US20190316601A1

US20190316601A1 - Fan unit

Info

Publication number: US20190316601A1
Application number: US16/472,240
Authority: US
Inventors: Masakazu SHIMAMOTO
Original assignee: Nidec Servo Corp
Current assignee: Nidec Advanced Motor Corp
Priority date: 2017-02-13
Filing date: 2018-02-07
Publication date: 2019-10-17
Also published as: EP3581804A4; WO2018147330A1; EP3581804A1; CN110325746A; JPWO2018147330A1

Abstract

A fan main body includes a blade that rotates and a frame that rotatably supports the blade, and a casing including a main body with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess. The housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward. The snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion. A lower surface of the claw portion is inclined upward toward the tip of the claw portion.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This is the U.S. national stage of PCT Application No. PCT/JP2018/004224, filed on Feb. 7, 2018, and priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2017-024095, filed Feb. 13, 2017; the entire disclosures of which are incorporated herein by reference.

1. FIELD OF THE INVENTION

The present disclosure relates to a fan unit.

2. BACKGROUND

A heat dissipation device (fan main body) may be attached to an electric device to dissipate heat generated internally to the outside. As a fixing structure of such a heat dissipation device, one employing screw fixing is known (JP 2000-209717 A).
It is conceivable to reduce costs by adopting a snap fit as a fixing structure of a heat dissipation device. However, in general, a fixing structure using a snap fit has a problem that it is easily loosened and rattled.

SUMMARY

Example embodiments of the present disclosure provide fan assemblies that each include a fixing structure that reduces costs and suppresses loosening and rattling.
One example embodiment of a fan assembly of the present disclosure includes a fan main body including a blade that rotates and a frame that rotatably supports the blade, and a casing including a main body provided with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess. The housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward. The snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion. A lower surface of the claw portion is inclined upward toward the tip of the claw portion. The frame is interposed between and in contact with the lower surface of the claw portion and the housing bottom.
According to one example embodiment of the present disclosure, it is possible to provide a fan assembly including a fixing structure that reduces costs and suppresses loosening and rattling.
The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a fan assembly of one example embodiment of the present disclosure.

FIG. 2 is a plan view of a fan assembly of one example embodiment of the present disclosure.

FIG. 3 is a cross-sectional view taken along line III-III of FIG. 2.

FIG. 4 is a plan view of a casing of one example embodiment of the present disclosure.

FIG. 5 is a partial cross-sectional view taken along line V-V of FIG. 4.

FIG. 6 is a cross-sectional view for explaining a process of housing a fan main body of one example embodiment of the present disclosure in a housing recess.

FIG. 7 is a perspective view of a positioning pin provided to a housing bottom of one example embodiment of the present disclosure.

FIG. 8 is a cross-sectional view of a positioning hole inserted in a positioning hole of one example embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, a fan assembly 1 according to an example embodiment of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, an xyz coordinate system is shown appropriately as a three-dimensional orthogonal coordinate system. In the xyz coordinate system, a z-axis direction is assumed to be a direction parallel to a central axis J of a fan main body 5. A y-axis direction is assumed to be a direction orthogonal to the z-axis direction, extending from the upper right to the lower left in FIG. 1. An x-axis direction is assumed to be a direction orthogonal to both the y-axis direction and the z-axis direction.
In the following description, the positive side (+z side, one side) in the z-axis direction is referred to as an “upper side”, and the negative side (−z side, the other side) in the z-axis direction is referred to as a “lower side”. It should be noted that the definitions of the upper side and the lower side are made simply for the sake of description, and are not meant to restrict actual relative positions or directions. Also, unless otherwise explained, a direction (z-axis direction) parallel to the central axis J is simply referred to as an “axial direction” or a “vertical direction”, a radial direction having its center on the central axis J is simply referred to as a “radial direction”, and a circumferential direction having its center on the central axis J, that is, a direction about the central axis J, is simply referred to as a “circumferential direction”.

FIG. 1 is a perspective view of a fan assembly 1 of the present example embodiment. FIG. 2 is a plan view of the fan assembly 1. FIG. 3 is a cross-sectional view taken along line of FIG. 2. The fan assembly 1 includes two fan main bodies 5 and a casing 2 that houses the two fan main bodies 5. The casing 2 is provided with housing recesses 30 opened to the upper side. The fan main body 5 is inserted into the housing recess 30 of the casing 2 from the upper side, and is housed in the housing recess 30.

