JP2000116098A - Brushless fan motor and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless fan motor which requires only a short time for a waterproof mold section to be cured and leaves no traces of bubbles on the outer surface of the mold section. SOLUTION: In order to prevent air contained in a winding section 3 of the stator 1 from being pulled out of the winding section 3 into a mold section MP, the winding section 3 is coated with a coating section CP which is made of insulating coating material such as silicone-rubber, etc. The whole or the main part of the surface of a circuit substrate 4 facing opposite a substrate housing section 13 is coated in advance with a partially molded section PMP, which is different from the waterproof mold section MP.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless fan motor in which a stator is waterproofed by a silicone rubber mold, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. Hei 10-191611 (Japanese Patent Application No. 8-349267) discloses that the stator side is made of silicone.
A structure of a brushless fan motor in which a waterproof molded portion is formed by molding with rubber and a method of manufacturing the same are disclosed. In the prior art shown in this publication, silicone
The mold portion is formed by injecting rubber.

[0003]

Inspection of the mold portion of the conventional brushless fan motor reveals that a mold portion having a concave portion formed by traces of air bubbles is formed on the surface of the mold portion. Conventionally, such a concave portion is filled with silicone rubber again to correct the appearance of the mold portion.

[0004] Conventionally, since the mold portion is formed by a single injection of silicone rubber, it takes a considerable amount of time for the inside of the mold portion to harden. In particular, the portion of silicone rubber injected into the space formed between the circuit board and the board housing of the stator side case,
Since the area of the outer surface exposed to the outside air was small, curing took a long time. By the way, conventionally, it took several weeks until the mold part was completely cured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a brushless fan motor in which no trace of air bubbles remains on the outer surface of a mold part, and a method of manufacturing the same.

Another object of the present invention is to provide a brushless fan motor and a method for manufacturing the same, which can shorten the curing time of the mold section.

[0007]

A brush fan motor to be improved by the present invention has a winding portion formed by winding a winding around a salient pole portion of an iron core having a plurality of salient pole portions. A stator having a plurality of stator magnetic poles and electronic components constituting a control circuit for controlling a current fixed to the stator and flowing through windings constituting the plurality of stator magnetic poles of the stator are mounted. A circuit board, a rotor having a plurality of rotor magnetic poles made of permanent magnets on the inner peripheral side and a plurality of blades on the outer peripheral side, and a bearing rotatably supporting a rotating shaft of the rotor are housed therein. A fixed portion including a cylindrical portion for supporting a bearing, a housing portion surrounding the outer periphery of a rotor blade, a substrate storage portion in which a circuit board is stored and fixed, and a plurality of webs connecting the substrate storage portion and the housing portion. And a child side case. A circuit board including at least the stator and the electronic components is molded with silicone rubber to form a waterproof mold portion. The fixed side case may be an integrally molded product, or may be configured by combining different parts. Also, when a single web is formed with a lead wire storage groove for storing a plurality of lead wires extending from the control circuit of the circuit board and guiding the lead wire toward the housing,
A communication path is formed between the lead wire housing groove and the board housing part to communicate the two, and the circuit board including the stator and the electronic components and the plurality of lead wires housed in the lead wire housing groove are made of silicone rubber. It will be molded. In this case, the injection of the silicone rubber into the lead wire accommodating groove may be performed at the same time as the formation of the mold portion, or may be performed separately.

In the present invention, the winding of the stator is covered with a coating made of an insulating coating material so that air contained in the winding during molding does not escape into the molding. Since the winding part is formed by winding the winding, there are a number of gaps inside the winding part, and the air in the gaps is an uncured silicone material that forms the mold part.
When the air escapes into the rubber, the air forms bubbles in the mold portion or a concave portion on the outer surface of the mold portion. In particular, when a concave portion is formed on the outer surface of the mold portion, the appearance of the mold portion deteriorates and the commercial value is reduced, so that not only correction is required but also the waterproof performance is affected depending on the shape of the concave portion. When the winding portion of the stator is covered with the coating portion as in the present invention, since air contained in the winding portion does not escape into the molding portion, a concave portion is hardly formed on the outer surface of the molding portion. Thus, no correction work is required. The material of the insulating coating material may be any material as long as it has an insulating property and can enter the inside of the winding part and confine air inside the winding part. Considering the bonding property with the mold portion, silicone rubber is preferable as the insulating coating material. When using silicone rubber as the insulating coating material, use silicone rubber having a lower viscosity than silicone rubber used to form the waterproof mold part. In this case, since silicone rubber penetrates deeply into the winding portion, the possibility that air will escape from the winding portion to the outside is reduced.

