Wound-field type rotary electric machine

Abstract

To suppress occurrence of trouble caused by a centrifugal force in a circuit module which is rotated integrally with a rotor.SOLUTION: In a wound-field type rotary electric machine, a rotor 60 comprises a rotor core including a main pole part, which is provided for each of magnetic poles arranged side by side in a circumferential direction, and a field winding which is wound around the main pole part. A circuit module 102 includes a first capacitor 91, which is connected to the field winding, and provided so as to be rotatable integrally with the rotor 60. The first capacitor 91 is a laminated capacitor in which a dielectric 151 and an internal electrode 152 are laminated, and disposed in the circuit module 102 in such a direction that a lamination direction of the dielectric 151 and the internal electrode 152 is orthogonal to a radial direction of the rotor 60.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The disclosure in this specification relates to a wound field type rotating electric machine. [Background technology]

[0002] In a wound-field type rotating electric machine, the rotor has a rotor core having a plurality of main poles (magnetic salient poles) provided for each of the magnetic poles arranged in the circumferential direction, and a field winding wound around the main poles. A configuration is also known in which a circuit module is provided as an electric component at the axial end of the rotor (see, for example, Patent Document 1). The circuit module has a capacitor, and the field winding and the capacitor form a resonant circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-124100 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, in a configuration in which a circuit module having a capacitor is provided at the axial end of the rotor in a wound-field type rotating electric machine, the circuit module rotates integrally with the rotor when the rotor rotates. In this case, there is a concern that the capacitor may be deformed due to the centrifugal force of the rotation. Specifically, when a multilayer capacitor is used and the dielectric and the electrodes are stacked in the radial direction, centrifugal force acts in the stacking direction. This may cause deformation of the dielectric layer and the electrode layer, leading to defects such as cracks. The multilayer capacitor is considered to be composed of a laminate of thin films, and there is a concern that the thin films may be bent or damaged if centrifugal force acts in the stacking direction.

[0005] The present disclosure has been made in consideration of the above circumstances, and aims to provide a wound-field type rotating electric machine that can suppress the occurrence of capacitor malfunctions caused by centrifugal force in a circuit module that rotates integrally with the rotor. [Means for solving the problem]

[0006] The present disclosure relates to a stator having stator windings; a rotor having a rotor core having main pole portions provided for the magnetic poles arranged in the circumferential direction and protruding in the radial direction, and a field winding wound around the main pole portions, A wound-field type rotating electric machine in which a high-frequency current for inducing a field current in the field winding flows in the stator winding, a circuit module provided so as to be rotatable integrally with the rotor and having a capacitor connected to the field winding; The capacitor is a multilayer capacitor in which a dielectric and electrodes are laminated, and is arranged in the circuit module such that the lamination direction of the dielectric and the electrodes is perpendicular to the radial direction of the rotor.

[0007] In a wound-field type rotating electric machine, in a configuration in which a circuit module having a stacked capacitor is provided so as to be rotatable integrally with the rotor, there is concern that malfunctions may occur due to centrifugal force in relation to the stacking direction of the capacitor. In consideration of this point, the capacitor is configured so that the stacking direction of the dielectric and electrodes is oriented perpendicular to the radial direction of the rotor. In this case, bending due to centrifugal force inside the capacitor is suppressed. As a result, it is possible to suppress malfunctions of the capacitor due to centrifugal force in a circuit module that rotates integrally with the rotor. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an overall configuration diagram of a control system for a rotating electric machine. [Diagram 2] FIG. 2 is a diagram showing an inverter and its peripheral configuration. [Diagram 3] FIG. [Figure 4] FIG. 4 is a diagram showing an electric circuit provided in the rotor. [Diagram 5] FIG. 2 is a perspective view showing the overall configuration of a rotor. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 4 is an exploded perspective view of a winding unit in the rotor main portion. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] FIG. [Figure 12] FIG. 4 is a perspective view showing an arrangement of capacitors and diodes. [Figure 13] FIG. [Figure 14] FIG. 4 is a perspective view showing an arrangement of capacitors, diodes, and bus bars. [Figure 15] FIG. 4 is a vertical cross-sectional view showing a schematic arrangement of capacitors in a circuit module. [Figure 16] FIG. 4 is a vertical cross-sectional view showing the capacitor after being resin-molded. [Figure 17] FIG. 4 is a vertical cross-sectional view showing a schematic arrangement of capacitors in a circuit module. [Figure 18] FIG. 4 is a plan view showing an arrangement of capacitors and bus bars arranged in the circumferential direction. [Figure 19] FIG. 4 is a vertical cross-sectional view showing the capacitor after being resin-molded. [Figure 20] FIG. 4 is a plan view showing an arrangement of capacitors arranged in the circumferential direction. [Figure 21] FIG. 4 is a plan view showing an arrangement of capacitors arranged in the circumferential direction. [Figure 22] FIG. 4 is a front view showing an arrangement of capacitors arranged in the circumferential direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotating electric machine according to an embodiment of the present disclosure will now be described with reference to the drawings.

