Winding field-type rotary electric machine

Abstract

A winding field-type rotary electric machine (40) includes: a stator (50) having a stator winding (52); a rotor (60) having a rotor core (61) and a field winding (70); and a circuit module (102) that is provided so as to be integrally rotatable with the rotor and has an electric component connected to the field winding. The field winding has a plurality of pole coils (110) formed by winding a conducting wire for respective main pole parts of the rotor core, and the pole coils of the main pole parts are electrically connected to each other via a conducting wire connection part (CN). The circuit module is provided on a first end side, which is one side in the axial direction of the rotor core, and the conducting wire connection part is provided on a second end side, which is the other end side in the axial direction of the rotor core.

Description

Wound-field type rotating electric machine CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-006944, filed on January 19, 2024, the contents of which are incorporated herein by reference.

[0002] The disclosure in this specification relates to a wound field type rotating electric machine.

[0003] In a wound-field rotating electric machine, the rotor has a rotor core with multiple main poles (magnetic salient poles) arranged circumferentially, and a field winding wound around the main poles. Also, a known configuration is one in which a circuit module equipped with capacitors and diodes as electrical components is provided at the axial end of the rotor (see Patent Document 1). The capacitors and other components are held in the circuit module by a component holder.

[0004] In the wound-field rotating electric machine described in Patent Document 1, a component holder for a circuit module has a component housing portion surrounding a rotating shaft for housing electrical components such as capacitors. The field winding has multiple winding portions (pole coils) provided for each main pole. The component holder has a winding fixing portion radially outward of the component housing portion to which conductor ends extending axially from each winding portion are fixed. The conductor ends extending from the winding portions of each main pole are connected to each other at the winding fixing portion by welding or the like.

[0005] Japanese Patent Application Laid-Open No. 2020-124100

[0006] In a wound-field rotor, as the electrical components mounted on the circuit module increase in size or the number of electrical components increases, the area required for accommodating the electrical components in the component holder increases, making it impossible to secure the area for fixing the wire ends extending from the field winding. In this case, a configuration in which the wire ends extending axially from each winding section are connected to each other in a region between the circuit module (component holder) and the field winding on one of the axial sides of the rotor is conceivable. However, in a configuration in which the connection portions between the wire ends of each winding section are located in a region between the circuit module and the field winding, it is necessary to extend the distance from the axial tip of the field winding to the circuit module to avoid interference between the circuit module and the wire ends of each winding section. This increases the axial length of one side of the rotor, which in turn raises concerns about an increase in the size of the rotating electric machine.

[0007] The present disclosure has been made in view of the above circumstances, and has an object to provide a wound field type rotating electric machine that can be made smaller in size.

[0008] The present disclosure relates to a wound field type rotating electric machine having: a stator having a stator winding; a rotor core having a plurality of main pole portions provided for each circumferentially arranged magnetic pole and protruding in the radial direction, and a field winding wound around each of the main pole portions; and a circuit module that is arranged to be rotatable integrally with the rotor and has electrical components connected to the field winding, wherein the field winding has a plurality of pole coils formed by winding a conductor material around each of the main pole portions, and the pole coils of each main pole portion are electrically connected to each other via a conductor connecting portion, and the circuit module is arranged on a first end side that is one axial side of the rotor core, and the conductor connecting portion is arranged on a second end side that is the other axial end side of the rotor core.

[0009] In a wound-field rotating electric machine, a rotor is provided with a pole coil for each main pole of a rotor core, and for example, adjacent pole coils in the circumferential direction are connected to each other via a conductor connection portion. The rotor also has a circuit module provided thereon so that the circuit module can rotate integrally with the rotor. In this case, if the conductor connection portion of the pole coil and the circuit module are provided on one axial side of the rotor core, it is necessary to avoid interference between the circuit module and the conductor connection portion, which raises concerns about the axial length of the rotor on one side.

[0010] In this regard, by providing a circuit module on one axial end of the rotor core, i.e., a first end, and providing a wire connector on the other axial end of the rotor core, i.e., a second end, interference between the circuit module and the wire connector can be avoided. Furthermore, in a rotating electric machine in which the rotor and stator are arranged radially opposite each other, a configuration in which the wire connectors of the pole coils and the circuit module are provided separately on both axial sides of the rotor prevents the circuit module from protruding axially outward beyond the stator windings. As a result, the physical size of the wound-field rotating electric machine can be reduced.

