JP2013167255A - Axial flow fan - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve connection strength between a hub and a boss in an axial flow fan in which the boss having an axial hole into which a drive motor shaft is inserted and which is formed at the axial center of the hub and a plurality of blades are integrally resin-molded together with the hub.SOLUTION: A hub (71) of an axial flow fan (70) has an outer peripheral-side cylindrical part (72) and a cover (73). The outer peripheral-side cylindrical part (72) is formed with a plurality of blades (91) protruding from an outer peripheral edge and a part having an opening (72a) at a shaft center. The cover (73) extends from the outer peripheral-side cylindrical part (72) toward a boss (81) so as to cover the opening (72a) of the outer peripheral-side cylindrical part (72) and is a part connecting the boss (81) and the outer peripheral-side cylindrical part (72). Reinforcing ribs (74, 75) are integrally resin-molded at both axial sides of the cover (73) together with the hub (71) and the boss (81) in order to reinforce connection between the hub (71) and the boss (81).

Description

  The present invention relates to an axial flow fan, and more particularly to an axial flow fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted at the axial center of a hub and a plurality of blades are integrally molded with a hub.

  Conventionally, as shown in Patent Documents 1 and 2 (Japanese Patent Laid-Open Nos. 5-340383 and 2011-74817), a boss in which a shaft hole into which a shaft of a drive motor is inserted is formed at the center of a hub. And an axial fan in which a plurality of blades are integrally molded with a resin together with a hub. Here, the hub has an outer peripheral side cylinder part and a cover part. The outer peripheral side cylindrical portion is a portion having a plurality of blades so as to protrude from the outer peripheral edge and having an opening in the axial center. The lid portion extends from the outer peripheral side cylinder portion toward the boss so as to cover the opening of the outer peripheral side cylindrical portion, and is a portion that connects the boss and the outer peripheral side cylindrical portion. That is, the boss is connected to the outer cylindrical portion by the lid and integrated with the hub. A reinforcing rib is also formed between the hub and the boss.

  In the conventional axial fan described above, the connection strength between the hub and the boss may not be sufficiently obtained.

  An object of the present invention is to connect a hub and a boss in an axial fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted and a plurality of blades are integrally molded with a resin together with the hub. It is to improve the strength.

  The axial fan according to the first aspect is an axial fan in which a boss formed with an axial hole into which the shaft of the drive motor is inserted at the center of the hub and a plurality of blades are integrally molded with the hub. The hub has an outer peripheral side cylinder part and a cover part. The outer peripheral side cylindrical portion is a portion having a plurality of blades so as to protrude from the outer peripheral edge and having an opening in the axial center. The lid portion extends from the outer peripheral side cylinder portion toward the boss so as to cover the opening of the outer peripheral side cylindrical portion, and is a portion that connects the boss and the outer peripheral side cylindrical portion. Reinforcing ribs for reinforcing the connection between the hub and the boss are integrally molded with the hub and the boss on both sides in the axial direction of the lid.

  In the conventional axial fan, the reinforcing rib is formed between the hub and the boss, but the reinforcing rib is formed only on one side of the lid in the axial direction. This is a cause of insufficient connection strength between the hub and the boss.

  Therefore, in this axial fan, reinforcing ribs are formed on both sides in the axial direction of the lid portion as described above.

  Thereby, in this axial fan, the reinforcement between the hub and the boss can be strengthened, and the connection strength between the hub and the boss can be improved.

  The axial fan according to the second aspect is the axial fan according to the first aspect, wherein the lid portion extends in the axial direction from the outer peripheral side cylinder portion toward the inner peripheral side. And the reinforcement rib has the outer peripheral side reinforcement rib which connects between an outer peripheral side cylinder part and a cover part, and the inner peripheral side reinforcement rib which connects between a cover part and a boss | hub.

  In this axial fan, the lid portion extends in the axial direction from the outer cylindrical portion toward the inner peripheral side. Therefore, a space is formed between the lid portion and the outer cylindrical portion on the one axial side of the lid portion, and between the boss and the lid portion on the other axial side of the lid portion. Another space is formed. And the outer peripheral side reinforcement rib is formed in the space of the axial direction one side of a cover part, and the inner peripheral side reinforcement rib is formed in the space of the axial direction other side of a cover part.

  Thereby, in this axial fan, the reinforcement between the hub and the boss can be strengthened by the two types of reinforcing ribs formed on both sides of the lid in the axial direction.

  The axial fan according to the third aspect is the axial fan according to the second aspect, wherein the boss extends from the inner peripheral edge of the lid portion toward the side closer to the drive motor. Further, a washer insertion portion formed of a recess for fitting a washer for preventing the shaft from rotating is formed on the end surface of the boss far from the drive motor.

  In this axial flow fan, a washer-inserted portion is formed on the end face on the side far from the drive motor of the boss. Therefore, a thin portion exists near the end face on the side far from the drive motor of the boss. For this reason, in this axial flow fan, the strength at the connecting portion between the boss and the inner peripheral edge of the lid portion tends to decrease.

  However, in this axial flow fan, as described above, the reinforcement between the boss and the lid is reinforced by the inner peripheral side reinforcing rib.

  Thereby, in this axial flow fan, although the strength at the connection portion between the boss and the inner peripheral edge of the lid portion is likely to be lowered, the connection strength between the boss and the lid portion can be sufficiently obtained. it can.

  The axial fan according to the fourth aspect is the axial fan according to the second or third aspect, wherein a plurality of outer peripheral side reinforcing ribs and inner peripheral side reinforcing ribs are arranged at intervals in the circumferential direction. Yes.

  The axial fan according to the fifth aspect is the axial fan according to the fourth aspect, wherein a plurality of columnar ribs are left at intervals in the circumferential direction in a portion on the outer peripheral side of the axial hole of the boss. The boss meat stealing part is formed.

  In this axial fan, the transmission of vibration such as cogging sound from the boss to the hub can be mitigated by the plurality of columnar ribs. That is, the plurality of columnar ribs function as a vibration absorbing structure of the axial fan.

  Thereby, in this axial flow fan, the noise resulting from vibrations, such as a cogging sound, can be suppressed.

  An axial fan according to a sixth aspect is the axial fan according to the fifth aspect, in which the columnar ribs are arranged at the same circumferential position as the inner peripheral reinforcing rib.

  In this axial fan, the columnar rib functions as an integral reinforcing rib that penetrates between the boss and the lid portion in the radial direction together with the inner peripheral reinforcing rib.

  Thereby, in this axial fan, between a boss | hub and a cover part can be connected still more firmly.

  An axial fan according to a seventh aspect is the axial fan according to any one of the fourth to sixth aspects, wherein the outer peripheral reinforcing ribs are arranged between the circumferential directions of the inner peripheral reinforcing ribs.

  As described above, according to the present invention, the following effects can be obtained.

  In the axial fan according to the first aspect, the reinforcement between the hub and the boss can be strengthened, and the connection strength between the hub and the boss can be improved.

  In the axial fan according to the second aspect, the reinforcement between the hub and the boss can be strengthened by two types of reinforcing ribs formed on both sides of the lid in the axial direction.

  In the axial fan according to the third, fourth, or seventh aspect, the strength between the boss and the inner peripheral edge of the lid portion tends to decrease, but the gap between the boss and the lid portion is low. A sufficient connection strength can be obtained.

  In the axial fan according to the fifth aspect, noise caused by vibration such as cogging noise can be suppressed.

