Winded field rotor

Abstract

To provide a wound field rotor capable of simply and appropriately winding a field winding.SOLUTION: A rotor includes a rotor core having a main pole portion provided for each magnetic pole arranged in the circumferential direction and protruding in the radial direction, and a field winding wound around the main pole portion. The field winding includes a coil body 90 in which a conducting wire material is wound in multiple layers in the radial direction for each main pole portion, the coil bodies 90 are connected in series in the circumferential direction. Each of the coil bodies 90 has a coil end portion 93, which is one end of the conductive wire material, at a position radially inside the coil body 90, and further includes a coil end 94, which is the other end of the conductor, located on the outside in the radial direction. In the coil body 90, the coil end 93 is connected to the coil end 93 of the other coil body 90 adjacent to one side in the circumferential direction, and the coil end 94 is connected to the coil end 94 of the other coil body 90 adjacent to the other side in the circumferential direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The disclosure in this specification relates to a wound-field magnetic rotor.

Background Art

[0002] In a wound-field type rotating electrical machine, field windings are wound around each main pole portion of the rotor core, and a field magnetic field is generated by energizing the field windings. In this case, for each pair of adjacent magnetic poles in the circumferential direction, the field windings are wound in opposite directions so that the N poles and S poles are arranged alternately.

[0003] Also, as a technique for winding field windings around each main pole portion, a configuration is known in which, for each magnetic pole, windings corresponding to the number of turns required for each main pole portion are wound, that is, the winding for each magnetic pole is completed, and then the windings are continued to the adjacent magnetic poles in the circumferential direction. For example, Patent Document 1 discloses a configuration in which, for each magnetic pole, windings in multiple layers in the radial direction are completed for each main pole portion, and between each pair of adjacent magnetic poles in the circumferential direction, the innermost position in the radial direction of one magnetic pole and the outermost position in the radial direction of the other magnetic pole are connected to continue the field windings for each pair of adjacent magnetic poles in the circumferential direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a configuration where each magnetic pole has its own complete winding while the windings are continuous in the circumferential direction, as described above, when connecting windings between adjacent magnetic poles in the circumferential direction, it is conceivable that the conductor material will be subjected to significant twisting in order to connect the innermost and outermost points in the radial direction. In this case, there are concerns that a large load will be placed on the conductor material and that the insulating coating of the conductor material may be damaged. Furthermore, in order to avoid excessive twisting of the conductor material, it is conceivable to connect the field windings of each magnetic pole using separate relay wires, but in such a case, there are concerns that the configuration will become more complicated and the number of work steps will increase.

[0006] This invention has been made in view of the above circumstances, and aims to provide a wound field rotor that allows for easy and proper winding of the field winding. [Means for solving the problem]

[0007] The wound field rotor in this invention is A wound-field rotor, applicable to a wound-field rotating electric machine, comprising a rotor core having main pole portions that protrude radially and are provided for each magnetic pole arranged in the circumferential direction, and a field winding wound around the main pole portions, The field winding has a coil body at each main pole portion, in which a conductor material is wound in multiple layers in the radial direction, and these coil bodies are connected in series in the circumferential direction. Each of the coils has an inner end, which is one end of the conductor, at a position radially inward of the coil, and an outer end, which is the other end of the conductor, at a position radially outward. The coil body is characterized in that the inner end is connected to the inner end of another coil body adjacent to it on one side in the circumferential direction, and the outer end is connected to the outer end of another coil body adjacent to it on the other side in the circumferential direction.

[0008] According to the above configuration, in the field winding of a wound field rotor, the coil bodies provided at each adjacent main pole in the circumferential direction are connected to each other at their inner ends (i.e., inner layer side) and at their outer ends (i.e., outer layer side) in the radial direction, thereby connecting them in series in the circumferential direction. In this case, since each coil body is connected in series in the circumferential direction by the connections between their inner ends and outer ends, excessive twisting of the conductor material in the radial direction is prevented. Therefore, excessive load on the conductor material and damage to the insulating coating of the conductor material are suppressed. As a result, the field winding can be wound simply and properly. [Brief explanation of the drawing]

[0009] [Figure 1] Overall configuration diagram of the control system for a rotating electric machine. [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 electrical circuitry installed in the rotor. [Figure 5] A perspective view showing the structure of the coil. [Figure 6] A schematic diagram showing the connections of each coil. [Figure 7] A schematic diagram showing the connections of each coil. [Figure 8] A schematic diagram showing the state in which coil bodies are wound around each main pole of the rotor core. [Figure 9] A perspective view showing an example of a coil structure. [Figure 10] A plan view showing multiple coil bodies arranged in the circumferential and radial directions. [Figure 11] A diagram showing the connection status between each winding, diode, and capacitor. [Figure 12] A schematic diagram showing a coil body wound around each main pole of the rotor core in an alternative example. [Modes for carrying out the invention]

[0010] Hereinafter, an embodiment in which the rotating electrical machine according to the present invention is embodied will be described with reference to the drawings. A control system including the rotating electrical machine is mounted on a vehicle. The rotating electrical machine is a driving power source for the vehicle.

[0011] As shown in FIG. 1, the control system includes a DC power supply 10, an inverter 20, a control device 30, and a rotating electrical machine 40. The rotating electrical machine 40 is a wound-field synchronous machine. For example, an integrated motor drive device is configured including the rotating electrical machine 40, the inverter 20, and the control device 30, or the rotating electrical machine 40, the inverter 20, and the control device 30 are each composed of respective components.

[0012] The rotating electrical machine 40 includes a housing 41, a stator 50 and a rotor 60 housed in the housing 41. The rotating electrical machine 40 of the present embodiment is an inner rotor type rotating electrical machine in which the rotor 60 is disposed radially inside the stator 50. The rotor 60 corresponds to a "wound-field rotor".