[Fan Main Body]

The fan main body 5 has an impeller (blade portion) 50 that rotates around a central axis J extending in the vertical direction, a motor (not shown) that causes the impeller 50 to rotate, and a frame 55 that supports the impeller 50 and the motor.
The impeller 50 has a cylindrical impeller cup 50 a connected to the rotation shaft of the motor along the central axis J, and a plurality of wings 50 b arranged along the circumferential direction from the outer peripheral surface of the impeller cup 50 a. The impeller 50 rotates in a counterclockwise direction as viewed from above, for example. The motor is disposed inside the impeller 50.
The frame 55 is in a form of a rectangular tube extending in the vertical direction. The outer shape of the frame 55 is substantially square when viewed from the vertical direction. The frame 55 circumferentially surrounds the impeller 50 and the motor from the radially outer side. The frame 55 rotatably supports the impeller 50. The frame 55 also supports the motor from below. The frame 55 has corner portions 55 a arranged at the four corners. The corner portion 55 a is substantially triangular when viewed from the vertical direction. The corner portion 55 a has a through hole 55 b. A screw for fixing the frame 55 to the casing 2 can be inserted into the through hole 55 b. Such a screw is used as a backup for a snap fit fixing structure described later. That is, the frame 55 can be fixed to the casing 2 with a screw inserted into the through hole 55 b and fastened to the casing 2, even if the fixing structure by the snap fit is damaged for any reason.
The frame 55 has an upper surface 55 c facing upward and a lower surface 55 d facing downward. The upper surface 55 c and the lower surface 55 d are provided with openings at least in a portion overlapping with the impeller 50 when viewed from the vertical direction, so that the air flow accompanying the rotation of the impeller 50 is not hindered.
As viewed from the upper side, the edge of the frame 55 is provided with four upper holding portions (first holding portions) 56. The upper holding portion 56 is in the form of a plate substantially parallel to the upper surface 55 c. The upper holding portion 56 is located below the upper surface 55 c. The upper holding portion 56 is recessed downward with respect to the upper surface 55 c. As shown in FIG. 3, the upper holding portion includes a first holding upper surface (upper surface) 56 a facing upward, and a first holding lower surface (lower surface) 56 b located on the opposite side of the first holding upper surface 56 a. The four upper holding portions 56 are respectively provided in pairs on two opposing sides of the four sides of the frame 55, when viewed from above. A space is provided above the upper holding portion 56. In the space above the upper holding portion 56, a claw portion 42 of the casing 2, described below, is housed.
As viewed from below, the edge of the frame 55 is provided with four lower holding portions (second holding portions) 59 having the same configuration as that of the upper holding portion 56. The lower holding portion 59 is located above the lower surface 55 d and below the upper holding portion 56. The lower holding portion 59 is recessed upward with respect to the lower surface 55 d. The lower holding portion 59 has a shape in which the upper holding portion 56 is vertically inverted. The lower holding portion 59 overlaps with the upper holding portion as viewed from the vertical direction. The lower holding portion 59 includes a second holding upper surface (upper surface) 59 a facing upward when the fan main body 5 is inverted, and a second holding lower surface (inversion lower surface) 59 b located opposite to the second holding upper surface 59 a. In FIG. 3, the second holding upper surface 59 a faces downward, and the second holding lower surface 59 b faces upward.
According to the present example embodiment, the fan main body 5 has the upper holding portion 56 and the lower holding portion 59 which are disposed at different positions in the vertical direction and overlap with each other when viewed from the vertical direction. In the upper holding portion 56 and the lower holding portion 59, claw portions are hooked to either the upper holding portion 56 or the lower holding portion 59 when the fan main body 5 is inverted. As a result, the fan main body 5 can be housed in the housing recess 30 in an inverted manner, and the air blowing direction to the casing 2 can be easily changed.
As shown in FIG. 3, the lower surface 55 d of the frame 55 contacts the housing bottom 31 in a state where the fan main body 5 is housed in the housing recess 30. The lower surface 55 d has a positioning hole 57 into which a positioning pin 33 provided to the housing bottom 31 is inserted. Similarly, the upper surface 55 c of the frame 55 has a positioning hole 57A. In the positioning hole 57A, the positioning pin 33 is inserted when the fan main body 5 is inverted and housed in the housing recess 30.

