JPH08182252A - Motor fan - Google Patents

Abstract

PURPOSE: To prevent water from being stayed at the lowermost part of boss part by forming an annular front drainage part from the front end face at the boss part to the inner circumferential face at a hole part, securing a yoke to a shroud while spacing the circumferential fringe thereof from the annular front drainage part, and integrating the outer circumferential part of rotor with the boss part. CONSTITUTION: A small quantity of water intrudes through a gap Z1 between the circumferential fringe 30A of a yoke 30 and the annular front drainage part 9 at the boss part 3 of a fan 2. The water passes between the yoke 30 and a rotor 5 and flows into the lowermost part of the annular front drainage part 9 at the boss part 3. Since the annular curved surface 11 at the annular front drainage part 9 has round cross-section, the majority of water flowing into the lowermost part of the annular front drainage part 9, upon stoppage of the fan 2, does not stay on the annular curved surface 11 at the annular front drainage part 9 but advances onto an annular inclination surface 10 while resisting against the surface tension and then it is discharged to the outside. A part of the water is introduced into a groove 7 and discharged to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor fan used for cooling a heat exchanger such as a radiator of an automobile, and more specifically, to a water removing structure on an inner peripheral surface of a hole formed in a boss of the fan. Regarding

[0002]

2. Description of the Related Art Generally, in an automobile, a motor fan, in which a fan and a motor are assembled, is installed in an engine room and used for cooling a heat exchanger such as a radiator. The engine room of a recent automobile is overcrowded, and a flat motor is required for the motor that gives driving force to the fan of the motor fan.

As an example of this type of motor fan, the one shown in Japanese Utility Model Laid-Open No. 56-25958 is known (shown in FIG. 12). In the figure, reference numeral 101 indicates a motor fan. This motor fan 101 is a fan 102
The flat motor 10 in the hole 103A of the boss 103 of
4, the rotor 10 of this flat motor 104
5, the fan 102 is directly rotated. The structure will be described below.

The motor fan 101 is composed of a stationary side X1 and a rotating side Y1. On the fixed side X1,
A plurality of mounting holes 1 of the mounting portion 106A of the shroud 106
The casing 107 is fixed to the 06B by the screw 106C. The casing 107 has a permanent magnet 108.
Has been fixed. A shaft 109 is inserted through the center of the casing 107, and a bearing 110 is mounted on one side of the shaft 109.

On the other hand, on the rotating side Y1, this bearing 1
A rotor 105 is rotatably supported on the rotor 10. The rotor 105 includes an iron yoke 111 and an armature core 11.
2. The three commutators 113 are integrally molded. Thus, the rotor 105 is rotatably supported on the shaft 109.

The yoke 111 of the rotor 105 is connected to the boss portion 103 of the fan 102 with a screw 114 made of metal. The reference numeral 115 represents a brush. In such a conventional motor fan 101, the armature core 112
When the yoke 111 rotates, the eddy current is generated in the yoke 111, the internal temperature of the motor fan 101 rises rapidly, abnormal heat generation occurs inside, and durability may be impaired.

In order to solve such a problem, a motor fan having a structure in which the yoke and the armature core are separated is considered. The motor fan having such a structure has a structure in which the flat motor is incorporated in the hole of the boss portion of the fan, and the fan is directly rotated by the armature core of the flat motor, and is fixed to the shroud and the fixed side including the brush, the permanent magnet, and the like. , A fan, a rotating side including an armature core integrated with a boss portion of the fan, a commutator, and the like.

[0008]

However, in the motor fan having a structure in which the yoke and the armature core are separated, water is introduced into the hole of the boss through the gap between the inner peripheral surface of the fan boss and the peripheral edge of the yoke. When water enters and accumulates at the bottom of the inner peripheral surface of the hole of the boss, especially when the temperature drops, accumulated water from the hole of the boss of the fan on the rotating side to the yoke on the fixed side is generated Then, when the fan of the motor fan rotates, an unreasonable force may be applied between the rotating side boss portion and the fixed side yoke, which are connected by freezing of the accumulated water, and the yoke and the boss portion may be damaged.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to prevent water from entering the hole portion of the boss portion and to bring it to the bottom of the inner peripheral surface of the hole portion of the boss portion. An object of the present invention is to provide a motor fan that can prevent water from accumulating.

