Vehicle drive system

Abstract

To efficiently place the rotation angle sensor inside the case in a configuration where the rotating electric machine and inverter device are housed in a common housing chamber of the case.SOLUTION: A vehicle drive device is disclosed, comprising a rotating electric machine having a rotor and a stator, an inverter device electrically connected to the rotating electric machine, a control board controlling the rotating electric machine, a rotation angle sensor acquiring rotation information of the rotor, and a case housing the rotating electric machine, inverter device, and control board in a common housing chamber, the rotation angle sensor having a sensing part mounted on the control board and a detected part provided on the shaft section of the rotor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a vehicle drive system. [Background technology]

[0002] To construct a rotation angle sensor that acquires rotation information of the rotor shaft, a technique is known in which a detected portion is provided on the axial end face and a detection element is provided at a position on the control board opposite the detected portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-075960 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-described conventional technology, a motor housing that houses a motor and a motor cover that houses a control board are provided, and the accommodation chambers within the motor housing and motor cover are divided into two by a heat sink provided between the motor housing and the motor cover and equipped with a bearing that supports the shaft portion. As a result, the problem is that the axial size tends to increase due to the provision of a detection target on the axial end face of the rotor shaft portion.

[0005] Therefore, in one aspect, an object of the present disclosure is to efficiently arrange a rotation angle sensor within a case in a configuration in which a rotating electric machine and an inverter device are housed in a common housing chamber of the case. [Means for solving the problem]

[0006] In one aspect, a rotating electric machine having a rotor and a stator; an inverter device electrically connected to the rotating electric machine; a control board for controlling the rotating electric machine; a rotation angle sensor for acquiring rotation information of the rotor; a case that houses the rotating electric machine, the inverter device, and the control board in a common housing chamber, The rotation angle sensor includes a sensing portion mounted on the control board and a detected portion provided on a shaft portion of the rotor. [Effects of the Invention]

[0007] According to one aspect of the present disclosure, in a configuration in which a rotating electric machine and an inverter device are housed in a common housing chamber of a case, it is possible to efficiently arrange a rotation angle sensor inside the case. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an example of an electric circuit including a rotating electric machine; [Figure 2] FIG. 1 is a skeleton diagram of a vehicle drive system including a rotating electric machine. [Figure 3] 1 is a cross-sectional view schematically showing a main part of a vehicle drive device according to an embodiment of the present invention. [Figure 4A] 1 is a perspective view of a motor drive device according to an embodiment of the present invention as viewed from the X1 side. [Figure 4B] FIG. 2 is a plan view schematically showing a control board according to the present embodiment. [Figure 5] FIG. 4 is an enlarged view of a portion Q1 in FIG. [Figure 6] 10 is a view of the sensor rotor and the sensing unit on the control board viewed in the axial direction from the X2 side. FIG. [Figure 7] 6 is a view seen in the axial direction from the X2 side when the sensor rotor in FIG. 5 is removed. [Figure 8] FIG. 8 is an explanatory diagram of the configuration of a sensor coil, and is an enlarged view of a portion Q2 in FIG. 7. [Figure 9] 3 is a diagram illustrating the relationship between a sensing unit and a sensor rotor of the rotation angle sensor according to the present embodiment. FIG. [Figure 10]3 is a view showing a portion of the sensor rotor according to the present embodiment that faces a sensing portion in the axial direction, as viewed in the axial direction. FIG. [Figure 11] 3A and 3B are schematic diagrams illustrating waveforms of sensor outputs (electrical signals) generated by a sensing unit according to the present embodiment. [Figure 12] FIG. 10 is a cross-sectional view schematically showing a part of a vehicle drive device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not intended to limit the scope of the invention. In addition, shapes and the like in the drawings may be partially exaggerated for the sake of explanation.

[0010] Below, an overview will be given of the electrical system (control system) of the vehicle drive device 10 of this embodiment and the entire drive system including the vehicle drive device 10 of this embodiment, and then the vehicle drive device 10 of this embodiment will be described in detail.

[0011] [Vehicle drivetrain electrical system] Fig. 1 is a schematic diagram of an example of an electric circuit 200 including a rotating electric machine 1 of this embodiment. Fig. 1 also shows a control device 500. In Fig. 1, dotted arrows associated with the control device 500 indicate the exchange of information (signals and data).

[0012] The rotating electric machine 1 is driven through the control of the inverter INV by the control device 500. In the electric circuit 200 shown in FIG. 1, the rotating electric machine 1 is electrically connected to the power source Va via the inverter INV. The inverter INV includes, for example, power switching elements (e.g., MOSFETs: Metal-Oxide-Semiconductor Field Effect Transistors, IGBTs: Insulated Gate Bipolar Transistors, etc.) on the high-potential side and low-potential side of the power source Va for each phase, and the power switching elements on the high-potential side and the power switching elements on the low-potential side form upper and lower arms. The inverter INV may include multiple pairs of upper and lower arms for each phase. Each power switching element may be PWM (Pulse Width Modulation) driven under the control of the control device 500 so as to generate a desired rotational torque. The power source Va may be, for example, a battery with a relatively high rated voltage, such as a lithium-ion battery or a fuel cell.