[Casing]

FIG. 4 is a plan view of the casing 2. FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4. As shown in FIG. 4, the casing 2 has a main body 3 provided with two housing recesses 30, and snap-fit portions 4 provided four for each housing recess 30. The housing recess 30 houses the fan main body 5 therein. The snap-fit portion 4 fixes the frame 55 of the fan main body 5 in each of the housing recesses 30.

[Main Body 3]

The main body 3 has a rectangular shape in a plan view in which one direction (in the present example embodiment, the y-axis direction) has long sides 3 a and 3 b when viewed from the vertical direction. The main body 3 has a symmetrical shape with respect to a center line L passing through the center of the pair of long sides 3 a and 3 b when viewed from the vertical direction. The main body 3 has an upper surface 3 c facing upward.
The housing recess 30 is recessed downward from the upper surface 3 c of the main body 3 and opens to the upper side. The two housing recesses 30 are provided side by side in the direction in which the long sides 3 a and 3 b of the main body 3 extend. The housing recess 30 has a substantially square shape as viewed from above. The housing recess 30 has a housing bottom 31 having a bottom surface (a surface facing upward) 31 a, and a housing inner circumferential portion 32 extending upward from the housing bottom 31.
The housing bottom 31 is substantially square when viewed from above. The housing bottom 31 has an opening 31 h penetrating in the vertical direction. The opening 31 h of the housing bottom 31 overlaps with at least the impeller 50 of the fan main body 5 when viewed from the vertical direction, and does not inhibit the air flow accompanying the rotation of the impeller 50.
The bottom surface 31 a of the housing bottom 31 is provided with positioning pins 33 for positioning the fan main body 5 in the housing bottom 31. The positioning pin 33 extends upward from the housing bottom 31. The positioning pin 33 is to be inserted into a positioning hole 57 provided in the frame 55.
The housing inner circumferential portion 32 surrounds the housing recess 30 from the radially outer side (horizontal direction). The housing inner circumferential portion 32 extends upward in an angular tube shape from the outer edge of the bottom surface 31 a. As shown in FIG. 4, the housing inner circumferential portion 32 is provided with four recesses 32 a that open to the upper side and to the inner side of the housing recess 30. Two of the four recesses 32 a, provided to one housing recess 30, are provided along one long side 3 b of the main body 3, and the other two are provided along the other long side 3 b. As shown in FIG. 3, the recess 32 a extends downward from the upper surface 3 c of the main body 3 up to the middle of the depth direction (vertical direction) of the housing recess 30. The recess 32 a has a recessed bottom surface 32 b facing upward. The recessed bottom surface 32 b is located between the bottom surface 31 a of the housing recess 30 and the upper surface 3 c of the main body 3 in the vertical direction.

[Snap-Fit Portion]

