Armature, rotating electrical machine, and method for manufacturing armature

Abstract

The present invention provides an armature whereby a manufacturing process can be simplified. An armature (10) comprises: an armature core (20) with a plurality of teeth (21); a plurality of conductor rods (31); and an upper PCB (40A). The upper PCB (40A) is a multilayer printed wiring board and has a plurality of conductor layers (L1 to L6) in which conductor patterns are formed and a plurality of through holes (40h) on the inner circumferential surfaces of which a conductor film (45) is formed at least partially. The ends of the plurality of conductor rods (31) are inserted into the plurality of through holes (40h), and the plurality of conductor rods (31) are electrically connected to the conductor patterns via the conductor film (45).

Description

Armature, rotating electric machine, and method for manufacturing the armature

[0001] The present disclosure relates to an armature, a rotating electric machine, and a method for manufacturing an armature.

[0002] The armature of a motor unit disclosed in Patent Document 1 below includes an armature core having a plurality of teeth and slot conductors arranged between adjacent teeth. The armature also includes a plurality of substrates arranged in the axial direction relative to the armature core. Each substrate has a plurality of crossover conductors connecting the ends of the slot conductors. Each crossover conductor is formed of a metal plate.

[0003] Japanese Patent Application Laid-Open No. 2023-174375

[0004] The manufacturing process of the stator unit disclosed in Patent Document 1 requires stacking multiple substrates in order. That is, the first substrate is placed on one side of the armature core, and the connecting conductors and slot conductors of this substrate are connected by soldering. Then, the second substrate is placed on top of the first substrate, and the connecting conductors and slot conductors of this second substrate are connected by soldering. Similar steps are required for the third and subsequent substrates. This type of work is undesirable from the standpoint of efficiency.

[0005] (1) The armature proposed in this disclosure includes an armature core having multiple teeth, a first multilayer printed circuit board (PCB) having multiple conductive rods, each inserted between two adjacent teeth, multiple conductive layers on which a conductive pattern is formed, and multiple through holes, the inner surfaces of which are at least partially formed with a conductive film. The ends of the multiple conductive rods are inserted into the multiple through holes, and the multiple conductive rods are electrically connected to the conductive patterns via the conductive film. This structure simplifies the manufacturing process of the armature, since the multiple conductive rods are connected by the multilayer PCB having multiple conductive layers.

[0006] (2) In the armature of (1), the plurality of conductor layers include a first conductor layer and a second conductor layer, the conductor pattern of the first conductor layer has a conductor line and a first conductor land that surrounds an edge of one of the plurality of through holes and is independent of the conductor line of the first conductor layer, and the conductor pattern of the second conductor layer has a conductor line and a second conductor land that surrounds an edge of the one of the plurality of through holes and is connected to the conductor line of the second conductor layer. The conductor film formed on the inner peripheral surface of the one of the plurality of through holes connects the first conductor land and the second conductor land. With this structure, the contact area between the conductor pattern and the conductor rod is increased by the first conductor land, thereby reducing current density and the skin effect of AC current.

[0007] (3) In the armature of (1) or (2), the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core. The multiple conductor layers include a first conductor layer formed on the first outer surface, a second conductor layer formed on the second outer surface, and at least one conductor layer formed between the first and second conductor layers. The first conductor layer, the second conductor layer, and the at least one conductor layer each have conductor lands surrounding the edges of the multiple through holes. A conductor film formed on the inner surfaces of the multiple through holes connects the conductor lands of the first conductor layer, the conductor lands of the second conductor layer, and the conductor lands of the at least one conductor layer. With this structure, the first conductor lands increase the contact area between the conductor pattern and the conductor rod, thereby reducing current density and the skin effect of AC current. Furthermore, since the contact area between the conductive film and the conductive rod increases, the electrical resistance between them decreases and the mechanical fixing strength can also be increased.

[0008] (4) In the armature of any one of (1) to (3), the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core. The plurality of conductor layers includes a first conductor layer formed on the first outer surface and a third conductor layer formed on the second outer surface or between the first and second outer surfaces. The conductor pattern of the first conductor layer includes a conductor line and a first conductor land surrounding an edge of one of the plurality of through holes and independent of the conductor line of the first conductor layer. The conductor pattern of the third conductor layer includes a conductor line and a third conductor land surrounding an edge of the one of the plurality of through holes and connected to the conductor line of the third conductor layer. The conductor film formed on the inner circumferential surface of the one of the plurality of through holes connects the first conductor land and the third conductor land. With this structure, when solder is supplied to the first conductive land formed on the first conductive layer, the solder penetrates between the conductive film and the conductive rod, connecting the conductive rod and the conductive line, thereby facilitating the connection work between the conductive rod and the PCB.

[0009] (5) In any of the armatures (1) to (4), the plurality of conductor rods include a conductor rod inserted into one of the plurality of through holes, and an end of the conductor rod is inserted into the one of the plurality of through holes and reaches the first outer surface.

[0010] (6) In the armature of any one of (1) to (5), the first PCB has a first outer surface facing away from the armature core, the plurality of conductor layers have a first conductor layer formed on the first outer surface, the first conductor layer has conductor lands surrounding the edges of each of the plurality of through holes, and the conductor films formed on the inner surfaces of the plurality of through holes are connected to the conductor lands. With this structure, when solder is supplied to the conductor lands formed on the first conductor layer, the solder penetrates between the conductor film and the conductor rod, connecting the conductor rod and the conductor line. As a result, the work of connecting the conductor rod and the PCB can be simplified.

[0011] (7) In the armature of (6), the ends of all the conductor rods are inserted into the plurality of through holes, respectively, and reach the first outer surface.

[0012] (8) In the armature of any one of (1) to (7), the plurality of conductive rods include a first conductive rod arranged between two adjacent teeth and a second conductive rod arranged between the two adjacent teeth and positioned adjacent to the first conductive rod in the radial direction. The plurality of through holes include a first through hole into which the first conductive rod is inserted and a second through hole into which the second conductive rod is inserted. The conductive pattern of a first conductive layer, which is one of the plurality of conductive layers, includes a first conductive land surrounding the edge of the first through hole, a second conductive land surrounding the edge of the second through hole, and a conductive line extending from the second conductive land. The thickness of the first conductive land is smaller than the thickness of the conductive line. This makes it easy to ensure a sufficient distance between the first conductive land and the second conductive land adjacent in the radial direction.

[0013] (9) In the armature of (8), the thickness of the second conductive land is also smaller than the thickness of the conductive line, which makes it easier to ensure a sufficient distance between the first conductive land and the second conductive land that are adjacent to each other in the radial direction.

[0014] (10) In the armature of any one of (1) to (9), the plurality of conducting rods include a plurality of first conducting rods to which a first-phase current is supplied and a plurality of second conducting rods positioned in the rotational direction relative to the plurality of first conducting rods to which a second-phase current is supplied. The plurality of through holes include a plurality of first through holes into which the plurality of first conducting rods are inserted and a plurality of second through holes into which the second conducting rods are inserted. A first conducting layer, which is one of the plurality of conducting layers, has a conductor pattern including a first conducting land surrounding an edge of one of the plurality of first through holes and a conductor line extending from the first conducting land. The conductor line has a portion extending radially from the conductor land and a portion positioned outside the second through hole and extending in the rotational direction.

[0015] (11) In the armature of (10), a second conductor layer, which is one of the plurality of conductor layers, has a conductor pattern including second conductor lands surrounding two edges of the plurality of second through holes and conductor lines extending from the second conductor lands. The conductor lines of the second conductor layer include a portion extending radially from the conductor land and a portion extending in the rotational direction. The conductor lines of the first conductor layer and the conductor lines of the second conductor layer partially overlap when viewed in the axial direction. This reduces leakage magnetic flux from the armature.

[0016] (12) The armature of any one of (1) to (11) further includes a multilayer second printed circuit board (PCB) having a plurality of conductor layers on which conductor patterns are formed and a plurality of through holes with conductor films at least partially formed on the inner circumferential surfaces thereof, the second printed circuit board (PCB) being disposed on the opposite side of the armature core from the first PCB. Ends of the plurality of conductor rods are inserted into the plurality of through holes formed in the second PCB. The plurality of conductor rods are connected to the conductor patterns via the conductor films formed on the second PCB. With this structure, the plurality of conductor rods are connected by two PCBs, eliminating the need to use conductor rods bent into a U-shape, for example, and reducing the size of the armature in the axial direction.

[0017] (13) In the armature of (12), the first PCB has a conductor layer for the first phase and a conductor layer for the second phase. The second PCB has a conductor layer for the first phase and a conductor layer for the second phase. The plurality of conductor rods include a first conductor rod constituting the first phase and a second conductor rod constituting the second phase. Both ends of the first conductor rod are connected to the conductor layer for the first phase of the first PCB and the conductor layer for the first phase of the second PCB, respectively. Both ends of the second conductor rod are connected to the conductor layer for the second phase of the first PCB and the conductor layer for the second phase of the second PCB, respectively. In the first PCB, the conductor layer for the first phase and the conductor layer for the second phase are arranged in this order from one side in the axial direction. In the second PCB, the conductor layer for the first phase and the conductor layer for the second phase are arranged in this order from the one side in the axial direction. This structure can prevent a difference in the distance from the first conductor layer of the first PCB connected to the conductor rod of the first phase to the first conductor layer of the lower PCB, and the distance from the second conductor layer of the first PCB connected to the conductor rod of the second phase to the second conductor layer of the second PCB, thereby making the electrical resistance of the coils of these two phases uniform.

[0018] (14) The rotating electric machine proposed in this disclosure has an armature having any of the structures described in (1) to (13) and a field magnet portion that is rotatable relative to the armature.

[0019] (15) A method for manufacturing an armature proposed in the present disclosure includes the steps of: preparing a first multilayer printed circuit board (PCB) having a plurality of conductor layers on which conductor patterns are formed and a plurality of through holes on whose inner surfaces at least a portion of which is formed with a conductor film; preparing a plurality of conductor rods; inserting the plurality of conductor rods into the plurality of through holes, respectively; and electrically connecting the plurality of conductor rods to the conductor patterns via the conductor film. This manufacturing method can simplify the armature manufacturing process.

[0020] (16) In the armature of (15), the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core. The multiple conductor layers include a first conductor layer formed on the first outer surface and a third conductor layer formed on the second outer surface or between the first and second outer surfaces. The first conductor layer includes a conductor pattern having a conductor line and a first conductor land surrounding an edge of one of the multiple through holes and independent from the conductor line of the first conductor layer. The third conductor layer includes a conductor pattern having a conductor line and a third conductor land surrounding an edge of the one of the multiple through holes and connected to the conductor line of the third conductor layer. In the step of electrically connecting the multiple conductor rods described in (15), the conductor rod is inserted into one of the multiple through holes and solder is supplied to the first conductor land on the first outer surface. According to this manufacturing method, the solder supplied to the first conductive land penetrates between the conductive rod and the conductive film formed on the inner circumferential surface of the through hole, and as a result, the conductive rod connects to the conductive land and conductive line of the third conductive layer via the conductive film.

