Air supply device

Abstract

The present application provides a blower device having a pair of fan sections, a housing section, and a cover section. The pair of fan sections are coaxially arranged and generate an airflow to an axial side along a center axis. The housing section extends along the center axis to be cylindrical and houses the pair of fan sections, and both axial end surfaces of the housing section are open. The cover section covers and ventilates each of the axial one end surface and the axial other end surface of the housing section. The cover section has a ring-shaped ring section. The ring section is in contact with an inner peripheral surface of the housing section, and a through hole penetrating in a radial direction is formed. The housing section has a fitting protrusion protruding from the inner peripheral surface to an inner side in the radial direction and fitting with a periphery of the through hole.

Description

TECHNICAL FIELD

[0001] The present application relates to an air-blowing device. BACKGROUND

[0002] The conventional air-blowing device is formed with a casing which links a first divided casing unit and a second divided casing unit in the axial direction to surround a center axis. The first divided casing unit houses a first motor which rotates a first impeller around the center axis. The second divided casing unit houses a second motor which rotates a second impeller around the center axis. At this time, a first support frame body half which fixes the first motor and a second support frame body half which fixes the second motor are disposed in opposition to the axial center portion inside the casing.(For example, refer to Patent Literature 1)

[0003] Patent Literature 1: Japanese Patent No. 3904595

[0004] However, in the conventional air-blowing device, the structure of linking the first divided casing unit and the second divided casing unit is complicated, and the assembly workability can be lowered. In addition, in the conventional air-blowing device, the airflow inside the casing is disturbed due to the first support frame body half and the second support frame body half, and there is a possibility that the air-blowing efficiency is lowered. In addition, in the conventional air-blowing device, there is a possibility that the vibration of the first divided casing unit and the vibration of the second divided casing unit resonate and the vibration of the entire casing becomes large. SUMMARY

[0005] The first application aims at providing an air-blowing device which can improve the assembly workability. The second application aims at providing an air-blowing device which can improve the air-blowing efficiency. The third application aims at providing an air-blowing device which can lower the vibration.

[0006] The air supply device of the first invention includes a pair of fan sections, a housing section, and a cover section. The pair of fan sections are coaxially arranged and generate airflow to one side in the axial direction along a central axis. The housing section extends in the axial direction along the central axis to form a cylindrical shape, and houses the pair of fan sections. Axial end surfaces of the housing section are open. The cover sections cover the axial end surfaces of the housing section, respectively, and are ventilated. The cover section has a ring-shaped ring section. The ring section is in contact with an inner peripheral surface of the housing section and has a through-hole formed to pass through in the radial direction. The housing section has a fitting projection that protrudes from the inner peripheral surface to the inner side in the radial direction and is fitted to the periphery of the through-hole. The air supply device of the second invention includes a pair of fan sections, a housing section, and a cover section. The pair of fan sections are coaxially arranged and generate airflow to one side in the axial direction along a central axis. The housing section extends in the axial direction along the central axis to form a cylindrical shape, and houses the pair of fan sections. Axial end surfaces of the housing section are open. The cover sections cover the axial end surfaces of the housing section, respectively, and are ventilated. The pair of fan sections are fixed to the cover sections, respectively, and have a motor that rotates an impeller. The impeller has an impeller cylinder section, an impeller cover section, and a blade section. The impeller cylinder section is arranged to the outer side in the radial direction of the motor and extends in the axial direction. The impeller cover section covers an axial end surface of the impeller cylinder section on the side opposite to the side on which the motor is fixed. The blade section is arranged in the circumferential direction on the outer surface in the radial direction of the impeller cylinder section. The impeller cover sections of the pair of fan sections directly face each other in the axial direction. The air supply device of the third invention includes a pair of fan sections, a housing section, and a cover section. The pair of fan sections are coaxially arranged and generate airflow to one side in the axial direction along a central axis. The housing section extends in the axial direction along the central axis to form a cylindrical shape, and houses the pair of fan sections. Axial end surfaces of the housing section are open. The cover sections cover the axial end surfaces of the housing section, respectively, and are ventilated. The material that constitutes the cover section is different from the material that constitutes the housing section.

[0007] According to the invention of the first invention, it is possible to provide an air supply device that can improve the assembly workability. According to the second invention, it is possible to provide an air supply device that can improve the air supply efficiency. According to the third invention, it is possible to provide an air supply device that can reduce the vibration. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a perspective view of an air supply device according to an embodiment of the invention.

[0009] Figure 2 is an exploded perspective view of an air supply device according to an embodiment of the invention.

[0010] Figure 3 is a side view of an air supply device according to an embodiment of the invention.

[0011] Figure 4 is a longitudinal sectional perspective view of an air supply device according to an embodiment of the invention.

[0012] Figure 5 is an enlarged perspective view showing a part of the air-blowing device of the embodiment of the present application.

[0013] Figure 6 is an enlarged perspective view showing a part of the air-blowing device of the embodiment of the present application.

[0014] Figure 7 is a perspective view showing a cover portion of the air-blowing device of the embodiment of the present application.

[0015] Figure 8 is a perspective view showing a part of the air-blowing device of the embodiment of the present application.

[0016] Explanation of Reference Numerals

[0017] 1: air-blowing device; 2a, 2b: fan portion; 4: housing portion; 5a, 5b: cover portion; 21a, 21b: impeller; 22: motor; 23: circuit board; 41: suction port; 42: discharge port; 44: engagement protrusion; 45: guide portion; 46: flange portion; 47: notch portion; 48: notch recess; 49: step portion; 51: fixing portion; 52: linking portion; 53: ring-shaped portion; 211a, 211b: impeller cup; 212a, 212b: blade; 221: shaft; 222: bearing; 223: stator; 223a: bearing holding portion; 223b: stator core; 223c: insulating member; 224: rotor; 224a: rotor yoke; 224b: magnet; 461: mounting hole; 511: fitting hole; 512: ring-shaped rib; 531: through-hole; 532: protruding piece; 533: groove portion; 534: holding piece; 535: holding recess; 536: protruding portion; 537: engagement recess; 2111a, 2111b: impeller cover portion; 2112a, 2112b: impeller barrel portion; 2113a, 2113b: impeller protruding portion; 5321: inclined portion; J: center axis; XI: axial lower side (one axial side); X2: axial upper side (the other axial side). DETAILED DESCRIPTION

[0018] Hereinafter, an exemplary embodiment of the first application will be described in detail with reference to the drawings. In the present specification, the direction in which the center axis J of the air-blowing device 1 extends will be simply referred to as "axial direction", the direction perpendicular to the center axis J with the center axis J of the air-blowing device 1 as the center will be simply referred to as "radial direction", and the direction along the circular arc with the center axis J of the air-blowing device 1 as the center will be simply referred to as "circumferential direction". Also, the cross section parallel to the axial direction will be referred to as "longitudinal cross section". Note that "parallel" does not mean parallel in the strict sense, but includes substantially parallel.

[0019] Also, for convenience of explanation, the axial direction will be taken as the up-down direction, and the radial direction will be taken as the left-right direction. Figure 1The up-and-down direction in the drawing is the up-and-down direction of the air supply device 1, and the shape and positional relationship of each part are described with reference to the up-and-down direction. For example, the one side in the axial direction is the lower side or the lower side in the axial direction. The other side in the axial direction is the upper side or the upper side in the axial direction. In addition, the one end in the axial direction is the lower end, and the other end in the axial direction is the upper end. In addition, the one end surface in the axial direction is the lower end surface, and the other end surface in the axial direction is the upper end surface. The "upper side" of the air supply device 1 is the "suction side", and the "lower side" is the "exhaust side". In addition, the definition of the up-and-down direction does not limit the orientation and positional relationship of the air supply device 1 when in use.

[0020] <1. Overall structure of air supply device>

[0021] Figure 1 is an overall perspective view of an example of the air supply device 1 of the embodiment of the present application, Figure 2 is an exploded perspective view of the air supply device 1. The air supply device 1 has a pair of fan sections 2a, 2b, a housing section 4, and cover sections 5a, 5b.

[0022] The fan sections 2a, 2b generate an airflow to the axial lower side (one side in the axial direction) X1 along the central axis J, and the fan sections 2a, 2b are coaxially arranged. The fan section 2a is arranged on the suction side, and has an impeller 21a, a motor 22, and a circuit board 23. The fan section 2b is arranged on the exhaust side, and has an impeller 21b, a motor 22, and a circuit board 23. In addition, in the present embodiment, the structure of the motor 22 and the circuit board 23 is the same for the fan section 2a and the fan section 2b, and the same reference numerals are used for description.

[0023] The housing section 4 is formed in a cylindrical shape extending along the central axis J, and houses the pair of fan sections 2a, 2b, with both end surfaces in the axial direction being open. The housing section 4 has an air supply flow path inside for the airflow to pass through. The housing section 4 has an exhaust port 42 on the lower end surface (one end surface in the axial direction), and a suction port 41 on the upper end side (the other end surface in the axial direction).

[0024] The cover section 5a covers the suction port 41 (the other end surface in the axial direction) of the housing section 4 and is ventilated. The cover section 5b covers the exhaust port 42 (one end surface in the axial direction) of the housing section 4 and is ventilated. The fan section 2a is fixed to the cover section 5a, and the fan section 2b is fixed to the cover section 5b.

[0025] The cover sections 5a, 5b and the housing section 4 are resin molded products, and the material constituting the cover sections 5a, 5b is different from the material constituting the housing section 4. Specifically, the Young's modulus of the material constituting the cover sections 5a, 5b is higher than the Young's modulus of the material constituting the housing section 4. Thereby, it is possible to change the vibration frequency of the cover sections 5a, 5b and the vibration frequency of the housing section 4. Therefore, it is possible to reduce the case of resonance of the cover sections 5a, 5b and the housing section 4. Thereby, it is possible to reduce the vibration of the air supply device 1.

[0026] Specifically, in the case where polyphenylene sulfide or polybutylene terephthalate is used as the material constituting the cover portions 5a, 5b, polyphenylene oxide can be appropriately used as the material constituting the housing portion 4. In the case where polyphenylene sulfide is used as the material constituting the cover portions 5a, 5b, polybutylene terephthalate can be preferably used as the material constituting the housing portion 4. By using these materials, it is possible to further reduce the vibration of the air-blowing device 1 while maintaining the strength of the cover portions 5a, 5b and the housing portion 4.

[0027] <2-1. Structure of Impeller>

[0028] Figure 3 is a side view of the air-blowing device 1, in which Figure 3 the housing portion 4 is omitted. The impeller 21a is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The impeller 21b is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The direction of rotation of the impeller 21a is opposite to that of the impeller 21b. Alternatively, depending on the shape of the impellers 21a, 21b, the direction of rotation of the impeller 21a can be made the same as that of the impeller 21b.

[0029] The impeller 21a has an impeller cup 211a and a plurality of blades 212a. The impeller cup 211a is fixed to the motor 22. The impeller cup 211a has an impeller cylinder portion 2112a and an impeller cover portion 2111a. The impeller cylinder portion 2112a is disposed radially outward of the motor 22 of the fan portion 2a and extends in the axial direction. The impeller cover portion 2111a covers the lower end surface (axial one end surface) of the impeller cylinder portion 2112a. The plurality of blades 212a are arranged in the circumferential direction on the outer surface of the impeller cylinder portion 2112a.

[0030] The impeller 21b has an impeller cup 211b and a plurality of blades 212b. The impeller cup 211b is fixed to the motor 22. The impeller cup 211b has an impeller cylinder portion 2112b and an impeller cover portion 2111b. The impeller cylinder portion 2112b is disposed radially outward of the motor 22 of the fan portion 2b and extends in the axial direction. The impeller cover portion 2111b covers the upper end surface (axial other end surface) of the impeller cylinder portion 2112b. The plurality of blades 212b are arranged in the circumferential direction on the outer surface of the impeller cylinder portion 2112b.

[0031] The inclination angle of the blades 212a with respect to the central axis J when the impeller 21a disposed on the air intake side is spread in the circumferential direction is smaller than the inclination angle of the blades 212b with respect to the central axis J when the impeller 21b disposed on the air exhaust side is spread in the circumferential direction. Thereby, it is possible to make the air volume of the impeller 21a larger than that of the impeller 21b to efficiently perform air intake, and to further improve the air-blowing efficiency of the air-blowing device 1. In addition, the inclination angle refers to the installation angle of the blades 212a and 212b.

[0032] The impeller cover portion 2111a and the impeller cover portion 2111b are not provided with other components therebetween, but directly oppose each other in the axial direction. Thus, the impeller 21a and the impeller 21b are arranged close to each other in the axial direction, and the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be reduced. Thus, the air flow inside the housing portion 4 can be smoothly circulated. Therefore, the air supply efficiency in the housing portion 4 can be improved.

