JP2001231190A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor in which the space factor of winding and the mechanical strength at the joint of core are enhanced while decreasing the magnetoresistance through a simple structure. SOLUTION: The motor 10 comprises a stator section 11 comprising a core 14 arranged annularly and parts 14a for winding coil projecting inward from the core in the radial direction, and a rotor section 20 comprising a rotor magnet 23 arranged on the radially inside of the core while being supported rotatably wherein the core is divided at a constant angular interval with respect to the central axis thereof and the joint 14b of adjacent divided core segments is welded by means of laser. Protrusions and recesses are provided in the circumferential direction at a part of the joint of each divided core segment such that the protrusions and recesses engage each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inner rotor type motor used as, for example, a power motor.

[0002]

2. Description of the Related Art Conventionally, such an inner rotor type motor is constructed as shown in FIG. FIG.
, The motor 1 comprises a fixedly arranged stator portion 2
And a rotor unit 3 rotatably supported by the stator unit 2.

[0003] The stator portion 2 includes a case 2a and a case 2a.
a, an iron core 2c annularly mounted on the inner peripheral surface of the case 2a, and a winding portion 2d protruding radially inward of the iron core 2c (see FIG. 6). And a coil 2e wound around the coil 2e.

Here, as shown in FIGS. 6 and 7, the iron core 2c is divided into a plurality (six in the illustrated case) at equal angular intervals around the central axis. Each of the divided iron cores 2c has a winding 2d projecting radially inward, and a coil 2e is wound around the winding 2d. Thereby, even if it is not possible to perform the winding operation from the slit portion of the iron core in order to increase the winding space factor in the power motor or the like, the coil is wound on the winding portion 2d of each iron core 2c. After winding 2e, the respective iron cores 2c are joined to each other by laser welding or the like, whereby the iron core 2c having the coil 2e wound around the winding portion 2d is manufactured.

[0005] On the other hand, as shown in FIG. 5, a rotor 3 is rotatably held by a bearing 2b.
a and a cylindrical rotor magnet 3c attached to the rotating shaft 3a via a rotor yoke 3b and facing the winding coil 2e from the radial inside.

According to the motor 1 configured as described above,
By appropriately energizing the winding coil 2e, a magnetic field generated in the winding coil 2e interacts with a magnetic field generated by the rotor magnet 3c and the rotor yoke 3b of the rotor section 3, so that the rotor section 3 can be driven to rotate. Will be.

[0007]

However, in the motor 1 configured as described above, as shown in FIG. 6, the iron core 2c of the stator portion 2 is divided into a plurality in the circumferential direction. After winding the coil 2e around the winding portion 2d of each iron core 2c, the joining portion 2f of each iron core 2c is joined to each other by laser welding. At the time of this laser welding, in order to increase the alignment accuracy and mechanical strength between the joints 2f of the iron core 2c and reduce the magnetic resistance, the joint width of the joints 2f facing each other of the iron core 2c is increased. Is desirable.

On the other hand, for example, the outer diameter is 10 to 30.
When it is desired to increase the number of windings of the coil 2e with respect to the iron core 2c of about mm, as shown in FIG. 8, the joint width (radial width) a of the joint portion of the iron core 2c is 1 to 1. 2m
m. Therefore, in order to reduce the effect of heat on the coil 2e due to laser welding, the depth b of the laser welding is limited to about 0.3 mm. As shown in the drawing, the gap 2g is defined, and the magnetic resistance between the iron cores 2c is increased, and the mechanical strength is reduced and the iron core 2c is easily deformed. For this reason, the case 2a surrounding the iron core 2c is made of metal to reinforce the mechanical strength of the iron core 2c, so that the cost increases and the weight of the entire motor increases. There was a problem.

SUMMARY OF THE INVENTION In view of the above, the present invention provides a motor having a simple structure that increases the space factor of a winding, increases the mechanical strength of an iron core joint, and reduces magnetic resistance. It is intended to be.

