JP2008172965A - Permanent magnet rotor, motor and electrical apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet rotor preventing cracking in a molded product in an integral injection molding method for integrally producing a metal member and a bonded magnet, a high-reliability and high-quality motor mounted with the permanent magnet rotor, and electrical apparatus. <P>SOLUTION: This permanent magnet rotor includes a metal shaft part for the central axis of rotation and an anisotropic bonded magnet part integrally injection-molded with magnetic field orientation in a mold on the circumference of the metal shaft part. In the permanent magnet rotor, the weld layers of gates in the permanent magnets are not aligned with interpolar positions. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotor structure of a permanent magnet motor equipped with a permanent magnet and a motor incorporating the rotor.

  The bond magnet is a composite permanent magnet in which ferrite-based or rare-earth-based permanent magnet powder is bound and solidified with a binder such as rubber, thermoplastic resin, or thermosetting resin. This bonded magnet has a low magnetic property because it contains the binder component as compared with a sintered magnet that does not contain the binder component and is produced by a sintering method. However, since there is no shrinkage due to sintering, it has a feature that a magnet having a special shape such as an annular shape, an arc shape, or a thin shape can be produced with high dimensional accuracy without cracking. For this reason, ring-shaped bonded magnets have been frequently used in home appliances and information motors in recent years. Bond magnets using ferrite-based magnet powder are widely used because the magnet powder itself is inexpensive, and manufactured while integrating metal members and bond magnets to reduce manufacturing man-hours and component costs. Many injection integral moldings are also used.

  However, when the metal member and the bonded magnet are integrally formed by injection, the linear expansion coefficients of the metal member and the bonded magnet are greatly different from each other, so that the molded product is likely to be cracked. This is because a large internal stress remains on the bonded magnet side due to the difference in shrinkage between the metal member and the bonded magnet when the bonded magnet is cooled and solidified. Although cracks may occur immediately after molding, they may appear after deterioration of the resin in the bonded magnet through aging changes, which may lead to a fatal failure of the equipment.

As an attempt to improve the mechanical characteristics of the magnet itself, an invention in which a reinforcing material such as carbon fiber or glass fiber or a softening agent such as rubber is added to the magnet material has been proposed as an attempt to improve the mechanical characteristics of the magnet itself. No. 102407 and JP-A-6-287445. Japanese Laid-Open Patent Publication No. 2005-151757 discloses a method of reducing residual stress by providing an intermediate layer at a contact portion between a metal member and a bonded magnet.
JP-A-6-287445 JP-A-9-102407 JP 2005-151757 A

  The problem to be solved by the present invention is that permanent magnet rotation that prevents cracking of a molded product in injection-integrated molding in which a metal member and a bonded magnet are integrated to reduce manufacturing man-hours and component costs. A child structure, a motor equipped with a permanent magnet rotor, and an electric device are provided. If a reinforcing fiber is added to increase the magnet strength as in Patent Document 1 or 2, or a rubber component is added to increase flexibility, the cracking resistance of the magnet can be improved. When the content of the magnet powder is increased, the strength and flexibility are decreased, and thus the improvement thereof is insufficient. Further, in the method of providing an intermediate layer at the contact portion between the metal member and the bonded magnet as in Patent Document 3 to relieve the residual stress, the intermediate layer absorbs the stress, and the crack resistance of the magnet can be improved. However, the number of intermediate layer materials and man-hours increased, which hindered the advantages of injection-integrated molding that reduced manufacturing man-hours and component costs.

  The present invention solves the above-described conventional problems, and provides a permanent magnet rotor structure and a manufacturing method that prevent the occurrence of cracks in a molded product in injection integral molding, and a motor equipped with a permanent magnet rotor, and It is to provide electrical equipment.

  In order to solve the above-described problems, the present invention provides, as a first invention, an anisotropic bonded magnet that is integrally molded by injection while being magnetically oriented in a mold on a metal shaft portion that is a central axis of rotation and its outer peripheral portion. The permanent magnet rotor according to the present invention is characterized in that the position of the interelectrode portion does not coincide with the weld layer of the gate in the permanent magnet portion.