[0010]

According to the first aspect of the present invention,
A flat motor, which separates the yoke and rotor, is placed in the boss where the hole is formed, and a front annular drain is formed from the front end surface of the boss to the inner peripheral surface of the hole, and the yoke is fixed to the shroud. The peripheral edge of the yoke is located at a position separated from the front annular drainage portion by a gap, and the outer peripheral portion of the rotor is integrated with the boss portion.

According to a second aspect of the present invention, a flat motor formed by separating the yoke and the rotor is arranged in the boss portion having the hole portion, and the rear motor is provided from the rear end surface of the boss portion to the inner peripheral surface of the hole portion. A side annular drainage portion is formed, a second rib is provided on the shroud or a base plate provided on the shroud at a position separated from the rear annular drainage portion, and the outer peripheral portion of the rotor is integrated with the boss portion. It is characterized by

According to a third aspect of the present invention, the boss portion on the rotation side is formed with a hole portion, and the boss portion is formed from the front end surface of the boss portion to the inner peripheral surface of the hole portion, and faces from the front end surface to the rear end surface. It is arranged in the hole of the boss and the front annular drainage part that is composed of a trapezoidal conical annular inclined surface that reduces in diameter and an annular curved surface that has a rounded cross-section that continuously extends to the inner peripheral surface. A fixed shaft, a yoke fixed to one end of the shaft and having a peripheral edge formed at a position spaced apart from the front annular drainage portion, and a base plate disposed inside the hole of the boss portion and facing the yoke. A brush provided on the base plate, a commutator rotatably supported on the shaft, a magnet yoke provided on the base plate, a permanent magnet provided on the magnet yoke, and between the yoke and the permanent magnet. Distribution Is made up of a rotor fixed to the commutator, the outer peripheral portion of the rotor is characterized in that it is integrated with the boss portion.

According to a fourth aspect of the present invention, a boss portion on the rotation side, in which a hole is formed, is formed from the rear end surface of the boss to the inner peripheral surface of the hole, and the rear end surface to the front end surface are formed. A trapezoidal cone-shaped annular inclined surface whose diameter is reduced toward the rear annular drainage portion formed of an annular curved surface having a rounded cross-section that continuously reaches the inner peripheral surface of the annular inclined surface, and in the hole of the boss portion. The fixed side shaft, the yoke fixed to one end of the shaft, the base plate located inside the hole of the boss section and opposed to the yoke, and the rear annular drainage section with a gap. The second rib provided on the shroud or the base plate, the brush provided on the base plate, the commutator rotatably supported on the shaft, the magnet yoke provided on the base plate, and the magnet yoke. A permanent magnet kicked, disposed between the yoke and the permanent magnet is composed of a rotor fixed to the commutator, the outer peripheral portion of the rotor is characterized in that it is integrated with the boss portion.

[0014]

According to the first aspect of the invention, a small amount of water enters from the gap from the peripheral edge of the yoke to the front annular drainage portion of the boss portion. This water flows between the yoke and the rotor and flows into the lowermost part of the front annular drainage portion of the boss portion. Then, when the fan is stopped, the water flowing into the lowermost part of the front annular drainage portion of the boss portion is discharged outside without stopping at the front annular drainage portion.

According to the second aspect of the present invention, a small amount of water enters the rear annular drainage portion of the boss portion through the gap from the second rib to the rear annular drainage portion of the boss portion. This water flows through the rear annular drainage part and flows into the lowermost part thereof. Then, when the fan is stopped, the water flowing into the lowermost portion after the rear annular drainage portion of the boss portion is discharged outside without stopping at the rear annular drainage portion.

According to the third aspect of the invention, from the gap from the peripheral edge of the yoke to the front annular drainage portion of the boss portion,
A small amount of water penetrates. This water flows between the yoke and the rotor and flows into the lowermost part of the front annular drainage portion of the boss portion.
Then, when the fan is stopped, the annular curved surface of the front annular drainage portion has a rounded cross-section, so that the water flowing into the lowermost part of the front annular drainage portion of the boss portion resists the surface tension and the front annular drainage portion. It is guided to the annular inclined surface without stopping on the annular curved surface of the drainage portion, and further discharged to the outside through the lowermost part of the annular inclined surface.

