to a compressor 13.

[0024] The compressor 13 compresses the low-temperature, low-pressure refrigerant flowing from the indoor heat exchanger 3 to the outdoor heat exchanger 2 during cooling operation to make it high-temperature, high-pressure, and compresses the low-temperature, low-pressure refrigerant flowing from the outdoor heat exchanger 2 to the indoor heat exchanger 3 during heating operation to make it high-temperature, high-pressure. Although not shown, an accumulator is usually connected before (upstream of) the compressor 13 to separate the refrigerant into gas and liquid to prevent the liquid refrigerant from returning to the compressor 13.

[0025] Another refrigerant pipe 4f extends from the compressor 13, and its downstream end is connected to the third port of the four-way valve 12. In the four-way valve 12, a refrigerant pipe 4g extends from the remaining fourth port that communicates with the third port during cooling operation, and its downstream end is connected to the upstream end of the refrigerant pipe 4h provided in the outdoor heat exchanger 2. Another refrigerant pipe 4i extends from the downstream end of the refrigerant pipe 4h in the outdoor heat exchanger 2, and its downstream end is connected to the expansion valve 14. The expansion valve 14 reduces the pressure of the refrigerant flowing from the outdoor heat exchanger 2 to the indoor heat exchanger 3 during cooling operation, and reduces the pressure of the refrigerant flowing from the indoor heat exchanger 3 to the outdoor heat exchanger 2 during heating operation.

[0026] Another refrigerant pipe 4j extends from the expansion valve 14, and its downstream end is connected to one port of a two-way valve 15. A refrigerant pipe 4k extends from the other port of the two-way valve 15, and its downstream end is connected to an indoor unit connection part 16 (the upstream connection part during cooling operation). Another refrigerant pipe 4m extends from the indoor unit connection part 16, and its downstream end is connected to the upstream end of the refrigerant pipe 4a in the indoor heat exchanger 3 described above.

[0027] In this way, the circulation path 4 is formed by the refrigerant pipes 4a to 4k, 4m. The circulation path 4 connects the indoor heat exchanger 3, the four-way valve 12, the compressor 13, the outdoor heat exchanger 2, the expansion valve 14, and the like. Among the above-mentioned components, the outdoor unit 1A of the air conditioner 1 is formed by the components from the two-way valve 11 to the two-way valve 15 along the flow of the refrigerant (i.e., the four-way valve 12, the compressor 13, the outdoor heat exchanger 2, and the expansion valve 14). The indoor unit 1B of the air conditioner 1 is formed by the components from the indoor unit liquid side connector 16 to the indoor unit liquid side connector 10 along the flow of the refrigerant (i.e., the indoor heat exchanger 3). It should be noted that each of the above-mentioned components themselves can be publicly known. In addition, the operation of the air conditioner 1 during cooling operation and heating operation is publicly known, so a description thereof will be omitted.

[0028] Examples of the refrigerant (working refrigerant) in the air conditioner 1 include flammable refrigerants that are heavier than air, such as isobutane and propane. The refrigerant may be a single refrigerant or a mixture of another type of refrigerant and a flammable refrigerant.

[0029] Next, a detailed description will be given of the configuration of the motor 5 in the air conditioner 1. Fig. 2 is a front view of the motor 5. Fig. 3 is a cross-sectional view of the motor 5 of Fig. 2 taken along line III-III.

[0030] In this embodiment, a brushless motor can be used as an example of the motor 5. As shown in Fig. 3, the motor 5 includes a main body case 20, a stator 21 having a plurality of (e.g., 12) pole teeth, a rotor 22 having a shaft 23, a first bracket 27, a second bracket 28, a substrate 30 on which electronic components 32 are provided, a first seal portion 40, and a second seal portion 50. A fan 7 (or fan 8) is attached to the tip of the shaft 23. The first bracket 27 corresponds to a first partition wall, and the second bracket 28 corresponds to a second partition wall.