[0013] In this embodiment, as in the electric circuit 200 shown in Fig. 1, a smoothing capacitor C is electrically connected in parallel with the inverter INV between the high potential side and the low potential side of the power supply Va. Note that multiple sets of smoothing capacitors C may be electrically connected in parallel with each other between the high potential side and the low potential side of the power supply Va. Also, a DC / DC converter may be provided between the power supply Va and the inverter INV.

[0014] [Entire drive system] Fig. 2 is a skeleton diagram of a vehicle drive system 100 including a rotating electric machine 1. Fig. 2 defines an X direction and an X1 side and an X2 side along the X direction. The X direction is parallel to the direction of a first axis A1 (hereinafter also referred to as the "axial direction").

[0015] 2, the vehicle drive system 100 includes a rotating electric machine 1 that serves as a drive source for the wheels W, and a drive transmission mechanism 7 provided in a power transmission path connecting the rotating electric machine 1 and the wheels W. The drive transmission mechanism 7 includes an input member 3, a counter gear mechanism 4, a differential gear mechanism 5, and left and right output members 61, 62.

[0016] The input member 3 has an input shaft 31 and an input gear 32. The input shaft 31 is a rotating member that rotates around the first axis A1. The input gear 32 is a gear that transmits rotational torque (driving force) from the rotating electric machine 1 to the counter gear mechanism 4. The input gear 32 is connected to the input shaft 31 of the input member 3 so as to rotate integrally with the input shaft 31 of the input member 3.

[0017] The counter gear mechanism 4 is disposed in the power transmission path between the input member 3 and the differential gear mechanism 5. The counter gear mechanism 4 has a counter shaft 41, a first counter gear 42, and a second counter gear 43.

[0018] The counter shaft 41 is a rotating member that rotates around the second axis A2. The second axis A2 extends parallel to the first axis A1. The first counter gear 42 is an input element of the counter gear mechanism 4. The first counter gear 42 meshes with the input gear 32 of the input member 3. The first counter gear 42 is connected to the counter shaft 41 so as to rotate integrally with the counter shaft 41.

[0019] The second counter gear 43 is an output element of the counter gear mechanism 4. In this embodiment, for example, the second counter gear 43 is formed to have a smaller diameter than the first counter gear 42. The second counter gear 43 is connected to the counter shaft 41 so as to rotate integrally with the counter shaft 41.

[0020] The differential gear mechanism 5 is disposed on a third axis A3 serving as its rotation axis. The third axis A3 extends parallel to the first axis A1. The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 to left and right output members 61, 62. The differential gear mechanism 5 includes a differential input gear 51 that meshes with the second counter gear 43 of the counter gear mechanism 4. The differential gear mechanism 5 also includes a differential case 52 that houses a pinion shaft, pinion gears, left and right side gears, etc. The left and right side gears are connected to the left and right output members 61, 62 so as to rotate integrally with them, respectively.

[0021] The left and right output members 61, 62 are drivingly connected to the left and right wheels W, respectively. The left and right output members 61, 62 transmit the driving force distributed by the differential gear mechanism 5 to the wheels W. Note that the left and right output members 61, 62 may be composed of two or more members.

[0022] In this way, the rotating electric machine 1 drives the wheels W via the drive transmission mechanism 7. However, in other embodiments, the rotating electric machine 1 may be disposed inside the wheels as a wheel-in motor. In this case, the vehicle drive system 100 may be configured not to include the drive transmission mechanism 7. Also, in other embodiments, multiple rotating electric machines 1 may be provided, with some or all of the drive transmission mechanism 7 being shared.

[0023] [Vehicle drivetrain details] The vehicle drive device 10 includes the above-described rotating electric machine 1, a case 2, and a motor drive device 8.

[0024] FIG. 3 is a cross-sectional view schematically illustrating a main portion of the vehicle drive device 10 of this embodiment. FIG. 3 is a cross-sectional view cut along a plane passing through the first axis A1, which is the rotation axis of the rotating electric machine 1, and illustrates a portion of one axial end side (X1 side) of the rotating electric machine 1. FIG. 4A is a perspective view of the motor drive device 8 as viewed from the X1 side. FIG. 4B is a plan view schematically illustrating the control board 84. Note that in FIG. 4A, the control board 84 of the motor drive device 8 is not illustrated. In the following description, unless otherwise specified, the axial direction refers to the direction in which the first axis A1, which is the rotation axis of the rotating electric machine 1, extends, and the radial direction refers to the radial direction centered on the first axis A1. Therefore, the radially outer side refers to the side away from the first axis A1, and the radially inner side refers to the side toward the first axis A1. The circumferential direction corresponds to the direction of rotation around the first axis A1. As in FIG. 2, FIG. 3 defines the X direction and the X1 side and X2 side along the X direction. In the following description, the terms X1 side and X2 side may be used to indicate the relative positional relationship.

