JP6851920B2 - Brushless motor and electric power steering device - Google Patents

Description

The present invention relates to a brushless motor and an electric power steering device.

For example, an inner rotor type brushless motor has a stator that is internally fitted and fixed to a motor case, and a rotor that is arranged at the center of the motor case in the radial direction and is rotatably supported by the stator. A plurality of permanent magnets are arranged on the outer peripheral surface of the rotor. The stator includes a substantially cylindrical stator core and a plurality of tooth portions protruding inward in the radial direction from the stator core.
An insulator formed of an insulating resin material is attached to each tooth portion, and a coil is wound through the insulator. Then, when electric power from an external power source is supplied to the coil, an attractive force or a repulsive force is generated between the magnetic flux generated in the coil and the permanent magnet, and the rotor rotates.

Here, as a method of connecting the coil of the brushless motor, there is a method of forming the coil so as to have a two-system three-phase structure (see, for example, Patent Document 1). According to this, coils of the same system and the same phase are wound around the teeth arranged point-symmetrically about the rotation axis.
By forming the coil into a two-system three-phase structure in this way, even if a problem or the like makes it impossible to supply power to one coil, it is possible to supply power to the other coil. Therefore, it is possible to prevent the brushless motor from completely stopping driving.

Japanese Unexamined Patent Publication No. 2004-201364

By the way, a bus bar unit may be used as a power feeding means for arbitrarily electrically connecting the coil ends (starting line and ending line) of each coil of the brushless motor described above to supply current to each coil. .. The bus bar unit is formed in a substantially annular shape by a resin mold with a plurality of metal bus bars insulated from each other. For example, when the coils are connected by the star connection method, the resin molded body has a plurality of phase bus bars for supplying power to the coils of each phase, and a neutral point forming a neutral point (common). The bus bars are laminated so as to be insulated from each other. Then, these phase bus bars and the neutral point bus bars are formed in a substantially annular shape by the resin mold.

However, when the coils of the same phase of the same system are arranged point-symmetrically with respect to the rotation axis as in the above-mentioned conventional technique, the distance for wiring them also becomes long. As a result, the number of stacked bus bars also increases, and there is a possibility that the brushless motor as a whole becomes large.

Therefore, the present invention has been made in view of the above circumstances, and provides a brushless motor and an electric power steering device capable of miniaturizing the connection portion of the coil when the coil is configured in a two-system three-phase structure. To do.

In order to solve the above problems, the brushless motor according to the present invention has a stator having 12 N teeth portions when N is a natural number, and a coil is wound around the teeth portions by a centralized winding method. A brushless motor including a bus bar in which the coils are star-connected so as to have a three-phase structure of two systems, and two coils of the same system and the same phase are arranged to face each other around the central axis of the stator. Therefore, the length of the start line at the start of winding of each of the coils wound around the teeth portion and the length of the end line at the end of winding are set to different lengths, and all the start lines are set. Is set to the same length, and the lengths of all the end lines are set to the same length.

By making the lengths of the start line and the end line different in this way, the connection position of the bus bar with the coil can be shifted. As a result, the wiring length of the bus bar can be set short, and as a result, the number of stacked bus bars can be reduced. Further, since the lengths of all the start lines are set to the same length and the lengths of all the end lines are set to the same length, the shape of each bus bar can be made the same as much as possible. Therefore, the bus bar can be simplified and the coil connection portion can be miniaturized.

The brushless motor according to the present invention is characterized in that the length of the start line is set longer than the length of the end line.

Here, as the length of the coil becomes longer, the dimensional control becomes complicated accordingly.
By the way, when winding a coil around each tooth portion, after arranging the start line, the coil is wound so as to overlap the start line, and finally the end line is drawn out. Therefore, since the start wire is fixed to the teeth portion by the coil wound later, the length of the start wire can be easily managed. By setting this easy-to-manage start line longer than the length of the last line, it is possible to facilitate the length management of the coil.

In the brushless motor according to the present invention, the start line lead-out position of the start line and the start line connection position of the corresponding start line to the bus bar are deviated in the circumferential direction, and the end line lead-out position of the end line. And the end line connection position of the corresponding end line to the bus bar is deviated in the circumferential direction, the amount of deviation of the start line connection position with respect to the start line lead-out position, and the end line of the end line connection position. The feature is that the amount of deviation with respect to the withdrawal position is set to be the same.

With this configuration, the start and end lines can be easily routed, and the route of each line can be aligned in the same direction. Therefore, the coil connection work can be facilitated, and the coil connection portion can be further miniaturized.

Brushless motor according to the present invention has a two teeth, a stator in which coil by concentrated winding system in the tooth portion is wound, said coil is a star connection to the three-phase structure of the two systems This is a brushless motor in which two coils of the same system and the same phase are arranged to face each other around the central axis of the stator, and a crossover coil connecting the coils of the same phase arranged to face each other. And the power supply side terminal part of the coil on the side connected to the power supply, the bus bar for power supply for connecting to the power supply, and the neutral point side terminal part of the coil on the side connected to the neutral point. The bus bar for the neutral point is provided with a bus bar for the neutral point for connecting to each other, the bus bar for the power supply is configured in two layers, the bus bar for the neutral point is configured in one layer, and the first layer for the power supply is provided. The bus bar includes a 1U phase power supply bus bar and a 1W phase power supply bus bar in the first system of the two systems, a second V phase power supply bus bar in the second system of the two systems, and a second W phase power supply bus bar. And are arranged, and the first V phase power bus bar in the first system and the second U phase power bus bar in the second system are arranged in the second layer power bus bar. The bus bar for a neutral point is characterized by including a first neutral point bus bar in the first system and a second neutral point bus bar in the second system .

As described above, by using the power supply bus bar, the neutral point bus bar, and the crossover coil in combination, the number of stacked bus bars can be reduced. Moreover, the bus bar is limited to the power supply bus bar and the neutral point bus bar without being used for connecting coils of the same system and the same phase having a long wiring distance. Therefore, the bus bar itself can be miniaturized. As a result, the connection portion of the coil can be miniaturized.

The brushless motor according to the present invention is characterized in that two coils of the same phase of the same system and the corresponding crossover coil are continuously formed by one coil.

With this configuration, two coils of the same phase of the same system can be wound around the teeth portion in a series in one operation. Therefore, it is possible to prevent the length of the crossover coil from becoming unnecessarily long, the coil connection portion can be further miniaturized, and the coil connection work can be facilitated.

In the brushless motor according to the present invention, the power supply bus bar and the neutral point bus bar are arranged on one end surface side in the axial direction of the stator, and the crossover coil is located on the other end surface side in the axial direction of the stator. It is characterized by being arranged.

With this configuration, it is possible to prevent each bus bar from interfering with the crossover coil. Therefore, when the connection work between each bus bar and the coil is performed, the crossover coil does not get in the way, and the connection work between each bus bar and the coil can be facilitated.

The electric power steering device according to the present invention is characterized in that the brushless motor described above is used to assist the steering operation based on the steering operation of the vehicle.

With this configuration, it is possible to reduce the size of the coil connection portion and provide a compact electric power steering device as a whole.

According to the present invention, the connection position of the bus bar with the coil can be shifted by making the lengths of the start line and the end line different. As a result, the wiring length of the bus bar can be set short, and as a result, the number of stacked bus bars can be reduced. Further, since the lengths of all the start lines are set to the same length and the lengths of all the end lines are set to the same length, the shape of each bus bar can be made the same as much as possible. Therefore, the bus bar can be simplified and the coil connection portion can be miniaturized.

