Stator, motor, and blower

This application claims the benefit of priority to Japanese Patent Application No. 2017-246700 filed on Dec. 22, 2017. The entire contents of this application are hereby incorporated herein by reference.

1. Field of the Invention

The present disclosure relates to a stator, a motor, and a blower.

2. Description of the Related Art

For example, Japanese Patent Laid-open Publication No. 2000-188839 discloses a conventional stator. The stator includes an annular core back, a plurality of teeth extending radially from the core back and being circumferentially arranged, a slot formed between adjacent teeth, and a conducting wire wound around the tooth to form a coil.

The plurality of coils are connected in series, and both ends of the conducting wire are drawn from the different slots to an outside of the stator. A jumper wire extending from one end of the conducting wire toward the coil and a jumper wire returning from the coil to the other end of the conducting wire are disposed on the same path.

However, in the stator disclosed in Japanese Laid-open Patent Application Publication 2000-188839, when the drive current is passed through the conducting wire, a direction of the current passed through the coil and a direction of the current passed through the jumper wire returning from the coil are different from each other. For this reason, inductance of the coil is changed by a magnetic field generated from the jumper wire returning from the coil, which results in uneven rotation of a rotor.

According to an exemplary embodiment of the present disclosure, a stator of a polyphase motor in which in-phase coils are connected in parallel includes a core back having an annular shape; a plurality of teeth extending radially from the core back and arranged circumferentially; a slot between an adjacent pair of the teeth; a conducting wire respectively wound around the teeth to define the coils; and a first connector and a second connector to which one end and the other end of each of the plurality of in-phase coils are connected, respectively. The conducting wire includes one or two jumper wires disposed between each coil and the first connector or the second connector, and at least one jumper wire extends in an identical circumferential direction from the first connector toward the second connector with respect to all the in-phase coils.

Exemplary embodiments of the present disclosure provide stators, motors, and blowers each capable of preventing uneven rotation of a rotor.

The above and other elements, features, steps, characteristics and advantages of the present discloser will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.

FIG. 1 is a perspective view illustrating a blower according to an exemplary embodiment of the present disclosure.

FIG. 2 is an exploded perspective view illustrating a blower according to an exemplary embodiment of the present disclosure.

FIG. 3 is a perspective view illustrating a portion of a motor of a blower according to an exemplary embodiment of the present disclosure.

FIG. 4 is a plan view illustrating a portion of a motor of a blower according to an exemplary embodiment of the present disclosure.

FIG. 5 is an example of a connection diagram illustrating a coil of a blower according to an exemplary embodiment of the present disclosure.

FIG. 6 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 7 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 8 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 9 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 10 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 11 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 12 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 13 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 14 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to an exemplary embodiment of the present disclosure.

FIG. 15 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 16 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 17 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 18 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 19 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 20 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 21 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 22 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

FIG. 23 is an explanatory view illustrating a winding pattern of a conducting wire of a blower according to another exemplary embodiment of the present disclosure.

Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. In the specification, a direction parallel to a center axis of a motor is referred to as an “axial direction”, a direction orthogonal to the center axis of the motor is referred to as a “radial direction”, and a direction along a circular arc having a center on the center axis of the motor is referred to as a “circumferential direction”. In the description of the present disclosure, it is also assumed that an axial direction is defined as a vertical direction, and that a side on which an impeller is disposed with respect to a motor is defined as an upper side. A shape and a positional relationship of each component will be described based on the above assumption. The vertical direction is simply used for the description, but does not limit an actual positional relationship and an actual direction.

A blower according to an exemplary embodiment of the present disclosure will be described. FIGS. 1 and 2 are respectively a perspective view and an exploded perspective view illustrating a blower 1 of the embodiment of the present disclosure.

The blower 1 includes a casing 2 , an impeller 10 , and a motor 50 , and the impeller 10 and the motor 50 are accommodated in an internal space of the casing 2 . The motor 50 is located below the impeller 10 , and rotates the impeller 10 about a center axis J.

The casing 2 is formed into a cylindrical shape, and includes a bottom wall 21 and a peripheral wall 22 . The motor 50 is attached to the bottom wall 21 , and the peripheral wall 22 extends axially upward from a peripheral edge of the bottom wall 21 . An air outlet 22 a is opened to an upper surface of the peripheral wall 22 , and a suction port (not illustrated) is opened to the bottom wall 21 . The motor 50 is attached to the bottom wall 21 .

