KR20160004547A - Motor - Google Patents

Abstract

Provided is a motor for preventing electric corrosion of a bearing supporting a rotary shaft of a motor. The motor comprises: a housing having a predetermined space formed by combining a front housing and a rear housing; a stator which is fixated in the housing and has a stator coil wound by coil; a rotor configured to rotate by electromagnetically interacting with the stator; a rotary shaft coupled to the rotor to be rotated with the rotor; a front end bearing and a rear end bearing respectively interposed between the rotary shaft and the front housing and between the rotary shaft and the rear housing so as to support the rotary shaft to be rotatable; and a current carrying unit provided to electrically short-circuit an inner ring and an outer ring of at least one bearing between the front end bearing and the rear end bearing.

Description

Motor {Motor}

Disclosed is an improved motor for preventing the bearing of a motor supporting the rotation axis of the motor from being transferred.

A motor is a machine that obtains rotational force from electric energy, and has a stator and a rotor. The rotor is configured to interact electromagnetically with the stator and is rotated by a force acting between the magnetic field and the current flowing in the coil.

The motor includes a housing, a rotor provided inside the housing and having a plurality of magnets mounted on an annular yoke and having a rotation shaft coupled to the center, a stator for generating a rotational driving force for the rotor, and a stator for rotatably supporting the rotation shaft And a bearing interposed between the rotary shaft and the housing. At this time, the bearings are respectively installed on the front side and the rear side of the rotary shaft for stably supporting the rotary shaft.

However, there is a problem in that when the motor is driven as described above, electric current (electrical corrosion) occurs in the motor. That is, since the inner ring of the bearing is driven in contact with the rotating shaft composed of a conductive metal, a potential difference occurs between the inner ring and the outer ring of the bearing, thereby causing corrosion in the outer ring. For example, when the preload of the bearing is changed due to internal or external factors of the motor, or a surge voltage generated when power is supplied to the motor causes a spark between the inner ring and the outer ring of the bearing, There are various reasons for the occurrence of the whole ceremony.

There is a problem that when the motor is driven, the noise is generated and the durability is lowered due to breakage of the bearing by the electric motor.

One aspect of the present invention provides a motor for preventing the bearing of the motor from rotating.

According to an aspect of the present invention, there is provided a motor including: a housing having a front housing and a rear housing coupled to each other and having a predetermined space therein; A stator fixed in the housing and having a stator core in which a coil is wound; A rotor configured to electromagnetically interact with the stator to rotate; A rotating shaft coupled to the rotor to rotate with the rotor; A front end bearing and a rear end bearing interposed between the rotary shaft and the front housing and between the rotary shaft and the rear housing to rotatably support the rotary shaft; And a conductive unit electrically shorting the inner ring and the outer ring of the bearing of at least one of the front end bearing and the rear end bearing.

The power transmission unit may be made of a wire or an electrically conductive material. One end of the power transmission unit may be connected to the outer ring of the front end bearing, and the other end may be connected to the stator core.

The power transmission unit according to an aspect of the present invention may include a first connection unit for electrically connecting the outer ring of the front end bearing to the stator core and a second connection unit for connecting the stator core and the rear housing .

Wherein the first connection portion and the second connection portion are made of a conductive wire or a metal material, one end of the first connection portion is connected to the outer ring of the front end bearing, the other end is connected to the stator core, May be connected to the stator core and the other end may be connected to the rear housing.

According to an aspect of the present invention, there is provided a power supply unit including: a first connection unit that electrically connects an outer ring of the front end bearing to a printed circuit board provided in the housing; and a second connection unit that connects the printed circuit board and the stator core And a connecting portion.

Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal member, one end of the first connection portion is connected to an outer ring of the front end bearing, the other end is connected to a terminal of the printed circuit board, One end of the connection portion may be connected to the terminal of the printed circuit board and the other end may be connected to the stator core.

According to another aspect of the present invention, there is further provided a bearing cover of a conductive material which is provided between the front end bearing and the front housing and surrounds the outer ring of the front end bearing, wherein the first connection portion and the second connection portion are conductive Wherein one end of the first connection part is connected to the bearing cover and the other end is connected to a terminal of the printed circuit board and one end of the second connection part is connected to a terminal of the printed circuit board And the other end may be connected to the stator core.

According to an aspect of the present invention, there is provided a power supply unit including: a first connection part for electrically connecting an outer ring of the front end bearing to a printed circuit board provided in the housing; and a second connection part for connecting the printed circuit board and the rear housing, And a connecting portion.

Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal member, one end of the first connection portion is connected to an outer ring of the front end bearing, the other end is connected to a terminal of the printed circuit board, One end of the connection portion may be connected to the terminal of the printed circuit board and the other end may be connected to the rear housing.

According to another aspect of the present invention, there is further provided a bearing cover of a conductive material which is provided between the front end bearing and the front housing and surrounds the outer ring of the front end bearing, wherein the first connection portion and the second connection portion are conductive Wherein one end of the first connection part is connected to the bearing cover and the other end is connected to a terminal of the printed circuit board and one end of the second connection part is connected to a terminal of the printed circuit board And the other end may be connected to the rear housing.

According to the embodiments of the present invention, it is possible to short-circuit the outer ring and the inner ring of the bearing of at least one of the front-end bearing and the rear-end bearing that support the rotation shaft of the motor, thereby preventing the occurrence of electric discharge due to the potential difference between the inner and outer rings.

Accordingly, it is possible to prevent the breakage of the bearing according to the electric drive, to reduce vibration and noise when the motor is driven, and to improve the reliability of the product.

1 is a perspective view showing a configuration of a motor according to a first embodiment of the present invention;
2 is a perspective view illustrating a state where a housing is removed from a motor according to a first embodiment of the present invention;
Fig. 3 is a sectional view of Fig. 1; Fig.
4 is a cross-sectional view of a motor according to a second embodiment of the present invention;
5 is a sectional view showing a motor according to a third embodiment of the present invention;
6 is a cross-sectional view illustrating a motor according to a fourth embodiment of the present invention;
7 is a cross-sectional view of a motor according to a fifth embodiment of the present invention.
8 is a cross-sectional view of a motor according to a sixth embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the construction of a motor according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a state where the housing is removed from the motor, and FIG. 3 is a sectional view of FIG.

1 to 3, a motor 100 includes a housing 110 forming an outer surface of a motor 100, a stator 120 disposed inside the housing 110, And bearings 142 and 142 for rotatably supporting a rotating shaft 131 provided to rotate together with the rotor 130 and the rotor 130 to be disposed.

The housing 110 may include a front housing 112 and a rear housing 114 that are separated in the axial direction of the motor 100. The housing 110 may be formed by a combination of the front housing 112 and the rear housing 114, Space is formed. The rear housing 114 is coupled to the front housing 112 so as to close the opened one side of the front housing 112. [ The front housing 112 is bent and formed so as to surround an outer circumferential surface of a front end bearing 142 to be described later, and the rear housing 114 is bent and formed so as to surround an outer circumferential surface of a rear end bearing 144 described later.

Meanwhile, a printed circuit board 150 is provided in the housing 110 for controlling the rotation of the motor 100 by receiving power.

The stator 120 is provided and fixed in the housing 110. As shown in FIG. 3, the stator 120 may be fixed to the front housing 112. The stator 120 may include a stator core 123, a first insulator 121, a second insulator 122, and a coil 124.

The stator core 123 is formed by stacking iron plates pressed to form the body of the stator 120. A space for receiving the rotor 130 is formed at the center of the stator core 123. That is, the stator core 123 is installed on the inner surface of the front housing 112 so as to surround the rotor 130 at a predetermined distance from the rotor 130. The stator core 123 is also provided with stator slots (not shown) for winding the coils 124 to the stator core 123.

The first insulator 121 and the second insulator 122 are formed of a material having electrical insulation and are respectively disposed on both sides of the stator core 123 with respect to the axial direction. Slots (not shown) are formed in the first insulator 121 and the second insulator 122 at positions corresponding to the stator slots formed in the stator core 123. Thus, the coils 124 are wound on the stator core 123 through the slots of the stator slots and the insulators 121 and 122, respectively.

The rotor 130 includes a rotor core 133 disposed in a space formed in the center of the stator core 123 and a plurality of magnets 134 installed in the rotor core 133. At this time, rotor cores 133 are formed with rotor slots (not shown) for receiving the magnets 134. The magnets 134 are arranged along the circumferential direction of the rotor 130 such that the magnets 134 are positioned radially around the rotating shaft 131 installed at the center of the rotor 130. Although the figure shows an example in which eight magnets 134 are arranged, the number of magnets 134 can be selectively increased or decreased. The magnet 134 may be a ferrite magnet or a magnet including rare earths such as Neodymium or Samarium. This rotor 130 is rotated by electromagnetically interacting with the magnet 134 and the coil 124 wound on the stator 120.

