JP7484549B2 - Vehicle drive device - Google Patents

Description

This disclosure relates to a vehicle drive system.

A technology is known that uses a mechanical hydraulic pump and an electric hydraulic pump to supply oil from the radially inner side of the coil end portion of the stator through an oil passage (rotor axis) inside the hollow interior of the rotor shaft, and also supplies oil from the radially outer side of the coil end portion.

JP 2019-129608 A

However, in the conventional technology described above, since an electric oil pump is provided, the oil supply function (cooling function) of the electric oil pump can be maintained even when the rotor is not rotating. However, on the other hand, costs cannot be reduced because the electric oil pump is relatively expensive.

Therefore, in one aspect, the present disclosure aims to reduce costs while ensuring appropriate cooling capacity for rotating electric machines.

According to one aspect, there is provided a vehicle drive device including a rotating electric machine electrically connected to a water-cooled inverter module,
The rotating electric machine includes:
a rotor having a hollow rotor shaft and a rotor core;
a stator having a stator core and a coil;
a case member that defines a first chamber in which the rotor and the stator are housed, that is adjacent to the stator in a radial direction, and that has a cooling water passage that communicates with the inside of the inverter module,
The vehicle drive device includes:
a mechanical oil pump that operates in conjunction with the rotation of the rotor;
and an oil passage structure that supplies oil discharged by the oil pump to a hollow interior of the rotor shaft.

In one aspect, the present disclosure makes it possible to reduce costs while ensuring adequate cooling capacity for the rotating electric machine.

FIG. 1 is a diagram illustrating an example of an overall configuration of a motor drive system. 1 is a cross-sectional view showing a configuration of a vehicle drive device according to a first embodiment. FIG. 2 is a skeleton diagram of a vehicle drive device. FIG. 2 is a perspective view showing a schematic appearance of a case. 1 is a schematic cross-sectional view perpendicular to an axial direction of a vehicle drive device; FIG. 3 is a diagram showing a schematic diagram of an oil flow in the cross-sectional view shown in FIG. 2 . FIG. 4 is an explanatory diagram of a cooling water passage and a perspective view of a case member. FIG. 2 is an explanatory diagram of a cooling water passage, and is a perspective view of a case member with a portion of an outer wall portion removed. FIG. 13 is an explanatory diagram of a cooling water passage, and is a perspective view of a case member with a portion of an outer wall portion cut away and a second partition wall portion disposed therein. FIG. FIG. 4 is a schematic plan view of a cooling water passage when expanded in the circumferential direction. FIG. 9 is a schematic cross-sectional view taken along line CC in FIG. 8. FIG. 9 is a diagram showing a schematic diagram of the flow of cooling water in the diagram shown in FIG. 8 . 1 is a diagram illustrating an overall configuration of a cooling structure for a vehicle drive device; FIG. 11 is a cross-sectional view showing a configuration of a vehicle drive device according to a second embodiment.

Each embodiment will be described in detail below with reference to the attached drawings.

Before describing the vehicle drive device according to this embodiment, we will first describe the motor drive system SM for an electric vehicle to which the vehicle drive device according to this embodiment is preferably applied. In the description of the motor drive system SM for an electric vehicle in FIG. 1, the term "connection" between various elements means "electrical connection" unless otherwise specified.

Figure 1 shows an example of the overall configuration of a motor drive system SM. The motor drive system SM is a system that drives a vehicle by driving a rotating electric machine 1 using power from a high-voltage battery HB. Note that the details of the electric vehicle and its configuration are arbitrary, so long as it runs by driving the rotating electric machine 1 using electric power. Electric vehicles typically include hybrid vehicles whose power sources are an engine and the rotating electric machine 1, and electric vehicles whose power source is only the rotating electric machine 1. Hereinafter, unless otherwise specified, a vehicle refers to a vehicle equipped with a motor drive system SM.

As shown in FIG. 1, the motor drive system SM includes a high-voltage battery HB (an example of a power source), a smoothing capacitor SC, an inverter IV (an example of a power converter), a rotating electric machine 1, and an inverter control device 6A.

The high-voltage battery HB is any power storage device that stores power and outputs a DC voltage, and may include a capacitive element such as a nickel-metal hydride battery, a lithium-ion battery, or an electric double-layer capacitor. The high-voltage battery HB is typically a battery with a rated voltage of more than 100 V, for example, 288 V.

The inverter IV includes U-phase, V-phase, and W-phase arms that are arranged in parallel between the positive and negative lines. The U-phase arm includes a series connection of switching elements (IGBTs: Insulated Gate Bipolar Transistors in this example) Q1 and Q2, the V-phase arm includes a series connection of switching elements (IGBTs in this example) Q3 and Q4, and the W-phase arm includes a series connection of switching elements (IGBTs in this example) Q5 and Q6. Diodes D11 to D16 are arranged between the collector and emitter of each of the switching elements Q1 to Q6 so that current flows from the emitter side to the collector side. The switching elements Q1 to Q6 may be other switching elements other than IGBTs, such as MOSFETs (metal oxide semiconductor field-effect transistors).

The rotating electric machine 1 is, for example, a three-phase AC motor, and one end of each of the three coils 110 of the U, V, and W phases is commonly connected at a neutral point. The other end of the U-phase coil is connected to a midpoint M1 of the switching elements Q1 and Q2, the other end of the V-phase coil is connected to a midpoint M2 of the switching elements Q3 and Q4, and the other end of the W-phase coil is connected to a midpoint M3 of the switching elements Q5 and Q6. A smoothing capacitor SC is connected between the collector of switching element Q1 and the negative line.

The inverter control device 6A is connected to various sensors, such as a current sensor (not shown) that detects the current flowing through the rotating electric machine 1. The inverter control device 6A controls the inverter IV based on sensor information from the various sensors. The inverter control device 6A includes, for example, a CPU, a ROM, a main memory (all not shown), and the various functions of the inverter control device 6A are realized by reading a control program recorded in the ROM or the like into the main memory and executing it by the CPU. The method of controlling the inverter IV is arbitrary, but basically, the two switching elements Q1 and Q2 associated with the U phase are turned on/off in opposite phases, the two switching elements Q3 and Q4 associated with the V phase are turned on/off in opposite phases, and the two switching elements Q5 and Q6 associated with the W phase are turned on/off in opposite phases.

In the example shown in FIG. 1, the motor drive system SM includes a single rotating electric machine 1, but may include an additional motor (including a generator). In this case, the additional motor (or motors) may be connected to the high-voltage battery HB in a parallel relationship with the rotating electric machine 1 and the inverter IV together with a corresponding inverter. In the example shown in FIG. 1, the motor drive system SM does not include a DC/DC converter, but may include a DC/DC converter between the high-voltage battery HB and the inverter IV.

As shown in FIG. 1, a cutoff switch SW1 for cutting off the power supply from the high-voltage battery HB is provided between the high-voltage battery HB and the smoothing capacitor SC. The cutoff switch SW1 may be configured as a semiconductor switch, a relay, or the like. The cutoff switch SW1 is normally on, and is turned off, for example, when a vehicle collision is detected. The on/off switching of the cutoff switch SW1 may be achieved by the inverter control device 6A, or by another control device.

Figure 2 is a cross-sectional view showing the configuration of a vehicle drive device 100 according to one embodiment (Example 1). Figure 2 is a cross-sectional view along the axial direction of the vehicle drive device 100, and also shows portions P1 to P3 cut locally at different cross sections (cross sections at different positions in the direction perpendicular to the page) for the purpose of explaining the oil passage structure 90. Figure 3 is a skeleton diagram of the vehicle drive device 100.

