Stator and brushless motor

Abstract

Stator of a motor, the stator comprising: a periphery with a cylindrical shape; a plurality of teeth extending from an inner peripheral surface of the periphery toward an inner peripheral side, the plurality of teeth being arranged at intervals along a circumferential direction of the periphery; a plurality of coil formers each attached to the plurality of teeth, each coil former surrounding a side surface of the corresponding tooth at an intermediate position between a first end of the tooth on a peripheral side and a second end of the tooth on a side opposite the first end; and a plurality of coils each provided on the plurality of coil bodies, wherein each of the plurality of coil bodies comprises: a first end side end located on a first end side; a circumferential surface having a pair of surface regions that are opposite to each other, viewed in a cross section along an extending direction of the corresponding tooth; and a groove located at the end of the first end face on at least the pair of surface areas, wherein each of the plurality of coils comprises: a wire insertion portion where a wire of the coil is inserted into the groove from outside the coil body; an adjustment portion provided continuously with the wire insertion portion, the adjustment portion having one or two adjacent turns of the wire in the groove from the turns of the wire wound once or twice around the coil body; and a plurality of wire layers, each of the plurality of wire layers having windings of the wire arranged adjacent to each other along the extending direction of the corresponding tooth, wherein a first wire layer of a lowermost layer arranged on the pair of surface regions of the plurality of wire layers contacts windings of the wire provided in the adjustment region and the peripheral surface of the coil body, and in each of the plurality of coils provided on the corresponding pair of surface areas: an odd-numbered wire layer of the plurality of wire layers arranged on the corresponding pair of surface regions has the wire wound from the first end side successively to a second end side, and a winding of the wire located at the end of the first end side is separated from the inner peripheral surface of the periphery by half a pitch; an even-numbered wire layer of the plurality of wire layers arranged on the corresponding pair of surface regions has the wire wound sequentially from the second end side to the first end side; each of two and subsequent wire layers of the plurality of wire layers has a winding of the wire located on an end face of the coil body on a wire insertion portion side and windings of the wire other than the winding of the wire located on the end face of the coil body; the windings of the wire other than the winding of the wire located on the end face of the coil body are arranged along recesses between two adjacent windings of the wire in a wire layer located on a layer below; and the winding of the wire located on the end face of the coil body is arranged in a direction that crosses the windings of the wire in the wire layer located one layer below.

Description

[0001] The technology disclosed here relates to a stator and a brushless motor.

[0002] JP 2006-67778 A discloses a technique for forming a coil by winding a wire on an insulator covering a tooth of an armature. Each coil has a first layer in which a plurality of turns of the wire are wound parallel to each other on an outer periphery of the insulator, and a second layer in which a plurality of turns of the wire are wound parallel to each other on the first layer. US 7 579 735 B2, a family member of JP 2006-67778 A, also discloses a technique for forming a coil by winding a wire on a tooth of an armature, and DE 10 2013 001 916 A1, DE 10 2012 209 221 A1, JP 2012-19574 A, JP 2007-89346 A and JP 2004-72970 A disclose further techniques for winding a coil.

[0003] When a wire is wound onto a bobbin attached to each tooth, the wire can be wound onto it while avoiding other parts of a stator, such as an outer wall of the stator.

[0004] In this specification, a technique is provided for appropriately winding a wire while avoiding other parts of a stator, and it is an object to provide a stator with a dense wire winding in which noise during winding can be avoided, and a corresponding brushless motor.

[0005] This object is achieved by a stator according to claim 1 or 10 or a brushless motor according to claim 9. Further developments are specified in the dependent claims.

[0006] On the surfaces of the bobbin where the grooves are provided, the even-numbered wire layer is wound from the second end toward the first end. With this structure, in a state where the wire is to be wound in a periphery vicinity in the even-numbered wire layer, the adjacent winding of the wire on the second end side to the wire to be wound is already arranged. Thereby, the wire in the periphery vicinity is guided by its neighboring wire and wound accordingly in the periphery vicinity. As a result, the wire or a device for winding the wire can perform the winding operation while avoiding interference with the periphery.

[0007] In contrast, on the surfaces of the coil bobbins where the grooves are provided, the odd-numbered wire layer is wound from the first end toward the second end. With this structure, when winding the wire in the odd-numbered layer is started, winding must be performed while avoiding the periphery. According to the above structure, a winding of the wire in the odd-numbered layer located at the outermost end of the first end side is separated from the inner peripheral surface of the periphery by half a pitch. As a result, compared with a structure in which the winding of the wire in the odd-numbered layer located at the outermost end of the first end side is arranged without separation from the inner peripheral surface of the periphery, the wire or the device for winding the wires can be prevented from interfering with the periphery during wire winding. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a vertical cross-sectional view of a fuel pump; Fig. 2 is a perspective view of a stator; Fig. 3 is a plan view of an expanded core main body; Fig. 4 is a top view showing a split core for explaining a process of winding wires on a bobbin according to a first embodiment; Fig. 5 is a top view showing the split core for explaining the process of winding the wires on the bobbin according to the first embodiment; Fig. 6 is a top view showing the split core for explaining the process of winding the wires on the bobbin according to the first embodiment; Fig. 7 is a view showing the split core from below for explaining the process of winding the wires on the bobbin according to the first embodiment; Fig. 8 is a top view showing the split core for explaining the process of winding the wires on the bobbin according to the first embodiment; Fig. 9 is a top view showing the split core for explaining the process of winding the wires on the bobbin according to the first embodiment; Fig. 10 is a diagram for explaining a winding state of the wires in the first embodiment; Fig. 11 is a plan view of a partial core of a comparative example; Fig. 12 is a top view showing the split core for explaining a process of winding the wires on a bobbin according to the comparative example; Fig. 13 is a top view showing a split core for explaining a process of winding wires on a bobbin according to a second embodiment; Fig. 14 is a view showing the split core from above for explaining a winding state of the wires in the second embodiment; Fig. 15 is a top view showing a split core for explaining a process of winding the wires on a bobbin according to a third embodiment; Fig. 16 is a top view showing the split core for explaining the process of winding the wires on the bobbin according to the third embodiment; Fig. 17 is a view showing the split core from above for explaining a winding state of the wires in the third embodiment; Fig. 18 is a top view showing a split core for explaining a process of winding the wires on a bobbin according to a variant; Fig. 19 is a view showing the split core from the right side for explaining the process of winding the wires on the bobbin according to the variant; Fig. 20 is a view showing the split core from a left side for explaining the process of winding the wires on the bobbin according to the variant; Fig. 21 is a diagram for explaining a winding state of the wires in a fourth embodiment; Fig. 22 is a diagram for explaining the winding state of the wires in the fourth embodiment; Fig. 23 is a plan view of a partial core according to a fifth embodiment; Fig. 24 is a diagram for explaining a winding state of the wires in the fifth embodiment; Fig. 25 is a plan view of a partial core according to a sixth embodiment; Fig. 26 is a diagram for explaining a winding state of the wires in the sixth embodiment; Fig. 27 is a plan view of a sub-core according to a seventh embodiment; Fig. 28 is a diagram for explaining a winding state of the wires in the seventh embodiment; Fig. 29 is a plan view of a sub-core according to an eighth embodiment; Fig. 30 is a diagram for explaining a winding state of the wires in the eighth embodiment; Fig. 31 is a plan view of a partial core according to a variant; Fig. 32 is a plan view of a partial core according to a variant; Fig. 33 is a plan view of a partial core according to a variant; and Fig. 34 is a plan view of a partial core according to a variant. DETAILED DESCRIPTION

[0008] Some primary features of the embodiments described herein are listed. The technical features described below are technical elements independent of each other and are technically useful alone or in various combinations.