[0025] The vehicle drive device 10 is mounted on a vehicle as part of a vehicle drive system 100, and generates a drive force to move the vehicle forward or backward. The vehicle may be in any form, and may be, for example, a four-wheeled automobile, a bus, a truck, a motorcycle, construction machinery, or the like. The vehicle drive device 10 may be mounted on the vehicle together with another drive source (for example, an internal combustion engine).

[0026] The rotating electric machine 1 has a rotor 310 and a stator 320. The rotating electric machine 1 is an inner rotor type, and the stator 320 is provided so as to surround the outside of the rotor 310 in the radial direction. In other words, the rotor 310 is disposed on the inside of the stator 320 in the radial direction.

[0027] The rotor 310 includes a rotor core 312 and a shaft portion 314 .

[0028] Rotor core 312 may be made of, for example, annular laminated steel plates made of magnetic material. Permanent magnets 325 may be embedded inside rotor core 312. Alternatively, permanent magnets 325 may be attached to the outer circumferential surface of rotor core 312. The arrangement of permanent magnets 325 is optional. Rotor core 312 is fixed to the outer circumferential surface of shaft portion 314 and rotates integrally with shaft portion 314.

[0029] The shaft portion 314 defines a first axis A1, which is the rotation axis of the rotary electric machine 1. The shaft portion 314 is rotatably supported by a cover member 252 (described later) of the case 2 via a bearing 240 on the X1 side of the portion to which the rotor core 312 is fixed. The shaft portion 314 is rotatably supported by the case 2 on the other axial end side (X2 side) of the rotary electric machine 1 via a bearing (not shown) corresponding to the bearing 240. In this way, the shaft portion 314 may be rotatably supported by the case 2 at both axial ends.

[0030] The shaft portion 314 is, for example, in the form of a hollow tube and has a hollow interior 314A. The hollow interior 314A may extend over the entire axial length of the shaft portion 314. The hollow interior 314A can function as an axial oil passage. In this case, the shaft portion 314 may be formed with an oil hole that discharges oil to the coil end portion 322A of the stator 320, etc.

[0031] A sensor rotor 91 of a rotation angle sensor 900 that acquires rotation angle information of the rotor 310 is provided on the shaft portion 314 on the X1 side of the portion to which the rotor core 312 is fixed. A preferred example of the rotation angle sensor 900 will be described later. In a modified example, the rotation angle sensor 900 may be, for example, a resolver or a rotary encoder that uses a sensor element such as a Hall element or a magnetoresistive element.

[0032] The stator 320 includes a stator core 321 and a stator coil 322 .

[0033] Stator core 321 may be made of, for example, laminated steel plates of a circular magnetic material. Teeth (not shown) are formed radially on the inner periphery of stator core 321, protruding radially inward.

[0034] The stator coil 322 may be, for example, a conductor having a rectangular or circular cross section and an insulating coating applied thereto. The stator coil 322 is wound around teeth (not shown) of the stator core 321. Note that, for example, one or more stator coils 322 may be electrically connected in a Y-connection or a Delta-connection in parallel.

[0035] The stator coil 322 has a coil end portion 322A that protrudes from the slot of the stator core 321 outward in the axial direction.

[0036] The case 2 may be made of aluminum, for example. The case 2 may be formed by casting or the like. The case 2 includes a motor case 250 and a cover member 252. The case 2 houses the rotating electric machine 1 and the motor drive device 8. In the case of the vehicle drive system 100 shown in FIG. 2, the case 2 may further house a drive transmission mechanism 7, as schematically shown in FIG. 2.

[0037] The motor case 250 forms a motor housing chamber SP1 that houses the rotating electric machine 1. The motor housing chamber SP1 may be an oil-tight space that contains oil for cooling and / or lubricating the rotating electric machine 1 (and / or the drive transmission mechanism 7). The motor case 250 has a peripheral wall that surrounds the outer side of the rotating electric machine 1 in the radial direction. The motor case 250 may be realized by joining multiple members together. Furthermore, the motor case 250 may be integrated at the other axial end side (X2 side) with another case member that houses the drive transmission mechanism 7.

[0038] The cover member 252 is coupled to one axial end (X1 side) of the motor case 250. The cover member 252 is in the form of a cover that covers one axial end (X1 side) of the motor housing chamber SP1. In this case, the cover member 252 may cover the opening of the one axial end (X1 side) of the motor case 250 in such a manner that it completely or almost completely blocks the opening.

