Winding field rotor

Abstract

A rotor (60) comprises: a rotor core (61) having a plurality of main pole parts (62) provided for each magnetic pole and arranged in the circumferential direction; and a field winding (70) wound around each main pole part. In the rotor, an outer peripheral coating part (102) formed by spirally winding a wire (171) in the axial direction is provided on the outside of each of the main pole parts and field windings in the radial direction. The outer peripheral coating part is configured such that current does not flow between wires that are adjacent to each other in the axial direction.

Description

Wound-field magnet rotor ,

[0008] , ,

[0007] Cross-reference to related applications

[0001] This application is based on Japanese Application No. 2025-026806 filed on February 21, 2025, the content of which is incorporated herein by reference.

[0002] The disclosure in this specification relates to a wound-field magnet rotor.

[0003] A wound-field type rotating electric machine includes a stator having stator windings and a rotor having field windings. The rotor includes a rotor core having a plurality of main pole portions (magnetic salient pole portions), and field windings are provided in a state of being wound around the main pole portions. Patent Document 1 discloses a configuration in which a metal wire is spirally wound around the outer peripheral sides of the rotor core and the field windings in the rotor.

[0004] Japanese Patent No. 5918484

[0005] In the configuration in which a metal wire is wound around the outer peripheral sides of the rotor core and the field windings as described above, the metal wires contact each other, and an electric current flows between the wires adjacent to each other in the axial direction. Then, there is a concern that the eddy current loss increases due to the energization between the wires.

[0006] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a wound-field magnet rotor capable of realizing an appropriate configuration as a fixing structure of a field winding by a wire.

[0007] The wound-field magnet rotor of the present disclosure is a wound-field magnet rotor including: a rotor core having a plurality of main pole portions provided for each of the poles arranged in the circumferential direction; and field windings provided in a state of being wound around each of the main pole portions, wherein an outer peripheral covering portion in which a wire is spirally wound in the axial direction is provided on the radially outer sides of each of the main pole portions and the field windings, and the outer peripheral covering portion is configured such that no electric current flows between the wires adjacent to each other in the axial direction.

[0008] In a wound-field rotor, an outer covering portion is provided on the radially outer side of each main pole and field winding, where wire is spirally wound in the axial direction. This allows for proper fixing of the field winding. Furthermore, since the outer covering portion is configured so that no current flows between axially adjacent wires, the flow of eddy currents between wires is suppressed, thereby reducing eddy current losses. As a result, an appropriate configuration for fixing the field winding using wire can be achieved.

[0009] The above-mentioned and other purposes, features and advantages of this disclosure will be further clarified by the following detailed description with reference to the attached drawings. The drawings are as follows: Figure 1 is an overall diagram of the rotating electric machine system; Figure 2 is a cross-sectional view of the rotor and stator; Figure 3 is a diagram showing the electrical circuit of the rotor; Figure 4 is a perspective view showing the overall configuration of the rotor; Figure 5 is a perspective view showing the rotor with the outer casing and coil end cover removed; Figure 6 is an exploded perspective view of the rotor; Figure 7 is a longitudinal section of the rotor; Figure 8 is a perspective view showing the configuration of the circuit module; Figure 9 is a diagram illustrating eddy current losses in the outer casing; and Figure 10 is a diagram illustrating the outer casing. Figure 11 is a schematic longitudinal cross-sectional view showing the structure of the outer periphery covering section, Figure 12 is a cross-sectional view of the wire in the outer periphery covering section, Figure 13 is a schematic longitudinal cross-sectional view showing the structure of the outer periphery covering section, Figure 14 is a schematic longitudinal cross-sectional view showing the structure of the outer periphery covering section, Figure 15 is a cross-sectional view of the wire in the outer periphery covering section, Figure 16 is a cross-sectional view showing the cross-sectional structure of a part of the rotor main section, Figure 17 is a cross-sectional view showing the cross-sectional structure of a part of the rotor main section, and Figure 18 is a transverse cross-sectional view showing the cross-sectional structure of a part of the rotor main section.

