Motor

Abstract

The invention provides a motor which is used for driving a fan of an air conditioner, and the motor comprises a stator; a rotor having a shaft, the rotor being disposed to be rotatable relative to the stator; a main body housing that accommodates the stator and accommodates the rotor such that a part of the shaft is exposed to the outside; an annular first sealing part which is arranged on the main body shell and seals the space between the shaft and the main body shell; and an annular second seal part which is provided on the shaft so as to be farther from the main body case than the first seal part in the direction of extension of the shaft, and which rotates together with the shaft, the first seal part having a first seal main body part intersecting the direction of extension of the shaft, and the second seal part having a second seal main body part intersecting the direction of extension of the shaft. The second seal body portion has a larger maximum dimension than the first seal body portion.

Description

Technical Field

[0001] The present invention relates to a motor for driving a fan in an air conditioner. Background Art

[0002] Conventionally, there are known sealing structures for a water pump motor and a motor installed in an engine room (Patent Documents 1 and 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-185055

[0006] Patent Document 2: Japanese Patent Application Publication No. 2003-348785 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] The sealed structure of the conventional motor is designed to prevent the intrusion of dust and the like, so it is difficult to prevent the intrusion of gas. For example, in an air conditioner using a flammable refrigerant, the motor is used to drive the fan of the heat exchanger. It is undesirable that the control circuit in the motor is exposed to the flammable refrigerant.

[0009] An object of the present invention is to provide a motor capable of suppressing or preventing the intrusion of a refrigerant used in an air conditioner.

[0010] A motor according to one embodiment of the present invention is used to drive a fan of an air conditioner, and the motor includes: a stator;

[0011] A rotor having an axis, the rotor being rotatable relative to the stator; a main body shell accommodating the stator and accommodating the rotor in a manner that a portion of the axis is exposed to the outside; an annular first sealing portion provided on the main body shell, the first sealing portion sealing between the axis and the main body shell; and an annular second sealing portion, which is provided on the axis in a manner that is farther away from the main body shell than the first sealing portion in the extension direction of the axis and rotates together with the axis, the first sealing portion having a first sealing main body portion intersecting the extension direction of the axis, the second sealing portion having a second sealing main body portion intersecting the extension direction of the axis, the second sealing main body portion having a maximum dimension larger than the first sealing main body portion.

[0012] The motor of one embodiment of the present invention adopts a dual structure including a first sealing part and a second sealing part arranged in a manner farther away from the main body shell than the first sealing part. In this dual structure, the second sealing body of the second sealing part intersects with the extension direction of the shaft and has a maximum size larger than the first sealing body. Even if the flammable refrigerant leaks from the heat exchanger of the air conditioner and reaches the motor, the flow rate of the refrigerant is attenuated due to the refrigerant hitting the second sealing body. As a result, it is difficult for the refrigerant with the attenuated flow rate to invade the interior of the main body shell from the gap between the first sealing body and the shaft. Therefore, it is possible to prevent the control circuit arranged in the main body shell from being exposed to the refrigerant.

[0013] It may also be that the first sealing portion has a first wall portion that intersects with the first sealing body portion and protrudes toward the second sealing portion, and the second sealing portion has: a second wall portion that intersects with the second sealing body portion, protrudes toward the first sealing portion, and is farther away from the axis than the first wall portion; and a third wall portion that intersects with the second sealing body portion, protrudes toward the first sealing portion, and is farther away from the axis than the second wall portion, and the first wall portion, the second wall portion, and the third wall portion are arranged relative to each other.

[0014] In the above structure, the first wall portion intersects with the first sealed main body portion, the second wall portion intersects with the second sealed main body portion, and the third wall portion intersects with the second sealed main body portion, and the first wall portion, the second wall portion, and the third wall portion are arranged relative to each other. The first wall portion, the second wall portion, and the third wall portion become obstacles on the intrusion path of the refrigerant between the second sealing portion and the first sealing portion. The intrusion path of the refrigerant includes a plurality of twists and turns. Therefore, it is more difficult for the refrigerant to invade the interior of the main shell.

