WO2022224603A1

WO2022224603A1 - Fan motor

Info

Publication number: WO2022224603A1
Application number: PCT/JP2022/009756
Authority: WO
Inventors: ▲方▼ 余; 祐司大村
Original assignee: ミネベアミツミ株式会社
Priority date: 2021-04-23
Filing date: 2022-03-07
Publication date: 2022-10-27
Also published as: JP2022167496A

Abstract

A fan motor (1) according to an embodiment of the present invention comprises an impeller (5), a motor (4), a circuit board (6), a casing (2), and a cover (3). The impeller (5) comprises a hub (5a), and a plurality of vanes (5b) provided on the hub (5a). The motor (4) rotates the impeller (5). An electronic component (7) for controlling the drive of the motor (4) is mounted on the circuit board (6). The casing (2) internally accommodates the impeller (5) and the motor (4). The cover (3) is provided at one end, in an axial direction, of the casing (2). The circuit board (6) is disposed by being bonded to a recessed portion (2f) formed at the other end, in the axial direction, of the casing (2). The electronic component (7) is disposed in an opening (2g) formed in a portion of the recessed portion (2f), and a portion of the electronic component (7) is exposed inside the casing (2). A potting agent (9) applied around the electronic component (7) penetrates into a gap between the casing (2) and the circuit board (6) to seal the same.

Description

fan motor

The present invention relates to fan motors.

Conventionally, in electronic devices such as personal computers and mobile phones, there are cases where fan motors are used to force heat dissipation and cooling in order to improve the heat dissipation of mounted electronic components.

In such electronic devices such as personal computers and mobile phones, it is difficult to secure a large space for incorporating the fan motor, so miniaturization and thinning of the fan motor are required.

In response to such needs, thin fan motors (cooling fans) have been proposed (for example, see Patent Document 1, etc.). In the fan motor described in Patent Document 1, the thickness is reduced by arranging the circuit board in a receiving space provided on one side of the housing.

U.S. Patent Application Publication No. 2015/0301567

However, the fan motor described in Patent Document 1 has a structure in which the soldering points of the circuit board and the electronic components are exposed to the air flow path, so there is the problem that it cannot meet the requirements for waterproof and dustproof functions. was there. That is, when moisture or foreign matter enters the inside of the fan motor, the pins and terminals of the electronic components may be short-circuited or corroded.

The present invention has been made in view of the above, and an object thereof is to provide a thin fan motor having a dustproof and waterproof structure.

To solve the above problems and achieve the object, a fan motor according to one aspect of the present invention includes an impeller, a motor, a circuit board, a casing, and a cover. The impeller includes a hub and a plurality of blades provided on the hub. The motor rotates the impeller. Electronic components for driving and controlling the motor are mounted on the circuit board. The casing houses the impeller and the motor inside. The cover is provided at one axial end of the casing. The circuit board is attached and arranged in a recess formed in the other axial end of the casing. The electronic component is placed in an opening formed in a portion of the recess, and a portion of the electronic component is exposed inside the casing. A potting agent applied around the electronic component enters and seals the gap between the casing and the circuit board.

A fan motor according to one aspect of the present invention has a dustproof and waterproof structure and can be made thin.

FIG. 1 is an external perspective view of a fan motor according to one embodiment. FIG. 2 is an exploded perspective view of the main components of the fan motor. FIG. 3 is an XY-XY cross-sectional view in FIG. 4 is an enlarged cross-sectional view of a main part in FIG. 3. FIG. FIG. 5 is a perspective view of the casing and circuit board. FIG. 6 is a plan view of the casing and circuit board. FIG. 7 is a plan view showing a state in which the periphery of the electronic component on the circuit board exposed through the opening of the casing is sealed with a potting agent. FIG. 8 is a bottom view of the casing. FIG. 9 is a perspective view of a circuit board. FIG. 10 is an external perspective view of a fan motor according to a comparative example.

