JP7179609B2 - axial fan - Google Patents

Description

The present invention relates to an axial fan.

Axial fans are widely used for cooling, ventilation, and air conditioning of electronic equipment, home appliances, OA equipment, industrial equipment, etc., and air conditioning and air blowing for vehicles. In an axial fan, one end of a lead wire for supplying power to an internal motor is generally connected to an internal circuit board, and the other end of the lead wire is led out of the casing (housing). (See, for example, Patent Documents 1 and 2, etc.).

In the process of assembling an axial flow fan, when a circuit board with one end of a lead wire connected to it is attached to the casing, the other end of the lead wire is pulled out through a plurality of spokes provided in the wind tunnel of the casing. be.

As another example of an axial flow fan, arm portions are radially provided on the outer periphery of a stator portion having a circuit board to which one end of a lead wire is connected. to the casing.

JP 2013-199861 A JP 2018-115615 A

In the above-described method of passing the lead wires through the plurality of spokes, there is a problem that the workability is poor because the work must be done while the casing is lifted. Also, when a connector is provided on the other end of the lead wire, depending on the size of the connector, it may not pass between the spokes. One end of a lead wire having a connector at the end must be passed between the spokes from the outside and then connected to the circuit board by soldering or the like. In this case, the space for soldering becomes narrower and the work becomes difficult, resulting in poor workability.

Fixing the arms of the stator to the casing eliminates the inconvenience of handling the lead wires, but the central axis of the stator may deviate from the central axis of the casing, and the air blown out from the exhaust port is affected. There is a risk that the flow will become uneven, resulting in a decrease in air volume characteristics and an increase in noise. In addition, since the lead wires drawn to the outside of the casing are not fixed to the casing, the air blown out from the exhaust port of the casing collides with the lead wires, vibrating the lead wires and causing noise.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an axial fan in which lead wires can be easily pulled out of the casing.

To solve the above-described problems and achieve the object, an axial fan according to one aspect of the present invention includes a casing and lead wires. The casing rotatably supports the impeller. The leads are housed in the casing and provide at least power to a motor that rotates the impeller. The casing is formed of two housings, one of which has a notch and the other of which has a projection inserted into the notch. The notch extends from one end of the one housing in the axial direction through a side wall surrounding a wind tunnel formed at the center of the two housings in a circumferential direction with a predetermined width and extends from the wind tunnel side to the outside of the side wall. , extends in the axial direction to just before the other end, and a bottom is formed at the end where the extension stops, and a lead wire space is formed between the protrusion and the bottom. The lead wire is pulled out of the casing through the lead wire space from the inside of the casing.

The axial fan according to one aspect of the present invention can facilitate the work of pulling out the lead wires to the outside of the casing.

FIG. 1 is a front view showing a configuration example of an axial fan according to an embodiment. FIG. 2 is a cross-sectional view showing a configuration example of the axial fan according to the embodiment. FIG. 3 is a perspective view showing a configuration example of a casing. FIG. 4 is a cross-sectional view showing a configuration example of a casing. FIG. 5 is a perspective view (1) showing how a circuit board to which lead wires are connected is incorporated into a casing. FIG. 6 is a perspective view (2) showing how the circuit board to which the lead wires are connected is incorporated into the casing. FIG. 7 is a perspective view (3) showing how the circuit board to which the lead wires are connected is incorporated into the casing. FIG. 8 is a cross-sectional view enlarging the vicinity of the notch. FIG. 9 is a diagram showing a first comparative example. FIG. 10 is a diagram showing a second comparative example.

An axial fan according to an embodiment will be described below with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, the dimensional relationship of each element in the drawings, the ratio of each element, and the like may differ from reality. Even between the drawings, there are cases where portions with different dimensional relationships and ratios are included. In principle, the contents described in one embodiment and modification are similarly applied to other embodiments and modifications.

FIG. 1 is a front view showing a configuration example of an axial fan 1 according to an embodiment. In FIG. 1, the casing 30 of the axial fan 1 includes a first housing 34A and a second housing 34B each having a substantially rectangular outer shape. The first housing 34A and the second housing 34B are superimposed, and only one of the first housings 34A is visible in FIG.

