Winded field rotor, method for manufacturing a wound field rotor

Abstract

To provide a winding field rotor capable of increasing a space factor of a field winding and a method for manufacturing the same.SOLUTION: A rotor 60 includes a field winding 80 constituted by multiply winding a conductive wire material around each main pole portion 72 so that the conductive wire material is arranged in a radial direction and a circumferential direction. The field winding has straight portions 81a and 82a extending in an axial direction along radial side surfaces of the main pole portion 72, and a crossover portion connecting ends of the straight portions 81a and 82a with each other. A cross section of the straight portions 81a and 82a has a rectangular shape having a long side in the radial direction. The field winding 80 is configured such that, of the straight portions 81a and 82a arranged in the circumferential direction and the radial direction in each main pole portion 72, a short-side direction size of a transverse cross section of the straight portion 82a on a radially inner side becomes smaller than that of the straight portion 81a on a radially outer side.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a wound field rotor and a method for manufacturing a wound field rotor. [Background Art]

[0002] As this type of wound field rotor, there is known a rotor that includes: a rotor core provided for each of magnetic poles arranged in a circumferential direction and having main pole portions protruding in a radial direction; and a field winding configured by multiple-winding a conductor wire around each main pole portion such that the conductor wires are arranged in the radial direction and the circumferential direction. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Patent Laid-Open No. 2008-178211 [Summary of Invention] [Problem to be Solved by Invention]

[0004] The field winding wound around each main pole portion has linear portions extending in an axial direction along radial side surfaces of the main pole portion, and crossover portions connecting ends of the linear portions to each other.

[0005] The distance between circumferentially adjacent main pole portions decreases as going radially inward. For this reason, among the circumferentially adjacent main pole portions, the radially innermost and circumferentially outermost linear portion of the field winding wound around one main pole portion may interfere with the radially innermost and circumferentially outermost linear portion of the field winding wound around the other main pole portion. In order to avoid the interference, it is also conceivable to reduce the number of turns of the field winding. However, in this case, there is a concern that a dead space between the circumferentially adjacent main pole portions increases and the space factor of the field winding decreases.

[0006] A main object of the present disclosure is to provide a wound field rotor capable of increasing the space factor of a field winding, and a method for manufacturing the wound field rotor. [Means for Solving the Problem]

[0007] This disclosure relates to a wound-field rotor applied to a wound-field rotating electric machine, A rotor core having main pole portions provided for each magnetic pole arranged in the circumferential direction and protruding radially, A field winding is constructed by winding multiple layers of the conductor material around each main pole so that the conductor material is arranged radially and circumferentially, Equipped with, The field windings wound around each of the main poles are, A straight portion extending axially along the radial side surface of the main pole portion, A connecting section that connects the ends of the aforementioned straight sections, It holds.

[0008] In this disclosure, the cross-section of the straight portion has a rectangular shape with the radial direction as the longer side. In each of the main pole portions, the field winding is configured such that, among the straight portions arranged in the circumferential and radial directions, the dimension in the short side direction of the cross-section of the radially inner straight portion is smaller than the dimension in the short side direction of the cross-section of the radially outer straight portion.

[0009] This makes it possible to increase the number of turns of the field winding on the radially inner side of the main pole while avoiding interference between the radially inner straight section of the field winding wound around one of the circumferentially adjacent main poles and the radially inner straight section of the field winding wound around the other. As a result, the dead space between circumferentially adjacent main poles can be reduced, and the space factor of the field winding can be increased. [Brief explanation of the drawing]

[0010] [Figure 1] A diagram showing the overall configuration of a control system for a rotating electric machine according to one embodiment. [Figure 2] A diagram showing the inverter and its peripheral components. [Figure 3] Cross-sectional view of the rotor. [Figure 4] A diagram showing the resonant circuit provided in the rotor. [Figure 5]Fig. 1 is a perspective view showing a configuration of a coil body. [Figure 6] Fig. 2 is a flowchart showing a rotor manufacturing process. [Figure 7] Fig. 3 is a perspective view showing a state where a conductor wire is wound around a base die. [Figure 8] Fig. 4 is a perspective view showing a state where a conductor wire is wound around a base die. [Figure 9] Fig. 5 is a perspective view showing a state after completion of winding of the conductor wire. [Figure 10] Fig. 6 is a perspective view showing a movement mode of side dies. [Figure 11] Fig. 7 is a perspective view showing a movement mode of a side die, a main movable die and a sub movable die. [Figure 12] Fig. 8 is a cross-sectional view showing a compression molding mode of the conductor wire. [Figure 13] Fig. 9 is a cross-sectional view showing a compression molding mode of the conductor wire. [Figure 14] Fig. 10 is a cross-sectional view showing a compression molding mode of the conductor wire. [Figure 15] Fig. 11 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 16] Fig. 12 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 17] Fig. 13 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 18] Fig. 14 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 19] Fig. 15 is a perspective view showing a state where a conductor wire is wound around a base die according to another embodiment. [Figure 20] Fig. 16 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 21] Fig. 17 is a cross-sectional view showing a compression molding mode of a conductor wire according to another embodiment. [Figure 22] Fig. 18 is a perspective view showing a configuration of a coil body according to another embodiment. [Figure 23] Fig. 19 is a perspective view showing a configuration of a coil body according to another embodiment. [Figure 24] Fig. 20 is a cross-sectional view of a rotor according to another embodiment. [Figure 25] Fig. 21 is a cross-sectional view of a rotor according to another embodiment. [Figure 26] A cross-sectional view showing a compression molding method for a conductive wire according to another embodiment. [Modes for carrying out the invention]

