KR20010085229A - Fan motor - Google Patents

Abstract

PURPOSE: To reduce the number of parts and decrease vibrations and noises by the use of a plastic magnet as an outside rotation motor. CONSTITUTION: An outward rotation magnet motor 18 is constituted by use of a plastic magnet 16, and also a fan part 17 is provided integrally in the outer periphery of this plastic magnet 16.

Description

Fan motor {FAN MOTOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fan motor having a fan unit integrally using an external magnet magnet motor.

Background Art Conventionally, a fan motor used in a refrigerator is known as this kind of fan motor, and such fan motor is configured to circulate and supply cool air to the inside of the refrigerator by the blowing operation. In recent years, in the fan motor, an external type (external rotor type) motor is adopted in which the compactness is expected to be improved in the radial direction and the axial direction in consideration of the installation space in the refrigerator.

11 is a longitudinal side view showing an example thereof. The fan motor shown in FIG. 11 is roughly a casing 1, a rear bearing assembly 2 attached to the casing 1, a stator 3 attached to the rear bearing assembly 2, and a stator. (3) integrally attached to the outer periphery of the rotor (6) and the rotor (6) having a central portion with a front bearing assembly (4) attached thereto, a motor shaft (5) rotatably supported by both bearing assemblies (2, 4) It is set as the structure provided with the fan part 7 provided normally.

In more detail, the rotor 6 is arranged on the outer circumference of the stator 3 to form a rotor yoke 8 made of a galvanized steel sheet formed in a cylindrical cup shape, and an inner circumferential surface of the rotor yoke 8. For example, it is composed of a 12-pole rotor magnet 9 attached thereto. The rotor magnet 9 is inserted into and fixed to the inner peripheral surface of the rotor yoke 8 at its rear end side. Then, one end of the motor shaft 5 is fixed to the center of one end of the rotor yoke 8 by press fitting. The rotor 6 thus configured has a motor shaft 5 rotatably supported by the front bearing assembly 4 and the rear bearing assembly 2 such that the rotor magnet 9 is slightly relative to the stator 3. They are arranged to face each other at intervals, and thus constitute a so-called external magnet type magnet motor 10 of an external rotor type.

On the other hand, the fan portion 7 is made of a synthetic resin material and is formed integrally by first inserting the rotor yoke 8 into a molding die (not shown) and injecting and molding molten material. This fan part 7 mainly consists of the fan base 7a which covers the outer periphery of the rotor yoke 8, and the three blade parts 7b which extend radially, for example.

Moreover, when the wing | blade part 7b is rotationally driven, the blowing direction is comprised so that it may flow in the direction shown by arrow W (shown to the right).

By the way, in the configuration in which the fan portion 7 is formed integrally with the rotor 6 by using the abduction type magnet motor 10 as described above, vibration from the rotor 6 side generated during rotational driving, or vice versa. The vibrations from the fan portion 7 are directly transmitted to each other, and in the case of a resonance state, the influence on the abduction type motor 10 is also large and affects the noise problem and the durability of the entire fan motor.

Therefore, in particular, it is necessary to suppress the generation of vibration as small as possible, but it is difficult to secure the assembling precision of the motor shaft 5 in the above configuration, and it is difficult to be stable. This not only makes the assembly work including positioning of the rotor magnet 9 to the inner surface of the rotor yoke 8 easy, but also presses and secures the motor shaft 5 to the structure to which the fan portion 7 is added. As a structure, there are many so-called assembly parts, and error is easy to come out by that much. Therefore, it is difficult to obtain the axial depths of the rotating fan portion 7, the rotor yoke 8, the rotor magnet 9, and the motor shaft 5 with high accuracy, and it is cumbersome to adjust the rotational balance of all of them. The problem is that it is difficult to suppress vibrations small for reasons such as difficulty in obtaining stabilized quality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to reduce the number of parts by using a plastic magnet in an external magnet motor and to increase the assembly precision of the motor shaft. To provide a fan motor.