  In the axial fan according to the sixth aspect, the boss and the lid can be more firmly connected.

It is a top view which shows the state which removed the top plate of the outdoor unit as which the outdoor fan as an axial fan concerning one Embodiment of this invention was employ | adopted. It is a front view of the outdoor unit by which the outdoor fan concerning one Embodiment of this invention was employ | adopted. It is a perspective view of the outdoor fan concerning one embodiment of the present invention. It is a negative surface side top view of the outdoor fan concerning one embodiment of the present invention. It is a positive pressure surface side top view of an outdoor fan concerning one embodiment of the present invention. It is II sectional drawing of FIG.4 and FIG.5. It is II-II sectional drawing of FIG.4 and FIG.5. It is sectional drawing of the outdoor fan concerning the modification 1, and is a figure corresponding to FIG. It is sectional drawing of the outdoor fan concerning the modification 1, and is a figure corresponding to FIG. It is a perspective view of the outdoor fan concerning the modification 2. It is a negative pressure side plan view of an outdoor fan according to Modification 2. FIG. 10 is a plan view of a positive pressure surface side of an outdoor fan according to a second modification. It is II sectional drawing of FIG.11 and FIG.12. It is II-II sectional drawing of FIG.11 and FIG.12.

  Hereinafter, an embodiment of an axial fan according to the present invention will be described with reference to the drawings. In addition, the specific structure of the axial fan concerning this invention is not restricted to the following embodiment, It can change in the range which does not deviate from the summary of invention. In the following description, an example in which the present invention is applied to an axial fan constituting an outdoor unit will be described. However, the present invention is not limited to this and can be applied to an axial fan used for other purposes. It is.

(1) Overall Configuration of Outdoor Unit FIGS. 1 and 2 are views showing an outdoor unit 2 of an air conditioner that employs an outdoor fan 70 as an axial fan according to an embodiment of the present invention. Here, FIG. 1 is a plan view showing a state in which the top plate 57 of the outdoor unit 2 is removed. FIG. 2 is a front view of the outdoor unit 2. In the following explanation, directions and surfaces such as “top”, “bottom”, “left”, “right”, “front”, “side”, “back”, “top”, “bottom” are shown. The wording means a direction and a surface when the outdoor unit 2 shown in FIG.

  The outdoor unit 2 has a structure (so-called trunk type structure) in which the blower chamber S1 and the machine chamber S2 are formed by dividing the internal space of the unit casing 51 into left and right by a partition plate 58 extending in the vertical direction. . The outdoor unit 2 is configured to suck outdoor air into the unit casing 51 from a part of the back surface and side surface of the unit casing 51 and blow out outdoor air from the front surface of the unit casing 51. The outdoor unit 2 mainly includes a unit casing 51, a compressor 21, an outdoor heat exchanger 24, refrigerant circuit components including refrigerant pipes connecting these devices, an outdoor fan 70 (axial fan), And a bell mouth 80. Here, an example in which the blower chamber S1 is formed near the left side surface of the unit casing 51 and the machine chamber S2 is formed near the right side surface of the unit casing 51 will be described, but the left and right sides may be reversed.

  The unit casing 51 is formed in a substantially rectangular parallelepiped shape, and mainly accommodates the compressor 21, the outdoor heat exchanger 24, refrigerant circuit components including refrigerant pipes connecting these devices, and the outdoor fan 70. doing. The unit casing 51 includes a bottom plate 52, a blower chamber side plate 53, a machine chamber side plate 54, a blower chamber side front plate 55, a machine chamber side front plate 56, and a top plate 57.

  The bottom plate 52 is a metal plate member that constitutes the bottom surface portion of the unit casing 51. Below the bottom plate 52, two foundation legs 59 and 60 fixed to the field installation surface are provided.

  The blower chamber side plate 53 is a metal plate-like member that constitutes a side surface portion of the unit casing 51 near the blower chamber S1. The lower part of the blower chamber side plate 53 is fixed to the bottom plate 52. The blower room side plate 53 is formed with an outdoor air suction port 53 a that is sucked into the unit casing 51 by the outdoor fan 70.

  The machine room side plate 54 is a metal plate-like member that constitutes a part of a side surface portion of the unit casing 51 near the machine room S2 and a back surface portion of the unit casing 51 near the machine room S2. The lower part of the machine room side plate 54 is fixed to the bottom plate 52. Here, the machine room side plate 54 covers a portion closer to the back surface of the side surface of the machine room S2. Between the rear side end of the blower chamber side plate 53 and the end of the machine chamber side plate 54 on the blower chamber S1 side, an outdoor air suction port 53b that is sucked into the unit casing 51 by the outdoor fan 70 is formed. Has been.

  The blower chamber side front plate 55 is a metal plate-like member that constitutes the front portion of the blower chamber S1 of the unit casing 51 and a part of the front portion of the machine chamber S2 of the unit casing 51. The blower chamber side front plate 55 is provided with an outlet 55 a for blowing outdoor air sucked into the unit casing 51 by the outdoor fan 70. The front side of the outlet 55a is covered with a fan grill 55b. The lower portion of the blower chamber side front plate 55 is fixed to the bottom plate 52, and the left end portion thereof is fixed to the front end portion of the blower chamber side plate 53.

  The machine room side front plate 56 is a metal plate that is removed during a trial run or maintenance in order to access the machine room S2 from the front side of the unit casing 51 and inspect the equipment disposed in the machine room S2. It is a member. The machine room side front plate 56 is a metal plate-like member that constitutes a part of the front part of the machine room S2 of the unit casing 51 and a part of the side part of the machine room S2 of the unit casing 51. The machine room side front plate 56 has an end on the fan chamber S1 side fixed to an end on the machine room S2 side of the fan room side front plate 55, and an end on the back side of the machine room side front plate 55 It is fixed to the end of the. In addition, although a part of front part of machine room S2 of the unit casing 51 is comprised here by the fan room side front board 55, you may be comprised by the machine room side front board 56 here. Further, the chamber side front plate 55 and the blower chamber side front plate 55 and the machine room side front plate 56 may be an integral member.

  The top plate 57 is a metal plate-like member that constitutes the top surface portion of the unit casing 51. The top plate 57 is fixed to the blower chamber side plate 53, the machine room side plate 54, and the blower chamber side front plate 55.

  The partition plate 58 is a metal plate-like member that is disposed on the bottom plate 52 and extends in the vertical direction. The partition plate 58 divides the internal space of the unit casing 51 into left and right to form a blower chamber S1 near the left side and a machine chamber S2 near the right side. The partition plate 58 has a curved shape such that a central portion in the front-rear direction protrudes toward the blower chamber S1. The lower portion of the partition plate 58 is fixed to the bottom plate 52, the front end portion thereof is fixed to the blower chamber side front plate 55, and the rear end portion thereof is the end of the outdoor heat exchanger 24 on the machine room S 2 side. It is fixed to the part.

