JP2002252940A - Plastic magnet rotor, electric motor using the plastic magnet rotor and air conditioner using the electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plastic magnet rotor, an electric motor using the plastic magnet rotor, and an air conditioner using the electric motor wherein an axis is not injured when an inertial mass is fitted and a low cost is attainable. SOLUTION: The plastic magnet rotor comprises the following components; a rotation axis 1, an inner cylindrical portion 3 of a plastic material which is closely fixed around the rotation axis 1 with the same axis as the rotation axis used and wherein one and the other end of the rotation axis 1 are exposed, a magnetic pole 4 of a plastic material which is provided in a cylindrical shape encircling an outer periphery of the inner cylinder 3 around the same axis as the rotation axis 1 and wherein a first end face 4a formed on one end side of the inner cylinder is formed to be shorter in an axial direction than one end 3a of the cylinder 3, a connection portion 5 to integrally connect the magnetic pole 4 to the inner cylinder 3, the inertial mass body 7 of a disk type disposed on the first face 4a of the magnetic pole 4 and having a hole through which the inner cylinder 3 is inserted in a rotary center of a rotor, and a fixing means 10 to fix the inertial mass body 7 to the first end face side of the magnetic pole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic magnet rotor used for a rotor such as a brushless motor or a stepping motor, an electric motor using the plastic magnet rotor, and an air conditioner using the electric motor.

[0002]

2. Description of the Related Art FIGS. 12 and 13 show a conventional plastic magnet rotor using a polar-oriented plastic magnet for a rotor. FIG. 12 is a sectional view and FIG. 13 is a plan view. In the figure, 1 is a rotation axis,
Reference numeral 2 denotes a plastic magnet portion integrally formed with the rotating shaft 1. The plastic magnet portion 2 includes a cylindrical inner cylinder portion 3 closely adhered and fixed so as to be coaxial with the rotating shaft 1 and a cylindrical magnetic pole portion 4 provided on the outer peripheral side so as to be coaxial with the rotating shaft 1. And a disk-shaped connecting portion 5 connecting the inner cylindrical portion 3 and the magnetic pole portion 4. Numeral 6 denotes convex portions integrally formed on the first end face portion of the magnetic pole portion 4 in the rotation axis direction, and four convex portions are provided at regular intervals of 90 ° in the rotation direction. Reference numeral 7 denotes a disk-shaped inertial mass provided on the side of the plastic magnet portion 2 on which the convex portion 6 is formed. Reference numeral 8 denotes an insertion hole provided at the center of rotation of the inertial mass 7 and fitted to the rotary shaft 1. Reference numerals 9 denote through holes which are provided at equal intervals on the peripheral edge of the inertial mass body 7 and are fitted with the projections 6 of the magnetic pole portion 4.

The plastic magnet portion 2 is formed integrally with the rotary shaft 1 by injection molding or the like using a plastic material in which a magnetic powder is mixed with a thermoplastic resin, and is tightly fixed to the rotary shaft 1. The magnetic pole part 4 is magnetized so as to be polar-oriented. The plurality of protrusions 6 protruding from the first end face portion 4a of the magnetic pole portion 4 are formed at the same time as the molding. The first end face portion 4a of the magnetic pole portion is formed to be longer in the axial direction than the one end portion 3a of the inner cylindrical portion 3. And the inertial mass 7
With the rotary shaft 1 inserted and fitted in the central insertion hole 8, the respective protrusions 6 of the magnetic pole portion 4 are inserted into the plurality of through holes 9 in the peripheral portion, and the first end face portion 4 a is contacted. It is fixed to the first end face 4a of the magnetic pole part 4 by heat-sealing the tip end protruding part of the convex part 6 which has been inserted through the through hole 9 and then to the contact position.