1 is a longitudinal side view of an overall configuration showing one embodiment of the present invention;

2 is a full rear view;

3 is a longitudinal sectional view of a plastic magnet having a motor shaft;

4 is a front view of FIG. 3;

5 is a cross-sectional view of the motor shaft cut along the line A-A of FIG.

6 is a longitudinal sectional side view of the main portion of the molded portion;

7 is a longitudinal sectional view for explaining a schematic configuration and molding process of a molding die;

8 is a longitudinal cross-sectional view for explaining a process different from FIG. 7;

9 is an enlarged cross-sectional view of a main part cut along the line B-B of FIG. 8;

10 is an enlarged cross-sectional view of a main part in another form of FIG. 9;

Fig. 11 is a diagram corresponding to Fig. 1 showing a conventional example.

* Explanation of symbols for main parts of the drawings

11: casing 13: stator

15: motor shaft 15b: incision

16: plastic magnet (rotor magnet) 16a: closed end

16b: tube 17: pan

17a: Fan Base 17b: Wings

18: Abduction magnet motor 31: thickness portion

32: uneven portion 35: mold

35a: fixed mold 35b: movable mold

36: first molded part 37: second molded part

46: magnetic field forming magnets 47a, 47b, 47c... Magnetic direction

In the fan motor of the present invention, in order to achieve the above object, the fan motor includes a rotor magnet disposed on an outer periphery of the stator, and the rotor magnet is formed of a plastic magnet and the fan unit is integrally provided on the outer periphery of the plastic magnet. It is characterized by (the invention of claim 1).

According to this configuration, the number of parts can be reduced, so that the shaft center adjustment can be managed only by the precision of both the plastic magnet and the fan part, so that a high precision shaft balance can be easily obtained, and vibration and noise can be reduced. In addition, the assembling work can be simplified, thereby providing a fan motor which is advantageous in terms of quality and at the same time.

And what was described in Claim 1 WHEREIN: When shape | molding a pan part with a thermoplastic resin, the plastic magnet was insert-molded (invention of Claim 2).

According to such a configuration, not only can it be easily configured (assembled) by the mold molding, but also the balance of the center of gravity between the plastic magnet and the pan part by insert molding can be roughly adjusted by the balance adjustment in the molding die, and even after the adjustment is balanced. It is possible to provide a fan motor which is stable and basically suppresses the amount of vibration.

Further, as described in claim 2, an uneven portion is formed on the outer circumferential surface of the plastic magnet, and the molding shrinkage ratio of the thermoplastic resin of the fan portion is larger than that of the plastic magnet (invention 3).

According to such a structure, since the fan part after shaping | molding keeps an inner plastic magnet like a compression, and the uneven | corrugated part provided in the outer peripheral surface of this plastic magnet couples together even more firmly, it slips between these joint parts (idle rotation). It is possible to obtain the so-called solid anti-rotation function without the occurrence of).

In addition, the plastic magnet is formed in a substantially cup shape in which one end side in the axial direction is almost closed, and inserts a motor shaft in the center of the closed end side. invent).

According to such a configuration, not only can be easily configured (assembled) by mold forming, but also can be molded around the motor shaft in the mold, so that the motor shaft, which is particularly important for achieving the core balance, can be easily adjusted in the mold and effectively. It is possible to provide a fan motor whose quality is stabilized by suppressing the amount of vibration.

Moreover, as described in Claim 1, the plastic magnet is anisotropically formed so that the magnetic force direction may be formed inside the magnet (invention of Claim 5).

According to this configuration, the magnetic force direction is formed by the stator, there is no magnetic flux leaking on the outer periphery of the plastic magnet, and therefore, no foreign matter (magnetic material) is attached, and the rotor yoke (back yoke) is unnecessary, so that the external magnet magnet motor is simple. Original compactness can be effectively achieved.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 10.

