JP3682397B2 - Fan motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fan motor that is integrally provided with a fan portion using an abduction magnet motor.
[0002]
[Prior art]
Conventionally, as this type of fan motor, a fan motor used in a refrigerator is known, and such a fan motor circulates and supplies cold air into the cabinet by its blowing action. In recent fan motors, an abduction type (outer rotor type) motor that is expected to be improved in the radial direction and the axial direction in consideration of the installation space in the cabinet is employed.
[0003]
FIG. 11 is a longitudinal sectional side view showing an example. The fan motor shown in FIG. 11 generally includes 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 front bearing assembly 4 attached to the stator 3. The rotor 6 has a motor shaft 5 that is rotatably supported by the both bearing assemblies 2 and 4 at the center, and the fan portion 7 is provided integrally around the outer periphery of the rotor 6.
[0004]
More specifically, the rotor 6 is disposed around the outer periphery of the stator 3, and a rotor yoke 8 made of a galvanized steel plate having a cylindrical cup shape and attached to the inner peripheral surface of the rotor yoke 8. The rotor magnet 9 has 12 poles. The rotor magnet 9 is inserted and fixed to the inner peripheral surface of the rotor yoke 8 from the 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. In the rotor 6 configured as described above, the motor shaft 5 is rotatably supported by the front bearing assembly 4 and the rear bearing assembly 2, and the rotor magnet 9 faces the stator 3 with a slight gap. Thus, an outer rotor type so-called abduction type magnet motor 10 is formed.
[0005]
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 a molten material. The fan portion 7 is mainly composed of a fan base portion 7a covering the outer periphery of the rotor yoke 8 and, for example, three blade portions 7b extending in the radial direction.
In addition, when the blade | wing part 7b is rotationally driven, it is comprised so that a ventilation direction may flow in the direction (illustration right side) shown by the arrow W. FIG.
[0006]
[Problems to be solved by the invention]
However, in the configuration in which the fan portion 7 is formed integrally with the rotor 6 using the abduction-type magnet motor 10 as described above, vibration from the rotor 6 side that occurs during rotation driving, or conversely, the fan The vibration from the part 7 side is directly transmitted to each other, and particularly in the case of the resonance state, the influence on the abduction motor 10 is great, and the noise problem and the durability of the entire fan motor are also affected. It will be.
[0007]
Therefore, it is necessary to suppress the generation of vibrations as much as possible. However, in the above configuration, it is difficult to ensure the assembly accuracy of the motor shaft 5 and it is difficult to stabilize it. This is not only easy assembly work including positioning of the rotor magnet 9 on the inner surface of the rotor yoke 8, but is also configured to press-fit and fix the motor shaft 5 to the structure in which the fan portion 7 is further added. There are so-called assembly parts, and errors are likely to occur. Therefore, it is difficult to obtain the axial center of the rotating fan unit 7, the rotor yoke 8, the rotor magnet 9 and the motor shaft 5 with high accuracy, and it is troublesome and stable to adjust the overall rotation balance. There is a problem that it is difficult to keep vibrations small for reasons such as difficulty in obtaining quality.
[0008]
The present invention has been made in view of the above circumstances, and its purpose is to use a plastic magnet for an abduction-type magnet motor to reduce the number of parts and increase the assembly accuracy of the motor shaft. The present invention also provides a fan motor that can contribute to noise reduction.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, a fan motor of the present invention is an abduction-type magnet motor in which a rotor magnet is arranged around the outer periphery of a stator, and the rotor magnet is formed of a plastic magnet. Around the outsideBy thermoplastic resinIntegrated fan sectionIn addition, the molding shrinkage rate of the thermoplastic resin of the fan part is made larger than that of the plastic magnet.(Invention of claim 1).
[0010]
  According to such a configuration, since the number of parts can be reduced, the axial center adjustment can be managed only by the precision of both the plastic magnet and the fan part, so that a highly accurate axial center balance can be easily obtained and vibration can be achieved. And reduce noise,The fan part after molding holds the inner plastic magnet so that it is compressed, so the connection between the two is ensured.As a result, the assembly work can be done easily, the quality can be stabilized, and a fan motor that is advantageous in cost can be provided..
[0012]
  Claims1In the described one, an uneven portion is formed on the outer peripheral surface of the plastic magnet.Completion(Claims)2Invention).
