Rotating electric machine

Abstract

Using materials with relatively high strength, the wiring between the power receiving device and the coil wire is appropriately arranged. [Solution] A rotating electric machine is disclosed, comprising a stator, a wound field rotor having a rotor core and rotor shaft around which coil wires are wound, a rotating member having an outer circumference formed of a metallic material, mounted on the axial end of the rotor shaft and rotating coaxially with the rotor shaft, a power supply device electrically connected to a power source, a power receiving device provided on the rotating member and electrically connected to the coil wires, receiving power from the power supply device in a contact or non-contact manner, and wiring provided axially on the rotating member and electrically connecting the power receiving device and the coil wires, wherein the rotating member has axial holes through which the wiring passes.

Description

Technical Field

[0001] The present disclosure relates to a rotating electric machine.

Background Art

[0002] In a rotating electric machine that supplies power to a rotor coil of a wound field magnet rotor in a contact manner, a structure in which a slip ring, wiring (wiring between the slip ring and the rotor coil), a seal ring, etc. are integrated with a resin molded body is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] [[ID=3�]]However, in the prior art as described above, there is a concern about insufficient strength of the resin molded body provided on the rotor shaft, and there is a possibility that functions such as a seal member and a bearing provided on the outer peripheral surface of the resin molded body may not be realized in the intended manner. Such problems are not limited to the contact power supply method of the prior art as described above, but also apply to a rotating electric machine having a wound field magnet rotor with a non-contact power supply method.

[0005] Therefore, on one aspect, an object of the present disclosure is to appropriately arrange wiring between a power receiving device and a coil wire using a member having relatively high strength.

Means for Solving the Problems

[0006] On one aspect, a stator, a wound field magnet rotor having a rotor core around which a coil wire is wound and a rotor shaft, A rotating member having an outer circumference formed of a metal material, mounted on the axial end of the rotor shaft, and rotating coaxially with the rotor shaft and together with the rotor shaft, A power supply device electrically connected to the power source, A power receiving device provided on the rotating member, electrically connected to the coil wire, and receiving power from the power supply device in a contact or non-contact manner, The rotating member is provided axially with wiring that electrically connects the power receiving device and the coil wire, The rotating member has an axial hole through which the wiring passes, thereby providing a rotating electric machine. [Effects of the Invention]

[0007] In one aspect, according to this disclosure, it becomes possible to properly arrange the wiring between the power receiving device and the coil wire using a member having relatively high strength. [Brief explanation of the drawing]

[0008] [Figure 1] This is a configuration diagram showing a vehicle drive system including a drive unit for a rotating electric machine according to Example 1. [Figure 2] This is a schematic cross-sectional view showing a portion of the cross-section of a rotating electric machine. [Figure 3] This is a cross-sectional view showing the configuration of related components at the axial end of the rotor according to Embodiment 1. [Figure 4] These are plan views (two-view drawings) of the subshaft, viewed axially from the X1 side and the X2 side, respectively. [Figure 5A] This is a cross-sectional view along line AA in Figure 4. [Figure 5B] This is a cross-sectional view along line BB in Figure 4. [Figure 6] This is a plan view of the diode module as seen in the axial direction. [Figure 7] These are two-view drawings of the axial end of the rotor shaft. [Figure 8]It is an explanatory diagram of an oil discharge structure between a sub-shaft and a rotor shaft according to Example 1, and is a cross-sectional view at a circumferential position (phase) different from that in FIG. 3. [Figure 9] It is an explanatory diagram of an oil discharge structure between a sub-shaft and a rotor shaft according to a modified example, and is a cross-sectional view at a circumferential position (phase) different from that in FIG. 3. [Figure 10] It is a configuration diagram showing a vehicle drive system 100 including a rotating electric machine 3 according to Example 2. [Figure 11] It is a cross-sectional view showing the configuration of related components at the axial end of the rotor according to Example 2. [Figure 12] It is an explanatory diagram of an oil discharge structure between a sub-shaft and a rotor shaft according to Example 2, and is a cross-sectional view at a circumferential position (phase) different from that in FIG. 11. [Figure 13] It is an explanatory diagram of an oil discharge structure between a sub-shaft and a rotor shaft according to a modified example of Example 2, and is a cross-sectional view at a circumferential position (phase) different from that in FIG. 11. [Figure 14] It is a cross-sectional view showing the configuration of related components at the axial end of the rotor according to a second modified example of Example 2. [Figure 15] It is a cross-sectional view showing the configuration of related components at the axial end of the rotor according to a third modified example of Example 2.

Modes for Carrying Out the Invention

[0009] Hereinafter, each example will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not limited thereto, and the shapes and the like in the drawings may be exaggerated partially for the sake of explanation. Also, in the drawings, for the sake of clarity, only some of the parts having the same attributes and existing in plurality may be provided with reference numerals.

