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; a rotor that has a shaft and is provided rotatably with respect to the stator; a body case that houses the stator and houses the rotor with the shaft that is partly exposed to an outside; a first seal part in an annular shape that is provided on the body case to seal between the shaft and the body case; and a second seal part in an annular shape that is provided on the shaft to be further away from the body case in an extension direction of the shaft than the first seal part is and that rotates together with the shaft. The first seal part includes a first seal body that intersects with the extension direction of the shaft, and the second seal part includes a second seal body that intersects with the extension direction of the shaft and has a larger maximum dimension than a maximum dimension of the first seal body.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 of water pumps and motors provided in engine compartments are known (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-185055 A [Patent Document 2] JP 2003-348785 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, because the sealed structure of a conventional motor is intended to prevent the intrusion of dust, etc., when the sealed structure is applied to a motor that drives a fan of a heat exchanger in an air conditioner that uses a refrigerant, it is difficult to prevent the intrusion of the refrigerant. Because the refrigerant used in air conditioners is flammable, it is undesirable to expose the control circuit to the refrigerant.

[0005] In view of the above, an object of the present disclosure is to provide a motor that is capable of suppressing or preventing the intrusion of a refrigerant used in an air conditioner. [Means for solving the problem]

[0006] The motor disclosed herein is a motor for driving a fan in an air conditioner, and comprises a stator, a rotor having a shaft and arranged to be rotatable relative to the stator, a main body case in which the stator is housed and the rotor is housed so that a portion of the shaft is exposed to the outside, a first annular seal portion arranged on the main body case and sealing between the shaft and the main body case, and a second annular seal portion arranged on the shaft so as to be spaced apart in the extension direction of the shaft from the main body case more than the first seal portion and rotates together with the shaft, wherein the first seal portion has a first seal main body portion that intersects with the extension direction of the shaft, and the second seal portion has a second seal main body portion that intersects with the extension direction of the shaft and has a maximum dimension larger than that of the first seal main body portion.

[0007] In the present disclosure, a double structure is adopted, which is made up of a first seal portion and a second seal portion provided so as to be spaced apart from the main body case more than the first seal portion. In this double structure, the second seal body portion of the second seal portion intersects with the extension direction of the shaft and has a maximum dimension larger than that of the first seal body portion. Therefore, when a flammable refrigerant flows out of a heat exchanger of an air conditioner and leaks from a connection portion of a pipe, the refrigerant hits the second seal body portion and the flow rate of the refrigerant is reduced. As a result, the refrigerant whose flow rate is reduced is less likely to enter the inside of the main body case through the gap between the first seal body portion and the shaft. Therefore, it is possible to prevent a control circuit provided in the main body case from being exposed to the refrigerant.

[0008] In the above disclosure, the first seal portion has a first wall portion that intersects with the first seal main body portion and protrudes toward the second seal portion, and the second seal portion has a second wall portion that intersects with the second seal main body portion and protrudes toward the first seal portion and is farther away from the shaft than the first wall portion, and a third wall portion that intersects with the second seal main body portion and protrudes toward the first seal portion at an outer edge of the second seal main body portion and is farther away from the shaft than the second wall portion, and the first wall portion, the second wall portion, and the third wall portion may be arranged facing each other.

[0009] According to the above configuration, the first wall portion intersects with the first seal body portion, the second wall portion intersects with the second seal body portion, and the third wall portion intersects with the second seal body portion, and the first wall portion, the second wall portion, and the third wall portion are arranged facing each other. This makes it possible to provide obstacles (i.e., the first wall portion, the second wall portion, and the third wall portion) with which the refrigerant attempting to infiltrate from between the second seal portion and the first seal portion collides on the path between the second seal portion and the first seal portion. This makes it possible to bend the infiltration path of the refrigerant at multiple points. Therefore, it becomes more difficult for the refrigerant to infiltrate into the inside of the main body case.

[0010] In the above disclosure, the first seal portion may further have a fourth wall portion that intersects with the first seal main body portion and protrudes toward the main body case at the outer edge of the first seal main body portion, and the end of the third wall portion on the main body case side may be located closer to the main body case than the first seal main body portion and farther away from the shaft than the fourth wall portion.

[0011] According to the above configuration, the end of the third wall portion facing the main body case is located closer to the main body case than the first seal main body portion and farther from the shaft than the fourth wall portion, thereby further reducing the possibility of the refrigerant infiltrating between the first seal portion and the second seal portion, thereby further improving the reliability of preventing the refrigerant from infiltrating.

[0012] In the above disclosure, the first seal portion and the second seal portion may be made of chloroprene rubber.

