Wound field rotor

Abstract

A rotor (60) comprises a rotor core (61), a field winding (70) wound around the rotor core, and a circuit module (102) disposed on one end side in the axial direction of the rotor core and provided with electrical components connected to the field winding. The circuit module includes a component holder (130) that holds the electrical components. The component holder comprises: a fitting and fixing portion (134a) that is fixedly fitted to a rotating member with interference, the rotating member being either a shaft portion (32) of the rotor core or an annular member that rotates integrally with the shaft portion; and component accommodating portions (136, 142) that are provided in positions on the radially outer side or the radially inner side of the fitting and fixing portion and that accommodate the electrical components. Strain absorbing portions (151, 152) that absorb radial strain caused by the interference are provided between the fitting and fixing portion and the component accommodating portions of the component holder.

Description

Wound field rotor CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-001409, filed on January 9, 2024, the contents of which are incorporated herein by reference.

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

[0003] In a wound-field rotating electric machine, the rotor has a rotor core with a plurality of main poles (magnetic salient poles) arranged in the circumferential direction, and a field winding wound around the main poles. Also, a known configuration is provided in which the rotor is provided with a component holder for accommodating electrical components connected to the field winding, and the component holder is fixed to an axial end of the rotor in a manner that allows it to rotate integrally with the rotor (see, for example, Patent Document 1).

[0004] Japanese Patent Application Laid-Open No. 2020-124100

[0005] In order to reduce weight imbalance in a rotor, it is desirable to ensure that the component holder and the rotating shaft are in secure contact with each other, and one possible configuration is to fit and fix the component holder to the rotating shaft with a predetermined interference by press-fitting, etc. However, when fitting and fixing the component holder to the rotating shaft with an interference, distortion occurs in the fitting and fixing portion of the component holder due to the interference, and there is a concern that this distortion may cause problems such as misalignment or damage to electrical components.

[0006] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a wound field rotor that can hold electrical components in a component holder in an appropriate state.

[0007] The present disclosure relates to a wound field rotor having a rotor core, a field winding wound around the rotor core, and a circuit module arranged on one axial end side of the rotor core and including electrical components connected to the field winding, wherein the circuit module has a component holder that holds the electrical components, and the component holder has a fitting and fixing portion that is fitted and fixed with an interference to a rotating member that is either a shaft portion of the rotor core or an annular member that rotates integrally with the shaft portion, and a component accommodating portion that is provided at a position radially outside or inside the fitting and fixing portion and that accommodates the electrical components, and a strain absorbing portion that absorbs radial strain due to the interference is provided in the component holder between the fitting and fixing portion and the component accommodating portion.

[0008] In a circuit module for a wound-field rotor, when a component holder is fitted and fixed with interference to a rotating member, which may be either the shaft portion of a rotor core or an annular member that rotates integrally with the shaft portion, there is a concern that radial stress due to the interference will cause distortion in the component holder, and that this distortion will affect the electrical components. In this regard, the above-described configuration provides a strain absorbing section between the fitting and fixing section of the component holder that absorbs radial distortion due to the interference, thereby preventing distortion of the component holder from affecting the electrical components. As a result, the component holder can hold the electrical components in an appropriate state.

[0009] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1 is an overall configuration diagram of a control system for a rotating electric machine, Fig. 2 is a diagram showing an inverter and its peripheral configuration, Fig. 3 is a cross-sectional view of a rotor and a stator, Fig. 4 is a diagram showing an electric circuit provided in the rotor, Fig. 5 is a perspective view showing the overall configuration of the rotor, Fig. 6 is an exploded perspective view of the rotor, Fig. 7 is a longitudinal cross-sectional view of the rotor, Fig. 8 is an exploded perspective view of a winding unit in a rotor main portion, Fig. 9 is a cross-sectional view of the rotor main portion, Fig. 10 is a perspective view of a circuit module, and Fig. 11 is a perspective view of a component holder. 12 is a plan view of the circuit module, FIG. 13 is a longitudinal cross-sectional view of the circuit module, FIG. 14 is a diagram showing the connection structure of the conductor ends in the winding fixing portion, FIG. 15 is a plan view of the component holder, FIG. 16 is a plan view of the component holder, FIG. 17 is a plan view of the circuit module, FIG. 18 is a plan view of the component holder, FIG. 19 is a longitudinal cross-sectional view of the component holder, FIG. 20 is a longitudinal cross-sectional view of the component holder, FIG. 21 is a plan view of the component holder, FIG. 22 is a longitudinal cross-sectional view of the component holder, and FIG. 23 is a plan view of the circuit module.

[0010] DETAILED DESCRIPTION OF THE INVENTION A rotating electric machine according to an embodiment of the present disclosure will now be described with reference to the drawings. Rotating electric machines are used as a power source for driving electric vehicles such as electric vehicles and hybrid vehicles.

[0011] 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 an electromechanical integrated drive device, or the rotating electric machine 40, the inverter 20, and the control device 30 may each be configured as a separate component.

[0012] 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.

[0013] The stator 50 includes a stator core 51 and a stator winding 52. The stator winding 52 is made of, for example, copper wire, and includes U-, V-, and W-phase windings 52U, 52V, and 52W that are arranged with an electrical angle offset of 120° from one another.

[0014] The rotor 60 includes a rotor core 61 and a field winding 70. The field winding 70 may be made of, for example, aluminum wire, which has a low specific gravity and is easily formed. The field winding 70 is not limited to aluminum wire, and may be made of, for example, copper wire or CNT (carbon nanotube). A rotating shaft 32 is attached to the center hole of the rotor core 61. The rotating shaft 32 is rotatably supported by bearings 42 and 43 in the housing 41.