[0010] 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 wound-field type synchronous machine. For example, the rotating electric machine 40, the inverter 20, and the control device 30 may be configured as a mechanically and electrically integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be configured with a respective component.

[0011] 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.

[0012] The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, a copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W that are arranged offset from each other by 120° in electrical angle.

[0013] The rotor 60 includes a rotor core 61 and a field winding 70. The field winding 70 may be made of, for example, an aluminum wire that has a low specific gravity and is easy to form. The field winding 70 is not limited to an aluminum wire, and may be made of, for example, a copper wire or a CNT (carbon nanotube). A rotating shaft 32 is attached to the central hole of the rotor core 61. The rotating shaft 32 is rotatably supported by the housing 41 via bearings 42 and 43.

[0014] As shown in FIG. 2, the inverter 20 includes a series connection of upper arm switches SUp, SVp, SWp of U, V, and W phases and lower arm switches SUn, SVn, SWn of U, V, and W phases. First ends of U, V, and W phase windings 52U, 52V, and 52W are connected to the connection points of the upper arm switches SUp, SVp, and SWp and the lower arm switches SUn, SVn, and SWn in 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 be delta-connected. In this embodiment, each switch SUp to SWn is an IGBT. A freewheel diode is connected in inverse parallel to each switch SUp to SWn.

[0015] The collectors of the upper arm switches SUp, SVp, SWp of each phase are connected to the positive terminal of the 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.

[0016] Next, the stator 50 and the rotor 60 will be described with reference to FIG.

[0017] 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.

[0018] 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 protruding 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 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 have a segment coil structure using a plurality of conductor segments. However, the structure of the stator winding 52 is arbitrary.

[0019] 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 protruding 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.

[0020] The field winding 70 includes a first winding portion 71a and a second winding portion 71b. The first winding portion 71a is wound around each main pole portion 62 on the radially outer side, and the second winding portion 71b is wound around each main pole portion 62 on the radially inner side of the first winding portion 71a. In each main pole portion 62, the winding directions of the first winding portion 71a and the second winding portion 71b are the same. In addition, among the main pole portions 62 adjacent in the circumferential direction, the winding directions of the winding portions 71a and 71b wound around one of the main pole portions 62 are opposite to the winding directions of the winding portions 71a and 71b wound around the other of the main pole portions 62. Therefore, the magnetization directions of the main pole portions 62 adjacent in the circumferential direction 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 of the main pole portions 62 form a plurality of magnetic poles (field poles) arranged in the circumferential direction.

[0021] FIG. 4 shows an electric circuit on the rotor 60 side including the winding parts 71a and 71b wound around the main pole part 62. The first winding part 71a and the second winding part 71b are connected in series, and a capacitor part CC consisting of a plurality of first capacitors 91 is connected in parallel to the second winding part 71b. In this embodiment, the capacitor part CC is configured as a parallel connection of, for example, eleven first capacitors 91. In addition, a second capacitor 92 is connected in parallel to the series connection of the first winding part 71a and the second winding part 71b. The second capacitor 92 is provided for noise suppression. In this embodiment, one second capacitor 92 is provided. The first capacitor 91 and the second capacitor 92 are multilayer ceramic capacitors and have the same configuration.

[0022] A diode 93 is connected as a rectifying element between both ends of the series-connected body consisting of the windings 71a and 71b. That is, a first end of the first winding 71a is connected to the cathode of the diode 93, and a first end of the second winding 71b is connected to the second end of the first winding 71a. An anode of the diode 93 is connected to the second end of the second winding 71b.

[0023] In this embodiment, a series resonant circuit is formed by the first winding portion 71a, the first capacitor 91, and the diode 93, and a parallel resonant circuit is formed by the second winding portion 71b and the first capacitor 91. If a first resonant frequency which is a resonant frequency of the series resonant circuit is f1 and a second resonant frequency which is a resonant frequency of the parallel resonant circuit is f2, these resonant frequencies f1 and f2 are expressed by the following equations (1) and (2). L1 is the inductance of the first winding portion 71a, L2 is the inductance of the second winding portion 71b, and C is the capacitance of the first capacitor 91. f1=1 / (2π√(L1×C)) …(1) f2=1 / (2π√(L2×C)) …(2) When a high-frequency excitation current flows through the stator winding 52, a fluctuation occurs in the magnetic circuit including the stator core 51 and the rotor core 61 due to the high-frequency component of the main magnetic flux. The fluctuation in the main magnetic flux generates an induced voltage in each of the winding parts 71a, 71b, and a current is induced in each of the winding parts 71a, 71b. At this time, if an induced voltage of the same polarity occurs in each of the winding parts 71a, 71b, the induced currents in the winding parts 71a, 71b are not offset, and the induced current increases. The current flowing through each of the winding parts 71a, 71b is rectified in one direction by the diode 93. As a result, a field current flows through the field winding 70 in the direction rectified by the diode 93, and the field winding 70 is excited.