[0009] In order to shorten the curing time of the mold part, the whole or main part of the surface of the circuit board facing the substrate housing part is covered with a partial mold part different from the waterproof mold part. I just need. Preferably, the partial mold portion is formed of silicon rubber. Conventionally, it took a long time for the mold part to completely cure because of the silicone resin injected into the space formed between the circuit board and the board storage part of the stator side case.
This is because the rubber was hard to cure. This is because most of the part sandwiched between the board storage part and the circuit board does not come into contact with the outside air, so it takes a longer time to complete curing compared to other parts that can take a large outer surface that comes in contact with the outside air. is there. Therefore, if the partial mold part is formed in advance, the volume of the space formed between the partial mold part and the substrate storage part of the stator side case when forming the mold part is reduced, and the part is injected into the part. The time required for the cured silicone rubber to fully cure is significantly reduced. Although depending on the volume of the partial mold portion, the curing time can be significantly reduced as compared with the conventional curing time. In particular, if the curing of the silicone rubber forming the partial mold portion and the curing of the silicone rubber forming the mold portion are performed not in normal temperature but in an environment of 40 ° C. to 60 ° C., the curing time can be further reduced. Note that the technique of forming the partial mold portion in advance is not a technique that must necessarily be combined with the technique of previously covering the winding portion with an insulating coating material.

[0010]

FIG. 1 is a half sectional view of a first embodiment of a brushless fan motor according to the present invention. In FIG. 1, reference numeral 1 denotes a stator, and a stator 1 includes a plurality of winding portions 3 each formed by winding a winding around each salient pole portion 2a of an iron core 2 having a plurality of salient pole portions 2a.
have. Specifically, the plurality of winding portions 3 are configured by winding the windings on a pair of insulating resin ISs fitted to the iron core 2 from both sides in the axial direction of the iron core 2. The winding part 3 is provided with a waterproof mold part MP made of silicone rubber, which will be described later, in which air contained in the winding part 3 is formed.
Coating C made of an insulating coating material so that it does not escape inside
Covered by P. The coating portion CP penetrates, for example, silicone rubber (insulating coating material) having a lower viscosity than the silicone rubber used to form the waterproof mold portion MP from the outer surface of the winding portion 3 into the inside. It is applied or impregnated so as to be cured, and then cured and formed.

These salient pole portions 2a act as stator magnetic poles when the winding portion 3 is excited. Therefore, the tip of the salient pole portion 2a becomes the magnetic pole surface 2a 'of the stator magnetic pole. 4 is the stator 1
The circuit board 4 has mounted thereon electronic components constituting a control circuit for controlling a current flowing through the winding portions 3 constituting a plurality of stator magnetic poles of the stator 1. ing. The control circuit of the circuit board 4 and the winding part 3 are passed through a through hole 4a of the circuit board 4 and one end is connected to a solder 4b.
The lead wire 3a of the winding part 3 is wound around a terminal pin 4c, which is attached and the other end is fixed to the insulator IS, and is connected by soldering. Reference numeral 5 denotes a rotor, which has a plurality of rotor magnetic poles 6 made of permanent magnets on the inner peripheral side and a plurality of blades 7 on the outer peripheral side. 8
Numeral denotes a stator side case, a bearing supporting cylinder portion 11 in which a bearing 10 for rotatably supporting the rotating shaft 9 of the rotor 5 is housed, and a housing portion 12 surrounding the outer periphery of the blade 7 of the rotor 5. , A circuit board 4 is accommodated and fixed therein, and a plurality of webs 14 connecting the substrate accommodating section 13 and the housing section 12 are provided. One of the plurality of webs 14 has a lead wire housing groove 16 for housing a plurality of lead wires 15 connected to a control circuit of the circuit board 4 and extending to guide the housing toward the housing 12. Is formed. Lead wire storage groove 1
A communication path 17 is formed between the substrate 6 and the substrate storage unit 13 to communicate the two.

