JP6825964B2 - Electric fan - Google Patents

Description

The present invention relates to an electric fan used for cooling a heat exchanger (radiator, capacitor, etc.) of an automobile or the like.

Electric fans using an electric motor as a drive source are widely used for cooling heat exchangers such as radiators of automobiles. This type of electric fan has a configuration in which a fan body is connected to a rotating member such as a rotor yoke of an electric motor with fasteners such as bolts and nuts.

The fan body generally has a substantially cup-shaped fan boss with a front wall located axially forward of the rotor and a peripheral side wall located laterally outward of the rotor. The fan boss is attached so as to cover the rotor, and is connected to the rotor by bolts, nuts, or the like at one or a plurality of connecting points in the radial center region of the front wall. Then, a plurality of fan blades extending radially outward are provided on the peripheral side wall of the fan boss, and the fan blades rotate to generate cooling air flowing in the axial direction.

By the way, in this type of electric fan, membrane surface vibration may occur on the front wall of the fan boss due to cogging vibration of the electric motor or the like during operation, which may generate jarring acoustic noise.

Therefore, as a technique for reducing such acoustic noise, a proposal has been proposed in which an opening is provided in the front wall of the fan boss to suppress vibration propagation from the connection point with the rotor to the peripheral side wall side (for example). , Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-209846

However, if an opening is simply provided in the front wall of the fan boss, water may easily enter the inside of the fan boss through the opening when it rains or the like.

In consideration of the above circumstances, an object of the present invention is to provide an electric fan capable of reducing the intrusion of water into the fan boss while ensuring the effect of reducing the membrane surface vibration of the fan boss.

In order to solve the above problems, the electric fan according to the present invention includes an electric motor and a fan body that rotates integrally with the rotor by being connected to a rotating member of the electric motor. A fan boss that has a front wall located axially forward of the rotating member of the electric motor and a peripheral side wall located radially outward of the rotating member of the rotor and covers the electric motor, and the fan boss. An electric fan comprising a fan blade extending radially outward from a peripheral side wall, and the fan boss is connected to the electric motor at a connection point in a radial center region of the front wall of the fan boss. , The front wall of the fan boss is positioned between the connecting point in the radial central region and the outer peripheral portion connected to the peripheral side wall to block the propagation of vibration from the connecting point to the peripheral side wall. An opening is provided, and a shielding wall located behind the rear surface is provided on the rear surface side of the front wall of the opening so as to secure a gap between the outer peripheral end of the shielding wall and the rear surface. The rear opening surface is formed, and the position of the front opening surface on the front side of the front wall of the opening and the position of the rear opening surface are displaced from each other so as to be invisible when viewed from the axial direction. It is characterized in that the surface direction of the front opening surface and the surface direction of the rear opening surface intersect with each other.

In such a configuration, the vibration transmitted from the rotor of the electric motor to the front wall of the fan boss causes membrane surface vibration on the front wall of the fan boss. However, by providing an opening in the front wall of the fan boss, the membrane surface vibration is significantly attenuated on the front wall of the fan boss, and as a result, the acoustic noise level generated during operation due to the influence of the vibration transmitted from the electric motor is increased. descend.
In addition, it is possible to more reliably prevent water from entering the inside of the fan boss from the outside.

In addition, since the positions of the opening surface on the front surface side of the front wall and the opening surface on the rear surface side of the front wall of the opening are displaced from each other in the axial direction, water that has entered from the opening surface on the front surface side of the front wall is in front. It becomes difficult to reach the opening surface on the rear surface side of the wall smoothly. As a result, even if water is splashed from the front in the axial direction of the fan boss, it is possible to prevent water from entering the inside of the fan boss, and it is possible to prevent water from being applied to the rotor side as much as possible.

In the electric fan according to the present invention, the penetration direction of the opening from the front surface side of the front wall toward the rear surface side of the front wall is set obliquely with respect to the axial direction of the rotor. It is characterized by.

With this configuration, the positions of the opening surface on the front surface side of the front wall and the opening surface on the rear surface side of the front wall of the opening can be easily displaced from each other when viewed from the front in the axial direction.

In the electric fan according to the present invention, the rotor has a rotor yoke having a front wall located axially forward of the stator and a peripheral side wall located radially outward of the stator, and the rotor yoke of the front wall of the rotor yoke. A drain hole for discharging water that has entered the inside of the rotor to the outside of the rotor is provided in the outer peripheral region, and the positions of the front opening surface of the opening and the drain hole when viewed from the axial direction are displaced from each other. It is characterized by being.