The rotary shaft 131 has a predetermined length and a part of one end of the rotary shaft 131 protrudes outside the housing 110 through the front housing 112 and the other end is provided in the housing 110. A bearing 130 is interposed between the front housing 112 and the rotary shaft 131 and between the rear housing 114 and the rotary shaft 131 for stable rotation of the rotary shaft 131 when the rotary shaft 131 rotates together with the rotor 130 142, and 144 are interposed.

The bearings 142 and 144 are constituted by a front end bearing 142 provided between the front housing 112 and the rotary shaft 131 and a rear end bearing 144 provided between the rear housing 114 and the rotary shaft 131 . Each of the bearings 142 and 144 is made of a ball bearing. The front end bearing 142 and the rear end bearing 144 constituted by the ball bearings have balls 142c and 144c interposed between the outer rings 142a and 144a and the inner rings 142b and 144b and the inner rings 142b and 144b and the outer rings 142a and 144a, And 144c. The structure of such ball bearings is well known and will not be described in detail. The front end bearing 142 and the rear end bearing 144 are provided in a state where the respective inner rings 142b and 144b are in contact with the rotary shaft 131 for supporting the rotary shaft 131. [ If a voltage difference is generated between the outer wheels 142a and 144a and the inner wheels 142b and 144b due to the internal or external factors of the motor 100 when the motor 100 is driven, In order to prevent the occurrence of such electromotive forces, electrical shorts must be maintained between the outer rings 142a and 144a and the inner rings 142b and 144b.

The motor 100 according to the present invention is provided with a conductive part (not shown) for electrically shorting the outer ring 142a, 144a of the bearing of at least one of the front end bearing 142 and the rear end bearing 144 and the inner rings 142b, 210 are provided. The conductive part 210 may be made of conductive wire or metal. Although it is shown that the conductive part 210 is formed of a wire, it is not limited thereto and any structure may be employed as long as the conductive part can perform a conductive function.

According to the first embodiment of the present invention, the conductive unit 210 is formed of electric wires, one end of which is connected to the outer ring 142a of the front end bearing 142, and the other end of which is connected to the stator core 123. That is, the outer ring 142a of the shear bearing 142 is electrically connected to the stator core 123 by the conductive part 210, so that the outer ring 142a and the inner ring 142b are electrically short-circuited. Thus, the electric discharge due to the potential difference between the outer ring 142a and the inner ring 142b is prevented. One end of the conductive portion 210 is inserted between the front housing 112 and the outer ring 142a of the portion surrounding the front end bearing 142 so as to be in contact with the outer ring 142a of the front end bearing 142, And can be connected. The other end of the conductive portion 210 may be inserted into the surface of the stator core 123 or may be connected to the surface.

The structure in which the conductive part 210 is connected to the outer ring 142a of the front end bearing 142 and the stator core 123 is one example of the structure in which the conductive part 210 can be stably contacted, it should be understood that a variety of connection structures, such as soldering or bolting, may be employed.

Hereinafter, a motor according to a second embodiment of the present invention will be described. Like reference numerals in the drawings of the first embodiment shown above denote members having the same function, and a description thereof will be omitted.

4 is a cross-sectional view showing a motor according to a second embodiment of the present invention. 4, the conductive part 220 includes a first connection part 221 for electrically connecting the outer ring 142a of the front end bearing 142 to the stator core 123, And a second connection part 222 for connecting the housing 114 to each other. That is, although the power supply unit 210 according to the first embodiment short-circuits the outer ring 142a and the inner ring 142b of the front end bearing 142, the motor 100 according to the second embodiment includes the power supply unit 220 The outer ring 142a and the inner ring 142b of the front end bearing 142 and the outer ring 144a and the inner ring 144b of the rear end bearing 144 are short-circuited.

The first connection part 221 and the second connection part 222 may be made of conductive wire or metal. Although the first and second connection portions 221 and 222 are shown as being made of electric wires, the present invention is not limited thereto, and any structure can be employed as long as the conductive portion can perform the conductive function.

The first connecting portion 221 has a structure for connecting the outer ring 142a of the front end bearing 142 and the stator core 123. [ That is, the connection structure of the first connection part 221 according to the present embodiment is the same as the connection structure of the conductive part 210 of the first embodiment, and a detailed description thereof will be omitted.