A fan motor 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 an external perspective view of a fan motor 1 according to one embodiment. FIG. 2 is an exploded perspective view of main components of the fan motor 1. FIG. FIG. 3 is an XY-XY cross-sectional view in FIG. 4 is an enlarged cross-sectional view of a main part in FIG. 3. FIG. FIG. 5 is a perspective view of the casing 2 and the circuit board 6. FIG. 6 is a plan view of the casing 2 and the circuit board 6. FIG. FIG. 7 is a plan view showing a state in which the periphery of the electronic component 7 of the circuit board 6 exposed through the opening 2g of the casing 2 is sealed with the potting agent 9. As shown in FIG. 8 is a bottom view of the casing 2. FIG. FIG. 9 is a perspective view of the circuit board 6. FIG.

1 to 9, the fan motor 1 according to one embodiment is a centrifugal fan (radial fan). The fan motor 1 includes a casing 2 , a cover 3 attached to the casing 2 , a motor 4 and an impeller 5 disposed inside the casing 2 . is provided with a cover 3. A circuit board 6 made of FPC (Flexible Printed Circuits) is arranged on the other end side (lower end side) of the casing 2 in the axial direction.

(Regarding the structure of the casing 2)
The casing 2 is substantially square in plan view, and has a base portion 2a and a side wall 2r. Among the sides of the base portion 2a, the side wall 2r is not formed on one side. An opening is formed between 3 and the casing 2 and acts as an exhaust port 1b.

An impeller 5 and a motor 4 for rotating the impeller 5 are arranged inside the space formed between the cover 3 and the casing 2, and the space formed between the cover 3 and the casing 2 is It constitutes a flow path 2p through which air flows. A tongue portion 2q projecting toward the central portion is formed at one end of the flow path 2p on the exhaust port 1b side.

An axially projecting annular portion 2o is formed on the surface of one end side of the base portion 2a in the axial direction, and a bottomed cylindrical bearing holding portion 2k projecting axially is integral with the center of the annular portion 2o. is formed in A portion of the base portion 2a surrounded by the annular portion 2o is a circular portion 2c. A concave portion 2f is formed on the surface on the other end side in the axial direction (in other words, the lower surface side), and a cylindrical boss portion 2e is integrated in the center of the base portion 2a in the concave portion 2f. is formed in

In addition, a plurality (three) of through holes 2d and an opening 2g (one) are formed in the recess 2f. The through hole 2d is a hole through which the end of the coil 4c of the motor 4 is inserted, and the through hole 2d is positioned outside the bearing holding portion 2k. An electronic component 7 (for example, a drive control IC) mounted on the circuit board 6 is arranged in the opening 2g.

In addition, recesses 2s extending in the axial direction are formed on the outer peripheral surface of the side walls 2r, and projections 2t are formed in each recesses 2s. The protrusion 2t engages with an opening 3c of a locking portion 3b provided on the cover 3. As shown in FIG.

Each of the above parts (base portion 2a, side wall 2r, bearing holding portion 2k, recessed portion 2f, boss portion 2e, projection 2t, etc.) is integrally formed by resin injection molding, for example.

(Regarding the structure of the cover 3)
The cover 3 attached to the casing 2 has a substantially square shape in plan view. As a procedure for manufacturing the cover 3, for example, a thin plate of metal material (for example, SUS304 material) is pressed. A circular opening 3a is formed in the center of the cover 3 and acts as an intake port 1a. Engagement portions 3b extending in the radial direction are formed on portions of three sides of the cover 3, respectively, and openings 3c are formed at the locations of the respective engagement portions 3b.

After being pressed from a thin plate, the engaging portion 3b is bent in a direction perpendicular to the surface of the cover 3 (90 degrees). The cover 3 is attached to one end of the casing 2 in the axial direction by engaging the projections 2t formed on the side surface of the casing 2 with the openings 3c formed in the locking portions 3b.