With this configuration, even if water enters the inside of the fan boss through the opening, it can be prevented from entering the inside of the rotor through the drain hole.

The electric fan according to the present invention is characterized in that a plurality of openings are provided at equal intervals in the circumferential direction of the rotor.

With this configuration, it is possible to eliminate the deterioration of the rotational balance of the fan body due to the provision of the opening in the front wall of the fan boss. As a result, the occurrence of rotation unevenness can be reduced.

According to the present invention, it is possible to reduce the intrusion of water into the fan boss while ensuring the effect of reducing the film surface vibration of the fan boss.

It is a perspective view seen from the oblique front of the fan body in the electric fan of the 1st reference example of this invention. It is a perspective view seen from the oblique rear of the fan body in the electric fan of the 1st reference example of this invention. It is a perspective view which shows the main part structure of the electric fan of 1st reference example of this invention as a partial cross section. It is a partially enlarged view of FIG. 3 for explaining the operation of the electric fan of the 1st reference example of this invention. It is an enlarged sectional view of the opening of the fan body of the 1st reference example of this invention. It is a perspective view seen from the oblique front of the fan body in the electric fan of the 2nd reference example of this invention. It is a perspective view seen from the oblique rear of the fan body in the electric fan of the 2nd reference example of this invention. It is a perspective view obliquely from the front of the fan main body of the electric fan of the implementation of the invention. Is a perspective view seen obliquely from the rear of the fan main body of the electric fan of the implementation of the invention. It is an enlarged sectional view of the opening of the fan main body of implementation of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(1st reference example )
FIG. 1 is a perspective view of the electric fan of the first reference example as viewed from diagonally forward of the fan body. FIG. 2 is a perspective view seen from diagonally rearward of the fan body. FIG. 3 is a perspective view showing a main part configuration of the electric fan as a partial cross section.

The fan body 1A shown in FIGS. 1 and 2 constitutes the electric fan 100 of the first reference example shown in FIG. The electric fan 100 is used for cooling the radiator of a vehicle.
As shown in FIG. 3, it includes an electric motor 101 as a drive source and a fan body 1A rotationally driven by the electric motor 101. The electric fan 100 is attached to the front side of the radiator, for example, via a fan shroud (not shown) or the like, with the fan body 1A facing forward.

(Electric motor)
The electric motor 100 is composed of an outer rotor type brushless motor (outer rotor type electric motor 101).
As briefly shown in FIG. 3, the outer rotor type brushless motor (electric motor 101) is an electric motor in which the rotor 103 arranged on the outer peripheral side of the stator (not shown) rotates. Neither is shown, but the stator is wound with a plurality of coils for excitation. Further, the stator is supported by a bracket, and the motor shaft is rotatably supported by the bracket. Then, the rotor 103 is coupled to the motor shaft so as to be integrally rotatable.

The rotor 103 has a rotor yoke 102 coupled to a motor shaft. The rotor yoke 102 is a member made of a magnetic material formed in a cup shape so as to cover the stator from the front surface thereof, and has a front wall 102a located axially forward of the stator and a peripheral side wall 102b located radially outward of the stator. have. A magnet facing the teeth of the stator is arranged on the inner circumference of the peripheral side wall 102 of the rotor yoke 102. Here, in a region on the outer peripheral side of the front wall 102a of the rotor yoke 102, a drain hole 110 for discharging water that has entered the rotor 103 to the outside of the rotor 103 may be provided.

(Fan body)
As shown in FIGS. 1 and 2, the fan body 1A has a fan boss 2 at the center in the radial direction, a fan blade 3 on the outer peripheral side thereof, and an outer peripheral ring 4. The fan boss 2 is formed in a cup shape including a front wall 2a located axially forward of the rotor yoke 102 (see FIG. 3) and a peripheral side wall 2b located laterally outward of the rotor yoke 102. A disk-shaped metal plate 7 for connection is embedded in the circular thick portion 6 at the center of the fan boss 2 by molding. At the center of the metal plate 7, a connecting hole 7a for connecting to the tip of the motor shaft is provided.