[0011] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is an overall configuration diagram of a control system for a rotating electric machine, Fig. 2 is a diagram showing an inverter and its peripheral configuration, Fig. 3 is a cross-sectional view of a rotor and a stator, Fig. 4 is a diagram showing an electric circuit provided in the rotor, Fig. 5 is an exploded perspective view of the rotor, Fig. 6 is a perspective view showing an exploded winding unit in the rotor main section, Fig. 7 is a cross-sectional view of the rotor main section, Fig. 8 is a perspective view showing an example configuration of a circuit module, and Fig. 9 is a diagram showing an electric circuit provided in the rotor. FIG. 10 is a diagram showing the configuration of a rotating electric machine, FIG. 11 is a diagram showing the configuration relating to the connection between a field winding and a circuit module, FIG. 12 is a diagram showing the configuration relating to the connection between a field winding and a circuit module, FIG. 13 is a front view of a stator, FIG. 14 is a front view of a conductor segment, FIG. 15 is a side view of a winding unit, and FIG. 16 is a view of the rotor main part as seen from one axial side.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wound-field rotating electric machine according to an embodiment of the present disclosure is used as a power source for driving electric vehicles such as electric vehicles and hybrid vehicles.

[0013] First, a control system including a rotating electric machine will be described with reference to Fig. 1. The control system includes 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 type synchronous machine. For example, the rotating electric machine 40, the inverter 20, and the control device 30 may be configured as an electromechanical integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be configured as a separate component.

[0014] The rotating electric machine 40 includes a housing 41, and a stator 50 and a rotor 60 housed in the housing 41. The rotating electric machine 40 of this embodiment is an inner rotor type rotating electric machine in which the rotor 60 is disposed radially inside the stator 50.

[0015] The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W that are arranged with an electrical angle offset of 120° from one another.

[0016] The rotor 60 includes a rotor core 61 and a field winding 70. The field winding 70 may be made of, for example, aluminum wire, which has a low specific gravity and is easily formed. The field winding 70 is not limited to aluminum wire, and may be made of, for example, copper wire or CNT (carbon nanotube). A rotating shaft 32 is attached to the center hole of the rotor core 61. The rotating shaft 32 is rotatably supported by bearings 42 and 43 in the housing 41.

[0017] As shown in FIG. 2 , the inverter 20 includes a series connection of upper-arm switches SUp, SVp, and SWp for U, V, and W phases and lower-arm switches SUn, SVn, and SWn for U, V, and W phases. First ends of U-, V-, and W-phase windings 52U, 52V, and 52W are connected to the connection points between the upper-arm switches SUp, SVp, and SWp and the lower-arm switches SUn, SVn, and SWn for each phase. Second ends of the U-, V-, and W-phase windings 52U, 52V, and 52W are connected at the neutral point. That is, in this embodiment, the stator winding 52 is star-connected. However, the stator winding 52 may also be delta-connected. In this embodiment, each of the switches SUp to SWn is, for example, an IGBT. A freewheel diode is connected in antiparallel to each of the switches SUp to SWn.

[0018] The collectors of the upper arm switches SUp, SVp, SWp of each phase are connected to the positive terminal of a DC power supply 10. The emitters of the lower arm switches SUn, SVn, SWn of each phase are connected to the negative terminal of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0019] Next, the stator 50 and the rotor 60 will be described with reference to FIG.

[0020] The stator 50 and the rotor 60 are both arranged coaxially with the rotating shaft 32. In the following description, the direction in which the rotating shaft 32 extends is referred to as the axial direction, the direction extending radially from the center of the rotating shaft 32 is referred to as the radial direction, and the direction extending circumferentially around the rotating shaft 32 is referred to as the circumferential direction.

[0021] The stator core 51 is made of laminated steel plates made of a soft magnetic material and has an annular back yoke 51a and multiple teeth 51b protruding radially inward from the back yoke 51a. Multiple slots 54 are formed between adjacent teeth 51b in the circumferential direction. The stator winding 52 is formed by accommodating the phase windings of each phase in a predetermined order in each of these slots 54. For example, the stator 50 may employ a segment coil structure using multiple conductor segments. However, the structure of the stator winding 52 is arbitrary.

[0022] 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 protrude radially outward from the cylindrical portion 61a. A field winding 70 is 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.

[0023] The field winding 70 includes a first winding portion 71 and a second winding portion 72. The first winding portion 71 is wound radially outward around each main pole portion 62, and the second winding portion 72 is wound radially inward relative to the first winding portion 71. In each main pole portion 62, the winding directions of the first winding portion 71 and the second winding portion 72 are the same. Furthermore, among circumferentially adjacent main pole portions 62, the winding direction of the winding portions 71, 72 wound around one is opposite to the winding direction of the winding portions 71, 72 wound around the other. Therefore, the magnetization directions of circumferentially adjacent main pole portions 62 are opposite to each other. In the rotor 60, the main pole portions 62 in the rotor core 61 and the field winding 70 wound around each main pole portion 62 form a plurality of magnetic poles (field poles) arranged circumferentially.