[0010] Hereinafter, embodiments of the wound-field rotating electric machine described herein will be explained with reference to the drawings. The rotating electric machine is used, for example, as a power source for electric vehicles such as electric cars and hybrid cars.

[0011] First, a rotating electric machine system including a rotating electric machine 40 and a control unit will be described using Figure 1. This system comprises a DC power supply 10, an inverter 20, a control device 30, and a rotating electric machine 40. The rotating electric machine 40 is a self-excited wound-field synchronous machine. For example, the rotating electric machine 40, inverter 20, and control device 30 may be configured as an electromechanical integrated drive unit, or the rotating electric machine 40, inverter 20, and control device 30 may each be configured as separate components.

[0012] 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 rotating electric machine in which the rotor 60 is positioned radially inward of the stator 50. The housing 41 corresponds to a stator holding portion that holds the stator 50.

[0013] The stator 50 comprises a stator core 51 and stator windings 52. The stator windings 52 are, for example, three-phase windings, and include U-phase windings, V-phase windings, and W-phase windings. The phase windings of each phase are arranged so that they are offset from each other by 120° in electrical angle. The stator windings 52 are constructed by connecting the three phase windings in a star configuration. However, the stator windings 52 may also be delta-connected.

[0014] The rotor 60 comprises a rotor core 61 and field windings 70. A rotating shaft 32 is assembled in the central hole of the rotor core 61. The rotating shaft 32 is rotatably supported by bearings 42 and 43 provided in the housing 41.

[0015] As is well known, the inverter 20 has switches made of semiconductor switching elements for each phase of the stator winding 52. The control device 30 controls the switching of each switch in the inverter 20, thereby controlling the current flowing through the phase windings of each phase. This controls the rotational speed of the rotating electric machine 40. The control device 30 is an electronic control unit (ECD) composed of a microcontroller and various memories. The control device 30 controls the inverter 20 by executing a program stored in a non-transitory tangible storage medium, which serves as its own memory unit.

[0016] Next, the stator 50 and rotor 60 will be described using Figure 2. Both the stator 50 and rotor 60 are arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is called the axial direction, the direction extending radially from the center of the rotating shaft 32 is called the radial direction, and the direction extending circumferentially with the rotating shaft 32 as the center is called the circumferential direction.

[0017] The stator core 51 is made of laminated steel plates made of soft magnetic material and has an annular back yoke 51a and a plurality of teeth 51b that protrude radially inward from the back yoke 51a. A plurality of slots 54 are formed between adjacent teeth 51b, arranged in the circumferential direction. The stator windings 52 are formed by housing the phase windings of each phase in a predetermined order in each of these slots 54. For example, a segment coil structure using a plurality of conductor segments may be adopted in the stator 50. However, the structure of the stator windings 52 is arbitrary.

[0018] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 that extend radially outward from the cylindrical portion 61a. The cylindrical portion 61a corresponds to the central part of the rotor core 61 in the radial direction. Field windings 70 are wound around the main pole portions 62 by concentrated winding. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0019] The field winding 70 comprises a first winding section 71 and a second winding section 72. The first winding section 71 is wound radially outward around each main pole section 62, and the second winding section 72 is wound radially inward from the first winding section 71. The first winding sections 71 wound around each main pole section 62 are connected in series in the circumferential order of the main pole section 62, and similarly, the second winding sections 72 are connected in series in the circumferential order of the main pole section 62. Furthermore, the series connections of the first winding sections 71 and the series connections of the second winding sections 72 are connected to each other.

[0020] In each main pole section 62, the winding directions of the conductor material in the first winding section 71 and the second winding section 72 are the same. Furthermore, among circumferentially adjacent main pole sections 62, the winding directions of the winding sections 71 and 72 wound around one main pole section 62 are opposite to those of the winding sections 71 and 72 wound around the other main pole section 62. Therefore, when the field winding 70 is energized, the magnetization directions of circumferentially adjacent main pole sections 62 are opposite to each other. In the rotor 60, multiple magnetic poles (field poles) arranged in the circumferential direction are formed by each main pole section 62 in the rotor core 61 and the field winding 70 wound around each main pole section 62. In this embodiment, the number of turns in the second winding section 72 is greater than the number of turns in the first winding section 71.