The fan body 1A is assembled to the electric motor 101 so that the cup-shaped fan boss 2 covers the rotor yoke 102. At that time, the central portion of the front wall 2a of the fan boss 2 is connected to the motor shaft by the fastener 108 such as bolts and nuts using the connecting hole 7a. Therefore, in this reference example , the radial center of the front wall 2a corresponds to the connecting point (where the connecting hole 7a is located). A plurality of fan blades 3 extend radially outward from the peripheral side wall 2b of the fan boss 2 and are arranged at equal intervals in the circumferential direction. An outer peripheral ring 4 is provided so as to connect the outer peripheral ends of the plurality of fan blades 3. The fan body 1A is integrally molded with a synthetic resin other than the metal plate 7.

(Fan boss)
As shown in FIG. 2, on the inner surface side of the fan boss 2, cylindrical ribs 2c extending axially rearward from the front wall 2a are provided concentrically with the peripheral side wall 2b.
As shown in FIG. 3, in the assembled body of the fan body 1 with the electric motor 101, the cylindrical rib 2c is located on the outer peripheral side of the peripheral side wall 102b of the rotor yoke 102. Further, on the rear surface (inner surface) of the front wall 2a, an annular shape having a low height concentrically with the cylindrical rib 2c is positioned between the cylindrical rib 2c and the thick portion 6 in which the metal plate 7 is embedded. The rib 2d is provided. Further, on the rear surface (inner surface) of the front wall 2a, radial ribs 2e having a low height are provided so as to extend from the thick portion 6 in which the metal plate 7 is embedded to the cylindrical ribs 2c. Further, a radial rib 2f is also provided between the cylindrical rib 2c and the peripheral side wall 2b.

FIG. 4 is a partially enlarged view of FIG.
As shown in FIGS. 1 to 4, the front wall 2a of the fan boss 2 configured in this way has a connection point at the center in the radial direction (a place where the connection hole 7a is provided) and an outer circumference connected to the peripheral side wall 2b. A plurality of openings 10 that are positioned between the portions and block the propagation of vibration from the connecting point to the peripheral side wall 2b are provided at equal intervals in the circumferential direction. Each opening 10 is arranged between the radial ribs 2e on the inner peripheral side of the cylindrical rib 2c.

FIG. 5 is an enlarged cross-sectional view of the opening.
As shown in the figure, each opening 10 has an opening surface 10a on the front surface 2ax side of the front wall (hereinafter referred to as a front opening surface 10a) and an opening surface 10b on the rear surface 2ay side of the front wall (hereinafter referred to as a rear opening surface 10b). The positions seen from the front in the axial direction are out of alignment with each other. That is, in the opening 10, the penetration direction from the front opening surface 10a to the rear opening surface 10b is set obliquely with respect to the axial direction. The rear opening surface 10b is located radially outward of the front opening surface 10a. Further, the inner peripheral end 10by of the rear opening surface 10b is located radially outward in the same radial direction with respect to the outer peripheral end 10ax of the front opening surface 10a. As a result, each opening 10 is invisible when viewed from the front in the axial direction. When the outer peripheral end 10ax of the front opening surface 10a and the inner peripheral end 10by of the rear opening surface 10b are located at the same radial position, the opening 10 can be opened by simply cutting vertically from the front and the rear in the axial direction. Can be easily molded.

(Action effect)
In the above configuration, vibration is transmitted to the front wall 2a of the fan boss 2 via the connection point due to cogging vibration of the electric motor 101 during operation. This vibration is caused by the membrane surface vibration of the front wall 2a of the fan boss 2. However, since the front wall 2a of the fan boss 2 is provided with the opening 10, the vibration is significantly attenuated on the front wall 2a of the fan boss 2. As a result, the acoustic noise level generated during operation is lowered due to the influence of the vibration transmitted from the motor 101.

Further, since the positions of the front opening surface 10a and the rear opening surface 10b of the opening 10 as viewed from the front in the axial direction are deviated from each other, they invade from the front opening surface 10a (see FIG. 5) as shown in FIG. It becomes difficult for the water W to reach the rear opening surface 10b (see FIG. 5) smoothly, and as a result, even if water is applied from the axial front of the fan boss 2, water does not enter the inside of the fan boss 2. Can be hindered. Then, it is possible to prevent water from being applied to the rotor 103 side as much as possible.

In particular, the positions of the front opening surface 10a and the rear opening surface 10b of the opening 10 when viewed from the front in the axial direction are deviated so that each opening 10 cannot be seen when viewed from the front in the axial direction. .. Therefore, it is possible to more reliably prevent water from entering the inside of the fan boss 2 from the outside.

