JP2007267558A - Motor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor and a manufacturing method thereof with no residual solvent, attaining excellent chemical resistance, water resistance and oil resistance, capable of bonding with permanent magnets in a simple process. <P>SOLUTION: A yoke 7 and permanent magnets 2 are bonded together by an adhesive 3 made from acid modified polyolefin. The adhesive 3 is placed on the respective permanent magnets 2 and melted by the application of heat to adhere to the respective permanent magnets 2. The respective permanent magnets 2 are placed on the yoke 7 through the adhesive 3 and melted by the application of heat to adhere to other permanent magnets 2 and the yoke 2. Falling temperature causes the acid modified polyolefin to harden, thereby bonding the permanent magnets 2 with the yoke 7 together. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor having a permanent magnet and a manufacturing method thereof.

  Conventionally, a reactive adhesive or an adhesive is used for bonding a permanent magnet bonded to a yoke provided on a rotor or stator of a motor. As the reactive adhesive, a two-component mixed resin, a thermosetting resin, an ultraviolet curable resin, or the like is used. As shown in Patent Document 1, a reactive adhesive applied between a permanent magnet and a rotor is cured by reacting with a curing agent, and both are bonded.

Moreover, the double-sided adhesive sheet etc. which have an acrylic resin, an epoxy resin, etc. in an adhesion layer are used as an adhesive. As shown in Patent Document 2, the pressure-sensitive adhesive sheet is stuck on a permanent magnet, and the yoke is pressure-bonded after the release paper is peeled off. Thereby, both are adhere | attached.
Japanese Patent Laid-Open No. 2001-115125 (page 3 to page 6, FIG. 1) Japanese Patent Laid-Open No. 6-17011 (pages 3 to 4 and FIG. 7)

  However, when a reactive adhesive is used for adhering the permanent magnet, an application process is required, and the adhesion process becomes complicated. Further, there is a problem that the chemical resistance is low and the strength deteriorates in an environment where the chemical is used. When an adhesive is used for adhering the permanent magnet, there is a problem that the solvent component remains in the adhesive layer and erodes the permanent magnet and the yoke. Further, there is a problem that the water resistance and oil resistance are low, and the strength deteriorates after long-term use.

  An object of the present invention is to provide a motor that has no residual solvent, is excellent in chemical resistance, water resistance, and oil resistance, and that can bond a permanent magnet in a simple process, and a method for manufacturing the motor.

  In order to achieve the above object, the motor of the present invention is characterized in that a yoke and a permanent magnet are bonded with an acid-modified polyolefin.

  According to the present invention, in the motor configured as described above, the permanent magnet is formed of a rare earth magnet.

  Further, the present invention provides a method for manufacturing a motor in which a permanent magnet is bonded to a yoke, wherein the acid-modified polyolefin is thermally melted and adhered to one of the permanent magnet and the yoke, and the adhesive surface is brought into contact with the other to lower the temperature. It is characterized by curing acid-modified polyolefin.

  According to the present invention, in the method of manufacturing a motor having the above-described configuration, an adhesive sheet in which an adhesive layer made of acid-modified polyolefin and a base material made of a heat-resistant resin are laminated so that the adhesive layer abuts the adhesive surface. The substrate is placed on an adhesive surface, and the base material is peeled after the adhesive layer is heated to adhere the adhesive layer to the adhesive surface.

  According to this configuration, the adhesive layer made of acid-modified polyolefin is placed on one of the permanent magnet and the yoke, and the base material is peeled when the adhesive layer melted by heating comes into close contact with the permanent magnet or the yoke. Thereby, the adhesive layer is transferred onto the permanent magnet or the yoke. Thereafter, the other is pressed onto the adhesive layer, and when the adhesive layer is cooled to room temperature, it is cured and the permanent magnet and the yoke are bonded.

  According to the motor of the present invention, since the yoke and the permanent magnet are bonded by the acid-modified polyolefin, the permanent magnet can be easily bonded to the yoke by heat fusion. In addition, the acid-modified polyolefin has no residual solvent and can prevent erosion of the permanent magnet and the yoke. Furthermore, since it is excellent in chemical resistance, water resistance and oil resistance, the adhesive strength can be maintained for a long time.

  Further, according to the motor of the present invention, the acid-modified polyolefin does not flow out of chlorine like an epoxy resin, and can prevent rusting of a rare earth magnet having low corrosion resistance.

  Further, according to the method of manufacturing a motor of the present invention, the acid-modified polyolefin is thermally melted and adhered to one of the adhesion surfaces of the permanent magnet and the yoke, and the acid-modified polyolefin is cured by lowering the temperature by contacting the adhesion surface to the other. The permanent magnet and the yoke can be easily bonded with the acid-modified polyolefin.

