JP2024072517A - On-vehicle inverter unit and vehicle drive system - Google Patents

Abstract

To appropriately configure a heat management system in a vehicle by an on-vehicle inverter unit for performing drive control of a rotary electric machine and a vehicle drive system as main components and to configure the on-vehicle inverter unit and the vehicle drive system in small size.SOLUTION: A refrigerant module 1 constituting a refrigerant circuit for circulating refrigerant for an on-vehicle air conditioner comprises: a refrigerant channel 29; and a plurality of functional components 31, 32, 41, and V. The refrigerant channel 29 is formed inside a cover 93 which blocks an opening 9a of a case 9 for accommodating an inverter module INV. The cover 93 comprises a projection 93p projecting on any side in a direction along the opening 9a to the case 9. The specific functional components 31, 32, 41 as at least a part of the plurality of functional components 31, 32, 41, and V are attached to a surface 93b facing a case side X2 in an opening direction at the projection 93p and connected with the refrigerant channel 29.SELECTED DRAWING: Figure 1

Description

The present invention relates to an on-board inverter unit and a vehicle drive device equipped with an on-board inverter unit.

JP 2019-170077 A discloses a vehicle drive device (1) including a rotating electric machine (rotor (20), stator (30)) that serves as a driving force source for wheels (803, 804), a drive control device (131) that drives and controls the rotating electric machine, a charger (136) that charges a battery (805) connected to the rotating electric machine via the drive control device (131) with power supplied from an external power source (900), and a case (10) that houses the rotating electric machine, the drive control device (131), and the charger (136) (reference numerals in parentheses in the background art are those of the referenced document). In the case (10), a first storage chamber is formed on the lower side in the vertical direction (Z) in a vehicle-mounted position in which the vehicle drive device (1) is mounted on the vehicle, and a second storage chamber is formed on the upper side in which the drive control device (131) and the charger (136) are accommodated. The first storage chamber is formed inside the cylindrical peripheral wall portion (10b) of the case (10). The second storage chamber is formed as a rectangular box-shaped space inside a square tube portion (10e) adjacent to the upper side of the peripheral wall portion (10b) in the vertical direction (Z) on the radially outer side of the peripheral wall portion (10b). The peripheral wall portion (10b) further includes a cooling portion (60) having a cooling flow path through which a refrigerant flows along the peripheral wall portion (10b).

The cooling flow path formed along the peripheral wall portion (10b) has an inlet (16) through which the refrigerant flows and an outlet (17) through which the refrigerant flows out, on the side of the square tube portion (10e). The drive control device (131) is arranged on the side of the refrigerant flow path closer to the inlet (16), i.e., on the upstream side of the refrigerant flow path, and the charger (136) is arranged on the side of the refrigerant flow path closer to the outlet (17), i.e., on the downstream side of the refrigerant flow path. This allows the drive control device (131), which generates heat when driving the rotating electric machine, to be efficiently cooled by the cold refrigerant. Since the battery (805) is charged by the external power source (900) while the vehicle is stopped, the temperature of the refrigerant is unlikely to rise due to heat exchange with the drive control device (131), and the charger (136) is appropriately cooled even if it is arranged on the downstream side of the refrigerant flow path. In addition, reactors (140) and smoothing capacitors (141) used to improve the power factor of the power system and stabilize the voltage are also arranged along the refrigerant flow path and are appropriately cooled by the refrigerant.

JP 2019-170077 A

As described above, the vehicle drive device disclosed in the above document has a cooling structure capable of efficiently cooling multiple cooling targets. However, the vehicle also has other devices that are subject to thermal management, such as an air conditioner. The lighter the vehicle is, the easier it is to increase the vehicle's energy efficiency, and appropriate heat utilization and waste heat management also contribute to improving the vehicle's energy efficiency. Therefore, it is preferable to configure the vehicle drive device, which accounts for a relatively large proportion of the weight of the on-board equipment, to be compact, and to implement more comprehensive thermal management of the on-board equipment by using the vehicle drive device and devices mounted on the vehicle drive device, such as an on-board inverter unit that is configured with a drive device for a rotating electric machine.

In light of the above background, it is desirable to provide technology that can appropriately configure a thermal management system for a vehicle with an on-board inverter unit or vehicle drive unit for driving and controlling a rotating electric machine at its core, as well as to configure the on-board inverter unit and vehicle drive unit in a compact size.

In view of the above, the vehicle-mounted inverter unit includes an inverter module for controlling the drive of a rotating electric machine that serves as a driving force source for the wheels, a case that houses the inverter module, a cover that closes the opening of the case, and a refrigerant module that constitutes a refrigerant circuit that circulates refrigerant for an in-vehicle air conditioner. The refrigerant module includes a refrigerant flow path that is a flow path of the refrigerant in the refrigerant circuit, and a plurality of functional parts that are connected to each other by the refrigerant flow path and constitute the refrigerant circuit. The refrigerant flow path is formed inside the cover, and the direction perpendicular to the opening surface of the opening is defined as the opening direction, and the side on which the case is arranged relative to the cover in the opening direction is defined as the opening direction case side. The cover includes a protrusion that protrudes from the case to either side in the direction along the opening surface, and a specific functional part that is at least a part of the plurality of functional parts is attached to the surface of the protrusion that faces the opening direction case side and is connected to the refrigerant flow path.

According to this configuration, the refrigerant module can be integrally provided with the inverter module and the case and cover for accommodating the inverter module. That is, the inverter module and the refrigerant module can be integrated. Therefore, compared to when the inverter module and the refrigerant module are independent, it is easier to reduce the number of parts, and the vehicle-mounted inverter unit can be easily mounted on a relatively small vehicle. Also, according to this configuration, the specific function parts of the refrigerant module are attached to the surface facing the opening direction of the protruding part of the cover toward the case side. As a result, the specific function parts are arranged outside the accommodation chamber in the case in which the inverter module is accommodated, side by side with the accommodation chamber. Therefore, while integrating the inverter module and the refrigerant module, they can be appropriately arranged separately inside and outside the accommodation chamber of the case. Furthermore, according to this configuration, the specific function parts of the refrigerant module, the case, and the inverter module can be arranged on the same side of the cover. Therefore, while integrating the inverter module and the refrigerant module, it is possible to suppress the increase in size of the vehicle-mounted inverter unit. In this way, with this configuration, it is possible to appropriately configure a thermal management system in a vehicle with an on-board inverter unit for driving and controlling a rotating electric machine as its core, and to configure the on-board inverter unit in a compact size.

Further features and advantages of the vehicle inverter unit and vehicle drive device will become apparent from the following description of exemplary and non-limiting embodiments, which are illustrated with reference to the drawings.

Exploded perspective view of a vehicle drive device Skeleton diagram of a vehicle drive system Schematic control block diagram of a vehicle drive device FIG. 2 is a schematic diagram showing a refrigerant circuit and a coolant circuit. FIG. 2 is a front view of the vehicle drive device as viewed from a first side in the front-rear direction; 1 is a rear view of the vehicle drive device as viewed from a second side in the front-rear direction; FIG. 1 is a side view of a vehicle drive device as viewed from a second axial side; FIG. 2 is a perspective view showing a schematic arrangement of a cooling unit, an inverter module, and a power supply module; FIG. 2 is a schematic diagram showing an example of a refrigerant path in a refrigerant manifold;

Below, an embodiment of the vehicle drive device will be described with reference to the drawings. The vehicle drive device 100 of this embodiment appropriately configures a thermal management system in the vehicle with the vehicle drive device 100 at its core while preventing the vehicle from becoming too large. For example, in small vehicles such as A-segment vehicles in Europe and minicars in Japan, it is required to improve mounting efficiency by making the vehicle drive device 100 and other on-board components as small and lightweight as possible. For example, it is preferable to shorten the length of connecting components such as wiring and piping by arranging on-board components close to each other, or to reduce wiring and piping by integrating different devices.

In addition, the cooling water that cools the heat-generating devices in the vehicle, such as the driving force source of the wheels, is waste heat by a radiator, but the radiator is generally located at the very front of the vehicle to waste heat by the wind while driving. In addition, small cars such as A-segment cars are often front-wheel drive in order to secure interior space for passengers, and the driving force source of the wheels is also located at the front of the vehicle. In addition, in vehicles equipped with an air conditioner that performs cooling and heating, the air conditioner, as well as many parts of the flow path through which the refrigerant used in the air conditioner flows, and the functional parts that perform heat exchange are also located at the front of the vehicle. In particular, with regard to heating, in conventional vehicles that used an internal combustion engine as the driving force source of the wheels, it was easy to use the internal combustion engine as a heat source, but in vehicles that do not have an internal combustion engine, such as electric vehicles, there is no such heat source, so a heat pump system is exclusively used for heating, and the number of mounted parts tends to increase compared to systems that use waste heat from the internal combustion engine. By properly piping and wiring these on-board parts in the limited space at the front of the vehicle, the space available for the passenger compartment can be expanded. In this embodiment, the vehicle drive device 100 integrates functional components that perform thermal management using cooling water or refrigerant with the vehicle drive device 100, thereby achieving overall miniaturization, weight reduction, and cost reduction of vehicle-mounted components.