[0033] In addition, the impeller cover portion 2111a and the impeller cover portion 2111b are arranged in parallel with a surface perpendicular to the center axis J. Thus, the impeller cover portion 2111a and the impeller cover portion 2111b can be arranged closer to each other. Therefore, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced.

[0034] In addition, the impeller cover portion 2111a has a ring-shaped impeller protrusion portion 2113a (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the lower side (one side in the axial direction) XI of the axial direction. The impeller cover portion 2111b has a ring-shaped impeller protrusion portion 2113b (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the upper side (the other side in the axial direction) X2 of the axial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, at least one of the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be provided in the radial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be formed in a plurality in the circumferential direction. Figure 4 Figure 4 In addition, the impeller cover portion 2111a has a ring-shaped impeller protrusion portion 2113a (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the lower side (one side in the axial direction) XI of the axial direction. The impeller cover portion 2111b has a ring-shaped impeller protrusion portion 2113b (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the upper side (the other side in the axial direction) X2 of the axial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, at least one of the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be provided in the radial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be formed in a plurality in the circumferential direction.

[0035] In addition, the impeller cover portion 2111a has a ring-shaped impeller protrusion portion 2113a (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the lower side (one side in the axial direction) XI of the axial direction. The impeller cover portion 2111b has a ring-shaped impeller protrusion portion 2113b (refer to FIG. 6) arranged at the radially outer end portion and protruding toward the upper side (the other side in the axial direction) X2 of the axial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, at least one of the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be provided in the radial direction. Thus, the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b can be further reduced. In addition, the impeller protrusion portion 2113a and the impeller protrusion portion 2113b can be formed in a plurality in the circumferential direction.

[0036] ​Further, the outer peripheral surfaces of the impeller cylinder portions 2112a, 2112b are parallel to the axial direction, and the outer diameter of the impeller cylinder portion 2112a is the same size as the outer diameter of the impeller cylinder portion 2112b. Thus, the air flow can be smoothly circulated from the outer peripheral surface of the impeller cylinder portion 2112a to the outer peripheral surface of the impeller cylinder portion 2112b. Further, the outer peripheral surfaces of the impeller cylinder portions 2112a, 2112b can be parallel to the axial direction, and the outer diameter of the impeller cylinder portion 2112a can be different from the outer diameter of the impeller cylinder portion 2112b. Further, the outer peripheral surfaces of the impeller cylinder portions 2112a, 2112b can be formed in a conical frustum shape that inclines to the radial direction outside as they approach each other in the axial direction.

[0037] <2-2. Structure of the motor>

[0038] Figure 4 is a longitudinal sectional view of the air blowing device 1. A pair of motors 22 are fixed to the cover portions 5a, 5b, respectively. The motor 22 on the air suction side (the other side in the axial direction) X2 rotates the impeller 21a around the center axis J. The motor 22 on the air discharge side (one side in the axial direction) XI rotates the impeller 21b around the center axis J. The motor 22 has a shaft 221, a bearing 222, a stator 223, and a rotor 224.

[0039] The shaft 221 extends along the center axis J. The shaft 221 is, for example, composed of a metal such as stainless steel, and is a columnar member that extends in the axial direction.

[0040] The bearing 222 is composed of, for example, a ball bearing, but can be composed of a sleeve bearing or the like. The pair of bearings 222 support the shaft 221 so as to be rotatable around the center axis J with respect to the housing portion 4.

[0041] The stator 223 has a bearing holding portion 223a, a stator core 223b, an insulating member 223c, and a coil (not shown). The bearing holding portion 223a is formed in a cylindrical shape, and holds the bearing 222 inside.

[0042] The upper end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2a is fitted into the fitting hole 511 of the cover portion 5a. Thus, the bearing holding portion 223a is fixed to the cover portion 5a, and the fan portion 2a and the cover portion 5a are fixed. Further, the bearing holding portion 223a and the cover portion 5a can be integrally formed of a metal.

[0043] The lower end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2b is fitted into the fitting hole 511 of the cover portion 5b. Thus, the bearing holding portion 223a is fixed to the cover portion 5b, and the fan portion 2b and the cover portion 5b are fixed. Further, the bearing holding portion 223b and the cover portion 5b can be integrally formed of a metal.

[0044] The stator core 223b is configured, for example, by stacking electromagnetic steel sheets such as silicon steel sheets one on top of another. The insulating member 223c is configured of a resin having insulating properties. The insulating member 223c is provided so as to surround the outer surface of the stator core 223b. The coil (not shown) is configured of a wire wound around the stator core 223b with the insulating member 223c interposed therebetween.

[0045] The rotor 224 rotates relative to the stator 223 about the central axis J. The rotor 224 has a rotor yoke 224a and a magnet 224b.

[0046] The rotor yoke 224a is configured of a magnetic body, is a substantially cylindrical member having a cover on the inner side in the axial direction. The rotor yoke 224a of the fan portion 2a is fixed to the lower end portion (axial inner end portion) of the shaft 221. The rotor yoke 224a of the fan portion 2b is fixed to the upper end portion (axial inner end portion) of the shaft 221. The magnet 224b is cylindrical, is fixed to the inner peripheral surface of the rotor yoke 224a. The magnet 224b is disposed radially outward of the stator 223.

[0047] <2-3. Structure of Circuit Board>

[0048] The circuit board 23 of the fan portion 2a is disposed between the stator core 223b and the cover portion 5a, and the circuit board 23 of the fan portion 2b is disposed between the stator core 223b and the cover portion 5b. The circuit board 23 is, for example, a circular plate shape extending in the radial direction with the central axis J as the center. The circuit board 23 has an electrically connected lead wire of the coil (not shown) drawn therefrom. The circuit board 23 has an electronic circuit mounted thereon for supplying a driving current to the coil (not shown).

[0049] The outer diameter of the circuit board 23 is equal to or smaller than the outer diameter of the impeller cylinder portion 2112a, 2112b. Thus, the air flow inside the housing portion 4 can be made to flow more smoothly.

[0050] In the fan portions 2a, 2b having the above-described structure, if a driving current is supplied to the coil (not shown) of the motor 22 via the circuit board 23, a radial magnetic flux is generated in the stator core 223b. A magnetic field generated by the magnetic flux of the stator core 223b and a magnetic field generated by the magnet 224b act, and a torque is generated in the circumferential direction of the rotor 224. By this torque, the rotor 224 and the impellers 21a, 21b rotate with the central axis J as the center, respectively. When the impellers 21a, 21b rotate, an air flow is generated by the plurality of blades 212a, 212b. Thus, by the fan portions 2a, 2b, an air flow that takes the axial upper side (axial other side) X2 as a suction side and the axial lower side (axial one side) XI as a discharge side can be generated, and air can be blown.

[0051] <3. Structure of Cover Portion>

[0052] Figure 5 、 Figure 6is an exploded perspective view of the housing portion 4 and the cover portion 5a, Figure 5 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial upper side (axial other side) X2. Figure 6 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial lower side (axial one side) XI. Figure 7 is a perspective view of the cover portion 5a, and shows a state in which the cover portion 5a is viewed from the axial lower side (axial one side) XI.

[0053] The cover portion 5a and the cover portion 5b have a fixing portion 51, a linking portion 52, and a ring portion 53. In addition, in the present embodiment, the fixing portion 51, the linking portion 52, and the ring portion 53 of the cover portion 5a and the cover portion 5b have the same structure, and the same reference numerals are attached to describe them. The fixing portion 51 is disposed on the radially inner side of the ring portion 53.

[0054] The fixing portion 51 of the cover portion 5a is a circular plate shape that expands radially with the center axis J as the center, and is disposed on the axial upper side (axial other side) X2 of the fan portion 2a. The fixing portion 51 of the cover portion 5b is disposed on the axial lower side (axial one side) XI of the fan portion 2b, and is a circular plate shape that expands radially with the center axis J as the center.

[0055] The fixing portion 51 has an insertion hole 511 and a ring rib 512 (see FIG. 6). Figure 7 The insertion hole 511 is disposed on the center axis J, and penetrates the fixing portion 51 in the axial direction. The ring rib 512 of the cover portion 5a protrudes in the axial direction from the lower surface (axial one end surface) of the fixing portion 51, and surrounds the insertion hole 511. The ring rib 512 of the cover portion 5b protrudes in the axial direction from the upper surface (axial other end surface) of the fixing portion 51, and surrounds the insertion hole 511.

[0056] By providing the ring rib 512, the inner surface of the ring rib 512 is in contact with the bearing holding portion 223a in a state in which the bearing holding portion 223a is inserted into the insertion hole 511. Thus, the bearing holding portion 223a can be stably supported.

[0057] The fixing portion 51 of the cover portion 5a is formed such that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (axial one side) XI. Thus, the airflow that flows into the inside of the housing portion 4 from the air intake port 41 diffuses to the radially outer side along the peripheral surface of the fixing portion 51, and flows smoothly. Therefore, it is possible to further improve the air supply efficiency of the air supply device 1.

[0058] The linking portion 52 is disposed in a plurality of numbers in the circumferential direction, extends to the radially outer side from the fixing portion 51, and links the ring portion 53 and the fixing portion 51. The air that flows in the inside of the housing portion 4 passes through between adjacent linking portions 52.

[0059] The shape of the link portion 52 of the cover portion 5b (link portion disposed on the axial lower side (one axial side) XI) is different from the shape of the link portion 52 of the cover portion 5a (link portion disposed on the axial upper side (the other axial side) X2). Thus, by changing the shape of the link portion 52 on the air intake side and the shape of the link portion 52 on the air exhaust side, the link portion 52 functions as a stator vane, and it is possible to improve the air supply efficiency in the housing portion 4.

[0060] The link portion 52 of the cover portion 5a is formed so that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (one axial side) XI. Thus, the airflow flowing into the inside of the housing portion 4 from the air intake port 41 flows smoothly along the link portion 52. Therefore, it is possible to further improve the air supply efficiency of the air supply device 1.

[0061] In addition, the link portion 52 of the cover portion 5b is inclined toward the circumferential one side as it goes toward the axial lower side (one axial side) XI. Thus, the airflow flowing out to the outside of the housing portion 4 from the air exhaust port 42 flows smoothly along the link portion 52. Therefore, it is possible to further improve the air supply efficiency of the air supply device 1.

[0062] In addition, the inclination angle of the link portion 52 on the axial upper side (the other axial side) X2 with respect to the center axis J is smaller than the inclination angle of the link portion 52 on the axial lower side (one axial side) XI with respect to the center axis J, as viewed in the radial direction. Thus, it is possible to make the airflow flowing into the inside of the housing portion 4 from the air intake port 41 flow smoothly along the link portion 52. Therefore, it is possible to further improve the air supply efficiency of the air supply device 1. In addition, the circumferential outer surface of the link portion 52 of the cover portion 5a can also be formed to be parallel to the axial direction.

[0063] The annular portion 53 is formed in a ring shape, and the outer peripheral surface of the annular portion 53 is in contact with the inner peripheral surface of the housing portion 4. The annular portion 53 is formed with a through-hole 531 that penetrates in the radial direction. In addition, the annular portion 53 has a protruding piece 532, a groove portion 533, a retaining piece 534, a retaining recess 535, a protruding portion 536, an engagement recess 537, and a notch hole 538. The through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 are arranged in a row in the axial direction.

[0064] One set of the through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 is provided at four places at equal intervals in the circumferential direction. The protruding portion 536 is arranged between the through-holes 531 adjacent in the circumferential direction, and four places are provided at equal intervals in the circumferential direction. The retaining piece 534 and the retaining recess 535 are provided at one place.

[0065] The protruding piece 532 of the cover portion 5a protrudes from the lower surface of the annular portion 53 toward the axial lower side XI. The through-hole 531 and the protruding piece 532 are arranged adjacent in the axial direction.

[0066] The protruding piece 532 of the cover portion 5b protrudes from the upper surface of the annular portion 53 toward the axial upper side X2. That is, the protruding piece 532 of the cover portion 5a, 5b protrudes in the axial direction from the axial end surface facing the inner side of the housing portion 4.

[0067] In the present embodiment, the through-hole 531 is formed across a portion of the protruding piece 532. Alternatively, the through-hole 531 can be formed only in the annular portion 53 without crossing a portion of the protruding piece 532. Alternatively, instead of the through-hole 531, a recessed portion recessed from the radially outer surface of the annular portion 53 toward the radially inner side can be formed.

[0068] The protruding piece 532 has an inclined portion 5321. The inclined portion 5321 of the cover portion 5a is disposed at a position on the outer peripheral surface of the protruding piece 532 closer to the axial lower side (the side closer to the fan portion 2a, 2b in the axial direction) X1 than the through-hole 531, and is inclined toward the radially outer side as it goes toward the axial upper side (the axial outer side of the housing portion 4) X2.