[0024] Returning to the explanation of Fig. 2, the control device 30 is mainly configured with a microcomputer (corresponding to a computer), and the microcomputer has a CPU. The control device 30 generates drive signals that turn on and off each of the switches SUp to SWn that configure the inverter 20. In detail, the control device 30 generates drive signals that turn on and off each of the switches SUp to SWn in order to convert the DC power output from the DC power source 10 into AC power and supply it to the U-, V-, and W-phase windings 52U, 52V, and 52W, and supplies the generated drive signals to the gates of each of the switches SUp to SWn.

[0025] The control device 30 turns on and off each of the switches SUp to SWn so that a composite current of a fundamental current and a high-frequency excitation current flows through each of the phase windings 52U, 52V, 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, 52W are shifted by 120° in electrical angle.

[0026] Next, a more detailed description will be given of the configuration of the rotor 60. Fig. 5 is a perspective view showing the overall configuration of the rotor 60, Fig. 6 is an exploded perspective view of the rotor 60, and Fig. 7 is a vertical cross-sectional view of the rotor 60.

[0027] The rotor 60 is roughly divided into a rotor main part 101, a circuit module 102 provided at one of both axial ends of the rotor main part 101, and coil end covers 103, 104 as annular members attached to one axial end and the other axial end of the rotor main part 101. The rotor main part 101 includes a rotor core 61 and a field winding 70 as described in FIG. 3, and a rotating shaft 32 is attached to the central hole of the rotor core 61. The field winding 70 is made up of a plurality of winding units 110 arranged in a circumferential direction. The circuit module 102 is fixed to the rotating shaft 32 with the rotating shaft 32 inserted through the hollow part. As shown in FIG. 7, in the field winding 70 (winding unit 110), a portion radially facing the rotor core 61 is a coil side portion CS, and a portion axially outward of the rotor core 61 is a coil end portion CE. The circuit module 102 is provided at a position axially opposite to the coil end portion CE of the field winding 70.

[0028] Fig. 8 is an exploded perspective view of the winding unit 110 in the rotor main part 101, and Fig. 9 is a cross-sectional view showing the cross-sectional structure of a portion of the rotor main part 101. The rotor main part 101 has a plurality of winding units 110 provided 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 part 62 of the rotor core 61 inserted into the hollow part.

[0029] The winding unit 110 has a first coil module 111 that is radially outward and a second coil module 112 that is radially inward when attached to the main pole portion 62. The first coil module 111 is a coil module that corresponds to the first winding portion 71a, and the second coil module 112 is a coil module that corresponds to the second winding portion 71b.

[0030] The first coil module 111 has an annular coil body 121 formed by multiple windings of a conductive wire 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 in the circumferential direction and covers the outer peripheral portions of the coil body 121 on the radially outer and inner sides, and a portion that extends in the radial direction 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.

[0031] The second coil module 112 has an annular coil body 123 formed by multiple windings of a conductive wire 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 in the circumferential direction and covers the outer peripheral portions of the coil body 123 on the radially outer and inner sides, and a portion that extends in the radial direction and covers the hollow portion of the coil body 123. In other words, the outer peripheral portion on the radially outer side and the inner peripheral portion and hollow portion of the coil body 123 are insulated and coated with the insulator 124.

[0032] The coil bodies 121 and 123 are air-core coils configured as, for example, α-wound coils. The flat wire used in the coil bodies 121 and 123 has a substantially rectangular cross-sectional shape (specifically, a substantially rectangular shape), and the flat wire is made of a conductor part made of aluminum or the like and an insulating layer covering the conductor part. However, it is also possible to use a round wire having a circular cross-sectional shape as the conductor material.

[0033] As shown in Fig. 9, in the first coil module 111, the conductive wire is wound in two layers in the radial direction, and in the second coil module 112, the conductive wire is wound in six layers in the radial direction. In addition, the coil modules 111, 112 have different numbers of turns in the circumferential direction (in other words, the number of rows of the conductive 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 in the radial direction.

[0034] Furthermore, in the rotor main section 101, holding plates 125, 126 are provided between the main pole sections 62 of the rotor core 61 to hold the first coil module 111 and the second coil module 112 in an assembled state when the first coil module 111 and the second coil module 112 are assembled to the main pole sections 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.

[0035] As shown in Fig. 6, the rotor 60 has a coil end ring 81 that is attached to an axial end of the winding unit 110. As shown in Fig. 7, the coil end ring 81 is disposed between the coil end portion of the first coil module 111 and the coil end portion of the second coil module 112 in the radial direction, and is sandwiched between the retaining plate 126 and the coil end cover 103 in the axial direction.

[0036] Next, the circuit module 102 will be described with reference to FIGS.

[0037] The circuit module 102 includes a first capacitor 91, a second capacitor 92, a diode 93, a component holder 130, a first bus bar 141, a second bus bar 142, and a third bus bar 143. The component holder 130 is made of an electrically insulating material such as synthetic resin.