Below, we will explain a preferred embodiment of such a vehicle drive device 100, but first we will explain its function as a drive unit for driving the wheels W.

In this specification, the term "driving connection" refers to a state in which two rotating elements are connected so as to be able to transmit a driving force, including a state in which the two rotating elements are connected so as to rotate integrally, or a state in which the two rotating elements are connected so as to be able to transmit a driving force via one or more transmission members. Such transmission members include various members that transmit rotation at the same speed or at a variable speed, such as shafts, gear mechanisms, belts, chains, etc. In addition, the transmission members may also include engagement devices that selectively transmit rotation and driving force, such as friction engagement devices and meshing engagement devices. However, when referring to each rotating element of a planetary gear mechanism as "driving connection," it refers to a state in which multiple rotating elements in the planetary gear mechanism are connected to each other without passing through other rotating elements. In addition, in this specification, "rotating integrally" refers to rotating integrally regardless of whether they are separable or not. In other words, multiple members that rotate integrally may be integrally formed from the same member, or may be made of different members and integrated by welding, spline connection, etc. Additionally, in this specification, with regard to the arrangement of two elements, "overlapped when viewed in a particular direction" means that when an imaginary line parallel to the line of sight is moved in each direction perpendicular to the imaginary line, there is at least a portion of an area where the imaginary line intersects both of the two elements.

As shown in the exploded oblique view of Figure 1 and the skeleton diagram of Figure 2, the vehicle drive device 100 comprises a rotating electric machine MG with a rotor 12, an output member drivingly connected to wheels W, and a power transmission mechanism GT that transmits driving force between the rotating electric machine MG and the output member. As will be described later, the direction along the rotation axis A of the rotor 12 is defined as the axial direction L, and the power transmission mechanism GT is disposed on one side of the axial direction L, that is, a first axial side L1, relative to the rotor 12. As will be described in detail later, the rotating electric machine MG is a source of driving force for the vehicle, and the power transmission mechanism GT includes a reduction gear 6 and a differential gear mechanism 5. Specifically, the vehicle drive device 100 includes a rotating electric machine MG with a rotor 12, a pair of output members each of which is drivingly connected to the wheels W, a reduction gear 6 that reduces the rotation of the rotor shaft 13, a differential gear mechanism 5 that distributes the driving force from the rotating electric machine MG transmitted to a differential input element (differential case 50) via the reduction gear 6 to the pair of output members, and a case 9 that forms an accommodation chamber (a second accommodation chamber E2 described later) that accommodates the rotating electric machine MG, the reduction gear 6, and the differential gear mechanism 5.

The pair of wheels W includes a first wheel W1 and a second wheel W2, the first wheel W1 is drivingly connected to the first drive shaft DS1, and the second wheel W2 is drivingly connected to the second drive shaft DS2. In this embodiment, the pair of side gears 52, which are output gears of the differential gear mechanism 5, include a first side gear 53 and a second side gear 54. The first side gear 53 is drivingly connected to the first drive shaft DS1 via a connecting shaft J, and the second side gear 54 is drivingly connected to the second drive shaft DS2. For example, the first side gear 53 and the connecting shaft J are connected by a spline connection, and the second side gear 54 and the second drive shaft DS2 are also connected by a spline connection. These connecting parts are spline engagement parts 59. The output member is, for example, these spline engagement parts 59. The output members may also be the first side gear 53, the second side gear 54, the first drive shaft DS1, the second drive shaft DS2, and the connecting shaft J.

In the following description, the direction along the rotation axis A of the rotor 12 is referred to as the "axial direction L" as described above. One side of the axial direction L is referred to as the "axial first side L1", and the other side of the axial direction L is referred to as the "axial second side L2". In this embodiment, the rotating electric machine MG, the reduction gear 6, and the differential gear mechanism 5 are arranged coaxially in the order described from the axial second side L2 to the axial first side L1. The vehicle drive device 100 of this embodiment has a single shaft configuration, and the shaft (rotation axis A) on which the rotating electric machine MG, the reduction gear 6, and the differential gear mechanism 5 are arranged is the rotation axis A of the vehicle drive device 100 and also the rotation axis of the rotating electric machine MG, the reduction gear 6, and the differential gear mechanism 5. In addition, the direction perpendicular to the rotation axis A of the rotor 12 is referred to as the "radial direction". In the radial direction, the side of the rotation axis A of the rotor 12 is referred to as the "radial inner side", and the opposite side is referred to as the "radial outer side". In addition, when the vehicle drive device 100 is mounted on the vehicle, the direction along the vertical direction is referred to as the "upper-lower direction Z", the upper side is referred to as the "upper side Z1 of the vertical direction Z", and the lower side is referred to as the "lower side Z2 of the vertical direction Z". When the vehicle drive device 100 is mounted horizontally on the vehicle, one of the radial directions coincides with the vertical direction Z. In addition, the direction perpendicular to the axial direction L and the vertical direction Z is referred to as the "front-rear direction H", and one side of the front-rear direction H is referred to as the "first front-rear direction side H1" and the other side is referred to as the "second front-rear direction side H2".

In this embodiment, regardless of whether the device is mounted on a vehicle or not, the "opening direction X", "opening surface direction Y", and "specific opening surface direction Ya (first direction)" are defined based on the vehicle drive device 100 as described below. The "opening surface direction Y" is a direction perpendicular to the "opening direction X", and the "specific opening surface direction Ya" is a specific direction of the "opening surface direction Y" and corresponds to the "first direction". In the vehicle mounted state, the "opening direction X" coincides with the "vertical direction Z", and the "specific opening surface direction Ya" coincides with the "front-rear direction H". In addition, the "opening direction first side X1", which is one side of the "opening direction X", coincides with the "upper side Z1 of the vertical direction Z", and the "opening direction second side X2", which is the other side, coincides with the "lower side Z2 of the vertical direction Z". In addition, one side of the "specific opening surface direction Ya (first direction)", the "specific opening surface direction first side Ya1 (first direction first side)", coincides with the "front-rear direction first side H1", and the other side, the "specific opening surface direction second side Ya2 (first direction second side)", coincides with the "front-rear direction second side H2".

As shown in Figures 1 and 3, the vehicle drive device 100 further includes an inverter module INV for driving and controlling the rotating electric machine MG, a power supply module PWR electrically connected to the vehicle battery BT and including a converter 61 (voltage conversion circuit) for converting the voltage of the vehicle battery BT and a charging circuit 62 for charging the vehicle battery BT from an external power source 60, and a refrigerant circuit module 2 that constitutes a refrigerant circuit 20 (see Figure 4) that circulates refrigerant for the air conditioner. The case 9 includes a first storage chamber E1 that houses the inverter module INV and the power supply module PWR, and a second storage chamber E2 that houses the rotating electric machine MG and the power transmission mechanism GT.

As shown in FIG. 1, the case 9 includes a case body 90, which is a core housing member for the first housing chamber E1 and the second housing chamber E2, and three cover members (first cover 93, second cover 94, and third cover 95). The case body 90 includes a first case portion 91 and a second case portion 92. The first case portion 91 is a portion in which the first housing chamber E1 that houses the inverter module INV and the power supply module PWR is formed. The second case portion 92 is a portion in which the second housing chamber E2 that houses the rotating electric machine MG and the power transmission mechanism GT is formed. In terms of the function of the drive unit for the wheels W, the power supply module PWR does not necessarily have to be mounted on the vehicle drive device 100. In this case, the first case portion 91 can also be said to be a case that houses the inverter module INV.

In this embodiment, the first case part 91 and the second case part 92 are integrally formed from the same material, but the structure of the case 9 is not limited to this. The case 9 may be configured such that the first case part 91 and the second case part 92 are formed from separate materials and are integrated together by fastening members such as bolts, welding, etc.