[0021] 8A is a perspective view of a rotating electric machine. It is a perspective view showing the upper side of an armature included in the rotating electric machine shown in FIG. 1. In this view, the resin portion of the printed wiring board included in the armature is omitted, and the input terminals are separated. It is a perspective view showing the lower side of the armature included in the rotating electric machine shown in FIG. 1. In this view, the resin portion of the printed wiring board included in the armature is omitted. It is an exploded perspective view of the armature. It is an exploded view of conductor layers formed on a printed wiring board. It is a perspective view showing an armature core and conductor rods. It is a perspective view showing the connection between conductor lines and conductor rods. This view shows conductor lines and conductor rods that make one revolution (360 degrees) around the axis. It is an enlarged perspective view of conductor lines and conductor lands included in the upper printed wiring board. It is a plan view of the portion shown in FIG. 7. It is an enlarged view of FIG. 8A. It is an enlarged perspective view of the connection portion of the conductor rod, the conductor lands, and the conductor lines. It is an enlarged perspective view of the connection portion of the conductor rod, the conductor lands, and the conductor lines. It is a cross-sectional view of the armature taken along line X-X shown in FIG. 8A. It is a diagram for explaining the connection of conductor rods via conductor lines. This view shows the first turn. This figure shows the second turn. This figure shows the third turn. This figure shows the fourth turn. A diagram for explaining the connection of conducting rods via a conductor line. A diagram for explaining a comparative example of the connection of conducting rods via a conductor line. This figure shows the first turn. This figure shows the second turn. This figure shows the third turn. This figure shows the fourth turn. A diagram for explaining a modified example of the connection of conducting rods via a conductor line. This figure shows the first turn. This figure shows the second turn. This figure shows the third turn. This figure shows the fourth turn. This figure shows the fifth turn. A diagram for explaining a modified example of the connection of conducting rods via a conductor line. This figure shows the first turn. This figure shows the second turn. This figure shows the third turn. This figure shows the fourth turn. A diagram for explaining a modified example of the connection of conducting rods via a conductor line. This figure shows the first turn. This figure shows the second turn. This figure shows the third turn. This figure shows the fourth turn.

[0022] The following describes the armature, rotating electric machine, and a method for manufacturing the armature proposed in this disclosure. Rotating electric machines are mounted on vehicles such as power-assisted bicycles, electric vehicles (vehicles that run solely on the driving force of an electric motor, such as electric two-wheeled vehicles, electric three-wheeled vehicles, and electric four-wheeled vehicles), and electric wheelchairs, and are used as electric motors.

[0023] In the following description, the direction along the axis Ax shown in Figure 1 will be referred to as the "axial direction," and the direction R1 around the axis Ax shown in the same figure will be referred to as the "rotational direction." The Z1 direction along the axis Ax will be referred to as the "upward direction," and the Z2 direction along the axis Ax will be referred to as the "downward direction."

[0024] 1, the rotating electric machine 1 has an armature 10 and a field magnet section 90. The rotating electric machine 1 is, for example, a synchronous motor, and the field magnet section 90 has a plurality of permanent magnets (not shown) aligned in the direction of rotation. The armature 10 functions as a stator, and the field magnet section 90 functions as a rotor.

[0025] The armature 10 is formed, for example, in a cylindrical shape surrounding the axis Ax. The field magnet portion 90 is disposed inside the armature 10. That is, the rotating electric machine 1 may be an inner rotor type rotating electric machine. Unlike the example shown in FIG. 1 , the structure proposed in this disclosure may be applied to an outer rotor type rotating electric machine. That is, the field magnet portion 90 may be formed in a cylindrical shape, and the armature 10 may be disposed inside the field magnet portion 90.

[0026] 3, the armature 10 has an armature core 20 and a plurality of conducting rods 31. The armature 10 also has an upper printed wiring board 40A arranged above the armature core 20 and the conducting rods 31 (on one side in the direction along the axis Ax), and a lower printed wiring board 40B arranged below the armature core 20 and the conducting rods 31 (on the opposite side in the direction along the axis Ax). (In the following description, the upper printed wiring board 40A will be referred to as the "upper PCB," and the lower printed wiring board 40B will be referred to as the "lower PCB.")

[0027] 5, the armature core 20 has a plurality of teeth 21 arranged in the rotation direction. The armature core 20 also has a cylindrical yoke 22 that surrounds the axis Ax. The teeth 21 extend from the yoke 22 to the center (axis Ax) in the radial direction.

[0028] The armature core 20 is made of, for example, a plurality of electromagnetic steel plates laminated in the axial direction. Each steel plate has a portion that forms the teeth portion 21 and a portion that forms the yoke portion 22.

[0029] 5, a slot S is formed between two adjacent teeth 21. A plurality of conductive rods 31 are inserted into each slot S in the axial direction. The conductive rods 31 arranged in the same slot S are aligned in a row in the radial direction.

[0030] The rotating electric machine 1 is, for example, a three-phase AC motor, and the armature core 20 has a conductor rod 31 that constitutes a U-phase coil, a conductor rod 31 that constitutes a V-phase coil, and a conductor rod 31 that constitutes a W-phase coil. Conductor rods 31 of the same phase are inserted into one slot S. The conductor rods 31 are made of, for example, copper.

[0031] The conductor rod 31 is a rod having a centerline that extends straight from its upper end to its lower end along the axis Ax. As shown in Fig. 5, the conductor rod 31 has connection portions 31a and 31b at its upper and lower ends, respectively. The conductor rod 31 also has a body portion 31c between the upper and lower connection portions 31a and 31b. When the armature 10 is assembled (the state shown in Fig. 1), the upper connection portion 31a protrudes upward from the upper surface of the armature core 20, the lower connection portion 31b protrudes downward from the lower surface of the armature core 20, and the body portion 31c is located between two adjacent teeth portions 21.

[0032] The connecting portions 31a and 31b are connected to the PCBs 40A and 40B, respectively. The conductor rods 31 are connected via conductor lines 41 (see FIG. 6) formed on the PCBs 40A and 40B to form a coil. The multiple conductor rods 31 are connected to form a distributed winding coil. The connection structure between the PCBs 40A and 40B and the conductor rods 31 will be described in detail later.

[0033] The cross-sectional area of ​​the body portion 31c (plane perpendicular to the axis Ax) is larger than the cross-sectional area of ​​the connection portions 31a and 31b. This reduces the electrical resistance of the conductor rod 31. The cross-sectional shapes of the connection portions 31a and 31b may be circular or elongated circular. On the other hand, the cross-sectional shape of the body portion 31c may be rectangular. This allows the conductor rod 31 to effectively utilize the space (slit S) formed between two adjacent teeth 21. In other words, the gap between the body portion 31c of the conductor rod 31 and the teeth 21 can be reduced.

[0034] [Printed Wiring Board (PCB)] The structure of the PCBs 40A and 40B will be described in detail below. The upper PCB 40A and the lower PCB 40B have roughly the same structure. Here, the structure of the upper PCB 40A will be mainly described.

[0035] 10, the upper PCB 40A is a multilayer printed wiring board and has multiple conductor layers L1 to L6 on which conductor patterns are formed. The upper PCB 40A has a resin layer 49 formed between two conductor layers L1 to L6 adjacent to each other in the axial direction. The conductor patterns (a conductor line 41 and conductor lands 42 and 43, described below) are formed by etching a conductor layer (e.g., a copper layer) formed on a resin base material.

[0036] In the example shown in FIG. 10 , the upper PCB 40A has six conductor layers L1 to L6. These six conductor layers L1 to L6 are arranged in this order from top to bottom. The first conductor layer L1 is the top layer of the upper PCB 40A, and the sixth conductor layer L6 is the bottom layer of the upper PCB 40A. The first conductor layer L1 is formed on the top surface of the upper PCB 40A, and the sixth conductor layer L6 is formed on the bottom surface of the upper PCB 40A. The first conductor layer L1 may be exposed on the top side of the upper PCB 40A (the side opposite the armature core 20). The sixth conductor layer L6 may be exposed on the bottom side of the upper PCB 40A (the side facing the armature core 20). Alternatively, the first conductor layer L1 may be coated with an insulating material.

[0037] 7, the conductor patterns of the conductor layers L1 to L6 each have conductor lines 41(1) to 41(6) that electrically connect the upper connection portions 31a of two conductor rods 31. The conductor lines 41(1) to 41(6) connect the conductor rods 31 to form the U-phase coil, the V-phase coil, and the W-phase coil.

[0038] For example, as shown in FIG. 7 , conductor line 41(1) formed on the first conductor layer L1 electrically connects the two conductor rods 31 that make up the U-phase coil. Conductor line 41(2) formed on the second conductor layer L2 also electrically connects the two conductor rods 31 that make up the U-phase coil. Conductor lines 41(3) and 41(4) formed on conductor layers L3 and L4, respectively, electrically connect the two conductor rods 31 that make up the V-phase coil. Conductor lines 41(5) and 41(6) formed on conductor layers L5 and L6, respectively, electrically connect the two conductor rods 31 that make up the V-phase coil. In the following description, when there is no need to distinguish between the conductor patterns formed on each of the conductor layers L1 to L6, the reference numeral "41" will be used to refer to the conductor line.

[0039] 10, a through hole 40h is formed in the upper PCB 40A. The through hole 40h penetrates the upper PCB 40A in the axial direction. A conductive film 45 is formed on the inner surface of the through hole 40h. The conductive film 45 is a film formed by, for example, electroless plating and / or electroplating.

[0040] 7 and 9A, the conductor line 41 has end conductor lands 42 at both ends thereof. The end conductor lands 42 surround the through hole 40h and are connected to a conductor film 45 formed on the inner circumferential surface of the through hole 40h. The upper connection portion 31a of the conductor rod 31 is inserted into the through hole 40h and is connected to the conductor line 41 via the conductor film 45 and the end conductor lands 42. The upper connection portion 31a and the conductor film 45 are connected by, for example, soldering.

[0041] The upper connection portion 31a of the conductor rod 31 may have a circular cross section that is elongated in the radial direction. The through-hole 40h may also have a circular cross section that is elongated in the radial direction. This allows, for example, a larger contact area between the conductor rod 31 and the conductor film 45 formed on the inner surface of the through-hole 40h compared to when the through-hole 40h is a perfect circle.

[0042] 9A and 10, the conductor patterns formed on each of the conductor layers L1 to L6 have an isolated conductor land 43. The isolated conductor land 43 is formed on a conductor layer different from the conductor layer on which the conductor line 41 is formed. The isolated conductor land 43 is independent from the conductor line 41 formed on the same conductor layer L1 to L6 as the isolated conductor land 43. The isolated conductor land 43 surrounds the through hole 40h and is connected to the conductor film 45.