  Further, according to the method for manufacturing a motor of the present invention, the adhesive sheet in which the base material made of acid-modified polyolefin and a heat-resistant resin is laminated is heated, and the base material is peeled off after the acid-modified polyolefin is adhered to the adhesive surface. The modified polyolefin can be easily transferred to the adhesive surface.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view showing a motor according to an embodiment. In the motor 1, a stator 4 is disposed on the outer periphery of a rotor 6 having a shaft portion 6a. FIG. 2 is a perspective view showing the rotor 6. In the rotor 6, a plurality of permanent magnets 2 are bonded with an adhesive 3 in the circumferential direction of the yoke 7. In addition, a coil 5 facing the permanent magnet 2 is provided on the inner peripheral surface of the stator 4.

  The yoke 7 is made of a metal such as iron, and the permanent magnet 2 is made of a rare earth magnet or a ferrite magnet. As the rare earth magnet, an R—Fe—B system such as Nd—Fe—B or an R—Co system such as Sm—Co (R is a rare earth element) is used. The adhesive 3 is made of acid-modified polypropylene (PPa).

  3 and 4 are a plan view and a cross-sectional view showing an adhesive sheet for bonding the permanent magnet 2 to the yoke 7. In the adhesive sheet 10, an adhesive layer 12 made of acid-modified polypropylene (PPa) is laminated on a base material 11 made of polyethylene terephthalate (PET).

  The base material 11 is formed in a tape shape having a thickness of about 50 μm, and positioning holes 10a are formed at a predetermined interval T in the longitudinal direction. A plurality of adhesive layers 12 are arranged on the substrate 11 at intervals T, and each adhesive layer 12 is formed in the same shape. A through hole penetrating the base material 11 and the adhesive layer 12 may be provided. The cylindrical permanent magnet and the yoke can be easily bonded by the through hole.

  The acid-modified polypropylene is melted by heating, and the acid-modified polypropylene melted on the substrate 11 is applied by extrusion with a T-die extruder. The acid-modified polypropylene applied on the base material 11 is sandwiched and fed together with the base material 11 by a roll. Thereby, the adhesive layer 12 having a thickness of about 50 μm can be easily formed.

  The positioning hole 10a can be easily formed by laminating the adhesive layer 12 on the substrate 11 and then punching it out by pressing. Further, the adhesive layer 12 can be formed into a desired shape by half-cutting from the adhesive layer 12 side. Unnecessary portions of the adhesive layer 12 are removed by being wound with a roll or the like.

  FIG. 5 is a diagram showing a bonding process in which the permanent magnet 2 is bonded to the yoke 7 using the adhesive sheet 10. The curved permanent magnet 2 is supported on a jig (not shown) and fed on the conveyor 20. The adhesive sheet 10 is wound around a supply roll 21 and fed by a feed roll 22 and a positioning roll 23. A pin 23 a is projected from the positioning roll 23 and is fitted into the positioning hole 10 a of the adhesive sheet 10 so that the adhesive layer 12 is positioned below the heater 24. At this time, the adhesive layer 12 is disposed below the substrate 11.

  When the permanent magnet 2 is positioned below the heater 24 by the conveyor 20, the heater 24 is lowered and the adhesive sheet 10 is pressed against the permanent magnet 2. The adhesive sheet 10 is heated by the heater 24, and the adhesive layer 12 melts and adheres to the permanent magnet 2. In addition, since the base material 11 has heat resistance, it does not melt. Alternatively, a heater may be contacted with the permanent magnet 2 and the adhesive layer 12 may be melted by heating the permanent magnet 2.

  The permanent magnet 2 and the adhesive sheet 10 are fed together by a conveyor 20, a feed roll 22 and a positioning roll 23. The substrate 11 is wound upward from the positioning roll 23 by the winding roll 25. Thereby, the base material 11 is peeled from the adhesive layer 12, and the adhesive layer 12 is transferred to the permanent magnet 2.

  The permanent magnet 2 to which the adhesive layer 12 has been transferred is placed on the yoke 7 disposed below the heater 26. The heater 26 is lowered and the permanent magnet 2 is pressed against the yoke 7. As a result, the adhesive layer 12 melts and adheres to the yoke 7. The adhesive layer 12 is cured when cooled, and the permanent magnet 2 and the yoke 7 are bonded. A plurality of permanent magnets 2 that are sequentially supplied by rotating the yoke 7 are similarly bonded. Then, the rotor 6 (see FIG. 2) in which the permanent magnet 2 is bonded to the yoke 7 with the adhesive 3 made of acid-modified polypropylene is completed. The permanent magnet 2 may be bonded after the adhesive layer 12 is transferred to the yoke 7.