The first case part 91 is formed in a rectangular box shape with an opening on the upper side Z1 in the vertical direction Z when mounted on the vehicle. Here, the direction perpendicular to the opening surface of the first opening 9a, which is the opening of the first case part 91, is defined as the "opening direction X". The first case part 91 has a peripheral wall part 96 that surrounds the first opening 9a and is arranged to extend along the opening direction X that coincides with the vertical direction Z when mounted on the vehicle. The first opening 9a is closed by a first cover 93. The first opening 9a corresponds to the opening of the case 9 (first case part 91) that houses the inverter module INV, and the first cover 93 corresponds to a cover that closes this opening (first opening 9a). In addition, the first storage chamber E1 and the second storage chamber E2 are arranged to be aligned in the opening direction X.

The second case portion 92 is formed in a cylindrical shape with both sides open in the axial direction L, and includes a cylindrical peripheral wall portion 97. The cylindrical peripheral wall portion 97 surrounds the power transmission mechanism GT from the radial outside, and corresponds to the portion surrounding the second storage chamber E2 of the case 9. The opening formed on the second axial side L2 is the second opening 9b, and the opening formed on the first axial side L1 is the third opening 9c. The second opening 9b is closed by the second cover 94, and the third opening 9c is closed by the third cover 95. The second cover 94 and the third cover 95 are formed with through holes through which the drive shafts (first drive shaft DS1, second drive shaft DS2) described above pass.

The rotating electric machine MG functions as a driving force source for the pair of wheels W. As shown in FIG. 3, the rotating electric machine MG is electrically connected to an on-board battery BT, which is a DC power source composed of a storage device such as a secondary battery or a capacitor, via an inverter circuit PM. The rotating electric machine MG has a function as a motor (electric motor) that receives power from the on-board battery BT to generate power, and a function as a generator (electric generator) that receives power from the wheels W to generate power. The rotating electric machine MG generates driving force by running using the power stored in the on-board battery BT, and also generates power using the driving force transmitted from the pair of wheels W to charge the on-board battery BT. The on-board battery BT is a high-voltage DC power source with a rated voltage of about 48 volts to 400 volts.

In this embodiment, the vehicle battery BT is configured to be charged not only by the power generated by the rotating electric machine MG, but also by power supplied from an external power source 60, such as a commercial power source rated at approximately 100 to 240 volts AC. For this reason, the vehicle battery BT is configured to be connectable to the external power source 60 via a charging circuit 62. In FIG. 3, the external power source 60 and the charging circuit 62 are shown as being connected by wire, for example, by a connector, but this is not limited to this. For example, power may be supplied from the external power source 60 to the charging circuit 62 in a non-contact manner by electromagnetic induction or the like. A charging control unit 64 is provided to control the charging circuit 62.

In this embodiment, the vehicle battery BT also supplies power to a low-voltage DC power source B having a rated voltage of about 12 to 24 volts. The low-voltage DC power source B serves as a power source for auxiliary devices such as headlights, power windows, power steering, air conditioners, and electric oil pumps, and as a power source for various control devices in the vehicle. Conventionally, in a typical vehicle, the low-voltage DC power source B is charged by power generated by an alternator linked to the vehicle's driving power source (e.g., an internal combustion engine). However, in this embodiment, the low-voltage DC power source B is configured to be charged by power from the vehicle battery BT (high-voltage DC power source) which has a higher voltage and a larger storage capacity than the low-voltage DC power source B. This eliminates the need to install an alternator, and also suppresses power loss in the vehicle's driving power source (the rotating electric machine MG in this embodiment) associated with the operation of the alternator.

In order to charge the low-voltage DC power source B with the power of the vehicle battery BT in this way, a converter 61 (voltage conversion circuit) is provided to convert the voltage of the vehicle battery BT. As described above, since the rated voltage of the vehicle battery BT is higher than the rated voltage of the low-voltage DC power source, the converter 61 is, for example, a step-down DC/DC converter. There are non-insulated DC/DC converters such as chopper and charge pump types, and insulated types using a transformer. If it is preferable that the circuit supplied with power from the vehicle battery BT and the circuit supplied with power from the low-voltage DC power source B are electrically insulated, the converter 61 may be an insulated type. The insulated DC/DC converter is configured with a switching element, and the converter 61 is controlled by the converter control unit 63.

Some vehicles are equipped with an AC power socket (alternating current power socket) for supplying power to general home appliances and the like. Such AC power sockets are configured to be capable of outputting alternating current with a rated voltage of 100 volts to 200 volts. The AC power supplied from the AC power socket is generated from the vehicle battery BT using an inverter (not shown). Such an inverter also corresponds to a voltage conversion circuit, and if the vehicle has such an inverter, the inverter and the inverter control unit that controls it can also be included in the power supply module PWR.

As described above, the power supply module PWR is electrically connected to the vehicle battery BT and includes a converter 61 (voltage conversion circuit) that converts the voltage of the vehicle battery BT, and a charging circuit 62 that charges the vehicle battery BT from the external power supply 60. In this embodiment, the charging control unit 64 and converter control unit 63 described above are also included in the power supply module PWR.

As shown in FIG. 2, the rotating electric machine MG includes a stator 11 fixed to the case 9 and a rotor 12 connected to the rotor shaft 13 so as to rotate integrally with the rotor shaft 13. The rotating electric machine MG is an inner rotor type rotating electric machine, and the rotor 12 is arranged radially inside the stator 11. The rotating electric machine MG is a rotating field type rotating electric machine, and the stator 11 includes a stator core 11a and a stator coil 11b wound around the stator core 11a. The rotor 12 also includes a rotor core 12a and a permanent magnet (not shown) fixed to the rotor core 12a. The rotor shaft 13 is formed in a cylindrical shape coaxial with the rotor core 12a, and a sun gear SG of a planetary gear mechanism constituting the reducer 6 is arranged on the outer periphery of the rotor shaft 13 on the axial first side L1 so as to rotate integrally with the rotor shaft 13. As described later, the sun gear SG is an input element of the reducer 6.

As shown in FIG. 3, the rotating electric machine MG is driven and controlled by the rotating electric machine control unit 17 based on the target torque of the rotating electric machine MG, which is set according to a command from the vehicle control unit 300, which is a higher-level control unit. The rotating electric machine control unit 17 controls the switching of the inverter circuit PM, which is composed of multiple switching elements, to cause the inverter circuit PM to convert power between DC and multiple-phase (three-phase in this embodiment) AC. The operating voltage of the rotating electric machine control unit 17 is about 3.3 volts to 5 volts, the input/output voltage of the inverter circuit PM is about 48 volts to 400 volts, and the voltage of the switching control signal of the switching element that constitutes the inverter circuit PM is about 15 volts to 24 volts. For this reason, a driver 18 is provided between the rotating electric machine control unit 17 and the inverter circuit PM, which amplifies the voltage of the switching control signal output from the rotating electric machine control unit 17, increases the driving force, and supplies it to the inverter circuit PM.

The inverter circuit PM is configured with multiple switching elements. The inverter circuit PM has multiple sets (three sets here) of arms for one AC phase, which are configured by a series circuit of an upper-stage switching element on the positive side of DC and a lower-stage switching element on the negative side. Each switching element is provided with a freewheel diode with the forward direction being from the negative electrode to the positive electrode (from the lower side to the upper side). It is preferable to apply power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors), power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), SiC-MOSFETs (Silicon Carbide - Metal Oxide Semiconductor FETs), SiC-SITs (SiC - Static Induction Transistors), and GaN-MOSFETs (Gallium Nitride - MOSFETs) to the switching elements. In this embodiment, the inverter circuit PM is configured as a power module in which switching elements are integrated together with freewheel diodes.

When the rotating electric machine MG is driven, a large current flows through the switching elements that make up the inverter circuit PM, causing the switching elements to heat up. Therefore, the inverter circuit PM, which has multiple switching elements, generates a large amount of heat. For this reason, in this embodiment, as shown in FIG. 8, a cooling unit 38 is provided to cool the switching elements. As will be described later, the cooling unit 38 is formed with a cooling water passage 39 through which cooling water flows.

The inverter module INV is configured to include at least the switching elements that constitute the inverter circuit PM and a cooling unit 38 that cools the switching elements. In this embodiment, as shown in FIG. 3, the inverter module INV further includes a rotating electric machine control unit 17 and a driver 18. That is, in this embodiment, the inverter module INV is configured to include the rotating electric machine control unit 17, the driver 18, the inverter circuit PM, and the cooling unit 38. Of course, the inverter module INV may be configured by the switching elements that constitute the inverter circuit PM and the cooling unit 38 without including the rotating electric machine control unit 17 and the driver 18.