As shown in FIG. 5, the snap-fit portion 4 includes an elastic portion 41 extending upward along the housing inner circumferential portion 32, a claw portion 42 projecting horizontally from the tip of the upper side the elastic portion 41 toward the inner side of the housing recess 30, and a grip portion 43 positioned above the claw portion 42 and projecting upward.
The elastic portion 41 extends upward from the recessed bottom surface 32 b of the recess 32 a. As shown in FIG. 4, the elastic portion 41 has a rectangular shape having a long side in a direction in which the long sides 3 a and 3 b of the main body 3 extend, when viewed from the vertical direction. The elastic portion 41 is easily bent in a direction (X-axis direction) orthogonal to the extending direction of the long sides 3 a and 3 b of the main body 3. As shown in FIG. 5, the elastic portion 41 has a front surface 41 a facing the inside of the housing recess 30. The elastic portion 41 is elastically deformed in a state where the fan main body 5 is housed in the housing recess 30, and applies a stress of pressing the claw portion 42 to the first holding upper surface 56 a of the fan main body 5.
The claw portion 42 is located at an upper end portion of the elastic portion 41. The claw portion 42 has a tip 42 t located inside the housing recess 30. The claw portion 42 protrudes from the front surface 41 a of the elastic portion 41 toward the tip 42 t. The claw portion 42 also has a claw upper surface (upper surface) 42 b facing upward and a claw lower surface (lower surface) 42 a located on the opposite side thereof and facing downward.
In the process of housing the fan main body 5 in the housing recess 30, when the fan main body 5 is moved downward toward the housing recess 30, the first holding lower surface 56 b of the fan main body 5 slides on the claw upper surface 42 b, and the elastic portion 41 bends and the claw portion 42 moves to the outside of the housing recess 30. Furthermore, at the stage when the first holding upper surface 56 a reaches below the claw lower surface 42 a, the claw portion 42 moves to the inside of the housing recess 30, and the claw portion 42 is caught by the upper holding portion 56.
The claw lower surface 42 a faces the bottom surface 31 a of the housing bottom 31 in a state where the fan main body 5 is not housed in the housing recess 30. The claw lower surface 42 a inclines upward toward the tip 42 t of the claw portion 42. As shown in FIG. 3, the claw lower surface 42 a contacts the first holding upper surface 56 a of the upper holding portion 56 of the frame 55 of the fan main body 5.
In the conventional snap-fit structure, when the dimensions of the object to be fixed by the snap-fit structure vary and become smaller, a gap is generated between the parts engaged with each other. Therefore, the object fixed by the snap fit structure may rattle by the amount of the gap generated.
On the other hand, in the present example embodiment, the distance from the base end in the projecting direction of the claw lower surface 42 a to the bottom surface 31 a is smaller than the distance along the vertical direction between the first holding upper surface 56 a and the lower surface 55 d of the frame 55. Meanwhile, the distance along the vertical direction from the tip in the projecting direction of the claw the lower surface 42 a to the bottom surface 31 a is larger than the distance along the vertical direction between the first holding upper surface 56 a and the lower surface 55 d of the frame 55. In the claw portion 42, the claw lower surface 42 a is inclined as described above. Since the claw lower surface 42 a of the claw portion is pressed to the inside of the housing recess 30 by the elasticity of the elastic portion 41, even if the dimensions along the vertical direction of the first holding upper surface 56 a and the lower surface 55 d of the frame 55 vary, the claw lower surface 42 a contacts the first holding upper surface 56 a at somewhere in the projecting direction. Thus, the frame 55 can be vertically interposed between the claw lower surface 42 a and the bottom surface 31 a, and a stress due to the elasticity of the elastic portion 41 can be applied. The frame 55 is interposed in a state of being in contact with the claw lower surface 42 a and the housing bottom 31, and rattling of the frame 55 is suppressed.
As shown in FIG. 4, four snap-fit portions 4 are provided to each of the housing recesses 30. Since the casing 2 of the present example embodiment is provided with two housing recesses 30, the casing 2 has a total of eight snap-fit portions 4. The four snap-fit portions 4 provided to one housing recess are classified into two first snap-fit portions 4A disposed along one long side 3 a of the main body 3 and two second snap-fit portions 4B arranged along the other long side 3 b. The first snap-fit portions 4A and the second snap-fit portions 4B are paired. The pair of first and second snap- fit portions 4A and 4B oppose each other along a direction (X-axis direction) orthogonal to the direction in which the long sides 3 a and 3 b of the main body 3 extend. The claw portions 42 of the pair of snap-fit portions (first and second snap- fit portions 4A and 4B) face each other. Since the claw lower surface 42 a inclines upward toward the opposed claw portion 42, stresses in the opposite direction are applied to the fan main body 5 from the claw lower surfaces 42 a of the pair of claw portions 42. That is, the claw portions 42 of the pair of snap- fit portions 4A and 4B press the frame 55 to the opposite side, whereby loosening and rattling of the frame 55 can be suppressed.
