JP2006121868A - Coil, coil cassette, and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coil, a coil cassette, and a motor that reduce an eddy current that may occurs to the coil and that make it possible to decrease the number of turns of coil winding. <P>SOLUTION: The coil 1 is made of a rectangular wire 2, which is bent twofold along its longitudinal direction. The motor is formed by winding the coil around teeth 11 with the folded and stacked side thereof facing the rotor side of the motor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a coil and a coil cassette constituting a motor, and a motor including such a coil or coil cassette, and more particularly, a coil capable of reducing eddy currents that can be generated in the coil and reducing the number of windings of the coil. And a motor provided with the coil cassette and the coil or coil cassette.

  One factor that reduces motor efficiency is iron loss, of which eddy current loss is a major factor. To reduce this eddy current loss, stator teeth (iron cores) are composed of laminated iron cores stacked with thin iron plates, and furthermore, the countermeasures from the tooth surface, such as forming the iron core with powder magnetic cores, There is a countermeasure from the coil surface wound around.

  As countermeasures from this coil surface, there is a method of providing a hook on the rotor side end surface to block the magnetic flux entering from the rotor side, a method using a round wire as thin as possible, or a rectangular wire For example, a method using a thinner flat wire can be considered. In addition, since the eddy current generated in the winding is generated particularly on the rotor side of the winding in which the magnetic flux directly enters from the rotor, a measure for preventing the magnetic flux from entering the rotor side of the winding, or the generated eddy current is Measures to reduce as much as possible are necessary.

  Patent Document 1 discloses an invention relating to a coil and a motor using this flat wire. In the coil according to the present invention, the portion of the rectangular wire constituting the coil that faces the slot of the stator is formed so that its thickness decreases from the yoke side toward the rotor side. The rectangular wire wound efficiently is accommodated. For this reason, the space factor of a coil improves and it becomes possible to aim at size reduction of a motor and improvement of motor efficiency.

Japanese Patent No. 326687

  According to the coil disclosed in Patent Document 1, it is possible to increase the space factor, but it is unclear whether eddy current loss can be reduced. Further, in the method of providing a hook on the end surface of the tooth on the rotor side, this hook is an obstacle when the coil bobbin is wound with a wire (flat wire) and is attached to the tooth. The present invention has been made in view of the above-described problems, and in a coil in the case of using a flat wire, a coil and a coil cassette capable of effectively reducing eddy current that can be generated in the coil, and such a coil or It aims at providing the motor provided with the coil cassette. In addition, the present invention provides a coil and a coil cassette, and a motor equipped with such a coil or coil cassette, which can reduce the labor required for forming a coil around teeth by reducing the number of windings of a rectangular wire. For the purpose.

  In order to achieve the above object, a coil according to the present invention is a coil wound around teeth projecting inward in the radial direction of a ring-shaped stator constituting a motor, and the coil comprises a rectangular wire, The flat wire has a portion that is bent in two along its longitudinal direction, and is characterized in that the flat wire is wound around the teeth in a bent state.

  The coil of the present invention is used by bending a rectangular wire having a portion bent in two along the longitudinal direction. As the rectangular wire is made thinner in order to reduce the eddy current loss, the number of windings is increased, so that there is a problem that the manufacturing effort of the coil increases. Therefore, in the present invention, the flat wire is wound around the teeth in a state where the flat wire is folded in two, so that the thickness of the flat wire is reduced, but the winding is substantially performed twice by one winding. The same effect can be obtained.

  In addition, when comparing the combination of two rectangular wires that are substantially bent and two rectangular wires of the same width and thickness by folding the rectangular wire into two, the former In the present invention, the amount of the insulating coating formed around the copper constituting the rectangular wire is reduced. Therefore, the space factor of the coil can be improved, and the motor efficiency can be improved. In addition, the manufacturing method of a flat wire forms the flat wire of predetermined shape with copper, apply | coats the insulating film which consists of enamel etc. around this, and shape | molds it by bending the flat wire into two along the longitudinal direction. be able to.