As shown in FIG. 3, a DC link capacitor 16 (smoothing capacitor) that smoothes the voltage on the DC side of the inverter circuit PM is provided on the DC side of the inverter circuit PM, that is, between the inverter circuit PM and the vehicle battery BT. The inverter module INV may include the DC link capacitor 16.

The rotating electric machine control unit 17 performs current feedback control based on the rotational position of the rotor 12 (magnetic pole position of the permanent magnet), the rotational speed of the rotor 12, and the current flowing through the stator coil 11b of each of the three phases, to drive and control the rotating electric machine MG via the inverter circuit PM. The current flowing through the stator coil 11b is detected by a current sensor 15. The current sensor 15 is preferably a non-contact type current sensor installed near a power line such as a bus bar connecting the inverter circuit PM and the stator coil 11b of the rotating electric machine MG, as shown in FIG. 8.

The power supply module PWR is configured to include at least a converter 61 (voltage conversion circuit) and a charging circuit 62. In this embodiment, as shown in FIG. 8, the converter 61 and the charging circuit 62 are configured using a common substrate. In this embodiment, the power supply module PWR is configured to include a converter 61, a converter control unit 63, a charging circuit 62, and a charging control unit 64, as shown in FIG. 3.

In this embodiment, the rotating machine control unit 17 included in the inverter module INV and the converter control unit 63 and the charging control unit 64 included in the power supply module PWR are formed on a single substrate to form a control board ECU. The control board ECU can also be called an integrated control board in which the functions of multiple control units are integrated.

In this embodiment, as shown in FIG. 8, the inverter circuit PM (switching element), the DC link capacitor 16, the converter 61, and the charging circuit 62 are attached to the cooling unit first surface 38a, which is the upper surface of the cooling unit 38. The DC link capacitor 16, which smoothes the pulsating DC voltage, generates heat due to the current flowing in and out. The converter 61 also has a switching element, which also generates heat due to the current flowing during switching operation. The charging circuit 62 also generates heat because a current is supplied from the external power source 60 to charge the vehicle battery BT. The cooling unit 38 has a cooling water passage 39 through which cooling water flows, and these heat-generating components are appropriately cooled by being attached to the cooling unit first surface 38a. Note that the inverter circuit PM generates the most heat and reaches the highest temperature.

For example, the cooling water passage 39 is formed in the cooling unit 38 so that the portion that cools the inverter circuit PM is downstream, that is, so that the cooling water flows from the power supply module PWR side to the inverter module INV side. By circulating the cooling water from an area that generates a low amount of heat to an area that generates a high amount of heat, the cooling object that generates heat can be appropriately cooled while suppressing the temperature rise of the cooling water. In addition, when the rotating electric machine MG is driven, that is, while the vehicle is running, the on-board battery BT is almost never charged from the external power source 60. Although there is a form in which power is supplied contactlessly from a power supply device installed on the road while the vehicle is running on the road, this is not generally put to practical use. Therefore, when the rotating electric machine MG is driven, the charging circuit 62 is often stopped. In addition, the current that flows when the low-voltage DC power source B is charged is smaller than the current that flows through the charging circuit 62 when the on-board battery BT is charged, and the amount of heat generated is also small. Therefore, even if the low-voltage DC power source B is charged while the rotating electric machine MG is running, the amount of heat generated by the converter 61 is smaller than that of the charging circuit 62. Therefore, even if the cooling water flows through this route, the inverter circuit PM can be properly cooled.

The driver 18 is arranged on the upper side Z1 (first side X1 in the opening direction) of the inverter circuit PM in the vertical direction Z. The control board ECU is arranged across the rotating electric machine control unit 17, the converter control unit 63, and the charging control unit 64. The control board ECU is arranged so that, generally, when viewed in the vertical direction (viewed in the opening direction), the inverter circuit PM, the driver 18, and the rotating electric machine control unit 17 overlap, the converter 61 and the converter control unit 63 overlap, and the charging circuit 62 and the charging control unit 64 overlap. In this embodiment, as shown in FIG. 1 and FIG. 8, the power supply module PWR is arranged adjacent to the inverter module INV on the first axial side L1. The control board ECU is arranged across the rotating electric machine control unit 17, the converter control unit 63, and the charging control unit 64 along the axial direction L. The control board ECU is arranged between the inverter circuit PM (switching element) and the refrigerant circuit module 2 in the vertical direction Z, as shown in FIG. 1.

As shown in FIG. 2, the reducer 6 is configured as a planetary gear mechanism including an input element that rotates integrally with the rotor shaft 13, a fixed element fixed to the case 9, an output element that rotates integrally with the differential input element (differential case 50), and planetary gears. This planetary gear mechanism is a composite planetary gear mechanism including one sun gear SG, two ring gears (first ring gear RG1, second ring gear RG2), two planetary gears (first planetary gear PG1, second planetary gear PG2) that rotate integrally, and a carrier CR that rotatably supports the two planetary gears. In this embodiment, the first planetary gear PG1 is formed with a smaller diameter than the second planetary gear PG2.

The sun gear SG rotates integrally with the rotor 12 and the rotor shaft 13. The second ring gear RG2 is fixed to the case 9. The first ring gear RG1 is disposed on the axial first side L1 relative to the second ring gear RG2 and is connected to the differential case 50 so as to rotate integrally with the differential case 50. The second planetary gear PG2 meshes with the sun gear SG and the second ring gear RG2, and the first planetary gear PG1 rotates integrally with the second planetary gear PG2 and meshes with the first ring gear RG1. In this embodiment, the sun gear SG is the input element, the second ring gear RG2 is the fixed element, and the first ring gear RG1 is the output element. The carrier CR is not connected to any rotating element or fixed element.

The differential gear mechanism 5 is a bevel gear type differential gear mechanism, and includes a pinion gear 51 and a side gear 52, both of which are bevel gears. The pinion gear 51 is supported by the differential case 50 and rotatably supported by a pinion shaft 55 arranged to extend radially. The pinion shaft 55 rotates integrally with the differential case 50, and the pinion gear 51 is configured to rotate (spin) around the pinion shaft 55 and to rotate (revolve) around the rotation axis A of the differential case 50. The multiple pinion shafts 55 are arranged radially (for example, in a cross shape) around the rotation axis A of the differential case 50, and a pinion gear 51 is attached to each of the multiple pinion shafts 55. The differential case 50 houses the pinion gear 51, the side gear 52, and the pinion shaft 55 inside.

The side gear 52 includes a first side gear 53 and a second side gear 54, and is arranged in a pair spaced apart in the axial direction L. The first side gear 53 and the second side gear 54 are arranged to mesh with each of the pinion gears 51 and rotate around the rotation axis A of the differential case 50. As shown in FIG. 2, the first side gear 53 is connected to a connecting shaft J that extends along the axial direction L through the reduction gear 6 and the radial inside of the hollow cylindrical rotor shaft 13. The connecting shaft J is connected to rotate integrally with the first drive shaft DS1 that is drivingly connected to the first wheel W1, which is the wheel W on the second axial side L2. Therefore, the first side gear 53 is drivingly connected to the first wheel W1 via the connecting shaft J. The second side gear 54 is connected to rotate integrally with the second drive shaft DS2 that is drivingly connected to the second wheel W2, which is the wheel W on the first axial side L1.

The first drive shaft DS1, the second drive shaft DS2, the connecting shaft J, the first side gear 53, and the second side gear 54, which are drivingly connected to the wheels W and rotate integrally with the wheels W, can all be considered to be rotating members corresponding to the output members. The first side gear 53 and the second side gear 54 are the differential gear mechanism 5 and can also be considered to be output members. The first side gear 53 and the second side gear 54 each have a gear portion that meshes with the pinion gear 51 and a spline engagement portion 59 that is connected to the connecting shaft J or the second drive shaft DS2. When considered functionally, the gear portion corresponds to the rotating member included in the differential gear mechanism 5, and the spline engagement portion 59 corresponds to the output member.

In such a vehicle drive device 100, the rotating electric machine MG and the power transmission mechanism GT are often lubricated (including cooled) by oil, and the vehicle drive device 100 of this embodiment is also lubricated by oil. For example, oil stored in an oil reservoir formed on the lower side Z2 of the case 9 is scooped up by the oil pump OP (see FIG. 4) and the gears of the power transmission mechanism GT, and is supplied to lubrication targets such as bearings and cooling targets such as the stator coil 11b of the rotating electric machine MG. The oil flow path 40 shown in FIG. 4 illustrates a form in which oil discharged from the oil pump OP is supplied to the rotating electric machine MG (the bearings of the stator coil 11b and the rotor shaft 13, etc.) and the power transmission mechanism GT (the bearings of each gear, etc.). Naturally, the temperature of the oil used for cooling rises, so an oil cooler OC for cooling the oil is also connected to the oil flow path 40. The oil cooler OC cools the oil by exchanging heat with cooling water.