First, FIG. 1 and FIG. 2 are longitudinal side and back views which show the whole structure of a fan motor. Based on these figures, the structure is roughly described, and the casing 11, the rear bearing assembly 12 attached to this casing 11, and the stator 13 attached to this rear bearing assembly 12 are described. ), A plastic magnet (16) which is a rotor magnet having a central bearing assembly (14) attached to the stator (13) and a motor shaft (15) rotatably supported by the bearings (12, 14). ) And a fan portion 17 provided on the outer circumference of the magnet 16.

Among these, detailed descriptions will be made later, but the plastic magnets 16 are arranged to face the outer circumference of the stator 13 at a slight distance, and thus constitute the external magnet magnet motor 18. 16 is a configuration that also serves as a rotor overall structure of a conventional configuration.

First, the casing 11 is made of a synthetic resin such as PBT (polybutadiene terephthalate), for example, and has a thin cylindrical portion 11a with an open rear face (right side in FIG. 1) at the center, and at the outer peripheral portion thereof. In particular, as shown in Fig. 2, four motor supports 11b extending in the radial direction are integrally installed at almost 90 degree intervals, and a short cylindrical bell mouth 11c is integrally installed at the outer circumference thereof. It is. Moreover, the ring-shaped attachment part 11d for attaching in the inside of the refrigerator of the refrigerator which is not shown in figure is integrally formed in three outer peripheral parts of this bellmouth 11c.

By the way, in the structure in which the said rear bearing assembly 12 fits and is attached to the cylindrical part 11a of this casing, the cylindrical bracket 19 which consists of a galvanized steel plate and inserts the said motor shaft 15 and And a bearing 20 made of a sintered metal attached to the inner rear portion thereof, an oil-containing felt 21 filled with lubricating oil, and the like, and the rear opening thereof is blocked by an appropriate lid member 22. Moreover, it is set as the structure which supports the front-end | tip of the said motor shaft 15 in the center part of the inner surface of this cover member 22. As shown in FIG.

The rear bearing assembly 12 is fitted into the casing 11 closely from the rear side so that the bracket 19 can be press-fitted.

In addition, the stator 13 briefly describes a winding 23 in the stator core 13a having a hole penetrating in the axial direction at the center thereof, and together with the connector 24, a mold of synthetic resin (PBT) is formed. It is set as the structure shape | molded by the sieve 25. As shown in FIG. Then, the rear end of the mold body 25 is engaged with the casing 11, and the center hole of the stator core 13a is press-fitted into the bracket 19 so that the rear bearing assembly 12 and the stator are fitted. (13) sandwiches the casing (11) from both sides and attaches the casing (11).

On the other hand, the front bearing assembly 14 has a configuration substantially symmetrically equivalent to the rear bearing assembly 12 described above, and thus has a cylindrical bracket 26, a bearing 27 made of sintered metal, and oil. It is in the structure provided with the containing felt 28, the cover member 29, etc. However, in this front bearing assembly 14, the motor shaft 15 penetrates completely and is inserted. As described above, the bracket 26 of the front bearing assembly 14 is press-fitted into the through hole of the stator core 22 to be fixed to the stator 13.

In addition, between the end portions of the brackets 19 and 26 of the bearing assembly 12 and 14, for example, a fall prevention member 30 formed in a ring shape from a nylon material is interposed therebetween. It is designed to prevent falling out.

Then, the stator 13 and the front bearing assembly 14 are covered to cover the plastic magnet 16 as the rotor magnet, and the motor shaft 15 is integrally attached to the center. Hereinafter, with reference to the specific structure of this plastic magnet 16, as shown in FIG. 3 and FIG. 4, the longitudinal side view and the front view of the plastic magnet 16 provided with the motor shaft 15, respectively, are as a whole shape. One end side in the axial direction is almost closed, forming a substantially cup shape, which is formed by injection molding, which will be described later by a material in which, for example, a nylon-based synthetic resin is added as a binder to a magnetic powder such as ferrite. 15) The shaft is insert molded and fixed.