  The substrate 11 may be any heat-resistant resin having heat resistance, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyphenylene sulfide (PPS), polymethylpentene (TPX (registered trademark)), polyacetal (POM). Non-stretched or stretched films such as cyclic polyolefin and polypropylene (PP) can be used. Polyethylene terephthalate is more desirable because it is inexpensive and has high strength, so that it can be easily handled in the bonding process. Further, a known release agent may be provided between the base material 11 and the adhesive layer 12 to adjust the peel strength between the base material 11 and the adhesive layer 12.

  Table 1 shows the results of measuring the adhesive strength of acid-modified polypropylene to ferrite magnets. The change with time was measured in (a) a dry state at 60 ° C., (b) a state maintained at 60 ° C. with a humidity of 90%, and (c) a state immersed in machine oil at 60 ° C.

  As shown in FIG. 4, the test piece S was obtained by laminating acid-modified polypropylene (PPa) on a base material obtained by laminating aluminum (AL) on a biaxially stretched nylon film (ONy). Thereby, peeling between a base material and acid-modified polypropylene is prevented. As a measuring method, the test piece S was bonded to the ferrite magnet F, and a tensile test was performed at a speed of 50 mm / min. The bonding condition was heated to 200 ° C. and pressurized with a pressure of 1 MPa for 20 seconds.

  As shown in Table 1, it has a high adhesive strength of about 30 N per 15 mm width under each condition. Further, the adhesive strength hardly changes with time and has water resistance and oil resistance.

  The adhesive layer 12 is not limited to acid-modified polypropylene, and the same adhesive strength can be maintained as long as it is an acid-modified polyolefin. In addition, acid-modified polyolefin has similar adhesive strength to other metals, resins, and ceramics, and also has high chemical resistance. For this reason, the permanent magnet 2 such as a rare earth magnet or a ferrite magnet can be bonded to the yoke 7 made of metal, resin, ceramic or the like with high adhesive strength.

  According to the present embodiment, since the yoke 7 and the permanent magnet 2 are bonded by the acid-modified polyolefin, the permanent magnet 2 can be easily bonded to the yoke 7 made of metal, resin, ceramic or the like by heat fusion. Further, the acid-modified polyolefin has no residual solvent and can prevent the permanent magnet 2 and the yoke 7 from being eroded. Furthermore, since it is excellent in chemical resistance, water resistance and oil resistance, the adhesive strength can be maintained for a long time. In addition, the acid-modified polyolefin does not flow out of chlorine like an epoxy resin, and can prevent rusting of a rare earth magnet having low corrosion resistance.

  Further, since the base material 11 made of heat-resistant resin is formed in a sheet shape by laminating the adhesive layer 12 made of acid-modified polyolefin, the adhesive 3 made of the adhesive layer 12 is simply heat-melted so that the permanent magnet 2 is yoked. 7.

  Alternatively, the acid-modified polyolefin may be extruded on one of the permanent magnet 2 and the yoke 7 and the other may be placed thereon and heated. Thereby, it is not necessary to form the adhesive 3 in a sheet shape, and the base material 11 can also be made unnecessary. Alternatively, the coil 5 may be provided on the rotor 6 and the permanent magnet 2 may be bonded to a yoke provided on the stator 4.

  The present invention can be used for a motor in which a permanent magnet is bonded to a yoke.

Front sectional view showing a motor of an embodiment of the present invention The perspective view which shows the rotor of the motor of embodiment of this invention. The top view which shows the adhesive sheet of the motor of embodiment of this invention Sectional drawing which shows the adhesive sheet of the motor of embodiment of this invention Schematic which shows the adhesion process of the permanent magnet of the motor of embodiment of this invention. The figure which shows the measuring method of the adhesive strength of the adhesive for permanent magnets of the motor of embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Permanent magnet 3 Adhesive 4 Stator 5 Coil 6 Rotor 7 Yoke 10 Adhesive sheet 10a Positioning hole 11 Base material 12 Adhesive layer 20 Conveyor 21 Supply roller 22 Feed roller 23 Positioning roller 24 Heater 25 Winding roller

Claims (4)

  A motor characterized in that a yoke and a permanent magnet are bonded with an acid-modified polyolefin.   The motor according to claim 1, wherein the permanent magnet is a rare earth magnet.   In a motor manufacturing method in which a permanent magnet is bonded to a yoke, the acid-modified polyolefin is thermally melted and adhered to one of the bonded surfaces of the permanent magnet and the yoke, and the acid-modified polyolefin is cured by lowering the temperature by bringing the bonded surface into contact with the other. A method for manufacturing a motor, characterized by comprising:   An adhesive sheet in which an adhesive layer made of acid-modified polyolefin and a base material made of a heat resistant resin are laminated is placed on the adhesive surface so that the adhesive layer abuts on the adhesive surface, and the adhesive layer is heated. The method for manufacturing a motor according to claim 3, wherein the base material is peeled after the adhesive layer is brought into close contact with the adhesive surface.

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