An impeller 20 having a hub 21 and blades 22 is rotatably supported in a cylindrical air channel formed in the center of the first housing 34A and the second housing 34B. In addition, a projecting portion 34A3 is provided on the back side of a portion of the first housing 34A on the front side of the drawing (upper right side surface in the drawing), and a notch portion 34B3 is provided on the corresponding position of the second housing 34B. The projecting portion 34A3 is inserted into the notch portion 34B3 while the side portion of the lead wire 60 is sandwiched between the portions 34B3. Details of the projecting portion 34A3 and the notch portion 34B3 will be described later.

Further, through holes 34A1 and 34B1 are provided at the four corners of the first housing 34A and the second housing 34B so that they can be attached to other devices using bolts or the like. The first housing 34A and the second housing 34B are simultaneously coupled by bolts or the like used for attachment to another device or the like. In addition, the outer shape of the first housing 34A and the second housing 34B is not limited to the rectangular shape shown in the drawing, and may be circular, for example. The number, spacing, and shape of the blades 22 of the impeller 20 are not limited to those illustrated.

FIG. 2 is a cross-sectional view (YY cross-sectional view in FIG. 1) showing a configuration example of the axial fan 1 according to the embodiment. 2, the axial fan 1 includes a motor 10, an impeller 20, a casing 30, bearings 40, a circuit board 50, and lead wires 60. As shown in FIG.

Motor 10 is, for example, an outer rotor type brushless DC motor, and rotates impeller 20 . The motor 10 has a stator core 11 , coils 12 and a rotor 13 .

The stator core 11 is formed by pressing a steel plate made of a soft magnetic material such as a silicon steel plate, and laminating a plurality of pressed steel plates in the axial direction. The stator core 11 has an annular main body portion and a plurality of teeth radially extending outward from the outer peripheral side of the main body portion.

In the following description, the radial direction, axial direction and circumferential direction of the axial fan 1 are defined as follows. Here, the “radial direction” is the direction perpendicular to the rotation axis AX of the impeller 20 rotating inside the axial fan 1, and the “axial direction” is the same as the axial direction of the rotation axis AX of the impeller 20. The “circumferential direction” is the direction that coincides with the rotation direction R of the impeller 20 .

The coil 12 is wound around each of the plurality of teeth via insulators (insulators divided into two in the axial direction) that cover the stator core 11 from both sides in the axial direction.

The rotor 13 rotates relative to the stator core 11 and the coils 12 around the rotation axis AX. The rotor 13 has a shaft 14 , a rotor yoke 15 and rotor magnets 16 . Impeller 20 has a hub 21 and a plurality of blades 22 .

The shaft 14 is cylindrical, extends in the axial direction, and is rotatably supported by a pair of bearings 40 mounted inside the bearing holder 31 .

The hub 21 is cup-shaped, and one end of the shaft 14 is press-fitted into and connected to a projection formed axially inward at the center. A plurality of blades 22 are supported on the outer peripheral surface of hub 21 . The blades 22 all have the same shape and are arranged at equal intervals in the circumferential direction, and for example, gaps are formed between adjacent blades 22 in a plan view. The hub 21 and the plurality of blades 22 are formed by integral molding of resin, for example.

The rotor yoke 15 is made of a soft magnetic material and fixed inside the hub 21 with an adhesive or the like. Alternatively, the rotor yoke may be formed in a cup shape, the central portion of the rotor yoke may be directly attached to the shaft 14, and the hub may be fixed to the outer peripheral surface of the rotor yoke.

The rotor magnet 16 is ring-shaped and joined to the inner peripheral surface of the rotor yoke 15 . The rotor magnet 16 is arranged to face the teeth of the stator core 11, and has a plurality of magnetic poles formed on the inner peripheral surface thereof, in which S poles and N poles are alternately magnetized in the circumferential direction.

The casing 30 has a bearing holder 31, a motor base 32, a plurality of spokes 33, a first housing 34A and a second housing 34B. The bearing holder 31 is made of metal and has a hollow cylindrical shape, and is arranged in an opening of a projecting portion formed in the center of a circular cup-shaped motor base 32 provided in the center of the second housing 34B. The bearing holder 31 may be fitted into the opening of the projecting portion of the motor base 32 , or may be integrally formed with the motor base 32 by inserting the bearing holder 31 . A pair of bearings 40 are mounted on the inner peripheral side of the bearing holder 31, and the stator core 11 and the like are mounted on the outer peripheral side. A motor base 32 to which the motor 10 is mounted is arranged at one end of the second housing 34B.