[0011] Multiple embodiments will be described with reference to the drawings. In multiple embodiments, functionally and / or structurally corresponding and / or related parts may be given the same reference numeral, or reference numerals that differ by hundreds or more digits. For corresponding and / or related parts, refer to the descriptions of other embodiments.

[0012] Hereinafter, an embodiment of the wound field rotor relating to this disclosure will be described with reference to the drawings.

[0013] First, a control system equipped with a rotating electric machine will be described using Figure 1. The control system comprises a DC power supply 10, an inverter 20, a control unit 30, and a rotating electric machine 40. The rotating electric machine 40 is a field-wound synchronous machine. In this embodiment, the control unit 30 controls the rotating electric machine 40 so that it functions as an ISG (Integrated Starter Generator) or MG (Motor Generator), which is a motor and generator. For example, the rotating electric machine 40, inverter 20, and control unit 30 may be configured as an integrated electromechanical drive unit, or the rotating electric machine 40, inverter 20, and control unit 30 may each be configured as separate components.

[0014] The rotating electric machine 40 will be described using Figure 1. The rotating electric machine 40 comprises a housing 41 and a stator 50 and a rotor 60 housed within the housing 41. The rotating electric machine 40 in this embodiment is an inner rotor type in which the rotor 60 is positioned radially inward of the stator 50.

[0015] The stator 50 comprises a stator core 51 and stator windings 52 wound around the stator core 51. The stator core 51 is made of laminated steel plates made of soft magnetic material and has an annular back yoke and a plurality of teeth protruding radially inward from the back yoke. The stator windings 52 are made of, for example, copper wire and include U, V, and W phase windings 52U, 52V, and 52W arranged at an electrical angle offset from each other by 120°.

[0016] The rotor 60 comprises a rotor core 70 and field windings 80. The rotor core 70 is made of a soft magnetic material, for example, laminated steel plates. The field windings 80 are formed, for example, by compression molding. The field windings 80 may be made of, for example, aluminum wire or copper wire.

[0017] A rotating shaft 32 is inserted through the central hole of the rotor core 70. The rotating shaft 32 is rotatably supported in the housing 41 via a bearing 42. The stator 50 and rotor 60 are both arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is referred to as the axial direction, the direction radiating from the center of the rotating shaft 32 is referred to as the radial direction, and the direction circumferentially extending around the rotating shaft 32 is referred to as the circumferential direction.

[0018] As shown in Figure 2, the inverter 20 comprises a series connection of U, V, W phase upper arm switches Sup, SVp, SWp and U, V, W phase lower arm switches SUn, SVn, SWn. The first ends of the U, V, W phase windings 52U, 52V, 52W are connected to the connection points between the U, V, W phase upper arm switches Sup, SVp, SWp and the U, V, W phase lower arm switches SUn, SVn, SWn. The second ends of the U, V, W phase windings 52U, 52V, 52W are connected at the neutral point. In other words, in this embodiment, the U, V, W phase windings 52U, 52V, 52W are star-connected. In this embodiment, each switch Sup to SWn is an IGBT. A freewheeling diode is connected in antiparallel to each switch Sup, SVp, SWp, SUn, SVn, SWn.

[0019] The collectors of the U, V, W phase upper arm switches Sup, SVp, and SWp are connected to the positive terminals of the DC power supply 10. The emitters of the U, V, W phase lower arm switches SUn, SVn, and SWn are connected to the negative terminals of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0020] Next, we will explain the rotor 60 using Figure 3.

[0021] The rotor core 70 has a cylindrical portion 71 as a yoke portion, a plurality of main pole portions 72 projecting radially outward from the cylindrical portion 71, and flange portions 74 extending radially from the tip of the main pole portion 72 on both sides. In this embodiment, each main pole portion 72 is provided at equal intervals in the circumferential direction.

[0022] The field winding 80 comprises a first winding section 81 and a second winding section 82. In each main pole section 72, the first winding section 81 is wound radially outward, and the second winding section 82 is wound radially inward from the first winding section 81. In each main pole section 72, the winding directions of the first winding section 81 and the second winding section 82 are the same. Furthermore, for adjacent main pole sections 72 in the circumferential direction, the winding directions of the winding sections 81 and 82 wound on one side are opposite to those of the winding sections 81 and 82 wound on the other side. As a result, the magnetization directions of adjacent main pole sections 72 in the circumferential direction are opposite to each other.