[0013]
  According to such a configuration, the molded fan part compresses the inner plastic magnet.In addition to holdingSince both are more firmly coupled by the concavo-convex portion provided on the outer peripheral surface of the plastic magnet, there is no occurrence of slippage (idle) between these joints, and a so-called firm rotation preventing function is obtained.
[0016]
  The plastic magnet according to claim 1 is anisotropically formed so as to form a magnetic path inside the magnet., Lose back yoke(Claims)3Invention).
[0017]
According to such a configuration, a magnetic path is formed with the stator, and there is no leakage magnetic flux on the outer periphery of the plastic magnet. Therefore, no foreign matter (magnetic body) is attached, and the rotor yoke (back yoke) is not required. With the configuration, the original downsizing magnet motor can be effectively made compact.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
First, FIG. 1 and FIG. 2 are a longitudinal side view and a rear view showing the overall configuration of the fan motor. Based on these drawings, the configuration is roughly described. The casing 11, the rear bearing assembly 12 attached to the casing 11, the stator 13 attached to the rear bearing assembly 12, and the front part attached to the stator 13. A bearing assembly 14, a plastic magnet 16 as a rotor magnet having a motor shaft 15 rotatably supported by the both bearing assemblies 12, 14, and a fan portion 17 provided on the outer periphery of the magnet 16. It is set as the structure provided with.
[0019]
Among these, although the details will be described later, the plastic magnet 16 is arranged opposite to the outer periphery of the stator 13 with a slight gap, thereby constituting an abduction-type magnet motor 18. Reference numeral 16 denotes a configuration that also serves as the entire structure of the rotor of the conventional configuration.
[0020]
First, the casing 11 is made of a synthetic resin such as PBT (polybutadiene terephthalate), for example, and has a thin cylindrical portion 11a whose rear surface (right side surface in FIG. 1) is open, and its outer peripheral portion. In particular, as clearly shown in FIG. 2, four motor supports 11b extending in the radial direction are integrally provided at intervals of approximately 90 degrees, and a short cylindrical bell mouth 11c is integrally provided on the outer periphery thereof. Yes. In addition, a ring-shaped attachment portion 11d for attachment in a refrigerator (not shown) is integrally formed at three locations on the outer peripheral portion of the bell mouth 11c.
[0021]
However, the cylindrical portion 11a of the casing has a configuration in which the rear bearing assembly 12 is fitted and attached. The cylindrical bracket 19 is made of a galvanized steel plate and passes through the motor shaft 15. The bearing 20 which consists of the sintered metal with which the rear part was mounted | worn, and the oil-impregnated felt 21 etc. which were filled with lubricating oil were comprised, and the rear surface opening part is block | closed with the appropriate cover member 22. FIG. It should be noted that the center of the inner surface of the lid member 22 is configured to receive the tip of the motor shaft 15.
Thus, the rear bearing assembly 12 is closely fitted into the casing 11 from the rear side, and the bracket 19 is press-fitted.
[0022]
In general, the stator 13 is formed by winding a winding 23 around a stator core 13a having a hole penetrating in the axial direction at the center, and is molded by a synthetic resin (PBT) mold body 25 together with a connector portion 24. It is configured. Then, the rear end portion of the molded body 25 is engaged with the casing 11, and the center hole of the stator core 13 a is press-fitted into the bracket 19, whereby the rear bearing assembly 12 and the stator 13 are connected to the casing 11. Is firmly fixed so as to be sandwiched from both sides.
[0023]
On the other hand, the front bearing assembly 14 has substantially the same configuration as that of the rear bearing assembly 12 described above. Therefore, the cylindrical bracket 26, the bearing 27 made of sintered metal, the oil-impregnated felt 28, and the like. The lid member 29 and the like are provided. However, in the front bearing assembly 14, the motor shaft 15 is completely inserted therethrough. Similarly to the above, the bracket 26 of the front bearing assembly 14 is press-fitted into the through hole of the stator core 22 and fixed to the stator 13.
A retaining member 30 formed in a ring shape from, for example, nylon material is interposed between the end portions of the brackets 19 and 26 of the both bearing assemblies 12 and 14, and will be described later. It is supposed to fulfill its function.