[0015] It is also possible that the above-mentioned first sealing portion also has a fourth wall portion, which intersects with the above-mentioned first sealing main body portion and protrudes toward the above-mentioned main body shell at the outer edge of the above-mentioned first sealing main body portion, and the above-mentioned third wall portion has an end portion on the above-mentioned main body shell side, and the above-mentioned end portion of the above-mentioned third wall portion is located closer to the above-mentioned main body shell than the above-mentioned first sealing main body portion and is located farther from the above-mentioned axis than the above-mentioned fourth wall portion.

[0016] In the above structure, since the end of the third wall portion is located closer to the main shell than the first sealing main body portion and farther from the axis than the fourth wall portion, the possibility of refrigerant intrusion from between the first sealing portion and the second sealing portion can be further reduced, thereby further improving the reliability of suppressing the intrusion of refrigerant.

[0017] The material of the first sealing portion and the material of the second sealing portion may be chloroprene rubber.

[0018] In the above structure, the refrigerant is less likely to penetrate the first sealing portion and the second sealing portion. This can further improve the reliability of suppressing the intrusion of the refrigerant.

[0019] According to the present invention, it is possible to provide a motor capable of suppressing or preventing the intrusion of a refrigerant used in an air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing the overall structure of an air conditioner according to one embodiment.

[0021] Figure 2 This is the front view of the motor.

[0022] Figure 3 yes Figure 2 A cross-sectional view of the motor along line III-III.

[0023] Description of Reference Numerals

[0024] 1 Air conditioner

[0025] 5 Motor

[0026] 7.8 Fan

[0027] 20 Main body shell

[0028] 21 stator

[0029] 22 rotors

[0030] 23 Axis

[0031] 40 first sealing part

[0032] 41 first sealing body

[0033] 42 first wall portion

[0034] 43 Fourth wall

[0035] 50 second sealing portion

[0036] 51 second sealing body

[0037] 52 second wall portion

[0038] 53 Third wall

[0039] 53a End of the third wall portion

[0040] Ds is the extension direction of the axis. DETAILED DESCRIPTION

[0041] Hereinafter, a motor according to an embodiment of the present invention will be described with reference to the accompanying drawings. The motor described below is only one embodiment of the present invention. Therefore, the present invention is not limited to the following embodiments, and additions, deletions, and changes can be made within the scope of the present invention.

[0042] Figure 1 1 is a diagram showing the overall structure of an air conditioner 1 according to one embodiment. Figure 1 As shown, the air conditioner 1 includes: an outdoor heat exchanger 2 that discharges heat to the outside during cooling operation, an indoor heat exchanger 3 that absorbs heat from the outside air, and a circulation path 4 composed of these heat exchangers 2 and 3. Fans 7 and 8 driven by motors 5a and 5b are respectively provided near the outdoor heat exchanger 2 and the indoor heat exchanger 3. Hereinafter, the case described as motor 5 includes motors 5a and 5b. The airflow generated by the rotation drive of the fan 7 flows through the outdoor heat exchanger 2, and the airflow generated by the rotation drive of the fan 8 flows through the indoor heat exchanger 3.

[0043] In the following description, for the sake of convenience, the expressions "upstream" and "downstream" are used. These expressions are based on the refrigerant flowing in the circulation path 4 when the air conditioner 1 performs cooling operation, and are "upstream" and "downstream" of the refrigerant flow. Figure 1 The arrows marked on the circulation path 4 show the direction in which the refrigerant flows from "upstream" to "downstream" during cooling operation. In addition, the refrigerant flow during heating operation is opposite to the refrigerant flow during cooling operation, as shown by the dotted line.

[0044] exist Figure 1 In the embodiment, a refrigerant pipe 4a constituting a part of the circulation path 4 is provided in the indoor heat exchanger 3. A refrigerant pipe 4b is extended from the downstream end of the refrigerant pipe 4a and is connected to the indoor unit liquid side connection part 10 (the connection part on the downstream side during cooling operation). Another refrigerant pipe 4c is extended from the indoor unit liquid side connection part 10. The downstream end of the refrigerant pipe 4c is connected to the upstream end of the refrigerant pipe 4d via a two-way valve 11. The downstream end of the refrigerant pipe 4d is connected to the first port of the four-way valve 12. In the four-way valve 12, a refrigerant pipe 4e is extended from the second port connected to the first port during cooling operation. The downstream end of the refrigerant pipe 4e is connected to the compressor 13.