[0031] The stator 21 is formed by winding a coil around each pole tooth of the stator core. The rotor 22 has a plurality of (e.g., eight) permanent magnets fixed to face the pole teeth of the stator 21, and is rotatably mounted on the stator 21 by ball bearings 24 and 25 described below. The motor 5 detects the magnetic pole position of the rotor 22 based on the voltage applied to the windings of the stator 21 and the current flowing therethrough. The coil through which the current flows is switched based on the detection result, causing the shaft 23 to rotate about its axis. This causes the fans 7 and 8 to rotate.

[0032] In the main body case 20, the stator 21 is integrally molded from resin, and the rotor 22 is housed so that a part of the shaft 23 is exposed to the outside. Such a main body case 20 has three main components. The main body case 20 has a cylindrical small diameter portion 20a, a cylindrical large diameter portion 20b, and a cylindrical case end portion 20c. The large diameter portion 20b is provided closer to the base end of the shaft 23 than the small diameter portion 20a, and has a larger diameter in a direction perpendicular to the extension direction Ds of the shaft 23 than the small diameter portion 20a. The case end portion 20c is provided closer to the base end of the shaft 23 than the large diameter portion 20b, and has a larger inner diameter than the large diameter portion 20b while having approximately the same outer diameter as the large diameter portion 20b.

[0033] The first bracket 27 is connected to the case end 20c so as to cover the opening of the case end 20c. This forms a first housing area R1, which is an area surrounded by the large diameter part 20b of the main body case 20 and the first bracket 27. The stator 21 and the rotor 22 are housed in the first housing area R1. The first bracket 27 may also be press-fitted into the case end 20c. In this case, the outer edge part of the bracket 27 is a double wall, and the case end 20c is press-fitted between one wall and the other wall.

[0034] A bearing portion for accommodating, for example, a ball bearing 24 is provided within small diameter portion 20a, and a bearing portion for accommodating, for example, a ball bearing 25 is provided in a recess formed in first bracket 27. Shaft 23 is supported by ball bearings 24 and 25 of main body case 20 so as to be rotatable about its own axis.

[0035] The first seal portion 40 is made of, for example, chloroprene rubber. The first seal portion 40 is formed in an annular shape and is rotationally symmetrical about the axis of the shaft 23. The first seal portion 40 is provided on the small diameter portion 20a of the main body case 20 with the shaft 23 inserted through the first seal portion 40. The first seal portion 40 does not rotate together with the shaft 23.

[0036] The first seal portion 40 has a first seal body portion 41, a first wall portion 42, and a fourth wall portion 43. The first seal body portion 41 is formed in an annular shape (more specifically, in a disk shape having a through hole) and is arranged so as to be perpendicular to the extending direction Ds of the shaft 23. The shaft 23 is inserted into a hole in the first seal body portion 41. The first wall portion 42 is formed in an annular shape, intersects with the first seal body portion 41, and protrudes toward the second seal portion 50, for example, in a diverging manner. The first wall portion 42 is connected to the inner edge of the first seal body portion 41. The fourth wall portion 43 is formed in a cylindrical shape having an inner diameter that is approximately the same as the outer diameter of the small diameter portion 20a, intersects with the first seal body portion 41, and protrudes toward the large diameter portion 20b of the main body case 20 at the outer edge of the first seal body portion 41.

[0037] Next, the second seal portion 50 will be described. The material of the second seal portion 50 may be the same as that of the first seal portion 40, for example, chloroprene rubber. The second seal portion 50 is formed in an annular shape and is rotationally symmetrical with respect to the axis of the shaft 23. The second seal portion 50 is provided on the shaft 23 so as to be spaced apart from the first seal portion 40 in the extension direction Ds of the shaft 23 with respect to the main body case 20. As a result, the second seal portion 50 rotates together with the shaft 23.