[0023] Figure 4 shows the electrical circuit on the rotor 60 side, which has windings 81 and 82 wound around a common main pole 72. The rotor 60 is provided with a diode 83 as a rectifier element and a capacitor 84. The first end of the first winding 81 is connected to the cathode of the diode 83, and the first end of the second winding 82 is connected to the second end of the first winding 81. The anode of the diode 83 is connected to the second end of the second winding 82. The capacitor 84 is connected in parallel to the second winding 82. Alternatively, the first end of the first winding 81 may be connected to the anode of the diode 83, and the second end of the second winding 82 may be connected to the cathode of the diode 83.

[0024] In this embodiment, a series resonant circuit consisting of a first winding section 81, a capacitor 84, and a diode 83 is configured, and a parallel resonant circuit consisting of a second winding section 82 and a capacitor 84 is configured.

[0025] Returning to the explanation of Figure 2, the control unit 30 generates drive signals to turn each of the switches Sup to SWn that make up the inverter 20 on and off. More specifically, the control unit 30 generates drive signals to turn each of the arm switches Sup to SWn on and off in order to convert the DC power output from the DC power supply 10 into AC power and supply it to the U, V, and W phase windings 52U, 52V, and 52W, and supplies the generated drive signals to the gates of each of the arm switches Sup to SWn.

[0026] The control unit 30 switches switches Sup~SWn on and off to allow a combined current of the fundamental wave current and harmonic current to flow through each phase winding 52U, 52V, and 52W. The fundamental wave current is the current that primarily generates torque in the rotating electric machine 40. The harmonic current is the current that primarily excites the field winding 80 and allows field current to flow through the field winding 80. The phase currents flowing through each phase winding 52U, 52V, and 52W are shifted by 120° in electrical angle.

[0027] Furthermore, some or all of the functions of the control unit 30 may be configured in hardware, for example, by one or more integrated circuits. Also, each function of the control unit 30 may be configured, for example, by software recorded on a non-transitional physical recording medium and a computer that executes it.

[0028] Next, we will explain the field winding 80 using Figure 3.

[0029] The conductor material constituting the field winding 80 is a flat rectangular wire with a rectangular cross-section (specifically, a rectangular shape). The field winding 80 is constructed by flatwinding the conductor material so that it is arranged radially and circumferentially. The conductor material consists of a conductor portion and an insulating layer (e.g., an insulating coating) that covers the conductor portion.

[0030] The field winding 80 comprises a straight section extending axially along the radial side surface of the main pole section 72, and a connecting section that connects the ends of the straight section and extends circumferentially. In Figure 3, 81a is the straight section of the first winding section 81, and 82a is the straight section of the second winding section 82.

[0031] In the example shown in Figure 3, the straight sections 81a of the first winding section 81 are arranged in two rows in the radial direction. In the first winding section 81, the first layer of straight sections 81a closest to the stator 50 in the radial direction consists of six sections arranged in the circumferential direction, while the second layer of straight sections 81a consists of five sections arranged in the circumferential direction. The straight sections 82a of the second winding section 82 are arranged in two rows in the radial direction. In the second winding section 82, the first layer of straight sections 82a closest to the stator 50 in the radial direction (i.e., the third layer of the field winding 80) consists of five sections arranged in the circumferential direction, while the second layer of straight sections 82a closest to the stator 50 (i.e., the fourth layer of the field winding 80) consists of four sections arranged in the circumferential direction.

[0032] In the first and second winding sections 81 and 82, the lengthwise dimension in the cross-section of the straight sections 81a and 82a is denoted as KA, the widthwise dimension in the cross-section of the straight sections 81a and 82a is denoted as KB, and the aspect ratio is denoted as KA / KB. In this embodiment, the first and second winding sections 81 and 82 are configured such that in the straight sections 81a and 82a arranged in the circumferential and radial directions in each main pole section 72, the aspect ratio of the radially inner straight section 82a is greater than the aspect ratio of the radially outer straight section 81a. This configuration is intended to increase the space factor of the field winding 80.

[0033] The aspect ratio of the straight section 81a constituting the first winding section 81 may be, for example, 1.8 to 10, 1.8 to 8, 1.9 to 6, or 2 to 5. The aspect ratio of the straight section 82a constituting the second winding section 82 may be, for example, 1.3 to 5 times, 1.5 to 5 times, 1.8 to 4 times, or 2 to 3 times the aspect ratio of the straight section 81a constituting the first winding section 81.

[0034] The central axis of the main pole portion 72, which passes through the rotational central axis O of the rotor 60's rotation axis 32 and extends radially, is defined as the first axis B1. The second axis B2 is defined as the axis that passes through the circumferential central position of adjacent first axes B1 and the rotational central axis O, and extends radially. The first axis B1 corresponds to the d-axis, and the second axis B2 corresponds to the q-axis. According to the winding configuration of this embodiment, the straight portion of the outermost circumferential layer of the field winding 80 can be brought closer to the second axis B2. This increases the proportion of the space occupied by the field winding 80 in the space between adjacent main pole portions 72 in the circumferential direction, thereby increasing the space factor of the field winding 80 in the rotor 60. The resistance value of the field winding 80 can be reduced by using flat wire with a large cross-sectional area, reducing losses in the field winding 80 and increasing the excitation of the field winding 80.