[0013] The stator 50 includes a stator core 51 and a stator winding 52. The stator core 51 is composed of laminated steel sheets made of a soft magnetic material, and has an annular back yoke and a plurality of teeth protruding radially inward from the back yoke. The stator winding 52 is composed of, for example, copper wire, and includes U, V, W phase windings 52U, 52V, 52W arranged in a state of being shifted from each other by 120° in electrical angle.

[0014] The rotor 60 includes a rotor core 61 and a field winding 70. The rotor core 61 is made of a soft magnetic material and is composed of, for example, laminated steel sheets. The field winding 70 is composed of, for example, aluminum wire. The aluminum wire has a small specific gravity and can reduce the centrifugal force when the rotor 60 rotates. Note that the field winding 70 is not limited to aluminum wire, and may be, for example, copper wire or CNT (carbon nanotube).

[0015] The rotation shaft 32 is inserted into the central hole of the rotor core 61. The rotation shaft 32 is rotatably supported by a bearing 42 in the housing 41. Both the stator 50 and the rotor 60 are arranged coaxially with the rotation shaft 32. In the following description, the direction in which the rotation shaft 32 extends is defined as the axial direction, the direction extending radially from the center of the rotation shaft 32 is defined as the radial direction, and the direction extending circumferentially around the rotation shaft 32 is defined as the circumferential direction.

[0016] As shown in FIG. 2, the inverter 20 includes a series connection body 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, 5V, 52W are connected to the connection points of 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. That is, in the present embodiment, the U, V, W-phase windings 52U, 52V, 52W are star-connected. In the present embodiment, each of the switches SUp to SWn is an IGBT. A freewheeling diode is connected in anti-parallel to each of the switches SUp to SWn.

[0017] The positive terminal of the DC power supply 10 is connected to the collectors of the U, V, W-phase upper arm switches SUp, SVp, SWp. The negative terminal of the DC power supply 10 is connected to the emitters of the U, V, W-phase lower arm switches SUn, SVn, SWn. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0018] Subsequently, the rotor 60 will be described using FIG. 3.

[0019] The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 that protrude radially outward from the cylindrical portion 61a. The cylindrical portion 61a corresponds to the yoke portion. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction. The radial tip of each main pole portion 62 is provided with a winding holder 63 that extends circumferentially in a flange shape and holds the field winding 70 from the radial outside.

[0020] The field winding 70 comprises a first winding section 71a and a second winding section 71b arranged radially. In each main pole section 62, the first winding section 71a is wound radially outward, and the second winding section 71b is wound radially inward from the first winding section 71a. In each main pole section 62, the direction of current flow (current direction) is the same for both the first winding section 71a and the second winding section 71b. Furthermore, for adjacent main pole sections 62 in the circumferential direction, the current direction of the winding sections 71a and 71b wound around one main pole section 62 is opposite to the current direction of the winding sections 71a and 71b wound around the other main pole section 62. As a result, the magnetization directions are opposite for adjacent main pole sections 62 in the circumferential direction. In the rotor 60, multiple magnetic poles (field poles) are formed in the circumferential direction by each main pole portion 62 in the rotor core 61 and the field winding 70 wound around each main pole portion 62. In this embodiment, the number of magnetic poles of the rotor 60 is set to 8, but this number can be changed.

[0021] Figure 4 shows the electrical circuit on the rotor 60 side, which includes winding sections 71a and 71b. The first winding section 71a and the second winding section 71b are connected in series, and a diode 81, acting as a rectifier, is connected between the ends of the series connection consisting of these winding sections 71a and 71b. That is, the first end of the first winding section 71a is connected to the cathode of the diode 81, and the first end of the second winding section 71b is connected to the second end of the first winding section 71a. The anode of the diode 81 is connected to the second end of the second winding section 71b. A capacitor 82 is connected in parallel to the second winding section 71b. In Figure 4, L1 represents the inductance of the first winding section 71a, L2 represents the inductance of the second winding section 71b, and C represents the capacitance of the capacitor 82.

[0022] In this embodiment, a series resonant circuit is configured consisting of a first winding section 71a, a capacitor 82, and a diode 81, and a parallel resonant circuit is configured consisting of a second winding section 71b and a capacitor 82. The first resonant frequency, which is the resonant frequency of the series resonant circuit, is denoted as f1, and the second resonant frequency, which is the resonant frequency of the parallel resonant circuit, is denoted as f2. The respective resonant frequencies f1 and f2 are expressed by the following equations (eq1) and (eq2).

[0023]

number

[0024]

number

[0025] The control device 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 70 and allows field current to flow through the field winding 70. In other words, the control device 30 controls the energization of the stator winding 52 with a current signal that superimposes the harmonic current on the fundamental wave current. The phase currents flowing through each phase winding 52U, 52V, and 52W are shifted by 120° in electrical angle.

[0026] In this embodiment, as described above, the field winding 70 is wound around the main pole portion 62 with the first winding portion 71a facing radially outward and the second winding portion 71b facing radially inward. This makes it easier for the first winding portion 71a, which is an excitation coil, to receive the harmonic magnetic flux generated by the harmonic current in the stator winding 52, thereby efficiently generating the excitation current in the rotor 60.

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

[0028] Next, the specific configuration of the field winding 70 will be described.