[0043] 9A shows a conductor line 41(4) formed on the fourth conductor layer L4. The conductor line 41(4) has an end conductor land 42 at its end. An isolated conductor land 43 is formed on the first conductor layer L1 to the third conductor layer L3, which are located above the fourth conductor layer L4. In addition, an isolated conductor land 43 is also formed on the fifth conductor layer L5 and the sixth conductor layer L6, which are located below the fourth conductor layer L4. This isolated conductor land 43 is not connected to the conductor lines 41 formed on the conductor layers L1 to L3, L5, and L6.

[0044] This is true regardless of which of the conductor layers L1 to L6 the conductor line 41 is formed on. For example, at a position where the conductor line 41 is formed on the second conductor layer L2, the isolated conductor land 43 is formed on the first conductor layer L1 and all of the conductor layers L3 to L6 below the second conductor layer L2.

[0045] 9B shows a conductor line 41(1) formed on the first conductor layer L1. The conductor line 41(1) has an end conductor land 42 at its end. An isolated conductor land 43 is formed on the second to sixth conductor layers L2 to L6. This isolated conductor land 43 is not connected to the conductor lines 41 formed on the conductor layers L2 to L6.

[0046] 10, the conductive film 45 formed on the inner surface of the through hole 40h continues from the isolated conductive land 43 (or end conductive land 42) on the first conductor layer L1 to the isolated conductive land 43 (or end conductor land 42) on the sixth conductor layer L6. The upper ends of the conductive rods 31 are inserted into the through holes 40h and reach the upper surface of the upper PCB 40A (the conductive land 42 or 43 on the first conductor layer L1). The ends of all the conductive rods 31 of the armature 10 are inserted into the multiple through holes 40h, respectively, and reach the upper surface of the upper PCB 40A (the conductive land 42 or 43 on the first conductor layer L1).

[0047] This increases the contact area between the conductive film 45 and the conductive rod 31 along the axial direction, thereby reducing the electrical resistance between the conductive film 45 and the conductive rod 31 and increasing the mechanical fixing strength between them. As shown in Fig. 10, the upper end of the conductive rod 31 may extend upward beyond the first conductive layer L1.

[0048] Furthermore, the isolated conductor lands 43 increase the contact area between the conductor pattern and the conductor rod 31. As a result, the current density decreases, and the skin effect of AC current can be alleviated. Furthermore, because either the end conductor lands 42 or the isolated conductor lands 43 are formed on each of the conductor layers L1 to L6, the conductor film 45 can be formed smoothly when it is formed by electroplating. In particular, in the upper PCB 40A, as described below, the conductor lines 41 are thick and six conductor layers L1 to L6 are formed, resulting in a large distance between the top layer (first conductor layer L1) and the bottom layer (sixth conductor layer L6). Even in such cases, because either the end conductor lands 42 or the isolated conductor lands 43 are formed on each of the conductor layers L1 to L6, the thickness of the conductor film 45 can be made uniform during electroplating.

[0049] 9A , even for through-holes 40h in which no conductor line 41 is formed on the first conductor layer L1 (the uppermost conductor layer), isolated conductor lands 43 are formed on the first conductor layer L1. This facilitates the connection between the upper PCB 40A and the conductor rod 31. For example, when solder is supplied to the isolated conductor land 43 (edge ​​of the through-hole 40h) on the first conductor layer L1, the solder spreads between the outer circumferential surface of the upper connection portion 31a of the conductor rod 31 and the conductor film 45 toward the sixth conductor layer L6. As a result, the outer surface of the upper connection portion 31a of the conductor rod 31 and the inner circumferential surface (conductor film 45) of the through-hole 40h are uniformly connected by the solder.

[0050] The upper PCB 40A has isolated conductor lands 43 or end conductor lands 42 formed on the first conductor layer L1 in all of the through holes 40h formed in the upper PCB 40A. Therefore, the connection work between all of the conductor rods 31 and the upper PCB 40A can be achieved by supplying solder to the first conductor layer L1.

[0051] The first conductor layer L1 of the upper PCB 40A does not have to be exposed to the upper side. For example, the upper surface of the upper PCB 40A (the surface opposite to the armature core 20) may be coated with an insulating material after soldering the conductor lands 42 and 43 of the first conductor layer L1 to the conductor rod 31, or other structures may be attached to the upper surface of the upper PCB 40A.

[0052] Unlike the example shown in Figure 9A etc., the isolated conductor land 43 does not necessarily have to be formed on all conductor layers L1 to L6. For example, for a through hole 40h in which a conductor line 41 is formed on a conductor layer below the first conductor layer L1, the isolated conductor land 43 may be formed only on the first conductor layer L1 (the uppermost layer) and not on the other conductor layers. Even in this case, the solder supplied to the isolated conductor land 43 on the first conductor layer L1 spreads between the outer peripheral surface of the upper connection portion 31a of the conductor rod 31 and the conductor film 45. As a result, the connection work between the conductor rod 31 and the upper PCB 40A can be performed efficiently.

[0053] In yet another example, the isolated conductor lands 43 may be formed only on the first conductor layer L1 and the sixth conductor layer L6 (the bottom layer), and not on the other conductor layers. This improves the efficiency of the soldering work of the conductor rod 31 to the upper PCB 40A. Furthermore, when forming the conductor film 45 on the inner surface of the through hole 40h by electroplating, a voltage can be applied to the isolated conductor lands 43 on the first conductor layer L1 and the isolated conductor lands 43 on the sixth conductor layer L6.

[0054] [Thickness of Conductive Lands and Conductive Lines] As shown in Figures 9A and 10, the thickness of the end conductor land 42 is smaller than the thickness T1 of the conductor line 41. The thickness of the isolated conductor land 43 is also smaller than the thickness T1 of the conductor line 41. In all of the first conductor layer L1 to the sixth conductor layer L6, the thickness of the conductor lands 42 and 43 is smaller than the thickness T1 of the conductor line 41. The thickness T1 of the conductor line 41 may be, for example, 100 µm or more and 500 µm or less. The thickness T1 of the conductor line 41 may more preferably be 200 µm or more. The thickness T1 of the conductor line 41 may even more preferably be 250 µm or more. On the other hand, the thickness of the conductor lands 42 and 43 may be 30 µm or more and less than 100 µm. The thickness of the conductor lands 42 and 43 may be 50 µm or more and less than 100 µm.

[0055] When the conductor pattern is formed by etching, the outer peripheral surfaces of the conductor lands 42 and 43 are not vertical but rather have slopes that extend horizontally. Therefore, if the conductor lands 42 and 43 were made as thick as the conductor line 41, it would be difficult to ensure a sufficient distance between the end conductor land 42 and the isolated conductor land 43. In contrast, in the armature 10, the thickness of the conductor lands 42 and 43 is smaller than the thickness T1 of the conductor line 41, so a sufficient distance D1 (see FIG. 8B ) can be ensured between the end conductor land 42 and the isolated conductor land 43 that are adjacent in the radial direction. Furthermore, because the thickness T1 of the conductor line 41 is greater than the thickness T1 of the conductor line 41, the current density in the conductor line 41 can be reduced.

[0056] As described above, the isolated conductor land 43 may be formed only on the first conductor layer L1. In this case, the thickness of the conductor lands 42 and 43 on the first conductor layer L1 may be smaller than the thickness T1 of the conductor line 41, while the thickness of the end conductor land 42 on the other conductor layers may be the same as the thickness T1 of the conductor line 41.

[0057] As yet another example, the end conductor lands 42 may have the same thickness as the conductor lines 41, while only the thickness of the isolated conductor lands 43 may be smaller than that of the conductor lines 41.

[0058] The thickness T1 of the conductor line 41 may preferably be more than twice the thickness of the conductor lands 42 and 43. This allows the distance D1 between the end conductor land 42 and the isolated conductor land 43 to be reduced while reducing the current density in the conductor line 41.

[0059] The thickness T1 of the conductor line 41 may more desirably be greater than three times the thickness of the conductor lands 42 and 43. Even more desirably, the thickness T1 of the conductor line 41 may be greater than four times the thickness of the conductor lands 42 and 43.

[0060] Such conductive lands 42 and 43 can be formed by half etching, which reduces the thickness of the conductive lands 42 and 43 in the etching process for forming the conductive pattern.

[0061] [Lower Printed Wiring Board (PCB)] The lower PCB 40B is also a multilayer printed wiring board and has generally the same structure as the upper PCB 40A. That is, the lower PCB 40B has multiple conductor layers L1 to L6. The six conductor layers L1 to L6 are arranged in this order from the top (the armature core 20 side). The first conductor layer L1 is formed on the top surface of the lower PCB 40B, and the sixth conductor layer L6 is formed on the bottom surface of the lower PCB 40B. The first conductor layer L1 may be exposed on the top side (the armature core 20 side) of the lower PCB 40B. The sixth conductor layer L6 may be exposed on the bottom side (the side opposite the armature core 20) of the lower PCB 40B. Alternatively, the sixth conductor layer L6 may be coated with an insulating material.

[0062] A plurality of through holes 40h are formed in the lower PCB 40. Lower connection portions 31b (see FIG. 5) located at the bottom of the plurality of conductor rods 31 are inserted into the plurality of through holes 40h, respectively. The conductor pattern of each of the conductor layers L1 to L6 of the lower PCB 40B includes a conductor line 41, an end conductor land 42, and an isolated conductor land 43. The thickness of the conductor lands 42 and 43 is smaller than the thickness T1 of the conductor line 41.

[0063] The lower PCB 40B has isolated conductor lands 43 or end conductor lands 42 formed on the sixth conductor layer L6 for all through holes 40h formed in the lower PCB 40B. Therefore, the connection work between all conductor rods 31 and the lower PCB 40B can be achieved by applying solder to the sixth conductor layer L6.

[0064] The sixth conductor layer L6 of the lower PCB 40B does not have to be exposed to the lower side. For example, the lower surface of the lower PCB 40B (the surface opposite to the armature core 20) may be coated with an insulating material after soldering the conductor lands 42 and 43 of the sixth conductor layer L6 to the conductor rod 31, or another structure may be attached to the lower surface of the lower PCB 40B.

[0065] In the lower PCB 40B, the conductor lands 42 and 43 do not necessarily have to be formed on all of the conductor layers L1 to L6. For example, the isolated conductor land 43 may be formed only on the sixth conductor layer L6 (the bottom layer) and not on the other conductor layers. Even in this case, the conductor rod 31 can be connected to the lower PCB 40B by supplying solder to the isolated conductor land 43 on the sixth conductor layer L6.

[0066] 6 and 7 , in the armature 10, the conducting rods 31 constituting the U-phase coil, the conducting rods 31 constituting the V-phase coil, and the conducting rods 31 constituting the W-phase coil are arranged in this order in the rotational direction. The conducting rod 31 (e.g., the U-phase conducting rod) arranged in the m-th slit S is connected to the conducting rod 31 (e.g., the U-phase conducting rod) arranged in the (m+3)-th slit S via the conducting line 41 of the upper PCB 40A. In this way, the coils of the armature 10 are distributed winding coils in which the coils of each phase are wound around the teeth 21 spaced apart in the rotational direction.