[0038] As shown in Fig. 11, the part holder 130 includes a main body 131 having an annular shape. The main body 131 includes a bottom plate 131a having a C-shape, an outer peripheral wall 131b extending in the axial direction from a radially outer end of the bottom plate 131a, and an inner peripheral wall 131c extending in the axial direction from a radially inner end of the bottom plate 131a. The main body 131 also includes a first side wall 131d extending in the axial direction from one end of the circumferential end of the bottom plate 131a, and a second side wall 131e extending in the axial direction from the other end of the circumferential end of the bottom plate 131a. The wall height (height dimension in the axial direction) of each of the walls 131b to 131e is greater than the height dimensions of the first capacitor 91 and the second capacitor 92.

[0039] In the main body 131, a storage section 132 which is a C-shaped space is formed by a bottom plate section 131a and each of the walls 131b to 131e, and the first capacitor 91 and the second capacitor 92 are stored in the storage section 132. Note that, within the above-mentioned space, a partition section 131f which separates the storage space for the first capacitor 91 from the space for the second condenser 92 is formed so as to extend in the axial direction from the bottom plate section 131a.

[0040] A central hole 133 through which the rotary shaft 32 is inserted is formed in the main body 131. Specifically, the central hole 133 is formed by the inner peripheral surface of the inner peripheral wall portion 131c.

[0041] The component holder 130 includes an element mounting portion 134 on which the diode 93 is provided. The element mounting portion 134 extends radially outward from a circumferential position of the inner circumferential wall portion 131c where the outer circumferential wall portion 131b is not provided. The element mounting portion 134 also extends radially outward from a middle position in the axial direction of the inner circumferential wall portion 131c. The diode 93 is fixed to the element mounting portion 134 by a fastener such as a bolt.

[0042] The component holder 130 has a plurality of winding fixing portions 135 that protrude radially outward from the main body portion 131. In this embodiment, the number of winding fixing portions 135 provided is the same as the number of main pole portions 62, specifically, eight winding fixing portions 135 provided at equal intervals in the circumferential direction. Each winding fixing portion 135 extends radially outward from a middle position in the axial direction of the outer circumferential wall portion 131b.

[0043] Each winding fixing portion 135 is formed with a plurality of insertion holes 136 penetrating in the axial direction. As shown in Fig. 8, in the rotor main portion 101, in each winding unit 110, two conductor ends 127 are drawn out from the axial end of the first coil module 111, and six conductor ends 128 are drawn out from the axial end of the second coil module 112. In the first coil module 111, the first winding portion 71a is formed of one air-core coil, so two conductor ends 127 are drawn out, and in the second coil module 112, the second winding portion 71b is formed of three air-core coils aligned in the radial direction, so six conductor ends 128 are drawn out.

[0044] Then, with the conductor ends 127 of two circumferentially adjacent first coil modules 111 inserted one by one into the insertion holes 136, the conductor ends 127 are connected to each other by welding or the like, so that the first coil modules 111 in the circumferential direction are connected in series. Also, with the conductor ends 128 of two circumferentially adjacent second coil modules 112 inserted one by one into the insertion holes 136, the conductor ends 128 are connected to each other by welding or the like, so that the second coil modules 112 in the circumferential direction are connected in series.

[0045] 12 to 14, eleven first condensers 91 and one second condenser 92 are arranged in an annular shape on an imaginary circle centered on the axis J of the rotor 60. Each of the condensers 91, 92 has a rectangular parallelepiped or cubic shape.

[0046] A first bus bar 141 having an arc shape (specifically, C-shape) is electrically connected to a first terminal of each of the first capacitors 91. A second bus bar 142 having an arc shape (specifically, C-shape) is electrically connected to a second terminal of each of the first capacitors 91 and the second capacitor 92. A third bus bar 143 having an arc shape is electrically connected to a first terminal of the second capacitor 92. The third bus bar 143 is a separate member from the first bus bar 141, and is disposed at a distance from the first bus bar 141. When the rotor 60 is viewed from the axial direction, the bus bars 141 to 143 are disposed so as to form an annular shape around the axis J.

[0047] Each of the busbars 141 to 143 is a plate-shaped wiring member, and is provided with its plate surface oriented in the axial direction. In this embodiment, the first busbar 141 and the third busbar 143 are provided side by side in the circumferential direction, and the second busbar 142 is provided so as to face the busbars 141, 143 in the axial direction. Then, each of the first capacitors 91 is arranged between the first busbar 141 and the second busbar 142, and the second capacitor 92 is arranged between the third busbar 143 and the second busbar 142.

[0048] The first busbar 141 is provided with a first connection terminal 141a electrically connected to a second end of the first winding portion 71a and a first end of the second winding portion 71b. The second busbar 142 is provided with a second connection terminal 142a electrically connected to a second end of the second winding portion 71b and the anode of the diode 93. The third busbar 143 is provided with a third connection terminal 143a electrically connected to the first end of the first winding portion 71a and the cathode of the diode 93.