[0029] As shown in Figure 3, the field winding 70 is constructed using a flat wire with a roughly rectangular cross-section (specifically, a roughly rectangular shape) as the conductor material, and the flat wire is wound in multiple layers so that it is arranged radially and circumferentially. The flat wire consists of a conductor portion and an insulating layer covering the conductor portion. In the example shown in Figure 3, the first winding portion 71a constituting the field winding 70 is arranged in two layers radially, and the second winding portion 71b is also arranged in two layers radially. However, the number of radial layers in each winding portion 71a, 71b may be other than two, and the number of layers may differ between the winding portions 71a, 71b.

[0030] Furthermore, the number of windings in each radially arranged layer (in other words, the number of flat wires arranged in the circumferential direction) differs between the radially inner and radially outer sides. Specifically, if we consider the layers as the 1st, 2nd, 3rd, and 4th layers from the radially outer side outwards, the 1st layer has 5 windings, the 2nd layer has 4 windings, the 3rd layer has 3 windings, and the 4th layer has 2 windings. Regarding the first winding section 71a and the second winding section 71b, in the first winding section 71a, the number of windings in the two radially arranged layers is 5 and 4, respectively, while in the second winding section 71b, the number of windings in the two radially arranged layers is 3 and 2, respectively.

[0031] As described above, the number of windings can be varied in each layer arranged radially to improve the space factor. Alternatively, the number of windings can be varied for each winding section 71a and 71b. If space factor is disregarded, it is also possible to make the number of windings the same for all layers arranged radially.

[0032] Furthermore, in this embodiment, the field winding 70 has a plurality of coil bodies 90, each consisting of a flat wire wound in multiple layers in the radial direction for each magnetic pole (each main pole portion 62), and these coil bodies 90 for each magnetic pole are connected in series in the circumferential direction.

[0033] Figure 5(a) is a perspective view showing the basic configuration of a coil body 90 using flat rectangular wire. 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 the number of windings may differ between the inside and outside the radial direction.

[0034] The coil body 90 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 electrode portion 62, the coil body 90 has an inner coil portion 91 and an outer coil portion 92, which are radially inward (inner layer side) and radially outward (outer layer side), respectively, and in each of these coil portions 91 and 92, flat rectangular wires are connected to each other on the inner circumference side of the coil. The coil body 90 can also be said to be a unit coil with two radial layers as one unit. Furthermore, the inner coil portion 91 has a coil end 93 extending axially from the circumferential portion, and the outer coil portion 92 has a coil end 94 extending axially from the circumferential portion. The coil end 93 corresponds to the "inner end," and the coil end 94 corresponds to the "outer end." The coil body 90 is mounted on the main electrode portion 62 by inserting the main electrode portion 62 through the hollow portion.

[0035] In the field winding 70, the coil bodies 90 of each magnetic pole adjacent to each other in the circumferential direction are connected in series by joining the coil ends 93 and 94 of each coil body 90 together. This configuration will be explained using Figures 5(b) and (c). Figure 5(b) shows two types of coil bodies 90 with different shapes of coil ends 93 and 94. In the following explanation, one of the two types of coil bodies 90 will also be referred to as "first coil body 90A" and the other as "second coil body 90B". Furthermore, the coil ends 93 and 94 of the first coil body 90A will be referred to as "coil ends 93a and 94a", and the coil ends 93 and 94 of the second coil body 90B will be referred to as "coil ends 93b and 94b".

[0036] As shown in Figure 5(b), in the first coil body 90A, the shape of the coil end 94a of the outer coil portion 92 differs from the coil end 94 shown in Figure 5(a). Specifically, the coil end 94a of the outer coil portion 92 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 90A, 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 93a of the inner coil portion 91.

[0037] Furthermore, in the second coil body 90B, the shape of the coil end 93b of the inner coil portion 91 differs from the coil end 93 shown in Figure 5(a). Specifically, the coil end 93b of the inner coil portion 91 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 90B, and is bent axially at a position shifted circumferentially by one magnetic pole pitch.

[0038] In short, the first coil body 90A and the second coil body 90B are two types of coil bodies 90, each based on one type of coil body 90 (the coil body 90 shown in Figure 5(a)), but with different shapes for their coil ends 93 and 94.

[0039] Figure 5(c) shows a configuration in which coil bodies 90A and 90B, arranged circumferentially, are connected in series. For convenience, Figure 5(c) shows the coil bodies 90A and 90B arranged in a straight line rather than in an arc. In this case, on the radially inner side, the coil ends 93a and 93b of each coil body 90A and 90B are joined to each other, while on the radially outer side, the coil ends 94a and 94b of each coil body 90A and 90B are joined to each other. The coil ends 93 and 94 are preferably joined by welding.

[0040] In the actual configuration, when the coil bodies 90A and 90B 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 93a and 93b 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 93. For example, the orientation of the surface joining of the coil ends 93 should be aligned with a straight line extending from the rotation center point of the rotor 60. The same applies to the coil ends 94a and 94b.

[0041] Figure 6 schematically shows the connections of each coil 90A and 90B in Figure 5(c) above, and the figure shows the connection state of each coil 90A and 90B arranged in the circumferential direction. In Figure 6, the left-right direction is the circumferential direction, and the up-down direction is the axial direction.

[0042] In Figure 6, the first coil body 90A and the second coil body 90B are arranged alternately in the circumferential direction, and the radially inner and outer coil ends 93 and 94 of each coil body 90A and 90B are connected at intervals of two magnetic pole pitches, respectively. In this case, the connection positions of each coil end 93 and 94 are between each magnetic pole, near the boundary (q-axis) of adjacent magnetic poles in the circumferential direction. The current directions in the rectangular wires of the first coil body 90A and the second coil body 90B are opposite to each other.

[0043] It is also possible to change the configuration of each coil body 90A and 90B. Specifically, the configurations shown in Figure 7(a) and Figure 7(b) can be considered. In these configurations in Figures 7(a) and (b), the configuration of the coil ends 93 and 94 of each coil body 90A and 90B is different from the configuration in Figure 6.