  Further, another embodiment of the coil according to the present invention is a coil wound around a tooth projecting inward in the radial direction of a ring-shaped stator constituting the motor, the coil comprising a rectangular wire, The flat wire is composed of a part that is folded in two along its longitudinal direction and a part that is not folded, and the part that is folded is wound around the teeth in a folded state. The unfolded part is also wound around the teeth.

  The present invention relates to a coil in the case where one continuous flat wire is composed of a part that is bent in two along its longitudinal direction and a part that is not bent. Here, the thickness of the portion that can be folded into two is formed to be half of the thickness of the portion that cannot be folded, and the portion that can be folded into two is folded by forming the former width twice that of the latter. In this case, all the flat wires have a uniform width and thickness over the longitudinal direction.

  In the coil of the present invention, when the coil is formed around the teeth, it is desirable to arrange a portion that is bent in two at a place where the eddy current loss generated in the coil can be effectively reduced. Since the thickness of the flat wire is relatively thin compared to the thickness of the portion that is not bent, the generated eddy current can be reduced.

  Further, another embodiment of the coil according to the present invention is characterized in that a resin film is formed only on one side from the overlapping center line on the surface where the bent portion is overlapped.

  For example, a resin film is applied around copper to form a rectangular wire, and when the rectangular wire is folded in two, two resin coating layers are formed on the superposed surface. Become. Therefore, in the present invention, in order to make one resin coating layer formed on the overlapping surface, a resin coating is formed in advance only on one side from the center line of the flat wire at the time of coil forming. By doing in this way, it becomes possible to aim at reduction of the amount of resin films.

  The coil cassette according to the present invention is characterized in that the coil is formed by being wound around a coil bobbin mounted around a tooth of a stator.

  The coil cassette here is composed of a coil bobbin and a flat wire wound around the coil bobbin. The coil bobbin is formed in a cylindrical shape so that it can be fitted into the teeth, and it is desirable that at least the end on the rotor side be provided with a flange when the coil bobbin is fitted into the teeth. When the rectangular wire is wound around the coil bobbin, the rectangular wire can be shielded from the magnetic flux entering from the rotor with this scissors. In addition, with this configuration, it is not necessary to provide a hook at the end of the tooth in advance, so that the problem that the hook becomes an obstacle and the coil cassette cannot be mounted on the tooth does not occur.

  The motor according to the present invention is a motor formed by winding the coil around the teeth of the stator, and includes a folding side and a superposition side formed by overlapping a flat wire while folding it into two. The rectangular wire is wound around the teeth of the stator in a posture in which the end face on the overlapping side faces the rotor side at the center of the motor.

  The folding side tends to swell slightly when bent compared to the overlapping side. Therefore, by winding around the teeth with the overlapping side facing the rotor side, the eddy current region generated by the magnetic flux entering from the rotor can be made a narrower region. Therefore, eddy current loss can be further reduced.

  Another embodiment of the motor according to the present invention is a motor in which the coil cassette is mounted around the teeth of the stator, and is overlapped with a folding side formed by overlapping a flat wire while folding it into two. The flat wire is wound around the coil bobbin with the end face on the overlapping side facing the rotor side at the center of the motor.

  The present invention relates to a motor formed by fitting a coil bobbin into a tooth, and the coil bobbin is in a state in which the end surface on the overlapping side of the rectangular wires to be overlapped while being folded in two is directed to the rotor side in the center of the motor As described above, it is possible to further reduce eddy current loss.

  Furthermore, another embodiment of the motor according to the present invention is such that, in the motor, when the rectangular wire is composed of a portion that is bent in two along its longitudinal direction and a portion that is not bent, 2 The portion bent into one is formed so as to come to the rotor side disposed in the center of the motor.

  Since eddy current can occur in a portion of the coil that is closer to the rotor, it is possible to effectively reduce the eddy current loss by arranging the portion that is bent in two to be on the rotor side. It becomes possible.