It is a perspective view of the brushless motor in the 1st Embodiment of this invention. It is a perspective view of the stator and the bus bar unit in 1st Embodiment of this invention. It is a perspective view of the split core in 1st Embodiment of this invention. It is a figure for demonstrating the phase allocation of each coil, and the routing of a start line and an end line in the 1st Embodiment of this invention. It is a top view of the bus bar unit in 1st Embodiment of this invention. It is a pattern arrangement figure of the 1st layer bus bar unit in 1st Embodiment of this invention. It is a pattern arrangement figure of the 2nd layer bus bar unit in 1st Embodiment of this invention. It is a pattern arrangement figure of the 3rd layer bus bar unit in 1st Embodiment of this invention. It is a figure which developed the coil and the bus bar unit of each phase in 1st Embodiment of this invention. It is a wiring diagram of the coil in the 1st Embodiment of this invention. It is a perspective view of the split core in the 2nd Embodiment of this invention. It is a figure for demonstrating the phase allocation of each coil and the routing of a start line, an end line, and a crossover coil in the 2nd Embodiment of this invention. It is a top view of the bus bar unit in the 2nd Embodiment of this invention. It is a pattern arrangement figure of the 1st layer bus bar unit in 2nd Embodiment of this invention. It is a pattern arrangement figure of the 2nd layer bus bar unit in 2nd Embodiment of this invention. It is a pattern arrangement figure of the 3rd layer bus bar unit in 2nd Embodiment of this invention. It is a figure which developed the coil and the bus bar unit of each phase in the 2nd Embodiment of this invention. It is a perspective view of the split core in the modification of the 2nd Embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment)
(Brushless motor)
FIG. 1 is a perspective view of the brushless motor 1, and FIG. 2 is a perspective view of the stator 2 and the bus bar unit 5.
As shown in FIGS. 1 and 2, the brushless motor 1 is used in an electric power steering device (EPS) 100. The brushless motor 1 includes a substantially bottomed cylindrical motor housing 4, a substantially cylindrical stator 2 fitted and fixed in the motor housing 4, and a rotor 3 rotatably arranged inside the stator 2 in the radial direction. And a bus bar unit 5 which is arranged on one end side in the axial direction of the stator 2 and for supplying power to the stator 2.
In the following description, the rotation axis L1 direction of the rotor 3 is simply referred to as an axial direction, the rotation direction of the rotor 3 is referred to as a circumferential direction, and the radial direction of the rotor 3 orthogonal to the axial direction and the circumferential direction is simply referred to as a radial direction. ..

A bracket 8 is provided in the opening on the side opposite to the bottom 4a of the motor housing 4 so as to close the opening. A recess 8a is formed in most of the bracket 8 on the side opposite to the motor housing 4. Then, one end of the rotating shaft 7 of the rotor 3 projects from the bottom of the recess 8a via a bearing (not shown). At one end of the rotating shaft 7, a sensor magnet 80 for detecting the rotational position of the rotor 3 is provided. The sensor magnet 80 detects the rotational position of the rotor 3 in cooperation with a detection unit (not shown) that detects the magnetic flux of the sensor magnet 80 provided in a control device (not shown).

Further, an opening 8b through which the terminal 72 can be inserted is formed at the bottom of the recess 8a provided in the bracket 8. (In the first embodiment, two terminals are provided so as to be located on opposite sides of the rotating shaft 7 as the center.) A plurality of terminals (six in the first embodiment) are provided through the openings 8b. One end 72a of 72 is projected. The other end (not shown) of each terminal 72 projects toward the bus bar unit 5 side housed in the motor housing 4. The other end of each terminal 72 is connected to each phase feeding terminal 25U to 26W of the bus bar unit 5, which will be described later.

The other end of the rotating shaft 7 of the rotor 3 projects outward in the axial direction via a bearing (not shown) provided at the bottom of the motor housing 4. A pinion gear 9 is externally fitted and fixed to the protruding end. A gear 102 provided in the steering 101 of the electric power steering device 100 is meshed with the pinion gear 9.

Further, the rotor 3 has a columnar rotor core 10 that is externally fitted and fixed at a position corresponding to the stator 2 of the rotating shaft 7. A plurality of magnets (not shown) (for example, eight in the first embodiment) are provided on the outer peripheral surface of the rotor core 10 at equal intervals in the circumferential direction. Each magnet is arranged so that the magnetic poles are in order in the circumferential direction. A magnetic attractive force or repulsive force is generated between the magnet and the magnetic field formed on the stator 2, and the rotor 3 rotates.

As will be shown in detail in FIG. 2, the stator 2 has a stator core 14 which is, for example, shrink-fitted and fixed to the inner peripheral surface of the peripheral wall 4b (see FIG. 1) of the motor housing 4. The stator core 14 is composed of a back yoke portion 12 formed in a substantially cylindrical shape and formed as a magnetic path, and twelve tooth portions 33 projecting from the back yoke portion 12 toward the center in the radial direction. The stator 2 is arranged so that the central axis L2 coincides with the rotation axis L1 of the rotor 3.

Here, the back yoke portion 12 of the stator core 14 adopts a split core system that can be divided in the circumferential direction. That is, the back yoke portion 12 of the stator core 14 is configured by annularly connecting the divided cores 30 divided into a plurality of parts in the circumferential direction.

FIG. 3 is a perspective view of the split core 30.
As shown in the figure, the split core 30 is formed by stacking a plurality of metal plates, for example, and has a split back yoke 31 extending in the circumferential direction. The split back yoke 31 is a portion that forms an annular magnetic path of the back yoke portion 12 when the split cores 30 are connected in an annular shape. The split back yoke 31 is formed in a substantially arc shape in cross section.

Both ends of the split back yoke 31 in the circumferential direction are connecting portions 31a and 31b that are connected to the other split back yoke 31 by press fitting. One connecting portion 31a has a convex shape, and the other connecting portion 31b has a concave shape that can accept the connecting portion 31a.
As shown in FIG. 2, in a state where the divided cores 30 are connected via the connecting portions 31a and 31b (a state in which the back yoke portion 12 is formed), the connecting portion is connected to the outer peripheral surface 12a of the back yoke portion 12. The concave portions 32 along the axial direction are formed by the connecting portions 31a and 31b at the locations where the 31a and 31b are formed.

Further, on the inner surface of the split back yoke 31, a tooth portion 33 is formed so as to project from substantially the center in the circumferential direction toward the inside in the radial direction (the rotation center side of the rotor). That is, each divided core 30 includes one tooth portion 33. The tooth portion 33 is formed in a substantially T shape having a flange portion 34 extending in the circumferential direction inward in the radial direction when viewed from the axial direction. A resin insulator 35 that covers the periphery of the teeth portion 33 is mounted between the split back yoke 31 of the teeth portion 33 and the flange portion 34.

The insulator 35 is divided in the axial direction, and is mounted so as to sandwich the teeth portion 33 from both sides in the axial direction of the teeth portion 33. In the state where the insulator 35 is attached, the teeth portion 33 exposes the axial end surfaces of the split back yoke 31, the connecting portions 31a and 31b, and the inner peripheral surface of the flange portion 34.

