Wound-field type rotary electric machine

Abstract

To suppress occurrence of trouble caused by receiving heat from a field winding regarding a capacitor which is disposed in an end of a rotor in an axial direction.SOLUTION: In a wound-field type rotary electric machine, a rotor 60 comprises a rotor core including a main magnetic pole part which is provided for each of magnetic poles arranged side by side in a circumferential direction, and a field winding 70 which is wound around the main pole part. The rotor 60 comprises a circuit module 102 including a plurality of capacitors 91 connected to the field winding. The circuit module 102 is provided at a position opposed to a coil end CE of the field winding 70 in an axial direction. The capacitor 91 is a laminated capacitor, in which a dielectric 151 and the internal electrode 152 are laminated, and disposed in such a direction that a lamination direction of the dielectric 151 and the internal electrode 152 is orthogonal to the axial direction of the rotor 60.SELECTED DRAWING: Figure 16

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, heat is transferred from the field winding, which is a heat source, to the capacitor, and there is a concern that the heat may cause deformation of the capacitor. Specifically, when a multilayer capacitor is used and the dielectric and the electrodes 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 the area close to the field winding. This may cause deformation due to thermal expansion at the end of the capacitor on the high temperature side, leading to defects such as cracks.

[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 malfunctions caused by heat reception from the field winding in a capacitor arranged at the axial end of 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 projecting 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, the rotor includes a circuit module having a plurality of capacitors connected to the field winding; 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, The capacitor is a multilayer capacitor in which a dielectric and electrodes are laminated, and the lamination direction of the dielectric and the electrodes is arranged perpendicular to the axial direction of the rotor.

[0007] In a wound-field type rotating electric machine, in a configuration in which a circuit module is provided at a position axially facing the coil end portion of the field winding, the capacitor of the circuit module is affected by heat from the field winding. In particular, in a laminated capacitor in which dielectrics and electrodes are laminated, there is a concern that a temperature difference will occur inside the capacitor because there is a difference in the way heat is transferred inside the capacitor depending on the lamination direction. In consideration of this point, the capacitor is configured so that the lamination direction of the dielectrics and electrodes is perpendicular to the axial direction of the rotor. In this case, the dielectrics and electrodes, which have different heat transfer coefficients in the capacitor, are each oriented in the axial direction, so that the temperature distribution inside the capacitor can be made uniform, unlike when the dielectrics and electrodes are each oriented perpendicular to the axial direction. This suppresses deformation in the capacitor due to a difference in thermal expansion. As a result, it is possible to suppress the occurrence of defects caused by heat reception from the field winding in the capacitor arranged at the axial end of 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 the 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 diagram showing electrical connections between each bus bar and a field winding. [Figure 16] FIG. 4 is a vertical cross-sectional view showing a schematic arrangement of capacitors in a circuit module. [Figure 17] FIG. 4 is a plan view showing an arrangement of capacitors and diodes. [Figure 18] FIG. 4 is a vertical cross-sectional view showing an arrangement of capacitors and diodes. [Figure 19] FIG. 3 is a plan view showing a schematic configuration of a first bus bar and a second bus bar. [Figure 20] FIG. 4 is a vertical cross-sectional view showing a schematic arrangement of capacitors in the circuit module. [Figure 21] FIG. 11 is a plan view showing an arrangement of capacitors and diodes in a further example. 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] Fig. 15 is a diagram showing electrical connections between each of the busbars 141 to 143 and the first winding portion 71a and the second winding portion 71b of the field winding 70. In Fig. 15, the first connection terminal 141a of the first busbar 141 is connected to a connection point A2 which is a midpoint between the first winding portion 71a and the second winding portion 71b. The second connection terminal 142a of the second busbar 142 is connected to a connection point A3 on the opposite side to the connection point A2 of the second winding portion 71b, and the third connection terminal 143a of the third busbar 143 is connected to a connection point A1 on the opposite side to the connection point A2 of the first winding portion 71a.

[0050] Incidentally, when multilayer ceramic capacitors (multilayer capacitors) are used as the capacitors 91, 92 in the circuit module 102 of the rotor 60, there is a concern that heat will be transferred from the field winding 70, which is a heat source, to the capacitors 91, 92, and that the heat may cause problems such as deformation of the capacitors 91, 92. Therefore, in this embodiment, as a measure against heat for the capacitors 91, 92, the lamination direction of the capacitors 91, 92 is set to a specific direction, thereby suppressing deformation of the capacitors 91, 92 caused by heat from the field winding 70.