The impeller 10 includes a cup 11 and a blade 12 . The cup 11 is formed into a closed cylindrical shape, and the motor 50 is disposed in the cup 11 . An insertion hole 11 a is made in a center (on the center axis J) of the cup 11 . A shaft 50 a coupled to a shaft 61 (see FIG. 3 ) of the motor 50 is inserted in the insertion hole 11 a . The shaft 50 a is fixed to a rotor holder 62 (to be described later), and the rotor holder 62 is fixed to the inside of the cup 11 . Consequently, the impeller 10 and the motor 50 are coupled to each other, and the impeller 10 is supported so as to be rotatable about the center axis J.

A plurality of blades 12 are circumferentially arranged at predetermined intervals while extending radially outward from an outer circumferential surface of the cup 11 . The impeller 10 is rotated by drive of the motor 50 , and an airflow flowing from the suction port into the casing 2 is blown out from the air outlet 22 a.

FIGS. 3 and 4 are respectively a perspective view and a top view illustrating a part of the motor 50 . The motor 50 includes a rotor 60 (see FIG. 2 ) and a stator 70 .

The rotor 60 includes a columnar shaft 61 that forms a rotating shaft extending along the center axis J, a rotor holder (see FIG. 2 ), and a rotor magnet (not illustrated). The shaft is supported by a bearing (not illustrated) so as to be rotatable about the center axis J. The rotor holder 62 has a closed cylindrical shape, and is fixed to the inside of the cup 11 . The rotor magnet is fixed to the inner circumferential surface of the rotor holder 62 , and disposed so as to be opposed to the radially outside of the stator 70 .

When the motor 50 is driven, torque is generated between the stator 70 and the rotor magnet. The motor 50 may be either an outer rotor type motor or an inner rotor type motor.

The stator 70 is disposed so as to be radially opposed to the rotor 60 . The stator 70 includes a core back 71 , a tooth T, and a coil C.

The core back 71 is annularly formed around the center axis J, and constructed with a laminated steel plate. The tooth T extends radially outward from the core back 71 , and are circumferentially disposed at equal intervals. Consequently, the stator 70 for the outer rotor type motor is formed, and the motor 50 that prevents rotational unevenness of the rotor 60 to reduce vibration of the rotor 60 can be provided.

The coil C is formed by winding a conducting wire L (see FIGS. 6 to 8 ) around the tooth T with an insulator 72 interposed between the conducting wire L and the tooth T. In the following description, reference numerals T 1 to T 9 are added to the circumferentially-arranged teeth. Reference numerals C 1 to C 9 are added to the coils arranged at the positions corresponding to the teeth T 1 to T 9 . Reference numerals L 1 to L 9 are added to the conducting wires constituting the coils C 1 to C 9 .

A slot 73 being a space is formed between adjacent teeth T 1 to T 9 . For example, terminal pins 76 extending in the axial direction are provided in the slots 73 between the teeth T 2 , T 3 , between the teeth T 3 , T 4 , between the teeth T 5 , T 6 , between the teeth T 6 , T 7 , between the teeth T 8 , T 9 , and between the teeth T 9 , T 1 . An upper end and a lower end of the terminal pin 76 protrude axially from the core back 71 , and the lower end of the terminal pin 76 is mounted on a mounting board 51 (see FIG. 2 ).

The upper end of the terminal pin 76 is connected to first connectors 74 U, 74 V, 74 W and second connectors 75 U, 75 V, 75 W (to be described later).

FIG. 5 illustrates an example of a connection diagram of the coils C 1 to C 9 . The coils C 1 to C 9 are classified into three kinds of coil groups of a U-phase group 90 U, a V-phase group 90 V, and a W-phase group 90 W corresponding to a three-phase AC current. The U-phase group 90 U, the V-phase group 90 V, and the W-phase group 90 W are connected to one another by delta connection.

The U-phase group 90 U is constructed with the coils C 1 , C 4 , C 7 . The V-phase group 90 V is constructed with the coils C 2 , C 5 , C 8 . The W-phase group 90 W is constructed with the coils C 3 , C 6 , C 9 . The coils C 1 to C 9 are circumferentially arranged in order of the U-phase, the V-phase and the W-phase, and the in-phase coils are not adjacent in the circumferential direction (see FIG. 4 ). The phases of the coils C adjacent to each other in the circumferential direction are different from each other, so that the rotational unevenness of the rotor 60 can be prevented to reduce the vibration of the rotor 60 .