[0021] Figure 3 shows an electrical circuit in the rotor 60 including the winding sections 71 and 72 of the field winding 70. The first winding section 71 and the second winding section 72 are connected in series by the connection of terminal A of the first winding section 71 and terminal C of the second winding section 72 to each other. In addition, a diode 81 is connected in series between terminal B of the first winding section 71 and terminal D of the second winding section 72, and a resonant capacitor 82 is connected in parallel with the diode 81. The diode 81 is provided to allow current IL1 to flow in the first winding section 71 with the forward direction from terminal B to terminal A, and current IL2 to flow in the second winding section 72 with the forward direction from terminal C to terminal D.

[0022] Furthermore, the terminals C and D of the second winding section 72 are connected to both ends of the diode 83, and a resonant capacitor 84 is connected in parallel with the diode 83. The diode 83 is provided in the second winding section 72 to allow current IL2 to flow with the forward direction from terminal C to terminal D.

[0023] The control device 30 shown in Figure 1 switches the phases of the inverter 20 on and off so that a combined current of a fundamental wave current and a high-frequency current (specifically, a high-frequency excitation current) with a frequency higher than the fundamental wave current flows through the phase windings of each phase of the stator winding 52. The fundamental wave current is a current whose main purpose is to generate torque in the rotating electric machine 40. The high-frequency current is a current whose main purpose is to excite the winding sections 71 and 72 that make up the field winding 70, thereby inducing a field current in the field winding 70. The phase currents flowing through the phase windings of each phase are shifted by 120° in electrical angle.

[0024] The high-frequency current flowing through the stator winding 52 may be a harmonic current whose fluctuating frequency is N times the frequency of the fundamental wave current (where N is an integer greater than or equal to 2), or it may be a current whose fluctuating frequency is outside of N times the frequency of the fundamental wave current.

[0025] When a high-frequency current flows through the stator winding 52, a voltage is induced in each winding section 71, 72 of the field winding 70, causing a field current to flow. The induced voltages in each winding section 71, 72 are, for example, in the same phase. The currents IL1, IL2 flowing through each winding section 71, 72 include the frequency components of the high-frequency current.

[0026] In the electrical circuit shown in Figure 3, when the stator winding 52 is energized, the windings 71 and 72 of the field winding 70 are energized, and current flows through the closed circuit (circulation path) including the first winding 71 and the second winding 72. Furthermore, when the voltage across the second winding 72 exceeds the forward voltage of the diode 83, a current IL2 greater than the current IL1 flowing through the first winding 71 flows through the second winding 72 in the closed circuit including the second winding 72 and the diode 83. The flow of current through the closed circuit including the second winding 72 and the diode 83 increases the DC component of the field current. This increases the DC component of the magnetic flux of the rotor 60, thereby increasing the torque of the rotating electric machine 40.

[0027] Next, the configuration of the rotor 60 will be described in more detail. Figure 4 is a perspective view showing the overall configuration of the rotor 60, and Figure 5 is a perspective view showing the rotor 60 with the outer peripheral covering portion 102 and coil end covers 103 and 104 that cover the rotor main portion 101 removed. Figure 6 is an exploded perspective view of the rotor 60, and Figure 7 is a longitudinal cross-sectional view of the rotor 60.

[0028] The rotor 60 is broadly composed of a rotor main section 101, a cylindrical outer peripheral covering section 102 provided to surround the outer circumference of the rotor main section 101, coil end covers 103 and 104 attached to one axial end and the other end of the rotor main section 101, and a busbar module 105 and a circuit module 106 provided on one of the axial sides of the rotor main section 101. The rotor main section 101 comprises a rotor core 61 and field windings 70, and a rotating shaft 32 is assembled in the central hole of the rotor core 61.