According to the fourth aspect of the invention, a small amount of water enters the rear annular drainage portion of the boss portion through the gap from the second rib to the rear annular drainage portion of the boss portion. This water flows through the rear annular drainage part and flows into the lowermost part thereof. Then, when the fan is stopped, the annular curved surface of the rear annular drainage portion has a rounded cross section, so that the water flowing into the lowermost portion of the rear annular groove of the boss portion resists the surface tension and is It is guided to the annular inclined surface without stopping on the annular curved surface of the side annular drainage portion, and is further discharged to the outside through the lowermost part of the annular inclined surface.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. An embodiment of the invention described in claims 1 and 2 is given by taking a motor fan according to the invention described in claims 3 and 4 as an example.
This will be described with reference to FIGS. In FIG. 1, reference numeral 1 indicates a motor fan according to this embodiment.

In this motor fan 1, a flat motor 4 is installed in a hole 3A formed in a boss portion 3 of the fan 2, and the rotor 5 of the flat motor 4 causes the fan 2 to move.
It has a structure that directly rotates the fixed side X and the rotating side Y.
It consists of and. This will be described below. The structure of the boss portion 3 is shown in FIGS. In the figure, cutout grooves 7 are arranged at a plurality of positions along the circumferential direction at the front end surface 6 of the boss portion 3 at predetermined intervals, and the cutout grooves 7 are formed in the front end surface 6 in the radial direction. The cross section of the groove is shown in Figure
It is semi-circular as shown in.

A front annular drainage portion 9 composed of an annular groove is formed from the front end surface 6 of the boss portion 3 to the inner peripheral surface 8 of the hole 3A. The front annular drainage portion 9 is composed of an annular inclined surface 10 and an annular curved surface 11, and the annular inclined surface 10 has a front end surface 6
Is formed in a trapezoidal conical shape whose diameter decreases from the rear end face 12 to the rear end face 12, and the inclination angle of its cross section is 4 ° or more (the case of θ1 = 4 ° is shown in FIG. 5).

The annular curved surface 11 is continuous with the annular inclined surface 10 and reaches the inner peripheral surface 8 of the hole 3A, and has a rounded cross section, and its radius is 2 mm or more (the radius in FIG. 5 is a radius. The case of R1 = 2 mm is shown). On the other hand, the notch grooves 13 are arranged on the rear end face 12 of the boss portion 3 at predetermined intervals along the circumferential direction, and the notch grooves 13 are formed on the rear end face 12 in the radial direction. The groove cross-sectional shape is semicircular as shown in FIG.

A rear annular drainage portion 14 formed of an annular groove is formed from the rear end surface 12 of the boss portion 3 to the inner peripheral surface 8 of the hole portion 3A. The rear annular drainage portion 14 has an annular inclined surface 15
And an annular curved surface 16, the annular inclined surface 15 is formed in a trapezoidal cone shape whose diameter decreases from the rear end surface 12 toward the front end surface 6, and the inclination angle of its cross section is 4 ° or more ( FIG. 5 shows the case where θ2 = 4 °).

The annular curved surface 16 is continuous with the annular inclined surface 15 to reach the inner peripheral surface 8 of the hole 3A and has a rounded cross section, and the radius thereof is 2 mm or more (the radius in FIG. 5 is a radius. The case of R2 = 2 mm is shown). Then, as shown in FIG. 1, a shroud 17 is used as a support member on the fixed side X of the motor fan 1. Shroud 1
The structure of 7 is shown in FIGS. 1, 5 and 6.

In the drawing, the shroud 17 has a mounting portion 18 at the center thereof, and the mounting portion 18 has three mounting hole portions 19
(Only one place is shown in FIG. 1) is formed. The mounting portion 18 of the shroud 17 is provided with a first rib 20 and a second rib 21 located outside the three mounting hole portions 19. The second rib 21 has a gap Z2 with the rear annular drain portion 14.
(Shown in FIG. 5).