Further, on both end faces in the axial direction of the insulator 35, the outer wall portion 36 is integrally molded on the outer side in the radial direction, and the inner wall portion 37 is integrally molded on the inner side in the radial direction.
The outer wall portion 36 is formed in an arc shape when viewed from the axial direction so as to rise along the axial direction and extend in the circumferential direction along the split back yoke 31. Two slits 36a and 36b (first slit 36a and second slit 36b) are formed on the outer wall portion 18a at equal intervals in the circumferential direction.

Under such a configuration, a coil 16 is wound around the teeth portion 33 of each divided core 30 from above the insulator 35 by a centralized winding method. More specifically, the start wire (winding start end) 16a of the coil 16 is arranged at the base of the teeth portion 33, that is, on the split back yoke 31 side of the teeth portion 33. Then, the coil 16 is spirally wound from here toward the flange portion 34 of the teeth portion 33. When the coil 16 reaches the inner side surface (diameter outer side surface) of the flange portion 34, the winding operation of the first stage coil 16 is completed.

Subsequently, the second-stage coil 16 is wound around the first-stage coil 16. At this time, the coil 16 is spirally wound from the flange portion 34 side of the teeth portion 33 toward the root. When the coil reaches the inner side surface (diameter inner side surface) of the split back yoke 31, the winding operation of the second stage coil 16 is completed. Then, by repeating the same operations as the winding operation of the first-stage coil 16 and the winding operation of the second-stage coil 16, the coil 16 is wound around the teeth portion 33 a predetermined number of times. The coils 16 in each stage are stacked in bales.

Since the coil 16 is wound around each tooth portion 33 in this way, the start wire 16a of the coil 16 is pressed against the teeth portion 33 by the coil 16 being wound forward. Therefore, the start wire 16a is fixed to the portion arranged on the teeth portion 33, that is, the root of the teeth portion 33 (the split back yoke 31 side of the teeth portion 33) by the coil 16 wound later.

On the other hand, the final line 16b of the coil 16 is fixed so as to be hooked on the two second slits 36b formed in the outer wall portion 36 of the insulator 35. As described above, the two slits 36a and 36b formed in the outer wall portion 36 are used for fixing the start line 16a and the end line 16b of the coil 16, and also are radially outward via the outer wall portion 36. It is used to draw out the start line 16a and the end line 16b.

Here, the length of the start line 16a of the coil 16 and the length of the end line 16b of the coil 16 are defined as the lengths drawn from the bales of coils 16 wound around the teeth portion 33, respectively. At this time, in the first embodiment, the length of the start line 16a of the coil 16 is set to be longer than the length of the end line 16b of the coil 16. Further, in each coil 16 of each divided core 30, the start lines 16a are all set to have the same length, and the end lines 16b are all set to the same length. Further, the start line 16a and the end line 16b of the coil 16 are drawn out to the control housing 8 side.

Further, the number M of the divided cores 30 is, when N is a natural number.
M = 12 × N ・ ・ ・ (1)
Is set to meet.
In this embodiment, N = 1 is set, and the number M of the divided cores 30 is set to "12".

By connecting the divided cores 30, a dovetail groove-shaped slot 17 is formed between the teeth portions 33 adjacent to each other in the circumferential direction. That is, the number of slots 17 is also set to 12. As described above, the brushless motor 1 of the present embodiment is an 8-pole 12-slot motor having 8 magnets 11 (8 poles) and 12 slots 17 (12 slots). ..

Here, the start line 16a and the end line 16b of each coil 16 drawn out to the control housing 8 side are connected to the bus bar unit 5. Each coil 16 is star-connected by a bus bar unit 5 so as to have a two-system three-phase (U-phase, V-phase, W-phase) structure. The details will be described below.

(Allocation of each phase coil)
FIG. 4 is a diagram for explaining the phase allocation of each coil 16 and the routing of the start line 16a and the end line 16b, and corresponds to a plan view of the stator 2 as viewed from the axial direction.
As shown in the figure, first, the phase allocation of each coil 16 wound around the teeth portion 33 will be described.
Each coil 16 has the same system arranged in every other teeth portion 33. Further, each coil 16 is assigned to an arbitrary phase of one of the two systems so that both sides of this phase in the circumferential direction are other phases of the other system and are different from each other. ing.

That is, the first coil 16 has the first U-phase coil 161Ua, the first W-phase coil 161Wa, the first V-phase coil 161Va, the first U-phase coil 161Ub, and the first W-phase on every other teeth portion 33 in a counterclockwise direction. The coil 161Wb and the first V-phase coil 161Vb are assigned in this order.
Further, the second coil 16 has a second U-phase coil 162Ua, a second V-phase coil 162Va, a second W-phase coil 162Wa, a second U-phase coil 162Ub, and a second V-phase coil on every other tooth portion 33 in a clockwise direction. 162Vb and 162Wb second W phase coil are assigned in this order.

In this way, there are two coils 161Ua to 162Wb for each phase, and in the same system, the coils 161Ua to 162Wb of the same phase are arranged to face each other around the rotation axis 7 (rotation axis L1, center axis L2) (points). (Symmetrical arrangement). Further, a first U-phase coil 161Ua is arranged between the second V-phase coil 162Vb and the second W-phase coil 162Wb.

Here, the specific lengths of the start line 16a and the end line 16b of the coil 16 will be described. The length of the start line 16a of the coil 16 is set to a length straddling the three tooth portions 33 arranged in the circumferential direction. That is, for example, the end of the start line 16a of the first U-phase coil 161Ua is routed so as to be located substantially directly above the first V-phase coil 161Va.
On the other hand, the length of the end line 16b of the coil 16 is set to a length that can be pulled out slightly diagonally upward in the same direction as the routing direction of the start line 16a and can be connected to the bus bar unit 5.

(Busbar unit)
FIG. 5 is a plan view of the bus bar unit 5. FIG. 6 is a pattern layout diagram of the first layer bus bar unit 5. FIG. 7 is a pattern layout diagram of the second layer bus bar unit 5. FIG. 8 is a pattern layout diagram of the third layer bus bar unit 5.
As shown in FIGS. 2, 5 and 8, the bus bar unit 5 has a three-layer structure formed in a substantially annular shape, and has a plurality of bus bars 21U to 22W. A predetermined bus bar 21U to 22W is arranged in each layer. Further, the bus bar unit 5 includes a resin bus bar holder 20 that secures an insulation distance between the bus bars 21U to 22W arranged in each layer and holds each bus bar 21U to 22W in a state of being arranged in three layers. ing. The bus bar holder 20 is formed in a substantially annular shape.

As shown in FIG. 6, on the first layer of the bus bar unit 5, the first power bus bars 21U, 21V, 21W of each phase of the first system (first U phase power bus bar 21U, first V phase power bus bar 21V, first W). The phase power bus bar 21W) and the second power bus bars 22U, 22V, 22W (second U phase power bus bar 22U, second V phase power bus bar 22V, second W phase power bus bar 22W) of each phase of the second system are insulated from each other. It is arranged with a sufficient distance.

The first power bus bars 21U, 21V, and 21W of each phase of the first system are centrally arranged in a semicircle of the bus bar holder 20 when viewed from the axial direction. The first power bus bars 21U, 21V, and 21W of each phase are formed by pressing a conductive plate-shaped member, and are individually configured.