[0029] The field winding 70 consists of a plurality of winding units 110 arranged in a circumferential direction. Each winding unit 110 is formed in an annular shape with its longitudinal direction in the axial direction, and is assembled to the rotor core 61 with the main pole portion 62 of the rotor core 61 inserted through its hollow portion. A winding unit 110 is provided for each magnetic pole of the rotor 60 and corresponds to a "pole coil". Coil end covers 103 and 104 are provided to cover the coil ends of the field winding 70 on both sides in the axial direction.

[0030] The busbar module 105 and the circuit module 106 are fixed to the rotating shaft 32 with the rotating shaft 32 inserted through their respective hollow portions. As a result, the busbar module 105 and the circuit module 106 are positioned axially opposite to the coil ends of the field winding 70. The busbar module 105 has multiple busbars for electrically connecting the winding units 110 for each magnetic pole.

[0031] As shown in Figure 6, the winding unit 110 is composed of two coil modules 111 and 112 that are radially outer and radially inner when mounted on the main pole portion 62. The radially outer first coil module 111 is a coil module corresponding to the first winding portion 71, and the radially inner second coil module 112 is a coil module corresponding to the second winding portion 72. The first coil module 111 has two wire ends 113 drawn out in the axial direction, and the second coil module 112 has two wire ends 114 drawn out in the axial direction. In each winding unit 110 arranged in the circumferential direction, multiple first coil modules 111 are connected in series by connecting each wire end 113 to each other, and multiple second coil modules 112 are connected in series by connecting each wire end 114 to each other.

[0032] Figure 8 is a perspective view showing the configuration of the circuit module 106. Figure 8 shows the configuration of the circuit module 106 as seen from the field winding 70 side (busbar module 105 side) in the axial direction.

[0033] The circuit module 106 is disc-shaped and has a component holder 141 that holds electrical components. The component holder 141 is made of a resin molded body and has a central hole 142 in its center. A highly rigid cylindrical member 143, made of, for example, metal, is assembled into the central hole 142. The component holder 141 is assembled to the rotating shaft 32 with the rotating shaft 32 inserted through the inner circumference of the cylindrical member 143.

[0034] The component holder 141 has an annular peripheral wall portion 144 provided on the radially outer side of the component holder 141, and a component housing portion 145 provided on the radially inner side of the peripheral wall portion 144. The component housing portion 145 houses the electrical components that constitute the electrical circuit described in Figure 3, arranged in the circumferential direction. That is, the component holder 141 holds diodes 81, 83 and capacitors 82, 84 as electrical components, surrounding the central hole 142. A busbar 147 is connected to each of these electrical components.

[0035] The component housing section 145 is filled with resin, and each electrical component is installed embedded in the resin. This prevents displacement of each electrical component even when radial or circumferential forces are applied to them during the rotation of the rotor 60.

[0036] As shown in Figures 6 and 7, the coil end cover 103 has an end plate portion 151 fixed to the rotating shaft 32 and extending in the radial direction, and an annular portion 152 extending axially from the outer circumference of the end plate portion 151 and surrounding the coil end of the field winding 70 from the radial outside. The coil end cover 104 has an end plate portion 161 fixed to the rotating shaft 32 and extending in the radial direction, and an annular portion 162 extending axially from the outer circumference of the end plate portion 161 and surrounding the coil end of the field winding 70 from the radial outside.

[0037] In the rotor 60, one of the coil end covers 103 and 104 on both axial sides, coil end cover 103, is provided such that it houses the busbar module 105 and the circuit module 106 inside the cover on one axial side and covers the rotor coil end of the field winding 70. The other coil end cover 104 is provided such that it covers the rotor coil end of the field winding 70 on the other axial end side. The coil end covers 103 and 104 are preferably made of a non-magnetic material, for example, aluminum. The coil end covers 103 and 104 may also be made of synthetic resin.

[0038] The outer periphery covering portion 102 is constructed by using a metal wire 171 and winding the wire 171 spirally around the outer circumference of a plurality of winding units 110 assembled on the rotor core 61. In other words, the outer periphery covering portion 102 is constructed by continuously winding the wire 171 around each main pole portion 62 and the field winding 70 from the radially outer side on the outer circumference of the rotor. The starting and ending ends of the wire 171 are preferably fixed to either the coil end cover 103 or 104.