  The outdoor fan 70 is a propeller type axial flow fan in which a hub 71 and a plurality of (here, three) blades 91 formed so as to protrude from the outer peripheral edge of the hub 71 are integrally molded with resin. . The outdoor fan 70 is provided so as to face the front surface of the unit casing 51 in the blower chamber S1. More specifically, the outdoor fan 70 is provided at a position on the front surface side of the outdoor heat exchanger 24 so as to face the air outlet 55 a formed in the blower room side front plate 55. Here, a recessed portion 101 that is recessed toward the front edge side of the blade 91 is formed on the rear edge of the blade 91 in order to improve air blowing performance and suppress noise. The outdoor fan 70 is rotationally driven by a fan motor 89 disposed between the outdoor fan 70 and the outdoor heat exchanger 24 in the front-rear direction. The fan motor 89 is supported by a fan motor base 61 that extends between the top plate 57 and the bottom plate 52 in the vertical direction. The detailed configuration of the outdoor fan 70 will be described later.

  The bell mouth 62 is a member having a bell-shaped opening 62 a having an opening at the center, and is provided on the outer peripheral side of the outdoor fan 70. That is, the bell mouth 62 is provided so as to face the front surface of the unit casing 51 in the blower chamber S <b> 1 like the outdoor fan 70, and the opening 62 a surrounds the outer periphery of the outdoor fan 70. The bell mouth 62 is fixed to the front surface of the unit casing 51. A portion of the bell mouth 62 near the blower room side plate 53 is disposed close to the front end of the outdoor heat exchanger 24. Further, the portion of the bell mouth 62 near the machine room S <b> 1 is disposed close to the partition plate 58.

  The outdoor heat exchanger 24 is a substantially L-shaped heat exchanger panel, and is disposed on the bottom plate 52 along the left side surface and the back surface of the unit casing 51 in the blower chamber S1.

  The compressor 21 is a vertical cylindrical hermetic compressor and is disposed in the machine room S2.

  In addition, although illustration is abbreviate | omitted here, refrigerant circuit components, such as apparatuses other than the compressor 21, and a refrigerant pipe, are also arrange | positioned in machine room S2.

(2) Detailed structure of outdoor fan Next, the detailed structure of the outdoor fan 70 as an axial fan concerning this embodiment is demonstrated using FIGS. Here, FIG. 3 is a perspective view of the outdoor fan 70. FIG. 4 is a plan view of the positive pressure surface side of the outdoor fan 70. FIG. 5 is a plan view of the negative pressure surface side of the outdoor fan 70. 6 is a cross-sectional view taken along the line II of FIG. 4 and FIG. 7 is a cross-sectional view taken along the line II-II in FIGS. 4 and 5. In the following description, the axis (rotation center) of the outdoor fan 70 is defined as the axis O, and the axis is defined as the rotation axis OO. Further, the direction along the rotational axis OO is defined as the axial direction, the state of the outdoor fan 70 viewed from the axial direction is defined as a plan view, and the direction orthogonal to the planar view (that is, the outdoor fan 70 is aligned with the rotational axis OO). The cross-sectional view is the direction in which the cross-section cut in the direction along the line is viewed.

  As described above, the outdoor fan 70 is a propeller fan in which the hub 71 and a plurality of (here, three) blades 91 formed so as to protrude from the outer peripheral edge of the hub 71 are integrally molded with resin. is there. The number of blades 91 is not limited to three, and may be four or more. Further, in the outdoor fan 70, a boss 81 in which a shaft hole 82 into which a shaft 89a of a fan motor 89 as a drive motor is inserted is formed in the hub 71 is integrally molded with the hub 71.

  The blades 91 have a blade shape that moves forward and forward. And the thickness of the blade | wing 72 is large in the base part with the hub 71, and is small as it goes to the outer peripheral side. The recessed part 101 formed in the rear edge of the blade | wing 91 is arrange | positioned rather than the base part at the outer peripheral side. Here, the surface on the side into which air flows when the outdoor fan 70 is rotated (the upstream side in the air flow direction) is defined as the negative pressure surface 91a, and the surface on the opposite side (the downstream side in the air flow direction) is the positive surface. The pressure surface 91b is used.

  The hub 71 mainly has an outer peripheral side cylinder portion 72 and a lid portion 73. A plurality of blades 91 are formed on the outer peripheral side cylindrical portion 72 so as to protrude from the outer peripheral edge, and the portion having an opening 72 a in the axis O. Here, the outer peripheral side cylinder part 72 has a cylindrical shape.

  The lid portion 73 extends from the outer peripheral side cylindrical portion 72 toward the boss 81 so as to cover the opening 72 a of the outer peripheral side cylindrical portion 72, and is a portion that connects between the boss 81 and the outer peripheral side cylindrical portion 72. Specifically, the lid portion 73 extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side and in the axial direction. Here, the cover part 73 has the outer peripheral side board part 73a, the intermediate | middle cylinder part 73b, and the inner peripheral side board part 73c. The outer peripheral side plate portion 73a is an annular portion that extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side. The outer peripheral side plate portion 73a extends from the end of the outer peripheral side cylindrical portion 72 on the axial fan motor 89 side toward the inner peripheral side, and is connected to the intermediate cylindrical portion 73b. The intermediate cylinder portion 73b is a cylindrical portion extending in the axial direction from the outer peripheral side plate portion 73a. The intermediate cylinder portion 73b extends from the inner peripheral edge of the outer peripheral side plate portion 73a in a direction away from the fan motor 89, and is connected to the inner peripheral side plate portion 73c. The inner peripheral side plate portion 73c is an annular portion that extends from the intermediate cylindrical portion 73b toward the inner peripheral side. The inner peripheral side plate portion 73 c extends from the end of the intermediate cylinder portion 73 b on the side opposite to the axial direction in the fan motor 89 toward the inner peripheral side, and is connected to the boss 81. That is, here, the outer peripheral side plate portion 73a and the inner peripheral side plate portion 73c extending toward the inner peripheral side and the intermediate cylindrical portion 73b extending in the axial direction as a whole from the outer peripheral side cylindrical portion 72 toward the inner peripheral side. And the cover part 73 extended in an axial direction is comprised.

  As described above, the boss 81 is a cylindrical portion in which the shaft hole 82 is formed, and extends from the inner peripheral edge of the lid portion 73 (here, the inner peripheral side plate portion 73c) toward the side closer to the fan motor 89. ing. A portion of the shaft hole 82 closer to the fan motor 89 is a circular round hole 82a having an inner diameter into which the shaft 89a of the fan motor 89 can be inserted. Further, the portion of the shaft hole 82 far from the fan motor 89 is a D-shaped D-shaped hole 82b into which a D-cut portion 89b having a D-shaped cross section formed at the tip of the shaft 89a can be inserted. Further, a washer fitting portion 83 a made of a recess for fitting a washer 87 for preventing the shaft 89 from rotating is formed on the end face 83 of the boss 81 far from the fan motor 89. Specifically, the shaft 89 is fixed to the boss 81 by screwing a nut 88 formed with a female screw to be screwed into a male screw portion formed at the tip of the shaft 89 while being inserted into the boss 81. The At this time, simply screwing the nut 88 into the shaft 89 may cause the shaft 89 to rotate relative to the boss 81. Therefore, first, as described above, the D-shaped hole 82b is formed in the shaft hole 82 of the boss 81, and the D-cut portion 89b of the shaft 89a is inserted into the D-shaped hole 82b. Moreover, the washer 87 is formed on the end face 83 of the boss 81 far from the fan motor 89, and a washer 87 having a D-shaped hole 87a having the same size as the D-shaped hole 82b is fitted into the washer fitting portion 83a. Does not rotate with respect to the boss 81. Here, the washer 87 has a quadrangular shape, and the washer fitting portion 83a is a quadrangular recess. Thus, the shaft 89 is prevented from rotating by the D-shaped hole 82 b formed in the boss 81 and the washer 87. Here, since the shaft 89 is a metal member, if the shaft 89 is prevented from rotating only by the D-shaped hole 82b formed in the resin-made boss 81, the shaft 89 causes damage in the vicinity of the D-shaped hole 82b of the boss 81. It tends to occur. However, here, since the rotation prevention by the metal washer 87 is added, the occurrence of damage near the D-shaped hole 82b of the boss 81 can be suppressed.