The vehicle drive device 100 includes a rotating electric machine 1 that serves as a driving force source for the wheels, and a drive transmission mechanism 10 that is provided in a power transmission path that connects the rotating electric machine 1 and the wheels W. In this embodiment, as an example, the rotating electric machine 1 and the drive transmission mechanism 10 are housed in a case 2. In this embodiment, as an example, the drive transmission mechanism 10 includes an input member 3, a counter gear mechanism 4, a differential gear mechanism 5, a first output member 61, and a second output member 62.

The rotating electric machine 1 is disposed on the first axis A1, which serves as its rotation axis. In this embodiment, as an example, the input member 3 is also disposed on the first axis A1. The counter gear mechanism 4 is disposed on the second axis A2, which serves as its rotation axis. The differential gear mechanism 5 is disposed on the third axis A3, which serves as its rotation axis. In this embodiment, as an example, the first output member 61 and the second output member 62 are also disposed on the third axis A3. The first axis A1, the second axis A2, and the third axis A3 are different virtual axes, and are disposed in parallel to each other.

In the following description, the direction parallel to the above-mentioned axes A1 to A3 is referred to as the "axial direction L" of the vehicle drive device 100. In the axial direction L, the side on which the rotating electric machine 1 is disposed relative to the input member 3 is referred to as the "axial first side L1" (an example of the first side), and the opposite side is referred to as the "axial second side L2" (an example of the second side). In addition, the direction perpendicular to each of the above-mentioned first axis A1, second axis A2, and third axis A3 is referred to as the "radial direction R" based on each axis. Note that when it is not necessary to distinguish which axis is used as the reference or when it is clear which axis is used as the reference, it may be simply referred to as the "radial direction R".

In this embodiment, as an example, the case 2 includes a case member 21, a first cover member 22, and a second cover member 23. The case member 21 is formed in a cylindrical shape surrounding the outer side of the rotating electric machine 1 and the drive transmission mechanism 10 in the radial direction R. The first cover member 22 and the second cover member 23 are formed to extend along the radial direction R. The first cover member 22 is fixed to an end of the case member 21 on the first axial side L1 so as to close the opening of the case member 21 on the first axial side L1. The second cover member 23 is fixed to an end of the case member 21 on the second axial side L2 so as to close the opening of the case member 21 on the second axial side L2.

In this embodiment, the case member 21 forms the partition wall 24 together with the peripheral wall portion, and is realized as a one-piece case member. The first cover member 22 is realized as a one-piece member, and the second cover member 23 is realized as a one-piece member. In this way, in this embodiment, the case 2 is essentially formed from three-piece members. This makes it possible to reduce the number of pieces of the case member compared to the conventional technology such as that described in the above-mentioned Patent Document 1, and to efficiently reduce costs.

The partition wall 24 of the case member 21 is a space inside the case member 21 in the radial direction R, and is formed to divide the space between the first cover member 22 and the second cover member 23 into two chambers SP1 and SP2 in the axial direction L. In this embodiment, as an example, the rotating electric machine 1 is disposed in the chamber SP1 (an example of a first chamber) between the partition wall 24 and the first cover member 22. And the drive transmission mechanism 10 is disposed in the chamber SP2 (an example of a second chamber) between the partition wall 24 and the second cover member 23.

The rotating electric machine 1 has a stator 11 and a rotor 12. The term "rotating electric machine" is used as a concept that includes a motor (electric motor), a generator (electric generator), and a motor generator that functions as both a motor and a generator as necessary.

The stator 11 has a stator core 111 fixed to a non-rotating member (for example, the case 2). The rotor 12 has a rotor core 121 that can rotate with respect to the stator 11 (the stator core 111) and a rotor shaft 122 that is connected to rotate integrally with the rotor core 121. In this embodiment, as an example, the rotating electric machine 1 is a rotating field type rotating electric machine. Therefore, the coil 110 is wound around the stator core 111 so that the coil end portion 112 that protrudes from the stator core 111 to both sides in the axial direction L (the axial first side L1 and the axial second side L2) is formed. Then, the rotor core 121 is provided with a permanent magnet 123. Also, in this embodiment, as an example, the rotating electric machine 1 is an inner rotor type rotating electric machine, so that the rotor core 121 is arranged inside the stator core 111 in the radial direction R. Then, the rotor shaft 122 is connected to the inner peripheral surface of the rotor core 121.

The rotor shaft 122 rotates around the first axis A1. The rotor shaft 122 is formed in a cylindrical shape extending along the axial direction L. In this embodiment, as an example, the rotor shaft 122 is rotatably supported with respect to the case 2 via the first rotor bearing B1a and the second rotor bearing B1b. Specifically, the end of the rotor shaft 122 on the first axial side L1 is rotatably supported with respect to the first cover member 22 of the case 2 via the first rotor bearing B1a. And the end of the rotor shaft 122 on the second axial side L2 is rotatably supported with respect to the partition wall portion 24 via the second rotor bearing B1b. Also, in this embodiment, as an example, both end faces of the rotor shaft 122 in the axial direction L are open. And the internal space of the rotor shaft 122 functions as a rotor shaft oil passage 122a through which oil flows.

The input member 3 is an input element of the drive transmission mechanism 10. 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 shaft 31 is formed to extend along the axial direction L. In this embodiment, as an example, the input shaft 31 is inserted into a through hole that penetrates the partition wall portion 24 in the axial direction L. Then, the end of the input shaft 31 on the first axial side L1 is connected to the end of the second axial side L2 of the rotor shaft 122. In the illustrated example, the end of the input shaft 31 on the first axial side L1 is inserted into the end of the second axial side L2 of the rotor shaft 122 so that the input shaft 31 is positioned inside the rotor shaft 122 in the radial direction R, and these ends are connected to each other by spline engagement.

In this embodiment, as an example, the input shaft 31 is rotatably supported relative to the case 2 via the first input bearing B3a and the second input bearing B3b. Specifically, a portion of the input shaft 31 that is closer to the first axial side L1 than the center in the axial direction L and closer to the second axial side L2 than the connection portion with the rotor shaft 122 is rotatably supported relative to the partition wall portion 24 via the first input bearing B3a. Then, the end of the input shaft 31 on the second axial side L2 is rotatably supported relative to the second cover member 23 via the second input bearing B3b.

In the present embodiment, as an example, the input shaft 31 is formed in a cylindrical shape with an open end face on the second axial side L2. The internal space of the input shaft 31 functions as an input shaft oil passage 31a through which oil from the mechanical hydraulic pump 71 flows.

The input gear 32 is a gear that transmits the 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 so as to rotate integrally with the input shaft 31. In this embodiment, as an example, the input gear 32 is formed integrally with the input shaft 31. Also, in this embodiment, as an example, the input gear 32 is disposed between the first input bearing B3a and the second input bearing B3b.

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.

The counter shaft 41 is a rotating member that rotates around the second axis A2. The counter shaft 41 is formed to extend along the axial direction L. In this embodiment, as an example, the counter shaft 41 is rotatably supported relative to the case 2 via the first counter bearing B4a and the second counter bearing B4b. Specifically, the end of the counter shaft 41 on the first axial side L1 is rotatably supported relative to the partition wall 24 via the first counter bearing B4a. And the end of the counter shaft 41 on the second axial side L2 is rotatably supported relative to the second cover member 23 via the second counter bearing B4b.

