JP2004328965A - Core and stator for motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core and a stator for a motor in which assembling is easy and which can reduce cogging torque and a torque ripple while the output of the motor is maintained high. <P>SOLUTION: The core 1 is split circumferentially at each teeth 3 on which a coil 4 is wound. A cylindrical stator 10 is constituted by combining a plurality of cores 1. The core body 2 of this core 1 has a wedge shape having both side faces 2c, 2d which secure a perimeter L1 having large axial one end 2a side and a perimeter L2 having the small axial other end 2b side. The stator 10 includes the plurality of cores 1. The cores 1 are alternately assembled with the axial one end 2a side and the axial other end 2b side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a motor core and a stator. The motor core and stator of the present invention are suitable for use in a brushless motor.
[0002]
[Prior art]
BACKGROUND ART Conventionally, a motor core and a stator are disclosed in Patent Document 1. This motor core is formed by laminating silicon steel plates, and is divided in the circumferential direction for each tooth around which a coil is wound. Each core includes a core body that forms a part of a cylinder, and teeth that are integral with the core body. The motor stator has a cylindrical shape in which a housing is shrink-fitted to a plurality of cores wound with coils, for example. In this stator, since the coil is wound around the core, other teeth do not hinder the winding of the coil, and the coil can be wound at a high density. Therefore, according to this stator, downsizing of the motor can be realized.
[0003]
[Patent Document 1]
JP-A-9-322439
[Problems to be solved by the invention]
However, in the above-mentioned conventional stator, the housing must be tightly fixed to the plurality of cores around which the coils are wound by shrink fitting or the like. Further, since the core is formed by laminating silicon steel sheets, irregularities in the dimensions of the laminated steel sheet and the like cause irregularities on the end face of the core, and the contact area between the cores is reduced or the cores are varied. As described above, since the contact area between the cores is reduced, the magnetic resistance is increased and the motor output is reduced. In addition, the variation in the contact area between the cores causes the magnetic resistance to fluctuate, increasing the cogging torque and the torque ripple.
[0005]
The present invention has been made in view of the above-described conventional circumstances, and provides a motor core and a stator that are easy to assemble and can reduce cogging torque and torque ripple while maintaining a high motor output. It is an issue to be solved.
[0006]
[Means for Solving the Problems]
The motor core of the present invention is divided in the circumferential direction for each tooth around which the coil is wound, and a plurality of the cores are combined to form a cylindrical motor stator. Of the core body and the teeth integral with the core body, the core body having a large circumferential length at one axial end and a small circumferential length at the other axial end. Characterized by having a wedge shape.
[0007]
The motor stator of the present invention includes a plurality of motor cores, and each of the motor cores is formed in a cylindrical shape by alternately combining one axial end and the other axial end. It is characterized by the following.
[0008]
The core body of the core of the present invention has a wedge shape having two side surfaces that secure a large circumferential length at one axial end and a small circumferential length at the other axial end. Therefore, the stator can be easily arranged by alternately arranging the cores at the one end in the axial direction and the other end in the axial direction in the cylindrical housing, and press-fitting the core at one end in the axial direction having a large circumferential length. Can be assembled. Further, the contact area between the cores is increased, and the variation in the contact area is reduced.
[0009]
Therefore, according to the motor core and the stator of the present invention, the assembling is easy, and the cogging torque and the torque ripple can be reduced while maintaining the motor output high.
[0010]
The core is preferably formed by integrally sintering a magnetic powder. This makes it difficult for unevenness to be generated on the side surface of the core, so that the contact area between the cores is further increased and the variation in the contact area is reduced.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0012]