According to the present example embodiment, it is possible to suppress loosening and rattling of the fan main body housed in the housing recess 30, without using a fastening structure such as a screw. As a result, the number of components can be reduced, the assembly process can be simplified, and cost reduction can be realized.
In the snap-fit portion 4, the pair of claw portions 42 may not necessarily be disposed to face each other. As an example, the snap-fit portion 4 may be disposed only on one long side 3 a of the pair of long sides 3 a and 3 b. In that case, the snap-fit portion 4 generates a stress that presses the fan main body 5 against the housing inner circumferential portion 32 on the other long side 3 b of the housing recess 30, thereby suppressing rattling of the fan main body 5.
The inclination angle θa (see FIG. 5) of the claw lower surface 42 a with respect to the horizontal plane is preferably larger than 0° and smaller than 45°, and more preferably, 3° or larger and 9° or smaller. By setting the inclination angle θa to be larger than 0°, the claw portion 42 can press the frame 55 against the inside of the housing recess 30 to achieve the above-described effect. Further, by setting the inclination angle to be 3° or larger, the stress that the claw portion 42 presses the frame 55 against the inside of the housing recess 30 can be sufficiently increased, and loosening and rattling of the frame 55 can be suppressed more effectively. By setting the inclination angle θa to be smaller than 45°, even in the case where an upward stress is caused in the fan main body 5 in a state where the fan main body 5 is housed in the housing recess 30, it is possible to suppress sliding between the claw lower surface 42 a and the first holding upper surface 56 a, and to suppress detachment of the fan main body 5 from the housing recess 30. Further, by setting the inclination angle θa to be 9° or smaller, detachment of the fan main body 5 can be suppressed more effectively.
The claw upper surface 42 b is inclined downward toward the tip 42 t of the claw portion 42. FIG. 6 is a cross-sectional view for explaining the process of moving the fan main body 5 downward and housing it in the housing recess 30. In the process of housing the fan main body 5 in the housing recess 30, the first holding lower surface 56 b of the fan main body 5 slides on the claw upper surface 42 b. Since the claw upper surface 42 b is inclined downward toward the tip of the claw portion 42, the elastic portion 41 is elastically deformed outward by the stress for moving the fan main body 5 downward, whereby the claw portion 42 can be moved to the outside of the housing recess 30. As a result, the distance between the claw portions 42 of the pair of snap- fit portions 4A and 4B is made wider than the width of the fan main body 5, and the fan main body 5 can be housed in the housing recess 30.
The claw upper surface 42 b is curved in a circular arc, and the inclination with respect to the projecting direction (−x direction in FIG. 5) of the claw portion 42 increases toward the tip 42 t of the claw portion 42. That is, the claw upper surface 42 b is inclined downward while the inclination with respect to the projecting direction of the claw portion 42 is increased toward the tip 42 t of the claw portion 42.
The inclination angle of the claw upper surface 42 b with respect to the projecting direction of the claw portion 42 is referred to as an upper surface inclination angle. When the upper surface inclination angle approaches 90°, the ratio of the component force in the lateral direction, of the force exerted from the first holding lower surface 56 b to the claw upper surface 42 b, increases in the housing process of the fan main body 5. Accordingly, the elastic portion 41 can be elastically deformed with a small force. Therefore, although the fan main body 5 can be housed in the housing recess 30 with a small force, the dimension along the vertical direction of the claw portion 42 is increased.
In the present example embodiment, the claw upper surface 42 b is curved and the inclination of the claw upper surface 42 b with respect to the projecting direction of the claw portion 42 is increased and gradually approached to 90° toward the tip 42 t. As a result, the housing operation of the fan main body 5 can be facilitated, and the dimension of the claw portion 42 in the vertical direction can be sufficiently reduced. In addition, according to the present example embodiment, since the claw upper surface 42 b has the above-described configuration, even when the posture of the claw portion 42 is inclined to the outside of the housing recess 30 due to the elastic deformation of the elastic portion 41, the inclination angle of the claw upper surface 42 b is secured to enable smooth housing operation.
The grip portion 43 protrudes upward from the claw portion 42. By gripping the grip portion 43, the operator can elastically deform the elastic portion 41 so as to move the claw portion 42 toward the outside of the housing recess 30. As a result, the operator can release the engagement of the claw portion 42 with the upper holding portion 56 and take out the fan main body 5 from the housing recess 30.