  Moreover, in 2nd invention, the number of the weld layers of the anisotropic bond magnet part and the number of poles are made into the same number, and the permanent magnet part has the permanent magnet part characterized by having arrange | positioned the gate in the area | region between poles. Magnet rotor.

  Furthermore, in the third invention, the magnet powder as the main component of the anisotropic bonded magnet portion is ferrite powder or a mixture of ferrite powder and other magnet powder. It is a permanent magnet rotor of description.

  Furthermore, in the fourth invention, there is provided a motor comprising the permanent magnet rotor according to any one of claims 1 to 3. An electric apparatus comprising the motor according to claim 4.

  In a permanent magnet rotor comprising a metal shaft portion that is a central axis of rotation and an anisotropic bonded magnet portion that is integrally molded with injection while being magnetically oriented in the mold on the outer periphery thereof, the gate of the permanent magnet portion By forming a permanent magnet rotor characterized in that the weld layer and the inter-electrode position do not coincide with each other, a weld layer portion having a low mechanical strength that is bonded while the bonded magnet material injected from the adjacent gate portion is cooled and hardened, and The magnet strength should be improved regardless of the magnet's filling amount without matching the weak inter-electrode area due to the strength difference between the anisotropic direction caused by the unique shape of the ferrite magnet powder and the direction perpendicular to it. Is possible.

  In addition, the number of pole layers and the number of poles of the anisotropic bonded magnet part are the same, and the gate is arranged in the inter-electrode part, so that the bonded magnet material injected and flowing from the gate does not straddle the inter-electrode. The magnetic powder in the compound once magnetized to the N pole is 180 ° when the plug magnet compound moves between the N pole and the S pole. Without changing the orientation), it is possible to obtain a permanent magnet rotor in which filling is completed and magnetic powder orientation disorder is eliminated.

  Further, the magnet powder which is the main component of the anisotropic bonded magnet part is a ferrite powder or a mixture of ferrite powder and other magnet powder, so that the weld layer and the inter-electrode position do not coincide with each other. The effect of improving the strength is great.

  Furthermore, by making the motor characterized by having the permanent magnet rotor mounted thereon, there is no defect such as motor lock such as cracking of the permanent magnet, high quality, or high characteristics without magnet powder orientation disturbance. It becomes possible to make it a motor. In addition, the quality of the device can be improved by using the electric device including the motor.

  In a permanent magnet rotor comprising a metal shaft portion serving as a central axis of rotation and an anisotropic bonded magnet portion that is integrally molded with injection while being magnetically oriented in the mold on the outer periphery thereof, the gate in the permanent magnet portion The permanent magnet rotor is characterized in that the position of the interelectrode portion does not coincide with that of the weld layer.

  The permanent magnet rotor having a permanent magnet part is characterized in that the number of the weld layers of the anisotropic bonded magnet part is the same as the number of poles, and the gate is arranged in the interpolar part.

  Furthermore, the permanent magnet rotor is characterized in that the magnet powder which is the main component of the anisotropic bonded magnet portion is ferrite powder or a mixture of ferrite powder and other magnet powder.

  Furthermore, the motor is characterized in that the permanent magnet rotor is mounted. Further, the present invention is an electrical device equipped with the motor.

  The following examples illustrate the present invention in more detail.

  The present invention example 1 will be described below. A rotating shaft comprising a shaft 1 having a diameter of 8 mm and a core 2 having an outer diameter of φ35 mm, an inner diameter of φ8 mm and a height of 22 mm fixed to the outer periphery of the shaft 1 as shown in FIG. 1 using an anisotropic ferrite compound manufactured by Mate Co., Ltd. Then, an anisotropic bonded magnet 3 having an outer diameter of Φ50 mm, an inner diameter of Φ35 mm, and a height of 30 mm is integrally formed by injection molding to obtain a permanent magnet rotor.