[0045] The compressor 13 compresses the low-temperature, low-pressure refrigerant from the indoor heat exchanger 3 to the outdoor heat exchanger 2 to increase its temperature and pressure during cooling operation, and compresses the low-temperature, low-pressure refrigerant from the outdoor heat exchanger 2 to the indoor heat exchanger 3 to increase its temperature and pressure during heating operation. In addition, a liquid storage tank is usually connected in front of the compressor 13 (upstream side) to perform gas-liquid separation of the refrigerant so that the liquid refrigerant does not return to the compressor 13, but this is not shown in the figure.

[0046] Another refrigerant pipe 4f is extended from the compressor 13. The downstream end of the refrigerant pipe 4f is connected to the third port of the four-way valve 12. In the four-way valve 12, a refrigerant pipe 4g is extended from the remaining fourth port that is connected to the third port during cooling operation. The downstream end of the refrigerant pipe 4g is connected to the upstream end of the refrigerant pipe 4h provided in the outdoor heat exchanger 2. Another refrigerant pipe 4i is extended from the downstream end of the refrigerant pipe 4h in the outdoor heat exchanger 2. The downstream end of the refrigerant pipe 4i is connected to the expansion valve 14. The expansion valve 14 reduces the pressure of the refrigerant from the outdoor heat exchanger 2 to the indoor heat exchanger 3 during cooling operation, and reduces the pressure of the refrigerant from the indoor heat exchanger 3 to the outdoor heat exchanger 2 during heating operation.

[0047] Another refrigerant pipe 4j is extended from the expansion valve 14. The downstream end of the refrigerant pipe 4j is connected to one port of the two-way valve 15. A refrigerant pipe 4k is extended from the other port of the two-way valve 15. The downstream end of the refrigerant pipe 4k is connected to the indoor unit connection portion 16 (the connection portion on the upstream side during cooling operation). Another refrigerant pipe 4m is extended from the indoor unit connection portion 16. The downstream end of the refrigerant pipe 4m is connected to the upstream end of the refrigerant pipe 4a in the indoor heat exchanger 3.

[0048] In this way, the circulation path 4 is formed by the refrigerant pipes 4a to 4k, 4m. The indoor heat exchanger 3, the four-way valve 12, the compressor 13, the outdoor heat exchanger 2, the expansion valve 14, etc. are connected through the circulation path 4. In addition, 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 refrigerant flow (that is, the four-way valve 12, the compressor 13, the outdoor heat exchanger 2 and the expansion valve 14). In addition, the indoor unit 1B of the air conditioner 1 is formed by the components from the indoor unit liquid side connection part 16 to the indoor unit liquid side connection part 10 along the refrigerant flow (that is, the indoor heat exchanger 3). In addition, the above-mentioned components themselves can adopt a known structure. In addition, the operation of such an air conditioner 1 when performing cooling operation and heating operation is well known, so its description is omitted.

[0049] Examples of the refrigerant (working refrigerant) in the air conditioner 1 include flammable refrigerants heavier than air, such as isobutane and propane. The refrigerant may be a single type of refrigerant or a mixed refrigerant of another type of refrigerant and a flammable refrigerant.

[0050] Next, the structure of the motor 5 in the air conditioner 1 will be described in detail. Figure 2 It is a front view of the motor 5. Figure 3 yes Figure 2 sectional view of motor 5 along line III-III.

[0051] In this embodiment, a brushless motor can be used as an example of the motor 5. Figure 3 As shown, the motor 5 includes a main body housing 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 circuit board 30 provided with electronic components 32, a first sealing portion 40, and a second sealing portion 50. A fan 7 (or fan 8) is installed at the front end of the shaft 23.