[0009] (Feature 1) In a stator, a specific wire to be wound to form a first winding in the first wire layer can be arranged together with turns of the wire wound in the adjustment area. According to this configuration, the wire wound into a first winding among the turns of the wires in the first wire layer can be appropriately positioned. As a result, the windings of the wire in the first wire layer can be prevented from being disturbed.

[0010] (Feature 2) In the stator, the adjustment portion may include a winding of the wire wound once adjacent to a sidewall defining the groove. The specific wire may be arranged along a recess between the winding of the wire wound on the adjustment portion and an upper end of the sidewall. According to this configuration, the wire to be wound into the first winding among the windings of the wires in the first wire layer can be properly positioned by the winding of the wire in the adjustment portion and the sidewall of each groove. As a result, the windings of the wire in the first wire layer can be prevented from being disturbed.

[0011] (Feature 3) In the stator, the adjustment portion may include two turns of wire arranged adjacent to each other. One of the two turns of wire may be located on the second end side and may be adjacent to a sidewall defining the groove. The specific wire may be arranged along a recess between one of the two turns of wire and an upper end of the sidewall. According to this configuration, the wire to be wound into the first turn among the turns of wires in the first wire layer can be properly positioned by winding the wire in the adjustment portion and the sidewall of each groove. As a result, the turns of wire in the first wire layer can be prevented from being disturbed.

[0012] (Feature 4) In the stator, the adjustment portion may include two adjacent turns of the wire arranged adjacent to each other. The specific wire may be wound along a recess between the two adjacent turns of the wire of the adjustment portion. According to this configuration, the wire to be wound into the first winding among the turns of the wires in the first wire layer can be properly positioned by the adjacent turns of the wire in the adjustment portion. As a result, the windings of the wire in the first wire layer can be prevented from being disturbed.

[0013] (Feature 5) In the stator, the odd-numbered wire layer may include the wire winding located at the first end side, separated from the inner peripheral surface of the periphery by half a pitch. The even-numbered wire layer may include the wire winding located at the first end side, in contact with the inner peripheral surface of the periphery. According to this structure, the number of wire windings can be increased.

[0014] (Feature 6) In the stator, the groove may surround the circumferential surface of the coil bobbin at the first end side. According to this configuration, in a state where the turns of the wire in the periphery vicinity are to be wound into the even-numbered wire layer, the adjacent turns of the wire on the second end side to the wire to be wound are already arranged by winding around each coil bobbin. Thereby, over the entire circumference of the coil bobbin, the turns of the wire in the periphery vicinity are guided by their adjacent turns of the wire and wound accordingly in the periphery vicinity. This allows the wire to be suitably arranged on the first end side.

[0015] (Feature 7) A brushless motor having the stator described above and a pump having the motor are also new and useful.

[0016] (Feature 8) In the stator, each of the grooves may be located on at least one pair of surface portions provided in the circumferential surface of the corresponding coil bobbin, the one pair of surface portions extending along an axial direction of the periphery. Each of the plurality of coil bobbins may have an extended width portion that expands a width of the groove at a portion of the groove located on the pair of surface portions. A width of the width portion may be smaller than a wire diameter of the wire. The insertion portion may be arranged in the groove on another one of the pair of surface portions. According to this configuration, the wire wound on the adjustment portion can be prevented from slipping off the adjustment portion. (First embodiment)

[0017] As in Fig. 1, a stator 60 and a motor 50 according to the present embodiment are arranged in a fuel pump 10. The fuel pump 10 is to be arranged in a fuel tank (not shown) and supplies fuel (for example, gasoline) to an internal combustion engine (not shown) of a vehicle, for example, a car. As shown in Fig. As shown in Figure 1, the fuel pump 10 further includes a pump 30 other than the motor 50. The motor 50 and the pump 30 are arranged in a housing 2. The housing 2 has a cylindrical shape with both ends open.

[0018] The pump 30 includes a housing 32 and an impeller 34. The housing 32 closes a lower end opening of the casing 2. A suction introduction portion 38 is provided at a lower end of the housing 32. A communication hole (not shown) for connecting an interior of the housing 32 to the motor 50 is provided at an upper end of the housing 32. The impeller 34 is housed in the housing 32.

[0019] The motor 50 is located above the pump 30. The motor 50 is a brushless motor and is a three-phase motor. The motor 50 has a rotor 54, a stator 60, and a terminal 70. The rotor 54 has a permanent magnet. A shaft 52 projects through a center of the rotor 54 and is fixed thereto. A lower end of the shaft 52 is inserted into and penetrates a center part of the impeller 34. The rotor 54 is rotatably supported via the shaft by bearings arranged at both ends of the shaft 52. According to the embodiments, a vertical direction is defined according to the Fig. 1. The pump 30 is therefore located "below" as seen from the motor 50, and the motor 50 is located "above" as seen from the pump 30.

[0020] The stator 60 is covered by a resin layer 66. The resin layer 66 closes the upper end opening of the housing 2. The discharge outlet 11 is provided at an upper end of the resin layer 11. The discharge outlet 11 connects the motor 50 and the exterior of the fuel pump 10. The discharge outlet 11 is an opening for discharging the fuel pressurized by the pump 30 to a fuel passage. In the resin layer 66, a portion covering the stator 60 and the discharge outlet 11 are integrally formed by resin. The portion covering the stator 60 and the discharge outlet 11 may be formed separately.

[0021] The stator 60 includes a core main body 90 and a plurality of (six in this embodiment) coils 96 arranged on the core main body 90. A terminal 70 is attached to the upper end of the stator 60. The terminal 70 is connected to a battery (both not shown) via a control circuit. The terminal 70 is a terminal for supplying electrical power to the coils 96 of the stator 60.

[0022] The core main body 90 includes a set of core plates (92, 92, ...) and an insulator 94 provided on one surface of the set of core plates (92, 92, ...). The set of core plates (92, 92, ...) is constructed from a plurality of pieces of core plates 92. In Fig. In FIG. 1, hatching indicating cross sections of the plurality of core plates 92 is omitted. The plurality of core plates 92 are laminated in a vertical direction, and each core plate 92 is formed of a magnetic material. The insulator 94 is formed of an insulating resin material. The insulator 94 covers the surface of the set of core plates (92, 92, ...) configured from the laminated plurality of core plates 92.

[0023] As in Fig. As shown in FIG. 2, the core main body 90 includes six sub-cores U1, V1, W1, U2, V2, and W2. The six sub-cores U1 to W2 are arranged in a cylindrical shape. The six sub-cores U1 to W2 are configured from two U-phase sub-cores U1, U2, two V-phase sub-cores V1, V2, and two W-phase sub-cores W1, W2. Since all sub-cores U1 to W2 have substantially identical structures, an explanation will be given using sub-core W1 as an example.