[0013] According to the above configuration, the coolant is less likely to permeate through the first seal portion and the second seal portion, which can further improve the reliability of preventing the coolant from entering. Effect of the Invention

[0014] According to the present disclosure, it is possible to provide a motor used in an air conditioner that is capable of suppressing or preventing the intrusion of a refrigerant. [Brief description of the drawings]

[0015] [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

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The electronic components 32 on the substrate 30 are electrically connected to the stator 21 or the control circuit of the air conditioner outside the main body case 20 via wiring 33a, 33b. The first bracket 27 is provided with a hole H1 through which the wiring 33a, 33b is inserted. The wiring 33a, 33b is inserted into the hole H1. A seal portion 34 is provided in the hole H1. The seal portion 34 seals the gap between the wiring 33a, 33b and the hole H1.

[0040] As described above, according to the motor 5 of this embodiment, a double structure is adopted, which is made up of the first seal portion 40 and the second seal portion 50 that is provided so as to be spaced apart from the main body case 20 more than the first seal portion 40. In this double structure, the second seal body portion 51 of the second seal portion 50 intersects with the extension direction Ds of the shaft 23 and has a maximum dimension larger than that of the first seal body portion 41. Therefore, when a flammable refrigerant that has flowed out from the heat exchangers 2 and 3 of the air conditioner 1 leaks from a connection portion of a pipe or the like, the refrigerant hits the second seal body portion 51, and the flow rate of the refrigerant is reduced. As a result, the refrigerant whose flow rate is reduced is less likely to enter the inside of the main body case 20 through the gap between the first seal body portion 41 and the shaft 23. Therefore, it is possible to prevent the electronic components 32 provided in the main body case 20 from being exposed to the refrigerant.

[0041] 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.

[0042] In the above embodiment, in order to prevent the electronic components 32 on the board 30 from being exposed to the coolant, the board 30 is disposed in the second housing area R2, which is an area surrounded by the first bracket 27 and the second bracket 28. However, in the above embodiment, in a mode in which a double seal structure of the first seal portion 40 and the second seal portion 50 is adopted, it is not necessary to form the second housing area R2. In this case, the board 30 may be disposed in the area surrounded by the main body case 20 and the second bracket 28 without providing the first bracket 27. However, by disposing the board 30 in the second housing area R2, which is an area surrounded by the first bracket 27 and the second bracket 28, the reliability of preventing the board 30 from being exposed to the coolant can be further improved.

[0043] 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.

[0044] Furthermore, in the above embodiment, the substrate 30 is fixed to the inner wall of the second bracket 28 by the fastener 31, but this is not limited thereto, and the substrate 30 may be fixed to the first bracket 27. [Explanation of symbols]

[0045] 1. Air conditioner 5 Motor 7,8 Fan 20 Main unit case 21 Stator 22 Rotor 23 Shaft 40 First seal part 41 First seal body 42 1st wall 43 4th wall 50 Second seal part 51 Second seal body 52 2nd wall section 53 Third wall 53a End of third wall Ds Shaft extension direction

Claims

1. A motor for driving a fan in an air conditioner, A stator; a rotor having a shaft and rotatably disposed relative to the stator; a main body case in which the stator is housed and in which the rotor is housed such that a portion of the shaft is exposed to the outside; a first annular seal portion provided in the main body case for sealing between the shaft and the main body case; a ring-shaped second seal portion provided on the shaft so as to be spaced apart from the main body case in the extension direction of the shaft relative to the first seal portion and rotates together with the shaft, The first seal portion has a first seal body portion that intersects with an extension direction of the shaft, The motor has a second seal body portion that intersects with the extension direction of the shaft and has a maximum dimension larger than that of the first seal body portion.

2. the first seal portion has a first wall portion that intersects with the first seal body portion and protrudes toward the second seal portion; the second seal portion has a second wall portion that intersects with the second seal main body portion, protrudes toward the first seal portion, and is farther away from the shaft than the first wall portion; and a third wall portion that intersects with the second seal main body portion, protrudes toward the first seal portion at an outer edge of the second seal main body portion, and is farther away from the shaft than the second wall portion, The motor according to claim 1 , wherein the first wall portion, the second wall portion, and the third wall portion are disposed facing each other.

3. the first seal portion further includes a fourth wall portion that intersects with the first seal body portion and protrudes toward the main body case at an outer edge of the first seal body portion, 3. The motor according to claim 2, wherein an end of the third wall portion on the side of the main body case is located closer to the main body case than the first seal main body portion and farther from the shaft than the fourth wall portion.

4. 2. The motor according to claim 1, wherein the first seal portion and the second seal portion are made of chloroprene rubber.

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