As shown in FIG. 1, the core 1 of the embodiment comprises a part of a cylinder, a wedge-shaped core body 2, and a tooth 3 formed integrally with the core body 2 and around which a coil 4 is wound. Is done. The core main body 2 has both side surfaces 2c and 2d in which one end 2a in the axial direction secures a large circumferential length L1 and the other end 2b in the axial direction secures a small circumferential length L2.
[0013]
Further, as shown in FIG. 3, the stator 10 of the embodiment is formed in a cylindrical shape by alternately assembling the cores 1 on the one end 2 a side in the axial direction and the other end 2 b side in the axial direction in the cylindrical housing 6. It is configured. However, in FIG. 3, the coil 4 wound around the teeth 3 is omitted.
[0014]
The core 1 and the stator 10 configured as described above are manufactured as follows. First, the magnetic powder is put into a cavity of a molding die and molded, and the obtained molded product is sintered, whereby the core body 2 and the teeth 3 are integrally manufactured. By winding the coil 4 after attaching an insulator (not shown) to the teeth 3, the core 1 shown in FIG. 1 is obtained. In the present embodiment, Nikkaalloy manufactured by Hitachi Powdered Metals is used as the magnetic powder.
[0015]
Next, as shown in FIG. 2, the cylindrical housing 6 is arranged with the axial direction up and down. The plurality of cores 1 are arranged in the housing 6 such that the one end 2a side of the core body 2 is downward and the other end 2b side is upward, and the core body 2 is in contact with the housing 6. Thereafter, the plurality of cores 1 with the one end 2a side of the core body 2 facing upward and the other end 2b side facing downward are press-fitted from above the housing 6 between the cores 1 arranged in the housing 6 as indicated by arrows. . At this time, the side surface 2c of each core 1 in the housing 6 and the side surface 2c of each core 1 above the housing 6 abut. The side surface 2d of each core 1 in the housing 6 and the side surface 2d of each core 1 above the housing 6 abut. However, in FIG. 2, the coil 4 wound around the teeth 3 is omitted. Thus, the stator 10 shown in FIG. 3 is obtained.
[0016]
The core 1 of the present embodiment is divided in the circumferential direction for each tooth 3 around which the coil 4 is wound, and a plurality of the cores 1 are combined to form a cylindrical stator 10. The core body 2 of the core 1 has a wedge shape having two side surfaces 2c and 2d that secure a large circumferential length L1 at one axial end 2a and a small circumferential length L2 at the other axial end 2b. Therefore, in the cylindrical housing 6, each of the cores 1 is arranged alternately at one end 2a in the axial direction and at the other end 2b in the axial direction, and the core 1 at the one end 2a in the axial direction having a large circumferential length L1 is pressed. Thereby, stator 10 can be easily assembled. Further, the contact area between the cores 1 is increased, and the variation in the contact area is reduced.
[0017]
Further, since the core 1 is formed by integrally sintering the magnetic powder, it is difficult to form irregularities on both side surfaces 2c and 2d of the core 1, so that the contact area between the cores 1 is further increased, and Variations in the contact area are also reduced.
[0018]
Therefore, according to the core 1 and the stator 10 of the embodiment, the assembling is easy, and the cogging torque and the torque ripple can be reduced while keeping the motor output high.
[Brief description of the drawings]
FIG. 1 is a perspective view of a core according to an embodiment.
FIG. 2 is an assembly diagram of a stator according to the embodiment.
FIG. 3 is a perspective view of a stator according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Core 2 ... Core main body 2a ... One end 2b ... Other end 2c, 2d ... Side surface L1, L2 ... Perimeter 3 ... Teeth 4 ... Coil 6 ... Housing 10 ... Stator

Claims (3)

In the motor core constituting a cylindrical motor stator by being divided in the circumferential direction for each tooth around which the coil is wound and being combined with a plurality of teeth,
Each core includes a core body that forms a part of a cylinder, and the teeth that are integral with the core body. The core body has a large circumferential length at one axial end and a small circumferential length at the other axial end. A motor core having a wedge shape having both side surfaces for securing the motor core. The motor core according to claim 1, wherein the magnetic powder is formed by integrally sintering magnetic powder. 3. A plurality of motor cores according to claim 1 or 2, wherein each of the motor cores is formed in a cylindrical shape by alternately combining one axial end and the other axial end. Motor stator.

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