JP2006042507A - Armature cooling structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent demagnetization of the magnet in a motor. <P>SOLUTION: Between the armatures 1, 2 and the magnet 4 of a motor M, a partition wall member 10 capable of enclosing the armatures 1, 2 and in which at least the surface opposing the magnet 4 is formed of a heat insulating material is provided. The gap between the partition wall member 10 and the armatures 1, 2 is filled with a thermally conductive material 15 and heat is dissipated from the armatures 1, 2 through a frame F. Temperature rise in the motor M is prevented by heat insulation effect of the partition wall member 10 and demagnetization of the magnet 4 is prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in an armature cooling structure in a motor.

  In general, magnets used in motors have the property that the magnetic flux density decreases as the temperature rises. In particular, rare earth magnets such as neodymium magnets have an irreversible decrease that cannot recover to the original magnetic force at high temperatures. It is known to produce magnetism.

  As described above, the demagnetization due to the temperature rise of the magnet leads to the performance deterioration that the output torque of the motor is reduced. Therefore, a proposal for preventing the demagnetization has been made.

  In this proposal, an armature stator is covered with a resin case, and the case is filled with a heat-dissipating resin material (see, for example, Patent Document 1).

In this proposal, the heat generated by the stator windings is transferred to the resin case side through the heat dissipating resin material disposed around the windings, and further, the heat is transferred through the resin case. It is supposed to dissipate outside.
Japanese Patent Laid-Open No. 7-147748 (action column, FIG. 1)

  However, in the above proposal, it can be said that the heat generated by the winding while the motor is driven is dissipated through the resin case, so that it can be prevented that the motor becomes high temperature. There is a fear that there is.

  That is, in the above proposal, heat is dissipated through the case, but naturally the heat generated by the winding is transmitted to the case in the process, and the case raises the temperature of the gas in the motor, that is, the inside of the motor. The temperature rise cannot be prevented.

  Then, since the magnet is demagnetized by the heat transmitted to the magnet due to the temperature rise inside the motor, especially during continuous driving and high rotation range, the torque is reduced and in some cases irreversible demagnetization is caused to cause the motor. There is a risk that the performance of the will deteriorate.

  Therefore, the present invention has been developed to solve the above-described problems, and its object is to prevent demagnetization of the magnet in the motor.

  In order to achieve the above object, the armature cooling structure in the problem solving means of the present invention can seal the armature between the armature of the motor and the magnet, and at least the surface facing the magnet is formed of a heat insulating material. The partition member is provided, and a heat conductive material is filled between the partition member and the armature.

  According to the invention of each claim, the partition member prevents the heat of the armature from being transferred to the magnet, and the heat of the armature is quickly dissipated to the outside of the motor by the heat conductive material. An internal temperature rise is prevented, a magnet temperature rise is prevented, and demagnetization of the magnet can be prevented.

  That is, even if the motor is driven for a long time, the magnet is prevented from becoming hot, so that the durability of the motor is improved and the motor performance is not deteriorated. Even if it is performed, stable torque can be generated.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a motor in which an armature cooling structure according to an embodiment of the present invention is embodied. FIG. 2 is a perspective view of a stator in which an armature cooling structure according to another embodiment is embodied.

  As shown in FIG. 1, the motor M in which the armature cooling structure in one embodiment is embodied includes a rotor R, an armature stator S, and a frame F, and is configured as a so-called brushless motor. .

  In the following, each part will be described in detail. The stator S as an armature is composed of a cylindrical stator core 1 mounted on the inner periphery of a cylindrical frame F and a winding 2 wound around the stator core 1. Yes.

  On the other hand, the rotor R is composed of a shaft 3 and a permanent magnet 4 which is a magnet mounted on the outer periphery of the shaft 3, and both end sides of the shaft 3 are rotated by ball bearings 5 and 6 fitted in the frame F. The permanent magnet 4 is supported by the stator S so as to face the stator S.

  In addition, a partition member 10 that covers the stator S is provided in the motor M. The partition member 10 includes a cylindrical portion 11 that faces the rotor R, and each opening end of the cylindrical portion 11, that is, FIG. A pair of annular portions 12 and 13 extending from the middle upper and lower ends are provided, and the outer peripheral sides of the annular portions 12 and 13 are mounted on the inner periphery of the frame F of the motor M, and the stator S is sealed by the partition member 10. It is said that.

  The partition member 10 is formed of a heat insulating material, and heat generated by the winding 2 when the winding 2 of the stator S is energized is prevented from being transmitted to the rotor R side by the partition member 10. Yes.

  Further, a heat conductive material 15 is filled between the partition wall member 10 and the stator S. That is, the heat generated by the stator core 1 due to a change in magnetic flux or the like and the heat generated by the winding 2 when energized is promptly transmitted to the heat conductive material 15. Since the partition member 10 is formed of a heat insulating material as described above, heat is not easily transmitted to the inner side of the motor M, and is dissipated into the external air through the surface of the frame F.