As described above, the inverter module INV is provided with a cooling unit 38 that cools the switching elements that constitute the inverter circuit PM. For this reason, the vehicle drive device 100 has a cooling water circuit module 3 that constitutes a cooling water circuit 30 that circulates the cooling water through a path that passes through the cooling unit 38 and the radiator 37 (vehicle radiator). As shown in FIG. 4, the cooling water circuit 30 is connected to the radiator 37, the first water pump 36, the cooling unit 38, and the three-way valve 35. The cooling water circuit module 3 includes at least a water passage formed in the case 9 and the cooling unit 38. The cooling water circuit module 3 may further include a three-way valve 35 and a first water pump 36. The cooling water cooled (heat dissipated) by the radiator 37 is sent to the cooling water circuit 30 by the first water pump 36, absorbs heat from the inverter module INV and the power supply module PWR in the cooling unit 38, and returns to the radiator 37 via the three-way valve 35 to be dissipated heat.

As shown in FIG. 4, the oil cooler OC described above is also connected to the cooling water circuit 30. The oil cooler OC cools the oil flowing through the oil passage 40 by exchanging heat with the cooling water flowing through the cooling water circuit 30. In addition, a water-cooled condenser 31 (refrigerant heat exchanger) is also connected to the cooling water circuit 30. The water-cooled condenser 31 exchanges heat between the air conditioner refrigerant and the cooling water to cool the refrigerant whose temperature has increased.

The cooling water, whose temperature has risen after passing through the cooling unit 38, oil cooler OC, and water-cooled condenser 31, passes through the three-way valve 35 and returns to the radiator 37, where heat is wasted. However, in cases where there is no need to waste heat, such as in cold weather, or conversely, when it is desired to raise the temperature of the oil using the cooling water, or when performing rapid heating using the air conditioner, heat dissipation by the radiator 37 is not necessary. In such cases, the three-way valve 35 switches the flow path of the cooling water so that the cooling water is circulated without passing through the radiator 37.

As described above, the water-cooled condenser 31 is connected to the refrigerant circuit 20 through which the refrigerant for the air conditioner flows. The refrigerant circuit 20 has a path (first flow path 20a) that runs from the water-cooled condenser 31 through the first valve V1, the evaporator 44, and the accumulator 41, and a path (second flow path 20b) that runs from the water-cooled condenser 31 through the second valve V2 to the accumulator 41, and then through the compressor 42, the cabin condenser 43, and the third valve V3 to return to the water-cooled condenser 31.

The evaporator 44 is a functional component that is the core of the air conditioning, and removes heat from the surroundings by vaporizing the refrigerant, releasing cool air into the vehicle cabin. The accumulator 41 separates the liquid from the refrigerant, which is a mixture of gas and liquid, and supplies only the gas (refrigerant gas) to the compressor 42. The compressor 42 compresses the relatively low-temperature, low-pressure refrigerant gas to a high temperature and high pressure. The cabin condenser 43 is a heat source for heating using the heat pump system, and releases the heat condensed by the compressor 42 into the vehicle cabin. The refrigerant that leaves the cabin condenser 43 flows to the water-cooled condenser 31 via the third valve V3, which is an expansion valve.

In this embodiment, the battery heat sink 34 also cools the vehicle battery BT by heat exchange with the cooling water, and the cooling water whose temperature has risen is cooled by heat exchange with the refrigerant in the chiller 32. Therefore, a third flow path 20c is formed as a path through which the refrigerant travels from the water-cooled condenser 31 to the accumulator 41 via the fourth valve V4 and the chiller 32.

The chiller 32 is connected to a second coolant circuit 30B through which the coolant flows from the chiller 32 through the battery heat sink 34 and the second water pump 33 and returns to the chiller 32. The chiller 32, like the water-cooled condenser 31, exchanges heat between the coolant and the refrigerant, and removes heat from the coolant to cool the coolant. The coolant whose temperature has increased due to heat exchange with the battery heat sink 34 is cooled in the chiller 32. By providing the second coolant circuit 30B for cooling the vehicle battery BT and the third flow path 20c for cooling the coolant flowing through the second coolant circuit 30B, it becomes easier to relax the restrictions on the input/output current to the vehicle battery BT even in cases where the current flowing through the vehicle battery BT increases and the temperature of the vehicle battery BT rises, such as during quick charging or high-speed driving.

As described above, the refrigerant circuit 20 includes a first flow path 20a including a refrigerant flow path from the water-cooled condenser 31 (refrigerant heat exchanger) to the evaporator 44, a second flow path 20b including a refrigerant flow path from the compressor 42 to the water-cooled condenser 31, and a third flow path 20c including a refrigerant flow path including the chiller 32. The refrigerant flowing through the first flow path 20a is at a lower temperature than the second flow path 20b and the third flow path 20c. Also, the refrigerant flowing through the third flow path 20c is at a lower temperature than the second flow path 20b.

In this embodiment, a part of the flow path constituting the refrigerant circuit 20 is formed by using the first cover 93 of the case 9. Also, as shown in FIG. 1 and FIG. 5, etc., the control valves V (first valve V1, second valve V2, third valve V3, fourth valve V4) that control the flow rate or flow path of the refrigerant in the refrigerant circuit 20 are attached to the first cover first surface 93a, which is the surface facing the opposite side (opening direction first side X1 (opening direction opposite case side)) from the opening direction second side X2 (opening direction case side) of the first cover 93. As shown in FIG. 1 and FIG. 5 to FIG. 7, the refrigerant circuit 20 and the control valves V formed in the first cover 93 constitute the refrigerant circuit module 2.

The refrigerant circuit module 2 is equipped with a water-cooled condenser 31, a chiller 32, and an accumulator 41 as functional components that constitute the refrigerant flow path in the refrigerant circuit 20. The refrigerant circuit module 2 and these functional components together constitute the refrigerant module 1. Note that if the vehicle battery BT is not cooled using cooling water, i.e., if the third flow path 20c is not formed, the chiller 32 does not need to be provided. Therefore, the refrigerant module 1 may be constituted by the refrigerant circuit module 2, the water-cooled condenser 31, and the accumulator 41.

The refrigerant path components include the control valve V and functional parts, including the water-cooled condenser 31, the chiller 32, and the accumulator 41. In this embodiment, the compressor 42, the cabin condenser 43, the evaporator 44, and the battery heat sink 34 are also functional parts, although they are not included in the refrigerant module 1. The second water pump 33 is also a functional part, and can be included in the refrigerant module 1 when the second water pump 33 is also integrally provided in the vehicle drive device 100, as shown in FIG. 4. The accumulator 41 is included in the refrigerant module 1 when attached to the first cover 93, as shown in FIG. 1, FIG. 5 to FIG. 7, and FIG. 9, but may be arranged separately from the vehicle drive device 100 and not included in the refrigerant module 1.

Of the functional parts exemplified above, at least the water-cooled condenser 31 corresponds to a specific functional part included in the refrigerant module 1. In addition, the chiller 32 and accumulator 41, which may constitute the refrigerant module 1 together with the water-cooled condenser 31, also correspond to specific functional parts depending on the aspect.

The portion of the first cover 93 where the refrigerant circuit 20 is formed is called the refrigerant manifold 21. As shown in FIG. 9, the refrigerant manifold 21 is divided into a first manifold 23 and a second manifold 24. The first manifold 23 and the second manifold 24 are configured to be connectable via the communication flow path 22. As described above, the refrigerant circuit 20 has a first flow path 20a through which a relatively low-temperature refrigerant flows and a second flow path 20b through which a relatively high-temperature refrigerant flows. The first flow path 20a, which is the flow path of the refrigerant from the water-cooled condenser 31 to the evaporator 44, is mainly formed in the first manifold 23. The second flow path 20b, which is the flow path of the refrigerant from the compressor 42 to the water-cooled condenser 31, is mainly formed in the second manifold 24. The first manifold 23 corresponds to the first flow path region 20A of the refrigerant circuit 20, and the second manifold 24 corresponds to the second flow path region 20B of the refrigerant circuit 20.