[0039] The wire 171 is preferably wound around the outer circumference of the rotor under tension. This makes it difficult for each winding unit 110 to be displaced even when centrifugal force acts on the rotor 60, and makes it possible to reduce the air gap between the stator 50 and the rotor 60.

[0040] In the rotor 60, an outer peripheral covering portion 102 is provided between the coil end covers 103 and 104 on both axial sides. More specifically, the outer peripheral covering portion 102 is provided between the annular portions 152 and 162 of each coil end cover 103 and 104. As shown in Figure 7, the axial range in which the outer peripheral covering portion 102 is provided is the range X that overlaps radially with the rotor core 61.

[0041] The wire 171 is preferably a flat steel wire with a rectangular cross-section. Furthermore, the wire 171 is preferably a magnetic metal wire, specifically SUS430, SUS631, piano wire, etc. The width dimension (axial dimension) of the cross-section of the wire 171 is, for example, about 0.5 to 1 mm. Here, the rotor core 61 consists of a laminated core formed by stacking core sheets in the axial direction, and the width dimension of the wire 171 is preferably greater than the thickness dimension of the core sheets.

[0042] Incidentally, in the outer circumference of the rotor, there is a concern that eddy current losses will occur if the metal wires 171, which are arranged axially, come into contact with each other. Specifically, the stator magnetic flux links with each wire 171 of the outer covering portion 102. In this case, the eddy current loss per unit volume is proportional to the square of the width of the member in the direction intersecting the magnetic flux, so if the width of the metal wire is small, the eddy current loss is relatively small. However, as shown in Figure 9(a), when the metal wires come into contact with each other and the effective width of the metal wire (width of the conductor) increases, the eddy current loss increases in proportion to the square of the width of the metal wire.

[0043] Therefore, in this embodiment, as shown in Figure 9(b), an insulating material A is interposed between the metal wires to suppress the unintended increase in the effective width of the metal wires (width of the conductor). In this case, the metal wires remain in a state of non-contact, and eddy loss can be reduced.

[0044] FIG. 10 is a longitudinal sectional view schematically showing the configuration of the outer peripheral covering portion 102 in the rotor 60. The outer peripheral covering portion 102 has a configuration in which the wire rods 171 are arranged in the axial direction by being spirally wound around the outer peripheral portion of the rotor. Also, an insulating material 172 is interposed between the wire rods 171 arranged in the axial direction. With this configuration, in the outer peripheral covering portion 102, no current flows between the wire rods 171 adjacent to each other in the axial direction.

[0045] Specifically, as the insulating material 172, an insulating wire rod 173 that does not contain a metal wire is used. In this case, the wire rod 171, which is a metal wire, and the insulating wire rod 173 that does not contain a metal wire are wound in the axial direction so as to be alternately arranged in the axial direction at the outer peripheral portion of the rotor. For example, it is possible to simultaneously wind the wire rod 171 and the insulating wire rod 173 as a set of two outside the radial direction of each main pole portion 62 and the field winding 70. Thereby, a configuration in which the insulating material 172 is interposed between the wire rods 171 (metal wires) adjacent to each other in the axial direction in the outer peripheral covering portion 102 can be realized.

[0046] The insulating wire rod 173 is provided for the purpose of insulating between the wire rods 171 arranged in the axial direction, and strength as high as that of the wire rod 171 is not required. In this case, the fixing strength for fixing the field winding 70 by the wire rod 171 containing a metal wire is ensured. However, in order to increase the strength of the insulating wire rod 173, it is also possible to use a material containing, for example, carbon fiber reinforced plastic (CFRP: Carbon Fiber Reinforced Plastics) or glass fiber reinforced plastic (GFRP: Glass Fiber Reinforced Plastic) as the insulating wire rod 173.