By tightening the nuts 23 to the screw members 22 described later in the three mounting hole portions 19 (only one position is shown in FIG. 1) of the mounting portion 18 of the shroud 17,
Shroud housing 24, shaft 29, yoke 3
0, base plate 31, brush 34, magnet yoke 3
6. A permanent magnet 37 is fixed to the shroud 17.

As shown in FIGS. 1 and 8, the shroud housing 24 includes a ring portion 25 located at the center of the shroud housing 24.
A plurality of stays 26 (three in this embodiment) radially provided integrally with the ring portion 25, and a plurality of curved plate-shaped brush pressing portions 25A protruding from the ring portion 25 (four locations in this embodiment). ) And have. At the center of the ring part 25,
A cylindrical portion 28 is provided on the opposite side of the brush pressing portion 25A. Each stay 26 is formed with an elongated attachment hole portion 26A along the circumferential direction. The shroud housing 24 is necessary for assembling the brush 34 on the commutator 40. The shroud housing 24 is assembled on the commutator 40 with the brush pressing portion 25A holding the brush 34. By rotating the brush holder 25A around the axial direction by a predetermined angle within the range of the mounting hole portion 26A, the positions of the brush pressing portion 25A and the brush 34 are circumferentially displaced so that the brush 34 directly contacts the commutator 40. Has become. FIG. 7 shows a state before the shroud housing 24 is rotated by a predetermined angle, and in that state, the nut 23 is temporarily tightened to the screw member 22. After rotating by a predetermined angle, the nut 23 is finally fastened to the screw member 22.

As shown in FIG. 1, the other end 29B of the shaft 29 opposite to the one end 29A of the shaft 29 is inserted into the cylindrical part 28, and the end 28A of the cylindrical part 28 is caulked, whereby the shaft 2
The other end 29B of 9 is fixed to the cylindrical portion 28. As a result, the shaft 29 is fixed to the shroud 17. A yoke 30 is fixed to one end 29A of the shaft 29. The yoke 30 is made of an iron ring-shaped plate material, and a gap Z1 (illustrated in FIG. 5) is formed between the peripheral edge 30A and the front annular drainage portion 9 of the boss portion 3. Here, the iron yoke 30 is for establishing a magnetic field from the permanent magnet 37.

A circular recess 30B is formed in the yoke 30, and the gap between the circular recess 30B and the rotor 5 is 0.6 mm. The smaller the gap, the higher the magnetic field of the permanent magnet 37. , The circular recess 30B and the rotor 5
Are subject to no contact. And york 3
The base plate 31 is arranged to face 0 in the axial direction. A hole portion 31C is formed in the center of the base plate 31, and the shaft 29 is inserted into the hole portion 31C. As shown in FIGS. 1 and 7, the base plate 31
Is made of resin and has three protrusions 32. The base plate 31 has a third rib 31A facing outward and an annular flange 31B, and the tip of the third rib 31A is in contact with the second rib 21 of the shroud 17. Thereby, the closed space M is formed between the shroud 17 and the third rib 31A.
Therefore, the water that has passed from the outside through the second rib 21 does not enter the closed space M.

The tip of the annular flange 31B is in contact with the magnet yoke 36. This prevents water from entering the base plate 31 and protects the brush 34 from water. The base plate 31 is assembled to the shroud 17 and the shroud housing 24 by penetrating the screw members 22 protruding from the magnet yoke 36, which will be described later, through the holes 32A of the protrusion 32.

As shown in FIGS. 6 and 9, on the base plate 31, there are four brush holders 3 each having a square cross section.
3, and the four brush holders 33 face each other in a cross shape. A brush 34 is held by each brush holder 33 so as to be movable in the radial direction, and each brush 34 is biased inward by a spring 35 incorporated in each brush holder 33. The tip of the brush 34 is in contact with the outer peripheral surface of the commutator 40 described later. An electric wire 34A for supplying an electric current is connected to each brush 34.