[0004]

Since the conventional plastic magnet rotor is constructed as described above, the shaft 1 is easily damaged when the inertial mass body 7 is fitted to the rotating shaft 1, and the shaft 1 is easily damaged. Since a bearing (not shown) is press-fitted into the rotating shaft 1, it causes a sound failure of the bearing. In addition, since the convex portion 6 of the magnetic pole portion 4 may be inclined due to shrinkage after molding, it is necessary to increase the clearance between the convex portion 6 and the through hole 9 fitted into the convex portion 6, and the inertial mass The body 7 tends to rattle in the rotation direction, which may cause sound vibration. Further, in order to mount a bearing (not shown) on the inertial mass body 7 side of the rotating shaft 1, a bearing retaining ring (not shown) and a groove for mounting the bearing retaining ring are provided on the rotating shaft, or a stepped bearing is provided. It is necessary to use a shaft, etc.
There were problems such as high costs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and a plastic magnet rotor capable of reducing the cost without damaging the shaft when the inertial mass body is mounted. An object of the present invention is to provide an electric motor using a plastic magnet rotor and an air conditioner using the electric motor.

[0006]

A plastic magnet rotor according to the present invention is closely fixed to a rotating shaft, around the rotating shaft and coaxially with the rotating shaft. An inner cylindrical portion made of a plastic material exposing one and the other shaft end portions of the shaft,
A first end face formed on one end side of the inner cylindrical portion is provided in a cylindrical shape so as to surround the outer periphery of the inner cylindrical portion coaxially with the rotation shaft. A magnetic pole portion made of a plastic material formed short in the axial direction, a connecting portion for integrally connecting the magnetic pole portion and the inner cylinder portion, and a magnetic pole portion disposed on a first end face portion of the magnetic pole portion and having a rotation center portion. A disk-shaped inertial mass having an insertion hole through which the inner cylindrical portion is inserted, and fixing means for fixing the inertial mass to the first end face of the magnetic pole portion.

Further, the electric motor is constituted by using the plastic magnet rotor constituted as described above.

Further, the fixing means is provided on a plurality of protrusions integrally formed on the first end face of the magnetic pole part, and on the periphery of the inertial mass body, and each of the protrusions on the first end face is provided. , And a heat-sealed body formed by heat-sealing the tips of the convex portions of the magnetic pole portions that pass through the through-holes.

Still further, an engaging portion is formed around the through hole of the inertial mass body so as to engage with a heat-sealed body formed at the time of heat-sealing.

The fixing means deforms the vicinity of the insertion hole of the inertial mass body in the direction of the outer peripheral surface of the inner cylindrical portion by caulking, thereby fixing the inertial mass body to the inner cylindrical portion. It is.

Further, the outer peripheral surface of the inner cylindrical portion and the insertion hole of the inertial mass body fitted to the outer peripheral surface engage with each other to rotate the inner cylindrical portion and the inertial mass body. The rotation preventing means for blocking is formed.

Further, the bearing press-fitted to the rotating shaft is disposed in contact with one end of the inner cylindrical portion.

In an air conditioner having an indoor unit or an outdoor unit having a blower driven by an electric motor,
An electric motor having the plastic magnet rotor described above is used as the electric motor.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention FIGS. 1 and 2 show a main part of a plastic magnet rotor according to Embodiment 1 of the present invention. FIG. Is a plan view thereof. In the figure, reference numeral 1 denotes a rotary shaft, and 2 denotes a plastic magnet portion integrally formed around the rotary shaft 1 coaxially with the rotary shaft 1. The plastic magnet portion 2 includes an inner cylindrical portion 3 that is fixed around the rotating shaft 1 in close contact with the rotating shaft 1, and a cylindrical magnetic pole portion 4 that surrounds the outer portion of the inner cylindrical portion 3. And a connecting portion 5 for integrally connecting the magnetic pole portion 4 and the inner cylindrical portion 3.