[0047] The outer peripheral covering portion 102 shown in FIG. 10 may be such that the wire 171 and the insulating material 172 are attached in separate operations performed successively. During the manufacture of the rotor 60, for example, the wire 171 is first spirally wound around the radially outer side of each main pole portion 62 and the field winding 70. At this time, the wires 171 arranged in the axial direction may be spirally wound in a state where they are separated from each other. Then, a thin wire-shaped insulating material 172 is assembled in the gap portion between the wires 171 in the axial direction. Thereby, the outer peripheral covering portion 102 shown in FIG. 10 is produced.

[0048] Also, as shown in FIG. 11, the wire 171 may be configured such that the wires 171 arranged in the axial direction are spirally wound in a state where they are separated from each other, and a resin material as an insulating material is filled between the wires 171 arranged in the axial direction. In this case, a resin layer 174 is formed between the wires 171 arranged in the axial direction.

[0049] The resin layer 174 may be produced as follows. After the wire 171 is spirally wound around the outer peripheral portion of the rotor, a cylindrical mold is assembled outside the wire 171, and a liquid resin material is poured into the mold. Then, the mold is removed after the resin is cured. Thereby, the resin layer 174 is formed between the spiral wires 171.

[0050] As shown in FIG. 12, the wire 171 may be a covered wire in which the metal wire 171a is covered with an insulating film 171b. The configuration of the outer peripheral covering portion 102 using the covered wire as the wire 171 is shown in FIG. The wire 171 is spirally wound in a state where the insulating films 171b contact each other in the axial direction. In this case, in the state where the wires 171 are arranged in the axial direction, the insulating films 171b intervening between the metal wires 171a serve as an insulating material.

[0051] In the configuration in which the wire 171 made of a covered wire is wound around the outer peripheral portion of the rotor, in addition to enhancing the insulation between the wires, insulation between the wire 171 and the rotor core 61 is possible. Further, since the insulation between the wires 171 can be imparted by winding the wire 171 (covered wire), it is not necessary to separately add an insulating material, and the assembling workability of the outer peripheral covering portion 102 is improved.

[0052] As shown in Figure 14, the outer covering portion 102 may be configured to wind the coated wire 171 in multiple layers in the radial direction. In addition to the two layers shown in the figure, the number of layers of the wire 171 can be three or more. In this case, since the wire 171 is a coated wire, the insulation between the wires 171 is maintained even if the position of the wires 171 in each radial layer is shifted in the axial direction.

[0053] It is also possible to use different wires 171 for each layer in the outer covering portion 102. In other words, it is possible to wrap different wires 171 around the inner layer and the outer layer in the outer covering portion 102. In this case, even if one of the wires 171 breaks or the like, the wires 171 can maintain the state in which they fix the field winding 70.

[0054] According to the embodiment described in detail above, the following excellent effects can be obtained.

[0055] In the rotor 60, an outer peripheral covering portion 102 is provided on the radially outer side of each main pole portion 62 of the rotor core 61 and the field winding 70, in which wire 171 is wound spirally in the axial direction. This allows for proper fixing of the field winding 70. Furthermore, since the outer peripheral covering portion 102 is configured so that no current flows between axially adjacent wires 171, the flow of eddy currents between the wires 171 is suppressed, thereby reducing eddy current losses. As a result, an appropriate configuration for fixing the field winding 70 using wire 171 can be achieved.

[0056] The wire 171 is a metal wire, and an insulating material is interposed between adjacent metal wires in the axial direction. This suppresses the flow of current between metal wires aligned in the axial direction, thereby reducing eddy current losses.

[0057] The configuration involves winding metal wires 171 and insulating wires 173 (which do not contain metal wires) alternately in the axial direction. This ensures sufficient fixing strength to secure the field winding 70 at the outer circumference of the rotor using the metal wires 171, while providing insulation between the wires 171 using the insulating wires 173.

[0058] The wires 171 are wound axially with the wires 171 aligned in the axial direction spaced apart from each other, and a resin material is filled between the axially aligned wires 171. This allows for proper suppression of current flow between the wires 171 while suppressing displacement of the wires 171 at the outer circumference of the rotor.