  In the outdoor fan 70 made of such a resin axial fan, it is preferable to sufficiently improve the connection strength between the hub 71 and the boss 81. In particular, since the washer fitting portion 83a is formed on the end surface 83 of the boss 81 far from the fan motor 89, a thin portion is formed near the end surface 83 of the boss 81 far from the fan motor 89. Is present. For this reason, in the outdoor fan 70, the strength at the connecting portion between the boss 81 and the inner peripheral edge of the lid portion 73 (here, the inner peripheral edge of the inner peripheral side plate portion 73c) tends to decrease.

  Therefore, in the outdoor fan 70, the reinforcing ribs 74 and 75 for reinforcing the connection between the hub 71 and the boss 81 are integrally molded with the hub 71 and the boss 81 on both sides in the axial direction of the lid 73. ing. The outer peripheral side reinforcing rib 74 is a rib that connects between the outer peripheral side cylindrical portion 72 and the lid portion 73. The outer peripheral reinforcing rib 74 is formed in a space S <b> 1 formed between the radial direction of the lid portion 73 and the outer cylindrical portion 72 on one axial side of the lid portion 73 (here, the side far from the fan motor 89). Has been. A plurality (six in this case) of outer peripheral side reinforcing ribs 74 are arranged at intervals in the circumferential direction. The outer peripheral side reinforcing rib 74 is a plate-like portion extending from the inner peripheral surface of the outer peripheral side cylindrical portion 72 toward the surface on the one axial side of the outer peripheral side plate portion 73a of the lid portion 73 and the outer peripheral surface of the intermediate cylindrical portion 73b. . The inner circumferential side reinforcing rib 75 is a rib that connects the lid portion 73 and the boss 81. The inner peripheral side reinforcing rib 75 is formed in a space S <b> 2 formed between the boss 81 and the lid portion 73 in the radial direction on the other axial side of the lid portion 73 (here, the side close to the fan motor 89). Yes. A plurality (six in this case) of inner circumferential side reinforcing ribs 75 are arranged at intervals in the circumferential direction. The inner peripheral reinforcing rib 75 is a plate-like portion extending from the inner peripheral surface of the intermediate cylinder portion 73 b of the lid portion 73 and the surface on the other axial side of the inner peripheral plate portion 73 toward the outer peripheral surface of the boss 81. Here, the outer peripheral side reinforcing ribs 74 are arranged between the inner peripheral side reinforcing ribs 75 in the circumferential direction.

  In such an outdoor fan 70, unlike the conventional axial fan in which the reinforcing rib is formed only on one side in the axial direction of the lid portion, the reinforcing ribs 74 and 75 are provided on both sides in the axial direction of the lid portion 73 as described above. Try to form.

  Thereby, in the outdoor fan 70, the reinforcement between the hub 71 and the boss 81 can be strengthened by the two types of reinforcing ribs 74 and 75 formed on both sides in the axial direction of the lid 73. The connection strength with 81 can be improved.

  Further, in the outdoor fan 70, as described above, the strength at the connection portion between the boss 81 and the inner peripheral edge of the lid portion 73 is likely to be reduced. The reinforcement between 81 and the cover part 73 is strengthened.

  Thereby, in the outdoor fan 70, although the intensity | strength in the connection part of the boss | hub 81 and the inner periphery of the cover part 73 is falling easily, sufficient connection strength between the boss | hub 81 and the cover part 73 is fully provided. Can get.

(3) Modification 1
In the outdoor fan 70 (see FIGS. 3 to 7) of the above embodiment, the lid portion 73 is moved from the outer peripheral side cylindrical portion 72 to the inner peripheral side as a whole by the outer peripheral side plate portion 73a, the intermediate cylindrical portion 73b, and the inner peripheral side plate portion 73c. It is configured to extend in the axial direction. However, the present invention is not limited to this. For example, as shown in FIGS. 8 and 9, a portion where the cover portion 73 extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side while being inclined in the axial direction. It may be. Thus, the shape of the cover part 73 is not limited to the thing of the said embodiment, You may make it into various shapes.

(4) Modification 2
In the outdoor fan 70 (see FIGS. 3 to 9) of the above embodiment and the modified example 1, it is preferable to provide a vibration absorbing structure for suppressing noise caused by vibration such as cogging sound.

  Therefore, in the outdoor fan 70 of this modification, as shown in FIGS. 10 to 14, a plurality of (here, six) arranged at intervals in the circumferential direction on the outer peripheral side portion of the shaft hole 82 of the boss 81. The boss meat stealing portion 84 may be formed so that the columnar ribs 85 are left behind.

  Thereby, in the outdoor fan 70 of this modification, the transmission of vibration such as cogging sound from the boss 81 to the hub 71 can be reduced by the plurality of columnar ribs 85. That is, the plurality of columnar ribs 85 function as a vibration absorption structure of the outdoor fan 70.

  Here, the columnar ribs 85 are arranged at the same circumferential position as the inner peripheral side reinforcing ribs 75. For this reason, in the outdoor fan 70 of this modification, the columnar rib 85 functions as an integral reinforcing rib that penetrates between the boss 81 and the lid portion 73 in the radial direction together with the inner peripheral reinforcing rib 84. .

  Thereby, in the outdoor fan 70 of this modification, between the boss | hub 81 and the cover part 73 can be connected still more firmly.

  Further, here, the columnar rib 85 is formed so as not to penetrate the end face 83 of the boss 81 far from the fan motor 89.

  Thereby, in the outdoor fan 70 of this modification, the strong connection between the boss 81 and the lid portion 73 and vibration are suppressed while suppressing a decrease in strength near the end face 83 on the side far from the fan motor 89 of the boss 81. Absorption structure can be installed.

  10 to 14, the boss meat stealing portion 84 and the columnar rib 85 are formed on the boss 81 of the outdoor fan 70 shown in FIGS. 3 to 7, but the outdoor fan shown in FIGS. 8 and 9 is used. The boss meat stealing portion 84 and the columnar rib 85 may be formed on the 70 bosses 81.

  The present invention is widely applicable to an axial fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted at the shaft center of a hub and a plurality of blades are integrally molded with a resin together with the hub.

70 Axial flow fan 71 Hub 72 Outer peripheral side cylinder part 72a Opening 73 Lid part 74 Outer peripheral side reinforcing rib 75 Inner peripheral side reinforcing rib 81 Boss 82 Axial hole 83 End face of boss far from fan motor 83a Washer fitting part 84 Boss meat Stealing part 85 Columnar rib 87 Washer 89 Fan motor (drive motor)
89a Shaft 91 Blade

JP-A-5-340383 JP 2011-74817 A

  The present invention relates to an axial flow fan, and more particularly to an axial flow fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted at the axial center of a hub and a plurality of blades are integrally molded with a hub.