[0067] 6, the conductor line 41 formed on the lower PCB 40B connects the conductor rod 31 (for example, a U-phase conductor rod) arranged in the m-th slit S to the conductor rod 31 (for example, a U-phase conductor rod) arranged in the (m-3)-th slit S. Therefore, the conductor lines 41 and the conductor rods 31 formed on the upper and lower PCBs 40A and 40B form a coil.

[0068] In the armature 10, four conductor rods 31 arranged radially are inserted into each slot S. Therefore, the coil makes four revolutions around the axis Ax. In the first revolution, the first conductor rod 31 is connected via the upper and lower PCBs 40 and 40B, and in the second revolution, the second conductor rod 31 is connected via the upper and lower PCBs 40 and 40B. In the third revolution, the third conductor rod 31 is connected via the upper and lower PCBs 40 and 40B. In the fourth revolution, the fourth conductor rod 31 is connected via the upper and lower PCBs 40 and 40B.

[0069] The winding method of the coil realized by the conductor rods 31 etc. is not limited to distributed winding. The coil winding method may be concentrated winding. In this case, the conductor rods 31 arranged in two adjacent slits S across one tooth portion 21 are connected by the conductor line 41.

[0070] 8A , the conductor line 41 has a portion 41 a extending radially from an end conductor land 42 located at the end of the conductor line 41, and a portion 41 b extending in the rotation direction of the rotating electric machine 1. Hereinafter, the portion 41 a will be referred to as the "radial extending portion," and the portion 41 b will be referred to as the "rotational extending portion."

[0071] The radially extending portions 41a are formed between two adjacent slits S (between two adjacent through holes 40h in the rotational direction). Each conductor line 41 has radially extending portions 41a at both ends (portions close to the end conductor lands 42). The thickness (width in the rotational direction) of the radially extending portions 41a may gradually increase radially outward, thereby reducing electrical resistance.

[0072] The rotational direction extending portion 41b is formed outside the slit S in which the conductor rod 31 of the other phase is arranged, and extends in the rotational direction. The rotational direction extending portion 41b connects the radial direction extending portions 41a located at both ends of the conductor line 41.

[0073] Such a shape of the conductor lines 41 is common to all of the conductor layers from the first conductor layer L1 to the sixth conductor layer L6. That is, the conductor line 41 connecting the U-phase conductor rods 31, the conductor line 41 connecting the V-phase conductor rods 31, and the conductor line 41 connecting the W-phase conductor rods 31 each have two radially extending portions 41a and a rotationally extending portion 41b therebetween.

[0074] 7, the conductor lines 41 constituting different phases at least partially overlap each other in a plan view (when viewed in the axial direction). This structure can reduce leakage magnetic flux from the conductor lines 41.

[0075] For example, as shown in FIG. 7 , the rotational direction extension portions 41b of the U-phase conductor lines 41(1) and 41(2) overlap with the rotational direction extension portions 41b of the V-phase conductor lines 41(3) and 41(4). Similarly, the rotational direction extension portions 41b of the V-phase conductor lines 41(3) and 41(4) overlap with the rotational direction extension portions 41b of the W-phase conductor lines 41(5) and 41(6). The rotational direction extension portions 41b of the three-phase (U-phase, V-phase, and W-phase) conductor lines 41(1) to 41(6) partially overlap. This reduces leakage magnetic flux from the rotational direction extension portions 41b. In other words, because the sum of the three-phase current vectors is zero, for example, the magnetic field generated by the U-phase current is canceled out by the magnetic fields generated by the V-phase and W-phase, thereby reducing leakage magnetic flux. The positions of the center lines (centers in the radial direction) of the two rotational direction extending portions 41b that overlap in a plan view are aligned.

[0076] Furthermore, the radially extending portions 41a of the U-phase conductor lines 41(1) and 41(2) overlap with the radially extending portions 41a of the V-phase conductor lines 41(3) and 41(4). The radially extending portions 41a of the V-phase conductor lines 41(3) and 41(4) overlap with the radially extending portions 41a of the W-phase conductor lines 41(5) and 41(6). The positions of the center lines (centers in the rotational direction) of the two overlapping radially extending portions 41a in a plan view are the same.

[0077] 8B , the radially extending portions 41 a are connected to the rotationally directed ends 42 a of the end conductor lands 42. The same applies to the conductor lines 41 connected to the outermost conductor rod 31 of the four conductor rods 31 arranged in each slot S. This shape of the radially extending portions 41 a can increase the overlapping range between the radially extending portion 41 a of one phase (e.g., U-phase) and the radially extending portion 41 a of another phase (e.g., V-phase) compared to a shape in which the radially extending portions 41 a are connected to the radial ends of the end conductor lands 42.

[0078] 7, in the upper PCB 40A, a U-phase conductor line 41 is formed on the first conductor layer L1 and the second conductor layer L2, a V-phase conductor line 41 is formed on the third conductor layer L3 and the fourth conductor layer L4, and a W-phase conductor line 41 is formed on the fifth conductor layer L5 and the sixth conductor layer L6. As described above, the lower PCB 40B also has multiple conductor layers L1 to L6. The six conductor layers L1 to L6 of the lower PCB 40B are arranged in this order from the top (the armature core 20 side). In the lower PCB 40B, as in the upper PCB 40A, U-phase conductor lines 41 are formed on the first conductor layer L1 and the second conductor layer L2, V-phase conductor lines 41 are formed on the third conductor layer L3 and the fourth conductor layer L4, and W-phase conductor lines 41 are formed on the fifth conductor layer L5 and the sixth conductor layer L6.

[0079] With this structure, for example, the distance from the end conductor land 42 of the upper PCB 40A connected to the U-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B can be made the same as the distance from the end conductor land 42 of the upper PCB 40A connected to the V-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B. Also, the distance from the end conductor land 42 of the upper PCB 40A connected to the V-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B can be made the same as the distance from the end conductor land 42 of the upper PCB 40A connected to the W-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B. This makes it possible to equalize the electrical resistance of the three-phase coils.

[0080] In the upper PCB 40A and the lower PCB 40B, the conductor lines 41 of the same phase (e.g., U-phase) are formed on two conductor layers adjacent to each other in the axial direction (e.g., the first conductor layer L1 and the second conductor layer L2). The arrangement of the U-phase, V-phase, and W-phase is not limited to the example described here. For example, the conductor lines 41 of the same phase may be formed on two conductor layers spaced apart in the axial direction.

[0081] For example, in each of the upper PCB 40A and the lower PCB 40B, the U-phase conductor line 41 may be formed on the first conductor layer L1 and the fourth conductor layer L4. Alternatively, the V-phase conductor line 41 may be formed on the second conductor layer L2 and the fifth conductor layer L5, and the W-phase conductor line 41 may be formed on the third conductor layer L3 and the sixth conductor layer L6. Even with this phase arrangement, the electrical resistance of the three phases can be made uniform. Furthermore, the conductor lines 41 constituting the three phases can be overlapped in a plan view, thereby reducing leakage magnetic flux.

[0082] [Input Terminals] Three input terminals 51u, 51v, and 51w (see FIG. 2) are connected to the upper PCB 40A. The upper PCB 40A has three through holes on its outer periphery, into which the three input terminals 51u, 51v, and 51w are inserted. A conductive film is formed on the inner surface of the through holes, similar to the through hole 40h for the conductive rod 31. The conductive patterns formed on each of the conductor layers L1 to L6 have terminal portions 46 (see FIG. 3B) surrounding the edges of the through holes. The input terminals 51u, 51v, and 51w are electrically connected to the terminal portions 46 via the conductive film formed on the inner surface of the through holes.

[0083] [Neutral Point (Output Terminal)] The armature 10 may also have a neutral point (output terminal) to which the U-phase coil, V-phase coil, and W-phase coil are connected. As shown in FIG. 2 , the upper PCB 40A has through-holes on its outer periphery, into which conductor posts 52 functioning as the neutral point are inserted. The conductor posts 52 are, for example, cylindrical members made of copper. The thickness (cross-sectional area) of the conductor posts 52 may be larger than that of the conductor rods 31. A conductor film is formed on the inner surface of the through-hole. The conductor patterns formed on each of the conductor layers L1 to L6 have terminal portions 47 (see FIG. 3B ) surrounding the edges of the through-holes. The conductor posts 52 are electrically connected to the terminal portions 47 via the conductor film formed on the inner surface of the through-holes. Using such conductor posts 52 can prevent excessive current density at the neutral point.

[0084] [Method of Manufacturing Armature] A method of manufacturing the armature 10 will be described.

[0085] First, prepare the upper PCB 40A and the lower PCB 40B. As described above, the PCBs 40A and 40B are multilayer printed wiring boards, and as described above, have the conductor layers L1 to L6 and the through-holes 40h in which the conductor films 45 are formed.

[0086] The plurality of conductor rods 31 are inserted into the slits S of the armature core 20. Then, the upper connection portions 31a of the conductor rods 31 are fitted into the through holes 40h of the upper PCB 40A, respectively, so that the upper ends of all the conductor rods 31 reach the upper surface of the upper PCB 40A.

[0087] Next, multiple conductor rods 31 are electrically connected to the conductor pattern formed on the upper PCB 40A. Specifically, liquid or paste solder is supplied to the isolated conductor lands 43 and the end conductor lands 42 formed on the first conductor layer L1 (top layer) of the upper PCB 40A, and the conductor lands 42, 43 are connected to the upper connection portions 31a by the solder. The solder penetrates between the conductor film 45 and the upper connection portions 31a of the conductor rods 31. As a result, the upper connection portions 31a are electrically connected to the conductor lines 41 and the end conductor lands 42 via the conductor film 45. Soldering may be performed by a flow method or a reflow method.

[0088] Next, the lower connection portions 31b of the conductor rods 31 are fitted into the through holes 40h of the lower PCB 40B, respectively. This causes the lower ends of all the conductor rods 31 to reach the lower surface of the lower PCB 40B. The conductor rods 31 are then electrically connected to the conductor pattern formed on the lower PCB 40B. Specifically, liquid or paste solder is applied to the isolated conductor lands 43 and the end conductor lands 42 formed on the sixth conductor layer L6 (the bottom layer) of the lower PCB 40B, connecting the conductor lands 42, 43 to the lower connection portions 31b with the solder. The solder penetrates between the conductor film 45 and the lower connection portions 31b of the conductor rods 31. As a result, the lower connection portions 31b are connected to the conductor line 41 and the end conductor lands 42 via the conductor film 45. This soldering may be performed by a flow method or a reflow method.