The refrigerant manifold 21 is provided with a piping connection 99 that connects the refrigerant manifold 21 to functional components that are not integrated with the vehicle drive device 100, such as the evaporator 44 and the cabin condenser 43. As with the control valve V, it is preferable that the connection 99 is formed on the first cover first surface 93a, which is the surface of the first cover 93 facing the opening direction first side X1 (the side opposite to the opening direction case side).

Figure 9 illustrates an example in which the third flow path 20c is formed in the first manifold 23. However, when at least a portion of the third flow path 20c is formed in the refrigerant manifold 21, the third flow path 20c may be formed in either the first manifold 23 or the second manifold 24. Of course, the third flow path 20c may be formed across both the first manifold 23 and the second manifold 24.

In this embodiment, the first storage chamber E1 and the second storage chamber E2 are formed using a case body 90 that is one member. However, for example, the first case body forming the first storage chamber E1 and the second case body forming the second storage chamber E2 may be formed of separate members, and the first case body and the second case body may be connected to form a case 9 having the first storage chamber E1 and the second storage chamber E2. The first cover 93 is a cover that closes the first storage chamber E1 that houses the inverter module INV, and the refrigerant circuit module 2 is configured by using the first cover 93 as a refrigerant manifold 21 and attaching a control valve V to the first cover 93. In addition, a plurality of refrigerant path components (control valve V, functional parts) are attached to the first cover 93 to configure the refrigerant module 1. Therefore, the vehicle-mounted inverter unit 10 can be said to be configured with the inverter module INV, a case 9 (first case portion 91) that houses the inverter module INV, a cover (first cover 93) that closes the opening (first opening 9a) of the case 9, and a refrigerant module 1 that constitutes a refrigerant circuit 20 that circulates refrigerant for the air conditioner.

As described above, the refrigerant module 1 includes a refrigerant flow path 29 (see FIG. 4) which is a flow path of the refrigerant in the refrigerant circuit 20, and a plurality of functional components which are connected to each other by the refrigerant flow path 29 to constitute the refrigerant circuit 20. The refrigerant flow path 29 is formed inside the first cover 93. As shown in FIG. 1 and FIG. 7, the first cover 93 includes a protruding portion 93p which protrudes toward either side of the direction along the opening surface of the first opening 9a (opening surface direction Y) relative to the case 9. As shown in FIG. 1, FIG. 5, FIG. 7, etc., a specific functional component which is at least a part of the plurality of functional components is attached to the first cover second surface 93b (the surface facing the opening direction case side of the first cover 93) of the protruding portion 93p and is connected to the refrigerant flow path 29. The power supply module PWR may or may not be accommodated in the first accommodation chamber E1.

According to this embodiment, the refrigerant module 1 can be integrally provided with the inverter module INV and the case 9 and first cover 93 for accommodating the inverter module INV. That is, the inverter module INV and the refrigerant module 1 can be integrated. Therefore, compared with the case where the inverter module INV and the refrigerant module 1 are independent, it is easier to reduce the number of parts, and the vehicle-mounted inverter unit 10 can be easily mounted on a relatively small vehicle. In addition, the specific function parts of the refrigerant module 1 are attached to the first cover second surface 93b. As a result, the specific function parts are arranged side by side with the first accommodation chamber E1 on the outside of the first accommodation chamber E1 in the case 9. Therefore, while integrating the inverter module INV and the refrigerant module 1, they can be appropriately arranged separately inside and outside the first accommodation chamber E1. Furthermore, the specific function parts of the refrigerant module 1, the case 9, and the inverter module INV can be arranged on the same side (opening direction second side X2 (opening direction case side)) with respect to the first cover 93. Therefore, the inverter module INV and the refrigerant module 1 can be integrated while preventing the size of the vehicle-mounted inverter unit 10 from increasing.

As described above, the first case part 91 of the case 9 includes a peripheral wall part 96 that surrounds the first opening 9a (opening of the case) and extends along the opening direction X. In this embodiment, as shown in FIG. 1, FIG. 7, etc., a specific direction in the opening surface direction Y that is a direction along the opening surface of the first opening 9a is set as a specific opening surface direction Ya (first direction), and the protrusion part 93p protrudes from the case 9 toward a specific opening surface direction first side Ya1 (first direction first side) that is one side in the specific opening surface direction Ya (first direction). The specific functional part is arranged at a position overlapping with the peripheral wall part 96 when viewed in the specific opening surface direction (first direction view) along the specific opening surface direction Ya (first direction).

When there are multiple specific functional parts, all of the specific functional parts are arranged in positions that overlap with the peripheral wall portion 96. For example, as shown in Figures 1 and 5, when the specific functional parts include a water-cooled condenser 31, an accumulator 41, and a chiller 32, the water-cooled condenser 31, the accumulator 41, and the chiller 32 are all arranged in positions that overlap with the peripheral wall portion 96.

The peripheral wall portion 96 surrounding the first opening 9a (opening) overlaps with the storage section in the case 9 that stores the inverter module INV when viewed in the specific opening surface direction (first direction). Since the inverter module INV is stored in the storage space, the specific functional parts of the refrigerant module 1, the case 9, and the inverter module INV can be arranged to overlap each other when viewed in the specific opening surface direction (first direction). Therefore, it is easy to prevent the in-vehicle inverter unit 10 from becoming larger in, for example, the opening direction X or in a direction perpendicular to the opening direction X and the specific opening surface direction Ya (first direction). In other words, according to this configuration, it is possible to prevent the in-vehicle inverter unit 10 from becoming larger while integrating the inverter module INV and the refrigerant module 1.

The vehicle drive device 100 of this embodiment can be configured to include an in-vehicle inverter unit 10, a rotating electric machine MG, an output member that is drivingly connected to the wheels W, and a power transmission mechanism GT that transmits driving force between the rotating electric machine MG and the output member. As described above, the case 9 includes a first storage chamber E1 that stores the inverter module INV, and a second storage chamber E2 that stores the rotating electric machine MG and the power transmission mechanism GT. As shown in Figures 1, 5 to 7, the first storage chamber E1 and the second storage chamber E2 are arranged to be aligned in the opening direction X. As shown in Figures 1 and 7, the specific functional part is arranged in a position that overlaps with the cylindrical peripheral wall portion 97, which is a portion that surrounds the second storage chamber E2 of the case 9, when viewed from the opening direction along the opening direction X.

A specific functional part is attached to the surface (first cover second surface 93b) of the protruding part 93p of the first cover 93 (cover) facing the case side in the opening direction. When the specific functional part and the part surrounding the second storage chamber E2 of the case 9 (cylindrical peripheral wall part 97) do not overlap when viewed in the opening direction, the protruding part 93p and the specific functional part will protrude in the direction in which the protruding part 93p protrudes relative to the part surrounding the second storage chamber E2 of the case 9 (cylindrical peripheral wall part 97). In other words, the vehicle drive device 100 with the specific functional part attached tends to be larger in the direction in which the protruding part 93p protrudes relative to the outer shape of the case 9. According to this configuration, since the specific functional part and the part surrounding the second storage chamber E2 of the case 9 (cylindrical peripheral wall part 97) overlap when viewed in the opening direction, it is easier to reduce the size of the vehicle drive device 100 when viewed in the opening direction compared to when they do not overlap.

1 and 7, the cylindrical peripheral wall portion 97, which is a portion of the second case portion 92 surrounding the second storage chamber E2, bulges out toward the first side Ya1 (first direction first side) in the specific opening surface direction relative to the first case portion 91 (the peripheral wall portion 96 of the first case portion 91). Therefore, between the protrusion 93p and the cylindrical peripheral wall portion 97, at least between the specific functional part and the cylindrical peripheral wall portion 97, a case outer arrangement area E3 is formed that is surrounded by the surface of the rectangular parallelepiped, the specific functional part, and the cylindrical peripheral wall portion 97 when a virtual rectangular parallelepiped circumscribing the vehicle drive device 100 is considered. By including, for example, the three-way valve 35 and the first water pump 36 in this case outer arrangement area E3, many of the components of the cooling water circuit module 3 described above can also be integrated with the vehicle drive device 100.

In addition, an oil pump OP and an oil cooler OC may be arranged in the case exterior arrangement area E3 instead of or in addition to the three-way valve 35 and the first water pump 36. If the oil pump OP is arranged inside the case 9, only the oil cooler OC may be arranged in the case exterior arrangement area E3.

The vehicle drive device 100 of this embodiment further includes an oil cooler OC for cooling the oil contained in the second storage chamber E2, and a coolant circuit module 3 constituting a coolant circuit 30 that circulates coolant through a path passing through the oil cooler OC and a radiator 37. In this embodiment, the coolant circuit module 3 is constituted by a three-way valve 35, a first water pump 36, and a cooling unit 38. However, the coolant circuit module 3 may be constituted without passing through the cooling unit 38. The specific functional parts also include a water-cooled condenser 31, which is a refrigerant heat exchanger for cooling the refrigerant by heat exchange between the air conditioner refrigerant and the coolant.