[0052] The stator 21 is formed by winding coils around the pole teeth of the stator core. The rotor 22 is fixed in a manner that a plurality of (e.g., 8) permanent magnets are opposite to the pole teeth of the stator 21, and is rotatably arranged relative to the stator 21 through ball bearings 24 and 25 described later. The motor 5 detects the magnetic pole position of the rotor 22 based on the voltage applied to the winding of the stator 21 and the current flowing. The shaft 23 is rotated around the axis by switching the coils through which the current flows based on the detection result. As a result, the fans 7 and 8 rotate.

[0053] In the main body shell 20, the stator 21 is integrally molded with resin, and the rotor 22 is housed in a manner that a portion of the shaft 23 is exposed to the outside. Such a main body shell 20 generally has three components. The main body shell 20 has a cylindrical small diameter portion 20a, a cylindrical large diameter portion 20b, and a cylindrical shell end portion 20c. The large diameter portion 20b is arranged at a position closer to the root end side of the shaft 23 than the small diameter portion 20a, and has a diameter in a direction orthogonal to the extension direction Ds of the shaft 23 than the small diameter portion 20a. In addition, the shell end portion 20c is arranged at a position closer to the root end side of the shaft 23 than the large diameter portion 20b, has an outer diameter substantially the same as that of the large diameter portion 20b, and has an inner diameter larger than that of the large diameter portion 20b.

[0054] The first bracket 27 is connected to the shell end 20c in a manner covering the opening of the shell end 20c. Thus, a first storage area R1, which is an area surrounded by the large diameter portion 20b of the main shell 20 and the first bracket 27, is formed. The stator 21 and the rotor 22 are stored in the first storage area R1. Alternatively, the first bracket 27 may be pressed into the shell end 20c. In this case, the outer edge portion of the bracket 27 becomes a double wall, and the shell end 20c is pressed between one wall and the other wall.

[0055] A bearing portion for accommodating a ball bearing 24 is provided in the small diameter portion 20a. A bearing portion for accommodating a ball bearing 25 is provided in a recess formed in the first bracket 27. The shaft 23 is provided rotatably around its axis through the ball bearings 24 and 25 of the main body case 20.

[0056] The material of the first sealing part 40 is, for example, chloroprene rubber. The first sealing part 40 is rotationally symmetrical about the axis of the shaft 23 and is formed in an annular shape. The first sealing part 40 is provided at the small diameter portion 20a of the main body shell 20 in a state where the shaft 23 is inserted through the first sealing part 40. The first sealing part 40 does not rotate together with the shaft 23.

[0057] The first sealing portion 40 includes a first sealing body portion 41, a first wall portion 42, and a fourth wall portion 43. The first sealing body portion 41 is formed into an annular shape (more specifically, a disc-shaped portion having a through hole) and is arranged in a manner orthogonal to the extension direction Ds of the shaft 23. The shaft 23 is inserted into the hole portion of the first sealing body portion 41. The first wall portion 42 is formed into an annular shape, intersecting the first sealing body portion 41 and protruding toward the second sealing portion 50. The first wall portion 42 has a root portion connected to the first sealing body portion 41 and a front end portion away from the first sealing body portion 41. The front end portion may have a larger diameter than the root end portion. The first wall portion 42 is connected to the inner edge of the first sealing body portion 41. The fourth wall portion 43 is formed into a cylindrical shape having an inner diameter substantially consistent with the outer diameter of the small diameter portion 20a, intersecting the first sealing body portion 41 and protruding toward the large diameter portion 20b of the main shell 20 at the outer edge of the first sealing body portion 41.

[0058] Next, the second sealing portion 50 is described. The material of the second sealing portion 50 can be the same as that of the first sealing portion 40, for example, chloroprene rubber. The second sealing portion 50 is rotationally symmetrical about the axis of the shaft 23 and is formed in an annular shape. The second sealing portion 50 is arranged on the shaft 23 in a manner that is farther away from the main body shell 20 than the first sealing portion 40 in the extension direction Ds of the shaft 23. Thus, the second sealing portion 50 rotates together with the shaft 23.