[0024] 4 shows an electrical circuit on the rotor 60 side, which includes the windings 71, 72 wound around the main pole 62. The first winding 71 and the second winding 72 are connected in series. A first capacitor 91 is connected across both ends of the second winding 72, and a second capacitor 92 is connected across both ends of the series connection of the first winding 71 and the second winding 72. The capacitors 91, 92 are, for example, ceramic capacitors or film capacitors.

[0025] A diode 93 serving as a rectifying element is connected between both ends of the series-connected body made up of the winding portions 71 and 72. That is, a first end of the first winding portion 71 is connected to the cathode of the diode 93, and a first end of the second winding portion 72 is connected to the second end of the first winding portion 71. The anode of the diode 93 is connected to the second end of the second winding portion 72. The electrical circuit of FIG. 4 can be modified, for example, by arranging capacitors in different positions in parallel with the winding portions 71 and 72, or by arranging diodes in different positions in parallel with the winding portions 71 and 72.

[0026] When a high-frequency excitation current flows through the stator winding 52, fluctuations occur in the magnetic circuit including the stator core 51 and the rotor core 61 due to the high-frequency components of the main magnetic flux. The fluctuations in the main magnetic flux generate induced voltages in each of the winding portions 71 and 72, inducing currents in each of the winding portions 71 and 72. If induced voltages of the same polarity are generated in each of the winding portions 71 and 72, the induced currents in each of the winding portions 71 and 72 do not cancel each other out, and the induced currents increase. Furthermore, the diode 93 rectifies the currents flowing through each of the winding portions 71 and 72 in one direction. As a result, a field current flows through the field winding 70 in the direction rectified by the diode 93, exciting the field winding 70.

[0027] 2, the control device 30 is mainly configured with a microcomputer (corresponding to a computer), which includes a processor and a memory. The control device 30 generates drive signals that turn on and off the switches SUp to SWn that constitute the inverter 20. Specifically, the control device 30 converts DC power output from the DC power supply 10 into AC power and supplies the AC power to the U-, V-, and W-phase windings 52U, 52V, and 52W. The control device 30 generates drive signals that turn on and off the switches SUp to SWn, and supplies the generated drive signals to the gates of the switches SUp to SWn.

[0028] The control device 30 turns on and off each of the switches SUp to SWn so that a composite current of the fundamental current and the high-frequency excitation current flows through each of the phase windings 52U, 52V, and 52W. The fundamental current is a current that mainly generates torque in the rotating electric machine 40. The high-frequency excitation current is a high-frequency current with a higher frequency than the fundamental current, and is a current that mainly excites the field winding 70. It is also possible to use a harmonic current as the high-frequency current. The phase currents flowing through the phase windings 52U, 52V, and 52W are shifted by 120 electrical degrees.

[0029] Next, the configuration of the rotor 60 will be described in more detail. Fig. 5 is an exploded perspective view of the rotor 60. Fig. 6 is an exploded perspective view of the winding unit 110 in the rotor main section 101, and Fig. 7 is a cross-sectional view showing the cross-sectional structure of a portion of the rotor main section 101.

[0030] The rotor 60 has a rotor main section 101 and a circuit module 102 provided at one end of the rotor main section 101 in the axial direction. As described in FIG. 3 , the rotor main section 101 includes the rotor core 61 and the field winding 70, and the rotating shaft 32 is attached to the center hole of the rotor core 61. The field winding 70 is made up of a plurality of winding units 110 arranged in the circumferential direction. The circuit module 102 is fixed to the rotating shaft 32 with the rotating shaft 32 inserted through the hollow portion. The circuit module 102 is provided at a position axially opposite a coil end of the field winding 70 that is axially outward of the rotor core 61.

[0031] The rotor main section 101 has a plurality of winding units 110, one for each magnetic pole of the rotor 60. Each winding unit 110 is formed in an annular shape with the axial direction as the longitudinal direction, and is assembled to the rotor core 61 with the main pole section 62 of the rotor core 61 inserted into its hollow section. In this embodiment, the winding units 110 form a "pole coil."

[0032] The winding unit 110 has a first coil module 111 that is located on the radially outer side when attached to the main pole portion 62, and a second coil module 112 that is located on the radially inner side. The first coil module 111 is a coil module that corresponds to the first winding portion 71, and the second coil module 112 is a coil module that corresponds to the second winding portion 72.

[0033] The first coil module 111 has an annular coil body 121 formed by multiple windings of a conductor material made of a rectangular wire in the circumferential and radial directions, and a thin plate-like insulator 122 provided integrally with the coil body 121. The insulator 122 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 121, and a portion that extends radially and covers the hollow portion of the coil body 121. In other words, the outer peripheral portion on the radially outer side and the inner peripheral portion and hollow portion of the coil body 121 are insulated and coated with the insulator 122.