In this embodiment, as an example, the countershaft 41 is formed in a cylindrical shape with both end faces in the axial direction L open. The internal space of the countershaft 41 functions as a countershaft oil passage 41a through which oil from the mechanical hydraulic pump 71 flows.

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. In this embodiment, as an example, the first counter gear 42 is connected to the counter shaft 41 by spline engagement. Also, in this embodiment, as an example, the first counter gear 42 is disposed between the first counter bearing B4a and the second counter bearing B4b, and on the first axial side L1 of the second counter gear 43. However, in a modified example, the first counter gear 42 may be disposed between the first counter bearing B4a and the second counter bearing B4b, and on the second axial side L2 of the second counter gear 43 (see FIG. 3).

The second counter gear 43 is an output element of the counter gear mechanism 4. In this embodiment, as an 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. In this embodiment, as an example, the second counter gear 43 is formed integrally with the counter shaft 41.

The differential gear mechanism 5 distributes the driving force transmitted from the rotating electric machine 1 to a first output member 61 and a second output member 62. The differential gear mechanism 5 includes a differential input gear 51, a differential case 52, a pinion shaft 53, a pair of pinion gears 54, a first side gear 55, and a second side gear 56. In this embodiment, as an example, the pair of pinion gears 54, and the first side gear 55 and the second side gear 56 are all bevel gears.

The differential input gear 51 is an input element of the differential gear mechanism 5. The differential input gear 51 meshes with the second counter gear 43 of the counter gear mechanism 4. The differential input gear 51 is connected to the differential case 52 so as to rotate integrally with the differential case 52. In this embodiment, as an example, the rotating electric machine 1 is disposed on the first axial side L1 relative to the differential input gear 51.

The differential case 52 is a rotating member that rotates around the third axis A3. In this embodiment, as an example, the differential case 52 is rotatably supported relative to the case 2 via the first differential bearing B5a and the second differential bearing B5b. Specifically, the end of the differential case 52 on the first axial side L1 is rotatably supported relative to the partition wall 24 via the first differential bearing B5a. And the end of the differential case 52 on the second axial side L2 is rotatably supported relative to the second cover member 23 via the second differential bearing B5b.

The differential case 52 is a hollow member. The differential case 52 houses a pinion shaft 53, a pair of pinion gears 54, a first side gear 55, and a second side gear 56.

The pinion shaft 53 extends along a radial direction R based on the third axis A3. The pinion shaft 53 is inserted into a pair of pinion gears 54 and rotatably supports them. The pinion shaft 53 is disposed so as to pass through the differential case 52. The pinion shaft 53 is engaged with the differential case 52 by a locking member 58, which may be, for example, a rod-shaped pin, and rotates integrally with the differential case 52.

The pair of pinion gears 54 are attached to the pinion shaft 53 in a state where they face each other with a gap in between along the radial direction R based on the third axis A3. The pair of pinion gears 54 are configured to be rotatable (spinning) around the pinion shaft 53 and rotatable (revolving) around the third axis A3.

The first side gear 55 and the second side gear 56 are rotating elements after distribution in the differential gear mechanism 5. The first side gear 55 and the second side gear 56 are arranged to face each other with a gap in the axial direction L, sandwiching the pinion shaft 53. The first side gear 55 is arranged on the first axial side L1 from the second side gear 56. The first side gear 55 and the second side gear 56 are configured to rotate in the circumferential direction, respectively, in the internal space of the differential case 52. The first side gear 55 and the second side gear 56 mesh with a pair of pinion gears 54. The first side gear 55 is connected to the first output member 61 so as to rotate integrally with it. On the other hand, the second side gear 56 is connected to the second output member 62 so as to rotate integrally with it.

The first output member 61 and the second output member 62 are each drivingly connected to the wheels W. The first output member 61 and the second output member 62 each transmit the driving force distributed by the differential gear mechanism 5 to the wheels W.

In this embodiment, as an example, the first output member 61 includes a first axle 611. The first axle 611 is drivingly connected to a wheel W on the first axial side L1. The first axle 611 is connected to the first side gear 55 so as to rotate integrally with the first axle 611. Note that a relay member (not shown) may be provided between the first axle 611 and the first side gear 55.

In the present embodiment, as an example, the second output member 62 includes a second axle 621. The second axle 621 is drivingly connected to the wheel W on the second axial side L2. The second axle 621 is connected to the second side gear 56 so as to rotate integrally with the second axle 621.

Next, referring to Figures 4 and 5 as well as Figure 2, the arrangement of the inverter module MJ and the electrical connection structure between the inverter module MJ and the rotating electric machine 1 will be described.

Figure 4 is a perspective view showing the exterior of the case 2, and Figure 5 is a schematic cross-sectional view perpendicular to the axial direction L of the vehicle drive device 100, which is a cross-sectional view through the room SP2 viewed from the L2 side to the L1 side. In the description of Figure 4, the vertical direction of the vehicle drive device 100 mounted on the vehicle is referred to as the "vertical direction V". The position of the upper side (V1 side) of the vertical direction V is expressed by using "upper", for example, as above, upper end, etc., and the position of the lower side (V2 side) of the vertical direction V is expressed by using "lower", for example, as below, lower end, etc. In addition, the direction perpendicular to the axial direction L when viewed in the vertical direction V is referred to as the "depth direction D". In the depth direction D, the side of the differential gear mechanism 5 with respect to the rotating electric machine 1 is referred to as the "D1 side", and the opposite side is referred to as the "D2 side". Note that the D1 side corresponds to the front side of the vehicle, for example, but may also correspond to the rear side of the vehicle.

In this embodiment, as an example, the case 2 includes an inverter case portion 2a. The inverter case portion 2a may be formed integrally with the case 2. That is, the inverter case portion 2a may be formed integrally with the case member 21 in such a manner that it is partitioned by a side wall portion of the case member 21 that forms the chamber SP1 in which the rotating electric machine 1 is housed. Alternatively, a part or all of the inverter case portion 2a may be separate from the case member 21 and attached to the case member 21.

As shown in FIG. 4, the inverter case section 2a is disposed on the upper part of the case 2. The inverter case section 2a houses the inverter module MJ. The inverter module MJ is a module that incorporates the above-mentioned inverter IV and inverter control device 6A, etc., and may further incorporate a smoothing capacitor SC. The inverter case section 2a is preferably closed from the outside by a lid member 25. That is, the inverter case section 2a forms a closed space, and the inverter module MJ is disposed in this space. This makes it possible to appropriately implement EMC (Electromagnetic Compatibility) measures related to the inverter module MJ, and also reduces problems such as spatial resonance.

The bus bars 7U, 7V, and 7W extend within the case 2. The bus bars 7U, 7V, and 7W are, for example, in the form of a plate (for example, a sheet metal member), but may be realized by a conductor wire having a circular cross section. The bus bars 7U, 7V, and 7W are provided corresponding to the U-phase, V-phase, and W-phase, respectively, and are connected to the power lines (lead wires) 1U, 1V, and 1W (see also FIG. 1) of each phase from the rotating electric machine 1. The power lines 1U, 1V, and 1W are drawn from the chamber SP1 into the chamber SP2 and connected to the bus bars 7U, 7V, and 7W. FIG. 5 shows the joints 9U, 9V, and 9W between the bus bars 7U, 7V, and 7W and the power lines 1U, 1V, and 1W. The joints between the bus bars 7U, 7V, and 7W and the power lines 1U, 1V, and 1W may be realized by, for example, fastening bolts.