The first power bus bars 21U, 21V, 21W of each phase are coil connection terminals 23U, 23V, 23W of each phase protruding outward in the radial direction, respectively (first U phase coil connection terminals 23U, first V phase coil connection). Terminal 23V, 1st W phase coil connection terminal 23W) and power supply terminals 25U, 25V, 25W (1st U phase power supply terminal 25U, 1st V phase power supply terminal) of each phase protruding toward the terminal unit 70 side along the axial direction. 25V, 1st W phase feeding terminal 25W), and the crossing parts 27U, 27V, 27W (1st U phase crossing part) of each phase connecting these in-phase coil connection terminals 23U, 23V, 23W and the feeding terminals 25U, 25V, 25W. It is composed of 27U, a first V crossing section 27V, and a first W crossing section 27W).

The 1st U phase coil connection terminal 23U is arranged substantially directly above the place where the end portion of the start wire 16a of the 1st U phase coil 161Ua is arranged, and the end portion of the start wire 16a of the 1st U phase coil 161Ua is connected. To.
The first V-phase coil connection terminal 23V is arranged substantially directly above the portion where the end of the start line 16a of the first V-phase coil 161V is arranged, and the end of the start line 16a of the first V-phase coil 161V is connected. To.
The 1st W phase coil connection terminal 23W is arranged substantially directly above the place where the end of the start line 16a of the 1st W phase coil 161W is arranged, and the end of the start line 16a of the 1st W phase coil 161W is connected. To.

The power supply terminals 25U, 25V, and 25W of each phase are arranged side by side in close proximity to each other. The power supply terminals 25U, 25V, and 25W of each phase are connected to the other ends of the corresponding terminals 72 of the terminal unit 70.
The crossovers 27U, 27V, and 27W of each phase are formed in an arc shape when viewed from the axial direction along the shape of the bus bar holder 20. The crossovers 27U, 27V, and 27W of each phase have different peripheral lengths.

On the other hand, the second power bus bars 22U, 22V, 22W of each phase of the second system are semicircular parts of the bus bar holder 20 on the side opposite to the place where the first power bus bars 21U, 21V, 21W of each phase are arranged. It is centrally arranged in. The second power bus bars 22U, 22V, and 22W of each phase are formed by pressing a conductive plate-shaped member, and are individually configured.

The basic configuration of the second power bus bars 22U, 22V, 22W of each phase is the same as that of the first power bus bars 21U, 21V, 21W of each phase, only the coil 16 to be connected is different.
That is, the second power bus bars 22U, 22V, 22W of each phase include a second U phase coil connection terminal 24U, a second V phase coil connection terminal 24V, and a second W phase coil connection terminal 24W. Further, the second power bus bars 22U, 22V, 22W of each phase include a second U phase feeding terminal 26U, a second V phase feeding terminal 26V, and a second W phase feeding terminal 26W. Further, the second power bus bars 22U, 22V, 22W of each phase include a second U phase crossover portion 28U, a second V phase crossover portion 28V, and a second W phase crossover portion 28W.

The end of the start line 16a of the second U-phase coil 162Ua is connected to the second U-phase coil connection terminal 24U.
The end of the start line 16a of the second V-phase coil 162Va is connected to the second V-phase coil connection terminal 24V.
The end of the start line 16a of the second W phase coil 162Wa is connected to the second W phase coil connection terminal 24W.

As shown in FIG. 7, in the second layer of the bus bar unit 5, the first neutral point bus bar 41 of the first system, the second neutral point bus bar 42 of the second system, and the second W phase of the second system The second W phase intermediate bus bar 44W, which connects the coil 162Wa and the second W phase coil 162Wb, is arranged in a state where an insulation distance is secured from each other.

The first neutral point bus bar 41 is arranged in a range slightly shorter than the semicircle of the bus bar holder 20 when viewed from the axial direction. The first neutral point bus bar 41 is formed by pressing a conductive plate-shaped member. The first neutral point bus bar 41 has coil connection terminals 45U, 45V, 45W of each phase protruding outward in the radial direction (first U phase coil connection terminal 45U, first V phase coil connection terminal 45V, first W phase coil connection). It is composed of a terminal 45W) and a first crossing portion 47 connecting the coil connection terminals 45U, 45V, 45W of each phase.

The 1st U-phase coil connection terminal 45U is arranged substantially directly above the place where the end of the end line 16b of the 1st U-phase coil 161Ub is arranged, and the end of the end line 16b of the 1st U-phase coil 161Ub is connected. To.
The 1st V-phase coil connection terminal 45V is arranged substantially directly above the place where the end of the end line 16b of the 1st V-phase coil 161Vb is arranged, and the end of the end line 16b of the 1st V-phase coil 161Vb is connected. To.
The 1st W phase coil connection terminal 45W is arranged substantially directly above the place where the end of the end line 16b of the 1st W phase coil 161Wb is arranged, and the end of the end line 16b of the 1st W phase coil 161Wb is connected. To.
The first crossover portion 47 is formed in an arc shape when viewed from the axial direction along the shape of the bus bar holder 20.

On the other hand, the second neutral point bus bar 42 is arranged in a range of line symmetry with respect to the first neutral point bus bar 41 about a straight line along an arbitrary radial direction. The basic configuration of the second neutral point bus bar 42 is the same as that of the first neutral point bus bar 41, except that the coil 16 to be connected is different.
That is, the second neutral point bus bar 42 connects the second U phase coil connection terminal 46U, the second V phase coil connection terminal 46V, and the second W phase coil connection terminal 46W to the coil connection terminals 46U, 46V, 46W of each phase. It is composed of a second crossing portion 48 and a second crossing portion 48.

The end of the final line 16b of the second U-phase coil 162Ub is connected to the second U-phase coil connection terminal 46U.
The end of the final line 16b of the second V-phase coil 162Vb is connected to the second V-phase coil connection terminal 46V.
The end of the final line 16b of the second W phase coil 162Wb is connected to the second W phase coil connection terminal 46W.

The second W phase intermediate bus bar 44W is formed by pressing a conductive plate-shaped member. The second W phase intermediate bus bar 44W is composed of two second W phase coil connecting terminals 52W and a second crossover portion 54W connecting these two second W phase coil connecting terminals 52W.
The two second W phase coil connection terminals 52W are arranged directly above the portion where the end line 16b of the second W phase coil 162Wa is arranged and the end portion of the start line 16a of the second W phase coil 162Wb, respectively. It is placed directly above the place where it is. The end line 16b of the second W phase coil 162Wa and the start line 16a of the second W phase coil 162Wb are connected to the two second W phase coil connection terminals 52W, respectively.

As shown in FIG. 8, the third layer of the bus bar unit 5 includes a first U-phase intermediate bus bar 43U connecting the first U-phase coil 161Ua and the first U-phase coil 161Ub of the first system, and a first V of the first system. The first V phase intermediate bus bar 43V connecting the phase coil 161V and the first V phase coil 161Vb, the first W phase intermediate bus bar 43W connecting the first system first W phase coil 161Wa and the first W phase coil 161Wb, and the second The 2nd U phase intermediate bus bar 44U connecting the 1st U phase coil 162Ua and the 2nd U phase coil 162Ub of the system, and the 2nd V phase intermediate bus bar 44V connecting the 1st V phase coil 162Va and the 2nd V phase coil 162Vb of the 2nd system. And are arranged in a state where the insulation distance is secured from each other.

The first U phase intermediate bus bar 43U is formed by pressing a conductive plate-shaped member. The 1st U phase intermediate bus bar 43U is composed of two 1st U phase coil connecting terminals 51U and a first crossover 53U connecting these two 1st U phase coil connecting terminals 51U.
The two first U-phase coil connection terminals 51U are arranged directly above the portion where the end of the end line 16b of the first U-phase coil 161Ua is arranged and the end of the start line 16a of the first U-phase coil 161Ub, respectively. It is placed directly above the place where it is. The end line 16b of the first U-phase coil 161Ua and the start line 16a of the first U-phase coil 161Ub are connected to the two first U-phase coil connection terminals 51U, respectively.