The plurality of spokes 33 are arranged on the outer peripheral side of the motor base 32 and extend in the radial direction to connect the motor base 32 and the second housing 34B. The first housing 34A and the second housing 34B are formed with a circular hole forming a wind tunnel inside, and each member of the axial flow fan 1 is accommodated in the wind tunnel formed by such a circular hole. The motor base 32, the spokes 33, and the second housing 34B are formed, for example, by integral molding of resin. The first housing 34A and the second housing 34B are divided into two above the spokes 33 of the second housing 34B.

In the casing 30, a suction port 35 is formed on one side (upper side in FIG. 2) of the first housing 34A in the axial direction, and a discharge port 35 is formed on the other side (lower side in FIG. 2) of the second housing 34B in the axial direction. An outlet 36 is formed. As the impeller 20 rotates in the predetermined rotation direction R, an air flow FL is formed from the suction port 35 toward the discharge port 36 .

The bearing 40 is a rolling bearing and supports the shaft 14 rotatably. Note that the bearing 40 may be a fluid bearing or a sliding bearing.

The circuit board 50 has electronic components mounted thereon, has a control circuit for controlling the motor 10 , and is arranged between the stator core 11 and the motor base 32 . One end of a lead wire 60 that supplies at least power to the motor 10 that rotates the impeller 20 is connected to the circuit board 50 . The lead wire 60 is used for, for example, transmission and reception of control signals in addition to power supply. The lead wire 60 is arranged along one spoke 33 within the casing 30 . The other end of the lead wire 60 passes through the lead wire space formed between the bottom of the notch 34B3 provided in the second housing 34B and the projecting portion 34A3 of the first housing 34A, and extends from the inside to the outside. pulled out. The projecting portion 34A3 of the first housing 34A presses the lead wire 60 against the bottom portion of the notch portion 34B3 in a state of being inserted into the notch portion 34B3 of the second housing 34B.

FIG. 3 is a perspective view showing a configuration example of the casing 30. As shown in FIG. In FIG. 3, on the side facing the second housing 34B of the portion provided with the through holes 34A1 at the four corners of the first housing 34A that constitutes the casing 30, there is retreated in the direction opposite to the second housing 34B in the axial direction. A concave portion 34A2 is provided. In addition, as described above, a portion of the first housing 34A (right side of the right front side in the drawing) is provided with a projecting portion 34A3 axially extending toward the second housing 34B side. The projecting portion 34A3 has a tip surface 34A4 facing the second housing 34B and side wall surfaces 34A5 and 34A6 continuing from the tip surface 34A4.

Protrusions 34B2 are provided on the sides facing the first housing 34A of the portions where the through holes 34B1 are provided at the four corners of the second housing 34B, and engage with the recesses 34A2 of the first housing 34A. The first housing 34A and the second housing 34B are accurately positioned by the recess 34A2 of the first housing 34A and the protrusion 34B2 of the second housing 34B.

Further, as described above, a cutout portion 34B3 is provided in a portion of the side wall of the second housing 34B (on the right side of the right front side in the figure). The notch portion 34B3 has a bottom portion 34B4 formed at the end portion in the notch direction, and the side wall portions 34B5 and 34B6 continue to the bottom portion 34B4. The notch portion 34B3 is provided so as to divide a part of the inner peripheral surface of the second housing 34B that faces the outer peripheral portion of the impeller 20, and in a state in which the protruding portion 34A3 of the first housing 34A is inserted, the continuous form a face.

In the illustrated example, the side wall surfaces 34A5 and 34A6 of the first housing 34A and the side wall portions 34B5 and 34B6 of the second housing 34B are flat surfaces. One may be provided with an axial key and the other with a keyway to enhance coupling during insertion. It is desirable that the width of the key protrudes from the surface and the width of the key groove increases as it extends deeper from the surface. In addition, by providing a locking claw on one of the contact surfaces of the projecting portion 34A3 of the first housing 34A and the notch portion 34B3 of the second housing 34B, and providing a concave portion that engages with the locking claw on the other, it is possible to prevent the housing from coming off. You can also plan.