[0035] In the example shown in Figure 3, there is a gap between adjacent field windings 80 in the circumferential direction. However, the configuration is not limited to having a gap; for example, the outer ends of each adjacent field winding 80 in the circumferential direction may be in contact with a sheet-like insulating member (e.g., insulating paper) provided along the second axis B2.

[0036] The field winding 80 has multiple coil bodies 100, each consisting of a flat wire wound in multiple layers radially around each magnetic pole (each main pole portion 72), and these coil bodies 100 of each magnetic pole are connected in series in the circumferential direction. In the configuration shown in Figure 3, the first winding portion 81 of each main pole portion 72 is composed of one coil body 100, and the second winding portion 82 of each main pole portion 72 is composed of one coil body 100.

[0037] Figure 5(a) is a perspective view showing the basic configuration of the coil body 100. In Figure 5(a), direction A is the radial direction, direction B is the axial direction, and direction C is the circumferential direction. In the configuration of Figure 5(a), the number of windings in each layer, both inside and outside the radial direction, is the same, but as shown in Figure 3, the number of windings may differ between the inside and outside the radial direction.

[0038] The coil body 100 is an air-core coil configured as an α-winding coil, with two layers of windings arranged radially and integrally formed. In other words, when mounted on the main pole portion 72, the coil body 100 has an inner coil portion 101 and an outer coil portion 102, which are radially inward (inner layer side) and radially outward (outer layer side), respectively, and in each coil portion 101 and 102, the conductor material 90 is connected to each other on the inner circumference side of the coil. The coil body 100 can also be said to be a unit coil with two radial layers as one unit. Furthermore, the inner coil portion 101 has a coil end 103 extending axially from the circumferential portion, and the outer coil portion 102 has a coil end 104 extending axially from the circumferential portion. The coil body 100 is mounted on the main pole portion 72 by inserting the main pole portion 72 through the hollow portion. As described above, the coil body 100 has a straight portion and a connecting portion. More specifically, the inner coil section 101 has a straight section 101a and a connecting section 101b, and the outer coil section 102 has a straight section 102a and a connecting section 102b.

[0039] In the field winding 80, the coil bodies 100 of each magnetic pole adjacent to each other in the circumferential direction are connected in series by joining the coil ends 103 and 104 of each coil body 100 together. An example of this configuration is explained using Figures 5(b) and (c). Figure 5(b) shows two types of coil bodies 100 with different shapes of coil ends 103 and 104. In the following explanation, one of the two types of coil bodies 100 will be referred to as "first coil body 100A" and the other as "second coil body 100B". Furthermore, the coil ends 103 and 104 of the first coil body 100A will be referred to as "coil ends 103a and 104a", and the coil ends 103 and 104 of the second coil body 100B will be referred to as "coil ends 103b and 104b".

[0040] As shown in Figure 5(b), in the first coil body 100A, the shape of the coil end 104a of the outer coil portion 102 differs from the coil end 104 shown in Figure 5(a), among the coil ends 103a and 104a of the inner coil portion 101 and the outer coil portion 102. Specifically, the coil end 104a of the outer coil portion 102 does not extend axially from the end position shown in Figure 5(a), but rather extends circumferentially along the upper surface of the circumferential portion of the first coil body 100A, and is bent axially at a position shifted circumferentially by one magnetic pole pitch, that is, at a position approximately parallel to the coil end 103a of the inner coil portion 101.

[0041] Furthermore, in the second coil body 100B, the shape of the coil end 103b of the inner coil portion 101 differs from the coil end 103 shown in Figure 5(a). Specifically, the coil end 103b of the inner coil portion 101 does not extend axially from the end position shown in Figure 5(a), but rather extends circumferentially on the opposite side from the circumferential portion of the second coil body 100B, and is bent axially at a position shifted circumferentially by one magnetic pole pitch.

[0042] In short, the first coil body 100A and the second coil body 100B are two types of coil bodies 100, each based on one type of coil body 100 (the coil body 100 shown in Figure 5(a)), but with different shapes for their coil ends 103 and 104.

[0043] Figure 5(c) shows a configuration in which coil bodies 100A and 100B, arranged circumferentially, are connected in series. For convenience, Figure 5(c) shows the coil bodies 100A and 100B arranged in a straight line rather than in an arc. In this case, the coil ends 103a and 103b of each coil body 100A and 100B are joined to each other on the radially inner side, and the coil ends 104a and 104b of each coil body 100A and 100B are joined to each other on the radially outer side. The coil ends 103 and 104 are joined, for example, by welding.

[0044] In the actual configuration, when the coil bodies 100A and 100B are arranged in an arc shape, they do not lie in a straight line in a plan view, but rather intersect each other. Therefore, it is preferable that at least one of the coil ends 103a and 103b that are joined to each other be raised axially on a line that intersects the extension direction at an angle. This allows for suitable surface joining of the coil ends 103. For example, the orientation of the surface joining of the coil ends 103 should be aligned with a straight line extending from the rotation center point of the rotor 60. The same applies to the coil ends 104a and 104b.