[0059] The second sealing portion 50 includes a second sealing body portion 51, a second wall portion 52, and a third wall portion 53. The second sealing body portion 51 is formed in an annular shape (more specifically, a disc shape having a through hole) and is arranged in a manner orthogonal to the extension direction Ds of the shaft 23. The second sealing body portion 51 has a maximum size larger than that of the first sealing body portion 41. Specifically, the maximum diameter of the second sealing body portion 51 is larger than the maximum diameter of the first sealing body portion 41. Therefore, the outer edge of the second sealing body portion 51 is located at a position farther from the shaft 23 in the radial direction than the outer edge of the first sealing body portion 41. The shaft 23 is installed in a state of being inserted into the hole portion of the second sealing body portion 51. The second wall portion 52 is formed in an annular shape, orthogonal to the second sealing body portion 51, and protrudes toward the first sealing portion 40. The second wall portion 52 is arranged at a position farther from the shaft 23 than the first wall portion 42 in a direction orthogonal to the extension direction Ds. The front end of the second wall portion 52 is arranged at a position closer to the main body shell 20 than the front end of the first wall portion 42 in the extension direction Ds of the shaft 23.

[0060] The third wall portion 53 is formed in an annular shape, intersecting the second sealing body portion 51, and protruding toward the first sealing portion 40 at the outer edge of the second sealing body portion 51. The third wall portion 53 is arranged at a position farther from the shaft 23 than the second wall portion 52 in a direction orthogonal to the extension direction Ds. In addition, the third wall portion 53 has an end 53a on the main body shell 20 side. The end 53a of the third wall portion 53 is located at a position closer to the main body shell 20 than the first sealing body portion 41 and farther from the shaft 23 in the radial direction outside than the fourth wall portion 43. In the above structure, the first wall portion 42, the second wall portion 52 and the third wall portion 53 are arranged opposite to each other. In addition, the above-mentioned opposite to each other includes not only the first wall portion 42, the second wall portion 52 and the third wall portion 53 being opposite to each other in parallel, but also being opposite to each other non-parallel, and being opposite to each other in parallel or non-parallel.

[0061] A third bracket 26 made of metal and accommodating a ball bearing 24 is fixed to the inner wall of the small diameter portion 20a of the main body case 20. The shaft 23 is inserted through a hole of the third bracket 26.

[0062] The second bracket 28 is connected to the first bracket 27 in a manner that covers the first bracket 27 from the outside. The second bracket 28 is formed into a substantially bottomed cylindrical shape in order to hold the circuit board 30 on which the electronic components 32 and various mounting components are provided. The second bracket 28 is connected to the first bracket 27, for example, by press-fitting. In this case, the second bracket 28 is pressed into the first bracket 27 in a manner that the outer peripheral edge 28a of the second bracket 28 protruding toward the first bracket 27 contacts the outer peripheral edge 27a of the first bracket 27. Thus, a second storage area R2, an area surrounded by the first bracket 27 and the second bracket 28, is formed. In this way, the second bracket 28 divides the second storage area R2 from the outside. In this embodiment, the second bracket 28 can also be connected to the first bracket 27 by a fixing member 29 such as a screw together with the above-mentioned press-fitting. In this case, the fixing member 29 is arranged along the extension direction Ds of the shaft 23, and the first bracket 27 and the second bracket 28 are fastened together to the shell end 20c.

[0063] The circuit board 30 is stored in the second storage area R2. In this way, the circuit board 30 is arranged in the second storage area R2 which is isolated from the first storage area R1 where the stator 21 and the rotor 22 are arranged. The circuit board 30 is provided with electronic components 32 for driving and controlling the stator 21 and the rotor 22, and various mounting components. The electronic components 32 are, for example, power transistors. The circuit board 30 is fixed to the inner wall of the second bracket 28 by fixing members 31 such as screws.

[0064] The electronic components 32 on the circuit board 30 are electrically connected to the stator 21 or the control circuit of the air conditioner outside the main body case 20 through the 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. The hole H1 is provided with a sealing portion 34. The gap between the wiring 33a, 33b and the hole H1 is sealed by the sealing portion 34.