[0010]

According to the present invention, there is provided, in accordance with the present invention, an iron core arranged in an annular shape, and a winding part for winding a coil provided to project radially inward from the iron core. ,
And a rotor portion having a rotor magnet disposed radially inward of the iron core and rotatably supported, wherein the iron core is disposed at a constant angular interval with respect to a center axis thereof. Divided, the joint of the adjacent divided iron core is a motor that is welded by laser welding, a part of the joint of each of the divided iron core, This is achieved by a motor characterized in that a protrusion or a recess is provided in the circumferential direction, and the protrusion and the recess are arranged so as to engage with each other.

[0011] According to the above configuration, a protrusion or a recess is provided in a part of the joint of the divided iron cores in the circumferential direction, and the protrusion and the recess engage with each other. When the joints of the divided iron cores are joined at the time of joining the joints of the adjacent divided iron cores, the protrusions and the recesses are formed at the respective joints. They will engage each other. Since the laser light is reliably blocked by the engaged convex and concave portions, the coil is not irradiated with the laser light passing between the joints. Therefore, since the laser welding depth can be sufficiently ensured, the joining portions of the adjacent divided iron cores are securely joined to each other, and the mechanical strength can be sufficiently increased, The magnetic resistance between iron cores can be reduced.

Preferably, in the motor according to the first aspect, the convex portion or the concave portion is arranged on a part of a radially inner side of a joint portion of each of the divided iron cores.

[0013] According to the above configuration, the convex portion or the concave portion includes:
Since it is arranged at a part of the radially inner side of the junction of the divided iron cores, the laser welding depth can be more sufficiently secured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. still,
Since the embodiments described below are preferred specific examples of the present invention, various technically preferred limitations are added.
The scope of the present invention is not limited to these embodiments unless otherwise specified in the following description.

FIGS. 1 to 3 show an inner rotor type motor according to an embodiment of the present invention. In FIG. 1, a motor 10 includes a fixedly arranged stator portion 11,
A rotor unit 20 rotatably supported by the stator unit 11.

The stator portion 11 includes a case 12, bearings 13 attached to both end surfaces of the case 12, and a case 12.
Iron core 14 annularly attached to the inner peripheral surface of
2a (see FIG. 2).
Coil 15 wound around the coil 15).

Here, as shown in FIG. 2, the iron core 14 is divided into six pieces in the illustrated case at equal angular intervals around the central axis. And the divided individual iron cores 14
Each has a winding part 14a protruding inward in the radial direction, and a coil 15 is wound around this winding part 14a. Thereby, even if it is not possible to perform the winding operation from the slit portion of the iron core 14 in order to increase the winding space factor in the power motor or the like, each iron core 14
After the coil 15 is wound around the winding portion 14a of
By joining the joining portions 14b, which are outer ring portions, to each other, the iron core 14 in which the coil 15 is wound around the winding portion 14a is manufactured.

On the other hand, the rotor section 20 is
And a cylindrical rotor magnet 23 attached to the rotating shaft 21 via a rotor yoke 22 and opposed to the winding coil 15 from the inside in the radial direction. I have.

The above configuration is substantially the same as the configuration of the conventional motor 1 shown in FIG. 5, but in the motor 10 according to the embodiment of the present invention, the individual iron cores 14 At the joint 14b to be joined to the iron core 14,
As shown in FIG. 3, the width a in the radial direction is, for example, 1.5.
mm or less, and a concave or convex engaging portion 14c is provided radially inward. The concave portions or convex portions provided on the individual iron cores 14 are configured to engage with each other as shown in FIGS. In addition, the engaging portion 14c of the concave portion or the convex portion has the joint portion 1 extending in the radial direction inside the joint portion 14b with respect to the width in the radial direction, preferably in a region of 50% or more from the radial inside.
4b is formed so as to be shifted in the circumferential direction with respect to the surface of 4b.

Then, at the time of laser welding of the joint portion 14b, as shown by an arrow X in FIG.
By irradiating the laser between the joints 14b of the individual iron cores 14 adjacent to each other, the laser light travels between the joints 14b and hits the engaging portion 14c between the concave and convex portions, thereby blocking the laser light. Is done. Thereby, the joint 14
b, the engaging portion 14 of the concave portion and the convex portion from the radial outer edge.
Laser welding is performed in the region up to c.