[0015] As shown in FIG. 2 , the inverter 20 includes a series connection of upper-arm switches SUp, SVp, and SWp for U, V, and W phases and lower-arm switches SUn, SVn, and SWn for U, V, and W phases. First ends of U-, V-, and W-phase windings 52U, 52V, and 52W are connected to the connection points between the upper-arm switches SUp, SVp, and SWp and the lower-arm switches SUn, SVn, and SWn for each phase. Second ends of the U-, V-, and W-phase windings 52U, 52V, and 52W are connected to the neutral point. That is, in this embodiment, the stator winding 52 is star-connected. However, the stator winding 52 may also be delta-connected. In this embodiment, each of the switches SUp to SWn is an IGBT. A freewheel diode is connected in antiparallel to each of the switches SUp to SWn.

[0016] The collectors of the upper arm switches SUp, SVp, SWp of each phase are connected to the positive terminal of a DC power supply 10. The emitters of the lower arm switches SUn, SVn, SWn of each phase are connected to the negative terminal of the DC power supply 10. A smoothing capacitor 11 is connected in parallel to the DC power supply 10.

[0017] Next, the stator 50 and the rotor 60 will be described with reference to FIG.

[0018] 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.

[0019] The stator core 51 is made of laminated steel plates made of a soft magnetic material and has an annular back yoke 51a and multiple teeth 51b protruding radially inward from the back yoke 51a. Multiple slots 54 are formed between adjacent teeth 51b in the circumferential direction. The stator winding 52 is formed by accommodating the phase windings of each phase in a predetermined order in each of these slots 54. For example, the stator 50 may employ a segment coil structure using multiple conductor segments. However, the structure of the stator winding 52 is arbitrary.

[0020] The rotor core 61 is made of a soft magnetic material, for example, laminated steel plates. The rotor core 61 has a cylindrical portion 61a and a plurality of main pole portions 62 that protrude radially outward from the cylindrical portion 61a. A field winding 70 is wound around the main pole portions 62 by concentrated winding. In this embodiment, eight main pole portions 62 are provided at equal intervals in the circumferential direction.

[0021] The field winding 70 includes a first winding portion 71a and a second winding portion 71b. The first winding portion 71a is wound radially outward around each main pole portion 62, and the second winding portion 71b is wound radially inward relative to 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. Furthermore, among circumferentially adjacent main pole portions 62, the winding directions of the winding portions 71a, 71b wound around one main pole portion 62 are opposite to those of the winding portions 71a, 71b wound around the other main pole portion 62. Therefore, the magnetization directions of adjacent main pole portions 62 are opposite to each other. In the rotor 60, the main pole portions 62 in the rotor core 61 and the field winding 70 wound around each main pole portion 62 form a plurality of magnetic poles (field poles) arranged circumferentially.

[0022] FIG. 4 shows an electrical circuit on the rotor 60 side, including the winding portions 71a and 71b wound around the main pole portion 62. The first winding portion 71a and the second winding portion 71b are connected in series, and a capacitor portion CC, which is composed of a plurality of first capacitors 91, is connected in parallel to the second winding portion 71b. In this embodiment, the capacitor portion 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 portion 71a and the second winding portion 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, for example, multilayer ceramic capacitors and have the same configuration.

[0023] A diode 93 serving as a rectifying element is connected between both ends of the series-connected body made up of the winding portions 71 a and 71 b. That is, the first end of the first winding portion 71 a is connected to the cathode of the diode 93, and the first end of the second winding portion 71 b is connected to the second end of the first winding portion 71 a. The anode of the diode 93 is connected to the second end of the second winding portion 71 b.

[0024] In this embodiment, the first winding portion 71a, the first capacitor 91, and the diode 93 form a series resonant circuit, and the second winding portion 71b and the first capacitor 91 form a parallel resonant circuit. If the first resonant frequency, which is the resonant frequency of the series resonant circuit, is f1 and the second resonant frequency, which is the 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, fluctuations due to high-frequency components of the main magnetic flux occur in the magnetic circuit including the stator core 51 and the rotor core 61. Fluctuations in the main magnetic flux generate induced voltages in each of the winding portions 71a and 71b, inducing currents in the winding portions 71a and 71b. When induced voltages of the same polarity are generated in the winding portions 71a and 71b, the induced currents in the winding portions 71a and 71b do not cancel each other out, and the induced currents increase. Furthermore, the diode 93 rectifies the currents flowing in the winding portions 71a and 71b in one direction. As a result, a field current flows through the field winding 70 in the direction rectified by the diode 93, exciting the field winding 70.

[0025] 2, the control device 30 is mainly configured with a microcomputer (corresponding to a computer), which includes a processor and a memory. The control device 30 generates drive signals that turn on and off the switches SUp to SWn that constitute the inverter 20. Specifically, the control device 30 converts DC power output from the DC power supply 10 into AC power and supplies the AC power to the U-, V-, and W-phase windings 52U, 52V, and 52W. The control device 30 generates drive signals that turn on and off the switches SUp to SWn, and supplies the generated drive signals to the gates of the switches SUp to SWn.

[0026] The control device 30 turns on and off each of the switches SUp to SWn so that a composite current of the fundamental current and the high-frequency excitation current flows through each of the phase windings 52U, 52V, and 52W. The fundamental current is a current that mainly generates torque in the rotating electric machine 40. The high-frequency excitation current is a high-frequency current with a higher frequency than the fundamental current, and is a current that mainly excites the field winding 70. It is also possible to use a harmonic current as the high-frequency current. The phase currents flowing through the phase windings 52U, 52V, and 52W are shifted by 120 electrical degrees.

[0027] 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.

[0028] The rotor 60 is broadly divided into a rotor main section 101, a circuit module 102 provided at one of the axial ends of the rotor main section 101, and coil end covers 103, 104 as annular members attached to one and the other axial ends of the rotor main section 101. As described with reference to FIG. 3 , the rotor main section 101 includes a rotor core 61 and a field winding 70, and a rotating shaft 32 is attached to the center hole of the rotor core 61. The field winding 70 is composed 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 portion. As shown in FIG. 7 , in the field winding 70 (winding unit 110), the portion radially facing the rotor core 61 is a coil side portion CS, and the 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 .