  Conventionally, as shown in Patent Documents 1 and 2 (Japanese Patent Laid-Open Nos. 5-340383 and 2011-74817), a boss in which a shaft hole into which a shaft of a drive motor is inserted is formed at the center of a hub. And an axial fan in which a plurality of blades are integrally molded with a resin together with a hub. Here, the hub has an outer peripheral side cylinder part and a cover part. The outer peripheral side cylindrical portion is a portion having a plurality of blades so as to protrude from the outer peripheral edge and having an opening in the axial center. The lid portion extends from the outer peripheral side cylinder portion toward the boss so as to cover the opening of the outer peripheral side cylindrical portion, and is a portion that connects the boss and the outer peripheral side cylindrical portion. That is, the boss is connected to the outer cylindrical portion by the lid and integrated with the hub. A reinforcing rib is also formed between the hub and the boss.

  In the conventional axial fan described above, the connection strength between the hub and the boss may not be sufficiently obtained.

  An object of the present invention is to connect a hub and a boss in an axial fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted and a plurality of blades are integrally molded with a resin together with the hub. It is to improve the strength.

  The axial fan according to the first aspect is an axial fan in which a boss formed with an axial hole into which the shaft of the drive motor is inserted at the center of the hub and a plurality of blades are integrally molded with the hub. The hub has an outer peripheral side cylinder part and a cover part. The outer peripheral side cylindrical portion is a portion having a plurality of blades so as to protrude from the outer peripheral edge and having an opening in the axial center. The lid portion extends from the outer peripheral side cylinder portion toward the boss so as to cover the opening of the outer peripheral side cylindrical portion, and is a portion that connects the boss and the outer peripheral side cylindrical portion. Reinforcing ribs for reinforcing the connection between the hub and the boss are integrally molded with the hub and the boss on both sides in the axial direction of the lid.

  In the conventional axial fan, the reinforcing rib is formed between the hub and the boss, but the reinforcing rib is formed only on one side of the lid in the axial direction. This is a cause of insufficient connection strength between the hub and the boss.

  Therefore, in this axial fan, reinforcing ribs are formed on both sides in the axial direction of the lid portion as described above.

  Thereby, in this axial fan, the reinforcement between the hub and the boss can be strengthened, and the connection strength between the hub and the boss can be improved.

Moreover, the axial fan has a lid portion that extends in the axial direction from the outer cylindrical portion toward the inner peripheral side. And the reinforcement rib has the outer peripheral side reinforcement rib which connects between an outer peripheral side cylinder part and a cover part, and the inner peripheral side reinforcement rib which connects between a cover part and a boss | hub.

  In this axial fan, the lid portion extends in the axial direction from the outer cylindrical portion toward the inner peripheral side. Therefore, a space is formed between the lid portion and the outer cylindrical portion on the one axial side of the lid portion, and between the boss and the lid portion on the other axial side of the lid portion. Another space is formed. And the outer peripheral side reinforcement rib is formed in the space of the axial direction one side of a cover part, and the inner peripheral side reinforcement rib is formed in the space of the axial direction other side of a cover part.

  Thereby, in this axial fan, the reinforcement between the hub and the boss can be strengthened by the two types of reinforcing ribs formed on both sides of the lid in the axial direction.

Further, in this axial fan, a plurality of outer peripheral side reinforcing ribs and inner peripheral side reinforcing ribs are arranged at intervals in the circumferential direction, and the outer peripheral side reinforcing ribs are disposed between the circumferential directions of the inner peripheral side reinforcing ribs. Is arranged.

The axial fan according to the second aspect is the axial fan according to the first aspect , wherein the boss extends from the inner peripheral edge of the lid portion toward the drive motor. Further, a washer insertion portion formed of a recess for fitting a washer for preventing the shaft from rotating is formed on the end surface of the boss far from the drive motor.

  In this axial flow fan, a washer-inserted portion is formed on the end face on the side far from the drive motor of the boss. Therefore, a thin portion exists near the end face on the side far from the drive motor of the boss. For this reason, in this axial flow fan, the strength at the connecting portion between the boss and the inner peripheral edge of the lid portion tends to decrease.

  However, in this axial flow fan, as described above, the reinforcement between the boss and the lid is reinforced by the inner peripheral side reinforcing rib.

  Thereby, in this axial flow fan, although the strength at the connection portion between the boss and the inner peripheral edge of the lid portion is likely to be lowered, the connection strength between the boss and the lid portion can be sufficiently obtained. it can.

In the axial fan according to the third aspect, in the axial fan according to the first or second aspect, the number of outer peripheral side reinforcing ribs is an integral multiple of the number of inner peripheral side reinforcing ribs.

The axial fan according to the fourth aspect is the axial fan according to any one of the first to third aspects, wherein the connection strength between the hub and the boss is increased by the outer peripheral side reinforcing rib and the inner peripheral side reinforcing rib. It has improved.

The axial fan according to the fifth aspect is the axial fan according to any one of the first to fifth aspects, wherein the outer peripheral reinforcing rib is thick when the outer peripheral reinforcing rib is viewed from the axial direction. The part is formed.

  As described above, according to the present invention, the following effects can be obtained.

In the axial fan according to the first , third to fifth aspects, the reinforcement between the hub and the boss can be strengthened, and the connection strength between the hub and the boss can be improved. And the reinforcement between a hub and a boss | hub can be strengthened with two types of reinforcement ribs formed in the axial direction both sides of a cover part.

In the axial fan according to the second aspect , the connection strength between the boss and the lid is sufficiently obtained even though the strength at the connection between the boss and the inner peripheral edge of the lid tends to decrease. be able to.

It is a top view which shows the state which removed the top plate of the outdoor unit as which the outdoor fan as an axial fan concerning one Embodiment of this invention was employ | adopted. It is a front view of the outdoor unit by which the outdoor fan concerning one Embodiment of this invention was employ | adopted. It is a perspective view of the outdoor fan concerning one embodiment of the present invention. It is a negative surface side top view of the outdoor fan concerning one embodiment of the present invention. It is a positive pressure surface side top view of an outdoor fan concerning one embodiment of the present invention. It is II sectional drawing of FIG.4 and FIG.5. It is II-II sectional drawing of FIG.4 and FIG.5. It is sectional drawing of the outdoor fan concerning the modification 1, and is a figure corresponding to FIG. It is sectional drawing of the outdoor fan concerning the modification 1, and is a figure corresponding to FIG. It is a perspective view of the outdoor fan concerning the modification 2. It is a negative pressure side plan view of an outdoor fan according to Modification 2. FIG. 10 is a plan view of a positive pressure surface side of an outdoor fan according to a second modification. It is II sectional drawing of FIG.11 and FIG.12. It is II-II sectional drawing of FIG.11 and FIG.12.

  Hereinafter, an embodiment of an axial fan according to the present invention will be described with reference to the drawings. In addition, the specific structure of the axial fan concerning this invention is not restricted to the following embodiment, It can change in the range which does not deviate from the summary of invention. In the following description, an example in which the present invention is applied to an axial fan constituting an outdoor unit will be described. However, the present invention is not limited to this and can be applied to an axial fan used for other purposes. It is.

(1) Overall Configuration of Outdoor Unit FIGS. 1 and 2 are views showing an outdoor unit 2 of an air conditioner that employs an outdoor fan 70 as an axial fan according to an embodiment of the present invention. Here, FIG. 1 is a plan view showing a state in which the top plate 57 of the outdoor unit 2 is removed. FIG. 2 is a front view of the outdoor unit 2. In the following explanation, directions and surfaces such as “top”, “bottom”, “left”, “right”, “front”, “side”, “back”, “top”, “bottom” are shown. The wording means a direction and a surface when the outdoor unit 2 shown in FIG.