(Regarding the structure of the motor 4)
The motor 4 is, for example, a three-phase brushless DC motor, and is composed of a stator 4a and a rotor 4d. The stator 4a is composed of a stator core 4b in which a predetermined number of thin cores made of electromagnetic steel sheets are laminated in the axial direction, and a coil 4c wound around the stator core 4b.

The stator core 4b has a ring-shaped core back and a plurality of (six in the embodiment) teeth radially extending from the outer periphery of the core back. An insulating coating is applied to the stator core 4b, an insulator is not attached for thinning, and a coil 4c is wound around each tooth via a coating film. In addition, when there is a margin in the constraint on the height in the axial direction, an insulator may be attached to the stator core 4b, and the coil 4c may be wound around each tooth via the insulator.

The rotor 4d is composed of a substantially cup-shaped rotor yoke 4h, a shaft 4f press-fitted into a through hole formed in the center of the rotor yoke 4h and coupled, and a ring-shaped magnet 4n arranged on the inner peripheral surface of the rotor yoke 4h. The magnet 4n is bonded and coupled to the rotor yoke 4h with an adhesive, for example.

The substantially cup-shaped rotor yoke 4h has an annular first plane 4i on one axial end side, and an annular second plane 4k radially outside the annular first plane 4i. The outer peripheral edge of the two planes 4k has a cylindrical portion 4m extending to the other end side (lower end side) in the axial direction. The second plane 4k is located on the other end side (lower end side) in the axial direction than the first plane 4i, and the first plane 4i and the second plane 4k are connected by an inclined surface 4j.

The circular opening of the core back of the stator core 4b is fitted to the outer peripheral surface of the bearing holding portion 2k, and the lowermost end surface of the stator core 4b abuts on the stepped portion 2m formed in the bearing holding portion 2k for axial positioning. is done.

A portion of the lower end of the cylindrical portion 4m of the rotor yoke 4h and a portion of the lower side of the coil 4c are positioned in a recess inside the annular portion 2o of the casing 2, thereby achieving a reduction in thickness in the axial direction. there is

A disk-shaped resin washer 4g with good slidability is arranged on the bottom surface of the cylindrical bearing holding portion 2k with a bottom. A bearing 4e is provided. The bearing 4e is, for example, a copper-based sintered oil-impregnated bearing, a slide bearing impregnated with lubricating oil, and rotatably supports the shaft 4f.

(Regarding the structure of the impeller 5)
An impeller 5 is coupled to the outer peripheral surface of the rotor yoke 4h. The impeller 5 is composed of a ring-shaped hub 5a and a plurality of blades 5b joined to the hub 5a. The blades 5b all have the same shape and are evenly arranged in the circumferential direction. The hub 5a and the blades 5b are integrally formed, for example, by injection molding of resin.

The outer peripheral surface of the cylindrical portion 4m of the rotor yoke 4h and the inner peripheral surface of the ring-shaped hub 5a are bonded together with an adhesive. A concave portion 5c is formed in the lower surface of the root side of the blade 5b on the side of the hub 5a. A part of the upper end of the annular portion 2o of the casing 2 is inserted into the concave portion 5c, thereby reducing the thickness in the axial direction.

(Regarding the structure of the circuit board 6)
A circuit board 6 is arranged in a concave portion 2f formed on the other end side (lower end side) of the base portion 2a of the casing 2 in the axial direction. A circular opening 6a is formed at one radial end side of the circuit board 6, and a circular boss portion 2e formed at the other axial end side (lower end side) of the base portion 2a is inserted into the opening 6a. be. The other radial end of the circuit board 6 extends outside the casing 2 through a notch 2b formed in a portion of the side wall 2r. Three through-holes 6b are formed around the opening 6a, and these through-holes 6b are through-holes formed in the lands of the wiring pattern.

An electronic component 7 (for example, a drive control IC) mounted on the circuit board 6 is inserted through an opening 2g formed in a recess 2f of the base portion 2a, and a part of the electronic component 7 (for example, a drive control IC) is inserted into the casing. 2 (channel 2p).

