JP2003219598A - Outer rotor type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer rotor type motor, having a bearing holder made from an insulating material, where the static electricity produced at a rotary shaft or a bearing is discharged at a low cost. <P>SOLUTION: A stator iron core 2, provided on the outer perimeter of a cylindrical bearing holder 1 of insulating material, is wound with a coil to constitute a stator 4. A rotary shaft 6 rotatably penetrates a bearing holder 1 via a bearing 5. The rotary shaft 6 supports a rotor yoke 8, and a permanent magnet 10 is fixed along the inner periphery of the rotor yoke 8 to constitute a rotor 11. A coil insulating layer 12 covering the plate surface of stator iron core 2 is protruded like a flange on the outer periphery of the bearing holder 1. A conductive layer 19 is provided from the inner surface of the bearing holder 1, contacting the bearing 5 to the surface of the coil insulating layer 12, and the conductive layer 19 is grounded. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer rotor type electric motor.

[0002]

2. Description of the Related Art A conventional outer rotor type electric motor is shown in FIG.
As shown in FIG. 1, a stator iron core 2 is supported on the outer periphery of a cylindrical bearing holder 1 made of an insulating material, and a coil 3 is wound around a salient pole of the stator iron core 2.
The stator 4 is configured to include and. A rotary shaft 6 is rotatably passed through the bearing holder 1 via a bearing 5. On the rotating shaft 6 protruding outside the bearing holder 1,
A cup-shaped rotor yoke 8 that surrounds and rotates the stator 4 is supported via a boss 9, and a permanent magnet 10 is fixed to the inner circumference of the rotor yoke 8 so as to face the salient poles of the stator iron core 2. Rotor 1 including 10 and
1 is configured. The coil 3 is wound around the salient pole of the stator core 2 via the coil insulating layer 12.

A mounting member 15 for mounting the stator 4 on the support 13 with screws 14 is mounted on the stator 4. The fitting 15 has an inner circumference fitted in a recess 16 on the outer circumference of the bearing holder 1 and is fixed to the stator 4 by being fastened with a screw 17 penetrating the coil insulating layer 11 and the stator core 2.

Between the stator 4 and the mounting member 15,
A controller 18 that controls the energization of the coil 3 is arranged and attached to the stator 4 and the mounting member 15.

Reference numeral 20 is a gear attached to the rotary shaft 6.

[0006]

In the outer rotor type electric motor having such a structure, when the rotating shaft 6 is supported by the bearing 5 and rotates as the rotor 10 rotates, the bearing holder 1
Since it is formed of an insulating material, there is a problem that static electricity is generated in the rotating shaft 6 and the bearing 5. When the discharge is generated by such static electricity, there is a problem that the electronic component is broken or malfunctions when the discharge voltage is applied to an electronic component having a withstand voltage of several tens of V although it depends on the discharge path.
Even if the discharge voltage is not directly applied to the electronic parts, there is a problem that malfunction occurs as noise of the power supply and the signal system.
Furthermore, depending on the installation location, it may cause an explosion or fire, which is not preferable.

An object of the present invention is to provide an outer rotor type electric motor in which a bearing holder is formed of an insulating material and, when static electricity is generated on a rotating shaft, a bearing or the like, the static electricity can be dissipated at low cost. It will be.

[0008]

According to the present invention, a stator iron core is supported on the outer periphery of a cylindrical bearing holder made of an insulating material, and a coil is wound around a salient pole of the stator iron core. The stator is configured to include, the rotary shaft is rotatably passed through the bearing in the bearing holder,
A cup-shaped rotor yoke that surrounds the stator and rotates is supported by a rotating shaft that extends outside the bearing holder, and a permanent magnet is fixed to the inner circumference of the rotor yoke so as to face the salient poles.
The target is an outer rotor type electric motor in which a rotor is configured to include a rotor yoke and a permanent magnet.

In the outer rotor type electric motor according to the present invention, a coil insulating layer covering the plate surface of the stator core is provided on the outer circumference of the bearing holder so as to project like a collar, and extends from the inner surface of the bearing holder in contact with the bearing to the surface of the coil insulating layer. A conductive layer is provided and the conductive layer is grounded.

According to such an outer rotor type motor, when static electricity is generated in the rotating shaft, the bearing, etc., the static electricity passes through the conductive layer provided from the inner surface of the bearing holder in contact with the bearing to the surface of the coil insulating layer. Flowed to the ground side. Since this conductive layer is not a separate component, it can be formed at low cost. Therefore, according to the present invention, even if static electricity is generated on the rotating shaft, the bearing, etc., it can be released at low cost.

In this case, the conductive layer can be formed at low cost by using a plating layer or a coating layer. Further, when the conductive layer is formed by a plating layer or a coating layer, the conductive layer can be thinly formed, and the influence on the concentricity of the bearing is small, which is preferable.

Further, it is preferable that the conductive layer is provided on the entire circumference of the inner surface of the bearing holder which is in contact with the bearing without deteriorating the concentricity of the bearing.

Further, it is preferable that the conductive layer is grounded through a screw that penetrates the conductive layer, the coil insulating layer, and the stator core to fix the mounting member, and the mounting member. With this configuration, the grounding can be easily performed by using the existing member.

[0014]

1 and 2 show an example of an embodiment of an outer rotor type electric motor according to the present invention, in which FIG. 1 is a vertical half view of an outer rotor type electric motor of the present embodiment,
FIG. 2 is a perspective view of the installation location of the conductive layer of the main part of this example.
The parts corresponding to those in FIG. 4 described above are denoted by the same reference numerals.