  The outdoor unit 2 has a structure (so-called trunk type structure) in which the blower chamber S1 and the machine chamber S2 are formed by dividing the internal space of the unit casing 51 into left and right by a partition plate 58 extending in the vertical direction. . The outdoor unit 2 is configured to suck outdoor air into the unit casing 51 from a part of the back surface and side surface of the unit casing 51 and blow out outdoor air from the front surface of the unit casing 51. The outdoor unit 2 mainly includes a unit casing 51, a compressor 21, an outdoor heat exchanger 24, refrigerant circuit components including refrigerant pipes connecting these devices, an outdoor fan 70 (axial fan), And a bell mouth 80. Here, an example in which the blower chamber S1 is formed near the left side surface of the unit casing 51 and the machine chamber S2 is formed near the right side surface of the unit casing 51 will be described, but the left and right sides may be reversed.

  The unit casing 51 is formed in a substantially rectangular parallelepiped shape, and mainly accommodates the compressor 21, the outdoor heat exchanger 24, refrigerant circuit components including refrigerant pipes connecting these devices, and the outdoor fan 70. doing. The unit casing 51 includes a bottom plate 52, a blower chamber side plate 53, a machine chamber side plate 54, a blower chamber side front plate 55, a machine chamber side front plate 56, and a top plate 57.

  The bottom plate 52 is a metal plate member that constitutes the bottom surface portion of the unit casing 51. Below the bottom plate 52, two foundation legs 59 and 60 fixed to the field installation surface are provided.

  The blower chamber side plate 53 is a metal plate-like member that constitutes a side surface portion of the unit casing 51 near the blower chamber S1. The lower part of the blower chamber side plate 53 is fixed to the bottom plate 52. The blower room side plate 53 is formed with an outdoor air suction port 53 a that is sucked into the unit casing 51 by the outdoor fan 70.

  The machine room side plate 54 is a metal plate-like member that constitutes a part of a side surface portion of the unit casing 51 near the machine room S2 and a back surface portion of the unit casing 51 near the machine room S2. The lower part of the machine room side plate 54 is fixed to the bottom plate 52. Here, the machine room side plate 54 covers a portion closer to the back surface of the side surface of the machine room S2. Between the rear side end of the blower chamber side plate 53 and the end of the machine chamber side plate 54 on the blower chamber S1 side, an outdoor air suction port 53b that is sucked into the unit casing 51 by the outdoor fan 70 is formed. Has been.

  The blower chamber side front plate 55 is a metal plate-like member that constitutes the front portion of the blower chamber S1 of the unit casing 51 and a part of the front portion of the machine chamber S2 of the unit casing 51. The blower chamber side front plate 55 is provided with an outlet 55 a for blowing outdoor air sucked into the unit casing 51 by the outdoor fan 70. The front side of the outlet 55a is covered with a fan grill 55b. The lower portion of the blower chamber side front plate 55 is fixed to the bottom plate 52, and the left end portion thereof is fixed to the front end portion of the blower chamber side plate 53.

  The machine room side front plate 56 is a metal plate that is removed during a trial run or maintenance in order to access the machine room S2 from the front side of the unit casing 51 and inspect the equipment disposed in the machine room S2. It is a member. The machine room side front plate 56 is a metal plate-like member that constitutes a part of the front part of the machine room S2 of the unit casing 51 and a part of the side part of the machine room S2 of the unit casing 51. The machine room side front plate 56 has an end on the fan chamber S1 side fixed to an end on the machine room S2 side of the fan room side front plate 55, and an end on the back side of the machine room side front plate 55 It is fixed to the end of the. In addition, although a part of front part of machine room S2 of the unit casing 51 is comprised here by the fan room side front board 55, you may be comprised by the machine room side front board 56 here. Further, the chamber side front plate 55 and the blower chamber side front plate 55 and the machine room side front plate 56 may be an integral member.

  The top plate 57 is a metal plate-like member that constitutes the top surface portion of the unit casing 51. The top plate 57 is fixed to the blower chamber side plate 53, the machine room side plate 54, and the blower chamber side front plate 55.

  The partition plate 58 is a metal plate-like member that is disposed on the bottom plate 52 and extends in the vertical direction. The partition plate 58 divides the internal space of the unit casing 51 into left and right to form a blower chamber S1 near the left side and a machine chamber S2 near the right side. The partition plate 58 has a curved shape such that a central portion in the front-rear direction protrudes toward the blower chamber S1. The lower portion of the partition plate 58 is fixed to the bottom plate 52, the front end portion thereof is fixed to the blower chamber side front plate 55, and the rear end portion thereof is the end of the outdoor heat exchanger 24 on the machine room S 2 side. It is fixed to the part.

  The outdoor fan 70 is a propeller type axial flow fan in which a hub 71 and a plurality of (here, three) blades 91 formed so as to protrude from the outer peripheral edge of the hub 71 are integrally molded with resin. . The outdoor fan 70 is provided so as to face the front surface of the unit casing 51 in the blower chamber S1. More specifically, the outdoor fan 70 is provided at a position on the front surface side of the outdoor heat exchanger 24 so as to face the air outlet 55 a formed in the blower room side front plate 55. Here, a recessed portion 101 that is recessed toward the front edge side of the blade 91 is formed on the rear edge of the blade 91 in order to improve air blowing performance and suppress noise. The outdoor fan 70 is rotationally driven by a fan motor 89 disposed between the outdoor fan 70 and the outdoor heat exchanger 24 in the front-rear direction. The fan motor 89 is supported by a fan motor base 61 that extends between the top plate 57 and the bottom plate 52 in the vertical direction. The detailed configuration of the outdoor fan 70 will be described later.

  The bell mouth 62 is a member having a bell-shaped opening 62 a having an opening at the center, and is provided on the outer peripheral side of the outdoor fan 70. That is, the bell mouth 62 is provided so as to face the front surface of the unit casing 51 in the blower chamber S <b> 1 like the outdoor fan 70, and the opening 62 a surrounds the outer periphery of the outdoor fan 70. The bell mouth 62 is fixed to the front surface of the unit casing 51. A portion of the bell mouth 62 near the blower room side plate 53 is disposed close to the front end of the outdoor heat exchanger 24. Further, the portion of the bell mouth 62 near the machine room S <b> 1 is disposed close to the partition plate 58.

  The outdoor heat exchanger 24 is a substantially L-shaped heat exchanger panel, and is disposed on the bottom plate 52 along the left side surface and the back surface of the unit casing 51 in the blower chamber S1.

  The compressor 21 is a vertical cylindrical hermetic compressor and is disposed in the machine room S2.

  In addition, although illustration is abbreviate | omitted here, refrigerant circuit components, such as apparatuses other than the compressor 21, and a refrigerant pipe, are also arrange | positioned in machine room S2.