Further, as shown in FIG. 1, a magnet yoke 36 is arranged between the yoke 30 and the base plate 31 so as to surround the shaft 29. Of the magnet yoke 36,
A permanent magnet 37 is fixed to the surface of the yoke 30 side with an adhesive. As shown in FIG. 10, the permanent magnet 37 has a plurality of N poles 37A and S poles 37B arranged alternately.
On the surface of the magnet yoke 36 on the base plate 31 side,
The screw member 22 is fixed. The screw member 22 penetrates the hole portion 32A of the protrusion 32 of the base plate 31 and the mounting hole portion 19 of the mounting portion 18 of the shroud 17, and by tightening this with the nut 23, the shroud 17, the shroud housing, the shaft. 29, a yoke 30, a base plate 31, and a magnet yoke 36 are assembled. Shroud housing 24, shaft 29, yoke 30, base plate 31, brush 3
4, the magnet yoke 36, and the permanent magnet 37 form the fixed side X.

Bearings 38, 38 are mounted on both ends of the shaft 29, respectively. On the other hand, on the rotating side Y, a cylindrical body 39 is fixed to the bearings 38, 38, and a commutator 40 is provided at a brush contact portion on the cylindrical body 39. Yoke 30 and permanent magnet 37
The rotor 5 described above is disposed between the two. The inner peripheral edge 5A of the rotor 5 is assembled to the commutator 40, and thus is rotatably supported on the shaft 29.

The rotor 5 is formed in a flat shape by embedding a winding in an epoxy resin material. As shown in FIG. 11, an annular flange portion 5B is formed on the outer peripheral portion of the rotor 5, and the annular flange portion 5B is formed. An annular rib 5C for increasing strength is formed on the inside. The fan 2 is formed of polypropylene resin, and the polypropylene resin is selected to improve moldability.

The annular flange portion 5B of the rotor 5 is the fan 2
The rotor 5 and the boss portion 3 are integrally connected by being embedded in the boss portion 3 and insert-molded. Then, a current flows through the brush 34 to the commutator 40, and further flows through the winding of the rotor 5 to another brush 34. As a result, the rotor 5 rotates under the influence of the magnetic field from the permanent magnet 37. The rotation of the rotor 5 is transmitted to the fan 2.

The yoke 30 is fixed to the shaft 29 fixed to the shroud 17, and the yoke 30 and the rotor 5 are separated from each other. Therefore, even if the rotor 5 rotates, the yoke 30 does not rotate. Generation of an eddy current in the yoke 30 is prevented, and an increase in internal temperature in the flat motor 4 is prevented. In this embodiment, however, the front side of the boss portion 3 of the fan 2 is covered with the yoke 30, which makes it difficult for water to enter from the yoke 30 into the boss, but from the peripheral edge 30A of the yoke 30 to the fan 2. Boss 3
A small amount of water intrudes through the gap Z1 extending to the front annular drainage portion 9. This water passes between the yoke 30 and the rotor 5 and the lowermost portion 9A of the front annular drainage portion 9 of the boss portion 3 (see FIG. 2).
(Illustrated in).

The annular curved surface 1 of the front annular drainage portion 9
Since 1 has a rounded shape in cross section, the lowermost portion 9A of the front annular drainage portion 9 of the boss portion 3 when the fan 2 is stopped
Most of the water that has flowed into the annular inclined surface 1 does not stop at the annular curved surface 11 of the front annular drain portion 9 against the surface tension.
It is guided to 0, and is further discharged from the annular inclined surface 10 to the outside. Further, a part of the water is guided to the cutout groove 7 and further discharged to the outside.

Here, the larger the inclination angle of the annular inclined surface 10, the better the water discharge, but the minimum inclination angle θ1 = 4.
It has been confirmed by experiments that the temperature is °. Further, the larger the radius of the annular curved surface 11, the better the water discharge, but it has been confirmed by experiments that the minimum radius R1 is 2 mm. Also, the first rib 20 of the shroud 17,
Although water is less likely to enter the rear annular drainage portion 14 of the boss portion 3 of the fan 2 due to the second ribs 21, the gap Z2 from the second rib 21 to the rear annular drainage portion 14 of the boss portion 3 of the fan 2 is reduced. A small amount of water enters the rear annular drain portion 14 of the boss portion 3 of the fan 2. This water flows into the lowermost portion 14A (shown in FIG. 2) of the rear annular drain portion 14.