[0024] The partial core W1 has a periphery 95 and a tooth 91 (see Fig. 3) and a coil body 99 (see Fig. 3). The periphery 95 is positioned on the outermost side of the sub-core W1. The periphery 95 is configured from a peripheral portion of the core plate 92, and the insulator 94 covers the peripheral portion of the core plate 92. An outer peripheral surface of the periphery 95 has a partially cylindrical shape. An inner peripheral surface of the periphery 95 has a flat plate shape. The periphery 95 is connected to the peripheries 95 of the adjacent sub-cores U2, V1. The cylindrical shape is formed by six sub-cores U1 to W2 connected by their peripheries 95.

[0025] As in Fig. 3, the tooth 91, which extends towards the center of the stator 60, is arranged at a central region of the periphery 95. In particular, in Fig. 3 the sub-core W1 and the sub-cores U2, V1 adjacent to the sub-core W1. In an expanded state of the core main body 90, as in Fig. 3, however, the six sub-cores U1 to W2 are arranged linearly, as shown by the sub-cores W1, V1, U2.

[0026] The tooth 91 is formed by a portion of the core plate 92 extending from the peripheral portion of the core plate 92 forming the periphery 95 toward an inner circumferential side of the periphery 95. In particular, the portion corresponding to the partial core W1 in Fig. 3, within the core plate 92, but in reality the core plate 92 has the areas corresponding to the six connected sub-cores U1 to W2.

[0027] As in Fig. 2, six teeth 91 arranged in the six partial cores U1 to W2 are arranged at regular intervals in the circumferential direction of the peripheries 95. As shown in Fig. 3, an intermediate portion 91a of each tooth 91 extends to the inner circumferential side of the periphery 95 (lower side in Fig. 3) from the corresponding periphery 95. An inner circumferential end of the tooth 91 extends in the circumferential direction of the peripheries 95 and has a shape that follows an outer circumferential surface of the rotor 54. The tooth 91 is covered by the insulator 94. An inner circumferential portion 91b covered by the insulator 94 is provided at an inner circumferential end of the tooth 91.

[0028] The coil bobbin 99 is formed by the insulator 94 covering the tooth 91 at a portion thereof covering the intermediate portion 91a. The coil bobbin 99 surrounds one side surface of the intermediate portion 91a. More specifically, the coil bobbin 99 covers four surfaces of the intermediate portion 91a positioned between the periphery 95 and the inner peripheral end of the tooth 91. Guides 99a for supporting a wire 97 are provided on an outer peripheral surface of the coil bobbin 99. The guides 99a have a recessed shape formed on the outer peripheral surface of the coil bobbin 99. The guides 99a are provided at least at four corners of the coil bobbin 99, respectively. Specifically, one guide 99a may be provided over an entire circumference of the outer peripheral surface of the coil bobbin 99. The guides 99a have a shape that follows an outer shape of the wire 97.

[0029] A groove 100 is provided at one end of the coil bobbin 99 on one side of the periphery 95. In the groove 100, the outer peripheral surface of the coil bobbin 99 is recessed compared to other portions of the outer peripheral surface of the coil bobbin 99. In other words, in the groove 100, the outer peripheral surface of the coil bobbin 99 is closer to the tooth 91 than other portions of the outer peripheral surface of the coil bobbin 99. The groove 100 is provided over an entire circumference of the outer peripheral surface of the coil bobbin 99. Thereby, a circumferential length of the coil bobbin 99 with the groove 100 provided thereon is shorter than a circumferential length of the coil bobbin 99 at other portions. A width of the groove 100 (i.e., a length of the groove 100 in a radial direction of the stator 60) is substantially equal to a wire diameter of the wire 97.A depth of the groove 100 (i.e., a length of the groove 100 in a vertical direction in a cross section of the groove 100) is substantially equal to the wire diameter of the wire 97.

[0030] As in Fig. 2, a coil 96 is arranged on each coil former 99. The coil 96 is formed by winding the wire 97 onto the coil former 99. The coil 96 is electrically connected to the terminal 70. The coil 96 of the split core W1 is connected to the coil 96 of the split core W2, and a like-phase potential is supplied to the coil 96 of the split core W1 and the coil 96 of the split core W2. Similarly, the coil 96 of the split core U1 is connected to the coil 96 of the split core U2, and a like-phase potential is supplied to the coil 96 of the split core U1 and the coil 96 of the split core U2. Similarly, the coil 96 of the split core V1 is connected to the coil 96 of the split core V2, and a like-phase potential is supplied to the coil 96 of the split core V1 and the coil 96 of the split core V2. (wire winding process)

[0031] Next, a method of manufacturing the coils 96 by winding wires 97 will be described with reference to FIG. Fig. 4 to 10. As described in Fig. 3, the wires 97 are wound in a state in which the partial cores U1 to W2 are arranged in a straight line. In the drawings according to Fig. 4 and the other drawings, in particular, the guides 99a provided on the coil bodies 99 have been omitted, and a further simplification has been made for better clarity. Each wire 97 is wound in the order of Fig. 4 to Fig. 9 wrapped. Fig. Fig. 7 is a view showing a wound state of the wire 97 at the same time as a state shown in Fig. 6 is shown, and Fig. 6 is a view showing the sub-core W1 from above, whereas Fig. 7 is a view showing the sub-core W1 from below. Fig. 10 shows a state after the coil 97 is manufactured, and the wire 97 is shown by a cross section at a portion on an upper surface of the coil body 99.

[0032] As in Fig. 4, first, one end of the wire 97 is inserted into an engaging portion 95a positioned at an upper end of the periphery 95. The wire 97 is supplied from a winding device 8. The wire 97 inserted into the engaging portion 95a is pulled from a left side of the coil body 99 to a right side of the coil body 99 by passing over the upper surface of the coil body 99. As shown in Fig. 5, the winding device 8 is then moved along the circumferential direction of the coil body 99, and the wire 97 is wound into the groove 100.

[0033] As a result, as in Fig. 5, the wire 97 is inserted through a wire insertion portion 97a from the engaging portion 95a to the groove 100, and is disposed within the groove 100. More specifically, the wire 97 is inserted from the wire insertion portion 97a into the groove 100 through an extended portion 95b provided in the periphery 95. The extended portion 95b expands the width of the groove 100 toward the periphery 95 side. The extended portion 95b is shaped such that the width of the groove 100 gradually becomes smaller toward the lower side. In other words, a length of the extended portion 95a in the radial direction of the rotor 94 gradually becomes shorter toward the lower side. The extended portion 95b disappears at a center portion of the groove 100 in the vertical (up-down) direction.The extended portion 95b is provided to prevent interference with the wire 97 located in the wire insertion portion 97a during winding of the wire 97 onto the coil body 99. Thus, the wire 97 in the extended portion 95b can move in a Y-axis direction by being pressed by other portions of the wire 97 during winding of the wire 97 onto the coil body 99.