The second connection portion 222 may have one end connected to the stator core 123 and the other end connected to the rear housing 114. The outer ring 144a of the rear end bearing 144 is electrically connected to the stator core 123 through the second connection portion 222 as it is in contact with the rear housing 114 so as to be electrically connected to the outer ring 144 of the rear end bearing 144 144a and the inner ring 144b are electrically short-circuited. Thus, the electric discharge due to the potential difference between the outer ring 144a and the inner ring 144b is prevented. One end of the second connection portion 222 may be inserted or connected to the stator core 123 and the other end may be directly connected to the rear housing 114 or may be attached and connected by a conductive adhesive.

The connection structure of the first connection portion 221 and the second connection portion 222 may be a soldering or a soldering process as long as the first and second connection portions 221 and 222 can stably contact the first connection portion 221 and the second connection portion 222. [ It is understood that a variety of connection structures, such as bolting, can be employed.

Hereinafter, a motor according to a third embodiment of the present invention will be described. The same reference numerals as those in the drawings denote the same elements, and a description thereof will be omitted.

5 is a cross-sectional view of a motor according to a third embodiment of the present invention. 5, the conductive unit 230 includes a first connection portion 231 for electrically connecting the outer ring 142a of the front end bearing 142 to the printed circuit board 150, a stator core 123, And a second connection part 232 connecting the printed circuit board 150 to the printed circuit board 150.

The first connection part 231 and the second connection part 232 may be made of conductive wire or metal. Although the first connection part 231 is shown as an electric wire and the second connection part 232 is shown as a terminal pin, the present invention is not limited thereto. It is possible.

One end of the first connection portion 231 may be connected to the outer ring 142a of the front end bearing 142 and the other end may be connected to the printed circuit board 150. One end of the first connection portion 231 is inserted between the front housing 112 and the outer ring 142a of the portion surrounding the front end bearing 142 so as to be in contact with the outer ring 142a of the front end bearing 142, And can be connected. The other end of the first connection portion 231 may be connected to the terminal of the printed circuit board 150 by soldering.

The second connection portion 232 may be formed of a terminal pin, one end thereof may be connected to the printed circuit board 150, and the other end thereof may be connected to the stator core 123. One end of the second connection portion 232 may be connected to the terminal of the printed circuit board 150 by soldering and the other end may be inserted into the stator core 123 and connected thereto. That is, the stator core 123 and the printed circuit board 150 are electrically connected by the second connection portion 232, and the first connection portion 231 connects the printed circuit board 150 and the outer ring of the front end bearing 142 The outer ring 142a and the inner ring 142b are electrically short-circuited. Thus, the front end bearing 142 is prevented from being turned on by the potential difference between the outer ring 142a and the inner ring 142b.

Meanwhile, although not shown, the second connection portion 232 may be formed of a wire to electrically connect the stator core 123 and the printed circuit board 150.

Hereinafter, a motor according to a fourth embodiment of the present invention will be described. The same reference numerals as those in the drawings denote the same elements, and a description thereof will be omitted.

6 is a cross-sectional view illustrating a motor according to a fourth embodiment of the present invention. 6, the conductive part 240 includes a first connection part 241 for electrically connecting the outer ring 142a of the front end bearing 142 to the printed circuit board 150, And a second connection part 242 connecting the rear housing 114 to the first housing part.

The first connection part 241 and the second connection part 242 may be made of conductive wire or metal. Although the first connection part 241 is shown as an electrical wire and the second connection part 242 is shown as a terminal pin, the present invention is not limited thereto. It is possible.

The first connection portion 241 has a structure for connecting the outer ring 142a of the front end bearing 142 to the printed circuit board 150. [ That is, the connection structure of the first connection portion 241 according to the present embodiment is the same as the connection structure of the first connection portion 231 of the third embodiment, and a detailed description thereof will be omitted.

One end of the second connection portion 242 may be connected to the printed circuit board 150 and the other end may be connected to the rear housing 114. One end of the second connection portion 144 may be connected to a terminal of the printed circuit board 150 by soldering and the other end may be connected to the rear housing 114 by a conductive adhesive and connected thereto or may be connected by soldering. The outer ring 142a of the front end bearing 142 is electrically connected to the printed circuit board 150 by the first connection portion 241 and the outer ring 144a of the rear end bearing 144 is electrically connected to the second connection portion 242, The outer rings 142a and 144a and the inner rings 142b and 144b of the front end bearing 142 and the rear end bearing 142 are short-circuited due to the electrical connection between the rear housing 114 and the printed circuit board 150 through the through- The front wheels 142a and 144a and the inner rings 142b and 144b are prevented from being turned on by a potential difference.