[0049] Incidentally, when the rotor 60 rotates, the circuit module 102 rotates together with the rotor 60. In this case, there is concern that the capacitors 91, 92, which are multilayer ceramic capacitors (multilayer type capacitors), may have defects due to centrifugal force in relation to the lamination direction. Specifically, if the lamination direction of the capacitors 91, 92 in the circuit module 102 is the radial direction, there is concern that the dielectric layers and electrode layers of the capacitors 91, 92 may be deformed, leading to defects such as cracks. Therefore, in this embodiment, the lamination direction of the capacitors 91, 92 is set to a specific direction, thereby suppressing deformation of the capacitors 91, 92 due to centrifugal force when the rotor rotates.

[0050] Fig. 15 is a diagram showing a schematic arrangement of the first capacitors 91 in the circuit module 102. In Fig. 15, the up-down direction is the axial direction, and the lower side of the figure is the field winding 70 side. Moreover, in Fig. 15, the left-right direction is the radial direction.

[0051] In component holder 130 of circuit module 102, a first bus bar 141 and a second bus bar 142 are arranged in axially opposing positions in accommodation section 132 formed in main body section 131, and a first capacitor 91 is arranged between these bus bars 141, 142. First capacitor 91 has dielectric 151, a plurality of internal electrodes 152 embedded in dielectric 151 at predetermined intervals, and a pair of external electrodes 153 electrically connected to internal electrode 152. Internal electrodes 152 are thin-film shaped and arranged parallel to each other.

[0052] The first capacitor 91 has a laminated structure in which the dielectric 151 and the internal electrodes 152 are alternately laminated, and the external electrodes 153 on both sides are alternately connected to the multiple internal electrodes 152 arranged in the lamination direction. Specifically, in the first capacitor 91, the ends of the multiple internal electrodes 152 are exposed on a pair of opposing surfaces of the dielectric 151, and a pair of external electrodes 153 are connected to the exposed parts of the internal electrodes 152. In addition, one of the pair of external electrodes 153 is electrically connected to the first bus bar 141, and the other external electrode 153 is electrically connected to the second bus bar 142. The pair of external electrodes 153 correspond to the first terminal and the second terminal of the first capacitor 91. The first capacitor 91 is a multilayer ceramic chip capacitor.

[0053] The first capacitor 91 is arranged such that a pair of external electrodes 153 are oriented so as to be separated into inner and outer radial directions. Although a specific configuration is not shown, the external electrode 153 on the left side of the figure may be electrically connected to the first bus bar 141 and insulated from the second bus bar 142 by forming an electrical insulating layer between the external electrode 153 and the second bus bar 142. The external electrode 153 on the right side of the figure may be electrically connected to the second bus bar 142 and insulated from the first bus bar 141 by forming an electrical insulating layer between the external electrode 153 and the first bus bar 141.

[0054] In the circuit module 102, the first capacitor 91 is arranged such that the lamination direction of the dielectric 151 and the internal electrodes 152 is perpendicular to the radial direction of the rotor 60, i.e., the up-and-down direction (axial direction) in Fig. 15. In this case, in the first capacitor 91, the internal electrodes 152 aligned in the lamination direction are oriented to extend in the radial direction. This prevents inconvenience such as bending of the dielectric 151 and the internal electrodes 152 due to centrifugal force acting on the first capacitor 91 when the rotor 60 rotates.

[0055] It is preferable that the first capacitor 91 and each of the bus bars 141, 142 are joined to each other by a conductive adhesive. This provides an electrical connection and a mechanical connection between the first capacitor 91 and each of the bus bars 141, 142. In this case, it is possible to more effectively suppress movement (displacement) of the first capacitor 91 due to centrifugal force, compared to a configuration using solder, which is a common joining means.

[0056] Alternatively, outer electrode 153 of first capacitor 91 and each of bus bars 141, 142 may be joined to each other by welding, which can further increase the joining strength of first capacitor 91.

[0057] A detailed explanation of the second capacitor 92 will be omitted, but it has a configuration similar to that of the first capacitor 91, and is arranged in the circuit module 102 such that the lamination direction of the dielectric 151 and the internal electrode 152 is perpendicular to the radial direction of the rotor 60.

[0058] In the circuit module 102, the capacitors 91, 92 may be molded with a resin material. Specifically, as shown in FIG. 16(a), the resin material may be filled in the housing section 132 of the component holder 130 to form a resin molded section 161. The resin material may be, for example, a thermosetting resin such as an epoxy resin. In this case, the capacitors 91, 92 and the bus bars 141 to 143 are embedded in the resin molded section 161 in the housing section 132 of the component holder 130. In FIG. 16(a), the resin molded section 161 is formed with the capacitors 91, 92 entirely covered with the resin material in the housing section 132.