[0059] In this configuration, insulated wires are used as the wires 171, and the wires 171 arranged in the axial direction are insulated from each other by the insulating film of the insulated wires. In this case, since the entire outer circumference of the wires 171 is covered with an insulator, the insulation between the wires can be improved. Furthermore, since radial insulation is possible in addition to axial insulation, insulation between the wires 171 and the rotor core 61 can be achieved when the wires 171 are wound around the outer circumference of the rotor.

[0060] In this configuration, a coated wire is used as the wire 171, and the wire 171 is wound in multiple layers radially around the outer circumference of the rotor. With this configuration, even if the position of the wire 171 in each radial layer is shifted in the axial direction, the insulation between the wires 171 can be maintained, and consequently, eddy current losses can be appropriately reduced.

[0061] Since the wire 171 wrapped around the outer circumference of the rotor is made of a magnetic material, the wire 171 can be used as a magnetic circuit in the rotating electric machine 40, thereby reducing the effective air gap between the stator 50 and the rotor 60. This makes it possible to improve the torque of the rotating electric machine 40.

[0062] The wire 171 was made such that its axial dimension (axial width) in the cross-section was greater than the thickness of the core sheet. This suppresses the inconvenience of the wire 171 falling into a recess formed by the thickness of the core sheet in the laminated rotor core 61.

[0063] (Other Embodiments) The above embodiments may be modified as follows, for example.

[0064] As shown in Figure 15, the wire 171 may consist of two wires: a metal wire 171a (exposed metal wire) that is not coated with an insulating film, and a coated wire 171X in which the metal wire 171a is coated with an insulating film 171b. These wires may be wound so that they are alternately aligned in the axial direction. In this case, the insulating film 171b of the coated wire 171X acts as an insulator between the metal wires aligned in the axial direction. It is also possible to use three or more wires, including the metal wire 171a (exposed metal wire) and the coated wire 171X.

[0065] In this configuration, even if not all of the multiple wires 171 are coated, the combination of metal wires (exposed metal wires) and coated wires can provide insulation between the wires. In this case, costs can be reduced compared to the case where all of the multiple wires 171 are coated. Furthermore, by winding the multiple wires 171 around the outer circumference of the rotor, even if one of the wires 171 breaks, the wires 171 can maintain their ability to fix the field winding 70 in place.

[0066] - In the field winding 70, which is made by winding multiple layers of conductive wire, variations in radial dimensions occur. Specifically, the radial dimensions of the winding unit 110, which is the pole coil for each magnetic pole, may be shorter or longer than the radial dimensions of the main pole portion 62 of the rotor core 61. In this case, if the radial dimensions of the winding unit 110 are shorter than the radial dimensions of the main pole portion 62, a gap may be unintentionally created on the radially inner or outer side of the winding unit 110. This gap may cause radial rattling in the winding unit 110, or a tightening force from the outer peripheral covering portion 102 may act locally between each main pole portion 62 in the circumferential direction, potentially damaging the winding unit 110.

[0067] Taking this into consideration, as shown in Figure 16, in a rotor 60 in which a winding unit 110 is arranged between the cylindrical portion 61a of the rotor core 61 and the outer peripheral covering portion 102, it is preferable that a spacer 181 made of an elastic material be provided radially inward of the winding unit 110. Alternatively, as shown in Figure 17, in a rotor 60 in which a winding unit 110 is arranged between the cylindrical portion 61a of the rotor core 61 and the outer peripheral covering portion 102, it is preferable that a spacer 181 made of an elastic material be provided radially outward of the winding unit 110. The spacer 181 is, for example, a plate-shaped rubber sheet.

[0068] According to the configuration in Figure 16 or Figure 17, the spacer 181 is interposed between the cylindrical portion 61a of the rotor core 61 and the winding unit 110, or between the winding unit 110 and the outer peripheral covering portion 102. This allows the dimensional difference to be absorbed even if the radial dimension of the winding unit 110 is shorter than the radial dimension of the main pole portion 62. This suppresses radial rattle in the winding unit 110 and prevents damage to the winding unit 110.

[0069] Furthermore, comparing the configurations in Figure 16 and Figure 17, the configuration in Figure 16 is advantageous because, since the spacer 181 does not contract when centrifugal force acts on the rotor 60, the load on the spacer 181 is reduced.