[0089] After connecting the upper PCB 40A and the conductive rods 31, the upper surface of the upper PCB 40A and the upper ends of the conductive rods 31 may be covered with an insulating material. Alternatively, another component (e.g., another board) may be attached to the upper surface of the upper PCB 40A. Similarly, after connecting the lower PCB 40B and the conductive rods 31, the lower surface of the lower PCB 40B and the lower ends of the conductive rods 31 may be covered with an insulating material. Alternatively, another component (e.g., another board) may be attached to the lower surface of the lower PCB 40B.

[0090] [Connection Structure of Conductor Rods] In the armature 10, four conductor rods 31 are arranged in each slot S. The coil of each phase makes four turns around the axis Ax. Hereinafter, as shown in Fig. 6, a conductor path formed by one of the four conductor rods 31 arranged in each slot S and the conductor line 41 connecting it will be referred to as one turn. The armature 10 has first to fourth turns.

[0091] In the armature 10, conductor patterns (conductor lines 41 and end conductor lands 42) each consisting of four turns are formed on two conductor layers formed on each of the PCBs 40A and 40B. For example, the conductor line 41 consisting of four turns for the U phase is formed on the first conductor layer L1 and the second conductor layer L2.

[0092] 11A to 11D are diagrams illustrating examples of conductor patterns formed by PCBs 40A and 40B. These diagrams use the conductor pattern forming the U-phase coil as an example. The upper part of Figure 11A shows the upper PCB 40A, and the lower part shows the lower PCB 40B.

[0093] Here, an armature 10 having 16 slots S for each phase will be described as an example. In Figures 11A to 11D, the slots S are numbered 1 to 16. In the following description, of the four conducting rods 31 arranged in each slot S, the outermost conducting rod will be referred to as the first conducting rod 31(1). The second, third, and fourth conducting rods from the outside will be referred to as the second conducting rod 31(2), the third conducting rod 31(3), and the fourth conducting rod 31(4), respectively.

[0094] 11A , the input terminal 51u is connected to the upper connection portion 31a of the first conducting rod 31(1) in the first slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of the first conducting rod 31(1) is connected to the second conducting rod 31(2) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this second conducting rod 31(2) is connected to the first conducting rod 31(1) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this first conducting rod 31(1) is connected to the second conducting rod 31(2) in the fourth slot S via the conductor line 41 of the lower PCB 40B.

[0095] 11A , in the first turn, the upper connection portion 31a of the conductor rod 31 arranged in the "2×i"-th slot S is connected to the upper connection portion 31a of the conductor rod 31 arranged in the "2×i+1"-th slot S via the conductor line 41 formed on the upper PCB 40A (where i is an integer in the range of 0≦i≦7). Also, the lower connection portion 31b of the conductor rod 31 arranged in the "2×i+1"-th slot S is connected to the lower connection portion 31b of the conductor rod 31 arranged in the "2×i+2"-th slot S via the conductor line 41 formed on the lower PCB 40B. This results in a clockwise wound coil in the first turn.

[0096] 11A and 11B, the second conducting rod 31(2) arranged in the 16th slot S is connected to the second conducting rod 31(2) in the first slot S via the conducting line 41 of the upper PCB 40A, thereby starting the second turn.

[0097] 11B, in the second turn, the lower connection portion 31b of the second conducting rod 31(2) in the first slot S is connected to the first conducting rod 31(1) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this first conducting rod 31(1) is connected to the second conducting rod 31(2) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this second conducting rod 31(2) is connected to the first conducting rod 31(1) in the fourth slot S via the conductor line 41 of the lower PCB 40B.

[0098] 11B , in the second turn, the upper connection portion 31a of the conductor rod 31 arranged in the "2×i"-th slot S is connected to the upper connection portion 31a of the conductor rod 31 arranged in the "2×i+1"-th slot S via the conductor line 41 formed on the upper PCB 40A (where i is an integer in the range of 0≦i≦7). Also, the lower connection portion 31b of the conductor rod 31 arranged in the "2×i+1"-th slot S is connected to the lower connection portion 31b of the conductor rod 31 arranged in the "2×i+2"-th slot S via the conductor line 41 formed on the lower PCB 40B. This results in a clockwise wound coil in the second turn.

[0099] 11B and 11C, the upper connection portion 31a of the first conducting rod 31(1) arranged in the 16th slot S is connected to the third conducting rod 31(3) in the first slot S via the conducting line 41 of the upper PCB 40A. This starts the third turn.

[0100] 11C, in the third turn, the lower connection portion 31b of the third conducting rod 31(3) in the first slot S is connected to the fourth conducting rod 31(4) in the sixteenth slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this fourth conducting rod 31(4) is connected to the third conducting rod 31(3) in the fifteenth slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this third conducting rod 31(3) is connected to the fourth conducting rod 31(4) in the fourteenth slot S via the conductor line 41 of the lower PCB 40B.

[0101] 11C , in the third turn, the upper connection portion 31a of the conductor rod 31 arranged in the "2×i"-th slot S is connected to the upper connection portion 31a of the conductor rod 31 arranged in the "2×i-1"-th slot S via the conductor line 41 formed on the upper PCB 40A (where i is an integer such that 2≦i≦8). Furthermore, the lower connection portion 31b of the conductor rod 31 arranged in the "2×i-1"-th slot S is connected to the lower connection portion 31b of the conductor rod 31 arranged in the "2×i-2"-th slot S via the conductor line 41 formed on the lower PCB 40B. This results in a counterclockwise wound coil in the third turn. That is, the first and second turns form a clockwise wound coil, and the third turn forms a counterclockwise wound coil.

[0102] 11C, the upper connection portion 31a of the fourth conducting rod 31(4) arranged in the second slot S is connected to the fourth conducting rod 31(4) in the first slot S via the conducting line 41 of the upper PCB 40A. This starts the fourth turn.

[0103] 11D, in the fourth turn, the lower connection portion 31b of the fourth conducting rod 31(4) in the first slot S is connected to the third conducting rod 31(3) in the sixteenth slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this third conducting rod 31(3) is connected to the fourth conducting rod 31(4) in the fifteenth slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this fourth conducting rod 31(4) is connected to the third conducting rod 31(3) in the fourteenth slot S via the conductor line 41 of the lower PCB 40B.

[0104] 11D, in the fourth turn, the upper connection portion 31a of the conductor rod 31 arranged in the "2×i"-th slot S is connected to the upper connection portion 31a of the conductor rod 31 arranged in the "2×i-1"-th slot S via the conductor line 41 formed on the upper PCB 40A (where i is an integer such that 2≦i≦8). Also, the lower connection portion 31b of the conductor rod 31 arranged in the "2×i-1"-th slot S is connected to the lower connection portion 31b of the conductor rod 31 arranged in the "2×i-2"-th slot S via the conductor line 41 formed on the lower PCB 40B. As a result, in the fourth turn, a coil wound in the counterclockwise direction is realized, similar to the third turn.

[0105] As shown in FIG. 11D, the third conducting rod 31(3) in the second slot S is connected to the conducting post 52 constituting the neutral point via the conducting line of the upper PCB 40A.

[0106] 11A to 11D are formed. In FIG. 11, the nth slot S to the (n+2)th slot S of the upper PCB 40A are shown (where "n" is, for example, the above-mentioned "2×i" or "2×i+1").

[0107] 12, in the first turn, the second conducting rod 31(2) arranged in the nth slot S and the first conducting rod 31(1) arranged in the (n+1)th slot S are connected by a conductor line 41 formed on the upper PCB 40A. In addition, in the third turn, the third conducting rod 31(3) arranged in the (n+1)th slot S and the fourth conducting rod 31(4) arranged in the (n+2)th slot S are connected by a conductor line 41 formed on the upper PCB 40A. These conductor lines 41 do not interfere with each other, so they can be formed on the same conductor layer. For example, the conductor line 41 of the first turn and the conductor line 41 of the third turn are formed on the first conductor layer L1 (see FIG. 10).

[0108] In the second turn, the first conducting rod 31(1) arranged in the nth slot S and the second conducting rod 31(2) arranged in the (n+1)th slot S are connected by a conductor line 41 formed on the upper PCB 40A. In the fourth turn, the fourth conducting rod 31(4) arranged in the (n+1)th slot and the fourth conducting rod 31(4) arranged in the (n+2)th slot S are connected by a conductor line 41 formed on the upper PCB 40A. These conductor lines 41 do not interfere with each other, so they can be formed on the same conductor layer. For example, the conductor line 41 of the second turn and the conductor line 41 of the fourth turn are formed on the second conductor layer L2 (see FIG. 10 ).

[0109] In this way, the four-turn conductor line 41 is formed on two conductor layers, so that the number of conductor layers can be reduced.

[0110] 13A to 13D are diagrams illustrating comparative examples of conductor patterns. The upper part of Fig. 13A shows the conductor pattern of the upper PCB 40A, and the lower part shows the conductor pattern of the lower PCB 40B. In Fig. 13A and other figures, numbers 1 to 16 are assigned to the slots S.

[0111] As shown in FIG. 13A , the input terminal 51u is connected to the upper connection portion 31a of the first conducting rod 31(1) in the first slot S via the conductor pattern of the upper PCB 40A. The lower connection portion 31b of the first conducting rod 31(1) is connected to the second conducting rod 31(2) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this second conducting rod 31(2) is connected to the first conducting rod 31(1) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this first conducting rod 31(1) is connected to the second conducting rod 31(2) in the fourth slot S via the conductor line 41 of the lower PCB 40B. As shown in FIG. 13A , subsequent conducting rods 31 are connected in the same order in the first turn. This results in a clockwise wound coil in the first turn.

[0112] 13A and 13B, the upper connection portion 31a of the second conducting rod 31(2) arranged in the 16th slot S is connected to the second conducting rod 31(2) in the first slot S via the conducting line 41 of the upper PCB 40A. This starts the second turn.

[0113] 13B , in the second turn, the lower connection portion 31b of the second conducting rod 31(2) in the first slot S is connected to the third conducting rod 31(3) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this third conducting rod 31(3) is connected to the second conducting rod 31(2) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this second conducting rod 31(2) is connected to the third conducting rod 31(3) in the fourth slot S via the conductor line 41 of the lower PCB 40B. In the second turn, subsequent conducting rods 31 are connected in the same order. This results in a clockwise wound coil in the second turn.

[0114] 13B and 13C, the third conducting rod 31(3) arranged in the 16th slot S is connected to the third conducting rod 31(3) in the first slot S via the conducting line 41 of the upper PCB 40A, thereby starting the third turn.

[0115] 13C , in the third turn, the lower connection portion 31b of the third conducting rod 31(3) in the first slot S is connected to the fourth conducting rod 31(4) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this fourth conducting rod 31(4) is connected to the third conducting rod 31(3) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this third conducting rod 31(3) is connected to the fourth conducting rod 31(4) in the fourth slot S via the conductor line 41 of the lower PCB 40B. In the third turn, subsequent conducting rods 31 are connected in the same order. This results in a clockwise wound coil in the third turn.