Meanwhile, although not shown, the second connection portion 242 may be formed of a wire to electrically connect the rear housing 114 and the printed circuit board 150.

Hereinafter, a motor according to a fifth embodiment of the present invention will be described. The same reference numerals as those in the drawings denote the same elements, and a description thereof will be omitted.

7 is a cross-sectional view illustrating a motor according to a fifth embodiment of the present invention. 7, the bearing unit 160 further includes a bearing cover 160 provided between the front end bearing 142 and the front housing part 112. The conductive part 250 is disposed between the outer circumference 142a of the front end bearing 142 and the outer circumference 142b of the front end bearing 142, A first connection portion 251 for electrically connecting the circuit board 150 and a second connection portion 252 for connecting the stator core 123 and the printed circuit board 150 may be provided.

The first connection part 251 and the second connection part 252 may be made of conductive wire or metal. Although the first connection part 251 is shown as an electrical wire and the second connection part 252 is shown as a terminal pin, the present invention is not limited thereto. It is possible.

At this time, the bearing cover 160 is provided to surround the outer ring 142a of the front end bearing 142 and is coupled to the front housing 112. The bearing cover 160 serves to support the shear bearing 142 so that the rotary shaft 131 can rotate more stably when the motor 100 is driven. The bearing cover 160 is made of a conductive material so that the outer ring 142a and the inner ring 142b are short-circuited through the conductive part 250 in contact with the outer ring 142a.

The first connection portion 251 may have one end connected to the bearing cover 160 and the other end connected to the printed circuit board 150. One end of the first connection portion 251 may be directly connected to the bearing cover 160, or may be connected by bolting or a conductive adhesive. The other end of the first connection portion 251 may be connected to the terminal of the printed circuit board 150 by soldering.

The second connection portion 252 may have one end connected to the printed circuit board 150 and the other end connected to the stator core 123. One end of the second connection portion 252 may be connected to the terminal of the printed circuit board 150 by soldering and the other end may be inserted into the stator core 123 and connected. That is, the stator core 123 and the printed circuit board 150 are electrically connected by the second connection portion 252, and the printed circuit board 150 and the bearing cover 160 are electrically connected to each other by the first connection portion 251 The outer ring 142a and the inner ring 142b of the shear bearing 142 are electrically short-circuited. Thus, the front end bearing 142 is prevented from being turned on by the potential difference between the outer ring 142a and the inner ring 142b.

Meanwhile, although not shown, the second connection portion 252 may be formed of a wire to electrically connect the stator core 123 and the printed circuit board 150.

Hereinafter, a motor according to a sixth embodiment of the present invention will be described. The same reference numerals as those in the drawings denote the same elements, and a description thereof will be omitted.

8 is a cross-sectional view of a motor according to a sixth embodiment of the present invention. 8, the bearing unit 160 further includes a bearing cover 160 provided between the front end bearing 142 and the front housing 112. The conductive unit 260 is disposed between the outer circumference 142a of the front end bearing 142 and the front end bearing 142, A first connecting portion 261 for electrically connecting the circuit board 150 and a second connecting portion 26 for connecting the printed circuit board 150 and the rear housing 114 to each other.

The first connection part 261 and the second connection part 262 may be made of an electrically conductive wire or a metal material. Although the first connection part 261 is shown as an electrical wire and the second connection part 262 is shown as a terminal pin, the present invention is not limited thereto, and any structure may be employed as long as it can perform a conductive function. It is possible.

The first connection portion 261 has a structure that connects the bearing cover 160 and the printed circuit board 150. That is, the connection structure of the first connection portion 261 according to this embodiment is the same as the connection structure of the first connection portion 251 of the fifth embodiment, and a detailed description thereof will be omitted.

Further, the bearing cover 160 is the same as the member of the fifth embodiment described above, and a description thereof will be omitted.

One end of the second connection portion 262 may be connected to the printed circuit board 150 and the other end may be connected to the rear housing 114. One end of the second connection portion 262 may be connected to the terminal of the printed circuit board 150 by soldering and the other end may be connected to the rear housing 114 by a conductive adhesive and connected thereto or may be connected by soldering.