[0038] The second seal portion 50 has a second seal body portion 51, a second wall portion 52, and a third wall portion 53. The second seal body portion 51 is formed in an annular shape (more specifically, in a disk shape having a through hole) and is disposed so as to be perpendicular to the extending direction Ds of the shaft 23. The second seal body portion 51 has a larger maximum dimension than the first seal body portion 41. Specifically, the second seal body portion 51 has a larger maximum diameter than the first seal body portion 41. Therefore, the outer edge of the second seal body portion 51 is located radially farther from the shaft 23 than the outer edge of the first seal body portion 41. The shaft 23 is inserted into the hole of the second seal body portion 51 and is attached. The second wall portion 52 is formed in an annular shape, perpendicular to the second seal body portion 51, and protrudes toward the first seal portion 40. The second wall portion 52 is disposed so as to be farther from the shaft 23 than the first wall portion 42 in a direction perpendicular to the extending direction Ds. The tip of the second wall portion 52 is disposed at a position closer to the main body case 20 than the tip of the first wall portion 42 in the extension direction Ds of the shaft 23.

[0039] The third wall portion 53 is formed in an annular shape, intersects with the second seal body portion 51, and protrudes toward the first seal portion 40 at the outer edge of the second seal body portion 51. The third wall portion 53 is disposed farther away from the shaft 23 than the second wall portion 52 in a direction perpendicular to the extending direction Ds. In addition, an end portion 53a of the third wall portion 53 on the side of the main body case 20 is located closer to the main body case 20 than the first seal body portion 41 and is located farther away from the shaft 23 in the radial direction than the fourth wall portion 43. In the above configuration, the first wall portion 42, the second wall portion 52, and the third wall portion 53 are disposed facing each other. Note that the above-mentioned facing each other includes not only that the first wall portion 42, the second wall portion 52, and the third wall portion 53 face each other parallel to each other, but also that they face each other non-parallel to each other, and that they face each other parallel or non-parallel to each other.

[0040] A metal third bracket 26 for accommodating a ball bearing 24 is fixed to the inner wall of the small diameter portion 20a of the main body case 20. A shaft 23 is inserted through a hole in the third bracket 26.

[0041] The second bracket 28 is connected to the first bracket 27 so as to cover the first bracket 27 from the outside. The second bracket 28 is formed in a substantially cylindrical shape with a bottom so as to hold the board 30 on which the electronic components 32 and various mounted components are provided. The second bracket 28 is connected to the first bracket 27 by, for example, press-fitting. In this case, the second bracket 28 is press-fitted into the first bracket 27 so that the outer periphery 28a of the second bracket 28 protruding toward the first bracket 27 contacts the outer periphery 27a of the first bracket 27. As a result, a second housing area R2 is formed, which is an area surrounded by the first bracket 27 and the second bracket 28. In this way, the second bracket 28 divides the second housing area R2 from the outside. In this embodiment, the second bracket 28 may be connected to the first bracket 27 by a fastener 29 such as a screw in addition to the press-fitting. In this case, the fastener 29 is disposed along the extending direction Ds of the shaft 23, and fastens the first bracket 27 and the second bracket 28 together to the case end portion 20c.

[0042] The substrate 30 is accommodated in the second accommodation area R2. Thus, the substrate 30 is arranged in the second accommodation area R2, which is isolated from the first accommodation area R1 in which the stator 21 and the rotor 22 are arranged. On the substrate 30, electronic components 32 for driving and controlling the stator 21 and the rotor 22 and various mounted components are provided. The electronic components 32 are, for example, power transistors. The substrate 30 is fixed to the inner wall of the second bracket 28 by fasteners 31, for example, screws.

[0043] The control circuit on the substrate 30 is electrically connected to the stator 21 or the control circuit of the air conditioner outside the main body case 20 via wires 33a, 33b. The first bracket 27 is provided with a hole H1 through which the wires 33a, 33b are inserted. The wires 33a, 33b are inserted into the hole H1. A seal portion 34 is provided in the hole H1. The seal portion 34 seals the gap between the wires 33a, 33b and the hole H1.