[0070] Furthermore, as shown in Figure 18, a spacer 182 made of an elastic material may be provided between the main pole portion 62 and the outer peripheral covering portion 102 of the rotor core 61. According to the configuration in Figure 18, even if the radial dimension of the winding unit 110 is longer than the radial dimension of the main pole portion 62, the dimensional difference can be absorbed. This makes it possible to avoid the action of localized loads on the outer circumference of the winding unit 110 and suppress damage to the outer peripheral covering portion 102 and the winding unit 110.

[0071] - In the outer covering portion 102, metal wires not covered with an insulating film (exposed metal wires) may be used as the wire material 171, and the wire materials 171 arranged in the axial direction may be spaced apart from each other, with the space between the wire materials 171 serving as the insulating portion. In this case, the insulation between the metal materials is provided by the spatial gaps.

[0072] - In the rotor 60, it is also possible to use non-metallic wires as the wires 171 that constitute the outer periphery covering portion 102. In this case, the wires 171 should not contain metal wires and should be made of an insulating material such as resin. By using non-metallic wires 171, the configuration ensures that no current flows between adjacent wires 171 in the axial direction.

[0073] - In the rotor 60, the field winding 70 may have a configuration different from that using the winding unit 110. For example, the conductor material may be directly wound around the main pole portion 62 of the rotor core 61.

[0074] - In the stator 50, the stator core may be a stator core without teeth.

[0075] 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.

[0076] The mobile body on which the rotating electric machine system is mounted is not limited to a vehicle; for example, it may be an aircraft or a ship. Furthermore, the rotating electric machine system is not limited to a system mounted on a mobile body; it may be a stationary system.

[0077] This disclosure is described in accordance with the embodiments, but it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the equivalence. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and concept of this disclosure.

Claims

1. A wound-field rotor (60) comprising: a rotor core (61) having a plurality of main pole portions (62) provided for each magnetic pole arranged in the circumferential direction; and a field winding (70) provided around each of the main pole portions, wherein an outer peripheral covering portion (102) is provided on the radially outer side of each of the main pole portions and the field winding, the outer peripheral covering portion being configured such that no current flows between adjacent wires in the axial direction.

2. The wound field rotor according to claim 1, wherein in the outer peripheral covering portion, the wire material is a metal wire, and an insulating material is interposed between adjacent metal wires in the axial direction.

3. The wound field rotor according to claim 2, wherein in the outer peripheral covering portion, the wire material and the insulating wire material not containing the metal wire are wound axially so as to be alternately arranged in the axial direction.

4. The wound field rotor according to claim 2, wherein the wires are wound in the axial direction with spaced apart from each other, and the resin material as an insulating material is filled between the wires arranged in the axial direction.

5. The wound field rotor according to claim 2, wherein the wire is a coated wire in which a metal wire is covered with an insulating film, the insulating films are wound spirally in the axial direction with the films in contact with each other, and the insulating film is the insulating material.

6. The wound field rotor according to claim 5, wherein the wire is wound in multiple layers in the radial direction.

7. The wound field rotor according to claim 2, wherein the wire material consists of a plurality of wires including a metal wire (171a) not covered with an insulating film and a coated wire (171X) in which the metal wire (171a) is covered with an insulating film (171b), and these wires are wound alternately in the axial direction, and the insulating film is the insulating material.

8. The wound field rotor according to any one of claims 1 to 7, wherein the wire is a magnetic material.

9. The wound field rotor according to any one of claims 1 to 7, wherein the rotor core has a central part (61a) that is the radial center and a plurality of main pole parts extending radially from the central part, and as the field winding, pole coils (110), which are windings for each magnetic pole, are wound around each of the main pole parts of the rotor core, and a spacer (181) made of an elastic material is provided on the radially inner or radially outer side of the pole coil which is positioned between the central part of the rotor core and the outer peripheral covering in the radial direction, or a spacer (182) made of an elastic material is provided between the main pole parts and the outer peripheral covering of the rotor core.

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