[0010] FIG. 1 is a configuration diagram showing a vehicle drive system 100 including a rotating electric machine 3 according to the present example. FIG. 2 is a schematic cross-sectional view showing a part of the cross-section of the rotating electric machine 3.

[0011] The vehicle drive system 100 has a two-power supply configuration including a low-voltage battery 2A and a high-voltage battery 2B, and includes a vehicle drive device 101. The vehicle drive device 101 includes a rotating electric machine 3 and a drive device 5.

[0012] The low-voltage battery 2A is, for example, a lead battery, and the rated voltage is, for example, 12V.

[0013] The high-voltage battery 2B is, for example, a lithium-ion battery, and the rated voltage is significantly higher than that of the low-voltage battery 2A, for example, the rated voltage is 40V or more. In this embodiment, as an example, it is assumed that the rated voltage of the high-voltage battery 2B is 300V or more. Note that the high-voltage battery 2B may be in the form of a fuel cell or the like.

[0014] The rotating electric machine 3 is of a wound-field type, and the rotor 310 includes a rotor core 312, a rotor coil 316, and a rotor shaft 318 (see FIG. 3 to be described later). The rotor coil 316 is formed by winding coil wires for the field coil around the rotor core 312. Note that the rotor core 312 has tooth portions 3122 protruding radially outward as shown in FIG. 2, and the coil wires for the field coil forming the rotor coil 316 are wound around the tooth portions 3122. A stator 320 is provided on the radially outer side of the rotor 310. The coil wires forming the stator coil 322 are wound around the tooth portions 3210 of the stator core 321 as shown in FIG. 2.

[0015] The drive device 5 includes a microcomputer 50 (hereinafter referred to as "microcontroller 50") and an electric circuit unit 60.

[0016] The microcontroller 50 may be realized, for example, as an ECU (Electronic Control Unit). The microcontroller 50 is connected to various electronic components (other ECUs and sensors) in the vehicle via a network 6 such as a CAN (Controller Area Network).

[0017] The microcontroller 50 receives various commands, such as control commands, from a higher-level ECU (not shown) via the network 6. Based on the control commands, the microcontroller 50 controls the rotating electric machine 3 via the electrical circuit section 60. The microcontroller 50 operates based on power from the low-voltage battery 2A.

[0018] The electrical circuit section 60 includes a smoothing capacitor 62, a power conversion circuit section 63, a power supply circuit section 64, and a power receiving circuit section 65. The power supply circuit section 64 and the power receiving circuit section 65 work in cooperation with the transformer Tr to provide non-contact power to the rotor coil 316. This eliminates wear and improves reliability (durability, etc.) compared to a contact-type power supply configuration. The transformer Tr has a primary coil 741 and a secondary coil 742.

[0019] The smoothing capacitor 62 is installed between the high-potential line 20 and the low-potential line 22 of the high-voltage battery 2B. A resistor R0 for passive discharge may be connected across the smoothing capacitor 62.

[0020] The power conversion circuit 63 is in the form of an inverter, for example, forming a three-phase bridge circuit. The power conversion circuit 63 supplies three-phase AC power to the stator 320 of the rotating electric machine 3 under the control of the microcontroller 50. The power conversion circuit 63 is connected in parallel with the smoothing capacitor 62 between the high-potential side line 20 and the low-potential side line 22. The power conversion circuit 63 includes switching elements SW3 for each arm on the high-potential side and switching elements SW4 for each arm on the low-potential side. The power conversion circuit 63 is controlled by the microcontroller 50 via the drive circuit 52.

[0021] The power supply circuit section 64 includes a bridge circuit section 641 and a drive circuit section 642.

[0022] The bridge circuit section 641 is connected in parallel with the smoothing capacitor 62 and the passive discharge resistor R0 between the high-potential line 20 and the low-potential line 22. The bridge circuit section 641 is in the form of a full bridge circuit and includes switching elements SW1-1, SW1-2 and switching elements SW2-1, SW2-2.

[0023] Switching elements SW1-1 and SW1-2 are connected in series between the high-potential line 20 and the low-potential line 22. One end of the rotor coil 316 is connected between switching elements SW1-1 and SW1-2. Switching elements SW2-1 and SW2-2 are connected in series between the high-potential line 20 and the low-potential line 22, in parallel with switching elements SW1-1 and SW1-2. The other end of the rotor coil 316 is connected between switching elements SW2-1 and SW2-2. Hereinafter, for distinction, the configurations related to switching elements SW1-1 and SW2-1 may be labeled "high-potential side," and the configurations related to switching elements SW1-2 and SW2-2 may be labeled "low-potential side."