By the way, as a specific shape of the plastic magnet 16, it forms the cup shape which consists of the closed end part 16a of one end and the cylinder part 16b continuous to this, and inserts the motor shaft 15 in the center of the closed end part 16a. It has the boss part 16c embedded by it. In the tube portion 16b, the right half of the opening end side of the rear side is a thickness portion 31, and the uneven portion 32 (especially see Figs. 3 and 4) having a step in the radial direction is provided on the outer circumferential surface of the remaining left half portion. The magnetic pole part is seated in the former thickness part 31 by the method of mentioning a pole of predetermined pole number, for example, 8 poles later. Moreover, in this structure, the shallow annular recessed groove 33 is formed also in the front surface of the said closed end part 16a.

In addition, the motor shaft 15 is made of, for example, a SUS material, forms a small diameter portion 15a in the middle portion, and is buried in the boss portion 16C, particularly as shown in the cross-sectional view of FIG. 5. The cutout 15b cut off in the radial direction is formed.

When integrally molding the plastic magnet 16 of such a structure, the said fan part 17 is insert-molded (it mentions later for details). As shown in FIG. 6, this fan part 17 is comprised from thermoplastic resins, such as a polypropylene, and is mainly comprised by the fan base 17a and three blade parts 17b, for example. In particular, the portion of the fan portion 17, excluding the wing portion 17b, which corresponds to the fan base 17a, is formed to cover the outer circumference of the plastic magnet 16, which is also formed in a substantially cup shape. . Then, after molding, the concave groove 33 and the molten resin introduced into the uneven portion 32 formed in the plastic magnet 16 are solidified by cooling, and at the same time, the rotation direction of the fan portion 17 is firmly combined. Anti-rotation function

However, the right half shown at the opening end side, which is the rear face of the fan base 17a, is positioned at a distance from the outer periphery of the thickness portion 31 of the plastic magnet 16 and is spaced apart from each other. In this case, the axial length L2 of the space | interval 34 becomes long with respect to the axial length L1 of the thickness part 31, and is the site | part substantially corresponded to the length L2 of this space | interval 34. As shown in FIG. It is a root part of the wing part 17b which extended | stretched to radial direction. The protruding portion 17c at the center of the fan base 17a hides the tip end of the motor shaft 15 together with the boss portion 16c of the plastic magnet 16. The fan portion 17 configured in this way is rotated in the direction indicated by the arrow W in FIG. 1, that is, from the front end side which is one end side in the axial direction of the plastic magnet 16 to the rear end side which is the other end side. It is configured to generate wind.

In this way, the structure consisting of the plastic magnet 16, the fan portion 17, and the motor shaft 15 integrally formed as shown in FIG. 6 has the motor shaft 15 as shown in FIG. And by inserting into the rear bearing assembly 14, 12. That is, the insertion preventing member 30 is inserted through the bearing 27 of the front bearing assembly 14 to the inside, and then the bearing 20 of the rear bearing assembly 12 is opened. It penetrates and it is assembled by inserting the front-end | tip to the cover member 22 until it is thrust-supported.

In addition, when the motor shaft 15 is inserted, the motor shaft 15 is inserted while pressing the opening of the release preventing member 30 to be widened. In the assembled state, the release preventing member 30 is inserted into the motor shaft 15. It is in the state fitted to the small diameter part 15a, and therefore, once assembled, the motor shaft 15 becomes the fall prevention structure which does not fall easily by the fall prevention member 30. FIG.

By the way, the motor shaft 15 integrated with the fan portion 17 and the plastic magnet 16 is rotatably supported by two bearings 27 and 20 in the front and rear portions, and the plastic magnet 16 as the rotor magnet is The inner circumferential surface of the cylindrical portion 16b covers the stator 13 in a state in which the stator 13 is in close proximity, and specifically, an inner circumferential surface substantially corresponding to the axial length L1 of the thickness portion 31 is slightly spaced apart from the outer circumferential surface of the stator core 22. Are arranged to face each other.