[0034] From the condition according to Fig. 5, the winding device 8 is further moved in the circumferential direction of the coil body 99 and parallel to the Y-axis toward the inner circumferential region 91b as the wire 97 advances along the Y-axis. Thereby, as shown in the Fig. 6 and Fig. 7, an adjustment portion 97b and a first wire layer CL1 are formed. The adjustment portion 97b is formed in the groove 100 by the wire 97 being wound once. In the wire layer CL1, the wire 97 is tightly wound from the side end of the periphery 95 of the coil body 99 toward its opposite end. The wire 97 is thus wound adjacently. A pitch of the coil 96 is therefore equal to the wire diameter of the wire 97. Specifically, the wire 97 is wound at the side end of the periphery 95 of the coil body 99 in the wire layer CL1 along a recess formed by the wire 97 of the adjustment portion 97b and a side surface of the groove 100 (see a recess X1 in Fig. 10). According to this structure, the wire 97 forming a first winding can be appropriately positioned among the windings of the wire 97 in the wire layer CL1. As a result, the windings of the wire 97 wound thereafter in the wire layer CL1 can be prevented from being disturbed. The winding of the wire 97 at the side end of the periphery 95 of the coil body 99 in the wire layer CL1 (i.e., the wires C3, C4 in Fig. 10) is separated from the inner peripheral surface of the periphery 95 by substantially half a pitch (i.e., a length that is 1 / 2 the wire diameter of the wire 97). On the other hand, the winding of the wire 97 forms a winding path at one side end of the inner peripheral portion 91b of the coil body 99 in the wire layer CL1 (i.e., the wires C11, C12 in Fig. 10) contact with the inner peripheral region 91b.

[0035] By comparing the Fig. 6, Fig. 7, it is apparent that in the wire layer CL1, which is the first layer, the windings of the wire 97 arranged on the upper end surface of the coil body 99 are inclined relative to an X-axis, whereas the windings of the wire 97 arranged on the lower end surface of the coil body 99 are wound vertically (i.e., parallel to the X-axis direction) to the advancing direction of the wire 97 (i.e., Y-axis direction).

[0036] Next, the winding device 8 is moved along the circumferential direction of the bobbin 99 and from the inner circumferential portion 91b toward the periphery 95 along with advance of the wire 97. As a result, as shown in Fig. 8, a wire layer CL2, which is a second layer, is formed. In the wire layer CL2, the wire 97 is tightly wound from the side end of the inner peripheral portion 91b of the coil body 99 toward the side end of the periphery 95. In the wire layer CL2, specifically, the winding of the wire 97 on the side end of the inner peripheral portion 91b of the coil body 99 (i.e., the wires C11, C12 in Fig. 10) makes contact with the inner peripheral portion 91b, and the winding of the wire 97 (i.e. the wires C19, C20 in Fig. 10) on the side end of the periphery 95 forms a contact with the periphery. Furthermore, the windings of the wire 97, except for both ends in the wire layer CL2 (i.e., the wires C13 to C18 in Fig. 10), wound along recesses formed between the windings of wire 97 in the wire layer CL1.

[0037] As in Fig. 8, when the winding of the wire 97 at the side end of the periphery 95 (i.e. the wires C19, C20 in Fig. 10), the wire 97 is wound by connecting it with the previously wound winding of the wire 97 at the side end of the periphery 95 (i.e. the wires C17, C18 in Fig. 10) is brought into contact. When the wire 97 is arranged at the position defined by the wire C21 in Fig. 10, and is wound there, the wire 97 slides down along the wire C17 and is placed at the position of the wire C19. This allows winding to be performed without having to bring the winding device 8 close to the periphery 95 to an extent at which the device can make contact with the periphery 95.

[0038] Further, in the wire layer CL2, the windings of the wire 97 arranged on the upper end surface of the coil body 99 are inclined in the direction of the advancing direction along the Y-axis of the wire 97 relative to the X-axis, whereas the windings of the wire 97 arranged on the lower end surface of the coil body 99 are wound to cross the windings of the wire 97 on the wire layer CL1.

[0039] From the Fig. 8, next, the winding device 8 is moved along the circumferential direction of the bobbin 99 to form a wire layer CL3, which is a third layer (see Fig. 10). As a result, the winding of the wire 97, which is located at the side end of the periphery 95 of the wire layer CL3 (i.e., the wires C21, C22 in Fig. 10) is wound along a recess X2 formed by two windings of the wire 97 extending from the side end of the periphery 95 of the wire layer CL2 (i.e., the wires C11 to C20 in Fig. 10) are wound.

[0040] As a result, the winding of the wire 97 at the side end of the periphery 95 of the coil body 99 of the wire layer CL3 (i.e. wires C21, C22 in Fig. 10) is separated from the inner peripheral surface of the periphery 95 by substantially half a pitch. According to this structure, winding can be performed without bringing the winding device 8 close to the periphery 95 to an extent at which the device can form contact with the periphery 95.

[0041] From the Fig. 9, the coil 96 is manufactured by winding the winding device 8 along the circumferential direction of the coil body 99 and between the periphery 95 and the inner peripheral portion 91b to form the wire layers CL3 and CL4. One end of the wire 97 of the coil 96 is connected to the wire 97 of the coil 96 arranged in the divided core W2. Similarly, one end of the wire 97 of the coil 96 of the divided core U1 is connected to the wire 97 of the coil 96 arranged in the divided core U2, and one end of the wire 97 of the coil 96 of the divided core V1 is connected to the wire 97 of the coil 96 arranged in the divided core V2.

[0042] As in Fig. As shown in Figure 10, in each coil 96, the wires C3, C4, C21, C22 are separated from the inner peripheral surface of the periphery 95 by 1 / 2 the wire diameter of the wire 97 in the odd-numbered wire layers CL1, CL3. Meanwhile, in the even-numbered wire layers CL2, CL4, the wires C19, C20, C37 contact the inner peripheral surface of the periphery 95. According to a variant, each coil 96 can be formed from five or more wire layers. According to this variant, the wire can also be separated from the inner peripheral surface of the periphery 95 by 1 / 2 the wire diameter of the wire 97 in the odd-numbered wire layers CL1, CL3, ..., and the wire can contact the inner peripheral surface of the periphery 95 in the even-numbered wire layers CL2, CL4, .... (Effects of the present exemplary embodiment)

[0043] The effects of the present embodiment will be shown in a comparison with one shown in the Fig. 11 and Fig. 12. In the comparative example, no groove 100 is provided in the coil bodies 199, and consequently, its circumferential length is the same overall from the side end of the periphery 59 to the side end of the inner circumferential portion 91b. In this comparative example, as shown in Fig. 12, the windings of the wire 97 in the first wire layer CL1 form contact with the inner peripheral surface of the periphery 95, whereas the windings of the wire 97 in the second wire layer CL2 are separated from the inner peripheral surface of the periphery 95 by substantially half a pitch. According to this structure, when the wire 97 is wound as tightly as possible in the coil 96, the winding of the wire 97 must be arranged at the side end of the periphery 95 in the third wire layer CL3 to form contact with the inner peripheral surface of the periphery 95.