[0029] Fig. 8 is an exploded perspective view of the winding unit 110 in the rotor main section 101, and Fig. 9 is a cross-sectional view showing the cross-sectional structure of a portion of the rotor main section 101. The rotor main section 101 has a plurality of winding units 110, one for each magnetic pole of the rotor 60. Each winding unit 110 is formed in an annular shape with the axial direction as the longitudinal direction, and is assembled to the rotor core 61 with the main pole section 62 of the rotor core 61 inserted into the hollow portion.

[0030] The winding unit 110 has a first coil module 111 that is located radially outward when attached to the main pole 62, and a second coil module 112 that is located radially inward. 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.

[0031] The first coil module 111 has an annular coil body 121 formed by multiple windings of a conductor material made of a rectangular wire in the circumferential and radial directions, and a thin plate-like insulator 122 provided integrally with the coil body 121. The insulator 122 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 121, and a portion that extends radially and covers the hollow portion of the coil body 121. In other words, the outer peripheral portion on the radially outer side and the inner peripheral portion and hollow portion of the coil body 121 are insulated and coated with the insulator 122.

[0032] The second coil module 112 has an annular coil body 123 formed by multiple windings of a conductor material made of a rectangular wire in the circumferential and radial directions, and a thin plate-like insulator 124 provided integrally with the coil body 123. The insulator 124 has a portion that extends circumferentially and covers the outer peripheral portions on the radially outer and inner sides of the coil body 123, and a portion that extends radially and covers the hollow portion of the coil body 123. In other words, the outer peripheral portion on the radially outer side, the inner peripheral portion on the radially inner side, and the hollow portion of the coil body 123 are insulated and coated with the insulator 124.

[0033] The coil bodies 121 and 123 are air-core coils configured as, for example, α-winding coils. The flat wire used for the coil bodies 121 and 123 has a substantially rectangular cross section (specifically, a substantially rectangular shape) and is composed of a conductor portion made of aluminum or the like and an insulating layer covering the conductor portion. However, it is also possible to use a round wire with a circular cross section as the conductor material.

[0034] As shown in Fig. 9, the first coil module 111 has two radially wound layers of conductor wire, while the second coil module 112 has six radially wound layers. The coil modules 111, 112 have different numbers of circumferential windings (i.e., the number of rows of conductor wire in the circumferential direction), with the number of windings being greater on the radially outer side than on the radially inner side. This improves the space factor of the field winding 70. Ignoring the space factor, it is also possible to make the number of circumferential windings the same for all of the radially arranged coil bodies 121, 123.

[0035] Furthermore, in the rotor main section 101, holding plates 125 and 126 are provided between the main pole sections 62 of the rotor core 61 to maintain the assembled state of the first coil module 111 and the second coil module 112 when these coil modules 111 and 112 are assembled to each main pole section 62. The holding plate 125 is attached to the radial outside of the first coil module 111, and the holding plate 126 is attached between the first coil module 111 and the second coil module 112.

[0036] 6, the rotor 60 has a coil end ring 81 attached to the axial end of the winding unit 110. As shown in FIG. 7, the coil end ring 81 is disposed radially between the coil end portion of the first coil module 111 and the coil end portion of the second coil module 112, and is sandwiched axially between the retaining plate 126 and the coil end cover 103.

[0037] Next, a description will be given of the circuit module 102. Fig. 10 is a perspective view of the circuit module 102, and Fig. 11 is a perspective view of a component holder 130 that constitutes the circuit module 102.

[0038] The circuit module 102 includes a first capacitor 91, a second capacitor 92, a diode 93, a component holder 130, and a plurality of bus bars 147. The component holder 130 is made of an electrically insulating material, and more specifically, is a resin molded body made of a resin material.

[0039] As shown in FIG. 11 , the component holder 130 includes a main body 131 having an annular shape. The main body 131 includes a bottom plate 132 extending radially and having an annular shape, an outer peripheral wall 133 extending axially from a radially outer end of the bottom plate 132, and an inner peripheral wall 134 extending axially from a radially inner end of the bottom plate 132. The inner peripheral wall 134 is formed in a continuous annular shape in the circumferential direction, while the outer peripheral wall 133 is provided in a portion of the main body 131 except for a portion of the circumferential direction. The main body 131 also includes side walls 135 extending radially between the outer peripheral wall 133 and the inner peripheral wall 134 at positions corresponding to both circumferential ends of the outer peripheral wall 133.

[0040] In the main body 131, a first housing section 136, which is a C-shaped space, is formed by a bottom plate section 132 and each of the wall sections 133 to 135, and the capacitors 91 and 92 serving as electrical components are housed in the first housing section 136. Note that a partition section 137 that separates the housing space for the first capacitor 91 from the space for the second capacitor 92 is formed so as to extend in the axial direction from the bottom plate section 132.

[0041] A central hole 141 through which the rotating shaft 32 is inserted is formed in the main body 131. Specifically, the central hole 141 is formed by the inner peripheral surface 134a of the inner peripheral wall 134. The part holder 130 is adapted to be assembled to the rotating shaft 32 with the rotating shaft 32 inserted through the central hole 141 (see FIG. 7 ).

[0042] The inner circumferential wall portion 134 of the main body portion 131 is fitted and fixed to the rotating shaft 32 with a predetermined interference. Specifically, the inner circumferential surface 134a of the inner circumferential wall portion 134 is fitted and fixed to the rotating shaft 32 by press fitting. However, instead of press fitting, techniques such as shrink fitting or cold fitting can also be used. In the part holder 130, the inner circumferential surface 134a of the inner circumferential wall portion 134 corresponds to the "fitting and fixing portion." The first accommodation portion 136 is provided at a position radially outward of the inner circumferential surface 134a of the inner circumferential wall portion 134 so as to surround the inner circumferential surface 134a of the inner circumferential wall portion 134.