One end of the busbars 7U, 7V, 7W is joined to the power lines 1U, 1V, 1W inside the case 2, and the other end is joined to a busbar (not shown) on the inverter IV side in the inverter module MJ outside the case 2. The busbars 7U, 7V, 7W may extend to the midpoints M1, M2, M3 of the inverter IV (see FIG. 1), or may be electrically connected to the midpoints M1, M2, M3 of the inverter IV via another busbar.

The bus bars 7U, 7V, and 7W may be sealed with a resin portion (not shown) in such a manner that the portions forming the joints 9U, 9V, and 9W are exposed. In this case, the resin portion may be fixed to the case 2 in the form of a terminal block that holds the bus bars 7U, 7V, and 7W. In FIG. 5, the bus bars 7U, 7V, and 7W are supported on the upper portion of the case 2.

The power lines 1U, 1V, 1W from the rotating electric machine 1 are joined to the coil 110 wound around the stator core 111. Alternatively, the power lines 1U, 1V, 1W may be formed as part of the coil 110 of the stator core 111. The power lines 1U, 1V, 1W may be in the same coil wire form (e.g., rectangular wire) as the coil 110 of the stator core 111. Alternatively, the power lines 1U, 1V, 1W may be in the same plate form (e.g., sheet metal member) as the bus bars 7U, 7V, 7W, or may be realized by a conductor wire with a circular cross section. In addition, another bus bar (intermediate bus bar) may be interposed between the power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W. In this case, the intermediate bus bar may also be sealed with a resin part and fixed to the case 2.

The power lines 1U, 1V, 1W extend to the upper part of the chamber SP2. In this case, the power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W preferably extend into the air in the chamber SP2. That is, the power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W are located above the oil reservoir 80 (see FIG. 11) below the chamber SP2. In this case, only a portion of the power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W may be located above the oil reservoir 80, or the entire power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W may be located above the oil reservoir 80. In this case, it is possible to prevent problems such as foreign matter that may be mixed into the oil stored in the oil reservoir 80 from adhering to the power lines 1U, 1V, 1W and the bus bars 7U, 7V, 7W.

In this way, according to the electrical connection structure between the inverter module MJ and the rotating electric machine 1 shown in Figures 4 and 5, wiring is realized using the chamber SP2 on the second axial side L2 of the rotating electric machine 1, so the size of the chamber SP1 of the case 2 can be reduced compared to when wiring is realized in the upper part of the chamber SP1 or on the first axial side L1 of the chamber SP1.

In the example shown in FIG. 5, the axis (second axis A2) of the counter gear mechanism 4 is disposed below both the axis (first axis A1) of the rotating electric machine 1 and the axis (third axis A3) of the differential gear mechanism 5. In the example shown in FIG. 5, the first axis A1, the second axis A2, and the third axis A3 are disposed from above in the order of the first axis A1, the third axis A3, and the second axis A2.

The inverter module MJ may be disposed on the first axial side L1 of the differential input gear 51 of the differential gear mechanism 5. The inverter module MJ may also be disposed offset toward the D1 side with respect to the first axis A1. Furthermore, the inverter module MJ may be disposed above the axis (A3) of the differential gear mechanism 5. The inverter module MJ may also be disposed at a position overlapping with the differential input gear 51 as viewed in the axial direction L. Note that, with regard to the arrangement of two elements, "overlapping as viewed in a specific direction" refers to the existence of at least a portion of an area where a virtual line parallel to the specific direction intersects with both of the two elements when the virtual line is moved in each direction perpendicular to the virtual line.

A portion of the inverter module MJ may be disposed between the rotating electric machine 1 and the differential input gear 51 in the axial direction L. A portion of the inverter module MJ may be disposed in a position overlapping with the counter gear mechanism 4 when viewed in the vertical direction V.

Next, we will explain the oil-related configuration with reference to Figure 6.

Figure 6 is a schematic diagram showing the flow of oil in the cross-sectional view shown in Figure 2, indicated by arrows R1 to R11.

In this embodiment, the vehicle drive device 100 includes a mechanical hydraulic pump 71 (an example of an oil pump) that is driven by a driving force transmitted through the power transmission path, but does not include an electric hydraulic pump that is driven by a dedicated driving force source that is independent of the power transmission path.

The mechanical hydraulic pump 71 is a pump that pumps up oil stored in an oil reservoir 80 (see FIG. 11) in the case 2 and discharges the pumped up oil. In this embodiment, as an example, the mechanical hydraulic pump 71 is housed in the case 2. In this embodiment, as an example, the mechanical hydraulic pump 71 is driven by the rotation of a rotating member provided in the drive transmission mechanism 10. Specifically, the mechanical hydraulic pump 71 is provided on an extension shaft 711 that is integrally connected coaxially to the counter shaft 41 at the L2 side end of the counter shaft 41. The mechanical hydraulic pump 71 may be in the form of a gear pump, for example. In a modified example, the mechanical hydraulic pump 71 may be connected to the L1 side end of the counter shaft 41, or may be connected so as to be driven by the rotation of the differential case 52 of the differential gear mechanism 5.

In this embodiment, the oil passage structure 90 provided in the vehicle drive device 100 includes a first cover oil passage 91 (an example of a first oil passage) formed in the first cover member 22 of the case 2, a rotor shaft oil passage 122a (an example of a second oil passage) formed in the rotor shaft 122, a second cover oil passage 93 (an example of a third oil passage) formed in the second cover member 23 of the case 2, and a case oil passage 94 formed in the case member 21. The oil passage structure 90 also includes an input shaft oil passage 31a, a counter shaft oil passage 41a, etc.

The first cover oil passage 91 extends in the axial direction L, and the end of the second axial side L2 is connected to the end of the first axial side L1 of the case oil passage 94. The first cover oil passage 91 is formed in the upper part of the first cover member 22 (above the first axis A1). As shown in part P1, the first cover oil passage 91 opens radially toward the coil end portion 112 of the first axial side L1. Specifically, a radial oil hole 911 is formed in the first cover member 22, and the radial outer side of the oil hole 911 is connected to the first cover oil passage 91, and the radial inner side opens to the chamber SP1. The radial inner opening of the oil hole 911 is formed in a position radially facing the coil end portion 112 of the first axial side L1.

As described above, the rotor shaft oil passage 122a is realized by the hollow interior of the rotor shaft 122. The rotor shaft oil passage 122a has the second axial side L2 connected to the input shaft oil passage 31a.

The second cover oil passage 93 includes a radial oil passage 931 and an axial oil passage 932. The radial oil passage 931 extends in the radial direction R2, with one end connected to the discharge side of the mechanical hydraulic pump 71 and the other end connected to the axial oil passage 932. The axial oil passage 932 has a second axial side L2 connected to the radial oil passage 931 and a first axial side L1 connected to the case oil passage 94 (see part P3). The axial oil passage 932 is formed above the first axis A1.

The case oil passage 94 extends in the axial direction, with the first axial side L1 connected to the first cover oil passage 91 and the second axial side L2 connected to the axial oil passage 932 of the second cover oil passage 93. The case oil passage 94 is formed above the first axis A1. As shown in part P2, the case oil passage 94 opens radially toward the coil end portion 112 of the second axial side L2. Specifically, a radial oil hole 941 is formed in the case member 21, and the radial outer side of the oil hole 941 is connected to the case oil passage 94 and the radial inner side opens to the chamber SP1. The radial inner opening of the oil hole 941 is formed at a position radially facing the coil end portion 112 of the second axial side L2.