[0044] As described above, according to the motor 5 of the present embodiment, in the main body case 20, the stator 21 and the rotor 22 are accommodated in the first accommodation area R1, and the board 30 on which the electronic components 32 are provided is accommodated in the second accommodation area R2. The first bracket 27 separates the first accommodation area R1 from the second accommodation area R2. As a result, the second accommodation area R2 of the main body case 20 is isolated from the first accommodation area R1 by the first bracket 27. Therefore, even if a flammable refrigerant enters the first accommodation area R1 through a portion where the wiring 33a, 33b connected to the board 30 is pulled out from the main body case 20 to the outside, and through a gap between the main body case 20 and the ball bearings 24, 25 that rotatably fix the shaft 23 of the rotor 22, the flammable refrigerant is unlikely to enter the second accommodation area R2 from the first accommodation area R1. Therefore, it is possible to suppress or prevent the board 30 accommodated in the second accommodation area R2 from being exposed to the refrigerant. Therefore, the risk of the electronic components 32 on the board 30 becoming an ignition source and igniting the refrigerant can be reduced, thereby improving safety. In addition, by adopting the above configuration, a special seal structure is not required at the portion where the wiring 33a, 33b connected to the board 30 is drawn out from the main body case 20 to the outside, and between the main body case 20 and the ball bearings 24, 25 that rotatably fix the shaft 23 of the rotor 22.

[0045] The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the present disclosure. For example, the following modifications are possible.

[0046] In the above embodiment, a double seal structure consisting of the first seal portion 40 and the second seal portion 50 is adopted as a configuration for making it difficult for the coolant to enter the first accommodation region R1. However, in a configuration in which the substrate 30 is disposed in the second accommodation region R2 as in the above embodiment, it is not necessarily necessary to provide the first seal portion 40 and the second seal portion 50. However, by providing the first seal portion 40 and the second seal portion 50, the reliability of preventing the coolant from entering the main body case 20 can be further improved.

[0047] In addition, in the above embodiment, the first bracket 27 is provided, but the present invention is not limited to this. By employing a case end portion 20c in which the opening is closed, the first bracket 27 becomes unnecessary.

[0048] In the above embodiment, the substrate 30 is fixed to the inner wall of the second bracket 28 by the fastener 31. However, this is not limiting and the substrate 30 may be fixed to the first bracket 27.

[0049] Furthermore, in the above embodiment, the hole H1 of the first bracket 27 is provided with a seal 34. The gap between the wiring 33a, 33b and the hole H1 is sealed by the seal 34. However, if a drip-proof material is filled in the second housing area R2, the seal 34 can be eliminated. [Explanation of symbols]

[0050] 1. Air conditioner 5 Motor 7,8 Fan 20 Main unit case 21 Stator 22 Rotor 23 Shaft 27 First Bracket 28 Second Bracket 30 Substrate 32 Electronic Components 33a, 33b Wiring 34 Seal part 40 First seal part 41 First seal body 42 1st wall section 43 4th wall 50 Second seal part 51 Second seal body 52 2nd wall section 53 Third wall Ds Shaft extension direction H1 hole R1 First Containment Area R2 Second Containment Area

Claims

1. A motor for driving a fan in an air conditioner, A stator on which a coil is wound; a rotor having a shaft and rotatably disposed relative to the stator; a substrate on which electronic components for driving and controlling the stator and the rotor are provided; a main body case including a first housing area that houses the stator and the rotor such that a portion of the shaft is exposed to the outside, and a second housing area that houses the substrate; a first partition wall that partitions the first storage area and the second storage area.

2. The motor according to claim 1 , further comprising a second partition wall that separates the second accommodation area from an outside and is connected to the first partition wall.

3. The motor of claim 2 , wherein the second partition wall is connected to the first partition wall by a press fit.

4. The motor according to claim 1 , wherein the second housing area is filled with a drip-proof material.

5. Wiring is further provided to electrically connect the electronic component to the rotor or the stator, The motor according to claim 1 , wherein the first partition wall has a hole through which the wiring is inserted.

6. The motor according to claim 5 , further comprising a seal portion that seals a gap between the wiring and the hole.

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