  The main points at the time of this injection integral molding will be described with reference to FIG. FIG. 2 is a schematic half top view at the time of injection integral molding of the present invention. 1 to 3 in the figure are the shaft 1, the core 2, and the anisotropic bonded magnet 3 as in FIG. 1. The injection integration of the anisotropic bonded magnet was performed in a magnetic field orientation mold including the orientation magnet 4 in order to make the magnet powder anisotropic. The anisotropic ferrite compound is injected from the gate 5 and flows in the flowing resin direction 6, and the anisotropic ferrite compound injected from the adjacent gate 5 is joined by the weld layer 7 to complete the integration. Since the anisotropic ferrite compound is joined while it cools and hardens, the strength of the weld layer decreases.

  Moreover, the magnetic force line 8 of the magnet for orientation is shown in FIG. The magnetic field lines 8 of the orientation magnet extend from the north pole to the adjacent south pole. According to the magnetic field lines, the ferrite powder in the anisotropic ferrite compound is oriented. FIG. 4 shows the shape of the ferrite powder. The ferrite powder 9 has a thin hexagonal columnar shape, and the easy magnetization axis 10 is in the direction in the figure. The direction of the easy axis 10 of the ferrite powder 9 and the direction of the magnetic lines of force of the magnet for orientation in FIG. Accordingly, the ferrite powder 9 is arranged as shown in the schematic diagram of the orientation of the ferrite powder in FIG. Since the poles of the oriented magnet are transferred to the poles of the anisotropic bonded magnet, the gap 11 is a portion in the figure. Due to the unique shape of the ferrite powder 9, cracks are more likely to occur in the circumferential direction between the poles 11 than in the center part of the poles. FIG. 6 shows the gap 11 where cracks easily occur and the above-described weak weld layer 7 at the same time. As shown in FIG. 6, a high-strength magnet can be manufactured by shifting the position of the weld layer 7 and the gap 11.

  Next, as Comparative Example 1, an example in which four gates are arranged between the electrodes will be described. The shape of the magnet is the same as that described above, only the number of gates and the position are different. FIG. 7 shows a schematic diagram thereof. When four gates 5 are arranged in the inter-electrode portion, four welds are generated in the other inter-electrode regions 11. Therefore, as shown in FIG. 8, the weld layer 7 and the gap 11 coincide with each other, and a magnet having a low magnet strength is manufactured.

  Next, as an example 2 of the present invention, FIG. 9 shows an example in which the number of gate points is 4 and arranged at the center of the pole. In this case, since the weld layer is formed at the center of the pole, the magnet strength is improved.

  Next, as Comparative Example 2, FIG. 10 shows an example in which the number of gate points is 8 and arranged at the center of the pole. In this case, since a weld layer is formed between the poles, a magnet having a low magnet strength is produced.

  The strength tests of Examples 1 and 2 of the present invention and Comparative Examples 1 and 2 were performed. In the strength test, the magnet was removed from the rotating shaft, an angled cylinder was inserted inside the magnet, the cylinder was pushed with a compression tester, the magnet was broken from the inner diameter side, and the breaking load was measured. FIG. 11 shows the breaking load under each condition. The magnet in which the position between the weld layer and the pole in the example of the present invention is shifted is improved by about 17% compared with the magnet in which the position between the weld layer and the pole is the same. Next, a thermal shock test was performed in Invention Example 1 and Comparative Example 1. Thermal shock resistance was confirmed. In the thermal shock test, 400 cycles of -20 ° C. on the low temperature side and 100 ° C. on the high temperature side were performed for 1 hour each, and the number of cracks was confirmed. The result is shown in FIG. 1 min and 3 min in the figure indicate the time spent in the heating cylinder of the anisotropic ferrite compound injection molding machine. The temperatures of 295 ° C., 305 ° C., and 315 ° C. indicate the temperature of the anisotropic ferrite compound injected from the nozzle. When the resin in the ferrite compound is exposed to a high temperature, it begins to decompose from the low molecular weight portion and degrades the strength of the magnet. Moreover, since decomposition progresses when the exposure time is long, this also leads to strength deterioration. The superiority of the present invention was confirmed with samples in which the temperature and residence time were changed. In Example 1 of the present invention, compared to Comparative Example 1, it was found that cracks were not generated at the temperatures of 295 ° C. and 305 ° C. and the thermal shock resistance was excellent.