[0045] Next, the manufacturing method of the field winding 80 will be explained using Figure 6. In the following, the first winding section 81 will be mainly described, out of the first and second winding sections 81 and 82 that constitute the field winding 80.

[0046] In step S10, the first conductor section 91, which is one end of the conductor 90 (specifically, a round wire) with a circular cross-section, is wound onto the basic mold 200 in a first direction, with the middle section 90a of the conductor 90 (specifically, a round wire) serving as the starting point for winding. Meanwhile, the second conductor section 92, which is the other end of the conductor 90 with respect to the starting point, is wound onto the basic mold 200 in a second direction opposite to the first direction (see Figures 7 and 8). The basic mold 200 is a mold that constitutes a press device and simulates the main pole section 72. The winding of each conductor section 91, 92 onto the basic mold 200 is carried out by a winding device.

[0047] In step S11, the central mold 210 is moved so that it is positioned between the first wire section 91 and the second wire section 92, which constitute the press device (see Figure 9). In this embodiment, the central mold 210 is divided into two parts in the vertical direction, consisting of a first central mold 211 and a second central mold 212.

[0048] In step S12, with the central mold 210 in place, the first conductor section 91 and the second conductor section 92 are further wound around the basic mold 200 using a winding device. As a result, an α-wound coil body 100 is manufactured, as shown in Figure 9. The portion of the coil body 100 composed of the first conductor section 91 is the inner coil section 101 (corresponding to the "first coil section"), and the portion of the coil body 100 composed of the second conductor section 92 is the outer coil section 102 (corresponding to the "second coil section"). The inner coil section 101 abuts against one side of the central mold 210, and the outer coil section 102 abuts against the other side of the central mold 210.

[0049] In step S13, the first side mold 221 is moved toward the central mold 210 (see Figure 10), so that the first side mold 221 comes into contact with the part of the inner coil section 101 that is opposite to the part that comes into contact with the central mold 210. Also, the second side mold 222 is moved toward the central mold 210, so that the second side mold 222 comes into contact with the part of the outer coil section 102 that is opposite to the part that comes into contact with the central mold 210.

[0050] In step S14 (corresponding to the "pressing process"), with the inner coil portion 101 sandwiched between the central mold 210 and the first side mold 221, as shown in Figure 11, the main movable mold 230 is pressed against the straight portion 101a constituting the inner coil portion 101 from above and below toward the side of the basic mold 200, thereby compressing the cross-section of the straight portion 101a constituting the inner coil portion 101 into a rectangular shape. Here, as shown in Figures 12 to 14, the straight portion 101a, which has a circular cross-section, is compressed in stages. As the straight portion 101a extends in a direction perpendicular to the compression direction of the straight portion 101a during compression molding, movement of the first side mold 221 may be permitted, as shown in Figure 13.

[0051] Furthermore, in step S14, with the outer coil portion 102 sandwiched between the central mold 210 and the second side mold 222, the main movable mold 230 is pressed against the straight portion 102a constituting the outer coil portion 102 from above and below toward the side of the basic mold 200, thereby compressing and molding the cross-section of the straight portion 102a constituting the outer coil portion 102 into a rectangular shape, similar to the inner coil portion 101. As a result of the compression molding, the straight portion 102a extends in a direction perpendicular to the compression direction of the straight portion 102a, so movement of the second side mold 222 may be permitted.

[0052] As a result of the pressing process by the main movable die 230, the cross-sections of the straight sections 101a constituting the inner coil section 101 and the straight sections 102a constituting the outer coil section 102 become rectangular, as shown in Figure 3. The straight sections 101a constituting the inner coil section 101 correspond to the five straight sections 81a arranged in the circumferential direction of the first winding section 81 shown in Figure 3. The straight sections 102a constituting the outer coil section 102 correspond to the six straight sections 81a arranged in the circumferential direction of the first winding section 81 shown in Figure 3.

[0053] In step S14, with the inner coil portion 101 sandwiched between the central mold 210 and the first side mold 221, as shown in Figure 11, the secondary movable mold 231 is pressed against the connecting portion 101b constituting the inner coil portion 101 from the left and right directions toward the side of the basic mold 200, thereby compressing the cross-section of the connecting portion 101b constituting the inner coil portion 101 into a rectangular shape. Here, similar to the straight portion 101a, the connecting portion 101b, which has a circular cross-section, is compressed in stages. As the connecting portion 101b extends in a direction perpendicular to the compression direction of the connecting portion 101b during compression molding, movement of the first side mold 221 may be permitted.

[0054] Furthermore, in step S14, with the outer coil portion 102 sandwiched between the central mold 210 and the second side mold 222, the auxiliary movable mold 231 is pressed against the connecting portion 102b constituting the outer coil portion 102 from the left and right directions toward the side of the basic mold 200, thereby compressing and molding the cross-section of the connecting portion 102b constituting the outer coil portion 102 into a rectangular shape, similar to the inner coil portion 101. As a result of the compression molding, the connecting portion 102b extends in a direction perpendicular to the compression direction of the connecting portion 102b, so movement of the second side mold 222 may be permitted.