In this oil passage structure 90, the oil discharged from the mechanical hydraulic pump 71 flows upward through the radial oil passage 931 of the second cover oil passage 93 (see arrow R1), and contains oil flowing into the axial oil passage 932 of the second cover oil passage 93 at the top (see arrow R2). This oil flows axially through the axial oil passage 932 and flows continuously from the axial oil passage 932 into the case oil passage 94. The oil that flows into the case oil passage 94 is supplied (dried) from the radial outside to the coil end portion 112 of the axial second side L2 through the oil hole 941 (see arrow R3). This cools the coil end portion 112 of the axial second side L2. In addition, the oil that flows into the case oil passage 94 in the axial direction without passing through the oil hole 941 (see arrow R4) flows into the first cover oil passage 91 at the axial first side L1. The oil that flows into the first cover oil passage 91 is supplied (dribbled) from the radial outside to the coil end portion 112 on the first axial side L1 through the oil hole 911 (see arrow R5). This cools the coil end portion 112 on the first axial side L1.

In addition, the oil discharged from the mechanical hydraulic pump 71 includes oil flowing into the counter shaft oil passage 41a, oil flowing upward through the radial oil passage 931 of the second cover oil passage 93 (see arrow R1), and oil flowing into the input shaft oil passage 31a. Such oil flows axially through the input shaft oil passage 31a (see arrow R7) and flows into the rotor shaft oil passage 122a. The oil that flows into the rotor shaft oil passage 122a flows axially along the inner circumferential surface 122d of the rotor shaft 122 due to the action of centrifugal force when the rotor 12 rotates (see arrow R9), cooling the rotor core 121 and the permanent magnet 123 from the radial inside. In addition, the oil that flows into the rotor shaft oil passage 122a flows into each of the first supply oil passage 122b (an example of an oil hole) and the second supply oil passage 122c (an example of an oil hole) formed to penetrate the rotor shaft 122 in the radial direction R (see arrows R8 and R10). Here, the first supply oil passage 122b is formed at a position overlapping the coil end portion 112 on the first axial side L1 when viewed in the radial direction R of the rotor shaft 122. Also, the second supply oil passage 122c is formed at a position overlapping the coil end portion 112 on the second axial side L2 when viewed in the radial direction R of the rotor shaft 122. Therefore, as the rotor shaft 122 rotates, oil is injected from the radial inside from each of the first supply oil passage 122b and the second supply oil passage 122c toward the corresponding coil end portion 112. Then, the coil end portion 112 is cooled by the oil adhering to the coil end portion 112. The oil discharged from each of the first supply oil passage 122b and the second supply oil passage 122c may be supplied directly to the coil end portion 112, or may be supplied via a member such as an end plate as shown in FIG. 6.

The oil used to cool the various cooling targets in this manner is returned to the oil reservoir 80 (see FIG. 11) via an oil passage 98 formed in the lower part of the case member 21 of the case 2. The oil returned to the oil reservoir 80 is supplied again to the second cover oil passage 93, etc. via the mechanical hydraulic pump 71. In this manner, the oil circulates in the oil passage structure 90 to cool the various cooling targets. The oil passing through the oil passage structure 90 may be used to lubricate various bearings (e.g., the first rotor bearing B1a, etc.).

Here, the oil circulated in the oil passage structure 90 in this manner is cooled by the oil cooler 73. The oil cooler 73 is configured to have, for example, a pipe through which the oil flows, and to cool the oil by performing heat exchange between a refrigerant (for example, cooling water, air, etc.) flowing outside the pipe and the oil in the pipe. Thus, in this embodiment, as an example, the oil cooler 73 is provided in a portion forming the chamber SP2 in the case member 21, as shown in FIG. 6. The oil cooler 73 is also provided near the inverter case portion 2a. In this case, the oil cooler 73 can realize heat exchange between the cooling water passing through the inverter module MJ and the oil in the axial oil passage 932. With this arrangement, the path for guiding the cooling water from the inverter module MJ to the oil cooler 73 can be shortened, and an efficient configuration can be realized.

The oil cooler 73 may be provided on the second axial side L2 of the second cover oil passage 93. In this case, however, the overall size of the vehicle drive device 100 in the axial direction L is likely to increase due to the oil cooler 73. In this regard, if the oil cooler 73 is provided on the upper part of the case 2 and near the inverter module MJ, there is substantially no increase in the overall size of the vehicle drive device 100 in the axial direction L.

Next, the configuration related to the cooling water will be explained with reference to Figures 2 and 7A to 10.

In this embodiment, the vehicle drive device 100 further has a cooling water passage 13 through which cooling water passes to cool the stator 11 and the like. Specifically, the cooling water passage 13 through which the cooling water passes is formed in the case member 21 of the case 2. The cooling water is, for example, LLC (Long Life Coolant). The cooling water passing through the cooling water passage 13 can remove heat from the stator 11 that is in radial contact with the case member 21. In other words, it can cool the stator 11 (and the coil 110 accordingly).

7A to 7D are explanatory diagrams of the cooling water passage 13. Specifically, FIG. 7A is a schematic perspective view of the case member 21 in the case 2, FIG. 7B is a schematic perspective view of the case member 21 in FIG. 7A with some surface parts (radially outer surface parts) cut away, and FIG. 7C shows a state in which some (several) second partition wall parts 135 are inserted into the space 130 for forming the cooling water passage in the case member 21, and is a schematic perspective view of the case member 21 in FIG. 7A with some surface parts (radially outer surface parts) cut away, similar to FIG. 7B. Also, FIG. 7D is a perspective view of the second partition wall part 135 in a single item state. FIG. 8 is a schematic plan view of the case member 21 (and the cooling water passage 13) in the case 2 when developed in the circumferential direction, FIG. 9 is a schematic cross-sectional view along the line C-C in FIG. 8, and FIG. 10 is a view showing the flow of the cooling water in the view shown in FIG. 8 with arrows R20. 8 to 10 show the case member 21 with the outer wall portion 214 cut away (see FIG. 7C). FIG. 10 also shows the first cover member 22 (wall portion 222) in a schematic manner. Inside the case member 21, as shown in FIGS. 2 and 7A, a space (cavity) 130 for forming the cooling water passage 13 is formed in a cylindrical shape. The space 130 is formed between the inner wall portion 213 and the outer wall portion 214 of the case member 21 (a radial gap). Both the inner wall portion 213 and the outer wall portion 214 are cylindrical in shape, and the inner wall portion 213 is disposed radially inward of the outer wall portion 214.

The space 130 formed between the inner wall portion 213 and the outer wall portion 214 in the radial direction is cylindrical, but is divided in the circumferential direction due to the case oil passage 94, and is discontinuous due to this division. The space 130 may be formed in such a manner that the radial width decreases toward the second axial side L2 (see FIG. 2). In this case, when the case member in which the space 130 is formed is formed by casting, it is easy to remove the mold to form the space 130. In other words, the case member 21 having the space 130 can be easily manufactured by using, for example, a mold whose opening and closing direction corresponds to the axial direction L.

As shown in FIG. 2, the space 130 (and therefore the cooling water passage 13) is closed by a wall portion 212 on the second axial side L2. The wall portion 212 is a part of the case member 21. It extends continuously in the circumferential direction in accordance with the circumferential extension range of the space 130.

The space 130 (and therefore the cooling water passage 13) in the case member 21 is open in the axial direction on the first axial side L1, as shown in FIG. 2. However, the space 130 (and therefore the cooling water passage 13) is closed by the first cover member 22 on the first axial side L1. Specifically, the first cover member 22 has an annular wall portion 222, which closes the first axial side L1 of the space 130. In this way, when the first cover member 22 is assembled to the case member 21 (i.e., when the case 2 is assembled), the space 130 is closed in the entire circumferential direction on both sides of the axial direction L.