The first V-phase intermediate bus bar 43V is formed by pressing a conductive plate-shaped member. The first V phase intermediate bus bar 43V is composed of two first V phase coil connection terminals 51V and a first crossover portion 53V connecting these two first V phase coil connection terminals 51V.
The two first V-phase coil connection terminals 51V are arranged directly above the portion where the end of the end line 16b of the first V-phase coil 161Va is arranged and the end of the start line 16a of the first V-phase coil 161Vb, respectively. It is placed directly above the place where it is. The end line 16b of the first V-phase coil 161Va and the start line 16a of the first V-phase coil 161Vb are connected to the two first V-phase coil connection terminals 51V, respectively.

The first W phase intermediate bus bar 43W is formed by pressing a conductive plate-shaped member. The first W phase intermediate bus bar 43W is composed of two first W phase coil connecting terminals 51W and a first crossover portion 53W connecting these two first W phase coil connecting terminals 51W.
The two first W phase coil connection terminals 51W are arranged directly above the portion where the end of the end line 16b of the first W phase coil 161Wa is arranged and the end of the start line 16a of the first W phase coil 161Wb, respectively. It is placed directly above the place where it is. The end line 16b of the first W phase coil 161Wa and the start line 16a of the first W phase coil 161Wb are connected to the two first W phase coil connection terminals 51W, respectively.

The second U phase intermediate bus bar 44U is formed by pressing a conductive plate-shaped member. The second U phase intermediate bus bar 44U is composed of two second U phase coil connecting terminals 52U and a second crossover portion 54U connecting these two second U phase coil connecting terminals 52U.
The two second U-phase coil connection terminals 52U are arranged directly above the portion where the end of the end line 16b of the second U-phase coil 162Ua is arranged and the end of the start line 16a of the second U-phase coil 162Ub, respectively. It is placed directly above the place where it is. The end line 16b of the second U-phase coil 162Ua and the start line 16a of the second U-phase coil 162Ub are connected to the two second U-phase coil connection terminals 52U, respectively.

The second V-phase intermediate bus bar 44V is formed by pressing a conductive plate-shaped member. The second V phase intermediate bus bar 44V is composed of two second V phase coil connection terminals 52V and a second crossover portion 54V connecting these two second V phase coil connection terminals 52V.
The two second V-phase coil connection terminals 52V are arranged directly above the portion where the end of the end line 16b of the second V-phase coil 162Va is arranged and the end of the start line 16a of the second V-phase coil 162Vb, respectively. It is placed directly above the place where it is. The end line 16b of the second V-phase coil 162Va and the start line 16a of the second V-phase coil 162Vb are connected to the two second V-phase coil connection terminals 52V, respectively.

By arranging predetermined bus bars 21U to 44W in each of the three layers in this way, as shown in FIG. 5, each coil is connected to the entire circumference so that the start line 16a and the end line 16b of each coil 16 can be connected. A bus bar unit 5 in which terminals 23U to 52W are arranged is configured.

FIG. 9 is a developed view of the coil 16 and the bus bar unit 5 of each phase.
As shown in the figure, by setting the length of the start line 16a of the coil 16 to be longer than the length of the end line 16b (see FIG. 3), the positions of the coil connection terminals 23U to 52W of the bus bars 21U to 44W are located. And the positions of the end of the start line 16a and the end of the end line 16b of the corresponding coil 16 are displaced by a predetermined amount in the circumferential direction.

Here, the amount of deviation between the coil connection terminals 23U to 52W and the start line 16a of the corresponding coil 16 in the circumferential direction, and the deviation between the coil connection terminals 23U to 52W and the end line 16b of the corresponding coil 16 in the circumferential direction. The amounts are set to the same amount of deviation. In other words, it can be said that the length of the start line 16a and the length of the end line 16b of each coil 16 are set so that the deviation amounts are all the same. Therefore, the start line 16a and the end line 16b of the coil 16 are all routed in the same direction and diagonally in the same manner.

FIG. 10 is a wiring diagram of the coil 16.
As shown in the figure, the coil 16 is connected by the bus bar unit 5 by a star connection method so as to have a three-phase (U-phase, V-phase, W-phase) structure of two systems. Further, in each system, the coils 16 having the same phase are connected in series.

As described above, in the above-described first embodiment, the coil 16 is provided with 12 teeth portions 33 (12 slots 17), the coil 16 is wound around the teeth portions 33 by a centralized winding method, and the rotating shaft 7 (12 slots 17) is further wound. In a brushless motor 1 provided with a stator 2 in which two coils 16 of the same system having the same phase are arranged to face each other (point-symmetrical arrangement) around the rotation axis L1 and the center axis L2), the length of the start line 16a of the coil 16 is long. Is set longer than the length of the final line 16b. Therefore, the positions of the coil connection terminals 23U to 52W of the bus bars 21U to 44W and the positions of the end of the start line 16a and the end of the end line 16b of the corresponding coil 16 are shifted in the circumferential direction by a predetermined amount. be able to. Thereby, the length (wiring length) in the circumferential direction of each of the crossovers 27U to 54W of each bus bar 21U to 44W can be set short. As a result, all the bus bars 21U to 44W can be arranged only by dividing the bus bar unit 5 into three layers. That is, the number of stacked bus bars constituting the bus bar unit can be reduced as compared with the conventional case.

Further, in each coil 16, the start lines 16a are all set to have the same length, and the end lines 16b are all set to the same length. Therefore, when each start line 16a and each end line 16b are routed, it is possible to easily bundle them.
Further, in each layer of the bus bar unit 5, the shapes of the bus bars 21U to 44W arranged in the same layer can be made the same as much as possible.

That is, in the first layer of the bus bar unit 5 (see FIG. 6), the first U-phase bus bar 21U and the second U-phase bus bar 22U can have substantially the same shape. In other words, the first U-phase bus bar 21U and the second U-phase bus bar 22U can have a line-symmetrical shape centered on a straight line in an arbitrary radial direction.
Further, in the first layer of the bus bar unit 5, the first V-phase bus bar 21V and the second W-phase bus bar 22W can have substantially the same shape. In other words, the first V-phase bus bar 21V and the second W-phase bus bar 22W can have a line-symmetrical shape centered on a straight line in an arbitrary radial direction.

Further, in the second layer of the bus bar unit 5 (see FIG. 7), the first neutral point bus bar 41 and the second neutral point bus bar 42 can have substantially the same shape. In other words, the first neutral point bus bar 41 and the second neutral point bus bar 42 can have a line-symmetrical shape centered on a straight line in an arbitrary radial direction.
Then, in the third layer of the bus bar unit 5 (see FIG. 8), the shapes of the intermediate bus bars 43U, 43V, 43W, 44U, 44V can be made substantially the same.

Further, in each divided core 30, when the coil 16 is wound around the teeth portion 33, the start line 16a fixed to the teeth portion 33 by its own coil 16 is set longer than the end line 16b. Here, if the length of the terminal portion (start line 16a, end line 16b) of the coil 16 becomes long, the dimension management becomes troublesome by this amount, but the length of the start line 16a that is securely fixed to the teeth portion 33. By setting the length longer, it is possible to facilitate the length management of the terminal portion of the coil 16.