[0051] Fig. 16 is a diagram showing a schematic arrangement of first capacitors 91 in a circuit module 102. In Fig. 16, the up-down direction is the axial direction, and the lower side of the figure is the field winding 70 side. Moreover, in Fig. 16, the left-right direction is the radial direction.

[0052] In the component holder 130 of the circuit module 102, a first capacitor 91 is disposed in a housing portion 132 formed in a main body portion 131, sandwiched between a first bus bar 141 and a second bus bar 142 arranged in the axial direction. The first capacitor 91 has a dielectric 151, a plurality of internal electrodes 152 embedded in the dielectric 151 at a predetermined interval, and a pair of external electrodes 153 electrically connected to the internal electrodes 152. The pair of external electrodes 153 correspond to a first terminal and a second terminal of the first capacitor 91. In the first capacitor 91, the dielectric 151 and the internal electrodes 152 are alternately laminated, and the external electrodes 153 on both sides are alternately connected to the plurality of internal electrodes 152 arranged in the lamination direction. In FIG. 16, the left-right direction (radial direction) is the lamination direction of the first capacitor 91. The first capacitor 91 is a multilayer ceramic chip capacitor.

[0053] 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 axial direction of the rotor 60 (the left-right direction in FIG. 16). Therefore, when heat is transferred to the first capacitor 91 by radiation from the coil end portion CE of the field winding 70, the heat is transferred to each internal electrode 152 in the first capacitor 91. In this case, the internal electrodes 152 are members having a relatively high thermal conductivity, and since the internal electrodes 152 are provided to extend in the axial direction, a localized temperature rise does not occur in the first capacitor 91, but an overall uniform temperature rise occurs. Therefore, inconveniences such as deformation caused by temperature generation inside the capacitor are suppressed.

[0054] Incidentally, in a comparative example in which the lamination direction of first capacitor 91 is set to the axial direction (the up-down direction in FIG. 16), heat transferred from coil end portion CE of field winding 70 is transferred to the dielectric layer in first capacitor 91 that is closest to field winding 70. In this case, since dielectric 151 has a low thermal conductivity, the dielectric layer functions as a heat insulating layer, inhibiting the transfer of heat inside the capacitor and causing a temperature difference inside the capacitor. This causes localized thermal expansion, and there is a concern that deformation (warping) due to thermal expansion will occur at the end of the capacitor on the high temperature side. In contrast, the configuration in FIG. 16 suppresses deformation due to localized thermal expansion.

[0055] 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 axial direction of the rotor 60.

[0056] FIG. 17 is a plan view showing an arrangement of the capacitors 91, 92 and the diode 93 in the circuit module 102. As shown in FIG.

[0057] In the circuit module 102, eleven first capacitors 91 and one second capacitor 92 are arranged in the circumferential direction, and the stacking direction of each of these capacitors 91, 92 is the radial direction. That is, each of the capacitors 91, 92 is arranged such that the internal electrodes 152 extend in the circumferential direction. In this case, the stacking direction of each of the capacitors 91, 92 is perpendicular to the axial direction of the rotor 60 and perpendicular to the circumferential direction.

[0058] In the circuit module 102, when a plurality of capacitors 91, 92 are arranged in a circumferential direction, it is considered that the circumferentially adjacent capacitors 91, 92 are mutually affected by heat. In this case, it is considered that the capacitor side portions, which are the opposing surfaces of the capacitors 91, 92, may become locally hot. In this regard, by arranging the stacking direction of each of the capacitors 91, 92 perpendicular to the circumferential direction of the rotor 60, the local temperature rise on the opposing surfaces of the capacitors 91, 92 (the capacitor side portions) is suppressed.

[0059] In addition, it is considered that the capacitors 91, 92 on both sides of the diode 93 are affected by heat from the diode 93 in the arrangement direction (circumferential direction) with respect to the diode 93. In this regard, the stacking direction of the capacitors 91, 92 adjacent to the diode 93 is oriented perpendicular to the arrangement direction (circumferential direction) with respect to the diode 93, so that a local temperature rise on the side surface of the capacitor on the diode 93 side is suppressed.