[0034] The second coil module 112 has an annular coil body 123 formed by multiple windings of a conductor material made of a rectangular wire in the circumferential and radial directions, and a thin plate-like insulator 124 provided integrally with the coil body 123. The insulator 124 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 123, and a portion that extends radially and covers the hollow portion of the coil body 123. In other words, the outer peripheral portion on the radially outer side, the inner peripheral portion on the radially inner side, and the hollow portion of the coil body 123 are insulated and coated with the insulator 124.

[0035] The coil bodies 121 and 123 are air-core coils configured as, for example, α-winding coils. The flat wire used for the coil bodies 121 and 123 has a substantially rectangular cross section (specifically, a substantially rectangular shape) and is composed of a conductor portion made of aluminum or the like and an insulating layer covering the conductor portion. However, it is also possible to use a round wire with a circular cross section as the conductor material.

[0036] 7, in the first coil module 111, for example, the conductor wire is wound in two layers in the radial direction, while in the second coil module 112, the conductor wire is wound in six layers in the radial direction. Furthermore, the coil modules 111, 112 have different numbers of turns in the circumferential direction (in other words, the number of rows of conductor wire in the circumferential direction), with the number of turns being greater on the radially outer side than on the radially inner side. This improves the space factor of the field winding 70. Note that, ignoring the space factor, it is also possible to make the number of turns in the circumferential direction the same for all of the coil bodies 121, 123 arranged radially.

[0037] Furthermore, in the rotor main section 101, holding plates 125 and 126 are provided between the main pole sections 62 of the rotor core 61 to maintain the assembled state of the first coil module 111 and the second coil module 112 when these coil modules 111 and 112 are assembled to each main pole section 62. The holding plate 125 is attached to the radial outside of the first coil module 111, and the holding plate 126 is attached between the first coil module 111 and the second coil module 112.

[0038] 6 , in the winding unit 110 of each magnetic pole, two conductor ends 127 are drawn out in the axial direction from the first coil module 111, and six conductor ends 128 are drawn out in the axial direction from the second coil module 112. In each of the winding units 110 arranged in the circumferential direction, the conductor ends 127, 128 are joined to each other by welding or the like, so that the multiple first coil modules 111 provided in each main pole portion 62 are connected in series, and the multiple second coil modules 112 provided in each main pole portion 62 are connected in series.

[0039] The configuration for connecting the windings (coil modules 111, 112) of the main pole parts 62 arranged in the circumferential direction may be other than the configuration in which the conductor ends 127, 128 of the coil modules 111, 112 are joined together by welding or the like as described above. For example, a configuration in which the conductor wire is continuously wound around the multiple main pole parts 62 so as to straddle the multiple main pole parts 62 (continuous winding configuration) may be used.

[0040] 8 is a perspective view showing an example configuration of the circuit module 102. The circuit module 102 has a component holder 130 made of an electrically insulating material. Specifically, the component holder 130 is a resin molded body made of a resin material. The component holder 130 is generally disk-shaped with a central hole 131 in the center. The component holder 130 is configured to be assembled to the rotating shaft 32 with the rotating shaft 32 inserted through the central hole 131.

[0041] The component holder 130 is provided with a plurality of housing sections 132 surrounding a central hole 131 for housing the capacitors 91, 92 and the diode 93. In the configuration shown in FIG. 8 , for example, five of the six housing sections 132 house the capacitors 91, 92, and the remaining housing section 132 houses the diode 93. In the component holder 130, the capacitors 91, 92 and the diode 93 are electrically connected by bus bars (not shown). In the component holder 130, the winding ends of the first coil module 111, which are both ends of the first winding section 71, and the winding ends of the second coil module 112, which are both ends of the second winding section 72, are electrically connected to an electric circuit including the capacitors 91, 92 and the diode 93 (see FIG. 4 ).

[0042] Incidentally, a configuration is conceivable in which the connection portions between the ends of the conductors extending from each winding unit 110 are provided in the region between the circuit module 102 (component holder 130) and the field winding 70. In this case, to avoid interference between the circuit module 102 and the ends of the conductors of each winding unit 110, it becomes necessary to increase the distance from the axial tip of each winding unit 110 (field winding 70) to the circuit module 102, which raises concerns that this may increase the physical size of the rotating electric machine 40.

[0043] For example, in rotor 60, if the electrical components mounted on circuit module 102 are made larger or the number of electrical components is increased, the area required to accommodate the electrical components in component holder 130 will increase, making it impossible to ensure an area for fixing the ends of the conductors extending from field winding 70. For this reason, the connection portions between the ends of the conductors of each winding unit 110 will be provided in an area between circuit module 102 and field winding 70. This configuration will be explained using FIG. 9, which is a schematic diagram of rotating electric machine 40.