Further, the positions of the coil connection terminals 23U to 52W of the bus bars 21U to 44W and the positions of the end of the start line 16a and the end of the end line 16b of the corresponding coil 16 are displaced by a predetermined amount in the circumferential direction. There is. Then, the amount of deviation in the circumferential direction between each coil connection terminal 23U to 52W and the start line 16a of the corresponding coil 16 and the amount of deviation in the circumferential direction between each coil connection terminal 23U to 52W and the end line 16b of the corresponding coil 16. Are set to the same amount of deviation. Therefore, the start line 16a and the end line 16b of the coil 16 can all be routed in the same direction and diagonally in the same manner, and the routing operation of the coil 16 can be facilitated. Further, the start line 16a and the end line 16b of the portion where the coil 16 is routed from the stator 2 to the bus bar unit 5 can be easily bundled, and the size can be reduced.

(Second Embodiment)
Next, the second embodiment will be described with reference to FIGS. 11 to 17. In the following figures, the same reference numerals as those in the above-described first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
Here, the brushless motor 201 of the second embodiment is used in the electric power steering device 100. The motor housing 4 has a substantially bottomed cylindrical shape, and the substantially cylindrical motor housing 4 is internally fitted and fixed in the motor housing 4. The shape of the stator 2 is provided with a rotor 3 rotatably arranged inside the stator 2 in the radial direction, and a bus bar unit 205 arranged on one end side of the stator 2 in the axial direction to supply power to the stator 2. The basic configuration such as the above-mentioned points is the same as that of the first embodiment described above. The basic configuration of the stator 2 is also described above, such as a point in which 12 divided cores 30 are connected and a point in which a coil 16 is wound around a tooth portion 33 of each divided core 30 by a centralized winding method. It is the same as the first embodiment.

Here, the differences between the first embodiment and the second embodiment described above are that the configuration of the bus bar unit 5 of the first embodiment and the bus bar unit 205 of the second embodiment are different, and that the bus bar unit 205 has a difference. The difference is that the coil 16 to be connected is routed differently.

FIG. 11 is a perspective view of the split core 30.
As shown in the figure, in the second embodiment, two teeth of the same system and the same phase are arranged so as to face each other (hereinafter, simply referred to as opposite arrangements) about the rotation axis 7 (rotation axis L1, central axis L2). A coil 16 is wound around the portion 33 in a series. Then, the coil 16 spanning the two teeth portions 33 functions as a crossover coil 216 connecting the coils 16 wound around the two teeth portions 33 to each other. The crossover coil 216 is pulled toward the bus bar unit 205 side of the stator 202. Further, the start line 16a of the coil 16 is drawn out to one of the two tooth portions 33 arranged so as to face each other, and the end line 16b of the coil 16 is drawn out to the other.

FIG. 12 is a diagram for explaining the phase allocation of each coil 16 and the routing of the start line 16a, the end line 16b, and the crossover coil 216, and corresponds to FIG. 4 described above.
As shown in the figure, the allocation of the coil 16 of each phase of each system is the same as that of the above-described first embodiment. Then, when all the divided cores 30 are connected, a total of six crossover coils 216 of each phase (1st U phase crossover coil 216U1, 1st V phase crossover coil 216V1, 1st W phase crossover coil 216W1, 2nd U phase) are connected. The crossover coil 216U2, the second V phase crossover coil 216V2, and the second W phase crossover coil 216W2) are routed to the bus bar unit 205 side of the stator 202. Further, either the start line 16a or the end line 16b of the coil 16 is drawn out from each of the divided cores 30 one by one.

(Busbar unit)
FIG. 13 is a plan view of the bus bar unit 205. FIG. 14 is a pattern layout diagram of the first layer bus bar unit 205. FIG. 15 is a pattern layout diagram of the second layer bus bar unit 205. FIG. 16 is a pattern layout diagram of the bus bar unit 205 of the third layer.
As shown in FIGS. 13 to 16, the bus bar unit 5 has a three-layer structure formed in a substantially annular shape, and has a plurality of bus bars 221U to 242. Then, predetermined bus bars 221U to 242 are arranged in each layer. Further, the bus bar unit 5 includes a resin bus bar holder 220 that secures an insulation distance between the bus bars 221U to 242 arranged in each layer and holds each bus bar 221U to 242 in a state of being arranged in three layers. ing. The bus bar holder 220 is formed in a substantially annular shape.

As shown in FIG. 14, on the first layer of the bus bar unit 205, the first system 1U phase power supply bus bar 221U and the first W phase power supply bus bar 221W, the second system second V phase power supply bus bar 222V, and the second system The 2W phase power bus bar 222W and the bus bar 222W are arranged so as to secure an insulation distance from each other.
The first U-phase power bus bar 221U and the first W-phase power bus bar 221W of the first system are centrally arranged in a semicircle of the bus bar holder 220 when viewed from the axial direction. Further, the first U-phase power bus bar 221U and the first W-phase power bus bar 221W of the first system are formed by pressing a conductive plate-shaped member, and are individually configured.

The first U-phase power bus bar 221U and the first W-phase power bus bar 221W of the first system have the first U-phase coil connection terminal 223U and the first W-phase coil connection terminal 223W protruding outward in the radial direction, respectively. The 1st U phase feeding terminal 225U and the 1st W phase feeding terminal 225W protruding toward the terminal unit 70 side along the direction, and the 1st U phase crossing connecting these coil connection terminals 223U, 223W and the feeding terminal 225U, 225W. It is composed of a portion 227U and a first W crossing portion 227W.

The 1st U phase coil connection terminal 223U is arranged substantially directly above the place where the end portion of the start wire 16a of the 1st U phase coil 161Ua is arranged, and the end portion of the start wire 16a of the 1st U phase coil 161Ua is connected. To.
The 1st W phase coil connection terminal 223W is arranged substantially directly above the place where the end portion of the start wire 16a of the 1st W phase coil 161Wa is arranged, and the end portion of the start wire 16a of the 1st W phase coil 161Wa is connected. To.

The 1st U phase feeding terminal 225U and the 1st W phase feeding terminal 225W are arranged side by side in close proximity to each other together with the 1st V phase feeding terminal 225V described later. The first U phase feeding terminal 225U and the first W phase feeding terminal 225W are connected to the other ends of the corresponding terminals 72 of the terminal unit 70, respectively.
The 1st U crossover portion 227U and the 1st W crossover portion 227W are formed in an arc shape when viewed from the axial direction along the shape of the bus bar holder 20. The first U crossover portion 227U and the first W crossover portion 227W have different peripheral lengths.

On the other hand, the 2nd V phase power bus bar 222V and the 2nd W phase power bus bar 222W of the 2nd system are on the opposite side from the place where the 1st U phase power bus bar 221U and the 1W phase power bus bar 221W of the 1st system are arranged. The bus bar holder 220 is arranged in a semicircle. The second V-phase power bus bar 222V and the second W-phase power bus bar 222W of the second system are formed by pressing a conductive plate-shaped member, and are configured separately.

The basic configuration of the 2nd system 2V phase power bus bar 222V and the 2W phase power bus bar 222W is the same as that of the 1st system 1U phase power bus bar 221U and the 1W phase power bus bar 221W, and they are connected. Only the coil 16 is different.
That is, the second V-phase power bus bar 222V of the second system includes a second V-phase coil connection terminal 224V, a second V-phase power supply terminal 226V, and a second V-phase crossover portion 228V. The second W phase power bus bar 222W includes a second W phase coil connection terminal 224W, a second W phase feeding terminal 226W, and a second W phase crossover portion 228W.