(2) Detailed structure of outdoor fan Next, the detailed structure of the outdoor fan 70 as an axial fan concerning this embodiment is demonstrated using FIGS. Here, FIG. 3 is a perspective view of the outdoor fan 70. FIG. 4 is a plan view of the positive pressure surface side of the outdoor fan 70. FIG. 5 is a plan view of the negative pressure surface side of the outdoor fan 70. 6 is a cross-sectional view taken along the line II of FIG. 4 and FIG. 7 is a cross-sectional view taken along the line II-II in FIGS. 4 and 5. In the following description, the axis (rotation center) of the outdoor fan 70 is defined as the axis O, and the axis is defined as the rotation axis OO. Further, the direction along the rotational axis OO is defined as the axial direction, the state of the outdoor fan 70 viewed from the axial direction is defined as a plan view, and the direction orthogonal to the planar view (that is, the outdoor fan 70 is aligned with the rotational axis OO). The cross-sectional view is the direction in which the cross-section cut in the direction along the line is viewed.

  As described above, the outdoor fan 70 is a propeller fan in which the hub 71 and a plurality of (here, three) blades 91 formed so as to protrude from the outer peripheral edge of the hub 71 are integrally molded with resin. is there. The number of blades 91 is not limited to three, and may be four or more. Further, in the outdoor fan 70, a boss 81 in which a shaft hole 82 into which a shaft 89a of a fan motor 89 as a drive motor is inserted is formed in the hub 71 is integrally molded with the hub 71.

  The blades 91 have a blade shape that moves forward and forward. And the thickness of the blade | wing 72 is large in the base part with the hub 71, and is small as it goes to the outer peripheral side. The recessed part 101 formed in the rear edge of the blade | wing 91 is arrange | positioned rather than the base part at the outer peripheral side. Here, the surface on the side into which air flows when the outdoor fan 70 is rotated (the upstream side in the air flow direction) is defined as the negative pressure surface 91a, and the surface on the opposite side (the downstream side in the air flow direction) is the positive surface. The pressure surface 91b is used.

  The hub 71 mainly has an outer peripheral side cylinder portion 72 and a lid portion 73. A plurality of blades 91 are formed on the outer peripheral side cylindrical portion 72 so as to protrude from the outer peripheral edge, and the portion having an opening 72 a in the axis O. Here, the outer peripheral side cylinder part 72 has a cylindrical shape.

  The lid portion 73 extends from the outer peripheral side cylindrical portion 72 toward the boss 81 so as to cover the opening 72 a of the outer peripheral side cylindrical portion 72, and is a portion that connects between the boss 81 and the outer peripheral side cylindrical portion 72. Specifically, the lid portion 73 extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side and in the axial direction. Here, the cover part 73 has the outer peripheral side board part 73a, the intermediate | middle cylinder part 73b, and the inner peripheral side board part 73c. The outer peripheral side plate portion 73a is an annular portion that extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side. The outer peripheral side plate portion 73a extends from the end of the outer peripheral side cylindrical portion 72 on the axial fan motor 89 side toward the inner peripheral side, and is connected to the intermediate cylindrical portion 73b. The intermediate cylinder portion 73b is a cylindrical portion extending in the axial direction from the outer peripheral side plate portion 73a. The intermediate cylinder portion 73b extends from the inner peripheral edge of the outer peripheral side plate portion 73a in a direction away from the fan motor 89, and is connected to the inner peripheral side plate portion 73c. The inner peripheral side plate portion 73c is an annular portion that extends from the intermediate cylindrical portion 73b toward the inner peripheral side. The inner peripheral side plate portion 73 c extends from the end of the intermediate cylinder portion 73 b on the side opposite to the axial direction in the fan motor 89 toward the inner peripheral side, and is connected to the boss 81. That is, here, the outer peripheral side plate portion 73a and the inner peripheral side plate portion 73c extending toward the inner peripheral side and the intermediate cylindrical portion 73b extending in the axial direction as a whole from the outer peripheral side cylindrical portion 72 toward the inner peripheral side. And the cover part 73 extended in an axial direction is comprised.

  As described above, the boss 81 is a cylindrical portion in which the shaft hole 82 is formed, and extends from the inner peripheral edge of the lid portion 73 (here, the inner peripheral side plate portion 73c) toward the side closer to the fan motor 89. ing. A portion of the shaft hole 82 closer to the fan motor 89 is a circular round hole 82a having an inner diameter into which the shaft 89a of the fan motor 89 can be inserted. Further, the portion of the shaft hole 82 far from the fan motor 89 is a D-shaped D-shaped hole 82b into which a D-cut portion 89b having a D-shaped cross section formed at the tip of the shaft 89a can be inserted. Further, a washer fitting portion 83 a made of a recess for fitting a washer 87 for preventing the shaft 89 from rotating is formed on the end face 83 of the boss 81 far from the fan motor 89. Specifically, the shaft 89 is fixed to the boss 81 by screwing a nut 88 formed with a female screw to be screwed into a male screw portion formed at the tip of the shaft 89 while being inserted into the boss 81. The At this time, simply screwing the nut 88 into the shaft 89 may cause the shaft 89 to rotate relative to the boss 81. Therefore, first, as described above, the D-shaped hole 82b is formed in the shaft hole 82 of the boss 81, and the D-cut portion 89b of the shaft 89a is inserted into the D-shaped hole 82b. Moreover, the washer 87 is formed on the end face 83 of the boss 81 far from the fan motor 89, and a washer 87 having a D-shaped hole 87a having the same size as the D-shaped hole 82b is fitted into the washer fitting portion 83a. Does not rotate with respect to the boss 81. Here, the washer 87 has a quadrangular shape, and the washer fitting portion 83a is a quadrangular recess. Thus, the shaft 89 is prevented from rotating by the D-shaped hole 82 b formed in the boss 81 and the washer 87. Here, since the shaft 89 is a metal member, if the shaft 89 is prevented from rotating only by the D-shaped hole 82b formed in the resin-made boss 81, the shaft 89 causes damage in the vicinity of the D-shaped hole 82b of the boss 81. It tends to occur. However, here, since the rotation prevention by the metal washer 87 is added, the occurrence of damage near the D-shaped hole 82b of the boss 81 can be suppressed.

  In the outdoor fan 70 made of such a resin axial fan, it is preferable to sufficiently improve the connection strength between the hub 71 and the boss 81. In particular, since the washer fitting portion 83a is formed on the end surface 83 of the boss 81 far from the fan motor 89, a thin portion is formed near the end surface 83 of the boss 81 far from the fan motor 89. Is present. For this reason, in the outdoor fan 70, the strength at the connecting portion between the boss 81 and the inner peripheral edge of the lid portion 73 (here, the inner peripheral edge of the inner peripheral side plate portion 73c) tends to decrease.

  Therefore, in the outdoor fan 70, the reinforcing ribs 74 and 75 for reinforcing the connection between the hub 71 and the boss 81 are integrally molded with the hub 71 and the boss 81 on both sides in the axial direction of the lid 73. ing. The outer peripheral side reinforcing rib 74 is a rib that connects between the outer peripheral side cylindrical portion 72 and the lid portion 73. The outer peripheral reinforcing rib 74 is formed in a space S <b> 1 formed between the radial direction of the lid portion 73 and the outer cylindrical portion 72 on one axial side of the lid portion 73 (here, the side far from the fan motor 89). Has been. A plurality (six in this case) of outer peripheral side reinforcing ribs 74 are arranged at intervals in the circumferential direction. The outer peripheral side reinforcing rib 74 is a plate-like portion extending from the inner peripheral surface of the outer peripheral side cylindrical portion 72 toward the surface on the one axial side of the outer peripheral side plate portion 73a of the lid portion 73 and the outer peripheral surface of the intermediate cylindrical portion 73b. . The inner circumferential side reinforcing rib 75 is a rib that connects the lid portion 73 and the boss 81. The inner peripheral side reinforcing rib 75 is formed in a space S <b> 2 formed between the boss 81 and the lid portion 73 in the radial direction on the other axial side of the lid portion 73 (here, the side close to the fan motor 89). Yes. A plurality (six in this case) of inner circumferential side reinforcing ribs 75 are arranged at intervals in the circumferential direction. The inner peripheral reinforcing rib 75 is a plate-like portion extending from the inner peripheral surface of the intermediate cylinder portion 73 b of the lid portion 73 and the surface on the other axial side of the inner peripheral plate portion 73 toward the outer peripheral surface of the boss 81. Here, the outer peripheral side reinforcing ribs 74 are arranged between the inner peripheral side reinforcing ribs 75 in the circumferential direction.