[0024] The switching elements SW1-1, SW1-2, SW2-1, and SW2-2 are switched on / off via the drive circuit 642. The switching elements SW1-1, SW1-2, SW2-1, and SW2-2 change the energization state to the rotor coil 316 under the control of the drive circuit 642. The switching elements SW1-1, SW1-2, SW2-1, and SW2-2 are, for example, IGBTs (Insulated Gate Bipolar Transistors), but may also be of other forms such as MOSFETs (Metal Oxide Semiconductor Field-Effect Transistors).

[0025] The drive circuit 642 supplies power to the rotor coil 316 via the power receiving circuit 65 by driving the gates of the switching elements SW1-1, SW1-2, SW2-1, and SW2-2 based on control signals from the microcontroller 50.

[0026] The power receiving circuit section 65 includes a rectifier circuit 652.

[0027] The rectifier circuit 652 is electrically connected between the transformer Tr and the rotor coil 316. The rectifier circuit 652 rectifies the secondary current (drive current) of the transformer Tr and supplies it to the rotor coil 316. The rectifier circuit 652 may be a diode bridge circuit, as shown in Figure 1.

[0028] Next, we will describe the characteristic configuration of this embodiment, mainly referring to Figure 3 and subsequent figures.

[0029] Figure 3 is a cross-sectional view showing the configuration of related components at the axial end of the rotor 310. The stator 320 is not shown in Figure 3.

[0030] In the following explanation, "axial direction" refers to the direction in which the central axis I of the rotor 310 (see Figure 3, etc.) extends, and "radial direction" refers to the radial direction centered on the central axis I. Therefore, "radial outward" refers to the side away from the central axis I from that position, and "radial inward" refers to the side toward the central axis I from that position. Also, in Figure 3, etc., the X direction parallel to the axial direction is defined. "Axial outward" refers to the side away from the axial center of the rotor 310 from that position, and "axial inward" refers to the side closer to the axial center of the rotor 310 from that position. Furthermore, the "circumferential direction" corresponds to the direction of rotation around the central axis I.

[0031] In this embodiment, a transformer Tr and a module DM (hereinafter also referred to as "diode module DM") related to the rectifier circuit 652 are provided at the axial end of the rotor 310.

[0032] The primary coil 741 of the transformer Tr is provided on the non-rotating ferrite core 711, and the secondary coil 742 is provided on the rotating annular ferrite core 722. The primary coil 741 and the secondary coil 742 may each be in the form of wiring patterns formed on the substrate. The ferrite core 711 is fixed to the cover member CV. The cover member CV faces the X1 side portion of the case CS in the axial direction, and forms a housing space S2 for the diode module DM and transformer Tr between itself and the X1 side portion of the case CS. The cover member CV may be formed as part of the case CS.

[0033] In this embodiment, the diode module DM is arranged so as to overlap the rotor shaft 318 in an axial view. In this case, the centrifugal force that may act on the diode module DM due to the rotation of the rotor shaft 318 can be substantially minimized. For example, the diode module DM may be arranged such that its centroid or center of gravity substantially coincides with the axis of the rotor shaft 318. In a modified example, the diode module DM may be in the form of multiple modules or chips, which may be positioned separately but each may be arranged so as to overlap the rotor shaft 318 in an axial view.

[0034] Furthermore, in this embodiment, the diode module DM is positioned axially outward from the axial end face 3182 of the rotor shaft 318. This improves the ease of assembly of the diode module DM. Specifically, the diode module DM can be assembled using the open space axially outward from the axial end face 3182 of the rotor shaft 318, thereby improving ease of assembly.

[0035] The diode module DM can take any form, but for example, it may be a module body 40 (see Figure 6) which may be in the form of a metal plate and have four diode chips 400 (see Figure 6) on it. The module body 40 may be provided with fastening holes 46. In this case, the diode module DM is fastened to the subshaft 330 (described later) by fasteners 47 that pass through the fastening holes 46. The diode module DM may also be provided with terminals 41 to 44 (see Figure 6). Terminals 41 and 42 are electrically connected to the secondary coil 742. This connection may be achieved by fasteners 48 that fasten terminals 41 and 42 to the ends of the secondary coil 742. Terminals 43 and 44 are electrically connected to the rotor coil 316 via wiring 319 (described later). This connection may be achieved by fasteners 49 that fasten terminals 43 and 44 to the ends 3192 (see Figure 5A) of the wiring 319.

[0036] In this embodiment, as shown in Figure 3, a sub-shaft 330 is provided at the axial end of the rotor shaft 318. The sub-shaft 330 is mounted on the axial end of the rotor shaft 318. The sub-shaft 330 rotates coaxially with the rotor shaft 318.