In this example, the board storage portion 13 of the circuit board 4 is used.
Most of the surface opposite to is covered with a partial mold part PMP made of silicone rubber. The partial molded portion PMP is formed in advance, and its thickness (thickness in a direction orthogonal to the circuit board 4) is measured in a space formed between the circuit board 4 and the board storage portion 13. It is determined so as to leave a gap in which silicone rubber can be injected for forming the mold part MP. The partial mold part PMP can be formed using the same material as the silicone rubber used to form the mold part MP.

The rotor 5 has a rotor-side case 1 in which a blade 7 is arranged on the outer periphery and a rotor magnetic pole 6 is arranged on the inner periphery.
8 and a bush 19 fixed to the rotating shaft 9 for fixing the rotor side case 8 to the rotating shaft. In particular, the rotor-side case 18 is formed of a flywheel 20 that supports the rotor magnetic pole 6 on the inner circumference and a blade mounting hub 21 that supports the blade 7 on the outer circumference. The flywheel 20 includes a cylindrical yoke portion 20a that supports the rotor magnetic pole 6 on the inner periphery thereof, and the yoke portion 20a.
And a bottom plate portion 20b fixed to the bush 19 in a state of receiving one end of the bottom plate 20b. The yoke portion 20a is fixed to a blade mounting hub 21 with an adhesive 22, and the blade mounting hub 21 is fixed to the bottom plate portion 20b by a fixing means (not shown).

Opening side end 18a of rotor side case 18
Further, the opening side end 13a of the substrate housing portion 13 of the stator side case 8 is configured so as to form a labyrinth structure in which both oppose each other via a slight gap 23 to prevent water from entering inside. Have been. The end 11a of the bearing support tube 11 and the bush 19 are configured to form a labyrinth structure that opposes each other through a slight gap 24 and prevents water from entering the inside. This prevents water from entering the case.

The stator 1, the circuit board 4 including the electronic components, and the plurality of lead wires 15 are integrally molded by injection of silicone rubber 25 in a state of being housed in the stator-side case 8 to provide waterproofing. A mold part MP is formed. The magnetic pole surface 2a 'of the stator magnetic pole of the stator 1 is also thinly covered with the silicone rubber 25. The process of injecting the silicone rubber 25 is described in JP-A-10-1
This is described in detail in Japanese Patent Application No. 91611 (Japanese Patent Application No. 8-349267), and a description thereof will not be repeated.

The curing of silicone rubber is generally performed at room temperature. This is because it is considered that when the composition is cured in a heated state, the curing is completed in a soft state. However, in this example, the curing of the silicone rubber forming the partial molded part PMP and the curing of the silicone rubber forming the molded part MP are performed at 40 ° C.
The test was performed in an environment of 60 ° C. (preferably in a temperature environment of about 50 ° C.). When the silicone rubber is cured in this temperature range, the partial mold portion PMP and the mold portion MP can be completely cured in a period of 1/4 or less of the conventional case. By the way, under this temperature condition, it takes about two to three days to cure the partial mold part PMP.
Takes about 6 to 8 days to cure. When the partial mold portion PMP is not formed in advance, it takes three weeks or more to completely cure.

FIG. 2 is a sectional view of a main part of another embodiment of the present invention. FIG. 3 is a bottom view (viewed from the circuit board side) of the stator unit 100 in which the partial molded part PMP used in the example of FIG. 2 is formed in advance, and FIG.
FIG. 4 is a sectional view taken along line IV. In these figures, the same parts as those in the embodiment of FIG.
The reference numeral of the number obtained by adding the number is attached and the description is omitted. In this example, a hook-shaped locking piece 127 is provided integrally with one insulator IS, and this locking piece 127 is attached to the circuit board 10.
4 is locked to the edge of the through-hole 104d provided in the base member 4. The lead wire 103a from the winding portion 103 is
7 and soldered to electrodes on the surface of the circuit board 4. Other configurations are substantially the same as those in the example of FIG. As can be seen from FIG.
P is formed in advance so as to cover most of the back surface of the circuit board 104 (the portion excluding the lead wire lead-out portion). Then, the stator unit 100 is positioned with respect to the substrate housing portion 113 of the stator side case 108, and thereafter, a waterproof molded portion MP is formed.