[0060] In the circuit module 102, the circumferential distance between the capacitors 91, 92 and the diode 93 is preferably greater than the distance between the capacitors 91, 92 arranged in the circumferential direction. In this case, it is possible to reduce the effect of heat from the diode 93 on the capacitors 91, 92, taking into consideration that the diode 93 generates more heat by itself than the capacitors 91, 92. More specifically, in FIG. 17, the distance (the radially inner distance) between the capacitors 91, 92 and the diode 93 at their closest positions is preferably greater than the distance (the radially inner distance) between the capacitors 91, 92 at their closest positions.

[0061] Fig. 18 is a vertical cross-sectional view that illustrates a schematic arrangement of first capacitors 91 and diodes 93 in circuit module 102. Note that bus bars 141 to 143 are not shown in Fig. 18.

[0062] As shown in FIG. 18, when the axial separation distance from the coil end portion CE of the field winding 70 to the first capacitor 91 is D1 and the axial separation distance from the coil end portion CE to the diode 93 is D2, it is preferable that the relationship D1 < D2 holds. In this case, considering that the diode 93 has a greater self-heating than the capacitors 91 and 92, by distancing the diode 93 from the field winding 70 which is the heat source, the temperature rise at the diode 93 can be suppressed.

[0063] Note that the diode 93 preferably has a smaller thickness dimension (axial dimension) than each of the capacitors 91 and 92. In this case, while setting the separation distance D1 from the coil end portion CE to each of the capacitors 91 and 92 and the separation distance D2 from the coil end portion CE to the diode 93 such that D1 < D2, it is preferable that the diode 93 does not protrude beyond the capacitors 91 and 92 in the axial direction towards the armature winding side.

[0064] Heat from the field winding 70 (the first winding portion 71a, the second winding portion 71b) is transmitted to each of the first capacitors 91 arranged in the circumferential direction via the first bus bar 141 and the second bus bar 142. Also, in these bus bars 141 and 142, it is considered that the amount of temperature rise due to heat transfer from the field winding 70 becomes large in the vicinity of the connection terminals 141a and 142a connected to the field winding 70. In this case, if the influence of the heat from the diode 93 and the influence of the heat of the field winding 70 transmitted from the bus bars 141 and 142 reach the same first capacitor 91, a temperature imbalance occurs in each of the first capacitors 91 arranged in the circumferential direction.

[0065] In view of this point, the first bus bar 141 and the second bus bar 142 are preferably configured as shown in FIGS. 19(a) and 19(b). In FIGS. 19(a) and 19(b), for convenience of explanation, the first capacitors 91 arranged in the circumferential direction are shown with numbers 1 to 11 attached.

[0066] 19(a), it is preferable that the first connection terminal 141a is provided in a position away from the first capacitor 91 that is closest to the diode 93 on the first bus bar 141. Specifically, the first capacitor 91 that is closest to the diode 93 is the first capacitor 91 numbered 1 on the left side of the figure, and the first capacitor 91 numbered 11 on the right side of the figure. The first connection terminal 141a is provided in the first bus bar 141 at a position near the fourth first capacitor 91. Note that the first connection terminal 141a may also be provided in a position near any of the second to tenth first capacitors 91.

[0067] 19(b), it is preferable that the second connection terminal 142a is provided on the second bus bar 142 at a position away from the first capacitor 91 that is closest to the diode 93. The second connection terminal 142a is provided on the second bus bar 142 at a position near the seventh first capacitor 91, for example. Note that the second connection terminal 142a may also be provided at a position near any of the second to tenth first capacitors 91.

[0068] In this case, the first capacitor 91 that is most susceptible to the effects of heat from the diode 93 is different from the first capacitor 91 that is most susceptible to the effects of heat transfer from each bus bar 141, 142, and temperature imbalance in each of the first capacitors 91 arranged circumferentially can be suppressed.

[0069] In addition, when the angle between the center position of the diode 93 in the circumferential direction, the position of the first connection terminal 141a, and the axis J is θ1, the angle θ1 should be 45° or more. Similarly, when the angle between the center position of the diode 93 in the circumferential direction, the position of the second connection terminal 142a, and the axis J is θ2, the angle θ2 should be 45° or more.