The end of the start line 16a of the second V-phase coil 162Va is connected to the second V-phase coil connection terminal 224V.
The end of the start line 16a of the second W phase coil 162Wa is connected to the second W phase coil connection terminal 224W.

As shown in FIG. 15, in the second layer of the bus bar unit 205, the first V-phase power bus bar 221V of the first system and the second U-phase power bus bar 222U of the second system are in a state of ensuring an insulation distance from each other. Have been placed.
The 1st V phase power supply bus bar 221V of the 1st system is concentrated in a semicircle of the bus bar holder 220 on the side where the 1st U phase power supply terminal 225U and the 1W phase power supply terminal 225W are arranged on the first layer when viewed from the axial direction. Have been placed. Further, the first V-phase power bus bar 221V of the first system is formed by pressing a conductive plate-shaped member.

The first V-phase power bus bar 221V of the first system has a first V-phase coil connection terminal 223V projecting outward in the radial direction and a first V-phase power supply terminal projecting toward the terminal unit 70 side along the axial direction. It is composed of 225V and a first V phase crossing portion 227V that connects the first V phase coil connection terminal 223V and the first V phase feeding terminal 225V.
The 1st V-phase coil connection terminal 223V is arranged substantially directly above the place where the end of the start line 16a of the 1st V-phase coil 161V is arranged, and the end of the start line 16a of the 1st V-phase coil 161V is connected. To.

On the other hand, the second U phase power bus bar 222U of the second system is the bus bar holder 220 on the side where the second V phase power bus bar 222V of the first layer and the second W phase power bus bar 222W of the first layer are arranged when viewed from the axial direction. It is centrally arranged in the half circle of. The second U-phase power bus bar 222U of the second system is formed by pressing a conductive plate-shaped member.

The basic configuration of the second U-phase power bus bar 222U of the second system is the same as that of the first V-phase power bus bar 221V of the first system, only the coil 16 to be connected is different.
That is, the second U phase power bus bar 222U of the second system includes a second U phase coil connection terminal 224U, a second U phase feeding terminal 226U, and a second U phase crossover portion 228U.
The second U-phase coil connection terminal 224U is arranged substantially directly above the portion where the end of the start line 16a of the second U-phase coil 162Ua is arranged. The end of the start line 16a of the second U-phase coil 162Ua is connected to the second U-phase coil connection terminal 224U.

As shown in FIG. 16, in the third layer of the bus bar unit 205, the first neutral point bus bar 241 of the first system and the second neutral point bus bar 242 of the second system ensure an insulation distance from each other. It is arranged in the state.

The first neutral point bus bar 241 is arranged in a range slightly shorter than the semicircle of the bus bar holder 220 when viewed from the axial direction. The first neutral point bus bar 241 is formed by pressing a conductive plate-shaped member. The first neutral point bus bar 241 has coil connection terminals 245U, 245V, 245W for each phase protruding outward in the radial direction (first U phase coil connection terminal 245U, first V phase coil connection terminal 245V, first W phase coil connection). It is composed of a terminal 245W) and a first crossing portion 247 connecting the coil connection terminals 245U, 245V, and 245W of each phase.

The 1st U-phase coil connection terminal 245U is arranged substantially directly above the place where the end of the end line 16b of the 1st U-phase coil 161Ub is arranged, and the end of the end line 16b of the 1st U-phase coil 161Ub is connected. To.
The 1st V-phase coil connection terminal 245V is arranged substantially directly above the place where the end of the end line 16b of the 1st V-phase coil 161Vb is arranged, and the end of the end line 16b of the 1st V-phase coil 161Vb is connected. To.
The 1st W phase coil connection terminal 245W is arranged substantially directly above the place where the end of the end line 16b of the 1st W phase coil 161Wb is arranged, and the end of the end line 16b of the 1st W phase coil 161Wb is connected. To.
The first crossover portion 247 is formed in an arc shape when viewed from the axial direction along the shape of the bus bar holder 20.

On the other hand, the second neutral point bus bar 242 is arranged in a range of line symmetry with respect to the first neutral point bus bar 241 about a straight line along an arbitrary radial direction. The basic configuration of the second neutral point bus bar 242 is the same as that of the first neutral point bus bar 241 except that the coil 16 to be connected is different.
That is, the second neutral point bus bar 242 connects the second U phase coil connection terminal 246U, the second V phase coil connection terminal 246V, and the second W phase coil connection terminal 246W to the coil connection terminals 246U, 246V, 246W of each phase. It is composed of a second crossing portion 248 and a second crossing portion 248.

The end of the final line 16b of the second U-phase coil 162Ub is connected to the second U-phase coil connection terminal 246U. The end of the final line 16b of the second V-phase coil 162Vb is connected to the second V-phase coil connection terminal 246V. The end of the final line 16b of the second W phase coil 162Wb is connected to the second W phase coil connection terminal 246W.

By arranging the predetermined bus bars 211,222 and 241,242 in the three layers in this way, as shown in FIG. 13, each coil 16a and the end line 16b of each coil 16 can be connected to each other. A bus bar unit 205 in which connection terminals 223U to 246W are arranged is configured.

FIG. 17 is a developed view of the coil 16 and the bus bar unit 205 of each phase.
As shown in the figure, a coil 16 is wound in a series around two teeth portions 33 of the same system and the same phase, and the coil 16 bridged over the two teeth portions 33 functions as a crossover coil 216. As a result, while reducing the number of bus bars 221,222, 241,242 constituting the bus bar unit 205, as shown in FIG. 10 described above, the coil 16 is provided with two systems of three phases (U phase, V phase, W). It can be connected by the star connection method so that it has a phase) structure.

As described above, in the above-described second embodiment, the coil 16 is provided with 12 teeth portions 33 (12 slots 17), the coil 16 is wound around the teeth portions 33 by a centralized winding method, and the rotating shaft 7 (12 slots 17) is further wound. In a brushless motor 1 provided with a stator 2 in which two coils 16 having the same phase of the same system are arranged to face each other (point-symmetrical arrangement) around the rotation axis L1 and the central axis L2), two coils of the same system have the same phase. The coil 16 is wound in a series. Then, the coil 16 spanning the two teeth portions 33 functions as a crossover coil 216 for connecting the coils 16 wound around the two teeth portions 33. Further, by forming the crossover coil 216, the bus bar unit 205 can be composed of each phase power supply bus bar 221U to 222W and each neutral point bus bar 241,242, and the bus bar unit 205 has a three-layer structure. it can. Moreover, the bus bar unit 205 is composed of each phase power supply bus bar 221U to 222W and each neutral point bus bar 241,242 without using the bus bar unit 205 for connecting the coils 16 of the same phase of the same system having a long wiring distance. There is. Therefore, the bus bar unit 205 itself can be miniaturized. As a result, the connection portion of the coil can be miniaturized.

Further, since each of the two coils 16 of the same system and the same phase and the corresponding crossover coil 216 are formed in a series by one coil 16, the winding work of the same system and the same phase is performed at once. This makes it possible to improve the efficiency of the winding work of the coil 16. Further, it is possible to prevent the length of the crossover coil 216 from becoming unnecessarily long, and it is possible to further reduce the size of the connection portion of the coil 16.