FIG. 4 is a cross-sectional view showing a configuration example of the casing 30, and is a cross-sectional view taken along the line VV in FIG. In FIG. 4, the inner wall of the first housing 34A is provided with a surface 34A11 whose diameter increases toward the suction port 35 side, and a surface 34A12 connected to the surface 34A11 and parallel to the axial direction. Further, the inner wall of the second housing 34B is provided with a surface 34B11 which continues to the surface 34A12 of the first housing 34A and whose diameter increases toward the discharge port 36 side. By increasing the diameters of the suction port 35 side and the discharge port 36 side, the resistance to the amount of air is reduced, and the characteristics of blowing air can be improved.

5 to 7 are perspective views showing how the circuit board 50 to which the lead wires 60 are connected is assembled into the casing 30. FIG. FIG. 5 shows a state in which the circuit board 50 to which the lead wires 60 are connected is incorporated into the second housing 34B on which the first housing 34A is not superimposed. In this case, when the circuit board 50 is arranged in the second housing 34B, the lead wire 60 is inserted from above into the opening of the notch portion 34B3. A connector 61 is connected to the end of the lead wire 60 opposite to the circuit board 50 . The circumference of the lead wire 60 is covered with a tube 62 . FIG. 6 is a bottom view of the casing 30 and the like in FIG. Note that the lead wire 60 does not have to be covered with the tube 62 .

In FIG. 7, the circuit board 50 is accommodated in the second housing 34B, the first housing 34A is superimposed on the second housing 34B, and the protrusion 34A3 of the first housing 34A is inserted into the notch 34B3 of the second housing 34B. is inserted. The lead wire 60 is held down by a lead wire space formed between the bottom portion 34B4 of the cutout portion 34B3 of the second housing 34B and the tip surface of the projecting portion 34A3 of the first housing 34A. FIG. 8 is an enlarged cross-sectional view of the vicinity of the notch 34B3. In FIG. 8, a projecting portion 34A7 is provided on the wind tunnel side of the tip surface 34A4 of the projecting portion 34A3 of the first housing 34A, and a notch portion 34B12 is provided on the wind tunnel side of the bottom portion 34B4 of the notch portion 34B3 of the second housing 34B. The lead wire 60 is locked by pressing the lead wire 60 toward the notch portion 34B12 with the protrusion 34A7.

FIG. 9 is a diagram showing a first comparative example. The left side of FIG. 9 shows a plurality of connectors 113 connected to the other end of a lead wire 112 having one end connected to a circuit board 111, provided in the wind tunnel portion of the casing 101 of the axial fan 100 from the back side of the drawing. , and the lead wire 112 is passed between the spokes 102 and 103 of the retainer 103 and the holding piece 104 . The right side of the drawing shows the state in which the lead wires 112 are arranged.

According to such a method, the work must be performed while the casing 101 is being lifted in order to insert the connector 113, which poses a problem of poor workability. Also, if the connector 113 on the other end of the lead wire 112 is relatively large, it may not pass between the spokes 102 and 103. In that case, the lead wire 112 should not be connected to the circuit board 111. , one end of a lead wire 112 having a connector 113 on the other end must be passed between the spokes 102 and 103 from the front side of the figure and then connected to the circuit board 111 by soldering or the like. In this case, the space for soldering becomes narrower and the work becomes difficult, resulting in poor workability.

FIG. 10 is a diagram showing a second comparative example. In FIG. 10, mounting grooves 202 to 205 are provided on the outer periphery of the wind tunnel portion of the end face of casing 201 of axial flow fan 200, and arm portions 212 to 215 are provided radially on the outer periphery of stator assembly 211. FIG. One end of lead wire 216 is connected to stator assembly 211 , and a connector 217 is connected to the other end of lead wire 216 . Then, the stator assembly 211 is inserted into the casing 201 from the right side of the drawing, and the arm portions 212 to 215 are engaged with the mounting grooves 202 to 205 of the casing 201 for assembly.