[0044] In Figure 7(a), the first coil body 90A has the same configuration as the coil body 90 (basic configuration of an α-winding coil) in Figure 5(a). In contrast, in the second coil body 90B, the coil ends 93b and 94b of the inner coil section 91 and the outer coil section 92 are extended circumferentially in the opposite direction to the circumferential portion of the second coil body 90B, and are bent axially at a position shifted circumferentially by one magnetic pole pitch. The radially inner coil ends 93 and radially outer coil ends 94 of each coil body 90A and 90B are joined to each other. In this case, the connection positions of the coil ends 93 and 94 are at an interval of one magnetic pole pitch and are near the boundary (q-axis) of adjacent magnetic poles in the circumferential direction.

[0045] Furthermore, in Figure 7(b), in the first and second coil bodies 90A and 90B, the coil ends 93 and 94 of the inner coil portion 91 and outer coil portion 92 are extended circumferentially as shown in the figure. The radially inner coil ends 93 and radially outer coil ends 94 of each coil body 90A and 90B are joined to each other. In this case, the connection positions of the coil ends 93 and 94 are at a distance of one magnetic pole pitch and are near the center (d axis) of each magnetic pole.

[0046] In the configurations shown in Figures 6, 7(a), and 7(b) above, in the first coil body 90A, one end of the flat wire (conductor material), which is the coil end 93, is connected to the coil end 93 of the adjacent second coil body 90B on one side in the circumferential direction, and the other end of the flat wire, which is the coil end 94, is connected to the coil end 94 of the adjacent second coil body 90B on the other side in the circumferential direction. The second coil body 90B has a similar configuration. In this case, each coil body 90 arranged in the circumferential direction has at least one of its coil ends 93 or 94 having an extended portion that extends toward the coil body 90 that it is connected to in the circumferential direction.

[0047] Furthermore, as described above, the field winding 70 comprises a first winding section 71a and a second winding section 71b, and these winding sections 71a and 71b are wound around each main pole section 62 with the first winding section 71a facing radially outward and the second winding section 71b facing radially inward. In this case, the first winding section 71a is formed by connecting coil bodies 90 mounted on each main pole section 62 in series in the circumferential direction. Similarly, the second winding section 71b is formed by connecting coil bodies 90 mounted on each main pole section 62 in series in the circumferential direction.

[0048] Figure 8 is a schematic diagram showing the state in which the coil bodies 90 of each winding section 71a, 71b are wound around each main pole portion 62 of the rotor core 61. In Figure 8, the two radially outer layers (equivalent to two layers of conductor) constitute the first winding section 71a, and the four radially inner layers (equivalent to four layers of conductor) constitute the second winding section 71b. If the coils that make up one rotation of the rotor, consisting of eight coil bodies 90, are considered as one annular coil, then the first winding section 71a is composed of one annular coil, and the second winding section 71b is composed of two annular coils. Each of these annular coils corresponds to a series winding section formed by connecting the coil bodies 90 that make up one rotation of the rotor in series. Here, the coil bodies 90 that make up the first winding section 71a are designated C11, C12, C13, ... C18 in order in a clockwise direction. Furthermore, the coil bodies 90 constituting the first turn of the annular coil in the second winding section 71b are designated as C21, C22, C23, ... C28 in order, and the coil bodies 90 constituting the second turn of the annular coil are designated as C31, C32, C33, ... C38 in order.

[0049] In the first winding section 71a, one end of the first coil C11 (the starting point of the first winding section 71a) is connected to the cathode of the diode 81, and the other end is connected to the second coil C12, which is adjacent in the circumferential direction. The second and subsequent coils C12 to C18 are connected in series with those adjacent in the circumferential direction. The eighth coil C18 (the end coil of the first winding section 71a) is connected to the capacitor 82 and to the coil C21, which is the starting coil of the second winding section 71b.

[0050] Furthermore, in the second winding section 71b, coil bodies C21 to C28 are connected in series in the circumferential direction on the radially inner side of the first winding section 71a (coil bodies C11 to C18), and coil bodies C31 to C38 are connected in series in the circumferential direction on the radially inner side of coil bodies C21 to C28. Then, coil body C38, which is the end coil of the second winding section 71b, is connected to the capacitor 82 and the anode of the diode 81.

[0051] Next, we will describe the structure of the connections between the winding sections 71a and 71b of the field winding 70, and the diode 81 and capacitor 82 that constitute the resonant circuit.

[0052] Figures 9(a) and 9(b) are perspective views showing examples of the configuration of the coil body 90, and Figure 10 is a plan view showing a state in which multiple coil bodies 90 are arranged in the circumferential and radial directions. The coil connection structure described here corresponds to the structure shown in Figure 7(b). In Figure 10, the first winding section 71a is composed of one row of annular coils on the outermost radial side, and the second winding section 71b is composed of three rows of annular coils radially inside the first winding section 71a.

[0053] As shown in Figure 9(a), the first coil body 90A has coil ends 93a and 94a on the radially inner and outer sides, respectively, and the second coil body 90B has coil ends 93b and 94b on the radially inner and outer sides, respectively. Each of these coil ends 93 and 94 extends in the circumferential direction as shown in the figure, and the radially inner coil ends 93 and radially outer coil ends 94 of each coil body 90A and 90B are joined to each other, thereby connecting them in series in the circumferential direction.