Terminals (U-phase, V-phase, W-phase) of the coils 4c wound around the stator core 4b of the motor 4 are inserted into predetermined through holes 2d formed in the base portion 2a. After being inserted into a predetermined through hole 6b formed in the circuit board 6, it is electrically connected to the wiring pattern by being soldered.

The soldered portion is housed in the recess 2f formed on the other end side of the base portion 2a, so that the soldered portion does not protrude from the lower end surface of the casing 2.

A circuit board 6 is arranged in a concave portion 2f formed on the other end side (lower end side) of the base portion 2a in the axial direction. The two are joined together by providing an adhesive material 8 (e.g., double-sided tape) on the portion of the circuit board 6 where the opening 6a and the through hole 6b are provided and where the electronic components 7 and the like are mounted (the hatched portion in FIG. 9). A circuit board 6 is attached to a concave portion 2f formed on the other end side of the base portion 2a of the casing 2. As shown in FIG. At this time, the electronic component 7 (drive control IC) mounted on the circuit board 6 is placed in the opening 2g.

After the circuit board 6 is attached to the casing 2, a potting agent 9 (for example, a heat-dissipating silicone rubber-based potting agent) is applied around the electronic component 7 (drive control IC). The pins of the drive control IC and the exposed wiring pattern are sealed by the application of the potting agent 9, and the applied potting agent 9 penetrates and permeates the gap between the circuit board 6 and the casing 2. Seal.

After that, the stator core 4b is attached to the bearing holding portion 2k of the casing 2, the ends of the coils 4c are inserted through the predetermined through holes 2d, and the ends of the coils 4c are soldered to be electrically connected to the wiring pattern.

(Comparative example)
FIG. 10 is an external perspective view of a fan motor 1' according to a comparative example. In FIG. 10, a fan motor 1' of a comparative example has a fan shell 10' formed from a base plate 11' and a shell cover 12', and an internal space 100' is formed inside the fan shell 10'. The blades 30' exposed from the opening 120' of the fan shell 10' are placed in the internal space 100' and rotated by the motor 20'.

The base plate 11' has a first surface facing the interior space 100' and a second surface opposite the first surface. A receiving space is formed in the second surface and the PCB 40' is disposed in the receiving space. The PCB 40' is formed flush with the second surface to reduce its thickness.

The PCB 40' has an annular substrate arranged coaxially with the rotating shaft of the motor 20', an arc-shaped substrate arranged on the outer periphery in the radial direction, and a linear substrate connecting the two. The substrate is provided with soldering points 411' at positions corresponding to the holes 1022'. Electronic components 422' are arranged on the arcuate substrate, and soldering points 421' to the cable are provided.

The fan motor 1' has the soldering points 421' and the electronic components 422' arranged in the air flow path, and the soldering points 421' and the electronic components 422' are exposed. does not have any Therefore, when foreign matter or moisture enters the inside of the fan motor 1', problems such as short circuits or corrosion of the electronic parts 422' and the pins and terminals of the cable may occur.

In this regard, in the fan motor 1 of one embodiment shown in FIGS. 1 to 9, the circuit board 6 is adhered to the casing 2 with the adhesive 8, and the potting agent is applied around the electronic component 7 (drive control IC). 9 is applied. As a result, the pins of the drive control IC and the exposed wiring pattern are sealed, and the applied potting agent 9 enters the gap between the circuit board 6 and the casing 2 to seal. As a result, even if foreign matter or moisture penetrates, the dust-proof and water-proof effects can be obtained. Even if the fan motor 1 is incorporated in an electronic device such as a personal computer or a mobile phone, and it is required to have a waterproof function or a dustproof function depending on the application or usage environment, these requirements are met. can satisfy

Also, it has a structure in which a part of the electronic component 7 (for example, drive control IC) mounted on the circuit board 6 is exposed to the air flow path inside the casing 2 . Therefore, the electronic component 7 (for example, the drive control IC) can be effectively cooled by the high-velocity airflow, and the thermal load on the electronic component 7 can be reduced.