[0037] Figures 4 to 5B are individual views of the subshaft 330. Figure 4 is a plan view (two-view drawing) of the subshaft 330 viewed axially from the X1 and X2 sides, respectively. Figure 5A is a cross-sectional view along line AA in Figure 4, and Figure 5B is a cross-sectional view along line BB in Figure 4. Figure 6 is a plan view of the diode module DM viewed axially. Figure 7 is a two-view drawing of the axial end of the rotor shaft 318.

[0038] The subshaft 330 may be made of any material, but may be made of a metal such as aluminum. In this case, thermal conductivity is improved, and cooling of the diode module DM and the like on the subshaft 330 is promoted via the oil described later.

[0039] The subshaft 330 may be fixed to the axial end of the rotor shaft 318 in any manner. For example, the subshaft 330 may be fixed to the axial end of the rotor shaft 318 with bolts or the like. In this embodiment, the subshaft 330 is fitted to the axial end of the rotor shaft 318. Specifically, as shown in Figure 3, the subshaft 330 has a shaft hole 332 that is closed on the X1 side and open on the X2 side, and the small-diameter portion 3184 of the axial end of the rotor shaft 318 is fitted into the shaft hole 332. In this case, the fitting of the shaft hole 332 and the small-diameter portion 3184 may involve press-fitting. The rotor shaft 318 is a hollow member and has a main body portion 3180 that is fitted to the rotor core 312, and the X1 side is terminated by a small-diameter portion 3184 which is smaller in diameter than the main body portion 3180. However, in the modified example, the rotor shaft 318 may have an axial end with the same outer diameter as the main body 3180 instead of the small-diameter portion 3184, or it may have an axial end with a larger outer diameter than the main body 3180.

[0040] In this embodiment, as an example, the shaft hole 332 has a non-circular shape (a shape in which a part of a circle is cut in a straight line), as shown in Figure 4, and is key-fittable to the small-diameter portion 3184 of the rotor shaft 318 having a corresponding cross-sectional shape. In this case, the rotor shaft 318 and the sub-shaft 330 are connected in a manner that prevents them from rotating relative to each other. Hereafter, the angular section of the outer shape portion of the shaft hole 332 that is linear when viewed in the axial direction will also be referred to as the "anti-rotation circumferential section," and the other angular sections will also be referred to as the "non-contact circumferential section." In the non-contact circumferential section, a gap may be formed radially between the rotor shaft 318 and the sub-shaft 330.

[0041] The sub-shaft 330 may be rotatably supported by the case CS via a bearing BR. In this case, the X1 side of the rotor shaft 318 is rotatably supported by the case CS via the sub-shaft 330 and the bearing BR. The case CS forms a motor housing chamber S1 that accommodates the rotor 310 and the stator 320. The case CS may be formed from multiple case members. In this embodiment, the sub-shaft 330 can be made of metal (e.g., aluminum), so it can withstand the load from the bearing BR without any strength issues. The bearing BR is provided on the outer circumference (metal portion) of the sub-shaft 330.

[0042] The sub-shaft 330 is configured such that the X2 side is located inside the motor housing chamber S1 and the X1 side is located in the housing space S2 (a space separated from the motor housing chamber S1 in an oil-tight manner), and is sealed to the case CS via a seal portion SL near the axial center. In this case as well, the sub-shaft 330 can be made of metal (for example, aluminum), so it is less prone to deformation (without causing strength problems) even at high rotational speeds, and high sealing performance can be maintained at the seal portion SL. The seal portion SL is provided on the outer circumference (metal portion) of the sub-shaft 330.

[0043] In this embodiment, a diode module DM is provided on the axial end face 337 of the subshaft 330.

[0044] The subshaft 330 has an axial end face 337 on the X1 side where the diode module DM is to be placed, and the axial end face 337 also has an end portion 3192 of the wiring 319. The end portion 3192 is in the form of a terminal portion with a fastening hole and is fastened to terminals 41 and 42 of the diode module DM.

[0045] Furthermore, the sub-shaft 330 may have a screw hole 334 into which a fastener 47 for fastening the diode module DM to the sub-shaft 330 is screwed.

[0046] In this embodiment, by arranging the diode module DM on the subshaft 330 in this manner, the diode module DM can be protected from the oil in the motor housing chamber S1 formed by the case CS, while being efficiently cooled via the oil in the oil passage 70 in the rotor shaft 318.