[0044] In Fig. 9, the conductor ends of the coil modules 111, 112 of each magnetic pole are joined together in a region between the circuit module 102 and the field winding 70 on one of the axial sides of the rotor 60. The coil modules 111, 112 of each magnetic pole are electrically connected to each other by this joining of the conductor ends. In Fig. 9, the portion where the coil modules 111, 112 are electrically connected to each other, i.e., the portion including the conductor ends of the coil modules 111, 112 and the joint between the conductor ends, is referred to as a "conductor connection portion CN." The coil modules 111, 112 provided for each main pole 62 are connected to each other via the conductor connection portion CN.

[0045] 9 , in order to avoid interference between the circuit module 102 and the conductor connection part CN, it is necessary to increase the distance from the axial end of the field winding 70 to the circuit module 102. This increases the axial length of one side of the rotor 60, which may result in an increase in the size of the rotating electric machine 40.

[0046] 10 , the present embodiment is configured such that a circuit module 102 is provided on one axial end, that is, a first end X1 (left side of the figure), of the rotor core 61, and a conductor connection portion CN is provided on the other axial end, that is, a second end X2 (right side of the figure), of the rotor core 61. This avoids interference between the circuit module 102 and the conductor connection portion CN, while also reducing the size of the rotating electric machine 40. The specific configuration will be described below.

[0047] FIG. 11 is a diagram schematically illustrating a configuration related to the connection between the field winding 70 (winding portions 71, 72) and the circuit module 102 in a comparative example. FIG. 12 is a diagram schematically illustrating a configuration related to the connection between the field winding 70 (winding portions 71, 72) and the circuit module 102 in this embodiment. In FIGS. 11 and 12 , a plurality of first coil modules 111 constituting the first winding portion 71 and a plurality of second coil modules 112 constituting the second winding portion 72 are shown aligned side by side. In FIGS. 11 and 12 , the vertical direction is the axial direction of the rotor 60, with the upper side of each winding portion 71, 72 being the first end X1 side, and the lower side of each winding portion 71, 72 being the second end X2 side.

[0048] 11 , which is a comparative example, in the coil modules 111 and 112 of each main pole portion 62, the conductor ends are drawn out to the first end X1, which is one axial side, and the conductor ends of the different coil modules 111 and 112 are connected to each other to form a conductor connection portion CN. Also, a circuit module 102 is provided on the same first end X1 side.

[0049] In this comparative example, the rotating electric machine 40 has the configuration shown in Fig. 9. In this case, the conductor connection portions CN of each of the coil modules 111, 112 and the circuit module 102 are provided on the first end X1 side of the rotor 60, so that the conductor connection portions CN of each of the coil modules 111, 112 and the circuit module 102 are arranged side by side in the axial direction. Therefore, there is a concern that the circuit module 102 may protrude in the axial direction beyond the first coil end SE1 of the stator coil ends at both axial ends of the stator winding 52.

[0050] 12 , in each of the coil modules 111, 112 of each main pole portion 62, a circuit module 102 is provided on the first end X1 side, which is one axial side. Furthermore, the conductor ends are drawn out to the second end X2 side, which is the other axial side, and the conductor ends of the different coil modules 111, 112 are connected to each other to form a conductor connection part CN. In this case, of the conductor ends of each of the coil modules 111, 112 provided for each main pole portion 62, only the conductor ends that form both ends of the first winding portion 71 and the conductor ends that form both ends of the second winding portion 72 are drawn out to the first end X1 side (the opposite axial side from the conductor connection part CN) and connected to the circuit module 102.

[0051] In this embodiment, the rotating electric machine 40 has the configuration shown in Fig. 10. In this case, the circuit module 102 and the wire connection portions CN of the coil modules 111, 112 are provided separately on the first end X1 side and the second end X2 side of the rotor 60. This prevents the axial length of the rotor 60 from becoming longer on one side in the axial direction.

[0052] Here, on the first end X1 side, if the axial dimension from the axial end face of the rotor core 61 to the tip end of the circuit module 102 on the side opposite the rotor core is L1 and the axial height of the first coil end SE1 of the stator winding 52 is H1, these L1 and H1 satisfy the relationship L1≦H1. This prevents the circuit module 102 from protruding axially beyond the first coil end SE1 of the stator 50.

[0053] The tip of the circuit module 102 on the side opposite the rotor core is, for example, the axial end face of the component holder 130 on the side opposite the rotor core. A plate-shaped cover (a cover that covers the electrical components) may be attached to the axial end face of the component holder 130 on the side opposite the rotor core. If a cover is attached to the component holder 130, the tip of the circuit module 102 on the side opposite the rotor core may be the axial end face of the cover on the side opposite the rotor core.