According to such a method, there is no inconvenience in handling the lead wire 216, but the central axis of the stator assembly 211 may deviate from the central axis of the casing 201. The gap between the outer peripheral end and the inner peripheral surface of the casing 201 is not uniform in the circumferential direction, and as a result, the flow of air blown out from the exhaust port is uneven, resulting in a decrease in air volume characteristics and an increase in noise. There is a risk that it will occur. In addition, since the lead wire 216 drawn to the outside of the casing 201 is not fixed to the casing 201, the air blown out from the exhaust port of the casing 201 collides with the lead wire 216, causing the lead wire 216 to vibrate and generate noise. There is a risk that it will occur.

Compared to these first and second comparative examples, the embodiment described with reference to FIGS. 1 to 8 has the following advantages.

First, in this embodiment, as shown in FIG. 5, for example, the circuit board 50 to which the lead wires 60 are connected is assembled from above with the second housing 34B of the casing 30 placed on a work desk, Since assembly can be performed by covering the first housing 34A thereon, work can be performed without lifting the casing 30, and workability is not lowered.

In addition, in this embodiment, since the side portion of the lead wire 60 is simply inserted into the opening of the notch portion 34B3 of the second housing 34B, it is not affected by the size of the connector 61, and additional work such as soldering is required. and workability is not lowered.

In addition, in the present embodiment, the motor base 32 is formed in the second housing 34B to ensure the accuracy of the center axis of the motor 10. Therefore, the deviation of the center axis of the stator section can be prevented from deteriorating airflow characteristics and increasing noise. there is no risk of it happening.

Further, in the present embodiment, the lead wire 60 is sandwiched and fixed between the projecting portion 34A3 of the first housing 34A and the notch portion 34B3 of the second housing 34B. will also vibrate and make less noise.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

As described above, the axial fan according to the embodiment includes a casing that rotatably supports an impeller, and lead wires that are housed in the casing and supply at least power to a motor that rotates the impeller. One housing is formed with a notch, the other housing is formed with a projection inserted into the notch, and the notch has a bottom formed at the end on the notch direction side A space for lead wires is formed between the projecting portion and the bottom, and the lead wires are pulled out from the space for lead wires from the inside of the casing to the outside of the casing. As a result, it is possible to provide an axial fan that facilitates the work of pulling out the lead wires to the outside of the casing.

Moreover, the projecting portion presses the lead wire against the bottom portion in a state of being inserted into the notch portion. As a result, the lead wires are fixed, and the generation of vibration and noise can be prevented.

In addition, the casing has an inner peripheral surface facing the impeller, the notch divides a part of the inner peripheral surface, and the projection forms a continuous surface together with the inner peripheral surface when inserted into the notch. Form. As a result, the flow of air sucked from the suction port is not disturbed, and the blowing characteristics are not affected.

Moreover, the present invention is not limited by the above embodiments. The present invention also includes those configured by appropriately combining each of the constituent elements described above. Further effects and modifications can be easily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the above-described embodiments, and various modifications are possible.

Reference Signs List 1 axial fan, 10 motor, 20 impeller, 30 casing, 34A first housing, 34B second housing, 34A3 protrusion, 34A4 tip surface, 34B3 notch, 34B4 bottom, 50 circuit board, 60 lead wire, 61 connector

Claims (3)

a casing that rotatably supports the impeller;
lead wires housed in the casing for supplying at least power to a motor that rotates the impeller;
with
The casing is formed of two housings, one of which has a notch and the other of which has a projection inserted into the notch,
The notch is
From one end of the one housing in the axial direction, a side wall surrounding a wind tunnel formed at the center of the two housings is circumferentially penetrated with a predetermined width from the wind tunnel side to the outside of the side wall, and axially the other. extending to just before the end,
A bottom is formed at the end where the extension stops,
A lead wire space is formed between the protrusion and the bottom,
The lead wire is drawn from the interior of the casing to the outside of the casing from the lead wire space.
axial fan. The projecting portion presses the lead wire against the bottom portion in a state of being inserted into the notch portion.
The axial fan according to claim 1. The casing has an inner peripheral surface facing the impeller,
The notch divides a part of the inner peripheral surface,
The protruding portion forms a continuous surface together with the inner peripheral surface in a state of being inserted into the notch,
The axial fan according to claim 1 or 2.

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