Further, the penetration direction of each opening 10 from the front wall front 2ax side (front opening surface 10a) to the front wall rear surface 2ay side (rear opening surface 10b) is set obliquely with respect to the axial direction of the rotor 103. Has been done. Therefore, the positions of the front opening surface 10a and the rear opening surface 10b of the opening 10 when viewed from the front in the axial direction can be easily shifted from each other.

Further, since a plurality of openings 10 are provided at equal intervals in the circumferential direction of the rotor 103, the deterioration of the rotational balance of the fan body 1A due to the provision of the openings 10 on the front wall 2a of the fan boss 2 is eliminated. be able to. Therefore, it is possible to reduce the occurrence of rotation unevenness.

As shown in FIGS. 3 and 5, when the drain hole 110 is provided on the outer peripheral side of the front wall 102a of the rotor yoke 102, the axial direction between the rear opening surface 10b of the opening 10 and the drain hole 110. It is desirable to shift the positions seen from the front to each other. By doing so, even if water enters the inside of the fan boss 2 from the opening 10, it is possible to prevent the water from entering the inside of the rotor 103 through the drain hole 110.

(2nd reference example )
Next, a second reference example of the present invention will be described with reference to FIGS. 6 and 7.
FIG. 6 is a perspective view of the electric fan of the second reference example as viewed from diagonally forward of the fan body. FIG. 7 is a perspective view seen from diagonally rearward of the fan body.

As shown in FIGS. 6 and 7, the fan main body 1B in the electric fan of the second reference example has a plurality of openings 20 having the same configuration and action added to the fan main body 1A of the first reference example. It was provided. The additionally provided opening 20 is located between the radial ribs 2e on the inner peripheral side of the annular rib 2d.
The basic configuration of the opening 20 is the same as that of the opening 10. That is, the opening 20 is set so that the penetration direction from the front wall front 2ax side to the front wall rear surface 2ay side is oblique with respect to the axial direction. The opening surface on the front surface 2ax side of the front wall is located inward in the radial direction with respect to the opening surface on the rear surface 2ay side of the front wall.

Therefore, according to the second reference example described above, the acoustic noise suppression effect of the electric fan can be further enhanced by providing the opening 20 additionally.

In the first reference example and the second reference example described above, the opening 10 is in the penetrating direction from the front wall front surface 2ax side (front side opening surface 10a) to the front wall rear surface 2ay side (rear side opening surface 10b). However, the case where the rotor 103 is set obliquely with respect to the axial direction has been described. Then, the case where the rear opening surface 10b is located radially outward from the front opening surface 10a has been described. Further, it was explained that the opening 20 has the same configuration as the opening 10. However, the present invention is not limited to this, and the openings 10 and 20 may have the opening surface on the front wall front surface 2ax side located radially outward from the opening surface on the front wall rear surface 2ay side. In this configuration, the centrifugal force when the fan body 1A is rotationally driven makes it difficult for the water that has hit the front wall front surface 2ax to be transmitted to the front wall rear surface 2ay.

(Implementation form)
Next, based on FIGS. 8 to 10, will be described implementation form of the present invention.
Figure 8 is a perspective view obliquely from the front of the fan main body of the electric fan of implementation forms. FIG. 9 is a perspective view seen from diagonally rearward of the fan body.

Fan body 1C in the electric fan of this implementation form, instead of the opening 10 of the fan main body 1A of the first reference example, in which it differs from the shape opening 30 of provided on the front wall 2a of the fan boss 2 .. As in the first reference example , each opening 30 is positioned between the connection point at the radial center of the front wall 2a (the place where the connection hole 7a is provided) and the outer peripheral portion connected to the peripheral side wall 2b. , The propagation of vibration from the connection point to the peripheral side wall 2b is blocked. Then, each opening 30 is arranged between the radial ribs 2e on the inner peripheral side of the cylindrical rib 2c.

FIG. 10 is an enlarged cross-sectional view of the opening.
As shown in the figure, each opening 30 is configured as a square recess when viewed from the front in the axial direction. Further, each opening 30 is configured such that the range of the recess on the front wall front surface 2ax is the opening surface 30a on the front wall front surface 2ax side (hereinafter, referred to as the front side opening surface 30a). Further, as the bottom wall of the recess, a shielding wall 32 located behind the front wall rear surface 2ay is provided on the rear surface side of each opening 30. Then, a gap is secured between the outer peripheral end of the shielding wall 32 and the front wall rear surface 2ay, and the gap is configured as an opening surface 30b (hereinafter, referred to as a rear opening surface 30b) on the front wall rear surface 2ay side. There is.