The first end face portion 4a of the magnetic pole portion 4 is formed to be shorter in the axial direction than the one end portion 3a of the inner cylindrical portion 3.
Numeral 6 denotes convex portions formed to protrude in the axial direction from the first end surface portion 4a of the magnetic pole portion 4, and in this example, four convex portions are provided at regular intervals of 90 ° in the circumferential direction. Reference numeral 7 denotes an inertial mass disposed on the side of the first end face 4a of the magnetic pole portion 4, reference numeral 8 denotes an insertion hole provided at the center of rotation of the inertial mass 7, and inserts the inner cylindrical portion 3; 4 protruding from the first end face portion 4a of the magnetic pole portion 4
It is a through hole through which each of the two convex portions 6 is inserted. Note that 6
Reference symbol a denotes a heat-sealed body formed when the portion of the projection 6 protruding from the through hole 9 is heat-sealed. Numeral 10 denotes a means for fixing the inertial mass body 7 to the first end face 4a of the magnetic pole part 4. In this embodiment, the fixing means 10 comprises the convex part 6 of the magnetic pole part 4 and the inertia through which the convex part 6 is inserted. Through hole 9 of mass body 7
And a heat-fused body 6a.

The plastic magnet portion 2 is formed integrally with the rotating shaft 1 by injection molding or the like using a plastic material in which a magnetic powder is mixed with a thermoplastic resin, and is formed by polar orientation of the magnet. Inertial mass 7
The inner diameter of the insertion hole 8 provided at the center of rotation of the
The inertial mass 7 is disposed on the first end face 4a of the magnetic pole portion 4 when the rotor is assembled, since the inner diameter is substantially the same as the outer diameter of the inner cylindrical portion 3 which is larger than the outer diameter of the inner cylindrical portion 3. At this time, it can be easily mounted without damaging the peripheral surface of the rotating shaft 1. In addition, the inertial mass body 7 is connected to the first end face 4 a of the magnetic pole section 4.
After that, the protrusions of the protrusions 6 are fixed to the first end face portion 4a by heat fusion.

A bearing such as a ball bearing (not shown) is press-fitted into the upper and lower portions of the rotating shaft 1 exposed from the inner cylindrical portion 3, respectively.
a, and a plastic magnet rotor of the electric motor are formed at positions that abut against the other end 3b on the opposite side.

As described above, according to the first embodiment, there is no danger of damaging the rotating shaft 1 at the time of assembling the rotor, and it is possible to reduce poor sound of the bearing. Further, when mounting a bearing such as a ball bearing (not shown), the bearing may be simply press-fitted from the shaft end to a position in contact with the end surfaces 3a, 3b of the inner cylindrical portion 3; It is not necessary to form a groove or to attach a retaining ring to the groove, and it is not necessary to use a stepped rotary shaft, so that processing is simplified and the cost can be reduced.

Embodiment 2 FIGS. 3 and 4 show a main part of a plastic magnet rotor according to Embodiment 2 of the present invention. FIG. 3 is a partially enlarged sectional view of FIG.
Is a partially enlarged plan view. In the figure, reference numeral 11 denotes an engaging portion comprising a groove provided coaxially around the through hole 9 of the inertial mass body 7, and the engaging portions 11 are not shown, but are equally spaced in the circumferential direction. Are provided around all the through-holes 9 provided by. Note that the other reference numerals are the same as those in the first embodiment, and the same reference numerals are used.
Description is omitted.

The plastic magnet portion 2 according to the second embodiment is formed integrally with the rotary shaft 1 as in the first embodiment, and the inner cylindrical portion 3 is inserted into the insertion hole 8 of the inertial mass body 7 while The protrusion 6 protruding from the magnetic pole portion 4 is inserted into a plurality of through holes 9 (only one portion is shown), and the inertial mass body 7 is disposed at a position in contact with the end face portion 4 a of the magnetic pole portion 4. Next, when the convex portion 6 is thermally fused, a portion of the convex portion 6 protruding from the through hole 9 is melted by heat, enters the engaging portion 11 formed of a concentric groove, and is thermally fused. Is formed, and the inertial mass body 7 is fixed to the plastic magnet portion 2.

As described above, according to the second embodiment of the present invention, by providing the engaging portion 11 of the heat seal 6a near the through hole 9, the inertial mass 7 with respect to the plastic magnet 2 is provided. It is possible to provide a plastic magnet rotor in which not only the fixing of the rotary shaft 1 is not damaged but also the play of the inertial mass body 7 is prevented. In the second embodiment, the engaging portion 11 is a single concentric groove. However, the present invention is not limited to this. For example, a plurality of grooves may be provided concentrically,
It may be provided in a mountain shape.