[0069] The inclined portion 5321 of the cover portion 5b is disposed at a position on the outer peripheral surface of the protruding piece 532 closer to the axial upper side (the side closer to the fan portion 2a, 2b in the axial direction) X2 than the through-hole 531, and is inclined toward the radially outer side as it goes toward the axial lower side (the axial outer side of the housing portion 4) X1.

[0070] The groove portion 533 of the cover portion 5a is recessed from the outer peripheral surface toward the radially inner side at the lower end portion (the end portion facing the axial direction of the inner side of the housing portion 4) of the protruding piece 532 and extends in the axial direction.

[0071] The groove portion 533 of the cover portion 5b is recessed from the outer peripheral surface toward the radially inner side at the upper end portion (the end portion facing the axial direction of the inner side of the housing portion 4) of the protruding piece 532 and extends in the axial direction.

[0072] The engagement recessed portion 537 of the cover portion 5a is disposed on the axial upper side (the side farther from the fan portion 2a, 2b in the axial direction than the through-hole 531) X2 of the through-hole 531 and is recessed from the outer peripheral surface of the annular portion 53 toward the radially inner side.

[0073] The engagement recessed portion 537 of the cover portion 5b is disposed on the axial lower side (the side farther from the fan portion 2a, 2b in the axial direction than the through-hole 531) X1 of the through-hole 531 and is recessed from the outer peripheral surface of the annular portion 53 toward the radially inner side.

[0074] The retaining piece 534 protrudes from the outer peripheral surface of the annular portion 53 toward the radially outer side and extends in the circumferential direction. The retaining recessed portion 535 is disposed in opposition to the retaining piece 534 in the radial direction and is recessed from the outer peripheral surface of the annular portion 53 toward the radially inner side.

[0075] The notch hole 538 is disposed in opposition to the notch recess 48 of the housing portion 4 described later and the holding piece 534 in the radial direction. The notch hole 538 of the cover portion 5a is formed by being notched from an end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial upper side (axial direction) X2. The notch hole 538 of the cover portion 5b is formed by being notched from an end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial lower side (axial direction) XI.

[0076] The lead wire (not shown) connected to the circuit board 23 of the fan portion 2a and the lead wire (not shown) connected to the circuit board 23 of the fan portion 2b are respectively led out to the outside of the housing portion 4 via the notch hole 538. Thereby, it is possible to prevent the lead wires from contacting the impeller 21a or the impeller 21b. In addition, by reducing the lead wires passing through the inside of the housing portion 4, it is possible to make the air flow inside the housing portion 4 more smoothly.

[0077] In addition, the led-out lead wire is held between the holding piece 534 and the holding recess 535. Thereby, it is possible to hold the lead wire led out to the outside of the housing portion 4 along the outer peripheral surface of the housing portion 4. Therefore, the lead wire becomes easy to be routed, and the assembly workability of the air supply device 1 is further improved.

[0078] <4. Structure of housing portion>

[0079] The housing portion 4 has the engaging protrusions 44, the guide portions 45, the flange portions 46, the notch portions 47, the notch recesses 48, and the step portions 49 at the lower end portion (axial one end portion) and the upper end portion (axial other end portion), respectively. The engaging protrusions 44, the guide portions 45, and the notch portions 47 are arranged in a line in the axial direction. One set of the engaging protrusions 44, the guide portions 45, and the notch portions 47 are each provided at four places at the upper end portion and the lower end portion of the housing portion 4 at equal intervals in the circumferential direction. The notch recesses 48 are arranged in the middle of the circumferentially adjacent engaging protrusions 44, and are each provided at four places at the upper end portion and the lower end portion of the housing portion 4 at equal intervals in the circumferential direction.

[0080] The inner peripheral surfaces of the step portions 49 are recessed toward the radial direction outer side at the both axial end portions of the housing portion 4, respectively. The step portions 49 are in contact with the annular portion 53 in the axial direction. By providing the step portions 49, the inner peripheral surface of the annular portion 53 and the inner peripheral surface of the housing portion 4 are formed as the same plane. Thereby, it is possible to make the air flow inside the housing portion 4 more smoothly.

[0081] The engaging protrusions 44 protrude toward the radial direction inner side from the inner peripheral surfaces of the both axial end portions of the housing portion 4, respectively. The engaging protrusions 44 engage with the periphery of the through hole 531 of the cover portion 5a at the upper end portion of the housing portion 4. The engaging protrusions 44 engage with the periphery of the through hole 531 of the cover portion 5b at the lower end portion of the housing portion 4.

[0082] The guide portion 45 is provided at the axially outer end portion. The guide portion 45 is provided at the upper end portion (axially other end portion) of the housing portion 4 at a position axially upward (axially outer side) X2 from the engaging protrusion 44. The guide portion 45 is provided at the lower end portion (axially one end portion) of the housing portion 4 at a position axially downward (axially outer side) XI from the engaging protrusion 44. The guide portion 45 protrudes from the inner peripheral surface of the housing portion 4 toward the radially inner side and extends in the axial direction.

[0083] The notch portion 47 is provided at the upper end portion (axially other end portion) of the housing portion 4 at a position axially downward (axially inner side) XI from the engaging protrusion 44, and the step portion 49 is formed to be recessed toward the axially downward (axially inner side) XI. In addition, the notch portion 47 is provided at the lower end portion (axially one end portion) of the housing portion 4 at a position axially upward (axially inner side) X2 from the engaging protrusion 44, and the step portion 49 is formed to be recessed toward the axially upward (axially inner side) X2.

[0084] The flange portion 46 is formed with a mounting hole 461 that protrudes from the axially outer end portion of the housing portion 4 toward the radially outer side and extends in the axial direction. The air blowing device 1 is screwed to other equipment via the mounting hole 461. The flange portion 46 is opposed to the engaging protrusion 44 in the radial direction, and four are provided at the upper end portion and the lower end portion of the housing portion 4, respectively. The engaging protrusion 44 and the guide portion 45 are adjacent to the mounting hole 461 in the radial direction. Thus, the periphery of the mounting hole 461 can be formed to be thick-walled.

[0085] The notch recessed portion 48 is provided at four at the upper end portion and the lower end portion of the housing portion 4, respectively. The notch recessed portion 48 is formed to be recessed from the axially upper end surface (axially other end surface) toward the axially downward (axially one side) XI at the upper end portion of the housing portion 4. In addition, the notch recessed portion 48 is formed to be recessed from the axially lower end surface (axially one end surface) toward the axially upward (axially other side) X2 at the lower end portion of the housing portion 4.

[0086] <5. Structure of the housing portion and the cover portion>

[0087] Figure 8 is a perspective view that enlarges a part of the upper end portion of the air blowing device 1. The cover portion 5a is attached to the housing portion 4 in a state where the fan portion 2a is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5a is inserted toward the axially downward (axially one side) XI.

[0088] The cover portion 5b is attached to the housing portion 4 in a state where the fan portion 2b is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5b is inserted toward the axially upward (axially other side) X2.

[0089] At this time, the guide portion 45 slides along the groove portion 533. Thus, the positioning of the circumferential direction of the cover portions 5a, 5b becomes easy, and the cover portions 5a, 5b can be smoothly inserted into the axially inner side.

[0090] When the engagement protrusion 44 is in contact with the inclined portion 5321, the protruding piece 532 is bent to the radial inner side, and further the cover portions 5a, 5b are inserted to the axial inner side, thereby the engagement protrusion 44 is inserted into the through hole 531. Thus, the engagement protrusion 44 is engaged with the periphery of the through hole 531, and the protruding piece 532 presses the inner peripheral surface of the housing portion 4 to the radial outer side. Thus, the cover portions 5a, 5b are firmly fixed to the housing portion 4. Therefore, the assembly workability of the cover portions 5a, 5b and the housing portion 4 can be improved.

[0091] At this time, by providing the inclined portion 5321, the protruding piece 532 is easily moved along the guide portion 45. Therefore, the assembly workability of the cover portions 5a and the housing portion 4 can be further improved.

[0092] Further, in the state where the engagement protrusion 44 is engaged with the periphery of the through hole 531, the protruding piece 532 is inserted into the notch portion 47. Further, the protruding portion 536 is inserted into the notch recessed portion 48. Further, the guide portion 45 is inserted into the engagement recessed portion 537. Further, the annular portion 53 is in contact with the step portion 49 in the axial direction. Further, the engaged one set of the through hole 531 and the engagement protrusion 44 are provided with a plurality of portions at substantially equal intervals in the circumferential direction. Thus, the housing portion 4 and the cover portions 5a are more firmly fixed in the axial direction and the circumferential direction.

[0093] Further, a gap can be locally formed between the outer peripheral surface of the annular portion 53 and the inner peripheral surface of the housing portion 4. Thus, the vibration transmitted from the cover portions 5a, 5b to the housing portion 4 can be reduced.

[0094] <5. Other>

[0095] The above describes the embodiments of the present application, but the scope of the present application is not limited to this, and various modifications can be made within the scope of the gist of the present application. Further, the above-described embodiments and the modified examples thereof can be appropriately combined arbitrarily.

[0096] In the present embodiment, the one set of the through hole 531, the protruding piece 532, the groove portion 533, and the engagement recessed portion 537 and the one set of the engagement protrusion 44, the guide portion 45, and the notch portion 47 are respectively provided with four portions at equal intervals in the circumferential direction, but can be provided with two portions, three portions, or five or more portions.

[0097] Further, the engagement protrusion 44 and the guide portion 45 are arranged adjacent to the mounting hole 461 in the radial direction, but the engagement protrusion 44 and the guide portion 45 can be arranged at positions different from the mounting hole 461 in the circumferential direction. Further, the engagement protrusion 44 can be arranged at a position different from the guide portion 45 in the circumferential direction.

[0098] Alternatively, the housing portion 4 can be configured such that its diameter decreases as it moves toward the axially downward side (one axial side). This allows the airflow inside the housing portion 4 to flow smoothly toward the exhaust side.

[0099] Hereinafter, exemplary embodiments of the second invention will be described in detail with reference to the accompanying drawings. In this specification, the direction in which the central axis J of the air supply device 1 extends is simply referred to as the "axial direction," the direction perpendicular to the central axis J of the air supply device 1 with the central axis J as its center is simply referred to as the "radial direction," and the direction along an arc centered on the central axis J of the air supply device 1 is simply referred to as the "circumferential direction." Furthermore, a section parallel to the axial direction is referred to as a "longitudinal section." Additionally, "parallel" does not strictly mean parallel, but includes approximately parallel.

[0100] Additionally, for ease of explanation, the axis is set as the vertical direction. Figure 1 The shape and positional relationship of each part are described using the vertical direction of the air supply device 1. For example, one axial side is designated as the lower axial side or lower side, and the other axial side is designated as the upper axial side or upper side. Additionally, one axial end is designated as the lower end, and the other axial end as the upper end. Furthermore, one axial end face is designated as the lower end face, and the other axial end face as the upper end face. The "upper side" of the air supply device 1 refers to the "intake side," and the "lower side" refers to the "exhaust side." However, this definition of the vertical direction does not limit the orientation or positional relationship of the air supply device 1 during use.

[0101] <1. Overall Structure of the Air Supply Device>

[0102] Figure 1 This is an overall perspective view of an example of the air supply device 1 according to an embodiment of the present invention. Figure 2 This is an exploded perspective view of the air supply device 1. The air supply device 1 has a pair of fan parts 2a and 2b, a housing part 4, and cover parts 5a and 5b.

[0103] Fan units 2a and 2b generate airflow axially downward (on one side of the axis) X1 along the central axis J, and are coaxially arranged. Fan unit 2a is located on the intake side and includes an impeller 21a, a motor 22, and a circuit board 23. Fan unit 2b is located on the exhaust side and includes an impeller 21b, a motor 22, and a circuit board 23. Furthermore, in this embodiment, the structures of the motor 22 and the circuit board 23 are identical for both fan units 2a and 2b, and are described using the same reference numerals.

[0104] The housing portion 4 extends along the central axis J and is formed into a cylindrical shape, housing a pair of fan portions 2a and 2b, with openings at both axial ends. The housing portion 4 has an airflow path inside for airflow. The housing portion 4 has an exhaust port 42 on the lower end face (one axial end face) and an intake port 41 on the upper end face (the other axial end face).

[0105] The lid portion 5a covers the air intake port 41 (axial other end surface) of the housing portion 4 and performs ventilation. The lid portion 5b covers the air exhaust port 42 (axial one end surface) of the housing portion 4 and performs ventilation. The fan portion 2a is fixed to the lid portion 5a, and the fan portion 2b is fixed to the lid portion 5b.

[0106] The lid portions 5a and 5b and the housing portion 4 are resin molded products, and the material that constitutes the lid portions 5a and 5b is different from the material that constitutes the housing portion 4. Specifically, the Young's modulus of the material that constitutes the lid portions 5a and 5b is higher than the Young's modulus of the material that constitutes the housing portion 4. Thereby, it is possible to change the vibration frequency of the lid portions 5a and 5b and the vibration frequency of the housing portion 4. Therefore, it is possible to reduce the case where the lid portions 5a and 5b and the housing portion 4 resonate. Thereby, it is possible to reduce the vibration of the air supply device 1.