[0047] Specifically, in this embodiment, the diode module DM is positioned axially outward from the seal portion SL between the subshaft 330 and the case CS, thereby protecting the diode module DM from oil in the motor housing chamber S1. In other words, in this embodiment, the motor housing chamber S1 is sealed to be oil-tight axially inward from the diode module DM, so that the diode module DM and transformer Tr in the housing space S2 are protected from oil in the motor housing chamber S1. Therefore, according to this embodiment, it is possible to supply oil to the motor housing chamber S1 and the oil passage 70 in the rotor shaft 318 while preventing oil from coming into contact with the diode module DM and transformer Tr.

[0048] Furthermore, the oil passage 70 within the rotor shaft 318 can be thermally connected to the diode module DM via the sub-shaft 330. The oil in the oil passage 70 can directly contact the sub-shaft 330, allowing for efficient cooling of the diode module DM by the oil circulating within the oil passage 70. Additionally, since the rotor shaft 318 extends into both the motor housing chamber S1 and the housing space S2 in a manner that straddles the seal portion SL, it can also function as a heat sink, releasing heat from the housing space S2 (for example, heat from the rotor core 312) into the housing space S2.

[0049] Further details regarding the structure of the oil passages related to the circulating oil within the oil passage 70 will be described later with reference to Figure 8.

[0050] In this embodiment, the sub-shaft 330 has an axial hole 338 through which wiring 319, which electrically connects the diode module DM and the rotor coil 316, passes. The axial hole 338 may penetrate the outer peripheral wall portion 333 of the sub-shaft 330 in the axial direction, with openings on both axial sides. The wiring 319 may be an insulated conductor wire, and its cross-sectional shape can be any shape such as rectangular or circular. Alternatively, the wiring 319 may be in the form of a metal plate (busbar). The wiring 319 may be fixed within the axial hole 338 by molded resin 3382. In this case, the molded resin 3382 may be formed by injection molding or the like. This prevents problems such as the wiring 319 being displaced radially outward due to centrifugal force when the rotor 310 rotates. The molded resin 3382 may be made of a material with relatively high thermal conductivity. Alternatively, the wiring 319 may be fixed within the axial hole 338 with adhesive, or fixed by mechanical engagement such as press-fitting.

[0051] Furthermore, the sub-shaft 330 has a groove 339 on its X2-side end face that is recessed towards X1 and extends radially. The radially inner side of the groove 339 communicates with the axial hole 338, and the radially outer side opens radially. In this case, the wiring 319 taken out from the X2 side of the axial hole 338 can be pulled out radially outward from the sub-shaft 330 through the groove 339. The radially outer end 3194 of the wiring 319 is joined to the lead wire from the coil end of the rotor coil 316. For this purpose, the groove 339 preferably faces the coil end radially from the radially inner side. In this case, the length of the portion of the wiring 319 that is pulled out radially outward from the groove 339 can be minimized to the rotor coil 316. The wiring 319 may be fixed to the groove 339 by a molded resin 3383. In this case as well, the molded resin 3383 may be formed by injection molding or the like. This prevents problems such as the wiring 319 flapping due to centrifugal force when the rotor 310 rotates. In the modified example, the wiring 319 may be fixed to the groove 339 with adhesive, or it may be fixed by mechanical engagement such as press-fitting.

[0052] The molded resin 3383 may be formed separately from the molded resin 3382. In this case, the wiring 319 may be fixed by the molded resin 3382 while passing through the axial hole 338. Then, the X2 side of the wiring 319 may be bent radially outward before the molded resin 3383 is formed.

[0053] In this embodiment, by utilizing the sub-shaft 330 mounted on the axial end of the rotor shaft 318, the arrangement of the diode module DM and various wirings related to the diode module DM (wirings 319, etc.) can be easily realized. Furthermore, since the axial extension range of the wiring 319 overlaps with that of the oil passage 70, it can be efficiently cooled by the oil in the oil passage 70.

[0054] In the illustrated example, the X2-side end of the outer peripheral wall portion 333 of the sub-shaft 330 has a flange shape with an enlarged diameter. This allows the groove portion 339 to extend relatively far outward in the radial direction, reducing the exposed length (radial exposed length) of the wiring 319. The sub-shaft 330 may have a function to adjust the rotational balance at the X2-side end of the outer peripheral wall portion 333. Specifically, the sub-shaft 330 may have a function to correct rotational imbalance by cutting at the X2-side end of the outer peripheral wall portion 333. Figure 3 shows a cut hole 3334. The depth (axial dimension), circumferential position, number, etc. of the cut hole 3334 may be adjusted for rotational balance adjustment.

[0055] Next, referring to Figures 4 through 7 and then to Figure 8, we will explain further details of the oil passage structure related to the circulating oil in the oil passage 70.

[0056] Figure 8 is an explanatory diagram of the oil discharge structure between the subshaft 330 and the rotor shaft 318, and is a cross-sectional view at a different circumferential position (phase) than Figure 3.