Third Embodiment FIGS. 5, 6, and 7 show a plastic magnet rotor according to a third embodiment of the present invention. FIG. 5 is a perspective view, and FIG. 7 is a plan view. In the figure, 3c is the inner cylinder 3
A projection 8a is formed in the insertion hole 8 of the inertial mass body 7 and is engaged with the projection 3c. . In addition,
The protrusion 3c on the peripheral surface of the inner cylinder 3 and the recess 8 on the insertion hole 8
"a" constitutes the detent means 12. Other reference numerals denote the same or corresponding parts as in the first embodiment, and a description thereof will not be repeated.

The protrusion 3c provided on the peripheral surface of the inner cylindrical portion 3 shown in the figure has a base portion integrally formed with the inner cylindrical portion 3 along the axial direction, so that it is unlikely to be inclined by shrinkage after molding, The clearance with the concave portion 8a provided in the insertion hole 8 of the inertial mass body 7 to be fitted can be reduced.

Therefore, according to the third embodiment of the present invention,
By providing the rotation preventing means 12, the play of the inertial mass body 7 against the plastic magnet portion 2 can be more effectively prevented.

Fourth Embodiment In the third embodiment of the present invention, the anti-rotation means 12 is provided with a projection 3c in the inner cylinder 3 and a recess 8a in the insertion hole 8 of the inertial mass body 7. However, the present invention is not limited to this. For example, the convex portion and the concave portion may be reversed, and the convex portion may be provided on the insertion hole 8 side, and the concave portion may be provided on the inner cylindrical portion 3.
Has a D-shaped cross section, for example, the shape of the insertion hole 8 of the inertial mass body 7 is configured to be a D-shape that fits into the inner cylindrical portion having the D-shaped cross section, or the inner cylindrical portion 3 has a □ -shaped cross section The same effect can be obtained by configuring the shape of the insertion hole 8 of the inertial mass body 7 as a □ shape that fits with the inner cylindrical portion having the cross section □ shape, or configuring the shape that engages with each other as a polygon. it can. Further, these detent means 12 may be added to the configuration example of the second embodiment. Further, in the first to third embodiments, the first end face 4
Although the description has been given of the case where the four convex portions 6 are provided on the portion a, the number of the convex portions 6 is not limited to four, and for example, two or more can be arbitrarily provided as desired.

Embodiment 5 FIGS. 8 and 9 show a plastic magnet rotor of an electric motor according to Embodiment 5 of the present invention. FIG. 8 is a sectional view and FIG. 9 is a plan view. In the figure, reference numeral 13 denotes through holes provided in the vicinity of the inner cylindrical portion 3 of the connecting portion 5, and as shown in FIG. 9, in this example, four through holes are provided at equal intervals on the circumference. 14a, 1
4b is an upper blade of caulking, and 15a and 15b are lower blades of caulking. The through hole 13 provided on the inner peripheral side of the connecting portion 5 is provided to allow the lower blade 15a of the caulking to pass therethrough. Other symbols are the same as those in the first embodiment.
Since the same or corresponding parts are shown, the description is omitted.

The inertial mass 7 is disposed on the end face 4 a of the magnetic pole 4. Next, the upper blade 14a of the caulking indicated by the broken line
Is moved in the direction of arrow A, and the lower blade 15a of the caulking is moved in the direction of arrow B. After the upper blade and the lower blade reach the positions 14b and 15b where they come into contact with the upper surface and the lower surface of the inertial mass 7 in the drawing, respectively, the inertial mass near the insertion hole 8 in the directions of arrows A and B. By pressing the surface of the inertial mass 7 from above and below, the vicinity of the pressed portion of the insertion hole 8 of the inertial mass body 7 is plastically deformed in the axial direction of the inner periphery of the insertion hole 8 and coked. 3 tightly fixed. Note that this caulking is performed at four locations at 90 ° intervals in the rotation direction, and constitutes the fixing means 10.