[0055] The pressing process using the auxiliary movable mold 231 results in rectangular cross-sections of the connecting portion 101b that constitutes the inner coil portion 101 and the connecting portion 102b that constitutes the outer coil portion 102.

[0056] After step S14, in step S15, the compression-molded coil body 100 is removed from the basic mold 200.

[0057] The coil body 100 constituting the first winding section 81 is manufactured by the steps S10 to S15 described above. Similarly, the coil body 100 constituting the second winding section 82 is manufactured by the steps S10 to S15. In this case, in step S14, the inner coil section 101 and the outer coil section 102 are compression molded such that the aspect ratio of the coil body 100 constituting the second winding section 82 (corresponding to the "inner coil body"), which is located radially inward of the main pole section 72, is greater than the aspect ratio of the coil body 100 constituting the first winding section 81 (corresponding to the "outer coil body"), which is located radially outward of the main pole section 72 (see Figure 3).

[0058] In the following step S16, the coil body 100 constituting the first winding section 81 and the coil body 100 constituting the second winding section 82 are inserted into the main electrode section 72.

[0059] Furthermore, the central mold 210, first side mold 221, second side mold 222, main movable mold 230, sub-movable mold 231, and winding device, which constitute the press molding apparatus described in Figure 6, and other devices necessary for the manufacturing process shown in Figure 6, are controlled by a controller.

[0060] In the embodiment described above, the cross-sections of the straight sections 81a and 82a constituting each winding section 81 and 82 are rectangular in shape, with the radial direction as the longer side. The aspect ratio of the straight section 82a constituting the second winding section 82 is greater than the aspect ratio of the straight section 81a constituting the first winding section 81. As a result, among the straight sections arranged in the circumferential and radial directions in each main pole section 72, the dimension in the short side direction of the straight section 82a in the cross-section of the straight section 81a of the first winding section 81 is smaller than the dimension in the short side direction of the straight section 82a in the cross-section of the second winding section 82. Consequently, it is possible to increase the number of turns of the field winding 80 on the radially inner side of the main pole section 72 while avoiding interference between the outermost circumferential straight section 82a of the second winding section 82 wound around one of the circumferentially adjacent main pole sections 72 and the outermost circumferential straight section 82a of the second winding section 82 wound around the other. As a result, the dead space between adjacent main pole portions 72 in the circumferential direction can be reduced, and the space factor of the field winding 80 can be increased. This reduces the resistance of the field winding 80 and increases the excitation of the field winding 80.

[0061] Furthermore, by setting the aspect ratio as described above, as shown in Figure 3, the number of circumferentially aligned straight sections (5) of the straight sections 82a constituting the second winding section 82 that are closest to the first winding section 81 in the radial direction can be made the same as the number of circumferentially aligned straight sections (5) of the straight sections 81a constituting the first winding section 81 that are closest to the second winding section 82 in the radial direction. Note that the number of circumferentially aligned straight sections (5) of the straight sections 82a constituting the second winding section 82 that are closest to the first winding section 81 in the radial direction may be greater than the number of circumferentially aligned straight sections (5) of the straight sections 81a constituting the first winding section 81 that are closest to the second winding section 82 in the radial direction.

[0062] <Other Embodiments> The above embodiment may be implemented with the following modifications.

[0063] In the pressing process of step S14 in Figure 6, the connecting portions 101b and 102b do not necessarily have to be compression molded by the auxiliary movable die 231. In this case, the cross-sections of the connecting portions 101b and 102b will be circular.

[0064] As shown in Figures 15 and 16, the straight sections 101a of the inner coil section 101 and 102a of the outer coil section 102 may be simultaneously compression-molded by the main movable mold 230. For convenience, Figures 15 and 16 show an example where there are five coil sections 101 and 102. In addition, there may be three or more layers of straight sections that are simultaneously molded.

[0065] Furthermore, as shown in Figure 17, by further winding the second conductor section 92, an additional straight section 102c may be placed above the straight section 102a, and as shown in Figure 18, it may be compression-molded in a movable mold 232 having an inclined surface 232a. This forms a straight section 102d with an inclined section. The straight section with an inclined section is the straight section adjacent to the second axis B2 shown in Figure 3. With a field winding 80 having a straight section with an inclined section, the distance between adjacent field windings 80 in the circumferential direction can be reduced, and the space factor of the field windings 80 can be further increased.

[0066] In the winding process of step S10 in Figure 6, instead of using one wire 90, two wires 90 arranged radially may be wound together onto the basic mold 200, as shown in Figure 19. In this case, two air-core coils, each composed of a first and second wire section 91 and 92, are manufactured. After the two air-core coils are manufactured, in the pressing process of step S14 in Figure 6, the portion composed of the first wire section 91 (inner coil section 101) and the portion composed of the second wire section 92 (outer coil section 102) of each air-core coil are compression molded by the main movable mold 230. Figures 20 and 21 show an example in which the straight section 101a of the portion composed of the first wire section 91 (inner coil section 101) of each air-core coil is compression molded. Schematic diagrams of the inner coil section 101 and outer coil section 102, which are two air-core coils, are shown in Figure 22. Subsequently, the ends 91a of the two first conductor sections 91 are joined together in the inner coil section 101 by welding using a welding device, and the ends 92a of the two second conductor sections 92 are joined together in the outer coil section 102 by welding using a welding device, thereby manufacturing a parallel connection of two air-core coils (inner coil section 101 and outer coil section 102) composed of the first and second conductor sections 91 and 92.