[0043] The component holder 130 also includes a second housing portion 142 that houses a diode 93 as an electrical component. The second housing portion 142 is provided radially outward of the inner circumferential wall portion 134, at a position in the circumferential direction where the outer circumferential wall portion 133 is not provided. The diode 93 is fixed to the second housing portion 142 with a fastener such as a bolt. In this embodiment, the first housing portion 136 and the second housing portion 142 correspond to the "component housing portion."

[0044] The component holder 130 has a plurality of winding fixing portions 145 that protrude radially outward from the main body portion 131. In this embodiment, the number of winding fixing portions 145 provided is the same as the number of main pole portions 62; specifically, eight winding fixing portions 145 are provided at equal intervals in the circumferential direction. Each winding fixing portion 145 extends radially outward from a central position in the axial direction of the outer circumferential wall portion 133.

[0045] Each winding fixing portion 145 has a plurality of through holes 146 formed therethrough 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. Note that in the first coil module 111, the first winding portion 71a is formed of a single 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.

[0046] The conductor ends 127 of two circumferentially adjacent first coil modules 111 are inserted into the through holes 146 one by one, and the conductor ends 127 are connected to each other by welding or the like, thereby connecting the first coil modules 111 in the circumferential direction in series. The conductor ends 128 of two circumferentially adjacent second coil modules 112 are inserted into the through holes 146 one by one, and the conductor ends 128 are connected to each other by welding or the like, thereby connecting the second coil modules 112 in the circumferential direction in series.

[0047] In each winding fixing portion 145, the conductor ends 127, 128 are inserted into the through-holes 146 and fixed to the winding fixing portion 145. For example, the conductor ends 127, 128 may be fixed in the through-holes 146 with molding resin or adhesive.

[0048] A first capacitor 91 and a second capacitor 92 are arranged side by side in the circumferential direction in the first housing portion 136 of the part holder 130. A bus bar 147 is connected to each of the capacitors 91, 92, and the capacitors 91, etc. and the field winding 70 are electrically connected via the bus bar 147.

[0049] However, in a configuration in which the component holder 130 is fitted and fixed to the rotation shaft 32 with a clamping margin in the circuit module 102, distortion occurs around the inner surface 134a of the component holder 130 due to the clamping margin, and there is a concern that this distortion may cause problems such as misalignment or damage to the capacitor 91, etc.

[0050] Therefore, in this embodiment, a strain absorbing portion that absorbs radial strain due to interference is provided on the inner peripheral wall portion 134 of the component holder 130 (i.e., between the inner peripheral surface 134a of the inner peripheral wall portion 134 and each of the housing portions 136, 142). This configuration prevents distortion of the component holder 130 from affecting the capacitor 91 and other components, thereby maintaining the capacitor 91 and other components in an appropriate state. The specific configuration is described below.

[0051] Fig. 12 is a plan view of the circuit module 102. Fig. 13 is a longitudinal cross-sectional view showing the cross section of the circuit module 102 taken along line 13-13 in Fig. 12.

[0052] In the part holder 130, the inner circumferential wall 134 is provided with a plurality of circumferentially arranged holes 151, each penetrating the axial direction, and a connecting portion 152 between adjacent holes 151 in the circumferential direction. In other words, the holes 151 and the connecting portions 152 are alternately arranged in the circumferential direction on the inner circumferential wall 134. The inner annular portion 153 is located radially inward (toward the inner circumferential surface 134a) of each of the circumferentially arranged holes 151, and the outer annular portion 154 is located radially outward (opposite the inner circumferential surface 134a) of each of the holes 151. In the part holder 130, the plurality of holes 151 and the connecting portions 152 located between the inner circumferential surface 134a of the inner circumferential wall 134 and each of the accommodation portions 136, 142 correspond to "strain absorbing portions."

[0053] The connecting portion 152 is a portion that is narrowed in the circumferential direction by being sandwiched between the hole portions 151 on both sides in the circumferential direction, and is a low-rigidity connecting portion that has lower connection rigidity compared to a configuration in which the hole portions 151 are not provided.

[0054] The holes 151 are elongated holes extending in the circumferential direction and have an arc shape in a plan view. Each hole 151 has the same circumferential length and is provided at a predetermined interval in the circumferential direction. The connecting portions 152 are provided to extend radially between the inner annular portion 153 and the outer annular portion 154. The circumferential width of the connecting portions 152 is shorter than the circumferential length of the holes 151. However, the circumferential width of the connecting portions 152 may be the same as or longer than the circumferential length of the holes 151. The holes 151 do not have to be elongated holes. The number of holes 151 and connecting portions 152 in the component holder 130 is not limited to that shown in the figure and can be changed.

[0055] 12 and 13 , if radial distortion occurs in the component holder 130 due to press-fitting, the distortion is absorbed by the circumferentially alternating holes 151 and connecting portions 152. This reduces the transmission of distortion from the inner circumferential surface 134 a (fitting and fixing portion) of the component holder 130 to the capacitor 91 and other components, thereby ensuring proper protection of the capacitor 91 and other electrical components.

[0056] In the first housing portion 136 of the component holder 130, the electrical components such as the capacitor 91 are covered with a resin sealing material. Specifically, as shown in FIG. 6 , the first housing portion 136 of the component holder 130 is filled with a resin material to form a resin molded portion 138. The resin material is, for example, a thermosetting resin such as epoxy resin. The capacitors 91 and 92 are embedded in the resin molded portion 138 in the first housing portion 136. Note that it is sufficient that at least a portion of the capacitor 91 and the like is covered with the resin material in the first housing portion 136.