[0107] Specifically, in the case where polyphenylene sulfide or polybutylene terephthalate is used as the material that constitutes the lid portions 5a and 5b, as the material that constitutes the housing portion 4, it is possible to appropriately use polyphenylene oxide. In addition, in the case where polyphenylene sulfide is used as the material that constitutes the lid portions 5a and 5b, as the material that constitutes the housing portion 4, it is possible to preferably use polybutylene terephthalate. By using these materials, it is possible to further reduce the vibration of the air supply device 1 while maintaining the strength of the lid portions 5a and 5b and the housing portion 4.

[0108] <2-1. Structure of Impeller>

[0109] Figure 3 is a side view of the air supply device 1, and Figure 3 the housing portion 4 is omitted in FIG. 1. The impeller 21a is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The impeller 21b is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The rotation direction of the impeller 21a is opposite to the rotation direction of the impeller 21b. In addition, depending on the shape of the impellers 21a and 21b, the rotation direction of the impeller 21a and the rotation direction of the impeller 21b can be made in the same direction.

[0110] The impeller 21a has an impeller cup 211a and a plurality of blades 212a. The impeller cup 211a is fixed to the motor 22. The impeller cup 211a has an impeller cylinder portion 2112a and an impeller lid portion 2111a. The impeller cylinder portion 2112a is disposed radially outward of the motor 22 of the fan portion 2a and extends in the axial direction. The impeller lid portion 2111a covers the lower end surface (axial one end surface) of the impeller cylinder portion 2112a. The plurality of blades 212a are arranged in the circumferential direction on the outer surface of the impeller cylinder portion 2112a.

[0111] Impeller 21b has an impeller cup 211b and multiple blades 212b. Impeller cup 211b is fixed to motor 22. Impeller cup 211b has an impeller cylinder portion 2112b and an impeller cover portion 2111b. Impeller cylinder portion 2112b is disposed radially outside of motor 22 of fan portion 2b and extends axially. Impeller cover portion 2111b covers the upper end face (the other end face axially) of impeller cylinder portion 2112b. Multiple blades 212b are arranged circumferentially on the outer surface of impeller cylinder portion 2112b.

[0112] When the impeller 21a on the intake side is circumferentially deployed, the tilt angle of its blades 212a relative to the central axis J is smaller than the tilt angle of its blades 212b relative to the central axis J when the impeller 21b on the exhaust side is circumferentially deployed. This allows for more efficient air intake by ensuring that the airflow from impeller 21a is greater than that from impeller 21b, further improving the air delivery efficiency of the air supply device 1. The tilt angle refers to the installation angle of blades 212a and 212b.

[0113] Impeller cover portions 2111a and 2111b are directly opposite each other in the axial direction without any other components between them. This axial proximity of the impellers 21a and 21b reduces the gap between them, allowing airflow to enter smoothly. This, in turn, improves the airflow efficiency within the housing 4.

[0114] Furthermore, impeller cover portions 2111a and 2111b are arranged parallel to a plane perpendicular to the central axis J. This allows the impeller cover portions 2111a and 2111b to be arranged closer together. Consequently, the gap between the impeller cover portions 2111a and 2111b can be further reduced.

[0115] Additionally, the impeller cover portion 2111a has an annular impeller protrusion 2113a disposed at the radially outer end and protruding axially downward (on one axial side) X1 (see reference). Figure 4 The impeller cover portion 2111b has an annular impeller protrusion 2113b disposed at the radially outer end and protruding axially upward (to the other axial side) X2 (see reference). Figure 4 This further reduces the gap between the impeller cover portion 2111a and the impeller cover portion 2111b. Alternatively, at least one of the multiple impeller protrusions 2113a and 2113b can be provided radially. This further reduces the gap between the impeller cover portion 2111a and the impeller cover portion 2111b. Furthermore, multiple impeller protrusions 2113a and 2113b can be formed discontinuously in the circumferential direction.

[0116] Further, the impeller protruding portion 2113a and the impeller protruding portion 2113b are opposed in the axial direction and extend in parallel with the axial direction. Thus, it is possible to suppress turbulence of the air flow passing along the impeller protruding portion 2113a and the impeller protruding portion 2113b. In addition, the impeller protruding portion 2113a and the impeller protruding portion 2113b can also be arranged in the radial direction with a deviation. In this case, it is preferable that the tip end of one of the impeller protruding portion 2113a and the impeller protruding portion 2113b extend to a position on the base side further than the tip end of the other. Thus, it is possible to further reduce the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b.

[0117] Further, the outer peripheral surfaces of the impeller cylinder portions 2112a, 2112b are parallel with the axial direction, and the outer diameter of the impeller cylinder portion 2112a and the outer diameter of the impeller cylinder portion 2112b are the same size. Thus, it is possible to smoothly pass the air flow from the outer peripheral surface of the impeller cylinder portion 2112a to the outer peripheral surface of the impeller cylinder portion 2112b. In addition, the outer peripheral surfaces of the impeller cylinder portions 2112a, 2112b can also be parallel with the axial direction, and the outer diameter of the impeller cylinder portion 2112a and the outer diameter of the impeller cylinder portion 2112b can be different sizes. In addition, the outer peripheral surface of the impeller cylinder portion 2112a and the outer peripheral surface of the impeller cylinder portion 2112b can also be formed in a conical frustum shape that inclines to the radial direction outside as they approach each other in the axial direction.

[0118] <2-2. Structure of the motor>

[0119] Figure 4 Fig. 1 is a longitudinal sectional view of the air blowing device 1. A pair of motors 22 are fixed to the cover portions 5a, 5b, respectively. The motor 22 on the air suction side (the other side in the axial direction) X2 rotates the impeller 21a about the center axis J. The motor 22 on the air discharge side (one side in the axial direction) XI rotates the impeller 21b about the center axis J. The motor 22 has a shaft 221, a bearing 222, a stator 223, and a rotor 224.

[0120] The shaft 221 extends along the center axis J. The shaft 221 is, for example, composed of a metal such as stainless steel, and is a columnar member extending in the axial direction.

[0121] The bearing 222 is composed of, for example, a ball bearing, but can also be composed of a sleeve bearing or the like. The pair of bearings 222 are arranged at least in opposition in the axial direction. The pair of bearings 222 support the shaft 221 so as to be rotatable about the center axis J with respect to the housing portion 4.

[0122] The stator 223 has a bearing holding portion 223a, a stator core 223b, an insulating member 223c, and a coil (not shown). The bearing holding portion 223a is formed in a cylindrical shape, and holds the bearing 222 inside.

[0123] The upper end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2a is fitted into the fitting hole 511 of the cover portion 5a. Thereby, the bearing holding portion 223a is fixed to the cover portion 5a, and the fan portion 2a and the cover portion 5a are fixed. In addition, the bearing holding portion 223a and the cover portion 5a can also be integrally formed of metal.

[0124] The lower end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2b is fitted into the fitting hole 511 of the cover portion 5b. Thereby, the bearing holding portion 223a is fixed to the cover portion 5b, and the fan portion 2b and the cover portion 5b are fixed. In addition, the bearing holding portion 223b and the cover portion 5b can also be integrally formed of metal.

[0125] The stator core 223b is configured, for example, by stacking electromagnetic steel sheets such as silicon steel sheets up and down. The insulating member 223c is configured of a resin having insulating properties. The insulating member 223c is provided in a manner of surrounding the outer surface of the stator core 223b. The coil (not shown) is configured of a wire wound around the stator core 223b with the insulating member 223c interposed.

[0126] The rotor 224 rotates with respect to the stator 223 about the center axis J. The rotor 224 has a rotor yoke 224a and a magnet 224b.

[0127] The rotor yoke 224a is configured of a magnetic body, and is a substantially cylindrical member having a cover on the axial inner side. The rotor yoke 224a of the fan portion 2a is fixed to the lower end portion (axial inner end portion) of the shaft 221. The rotor yoke 224a of the fan portion 2b is fixed to the upper end portion (axial inner end portion) of the shaft 221. The magnet 224b is cylindrical, and is fixed to the inner peripheral surface of the rotor yoke 224a. The magnet 224b is disposed radially outward of the stator 223.

[0128] <2-3. Structure of Circuit Board>

[0129] The circuit board 23 of the fan portion 2a is disposed between the stator core 223b and the cover portion 5a, and the circuit board 23 of the fan portion 2b is disposed between the stator core 223b and the cover portion 5b. The circuit board 23 is, for example, a circular plate shape extending radially with the center axis J as the center. The lead wire of the coil (not shown) is electrically connected to the circuit board 23. An electronic circuit for supplying a driving current to the coil (not shown) is mounted on the circuit board 23.

[0130] The outer diameter of the circuit board 23 is equal to or smaller than the outer diameter of the impeller cylinder portion 2112a, 2112b. Thereby, the airflow inside the housing portion 4 can be made to flow more smoothly.

[0131] In the fan portion 2a, 2b of the above structure, if a driving current is supplied to the coil (not shown) of the motor 22 via the circuit board 23, a radial magnetic flux is generated in the stator core 223b. A magnetic field generated by the magnetic flux of the stator core 223b and a magnetic field generated by the magnet 224b act, and a torque is generated in the circumferential direction of the rotor 224. By this torque, the rotor 224 and the impeller 21a, 21b are rotated about the center axis J, respectively. When the impeller 21a, 21b is rotated, an air flow is generated by the plurality of blades 212a, 212b. Thus, by the fan portion 2a, 2b, an air flow that takes the axial upper side (axial other side) X2 as a suction side and the axial lower side (axial one side) XI as a discharge side is generated, and air supply is performed.

[0132] <3. Structure of the cover portion>

[0133] Figure 5 Figure 6 is an exploded perspective view of the housing portion 4 and the cover portion 5a, Figure 5 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial upper side (axial other side) X2. Figure 6 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial lower side (axial one side) XI. Figure 7 is a perspective view of the cover portion 5a, showing a state in which the cover portion 5a is viewed from the axial lower side (axial one side) XI.

[0134] The cover portion 5a and the cover portion 5b have a fixing portion 51, a linking portion 52, and a ring-shaped portion 53. In the present embodiment, the fixing portion 51, the linking portion 52, and the ring-shaped portion 53 of the cover portion 5a and the cover portion 5b have the same structure, and the same reference numerals are attached to describe them. The fixing portion 51 is disposed on the radially inner side of the ring-shaped portion 53.

[0135] The fixing portion 51 of the cover portion 5a is a circular plate shape that is disposed on the axial upper side (axial other side) X2 of the fan portion 2a and that extends in the radial direction about the center axis J. The fixing portion 51 of the cover portion 5b is disposed on the axial lower side (axial one side) XI of the fan portion 2b and is a circular plate shape that extends in the radial direction about the center axis J.

[0136] The fixing portion 51 has an insertion hole 511 and a ring-shaped rib 512 (see FIG. 6). Figure 7 The insertion hole 511 is disposed on the center axis J and penetrates the fixing portion 51 in the axial direction. The ring-shaped rib 512 of the cover portion 5a protrudes in the axial direction from the lower surface (axial one end surface) of the fixing portion 51 and surrounds the insertion hole 511. The ring-shaped rib 512 of the cover portion 5b protrudes in the axial direction from the upper surface (axial other end surface) of the fixing portion 51 and surrounds the insertion hole 511.

[0137] ​By providing the annular rib 512, the inner surface of the annular rib 512 is in contact with the bearing holding portion 223a in a state where the bearing holding portion 223a is fitted into the fitting hole 511. Thus, the bearing holding portion 223a can be stably supported.

[0138] The fixing portion 51 of the cover portion 5a is formed so that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 diffuses toward the radial outer side along the peripheral surface of the fixing portion 51 and flows smoothly. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0139] The linking portions 52 extend toward the radial outer side from the fixing portion 51 and are arranged in a plurality in the circumferential direction, and link the annular portion 53 and the fixing portion 51. The air flowing in the inside of the housing portion 4 passes between the adjacent linking portions 52.

[0140] The linking portions 52 (linking portions arranged on the axial lower side (axial one side) X1) of the cover portion 5b are different in shape from the linking portions 52 (linking portions arranged on the axial upper side (axial other side) X2) of the cover portion 5a. Thus, by changing the shape of the linking portions 52 on the air inlet side and the shape of the linking portions 52 on the air outlet side, the linking portions 52 function as a stator vane, and the air supply efficiency in the housing portion 4 can be improved.