[0067] Increasing the aspect ratio requires increasing the pressure from the main movable type 230 to the conductor 90, which raises concerns about damage to the insulating coating on the surface of the conductor 90. Therefore, as shown in Figure 19, two conductors 90 are used, arranged radially. When the aspect ratio of the two compression-molded conductors 90 is made equivalent to the aspect ratio of one compression-molded conductor 90 (see Figure 14, etc.), the amount of compression of the two conductors 90 in the direction of movement of the main movable type 230 can be made smaller than the amount of compression of one conductor 90. As a result, the pressure required for compression molding can be reduced, and even when a molded winding with a larger aspect ratio is required, damage to the insulating coating can be reduced. Furthermore, according to the embodiments shown in Figures 19 to 21, an insulating coating can be interposed between the two conductors 90 (for example, the straight section), and an eddy current reduction effect can be obtained compared to when a single conductor 90 is used.

[0068] Alternatively, after manufacturing the inner coil section 101 and the outer coil section 102, which are two air-core coils, using the method described above, a series connection of the inner coil section 101 and the outer coil section 102 may be manufactured by joining the tip 91a of the two first conductor sections 91 in the inner coil section 101, which is located on the outer coil section 102 side, and the tip 92a of the two second conductor sections 92 in the outer coil section 102, which is located on the inner coil section 101 side, by welding using a welding device, as shown in Figure 23.

[0069] Incidentally, it is not limited to two conductors 90; N conductors 90 (where N is an integer of 3 or more) arranged radially may be wound together onto the basic type 200. In this case, the ends of the N first conductor sections 91 are joined together by welding using a welding device, and the ends of the N second conductor sections 92 are joined together by welding using a welding device, thereby producing a parallel connection of N air-core coils consisting of the first and second conductor sections 91 and 92. In the case of N, it is possible to produce a molded winding with an even larger aspect ratio.

[0070] As shown in Figure 24, in each layer of the first winding section 81, the straight sections 81a may be press-molded by the main movable mold 230 so that their aspect ratios are different. Similarly, in each layer of the second winding section 82, the straight sections 82a may be press-molded by the main movable mold 230 so that their aspect ratios are different. In the example shown in Figure 24, each winding section 81 and 82 is shown to have 7, 6, 6, and 5 straight sections formed in order from the radially outer side. By adopting an α-winding configuration, concentrated winding in units of two layers becomes possible, and the aspect ratio can be changed midway through a layer in each winding section 81 and 82.

[0071] As shown in Figure 25, a synthetic resin layer 120, which is an electrically insulating molded resin, may be formed on at least the contact portion of the main pole portion 72 of each winding portion 81, 82 (coil body). In the example shown in Figure 25, the synthetic resin layer 120 is formed over the entire circumference of each winding portion 81, 82. The thickness of the synthetic resin layer 120 may be, for example, the same as or smaller than the short side dimension of the straight portion 82a that constitutes the second winding portion 82. The step of forming the synthetic resin layer 120 may be provided, for example, between steps S15 and S16 in Figure 6.

[0072] Generally, in the case of round wire, the contact area between the main pole portion 72 and the round wire is small, and the pressure applied to the insulating layer (insulating coating) of the round wire becomes large. In this case, a bobbin is required around which the field winding 80 is wound. In contrast, the straight sections 81a and 82a shown in Figure 25 are flat rectangular wires, and the contact area with the main pole portion 72 is large. Therefore, the pressure applied to the insulating layer of the straight sections 81a and 82a is reduced, and a bobbin is not required. As a result, the packing factor of the field winding 80 can be increased.

[0073] In step S14 of Figure 6, the round wire is compression-formed during the pressing process. In this case, each straight section 101a, 102a may have irregularities on their contact surfaces, as shown in Figure 26. Even in this case, because they are compression-formed, each straight section 101a, 102a can come into close contact with each other while having irregularities on their contact surfaces, thereby increasing the space factor of the field winding 80. Incidentally, in this case, the height dimension of the irregularities of each straight section 101a, 102a is, for example, 0.1 to 0.2 mm. Also, the radius of the rounded corners (corner radius) of each straight section 101a, 102a is, for example, 0.2 mm or less.

[0074] • Each main pole portion 72 may be provided with three or more coil bodies, each in which a conductor is wound in two layers in the radial direction.

[0075] The capacitor 84 constituting the resonant circuit may be connected in parallel to the first winding section 81 instead of the second winding section 82. Also, the orientation of the diode 83 may be such that the cathode and anode are reversed. For details, refer to Figure 4, in which the anode of the diode 83 may be connected to one end of the first winding section 81 and the cathode of the diode 83 may be connected to one end of the second winding section 82.

[0076] The rotating electric machine is not limited to an inner rotor type; an outer rotor type may also be used. In this case, the main pole portion protrudes radially inward from the rotor core.