[0057] The oil discharge structure between the subshaft 330 and the rotor shaft 318 relates to a structure that discharges the oil flowing towards the X1 side in the oil passage 70 into the space within the motor housing chamber S1.

[0058] In this embodiment, the axial end face 3182 on the X1 side of the rotor shaft 318 abuts against the subshaft 330 in the axial direction, but the axial end on the X1 side of the rotor shaft 318 has a discharge opening 82 that opens radially. Any number of discharge openings 82 may be provided. In this embodiment, as an example, the discharge openings 82 are provided in pairs at diagonal positions in the non-contact circumferential section described above, as shown in Figure 7. The small diameter portion 3184 of the rotor shaft 318 may have a cylindrical shape at the X1 side end, and in this case, the outer diameter may be slightly smaller than the inner diameter of the subshaft 330 (inner diameter of the hollow interior 335) at the corresponding axial position.

[0059] In this embodiment, a return passage 84 is formed radially between the subshaft 330 and the rotor shaft 318. The X1-side end of the return passage 84 communicates with the discharge opening 82 and extends axially. Any number of return passages 84 may be provided at any position in the circumferential direction. In this embodiment, as an example, the return passages 84 are provided in pairs at diagonal positions in the non-contact circumferential section described above. In other words, the return passages 84 are formed by the gap that forms the non-contact circumferential section described above.

[0060] The return channel 84 is continuous with the radial channel 85 at its X2-side end. The radial channel 85 is formed on the X2-side end face of the subshaft 330. Specifically, a radial channel 85 is formed on the X2-side end face of the subshaft 330, recessed toward the X1 side and extending radially. The radial channel 85 may be formed at a different circumferential position (for example, a circumferential position shifted by 90 degrees) from the groove 339 described above. The radial channel 85 has its radially inner side communicating with the X2-side end of the return channel 84, and its radially outer side opening radially. The X2 side of the radial channel 85 is bounded by a stepped surface 3186 between the small-diameter portion 3184 and the main body portion 3180 of the rotor shaft 318.

[0061] With this oil discharge structure, as shown by arrows R80 to R83 in Figure 8, the oil flowing through the oil passage 70 towards X1 (arrow R80) reaches the X1-side end of the hollow interior 335 of the subshaft 330, and then flows radially outward through the discharge opening 82 (arrow R81). The oil then flows axially towards X2 through the return passage 84 in a reversing manner (arrow R82), and is discharged radially outward through the radial passage 85 (arrow R83). When the rotor 310 rotates, centrifugal force promotes the radially outward flow of oil in the radial passage 85, and the oil is discharged radially outward. As shown in Figure 8, in this embodiment, the axial end of the rotor coil 316 is located radially outward of the radial passage 85. In this case, the axial end (i.e., the coil end) of the rotor coil 316 can be efficiently cooled by the oil discharged radially outward through the radial passage 85.

[0062] In this embodiment, the oil flowing through the oil passage 70 can be returned to the motor housing chamber S1 through the hollow interior 335 of the subshaft 330. This efficiently increases the contact area between the subshaft 330 and the oil, allowing the subshaft 330 to be efficiently cooled by the oil. As a result, the diode module DM can be efficiently cooled, and the wiring 319 (see Figures 3 and 5A) can also be efficiently cooled.

[0063] Figure 9 is an explanatory diagram of the oil discharge structure between the subshaft 330A and the rotor shaft 318A, which is a modified example of Example 1, and is a cross-sectional view at a different circumferential position (phase) than Figure 3.

[0064] In this modified example, the subshaft 330A and the rotor shaft 318A are connected by a key fitting. Even when the power supply method is contact type, the radial gap between the key groove 333A and the key 31842A of the key fitting can form a return flow path 84. In this modified example, the key 31842A is not formed in the small diameter portion 3184A of the rotor shaft 318A of the rotor 310A, but it may be formed therein.

[0065] Next, other embodiments that may be implemented instead of the embodiments described above will be described. For the purpose of distinction, the embodiments described above will also be referred to as "Embodiment 1," and the other embodiments described below will be referred to as "Embodiment 2." In the description of the other embodiments described below, components that may be the same as those in Embodiment 1 above may be given the same reference numerals and their descriptions may be omitted.

[0066] Figure 10 is a configuration diagram showing the vehicle drive system 100B, including the rotating electric machine 3B of the vehicle drive unit 101B according to Embodiment 2.

[0067] The rotor 310B according to Embodiment 2 differs from the rotor 310 according to Embodiment 1 in that its power supply method is contact-type. That is, while the rotor 310 according to Embodiment 1 supplies power to the rotor coil 316 in a non-contact manner using a transformer Tr, the rotor 310B according to Embodiment 2 supplies power to the rotor coil 316 in a contact manner using brushes 69 and slip rings 71.