[0141] The linking portions 52 of the cover portion 5a are formed so that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 flows smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0142] In addition, the linking portions 52 of the cover portion 5b are inclined toward the circumferential one side as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing out to the outside of the housing portion 4 from the air outlet 42 flows smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0143] In addition, the inclination angle of the linking portions 52 on the axial upper side (axial other side) X2 with respect to the center axis J is smaller than the inclination angle of the linking portions 52 on the axial lower side (axial one side) X1 with respect to the center axis J, as viewed in the radial direction. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 can flow smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved. In addition, the circumferential outer surface of the linking portions 52 of the cover portion 5a can also be formed to be parallel to the axial direction.

[0144] The annular portion 53 is formed in an annular shape, and an outer peripheral surface of the annular portion 53 is in contact with an inner peripheral surface of the housing portion 4. The annular portion 53 is formed with a through-hole 531 that penetrates in the radial direction. In addition, the annular portion 53 has a protruding piece 532, a groove portion 533, a retaining piece 534, a retaining recess 535, a protruding portion 536, an engagement recess 537, and a notch hole 538. The through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 are arranged in a row in the axial direction.

[0145] One set of the through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 is provided at four places at equal intervals in the circumferential direction. The protruding portion 536 is arranged between the through-holes 531 that are adjacent in the circumferential direction, and four places are provided at equal intervals in the circumferential direction. The retaining piece 534 and the retaining recess 535 are provided at one site.

[0146] The protruding piece 532 of the cover portion 5a protrudes from the lower surface of the annular portion 53 toward the axial direction lower side XI. The through-hole 531 and the protruding piece 532 are arranged adjacent in the axial direction.

[0147] The protruding piece 532 of the cover portion 5b protrudes from the upper surface of the annular portion 53 toward the axial direction upper side X2. That is, the protruding pieces 532 of the cover portions 5a, 5b protrude in the axial direction from the axial end surface that faces the inner side of the housing portion 4.

[0148] In the present embodiment, the through-hole 531 is formed so as to cross a portion of the protruding piece 532. In addition, the through-hole 531 can also be formed only in the annular portion 53 without crossing a portion of the protruding piece 532. In addition, instead of the through-hole 531, a recess that is recessed from the radial direction outer surface of the annular portion 53 toward the radial direction inner side can also be formed.

[0149] The protruding piece 532 has an inclined portion 5321. The inclined portion 5321 of the cover portion 5a is arranged at a position on the outer peripheral surface of the protruding piece 532 that is closer to the axial direction lower side (the side closer to the fan portion 2a, 2b in the axial direction) XI than the through-hole 531, and is inclined toward the radial direction outer side as it goes toward the axial direction upper side (the axial direction outer side of the housing portion 4) X2.

[0150] The inclined portion 5321 of the cover portion 5b is arranged at a position on the outer peripheral surface of the protruding piece 532 that is closer to the axial direction upper side (the side closer to the fan portion 2a, 2b in the axial direction) X2 than the through-hole 531, and is inclined toward the radial direction outer side as it goes toward the axial direction lower side (the axial direction outer side of the housing portion 4) XI.

[0151] The groove portion 533 of the cover portion 5a is recessed from the outer peripheral surface toward the radial direction inner side at the lower end portion (the end portion that faces the axial end surface of the inner side of the housing portion 4) of the protruding piece 532 and extends in the axial direction.

[0152] The groove portion 533 of the cover portion 5b is recessed from the outer peripheral surface of the protruding piece 532 at the upper end portion (the end portion in the axial direction facing the inner side of the housing portion 4) and extends in the axial direction.

[0153] The engagement recess 537 of the cover portion 5a is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side on the axial direction upper side (the side farther from the fan portion 2a, 2b in the axial direction) X2 of the through-hole 531.

[0154] The engagement recess 537 of the cover portion 5b is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side on the axial direction lower side (the side farther from the fan portion 2a, 2b in the axial direction) XI of the through-hole 531.

[0155] The holding piece 534 protrudes from the outer peripheral surface of the annular portion 53 toward the radial direction outer side and extends in the circumferential direction. The holding recess 535 is disposed in opposition to the holding piece 534 in the radial direction and is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side.

[0156] The notch hole 538 is disposed in opposition to the notch recess 48 of the housing portion 4 described later and the holding piece 534 in the radial direction. The notch hole 538 of the cover portion 5a is formed by being notched from the end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial direction upper side (axial direction) X2. The notch hole 538 of the cover portion 5b is formed by being notched from the end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial direction lower side (axial direction) XI.

[0157] The lead wire (not shown) connected to the circuit board 23 of the fan portion 2a and the lead wire (not shown) connected to the circuit board 23 of the fan portion 2b are respectively drawn out to the outside of the housing portion 4 via the notch hole 538. Thereby, it is possible to prevent the lead wires from coming into contact with the impeller 21a or the impeller 21b. In addition, by reducing the lead wires passing through the inside of the housing portion 4, it is possible to make the air flow in the inside of the housing portion 4 more smoothly.

[0158] In addition, the drawn-out lead wires are held between the holding piece 534 and the holding recess 535. Thereby, it is possible to hold the lead wires drawn out to the outside of the housing portion 4 along the outer peripheral surface of the housing portion 4. Therefore, the lead wire routing becomes easy, and the assembly workability of the air blowing device 1 is further improved.

[0159] <4. Structure of the housing portion>

[0160] The housing portion 4 has, at the lower end portion (one axial end portion) and the upper end portion (the other axial end portion), engaging projections 44, guide portions 45, flange portions 46, notch portions 47, notch recesses 48, and step portions 49, respectively. The engaging projections 44, the guide portions 45, and the notch portions 47 are arranged in a row in the axial direction. One set of the engaging projections 44, the guide portions 45, and the notch portions 47 are each provided at four locations equiangularly spaced apart in the circumferential direction at the upper end portion and the lower end portion of the housing portion 4. The notch recesses 48 are provided at four locations equiangularly spaced apart in the circumferential direction at the upper end portion and the lower end portion of the housing portion 4, respectively, between the engaging projections 44 adjacent in the circumferential direction.

[0161] At the both axial end portions of the housing portion 4, the inner peripheral surfaces of the step portions 49 are recessed toward the radial direction outer side, respectively. The step portions 49 are in contact with the annular portion 53 in the axial direction. By providing the step portions 49, the inner peripheral surface of the annular portion 53 and the inner peripheral surface of the housing portion 4 are formed as one flat surface. Thus, the air flow inside the housing portion 4 can be made to flow more smoothly.

[0162] The engaging projections 44 protrude toward the radial direction inner side from the inner peripheral surfaces of the both axial end portions of the housing portion 4, respectively. The engaging projections 44 engage around the through holes 531 of the cover portions 5a at the upper end portion of the housing portion 4. The engaging projections 44 engage around the through holes 531 of the cover portions 5b at the lower end portion of the housing portion 4.

[0163] The guide portions 45 are provided at the axial direction outer end portions. The guide portions 45 are provided at the upper end portion (the other axial end portion) of the housing portion 4 at positions X2 further toward the axial direction upper side (axial direction outer side) than the engaging projections 44. The guide portions 45 are provided at the lower end portion (one axial end portion) of the housing portion 4 at positions XI further toward the axial direction lower side (axial direction outer side) than the engaging projections 44. The guide portions 45 protrude toward the radial direction inner side from the inner peripheral surfaces of the housing portion 4 and extend in the axial direction.

[0164] The notch portions 47 are provided at the upper end portion (the other axial end portion) of the housing portion 4 at positions XI further toward the axial direction lower side (axial direction inner side) than the engaging projections 44, and the step portions 49 are formed to be recessed toward the axial direction lower side (axial direction inner side) XI. Also, the notch portions 47 are provided at the lower end portion (one axial end portion) of the housing portion 4 at positions X2 further toward the axial direction upper side (axial direction inner side) than the engaging projections 44, and the step portions 49 are formed to be recessed toward the axial direction upper side (axial direction inner side) X2.

[0165] The flange portions 46 are formed with mounting holes 461 protruding toward the radial direction outer side from the axial direction outer end portions of the housing portion 4 and extending in the axial direction. The air supply device 1 is screwed to other equipment via the mounting holes 461. The flange portions 46 are opposed to the engaging projections 44 in the radial direction, and are provided at four locations at the upper end portion and the lower end portion of the housing portion 4, respectively. The engaging projections 44 and the guide portions 45 are adjacent to the mounting holes 461 in the radial direction. Thus, the periphery of the mounting holes 461 can be formed as a thick wall.

[0166] The notch recesses 48 are provided at four locations each at the upper end portion and the lower end portion of the housing portion 4. The notch recess 48 at the upper end portion of the housing portion 4 is formed by being notched from the axial upper end face (axial other end face) toward the axial lower side (axial one side) XI. Also, the notch recess 48 at the lower end portion of the housing portion 4 is formed by being notched from the axial lower end face (axial one end face) toward the axial upper side (axial other side) X2.

[0167] <5. Structure of the housing portion and the cover portion>

[0168] Figure 8 is an enlarged view showing a part of the upper end portion of the air-blowing device 1. The cover portion 5a is attached to the housing portion 4 in a state where the fan portion 2a is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5a is inserted toward the axial lower side (axial one side) XI.

[0169] The cover portion 5b is attached to the housing portion 4 in a state where the fan portion 2b is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5b is inserted toward the axial upper side (axial other side) X2.

[0170] At this time, the guide portion 45 slides along the groove portion 533. Thereby, the positioning of the circumferential direction of the cover portion 5a, 5b becomes easy, and the cover portion 5a, 5b can be smoothly inserted into the axial inner side.

[0171] When the engagement protrusion 44 comes into contact with the inclined portion 5321, the protruding piece 532 is flexed toward the radial inner side, and further the cover portion 5a, 5b is inserted toward the axial inner side, thereby the engagement protrusion 44 is inserted into the through-hole 531. Thereby, the engagement protrusion 44 is engaged with the periphery of the through-hole 531, and the protruding piece 532 presses the inner peripheral face of the housing portion 4 toward the radial outer side. Thereby, the cover portion 5a, 5b is firmly fixed to the housing portion 4. Therefore, the assembly workability of the cover portion 5a, 5b and the housing portion 4 can be improved.

[0172] At this time, by providing the inclined portion 5321, the protruding piece 532 is easily moved along the guide portion 45. Therefore, the assembly workability of the cover portion 5a and the housing portion 4 can be further improved.

[0173] Also, in a state where the engagement protrusion 44 is engaged with the periphery of the through-hole 531, the protruding piece 532 is fitted into the notch portion 47. Also, the protruding portion 536 is fitted into the notch recess 48. Also, the guide portion 45 is fitted into the engagement recess 537. Also, the annular portion 53 is in contact with the step portion 49 in the axial direction. Also, the engaged one set of the through-hole 531 and the engagement protrusion 44 are provided with a plurality of them at substantially equal intervals in the circumferential direction. Thereby, the housing portion 4 and the cover portion 5a are more firmly fixed in the axial direction and the circumferential direction.

[0174] Further, a gap can be formed locally between the outer peripheral surface of the ring portion 53 and the inner peripheral surface of the housing portion 4. Thus, the vibration transmitted from the cover portions 5a, 5b to the housing portion 4 can be reduced.

[0175] <5. Other>

[0176] The above describes the embodiments of the present application, but the scope of the present application is not limited to this, and various modifications can be made within the scope of the gist of the present application. Further, the above-described embodiments and modifications thereof can be appropriately combined arbitrarily.

[0177] In the present embodiment, the set of through holes 531, the protruding pieces 532, the groove portions 533, and the engagement recesses 537 and the set of the engagement protrusions 44, the guide portions 45, and the notch portions 47 are provided at four places at equal intervals in the circumferential direction, respectively, but can be provided at two, three, or five or more places.

[0178] Further, the engagement protrusions 44 and the guide portions 45 are arranged radially adjacent to the mounting holes 461, but the engagement protrusions 44 and the guide portions 45 can be arranged at positions different from the mounting holes 461 in the circumferential direction. Further, the engagement protrusions 44 can be arranged at positions different from the guide portions 45 in the circumferential direction.

[0179] Further, the housing portion 4 can be formed so as to decrease in diameter toward the axial lower side (one side in the axial direction). Thus, the air flow inside the housing portion 4 can be smoothly circulated toward the exhaust side.

[0180] Technical Solution 1. An air supply device having: a pair of fan portions coaxially arranged and generating an air flow toward one side in the axial direction along a center axis; a housing portion extending along the center axis in a cylindrical shape to house the pair of fan portions, both end surfaces in the axial direction of the housing portion being open; and cover portions covering the one end surface and the other end surface in the axial direction of the housing portion, respectively, and ventilating, the pair of fan portions being fixed to the cover portions, respectively, and having a motor rotating an impeller, the impeller having: an impeller cylinder portion arranged at a radially outer side of the motor and extending in the axial direction; an impeller cover portion covering an axial end surface of the impeller cylinder portion at an axial direction opposite to the cover portion in which the motor is fixed; and a blade portion in which a plurality of blades are arranged in the circumferential direction at a radially outer surface of the impeller cylinder portion, the impeller cover portions of the pair of fan portions directly facing each other in the axial direction.