[0039] The cover member 252 forms an inverter accommodating chamber SP2 that accommodates the motor drive device 8. Note that a portion of the inverter accommodating chamber SP2 may be formed by the motor case 250, and conversely, a portion of the motor accommodating chamber SP1 may be formed by the cover member 252.

[0040] The cover member 252 supports the motor drive device 8. For example, the motor drive device 8 may be attached to the cover member 252 in the form of a module, which will be described later. This allows the motor drive device 8 to be partially or entirely assembled to the cover member 252, and then the cover member 252 and the motor case 250 to be joined, improving the ease of assembly of the motor drive device 8.

[0041] The cover member 252 is provided with a bearing 240 that rotatably supports the rotor 310. That is, the cover member 252 has a bearing support portion 2524 that supports the bearing 240. The bearing support portion 2524 refers to the entire axial range of the cover member 252 where the bearing 240 is provided. As described above, in this embodiment, the cover member 252 is axially coupled to the X1-side end portion of the motor case 250, faces the rotating electric machine 1 in the axial direction, and has the bearing support portion 2524 that rotatably supports the rotor 310.

[0042] 3, bearing 240 is provided on the radially outer side of the end portion on the X1 side of shaft portion 314. Specifically, bearing 240 has the radially outer side of the outer race supported by cover member 252, and the radially inner side of the inner race supported by the outer peripheral surface of shaft portion 314. Note that in a modified example, bearing 240 may be configured in the reverse manner, with the radially inner side of the inner race supported by cover member 252, and the radially outer side of the outer race supported by the inner peripheral surface of shaft portion 314.

[0043] 3, the cover member 252 includes an annular bottom portion 2521 centered on the first axis A1 and a peripheral wall portion 2522 protruding from the outer periphery of the bottom portion 2521 toward the other axial end side (X2 side), and the bottom portion 2521 and the peripheral wall portion 2522 define the inverter accommodating chamber SP2. A cylindrical portion 25211 protruding toward the other axial end side (X2 side) is formed in a central portion (a portion centered on the first axis A1) of the other axial end side (X2 side) of the bottom portion 2521, and a bearing support portion 2524 is set in the cylindrical portion 25211. The cylindrical portion 25211 is formed concentrically about the first axis A1.

[0044] The inverter accommodating chamber SP2 may be an empty space, but is preferably sealed with a resin containing a filler with relatively high thermal conductivity. In this case, the resin molded portion may also function to fix the motor driving device 8 (described later) to the cover member 252.

[0045] The cover member 252 is preferably formed of a material (e.g., aluminum) having relatively high thermal conductivity and has a cooling water passage 2528 therein. Water flows through the cooling water passage 2528 as coolant. Note that the water may be water containing LLC (Long Life Coolant), for example. In this case, the coolant flowing through the cooling water passage 2528 can be maintained at a relatively low temperature by dissipating heat in a radiator (not shown) mounted on the vehicle. When the coolant flows through the cooling water passage 2528 of the cover member 252, the heat of the cover member 252 is absorbed by the coolant, thereby cooling the cover member 252. This allows the cover member 252 to have the function of cooling the motor drive device 8 disposed adjacent to it in the axial direction. In other words, heat from the motor drive device 8 is absorbed by the coolant via the cover member 252, facilitating cooling of the motor drive device 8. Note that in a modified example, another refrigerant (e.g., oil) may be used instead of the coolant.

[0046] The cooling water passage 2528 may have any shape when viewed in the axial direction, for example, it may have an annular shape, a spiral shape, or a shape that extends along the circumferential direction while snaking radially outward and inward. Fins or the like may be formed on the cooling water passage 2528. Note that when the cover member 252 is manufactured using a core or the like, the degree of freedom in the shape, etc. of the cooling water passage 2528 can be increased.

[0047] The motor drive device 8 includes a power module 80, a capacitor module 82, and a control board 84.

[0048] In this embodiment, as shown in Fig. 4A, the power modules 80 and the capacitor modules 82 form a plurality of sets (12 sets in the example shown in Fig. 4A) and are arranged along the circumferential direction. The number of sets of power modules 80 and capacitor modules 82 is changed according to the specifications of the rotating electric machine 1. Basically, as the number of sets of power modules 80 and capacitor modules 82 increases, the output of the rotating electric machine 1 increases. Therefore, when designing the rotating electric machine 1, multiple variations can be set, each with a different number of sets of power modules 80 and capacitor modules 82.

[0049] The power modules 80 and capacitor modules 82 are preferably in the form of an integrated assembly in each of a plurality of sets, i.e., the power modules 80 and capacitor modules 82 in each set form an integrated block assembly 89.