[0057] The elastic modulus of the resin material of the resin molded portion 138 is higher than the elastic modulus of the resin material that constitutes the component holder 130. In this case, strain caused by press-fitting is transmitted to the component holder 130 but is less likely to be transmitted to the electrical components, thereby making it possible to protect the electrical components.

[0058] Furthermore, as described above, the component holder 130 is provided with a plurality of winding fixing portions 145 radially outward from the first housing portion 136, and the conductor ends 127, 128 extending in the axial direction from the field winding 70 are fixed to the through holes 146 of each of the winding fixing portions 145. Fig. 14 shows the connection structure of the conductor ends 127, 128 at the winding fixing portions 145.

[0059] 14 shows two through holes 146 in the winding fixing portion 145, with the conductor end 127 fixed in one through hole 146 and the conductor end 128 and the end of a bus bar 129 electrically connected to the conductor end 128 fixed in the other through hole 146. The bus bar 129 may be a relay bus bar that connects the winding ends to the capacitors 91, 92 and the diode 93. In the component holder 130, only the conductor end portions 127, 128 or only the bus bar 129 may be fixed to the through hole 146 of the winding fixing portion 145.

[0060] As described above, in a configuration in which strain absorbing portions are provided on the inner peripheral wall portion 134 of the component holder 130, it is conceivable that the component holder 130 may be more susceptible to vibration due to reduced rigidity of the strain absorbing portions. To address this issue, the component holder 130 is configured such that the conductor ends 127, 128 and the bus bar 129 are fixed to the winding fixing portion 145 while being inserted through the through-hole 146, radially outward of the first housing portion 136, i.e., radially opposite the inner peripheral surface 134a (fitting fixing portion) across the first housing portion 136. In this case, vibration can be reduced by fixing the windings radially outward of the first housing portion 136 in the component holder 130.

[0061] The configurations of FIGS. 12 and 13 may be partially modified as follows.

[0062] FIG. 15 is a plan view of the component holder 130. In the configuration of FIG. 15 , the connecting portions 152 are inclined relative to a radial line LA that extends linearly from the center of rotation of the rotor 60 (the center point CP of the rotation shaft 32) in the radial direction when viewed from above. Specifically, the center line LB of the connecting portions 152 extends linearly and is inclined relative to the radial line LA between the inner annular portion 153 and the outer annular portion 154 of the inner circumferential wall portion 134 in a plan view. The multiple connecting portions 152 in the circumferential direction are all inclined in the same direction. In this configuration, by arranging each connecting portion 152 to extend in a direction inclined relative to the radial line LA, the radial strain absorption effect can be enhanced. Note that some of the connecting portions 152 may have different inclination directions, for example, the inclination directions may be alternately different in the circumferential direction.

[0063] 16 , the connecting portions 152 are bent connecting portions that are bent in a plan view of the component holder 130. Specifically, the connecting portions 152 have two inclined portions that are opposite to each other with respect to the radial line LA between the inner annular portion 153 and the outer annular portion 154 of the inner circumferential wall portion 134, forming a substantially L-shaped bent shape. The bending directions of the connecting portions 152 may all be the same in the circumferential direction, or may include portions that are different in the circumferential direction.

[0064] The bending shape of the connecting portion 152 can enhance the effect of absorbing strain in the radial direction. Furthermore, the bending shape of the connecting portion 152 can suppress circumferential rotation on the radially outer side of the connecting portion 152 compared to the configuration in which the connecting portion 152 has a linearly inclined shape (the configuration in FIG. 15 ).

[0065] Fig. 17 is a plan view of the circuit module 102. Note that Fig. 17 is a diagram showing the circuit module 102 shown in Fig. 12 with the bus bar 147 on the front side of the page removed, and shows the circumferential arrangement of the capacitors 91 and 92 and the diode 93, which are electrical components.

[0066] 17 , each housing 136, 142 accommodates a plurality of the electrical components (capacitors 91, 92 and diode 93) arranged in a circumferential direction, with electrical component-present areas and no-electrical-component areas arranged alternately in the circumferential direction. On the other hand, in a configuration in which the inner peripheral wall 134 of the component holder 130 has holes 151 and connecting portions 152 arranged alternately in the circumferential direction, when distortion due to interference occurs, the transmission of distortion itself is reduced, but some distortion may still be transmitted radially. In this case, there is a difference in the radial transmission of distortion between the holes 151 and the connecting portions 152, with the degree of distortion being greater in the connecting portions 152.

[0067] 17, component holder 130 is configured to have connecting portions 152 at positions corresponding to the electrical component-present areas and the electrical component-absent areas, thereby further reducing the effects of distortion on the electrical components.

[0068] The following describes another configuration of the strain absorbing portion in the component holder 130. Modifications to the above configuration will be described below.

[0069] Fig. 18 is a plan view of the component holder 130. Fig. 19 is a vertical cross-sectional view showing the cross section of the component holder 130 taken along line 19-19 in Fig. 18.

[0070] 18 and 19 , an annular groove 161 is provided on the inner peripheral wall 134 of the part holder 130. The annular groove 161 opens on one of the axially opposite end faces and extends circumferentially. The thin-walled portion 162 is located in the axially thinner portion of the inner peripheral wall 134. The annular groove 161 opens on the opposite side of the axially opposite end face of the part holder 130 from the bottom plate 132 (the upper side in FIG. 19 ). This provides the thin-walled portion 162 in the part holder 130, radially adjacent to the bottom plate 132. The thin-walled portion 162 is preferably thinner than the bottom plate 132. In this configuration, the annular groove 161 and the thin-walled portion 162 correspond to a "strain absorbing portion." The thin-walled portion 162 is a portion thinned in the axial direction by the annular groove 161, and serves as a low-rigidity connection portion with lower connection rigidity than a configuration without the annular groove 161.