[0181] Technical Solution 2. The impeller cover portions are arranged in parallel with a surface perpendicular to the center axis.

[0182] Technical Solution 3. At least one of the facing impeller cover portions has an impeller protrusion portion protruding in the axial direction from a radially outer end portion.

[0183] Technical Solution 4. The impeller protrusion extends in axial parallel.

[0184] Technical Solution 5. The outer diameter of the impeller cylinder of the pair of fan portions is the same size.

[0185] Technical Solution 6. The angle of inclination of the blade portion with respect to the center axis when the impeller disposed on the other side in the axial direction is spread in the circumferential direction is smaller than the angle of inclination of the blade portion with respect to the center axis when the impeller disposed on one side in the axial direction is spread in the circumferential direction.

[0186] Technical Solution 7. The cover portion has a ring-shaped ring portion that is in contact with the inner peripheral surface of the housing portion, a fixed portion that is disposed on the radially inner side of the ring portion and in which the fan portion is fixed, and a link portion that extends from the fixed portion to the radially outer side, is disposed on the one side in the axial direction, and links the ring portion and the fixed portion, and the shape of the link portion disposed on the other side in the axial direction is different from the shape of the link portion disposed on one side in the axial direction.

[0187] Technical Solution 8. The angle of inclination of the link portion disposed on the other side in the axial direction with respect to the center axis is smaller than the angle of inclination of the link portion disposed on one side in the axial direction with respect to the center axis when viewed in the radial direction.

[0188] Technical Solution 9. The link portion disposed on the other side in the axial direction is formed so that the cross-sectional area perpendicular to the center axis increases toward one side in the axial direction.

[0189] Technical Solution 10. The circumferential outer surface of the link portion disposed on the other side in the axial direction is formed in parallel with the axial direction.

[0190] Technical Solution 11. The fixed portion of the cover portion disposed on the other side in the axial direction is formed so that the cross-sectional area perpendicular to the center axis increases toward one side in the axial direction.

[0191] Technical Solution 12. The fixed portion has an insertion hole that is disposed on the center axis and penetrates in the axial direction, and a ring-shaped rib that surrounds the insertion hole and protrudes in the axial direction, and the fan portion has a cylindrical bearing holding portion that holds a bearing inside, the bearing rotatably supporting a shaft that extends in the center axis, and an axial outer end portion of the bearing holding portion is inserted into the insertion hole.

[0192] Technical Solution 13. The housing is formed so that the diameter decreases toward one side in the axial direction.

[0193] Hereinafter, an exemplary embodiment of the third application will be described in detail with reference to the drawings. In the present specification, the direction in which the central axis J of the air-blowing device 1 extends will be simply referred to as "axial direction", the direction perpendicular to the central axis J with the central axis J of the air-blowing device 1 as the center will be simply referred to as "radial direction", and the direction along the circular arc with the central axis J of the air-blowing device 1 as the center will be simply referred to as "circumferential direction". Also, the cross section parallel to the axial direction will be referred to as "longitudinal cross section". Note that "parallel" does not mean parallel in the strict sense, but includes substantially parallel.

[0194] Also, for convenience of explanation, the axial direction will be set as the up-down direction, and the up-down direction in the Figure 1 will be set as the up-down direction of the air-blowing device 1 to describe the shape and positional relationship of each part. For example, the axial direction one side will be set as the axial direction lower side or lower side. The axial direction other side will be set as the axial direction upper side or upper side. Also, the axial direction one end will be set as the lower end, and the axial direction other end will be set as the upper end. Also, the axial direction one end surface will be set as the lower end surface, and the axial direction other end surface will be set as the upper end surface. The "upper side" of the air-blowing device 1 is the "suction side", and the "lower side" is the "discharge side". Furthermore, the definition of this up-down direction does not limit the orientation and positional relationship at the time of use of the air-blowing device 1.

[0195] <1. Overall structure of air-blowing device>

[0196] Figure 1 is an overall perspective view of an example of the air-blowing device 1 of the embodiment of the present application, Figure 2 is an exploded perspective view of the air-blowing device 1. The air-blowing device 1 has a pair of fan sections 2a, 2b, a housing section 4, and cover sections 5a, 5b.

[0197] The fan sections 2a, 2b generate airflow toward the axial direction lower side (axial direction one side) XI along the central axis J, and the fan sections 2a, 2b are coaxially arranged. The fan section 2a is arranged on the suction side, and has an impeller 21a, a motor 22, and a circuit board 23. The fan section 2b is arranged on the discharge side, and has an impeller 21b, a motor 22, and a circuit board 23. Also, in the present embodiment, as for the fan section 2a and the fan section 2b, the structure of the motor 22 and the circuit board 23 is the same, and the same reference numerals are attached to describe them.

[0198] The housing section 4 is formed in a cylindrical shape extending along the central axis J, and houses the pair of fan sections 2a, 2b with both axial end surfaces open. The housing section 4 has an air-blowing flow path for the airflow to pass through inside. The housing section 4 has a discharge port 42 on the lower end surface (axial direction one end surface), and a suction port 41 on the upper end side (axial direction other end surface).

[0199] The lid portion 5a covers the air intake port 41 (axial other end surface) of the housing portion 4 and performs ventilation. The lid portion 5b covers the air exhaust port 42 (axial one end surface) of the housing portion 4 and performs ventilation. The fan portion 2a is fixed to the lid portion 5a, and the fan portion 2b is fixed to the lid portion 5b.

[0200] The lid portions 5a and 5b and the housing portion 4 are resin molded products, and the material that constitutes the lid portions 5a and 5b is different from the material that constitutes the housing portion 4. Specifically, the Young's modulus of the material that constitutes the lid portions 5a and 5b is higher than the Young's modulus of the material that constitutes the housing portion 4. Thereby, it is possible to change the vibration frequency of the lid portions 5a and 5b and the vibration frequency of the housing portion 4. Therefore, it is possible to reduce the case where the lid portions 5a and 5b and the housing portion 4 resonate. Thereby, it is possible to reduce the vibration of the air supply device 1.

[0201] Specifically, in the case where polyphenylene sulfide or polybutylene terephthalate is used as the material that constitutes the lid portions 5a and 5b, as the material that constitutes the housing portion 4, it is possible to appropriately use polyphenylene oxide. In addition, in the case where polyphenylene sulfide is used as the material that constitutes the lid portions 5a and 5b, as the material that constitutes the housing portion 4, it is possible to preferably use polybutylene terephthalate. By using these materials, it is possible to further reduce the vibration of the air supply device 1 while maintaining the strength of the lid portions 5a and 5b and the housing portion 4.

[0202] <2-1. Structure of Impeller>

[0203] Figure 3 is a side view of the air supply device 1, and Figure 3 The housing portion 4 is omitted in FIG. 1. The impeller 21a is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The impeller 21b is disposed radially outward of the motor 22 and rotates around the central axis J by the motor 22. The rotation direction of the impeller 21a is opposite to the rotation direction of the impeller 21b. In addition, depending on the shape of the impellers 21a and 21b, the rotation direction of the impeller 21a and the rotation direction of the impeller 21b can be made in the same direction.

[0204] The impeller 21a has an impeller cup 211a and a plurality of blades 212a. The impeller cup 211a is fixed to the motor 22. The impeller cup 211a has an impeller cylinder portion 2112a and an impeller lid portion 2111a. The impeller cylinder portion 2112a is disposed radially outward of the motor 22 of the fan portion 2a and extends in the axial direction. The impeller lid portion 2111a covers the lower end surface (axial one end surface) of the impeller cylinder portion 2112a. The plurality of blades 212a are arranged in the circumferential direction on the outer surface of the impeller cylinder portion 2112a.

[0205] Impeller 21b has an impeller cup 211b and multiple blades 212b. Impeller cup 211b is fixed to motor 22. Impeller cup 211b has an impeller cylinder portion 2112b and an impeller cover portion 2111b. Impeller cylinder portion 2112b is disposed radially outside of motor 22 of fan portion 2b and extends axially. Impeller cover portion 2111b covers the upper end face (the other end face axially) of impeller cylinder portion 2112b. Multiple blades 212b are arranged circumferentially on the outer surface of impeller cylinder portion 2112b.

[0206] When the impeller 21a on the intake side is circumferentially deployed, the tilt angle of its blades 212a relative to the central axis J is smaller than the tilt angle of its blades 212b relative to the central axis J when the impeller 21b on the exhaust side is circumferentially deployed. This allows for more efficient air intake by ensuring that the airflow from impeller 21a is greater than that from impeller 21b, further improving the air delivery efficiency of the air supply device 1. The tilt angle refers to the installation angle of blades 212a and 212b.

[0207] Impeller cover portions 2111a and 2111b are directly opposite each other in the axial direction without any other components between them. This axial proximity of the impellers 21a and 21b reduces the gap between them, allowing airflow to enter smoothly. This, in turn, improves the airflow efficiency within the housing 4.

[0208] Furthermore, impeller cover portions 2111a and 2111b are arranged parallel to a plane perpendicular to the central axis J. This allows the impeller cover portions 2111a and 2111b to be arranged closer together. Consequently, the gap between the impeller cover portions 2111a and 2111b can be further reduced.

[0209] Additionally, the impeller cover portion 2111a has an annular impeller protrusion 2113a disposed at the radially outer end and protruding axially downward (on one axial side) X1 (see reference). Figure 4 The impeller cover portion 2111b has an annular impeller protrusion 2113b disposed at the radially outer end and protruding axially upward (to the other axial side) X2 (see reference). Figure 4 This further reduces the gap between the impeller cover portion 2111a and the impeller cover portion 2111b. Alternatively, at least one of the multiple impeller protrusions 2113a and 2113b can be provided radially. This further reduces the gap between the impeller cover portion 2111a and the impeller cover portion 2111b. Furthermore, multiple impeller protrusions 2113a and 2113b can be formed discontinuously in the circumferential direction.

[0210] Further, the impeller protruding portion 2113a and the impeller protruding portion 2113b are opposed in the axial direction and extend in parallel with the axial direction. Thereby, it is possible to suppress turbulence of the air flow passing along the impeller protruding portion 2113a and the impeller protruding portion 2113b. In addition, the impeller protruding portion 2113a and the impeller protruding portion 2113b can also be arranged in the radial direction with a deviation. In this case, it is preferable that the tip end of one of the impeller protruding portion 2113a and the impeller protruding portion 2113b extend to a position on the base side further than the tip end of the other. Thereby, it is possible to further reduce the inflow of the air flow into the gap between the impeller cover portion 2111a and the impeller cover portion 2111b.

[0211] Further, the outer peripheral surface of the impeller cylinder portion 2112a, 2112b is parallel with the axial direction, and the outer diameter of the impeller cylinder portion 2112a and the outer diameter of the impeller cylinder portion 2112b are the same size. Thereby, it is possible to smoothly pass the air flow from the outer peripheral surface of the impeller cylinder portion 2112a to the outer peripheral surface of the impeller cylinder portion 2112b. In addition, the outer peripheral surface of the impeller cylinder portion 2112a, 2112b can also be parallel with the axial direction, and the outer diameter of the impeller cylinder portion 2112a and the outer diameter of the impeller cylinder portion 2112b can be different sizes. In addition, the outer peripheral surface of the impeller cylinder portion 2112a and the outer peripheral surface of the impeller cylinder portion 2112b can also be formed in a conical frustum shape inclined to the radial direction outer side as they approach each other in the axial direction.

[0212] <2-2. Structure of the motor>

[0213] Figure 4 is a longitudinal sectional view of the air blowing device 1. A pair of motors 22 are fixed to the cover portions 5a, 5b, respectively. The motor 22 on the air suction side (axial direction other side) X2 rotates the impeller 21a around the center axis J. The motor 22 on the air discharge side (axial direction one side) XI rotates the impeller 21b around the center axis J. The motor 22 has a shaft 221, a bearing 222, a stator 223, and a rotor 224.

[0214] The shaft 221 extends along the center axis J. The shaft 221 is, for example, composed of a metal such as stainless steel, and is a columnar member extending in the axial direction.

[0215] The bearing 222 is composed of, for example, a ball bearing, but can also be composed of a sleeve bearing or the like. The pair of bearings 222 are arranged at least in opposition in the axial direction. The pair of bearings 222 support the shaft 221 so as to be rotatable around the center axis J with respect to the housing portion 4.

[0216] The stator 223 has a bearing holding portion 223a, a stator core 223b, an insulating member 223c, and a coil (not shown). The bearing holding portion 223a is formed in a cylindrical shape, and holds the bearing 222 inside.

[0217] The upper end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2a is fitted into the fitting hole 511 of the cover portion 5a. Thereby, the bearing holding portion 223a is fixed to the cover portion 5a, and the fan portion 2a and the cover portion 5a are fixed. In addition, the bearing holding portion 223a and the cover portion 5a can also be integrally formed of metal.