[0054] Furthermore, on the second end X2 side, if the axial dimension from the axial end face of the rotor core 61 to the tip of the conductor connection portion CN on the side opposite the rotor core is L2 and the axial height of the second coil end SE2 of the stator winding 52 is H2, then L2 and H2 satisfy the relationship L2≦H2. This prevents the conductor connection portion CN from protruding axially beyond the second coil end SE2 of the stator 50.

[0055] The stator 50 has a stator winding 52 with a segmented structure, and its configuration will be described with reference to Fig. 13. In the stator 50, the stator winding 52, which is made up of a plurality of conductor segments 151, is wound around a stator core 51. As shown in Fig. 14, each conductor segment 151 is formed by folding a conductor wire material back into a generally U-shape, with the two end portions opposite the folded portion being bent in the circumferential direction. In each conductor segment 151, the folded end side is a turn portion 152, and both ends opposite the turn portion 152 are conductor wire end portions 153. The conductor segments 151 correspond to the "conductor wire material for the stator winding."

[0056] The conductor segments 151 are inserted into the slots 54 with the turn portions 152 at one axial end, and in this state, different conductor segments are connected to each other at conductor wire ends 153 on the opposite side from the turn portions 152. As a result, on one of the axial ends of the stator winding 52 (lower side in FIG. 13 ), a second coil end SE2 is formed by the turn portions 152 of the conductor segments 151, and on the other side (upper side in FIG. 13 ), a first coil end SE1 is formed by joining the conductor wire ends 153 of the conductor segments 151. In other words, the first coil end SE1 has a joint where the ends of the conductor segments 151 are joined, while the second coil end SE2 does not have a joint where the ends of the conductor segments 151 are joined.

[0057] In this case, the coil end heights of the coil ends SE1 and SE2 differ from the axial end face of the stator core 51, with the coil end height being relatively higher on the first coil end SE1 side. As explained in Figure 10, if the axial height of the first coil end SE1 is H1 and the axial height of the second coil end SE2 is H2, then H1 > H2.

[0058] On the other hand, it is assumed that the axial thickness dimension of the circuit module 102 is larger than the axial dimension of the conductor connection portion CN. For example, if the electrical components in the circuit module 102 are increased in size or the number of components is increased, the thickness dimension of the circuit module 102 may increase.

[0059] 10 , the first end X1 where the circuit module 102 is provided is the first coil end SE1 of the stator winding 52, and the second end X2 where the conductor connection portions CN of each coil module 111, 112 are provided is the second coil end SE2 of the stator winding 52. In this case, by arranging the circuit module 102 on the inner circumferential side of the first coil end SE1, which is the higher of the coil ends SE1, SE2 of the stator winding 52, the circuit module 102 is suitably prevented from protruding axially from the first coil end SE1 of the stator 50.

[0060] The configuration of the conductor connection portion CN on the second end X2 side of the rotor 60 will be further described with reference to Figures 15 and 16. Figure 15 is a side view of the winding unit 110, and Figure 16 is a view of the rotor main section 101 as viewed from the second end X2 side in the axial direction.

[0061] In the field winding 70, the coil modules 111, 112 (winding units 110) that make up the pole coils have a larger number of turns of wire material on the radially outer side than on the radially inner side (see FIG. 7). Therefore, as shown in FIG. 15, when the winding unit 110 is viewed from the side, the coil end height from the axial end face of the rotor core 61 is relatively high on the radially outer side of the field winding 70 (left side of the figure), and the coil end height is relatively low on the radially inner side (right side of the figure). In other words, the coil end height of the coil end portion CE of the field winding 70 is higher on the radially outer side than on the radially inner side.

[0062] As shown in FIG. 16, on the second end X2 side of the rotor main section 101, for example, the conductor end portions 127 of the first coil modules 111 are arranged for each magnetic pole from the radially outer side toward the radially inner side.

[0063] For these reasons, as shown in FIG. 15 , in the coil end portion CE on the second end X2 side, the conductor connection portion CN is preferably arranged using the inner space that is more inward than the highest coil end portion. That is, in the winding unit 110, the conductor end portion 127 extends along the slope of the axial end surface of the coil end portion CE, and is arranged so that, as viewed in the axial direction, it slopes toward the axial center as it moves radially inward. Furthermore, the conductor end portion 127 is bent axially at its radially innermost portion, and this bent portion serves as a joint for joining other conductor end portions 127, etc. In this case, the conductor connection portion CN that connects the coil modules 111, 112 of different magnetic poles to each other is preferably arranged in the inner space that is recessed in a substantially conical shape in the coil end portion CE on the second end X2 side. This makes it possible to reduce the axial dimension from the axial end surface of the rotor core 61 to the tip of the conductor connection portion CN on the opposite side of the rotor core on the second end X2 side.