[0059] Also, as shown in FIG. 16(b), the resin molded portion 161 may be provided only on the radially outer side of each of the capacitors 91, 92. In other words, the inner peripheral portion of each of the capacitors 91, 92, which is the radially inner side, is not resin molded. If the entire capacitors 91, 92 are resin molded, the difference in linear expansion between the capacitors 91, 92 and the resin material will increase the thermal stress on the capacitors 91, 92, which may result in problems. In view of this, in the configuration of FIG. 16(b), the inner peripheral portion of each of the capacitors 91, 92, which is the radially inner side, is not resin molded.

[0060] 16(a) and 16(b), each of the capacitors 91, 92 is configured to be molded with a resin material in an area including at least the outer peripheral portion that is the radially outer side in the housing portion 132. This enhances the effect of suppressing defects caused by centrifugal force in each of the capacitors 91, 92.

[0061] The configuration of circuit module 102 may be changed as shown in Fig. 17. In Fig. 17, the positions of first bus bar 141 and second bus bar 142 in housing portion 132 are different from the configuration in Fig. 15, and these bus bars 141, 142 are arranged at positions facing each other in the radial direction. Specifically, first bus bar 141 and second bus bar 142 are arranged with the bus bar plate surfaces extending in the axial direction, with first bus bar 141 on the radial inner side and second bus bar 142 on the radial outer side, and first capacitor 91 is attached therebetween.

[0062] In the first capacitor 91, a pair of external electrodes 153 are arranged separately on the inside and outside in the radial direction, as in the case of Fig. 15. The lamination direction of the first capacitor 91 is perpendicular to the radial direction of the rotor 60, as in the case of Fig. 15. Although not shown, the second capacitor 92 may have a similar configuration.

[0063] Fig. 18 is a plan view showing a state in which the capacitors 91, 92 and the bus bars 141 to 143 of the configuration in Fig. 17 are arranged in the accommodation portion 132 of the component holder 130. In Fig. 18, the second bus bar 142 is arranged in an annular shape so as to surround all the capacitors 91, 92 from the radially outer side. The first bus bar 141 is arranged on the radially inner side with the first capacitor 91 in between, and the third bus bar 143 is arranged on the radially inner side with the second capacitor 92 in between. According to the configuration in Figs. 17 and 18, the second bus bar 142 is arranged so as to be in contact with the outer peripheral surfaces of the radially outer sides of the capacitors 91, 92, so that the centrifugal force acting on the capacitors 91, 92 can be supported by the second bus bar 142.

[0064] Further, the second bus bar 142 surrounds the capacitors 91, 92 arranged in the circumferential direction from the radial outside, and has a length of at least a semicircle in a plan view. As a result, when centrifugal force is generated in the capacitors 91, 92 arranged in the circumferential direction as the rotor 60 rotates, the centrifugal force acts from the capacitors 91, 92 in opposite radial directions on the second bus bar 142. In this case, the forces in the opposite directions from the capacitors 91, 92 prevent the second bus bar 142 from being displaced in the radial direction, and thus the positional deviation of the capacitors 91, 92 is prevented.

[0065] It is also possible that first bus bar 141 and third bus bar 143 are disposed radially outside of each of capacitors 91, 92, and second bus bar 142 is disposed radially inside of each of capacitors 91, 92.

[0066] Fig. 19 is a diagram showing a configuration in which first capacitor 91 is molded with a resin material in circuit module 102 shown in Fig. 17. In Fig. 19, resin molded portion 161 is provided only on the radially outer side in accommodation portion 132 of component holder 130. However, resin molded portion 161 may be formed so as to entirely cover first capacitor 91 and bus bars 141, 142 in accommodation portion 132 of component holder 130.

[0067] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0068] In the circuit module 102, the capacitors 91, 92 are arranged such that the lamination direction of the dielectric 151 and the internal electrode 152 is perpendicular to the radial direction of the rotor 60. In this case, bending due to centrifugal force is suppressed inside the capacitor. As a result, in the circuit module 102 which rotates integrally with the rotor 60, it is possible to suppress the occurrence of malfunctions of the capacitors 91, 92 due to centrifugal force.

[0069] Since each of the condensers 91, 92 is configured to be resin molded in an area including at least the outer circumferential side portion that is the radially outer side, it is possible to enhance the effect of suppressing defects in each of the condensers 91, 92 due to centrifugal force.

[0070] If the entire capacitors 91, 92 were resin-molded, the difference in linear expansion between the capacitors 91, 92 and the resin material would cause large thermal stress on the capacitors 91, 92, which could lead to problems. In view of this, the inner peripheral portions of the capacitors 91, 92 that are radially inward are not resin-molded. This makes it possible to increase the resistance of the capacitors 91, 92 to both centrifugal force and thermal stress.