Further, the depth of the recess 2f of the casing 2 in which the circuit board 6 is arranged is set so that the thickness of the circuit board 6 is larger than the thickness of the soldering of the end of the coil 4c. does not protrude from the casing 2, and interference with other members can be avoided.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention.

As described above, the fan motor according to the embodiment includes an impeller having a hub, a plurality of blades provided on the hub, a motor for rotating the impeller, and electronic components for driving and controlling the motor. A fan motor comprising: a mounted circuit board; a casing housing an impeller and a motor; and a cover provided at one axial end of the casing, wherein the circuit board The electronic component is placed in an opening formed in a part of the recess, and the electronic component is partially exposed to the inside of the casing. A potting agent applied to the periphery enters and seals the gap between the casing and the circuit board. As a result, it is possible to provide a dustproof and waterproof structure and to make it thin.

Further, the terminals of the coil wound around the motor are electrically connected to the wiring pattern formed on the circuit board by passing through the through hole formed in the casing and the through hole formed in the circuit board, The through-hole of the casing and the through-hole of the circuit board are arranged at positions facing each other in the axial direction. As a result, the terminals of the coil can be connected in a short path, the space can be effectively used, and the electrical characteristics of the motor can be improved.

Also, the casing and the circuit board are adhered with an adhesive. This facilitates mounting of the circuit board.

In addition, the potting agent is a heat-dissipating silicone rubber system. As a result, it is possible not only to perform dustproofing and waterproofing, but also to improve heat dissipation characteristics.

Also, in the motor, the stator core is coated with an insulating coating, and the coil is wound without an insulator. This makes it possible to reduce the thickness by the thickness of the insulator.

In addition, the casing has another recess on the surface opposite to the recess where the circuit board is arranged in the axial direction, and the rotor yoke and the lower ends of the coils of the motor are positioned inside the other recess. This makes it possible to reduce the thickness of the device.

In addition, the present invention is not limited by the above-described embodiment. The present invention also includes those configured by appropriately combining the respective 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.

1 fan motor, 1a intake port, 1b exhaust port, 2 casing, 2d through hole, 2f recess, 2g opening, 3 cover, 4 motor, 4c coil, 5 impeller, 5a hub, 5b blades, 6 circuit board, 6b through hole , 7 Electronic parts, 8 Adhesive material, 9 Potting agent

Claims

an impeller comprising a hub and a plurality of blades provided on the hub;
a motor for rotating the impeller;
a circuit board on which electronic components for driving and controlling the motor are mounted;
a casing housing the impeller and the motor therein;
a cover provided at one axial end of the casing;
A fan motor comprising
The circuit board is attached and arranged in a recess formed in the other axial end of the casing,
the electronic component is disposed in an opening formed in a portion of the recess, and a portion of the electronic component is exposed inside the casing;
The potting agent applied around the electronic component penetrates into and seals the gap between the casing and the circuit board,
fan motor.
Terminals of the coil wound around the motor are inserted through through holes formed in the casing and through holes formed in the circuit board, and are electrically connected to wiring patterns formed on the circuit board. is,
The through-hole of the casing and the through-hole of the circuit board are arranged at positions facing each other in the axial direction,
A fan motor according to claim 1.
The casing and the circuit board are adhered with an adhesive material,
A fan motor according to claim 1 or 2.
The potting agent is a heat-dissipating silicone rubber system,
A fan motor according to any one of claims 1 to 3.
In the motor, the stator core is coated with an insulating coating, and the coil is wound without an insulator.
A fan motor according to any one of claims 1 to 4.
The casing has another recess on a surface opposite to the recess in the axial direction where the circuit board is arranged, and the lower ends of the rotor yoke and the coil of the motor are located inside the other recess.
A fan motor according to any one of claims 1 to 5.