[0018]

According to the present invention, since the winding of the stator is covered with the coating made of the insulating coating material, the air contained in the winding does not escape into the waterproof mold. In addition, there is an advantage that the concave portion is hardly formed on the outer surface of the waterproof mold portion, and the repair work becomes unnecessary.

Also, the entire or main surface of the circuit board on the side facing the substrate housing portion is covered with a partial mold portion different from the waterproof mold portion, so that the curing time of the mold portion is greatly reduced. There are advantages that can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of an example of an embodiment of a brushless fan motor according to the present invention.

FIG. 2 is a longitudinal sectional view of a main part of another example of the embodiment of the brushless fan motor according to the present invention.

FIG. 3 is a bottom view of the stator unit used in the embodiment of FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of the stator unit of FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator 2 Iron core 2a Salient pole part 3 Winding part 4 Circuit board 5 Rotor 7 Blade 8 Stator side case 9 Rotating shaft 10 Bearing 12 Housing part 13 Substrate storing part 14 Web 15 Lead wire 16 Lead wire storing groove 18 Rotation Child case 25 Silicone rubber IS Insulator CP Coating PMP Partial mold part MP Mold part

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02K 15/12 H02K 15/12 D // H02K 7/14 7/14 A (72) Inventor Osamu Kawakami Tokyo 1-15-1, Kita-Otsuka, Toshima-ku, Tokyo, Sanyo Denki Co., Ltd. (72) Inventor Hisashi Toshizawa 1-15-1, Kita-Otsuka, Toshima-ku, Tokyo, Sanyo Electric Co., Ltd. (72) Inventor Aoki Nobuyuki F-term (reference) 1-5-15-1 Kita-Otsuka, Toshima-ku, Tokyo 5H019 CC04 DD01 EE10 EE14 GG01 5H604 BB01 BB14 BB17 CC01 CC05 CC16 DA25 DB16 PB03 PE06 5H605 AA02 BB05 CC01 CC03 DD09 EA19 EC01 GG18 5H607 AA05 AA12 BB01 BB09 BB14 CC01 CC05 DD01 DD03 FF04 JJ01 5H615 AA01 BB01 BB14 PP01 PP14 QQ02 RR07 SS44 TT31 TT33

Claims (9)