Since the annular curved surface 16 of the rear annular drainage portion 14 has a rounded cross section, it flows into the lowermost portion 14A of the rear annular drainage portion 14 of the boss portion 3 when the fan 2 is stopped. Most of the water is guided to the annular inclined surface 15 without stopping at the annular curved surface 16 of the rear annular drainage portion 14 against the surface tension, and is further discharged from the annular inclined surface 15 to the outside. In addition, part of the water is guided to the notch groove 13,
Furthermore, it is discharged to the outside.

Here, the greater the inclination angle of the annular inclined surface 15, the better the water drainage, but the minimum inclination angle θ1 = 4.
It has been confirmed by experiments that the temperature is °. Further, the larger the value of the radius of the annular curved surface 16, the better the water discharge, but it has been confirmed by experiments that the minimum radius R1 is 2 mm. In addition, as described above, by the third rib 31A and the annular flange 31B of the base plate 31,
Water is prevented from entering the base plate 31.

According to the above-described structure, the front annular drainage portion 9 is formed on the boss portion 3 of the fan 2, the annular curved surface 11 has a rounded cross-section, and the annular inclined surface 10 that follows is formed. Therefore, when the fan 2 is stopped, the water flowing into the lowermost portion 9A of the front annular drainage portion 9 of the boss portion 3 can be discharged to the outside from the annular inclined surface 10 by gravity.

Therefore, water does not collect in the lowermost portion 9A of the front annular drainage portion 9 of the boss portion 3 of the fan 2, and particularly when the temperature drops, the front annular drainage portion 9 of the boss portion 3 of the fan 2 on the rotating side is removed. It is possible to eliminate the risk of damage to the yoke 30 and the boss portion 3 of the fan 2 due to freezing of accumulated water on the fixed side yoke 30. Further, the shroud 17 is provided with a second rib 21, the second rib 21 is arranged at a position separated from the rear annular drainage portion 14, and the annular curved surface 16 of the rear annular drainage portion 14 has a cross-sectional radius. Since it has a shape and there is an annular inclined surface 15 following it, the water flowing into the lowermost portion 14A of the rear annular drainage portion 14 of the boss portion 3 when the fan 2 is stopped is gravitationally acted on by the annular shape. It can be discharged from the inclined surface 15 to the outside.

Accordingly, water does not collect in the lowermost portion 14A of the rear annular drainage portion 14 of the boss portion 3 of the fan 2, and in particular,
When the temperature decreases, it is possible to eliminate the risk of damage to the boss portion 3 of the fan 2 due to freezing of accumulated water from the rear annular drain portion 14 of the boss portion 3 of the rotating fan 2 to the fixed yoke 30. Although the second rib 21 is provided on the shroud 17 in the present embodiment, the second rib 21 may be provided on the base plate 31.

Further, in this embodiment, a cutout groove 7 is formed in the front end face 6 of the boss portion 3 of the fan 2 so that the fan 2
Although the notch groove 13 is formed on the rear end surface 12 of the boss portion 3, the notch groove 7 and the notch groove 13 are not necessarily required. Then, as described above, one embodiment of the invention described in claim 1 will be described by taking a motor fan according to the embodiment of the invention described in claim 3 as an example, and one embodiment of the invention described in claim 2. Although the motor fan according to the embodiment of the invention described in claim 4 has been described as an example, the invention according to claim 1 is not limited to the motor fan according to the embodiment of the invention described in claim 3. According to the invention described in claim 1, the flat motor 4 formed by separating the yoke 30 and the rotor 5 is arranged in the boss portion 3 in which the hole portion 3A is formed, and from the front end face 6 of the boss portion 3 to the inside of the hole portion 3A. A front annular drainage portion 9 is formed over the peripheral surface 8, and a yoke 30 is provided at a position where a peripheral edge 30A of the yoke 30 is separated from the front annular drainage portion 9 by a gap Z1.
The outer peripheral portion of the rotor 5 may be integrated with the boss portion 3. The invention according to claim 2 is not limited to the motor fan according to the embodiment of the invention according to claim 4. According to the second aspect of the present invention, the flat motor 4 formed by separating the yoke 30 and the rotor 5 is arranged in the boss portion 3 in which the hole portion 3A is formed. A rear annular drainage portion 14 is formed over the inner peripheral surface 8, and a second rib 21 is provided on the shroud 17 or a base plate 31 provided on the shroud 17 at a position separated from the rear annular drainage portion 14 by a gap Z2. The outer peripheral portion of 5 may be integrated with the boss portion 3. In the motor fan according to the first and second aspects of the present invention, the permanent magnet 108 is fixed to the casing 107, and the brush 115 is arranged inside the permanent magnet 108 in the radial direction in the above structure, for example, as shown in FIG. However, the commutator 113 for contacting the brush 115 may be formed in a ring shape and combined.