  Moreover, the polar angle of the magnet in each above-mentioned conditions was measured. The polar angle is a mechanical angle corresponding to one pole of the surface magnetic flux. In this embodiment, since an 8-pole magnet is used, 360 ° / 8 = 45 ° and one pole is 45 °. Is desirable. If this shifts, a magnetic defect will be caused. The maximum value of the polar angle for each of the above conditions is shown in FIG. Only Example 2 of the present invention greatly deviated from the 45 ° polar angle. This is because, in the case of the present invention example 2, since the resin injected from the gate portion moves across the poles, the magnet arranged in a certain direction by the force of the orientation magnet moves between the poles, Although it must be reversed, it is considered that the resin was solidified by the mold temperature during the flow of the resin and could not be reversed sufficiently. On the other hand, since Example 1 of the present invention and Comparative Examples 1 and 2 can be molded without straddling the poles, the polar angles were not shifted. Disturbances due to this orientation can be reduced by changing the injection temperature, speed, etc., but the number of weld layers and the number of poles in the anisotropic bonded magnet part can be the same, and the gate can be placed between the poles. desirable.

  Furthermore, when the motor having the permanent magnet rotor of the present invention is mounted, the motor becomes highly reliable.

  As examples of the electrical equipment according to the present invention, an air conditioner outdoor unit, an air conditioner indoor unit, a water heater, and an air cleaner will be described. First, the configuration of the air conditioner indoor unit will be described in detail. In FIG. 14, a motor 201 is mounted in the casing 211 of the air conditioner indoor unit 210. A cross flow fan 212 is attached to the rotating shaft of the motor 201. The motor 201 is driven by a motor driving device 213. By energization from the motor driving device 213, the motor 201 rotates, and the crossflow fan 212 rotates accordingly. By the rotation of the cross flow fan 212, air conditioned by an indoor unit heat exchanger (not shown) is blown into the room. Here, for example, the motor of the embodiment can be applied to the motor 201. The electric device of the present invention includes a motor and a housing on which the motor is mounted, and employs the motor of the present invention having the above-described configuration as the motor. Thereby, an electrical apparatus with high long-term reliability can be provided.

  Next, as an example of the electrical apparatus according to the present invention, a detailed configuration of an air conditioner outdoor unit will be described.

  In FIG. 15, the air conditioner outdoor unit 301 has a motor 308 mounted inside a housing 311. The motor 308 has a fan 312 attached to a rotating shaft, and functions as a fan motor for blowing air.

The air conditioner outdoor unit 301 is separated by a partition plate 304 erected on the bottom plate 302 of the housing 311.
It is divided into a compressor chamber 306 and a heat exchanger chamber 309. A compressor 305 is disposed in the compressor chamber 306. A heat exchanger 307 and the blower fan motor are disposed in the heat exchanger chamber 309. An electrical component box 310 is disposed above the partition plate 304.

  The blower fan 312 is rotated by the rotation of the motor 308 driven by the motor driving device 303 housed in the electrical component box 310, and the blower fan 312 rotates into the heat exchanger chamber 309 through the heat exchanger 307. Blow. Here, for example, the motor of the embodiment can be applied to the motor 308, for example. The electric device of the present invention includes a motor and a housing on which the motor is mounted, and employs the motor of the present invention having the above-described configuration as the motor. Thereby, an electrical apparatus with high long-term reliability can be provided.

  Next, the configuration of a water heater will be described in detail as an example of the electrical apparatus according to the present invention.

  In FIG. 16, a motor 333 is mounted in a housing 331 of the water heater 330. A fan 332 is attached to the rotating shaft of the motor 333. The motor 333 is driven by a motor driving device 334. The motor 333 is rotated by energization from the motor driving device 334, and the fan 332 is rotated accordingly. The rotation of the fan 332 blows air necessary for combustion to a fuel vaporization chamber (not shown). Here, for example, the motor of the embodiment can be applied to the motor 333. The electric device of the present invention includes a motor and a housing on which the motor is mounted, and employs the motor of the present invention having the above-described configuration as the motor. Thereby, an electrical apparatus with high long-term reliability can be provided.