[0054] In Figure 9(b), X1 to X7 are junctions between coil ends, and these junctions X1 to X7 are arranged circumferentially at a 1-pole pitch, with alternating radially inward and radially outward junctions. The positions of each junction X1 to X7 are near the d-axis of each magnetic pole. X0 is a terminal that connects to another row of coil bodies 90, or to a diode 81 or capacitor 82 that constitutes a resonant circuit. In addition, one of the radially inward coil ends 93 of the coil body 90 (the coil end 93 that ends after one rotation of the rotor) extends toward the adjacent magnetic pole in the circumferential direction and is a connecting portion 95 that connects to another row of coil bodies 90 radially inward, and the tip of this connecting portion 95 is a terminal that connects to another coil body 90. The connecting portion 95 extends in a radially offset state and is a radial switching line that switches the radial row of coil bodies 90.

[0055] As shown in Figure 10, the first winding section 71a and the second winding section 71b are connected by a connecting portion 95 of one coil body 90 of the first winding section 71a. In the second winding section 71b, of the three radial rows of annular coils, the annular coil in the first outer row and the annular coil in the second outer row are connected by a connecting portion 95 extending from the annular coil in the first outer row, and the annular coil in the second outer row and the annular coil in the third outer row are connected by a connecting portion 95 extending from the annular coil in the second outer row.

[0056] In Figure 10, the connection between the first winding section 71a and the second winding section 71b is configured such that a connecting portion 95 is provided at the radially inner coil end 93 of the first winding section 71a. However, this may be changed so that the connecting portion 95 is provided at the radially inner coil end 93 of the outermost annular coil (the annular coil closest to the first winding section 71a) of the three radially arranged annular coils in the second winding section 71b. In this case, the connecting portion 95 may be formed by offsetting the tip of the coil end 93 of the coil body 90 in the second winding section 71b radially outward. Alternatively, the connecting portion 95 may be provided at both the radially inner coil end 93 of the first winding section 71a and the radially inner coil end 93 of the outermost annular coil of the three radially arranged annular coils in the second winding section 71b. Furthermore, it is also possible to have a configuration in which a connecting portion 95 is provided at least one of the radially outer coil end 94 of the first winding section 71a and the radially outer coil end 94 of the first outer row of annular coils among the three radially arranged annular coils in the second winding section 71b.

[0057] Furthermore, the coil body 90 of the first winding section 71a and the coil body 90 of the second winding section 71b are spaced apart from each other, and an annular gap is preferably formed between the two winding sections 71a and 71b. Alternatively, a plate-shaped partition member extending in the circumferential direction may be provided between the winding sections 71a and 71b. The partition member is preferably made of a magnetic material, and more specifically, it is preferably made of laminated steel plates stacked in the radial direction.

[0058] Figure 11 shows the connection status between each winding section 71a, 71b and the diode 81 and capacitor 82.

[0059] In Figure 11(a), the cylindrical portion 61a of the rotor core 61 is shown by a dashed line, and a diode 81 and a capacitor 82 are fixed to the axial end face of this cylindrical portion 61a. That is, one axial end face of the cylindrical portion 61a is the mounting surface 65 on which the diode 81 and capacitor 82 are placed. These diode 81 and capacitor 82 are arranged on concentric circles that are concentric with the rotation center of the rotor 60. The capacitor 82 may be configured as a capacitor module in which multiple capacitor elements are connected in the circumferential direction. Note that points P1, P2, and P3 in Figure 11(a) correspond to P1 to P3, respectively, in the resonant circuit shown in Figure 11(b).

[0060] In Figure 11(a), the cathode of diode 81 is connected to point P1, and one end of capacitor 82 (capacitor module) is connected to point P2, which is the midpoint between the respective winding sections 71a and 71b. The other end of capacitor 82 (capacitor module) is connected to the anode of diode 81 at point P3. In this case, the connection ends of each winding section 71a and 71b corresponding to points P1 to P3 protrude in the axial direction on the same side as the mounting surface 65, and these protruding parts are connected to diode 81 and capacitor 82.

[0061] According to the embodiment described in detail above, the following excellent effects can be obtained.

[0062] In the field winding 70 of the rotor 60, the coil bodies 90 provided at each circumferentially adjacent main pole portion 62 are connected to each other at their radially inner coil ends 93 and also at their radially outer coil ends 94, thereby connecting them in series in the circumferential direction. In this case, since each coil body 90 is connected in series in the circumferential direction by the connections of the coil ends 93 and coil ends 94, excessive twisting of the rectangular wire in the radial direction is prevented. Therefore, it is possible to prevent large loads on the rectangular wire and damage to the insulating coating of the rectangular wire. As a result, the field winding 70 can be wound simply and properly.

[0063] Each coil body 90 arranged in the circumferential direction has at least one of its coil ends 93, 94 having an extended portion that extends toward the coil body 90 it will connect to in the circumferential direction. In this case, the coil bodies 90 can be suitably connected to each other by adding a simple configuration such as extending the coil ends 93, 94 in the circumferential direction in each coil body 90.

[0064] In this embodiment, each coil body 90 is an α-winding coil using flat wire, which increases the coil space ratio in the rotor 60 while allowing for easy connection of the coil bodies 90 to each other. In this case, since the coil ends 93 and 94 of each coil body 90 are pulled out in the axial direction, the space between adjacent coil bodies 90 in the circumferential direction is not used as a space for pulling out the conductor, thus improving the space ratio. As a result, the work efficiency for manufacturing the coil bodies 90 and connecting the coil bodies 90 to each other is increased, leading to improved productivity.

[0065] For example, in the configurations shown in Figures 7(a) and 7(b), in each adjacent coil body 90 in the circumferential direction, the joints of the radially inner coil end 93 and the radially outer coil end 94 are arranged alternately in the circumferential direction and at intervals of one magnetic pole pitch. In this case, by spacing out the radially inner and outer joints from each other, the welding or other joining work at these joints can be carried out easily and properly.