As described above, according to the fifth embodiment, in the vicinity of the insertion hole 8 of the inertial mass body 7, the fixing means 1 by caulking for preventing the inertial mass body 7 and the inner cylindrical portion 3 from rotating relative to each other.
By providing 0, it is possible to fix the inertial mass body 7 so that the rotating shaft 1 is not damaged, and it is possible to eliminate the need for a protrusion projecting from the one end surface 4a of the magnetic pole portion 4. In the above example, caulking was performed at four locations on the circumference.
It is not limited to each location.

In the fifth embodiment, the inner cylindrical portion 3
And the insertion hole 8 of the inertial mass body 7 is formed in a circular shape, but is not limited to this. For example, in the third embodiment,
Similarly to the examples of FIGS. 4 and 4, the inner cylindrical portion 3 has a convex portion and the insertion hole 8 has a concave portion, or the inner cylindrical portion has a D-shaped cross section, and the insertion hole 8 of the inertial mass body has a D-shaped cross section. Further, the fitting portions may be formed in a polygonal shape, and caulking may be applied. In this case, the play of the inertial mass body 7 can be more reliably eliminated. Further, a convex portion is provided on one end surface portion 4a of the magnetic pole portion 4 and a through hole for fitting the convex portion is provided on the inertial mass body 7 used in the first embodiment, and a means for heat-sealing the convex portion is added. By doing so, the play of the inertial mass body 7 can be more reliably eliminated.

Embodiment 6 of the Invention FIG. 10 is a sectional view showing a main part of an electric motor according to a sixth embodiment of the present invention.
In the figure, 16 is a resin-molded stator, 17 is the plastic magnet rotor described in the first embodiment, 18 is a bearing, and 19 is a bracket. The same reference numerals are given to the same parts as those in the above-described embodiment, and the description is omitted.

When the bearings 18 are attached to the rotating shaft 1 of the plastic magnet rotor 17, the pair of bearings 18 are respectively formed on one end face 3a and the other end face 3a of the inner cylindrical portion 3.
Press-fit until it contacts b. Next, the plastic magnet rotor 17 to which the bearing 18 is attached is inserted into the hollow inside the stator 16, and the stator 16 and the bracket 19 are inserted.
Then, a bracket 19 is press-fitted into the stator 16 so as to hold the pair of bearings 18, respectively, to form an electric motor.

As described above, according to the sixth embodiment of the present invention, the plastic magnet rotor 17 has the inertial mass body 7, which not only reduces the torque pulsation and the drive turbulence, but also reduces the bearing 18 Noise and vibration of the inertial mass body 7 due to backlash can be reduced.
Quality can be improved. In addition, since the bearing on the inertial mass body 7 side is abutted against the end face 3a of the inner cylindrical portion 3, the number of parts such as shaft machining and retaining rings can be reduced, and the cost can be reduced. . Note that any one of the second to fifth embodiments may be used as the plastic magnet rotor 17.

It should be noted that what is illustrated in each of the above embodiments is the first end face portion 4 of the magnetic pole portion 4 on which the inertial mass body 7 is disposed.
Although a is set on the output shaft side, the present invention is not limited to this, and the same effect can be obtained by disposing it on the opposite output shaft side. Further, the same effect can be expected even when both ends of the rotating shaft 1 are used as output shafts.

Embodiment 7 of the Invention FIG. 11 is a block diagram of an air conditioner according to Embodiment 7 of the present invention. FIG.
, 20 is an indoor unit of an air conditioner, 21 is an outdoor unit of an air conditioner connected to the indoor unit 20, 22 is an indoor blower driven by the electric motor described in the sixth embodiment, and 23 is the same as above. It is an outdoor blower driven by the electric motor described in Embodiment 6. (Details not shown)

The air conditioner shown in FIG. 11 has the same configuration as the known prior art except that the electric motor according to the sixth embodiment shown in FIG. 10 is used as a blower for the indoor and outdoor units.