[0024]
A plastic magnet 16 serving as the rotor magnet is provided so as to cover the stator 13 and the front bearing assembly 14, and the motor shaft 15 is integrally attached to the center. Hereinafter, a specific configuration of the plastic magnet 16 will be described. In particular, as shown in FIGS. 3 and 4, a longitudinal side view and a front view of the plastic magnet 16 provided with the motor shaft 15 are respectively shown in the axial direction. It is generally cup-shaped in which one end side is almost closed, which is formed by injection molding, which will be described later, by adding a nylon-based synthetic resin, for example, as a binder to magnetic powder such as ferrite. 15 is assembled and fixed by insert molding.
[0025]
However, as a specific shape of the plastic magnet 16, it has a cup shape composed of a closed end portion 16a at one end and a cylindrical portion 16b continuous therewith, and a motor shaft 15 is provided at the center of the closed end portion 16a. It has a boss portion 16c embedded by an insert. The cylindrical portion 16b has a right half on the opening end side of the rear surface as a thick portion 31, and an uneven portion 32 having a step in the radial direction on the outer peripheral surface of the remaining left half (see particularly FIGS. 3 and 4). The former thick-walled portion 31 is magnetized with a predetermined number of poles, for example, eight poles by a method described later. In this configuration, a shallow annular groove 33 is also formed on the front surface of the closed end portion 16a.
The motor shaft 15 is made of, for example, a SUS material, and has a small diameter portion 15a in the middle, and the end portion embedded in the boss portion 16c is particularly as shown in the sectional view of FIG. A cutout portion 15b cut in the radial direction is formed.
[0026]
When the plastic magnet 16 having such a configuration is integrally formed, the fan portion 17 is insert-molded (details will be described later). As shown in FIG. 6, the fan portion 17 is made of a thermoplastic resin such as polypropylene, and mainly includes a fan base portion 17a and, for example, three blade portions 17b. In particular, the portion of the fan portion 17 excluding the blade portion 17b corresponds to the fan base portion 17a, and is formed so as to cover the outer periphery of the plastic magnet 16, and thus is also generally cup-shaped. It is formed. After the molding, the groove 33 formed in the plastic magnet 16 and the molten resin flowing into the concavo-convex portion 32 are cooled and solidified to firmly bond both of them and to rotate the fan portion 17. Serves as a detent in the direction.
[0027]
However, the right half of the opening end side, which is the rear surface of the fan base portion 17a, is located with a gap 34 between the outer periphery of the thick portion 31 of the plastic magnet 16 and is covered in a non-adherent form. In this case, the axial length L2 of the gap 34 is longer than the axial length L1 of the thick portion 31, and the blade substantially extends in a radial direction at a portion substantially corresponding to the length L2 of the gap 34. The root portion of the portion 17b is used. Further, the protrusion 17 c at the center of the fan base 17 a covers the tip of the motor shaft 15 together with the boss 16 c of the plastic magnet 16. When the fan unit 17 configured as described above is driven to rotate, the direction indicated by an arrow W in FIG. 1, that is, the rear side from the front end side which is one end side in the axial direction of the plastic magnet 16 to the other end side. Wind is generated toward the end side.
[0028]
As shown in FIG. 6, the structure comprising 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. It is assembled by being inserted into the bearing assemblies 14 and 12. That is, after passing through the bearing 27 of the front bearing assembly 14 and inserting further through the above-described retaining member 30, the bearing 20 of the rear bearing assembly 12 is penetrated, and the tip thereof is a lid. It is assembled by being pressed into contact with the member 22 until it is thrust-supported.
When the motor shaft 15 is inserted, the motor shaft 15 is inserted while expanding the opening of the retaining member 30, and in the assembled state, the retaining member 30 is fitted to the small diameter portion 15a of the motor shaft 15. Thus, once assembled, the motor shaft 15 is prevented from being easily detached by the retaining member 30.
[0029]
Thus, the motor shaft 15 integrated with the fan portion 17 and the plastic magnet 16 is rotatably supported by the two bearings 27 and 20 at the front and rear portions, and the plastic magnet 16 as the rotor magnet has its cylinder. The inner peripheral surface of the portion 16b covers the stator 13 in a close proximity. Specifically, at least the inner peripheral surface substantially corresponding to the axial length L1 of the thick portion 31 is slightly spaced from the outer peripheral surface of the stator core 22. Are arranged so as to face each other.