In this case, since the laser beam is cut off by the engaging portion 14c between the concave portion and the convex portion, it is not necessary to consider the influence of the heat of the laser welding on the coil 15, and the laser welding depth c is set to be outside the radial direction. From 50% to 95% of the width a
The laser welding of the joint 14b is performed sufficiently so that
b is surely joined. When the laser welding depth is 50% or less, the mechanical strength by welding of the joint 14b is not sufficient, and when the laser welding depth is 95% or more,
Due to the variation, the uneven shape 14c may be melted by welding, and the coil 15 may be irradiated with laser. Here, since laser welding is performed by laser irradiation for about 200 msec using, for example, a 1 kW class high output YAG laser welding machine, distortion of the iron core 14 due to laser welding can be sufficiently suppressed.

The motor 10 according to the embodiment of the present invention
When the coil 15 is appropriately energized as described above, the magnetic field generated in the coil 15 is generated by the rotor magnet 23 and the rotor yoke 22 of the rotor unit 20.
Interacts with the magnetic field of the rotor section to rotate the rotor section 20. In this case, since the joining portions 14b of the individual iron cores 14 are securely joined as described above,
The mechanical strength of the iron core 14 can be sufficiently ensured, and the magnetic resistance between the joints 14b of the individual iron cores 14 can be sufficiently reduced. Therefore, in order to increase the winding space factor, even if the radial width of the joint portion 14b of each iron core 14 is 1.5 mm or less, the magnetic resistance is reduced, so that a small-sized and high-output A motor will be configured. In addition, since the mechanical strength of the iron core 14 is increased, it is not necessary to reinforce the iron core 14 with a case as in the conventional case. And weight reduction can be easily realized.

In the above embodiment, the iron core 14
Is divided into six at equal angular intervals, but is not limited to this.
It is apparent that the present invention can be applied to a case where the iron core is divided into a plurality of parts at equal angular intervals.

[0024]

As described above, according to the present invention, with a simple structure, the space factor of the winding is increased, the mechanical strength of the iron core joint is increased, and the magnetic resistance is reduced. A motor can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a motor according to the present invention.

2A is an end view and FIG. 2B is a perspective view of an iron core in the motor of FIG. 1;

FIG. 3 is a partially enlarged end view showing a joint portion of the iron core of FIG. 2;

FIG. 4 is an enlarged view of a joint of FIG. 3;

FIG. 5 is a schematic sectional view showing a configuration of an example of a conventional motor.

6A is an end view and FIG. 6B is a perspective view of an iron core in the motor shown in FIG. 5;

FIG. 7 is a partially enlarged end view showing a joint portion of the iron core in FIG. 6;

FIG. 8 is an enlarged view of a joint of FIG. 7;

[Explanation of symbols]

10 ... motor, 11 ... stator part, 12 ...
Case, 13 ... bearing, 14 ... iron core, 14a ...
-Winding part, 14b ... joining part, 15 ... coil, 2
0: rotor part, 21: rotating shaft, 22: rotor yoke, 23: rotor magnet

Claims (4)

[Claims] A stator portion having an annularly arranged iron core, a winding portion provided to project radially inward from the iron core for winding a coil, and a radially inner side of the iron core. And a rotor portion having a rotor magnet rotatably supported at the same position, wherein the iron core is divided at a fixed angular interval with respect to a center axis thereof, and each of the divided iron cores is adjacent to each other. The joint of the iron core is welded by laser welding, a part of the joint of the divided iron core is provided with a convex portion or a concave portion in the circumferential direction, respectively, and A motor characterized in that the projection and the recess are arranged so as to engage with each other. 2. The motor according to claim 1, wherein the convex portion or the concave portion is disposed on a part of a radially inner side of the joint portion of each of the divided iron cores. 3. The method according to claim 1, wherein the protrusions or the recesses are arranged in a region of 50% or more from the inside with respect to the radial width of the joint portion of each of the divided iron cores. Motor as described. 4. The motor according to claim 1, wherein the joint portion of each of the divided iron cores is laser welded to a depth of 50% to 95% from the outside with respect to a radial width.