With this configuration, the air conditioner refrigerant flowing through the refrigerant circuit 20 can be cooled by the cooling water. The cooling water circulates through a path that passes through the radiator 37 (vehicle radiator), so the heat of the air conditioner refrigerant can be discharged outside the vehicle by the radiator 37. Furthermore, with this configuration, the water-cooled condenser 31 (refrigerant heat exchanger) is fixed integrally to the case 9 via a refrigerant path component. Therefore, the amount of piping, etc. that connects the functional components that make up the refrigerant circuit 20 can be reduced.

As described above, the functional parts include a control valve V that controls the flow rate or flow path of the refrigerant in the refrigerant circuit 20. The specific functional parts may also include an accumulator 41 for separating the refrigerant into liquid and gas. The control valve V is attached to a surface (first cover first surface 93a) of the first cover 93 (cover) facing the opposite side to the opening direction second side X2 (opening direction case side). The water-cooled condenser 31 (refrigerant heat exchanger) and the accumulator 41 are arranged side by side along a wall portion (peripheral wall portion 96) that surrounds the first storage chamber E1 of the case 9.

By attaching the control valve V to the surface (first cover first surface 93a) of the first cover 93 (cover) facing the opposite side to the opening direction second side X2 (opening direction case side), for example, the control valve V and the specific functional parts can be arranged relatively close to each other across the first cover 93 (cover). In addition, by arranging multiple specific functional parts along the wall portion (peripheral wall portion 96), these multiple specific functional parts can be arranged efficiently. Therefore, with this configuration, the multiple functional parts of the refrigerant module 1 can be appropriately arranged while preventing the vehicle drive device 100 from becoming larger.

As described above, in this embodiment, the power supply module PWR, which is electrically connected to the vehicle battery BT and includes a converter 61 (voltage conversion circuit) that converts the voltage of the vehicle battery BT and a charging circuit 62 that charges the vehicle battery BT from an external power source 60, is also accommodated in the first accommodation chamber E1 together with the inverter module INV. In this case, the above-mentioned vehicle inverter unit 10 may include the power supply module PWR.

That is, the vehicle drive device 100 includes a rotating electric machine MG having a rotor 12, an output member that is drivingly connected to the wheels W, a power transmission mechanism GT that transmits driving force between the rotating electric machine MG and the output member, an inverter module INV for driving and controlling the rotating electric machine MG, a power supply module PWR that is electrically connected to the vehicle battery BT and includes a converter 61 (voltage conversion circuit) that converts the voltage of the vehicle battery BT and a charging circuit 62 for charging the vehicle battery BT from an external power supply 60, a refrigerant circuit module 2 that constitutes a refrigerant circuit 20 that circulates a refrigerant for an air conditioner, and a case 9 that includes a first storage chamber E1 that accommodates the inverter module INV and the power supply module PWR, and a second storage chamber E2 that accommodates the rotating electric machine MG and the power transmission mechanism GT. As shown in FIG. 1 and FIG. 2, the power transmission mechanism GT is disposed on the first axial side L1 with respect to the rotor 12. The inverter module INV includes a switching element that constitutes the inverter circuit PM and a cooling unit 38 that cools the switching element.

As shown in Figures 1, 5, 6, etc., the inverter module INV is disposed above the rotating electric machine MG at a position Z1 that overlaps with the rotating electric machine MG when viewed in the vertical direction Z. Also, as shown in Figures 1, 5, 6, 8, 9, etc., the power supply module PWR is disposed adjacent to the inverter module INV on the first axial side L1. As shown in Figures 1, 5, 6, and 7, the refrigerant circuit module 2 is disposed above the inverter module INV and the power supply module PWR at a position Z1 in the vertical direction Z that overlaps with the inverter module INV and the power supply module PWR when viewed in the vertical direction. Also, the refrigerant circuit module 2 is fixed integrally to the case 9 as shown in Figures 5 to 7, etc.

As shown in Figures 1, 5, 6, etc., the power supply module PWR is disposed above the power transmission mechanism GT on the Z1 side and in a position overlapping with the power transmission mechanism GT when viewed in the vertical direction Z.

In this embodiment, the vehicle drive device 100 not only includes an inverter module INV for driving and controlling the rotating electric machine MG in a drive unit including a rotating electric machine MG and a power transmission mechanism GT, but also includes a power supply module PWR and a refrigerant circuit module 2 for an air conditioner, which are integrated into the drive unit. Therefore, the wiring and piping connecting the drive unit and the inverter module INV to the power supply module PWR and the refrigerant circuit module 2 can be reduced, and the case 9 that houses them can be integrated to make the vehicle drive device 100, which has many functions, smaller overall. In addition, according to this configuration, the inverter module INV equipped with the cooling unit 38 is arranged on the upper side Z1 of the rotating electric machine MG, which generates a large amount of heat because a large current flows through the stator coil, and the power supply module PWR is arranged adjacent to the inverter module INV on the axial first side L1, i.e., the side where the power transmission mechanism GT is arranged relative to the rotating electric machine MG. The refrigerant circuit module 2 is disposed on the upper side Z1 relative to the inverter module INV and the power module PWR, and the heat generated by the rotating electric machine MG is prevented from being transmitted to the refrigerant circuit module 2 by the inverter module INV and the power module PWR equipped with the cooling unit 38. Therefore, it is easy to minimize the effect of heat generated by the rotating electric machine MG on the refrigerant circuit module 2.

As shown in FIG. 4, the vehicle drive device 100 further includes an oil cooler OC for cooling the oil contained in the second storage chamber E2, and a coolant circuit module 3 that constitutes a coolant circuit 30 that circulates coolant through a path passing through the oil cooler OC and a radiator 37 (vehicle radiator). The refrigerant circuit module 2 also includes a refrigerant manifold 21 (refrigerant path component) that constitutes a flow path of the refrigerant in the refrigerant circuit 20, and a control valve V attached to the refrigerant manifold 21. The refrigerant manifold 21 is further provided with a water-cooled condenser 31 (refrigerant heat exchanger) that cools the refrigerant by heat exchange between the refrigerant and the coolant as a functional component that constitutes the refrigerant circuit 20.

According to this configuration, the air conditioner refrigerant flowing through the refrigerant circuit 20 can be cooled by the cooling water. The cooling water circulates through a path that passes through the radiator 37 (vehicle radiator), so the heat of the air conditioner refrigerant can be discharged outside the vehicle by the radiator 37. In addition, according to this configuration, such a water-cooled condenser 31 (refrigerant heat exchanger) is fixed integrally to the case 9 via the refrigerant manifold 21 (refrigerant path component). Therefore, the amount of piping, etc. that connects the functional components that make up the refrigerant circuit 20 can be reduced.

As described above with reference to Figures 4 and 9, in this embodiment, the refrigerant circuit 20 includes a first flow path region 20A, which is a refrigerant flow path from the water-cooled condenser 31 (refrigerant heat exchanger) to the evaporator 44, and a second flow path region 20B, which is a refrigerant flow path from the compressor 42 to the water-cooled condenser 31 (refrigerant heat exchanger). The first flow path region 20A is arranged so as to overlap with the inverter module INV when viewed in the vertical direction, and the second flow path region 20B is arranged so as to overlap with the power supply module PWR when viewed in the vertical direction.

The switching elements constituting the inverter circuit PM tend to generate heat because a large current flows through them. For this reason, it is preferable that the temperature near the switching elements not become high in consideration of heat dissipation. In addition, when the inverter module INV includes a control circuit (rotating motor control unit 17, driver 18: see FIG. 3) that controls the inverter circuit PM, the electronic components constituting the control circuit are often relatively vulnerable to heat. For this reason, it is preferable that the temperature near the control circuit not become high. According to this configuration, the first flow path region 20A in the refrigerant circuit 20, which is relatively low temperature, is disposed in a position close to the inverter module INV, and the second flow path region 20B in the refrigerant circuit 20, which is relatively high temperature, is disposed in a position close to the power supply module PWR. Therefore, it is possible to make it difficult for heat from the refrigerant circuit module 2 to be transmitted to the switching elements constituting the inverter circuit PM in the inverter module INV and the control circuit of the inverter circuit PM.