By the way, the shaping | molding means which integrates the said fan part 17, the plastic magnet 16, and the motor shaft 15 is demonstrated with reference to FIG. 7 and FIG. 7 and 8 are longitudinal cross-sectional views showing a schematic structure of one molding die 35, showing another state for explaining the molding process. The mold 35 has a fixed mold 35a on the left side and a movable mold 35b on the right side. In particular, in this embodiment, different types of moldings can be simultaneously performed in the upper and lower portions of one mold 35. One 1st shaping | molding part 36 and the 2nd shaping | molding part 37 are provided. Therefore, the flow paths 39 and 41 and the gates 40 and 43 communicating with the cavities 38 and 41 formed by the mold fastening are formed in the upper and lower portions of the fixed mold 35a, respectively.

In other words, the first molding part 36 performs molding of the plastic magnet 16 and insert molding of the motor shaft 15, while the second molding part 37 performs the first molding part 36. In the molding step subsequent to molding in the above step, the fan 17 is molded. Therefore, since the molded parts, such as the fan part 17 and the plastic magnet 16, are all in the shape of a cup, it is set as the structure which fits to the fixed mold 35a by making one movable mold 35b into a male shape at the time of metal mold clamping. have. In addition, the movable die 35b has bearing portions 44 and 45 for holding and inserting the motor shaft 15 and holding the motor shaft 15 as the center of positioning.

In the present embodiment, when the plastic magnet 16 is molded in the first molding part 36, the magnetic force of the anisotropic orientation is formed in the magnet 16 in the mold 35 as well. Therefore, the magnetic field forming magnet 46 is provided in the movable mold 35b, which is disposed corresponding to the thickness of the plastic magnet 16. As shown in FIG.

In the molding mold 35 having the above-described configuration, the shaping means for the plastic magnet 16 in the upper first molding portion 36 will be described with reference to FIG. 7. First, the motor shaft 15 for insert molding is first described. The fixing is fixed to the predetermined position of the shaft support part 44 of the movable die 35b. After the mold is fastened, molten material (nylon-based magnetic powder) is injected from the gate 40 and the runway 39 to be filled in the cavity 38. Thereby, as shown in FIG. 8, the cup-shaped plastic magnet 16 is formed in the 1st shaping | molding part 36, and at the same time, the one end of the front end side of the motor shaft 15 is embedded in the boss | hub part 16c. And so-called insert molding.

In this case, since the cutout portion 15b shown in Figs. 3 and 5 is formed at the embedded end of the motor shaft 15, the molded plastic magnet 16 cools and solidifies the motor shaft 15. ) Is firmly fixed without falling out or idling. The motor shaft 15 is reliably held and fixed without falling down to the predetermined position of the movable die 35b via the shaft support 44. Therefore, since the insert is molded while being supported at the center position of the plastic magnet 16 (cavity portion 38), it is integrated (assembled) with high accuracy without shifting the shaft center with the plastic magnet 16.

In addition, the molten material such as the magnetic powder filled in the cavity 38 is oriented in the flow direction of the magnetic flux generated in the magnetic field forming magnet 46 in correspondence with the thickness portion 31 to perform anisotropic treatment. That is, FIGS. 9 and 10 are enlarged cross-sectional views of the main part cut along the line BB of FIG. 8 to explain the operation thereof, and as shown in FIG. 9, through the N and S poles of the magnetic field forming magnet 46. A magnetic force direction is formed in the magnetic field with the thickness 31 of the plastic magnet 16, and magnetic particles of the molten material during molding are provided along this magnetic force direction to achieve anisotropic orientation.

