JP2007166681A - Motor core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce an iron loss in a motor core comprising a plurality of partial cores as a dust core formed by pressing and molding magnetic powder bound by an insulative binding agent. <P>SOLUTION: The motor core 1 comprises the dust core obtained by pressing and molding the magnetic powder bound by the insulative binding agent, and is provided with an annular base 2, and a plurality of coil winding sections 3 protruded within the annular base 2 and having wound coils. The motor core 1 comprises a plurality of the partial cores 4 circumferentially divided. The partial core 4 comprises a partial annular base 5, and at least one coil winding section 3 protruded within the partial annular base 5. The partial cores 4 are fixed by welding outer circumferences of contact faces of the partial cores 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor core comprising a dust core.

  As a motor core, a powder core obtained by press-molding magnetic powder such as iron bound with an insulating binder is used. Compared with a core obtained by laminating electromagnetic steel sheets, a dust core has an advantage that it can be easily formed into a complicated shape, and is frequently used.

  For example, Patent Document 1 discloses a dust core composed of a plurality of parts divided in the circumferential direction. The dust core has a plurality of portions arranged in contact with each other in an annular shape, and is used by being housed in a cylindrical housing. The housing fastens and fixes a dust core composed of a plurality of portions from the outside.

JP 2004-328965 A

  Since the dust core is fastened and fixed by the housing (fastening member), it receives a predetermined compressive stress from the outside. Therefore, there is a problem that distortion is likely to occur inside the dust core, and hysteresis loss increases due to the occurrence of the distortion, which in turn increases iron loss.

  The motor core according to the present invention is a motor core composed of a powder core obtained by pressure molding magnetic metal powder bound with an insulating binder resin, the core being divided into a plurality of divided cores. It consists of partial cores, and is characterized by fixing the partial cores by welding the outer periphery of the contact surface between the partial cores.

  In the motor core, the core has an annular base portion and a plurality of coil winding portions that are provided on the inner side of the annular base portion and wound with a coil, and are divided in a circumferential direction. It consists of a core, and the partial core consists of a partial annular base and at least one coil winding part protruding inside the partial annular base, and welds the outer periphery of the contact surface between the partial cores, It is desirable to fix.

  Further, in the motor core, it is preferable that the joint cores are provided at both ends of the partial annular bases of the partial cores, and the joint cores are welded on the outer periphery of the contact surfaces of the partial cores to fix the partial cores.

  ADVANTAGE OF THE INVENTION According to this invention, the core for motors which consists of a dust core with a small iron loss can be provided.

  Hereinafter, embodiments according to the present invention will be described in detail. First, the motor core according to the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a motor core according to the first embodiment. The core 1 includes an annular base portion 2 and a plurality of coil winding portions 3 that protrude from the inside of the annular base portion 2 and are wound with a coil.

  As shown in FIG. 2, the core 1 includes a plurality of partial cores 4 divided in the circumferential direction. The partial core 4 includes a partial annular base portion 5 in which the annular base portion 2 is divided in the circumferential direction, and at least one coil winding portion 3 that protrudes inside the partial annular base portion 5. In addition, although the partial core 4 which concerns on this embodiment is provided with only one coil winding part 3, it may be provided with two or more coil winding parts 3 in other embodiment. The coil winding part 3 is located at the end of the coil winding area part 6 and the coil winding area part 6, which is an area around which the coil is wound, and is more circular than the coil winding area part 6. It consists of a peripheral end 7 which is wide in the circumferential direction. The coil is concentratedly wound around the coil winding area 6 of the coil winding section 3, but the coil winding section 3 or the coil winding area 6 is usually covered with an insulating material such as plastic.

  As shown in FIG. 2, the partial core 4 includes joint protrusions 10 at upper ends (both ends in the circumferential direction on the upper surface of the partial annular base 5) on both side surfaces 8, 8 of the partial annular base 5. In the present embodiment, the partial cores 4 are fixed together by joining the joint convex part 10 of one partial core 4 and the joint convex part 10 of the other adjacent partial core 4 and welding the joint convex part 10. Is done. As a welding method, a normal welding method such as arc welding, gas welding, TIG welding, MIG welding, laser welding, brazing, or the like can be applied.

  FIG. 3 shows a perspective view of the partial core 4 fixed by welding the joint convex portion 10. The fixing of the partial cores 4 of the motor core 1 according to the present invention is performed by contacting the side surface 8 of the partial annular base 5 of one partial core 4 with the side surface 8 of the partial cyclic base 5 of the other adjacent partial core 4. For the surface 11, the outer periphery of the contact surface 11 is welded. Further, the joint convex portion 10 is provided on at least a part of the outer periphery of the contact surface 11. If desired, a part or all of the outer periphery of the contact surface 11 may be welded without providing the joint projection 10.

  In some cases, the magnetic powder collects at the weld and the assembly causes eddy currents. Eddy current loss causes iron loss. In order to reduce the influence of eddy current loss, it is desirable to weld and fix the joint protrusions 10 on the outer periphery of the contact surface 11.

  The motor core 1 composed of a plurality of partial cores 4 according to this embodiment is manufactured, for example, by pressure-molding magnetic metal powder bound with an insulating binder using a predetermined mold. The Examples of magnetic metal powders include iron, cobalt, nickel, iron-silicon alloys, iron-nitrogen alloys, iron-nickel alloys, iron-carbon alloys, iron-boron alloys, iron-cobalt alloys, An iron-phosphorus alloy, an iron-nickel-cobalt alloy, an iron-aluminum-silicon alloy, or the like is used.