[Claims] A stator provided with a plurality of stator magnetic poles having a winding portion formed by winding a winding around the salient pole portion of an iron core having a plurality of salient pole portions; A circuit board on which electronic components constituting a control circuit for controlling a current flowing through the windings constituting the plurality of stator magnetic poles of the stator are fixed; and a plurality of rotors comprising permanent magnets A rotor provided with a magnetic pole on the inner peripheral side and having a plurality of blades on the outer peripheral side, a bearing support tubular portion in which a bearing rotatably supporting a rotating shaft of the rotor is housed, and a rotor for the rotor. A housing portion surrounding the outer periphery of the blade, a substrate storage portion in which the circuit board is stored and fixed, and a stator side case including a plurality of webs connecting the substrate storage portion and the housing portion. And at least the stator and the A brushless fan motor in which the circuit board including components is molded with silicone rubber to form a waterproof mold portion, wherein the winding portion of the stator is covered with a covering portion made of an insulating covering material. Brushless fan motor characterized by being performed. 2. A stator having a plurality of stator magnetic poles having a winding portion formed by winding a winding around the salient pole portion of an iron core having a plurality of salient pole portions; A circuit board on which electronic components constituting a control circuit for controlling a current flowing through the windings constituting the plurality of stator magnetic poles of the stator are fixed; and a plurality of rotors comprising permanent magnets A rotor provided with a magnetic pole on the inner peripheral side and having a plurality of blades on the outer peripheral side, a bearing support tubular portion in which a bearing rotatably supporting a rotating shaft of the rotor is housed, and a rotor for the rotor. A housing portion surrounding the outer periphery of the blade, a substrate storage portion in which the circuit board is stored and fixed, and a stator side case including a plurality of webs connecting the substrate storage portion and the housing portion. And one of the webs has the circuit board A lead wire storage groove for receiving a plurality of lead wires extending from the control circuit and guiding the lead wire toward the housing; and a communication passage communicating between the lead wire storage groove and the substrate storage portion. The plurality of lead wires accommodated in the stator, the circuit board including the electronic component, and the lead wire accommodating groove are molded with silicone rubber to form a waterproof mold portion. A brushless fan motor, wherein the winding portion of the stator is covered with a coating made of an insulating coating material so that air contained in the winding portion does not escape into the waterproof mold portion. A brushless fan motor. 3. The brushless fan motor according to claim 1, wherein the insulating coating material is a silicone rubber having a lower viscosity than a silicone rubber used for forming the waterproof mold part. 4. The whole or main part of the surface of the circuit board on the side facing the substrate storage part is covered by a partial mold part different from the waterproof mold part, and the partial mold part is 4. The brushless fan motor according to claim 1, wherein the brushless fan motor is made of silicone rubber. 5. A stator having a plurality of stator magnetic poles having a winding portion formed by winding a winding around said salient pole portion of an iron core having a plurality of salient pole portions; A circuit board on which electronic components constituting a control circuit for controlling a current flowing through the windings constituting the plurality of stator magnetic poles of the stator are fixed; and a plurality of rotors comprising permanent magnets A rotor provided with a magnetic pole on the inner peripheral side and having a plurality of blades on the outer peripheral side, a bearing support tubular portion in which a bearing rotatably supporting a rotating shaft of the rotor is housed, and a rotor for the rotor. A housing portion surrounding the outer periphery of the blade, a substrate storage portion in which the circuit board is stored and fixed, and a stator side case including a plurality of webs connecting the substrate storage portion and the housing portion. And at least the stator and the A method of manufacturing a brushless fan motor, wherein said circuit board including components is molded with silicone rubber to form a waterproof mold portion, wherein said winding portion is formed before said waterproof mold portion is formed. A method of manufacturing a brushless fan motor, comprising covering the winding portion of the stator with an insulating coating material so that air contained in the stator does not escape into the mold portion when forming the mold portion. . 6. The method for manufacturing a brushless fan motor according to claim 5, wherein the insulating coating material is silicone rubber having a lower viscosity than silicone rubber used for forming the waterproof mold portion. 7. The waterproofing mold part, wherein the whole or main part of the surface of the circuit board on the side facing the substrate housing part is covered with silicone rubber before forming the waterproofing mold part. The method for manufacturing a brushless fan motor according to claim 5, wherein a partial mold portion different from the above is formed. 8. A stator having a plurality of stator magnetic poles having a winding portion formed by winding a winding around said salient pole portion of an iron core having a plurality of salient pole portions; A circuit board on which electronic components constituting a control circuit for controlling a current flowing through the windings constituting the plurality of stator magnetic poles of the stator are fixed; and a plurality of rotors comprising permanent magnets A rotor provided with a magnetic pole on the inner peripheral side and having a plurality of blades on the outer peripheral side, a bearing support tubular portion in which a bearing rotatably supporting a rotating shaft of the rotor is housed, and a rotor for the rotor. A housing portion surrounding the outer periphery of the blade, a substrate storage portion in which the circuit board is stored and fixed, and a stator side case including a plurality of webs connecting the substrate storage portion and the housing portion. And one of the webs has the circuit board A lead wire storage groove for receiving a plurality of lead wires extending from the control circuit and guiding the lead wire toward the housing; and a communication passage communicating between the lead wire storage groove and the substrate storage portion. The plurality of lead wires accommodated in the stator, the circuit board including the electronic component, and the lead wire accommodating groove are molded with silicone rubber to form a waterproof mold portion. A method of manufacturing a brushless fan motor, wherein before forming a waterproof mold part, all or a main part of a surface of the circuit board on a side facing the board storage part is
A method of manufacturing a brushless fan motor, comprising forming a partial mold part different from the waterproof mold part by covering with silicone rubber. 9. The method according to claim 1, wherein the curing of the silicone rubber forming the partial mold portion and the curing of the silicone rubber forming the mold portion are performed in an environment of 40 ° C. to 60 ° C. 9. The method for manufacturing a brushless fan motor according to item 8.