[0077] The rotating electric machine is not limited to a star-connected rotating electric machine; a delta-connected rotating electric machine may also be used.

[0078] The stator core may be one without teeth.

[0079] The configuration for supplying field current to the field winding is not limited to the circuit shown in Figure 4. For example, a configuration comprising a brush electrically connected to the field winding and a power supply electrically connected to the brush may also be used. In this case, it is not necessary to apply a harmonic voltage to induce field current to the stator winding.

[0080] The rotating electric machine is not limited to those used as vehicle-mounted main engines; for example, it may also be a rotating electric machine used as an ISG (Integrated Starter Generator), which is both an electric motor and a generator.

[0081] The mobile body on which the control system is installed is not limited to a vehicle; for example, it may be an aircraft or a ship. Furthermore, the control system is not limited to a system installed on a mobile body; it may be a stationary system. [Explanation of Symbols]

[0082] 40...rotating electric machine, 60...rotor, 70...rotor core, 72...main pole section, 80...field winding.

Claims

1. In a method for manufacturing a wound-field rotor (60) applied to a wound-field rotating electric machine (40), The aforementioned winding field rotor is A rotor core (70) having main pole portions (72) provided for each magnetic pole arranged in the circumferential direction and protruding radially, A field winding (80) is constructed by winding multiple conductors (90) around each main pole so that the conductors (90) are arranged radially and circumferentially, Equipped with, The field windings wound around each of the main poles are, A straight section (81a, 82a, 101a, 102a) extending axially along the radial side surface of the main pole portion, A connecting section (101b, 102b) that connects the ends of the aforementioned straight section, It has, The cross-section of the aforementioned straight section is rectangular in shape, with the radial direction as the longer side. The field winding has multiple coil bodies (100) in which the conductor material is wound in multiple layers in the radial direction for each of the main pole portions. A process for manufacturing the coil body is to wind a conductor (90) around a basic mold (200) which is a mold that simulates the main pole portion, such that a first conductor portion (91) is formed on one end of the conductor (90) with a circular cross-section relative to the middle portion (90a) of the conductor, and a second conductor portion (92) is formed on the other end of the conductor relative to the middle portion. A pressing step is performed in which the first coil portion and the second coil portion are brought into contact with a central mold (210) positioned between the first coil portion (101) composed of the first conductor portion of the coil body and the second coil portion (102) composed of the second conductor portion of the coil body, the first coil portion is brought into contact with a first side mold (221) positioned on the opposite side of the first coil portion from the central mold, and the second coil portion is brought into contact with a second side mold (222) positioned on the opposite side of the second coil portion from the central mold, and the main movable mold (230) is pressed against the straight portion (101a) constituting the first coil portion toward the side of the basic mold to compress and mold the cross-section of the straight portion constituting the first coil portion into a rectangular shape, and the main movable mold is pressed against the straight portion (102a) constituting the second coil portion toward the side of the basic mold to compress and mold the cross-section of the straight portion constituting the second coil portion into a rectangular shape. Equipped with, In the pressing process, the straight sections constituting the first coil section and the second coil section are compression-molded so that their cross-sections have longer sides in directions perpendicular to the direction in which the straight sections extend and the compression direction, respectively. A method for manufacturing a wound field rotor, wherein in the pressing step, the outer coil body (81), which is the coil body arranged radially outward, and the inner coil body (82), which is the coil body arranged radially inward from the outer coil body, are compression molded such that the aspect ratio of the straight portion (82a) constituting the inner coil body is greater than the aspect ratio of the straight portion (81a) constituting the outer coil body.

2. The method for manufacturing a wound field rotor according to Claim 1, wherein the step of manufacturing the coil body is to use the intermediate portion as the starting portion for winding, wind the first conductor portion of the conductor material, which is one end of the conductor material relative to the starting portion for winding, in a first direction, and wind the second conductor portion of the conductor material, which is the other end of the conductor material relative to the starting portion for winding, around the basic mold in a second direction opposite to the first direction, thereby manufacturing the α-wound coil body.

3. The method for manufacturing a wound field rotor according to claim 2, wherein in the pressing step, the coil body is compression molded such that the dimension in the short side direction of the cross-section of the radially outer linear portion of the two layers constituting the coil body is different from the dimension in the short side direction of the cross-section of the radially inner linear portion.

4. In the pressing process, the cross section of the connecting portion (101b) constituting the first coil portion is compressed into a rectangular shape by pressing the auxiliary movable die (231) toward the side of the basic die, and the cross section of the connecting portion constituting the second coil portion is compressed into a rectangular shape by pressing the auxiliary movable die toward the side of the basic die on the connecting portion (102b) constituting the second coil portion. A method for manufacturing a wound field rotor according to claim 2 or 3, wherein in the pressing step, the rotor is compression molded such that the aspect ratio of the straight portion and the aspect ratio of the cross portion are different.

5. A method for manufacturing a wound field rotor according to claim 2 or 3, wherein in the coil body compressed and molded in the pressing step, each of the straight sections arranged in the circumferential direction is in close contact with each other, with irregularities on their contact surfaces.

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