(Modified example of the second embodiment)
Next, a modified example of the second embodiment will be described with reference to FIG.
FIG. 18 is a perspective view of the split core 30 in the modified example of the second embodiment, and corresponds to FIG. 11 in the above-mentioned second embodiment.
Here, in the above-described second embodiment, the case where the crossover coil 216 spanning the two teeth portions 33 of the same system and the same phase is drawn on the bus bar unit 205 side of the stator 202 has been described. However, as shown in FIG. 18, the crossover coil 216 may be routed to the side opposite to the bus bar unit 205 of the stator 202.

In such a case, the number of turns of the crossover coil 216 is increased by 1/2 turn by the amount of the crossover coil 216 being routed to the side opposite to the bus bar unit 205. However, since both of the two coils 16 wound around the two teeth portions 33 in the same system and in the same phase increase by 1/2 turn, the magnetic balance is in the same system and in the same phase. Is kept.

With this configuration, in addition to achieving the same effect as in the second embodiment described above, the crossover coil 216 is routed to the side opposite to the bus bar unit 205 of the stator 202, so that the bus bar unit 205 and the crossover coil are routed. It is possible to prevent interference with 216. Therefore, when the connection work between the bus bar unit 205 and each coil 16 is performed, the crossover coil 216 does not get in the way, and the connection work between the bus bar unit 205 and each coil 16 can be facilitated.

In the above-described second embodiment and the modified example of the second embodiment, two coils 16 of the same system and the same phase and the corresponding crossover coil 216 are formed in a series by one coil 16. The case was explained. However, the present invention is not limited to this, and the coil 16 wound around each tooth portion 33 and the crossover coil 216 are separately formed, and these coils 16 and the crossover coil 216 are, for example, crimp terminals or the like. It may be configured to connect using. With such a configuration, the degree of freedom in the winding work of the coil 16 can be increased, for example, by attaching each tooth portion 33 to a separate jig and winding the coil 16.

Further, the present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the brushless motor 1 is used for the electric power steering device 100 has been described. However, the present invention is not limited to this, and the brushless motor 1 can be used in various electric drive devices.

Further, in the above-described embodiment, the case where the number M of the divided cores 30 constituting the stators 2 and 202 is 12 has been described. However, the number M of the divided cores 30 is not limited to this, and may be set so as to satisfy the above equation (1).

1,201 ... Brushless motor 2,202 ... Stator 5,205 ... Bus bar unit 16 ... Coil 16a ... Start line 16b ... End line 21U, 221U ... First U phase power supply bus bar (power supply bus bar)
21V, 221V ... Phase 1V power bus bar (power bus bar)
21W, 221W ... Phase 1W power bus bar (power bus bar)
22U, 222U ... Phase 2U power bus bar (power bus bar)
22V, 222V ... Phase 2V power bus bar (power bus bar)
22W, 222W ... Phase 2W power bus bar (power bus bar)
23U, 223U ... 1st U phase coil connection terminal (starting line connection position)
23V, 223V ... 1st V phase coil connection terminal (starting line connection position)
23W, 223W ... 1st W phase coil connection terminal (starting line connection position)
24U, 224U ... 2nd U phase coil connection terminal (starting line connection position)
24V, 224V ... 2nd V phase coil connection terminal (starting line connection position)
24W, 224W ... 2nd W phase coil connection terminal (starting line connection position)
33 ... Teeth section 41,241 ... 1st neutral point bus bar (neutral point bus bar)
42, 242 ... 2nd neutral point bus bar (neutral point bus bar)
43U ... Phase 1U intermediate bus bar (bus bar)
43V ... 1st V phase intermediate bus bar (bus bar)
43W ... Phase 1W intermediate bus bar (bus bar)
44U ... Phase 2U intermediate busbar (busbar)
44V ... Phase 2V intermediate bus bar (bus bar)
44W ... Phase 2W intermediate bus bar (bus bar)
45U, 51U, 245U ... 1st U phase coil connection terminal (end line connection position)
45V, 51V, 245V ... 1st V phase coil connection terminal (end line connection position)
45W, 51W, 245W ... 1st W phase coil connection terminal (end line connection position)
46U, 52U, 246U ... 2nd U phase coil connection terminal (end line connection position)
46V, 52V, 246V ... 2nd V phase coil connection terminal (end line connection position)
46W, 52W, 246W ... 2nd W phase coil connection terminal (end line connection position)
100 ... Electric power steering device 101 ... Steering 161Ua, 161Ub ... First U phase coil (coil)
161Va, 161Vb ... 1st V-phase coil (coil)
161Wa, 161Wb ... 1st W phase coil (coil)
162Ua, 162Ub ... Second U-phase coil (coil)
162Va, 162Vb ... Second V-phase coil (coil)
162Wa, 162Wb ... Second W phase coil (coil)
216 ... Crossover coil

Claims (7)

When N is a natural number, a stator having 12 N teeth and a coil wound around the teeth by a centralized winding method.
The coil is provided with a bus bar for star-connecting the coils so as to have a two-system three-phase structure.
A brushless motor in which two coils of the same system and the same phase are arranged to face each other around the central axis of the stator.
The length of the start line at the start of winding of each of the coils wound around the teeth portion and the length of the end line at the end of winding are set to different lengths, and the lengths of all the start lines are set. Is set to the same length, and the lengths of all the end lines are set to the same length. The brushless motor according to claim 1, wherein the length of the start line is set longer than the length of the end line. The start line pull-out position of the start line and the start line connection position of the corresponding start line to the bus bar are deviated in the circumferential direction, and
The end line pull-out position of the end line and the end line connection position of the corresponding end line to the bus bar are deviated in the circumferential direction.
Claim 1 or claim 1, wherein the deviation amount of the start line connection position with respect to the start line lead-out position and the deviation amount of the end line connection position with respect to the end line lead-out position are set to be the same, respectively. The brushless motor according to claim 2. It has 12 teeth parts, and the teeth parts are provided with a stator in which a coil is wound by a centralized winding method.
The coil is star-connected to a two-system three-phase structure.
A brushless motor in which two coils of the same system and the same phase are arranged to face each other around the central axis of the stator.
A crossover coil that connects the coils of the same phase arranged so as to face each other,
A power bus bar for connecting the power supply side terminal of the coil on the side connected to the power supply to the power supply, and
A bus bar for the neutral point for connecting the terminal portion on the neutral point side of the coil on the side connected to the neutral point to each other, and a bus bar for the neutral point.
Equipped with a,
The power supply bus bar is configured in two layers, and the neutral point bus bar is configured in one layer.
The first layer of the power bus bar includes a first U phase power bus bar and a first W phase power bus bar in the first system of the two systems, and a second V phase power bus bar in the second system of the two systems. , And the 2nd W phase power bus bar are arranged.
The first V-phase power bus bar in the first system and the second U-phase power bus bar in the second system are arranged in the second layer of the power bus bar.
The neutral point bus bar is a brushless motor including a first neutral point bus bar in the first system and a second neutral point bus bar in the second system. The brushless motor according to claim 4, wherein two coils having the same phase of the same system and the corresponding crossover coil are continuously formed by one coil. The power supply bus bar and the neutral point bus bar are arranged on one end surface side in the axial direction of the stator.
The brushless motor according to claim 4 or 5, wherein the crossover coil is arranged on the other end surface side in the axial direction of the stator. An electric power steering device according to any one of claims 1 to 6, wherein the brushless motor is used to assist the steering operation based on the steering operation of the vehicle.

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