The coils C 1 , C 4 , C 7 of the U-phase group 90 U are connected in parallel. One end of each of the coils C 1 , C 4 , C 7 is connected by the first connector 74 U and the other end is connected by the second connector 75 U. The first connector 74 U is connected to the upper end of the terminal pin 76 disposed between the teeth T 5 , T 6 . The second connector 75 U is connected to the upper end of the terminal pin 76 disposed between the teeth T 8 , T 9 (see FIG. 4 ).

The coils C 2 , C 5 , C 8 of the V-phase group 90 V are connected in parallel. One end of each of the coils C 2 , C 5 , C 8 is connected by the first connector 74 V and the other end is connected by the second connector 75 V. The first connector 74 V is connected to the upper end of the terminal pin 76 disposed between the teeth T 9 , T 1 . The second connector 75 V is connected to the upper end of the terminal pin 76 disposed between the teeth T 3 , T 4 (see FIG. 4 ).

The coils C 3 , C 6 , C 9 of the W-phase group 90 W are connected in parallel. One end of each of the coils C 3 , C 6 , C 9 is connected by the first connector 74 W, and the other end is connected by the second connector 75 W. The first connector 74 W is connected to the upper end of the terminal pin 76 disposed between the teeth T 2 , T 3 . The second connector 75 W is connected to the upper end of the terminal pin 76 disposed between the teeth T 6 , T 7 (see FIG. 4 ).

Each of the three in-phase coils C 1 , C 4 , C 7 , the three in-phase coils C 2 , C 5 , C 8 , and the three in-phase coils C 3 , C 6 , C 9 is connected in parallel, so that a resistance value of each coil group can be decreased to improve efficiency and output of the motor 50 as compared with the case that the three in-phase coils are connected in series.

By connecting the coil groups in each of which the three in-phase coils C are connected in parallel by the delta connection, the resistance value of each coil group can be decreased as compared with the case that the coil groups are connected by Y connection. Additionally, because necessity to gather common wires in performing the connection by the Y connection is eliminated, workability of connection is improved and productivity is also improved.

FIGS. 6 to 14 are explanatory views illustrating winding patterns of the conducting wires constituting the U-phase group 90 U, the V-phase group 90 V, and the W-phase group 90 W. FIGS. 6 to 14 illustrate the state in which the direction of the center axis J is viewed from the radial outside while the teeth T 1 to T 9 circumferentially arranged side by side are linearly developed.

The conducting wire L constituting the coil C includes a first winding unit 82 , a first jumper wire 83 a , a second jumper wire 83 b , a first lead wire 84 a , and a second lead wire 84 b . For example, the coil C is formed by winding the conducting wire L clockwise around the tooth T a plurality of times when the direction of the center axis J is viewed from the radial outside.

In the coil C, the conducting wire L is wound radially outward from the radially inner end of the tooth T, and then wound toward the radially inner end again. The conducting wire L reciprocates between the radial inside and the radial outside of the tooth T, and ends the winding in the vicinity of the radially inner end to form the coil C.

The first lead wire 84 a is disposed at one end side of the conducting wire L, and the upper end of the first lead wire 84 a is connected to one of the first connectors 74 U, 74 V, 74 W. The first lead wire 84 a extends axially downward from the axially upper side toward the lower surface side of the tooth T through a slot 73 .

The second lead wire 84 b is disposed on the other end side of the conducting wire L, and the upper end of the second lead wire 84 b is connected to one of the second connectors 75 U, 75 V, 75 W. The second lead wire 84 b extends axially upward from the lower surface side of the tooth T through the slot 73 .

The parallel-connected in-phase conducting wires L are extracted from the same slot 73 by the first lead wire 84 a and the second lead wire 84 b . Consequently, the parallel-connected conducting wires L are gathered to further improve connection workability.

The first jumper wire 83 a is disposed between the coil C and the first connectors 74 U, 74 V, 74 W, and the second jumper wire 83 b is disposed between the coil C and the second connectors 75 U, 75 V, 75 W. When the conducting wire L is wound around the tooth T from the lower ends of the first lead wire 84 a and the second lead wire 84 b , and when the first lead wire 84 a and the second lead wire 84 b are adjacent to the coil C, the first jumper wire 83 a or the second jumper wire 83 b are not provided. For example, in FIG. 12 , the first lead wire 84 a and the coil C 3 are adjacent to each other, and the first jumper wire 83 a is not provided. That is, the conducting wire L has one or two jumper wires disposed between the coil C and the first connectors 74 U, 74 V, 74 W or the second connectors 75 U, 75 V, 75 W.