[0044] The winding of the wire 97 at the side end of the periphery 95 is the wire wound as the first winding among the windings of the wire 97 in the third wire layer CL3. As a result, the third wire layer does not have a wire wound thereon that would guide the winding of the wire 97 at the side end of the periphery 95. The wire 97 at the side end of the periphery 95 is thus wound along a recess between the winding of the wire 97 at the side end of the periphery 95 in the second wire layer and the inner peripheral surface of the periphery 95. As a result, the wire 97 must be wound in the state where the winding device 8 is brought close to the periphery 95.In this state, when the wire 97 extending from the winding device 8 is strongly pulled, the wire 97 slips out of the recess between the winding of the wire 97 at the side end of the periphery 95 in the second wire layer and the inner peripheral surface of the periphery 95, and there is a case where it cannot be wound appropriately.

[0045] As in Fig. As shown in FIG. 10, the adjustment portions 97b are provided on the stator 60 according to the present embodiment. Thus, the odd-numbered wire layers CL1, CL3 (i.e., the wires C3, C4, C21, C22) are separated from the inner peripheral surface of the periphery 95 by substantially half a pitch. This can prevent a situation like that in the comparative example. Furthermore, the even-numbered wire layers CL2, CL4 (i.e., the wires C19, C20, C37) make contact with the inner peripheral surface of the periphery 95, but in the even-numbered wire layers CL2, CL4, the wire 97 is wound from the inner peripheral portion 91b toward the periphery 95.Therefore, in the state where the windings for the wires C19, C20, C37 are wound, the winding of the wire 97 adjacent to the winding of the wire 97 for contact with the inner peripheral surface of the periphery 95 (i.e., the wires C17, C18, C35) is already wound in the even-numbered wire layers CL2, CL4. Thus, the wires C19, C20, C37 are properly wound by passing through the wires C17, C18, C35. According to the structure of the present embodiment, the wire 97 can be properly wound at a high density without being brought into close contact with the periphery 95.

[0046] In the Fig. 12, in the third wire layer, the wire 97 interferes with the winding of the wire 97 at the wire insertion portion 97a when winding the wire 97 to form the first winding. This makes it difficult to wind the wire 97 to contact the inner circumferential surface of the periphery 95. In the present embodiment, however, as shown in Fig. 9, the winding of the wire 97 wound at the side end of the periphery 95 in the third wire layer CL3 is wound along the recess between two windings of the wire 97 on the side of the periphery 95 of the wire layer CL2, which includes the winding of the wire 97 wound at the side end of the periphery 95 in the second wire layer CL2 (wires C17 and C19, C18 and C20), and thus are not influenced during their winding process by the winding of the wire 97 in the wire insertion portion 97a. According to the stator 60 of the present embodiment, the wire 97 can be prevented from making contact with the wire insertion portion 97a when the wire 97 is wound, which would result in defective winding. (Second embodiment)

[0047] Points different from the first embodiment will be explained with reference to the Fig. 13 and Fig. 14. In the present embodiment, compared with the first embodiment, a shape of a groove 200 differs from a shape of the groove 100 in the first embodiment. Furthermore, in the present embodiment, a winding method of the wires 97 constituting the coil 96 is different from the first embodiment.

[0048] As in Fig. As shown in Fig. 14, the groove 200 is provided at the side end of the periphery 95 of the coil bobbin 99, similar to the groove 100, and in the groove 200, the outer peripheral surface of the coil bobbin 99 is recessed compared with other portions of the outer peripheral surface of the coil bobbin 99. A width of the groove 200 is substantially equal to twice the wire diameter of the wire 97. Other configurations of the groove 200 are identical to those of the groove 100. (wire winding process)

[0049] As in Fig. As shown in Fig. 13, the wire 97 passes through the wire insertion portion 97a similarly to the first embodiment and is arranged in the groove 200. Then, the wire 97 is wound twice in the groove 200. As a result, two turns of the wire 97, which are adjacent in the Y-axis direction, are arranged in the groove 200. As shown in Fig. As shown in Fig. 14, the wire 97 is wound in the groove 200 along a direction from the periphery 95 to the inner circumferential region 91b, that is, in a sequence of wires C1, C2, C3, C4. This forms an adjustment region 297b within the groove 200.

[0050] When the setting area 297b is formed, then, as indicated by an arrow in Fig. 13, the wire 97 is wound on the adjustment portion 297b. As a result, the first winding of the wires C5, C6 for the wire layer CL1 is wound. The winding of the wires C5, C6 is performed along a recess X201 formed by the windings of the wires C1, C2, C3, C4 in the adjustment portion 297b. According to this configuration, the first winding of the wire 97 can be properly positioned among the windings of the wire 97 in the wire layer CL1. As a result, the windings of the wire 97 in the wire layer CL1 to be subsequently wound can be prevented from being disturbed. In this winding method, the wire 97 for forming the first winding of the wire 97, among the windings of the wire 97 in the wire layer CL1, crosses the windings of the wire 97 forming the adjustment portion 297b on an upper end side of the coil body 99.

[0051] Next, as in Fig. As shown in Figure 14, similarly to the first embodiment, the wire 97 is wound to form the wire layers CL1 to CL4, thereby fabricating the coil 96. Each coil 96 may have five or more wire layers.

[0052] In the present embodiment, the same or similar effects as in the first embodiment can be achieved. (Third embodiment)

[0053] Points different from the second embodiment will be explained with reference to the Fig. 15 to 17. In the present embodiment, compared with the second embodiment, a winding method of the wires 97 for forming the coils 96 is different. (wire winding process)

[0054] As in Fig. As shown in Fig. 15, the wire 97 passes through the wire insertion portion 97a, similar to the second embodiment, and is arranged in the groove 200. The wire 97 is then wound twice in the groove 200. As a result, two turns of the wire 97, which are adjacent in the direction from the periphery 95 to the inner circumferential portion 91b, are arranged in the groove 200. As shown in Fig. As shown in Fig. 17, the wire 97 is wound in the groove 200 along the direction from the periphery 95 toward the inner circumferential region 91b, that is, in the order of the wires C1, C2, C3, C4. This forms an adjustment region 397b in the groove 200.

[0055] When the adjustment area 397b is formed, the wire 97 is wound to form the first winding in the wire layer CL1 along a recess X301 (see Fig. 17) formed by the winding of the wire 97 at the side end of the inner peripheral portion 91b in the adjustment portion 397b and the side surface of the groove 200. According to this configuration, the first winding of the wire 97 can be properly positioned among the windings of the wire 97 in the wire layer CL1. As a result, the windings of the wire 97 in the wire layer CL1 that are subsequently wound can be prevented from being disturbed.

[0056] Next, the wire 97 is wound toward the inner peripheral portion 91b. As shown in Fig. 16, when the wire 97 is wound in the wire layer C1 until it forms contact with the inner peripheral portion 91b (wires C9, C10 in Fig. 17), similarly to the first and second embodiments, the wire layer CL2 is wound after the wire 97 is wound on the side end of the inner peripheral portion 91b of the wire layer CL2 (wires C11, C12 in Fig. 17) was formed.