In addition, in the motor fan according to the third aspect of the present invention, the front annular drainage portion 9 is formed of the annular inclined surface 10 and the annular curved surface 11.
The front annular drainage portion in the described invention may be configured only by the inclined surface from the front end surface 6 of the boss portion 3 to the inner peripheral surface 8 of the hole portion 3A. In the motor fan according to the embodiment of the invention described in claim 4, the rear annular drainage portion 1
4 is composed of an annular inclined surface 15 and an annular curved surface 16, the rear annular drainage portion in the invention according to claim 2 extends from the rear end surface 12 of the boss portion 3 to the inner peripheral surface 8 of the hole portion 3A. It is also possible to configure only with the inclined surface.

[0045]

As described above, according to the invention described in claim 1, since the front annular drainage portion is formed from the front end surface of the boss portion to the inner peripheral surface of the hole portion, when the fan is stopped. , Is discharged to the outside from the annular drainage part on the front side of the boss part. Therefore, water does not collect at the lowermost part of the front annular drainage portion of the boss portion, and particularly when the temperature drops, the yoke and boss due to freezing of accumulated water from the front annular drainage portion of the rotating side boss portion to the fixed side yoke. It is possible to eliminate the risk of part damage.

According to the second aspect of the present invention, since the rear annular drainage portion is formed from the rear end surface of the boss portion to the inner peripheral surface of the hole portion, the rear side of the boss portion is formed when the fan is stopped. The water flowing into the lowermost part of the annular drainage portion is discharged outside from the annular inclined surface. Therefore, water does not collect in the lowermost part of the rear annular drainage portion of the boss portion, and especially when the temperature drops, the boss due to freezing of accumulated water from the rear annular drainage portion of the rotating boss portion to the fixed rib It is possible to eliminate the risk of part damage.

According to the third aspect of the present invention, the front annular groove is formed in the boss portion, the annular curved surface has a rounded cross section, and there is an annular inclined surface following this, so that the fan stops. At some time, the water that has flowed into the lowermost part of the front annular groove of the boss is discharged to the outside from the annular inclined surface. Therefore, water does not collect in the lowermost part of the front annular groove of the boss portion, and particularly when the temperature drops, the yoke and boss portion of the rotating side boss portion due to freezing of accumulated water from the front annular groove to the fixed yoke. The risk of damage can be eliminated.

According to the fourth aspect of the present invention, the rear annular groove is formed in the boss portion, the annular curved surface of the rear annular groove has a rounded cross section, and there is an annular inclined surface that follows it. Therefore, when the fan is stopped, the water flowing into the lowermost part of the rear annular groove of the boss portion is discharged to the outside from the annular inclined surface. Therefore, water does not collect in the lowermost part of the rear annular groove of the boss portion, and particularly when the temperature drops, the boss due to freezing of accumulated water from the rear annular groove of the rotating boss portion to the fixed second rib. It is possible to eliminate the risk of part damage.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a motor fan according to an embodiment of the invention described in claims 1, 2, 3, and 4.

FIG. 2 is a partial vertical cross-sectional view of a fan of the motor fan.

FIG. 3 is a front view of a fan of the motor fan.

FIG. 4 is a view in the direction of arrow C in FIG.

FIG. 5 is an enlarged view of a boss portion of the fan.

FIG. 6 is a view on arrow A in FIG.

7 is a cross-sectional view taken along line BB of FIG.

8 is a front view of the shroud housing of FIG. 1. FIG.

FIG. 9 is a cross-sectional explanatory view showing a housed state of a brush.

10 is a front view of the permanent magnet of FIG. 1. FIG.

FIG. 11 is a cross-sectional view showing joining of a boss portion of a fan and a rotor by insert molding.