The case member 21 is formed with a cooling water inlet portion 131 and an outlet portion 132 that communicate with the space 130. The inlet portion 131 and the outlet portion 132 communicate with the space 130 in the radial direction.

Specifically, the inlet portion 131 extends in the radial direction, the radial outer side opens at the outer circumferential surface of the case member 21, and the radial inner side opens to the space 130. The inlet portion 131 may be provided adjacent to the case oil passage 94 in the circumferential direction, as shown in FIG. 7A. The inlet portion 131 may also be provided on the first axial side L1 of the case member 21.

The outlet portion 132 extends in the radial direction, like the inlet portion 131, and the radial outer side opens on the outer circumferential surface of the case member 21, and the radial inner side opens to the space 130. The outlet portion 132 may be provided adjacent to the case oil passage 94 in the circumferential direction, as shown in FIG. 7A. The outlet portion 132 may also be provided on the first axial side L1 of the case member 21. In this case, the outlet portion 132 is adjacent to the inlet portion 131 in the circumferential direction, sandwiching the case oil passage 94 therebetween. That is, the cooling water passage 13 has the inlet portion 131 and the outlet portion 132 at positions sandwiching the case oil passage 94 in the circumferential direction. As a result, the cooling water introduced from the inlet portion 131 can be circulated around the axis through the cooling water passage 13 in the case member 21 and then discharged from the outlet portion 132. As a result, the cooling function of the cooling water can be improved along the circumferential direction of the case member 21, while the cooling function of the cooling water can be uniformed along the circumferential direction.

In a modified example, the inlet portion 131 and the outlet portion 132 may be provided in a manner that communicates with the space 130 in the axial direction. For example, a flow path related to the inlet portion 131 and the outlet portion 132 may be formed in the first cover member 22. In this case, the flow path is formed in a manner that does not communicate with the oil hole 911, etc. In this case, the space 130 may be opened in the axial direction at a local position related to the inlet portion 131 and the outlet portion 132.

The case member 21 has a first partition wall portion 211 extending radially between the inner wall portion 213 and the outer wall portion 214. The first partition wall portion 211 is connected to the inner wall portion 213 at its radially inner side and to the outer wall portion 214 at its radially outer side. The first partition wall portion 211 circumferentially divides the space 130 (and the cooling water passage 13 therewith) in a partial range d1 in the axial direction L. The first partition wall portion 211 is formed integrally with the case member 21. The first partition wall portion 211 has a second axial side L2 connected to the wall portion 212, and the first axial side L1 terminates at a position on the second axial side L2 a predetermined distance d2 from the end face 219 of the first axial side L1 of the case member 21 (see FIG. 7B).

In addition, a second partition wall portion 135 is provided between the inner wall portion 213 and the outer wall portion 214 of the case member 21. The second partition wall portion 135 has a radial inner side abutted against the inner wall portion 213 and a radial outer side abutted against the outer wall portion 214. The second partition wall portion 135 circumferentially divides the space 130 (and the cooling water passage 13 therewith) in a partial range d3 in the axial direction L. The second partition wall portion 135 has an axial first side L1 that extends to an end face 219 of the axial first side L1 of the case member 21, and an axial second side L2 that terminates at a position on the axial first side L1 a predetermined distance d4 from the wall portion 212. The predetermined distance d4 may be the same as the predetermined distance d2 described above. The second partition wall portion 135 is arranged alternately with the first partition wall portion 211 described above in the circumferential direction. The distance (circumferential length) between adjacent first partition wall portions 211 and second partition wall portions 135 in the circumferential direction may be the same as the predetermined distance d2 described above (see FIG. 7C).

Here, a part of the space 130 remains between the second partition wall portion 135 and the wall portion 212 in the axial direction L, so the second partition wall portion 135, unlike the first partition wall portion 211, cannot be formed integrally with the case member 21 by normal casting. Therefore, in this embodiment, the second partition wall portion 135 is a separate member from the case member 21 and is attached to the case member 21. However, in a modified example, the case member 21 may be formed using a collapsible core. In this case, the case member 21 including the first partition wall portion 211 and the second partition wall portion 135 can be formed integrally.

The second partition wall portion 135 is formed, for example, by a metal gasket. The second partition wall portion 135 may be attached by being inserted into the space 130 so as to fit into the axial groove portion 215, as shown in, for example, FIG. 7D and FIG. 9. In this case, the second partition wall portion 135 has a protruding portion 1351 that fits into the groove portion 215. This improves the adhesion between the second partition wall portion 135 and the outer wall portion 214 and the inner wall portion 213, and effectively reduces the amount of cooling water that flows circumferentially over both radial end faces of the second partition wall portion 135. The groove portion 215 is formed on both the outer wall portion 214 and the inner wall portion 213 of the case member 21, but may be formed on only one of them.

In this way, in this embodiment, the cooling water passage 13 is formed by the space 130 divided by the first partition wall portion 211 and the second partition wall portion 135. That is, the cooling water passage 13 includes a plurality of axial water passages 13A (see FIG. 8) extending axially from the end of the axial first side L1 to the end of the axial second side L2 around the first axis A1 in the case member 21. The plurality of axial water passages 13A communicate with each other at the end of the axial first side L1 or the end of the axial second side L2. That is, the axial water passages 13A on both sides of the first partition wall portion 211 in the circumferential direction communicate with each other at the end of the axial first side L1 (section of the predetermined distance d2), and the axial water passages 13A on both sides of the second partition wall portion 135 in the circumferential direction communicate with each other at the end of the axial second side L2 (section of the predetermined distance d4). Therefore, the cooling water passage 13 rotates around the first axis A1 in a serpentine manner between the first axial side L1 and the second axial side L2. Specifically, the cooling water introduced from the inlet 131 rotates around the first axis A1 in a serpentine manner between the first axial side L1 and the second axial side L2 as shown by the arrow R20 in FIG. 10, and is discharged from the outlet 132. This allows the cooling water to flow evenly along the axial direction L around the entire circumference of the case member 21. As a result, the stator 11 can be evenly cooled.

Next, referring to FIG. 11, we will explain the overall oil cooling using the oil passage structure 90 and the water cooling using the cooling water passage 13 described above.

Figure 11 is a diagram showing the overall configuration of the cooling structure of the vehicle drive device 100.

In the example shown in FIG. 11, the cooling water passage 13 communicates with the inverter module MJ. Specifically, the water pump 78 circulates the cooling water so that it passes through the inverter module MJ, the cooling water passage 13, and the oil cooler 73 in this order (see arrows R120 to R122). The cooling water from the oil cooler 73 is cooled by the radiator 79. The radiator 79 may be a device that realizes heat exchange between air (e.g., air passing through when the vehicle is running) and the cooling water. The positions of the water pump 78 and the radiator 79 are not limited to the positions shown in FIG. 11. For example, the water pump 78 may be provided between the oil cooler 73 and the radiator 79. In this way, in the example shown in FIG. 11 , the cooling water removes heat from a heat generating element such as a power module (not shown) in the inverter module MJ, then removes heat from the stator 11 in the cooling water passage 13, then removes heat from the oil in the oil passage structure 90 in the oil cooler 73, and is then cooled by the radiator 79. In this case, the inverter module MJ (and the power module therewith) is disposed most upstream with respect to the radiator 79, and is therefore effectively cooled by the cooling water. Also, in the example shown in FIG. 11 , the cooling water passage 13 in the case member 21 is disposed next upstream from the inverter module MJ (and the power module therewith) with respect to the radiator 79, and therefore the stator 11 can be effectively cooled. However, in a modified example, the cooling water passage 13 and the inverter module MJ may be provided in this order from the upstream side with respect to the radiator 79. Also, in yet another modified example, the circulation path from the radiator 79 may be branched into a path to the inverter module MJ and a path to the cooling water passage 13. In this case, the branch path from the inverter module MJ and the branch path from the cooling water passage 13 may merge and then be led to the radiator 79.