[Positioning Pin and Positioning Hole]

FIG. 7 is a perspective view of the positioning pin 33 provided to the housing bottom 31. FIG. 8 is a cross-sectional view of the positioning hole 57 inserted in the positioning hole 57.
As shown in FIG. 7, the positioning pin 33 protrudes upward from the bottom surface 31 a of the housing bottom 31. The positioning pin 33 is located inside the recess 33 h formed on the bottom surface 31 a of the housing bottom 31. The recess 33 h is recessed downward. The outer shape of the recess 33 h in the plan view is circular. When viewed from the vertical direction, the positioning pin 33 and the recess 33 h have concentric circular shapes.
The positioning pin 33 has a pin main body 34 extending in the vertical direction along an axis O1 parallel to the vertical direction, and a plurality of ribs 35 provided to the outer peripheral surface of the pin main body 34.
The pin main body 34 has a cylindrical portion 34 b and a tapered portion 34 a. That is, the positioning pin 33 has the cylindrical portion 34 b and the tapered portion 34 a. The cylindrical portion 34 b extends along the axis O1 about the axis O1. The diameter of the cylindrical portion 34 b is uniform. The tapered portion 34 a is located above the cylindrical portion 34 b. In the tapered portion 34 a, the diameter of the positioning pin 33 decreases, from base end 33 b side of the positioning pin 33 toward the tip 34 t. Since the tapered portion 34 a is provided, it facilitates insertion of the positioning pin 33 into the positioning hole 57. That is, the operator can insert the positioning pin 33 into the positioning hole 57 along the tapered portion 34 a only by moving the fan main body 5 downward toward the housing bottom 31. Thereby, positioning can be realized easily.
As shown in FIG. 6, in the process of housing the fan main body 5 in the housing recess 30, the first holding lower surface 56 b contacts the claw upper surface 42 b. Thus, in a state where the first holding lower surface 56 b and the claw upper surface 42 b are in contact with each other, a distance D3 between the lower end of the positioning hole 57 and the housing bottom 31 is smaller than a height d of the positioning pin 33. Therefore, the positioning pin 33 is inserted into the positioning hole 57 before the first holding lower surface 56 b and the claw upper surface 42 b contact each other in the process of moving the fan main body 5 downward and housing it in the housing recess 30. The positioning pin 33 can be inserted into the positioning hole 57 before pressing the fan main body 5 downward to elastically deform the elastic portion 41 of the snap-fit portion 4. The operator does not have to align the positioning pin 33 with the positioning hole 57 while pressing the fan main body 5 downward. Here, the positional relationship in the vertical direction between the upper holding portion 56, the positioning hole 57, and the positioning pin 33 has been described. Such a relationship is also applied to the relationship between the lower holding portion 59, the positioning hole 57A, and the positioning pin 33 when the fan main body 5 is housed in the housing recess 30 in an inverted state. That is, in the state where the fan main body 5 is inverted and the fan main body 5 is moved downward to bring the second holding lower surface 59 b into contact with the claw upper surface 42 b, the distance between the lower end of the positioning hole 57A and the housing bottom 31 is smaller than the height of the positioning pin 33.
The plurality of ribs 35 project radially outward in the radial direction of the axis O1 from the cylindrical portion 34 b of the pin main body 34. Also, the ribs 35 extend along the axis O1. In the present example embodiment, the rib 35 has a prismatic shape elongated in the vertical direction. The rib 35 extends upward along the outer peripheral surface of the cylindrical portion 34 b from the bottom surface of the recess 33 h. The plurality of ribs 35 are equally spaced along the axis O1. In the present example embodiment, four ribs 35 are provided at intervals of 90° around the axis O1 with respect to one pin main body 34.
When the positioning pin 33 is inserted into the positioning hole 57, the plurality of ribs 35 contact the inner circumferential surface of the positioning hole 57. Therefore, the positioning pin 33 can be press-fit into the positioning hole by elastically deforming the ribs 35 inward in the radial direction. Thus, the position of the positioning pin 33 can be suppressed from being shifted with respect to the positioning hole 57. Therefore, the fan main body 5 can be fixed in the housing recess 30 with high positional accuracy without being displaced. Further, as shown in FIG. 7, in the rib 35 of the present example embodiment, the protruding height of the upper end portion decreases from the lower side toward the upper side. Thereby, the easiness in press-fitting the positioning pin 33 into the positioning hole 57 is enhanced.
When the positioning pin 33 is pressed into the positioning hole 57, part of the rib 35 that elastically deforms may be scraped off. According to the present example embodiment, since the recess 33 h is provided, part of the scraped rib 35 falls into the recess 33 h. Therefore, the scraped rib 35 is not pinched between the lower surface 55 d of the frame 55 of the fan main body 5 and the bottom surface 31 a of the housing recess 30, so that the fan main body 5 can be suppressed from rising from the bottom surface 31 a.
The present disclosure is not limited to the above-described example embodiment, and other configurations can be adopted. For example, the number of fan main bodies 5 attached to the casing 2 is not limited to that described in the example embodiment. Moreover, the number of snap-fit portions 4 with respect to one housing recess 30 is not limited to that described in the example embodiment. Further, in the case of having a plurality of snap-fit portions, the claw lower surface 42 a of at least one snap-fit portion 4 may be inclined. Further, the shape of the claw upper surface 42 b is not limited to that described in the example embodiment. Moreover, although the case where the claw portion 42 hooks on the upper holding portion 56 has been illustrated in the example embodiment, it is also possible to employ a structure that it hooks on the upper surface 55 c of the frame 55. Further, the above-described example embodiment employs the configuration in which the lower holding portion 59 is provided to the frame 55 so that the fan main body 5 can be attached to the casing 2 even when the fan main body 5 is inverted. However, it is possible to adopt a structure in which the lower holding portion 59 is not provided, and the fan main body 5 may not be attached to the casing 2 when it is inverted. In that case, it can suppress the case where the fan main body 5 is assembled while being inverted.
The respective configurations can be appropriately combined within a range not inconsistent with each other.
While example embodiments of the present disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The scope of the present disclosure, therefore, is to be determined solely by the following claims.