[0066] The field winding 70 is configured to have multiple series winding sections, each consisting of a coil body 90 equivalent to one rotation of the rotor connected in series (i.e., each winding section 71a, 71b being annular coils), and the series winding sections aligned radially are connected in series. At least one of the ends of the coil body 90 on the inner layer side of the radially outer series winding section (first winding section 71a) and the coil body 90 on the inner layer side of the radially inner series winding section (second winding section 71b) is offset radially, and the series winding sections are connected to each other at the offset portion. Alternatively, instead of connecting the inner layer coil ends 93 of each radially aligned series winding section as described above, the outer layer coil ends 94 are connected. In this case, by shifting the coil ends 93 and 94 of the coil body 90 radially by the minimum necessary amount in each series winding section (first and second winding sections 71a and 71b), the series winding sections aligned radially can be connected to each other in a suitable manner.

[0067] In a configuration where the field winding 70 has a first winding section 71a and a second winding section 71b, and a diode 81 and a capacitor 82 are connected to the field winding 70 to form a resonant circuit, the first winding section 71a and the second winding section 71b each form a series winding section consisting of at least one full turn of a coil body 90 connected in series, and these winding sections 71a and 71b are connected in series. In this configuration, the first winding section 71a is positioned radially outward (towards the stator 50), and the second winding section 71b is positioned radially inward (opposite the stator). This makes it easier for the first winding section 71a to absorb harmonic magnetic flux from the stator 50, and allows for efficient generation of excitation current in the rotor 60.

[0068] Furthermore, in the first winding section 71a and the annular coil that is the first outer row of the three radially arranged annular coils of the second winding section 71b, at least one of the coil ends 93, 94 on the inner layer side and the outer layer side is offset radially, and the winding sections 71a and 71b are connected at the offset portion. In other words, at least one of the ends of the inner or outer layer of the first winding section 71a (specifically, the coil ends 93, 94 of either the inner or outer layer) and at least one of the ends of the inner or outer layer of the second winding section 71b that is on the same side as the first winding section 71a (specifically, the coil ends 93, 94 of the inner or outer layer of the annular coil closest to the first winding section 71a that is on the same side as the first winding section 71a) is offset radially, and the winding sections 71a and 71b are connected at the offset portion. This allows for efficient excitation of the rotor 60 as described above, while also enabling suitable connections between the radially aligned winding sections 71a and 71b.

[0069] In the cylindrical portion 61a of the rotor core 61, one end face in the axial direction is designated as the mounting surface 65 on which the diode 81 and capacitor 82 are arranged. Furthermore, in the first winding portion 71a and the second winding portion 71b, the connection ends that connect to the diode 81 and capacitor 82 are made to protrude in the axial direction on the same side as the mounting surface 65, and the diode 81 and capacitor 82 are connected at these protruding portions. This makes it easy to connect each winding portion 71a, 71b to the diode 81 and capacitor 82 in the rotor 60, and allows for the suitable formation of a resonant circuit consisting of these components.

[0070] (Other embodiments) The above embodiment may be modified as follows, for example.

[0071] The winding structure described in Figure 8 may be modified as shown in Figure 12. In Figure 12, the two radially outer layers (equivalent to two conductor layers) constitute the first winding section 71a, and the four radially inner layers (equivalent to four conductor layers) constitute the second winding section 71b. Here, in the first winding section 71a, an annular coil (series winding section) is formed by eight coil bodies 90 in the circumferential direction, and similarly in the second winding section 71b, an annular coil (series winding section) is formed by eight coil bodies 90 in the circumferential direction. However, the number of layers in the radial direction of each coil body 90 differs between the first winding section 71a and the second winding section 71b, with the first winding section 71a having two layers of coil bodies 90 and the second winding section 71b having four layers of coil bodies 90. In Figure 12, the coil bodies 90 constituting the first winding section 71a are designated C11, C12, C13, ... C18 in a clockwise direction. Furthermore, the coil bodies 90 constituting the second winding section 71b are designated C21, C22, C23, ... C28 in a clockwise direction.

[0072] Thus, the number of radial layers in each coil body 90 does not have to be 2, but it is preferable to make it a multiple of 2.

[0073] As a configuration for connecting the first winding section 71a and the second winding section 71b, instead of connecting the winding sections 71a and 71b by connecting sections 95 provided at the coil ends 93 and 94 of each winding section 71a and 71b, a configuration in which the winding sections 71a and 71b are connected using a relay wire may also be used.

[0074] • In the coil body 90, round wire may be used instead of flat rectangular wire as the conductor material. The coil body 90 may be other than an α-wound coil. For example, an edgewise wound coil may be used as the coil body 90.

[0075] The rotating electric machine is not limited to an inner rotor type; it may also be an outer rotor type. In this case, the main pole portion 62 protrudes radially inward from the annular yoke portion of the rotor core. In the field winding 70, the first winding portion 71a is preferably arranged radially inward (towards the stator 50), and the second winding portion 71b is preferably arranged radially outward (towards the opposite side of the stator).

[0076] The rotating electric machine is not limited to a star-connected rotating electric machine; a delta-connected rotating electric machine may also be used.

[0077] The stator core may be one without teeth.

[0078] 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, the control device 30 controls the field current flowing through the field winding by increasing the output voltage of the power supply electrically connected to the brush when the rotor 60 is rotating at high speed. When a brush is used, it is not necessary to supply a harmonic current to induce field current to the stator winding.

[0079] 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.

[0080] The mobile body on which the rotating electric machine 40 is mounted is not limited to a vehicle; for example, it may be an aircraft or a ship. Furthermore, the system equipped with the rotating electric machine 40 is not limited to a system mounted on a mobile body; it may be a stationary system.