That is, the outer ring 142a of the front end bearing 142 is electrically connected to the printed circuit board 150 by the first connection portion 261 connected to the bearing cover 160, and the outer ring 144a of the rear end bearing 144, 144a of the front end bearing 142 and the rear end bearing 144 and the inner ring 142b of the rear end bearing 144 as the rear housing 114 and the printed circuit board 150 are electrically connected through the second connection portion 262. [ And 144b are short-circuited to prevent the electromotive force due to the potential difference between the outer rings 142a and 144a and the inner rings 142b and 144b.

Although not shown, the second connection portion 262 may be formed of a wire to electrically connect the rear housing 114 to the printed circuit board 150.

The connection between the outer ring 142a and the inner ring 142b of the front end bearing 142 and the rear end bearing 144 of the power transmission parts 210, 220, 230, 240, 250 and 260 of the above- The electric wires connected to the outer ring 142a and the inner ring 144b of the bearing 142a and 144b are electrically connected to each other through the housing 110. However, 144a and the inner rings 142b, 144b can be short-circuited. For example, the wires may be embedded in the housing 110 by an insert molding method.

The foregoing has shown and described specific embodiments. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. The present invention is not limited thereto.

100: motor 110: housing
112: front housing 114: rear housing
120: stator 123: stator core
130: Rotor 131:
142: shearing bearing 142a: outer ring
142b: inner ring 144: rear end bearing
144a: outer ring 144b: inner ring
150: printed circuit board 160: bearing cover
210, 220, 230, 240, 250, 260:
221, 231, 241, 251, 261:
222, 232, 242, 252, 262:

Claims (10)

A housing coupled to the front housing and the rear housing to define a predetermined space therein;
A stator fixed in the housing and having a stator core in which a coil is wound;
A rotor configured to electromagnetically interact with the stator to rotate;
A rotating shaft coupled to the rotor to rotate with the rotor;
A front end bearing and a rear end bearing interposed between the rotary shaft and the front housing and between the rotary shaft and the rear housing to rotatably support the rotary shaft; And
And a conductive part electrically connected to the inner ring and the outer ring of the bearing of at least one of the front end bearing and the rear end bearing. The method according to claim 1,
Wherein the conductive portion is made of a conductive wire or a conductive material,
Wherein one end of the conductive portion is connected to the outer ring of the front end bearing and the other end is connected to the stator core. The method according to claim 1,
The power-
A first connecting portion for electrically connecting the outer ring of the front end bearing to the stator core; and a second connecting portion for connecting the stator core and the rear housing. The method of claim 3,
Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal material,
One end of the first connection portion is connected to the outer ring of the front end bearing and the other end is connected to the stator core,
Wherein one end of the second connection portion is connected to the stator core and the other end is connected to the rear housing. The method according to claim 1,
The power-
A first connection part electrically connecting an outer ring of the shear bearing to a printed circuit board provided in the housing; and a second connection part connecting the printed circuit board and the stator core. 6. The method of claim 5,
Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal material,
One end of the first connection portion is connected to the outer ring of the front end bearing and the other end is connected to a terminal of the printed circuit board,
Wherein one end of the second connection portion is connected to a terminal of the printed circuit board and the other end is connected to the stator core. 6. The method of claim 5,
And a bearing cover provided between the front end bearing and the front housing and surrounding the outer ring of the front end bearing,
Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal material,
One end of the first connection portion is connected to the bearing cover and the other end is connected to a terminal of the printed circuit board,
Wherein one end of the second connection portion is connected to a terminal of the printed circuit board and the other end is connected to the stator core. The method according to claim 1,
The power-
A first connection part electrically connecting the outer ring of the shear bearing to a printed circuit board provided in the housing; and a second connection part connecting the printed circuit board and the rear housing. 9. The method of claim 8,
Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal material,
One end of the first connection portion is connected to the outer ring of the front end bearing and the other end is connected to a terminal of the printed circuit board,
Wherein one end of the second connection portion is connected to a terminal of the printed circuit board and the other end is connected to the rear housing. 9. The method of claim 8,
And a bearing cover provided between the front end bearing and the front housing and surrounding the outer ring of the front end bearing,
Wherein the first connection portion and the second connection portion are made of an electrically conductive wire or a metal material,
One end of the first connection portion is connected to the bearing cover and the other end is connected to a terminal of the printed circuit board,
Wherein one end of the second connection portion is connected to a terminal of the printed circuit board and the other end is connected to the rear housing.

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