[0116] 13C, the fourth conducting rod 31(4) arranged in the 16th slot S is connected to the fourth conducting rod 31(4) in the first slot S via the conducting line 41 of the upper PCB 40A. This starts the fourth turn.

[0117] 13D , in the fourth turn, the lower connection portion 31b of the fourth conducting rod 31(4) in the first slot S is connected to the first conducting rod 31(1) in the sixteenth slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this first conducting rod 31(1) is connected to the fourth conducting rod 31(4) in the fifteenth slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this fourth conducting rod 31(4) is connected to the first conducting rod 31(1) in the fourteenth slot S via the conductor line 41 of the lower PCB 40B. In the fourth turn, subsequent conducting rods 31 are connected in the same order. As a result, a counterclockwise wound coil is realized in the fourth turn.

[0118] That is, in the comparative example shown in Figures 13A to 13D, a clockwise coil is formed by the first, second, and third turns, and a counterclockwise coil is formed by the fourth turn. In this comparative example, the upper connection portions 31a of the three conductor rods 31 arranged in the "2xi"-th slot S are connected to the upper connection portions 31a of the three conductor rods 31 arranged in the "2xi+1"-th slot S on the upper PCB 40A. Therefore, the conductor lines 41 connecting these must be formed on three conductor layers to avoid mutual interference. In other words, the comparative example requires at least three conductor layers for each phase (e.g., the U-phase). Similarly, in this comparative example, the lower connection portions 31b of the three conductor rods 31 arranged in the "2xi+1"-th slot S are connected to the lower connection portions 31b of the three conductor rods 31 arranged in the "2xi+2"-th slot S on the lower PCB 40B. Therefore, the lower PCB 40B also requires at least three conductor layers for one phase (for example, the U phase).

[0119] 11A to 12, in the upper PCB 40A, the conductor lines 41 constituting the first and third turns can be formed on the same conductor layer (for example, the first conductor layer L1), and the conductor lines 41 constituting the second and fourth turns can also be formed on the same conductor layer (for example, the second conductor layer L2). In this way, the structure of the armature 10 can reduce the number of conductor layers compared to the structure of the comparative example shown in FIGS. 13A to 13D.

[0120] [Position where the connection direction is reversed] Here, a plurality of conductor rods 31 including one of the four conductor rods 31 arranged in each slot S and surrounding the axis Ax is defined as a "conductor rod set." A conductor rod set is made up of a plurality of conductor rods 31 (16 conductor rods in the example of the armature 10) that make up each turn. The armature 10 has four conductor rod sets.

[0121] When "conductor rod set" is defined in this way, the conductor rod set of the first turn (FIG. 11A) and the conductor rod set of the second turn (FIG. 11B) are composed of conductor rods 31 connected in a clockwise direction. In other words, when a voltage is applied to the input terminal 51u, a current flows in a clockwise direction. On the other hand, the conductor rod set of the third turn (FIG. 11C) and the conductor rod set of the fourth turn (FIG. 11D) are composed of conductor rods 31 connected in a counterclockwise direction. In other words, when a voltage is applied to the input terminal 51u, a current flows in a counterclockwise direction.

[0122] Therefore, the number of conductor rod sets formed by conductor rods 31 connected in the clockwise direction is the same as the number of conductor rod sets formed by conductor rods 31 connected in the counterclockwise direction, 2. This allows the multiple conductor layers to be used efficiently, and the number of conductor layers can be reduced.

[0123] As will be explained later, the number of conductor rods 31 arranged in each slot S may be an odd number (see FIGS. 14A to 14E). For example, five conductor rods 31 may be arranged in each slot S. In this case, the difference between the number of conductor rod sets formed by conductor rods 31 connected in the clockwise direction and the number of conductor rod sets formed by conductor rods 31 connected in the counterclockwise direction may be 1. Even in this case, multiple conductor layers can be used efficiently, and the number of conductor layers can be reduced.

[0124] [Conductive Pattern Formed on Upper PCB] Focus on three consecutive slots S in the rotational direction. Here, the three slots S (n-th slot S, n+1-th slot S, and n+2-th slot S) shown in Fig. 12 are referred to as the first slot S(n), the second slot S(n+1), and the third slot S(n+2), respectively.

[0125] 12 , the number of conductor lines 41 connecting the conductor rod 31 arranged in the first slot S(n) and the conductor rod 31 arranged in the second slot S(n+1) is 2. The number of conductor lines 41 connecting the conductor rod 31 arranged in the second slot S(n+1) and the conductor rod 31 arranged in the third slot S(n+2) is also 2. In other words, the number of conductor lines 41 formed between the first slot S(n) and the second slot S(n+1) is the same as the number of conductor lines 41 formed in the second slot S(n+1) and the third slot S(n+2).

[0126] In this way, in the upper PCB 40A of the armature 10, the number of conductor lines 41 formed between the first slot S and the second slot S is balanced with the number of conductor lines 41 formed between the second slot S and the third slot S. This holds true for any three consecutive slots S formed in the upper PCB 40A. As a result, the multiple conductor layers L1 to L6 can be used efficiently, and the number of conductor layers can be reduced. The same holds true for the lower PCB 40B.

[0127] As will be explained later, the number of conductor rods 31 arranged in each slot S may be odd (see FIGS. 14A to 14D). In this case, the difference between the number of conductor lines 41 formed between the first slot S(n) and the second slot S(n+1) and the number of conductor lines 41 formed between the second slot S(n+1) and the third slot S(n+2) may be 1.

[0128] [Balance in the Number of Conductor Lines Between the Upper PCB and the Lower PCB] Next, attention will be focused on two consecutive slots S in the rotation direction. Here, these two slots S are referred to as the first slot S and the second slot S. As shown in FIG. 10D , in the upper PCB 40A of the armature 10, the number of conductor lines 41 connecting the conductor rods 31 arranged in the first slot S and the conductor rods 31 arranged in the second slot S is two. Similarly, in the lower PCB 40B, the number of conductor lines 41 connecting the conductor rods 31 arranged in the first slot S and the conductor rods 31 arranged in the second slot S is also two. In other words, the number of conductor lines 41 formed on the upper PCB 40A is the same as the number of conductor lines 41 formed on the lower PCB 40B. This holds true for any two consecutive slots S formed on the PCBs 40A and 40B.

[0129] In this way, the number of conductor lines 41 formed on the upper PCB 40A and the number of conductor lines 41 formed on the lower PCB 40B are balanced in the armature 10. This makes it possible to reduce the number of conductor layers L1 to L6 formed on each of the PCBs 40A and 40B.

[0130] As will be explained later, the number of conductor rods 31 arranged in each slot S may be an odd number (see FIGS. 14A to 14D). In this case, the difference between the number of conductor lines 41 formed between the first slot S and the second slot S on the upper PCB 40A and the number of conductor lines 41 formed between the first slot S and the second slot S on the lower PCB 40B may be 1.

[0131] [Armature with an odd number of conducting rods in each slot] Figures 14A to 14E are diagrams showing modified examples of the armature 10 shown in Figure 11A and other figures. In the armature 110 shown in these figures, five conducting rods 31 are arranged in each slot S. Therefore, the coils of each phase make five turns around the axis Ax. As with Figure 11A and other figures, these figures show an example of a conductor pattern forming a U-phase coil. Figures 14A to 14E show the first to fifth turns, respectively.

[0132] 14A to 14E, as in Fig. 11A etc., each slot S is numbered 1 to 16. In the following explanation, of the five conducting rods 31 arranged in each slot S, the outermost conducting rod will be referred to as the first conducting rod 31(1). The second, third, fourth, and fifth conducting rods from the outside will be referred to as the second conducting rod 31(2), third conducting rod 31(3), fourth conducting rod 31(4), and fifth conducting rod 31(5), respectively.

[0133] The first to fourth turns shown in FIGS. 14A to 14D are the same as the first to fourth turns of the PCBs 40A and 40B illustrated in FIGS. 11A to 11D, and therefore will not be described here.

[0134] 14D and 14E, at the rear end of the fourth turn, the upper connection portion 31a of the third conducting rod 31(3) in the second slot S is connected to the upper connection portion 31a of the fifth conducting rod 31(5) in the first slot S via the conductor line 41 of the upper PCB 40A, thereby starting the fifth turn.

[0135] 14E, the lower connection portion 31b of the fifth conducting rod 31(5) in the first slot S is connected to the lower connection portion 31b of the fifth conducting rod 31(5) in the second slot S via the conductor line 41 of the lower PCB 40B. The upper connection portion 31a of this fifth conducting rod 31(5) is connected to the upper connection portion 31a of the fifth conducting rod 31(5) in the third slot S via the conductor line 41 of the upper PCB 40A. The lower connection portion 31b of this fifth conducting rod 31(5) is connected to the lower connection portion 31b of the fifth conducting rod 31(5) in the fourth slot S via the conductor line 41 of the lower PCB 40B.

[0136] 14E, in the fifth turn, the upper connection portion 31a of the fifth conducting rod 31(5) arranged in the "2×i"-th slot S is connected to the upper connection portion 31a of the fifth conducting rod 31(5) arranged in the "2×i+1"-th slot S via the conductor line 41 formed on the upper PCB 40A (where i is an integer in the range of 0≦i≦7). Also, the lower connection portion 31b of the fifth conducting rod 31(5) arranged in the "2×i+1"-th slot S is connected to the lower connection portion 31b of the fifth conducting rod 31(5) arranged in the "2×i+2"-th slot S via the conductor line 41 formed on the lower PCB 40B.

[0137] This results in a clockwise wound coil in the fifth turn. The fifth conducting rod 31(5) arranged in the sixteenth slot S is connected to the conducting post 52 that forms the neutral point via the conducting line of the upper PCB 40A.

[0138] 14E, the number of conductor lines 41 connecting the conductor rod 31 arranged in the "2×i"th slot S (e.g., the second slot S) and the conductor rod 31 arranged in the "2×i+1"th slot S (e.g., the third slot S) is three. The conductor lines 41 constituting the first turn, the second turn, and the fifth turn are formed between these two slits S. These three conductor lines 41 are formed on three conductor layers (e.g., conductor layers L1 to L3), respectively.

[0139] 14E, the number of conductor lines 41 connecting the conductor rod 31 arranged in the "2×i+1"th slot S (for example, the third slot S) and the conductor rod 31 arranged in the "2×i+2"th slot S (the fourth slot S) is two. The conductor lines 41 constituting the third and fourth turns are formed between these two slits S. These two conductor lines 41 do not interfere with the conductor lines 41 constituting the first, second, and fifth turns. Therefore, these two conductor lines 41 are formed on two of the conductor layers L1 to L3.

[0140] Thus, the armature 110 shown in Figures 14A-14E has three conductor layers for each phase.

[0141] In Fig. 14A etc., attention is focused on three consecutive slots S in the rotational direction. For example, in Fig. 14E, attention is focused on the second slit S, the third slit S, and the fourth slit S. In this case, the number of conductor lines 41 connecting the conductor rod 31 arranged in the second slot S and the conductor rod 31 arranged in the third slot S is three. On the other hand, the number of conductor lines 41 connecting the conductor rod 31 arranged in the second slot S and the conductor rod 31 arranged in the fourth slot S is two.