[0057] As in Fig. As shown in Fig. 17, when the winding of the wires C15, C16 is wound in the wire layer CL2, the wire 97 is wound on the windings of the wires C1 to C4 of the adjustment portion 397b. Thus, when the winding of the wires C15, C16 is wound, the wire 97 is wound to form the wire layer CL1. Next, the winding of the wires C19, C20 constituting the wire layer CL2 is formed on the windings of the wires C5, C6, C17, C18, and then the winding of the wires C21, C22 is wound. This forms the wire layer CL2. Subsequently, the wire 97 is wound similarly to the first and second embodiments to produce the coil 96 having the wire layers CL1 to CL4.

[0058] In the present embodiment, similar effects are also achieved as in the first and second embodiments. (Fourth embodiment)

[0059] In the above-mentioned embodiments, the grooves 100, 200 are provided over the entire circumference of the outer peripheral surfaces of the coil bobbins 99. In this embodiment, however, the grooves 100 are provided on a pair of surfaces of each tooth 91 that are opposite to each other, with the intermediate portion 91a (the pair of surfaces extending in the vertical direction) on the outer peripheral surface of each coil bobbin 99 therebetween. In this case, the lower end of the wire insertion portion 97a is continued to the wire 97 arranged in the groove 100. Fig. 21 and Fig. 22 show a winding state of the wire 97 in the case where the grooves 100 are provided on the pair of surfaces extending in the vertical (up-down) direction in the bobbin 99. Fig. Figure 21 shows the wire 97 in a cross-section along a position on the upper surface of the coil body 99, and Fig. Figure 22 shows the wire 97 in a vertical cross-section of the upper surface of the coil former 99 at the center position on the upper surface of the coil former 99. The numbers in the wires indicate the number of windings of the wire 97.

[0060] As in Fig. 21, the wire 97 of the first winding (i.e., with the number “1” in the wire 97) is arranged in the grooves 100. On the surfaces where the grooves 100 are not provided, as in Fig. 22, the first winding of the wire 97 corresponds to the wire to be wound first in the first wire layer. On the areas provided with the grooves 100, the wire 97 is wound four times, five times, four times, and five times, respectively, in the first wire layer CL1 up to the fourth wire layer CL4. On the other hand, on the areas where the grooves 100 are not provided, the wire 97 is wound five times, four times, five times, and four times, respectively, in the first wire layer CL1 up to the fourth wire layer CL4.

[0061] The wire 97 located at the side end of the periphery 95 of the second wire layer CL2 (i.e. with the number “10” in the wire 97 in Fig. 21), slides along its neighboring wire (i.e. with the number “9” in the wire 97 in Fig. 21), similar to the first to third embodiments, and is located at the side end of the periphery 95 of the second wire layer. As in Fig. 22, the wire 97 positioned at the side end of the periphery 95 of the second wire layer on the surfaces extending in the vertical (top-bottom) direction is positioned at the side end of the periphery 95 of the third wire layer on the upper and lower end surfaces of the coil body 99. Even in this case, the wire 97 is guided by the winding of the wire in the second layer on the surfaces extending in the vertical (top-bottom) direction (i.e., with the number "9" in the wire 97 according to Fig. 21), whereby the winding can consequently be carried out without the winding device 8 having to be brought close to the periphery 95 to an extent at which the device can form contact with the periphery 95.

[0062] In the present embodiment, similar effects are achieved as in the first to third embodiments.

[0063] According to a variant, the grooves 100 may be formed on an upper and lower end surface of the coil body 99, at least on the pair of surfaces of the tooth 91 that are opposite to each other with the intermediate portion 91a therebetween. In this case, the lower end of the wire insertion portion 97a may continue the wire 97 disposed in the groove 100.

[0064] Specific examples of the teachings disclosed herein have been described in detail, but these are merely exemplary and do not limit the scope of the claims. The teachings presented in the claims include modifications and variations of the specific examples given above.

[0065] (1) In the above-mentioned embodiments, a brushless motor is used in the fuel pump 10, but the brushless motor described here can be used in other devices such as a cooling water pump, an electric pump, and the like.

[0066] (2) In the above-mentioned second embodiment, the wire 97 is wound in the groove 200 sequentially in the direction from the periphery 95 toward the inner circumferential portion 91b. Fig. 18 to 20, in the adjustment portion 297b, after the wire 97 is inserted into the groove 200 from the wire insertion portion 97a, it can be guided along the side end of the inner peripheral portion 91b of the groove 200 (which is indicated by P in Fig. 18) while winding a coil in the groove 200. Then, the wire 97 is arranged parallel to the X-axis at the upper end of the coil body 99. As shown in Fig. 19, the windings of the wire 97 can then be wound in such a way that they cross on one of the side surfaces of the coil body 99 (the right side surface in Fig. 18), and that they are arranged parallel on the other surface of the coil body 99 (the left side surface in Fig. 18).

[0067] (3) The above embodiments describe the motor 50 as a six-slot three-phase motor, however, the motor may be a 3xN-slot three-phase motor (where N is a positive integer). In this case, 3xN pieces of sub-cores may be provided in the stator. Further, the 3xN pieces of sub-cores may be categorized into N core groups. Of the three sub-cores belonging to a core group, their opposing surfaces may contact each other. On the other hand, at least one pair of opposing surfaces positioned between core groups may be arranged with a gap therebetween. A pair of opposing surfaces belonging to adjacent sub-cores in the same core group may be arranged with a gap therebetween. (Fifth embodiment)

[0068] Points different from the first embodiment will be explained with reference to the Fig. 23, Fig. 24. In the present embodiment, compared with the first embodiment, a width of the groove 100, that is, the length of the groove 100 in the radial direction of the stator 60 (that is, the Y-axis direction), at a portion of the groove 100 is k larger or longer than the width of the groove 100 according to the first embodiment. k is larger than 0 and smaller than the wire diameter of the wire 97. Thereby, the width of the groove 100 becomes W+k (where W is a value obtained by multiplying the wire diameter D of the wire 97 by the number of turns wound in the groove 100, and 0 <k<D). Beispielsweise kann k gleich oder größer als 1 / 4 sein, jedoch gleich oder kleiner als 3 / 4 des Drahtdurchmessers des Drahts 97.

[0069] Specifically, within the groove 100 provided over the entire circumference of the outer peripheral surface of the coil body 99, an enlarged width portion 100a is provided at a portion which is a portion extending in the axial direction of the periphery 95 (i.e., vertical direction relative to a sheet surface of Fig. 23), on a side where no extended portion 95b is provided. The extended width portion 100a is located on the side end of the periphery 95 of the groove 100. The extended width portion 100a is provided on the inner peripheral surface of the periphery 95. A depth of the extended width portion 100a, that is, the length of the groove 100 in the radial direction of the stator 60, is the above-mentioned k. Further, a height of the extended width portion 100a, that is, a length in the direction parallel to the inner peripheral surface of the periphery 95 (that is, the X-axis direction), is substantially equal to the wire diameter of the wire 97. The extended width portion 100a has the same length as the bobbin 99 in a direction vertical to an XY plane. According to a variant, the extended width region 100a may be smaller or shorter than the coil body 99 in the direction vertical to the XY plane.