[0050] In each of the block assemblies 89, the power modules 80 have the same configuration, and the capacitor modules 82 have the same configuration (electrical characteristics, shape, etc.). This allows replacement and maintenance of each block assembly 89, improving versatility. In this embodiment, in each of the block assemblies 89, the power module 80 includes a sub-module 800 and a heat dissipation member 810.

[0051] Each of the sub-modules 800 forms an upper and lower arm associated with one phase of the inverter INV (see FIG. 1).

[0052] The heat dissipation member 810 is made of a material (e.g., aluminum) having relatively high thermal conductivity. In this embodiment, the heat dissipation member 810 is in the form of a solid block. This allows the heat capacity of the heat dissipation member 810 to be efficiently increased.

[0053] The control board 84 forms part or the entire control device 500 (see FIG. 1 ). The control board 84 may be formed, for example, by a multilayer printed circuit board. The control board 84 is disposed such that the normal direction to the board surface is axially oriented. This allows the control board 84 to be disposed using a small gap in the axial direction. For example, in this embodiment, the control board 84 may be disposed axially between the rotating electric machine 1 and the block assembly 89, as shown in FIG. 3 . More specifically, the control board 84 may be disposed axially between the coil end portion 322A of the rotating electric machine 1 and the power module 80 and capacitor module 82. This allows for efficient placement by utilizing space that would otherwise be dead space. Furthermore, the control board 84 can extend radially outward to a radial position overlapping the coil end portion 322A when viewed in the axial direction, thereby maximizing the area of ​​the control board 84 (the area in which the circuit section is formed).

[0054] As shown in Fig. 4B, the control board 84 is preferably in the form of an annular ring having a central hole 84a through which the shaft portion 314 (see also Fig. 3) of the rotor 310 passes. In this case, the control board 84 can be disposed near any of the multiple power modules 80 arranged along the circumferential direction. This facilitates electrical connection (not shown) between the power semiconductor chips 801, 802 (e.g., gate terminals of power switching elements) (see Fig. 4A) that form the submodule 800 of the power module 80 and the drive circuit 846 (see Fig. 4B) of the control board 84.

[0055] As shown in FIG. 4B , the control board 84 has an annular low-voltage region 841 around the central hole 84a and an annular high-voltage region 842 radially outward of the low-voltage region 841. The high-voltage region 842 and the low-voltage region 841 are electrically insulated from each other via an annular insulating region 843. This allows low-voltage and high-voltage circuits to coexist in each of the two annular regions (the low-voltage region 841 and the high-voltage region 842) of the control board 84. The high-voltage region 842 of the control board 84 is provided with circuit sections and elements that handle high voltages related to the power supply Va. For example, the high-voltage region 842 may be provided with a drive circuit 846 for driving the power semiconductor chips 801 and 802 as a high-voltage electronic component. The low-voltage region 841 may also be provided with a microcomputer 502 and a power supply circuit 503 that implement the control device 500 as low-voltage electronic components. The control board 84 may also be mounted with electronic components for an electric oil pump that circulates oil within the motor housing chamber SP1.

[0056] In this way, according to this embodiment, the motor drive device 8 is arranged between the cover member 252 and the rotating electric machine 1, so that the overall size of the vehicle drive device 10 can be reduced compared to a comparative example (not shown) in which the motor drive device is mounted outside the motor case.

[0057] In particular, according to this embodiment, by providing the bearing support portion 2524 in the cover member 252 and arranging the motor drive device 8 between the cover member 252 and the rotating electric machine 1 in the axial direction, it is possible to reduce the axial size of the vehicle drive device 10. Specifically, if the motor drive device 8 is provided axially on the X1 side of the cover member 252, a separate cover member is required to cover the X1 side of the motor drive device 8, which tends to increase the axial size of the vehicle drive device 10. In this regard, according to this embodiment, the cover member 252 can function as an X1-side cover not only for the rotating electric machine 1 but also for the motor drive device 8, so it is possible to reduce the axial size of the vehicle drive device 10.

[0058] Furthermore, in this embodiment, the bearing support portion 2524 of the cover member 252 is disposed radially inward of the motor drive device 8 (such as the power module 80 and the capacitor module 82) as viewed in the axial direction, and overlaps the motor drive device 8 as viewed in the radial direction. This allows the motor drive device 8 to be disposed axially between the cover member 252 and the rotating electric machine 1, thereby further effectively reducing the axial size of the vehicle drive device 10.

[0059] Furthermore, according to this embodiment, a bracket having a bearing support portion corresponding to the bearing support portion 2524 is not provided between the motor drive device 8 and the rotating electric machine 1 in the axial direction. This reduces the number of parts and the axial distance between the motor drive device 8 and the rotating electric machine 1 compared to a configuration in which such a bracket is provided, and as a result, the axial size of the vehicle drive device 10 can be reduced as described above. Furthermore, because there is no wall portion (bracket) separating the motor drive device 8 and the rotating electric machine 1 in the axial direction, the length of the wiring between the motor drive device 8 and the rotating electric machine 1 can be reduced, and the efficiency of the wiring between the motor drive device 8 and the rotating electric machine 1 can be improved.