[0065] As described above, the motor 5 of the present embodiment adopts a double structure including a first sealing portion 40 and a second sealing portion 50 disposed in a manner farther from the main body shell 20 than the first sealing portion 40. The second sealing portion 50 is disposed in a manner farther from the main body shell 20 than the first sealing portion 40. In this double structure, the second sealing body portion 51 of the second sealing portion 50 intersects with the extension direction Ds of the shaft 23 and has a maximum size larger than the first sealing body portion 41. Even if the flammable refrigerant leaks from the heat exchanger of the air conditioner and reaches the motor, the flow rate of the refrigerant is attenuated because the refrigerant hits the second sealing body portion 51. As a result, it is difficult for the refrigerant after the flow rate is attenuated to invade the interior of the main body shell 20 from the gap between the first sealing body portion 41 and the shaft 23. Therefore, it is possible to prevent the electronic components 32 disposed in the main body shell 20 from being exposed to the refrigerant.

[0066] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, the following modifications are possible.

[0067] In the above embodiment, in order to prevent the electronic components 32 on the circuit board 30 from being exposed to the refrigerant, the circuit board 30 is arranged in the second storage area R2, which is an area surrounded by the first bracket 27 and the second bracket 28. However, in the method of adopting the double sealing structure of the first sealing portion 40 and the second sealing portion 50 as in the above embodiment, it is not necessary to form the second storage area R2. In this case, it is also possible to arrange the circuit board 30 in the area surrounded by the main body shell 20 and the second bracket 28 without providing the first bracket 27. However, by arranging the circuit board 30 in the area surrounded by the first bracket 27 and the second bracket 28, that is, the second storage area R2, the reliability of preventing the circuit board 30 from being exposed to the refrigerant can be further improved.

[0068] In addition, in the above-mentioned embodiment, the first bracket 27 is provided, but the present invention is not limited thereto. By adopting the case end portion 20c with the opening closed, it is not necessary to provide the first bracket 27.

[0069] Furthermore, in the above embodiment, the circuit board 30 is fixed to the inner wall of the second bracket 28 by the fixing member 31 , but the present invention is not limited thereto and the circuit board 30 may be fixed to the first bracket 27 .

Claims

1. A motor for driving a fan of an air conditioner, wherein the motor comprises: stator; a rotor having a shaft, the rotor being arranged to be rotatable relative to the stator; a main body case that accommodates the stator and accommodates the rotor in a manner that a portion of the shaft is exposed to the outside; an annular first sealing portion provided on the main body shell, the first sealing portion sealing between the shaft and the main body shell; and an annular second seal portion, which is provided on the shaft so as to be farther from the main body shell than the first seal portion in the extending direction of the shaft and rotates together with the shaft, The first sealing portion includes a first sealing body portion intersecting with the extending direction of the axis. The second seal portion includes a second seal body portion intersecting with the extending direction of the axis, and the second seal body portion has a maximum dimension larger than that of the first seal body portion.

2. The motor according to claim 1, characterized in that: The first sealing portion includes a first wall portion intersecting the first sealing body portion and protruding toward the second sealing portion. The second sealing portion has a second wall portion and a third wall portion, wherein: The second wall portion intersects with the second sealing body portion and protrudes toward the first sealing portion and is farther from the axis than the first wall portion. The third wall portion intersects with the second sealing body portion and protrudes toward the first sealing portion, and is farther from the axis than the second wall portion. The first wall portion, the second wall portion, and the third wall portion are arranged to face each other.

3. The motor according to claim 2, characterized in that: The first sealing portion further includes a fourth wall portion, the fourth wall portion intersecting the first sealing main body portion and protruding toward the main body shell at the outer edge of the first sealing main body portion. The third wall portion has an end portion on the main body shell side, The end portion of the third wall portion is located closer to the main body case than the first seal main body portion and is located farther from the axis than the fourth wall portion.

4. The motor according to claim 1, characterized in that: The material of the first sealing part and the material of the second sealing part are chloroprene rubber.

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