Thereby, the magnetic force directions 47a, 47b, 47c in the arrow direction shown by the broken line of FIG. 9 which are a part of the magnetic force direction are formed in the thickness part 31 of the plastic magnet 16. As shown in FIG. Thus, the thickness part 31 is made into the thickness dimension in which sufficient magnetic force direction 47a etc. were formed inside. 10 shows that once the magnetic poles have been seated on the plastic magnet 16 after being molded through the above process as necessary, the magnetic poles are seated with 8 poles in a predetermined number by the well-known magnetic pole mounting device. In this case, the magnetic flux is provided in the same direction as the magnetic force direction 47a or the like formed in the molding.

Therefore, according to this structure, the magnetic force direction can be formed between the stator 13 arrange | positioned inside, and the external magnet type magnet motor 18 which does not require the conventional rotor yoke (back yoke) can be comprised. .

7 and 8, the plastic magnet 16 after being molded in the first molding part 36 in the second molding part 37 is newly formed in the lower part of the molding mold 35. It is attached in the inside, and the fan part 17 is shape | molded. That is, the plastic magnet 16 molded by inserting the motor shaft 15 in the first molding part 36 is opened by using a check arm of a robot (not shown) to open the mold, and the second molding part in the lower part is opened. It attaches to (37). In this case, also in the 2nd shaping | molding part, it is made to hold | maintain and fix the bearing part 45 of the movable die 35b centering on the motor shaft 15. As shown in FIG.

Thereafter, the mold part is clamped again and the molten material is filled into the cavity portion 41 through the cage 43 and the runway 42, and as shown in FIG. 8, as shown in FIG. 17 is molded outsert. In other words, when molding the fan portion 17, the plastic magnet 16 is insert molded. In this case, since the molding shrinkage ratio of the thermoplastic resin (polypropylene), which is the material of the fan section 17, is larger than that of the plastic magnet 16, the fan section 17 is bonded to the plastic magnet 16 so as to compress it after molding. do. Therefore, the molten material flows in between the concave-convex portion 32 or the concave groove 33 of the outer circumference between the fan portion 17 and the plastic magnet 16 and is further firmly coupled.

Thus, the plastic magnet 16 and the fan part 17 are simultaneously molded in the 1st, 2nd shaping | molding part 36 and 37, ie, the plastic magnet 16 and the fan part 17 which inserted the motor shaft 15. FIG. Assembly can be simplified in one mold 35, and the three cores can also be integrally formed in a state of maintaining high accuracy.

And the fan motor (refer FIG. 1 and FIG. 2) which consists of the said structure is inserted in the inside of the refrigerator of the refrigerator which is not shown in figure through the attachment part 11d, and is used for cold air circulation in the inside of a refrigerator.

As described above, the present invention has the following effects.

Now, the stator coil 23 shown in FIG. 1 is energized and the plastic magnet 16 as a rotor magnet is rotated. That is, the abduction type magnet motor 18 is energized and driven, whereby the fan unit 17 also rotates integrally, and cool air is blown in the direction of the arrow (W). When the motor 18 is rotated in this manner, a suction force and a repulsive force are generated by the electromagnetic force acting between the stator 13 and the thickness 31 of the plastic magnet 16 on which the magnetic pole is seated, and the vibration is based on this. This happens. In particular, in this configuration, the conventional rotor yoke does not exist, and the vibration is propagated from the plastic magnet 16 directly to the fan portion 17.

By the way, according to the present embodiment, the vibration propagation can be effectively reduced because it is provided at a distance 34 from the fan base 17a corresponding to the outer circumference of the thickness portion 31 and the root of the wing portion 17b. have. This is also effective for blocking and reducing vibration propagation in the case where vibration due to blowing resistance or resonance phenomenon occurs in the three blade portions 17b of the fan unit 17.

In addition, according to this embodiment, in particular, the common shaft center of the motor shaft 15, the plastic magnet 16 as the rotor magnet, and the fan portion 17 can be secured with high accuracy, and a low vibration fan motor can be obtained. That is, in the conventional structure shown in FIG. 11, the motor shaft 5 is press-fitted to the rotor yoke 8 (rotor 6) with the rotor magnet 9 inserted therein, and the insert is formed when the fan portion 7 is formed. Since molding is integrated, the number of parts is large and the variation in parts precision and assembly error are large. In addition, assembling work is cumbersome, and it is difficult to secure the precision of fitting these parts coaxially, which makes it difficult to reduce vibration and noise caused by unbalance.