At least the first jumper wire 83 a or the second jumper wire 83 b extends in the same circumferential direction from the first connectors 74 U, 74 V, 74 W toward the second connectors 75 U, 75 V, 75 W with respect to all the in-phase coils C. This enables the reduction of the change in inductance of the coil C due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b . Thus, the rotation unevenness of the rotor 60 can be prevented.

The first jumper wire 83 a and the second jumper wire 83 b extend circumferentially on the lower surface side of the tooth T. That is, the first jumper wire 83 a and the second jumper wire 83 b are disposed on one side in the axial direction of the tooth T. The first connectors 74 U, 74 V, 74 W and the second connectors 75 U, 75 V, 75 W are disposed on the other side in the axial direction of the tooth T.

Consequently, when the first connectors 74 U, 74 V, 74 W and the second connectors 75 U, 75 V, 75 W are connected to the terminal pins 76 by, for example, soldering, the first jumper wires 83 a and the second jumper wires 83 b do not become an obstacle, and the workability is improved. On the other hand, when the first jumper wire 83 a and the second jumper wire 83 b are circumferentially extended, the first connectors 74 U, 74 V, 74 W and the second connectors 75 U, 75 V, 75 W do not become an obstacle, and the workability of winding the conducting wire L is improved.

The first winding unit 82 relays the first jumper wire 83 a or the second jumper wire 83 b , and can prevent looseness of the first jumper wire 83 a or the second jumper wire 83 b extending circumferentially.

The first winding unit 82 is formed by winding the conducting wire L clockwise around the tooth T more than a half turn and less than one turn when the direction of the center axis J is viewed from the radial outside. Specifically, the conducting wire L extends axially upward from the lower surface side of the tooth T through the slot 73 , extends circumferentially on the upper surface of one tooth T, and extends axially downward from the adjacent slot 73 .

The first winding unit 82 in which the conducting wire L is wound around the tooth T a half turn is disposed on the tooth T in which the in-phase coil C is disposed. Consequently, the first winding unit 82 is disposed in the vicinity of the middle of the first jumper wire 83 a or the second jumper wire 83 b , so that the looseness of the first jumper wire 83 a or the second jumper wire 83 b can further be prevented.

The first winding unit 82 is wound in the same direction as the winding direction of the coil C. Consequently, the first winding unit 82 can be prevented from canceling the magnetic field of the coil C.

When having a small influence on the inductance of the coil C, the first winding unit 82 may be formed by winding the conducting wire L around the tooth T at least one turn. At this point, the looseness of the first jumper wire 83 a or the second jumper wire 83 b can further be prevented.

The first winding unit 82 is disposed in the tooth T in which the in-phase coil C is disposed. Consequently, the first winding unit 82 is disposed in the vicinity of the middle of the first jumper wire 83 a or the second jumper wire 83 b , so that the looseness of the first jumper wire 83 a or the second jumper wire 83 b can further be prevented.

The winding patterns of the conducting wires L 1 to L 9 constituting the coils C 1 to C 9 will be specifically described below. As illustrated in FIGS. 6 to 8 , in the conducting wires L 1 , L 4 , L 7 constituting the coils C 1 , C 4 , C 7 of the U phase group 90 U, the first lead wire 84 a extends to the lower surface side of the tooth T 5 through the slot 73 between the teeth T 5 , T 6 .

The second lead wire 84 b of the conducting wires L 1 , L 4 extends axially upward from the lower surface side of the tooth T 9 through the slot 73 between the teeth T 8 , T 9 . The second lead wire 84 b of the conducting wire L 7 extends axially upward from the lower surface side of the tooth T 8 through the slot 73 between the teeth T 8 , T 9 .

The conducting wires L 1 , L 4 , L 7 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the U-phase group 90 U, all the first jumper wire 83 a and the second jumper wire 83 b of the conducting wires L 1 , L 4 and the first jumper wire 83 a of the conducting wire L 7 extend from the first connector 74 U toward the second connector 75 U in a counterclockwise direction X 2 in planar view. Thus, the change in inductance of the coils C 1 , C 4 , C 7 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced. Thus, the rotation unevenness of the rotor 60 can be prevented.

The second jumper wire 83 b of the conducting wire L 7 extends from the first connector 74 U toward the second connector 75 U in a clockwise direction X 1 in planar view. However, the second jumper wire 83 b of the conducting wire L 7 is shorter than the first jumper wire 83 a of the conducting wire L 7 , and the magnetic field generated by the second jumper wire 83 b of the conducting wire L 7 is smaller than the magnetic field generated by the first jumper wire 83 a of the conducting wire L 7 . For this reason, the influence on the inductance can be ignored.