[0064] In addition, only a portion of the conductor connection portion CN may be arranged in the inner space that is recessed in an approximately conical shape in the coil end portion CE, or the entire portion may be arranged in the inner space that is recessed in an approximately conical shape in the coil end portion CE.

[0065] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0066] The circuit module 102 is provided on the first end X1, which is one axial end of the rotor core 61, and the conductor connection portion CN is provided on the second end X2, which is the other axial end of the rotor core 61. This configuration prevents interference between the circuit module 102 and the conductor connection portion CN. Furthermore, in a rotating electric machine 40 in which the rotor 60 and the stator 50 are disposed radially opposite each other, the circuit module 102 is prevented from protruding axially outward from the stator windings 52. As a result, the size of the rotating electric machine 40 can be reduced.

[0067] At the first end X1 of the rotor 60, the axial dimension from the axial end face of the rotor core 61 to the tip of the circuit module 102 on the side opposite the rotor core is set to be equal to or less than the axial height of the stator coil end (SE1) at the first end X1. This makes it possible to reduce the size of the rotor 60 at the first end X1.

[0068] At the second end X2 of the rotor 60, the axial dimension from the axial end face of the rotor core 61 to the tip of the conductor connection part CN on the opposite side from the rotor core is set to be equal to or less than the axial height of the stator coil end (SE2) at the second end X2. This makes it possible to reduce the size of the rotor 60 at the second end X2.

[0069] The stator winding 52 has a joint at the first coil end SE1 of the stator 50 where the ends of the conductor segments 151 are joined, and does not have a joint at the second coil end SE2 where the ends of the conductor segments 151 are joined. The rotor 60 is oriented so that the first end X1 of the rotor core 61 is on the first coil end SE1 side of the stator winding 52 and the second end X2 of the rotor core 61 is on the second coil end SE2 side of the stator winding 52. In this case, the axial heights (axial length dimensions) of the first coil end SE1 and the second coil end SE2 of the stator winding 52 are different, with the first coil end SE1 being higher, but the circuit module 102 and the conductor connection portion CN of the field winding 70 can be appropriately positioned while taking into account the difference in axial height.

[0070] In each winding unit 110 of the field winding 70, the number of turns of the conductor material is increased on the radially outer side compared to the radially inner side, thereby increasing the space factor of the field winding 70. In this case, the coil end height of the field winding 70 is higher on the radially outer side compared to the radially inner side. In addition, in the coil end on the second end X2 side of the field winding 70, the conductor connection portion CN is arranged in at least a part of the inner space that is inner than the part where the coil end height is highest. This makes it possible to reduce the physical size of the rotor 60 on the second end X2 side.

[0071] (Other Embodiments) The above embodiment may be modified as follows, for example.

[0072] In the above embodiment, the conductor connection portion CN is formed by joining the ends of the conductor wires extending from the coil modules 111, 112 in the rotor 60, but this may be modified. For example, in the rotor 60, the field winding 70 can be formed by continuously winding conductor wire around each of the main pole portions 62 arranged circumferentially. In this case, the pole coil is wound around each main pole portion 62 by continuous winding, and the crossover portion of the conductor wire connecting the pole coils for each main pole portion 62 becomes the "conductor connection portion CN."

[0073] When the conductor connection portion CN is formed by joining the ends of the conductors extending from the coil modules 111, 112, the conductor connection portion CN can be referred to as an "inter-winding connection portion." When the crossover wire connecting the winding portions of each main pole portion 62 serves as the conductor connection portion CN, the conductor connection portion CN can be referred to as an "inter-winding crossover portion."

[0074] The field winding 70 is not limited to a configuration including the first winding portion 71 and the second winding portion 72. For example, the field winding 70 may be configured such that the winding portions (pole coils) for each main pole portion 62 are connected in series without being divided into the first and second winding portions 71, 72. Furthermore, the field winding 70 may be configured such that a diode is connected to both ends thereof, or a diode and a capacitor are connected in parallel.

[0075] In other words, in the above embodiment, the pole coil of each magnetic pole is configured by a winding unit 110 consisting of two coil modules (first coil module 111 and second coil module 112) for each magnetic pole, but this may be changed so that the pole coil of each magnetic pole is configured by one coil module for each magnetic pole.

[0076] In the stator 50, the stator core may not be provided with teeth.

[0077] The rotating electric machine is not limited to a rotating electric machine used as an in-vehicle main engine, but may be, for example, a rotating electric machine used as an ISG (Integrated Starter Generator) that is both a motor and a generator.

[0078] The moving body on which the rotating electric machine system is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. Furthermore, the rotating electric machine system is not limited to a system mounted on a moving body, but may be a stationary system.