[0142] In this way, when the number of conductor rods 31 arranged in each slot S is odd, the difference between the number of conductor lines 41 formed between the first two slots S and the number of conductor lines 41 formed between the last two slits S is 1. Because this difference is small, the conductor layers formed on each PCB 40A, 40B can be used efficiently, and the number of required conductor layers can be reduced. Note that in the comparative example shown in FIG. 13A etc., this difference is 2.

[0143] 14A and other figures, attention is focused on two slots S that are consecutive in the rotational direction. In this case, the difference between the number of conductor lines 41 formed between these two slots S on the upper PCB 40A and the number of conductor lines 41 formed between the same two slots S on the lower PCB 40B is 1.

[0144] For example, let us look at the second slot S and the third slot S shown in Fig. 14E. The number of conductor lines 41 formed on the upper PCB 40A that connect the conductor rod 31 arranged in the second slot S with the conductor rod 31 arranged in the third slot S is three. On the other hand, the number of conductor lines 41 formed on the lower PCB 40B that connects the conductor rod 31 arranged in the second slot S with the conductor rod 31 arranged in the third slot S is two. Therefore, the difference between them is one.

[0145] In this way, in the armature 110, the difference between the number of conductor lines 41 formed on the upper PCB 40A and the number of conductor lines 41 formed on the lower PCB 40B is small. This allows the conductor layers formed on each PCB 40A, 40B to be used efficiently, and the number of required conductor layers can be reduced. Note that in the comparative example shown in FIG. 13A etc., this difference is 2.

[0146] The number of conductor layers in the lower PCB 40B is the same as the number of conductor layers in the upper PCB 40A.

[0147] A plurality of conductor rods 31, including one of the five conductor rods 31 arranged in each slot S, surrounding the axis Ax is defined as a "conductor rod set." A conductor rod set is made up of a plurality of conductor rods 31 (16 conductor rods in the example of the armature 10) that make up each turn. The armature 110 has five conductor rod sets.

[0148] When the conductor rod sets are defined in this way, the conductor rod set of the first turn (FIG. 14A), the conductor rod set of the second turn (FIG. 14B), and the conductor rod set of the fifth turn (FIG. 14E) are composed of conductor rods 31 connected in a clockwise direction. When a voltage is applied to the input terminal 51u, a current flows through these turns in a clockwise direction. On the other hand, the conductor rod set of the third turn (FIG. 11C) and the conductor rod set of the fourth turn (FIG. 11D) are composed of conductor rods 31 connected in a counterclockwise direction. When a voltage is applied to the input terminal 51u, a current flows through these turns in a counterclockwise direction.

[0149] 14A etc., the difference between the number of conductor rod sets formed by conductor rods 31 connected in the clockwise direction and the number of conductor rod sets formed by conductor rods 31 connected in the counterclockwise direction is 1. This allows the multiple conductor layers to be used efficiently, and the number of conductor layers can be reduced.

[0150] [Modifications for the Position Where the Conductor Rod Connection Direction is Reversed] In the armatures 10 and 110, as shown in Figures 11A to 11D and 14A to 14E, the connection direction of the conductive rods 31 (the winding direction of the coil) is reversed between the second turn (Figures 11B and 14B) and the third turn (Figures 11C and 14C). The position where the connection direction of the conductive rods 31 is reversed is not limited to this. As long as the structure allows the number of conductor lines 41 connecting the conductive rods 31 arranged in two adjacent slots S to be balanced between the upper PCB 40A and the lower PCB 40B, the connection direction of the conductive rods 31 may be reversed at another position.

[0151] 15A to 15D are diagrams showing yet another modified example of the armature 10 illustrated in FIG. 11A and other figures. In the armature 210 shown in these figures, four conductor rods 31 are arranged in each slot S, and the coils of each phase make four turns around the axis Ax. As with FIG. 11A and other figures, these figures show an example of a conductor pattern forming a U-phase coil. FIGS. 15A to 15D show the first to fourth turns, respectively.

[0152] In the first turn shown in Fig. 15A, the conductor rods 31 are connected in a clockwise direction, as in Fig. 11A. As shown in Fig. 15B, the second turn is composed of conductor rods 31 connected in a counterclockwise direction, as shown in Fig. 15C, the third turn is composed of conductor rods 31 connected in a clockwise direction, as shown in Fig. 15D. The fourth turn is composed of conductor rods 31 connected in a clockwise direction.

[0153] 15A to 15D, the conductor line 41 of the first turn and the conductor line 41 of the third line do not interfere with each other, so they can be formed on the same conductor layer. For example, the conductor line 41 of the first turn and the conductor line 41 of the third turn are formed on the first conductor layer L1 (see FIG. 10). The conductor line 41 of the second turn and the conductor line 41 of the fourth line do not interfere with each other, so they can be formed on the same conductor layer. For example, the conductor line 41 of the second turn and the conductor line 41 of the fourth turn are formed on the second conductor layer L2 (see FIG. 10). In this way, the conductor line 41 of four turns is formed on two conductor layers, so the number of conductor layers can be reduced.

[0154] [Modifications for Connection of Conducting Rods] In the armatures 10 and 110 described above, the positions of the two conducting rods 31 connected via the conductor line 41 are different. For example, in the example shown in FIG. 12 , the second conducting rod 31(2) in the nth slot S is connected to the first conducting rod 31(1) in the n+1th slit S. Furthermore, the first conducting rod 31(1) in the nth slot S is connected to the second conducting rod 31(2) in the n+1th slit S. This makes it possible to obtain an effect equivalent to that of a twisted wire. Alternatively, conducting rods 31 in the same position may be connected via the conductor line 41.

[0155] 16A to 16D are diagrams showing yet another modified example of the armature 10 shown in FIG. 11A and other figures. In the armature 310 shown in these figures, four conductor rods 31 are arranged in each slot S, and the coils of each phase make four turns around the axis Ax. As with FIG. 11A and other figures, these figures show an example of a conductor pattern forming a U-phase coil. FIGS. 16A to 16D show the first to fourth turns, respectively.

[0156] In the first turn shown in Fig. 16A, first conducting rods 31(1) arranged in two adjacent slots S are connected by a conductor line 41. In the second turn shown in Fig. 16B, second conducting rods 31(2) arranged in two adjacent slots S are connected by a conductor line 41, in the third turn shown in Fig. 16C, third conducting rods 31(3) arranged in two adjacent slots S are connected by a conductor line 41, and in the fourth turn shown in Fig. 16D, fourth conducting rods 31(4) arranged in two adjacent slots S are connected by a conductor line 41.

[0157] In this structure, the first turn conductor line 41 and the third turn conductor line 41 do not interfere with each other, so they can be formed on the same conductor layer. Similarly, the second turn conductor line 41 and the fourth turn conductor line 41 do not interfere with each other, so they can be formed on the same conductor layer. In this way, the four turns of conductor line 41 are formed on two conductor layers, so the number of conductor layers can be reduced.

[0158] Other Examples The armatures proposed in the present disclosure are not limited to the above-described examples.

[0159] For example, the number of turns (number of conductor rod sets) may be more than 5. The number of turns may also be 6 or 7.

[0160] As yet another example, the armature 10 may not have one of the upper PCB 40A and the lower PCB 40B. In this case, the conductor rod 31 may be a rod bent into a substantially U-shape. Both ends of the rod may be inserted into different slits S and connected to the PCB.

[0161] Furthermore, the upper PCB 40A may have another conductor layer above the first conductor layer L1. This conductor layer may have, for example, a conductor pattern formed thereon for mounting electrical components.

[0162] [Summary] (1) The armature 10 includes an armature core 20 having a plurality of teeth 21, a plurality of conducting rods 31, and an upper PCB 40A. The upper PCB 40A is a multilayer printed wiring board that includes a plurality of conducting layers L1 to L6 on which conducting patterns are formed, and a plurality of through holes 40h on whose inner circumferential surfaces a conducting film 45 is formed at least partially. The ends of the conducting rods 31 are inserted into the through holes 40h, and the conducting rods 31 are electrically connected to the conducting patterns via the conducting film 45. With this structure, the conducting rods 31 are connected by the multilayer PCB 40A having a plurality of conducting layers L1 to L6, which simplifies the manufacturing process of the armature 10.

[0163] (2) In the structure of (1), the conductor film 45 formed in the through hole 40h connects the isolated conductor land 43 and the end conductor land 42. With this structure, the contact area between the conductor pattern and the conductor rod 31 is increased by the isolated conductor land 43, so the current density is reduced and the skin effect of AC current can be alleviated.

[0164] (3) In the structure of (1) or (2), the conductive film 45 formed in the through hole 40h connects the conductive land 43 (or 42) on the first conductive layer L1 (top layer), the conductive land 43 (or 42) on the sixth conductive layer L6 (bottom layer), and the conductive lands 43 (or 42) on the conductive layers L2 to L5. With this structure, the conductive land 43 increases the contact area between the conductive pattern and the conductive rod 31, thereby reducing the current density and mitigating the skin effect of AC current. Furthermore, the increased contact area between the conductive film 45 and the conductive rod 31 reduces the electrical resistance between them and also increases the mechanical fixing strength.

[0165] (4) In any of the structures (1) to (3), the conductive film 45 formed on the inner surface of the through hole 40h connects the isolated conductive land 43 formed on the first conductor layer L1 (top layer) to the end conductive land 42 formed on a conductive layer other than the first conductor layer L1. With this structure, when solder is supplied to the isolated conductive land 43 formed on the first conductor layer L1, the solder penetrates between the conductive film 45 and the conductive rod 31, electrically connecting the conductive rod 31 and the conductor line 41. As a result, the work of connecting the conductive rod 31 to the upper PCB 40A can be facilitated.

[0166] (5) In the structure of (4), the end of the conductor rod 31 is inserted into the through hole 40h and reaches the upper surface of the upper PCB 40A.

[0167] (6) In any of the structures (1) to (5), the conductor pattern of the first conductor layer L1 formed on the upper surface of the upper PCB 40A has, for all of the multiple through holes 40h, isolated conductor lands 43 or end conductor lands 42 surrounding the edges of each through hole 40h. The conductor film 45 formed on the inner surface of each through hole 40h is connected to the isolated conductor land 43 or end conductor land 42. This structure further facilitates the connection work between the conductor rod 31 and the upper PCB 40A.

[0168] (7) In the structure of (6), the ends of all the conductor rods 31 are inserted into the respective through holes 40h and reach the upper surface of the upper PCB 40A.

[0169] (8) In any of the structures (1) to (7), the thickness of the isolated conductor land 43 is smaller than the thickness of the conductor line 41. This makes it easy to ensure a sufficient distance D1 (see FIG. 8B ) between the end conductor land 42 and the isolated conductor land 43 that are adjacent in the radial direction.