In the example shown in FIG. 11, the oil in the oil passage structure 90 is cooled by the oil cooler 73 through which the cooling water from the radiator 79 passes, so that the various cooling target parts described above can be appropriately cooled. Specifically, the oil discharged from the mechanical hydraulic pump 71 is cooled by the oil cooler 73 and then supplied from the radial outside toward the coil end portion 112 (see arrow R110). The oil discharged from the mechanical hydraulic pump 71 is also supplied from the radial inside toward the coil end portion 112 (see arrow R111). This allows the coil end portion 112 to be effectively cooled from both radial sides. The oil used to cool the coil end portion 112 in this way falls and accumulates in the oil reservoir 80 (see arrow R112). The oil in the oil reservoir 80 is then discharged again by the mechanical hydraulic pump 71 through the strainer 74 or the like (see arrow R113) to the coil end portion 112 or the like.

In this way, according to this embodiment, the coil end portion 112 can be effectively cooled from both radial sides by oil, and the stator 11 can be effectively cooled from the radial outside by cooling water. In addition, since the oil is passed through the rotor shaft oil passage 122a, the rotor core 121 and the permanent magnets 123 can be cooled from the radial inside. In this way, according to this embodiment, the entire rotating electric machine 1 can be efficiently cooled.

In addition, the cooling water used to cool the stator 11 is the same as the cooling water used to cool the inverter module MJ, so a simpler configuration can be achieved compared to circulating these separately and independently. In other words, the stator 11 and the inverter module MJ can be cooled by cooling water using a single water pump 78.

In the example shown in FIG. 11, the oil cooler 73 is provided in the oil passage between the mechanical hydraulic pump 71 and the case member 21 (for example, the oil passage 932 as shown in FIG. 6), but is not limited to this. For example, the oil cooler 73 may be provided between the strainer 74 and the mechanical hydraulic pump 71, or between the mechanical hydraulic pump 71 and the rotor shaft oil passage 122a.

The above-described embodiment provides the following advantages:

According to this embodiment, as described above, the oil discharged by the mechanical hydraulic pump 71 is supplied to the hollow interior (rotor shaft oil passage 122a) of the rotor shaft 122, so that the cooling capacity for the rotor core 121 (and the permanent magnets 123 that may be provided in the rotor core 121) can be ensured when the rotor 12 is rotating. Also, when the rotor 12 is not rotating, the mechanical hydraulic pump 71 cannot supply oil. However, even in this case, the stator core 111 and the coils 110 can be cooled from the radial outside via the cooling water passage 13. Also, when the rotor 12 is not rotating, the need for cooling the rotor core 121 is relatively low, so stopping the supply of oil from the mechanical hydraulic pump 71 does not cause any substantial inconvenience. In this way, according to this embodiment, the cooling capacity for the rotating electric machine 1 can be appropriately ensured while eliminating the electric hydraulic pump to reduce costs.
In addition, since the water pump 78 for supplying cooling water to the cooling water passage 13 is an existing component installed in the vehicle, there is no need to add a separate component, and the vehicle drive device 100 only requires the addition of the mechanical hydraulic pump 71.

In addition, according to this embodiment, as described above, the oil passage structure 90 and the cooling water passage 13 are provided, so that the coil end portion 112 can be effectively cooled by the oil passage structure 90, while the stator 11 can be effectively cooled by the cooling water passage 13. This further increases the cooling capacity for the stator 11 compared to the case where the coil end portion 112 is cooled only by the oil passage structure 90.

In addition, according to this embodiment, as described above, the cooling water passage 13 is formed in the case member 21 that forms the peripheral wall portion, and the cooling water passage 13 opens in the axial direction only on the first axial side L1, and the second axial side L2 is blocked by a portion of the case member 21. This eliminates the need for a cover member to block the second axial side L2 of the cooling water passage 13, and allows the case 2 to be formed from three pieces. As a result, the number of parts for the case 2 can be reduced, thereby reducing costs.

In addition, according to this embodiment, as described above, the cooling water passage 13 is formed in a manner that it circles around the first axis A1 while moving between the first axial side L1 and the second axial side L2 in the axial direction. This makes it possible to uniformize the cooling performance of the cooling water for the stator 11 in both the circumferential and axial directions.

In addition, according to this embodiment, as described above, electrical wiring between the coil 110 and the inverter module MJ is realized through the chamber SP2. This allows for greater freedom in arranging the cooling water passage 13 than when the electrical wiring is realized from the upper part of the chamber SP1 or the first axial side L1 of the chamber SP1. In other words, the cooling water passage 13 can be formed without considering space for wiring, and can be formed in an optimal formation range for cooling. In addition, the possibility that such wiring will cause significant constraints on the layout of other peripheral elements (not shown) around the chamber SP1 in the case member 21 can be reduced. In other words, it becomes easier to secure mounting space for other peripheral elements around the part of the case member 21 that forms the first chamber.

In addition, according to this embodiment, as described above, the cooling water passage 13 is connected to the inside of the inverter module MJ, so the stator 11 can be cooled using the cooling water that is connected to the inside of the inverter module MJ. In other words, the supply of cooling water to the cooling water passage 13 can be made more efficient.

In addition, according to this embodiment, as described above, the oil cooler 73 is disposed near the inverter module MJ, making it easy and efficient to connect the cooling water pipes between the oil cooler 73 and the inverter module MJ.

In addition, according to this embodiment, as described above, the case oil passage 94 is formed in the case member 21, so that oil can pass between the first axial side L1 and the second axial side L2 through the case oil passage 94. In addition, the case oil passage 94 can be formed above the first axis A1 (e.g., the zenith portion) without imposing significant restrictions on the formation range of the cooling water passage 13 in the case member 21. In addition, since the case oil passage 94 is formed above the first axis A1 (e.g., the zenith portion), it is easy to connect to the first cover oil passage 91 having the oil hole 911 that is preferably formed above the first axis A1 (e.g., the zenith portion), and to the oil hole 941 that is preferably formed above the first axis A1 (e.g., the zenith portion).

In addition, according to this embodiment, as described above, the cooling water passage 13 has an inlet portion 131 and an outlet portion 132 at positions that sandwich the case oil passage 94 in the circumferential direction. In this case, the case oil passage 94 and the cooling water passage 13 can be efficiently arranged in the case member 21. In addition, since the case oil passage 94 and the cooling water passage 13 are close to each other (i.e., adjacent to each other in the circumferential direction), heat exchange can be realized at the close locations.

In addition, according to this embodiment, as described above, the case oil passage 94 passes above the vertical center position of the stator 11 (the position of the first axis A1) and communicates with the first cover oil passage 91. In this case, even if the first cover oil passage 91 is formed relatively high (for example, near the zenith) where oil is suitable for dripping toward the coil end portion 112, the case oil passage 94 can be efficiently connected to the first cover oil passage 91.