  In such an outdoor fan 70, unlike the conventional axial fan in which the reinforcing rib is formed only on one side in the axial direction of the lid portion, the reinforcing ribs 74 and 75 are provided on both sides in the axial direction of the lid portion 73 as described above. Try to form.

  Thereby, in the outdoor fan 70, the reinforcement between the hub 71 and the boss 81 can be strengthened by the two types of reinforcing ribs 74 and 75 formed on both sides in the axial direction of the lid 73. The connection strength with 81 can be improved.

  Further, in the outdoor fan 70, as described above, the strength at the connection portion between the boss 81 and the inner peripheral edge of the lid portion 73 is likely to be reduced. The reinforcement between 81 and the cover part 73 is strengthened.

  Thereby, in the outdoor fan 70, although the intensity | strength in the connection part of the boss | hub 81 and the inner periphery of the cover part 73 is falling easily, sufficient connection strength between the boss | hub 81 and the cover part 73 is fully provided. Can get.

(3) Modification 1
In the outdoor fan 70 (see FIGS. 3 to 7) of the above embodiment, the lid portion 73 is moved from the outer peripheral side cylindrical portion 72 to the inner peripheral side as a whole by the outer peripheral side plate portion 73a, the intermediate cylindrical portion 73b, and the inner peripheral side plate portion 73c. It is configured to extend in the axial direction. However, the present invention is not limited to this. For example, as shown in FIGS. 8 and 9, a portion where the cover portion 73 extends from the outer peripheral side cylindrical portion 72 toward the inner peripheral side while being inclined in the axial direction. It may be. Thus, the shape of the cover part 73 is not limited to the thing of the said embodiment, You may make it into various shapes.

(4) Modification 2
In the outdoor fan 70 (see FIGS. 3 to 9) of the above embodiment and the modified example 1, it is preferable to provide a vibration absorbing structure for suppressing noise caused by vibration such as cogging sound.

  Therefore, in the outdoor fan 70 of this modification, as shown in FIGS. 10 to 14, a plurality of (here, six) arranged at intervals in the circumferential direction on the outer peripheral side portion of the shaft hole 82 of the boss 81. The boss meat stealing portion 84 may be formed so that the columnar ribs 85 are left behind.

  Thereby, in the outdoor fan 70 of this modification, the transmission of vibration such as cogging sound from the boss 81 to the hub 71 can be reduced by the plurality of columnar ribs 85. That is, the plurality of columnar ribs 85 function as a vibration absorption structure of the outdoor fan 70.

  Here, the columnar ribs 85 are arranged at the same circumferential position as the inner peripheral side reinforcing ribs 75. For this reason, in the outdoor fan 70 of this modification, the columnar rib 85 functions as an integral reinforcing rib that penetrates between the boss 81 and the lid portion 73 in the radial direction together with the inner peripheral reinforcing rib 84. .

  Thereby, in the outdoor fan 70 of this modification, between the boss | hub 81 and the cover part 73 can be connected still more firmly.

  Further, here, the columnar rib 85 is formed so as not to penetrate the end face 83 of the boss 81 far from the fan motor 89.

  Thereby, in the outdoor fan 70 of this modification, the strong connection between the boss 81 and the lid portion 73 and vibration are suppressed while suppressing a decrease in strength near the end face 83 on the side far from the fan motor 89 of the boss 81. Absorption structure can be installed.

  10 to 14, the boss meat stealing portion 84 and the columnar rib 85 are formed on the boss 81 of the outdoor fan 70 shown in FIGS. 3 to 7, but the outdoor fan shown in FIGS. 8 and 9 is used. The boss meat stealing portion 84 and the columnar rib 85 may be formed on the 70 bosses 81.

  The present invention is widely applicable to an axial fan in which a boss formed with an axial hole into which a shaft of a drive motor is inserted at the shaft center of a hub and a plurality of blades are integrally molded with a resin together with the hub.

70 Axial flow fan 71 Hub 72 Outer peripheral side cylinder part 72a Opening 73 Lid part 74 Outer peripheral side reinforcing rib 75 Inner peripheral side reinforcing rib 81 Boss 82 Axial hole 83 End face of boss far from fan motor 83a Washer fitting part 84 Boss meat Stealing part 85 Columnar rib 87 Washer 89 Fan motor (drive motor)
89a Shaft 91 Blade

JP-A-5-340383 JP 2011-74817 A

Claims (7)

The boss (81) in which the shaft hole (82) into which the shaft (89a) of the drive motor (89) is inserted is formed at the shaft center of the hub (71), and the plurality of blades (91) are resin together with the hub. In the integrally formed axial fan,
The hub is formed with the plurality of blades so as to protrude from an outer peripheral edge, and has an outer peripheral side cylinder part (72) having an opening (72a) in an axial center, and the opening of the outer peripheral side cylinder part. A lid portion (73) extending from the outer cylindrical portion toward the boss and connecting between the boss and the outer cylindrical portion;
Reinforcing ribs (74, 75) for reinforcing the connection between the hub and the boss are integrally formed with the hub and the boss on both sides in the axial direction of the lid portion.
An axial fan (70). The lid part (73) extends in the axial direction from the outer peripheral side cylinder part (72) toward the inner peripheral side,
The reinforcing rib includes an outer peripheral reinforcing rib (74) that connects between the outer peripheral cylindrical portion and the lid portion, and an inner peripheral reinforcing rib (74) that connects between the lid portion and the boss (81). 75)
The axial fan (70) according to claim 1. The boss (81) extends from the inner peripheral edge of the lid (73) toward the side closer to the drive motor (89),
On the end surface (83) of the boss remote from the drive motor, a washer fitting portion (83a) is formed which is a recess for fitting a washer (87) for preventing the shaft (89a) from rotating. ing,
The axial fan (70) according to claim 2. A plurality of the outer peripheral side reinforcing ribs (74) and the inner peripheral side reinforcing ribs (75) are arranged at intervals in the circumferential direction.
The axial fan (70) according to claim 2 or 3. A boss meat stealing portion (84) is formed in a portion of the boss (81) on the outer peripheral side of the shaft hole (82) so that a plurality of columnar ribs (85) are left at intervals in the circumferential direction. ing,
The axial fan (70) according to claim 4. The columnar rib (85) is disposed at the same circumferential position as the inner circumferential reinforcing rib (75).
The axial fan (70) according to claim 5. The outer circumferential reinforcing rib (74) is disposed between the circumferential directions of the inner circumferential reinforcing rib (75).
The axial fan (70) according to any one of claims 4 to 6.

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