[0071] In the circuit module 102, any one of the bus bars 141 to 143 is arranged so as to be in contact with the radially outer peripheral surface of each of the capacitors 91, 92. This allows the centrifugal force acting on each of the capacitors 91, 92 to be supported by the bus bars, thereby further increasing the resistance of the capacitors 91, 92 to the centrifugal force.

[0072] In circuit module 102, for example, second bus bar 142 surrounds each of capacitors 91, 92 arranged in the circumferential direction from the radial outside and has a length of at least a semicircle in a plan view. This makes it possible to prevent a problem such as a radially biased force acting on second bus bar 142 and causing displacement of second bus bar 142 during rotor rotation.

[0073] (Other embodiments) The above embodiment may be modified, for example, as follows.

[0074] In the rotating electric machine 40, if the circuit module 102 is provided at a position axially opposite to the coil end portion CE of the field winding 70, there is a concern that the heat from the field winding 70 will affect each of the capacitors 91, 92, causing a temperature difference inside the capacitor. In a multilayer capacitor, there is a concern that a temperature difference will occur inside the capacitor due to a difference in the way heat is transferred inside the capacitor in relation to the stacking direction. For example, if the dielectric 151 and the internal electrode 152 are stacked in the axial direction, a temperature difference is likely to occur inside the capacitor in the axial direction, and a relatively large expansion occurs in a portion close to the field winding 70. As a result, there is a concern that deformation due to thermal expansion will occur at the end of the capacitor on the high temperature side, leading to defects such as cracks.

[0075] In consideration of this, as shown in FIG. 20, the lamination direction of the capacitors 91, 92 may be orthogonal to the radial direction of the rotor 60 and circumferential to the rotor 60. In this case, by making the lamination direction of the capacitor the circumferential direction, the dielectric 151 and the internal electrode 152, which have different heat transfer coefficients, extend in the axial direction. Therefore, unlike the case where the dielectric 151 and the internal electrode 152 are orthogonal to the axial direction (the lamination direction is the axial direction), the temperature distribution inside the capacitor can be made uniform even if heat is transmitted from the field winding 70. This suppresses deformation of the capacitors 91, 92 due to the difference in thermal expansion. In other words, according to the configuration of FIG. 20, both defects that may occur due to centrifugal force and defects that may occur due to heat from the field winding can be suppressed in the capacitors 91, 92 of the circuit module 102.

[0076] In FIG. 20, the first capacitors 91 are arranged in pairs, with two circumferentially adjacent capacitors, lined up in the circumferential direction, and at the circumferential center of the pair of capacitors, the radially inner capacitor side surface is perpendicular to the radial direction.

[0077] As shown in FIG. 21, each of capacitors 91, 92 arranged in the circumferential direction may have a radially inner capacitor side surface portion perpendicular to the radial direction at the circumferential center portion.

[0078] The capacitors 91, 92 may be arranged in the component holder 130 in the orientation shown in Figs. 22(a) and (b). In Figs. 22(a) and (b), the up-down direction is the axial direction, and the left-right direction is the circumferential direction. In Fig. 22(a), the first capacitor 91 is arranged such that the lamination direction of the dielectric 151 and the internal electrode 152 is the axial direction (i.e., a direction perpendicular to the radial direction of the rotor 60), and the pair of external electrodes 153 extend in the radial direction. The pair of external electrodes 153 are arranged at positions on both sides in the circumferential direction of the first capacitor 91. That is, in the first capacitor 91, one external electrode 153 is provided on one circumferential side surface of the approximately rectangular parallelepiped dielectric 151, and the other external electrode 153 is provided on the other circumferential side surface of the dielectric 151.

[0079] 22(b) is different from FIG. 22(a) in that the lamination direction of first capacitor 91 is the circumferential direction, and a pair of external electrodes 153 are provided at positions on both axial sides of first capacitor 91, extending in the radial direction. The configuration of FIG. 22(b) corresponds to the configuration of FIG. 20. The configurations of FIG. 22(a) and (b) can prevent problems such as deformation (bending, etc.) of external electrodes 153 of each capacitor 91, 92 due to centrifugal force during rotor rotation.

[0080] The first capacitor 91 constituting the resonant circuit may be connected in parallel to the first winding portion 71a instead of the second winding portion 71b. Also, in the resonant circuit, in the series connection of the first and second winding portions 71a, 71b, the anode of the diode 93 may be connected to the first winding portion 71a side, and the cathode of the diode 93 may be connected to the second winding portion 71b side.

[0081] In the rotor 60, the second winding portion 71b may be disposed radially outward (on the stator 50 side) than the first winding portion 71a.

[0082] In the stator 50, the stator core may not be provided with teeth.

[0083] 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 serves as both a motor and a generator.

[0084] The moving object 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 object, but may be a stationary system.