As illustrated in FIGS. 9 to 11 , in the conducting wires L 2 , L 5 , L 8 constituting the coils C 2 , C 5 , C 8 of the V-phase group of 90 V, the first lead wire 84 a extends to the lower surface side of the tooth T 9 through the slot 73 between the teeth T 1 , T 9 .

The second lead wire 84 b of the conducting wire L 2 extends axially upward from the lower surface side of the tooth T 3 through the slot 73 between the teeth T 3 , T 4 . The second lead wire 84 b of the conducting wires L 5 , L 8 extends axially upward from the lower surface side of the tooth T 4 through the slot 73 between the teeth T 3 , T 4 .

The conducting wires L 2 , L 5 , L 8 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the V-phase group 90 V, all the first jumper wire 83 a of the conducting wire L 2 and the first jumper wire 83 a and the second jumper wire 83 b of the conducting wires L 5 , L 8 extend from the first connector 74 V toward the second connector 75 V in the counterclockwise direction X 2 in planar view. Thus, the change in inductance of the coils C 2 , C 5 , C 8 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced.

The second jumper wire 83 b of the conducting wire L 2 extends from the first connector 74 V toward the second connector 75 V in the clockwise direction X 1 in planar view. However, the second jumper wire 83 b of the conducting wire L 2 is shorter than the first jumper wire 83 a of the conducting wire L 2 , and the magnetic field generated by the second jumper wire 83 b of the conducting wire L 2 is smaller than the magnetic field generated by the first jumper wire 83 a of the conducting wire L 2 . For this reason, the influence on the inductance can be ignored.

As illustrated in FIGS. 12 to 14 , in the conducting wire L 3 constituting the coil C 3 of the W-phase group 90 W, the first lead wire 84 a extends to the lower face side of the tooth T 3 through the slot 73 between the teeth T 2 , T 3 . The conducting wire L 3 is wound around the teeth T 3 a plurality of times to form the coil C 3 , and then extends to the lower face side of the tooth T 2 .

In the conducting wires L 6 , L 9 constituting the coils C 6 , C 9 of the W-phase group 90 W, the first lead wire 84 a extends to the lower surface side of the tooth T 2 through the slots 73 between the teeth T 2 , T 3 .

The second lead wire 84 b of the conducting wires L 3 , L 9 extends axially upward from the lower face side of the tooth T 7 through the slot 73 between the teeth T 6 , T 7 . The second lead wire 84 b of the conducting wire L 6 is wound around the tooth T 6 a plurality of times to form the coil C 6 , and then extends axially upward from the lower surface side of the tooth T 6 through the slot 73 between the teeth T 6 , T 7 .

The conducting wires L 3 , L 6 , L 9 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the V phase group 90 V, all the first jumper wire 83 a of the conducting wire L 2 and the first jumper wire 83 a and the second jumper wire 83 b of the conducting wires L 5 , L 8 extend from the first connector 74 W toward the second connector 75 W in the counterclockwise direction X 2 in planar view. Thus, the change in inductance of the coils C 3 , C 6 , C 9 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced.

Another exemplary embodiment of the present disclosure will be described below. FIGS. 15 to 23 are explanatory views illustrating the winding patterns of the conducting wires constituting the U-phase group 90 U, the V-phase group 90 V, and the W-phase group 90 W. FIGS. 15 to 23 illustrate the state in which the direction of the center axis J is viewed from the radial outside while the teeth T 1 to T 9 circumferentially arranged side by side are linearly developed. For convenience, the same component as that of the exemplary embodiment illustrated in FIGS. to 14 is denoted by the same reference numeral. Another exemplary embodiment differs from the exemplary embodiment in the winding pattern of the conducting wire. The other configurations are similar to those of the exemplary embodiment.

The coils C 1 to C 9 are formed by winding the conducting wires L 1 to L 9 counterclockwise around the teeth T 1 to T 9 a plurality of times when the direction of the center axis J is viewed from the radial outside.

The first winding unit 82 is formed by winding the conducting wires L 1 to L 9 counterclockwise around the tooth T a half turn when the direction of the center axis J is viewed from the radially outer side. In the conducting wires L 6 , L 9 , the first winding unit 82 is formed by winding the first winding unit 82 counterclockwise around the tooth T 3 one turn.

As illustrated in FIGS. 15 to 17 , in the conducting wires L 1 , L 4 constituting the coils C 1 , C 4 of the U phase group 90 U, the first lead wire 84 a extends to the lower surface side of the tooth T 8 through the slot 73 between the teeth T 7 , T 8 .