In addition, according to this embodiment, as described above, the mechanical hydraulic pump 71 is provided at the end of the second axial side L2 of the counter shaft 41 of the counter gear mechanism 4. In this case, the oil discharged from the mechanical hydraulic pump 71 can be guided from the second axial side L2 to the first axial side L1 while cooling various parts to be cooled.

In addition, according to this embodiment, as described above, the oil discharged by the mechanical hydraulic pump 71 flows in the order of the second cover oil passage 93, the case oil passage 94, the first cover oil passage 91, and the rotor shaft oil passage 122a. In this case, the oil discharged by the mechanical hydraulic pump 71 can be guided in the order of the second cover oil passage 93, the case oil passage 94, the first cover oil passage 91, and the rotor shaft oil passage 122a, thereby efficiently cooling various parts to be cooled.

Next, another embodiment will be described with reference to FIG. 12. Hereinafter, for the sake of distinction, the above-mentioned embodiment will also be referred to as "embodiment 1," and this embodiment will also be referred to as "embodiment 2."

Figure 12 is a cross-sectional view showing the configuration of a vehicle drive device 100A according to the second embodiment.

The vehicle drive device 100A according to the second embodiment differs from the vehicle drive device 100 according to the first embodiment described above mainly in that the case 2 is replaced with the case 2A and the input shaft 31 is replaced with the input shaft 31A. The case 2A according to the second embodiment differs from the case 2 according to the first embodiment described above in that the first cover member 22 is replaced with the first cover member 22A.

The first cover member 22A differs from the first cover member 22 according to the first embodiment described above in that a radial oil passage 912 is formed. The radial oil passage 912 extends in the radial direction, with the radial inner side connected to the rotor shaft oil passage 122a and the radial outer side connected to the first cover oil passage 91 (axial oil passage).

The input shaft 31A is different from the input shaft 31 according to the first embodiment described above in that it is solid. That is, the input shaft 31A does not have an input shaft oil passage 31a. In this case, the oil discharged from the mechanical hydraulic pump 71 is supplied to the rotor shaft oil passage 122a via the second cover oil passage 93, the case oil passage 94, the first cover oil passage 91, and the radial oil passage 912.

The oil passage structure 90A according to this embodiment 2 also achieves the same effect as the oil passage structure 90 according to the above-mentioned embodiment 1. In particular, according to this embodiment, the oil cooled by the oil cooler 73 is supplied to the rotor shaft oil passage 122a without passing through the oil reservoir 80, so that the cooling capacity of the oil via the rotor shaft oil passage 122a can be improved.

In this embodiment 2, as in the above-mentioned embodiment 1, the oil discharged from the mechanical hydraulic pump 71 is supplied from the second axial side L2 to the first axial side L1, but is not limited to this. For example, the oil discharged from the mechanical hydraulic pump 71 may be supplied to the first cover oil passage 91 and the case oil passage 94 via the radial oil passage 912, and also to the rotor shaft oil passage 122a via the radial oil passage 912. In this case, for example, the mechanical hydraulic pump 71 may be connected to the L1 side end of the countershaft 41. Also, in this case, the oil cooler 73 may be provided between the mechanical hydraulic pump 71 and the radial oil passage 912.

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

For example, in the above-mentioned Example 1 (similar to Example 2), the partition wall portion 24 is formed integrally with the case member 21, but it may be formed as a separate piece. In this case, the oil hole 941 may be formed in the member forming the partition wall portion 24. In addition, in this case, the cooling water passage 13 may also be opened on the second axial side L2, in which case the second axial side L2 side of the cooling water passage 13 may be blocked by the member forming the partition wall portion 24. In this case, the second partition wall portion 135 can be formed integrally with the case member 21, similar to the first partition wall portion 211.

1: rotating electric machine, 4: counter gear mechanism, 10: drive transmission mechanism, 11: stator, 12: rotor, 13: cooling water passage, 21: case member, 22: first cover member, 23: second cover member, 41: counter shaft, 71: mechanical hydraulic pump (oil pump), 73: oil cooler, 90, 90A: oil passage structure, 91: first cover oil passage (first oil passage), 93: second cover oil passage, 94: case oil passage, 100: vehicle drive device, 111: stator core, 112: coil end portion, 121: rotor core, 122: rotor shaft, 122a: rotor shaft oil passage (second oil passage), 122b: first supply oil passage, 122c: second supply oil passage, 131: inlet portion, 132: outlet portion, SP1: chamber (first chamber), SP2: chamber (second chamber), MJ: inverter module

Claims (11)

A vehicle drive device including a rotating electric machine electrically connected to a water-cooled inverter module,
The rotating electric machine includes:
a rotor having a hollow rotor shaft and a rotor core;
a stator having a stator core and a coil;
a case member that defines a first chamber in which the rotor and the stator are housed, that is adjacent to the stator in a radial direction, and that has a cooling water passage formed therein that communicates with the inside of the inverter module;
The vehicle drive device includes:
a mechanical oil pump that operates in conjunction with the rotation of the rotor;
an oil passage structure that supplies oil discharged by the oil pump to a hollow interior of the rotor shaft ,
the rotating electric machine further includes a first cover member attached to a first side in the axial direction of the case member so as to cover the first chamber,
The oil passage structure includes a first oil passage formed in the first cover member,
The first oil passage opens radially toward a coil end portion on the first side in the axial direction of the coil . The vehicle drive device according to claim 1, wherein the oil passage structure further supplies oil discharged by the oil pump to the coil end portion of the coil from the radial outside. The vehicle drive device according to claim 1 or 2, further comprising an oil cooler that realizes heat exchange between the cooling water flowing through the cooling water passage and the oil discharged by the oil pump. Further including a drive transmission mechanism including gears,
the case member further defines a second chamber in which the drive transmission mechanism is housed,
The vehicle drive device according to claim 3 , wherein the oil cooler is attached to a portion of the case member that defines the second chamber. The vehicle drive device according to claim 4, wherein the inverter module is attached to the case member near the oil cooler. The oil passage structure further includes a case oil passage formed in the case member,
The vehicle drive device according to claim 1 , wherein the case oil passage passes above a center position of the stator in a vertical direction and communicates with the first oil passage. The vehicle drive device according to claim 6 , wherein the case oil passage opens radially toward a coil end portion on a second side of the coil, the second side being opposite to the first side in the axial direction. The oil passage structure further includes a second oil passage realized by a hollow interior of the rotor shaft, and an oil hole radially penetrating from an inner circumferential surface to an outer circumferential surface of the rotor shaft,
the oil hole is provided at a position overlapping with the coil end portion as viewed in the radial direction,
The vehicle drive device according to claim 7 , wherein the second oil passage communicates with the first oil passage. the drive transmission mechanism includes a counter gear mechanism provided between the rotor shaft and a differential gear mechanism,
9. The vehicle drive device according to claim 8 , wherein the oil pump is provided at an end portion on the second side in the axial direction of a counter shaft of the counter gear mechanism. a second cover member attached to the second side of the case member in the axial direction and covering the second chamber;
The oil passage structure further includes a third oil passage formed in the second cover member,
The vehicle drive device according to claim 9 , wherein the oil discharged by the oil pump flows through the third oil passage, the case oil passage, the first oil passage, and the second oil passage in this order. 11. The vehicle drive device according to claim 9 or 10, wherein the cooling water passage has an inlet portion and an outlet portion at positions circumferentially sandwiching the case oil passage, and runs around the rotating shaft of the rotating electric machine in a serpentine form between the first side and the second side in the axial direction from the inlet portion to the outlet portion.