  In addition, although this invention is embodiment which winds around the teeth or coil bobbin continuously about one flat wire comprised from the part bend | folded in two and the part which is not bend | folded, respectively, It may be an embodiment in which a rectangular wire is used. Also in this case, it is desirable that a rectangular wire that is bent in two is wound around the rotor side, and a rectangular wire that is not bent is wound around the yoke side of the stator.

  As can be understood from the above description, according to the coil, coil cassette and motor of the present invention, it is possible to effectively reduce eddy current loss and reduce the number of windings of a rectangular wire. Therefore, it is possible to satisfy the improvement of the motor efficiency and the reduction of the manufacturing effort of the motor at the same time.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a part of a motor in which a coil of the present invention is wound around a tooth, and FIG. 2 is an enlarged perspective view of a portion II in FIG. 3 shows a perspective view of the coil cassette of the present invention, and FIG. 4 shows a view taken along arrows IV-IV in FIG. FIG. 5 is a perspective view showing another embodiment of the rectangular wire constituting the coil before and after folding the portion to be folded in two. FIG. 6 is a cross-sectional view showing another embodiment of the coil cassette of the present invention. In addition, although the coil of embodiment shown in figure has shown the case of the concentrated winding system, it is not limited to this embodiment, Embodiment of a distributed winding system may be sufficient.

  FIG. 1 is a cross-sectional view of a stator 10 in which a coil 1 is formed around a tooth 11. The coil 1 is formed from a flat wire 2, and the flat wire 2 is wound in a state where it is bent in two along its longitudinal direction. Here, the rectangular wire 2 is wound in a state where the overlapping side is directed to the rotor side disposed in the center of the motor among the folding side and the overlapping side that can be formed by bending the flat wire 2 into two. Yes. The rectangular wire 2 is formed by applying an insulating coating such as enamel around a rectangular wire of a predetermined length formed from copper, for example, to form the rectangular wire 2, and 2 along the longitudinal direction at the center of the rectangular wire 2. It can be molded by simply bending it into one.

  FIG. 2 is an enlarged view of the II part of FIG. 1, and shows a folding side 2a and a superposition side 2b that can be formed by folding the flat wire 2 into two. When the plate material is folded in two, the thickness of the folded side is generally larger than the thickness of the superimposed side. In the figure, the thickness t1 of the overlapping side 2a is thinner than the thickness t2 of the folding side 2b.

  By winding the rectangular wire 2 around the teeth in a state where the overlapping side 2a where the thickness is relatively thin is directed to the rotor side, the passage region of the magnetic flux entering from the rotor side can be further narrowed. As a result, eddy current loss can be reduced. That is, the eddy current loss can be obtained by the following equation.

Here, w is an eddy current loss, k is a proportional constant, t is the thickness of the iron core and the coil, f is the power supply frequency, and _Bm is the maximum magnetic flux density.

  Therefore, when the power supply frequency and the maximum magnetic flux density are constant, the eddy current loss is reduced in proportion to the square of the coil by reducing the thickness of the coil. Therefore, eddy current loss can be reduced by making the thickness of the flat wire as thin as possible. Furthermore, in the present invention, the coil is formed in a state where the flat wire is folded in two while the thickness of the flat wire is reduced, so that it is possible to prevent an increase in the number of windings of the flat wire.

  FIG. 3 shows a coil cassette 4 in which the coil 1 is formed around the coil bobbin 3. In the coil bobbin 3, hooks 31 and 31 are fixed to both ends of a cylindrical body having a through hole 32 into which a tooth is fitted, and the flat wire 2 is wound between the hooks 31 and 31. The outer surface of the formed coil 1 is configured to be accommodated inside the flange 31, and therefore, the coil 1 can be cut off from the magnetic flux entering from the rotor side. FIG. 4 shows a cross-sectional view of the coil cassette 4, which is substantially the same as forming a coil directly around the teeth. However, it is possible to further reduce the manufacturing effort by fitting a separately manufactured coil cassette 4 into the teeth.