In the conducting wire L 7 constituting the coil C 7 of the U phase group 90 U, the first lead wire 84 a extends to the lower surface side of the tooth T 7 through the slot 73 between the teeth T 7 , T 8 . The conducting wire L 7 is wound around the tooth T 7 a plurality of times to form the coil C 7 , and then extends to the lower surface side of the tooth T 8 .

The second lead wire 84 b of the conducting wires L 1 , L 4 , L 7 extends axially upward from the lower face side of the tooth T 6 through the slot 73 between the teeth T 6 , T 7 .

All the conducting wires L 1 , L 4 , L 7 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the U-phase group 90 U, all the first jumper wire 83 a and the second jumper wire 83 b of the conducting wires L 1 , L 4 and the second jumper wire 83 b of the conducting wire L 7 extend from the first connector 74 U toward the second connector 75 U in the clockwise direction X 1 in planar view. Thus, the change in inductance of the coils C 1 , C 4 , C 7 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced. Thus, the rotation unevenness of the rotor 60 can be prevented.

As illustrated in FIGS. 18 to 20 , in the conducting wires L 2 , L 8 constituting the coils C 2 , C 8 of the V-phase group of 90 V, the first lead wire 84 a extends to the lower surface side of the tooth T 6 through the slot 73 between the teeth T 5 , T 6 .

In the conducting wire L 5 constituting the coil C 5 of the V-phase group 90 V, the first lead wire 84 a extends to the lower surface side of the tooth T 5 through the slot 73 between the teeth T 5 , T 6 . The conducting wire L 5 is wound around the tooth T 5 a plurality of times to form the coil C 5 , and then extends to the lower surface side of the tooth T 6 .

The second lead wire 84 b of the conducting wires L 2 , L 5 , L 8 extends axially upward from the lower face side of the tooth T 4 through the slot 73 between the teeth T 4 , T 5 .

All the conducting wires L 2 , L 5 , L 8 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the V-phase group 90 V, all the first jumper wire 83 a and the second jumper wire 83 b of the conducting wires L 2 , L 8 and the second jumper wire 83 b of the conducting wire L 5 extend from the first connector 74 V toward the second connector 75 V in the clockwise direction X 1 in planar view. Thus, the change in inductance of the coils C 2 , C 5 , C 8 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced. Thus, the rotation unevenness of the rotor 60 can be prevented.

As illustrated in FIGS. 21 to 23 , in the conducting wire L 3 constituting the coil C 3 of the W-phase group 90 W, the first lead wire 84 a extends to the lower face side of the tooth T 3 through the slot 73 between the teeth T 3 , T 4 . The conducting wire L 3 is wound around the tooth T 3 a plurality of times to form the coil C 3 , and then extends to the lower surface side of the tooth T 4 .

In the conducting wires L 6 , L 9 constituting the coils C 6 , C 9 of the W-phase group 90 W, the first lead wire 84 a extends to the lower surface side of the tooth T 3 through the slots 73 between the teeth T 3 , T 4 . The conducting wire L 3 is wound around the tooth T 3 one turn, and then extends to the lower surface side of the tooth T 4 .

The second lead wire 84 b of the conducting wires L 3 , L 6 extends axially upward from the lower face side of the tooth T 8 through the slot 73 between the teeth T 8 , T 9 .

The second lead wire 84 b of the conducting wire L 9 is wound around the tooth T 9 a plurality of times to form the coil C 9 , and then extends axially upward from the lower surface side of the tooth T 9 through the slot 73 between the teeth T 8 , T 9 .

All the conducting wires L 3 , L 6 , L 9 disposed between the first lead wire 84 a and the second lead wire 84 b pass through the far side in the circumferential direction. In the W-phase group 90 W, all the second jumper wire 83 b of the conducting wire L 3 , the first jumper wire 83 a and the second jumper wire 83 b of the conducting wire L 6 , and the first jumper wire 83 a of the conducting wire L 9 extend from the first connector 74 V toward the second connector 75 V in the clockwise direction X 1 in planar view. Thus, the change in inductance of the coils C 3 , C 6 , C 9 due to the magnetic field generated by the first jumper wire 83 a or the second jumper wire 83 b can be reduced. Thus, the rotation unevenness of the rotor 60 can be prevented.

For example, the present disclosure can be used for blowers mounted on OA instruments, medical instruments, household electrical appliances, and transportation instruments.

Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.

While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.