Recent air conditioners have low noise, low vibration,
Cost reduction is required, and the indoor unit 20 includes, for example, vibration of a motor used for a blower, noise, vibration of a fan blade, wind noise, refrigerant flow sound, and vibration propagation to an indoor unit housing. Becomes a problem, and in the outdoor unit 21,
In addition to these factors, the vibration and noise of the compressor pose a problem, and various improvement measures have been proposed.
According to the above, by eliminating the damage of the shaft when the inertial mass body 7 is attached and by preventing the inertial mass body 7 from rattling, it is possible to further reduce noise and vibration compared to the conventional air conditioner. Further, since the processing of the bearing 1 is simplified and the number of parts can be reduced, there is an effect that a cost-effective air conditioner can be provided.

Embodiment 7 shows an example in which when the electric motor having the plastic magnet rotor of the present invention is used for a blower of an air conditioner, quality can be improved in terms of vibration and noise and cost can be reduced. However, the electric motor itself of the present invention is not limited to applications such as an air conditioner, but can be used for various applications.
It can be configured as a stepping motor or used as a power source for various blowers such as fan heaters, electric fans, dehumidifiers, dryers, air purifiers, and other general electric appliances. Nor.

[0038]

Since the present invention is configured as described above, the following effects can be obtained.

The first end face of the magnetic pole formed at one end of the inner cylinder is formed to be shorter in the axial direction than the one end of the inner cylinder, and the inertial mass body is fitted to the inner cylinder. With such a configuration, it is possible to provide a plastic magnet rotor and an electric motor that can prevent the occurrence of scratches on the surface of the rotating shaft and can improve the sound failure of the bearing.

Further, a plurality of projections are formed on the first end face of the magnetic pole portion, and a plurality of through holes are provided in the inertial mass body so as to penetrate these projections. By fixing the inertial mass body to the axial end face of the magnetic pole part by heat-sealing the convex part of the magnetic pole part, it is possible to provide an electric motor in which play of the inertial mass body is prevented.

Further, a detent for preventing rotation of the inertial mass body and the inner cylinder by mutually engaging the insertion hole of the inertial mass and the peripheral surface of the inner cylinder facing the insertion hole. Providing the means has an effect of providing an electric motor in which generation of backlash of the inertial mass body is prevented.

Further, in the air conditioner provided with an indoor unit or an outdoor unit having a blower driven by an electric motor, the electric motor may be a first end face of a magnetic pole formed at one end of the inner cylinder. Is formed using an electric motor having a plastic magnet rotor formed so as to be shorter in the axial direction than one end of the inner cylindrical portion, and the inertial mass body is fitted to the inner cylindrical portion, so that vibration and noise levels are reduced. There is an effect that an air conditioner with a low air temperature can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a plastic magnet rotor of an electric motor according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of the plastic magnet rotor shown in FIG.

FIG. 3 is a cross-sectional view illustrating a plastic magnetor rotor of an electric motor according to Embodiment 2 of the present invention.

FIG. 4 is a partially enlarged plan view of the plastic magnet rotor shown in FIG. 3;

FIG. 5 is a perspective view showing a plastic magnet rotor of an electric motor according to Embodiment 3 of the present invention.

6 is a cross-sectional view of the plastic magnet rotor shown in FIG.

FIG. 7 is a plan view of the plastic magnet rotor shown in FIG.

FIG. 8 is a sectional view showing a plastic magnetrotor of an electric motor according to Embodiment 5 of the present invention.

9 is a plan view of the plastic magnet rotor shown in FIG.

FIG. 10 is a sectional view showing an electric motor according to Embodiment 6 of the present invention.

FIG. 11 is a configuration diagram showing an air conditioner according to Embodiment 7 of the present invention.

FIG. 12 is a sectional view showing a conventional plastic magnet rotor.

FIG. 13 is a plan view showing a conventional plastic magnet rotor.