[0071] The annular groove 161 is provided in the inner peripheral wall 134 of the part holder 130, and thus the thin-walled portion 162 formed by the annular groove 161 has low rigidity. In this case, the thin-walled portion 162 can effectively absorb distortion caused by press-fitting of the inner peripheral wall 134. Compared to a configuration in which holes (holes) are provided between the inner peripheral surface 134a, which is the fitting and fixing portion, and each of the accommodation portions 136 and 142, the configuration in Figures 18 and 19 suppresses a decrease in circumferential rigidity in the distortion absorbing portion, resulting in a structure that is resistant to loads caused by rotational fluctuations.

[0072] 19, the annular grooves 161 are provided on both axial end faces of the inner circumferential wall portion 134, opening on the side opposite the bottom plate portion 132. However, this may be changed so that the annular grooves 161 are provided on the bottom plate portion 132 side. Alternatively, the annular grooves 161 may be provided on both axial end faces of the inner circumferential wall portion 134, opening on the side opposite the bottom plate portion 132.

[0073] 20, the inner peripheral wall portion 134 is configured so that annular grooves 161A and 161B are open to both axial end faces, and the space between the annular grooves 161A and 161B on both axial sides is a thin-walled portion 162. The thin-walled portion 162 is provided so as to extend in a direction inclined with respect to a direction perpendicular to the axial direction.

[0074] In this case, the thin-walled portion 162 has low rigidity due to its thin wall, and is easily compressed and deformed in the radial direction because it is inclined relative to the direction perpendicular to the axial direction, thereby effectively absorbing distortion caused by press-fitting of the inner circumferential wall portion 134, etc.

[0075] 21 , a metal ring 171, which has higher rigidity than resin, is insert-molded into a resin-molded component holder 130 closer to the rotation shaft 32 than a strain-absorbing portion (e.g., connecting portion 152). Ring 171 is, for example, an aluminum cylindrical body. In this configuration, ring 171 serves as a fitting and fixing portion of component holder 130, and is fitted and fixed to the rotation shaft 32 with an interference fit. In this case, by molding component holder 130 from a resin with a lower modulus of longitudinal elasticity (Young's modulus) than ring 171, transmission of strain due to the interference fit to the resin portion is suppressed, thereby suppressing strain in the resin portion of component holder 130.

[0076] As a measure to reduce vibrations when the component holder 130 is provided with strain absorbers, metal reinforcing members may be provided near each of the housing sections 136, 142 of the component holder 130. Specifically, as shown in FIG. 22 , a reinforcing member 172 extending annularly around the rotation shaft 32 may be integrally provided in the portion of the component holder 130 surrounding the first housing section 136. The reinforcing member 172 is a metal reinforcing member, and may be made of a metal plate such as aluminum. The reinforcing member 172 is embedded in the bottom plate 132 with the plate surface oriented axially. In this case, the portion of the component holder 130 surrounding the first housing section 136 is earthquake-resistant, reducing the impact of vibrations on the electrical components.

[0077] The metal reinforcement configuration near the first accommodating portion 136 of the part holder 130 may be a configuration in which the outer wall portion 133 is metal reinforced, or a configuration in which the outer annular portion 154 in the inner wall portion 134, which is radially outer than the hole portion 151, the annular groove portion 161, etc., is metal reinforced.

[0078] In a configuration in which the component holder 130 accommodates the capacitors 91, 92 and the diode 93 arranged in the circumferential direction as electrical components, it is conceivable that the degree of influence of strain due to interference will differ between the capacitors 91, 92 and the diode 93. In consideration of this, the component holder 130 may be configured such that the degree of strain absorption in the strain absorbing portion differs between the circumferential positions corresponding to the capacitors 91, 92 and the circumferential position corresponding to the diode 93.

[0079] Specifically, the configuration shown in Fig. 23 may be used. Fig. 23 schematically shows the configuration of the circuit module 102. In Fig. 23, an annular component housing portion 136 is provided in the component holder 130, and four capacitors 91 and two diodes 93 are arranged in the circumferential direction in the component housing portion 136. For example, the two diodes 93 are arranged on opposite sides (180° opposite sides) of the rotor center point.

[0080] Among the thin-walled portions 162 provided in an annular shape as strain absorbing portions, thin-walled portion 162A is provided at a circumferential position corresponding to capacitors 91 and 92, i.e., a position radially inward of capacitors 91 and 92, and thin-walled portion 162B is provided at a circumferential position corresponding to diode 93, i.e., a position radially inward of diode 93. The thin-walled portions 162A and 162B have different axial thicknesses, such that "thickness T1 of thin-walled portion 162A is smaller than thickness T2 of thin-walled portion 162B." In this case, thin-walled portion 162A has a greater degree of strain absorption than thin-walled portion 162B, thereby preferentially reducing the effects of strain on capacitors 91 and 92. Furthermore, thin-walled portion 162B can be made stronger. However, "thickness T1 of thin-walled portion 162A may be larger than thickness T2 of thin-walled portion 162B."

[0081] The configuration of FIG. 23 can provide appropriate strength to the strain absorbing portion of the component holder 130 while appropriately reducing the influence of strain on the electrical component.

[0082] 23, a configuration may be adopted in which holes 151 and connecting portions 152 are provided as strain absorbing portions, and in such a configuration, the circumferential width of connecting portion 152 may be changed at a position corresponding to capacitors 91, 92 and a position corresponding to diode 93. For example, the width of connecting portion 152 may be made relatively small at a position corresponding to capacitors 91, 92, and the width of connecting portion 152 may be made relatively large at a position corresponding to diode 93. However, the opposite may also be true.