[0070] As in Fig. 24, when the wire 97 is wound using the same winding method as in the first embodiment, the wire C2 is wound to the same position in the Y-axis direction as the wire C1 in the phase of winding the wire C2. Further, in the phase of winding the wire C4, the wire C4 is disposed between the wire C2 and the side surface of the groove 100. On this occasion, the wire C2 is pushed toward one side of the expanded width portion 100a by the wire C4 and moves until it comes into contact with the periphery 95. Thereby, a recess X5 is formed between the wire C2 and the side surface of the groove 100. A length of the recess X5 in the Y-axis direction is equal to the above-mentioned k. The wire C4 is wound along the recess X5 while being in a state of being fitted into the recess X5.According to this structure, the wire C4 can be properly positioned through the recess X5. As a result, during the winding phases, the wire C5 and further the wire C4 are prevented from moving toward the inner peripheral portion 91b side of the recess X5, which would cause disturbance in the windings of the wire 97 in the wire layer CL1. (Sixth embodiment)

[0071] Points different from the second embodiment will be explained with reference to the Fig. 25, Fig. 26. In the present embodiment, compared with the second embodiment, a width of the groove 200, that is, the length of the groove 200 in the radial direction of the stator 60 (Y-axis direction), is longer by k at a part of the groove 200 than the width of the groove 200 according to the second embodiment. This k is greater than 0 and smaller than the wire diameter of the wire 97. For example, k may be equal to or greater than 1 / 4, but equal to or less than 3 / 4 of the wire diameter of the wire 97.

[0072] Specifically, an extended width portion 200a similar to the extended width portion 100a is provided at the peripheral side end of the groove 200. As shown in Fig. 26, when the wire 97 is wound using the same winding method as in the second embodiment, in the phase of winding the wires C1 to C4, the wires C2, C4 are wound to the respective same positions as the wires C1, C3 in the Y-axis direction. Further, in the phase of winding the wire C6, the wire C6 is disposed between the wire C2 and the wire C4. Thereby, the wire C2 is pushed and moved toward the side of the expanded width portion 200a by the wire C6 until it comes into contact with the periphery 95. Thereby, a recess X6 is formed between the wire C2 and the wire C4. A length of the recess X6 in the Y-axis direction is equal to the above-mentioned k. The wire C6 is wound along the recess X6 while being fitted into the recess X6. According to this structure, the wire C6 can be appropriately positioned through the recess X6.As a result, in the phases of winding the wire C6, the wire C6 is prevented from moving toward the inner peripheral portion 91b side of the recess X6, which would cause disturbance of the windings of the wire 97 in the wire layer CL1. (Seventh embodiment)

[0073] Points different from the fifth embodiment will be explained with reference to the Fig. 27, Fig. 28. In the present embodiment, an extended width portion 300a is arranged on the inner peripheral portion 91b of the groove 100. In other words, the width of the groove 100 is larger by k toward the inner peripheral portion 91b side at the portion where the extended width portion 300a is arranged. The extended width portion 300a has the same length as the coil bobbin 99 in the direction vertical to the XY plane. According to a variation, the extended width portion 300a may be smaller than the coil bobbin 99 in the direction vertical to the XY plane.

[0074] As in Fig. As shown in Fig. 28, when the wire 97 is wound using the same winding method as in the first embodiment, the wire C2 is wound to the same position as the wire C1 in the phase of winding the wire C2. Further, in the phase of winding the wire C4, the wire C4 is wound along a recess X7 created between the wire C2 and the side surface of the groove 100 while being fitted into the recess X7. According to this configuration, the wire C4 can be properly positioned by the recess X7. As a result, in the phases of winding the wire C7, the wire C4 is prevented from moving toward the inner peripheral portion 91b side of the recess X7, which would cause disturbance of the windings of the wire 97 in the wire layer CL1. (Eighth embodiment)

[0075] Points different from the sixth embodiment will be explained with reference to the Fig. 29, Fig. 30. In the present embodiment, an extended width portion 400a is arranged on the inner peripheral portion 91b of the groove 200, similar to the extended width portion 300a. In this structure, as shown in Fig. 30, in the phase of winding the wires C1 to C4, the wires C2, C4 are wound to correspondingly equal positions to the wires C1, C3, respectively, in the Y-axis direction. Further, in the phase of winding the wire C6, the wire C6 is interposed between the wire C2 and the wire C4. Thereby, the wire C4 is pushed toward the inner peripheral portion 91b side by the wire C6 and moves until it comes into contact with the side wall of the expanded width portion 400a. Thereby, a recess X8 is formed between the wire C2 and the wire C4. The wire C6 is wound along the recess X8 while being in a state of being fitted into the recess X8. According to this configuration, the wire C6 can be appropriately positioned by the recess X8.As a result, in phases of winding the wire C6, the wire C6 can be prevented from moving toward the inner peripheral portion 91b side of the recess X8, which would generate a disturbance in the windings of the wire 97 in the wire layer CL1.

[0076] Specific examples of the teachings disclosed herein have been described in detail, but these are merely exemplary and do not limit the scope of the claims. The technology described in the claims includes modifications and variations of the specific examples mentioned above.

[0077] For example, the extended width portion 300a of the seventh embodiment has the same depth as the groove 100 (its length in the X-axis direction), but a shape of the extended width portion 300a is not limited thereto. As shown in Fig. For example, as shown in Fig. 31, a depth of an extended width region 500a may be narrower than the groove 100. Shapes of other extended width regions 500a may be similar to that of the extended width region 300a.

[0078] Furthermore, for example, the width of the extended width region 300a according to the seventh embodiment (i.e., its length in the Y-axis direction) is constant along the X-axis direction, but the shape of the extended width region 300a is not limited thereto. As shown in Fig. For example, as shown in FIG. 32, a width of an extended portion 600a may vary along the X-axis direction. The extended width portion 600a may be formed by chamfering the side surface of the groove 100 on the inner peripheral portion 91b side.

[0079] As in Fig. 33, a surface of the coil body 99 where the groove 100 is provided may be formed by a curved surface 700a to form an extended width region. As shown in Fig. 34, the groove 100 may alternatively be widened by providing an inclined surface 800a, wherein the end of the bobbin 99 on the side of the groove 100 is gradually lowered from the side where the widened portion 95b is provided.

[0080] The above-mentioned extended width ranges 500a to 800a can be generalized as "an extended width range that extends a width of at least one side end of an outer peripheral side of a coil bobbin (or an end thereof separated from a tooth side surface)." Further, each of the extended width ranges 500a to 800a corresponds to the structure in which "a width of a groove is equal to W+k (where W is a value obtained by multiplying the wire diameter D of the wire 97 by a number of turns wound in the setting range, and 0 <k<D)“, und dem Aufbau, bei dem „eine Breite einer Rille an einem Bereich erweitert ist, der sich auf einer von einem Paar von Flächen in der Rille befindet“. Jeder der erweiterten Breitenbereiche 500a bis 800a kann angepasst sein als erweiterter Breitenbereich zur Erweiterung der Breite der Rille 200.