[0079] The technical concepts extracted from the above-described embodiments are described below. [Configuration 1] A wound-field rotating electric machine (40) including: a stator (50) having a stator winding (52), a rotor (60) having a rotor core (61) having a plurality of main pole portions (62) provided for each circumferentially arranged magnetic pole and protruding in the radial direction, and a field winding (70) wound around each of the main pole portions, and a circuit module (102) provided to be rotatable integrally with the rotor and having electrical components connected to the field winding, wherein the field winding has a plurality of pole coils (110) formed by winding a conductor material around each of the main pole portions, the pole coils of each main pole portion being electrically connected to each other via a conductor connecting portion (CN), and the circuit module is provided on a first end side, which is one axial end of the rotor core, and the conductor connecting portion is provided on a second end side, which is the other axial end of the rotor core. [Configuration 2] The wound-field rotating electric machine according to Configuration 1, wherein both axial ends of the stator winding are stator coil ends, and at the first end of the rotor, an axial dimension from an axial end face of the rotor core to a tip end of the circuit module on the side opposite the rotor core is equal to or less than an axial height of the stator coil end (SE1) at the first end. [Configuration 3] The wound-field rotating electric machine according to Configuration 1 or 2, wherein both axial ends of the stator winding are stator coil ends, and at the second end of the rotor, an axial dimension from an axial end face of the rotor core to a tip end of the conductor connection portion on the side opposite the rotor core is equal to or less than an axial height of the stator coil end (SE2) at the second end.[Configuration 4] A wound-field rotating electric machine according to any one of configurations 1 to 3, wherein in the stator winding, one of the stator coil ends at both axial ends is a first coil end (SE1) and the other is a second coil end (SE2), the first coil end has a joint where ends of the conductor wire for the stator winding are joined together, and the second coil end does not have a joint where ends of the conductor wire for the stator winding are joined together, and the rotor is oriented such that the first end side of the rotor core is on the side of the first coil end of the stator winding and the second end side of the rotor core is on the side of the second coil end of the stator winding. [Configuration 5] A wound-field rotating electric machine according to any one of configurations 1 to 4, wherein in the field winding, the pole coil has a larger number of turns of the wire material on the radially outer side than on the radially inner side, and the coil end of the field winding has a higher coil end height on the radially outer side than on the radially inner side, and the wire connecting portion is arranged in at least a part of an inner space that is on the inner circumferential side of the coil end on the second end side of the field winding, which is higher than the part where the coil end height is highest.

[0080] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A wound-field rotating electrical machine (40) comprising: a stator (50) having a stator winding (52); a rotor core (61) having a plurality of main pole portions (62) provided for each of the circumferentially arranged magnetic poles and protruding in the radial direction; a rotor (60) having a field winding (70) wound around each of the main pole portions; and a circuit module (102) provided so as to be rotatable integrally with the rotor and having an electrical component connected to the field winding, wherein the field winding has a plurality of pole coils (110) each formed by winding a conductor around each of the main pole portions, and the pole coils of each of the main pole portions are electrically connected to each other via a conductor connection portion (CN), and the circuit module is provided on a first end side which is one axial side of the rotor core, while the conductor connection portion is provided on a second end side which is the other axial side of the rotor core.

2. In the stator winding, both axial sides are stator coil ends, and in the first end side of the rotor, the axial dimension from the axial end face of the rotor core to the tip portion on the side opposite to the rotor core of the circuit module is equal to or less than the axial height of the stator coil end (SE1) on the first end side. The wound-field rotating electrical machine according to claim 1.

3. In the stator winding, both axial sides are stator coil ends, and in the second end side of the rotor, the axial dimension from the axial end face of the rotor core to the tip portion on the side opposite to the rotor core of the conductor connection portion is equal to or less than the axial height of the stator coil end (SE2) on the second end side. The wound-field rotating electrical machine according to claim 1 or 2.

4. In the stator winding, one of the stator coil ends at both axial ends is a first coil end (SE1), and the other is a second coil end (SE2). The first coil end has a joint portion where the ends of the conductor for the stator winding are joined, and the second coil end does not have a joint portion where the ends of the conductor for the stator winding are joined. The rotor is oriented such that the first end side of the rotor core is on the side of the first coil end of the stator winding, and the second end side of the rotor core is on the side of the second coil end of the stator winding. The wound-field rotating electrical machine according to claim 1.

5. In the field winding, in the pole coil, the number of turns of the conductor material is larger on the radially outer side than on the radially inner side, and the coil end height of the field winding is higher on the radially outer side than on the radially inner side. At least a part of the inner space, which is on the inner peripheral side of the part where the coil end height is the highest, is provided with the conductor connection part at the coil end on the second end side of the field winding. The wound-field type rotating electrical machine according to claim 1.

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