[0083] The configurations shown in the above figures can be combined as appropriate. For example, a configuration in which the inner circumferential wall 134 is provided with multiple holes 151 and connecting portions 152 as strain-absorbing portions (see FIGS. 12, 13, and 15-17) can be combined with a configuration in which the inner circumferential wall 134 is provided with an annular groove 161 and thin-walled portions 162 as strain-absorbing portions (see FIGS. 18-20). Specifically, as shown in FIGS. 18-20, a thin-walled portion 162 may be formed by an annular groove 161 provided on at least one of the axial end faces of the component holder 130, and multiple holes 151 may be provided axially through the thin-walled portion 162 extending circumferentially. The multiple holes 151 provided in the thin-walled portion 162 may be provided in any of the configurations shown in FIGS. 12, 15-17. In this case, the inner peripheral wall portion 134 is provided with a connecting portion 152 as a strain absorbing portion, the connecting portion 152 having an axial thickness dimension reduced compared to the inner annular portion 153 and the outer annular portion 154. In this configuration, it is preferable that the circumferential width dimension of the connecting portion 152 is longer than the circumferential length dimension of the hole portion 151.

[0084] Other Embodiments The above embodiment may be modified as follows, for example.

[0085] In the above embodiment, the rotor 60 is configured such that the inner circumferential side of the part holder 130, i.e., the inner circumferential surface 134a of the inner circumferential wall portion 134, serves as a fitting and fixing portion, and the inner circumferential surface 134a is fitted and fixed to the rotating shaft 32 by press-fitting or the like. However, this configuration may be modified. In the rotor 60, the outer circumferential side of the part holder 130, i.e., the outer circumferential surface of the outer circumferential wall portion 133, may serve as a fitting and fixing portion. For example, the outer circumferential surface of the outer circumferential wall portion 133 may be fitted and fixed to the inner circumferential side of the coil end cover 103 (see FIGS. 5 and 6 ), which rotates integrally with the rotating shaft 32, by press-fitting or the like. In this case, the coil end cover 103, which is an annular member, corresponds to the “rotating member” to be fitted and fixed. In this configuration, the part holder 130 may be provided with a part housing portion radially inward of the outer circumferential surface of the outer circumferential wall portion 133, and a strain absorbing portion may be provided between the outer circumferential surface of the outer circumferential wall portion 133 and the part housing portion.

[0086] The field winding 70 may have a configuration other than that described above. For example, the first coil module 111 of the field winding 70 may be configured so that the conductor material is wound continuously in two layers in the radial direction, starting from one end and ending at the other end. Furthermore, the second coil module 112 may be configured so that the conductor material is wound continuously in six layers in the radial direction, starting from one end and ending at the other end.

[0087] The first capacitor 91 constituting the resonant circuit may be connected in parallel to the first winding portion 71 a instead of the second winding portion 71 b. Also, in the resonant circuit, the anode of the diode 93 may be connected to the first winding portion 71 a side of the series-connected first and second winding portions 71 a, 71 b, and the cathode of the diode 93 may be connected to the second winding portion 71 b side.

[0088] In the rotor 60, the second winding portion 71b may be disposed radially outward (closer to the stator 50) than the first winding portion 71a.

[0089] In the stator 50, the stator core may not be provided with teeth.

[0090] The rotating electric machine is not limited to a rotating electric machine used as an in-vehicle main engine, but may be, for example, a rotating electric machine used as an ISG (Integrated Starter Generator) that is a motor and generator.

[0091] The moving body on which the rotating electric machine system is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. Furthermore, the rotating electric machine system is not limited to a system mounted on a moving body, but may be a stationary system.

[0092] The technical concepts extracted from the above-described embodiments are described below. [Configuration 1] A wound field rotor (60) having a rotor core (61), a field winding (70) wound around the rotor core, and a circuit module (102) arranged on one axial end side of the rotor core and including electrical components connected to the field winding, wherein the circuit module has a component holder (130) that holds the electrical components, and the component holder has a fitting and fixing portion (134a) that is fitted and fixed with an interference to a rotating member that is either a shaft portion (32) of the rotor core or an annular member that rotates integrally with the shaft portion, and a component accommodating portion (136, 142) that is provided at a position radially outside or inside the fitting and fixing portion and that accommodates the electrical components, and wherein the wound field rotor has a strain absorbing portion (152, 162) that absorbs radial strain due to the interference in the component holder between the fitting and fixing portion and the component accommodating portion. [Configuration 2] The wound field rotor according to Configuration 1, wherein the component holder is provided with a plurality of circumferentially arranged holes (151) each passing through in the axial direction, and a radially extending connecting portion (152) located between adjacent circumferentially arranged holes, as the strain absorbing portion. [Configuration 3] The wound field rotor according to Configuration 2, wherein the connecting portion is an inclined connecting portion that is inclined with respect to a radial line extending linearly in the radial direction from a center point of the shaft portion in a plan view of the component holder. [Configuration 4] The wound field rotor according to Configuration 2, wherein the connecting portion is a bent connecting portion that has a bent shape in a plan view of the component holder. [Configuration 5] A wound field rotor according to any one of configurations 2 to 4, wherein the component storage section stores a plurality of the electrical components lined up in a circumferential direction, the component storage section has a presence section in the circumferential direction where the electrical components are present and an absence section in the circumferential direction where the electrical components are not present, and the component holder is provided with the connecting section at a position in the circumferential direction that corresponds to one of the presence section and the absence section.[Configuration 6] The wound field rotor according to Configuration 1, wherein the part holder has an annular groove (161) between the fitting-fixing portion and the part accommodating portion, the annular groove (161) opening on at least one of the axial end faces of the part holder and extending in the circumferential direction, and the thin-walled portion (162) thinned in the axial direction by the annular groove serves as the strain-absorbing portion. [Configuration 7] The wound field rotor according to Configuration 1, wherein the part holder has annular grooves (161) between the fitting-fixing portion and the part accommodating portion, the annular grooves (161) opening on the axial end faces of the part holder and extending in the circumferential direction, and the thin-walled portion (162) between the annular grooves on both axial sides serves as the strain-absorbing portion, and the thin-walled portion extends in a direction inclined with respect to a direction perpendicular to the axial direction, between the fitting-fixing portion and the part accommodating portion. [Configuration 8] The wound field rotor according to any one of Configurations 1 to 7, wherein the component accommodating portion accommodates capacitors (91, 92) and a diode (93) as the electrical components, arranged in a circumferential direction, and wherein the degree of strain absorption in the strain absorbing portion differs between a circumferential position on the component holder corresponding to the capacitor and a circumferential position on the component holder corresponding to the diode. [Configuration 9] The wound field rotor according to any one of Configurations 1 to 8, wherein the component holder is a resin molded body, and wherein a metal ring body (171) is insert-molded into the component holder on the side of the strain absorbing portion facing the rotating member. [Configuration 10] The wound field rotor according to any one of Configurations 1 to 9, wherein the component holder is a resin molded body, and wherein at least a portion of the electrical component in the component accommodating portion is covered with a resin sealing material, and wherein the resin sealing material has a modulus of elasticity higher than the modulus of elasticity of the resin material constituting the component holder.[Configuration 11] The wound field rotor according to any one of Configurations 1 to 10, wherein the field winding is formed by winding a conductor wire and has conductor end portions (127, 128) extending in the axial direction, the component holder has a through hole (146) passing through in the axial direction, and at least one of the conductor end portions and an end portion of a bus bar (129) electrically connected to the conductor end portions is inserted into the through hole and fixed to the component holder on the radially opposite side of the component accommodating portion from the fitting-fixing portion, with the component holder sandwiching the component accommodating portion therebetween. [Configuration 12] The wound field rotor according to any one of Configurations 1 to 11, wherein the component holder is integrally provided with a reinforcing portion (172) extending annularly about the shaft portion at a portion surrounding the component accommodating portion.