[0218] The lower end portion (axial outer end portion) of the bearing holding portion 223a of the fan portion 2b is fitted into the fitting hole 511 of the cover portion 5b. Thereby, the bearing holding portion 223a is fixed to the cover portion 5b, and the fan portion 2b and the cover portion 5b are fixed. In addition, the bearing holding portion 223b and the cover portion 5b can also be integrally formed of metal.

[0219] The stator core 223b is configured, for example, by stacking electromagnetic steel sheets such as silicon steel sheets up and down. The insulating member 223c is configured of a resin having insulating properties. The insulating member 223c is provided in a manner of surrounding the outer surface of the stator core 223b. The coil (not shown) is configured of a wire wound around the stator core 223b with the insulating member 223c interposed.

[0220] The rotor 224 rotates with respect to the stator 223 about the center axis J. The rotor 224 has a rotor yoke 224a and a magnet 224b.

[0221] The rotor yoke 224a is configured of a magnetic body, and is a substantially cylindrical member having a cover on the axial inner side. The rotor yoke 224a of the fan portion 2a is fixed to the lower end portion (axial inner end portion) of the shaft 221. The rotor yoke 224a of the fan portion 2b is fixed to the upper end portion (axial inner end portion) of the shaft 221. The magnet 224b is cylindrical, and is fixed to the inner peripheral surface of the rotor yoke 224a. The magnet 224b is disposed radially outward of the stator 223.

[0222] <2-3. Structure of Circuit Board>

[0223] The circuit board 23 of the fan portion 2a is disposed between the stator core 223b and the cover portion 5a, and the circuit board 23 of the fan portion 2b is disposed between the stator core 223b and the cover portion 5b. The circuit board 23 is, for example, a circular plate shape extending in the radial direction with the center axis J as the center. The lead wire of the coil (not shown) is electrically connected to the circuit board 23. An electronic circuit for supplying a driving current to the coil (not shown) is mounted on the circuit board 23.

[0224] The outer diameter of the circuit board 23 is equal to or smaller than the outer diameter of the impeller cylinder portion 2112a, 2112b. Thereby, the airflow inside the housing portion 4 can be made to flow more smoothly.

[0225] In the fan portion 2a, 2b of the above-described structure, if a driving current is supplied to the coil (not shown) of the motor 22 via the circuit board 23, a radial magnetic flux is generated in the stator core 223b. A magnetic field generated by the magnetic flux of the stator core 223b and a magnetic field generated by the magnet 224b act, and a torque is generated in the circumferential direction of the rotor 224. By this torque, the rotor 224 and the impeller 21a, 21b are rotated about the center axis J, respectively. When the impeller 21a, 21b is rotated, an air flow is generated by the plurality of blades 212a, 212b. Thus, by the fan portion 2a, 2b, an air flow that takes the axial upper side (axial other side) X2 as a suction side and the axial lower side (axial one side) XI as a discharge side is generated, and air supply is performed.

[0226] <3. Structure of the cover portion>

[0227] Figure 5 、 Figure 6 is an exploded perspective view of the housing portion 4 and the cover portion 5a, Figure 5 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial upper side (axial other side) X2. Figure 6 shows a state in which the housing portion 4 and the cover portion 5a are viewed from the axial lower side (axial one side) XI. Figure 7 is a perspective view of the cover portion 5a, and shows a state in which the cover portion 5a is viewed from the axial lower side (axial one side) XI.

[0228] The cover portion 5a and the cover portion 5b have a fixing portion 51, a linking portion 52, and a ring-shaped portion 53. In the present embodiment, the fixing portion 51, the linking portion 52, and the ring-shaped portion 53 of the cover portion 5a and the cover portion 5b have the same structure, and the same reference numerals are attached to describe them. The fixing portion 51 is disposed on the radially inner side of the ring-shaped portion 53.

[0229] The fixing portion 51 of the cover portion 5a is a circular plate shape that is disposed on the axial upper side (axial other side) X2 of the fan portion 2a and that extends in the radial direction about the center axis J. The fixing portion 51 of the cover portion 5b is disposed on the axial lower side (axial one side) XI of the fan portion 2b and is a circular plate shape that extends in the radial direction about the center axis J.

[0230] The fixing portion 51 has an insertion hole 511 and a ring-shaped rib 512 (see FIG. 6). Figure 7 The insertion hole 511 is disposed on the center axis J and penetrates the fixing portion 51 in the axial direction. The ring-shaped rib 512 of the cover portion 5a protrudes in the axial direction from the lower surface (axial one end surface) of the fixing portion 51 and surrounds the insertion hole 511. The ring-shaped rib 512 of the cover portion 5b protrudes in the axial direction from the upper surface (axial other end surface) of the fixing portion 51 and surrounds the insertion hole 511.

[0231] By providing the annular rib 512, the inner surface of the annular rib 512 is in contact with the bearing holding portion 223a in a state where the bearing holding portion 223a is fitted into the fitting hole 511. Thus, the bearing holding portion 223a can be stably supported.

[0232] The fixing portion 51 of the cover portion 5a is formed so that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 diffuses toward the radial outer side along the peripheral surface of the fixing portion 51 and flows smoothly. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0233] The linking portions 52 extend toward the radial outer side from the fixing portion 51 and are arranged in a plurality in the circumferential direction, and link the annular portion 53 and the fixing portion 51. The air flowing in the inside of the housing portion 4 passes between the adjacent linking portions 52.

[0234] The linking portions 52 (linking portions arranged on the axial lower side (axial one side) X1) of the cover portion 5b are different in shape from the linking portions 52 (linking portions arranged on the axial upper side (axial other side) X2) of the cover portion 5a. Thus, by changing the shape of the linking portions 52 on the air intake side and the shape of the linking portions 52 on the air exhaust side, the linking portions 52 function as stator vanes, and the air supply efficiency in the housing portion 4 can be improved.

[0235] The linking portions 52 of the cover portion 5a are formed so that the cross-sectional area perpendicular to the center axis J becomes larger as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 flows smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0236] In addition, the linking portions 52 of the cover portion 5b are inclined toward the circumferential one side as it goes toward the axial lower side (axial one side) X1. Thus, the air flow flowing out to the outside of the housing portion 4 from the air outlet 42 flows smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved.

[0237] In addition, the inclination angle of the linking portions 52 on the axial upper side (axial other side) X2 with respect to the center axis J is smaller than the inclination angle of the linking portions 52 on the axial lower side (axial one side) X1 with respect to the center axis J, as viewed in the radial direction. Thus, the air flow flowing into the inside of the housing portion 4 from the air inlet 41 can flow smoothly along the linking portions 52. Therefore, the air supply efficiency of the air supply device 1 can be further improved. In addition, the circumferential outer surface of the linking portions 52 of the cover portion 5a can also be formed to be parallel to the axial direction.

[0238] The annular portion 53 is formed in an annular shape, and an outer peripheral surface of the annular portion 53 is in contact with an inner peripheral surface of the housing portion 4. The annular portion 53 is formed with a through-hole 531 that penetrates in the radial direction. In addition, the annular portion 53 has a protruding piece 532, a groove portion 533, a retaining piece 534, a retaining recess 535, a protruding portion 536, an engagement recess 537, and a notch hole 538. The through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 are arranged in a row in the axial direction.

[0239] One set of the through-hole 531, the protruding piece 532, the groove portion 533, and the engagement recess 537 is provided at four places at equal intervals in the circumferential direction. The protruding portion 536 is arranged between the through-holes 531 that are adjacent in the circumferential direction, and four places are provided at equal intervals in the circumferential direction. The retaining piece 534 and the retaining recess 535 are provided at one site.

[0240] The protruding piece 532 of the cover portion 5a protrudes from the lower surface of the annular portion 53 toward the axial direction lower side XI. The through-hole 531 and the protruding piece 532 are arranged adjacent in the axial direction.

[0241] The protruding piece 532 of the cover portion 5b protrudes from the upper surface of the annular portion 53 toward the axial direction upper side X2. That is, the protruding pieces 532 of the cover portions 5a, 5b protrude in the axial direction from the axial end surface that faces the inner side of the housing portion 4.

[0242] In the present embodiment, the through-hole 531 is formed so as to cross a portion of the protruding piece 532. In addition, the through-hole 531 can also be formed only in the annular portion 53 without crossing a portion of the protruding piece 532. In addition, instead of the through-hole 531, a recess that is recessed from the radial direction outer surface of the annular portion 53 toward the radial direction inner side can also be formed.

[0243] The protruding piece 532 has an inclined portion 5321. The inclined portion 5321 of the cover portion 5a is arranged at a position on the outer peripheral surface of the protruding piece 532 that is on the axial direction lower side (the side closer to the fan portion 2a, 2b in the axial direction) XI than the through-hole 531, and is inclined toward the radial direction outer side as it goes toward the axial direction upper side (the axial direction outer side of the housing portion 4) X2.

[0244] The inclined portion 5321 of the cover portion 5b is arranged at a position on the outer peripheral surface of the protruding piece 532 that is on the axial direction upper side (the side closer to the fan portion 2a, 2b in the axial direction) X2 than the through-hole 531, and is inclined toward the radial direction outer side as it goes toward the axial direction lower side (the axial direction outer side of the housing portion 4) XI.

[0245] The groove portion 533 of the cover portion 5a is recessed from the outer peripheral surface toward the radial direction inner side at the lower end portion (the end portion that faces the axial end surface of the inner side of the housing portion 4) of the protruding piece 532 and extends in the axial direction.

[0246] The groove portion 533 of the cover portion 5b is recessed from the outer peripheral surface of the protruding piece 532 at the upper end portion (the end portion in the axial direction facing the inner side of the housing portion 4) and extends in the axial direction.

[0247] The engagement recess 537 of the cover portion 5a is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side on the axial direction upper side (the side farther from the fan portion 2a, 2b in the axial direction) X2 of the through-hole 531.

[0248] The engagement recess 537 of the cover portion 5b is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side on the axial direction lower side (the side farther from the fan portion 2a, 2b in the axial direction) XI of the through-hole 531.

[0249] The holding piece 534 protrudes from the outer peripheral surface of the annular portion 53 toward the radial direction outer side and extends in the circumferential direction. The holding recess 535 is disposed in opposition to the holding piece 534 in the radial direction and is recessed from the outer peripheral surface of the annular portion 53 toward the radial direction inner side.

[0250] The notch hole 538 is disposed in opposition to the notch recess 48 of the housing portion 4 described later and the holding piece 534 in the radial direction. The notch hole 538 of the cover portion 5a is formed by being notched from the end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial direction upper side (axial direction) X2. The notch hole 538 of the cover portion 5b is formed by being notched from the end surface of the annular portion 53 facing the inner side of the housing portion 4 toward the axial direction lower side (axial direction) XI.

[0251] The lead wire (not shown) connected to the circuit board 23 of the fan portion 2a and the lead wire (not shown) connected to the circuit board 23 of the fan portion 2b are respectively drawn out to the outside of the housing portion 4 via the notch hole 538. Thereby, it is possible to prevent the lead wires from coming into contact with the impeller 21a or the impeller 21b. In addition, by reducing the lead wires passing through the inside of the housing portion 4, it is possible to make the air flow in the inside of the housing portion 4 more smoothly.

[0252] In addition, the drawn-out lead wires are held between the holding piece 534 and the holding recess 535. Thereby, it is possible to hold the lead wires drawn out to the outside of the housing portion 4 along the outer peripheral surface of the housing portion 4. Therefore, the lead wire routing becomes easy, and the assembly workability of the air blowing device 1 is further improved.

[0253] <4. Structure of the housing portion>

[0254] The housing portion 4 has, at the lower end portion (one axial end portion) and the upper end portion (the other axial end portion), engaging projections 44, guide portions 45, flange portions 46, notch portions 47, notch recesses 48, and step portions 49, respectively. The engaging projections 44, the guide portions 45, and the notch portions 47 are arranged in a row in the axial direction. One set of the engaging projections 44, the guide portions 45, and the notch portions 47 are each provided at four locations equiangularly spaced apart in the circumferential direction at the upper end portion and the lower end portion of the housing portion 4. The notch recesses 48 are provided at four locations equiangularly spaced apart in the circumferential direction at the upper end portion and the lower end portion of the housing portion 4, respectively, between the engaging projections 44 adjacent in the circumferential direction.

[0255] At the both axial end portions of the housing portion 4, the inner peripheral surfaces of the step portions 49 are recessed toward the radial outer side, respectively. The step portions 49 are in contact with the annular portion 53 in the axial direction. By providing the step portions 49, the inner peripheral surface of the annular portion 53 and the inner peripheral surface of the housing portion 4 are formed as one flat surface. Thus, the air flow inside the housing portion 4 can be made to flow more smoothly.