[0070] In addition, in terms of the relationship between the first connection terminal 141a of the first bus bar 141 and the second connection terminal 142a of the second bus bar 142, it is preferable that these connection terminals 141a, 142a are arranged so that the first capacitor 91 closest to the first connection terminal 141a (first capacitor 91 number 4 in Figure 19) and the first capacitor 91 closest to the second connection terminal 142a (first capacitor 91 number 7 in Figure 19) are different from each other.

[0071] In the circuit module 102, the capacitors 91, 92 may be molded with a resin material. Specifically, as shown in Fig. 20, the inside of the accommodation portion 132 of the component holder 130 may be filled with a resin material to form a resin molded portion 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 portion 161 in the accommodation portion 132 of the component holder 130.

[0072] According to the present embodiment described above in detail, the following excellent effects can be obtained.

[0073] In the circuit module 102, the capacitors 91, 92 are arranged so that the lamination direction of the dielectric 151 and the internal electrodes 152 is perpendicular to the axial direction of the rotor 60. In this case, the dielectric 151 and the internal electrodes 152, which have different heat transfer coefficients, are oriented to extend in the axial direction in each of the capacitors 91, 92. This makes it possible to achieve a uniform temperature distribution inside the capacitor, unlike the case in which the dielectric 151 and the internal electrodes 152 are oriented perpendicular to the axial direction. This suppresses deformation in each of the capacitors 91, 92 due to the difference in thermal expansion. As a result, it is possible to suppress the occurrence of defects in each of the capacitors 91, 92 due to heat reception from the field winding 70.

[0074] In the circuit module 102, when a plurality of capacitors 91, 92 are arranged in the circumferential direction, it is considered that the circumferentially adjacent capacitors 91, 92 are mutually affected by heat. In this case, it is considered that the side portions of the capacitors, which are the opposing surfaces of the capacitors 91, 92, become locally hot. In consideration of this point, the lamination direction of each of the capacitors 91, 92 is set to be perpendicular to the circumferential direction of the rotor 60. In this way, it is possible to uniform the temperature distribution inside the capacitors while taking into consideration that each of the capacitors 91, 92 receives heat from the field winding 70 in the axial direction as well as heat from the circumferentially adjacent capacitors 91, 92.

[0075] In the circuit module 102, when the capacitors 91, 92 and the diode 93 are arranged side by side, it is considered that the capacitors 91, 92 are affected by the heat from the diode 93. In this case, it is considered that the side portions of the capacitors 91, 92 that face the diode 93 locally become hot. In consideration of this point, the stacking direction of the capacitors 91, 92 adjacent to the diode 93 is set to be perpendicular to the axial direction of the rotor 60 and perpendicular to the side-by-side arrangement direction (circumferential direction) with the diode 93. In this way, it is possible to uniform the temperature distribution inside the capacitors while taking into consideration that each of the capacitors 91, 92 receives heat from the field winding 70 in the axial direction as well as heat from the diode 93 adjacent in the circumferential direction.

[0076] Comparing the capacitors 91, 92 and the diode 93 in the circuit module 102, the diode 93 generates more heat by itself. Therefore, there is a concern that a temperature difference may occur between the capacitor adjacent to the diode 93 and the other capacitors among the capacitors 91, 92 lined up in the circumferential direction. In consideration of this point, the axial distance D2 from the coil end portion CE of the field winding 70 to the diode 93 is made larger than the axial distance D1 from the coil end portion CE to the capacitors 91, 92. This makes it possible to equalize the temperatures of the capacitors 91, 92 lined up in the circumferential direction.

[0077] The diode 93 generates more heat by itself than the capacitors 91, 92, and therefore has a relatively large effect on the circumferentially adjacent capacitors 91, 92. Taking this into consideration, the circumferential distance between the capacitors 91, 92 and the diode 93 is made greater than the circumferential distance between the capacitors 91, 92. In this case, the diode 93 is located away from the field winding 70, which is a heat source, and the temperatures of the capacitors 91, 92 arranged in the circumferential direction can be made uniform.

[0078] In the first and second bus bars 141, 142, the connection terminals 141a, 142a which are the connection parts with the field winding 70 are provided at positions away from the first capacitor 91 which is closest to the diode 93. This makes it possible to suppress the inconvenience that the heat from the diode 93 and the heat of the field winding 70 transmitted via the bus bars 141, 142 are concentrated on one first capacitor 91, which causes a temperature imbalance between the first capacitors 91.