[0093] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and equivalent modifications. In addition, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A wound field rotor (60) having a rotor core (61), a field winding (70) wound around the rotor core, and a circuit module (102) disposed on one axial end side of the rotor core and including an electrical component connected to the field winding, wherein the circuit module has a component holder (130) for holding the electrical component, the component holder has a fitting and fixing portion (134a) that is fitted and fixed with a tightening margin to a rotating member that is either the shaft portion (32) of the rotor core or an annular member that rotates integrally with the shaft portion, and a component accommodating portion (136, 142) that is provided at a position on the outer or inner side in the radial direction of the fitting and fixing portion and accommodates the electrical component, and a distortion absorbing portion (151, 152, 161, 162) for absorbing radial distortion due to the tightening margin is provided between the fitting and fixing portion and the component accommodating portion in the component holder.

2. The wound field rotor according to claim 1, wherein the component holder is provided with a plurality of holes (151) that are arranged in the circumferential direction and each penetrate in the axial direction as the distortion absorbing portion, and a connecting portion (152) that is located between the adjacent holes in the circumferential direction and extends in the radial direction.

3. The wound field rotor according to claim 2, wherein the connecting portion is an inclined connecting portion that is inclined with respect to a radiation that linearly extends in the radial direction from the center point of the shaft portion in a plan view of the component holder.

4. The wound field rotor according to claim 2, wherein the connecting portion is a bent connecting portion that forms a bent shape in a plan view of the component holder.

5. The wound field rotor according to claim 2, wherein a plurality of the electrical components are accommodated side by side in the circumferential direction in the component accommodating portion, the component accommodating portion has a present site where the electrical component exists and an absent site where the electrical component does not exist in the circumferential direction, and the connecting portion is provided at a position corresponding to the absent site among the present site and the absent site in the circumferential direction in the component holder.

6. The wound field rotor according to claim 1, wherein an annular groove portion (161) that opens at at least one of the end faces on both axial sides of the component holder and extends in the circumferential direction is provided between the fitting and fixing portion and the component accommodating portion in the component holder, and a thin wall portion (162) that is thinned in the axial direction by the annular groove portion serves as the distortion absorbing portion.

7. In the component holder, between the fitting and fixing portion and the component accommodating portion, annular groove portions (161) that open at the axial end faces and extend in the circumferential direction are provided on both axial sides of the component holder, and a thin-walled portion (162) between the annular groove portions on both axial sides is the distortion absorbing portion. The thin-walled portion is provided so as to extend in a direction inclined with respect to a direction orthogonal to the axial direction between the fitting and fixing portion and the component accommodating portion. The wound-field magnet rotor according to claim 1.

8. In the component accommodating portion, a capacitor (91, 92) and a diode (93) are accommodated side by side in the circumferential direction as the electrical components. In the component holder, the degree of distortion absorption in the distortion absorbing portion is different at the circumferential position corresponding to the capacitor and the circumferential position corresponding to the diode. The wound-field magnet rotor according to any one of claims 1 to 7.

9. The component holder is a resin molded body. In the component holder, a metal ring body (171) is insert molded on the side of the rotating member of the distortion absorbing portion. The wound-field magnet rotor according to any one of claims 1 to 7.

10. The component holder is a resin molded body. In the component accommodating portion, at least a part of the electrical component is covered with a resin sealing material. The elastic modulus of the resin sealing material is higher than the elastic modulus of the resin material constituting the component holder. The wound-field magnet rotor according to any one of claims 1 to 7.

11. The field winding is constituted by winding a conductor wire and has conductor end portions (127, 128) extending in the axial direction. The component holder has a through hole (146) penetrating in the axial direction. In the component holder, at least one of the conductor end portion and the end portion of a bus bar (129) electrically connected to the conductor end portion is fixed to the component holder in a state of being inserted into the through hole on the radially opposite side of the fitting and fixing portion with the component accommodating portion interposed therebetween. The wound-field magnet rotor according to any one of claims 1 to 7.

12. In the component holder, a reinforcing portion (172) extending annularly around the component accommodating portion with the shaft portion as the center is integrally provided. The wound-field magnet rotor according to any one of claims 1 to 7.

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