[0030]
The forming means for integrating the fan unit 17, the plastic magnet 16 and the motor shaft 15 will be described with reference to FIGS. FIGS. 7 and 8 are longitudinal sectional views showing a schematic structure of one molding die 35, and show different states 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 the present embodiment, in particular, in the upper and lower portions of one mold 35, different forms can be simultaneously formed. A part 36 and a second molding part 37 are provided. Accordingly, the runners 39 and 42 and the gates 40 and 43 communicating with the cavities 38 and 41 formed by clamping are respectively formed on the upper and lower portions of the fixed mold 35a.
[0031]
Incidentally, at the same time as the molding of the plastic magnet 16 is performed in the first molding part 36, the insert molding of the motor shaft 15 is performed, while in the second molding part 37, the molding in the first molding part 36 is followed. The fan part 17 in the molding process is molded. Therefore, since the molded parts such as the fan portion 17 and the plastic magnet 16 are all cup-shaped, one movable mold 35b is fitted as a male mold to the fixed mold 35a when the mold is clamped. Further, the movable die 35b has shaft support portions 44 and 45 for insert-molding the motor shaft 15 and for fixing and supporting the motor shaft 15 as positioning contacts.
[0032]
Furthermore, in this embodiment, when the plastic magnet 16 is molded in the first molding portion 36, an anisotropic orientation magnetic path is formed in the magnet 16 in the mold 35. For this reason, the magnetic field forming magnet 46 is provided on the movable die 35 b and is disposed corresponding to the thick portion of the plastic magnet 16.
[0033]
In the molding die 35 having such a configuration, the molding means of the plastic magnet 16 in the upper first molding portion 36 will be described with reference to FIG. 7. First, the motor shaft 15 to be insert-molded at the same time is used as the shaft support portion of the movable die 35b. It is held and fixed at a predetermined position 44. After the mold is clamped, molten material (nylon-based magnetic powder) is injected from the gate 40 and the runner 39 and filled into the cavity 38. Thereby, as shown in FIG. 8, in the first molding portion 36, the cup-shaped plastic magnet 16 is formed, and at the same time, one end of the front end side of the motor shaft 15 is embedded in the boss portion 16c, so-called insert molding. The
[0034]
In this case, since the notched portion 15b shown in FIGS. 3 and 5 is formed at the embedded end portion of the motor shaft 15, the molded plastic magnet 16 is cooled and solidified, whereby the motor shaft 15 Is firmly fixed without falling off or spinning around. The motor shaft 15 is securely held and fixed via the shaft support portion 44 without falling to a predetermined position of the movable die 35b. Therefore, since it is insert-molded while being set and supported at the center position of the plastic magnet 16 (cavity 38), the plastic magnet 16 is integrated (assembled) with high accuracy without shifting its axis. The
[0035]
At the same time, the molten material such as magnetic powder filled in the cavity 38 is oriented in the flow direction of the magnetic flux generated from the magnetic field forming magnet 46 corresponding to the thick portion 31 and is subjected to an anisotropic treatment. . That is, FIGS. 9 and 10 are enlarged cross-sectional views of the main part cut along the line BB in FIG. 8 for explaining the operation. As shown in FIG. A magnetic path is formed in the magnetic field with the thick part 31 of the plastic magnet 16 via the S pole, and the magnetic particles of the molten material being formed are aligned along the magnetic path to achieve anisotropic orientation.
[0036]
Thereby, magnetic paths 47a, 47b, 47c,... Indicated by broken lines in FIG. 9, which are part of the magnetic path, are formed in the thick part 31 of the plastic magnet 16. Thus, the thick portion 31 has a thickness dimension in which a sufficient magnetic path 47a and the like are formed inside. In FIG. 10, the plastic magnet 16 formed through the above steps is demagnetized once if necessary, and then a predetermined number of poles is set to 8 in this embodiment by a known magnetizing device. In this case, the magnetic flux is aligned in the same direction as the magnetic path 47a formed at the time of molding.
[0037]
Therefore, according to this configuration, a magnetic path can be formed between the stator 13 and the outer rotor magnet motor 18 that does not require a conventional rotor yoke (back yoke).