Claims

1-12. (canceled)

13. A fan assembly comprising:

a fan main body including a blade that rotates, and a frame that rotatably supports the blade; and

a casing including a main body provided with a housing recess in which the fan main body is to be housed, and a snap-fit portion to fix the frame in the housing recess; wherein

the housing recess includes a housing bottom including a surface facing upward and a housing inner circumferential portion extending upward from the housing bottom, and opens upward;

the snap-fit portion includes an elastic portion extending upward along the housing inner circumferential portion, and a claw portion projecting horizontally from a tip end portion of the elastic portion;

a lower surface of the claw portion is inclined upward toward a tip of the claw portion; and

the frame is interposed between and in contact with the lower surface of the claw portion and the housing bottom.

14. The fan assembly according to claim 13, wherein the casing includes at least a pair of the snap-fit portions, and the claw portions of the pair of the snap-fit portions face each other.

15. The fan assembly according to claim 13, wherein an upper surface of the claw portion is inclined downward and increasingly inclined with respect to a projecting direction of the claw portion toward the tip of the claw portion.

16. The fan assembly according to claim 13, wherein the main body includes a positioning pin extending upward from the housing bottom, and the frame includes a positioning hole into which the positioning pin is inserted.

17. The fan assembly according to claim 16, wherein the positioning pin includes a tapered portion in which a diameter of the positioning pin decreases from a base end side toward a tip.

18. The fan assembly according to claim 17, wherein

the fan main body includes a holding portion including an upper surface on which the lower surface of the claw portion contacts and hooks;

a lower surface of the holding portion contacts the upper surface of the claw portion when the fan main body is housed in the housing recess; and

in a state where the lower surface of the holding portion is in contact with the upper surface of the claw portion, a distance between a lower end of the positioning hole and the housing bottom is smaller than a height of the positioning pin.

19. The fan assembly according to claim 16, wherein the positioning pin includes a pin main body extending in a vertical direction, and a plurality of ribs projecting from an outer peripheral surface of the pin main body and extending in the vertical direction.

20. The fan assembly according to claim 13, wherein the fan main body includes a first holding portion and a second holding portion which are at different positions in a vertical direction and overlap with each other when viewed in the vertical direction, and the claw portion hooks on the first holding portion and the second holding portion respectively when the fan main body is inverted.

21. The fan assembly according to claim 20, wherein the main body includes a positioning pin extending upward from the housing bottom, and each of an upper surface and a lower surface of the frame includes a positioning hole into which the positioning pin is inserted when the fan main body is inverted.

22. The fan assembly according to claim 21, wherein the positioning pin includes a tapered portion in which a diameter of the positioning pin decreases from a base end side toward a tip.

23. The fan assembly according to claim 22, wherein a lower surface of one of the first holding portion and the second holding portion contacts the upper surface of the claw portion when the fan main body is housed in the housing recess, and in a state where the lower surface is in contact with the upper surface of the claw portion, a distance between a lower end of the positioning hole and the housing bottom is smaller than a height of the positioning pin.

24. The fan assembly according to claim 21, wherein the positioning pin includes a pin main body extending in a vertical direction, and a plurality of ribs projecting from an outer peripheral surface of the pin main body and extending in the vertical direction.