[0068] Specifically, the positive terminal end of the rotor coil 316 is electrically connected to the switching element SW1 of the bridge circuit section 641B and the diode D1 via the positive terminal slip ring 71 and brush 69. Furthermore, the switching element SW2 is connected in series with the diode D2 in such a manner that it is connected to the low-potential anode of the diode D2. The negative terminal end of the rotor coil 316 is electrically connected to the switching element SW2 and the diode D2 via the negative terminal slip ring 71 and brush 69.

[0069] Figure 11 is a cross-sectional view showing the configuration of related components at the axial end of the rotor 310B according to Embodiment 2. The stator 320 is not shown in Figure 11.

[0070] In Embodiment 2, the slip rings 71 are provided on the subshaft 330B. The slip rings 71 may be provided in pairs, with a positive side and a negative side, at different positions in the axial direction. Each slip ring 71 is positioned axially outward from the seal portion SL. This prevents oil from the motor housing chamber S1 from coming into contact with the slip rings 71 and brushes 69.

[0071] In Embodiment 2, the wiring 319B from the slip ring 71 to the rotor coil 316 is provided in the same manner as the wiring 319 in Embodiment 1 described above, passing through the axial hole 338B of the subshaft 330B. In other words, the wiring 319B is substantially the same as the wiring 319 in Embodiment 1 described above, except that the connection target on the X1 side is different. Therefore, the molded resin 3382B and molded resin 3383 may be provided in the same manner. In addition, the wiring from the positive slip ring 71 and the wiring from the negative slip ring 71 of the wiring 319B may be arranged at diagonal positions.

[0072] In Example 2, the molded resin 3382B forms the outer circumference of the subshaft 330B at the X1 side end of the subshaft 330B. However, even in this case, the subshaft 330B has a metal outer circumference on the X2 side, and the seal portion SL and bearing BR are arranged on the metal outer circumference. This allows for high sealing performance at the seal portion SL without causing strength problems, and also allows for receiving loads from the bearing BR.

[0073] Figure 12 is an explanatory diagram of the oil discharge structure between the subshaft 330B and the rotor shaft 318 according to Embodiment 2, and is a cross-sectional view at a different circumferential position (phase) than Figure 11.

[0074] The oil discharge structure according to Example 2 is the same as the oil discharge structure according to Example 1 described above.

[0075] According to the oil discharge structure of Embodiment 2, as shown by arrows R120 to R123 in Figure 12, the oil flowing through the oil passage 70 towards X2 (arrow R120) reaches the X1 side end of the hollow interior 335 of the subshaft 330B, and then flows radially outward through the discharge opening 82 (arrow R121). The oil then flows axially towards X2 through the return passage 84 (arrow R122) and is discharged radially outward through the radial passage 85 (arrow R123). When the rotor 310 rotates, centrifugal force promotes the flow of oil radially outward in the radial passage 85, and the oil is discharged radially outward. As shown in Figure 12, in this embodiment, the axial end of the rotor coil 316 is located radially outward of the radial passage 85. In this case, the axial end (i.e., coil end) of the rotor coil 316 can be efficiently cooled by the oil discharged radially outward through the radial passage 85.

[0076] The same effects as those described in Example 1 are achieved in Example 2.

[0077] Figure 13 is an explanatory diagram of the oil discharge structure between the subshaft 330C and the rotor shaft 318C according to the first modification of Example 2, and is a cross-sectional view at a different circumferential position (phase) than Figure 11.

[0078] In the first modified example, the subshaft 330C and the rotor shaft 318C are connected by a key fitting. Even when the power supply method is contact type, the radial gap between the key groove 333C and the key 31842C of the key fitting can form a return flow path 84. In this modified example, the key 31842C is not formed in the small diameter portion 3184C of the rotor shaft 318C of the rotor 310C, but it may be formed therein.

[0079] Figure 14 is a cross-sectional view showing the configuration of related components at the axial end of the rotor 310D according to a second modification of Embodiment 2. The stator 320 is not shown in Figure 14.

[0080] The rotor 310D according to the second modification has the following differences in addition to the differences in Example 2 compared to Example 1 described above.

[0081] In the second modified example, the rotor shaft 318D does not have an oil passage 70 and is solid. Also, the subshaft 330D is open on the X1 side. That is, the subshaft 330D does not cover the axial end face 3182D on the X1 side of the rotor shaft 318D. In this case, a seal portion SL2 such as an O-ring may be provided between the subshaft 330D and the rotor shaft 318D. The axial end face 3182D on the X1 side of the rotor shaft 318D terminates on the X1 side of the seal portion SL. In this case, as with the embodiments described above (including the modified examples), the rotor shaft 318D can increase the strength of the seal portion SL in the subshaft 330D, thereby stabilizing the sealing performance by the seal portion SL. Note that the subshaft 330D terminates on the X2 side of the axial end face on the X1 side.