[0038]
On the other hand, in FIGS. 7 and 8, in the second molding part 37 at the lower part of the molding die 35, the plastic magnet 16 molded by the first molding part 36 is mounted in the mold 35 again. Thus, the fan part 17 is formed. That is, the plastic magnet 16 in which the motor shaft 15 is incorporated and molded by the first molding unit 36 is opened and taken out by using a chuck arm or the like of a robot (not shown). Mounting. In this case, the motor shaft 15 is held and fixed to the shaft support portion 45 of the movable die 35b also in the second molding portion.
[0039]
Thereafter, the mold part is again clamped and the molten material is filled into the cavity 41 through the gate 43 and the runner 42, whereby the fan part 17 is outsert-molded around the outer periphery of the plastic magnet 16 as shown in FIG. . In other words, when the fanb 17 is formed, the plastic magnet 16 is insert-molded. In this case, since the molding shrinkage rate of the thermoplastic resin (polypropylene) that is the material of the fan part 17 is larger than that of the plastic magnet 16, the fan part 17 is joined to the plastic magnet 16 so as to compress it after molding. To do. Therefore, between the fan portion 17 and the plastic magnet 16, the molten material flows into the concave and convex portion 32 on the outer peripheral surface, and further into the concave groove 33, and is further firmly coupled.
[0040]
Thus, the plastic magnet 16 and the fan part 17 are simultaneously formed by the first and second molding parts 36 and 37, that is, the assembly of the plastic magnet 16 and the fan part 17 with the motor shaft 15 inserted therein is one. In addition to being simple in the mold 35, the three axes can be integrated and maintained with high accuracy.
Thus, the fan motor (see FIGS. 1 and 2) having the above-described configuration is incorporated into, for example, a refrigerator (not shown) via the mounting portion 11d and used for circulating cold air in the refrigerator. is there.
[0041]
Thus, the present invention has the following effects according to the above embodiment.
Now, the stator coil 23 shown in FIG. 1 is energized to rotate the plastic magnet 16 as the rotor magnet. That is, the abduction magnet motor 18 is energized and driven, whereby the fan unit 17 also rotates together, and the cool air is blown in the direction of the arrow W. When the motor 18 is rotationally driven in this way, an attractive force or a repulsive force is generated by the electromagnetic force acting between the stator 13 and the thick portion 31 of the magnetized plastic magnet 16, and vibration is generated based on this. Occur. In particular, in this configuration, there is no conventional rotor yoke, and the vibration is transmitted directly from the plastic magnet 16 to the fan unit 17.
[0042]
However, according to the present embodiment, since the outer periphery of the thick portion 31 and the fan base portion 17a corresponding to the root of the blade portion 17b are provided with the gap 34, vibration propagation can be effectively reduced. This is effective for blocking and reducing vibration propagation in the same manner even when the blowing resistance from the three blade portions 17b of the fan portion 17 or the vibration accompanying the resonance phenomenon occurs.
[0043]
In addition, according to the present 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 configuration shown in FIG. 11 described above, the motor shaft 5 is press-fitted into the rotor yoke 8 (rotor 6) incorporating the rotor magnet 9, and insert molding is performed when the fan portion 7 is molded. As a result, the number of parts is large, and variations in parts accuracy and assembly errors are large. Also, the assembly work is cumbersome, and it is difficult to ensure the accuracy of assembling these parts coaxially, so it has been difficult to reduce vibration and noise due to unbalance.
[0044]
On the other hand, in this embodiment, the motor shaft 15, the plastic magnet 16, and the fan portion 17 are composed of three points, so that not only the parts of the so-called conventional rotor yoke 8 are reduced, but these 3 The parts can be easily assembled by molding means using the molding die 35, and can be constructed with high precision by molding, and insert molding is performed with the motor shaft 15 as the center as the center. An excellent fan motor can be obtained. Moreover, since the notch portion 15b at the end of the motor shaft 15 is embedded in the boss portion 16c of the plastic magnet 16, the position of the motor shaft 15 can be reliably fixed without falling or rotating.
Therefore, according to the present embodiment, it is possible to greatly improve the vibration due to imbalance caused by component accuracy, assembly accuracy, etc., and to reduce the vibration and noise of the entire fan motor. Of course, the number of parts is small, the assembly work can be simplified, and the unbalance adjustment work is also reduced. This is advantageous in terms of cost and ensures stable quality.