FIG. 12 is a vertical cross-sectional view of a conventional motor fan.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 motor fan 2 fan 3 boss part 3A hole part 4 flat motor 5 rotor 6 front end face 8 inner peripheral face 9 front annular drainage part 10 annular inclined face 11 annular curved face 12 rear end face 14 rear annular drainage part 15 annular inclined face 16 annular curved surface 17 shroud 21 second rib 29 shaft 29A one end 30 yoke 30A peripheral edge 31 base plate 34 brush 36 magnet yoke 37 permanent magnet 40 commutator X fixed side Y rotation side Z1 gap Z2 gap

Claims (4)

[Claims] 1. A boss portion (3) having a hole (3A) formed therein.
A flat motor (4), which is obtained by separating the yoke (30) and the rotor (5), is arranged in the direction from the front end face (6) of the boss (3) to the inner peripheral surface (8) of the hole (3A). The front annular drainage part (9) is formed, the yoke (30) is fixed via the shaft (29), and the peripheral edge (30A) of the yoke (30) is a gap (Z1) with the front annular drainage part (9). A motor fan, characterized in that the outer peripheral portion of the rotor (5) is integrated with the boss portion (3). 2. A boss portion (3) having a hole (3A) formed therein.
A flat motor (4) formed by separating the yoke (30) and the rotor (5) is arranged on the inner surface (8) of the hole (3A) from the rear end surface (12) of the boss (3). The rear annular drainage portion (14) is formed over the rear side, and the second rib (21) is provided in the shroud (17) or the base plate (31) provided on the shroud (17) to form a gap with the rear annular drainage portion (14). Z2) is provided at a distance, and the outer peripheral portion of the rotor (5) is integrated with the boss portion (3). 3. A boss portion (3) on the rotating side (Y) in which a hole portion (3A) is formed, and a front end face (6) of the boss portion (3) to an inner peripheral surface of the hole portion (3A). A trapezoidal conical annular inclined surface (10) formed over the front end surface (6) toward the rear end surface (12) and an inner peripheral surface continuous with the annular inclined surface (10). The front annular drainage portion (9) composed of an annular curved surface (11) having a rounded cross-section leading to (8) and the hole portion (3A) of the boss portion (3) are disposed on the fixed side (X). It is fixed to the shaft (29) and one end (29A) of the shaft (29), and has a peripheral edge (3) at a position separated from the front annular drainage part (9) by a gap (Z1).
0A) and the yoke (3) located in the hole (3A) of the boss (3).
0) and a base plate (31) arranged to face each other, and a brush (34) provided on the base plate (31).
A commutator (40) rotatably supported on the shaft (29), and a magnet yoke (3) provided on the base plate (31).
6) and a permanent magnet (37) provided on the magnet yoke (36)
And a rotor (5) fixed between the yoke (30) and the permanent magnet (37) and fixed to the commutator (40). The outer peripheral portion of the rotor (5) is integrated with the boss (3). A motor fan that is characterized by 4. A boss part (3) on the rotating side (Y) in which a hole part (3A) is formed, and an inner circumference of the hole part (3A) from a rear end face (12) of the boss part (3). A trapezoidal conical annular inclined surface (15) that is formed over the surface (8) and has a diameter that decreases from the rear end surface (12) toward the front end surface (6) and the inner periphery that is continuous with this annular inclined surface (15). The rear annular drainage portion (14), which is composed of an annular curved surface (16) having a rounded cross-section that reaches the surface (8), and the hole (3A) of the boss portion (3), and the fixed side (X). A shaft (29), a yoke (30) fixed to one end (29A) of the shaft (29), and a yoke (3) located in a hole (3A) of the boss (3).
0), the second rib provided on the shroud (17) or the base plate (31), which is arranged at a position separated from the rear annular drainage part (14) by a gap (Z2). (21) and a brush (34) provided on the base plate (31)
A commutator (40) rotatably supported on the shaft (29), and a magnet yoke (3) provided on the base plate (31).
6) and a permanent magnet (37) provided on the magnet yoke (36)
And a rotor (5) fixed between the yoke (30) and the permanent magnet (37) and fixed to the commutator (40). The outer peripheral portion of the rotor (5) is integrated with the boss (3). A motor fan that is characterized by