[Explanation of symbols]

 Reference Signs List 1 rotating shaft, 2 plastic magnet part, 3 inner cylinder part, 3a one end of inner cylinder part, 4 magnetic pole part, 4a first end face part, 5 connecting part, 6 convex part, 6a heat-fused body, 7 inertial mass Body, 8 insertion hole, 9 through hole, 10 fixing means, 11 engaging portion, 12 detent means, 17 plastic magnet rotor, 18 bearing,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Mineo Yamamoto, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Togo Yamazaki 2-3-2, Marunouchi, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd. (72) Inventor Takashi Matsunaga 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5H621 GA01 GB10 JK13 JK17 5H622 CA01 CA05 CB04 DD04 PP03 PP10 PP11 PP12 QA03 QA10

Claims (8)

[Claims] 1. A rotating shaft, which is coaxially fixed to and around the rotating shaft so as to be coaxial with the rotating shaft. One end and the other end of the rotating shaft are exposed from one end and the other end in the axial direction, respectively. An inner cylinder portion made of a plastic material, and a first portion formed on one end side of the inner cylinder portion is provided in a cylindrical shape so as to surround the outer periphery of the inner cylinder portion coaxially with the rotation axis. A magnetic pole portion made of a plastic material having an end surface portion formed to be shorter in the axial direction than one end portion of the inner cylindrical portion, a connecting portion integrally connecting these magnetic pole portions and the inner cylindrical portion, and a first of the magnetic pole portions And a disk-shaped inertial mass body having an insertion hole through which the inner cylindrical portion is inserted at a rotation center portion, and fixing the inertial mass body to the first end surface side of the magnetic pole portion. And a plastic magnet rotor. 2. An electric motor having a plastic magnet rotor, wherein the plastic magnet rotor is closely fixed to a rotating shaft and around the rotating shaft coaxially with the rotating shaft. An inner cylinder portion made of a plastic material, which exposes one and the other shaft end portions of the rotation shaft, and a cylindrical shape surrounding the outer periphery of the inner cylinder portion coaxially with the rotation shaft; A magnetic pole portion made of a plastic material having a first end face formed on one end side of the inner cylindrical portion shorter in the axial direction than the one end portion of the inner cylindrical portion, and these magnetic pole portions and the inner cylindrical portion are integrated. A disk-shaped inertial mass body having a through hole that is provided on the first end face of the magnetic pole part and has a through hole that penetrates the inner cylindrical part at the center of rotation; The first of the above magnetic pole portions
A fixing means for fixing to an end face side of the motor. 3. The fixing means is provided on a plurality of protrusions integrally formed on the first end face of the magnetic pole part, and on the periphery of the inertial mass body, and each of the protrusions on the first end face is provided. A plurality of through-holes, each of which is inserted through the through-hole, and a heat-fused body formed by heat-sealing the tip of the convex portion of the magnetic pole portion inserted through the through-hole. Claim 2
A plastic magnet rotor or electric motor as described. 4. The plastic magnet according to claim 3, wherein an engagement portion is formed around the through hole of the inertial mass body to engage with a heat-sealed body formed at the time of heat-sealing. Rotor or electric motor. 5. The fixing means deforms the vicinity of the insertion hole of the inertial mass body in the direction of the outer peripheral surface of the inner cylindrical portion by caulking,
3. The plastic magnet rotor or electric motor according to claim 1, wherein the inertial mass body is fixed to the inner cylindrical portion. 6. An outer peripheral surface portion of the inner cylinder portion and an insertion hole of the inertial mass body fitted to the outer peripheral surface engage with each other to prevent rotation of the inner cylinder portion and the inertial mass body. The plastic magnet rotor or the electric motor according to any one of claims 1 to 5, wherein a detent means is formed. 7. The bearing according to claim 1, wherein a bearing press-fitted to the rotating shaft is disposed in contact with one end of the inner cylindrical portion.
A plastic magnet rotor or an electric motor according to claim 6. 8. An air conditioner having an indoor unit or an outdoor unit having a blower driven by an electric motor, wherein the electric motor having the plastic magnet rotor according to any one of claims 2 to 7 is used as the electric motor. An air conditioner characterized by using.