As a result, the positions of the front opening surface 30a and the rear opening surface 30b when viewed from the front in the axial direction are displaced from each other. Then, each opening 30 becomes invisible when viewed from the front in the axial direction.

Therefore, also in the fan body 1C configured as described implementation described above, it is possible to achieve the same effect as the first embodiment. That is, the presence of the opening 30 significantly attenuates the vibration transmitted from the rotor 103 of the electric motor 101 to the front wall 2a of the fan boss 2 via the connecting point. As a result, the acoustic noise level generated during operation is lowered due to the influence of the vibration transmitted from the motor 101.

Further, since the positions of the front opening surface 30a and the rear opening surface 30b of the opening 30 as viewed from the front in the axial direction are deviated from each other, water that has entered from the front opening surface 30a enters the opening surface on the front wall rear surface 2ay side. It becomes difficult to reach 30b smoothly. As a result, even if water is splashed from the front of the fan boss 2 in the axial direction, it is possible to prevent the water from entering the inside of the fan boss 2 and prevent the rotor 103 from being flooded as much as possible. Moreover, each opening 30 is invisible when viewed from the front in the axial direction. Therefore, it is possible to more reliably prevent water from entering the inside of the fan boss 2 from the outside.

The present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.

For example, in the above embodiment, the case where one point (the connection point with the motor shaft) at the center of the front wall 2a of the fan boss 2 is used as the connection point has been described. However, the present invention is not limited to this, and the fan boss 2 may be connected to the rotor by bolts, nuts, or the like at a plurality of connecting points in the radial center region of the front wall.
Further, in the above embodiment, the case where the electric motor 101 is an outer rotor type electric motor has been described. However, the present invention is not limited to this, and an inner rotor type electric motor may be adopted as the electric motor 101.

1A, 10B, 10C ... Fan body 2 ... Fan boss 2a ... Front wall 2ax ... Front wall front 2ay ... Front wall rear (rear)
2b ... Peripheral side wall 3 ... Fan blade 7a ... Connecting hole (connection point)
10 ... Opening 10a ... Front opening surface 10b ... Rear opening surface 20 ... Opening 30 ... Opening 30a ... Front wall front opening surface (front opening surface)
30b ... Opening surface on the rear surface side of the front wall (rear opening surface)
32 ... Shielding wall 100 ... Electric fan 101 ... Electric motor 102 ... Rotor yoke 102a ... Front wall 102b ... Peripheral side wall 103 ... Rotor 110 ... Drainage hole

Claims (4)

It includes an electric motor and a fan body that rotates integrally with the rotor by being connected to the rotating member of the electric motor.
The fan body
A fan boss that has a front wall located axially forward of the rotating member of the electric motor and a peripheral side wall located radially outward of the rotating member of the rotor and covers the electric motor.
A fan blade extending radially outward from the peripheral side wall of the fan boss,
With
An electric fan in which the fan boss is connected to the electric motor at a connection point in the radial center region of the front wall of the fan boss.
An opening located in the front wall of the fan boss between the connecting point in the radial central region and the outer peripheral portion connected to the peripheral side wall to block the propagation of vibration from the connecting point to the peripheral side wall. The part is provided,
A shielding wall located behind the rear surface is provided on the rear surface side of the front wall of the opening .
A rear opening surface is formed so as to secure a gap between the outer peripheral edge of the shielding wall and the rear surface.
The position of the front opening surface on the front side of the front wall of the opening and the position of the rear opening surface are deviated from each other so as to be invisible when viewed from the axial direction .
Moreover, the electric fan is characterized in that the surface direction of the front opening surface and the surface direction of the rear opening surface intersect . According to claim 1, the penetration direction of the opening from the front surface side of the front wall toward the rear surface side of the front wall is set obliquely with respect to the axial direction of the rotor. The described electric fan. The electric motor is an outer rotor type electric motor in which a rotor arranged on the outer peripheral side of the stator rotates.
The rotor has a rotor yoke having a front wall located axially forward of the stator and a peripheral side wall located radially outward of the stator.
A drain hole is provided in a region on the outer peripheral side of the front wall of the rotor yoke to discharge water that has entered the inside of the rotor to the outside of the rotor.
The electric fan according to claim 1 or 2, wherein the front opening surface of the opening and the drain hole are displaced from each other when viewed from the axial direction. The electric fan according to any one of claims 1 to 3, wherein a plurality of openings are provided at equal intervals in the circumferential direction of the rotor.

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