[0079] Since each of the capacitors 91, 92 is configured to be resin molded, the effect of suppressing deformation of each of the capacitors 91, 92 can be enhanced.

[0080] (Other embodiments) The above embodiment may be modified, for example, as follows.

[0081] 21, in the circuit module 102, the stacking direction of the capacitors 91, 92 may be the circumferential direction in a plan view. That is, the capacitors 91, 92 may be arranged such that the internal electrodes 152 extend in the radial direction. In this case, the stacking direction of the capacitors 91, 92 is perpendicular to the axial direction of the rotor 60 and perpendicular to the radial direction.

[0082] 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.

[0083] 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.

[0084] In the stator 50, the stator core may not be provided with teeth.

[0085] 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.

[0086] 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.

[0087] 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, the rotor includes a circuit module (102) having a plurality of capacitors (91, 92) connected to the field winding; 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, The capacitor is a laminated capacitor in which a dielectric (151) and an electrode (152) are laminated, and the laminated direction of the dielectric and the electrodes is arranged perpendicular to the axial direction of the rotor. [Configuration 2] The plurality of capacitors are arranged in a circumferential direction on the circuit module, 2. The wound-field type rotating electric machine according to configuration 1, wherein the lamination direction in each of the capacitors is perpendicular to both the axial direction and the circumferential direction of the rotor. [Configuration 3] The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged side by side. 3. The wound-field type rotating electric machine according to configuration 1 or 2, wherein the stacking direction of the capacitor adjacent to the diode is perpendicular to the axial direction of the rotor and perpendicular to the arrangement direction of the diode. [Configuration 4] The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged side by side. 4. The wound-field type rotating electric machine according to any one of configurations 1 to 3, wherein an axial distance from a coil end portion of the field winding to the diode is greater than an axial distance from the coil end portion to the capacitor. [Configuration 5] The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged in a circumferential direction. 5. The wound-field type rotating electric machine according to any one of configurations 1 to 4, wherein a distance between the capacitor and the diode in the circumferential direction is greater than a distance between the capacitors themselves. [Configuration 6] The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged in a circumferential direction. The capacitor is electrically connected to the field winding via bus bars (141 to 143), The bus bar has a connection terminal (141a to 143a) which is a connection portion with the field winding, and the connection terminal is provided at a position away from the capacitor closest to the diode. [Configuration 7] 7. The wound-field type rotating electric machine according to any one of configurations 1 to 6, wherein the capacitor is molded with a resin material. [Explanation of symbols]

[0088] 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, The rotor includes a circuit module (102) having a plurality of capacitors (91, 92) connected to the field winding; 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, The capacitor is a laminated capacitor in which a dielectric (151) and an electrode (152) are laminated, and the laminated direction of the dielectric and the electrodes is arranged perpendicular to the axial direction of the rotor.

2. The plurality of capacitors are arranged in a circumferential direction on the circuit module, 2. The wound-field type rotating electric machine according to claim 1, wherein the lamination direction in each of the capacitors is perpendicular to both the axial direction and the circumferential direction of the rotor.

3. The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged side by side.

3. The wound-field type rotating electric machine according to claim 1, wherein the stacking direction of the capacitor adjacent to the diode is perpendicular to the axial direction of the rotor and perpendicular to the arrangement direction of the diode.

4. The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged side by side.

3. The wound-field type rotating electric machine according to claim 1, wherein an axial distance from a coil end portion of said field winding to said diode is greater than an axial distance from said coil end portion to said capacitor.

5. The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged in a circumferential direction.

3. The wound-field type rotating electric machine according to claim 1, wherein a distance between said capacitors and said diodes in a circumferential direction is greater than a distance between said capacitors themselves.

6. The circuit module has a rectifying diode (93), and the capacitor and the diode are arranged in a circumferential direction. The capacitor is electrically connected to the field winding via bus bars (141 to 143), 3. The wound-field type rotating electric machine according to claim 1, wherein the busbar has connection terminals (141a to 143a) which are connection portions with the field winding, and the connection terminals are provided at positions away from the capacitor closest to the diode.

7. 3. The wound-field type rotating electric machine according to claim 1, wherein the capacitor is molded with a resin material.

Images