[0060] Furthermore, according to this embodiment, when the cooling water passage 2528 is formed in the cover member 252, the cover member 252 can be thermally connected (connected in a manner that allows heat conduction) to the motor drive device 8. That is, the motor drive device 8 can be cooled by the cooling water in the cooling water passage 2528 via the cover member 252. Since the cooling water can be stably flowed through the cooling water passage 2528, the cooling of the motor drive device 8 can be stabilized. Furthermore, if the flow rate of the cooling water can be controlled, it is also possible to optimize the cooling according to the state of the motor drive device 8.

[0061] Furthermore, according to this embodiment, by shortening the axial distance between the motor drive device 8 and the rotating electric machine 1, it becomes possible to cool not only the motor drive device 8 but also part of the rotating electric machine 1 using the cover member 252 (cover member 252 having the cooling water passage 2528).

[0062] Furthermore, in this embodiment, the capacitor module 82 is disposed closer to the X1 side than the control board 84. This configuration allows the control board 84 to have a larger diameter (or be disposed radially outward). Specifically, as shown in FIG. 3 , the control board 84 can extend radially outward to a position where it overlaps with the capacitor module 82 or extends radially outward beyond the capacitor module 82 in an axial view. In this way, this embodiment increases the degree of freedom in the location and size of the control board 84. However, in a modified example, the X2-side end of the capacitor module 82 may be disposed so as to overlap with the coil end portion 322A in a radial view. In this case, instead of increasing the diameter of the control board 84, the axial size of the capacitor module 82 can be increased (to increase its capacity).

[0063] Next, a preferred configuration of the rotation angle sensor 900 in the above-described embodiment will be described with reference to FIG. 5 and subsequent figures.

[0064] Fig. 5 is an enlarged view of part Q1 in Fig. 3. Fig. 6 is a view from the X2 side showing the relationship between the sensor rotor 91 and the sensing unit 92 on the control board 84, and Fig. 7 is a view from the X2 side when the sensor rotor 91 in Fig. 5 is removed, as viewed in the axial direction. Fig. 8 is an explanatory diagram of the configuration of the sensor coil 921, and is an enlarged view of part Q2 in Fig. 7.

[0065] The rotation angle sensor 900 includes a sensor rotor 91 and a sensing unit 92 .

[0066] The sensor rotor 91 is made of a conductor and rotates integrally with the rotor 310. As shown in Fig. 6, the sensor rotor 91 has an annular shape having a circular center hole 911 centered on the first axis A1. The sensor rotor 91 may be attached so as to rotate together with the shaft portion 314 by having the shaft portion 314 pass through the center hole 911. For example, the shaft portion 314 may be formed with a radial recess or protrusion, and the inner circumferential edge of the center hole 911 of the sensor rotor 91 may be formed with a radial protrusion or recess that fits into the radial recess or protrusion of the shaft portion 314.

[0067] The sensor rotor 91 has an outer diameter that changes periodically. As a result, the outer diameter of the sensor rotor 91 at a circumferential position axially facing the sensing unit 92 changes periodically every time the rotation angle of the rotor 310 changes by a predetermined angle. The predetermined angle may be determined appropriately during design depending on the number of magnetic poles, etc. In this embodiment, the sensor rotor 91 has four radially alternating convex and concave portions per revolution. In this case, the outer diameter of the sensor rotor 91 at a circumferential position axially facing the sensing unit 92 changes periodically every time the rotation angle of the rotor 310 changes by 90 degrees.

[0068] In a modified example, the sensor rotor 91 may have a periodically changing thickness (axial thickness) instead of or in addition to the periodically changing outer diameter. In this case, the thickness of the sensor rotor 91 at a circumferential position axially facing the sensing unit 92 periodically changes every time the rotation angle of the rotor 310 changes by a predetermined angle.

[0069] The sensing unit 92 is mounted on the control board 84. This allows the wiring between the sensing unit 92 and the control device 500 to be easily achieved by wiring within the control board 84, and also makes it possible to shorten the length of the wiring between the sensing unit 92 and the control device 500.