[0081] Technical features described in the description and drawings may be technically useful alone or in various combinations and are not limited to the combinations originally claimed. Furthermore, the technique described in the description and drawings simultaneously achieves a plurality of objectives, and its technical relevance lies in the achievement of any one of these objectives. List of reference symbols

[0082] 10: Fuel pump, 30: Pump, 50: Motor, 54: Rotor, 60: Stator, 90: Core main body, 91: Teeth, 91a: Intermediate portion, 91b: Inner peripheral portion, 95: Periphery, 96: Coil, 99: Coil body, U1, V1, W1, U2, V2, W2: Partial core

Claims

[1] Stator of a motor, the stator comprising: a periphery with a cylindrical shape; a plurality of teeth extending from an inner peripheral surface of the periphery toward an inner peripheral side, the plurality of teeth being arranged at intervals along a circumferential direction of the periphery; a plurality of coil formers each attached to the plurality of teeth, each coil former surrounding a side surface of the corresponding tooth at an intermediate position between a first end of the tooth on a peripheral side and a second end of the tooth on a side opposite the first end; and a plurality of coils each provided on the plurality of coil bodies, wherein each of the plurality of coil bodies comprises: a first end side end located on a first end side; a circumferential surface having a pair of surface regions that are opposite to each other, viewed in a cross section along an extending direction of the corresponding tooth; and a groove located at the end of the first end face on at least the pair of surface areas, wherein each of the plurality of coils comprises: a wire insertion portion where a wire of the coil is inserted into the groove from outside the coil body; an adjustment portion provided continuously with the wire insertion portion, the adjustment portion having one or two adjacent turns of the wire in the groove from the turns of the wire wound once or twice around the coil body; and a plurality of wire layers, each of the plurality of wire layers having windings of the wire arranged adjacent to each other along the extending direction of the corresponding tooth, wherein a first wire layer of a lowermost layer arranged on the pair of surface regions of the plurality of wire layers contacts windings of the wire provided in the adjustment region and the peripheral surface of the coil body, and in each of the plurality of coils provided on the corresponding pair of surface areas: an odd-numbered wire layer of the plurality of wire layers arranged on the corresponding pair of surface regions has the wire wound from the first end side successively to a second end side, and a winding of the wire located at the end of the first end side is separated from the inner peripheral surface of the periphery by half a pitch; an even-numbered wire layer of the plurality of wire layers arranged on the corresponding pair of surface regions has the wire wound sequentially from the second end side to the first end side; each of two and subsequent wire layers of the plurality of wire layers has a winding of the wire located on an end face of the coil body on a wire insertion portion side and windings of the wire other than the winding of the wire located on the end face of the coil body; the windings of the wire other than the winding of the wire located on the end face of the coil body are arranged along recesses between two adjacent windings of the wire in a wire layer located on a layer below; and the winding of the wire located on the end face of the coil body is arranged in a direction that crosses the windings of the wire in the wire layer located one layer below. [2] Stator according to claim 1, wherein each of the grooves is located on at least one pair of surface portions provided in the peripheral surface of the corresponding coil body, the one pair of surface portions extending along an axial direction of the periphery; each of the plurality of coil bodies has an extended width portion that extends a width of the groove at a portion of the groove located on one of the pair of surface portions, wherein a width of the extended width portion is smaller than a wire diameter of the wire, and the insertion region is arranged at a region of the groove which is located on the other of the pair of surface regions. [3] A stator according to claim 1 or 2, wherein a specific wire to be wound to form a first winding in the first wire layer is arranged along the windings of the wire wound in the adjustment region. [4] Stator according to claim 3, wherein the adjustment region has a winding of the wire wound once adjacent to a side wall defining the groove, and the specific wire is arranged along a recess between the winding of the wire wound on the adjustment portion and an upper end of the side wall. [5] Stator according to claim 3, wherein the adjustment area has two windings of the wire arranged adjacent to each other, one of the two turns of wire is located on the second end side and is adjacent to a side wall defining the groove, and the particular wire is arranged along a recess between one of the two windings of the wire and an upper end of the side wall. [6] Stator according to claim 3, wherein the adjustment area has two adjacent windings of the wire arranged adjacent to each other, and the particular wire is wound around and along a recess between the two adjacent windings of the wire of the adjustment area. [7] Stator according to one of claims 1 to 6, in which the odd-numbered wire layer has the winding of the wire located at the end of the first end side separated from the inner peripheral surface of the periphery by half a pitch, and the even-numbered wire layer has a winding of the wire located at the end of the first end side in contact with the inner peripheral surface of the periphery. [8] A stator according to any one of claims 1 to 7, wherein the groove surrounds the circumferential surface of the coil body at the end of the first end side. [9] A brushless motor comprising the stator according to any one of claims 1 to 8; and a rotor arranged to face the second ends of the teeth. [10] Stator of a motor, the stator comprising: a periphery with a cylindrical shape; a plurality of teeth extending from an inner peripheral surface of the periphery to an inner peripheral side, the plurality of teeth being arranged along a circumferential direction of the periphery at intervals from each other; a plurality of coil formers each attached to the plurality of teeth, each coil former surrounding a side surface of the corresponding tooth at an intermediate position between a first end of the tooth on the peripheral side and a second end of the tooth on a side opposite the first side; and a plurality of coils arranged on the plurality of coil bodies, wherein each of the plurality of coil bodies comprises: a first end side end located on a first end side; a circumferential surface having a pair of opposing surface regions when viewed in a cross-sectional direction along an extending direction of the corresponding tooth; a groove located at the end of the first end face on at least the pair of surface areas; and an extended width portion that extends a width of the groove at a portion of the groove located on one of the pair of surface portions, wherein a width of the extended width portion is smaller than a wire diameter of a wire of the coil, each of the plurality of coils comprises: a wire insertion portion where the wire of the coil is inserted into the groove from outside the coil body at a portion located on the other of the pair of surface portions; an adjustment portion arranged continuously with the wire insertion portion, the adjustment portion having one or two adjacent turns of the wire in the groove, of turns of the wire wound once or twice around the coil body; and a plurality of wire layers, each of the plurality of wire layers having the windings of the wire arranged adjacent to each other along the extending direction of the corresponding tooth, wherein a lowermost layer arranged on the pair of surface regions of the plurality of wire layers contacts windings of the wire provided in the adjustment region and the peripheral surface of the coil body; in each of the plurality of coils arranged on the corresponding pair of surface areas: an odd-numbered wire layer of the plurality of wire layers arranged on the at least one pair of surface regions has the wire wound sequentially from the first end side to a second end side; an even-numbered wire layer of the plurality of wire layers arranged on the at least one pair of surface regions has the wire wound sequentially from the second end side to the first end side; each of the second and subsequent wire layers of the plurality of wire layers has a winding of the wire located on an end surface of the coil body on a wire insertion portion side and windings of the wire other than the winding of the wire located on the end surface of the coil body; the windings of the wire other than the winding of the wire located on the end face of the coil body are arranged along recesses between two adjacent windings of the wire in a wire layer located on a layer below; and the winding of the wire located on the end face of the coil body is arranged in a direction that crosses the windings of the wire in the wire layer located one layer below.

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