In the outer rotor type electric motor of the present example, FIG.
As shown in FIG. 3, a coil insulating layer 12 that covers the plate surface of the stator iron core 2 is provided on the outer periphery of the bearing holder 1 made of an insulating material so as to project like a collar. The coil insulating layer 12 can be formed together when the bearing holder 1 is molded with an insulating resin while the stator core 2 is positioned. As shown in FIGS. 1 and 2, a conductive layer 19 is provided from the inner surface of the bearing holder 1 in contact with the bearing 5 to the surface of the coil insulating layer 12. The conductive layer 19 is formed of a plating layer or a coating layer. The conductive layer 19 is grounded. In this example, the conductive layer 19 is grounded through the screw 17 that penetrates the conductive layer 19, the coil insulating layer 12, and the stator core 2 to fix the mounting member 15, and the mounting member 15.

According to such an outer rotor type motor, when static electricity is generated on the rotary shaft 6, the bearing 5, etc., the static electricity is provided from the inner surface of the bearing holder 1 in contact with the bearing 5 to the surface of the coil insulating layer 12. It is made to flow to the ground side through the conductive layer 19 which exists. Since the conductive layer 19 is not a separate component, it can be formed at low cost. Therefore, according to the present invention, even if static electricity is generated in the rotating shaft 6, the bearing 5, etc., it can be dissipated at low cost.

In this case, the conductive layer 19 can be formed at low cost by forming it by a plating layer or a coating layer.

Further, if the conductive layer 19 is grounded through the screw 17 for fixing the mounting member 15 through the conductive layer 19, the coil insulating layer 12, and the stator core 2, the existing mounting member 15 is used. Grounding can be easily performed using the member.

FIG. 3 shows a conductive layer 1 provided from the inner surface of the bearing holder 1 in contact with the bearing 5 to the surface of the coil insulating layer 12.
It is a perspective view showing other examples of how to provide 9.

Unlike the case of FIG. 2, the conductive layer 19 of this example is provided on the entire circumference of the inner surface of the bearing holder 1 which is in contact with the bearing 5.

With such a structure, the static electricity generated by the rotation of the rotary shaft 6 can be collected and grounded more efficiently.

[0022]

According to the outer rotor type electric motor of the present invention, when static electricity is generated on the rotating shaft or the bearing, the static electricity is provided from the inner surface of the bearing holder which is in contact with the bearing to the surface of the coil insulating layer. It can flow through the layers to the ground side. Since this conductive layer is not a separate component, it can be formed at low cost. Therefore, according to the present invention,
Even if static electricity is generated on the rotating shaft or the bearing, it can be dissipated at low cost.

In this case, if the conductive layer is formed of a plating layer or a coating layer, it can be formed at low cost. Further, when the conductive layer is formed by a plating layer or a coating layer, the conductive layer can be thinly formed, and the influence on the concentricity of the bearing is small, which is preferable.

Further, it is preferable that the conductive layer is provided on the entire circumference of the inner surface of the bearing holder which is in contact with the bearing without deteriorating the concentricity of the bearing.

Further, if the conductive layer is grounded through a screw that penetrates the conductive layer, the coil insulating layer, and the stator iron core to fix the fitting, and the fitting is used, the existing member is used for grounding. It can be done easily.

[Brief description of drawings]

FIG. 1 is a vertical half-sectional view showing an example of an embodiment of an outer rotor type electric motor according to the present invention.

FIG. 2 is a perspective view of an installation location of a conductive layer of a main part of this example.

FIG. 3 is a perspective view showing another example of how to install a conductive layer.

FIG. 4 is a vertical half-sectional view of a conventional outer rotor type electric motor.

[Explanation of symbols]

1 Bearing holder 2 Stator core 3 coils 4 stator 5 bearings 6 rotation axes 8 rotor yoke 9 Boss 10 permanent magnet 11 rotor 12 Coil insulation layer 13 Support 14 screws 15 Mounting bracket 16 recess 17 screws 18 Controller 19 Conductive layer

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J101 AA01 AA42 AA62 BA54 BA56                       FA11 GA24                 5H605 AA00 AA07 BB05 BB19 CC03                       CC04 EA06 EB10 EB17 EB30                       GG10                 5H607 AA00 BB01 BB07 BB14 BB17                       CC01 DD02 DD03 DD16 GG08                 5H621 BB07 GA01 GA04 HH01 JK19

Claims (5)

[Claims] 1. A stator iron core is supported on the outer periphery of a cylindrical bearing holder made of an insulating material, a coil is wound around a salient pole of the stator iron core, and a stator is formed including the stator iron core and the coil. A rotating shaft is rotatably passed through the bearing holder via a bearing, and a cup-shaped rotor yoke that rotates to surround the stator is supported on the rotating shaft protruding outside the bearing holder. In an outer rotor type electric motor in which a permanent magnet is fixed to the inner circumference of a rotor yoke so as to face the salient poles, and a rotor is configured to include the rotor yoke and the permanent magnet, coil insulation covering a plate surface of the stator core. A layer is projected on the outer circumference of the bearing holder in a flange shape, and a conductive layer is provided from the inner surface of the bearing holder in contact with the bearing to the surface of the coil insulating layer. An outer rotor type electric motor in which the conductive layer is grounded. 2. The outer rotor type electric motor according to claim 1, wherein the conductive layer is formed of a plated layer. 3. The outer rotor type electric motor according to claim 1, wherein the conductive layer is formed of a coating layer. 4. The outer rotor type electric motor according to claim 1, wherein the conductive layer is provided on the entire circumference of the inner surface of the bearing holder that is in contact with the bearing. 5. The grounding of the conductive layer is performed through a screw that penetrates the conductive layer, the coil insulating layer, and the stator core to fix a mounting metal, and the mounting metal. The outer rotor type electric motor according to 2, 3, or 4.