  FIG. 5 shows a flat wire 2a composed of a portion 21 that is bent in two and a portion 22 that is not bent. The upper drawing of FIG. 5 shows a state before the bent portion 21 is bent. For example, the thickness t1 of the part 21 to be bent is manufactured to be half of the thickness t2 of the part 22 that cannot be bent, and the width b1 of the part 21 to be bent is twice the width b2 of the part 22 that cannot be bent. Keep it. By bending the portion 21 to be bent into two, a flat wire 2a having a uniform width and thickness over the longitudinal direction can be formed as shown in the lower diagram of FIG.

  FIG. 6 shows a coil cassette 4 a formed by winding the rectangular wire 2 a of FIG. 5 around the coil bobbin 3.

  The flat wire 2a is wound so that the bent portion 21 is on the rotor side (X direction), and the overlapping side is the rotor side.

  The flat wire 2a used here is, for example, an embodiment in which a portion 21 that is bent and a portion 22 that is not bent are alternately and continuously formed in the longitudinal direction, An appropriate flat wire 2a can be used such as an embodiment in which a portion 21 that is bent in the middle of the entire length and a portion 22 that is not bent are connected.

  Furthermore, in FIG. 6, two rectangular wires are used, one is a flat wire that is a part that is bent into two, and the other is a flat wire that is not bent into two. Also good.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention. For example, the resin film on the overlapping surface of the folded portion of the coil can be formed only on one side from the overlapping center line.

The cross-sectional view of a part of a motor in which the coil of the present invention is wound around a tooth. The perspective view which expanded the II part of FIG. The perspective view of the coil cassette of this invention. IV-IV arrow line view of FIG. The perspective view which showed other embodiment of the flat wire which comprises a coil, before and after bending the part folded in two. The cross-sectional view which showed other embodiment of the coil cassette of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Coil, 2 ... Flat wire, 2a ... Overlapping side, 2b ... Bending side, 3 ... Coil bobbin, 4 ... Coil cassette, 10 ... Stator, 11 ... Teeth, 12 ... Yoke, 21 ... Part to be bent, 22 ... Bending Inaccessible part, 31 ... 鍔, 32 ... through hole

Claims (7)

A coil wound around teeth projecting radially inward of a ring-shaped stator constituting the motor,
The coil is formed of a flat wire, and the flat wire has a portion that is bent in two along its longitudinal direction, and is wound around the teeth in a posture in which the flat wire is bent in two. A coil characterized by that. A coil wound around teeth projecting radially inward of a ring-shaped stator constituting the motor,
The coil is composed of a flat wire, and the flat wire is composed of a portion that is bent in two along its longitudinal direction and a portion that is not bent, and the teeth that are bent are folded in two. The coil is wound around the teeth, and the part that cannot be bent is also wound around the teeth.   3. The coil according to claim 1, wherein a resin film is formed only on one side of the overlapping surface of the bent portion from the center line of the overlapping.   A coil cassette, wherein the coil according to any one of claims 1 to 3 is formed by being wound around a coil bobbin mounted around a tooth of a stator. A coil formed by winding the coil according to any one of claims 1 to 3 around teeth of a stator,
The flat wire is wound around the teeth of the stator, with the end face of the overlap side facing the rotor side in the center of the motor, of the folding side and the overlapping side, which can be obtained by folding the flat wire into two. A motor characterized by being made. The coil cassette according to claim 4, wherein the motor is mounted around the teeth of the stator,
The flat wire is wound around the coil bobbin with the end face on the overlapping side facing the rotor side in the center of the motor, of the folding side and the overlapping side, which can be created by folding the flat wire into two. A motor characterized by   When the flat wire is composed of a portion that is bent in two along its longitudinal direction and a portion that is not bent, the portion that is bent in two is on the rotor side disposed in the center of the motor. The motor according to claim 5 or 6, wherein the motor is formed so as to be formed.

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