[0045]
Further, when the thermoplastic resin fan part 17 is molded, the plastic magnet 16 is insert-molded. The heat shrinkage ratio of the material of the fan part 17 is more than that of the plastic magnet 16 (for example, nylon magnetic material). Since it is large, it acts in the direction of compressing and joining to the internal plastic magnet 16 due to shrinkage after molding, and the concave and convex portions 32 are formed on the outer peripheral surface of the plastic magnet 16 to be joined. There is no risk of slipping (idling) between the fan unit 17 and the magnet 16 by obtaining a state.
[0046]
The plastic magnet 16 is formed with magnetic paths 47a, 47b, 47c... (See FIG. 9) anisotropically processed in the thick portion 31 inside the magnet 16, so that a rotor yoke (such as a conventional one) Even if there is no back yoke, there is no leakage magnetic flux, and a necessary magnetic path can be formed between the stator 13 and the abduction type magnet motor 18 that can be further reduced in size with a simple configuration can be obtained.
Moreover, although the fan portion 17 and the plastic magnet 16 are integrally connected to transmit vibration directly, the amount of vibration can be kept small, such as high axial center balance as described above, and practical. It is possible to provide a fan motor that can be used for
It should be noted that the present invention is not limited to the above-described embodiments shown in the drawings and can be implemented with various design changes such as specific shapes within the scope not departing from the gist of implementation.
[0047]
【The invention's effect】
  As is apparent from the above description, the present invention is an abduction type magnet motor, the rotor magnet of which is a plastic magnet, and the outer periphery of the plastic magnet.By thermoplastic resinIntegrated fan sectionIn addition, the molding shrinkage rate of the thermoplastic resin of the fan part is made larger than that of the plastic magnet.It is a thing.
  As a result, the number of parts can be reduced, and the shaft center adjustment can be managed only with the precision of both the plastic magnet and the fan part, so that a highly accurate shaft center balance can be easily obtained and vibration and noise can be reduced. IsThe fan part after molding holds the inner plastic magnet so that it is compressed, so the connection between the two is ensured.Assembling work can be simplified, and a fan motor that is advantageous in terms of cost as well as stabilizing quality can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of an overall configuration showing an embodiment of the present invention.
FIG. 2 is an overall rear view.
FIG. 3 is a longitudinal sectional view of a plastic magnet having a motor shaft.
4 is a front view of FIG. 3. FIG.
5 is a cross-sectional view of a motor shaft cut along line AA in FIG. 3;
FIG. 6 is a longitudinal side view of a main part after molding.
FIG. 7 is a longitudinal sectional view for explaining a schematic configuration of a molding die and a molding process.
8 is a longitudinal sectional view for explaining a process different from FIG.
FIG. 9 is an enlarged cross-sectional view of a main part cut along the line BB in FIG.
10 is an enlarged cross-sectional view of the main part in the different mode of FIG. 9;
11 is a view corresponding to FIG. 1 showing a conventional example.
[Explanation of symbols]
11 is a casing, 13 is a stator, 15 is a motor shaft, 15b is a notch, 16 is a plastic magnet (rotor magnet), 16a is a closed end, 16b is a cylinder, 17 is a fan, 17a is a fan base, and 17b is The blade part, 18 is an abduction magnet motor, 31 is a thick part, 32 is an uneven part, 35 is a mold, 35a is a fixed mold, 35b is a movable mold, 36 is a first molding part, and 37 is a second part. The forming part 46 is a magnetic field forming magnet, and 47a, 47b, 47c... Are magnetic paths.

Claims (3)

In an abduction-type magnet motor with a rotor magnet around the outer periphery of the stator,
Said rotor magnet are constituted by plastic magnet, the outside periphery of the plastic magnet of a thermoplastic resin provided the fan unit integrally Rutotomoni, the molding shrinkage of the thermoplastic resin of the fan section larger than the plastic magnet A fan motor characterized by that. 2. The fan motor according to claim 1, wherein an uneven portion is formed on the outer peripheral surface of the plastic magnet . Plastic magnet, the fan motor according to claim 1, wherein that the turned into anisotropic so as to form a magnetic path within the magnet, lost back yoke.

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