[0081] The technical concepts extracted from the above-described embodiments are described below. [Configuration 1] A wound-field rotor (60) is applied to a wound-field rotating electric machine (40) and has a rotor core (61) having main pole portions (62) that are provided for each magnetic pole arranged in the circumferential direction and protrude radially, and a field winding (70) that is wound around the main pole portions, The field winding has a coil body (90) at each of the main poles, in which a conductor material is wound in multiple layers in the radial direction, and each of these coil bodies is connected in series in the circumferential direction. Each of the coils has an inner end (93), which is one end of the conductor, located radially inward, and an outer end (94), which is the other end of the conductor, located radially outward. A wound field rotor, wherein the inner end of the coil body is connected to the inner end of another coil body adjacent to it on one side in the circumferential direction, and the outer end of the coil body is connected to the outer end of another coil body adjacent to it on the other side in the circumferential direction. [Configuration 2] The winding field rotor according to configuration 1, wherein at least one of the inner and outer ends of each of the circumferentially adjacent coil bodies has an extended portion that extends toward the coil body to which it is connected in the circumferential direction. [Configuration 3] The coil body is an α-winding coil having an inner coil portion (91) that is radially inward and an outer coil portion (92) that is radially outward, using a flat rectangular wire as the conductor material. The inner coil portion is provided with the inner end, and the outer coil portion is provided with the outer end, The winding field rotor according to configuration 1, wherein at least one of the inner and outer ends of each of the circumferentially adjacent coil bodies has an extended portion that extends toward the coil body to which it is connected in the circumferential direction. [Structure 4] A wound field rotor according to configuration 2 or 3, wherein in each of the circumferentially adjacent coil bodies, the joints at the inner end and the outer end are arranged alternately in the circumferential direction and at intervals of one magnetic pole pitch. [Composition 5] The field winding has a plurality of series winding sections formed by connecting in series the coil bodies that make up one rotation of the rotor and are wound around each of the main poles arranged in the circumferential direction, and the series winding sections arranged in the radial direction are connected in series to each other, as described in any one of configurations 1 to 4. [Composition 6] A wound field rotor according to configuration 5, wherein at least one of the inner end of the radially outer series winding section and the inner end of the radially inner series winding section, or at least one of the outer end of the radially outer series winding section and the outer end of the radially inner series winding section, is offset radially, and the series winding sections are connected to each other at the offset portion. [Composition 7] The field winding has a first winding section (71a) and a second winding section (71b) connected in series with respect to each other. A rectifier element (81) is connected between the ends of the first winding section and the second winding section, and a capacitor (82) is connected in parallel to the second winding section (71b). The first winding section and the second winding section are series winding sections formed by connecting in series the coil bodies, each consisting of at least one rotation of the rotor, which are wound around the respective main poles arranged in the circumferential direction, with the first winding section wound around the main poles on the side of the stator (50) of the rotating electric machine and the second winding section wound around the main poles on the side opposite the stator in the radial direction. A wound field rotor according to any one of configurations 1 to 4, wherein at least one of the inner end and outer end of the first winding portion and at least one of the inner end and outer end of the second winding portion on the same side as the first winding portion are radially offset, and the first winding portion and the second winding portion are connected at the offset portion. [Structure 8] The rotor core has a yoke portion (61a) extending in the circumferential direction, and the main pole portion protrudes radially from the yoke portion. In the yoke portion, one end face in the axial direction is the mounting surface (65) on which the rectifier element and the capacitor are arranged. The wound field rotor according to configuration 7, wherein in the first winding section and the second winding section, the connection ends connected to the rectifier element and the capacitor protrude in the axial direction to the same side as the mounting surface, and are connected to the rectifier element and the capacitor at the protruding portions. [Explanation of Symbols]

[0082] 40...rotating electric machine, 60...rotor, 61...rotor core, 62...main pole section, 70...field winding, 90...coil body.

Claims

1. A wound-field rotor (60) is applied to a wound-field rotating electric machine (40) and has a rotor core (61) having main pole portions (62) that are provided for each magnetic pole arranged in the circumferential direction and protrude radially, and a field winding (70) that is wound around the main pole portions, The field winding has a coil body (90) at each of the main poles, in which a conductor material is wound in multiple layers in the radial direction, and each of these coil bodies is connected in series in the circumferential direction. Each of the coils has an inner end (93), which is one end of the conductor, located radially inward, and an outer end (94), which is the other end of the conductor, located radially outward. A wound field rotor, wherein the inner end of the coil body is connected to the inner end of another coil body adjacent to it on one side in the circumferential direction, and the outer end of the coil body is connected to the outer end of another coil body adjacent to it on the other side in the circumferential direction.

2. A wound-field rotor (60) is applied to a wound-field rotating electric machine (40) and has a rotor core (61) having main pole portions (62) that are provided for each magnetic pole arranged in the circumferential direction and protrude radially, and a field winding (70) that is wound around the main pole portions, The field winding has a coil body (90) at each of the main poles, in which a conductor material is wound in multiple layers in the radial direction, and each of these coil bodies is connected in series in the circumferential direction. Each of the coils has an inner end (93), which is one end of the conductor, located radially inward, and an outer end (94), which is the other end of the conductor, located radially outward. A wound field rotor in which the inner end of the coil body is connected to another adjacent coil body on one side in the circumferential direction, and the outer end is connected to another adjacent coil body on the other side in the circumferential direction.

3. The wound field rotor according to claim 1 or 2, wherein at least one of the inner and outer ends of each circumferentially adjacent coil body has an extended portion that extends toward the coil body to which it is connected in the circumferential direction.