  Next, the structure of an air cleaner is demonstrated in detail as an example of the electric equipment concerning this invention.

  In FIG. 17, a motor 343 is mounted in the housing 341 of the air purifier 340. An air circulation fan 342 is attached to the rotating shaft of the motor 343. The motor 343 is driven by a motor driving device 344. The motor 343 is rotated by energization from the motor driving device 344, and the fan 342 is rotated accordingly. Air is circulated by the rotation of the fan 342. Here, for example, the motor of the embodiment can be applied to the motor 343. The electric device of the present invention includes a motor and a housing on which the motor is mounted, and employs the motor of the present invention having the above-described configuration as the motor.

  In the above description, the fan motor mounted on the air conditioner outdoor unit, the air conditioner indoor unit, the water heater, the air purifier, etc. is taken up as an example of the electric device according to the present invention. Needless to say, the present invention can also be applied to motors mounted on various information devices and motors used in industrial devices.

  By using a motor having the permanent magnet rotor of the present invention mounted thereon, a high-quality motor free from defects such as motor lock caused by cracks in the permanent magnet and free from magnet powder orientation disturbance It becomes possible. Further, by mounting the motor, it is possible to obtain a high-quality electric device.

Schematic diagram of permanent magnet rotor The schematic top view at the time of injection integral molding of the present invention 1 Diagram showing magnetic field lines of magnet for orientation Diagram showing shape of ferrite powder Ferrite powder orientation schematic The figure which shows the position between the weld layer of this invention example 1, and an electrode Schematic top view during injection integral molding of Comparative Example 1 The figure which shows the position between the weld layer and the pole of the comparative example 1 The figure which shows the position between the weld layer of this invention 2, and an electrode The figure which shows the position between the weld layer and the pole of the comparative example 2 The graph which shows the destruction load of this invention example and a comparative example The graph which shows the number of magnet cracks by the thermal shock test of this invention example and a comparative example Graph showing polar angle misalignment between inventive example and comparative example Structural diagram of electrical equipment (air conditioner indoor unit) of the present invention Structure diagram of electrical equipment (air conditioner outdoor unit) of the present invention Structure diagram of electrical equipment (water heater) of the present invention Structure diagram of electrical equipment (air purifier) of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft 2 Core 3 Anisotropic bond magnet 4 Orientation magnet 5 Gate 6 Flowing resin direction 7 Weld layer 8 Magnetic field line of orientation magnet 9 Ferrite powder 10 Easy magnetization axis 11 Between poles 201 Motor 210 Air conditioner indoor unit 211 Case 212 Cross Flow fan 213 Motor drive unit 301 Air conditioner outdoor unit 302 Bottom plate 303 Motor drive unit 304 Partition plate 305 Compressor 306 Compressor chamber 307 Heat exchanger 308 Motor 309 Heat exchanger chamber 310 Electrical component box 311 Housing 312 Fan 330 Water heater 331 Housing 332 Fan 333 Motor 334 Motor driving device 340 Air cleaner 341 Housing 342 Fan 343 Motor 344 Motor driving device

Claims (5)

In a permanent magnet rotor comprising a metal shaft portion that is a central axis of rotation and an anisotropic bonded magnet portion that is integrally molded with injection while being magnetically oriented in the mold on the outer periphery thereof, the gate of the permanent magnet portion A permanent magnet rotor, wherein the weld layer and the inter-electrode position do not coincide. The permanent magnet rotor according to claim 1, wherein the permanent magnet rotor has a permanent magnet portion in which the number of the weld layers and the number of poles of the anisotropic bonded magnet portion are the same, and the gate is disposed in the interpolar portion. The permanent magnet rotor according to claim 1 or 2, wherein the magnet powder as a main component of the anisotropic bonded magnet portion is ferrite powder or a mixture of ferrite powder and other magnet powder. A motor comprising the permanent magnet rotor according to any one of claims 1 to 3. An electric device comprising the motor according to claim 4.