  Accordingly, in addition to the heat dissipation through the frame F, the temperature rise of the permanent magnet 4 is prevented by preventing the temperature rise of the gas inside the motor M due to the heat insulating effect of the partition member 10, and consequently the permanent magnet. Thus, demagnetization of 4 is prevented.

  That is, even if the motor M is driven for a long time, the permanent magnet 4 is prevented from becoming high temperature, so that the durability of the motor M is improved and the performance of the motor M is not deteriorated. M can generate stable torque even when driven for a long time.

  In addition, since the armature is quickly cooled, the temperature rise of the winding 2 is suppressed, so that the insulation is deteriorated due to a chemical change of the insulating film of the conductive wire forming the winding 2 to cause electric leakage and the like. There is no fear that M itself will be damaged.

  As the heat insulating material, a material having a low thermal conductivity, such as a phenolic resin, can be used, and it is desirable to use the entire partition member 10 as a heat insulating material as in the present embodiment to prevent demagnetization. Although the effect is high, heat transfer to the permanent magnet 4 can be prevented even if the portion formed of the heat insulating material is only the cylindrical portion 11 of the partition wall member 10, that is, the surface facing the rotor R.

  In addition, as described above, the partition member 10 itself is made of a heat insulating material, but a layer formed by applying a heat insulating paint or forming the heat insulating material on the outer surface of the partition member 10, that is, the surface facing the rotor R side. In this case, the temperature increase in the motor M can be prevented and the demagnetization of the permanent magnet 4 can be prevented.

  Furthermore, as the heat conductive substance 15, not only a solid such as a highly heat conductive resin but also a liquid such as oil may be used.

  Next, an armature cooling structure in another embodiment shown in FIG. 2 will be described. In this armature cooling structure, the partition members 20 are respectively provided on the inner peripheral side and the outer peripheral side of the cylindrical stator S configured by the stator core 1 and the winding 2 similar to those in the above-described embodiment. The partition member 20 includes a pair of cylindrical portions 21 and 22 and a pair of annular portions 23 and 24 that extend from the open ends of the cylindrical portions 21 and 22 and seal the inside. The stator S is installed in a sealed state, and the thermal conductive material 15 is filled between the partition wall member 20 and the stator S as in the embodiment.

  More specifically, the stator core 1 of the stator S is mounted on the inner peripheral side of the cylindrical portion 22 of the partition wall member 20, the cylindrical portion 22 is formed of a high thermal conductive resin, and the partition wall members other than the cylindrical portion 22 are further provided. Each part of 20, ie, the cylinder part 21 and the annular parts 23 and 24, is formed of a heat insulating material.

  The partition member 20 and the stator S thus configured are fixed to the inner peripheral side of the motor frame (not shown), and are installed so that the inner peripheral side of the cylindrical portion 21 faces the rotor (not shown). As in the armature cooling structure of the embodiment, the heat generated by the winding 2 and the stator core 1 can be prevented from being transmitted to the inside of the motor.

  In this case, the same effect as that of the above-described embodiment can be obtained, and at the same time, the stator S side can be completely structured separately, so that the motor can be easily assembled and the cost can be reduced.

  In each of the above-described embodiments, the case where the armature cooling structure is applied to the cylindrical armature has been described. In this case, the partition member is provided on the rotor side to seal the armature, and the surface of the partition member facing the magnet is formed of a heat insulating material. If a layer made of a heat insulating material is provided on the surface facing the magnet, the temperature inside the motor can be prevented from rising, and heat can be dissipated outside via the rotor shaft. And can prevent demagnetization of the magnet.

  Further, in order to increase the efficiency of heat dissipated by the armature to the outside, a plurality of fins may be provided on the frame or rotor of the motor to which the armature is connected.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a longitudinal cross-sectional view of the motor with which the armature cooling structure in one embodiment of this invention was embodied. It is a perspective view of the stator by which the armature cooling structure in other embodiment was embodied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator core 2 Winding 3 Shaft 4 Permanent magnets 5 and 6 Ball bearings 10 and 20 Bulkhead members 11, 21, 22 Cylindrical parts 12, 13, 23, 24 Annular part 15 Thermally conductive substance F Frame M Motor R Rotor S Stator

Claims (3)

Provided with a partition member capable of sealing the armature between the armature and the magnet of the motor and having at least a surface facing the magnet formed of a heat insulating material, and a thermally conductive material between the partition member and the armature Armature cooling structure characterized by being filled with. The partition wall member includes a cylindrical portion facing the magnet and a pair of annular portions extending from each opening end of the cylindrical portion, and each annular portion is mounted on the inner periphery of the motor frame or the outer periphery of the rotor. The armature cooling structure according to claim 1, wherein: A partition member is provided with a pair of cylindrical portions respectively disposed on the inner peripheral side and the outer peripheral side of the cylindrical armature, and a pair of annular portions extending from each open end of each cylindrical portion and sealing the inside. The armature cooling structure according to claim 1.

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