[0085] The technical ideas extracted from the above-described embodiments will be described below. [Configuration 1] a stator (50) having a stator winding (52); a rotor (60) having a rotor core (61) having main pole portions (62) provided for each of the magnetic poles arranged in the circumferential direction and projecting in the radial direction, and a field winding (70) wound around the main pole portions, A wound-field type rotating electric machine (40) in which a high-frequency current for inducing a field current in the field winding flows in the stator winding, a circuit module (102) provided so as to be rotatable integrally with the rotor and having a capacitor (91, 92) connected to the field winding; the capacitor is a stacked capacitor in which a dielectric (151) and an electrode (152) are stacked, and in the circuit module, the stacking direction of the dielectric and the electrodes is arranged perpendicular to the radial direction of the rotor. [Configuration 2] 2. The wound-field type rotating electric machine according to claim 1, wherein the capacitor is molded with a resin material in an area including at least an outer peripheral portion that is a radially outer side of the circuit module. [Configuration 3] 3. The wound-field type rotating electric machine according to configuration 2, wherein the capacitor has an inner peripheral portion that is a radially inner side and is not resin-molded. [Configuration 4] The capacitor is A laminated structure is formed by laminating the dielectric and the internal electrodes by embedding a plurality of internal electrodes (152) as the electrodes in the dielectric, and ends of the internal electrodes are exposed on a pair of opposing surfaces of the dielectric, and a pair of external electrodes (153) are provided, 4. The wound-field type rotating electric machine according to any one of configurations 1 to 3, wherein a lamination direction of the dielectric and the internal electrodes is perpendicular to a radial direction of the rotor, and the pair of external electrodes are arranged on both sides in the circumferential direction. [Configuration 5] the circuit module is provided at a position axially opposed to a coil end portion of the field winding that is axially outer than the rotor core, 4. The wound-field type rotating electric machine according to any one of configurations 1 to 3, wherein the lamination direction in the capacitor is oriented perpendicular to the radial direction of the rotor and coincides with the circumferential direction. [Configuration 6] In the circuit module, the capacitors are arranged in a row in a circumferential direction, and each of the capacitors is electrically connected to the field winding via a bus bar (141 to 143), 6. The wound-field type rotating electric machine according to any one of configurations 1 to 5, wherein the bus bar is disposed so as to be in contact with an outer peripheral surface on a radially outer side of the capacitor. [Configuration 7] 7. The wound-field type rotating electric machine according to claim 6, wherein the bus bar surrounds the capacitors arranged in the circumferential direction from the radial outside and has a length of at least a semicircle when viewed in a plan view from the axial direction. [Explanation of symbols]

[0086] 40... rotating electric machine, 50... stator, 52... stator winding, 60... rotor, 61... rotor core, 62... main pole portion, 70... field winding, 91, 92... capacitor, 102... circuit module, 151... dielectric, 152... internal electrode.

Claims

1. a stator (50) having stator windings (52); a rotor (60) having a rotor core (61) having main pole portions (62) provided for each magnetic pole arranged in the circumferential direction and projecting in the radial direction, and a field winding (70) wound around the main pole portions, A wound-field type rotating electric machine (40) in which a high-frequency current for inducing a field current in the field winding flows in the stator winding, a circuit module (102) provided to be rotatable integrally with the rotor and having a capacitor (91, 92) connected to the field winding; The capacitor is a stacked capacitor in which a dielectric (151) and an electrode (152) are stacked, and in the circuit module, the stacking direction of the dielectric and the electrodes is arranged in a direction perpendicular to the radial direction of the rotor.

2. 2. The wound-field type rotating electric machine according to claim 1, wherein the capacitor is molded with a resin material in an area including at least an outer peripheral portion that is a radially outer side of the circuit module.

3. 3. The wound-field type rotating electric machine according to claim 2, wherein a radially inner circumferential portion of the capacitor is not resin-molded.

4. The capacitor is A laminated structure is formed by laminating the dielectric and the internal electrodes by embedding a plurality of internal electrodes (152) as the electrodes in the dielectric, and ends of the internal electrodes are exposed on a pair of opposing surfaces of the dielectric, and a pair of external electrodes (153) are provided, 4. The wound-field type rotating electric machine according to claim 1, wherein a lamination direction of the dielectric and the internal electrodes is perpendicular to a radial direction of the rotor, and the pair of external electrodes are arranged in a direction extending in the radial direction of the rotor.

5. the circuit module is provided at a position axially opposed to a coil end portion of the field winding that is axially outer than the rotor core, 4. The wound-field type rotating electric machine according to claim 1, wherein the lamination direction in the capacitor is oriented perpendicular to a radial direction of the rotor and in a circumferential direction.

6. In the circuit module, a plurality of the capacitors are arranged in a line in a circumferential direction, and each of the capacitors is electrically connected to the field winding via a bus bar (141 to 143); 4. The wound-field type rotating electric machine according to claim 1, wherein the bus bar is arranged so as to be in contact with an outer peripheral surface on a radially outer side of the capacitor.

7. 7. The wound-field type rotating electric machine according to claim 6, wherein the bus bar radially surrounds the capacitors arranged in the circumferential direction, and has a length of at least a semicircle when viewed in a plan view from the axial direction.

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