[0082] Even with this second modification, although the cooling effect of oil cannot be obtained, the corresponding effects of Example 1 described above can be obtained.

[0083] Figure 15 is a cross-sectional view showing the configuration of related components at the axial end of the rotor 310E according to a third modification of Embodiment 2. The stator 320 is not shown in Figure 15.

[0084] The rotor 310E according to the third modification has the following differences in addition to the differences in Example 2 compared to Example 1 described above.

[0085] In the third modified example, the rotor shaft 318E does not have an oil passage 70 and is solid.

[0086] Even with this third modification, although the cooling effect of oil cannot be obtained, the corresponding effects of Example 1 described above can be obtained.

[0087] Although each embodiment has been described in detail above, the invention is not limited to any particular embodiment, and various modifications and changes are possible within the scope described in the claims. Furthermore, it is possible to combine all or more of the components of the embodiments described above.

[0088] With regard to each of the above embodiments, the following is further disclosed.

[0089] [Note 1] stator and, A wound field rotor having a rotor core and rotor shaft around which coil wires are wound, A rotating member having an outer circumference formed of a metal material, mounted on the axial end of the rotor shaft, and rotating coaxially with the rotor shaft and together with the rotor shaft, A power supply device electrically connected to the power source, A power receiving device provided on the rotating member, electrically connected to the coil wire, and receiving power from the power supply device in a contact or non-contact manner, The rotating member is provided axially with wiring that electrically connects the power receiving device and the coil wire, The rotating member is a rotating electric machine having an axial hole through which the wiring passes.

[0090] [Note 2] The aforementioned wiring is fixed to the axial hole by the first resin material, as described in Appendix 1, for the rotating electric machine.

[0091] [Note 3] The rotating member further has a groove through which the wiring passes, The groove portion communicates with the axial hole and extends in the radial direction. The aforementioned wiring is fixed to the groove portion by a second resin material, as described in Appendix 2, for the rotating electric machine.

[0092] [Note 4] A case forming a housing space for housing the stator and the winding field rotor, Further comprising, between the rotating member and the case in the radial direction, a sealing portion that oil-tightly partitions the housing space, The sealing portion is provided on the outer circumference of the rotating member, as described in Appendix 1 of the rotating electric machine.

[0093] [Note 5] The case further comprises a housing space for housing the stator and the winding field rotor, The rotating member is rotatably supported in the case via a bearing provided on its outer circumference, as described in Appendix 4, for the rotating electric machine.

[0094] [Note 6] The coil wire has a coil end portion that is axially outward from the axial end face of the rotor core. The groove portion is open on the radially outer side and faces the coil end portion radially from the radially inner side, as described in any one of the appendices 1 to 5 of the rotating electric machine. [Explanation of Symbols]

[0095] 2 Case, 3 Rotating electric machine, 320 Stator, 310 Rotor (winding field rotor), 318 Rotor shaft, 316 Rotor coil (coil wire), coil end section 3162, 319 Wiring, 330 Subshaft (rotating member), 338 Axial hole, 3382 Molding resin (first resin material), 3383 Molding resin (second resin material), 339 Groove section, 64 Power supply circuit section (power supply device), 65 Power receiving circuit section (power receiving device)

Claims

1. stator and, A wound field rotor having a rotor core and rotor shaft around which coil wires are wound, A rotating member having an outer circumference formed of a metal material, mounted on the axial end of the rotor shaft, and rotating coaxially with the rotor shaft and together with the rotor shaft, A power supply device electrically connected to the power source, A power receiving device provided on the rotating member, electrically connected to the coil wire, and receiving power from the power supply device in a contact or non-contact manner, The rotating member is provided axially with wiring that electrically connects the power receiving device and the coil wire, The rotating member is a rotating electric machine having an axial hole through which the wiring passes.

2. The rotating electric machine according to claim 1, wherein the wiring is fixed in the axial hole with a first resin material.

3. The rotating member further has a groove through which the wiring passes, The groove portion communicates with the axial hole and extends in the radial direction. The rotating electric machine according to claim 2, wherein the wiring is fixed to the groove portion by a second resin material.

4. A case forming a housing space for housing the stator and the winding field rotor, Further comprising, between the rotating member and the case in the radial direction, a sealing portion that oil-tightly partitions the housing space, The rotating electric machine according to claim 1, wherein the sealing portion is provided on the outer circumference of the rotating member.

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