Insulating binders include organic insulating binders such as silicone resins, phenolic resins, imide resins, and epoxy resins, and inorganic insulating materials such as Al ₂ O ₃ , SiO ₂ , SiN, water glass, and low melting point glass. Sexual binders can be used.

  The core 1 (partial core 4) according to the present embodiment in which magnetic metal powder is bound with an insulating binder has an interval between magnetic metal powders (thickness of the insulating binder) of 0.005 μm to 20 μm. A range is preferable. If the distance is less than 0.005 μm, it is difficult to reduce eddy current loss between the magnetic metal powders. If the distance exceeds 20 μm, the proportion of the insulating material (insulating binder) becomes excessive. The desired magnetic flux cannot be obtained.

  The partial core 4 can be manufactured, for example, by pressure molding. The partial core 4 is molded, for example, by filling a predetermined metal mold with magnetic metal powder bound with an insulating binder and applying a predetermined pressure. In order to facilitate the demolding of the partial core 4, a lubricant such as zinc stearate may be added to the magnetic metal powder bound with an insulating binder.

  In the motor core 1 according to the present embodiment, the partial cores 4 are fixed to each other without being fastened by the fastening member from the outer peripheral surface of the core 1 (outside the annular base portion 2). Does not cause hysteresis loss. Therefore, the motor core 1 according to the present embodiment has an advantage that the iron loss is small. Further, since the core 1 does not require a fastening member, the outer periphery can be made larger by the amount of the fastening member. When the outer circumference can be increased, the coil wound around the coil winding portion 3 and the coil winding region portion 6 can be thickened and the resistance of the coil can be reduced. In addition, many coils can be wound, the magnetic force can be increased, and a large torque can be obtained.

  Next, the motor core 21 according to the second embodiment will be described with reference to FIGS. 4 and 5. FIG. 4 is a perspective view of the motor core 21 according to the second embodiment. The core 21 includes an annular base portion 2 and a plurality of coil winding portions 3 that protrude from the inside of the annular base portion 2 and are wound with a coil. The core 21 includes a partial core 24 divided in the circumferential direction. FIG. 5 shows a perspective view of two fixed partial cores 24. The partial core 24 includes a partial annular base portion 5 in which the annular base portion 2 is divided in the circumferential direction, and at least one coil winding portion 3 projecting from the partial annular base portion 5. In addition, about the part of the same structure as said 1st embodiment, the same code | symbol is used and description is abbreviate | omitted.

  The core 21 according to the present embodiment has a welded portion on the outer peripheral surface of the annular base 2. On the outer peripheral surface of the partial annular base 5 of each partial core 24, the joint protrusions 10 are provided at both ends in the circumferential direction. The joining cores 10 of one partial core 24 and the joining projection 10 of the other partial core 24 are brought together and welded to fix the partial cores 24 to each other.

  The core 21 according to this embodiment is fixed to the cores 24 according to the first embodiment without being fastened by the fastening member from the outer peripheral surface (outside of the annular base 2) in the same manner as the core 1 according to the first embodiment. The hysteresis loss caused by the compressive stress from the fastening member is not caused. Therefore, the motor core 21 according to the present embodiment also has an advantage of low iron loss.

  Furthermore, as another embodiment, as shown in FIG. 6, the side surface of the partial annular base portion 5 of the partial core 34 may be provided with a convex portion 35 on one surface and a concave portion 36 on the other surface. Thus, the partial cores 34 are positioned by fitting the convex portion 35 on one side surface of the partial annular base 5 of the partial core 34 into the concave portion 36 of the partial annular base 5 of the other adjacent partial core 34. It becomes easy. The partial cores 34 positioned in this manner can be easily welded together, and work efficiency can be improved.

The perspective view of the core for motors concerning a first embodiment of the present invention is shown. The perspective view of a partial core is shown. The perspective view of two partial cores which welded and fixed the joint convex part of the upper surface of a partial annular base part is shown. The perspective view of the core for motors concerning 2nd embodiment of this invention is shown. The perspective view of two partial cores which welded and fixed the joint convex part of the outer peripheral surface of a partial annular base part is shown. The perspective view of the partial core which concerns on other embodiment is shown.

Explanation of symbols

  1,21 Motor core, 2 Annular base, 3 Coil winding part, 4, 24, 34 Partial core, 5 Partial annular base, 6 Coil winding area part, 7 Circumferential end, 8 Side surface of partial annular base, 9 Upper surface of partial annular base, 10 joint convex portion, 11 contact surface, 35 convex portion, 36 concave portion.

Claims (3)

A core for a motor consisting of a dust core obtained by press molding a magnetic metal powder bound with an insulating binder resin,
The core is composed of a plurality of divided partial cores,
A core for a motor, wherein the outer periphery of the contact surface between the partial cores is welded to fix the partial cores. The motor core according to claim 1,
The core is
An annular base;
A plurality of coil winding portions projecting on the inner side of the annular base portion and wound with a coil;
It consists of multiple partial cores divided in the circumferential direction,
Partial core is
A partial annular base;
Comprising at least one coil winding portion projecting inside the partial annular base,
A motor core, wherein the outer periphery of the contact surface between the partial cores is welded to fix the partial cores together. The motor core according to claim 2,
Provided with joint protrusions at both ends of the partial annular base of the partial core,
A motor core characterized in that a bonding convex portion is welded on an outer periphery of a contact surface between partial cores, and the partial cores are fixed to each other.

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