[0256] The engaging projections 44 protrude toward the radial inner side from the inner peripheral surfaces of the both axial end portions of the housing portion 4, respectively. The engaging projections 44 engage around the through holes 531 of the cover portions 5a at the upper end portion of the housing portion 4. The engaging projections 44 engage around the through holes 531 of the cover portions 5b at the lower end portion of the housing portion 4.

[0257] The guide portions 45 are provided at the axial outer end portions. The guide portions 45 are provided at the upper end portion (the other axial end portion) of the housing portion 4 at positions X2 that are more axially upward (axially outward) than the engaging projections 44. The guide portions 45 are provided at the lower end portion (one axial end portion) of the housing portion 4 at positions XI that are more axially downward (axially outward) than the engaging projections 44. The guide portions 45 protrude toward the radial inner side from the inner peripheral surfaces of the housing portion 4 and extend in the axial direction.

[0258] The notch portions 47 are provided at the upper end portion (the other axial end portion) of the housing portion 4 at positions XI that are more axially downward (axially inward) than the engaging projections 44, and the step portions 49 are formed to be recessed toward the axial downward side (axially inward) XI. Also, the notch portions 47 are provided at the lower end portion (one axial end portion) of the housing portion 4 at positions X2 that are more axially upward (axially inward) than the engaging projections 44, and the step portions 49 are formed to be recessed toward the axial upward side (axially inward) X2.

[0259] The flange portions 46 are formed with mounting holes 461 that protrude toward the radial outer side from the axial outer end portions of the housing portion 4 and extend in the axial direction. The air supply device 1 is screwed to other equipment via the mounting holes 461. The flange portions 46 are opposed to the engaging projections 44 in the radial direction, and are each provided at four locations at the upper end portion and the lower end portion of the housing portion 4. The engaging projections 44 and the guide portions 45 are adjacent to the mounting holes 461 in the radial direction. Thus, the periphery of the mounting holes 461 can be formed as a thick wall.

[0260] The notch recesses 48 are provided at four locations each at the upper end portion and the lower end portion of the housing portion 4. The notch recess 48 is formed at the upper end portion of the housing portion 4 by being notched from the axial upper end face (axial other end face) toward the axial lower side (axial one side) XI. Also, the notch recess 48 is formed at the lower end portion of the housing portion 4 by being notched from the axial lower end face (axial one end face) toward the axial upper side (axial other side) X2.

[0261] <5. Structure of the housing portion and the cover portion>

[0262] Figure 8 is an enlarged perspective view showing a part of the upper end portion of the air blowing device 1. The cover portion 5a is attached to the housing portion 4 in a state where the fan portion 2a is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5a is inserted toward the axial lower side (axial one side) XI.

[0263] The cover portion 5b is attached to the housing portion 4 in a state where the fan portion 2b is fixed. At this time, the groove portion 533 of the protruding piece 532 is brought into abutment with the guide portion 45, and the cover portion 5b is inserted toward the axial upper side (axial other side) X2.

[0264] At this time, the guide portion 45 slides along the groove portion 533. Thereby, the positioning of the circumferential direction of the cover portion 5a, 5b becomes easy, and the cover portion 5a, 5b can be smoothly inserted into the axial inner side.

[0265] When the engagement protrusion 44 comes into contact with the inclined portion 5321, the protruding piece 532 is flexed toward the radial inner side, and further the cover portion 5a, 5b is inserted toward the axial inner side, thereby the engagement protrusion 44 is inserted into the through hole 531. Thereby, the engagement protrusion 44 is engaged with the periphery of the through hole 531, and the protruding piece 532 presses the inner peripheral face of the housing portion 4 toward the radial outer side. Thereby, the cover portion 5a, 5b is firmly fixed to the housing portion 4. Therefore, the assembly workability of the cover portion 5a, 5b and the housing portion 4 can be improved.

[0266] At this time, by providing the inclined portion 5321, the protruding piece 532 is easily moved along the guide portion 45. Therefore, the assembly workability of the cover portion 5a and the housing portion 4 can be further improved.

[0267] Also, in a state where the engagement protrusion 44 is engaged with the periphery of the through hole 531, the protruding piece 532 is embedded in the notch portion 47. Also, the protruding portion 536 is embedded in the notch recess 48. Also, the guide portion 45 is embedded in the engagement recess 537. Also, the annular portion 53 is in contact with the step portion 49 in the axial direction. Also, the engaged one set of the through hole 531 and the engagement protrusion 44 are provided with a plurality of them at substantially equal intervals in the circumferential direction. Thereby, the housing portion 4 and the cover portion 5a are more firmly fixed in the axial direction and the circumferential direction.

[0268] Further, a gap can be formed locally between the outer peripheral surface of the ring-shaped portion 53 and the inner peripheral surface of the housing portion 4. Thus, the vibration transmitted from the cover portions 5a, 5b to the housing portion 4 can be reduced.

[0269] <5. Other>

[0270] The above describes embodiments of the present application, but the scope of the present application is not limited to this, and various modifications can be made within the scope of the gist of the present application. Further, the above-described embodiments and modifications thereof can be appropriately combined arbitrarily.

[0271] In the present embodiment, the set of through holes 531, the protruding pieces 532, the groove portions 533, and the engagement recesses 537 and the set of the engagement protrusions 44, the guide portions 45, and the notch portions 47 are provided at four places at equal intervals in the circumferential direction, respectively, but two, three, or five or more places can be provided.

[0272] Further, the engagement protrusions 44 and the guide portions 45 are disposed radially adjacent to the mounting holes 461, but the engagement protrusions 44 and the guide portions 45 can be disposed at positions different from the mounting holes 461 in the circumferential direction. Further, the engagement protrusions 44 can be disposed at positions different from the guide portions 45 in the circumferential direction.

[0273] Further, the housing portion 4 can be formed so as to decrease in diameter toward the axial lower side (one side in the axial direction). Thus, the airflow inside the housing portion 4 can be made to flow smoothly toward the exhaust side.

[0274] Technical Solution 1. An air supply device having: a pair of fan portions coaxially disposed and generating airflow toward one side in the axial direction along a center axis; a housing portion extending in a cylindrical shape along the center axis to house the pair of fan portions, both end surfaces in the axial direction of the housing portion being open; and cover portions covering the one end surface and the other end surface in the axial direction of the housing portion, respectively, and ventilating, the material constituting the cover portions being different from the material constituting the housing portion.

[0275] Technical Solution 2. The Young's modulus of the material constituting the cover portions is higher than the Young's modulus of the material constituting the housing portion.

[0276] Technical Solution 3. The cover portions have: a ring-shaped ring-shaped portion in contact with the inner peripheral surface of the housing portion; a fixed portion disposed radially inward of the ring-shaped portion, the fan portions being fixed to the fixed portion; and a link portion extending radially outward from the fixed portion, a plurality of the link portions being disposed in the circumferential direction and linking the ring-shaped portion and the fixed portion, a gap being locally formed between the outer peripheral surface of the ring-shaped portion and the inner peripheral surface of the housing portion in the radial direction.

[0277] Technical Solution 4. The housing portion has a guide portion provided at the axially outer end portion, the guide portion protruding from the inner peripheral surface to the radially inner side and extending in the axial direction, and the ring-shaped portion has an engagement recess recessed from the outer peripheral surface to the radially inner side and into which the guide portion is fitted.

[0278] Technical Solution 5. The housing portion has a flange portion protruding from the axially outer end portion to the radially outer side, the flange portion being formed with a mounting hole extending in the axial direction, and the guide portion is adjacent to the mounting hole in the radial direction.

[0279] Technical Solution 6. The ring-shaped portion has a through-hole extending in the radial direction, the housing portion has an engagement protrusion protruding from the inner peripheral surface to the radially inner side and engaging with the periphery of the through-hole, and the engagement protrusion is provided at a position different from the guide portion in the circumferential direction.

[0280] Technical Solution 7. The housing portion has a notch recess formed by being notched from the axially outer end surface to the axially inner side, the ring-shaped portion has a notch hole formed by being notched from the axially end surface facing the inner side of the housing portion to the axial direction, the notch recess and the notch hole are opposed to each other in the radial direction, and a lead wire connected to the fan portion is drawn out to the outside of the housing portion via the notch recess and the notch hole.

[0281] Technical Solution 8. A pair of the fan portions have a motor fixed to the cover portion and rotating an impeller, respectively, and a circuit board disposed between the impeller and the cover portion in the axial direction and connected to the motor, the impeller has an impeller cylinder portion disposed at the radially outer side of the motor and extending in the axial direction, an impeller cover portion covering an axial end surface of the impeller cylinder portion at the axially opposite side of the cover portion in which the motor is fixed, and a blade portion in which a plurality of blades are arranged in the circumferential direction on the radially outer surface of the impeller cylinder portion, and an outer diameter of the circuit board is equal to or smaller than an outer diameter of the impeller cylinder portion.

[0282] Technical Solution 9. The cover portion is composed of polyphenylene sulfide or polybutylene terephthalate, and the housing is composed of polyphenylene ether.

[0283] Technical Solution 10. The cover portion is composed of polyphenylene sulfide, and the housing is composed of polybutylene terephthalate.

[0284] Industrial Applicability

[0285] The present application can be utilized, for example, in a cooling device having a blower.

Claims

1. An air supply device, comprising: A pair of fan sections, which are coaxially arranged and generate airflow along the central axis to one side; A housing portion, extending along the central axis and formed into a cylindrical shape, and housing a pair of fan portions, wherein the housing portion has axially open end faces; and The cover covers one axial end face and the other axial end face of the housing portion, respectively, and allows for ventilation. The cover has an annular portion that contacts the inner circumferential surface of the housing portion and forms a radially penetrating through hole. The housing portion has a engaging protrusion that protrudes radially inward from the inner circumferential surface and engages with the periphery of the through hole. The annular portion has a protruding piece that protrudes axially from the axial end face facing the inner side of the housing portion. The through hole and the protruding piece are arranged adjacent to each other in the axial direction.

2. The air supply device according to claim 1, wherein, The set of through holes and the engaging protrusions are arranged at equal intervals in the circumferential direction.

3. The air supply device according to claim 1, wherein, The protruding piece has an inclined portion that is positioned on the side closer to the fan portion in the axial direction than the through hole and is inclined radially outward as it moves outward in the axial direction.

4. The air supply device according to claim 1 or 2, wherein, The housing portion has a guide portion disposed axially outward of the engaging protrusion, the guide portion protruding radially inward from the inner circumferential surface and extending axially. The protruding piece has a groove at its axial end facing the inner side of the housing portion, which is recessed radially inward from the outer peripheral side and extends axially. The guide portion slides along the groove to insert the cover portion into the interior of the housing portion.

5. The air supply device according to claim 4, wherein, The protruding piece has an engaging recess that is located axially further away from the fan section than the through hole and is recessed radially inward from the outer peripheral surface. The guide portion is embedded in the engaging recess.

6. The air supply device according to claim 1 or 2, wherein, The housing portion has a flange portion that protrudes radially outward from the axially outer end. The flange portion has a mounting hole extending axially. The engaging protrusion is radially adjacent to the mounting hole.

7. The air supply device according to claim 1 or 2, wherein, The housing portion has: A stepped portion, which is formed by a radially outward recess on the inner circumferential surface of the housing portion at its axially outer end, is in axial contact with the annular portion; and A notch is provided on the axially inner side of the engaging protrusion, and this notch is formed by the stepped portion being recessed axially inward. The protruding piece fits into the notch.

8. The air supply device according to claim 1 or 2, wherein, The annular portion has: A retaining plate, which protrudes radially outward from the outer peripheral surface and extends circumferentially; and The retaining recess is radially opposed to the retaining piece and is recessed radially inward from the outer peripheral surface. The wire connected to the fan section is held between the retaining plate and the retaining recess.

9. The air supply device according to claim 1 or 2, wherein, The cover portion has: A fixing part, disposed radially inside the annular portion, fixes the fan portion; and A connecting portion, which extends radially outward from the fixing portion, has multiple portions arranged circumferentially, and connects the annular portion to the fixing portion. The connecting portion of the cover located on the other side of the axial direction is formed such that the cross-sectional area perpendicular to the central axis increases as it moves toward the axial side.

10. The air supply device according to claim 9, wherein, The fixing part of the cover, which is located on the other side of the axial direction, is formed such that the cross-sectional area perpendicular to the central axis increases as it faces the axial direction.

11. The air supply device according to claim 9, wherein, The fixing part has: A fitting hole, disposed on the central axis and extending axially; and Annular ribs surround the fitting hole and protrude axially. The fan section has a cylindrical bearing retainer that internally holds the bearing, which supports a shaft extending along the central axis to enable rotation. The outer axial end of the bearing retainer engages with the fitting hole.

12. The air supply device according to claim 1 or 2, wherein, The shell is formed such that its diameter decreases as it faces one axial direction.

Images