4. The coil body includes a first coil body (90A) and a second coil body (90B) whose inner and outer end shapes differ from each other, and the first coil body and the second coil body are arranged alternately in the circumferential direction. The first coil body and the second coil body are connected to each other at their inner ends and outer ends via the extended portion, as described in claim 3.

5. The first coil body and the second coil body are connected such that the current-carrying directions of the conductor material wound around the main electrode portion are opposite to each other. The first coil body has the extended portion at the inner end and the outer end of the outer end, and the second coil body has the extended portion at the inner end and the outer end, In the first coil body, the outer end having the extended portion and in the second coil body, the outer end not having the extended portion are connected to each other. The winding field rotor according to claim 4, wherein the inner end of the first coil body that does not have the extended portion and the inner end of the second coil body that has the extended portion are connected to each other.

6. The extended portion provided at the outer end of the first coil body has a length that is equal to the circumferential width of the first coil body and the distance to the outer end of the second coil body, The winding field rotor according to claim 5, wherein the extended portion provided at the inner end of the second coil body has a length that is equal to the circumferential width of the first coil body and corresponds to the distance to the inner end of the first coil body.

7. The coil body includes a first coil body (90A) and a second coil body (90B) whose inner and outer end shapes differ from each other, and the first coil body and the second coil body are arranged alternately in the circumferential direction. The first coil and the second coil are connected such that the current-carrying directions of the conductor material wound around the main electrode are opposite to each other. The second coil body, among the first and second coil bodies, has an extended portion at its inner end and outer end that extends circumferentially toward the first coil. The winding field rotor according to claim 1 or 2, wherein the inner end and outer end having the extended portion in the second coil body are connected to the inner end and outer end not having the extended portion in the first coil body, respectively.

8. The winding field rotor according to claim 7, wherein the extended portions provided at the inner end and the outer end of the second coil body are equal to the circumferential width of the first coil body and have a length corresponding to the distance to the inner end and the outer end of the first coil body.

9. The coil body is an α-winding coil having an inner coil portion (91) that is radially inward and an outer coil portion (92) that is radially outward, using a flat rectangular wire as the conductor material. The inner coil portion is provided with the inner end, and the outer coil portion is provided with the outer end, The wound field rotor according to claim 1 or 2, wherein at least one of the inner and outer ends of each circumferentially adjacent coil body has an extended portion that extends toward the coil body to which it is connected in the circumferential direction.

10. The field winding has a plurality of series winding sections formed by connecting in series the coil bodies that make up one rotation of the rotor and are wound around each of the main poles arranged in the circumferential direction, and the series winding sections arranged in the radial direction are connected in series to each other, as described in claim 1 or 2.

11. A winding field rotor according to claim 10, wherein at least one of the inner end of the radially outer series winding portion and the inner end of the radially inner series winding portion, or at least one of the outer end of the radially outer series winding portion and the outer end of the radially inner series winding portion, is offset radially, and the series winding portions are connected to each other at the offset portion.

12. The field winding has a first winding section (71a) and a second winding section (71b) connected in series with respect to each other. A rectifier element (81) is connected between the ends of the first winding section and the second winding section, and a capacitor (82) is connected in parallel to the second winding section (71b). The first winding section and the second winding section are series winding sections formed by connecting in series the coil bodies, each consisting of at least one rotation of the rotor, which are wound around the respective main poles arranged in the circumferential direction, with the first winding section wound around the main poles on the side of the stator (50) of the rotating electric machine and the second winding section wound around the main poles on the side opposite the stator in the radial direction. A wound field rotor according to claim 1 or 2, wherein at least one of the inner end and the outer end of the first winding portion and at least one of the inner end and the outer end of the second winding portion on the same side as the first winding portion are offset radially, and the first winding portion and the second winding portion are connected at the offset portion.

13. The rotor core has a yoke portion (61a) extending in the circumferential direction, and the main pole portion protrudes radially from the yoke portion. In the yoke portion, one end face in the axial direction is the mounting surface (65) on which the rectifier element and the capacitor are arranged. The wound field rotor according to claim 12, wherein in the first winding portion and the second winding portion, the connection ends connected to the rectifier element and the capacitor protrude in the axial direction to the same side as the mounting surface, and are connected to the rectifier element and the capacitor at the protruding portions.

14. A wound-field rotor (60) is applied to a wound-field rotating electric machine (40) and has a rotor core (61) having main pole portions (62) that are provided for each magnetic pole arranged in the circumferential direction and protrude radially, and a field winding (70) that is wound around the main pole portions, The field winding has a coil body (90) at each of the main poles, in which a conductor material is wound in multiple layers in the radial direction, and each of these coil bodies is connected in series in the circumferential direction. Each of the coils has an inner end (93), which is one end of the conductor, located radially inward, and an outer end (94), which is the other end of the conductor, located radially outward. In the coil body, the inner end is connected to the inner end of another coil body adjacent to it on one side in the circumferential direction, and the outer end is connected to the outer end of another coil body adjacent to it on the other side in the circumferential direction. In the field winding, the coil bodies are arranged in multiple layers in the radial direction at each main pole portion, and a series winding section is provided in each layer by connecting coil bodies of the same layer in the radial direction in series in the circumferential direction, and the series winding sections arranged in the radial direction are connected in series with each other. At least one of the inner end of the radially outer series winding section and the inner end of the radially inner series winding section, or at least one of the outer end of the radially outer series winding section and the outer end of the radially inner series winding section, is offset radially, and the series winding sections are connected to each other at the offset portion. A wound field rotor having multiple offset portions, each of which is positioned to overlap with the others in the circumferential direction and to be aligned in the radial direction.

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