On the other hand, in the present embodiment, the motor shaft 15, the plastic magnet 16, and the fan 17 are made of three parts, so as to reduce the parts of the so-called conventional rotor yoke 8, as well as in Figs. As shown in the drawing, these three parts can be easily assembled by means of molding using the molding die 35, and the mold can be formed with high precision, and the insert is centered on the motor shaft 15 serving as the shaft core. Since shaping | molding etc. are performed, the fan motor excellent in axial center precision can be obtained further. In addition, since the cutout 15b at the end of the motor shaft 15 is embedded in the boss portion 16c of the plastic magnet 16, the fixed position fixation without causing the motor shaft 15 to fall or rotate. can do.

Therefore, according to the present embodiment, the vibration caused by the unbalance caused by the part precision, the assembly precision, etc. can be greatly improved, and the vibration and noise of the entire fan motor can be reduced. Of course, the number of parts is small and the assembly work can be done easily, and the adjustment work for unbalance can be reduced, which is advantageous in terms of cost, thereby ensuring stable quality.

The plastic magnet 16 is insert-molded when the fan portion 17 of the thermoplastic resin is molded, and the heat shrinkage rate of the material of the fan portion 17 is the material of the plastic magnet 16 (for example, a nylon magnetic material). Since it is larger, it acts in the direction to compress and bond with respect to the inner plastic magnet 16 by shrinkage | contraction after shaping | molding, and since the uneven part 32 is formed in the outer peripheral surface of this plastic magnet 16 to join, it is hard There is no fear of slipping (idling) between the fan portion 17 and the magnet 16 by obtaining the engaged state.

Since the plastic magnet 16 is formed to form anisotropically treated magnetic force directions 47a, 47b, 47c ... (see Fig. 9) in the thickness portion 31 inside the magnet 16, as in the prior art. Even if there is no rotor yoke (back yoke), there is no leaking magnetic flux, and the required magnetic force direction can be configured between the stator 13, and the abduction magnet motor 18 which can be further compacted with a simple configuration can be obtained.

In addition, the fan unit 17 and the plastic magnet 16 are integrally connected to directly transmit vibration, and as described above, the amount of vibration, such as high accuracy of the axial center balance, can be reduced to contribute to practical use. Can provide fan motor.

In addition, this invention is not limited to the said Example shown in the above-mentioned figure, It can change and implement variously in a design etc. within the range which does not deviate from the summary at the time of implementation.

As can be seen from the above description, in the outboard magnet motor, the rotor magnet is composed of a plastic magnet, and a fan portion is integrally provided on the outer periphery of the plastic magnet.

As a result, the number of parts can be reduced, and the shaft center adjustment can be managed only by the precision of both the plastic magnet and the fan part, so that a high precision shaft balance can be easily obtained, and vibration and noise can be reduced. Assembly can also be simplified, providing quality fan stability and cost advantages.

Claims (5)

In the outboard magnet motor in which the rotor magnet is disposed on the outer periphery of the stator, And said rotor magnet is composed of a plastic magnet, and a fan portion is integrally provided on the outer circumference of said plastic magnet. The method of claim 1, A fan motor comprising insert molding a plastic magnet when molding a fan part with a thermoplastic resin. The method of claim 2, A fan motor, wherein an uneven portion is formed on an outer circumferential surface of the plastic magnet, and the molding shrinkage ratio of the thermoplastic resin of the fan portion is larger than that of the plastic magnet. The method of claim 1, A plastic magnet is formed into a substantially cup shape in which one end side in the axial direction is almost closed, and a motor shaft is inserted into the center of the closed end side. The method of claim 1, And a plastic magnet is anisotropically formed so as to form a magnetic direction in the magnet.