[0070] The sensing unit 92 is disposed adjacent to and facing the sensor rotor 91 in the axial direction. As shown in FIG. 4B , the control board 84 may be arc-shaped when viewed in the axial direction, and the sensing unit 92 may extend only along a portion of the entire circumference of the control board 84. In this embodiment, the control board 84 has a protruding region 840 ( FIG. 4B ) that protrudes radially inward around the periphery of the central hole 84a. The sensing unit 92 (not shown in FIG. 4B , see FIG. 7 , etc.) is mounted in the protruding region 840. The protruding region 840 forms a portion of the central hole 84a of the control board 84 and extends radially inward relative to other circumferential portions, as shown in FIG. 4B . This allows the sensing unit 92 to be positioned radially adjacent to the shaft portion 314, thereby enabling the sensor rotor 91 to have a smaller diameter. However, in a modified example, the central hole 84a may be circular, and the sensing unit 92 may be formed around the circular central hole 84a.

[0071] The sensing unit 92 detects the rotation angle of the rotor 310 using eddy currents. FIGS. 9 to 11 are explanatory diagrams of the detection principle of the sensing unit 92. FIG. 9 is a diagram showing the relationship between the sensing unit 92 and the sensor rotor 91 of the rotation angle sensor 900, and FIG. 10 is a diagram showing the portion of the sensor rotor 91 that faces the sensing unit 92 in the axial direction, as viewed in the axial direction. FIG. 11 is a schematic diagram explaining the waveform of the sensor output (electrical signal) generated by the sensing unit 92. In FIG. 11, the horizontal axis represents the rotation angle of the rotor 310, and the vertical axis represents the magnitude of the sensor output, and the time-series waveform of the sensor output (electrical signal) generated by the sensing unit 92 is schematically shown. Note that FIG. 11 schematically shows the time-series waveform for a predetermined angle (90 degrees in this embodiment) of the rotation angle of the rotor 310.

[0072] 6 to 8, the sensing unit 92 includes a sensor coil 921 and a processing circuit unit 922. The processing circuit unit 922 may be realized by the above-mentioned microcomputer 502. Furthermore, some or all of the functions of the processing circuit unit 922 may be realized by an external control device (not shown).

[0073] 9, the sensor coil 921 may be formed on the surfaces of both sides of the control board 84. In a modified example, the sensor coil 921 may be formed on an inner layer of the control board 84 instead of or in addition to the surfaces of both sides of the control board 84. The sensor coil 921 may be formed of, for example, a printed conductor. The sensor coil 921 is wound around a central axis O that is parallel to the X direction.

[0074] A plurality of sensor coils 921 may be provided along the circumferential direction. For example, four sets of sensor coils 921 may be arranged along the circumferential direction as shown in FIG.

[0075] The processing circuit unit 922 generates eddy currents in the sensor rotor 91 by energizing the sensor coil 921. Specifically, as shown schematically in FIG. 9, when the sensor coil 921 is energized, a magnetic flux B1 is generated that penetrates the sensor coil 921. When the magnetic flux B1 that penetrates the sensor coil 921 comes into contact with the surface of the sensor rotor 91 that faces the sensor coil 921 in the axial direction, an eddy current is generated on the surface of the sensor rotor 91. In FIG. 10, the manner in which the eddy current is generated is schematically indicated by an arrow Ie. Note that while FIG. 10 schematically illustrates eddy currents in a specific direction, the direction of the eddy current is determined by the direction of the current flowing through the sensor coil 921. The eddy current is generated in a direction that generates a magnetic flux that reduces the magnetic flux B1. Therefore, the eddy current generates a magnetic flux B2 (not shown) that reduces the magnetic flux B1. The magnitude of the magnetic flux B2 is proportional to the magnitude of the eddy current. The magnitude of the eddy current increases as the surface area of ​​the portion of the sensor rotor 91 axially facing the sensor coil 921 increases. In this embodiment, since the sensor rotor 91 has an outer diameter that changes periodically as described above, the surface area of ​​the portion of the sensor rotor 91 axially facing the sensor coil 921 changes as the rotation angle of the rotor 310 changes. More specifically, the surface area of ​​the portion of the sensor rotor 91 axially facing the sensor coil 921 changes sinusoidally as the rotation angle of the rotor 310 changes. Therefore, in this embodiment, the time-series waveform of the sensor output (electrical signal) generated by the sensing unit 92 traces one cycle of a sine wave every time the rotation angle of the rotor 310 changes by 90 degrees, as shown in FIG. 11 . Therefore, the rotation angle of the rotor 310 can be detected based on this sensor output (electrical signal).

[0076] As described above, according to this embodiment, the rotation angle sensor 900 has the sensing unit 92 mounted on the control board 84 that forms the control device 500. This reduces the number of boards required, thereby achieving an efficient configuration, compared to when the sensing unit 92 is mounted on another board. In particular, in a configuration in which the rotating electric machine 1 and the block assembly 89 are disposed in the motor accommodating chamber SP1 and the inverter accommodating chamber SP2 that communicate with each other (i.e., a configuration in which the rotating electric machine 1 and the block assembly 89 are accommodated in a common accommodation chamber of the case 2), the space between the rotating electric machine 1 and the block assembly 89 in the axial direction is likely to become dead space. Therefore, by utilizing this space that is likely to become dead space, an efficient arrangement of the control board 84 and the rotation angle sensor 900 can be achieved.