[0170] In the structures (9) and (8), the thickness of the end conductor land 42 is also smaller than the thickness of the conductor line 41. This makes it easier to ensure a sufficient distance D1 (see FIG. 8B ) between the end conductor land 42 and the isolated conductor land 43 that are adjacent in the radial direction.

[0171] (10) In any of the structures (1) to (9), the conductor line 41 has a portion 41a (FIG. 8A) extending radially from the end conductor land 42, and a portion 41b (FIG. 8A) located outside the second through hole 40h and extending in the rotational direction.

[0172] (11) In the structure of (10), the conductor lines 41 of the first conductor layer L1 partially overlap with the conductor lines 41 of the conductor layers L2 to L6 when viewed in the axial direction. This reduces leakage magnetic flux from the armature 10.

[0173] (12) In any of the structures (1) to (11), the lower PCB 40B is a multilayer printed wiring board and has multiple conductor layers L1 to L6 on which conductor patterns are formed and multiple through holes 40h on whose inner surfaces at least a portion of a conductor film 45 is formed. The ends of multiple conductor rods 31 are inserted into the multiple through holes 40h formed in the lower PCB 40B. The multiple conductor rods 31 are electrically connected to the conductor patterns via the conductor film 45 formed on the lower PCB 40B. With this structure, the multiple conductor rods 31 are connected by the two PCBs 40A and 40B, eliminating the need to use conductor rods bent into a U-shape, for example, and reducing the size of the armature 10 in the axial direction.

[0174] (13) In the upper PCB 40A of (12), the conductor layers L1 and L2 for the U phase and the conductor layers L3 and L4 for the V phase are arranged in this order from top to bottom in the axial direction. Similarly, in the lower PCB 40B, the conductor layers L1 and L2 for the U phase and the conductor layers L3 and L4 for the V phase are arranged in this order from top to bottom in the axial direction. This structure allows the distance from the end conductor land 42 of the upper PCB 40A connected to the U-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B to be the same as the distance from the end conductor land 42 of the upper PCB 40A connected to the V-phase conductor rod 31 to the end conductor land 42 of the lower PCB 40B. As a result, the electrical resistance of the coils of these two phases can be made uniform.

[0175] (14) The rotating electric machine 1 has an armature 10 having any one of the structures (1) to (13) and a field magnet portion 90 that is rotatable relative to the armature 10. (15) A method for manufacturing the armature 10 includes the steps of preparing a multilayer upper PCB 40A, preparing a plurality of conductor rods 31, inserting the plurality of conductor rods 31 into the plurality of through holes 40h, and electrically connecting the plurality of conductor rods 31 to a conductor pattern formed on the upper PCB 40A via a conductor film 45 formed on the inner surface of the through holes 40h of the upper PCB 40A.

[0176] In (16) and (15), the first conductor layer L1 (top layer) of the upper PCB 40A has a conductor line 41 and an isolated conductor land 43 that surrounds the edge of the through hole 40h and is independent of the conductor line 41. The conductor layers L2 to L6 have a conductor line 41 and an end conductor land 42 that surrounds the edge of the through hole 40h and is connected to the conductor line 41. In the process of electrically connecting multiple conductor rods 31, the conductor rod 31 is inserted into one of the multiple through holes 40h, and solder is applied to the isolated conductor land 43. This allows the solder supplied to the isolated conductor land 43 to penetrate between the conductor rod 31 and the conductor film 45 formed on the inner surface of the through hole 40h, resulting in the conductor rod 31 connecting to the end conductor land 42 and the conductor line 41 via the conductor film 45. This facilitates the process of connecting the conductor rod 31 to the upper PCB 40A.

Claims

1. An armature comprising: an armature core having a plurality of teeth; a plurality of conductive rods, each inserted between two adjacent teeth; and a multilayer first printed circuit board (PCB) having a plurality of conductive layers on which conductive patterns are formed, and a plurality of through holes, the inner surfaces of which are at least partially formed with conductive films, wherein the ends of the conductive rods are inserted into the through holes, and the conductive rods are electrically connected to the conductive patterns via the conductive films.

2. The armature according to claim 1, wherein the plurality of conductor layers include a first conductor layer and a second conductor layer, the conductor pattern of the first conductor layer has a conductor line and a first conductor land that surrounds an edge of one of the plurality of through holes and is independent from the conductor line of the first conductor layer, the conductor pattern of the second conductor layer has a conductor line and a second conductor land that surrounds an edge of the one of the plurality of through holes and is connected to the conductor line of the second conductor layer, and the conductor film formed on the inner peripheral surface of the one of the plurality of through holes connects the first conductor land and the second conductor land.

3. The armature according to claim 1, wherein the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core, the plurality of conductor layers having a first conductor layer formed on the first outer surface, a second conductor layer formed on the second outer surface, and at least one conductor layer formed between the first and second conductor layers, the first conductor layer, the second conductor layer, and the at least one conductor layer each having a conductor land surrounding the edges of the plurality of through holes, and a conductor film formed on the inner peripheral surfaces of the plurality of through holes connecting the conductor land of the first conductor layer, the conductor land of the second conductor layer, and the conductor land of the at least one conductor layer.

4. The armature according to claim 1, wherein the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core, the plurality of conductor layers have a first conductor layer formed on the first outer surface and a third conductor layer formed on the second outer surface or between the first outer surface and the second outer surface, the conductor pattern of the first conductor layer has a conductor line and a first conductor land surrounding an edge of one of the plurality of through holes and being independent from the conductor line of the first conductor layer, the conductor pattern of the third conductor layer has a conductor line and a third conductor land surrounding an edge of the one of the plurality of through holes and being connected to the conductor line of the third conductor layer, and the conductor film formed on the inner peripheral surface of the one of the plurality of through holes connects the first conductor land and the third conductor land.

5. An armature according to claim 4, wherein the plurality of conducting rods includes a conducting rod inserted into said one of said plurality of through holes, and an end of said conducting rod is inserted into said one of said plurality of through holes and reaches said first outer surface.

6. An armature as described in claim 1, wherein the first PCB has a first outer surface facing away from the armature core, the plurality of conductor layers have a first conductor layer formed on the first outer surface, the first conductor layer has conductor lands surrounding the edges of each of the plurality of through holes for all of the plurality of through holes, and the conductor films formed on the inner surfaces of the plurality of through holes are connected to the conductor lands.

7. An armature according to claim 6, wherein the ends of all of the conductor rods are inserted into the plurality of through holes, respectively, and reach the first outer surface.

8. The armature according to claim 1, wherein the plurality of conducting rods include a first conducting rod arranged between two adjacent teeth and a second conducting rod arranged between the two adjacent teeth and positioned adjacent to the first conducting rod in the radial direction; the plurality of through holes include a first through hole into which the first conducting rod is inserted and a second through hole into which the second conducting rod is inserted; the conductor pattern of a first conducting layer that is one of the plurality of conductor layers includes a first conducting land surrounding an edge of the first through hole, a second conducting land surrounding an edge of the second through hole, and a conducting line extending from the second conducting land; and the thickness of the first conducting land is smaller than the thickness of the conducting line.

9. The armature according to claim 8, wherein the thickness of the second conductor land is also smaller than the thickness of the conductor line.

10. The armature according to claim 1, wherein the plurality of conducting rods include a plurality of first conducting rods to which a first phase current is supplied and a plurality of second conducting rods that are positioned in the rotational direction relative to the plurality of first conducting rods and are supplied with a second phase current; the plurality of through holes have a plurality of first through holes into which the plurality of first conducting rods are inserted and a plurality of second through holes into which the second conducting rods are inserted; the conductor pattern of a first conductor layer that is one of the plurality of conductor layers has a conductor land that surrounds an edge of one of the plurality of first through holes and a conductor line that extends from the conductor land, and the conductor line has a portion that extends radially from the conductor land and a portion that is positioned outside the second through hole and extends in the rotational direction.

11. An armature as described in claim 10, wherein a second conductor layer which is one of the plurality of conductor layers has a conductor pattern having second conductor lands surrounding two edges of the plurality of second through holes and conductor lines extending from the second conductor lands, the conductor lines of the second conductor layer including a portion extending in the radial direction from the conductor land and a portion extending in the rotational direction, and the conductor lines of the first conductor layer and the conductor lines of the second conductor layer partially overlap when viewed in the axial direction.

12. An armature as described in claim 1, further comprising a multi-layer second printed circuit board (PCB) having a plurality of conductor layers on which conductor patterns are formed and a plurality of through holes with conductor films at least partially formed on their inner surfaces, the second printed circuit board being disposed on the opposite side of the armature core from the first PCB, wherein ends of the plurality of conductor rods are inserted into the plurality of through holes formed in the second PCB, and the plurality of conductor rods are connected to the conductor patterns via the conductor films formed on the second PCB.

13. The armature according to claim 12, wherein the first PCB has a conductor layer for a first phase and a conductor layer for a second phase; the second PCB has a conductor layer for the first phase and a conductor layer for the second phase; the plurality of conductor rods have a first conductor rod constituting the first phase and a second conductor rod constituting the second phase; both ends of the first conductor rod are connected to the conductor layer for the first phase of the first PCB and the conductor layer for the first phase of the second PCB, respectively; both ends of the second conductor rod are connected to the conductor layer for the second phase of the first PCB and the conductor layer for the second phase of the second PCB, respectively; in the first PCB, the conductor layer for the first phase and the conductor layer for the second phase are lined up in this order from one side in the axial direction; and in the second PCB, the conductor layer for the first phase and the conductor layer for the second phase are lined up in this order from the one side in the axial direction.

14. A rotating electric machine comprising: the armature according to claim 1; and a field magnet portion rotatable relative to said armature.

15. A method for manufacturing an armature, comprising the steps of: preparing a first multilayer printed circuit board (PCB) having a plurality of conductor layers on which conductor patterns are formed and a plurality of through holes on whose inner surfaces at least a portion of which is formed a conductor film; preparing a plurality of conductor rods; inserting the plurality of conductor rods into the plurality of through holes, respectively; and electrically connecting the plurality of conductor rods to the conductor patterns via the conductor film.

16. A method for manufacturing an armature as described in claim 15, wherein the first PCB has a first outer surface facing away from the armature core and a second outer surface facing the armature core, the plurality of conductor layers have a first conductor layer formed on the first outer surface and a third conductor layer formed on the second outer surface or between the first outer surface and the second outer surface, the conductor pattern of the first conductor layer has a conductor line and a first conductor land surrounding an edge of one of the plurality of through holes and being independent from the conductor line of the first conductor layer, the conductor pattern of the third conductor layer has a conductor line and a third conductor land surrounding an edge of the one of the plurality of through holes and connected to the conductor line of the third conductor layer, and the step of electrically connecting the plurality of conductor rods includes inserting the conductor rod into the one of the plurality of through holes and supplying solder to the first conductor land on the first outer surface.

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