[0077] Furthermore, according to this embodiment, the sensor rotor 91 is provided at a location on the X2 side of the axial end face on the X1 side of the shaft portion 314 (and at a location on the X1 side of the rotor core 312), and the control board 84 is provided on the X2 side of the axial end face on the X1 side of the shaft portion 314. This makes it possible to eliminate the need for space for the rotation angle sensor 900 on the X1 side of the axial end face on the X1 side of the shaft portion 314, unlike the configuration shown in Patent Document 1 mentioned above (a configuration in which a detection target is provided on the axial end face of the shaft portion and a control board faces the axial end face). As a result, according to this embodiment, it is possible to reduce the axial size of the vehicle drive device 10.

[0078] 3, the rotation angle sensor 900 is disposed axially between the bearing 240 (or the bearing support portion 2524) and the rotating electric machine 1, thereby realizing an efficient arrangement that utilizes a space that tends to become a dead space. As a result, the axial size of the vehicle drive device 10 can be reduced.

[0079] Furthermore, according to this embodiment, the rotation angle sensor 900 is formed using the flat sensor rotor 91, so that the axial mounting space required is relatively small. Furthermore, the sensor rotor 91 itself can be formed inexpensively, so that costs can be reduced.

[0080] In this embodiment, the sensor rotor 91 is disposed on the X2 side relative to the control board 84 (and the sensing unit 92 accordingly), but may be disposed on the X1 side.

[0081] FIG. 12 is an explanatory diagram of a rotation angle sensor 900A according to a modified example, and is a cross-sectional view of a portion of a vehicle drive device 10A.

[0082] In this modified example, in the rotation angle sensor 900A, the detection target portion 91A and the sensing unit 92A face each other in the radial direction. For example, the detection target portion 91A overlaps with the control board 84 when viewed in the radial direction. If the sensor element of the sensing unit 92A is a Hall element, the detection target portion 91A may be realized by a permanent magnet provided on the outer periphery of the shaft portion 314. In this case, the permanent magnet may be arranged so that the magnetic pole of the outer periphery of the shaft portion 314 changes periodically along the circumferential direction, and multiple sensor elements of the sensing unit 92A may be arranged at equal intervals around the first axis A1 so as to face the detection target portion 91A in the radial direction. The detection target portion 91A may be in the form of a ring attached to the shaft portion 314, or may be formed integrally with the shaft portion 314.

[0083] Although each embodiment has been described in detail above, it is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. It is also possible to combine all or a plurality of components of the above-described embodiments. [Explanation of symbols]

[0084] 10, 10A... Vehicle drive device, 1... Rotating electric machine, 2... Case, 250... Motor case (housing member), 252... Cover member, 2524... Bearing support portion (support portion), 310... Rotor, 314... Shaft portion, 320... Stator, 84... Control board, 84a... Central hole, 840... Protruding region (region), 89... Block assembly (inverter device), 900... Rotation angle sensor, 91... Sensor rotor (detected portion), 91A... Detected portion, 92, 92A... Sensing portion, 921... Sensor coil (coil), SP1... Motor housing chamber (common housing chamber), SP2... Inverter housing chamber (common housing chamber)

Claims

1. a rotating electric machine having a rotor and a stator; an inverter device electrically connected to the rotating electric machine; a control board for controlling the rotating electric machine; a rotation angle sensor for acquiring rotation information of the rotor; a case that houses the rotating electric machine, the inverter device, and the control board in a common housing chamber, the rotation angle sensor includes a sensing unit mounted on the control board and a detected unit provided on a shaft portion of the rotor, a drive circuit for driving the inverter device is mounted on the control board; the case has a support portion that rotatably supports the rotor, The control board is disposed axially closer to the rotating electric machine than the support portion.

2. The control board has a through hole through which the shaft portion passes, The vehicle drive device according to claim 1 , wherein at least a portion of the sensing portion is provided on a periphery of the through hole.

3. The vehicle drive device according to claim 1 , wherein the control board has a central hole through which the shaft portion passes.

4. a peripheral portion of the central hole of the control board having a region that protrudes radially inward; The vehicle drive device according to claim 3 , wherein at least a portion of the sensing unit is provided in the region.

5. the detected part includes a sensor rotor that rotates integrally with the rotor, the sensing unit includes a coil; The vehicle drive device according to claim 1 , wherein the coil is disposed so as to axially face at least a portion of the sensor rotor.

6. 5. The vehicle drive device according to claim 1, wherein the control board is arranged axially closer to the rotating electric machine than the inverter device and overlaps with the inverter device when viewed in the axial direction.

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