As described above with reference to FIG. 4, the refrigerant circuit 20 includes an accumulator 41 for separating the refrigerant into liquid and gas. As shown in FIGS. 1, 7, 9, etc., the water-cooled condenser 31 (refrigerant heat exchanger) and the accumulator 41 do not overlap with the inverter module INV and the power supply module PWR when viewed in the vertical direction, and are arranged in a position where their placement areas in the vertical direction Z overlap with the inverter module INV and the power supply module PWR, as shown in FIG. 7.

Of the components that make up the refrigerant circuit 20, the water-cooled condenser 31 (refrigerant heat exchanger) and the accumulator 41 tend to be relatively large. With this configuration, the water-cooled condenser 31 (refrigerant heat exchanger) and the accumulator 41 can be arranged alongside the inverter module INV and the power supply module PWR. This makes it easier to reduce the dimensions of the vehicle drive device 100 in the vertical direction Z.

As described above with reference to FIG. 4, in this embodiment, the refrigerant circuit 20 is provided with a chiller 32, which is a coolant heat exchanger for cooling the coolant by heat exchange between the coolant flowing through the second coolant circuit 30B and the refrigerant. As shown in FIGS. 1, 7, 9, etc., the chiller 32 does not overlap with the inverter module INV and the power module PWR when viewed in the vertical direction, and is arranged in a position where the arrangement area in the vertical direction Z overlaps with the inverter module INV and the power module PWR, as shown in FIG. 7. Of the components that make up the refrigerant circuit 20, the chiller 32 also tends to be relatively large. With this configuration, such a chiller 32 can also be arranged side by side with the inverter module INV and the power module PWR. Therefore, it is easy to reduce the size of the vehicle drive device 100 in the vertical direction Z.

Although detailed paths are omitted, as shown in Figures 1 and 8, the cooling unit 38 has a cooling water passage 39 through which cooling water flows. The switching elements that constitute the inverter circuit PM are attached to the cooling unit first surface 38a, which is the upper surface of the cooling unit 38. The control board ECU that controls the inverter circuit PM is disposed between the switching elements and the refrigerant circuit module 2 in the vertical direction Z.

The switching elements that make up the inverter circuit PM tend to generate heat because a large current flows through them. In addition, the electronic components that are mounted on the control board ECU that controls the inverter circuit PM and that make up the control circuit that controls the inverter circuit PM are often relatively sensitive to heat. With this configuration, the cooling unit 38 allows the switching elements and the control board ECU to be located in a location where heat from the rotating electric machine MG is not easily transmitted, and the cooling unit 38 can properly cool the switching elements attached to the upper surface (cooling unit first surface 38a) of the cooling unit 38, while also making it difficult for heat from the rotating electric machine MG to be transmitted to the control board ECU.

Other embodiments
Other embodiments will be described below. Note that the configurations of the embodiments described below are not limited to being applied independently, and may be applied in combination with the configurations of other embodiments as long as no contradiction occurs.

(1) In the above, the power transmission mechanism GT is exemplified as having a reduction gear 6 and a differential gear mechanism 5. However, the power transmission mechanism GT is not limited to this configuration. For example, the power transmission mechanism GT may be exemplified as having only the differential gear mechanism 5 without having the reduction gear 6. Furthermore, the power transmission mechanism GT may be exemplified as having only the reduction gear 6 without having the differential gear mechanism 5, and may be configured to transmit power from one rotating electric machine MG to one wheel W. Furthermore, in this embodiment, a planetary gear mechanism with a fixed gear ratio is exemplified as the reduction gear 6, but the reduction gear 6 may have multiple gear ratios.

(2) As shown in FIG. 8, in a configuration in which the DC link capacitor 16 is arranged on the cooling unit first surface 38a alongside the inverter circuit PM, the DC link capacitor 16 may be included in the inverter module INV. However, for example, in a case in which the DC link capacitor 16 is arranged on the back side of the cooling unit first surface 38a, the DC link capacitor 16 may not be included in the inverter module INV. For example, the DC link capacitor 16 may be arranged on the lower side Z2 of the cooling unit 38 and in a position overlapping with the power transmission mechanism GT in the up-down direction. The DC link capacitor 16 is a relatively heat-resistant component, and by arranging such a component closer to the rotating electric machine MG than the cooling unit 38 in the up-down direction Z and on the side of the power transmission mechanism GT away from the rotating electric machine MG in the axial direction L, the space on the lower side Z2 of the cooling unit 38 can be effectively utilized, and the vehicle drive device 100 can be easily miniaturized as a whole.

It is preferable that the vehicle-mounted inverter unit 10 is configured to include a DC link capacitor 16, regardless of the position of the DC link capacitor 16.

(3) In cases where the converter 61 and the charging circuit 62 provided in the power supply module PWR are both transformer-type, it is preferable to share the transformer components, which tend to be large in size. Also, like the DC link capacitor 16, the transformer is a component that is relatively resistant to heat. Therefore, it is preferable that the transformer is also located below the cooling unit 38 Z2 and in a position that overlaps with the power transmission mechanism GT when viewed in the up-down direction. This makes it possible to effectively utilize the space below the cooling unit 38 Z2, making it easier to reduce the overall size of the vehicle drive device 100.

(4) In the above, as shown in FIG. 5 etc., the refrigerant circuit module 2 arranged on the upper side Z1 in the vertical direction Z with respect to the inverter module INV and the power supply module PWR is configured with a refrigerant manifold 21 (refrigerant path component) that configures the refrigerant flow path in the refrigerant circuit 20 and a control valve V attached to the refrigerant manifold 21, and the water-cooled condenser 31 (refrigerant heat exchanger) is not included in the refrigerant circuit module 2, but is attached to the first cover second surface 93b on the lower side Z2 of the refrigerant manifold 21. However, as with the control valve V, if the water-cooled condenser 31 is attached to the first cover first surface 93a on the upper side Z1 of the refrigerant manifold 21, the refrigerant circuit module 2 may include the water-cooled condenser 31.

(5) In the above, an example is given in which the refrigerant flow path 29 is formed inside the first cover 93 as the refrigerant manifold 21. Naturally, it is not necessary for almost all of the refrigerant flow path 29 to be formed inside the first cover 93, and a part of the refrigerant flow path 29 may be formed using another member of the case 9 or a pipe formed of a member other than the case 9.

(6) In the above, an example is given of a configuration in which the protrusion 93p of the first cover 93 protrudes from the case 9 toward the specific opening surface direction first side Ya1 (first direction first side), which is one side in the specific opening surface direction Ya (first direction). However, the protrusion 93p may be formed to protrude in multiple directions in the opening surface direction Y. In the above, an example is given of the protrusion 93p protruding from one side (face) of the first case part 91 formed in a rectangular box shape toward the outside of the first opening 9a. However, the protrusion 93p may be formed to protrude from multiple sides of the first case part 91 toward the outside of the first opening 9a.

(7) In the above, the specific functional components, which are at least some of the multiple functional components attached to the surface (first cover second surface 93b) of the protrusion 93p facing the opening direction second side X2 (opening direction case side) and connected to the refrigerant flow path 29, are the water-cooled condenser 31, the accumulator 41, and the chiller 32. Also, in the above, the specific functional components are arranged on the surface (first cover first surface 93a) of the protrusion 93p facing the opening direction first side X1. However, at least some of these control valves V may be included in the specific functional components and attached to the first cover second surface 93b.

1: refrigerant module, 3: cooling water circuit module, 9: case, 9a: first opening (opening of case), 10: vehicle-mounted inverter unit, 20: refrigerant circuit, 29: refrigerant flow path, 30: cooling water circuit, 31: water-cooled condenser (heat exchanger for refrigerant, specific functional part, functional part), 32: chiller (specific functional part, functional part), 37: radiator (vehicle-mounted radiator), 41: accumulator (specific functional part, functional part), 42: compressor (vehicle-mounted compressor), 52: side gear (output member), 53: first side gear (output member), 54: second side gear (output member), 59: spline engagement portion (output member), 93: first cover (cover), 93a: first cover first surface (surface facing the opposite side to the opening direction case side), 93b: First cover second surface (surface facing the opening direction case side), 93p: protrusion, 96: peripheral wall portion, 97: cylindrical peripheral wall portion (portion surrounding the second housing chamber of the case), 100: vehicle drive device, DS1: first drive shaft (output member), DS2: second drive shaft (output member), E1: first housing chamber, E2: second housing chamber, GT: power transmission mechanism, INV: inverter module, J: connecting shaft (output member), MG: rotating electric machine, OC: oil cooler, V: control valve (functional part), W: wheel, X: opening direction, X1: opening direction first side (opposite side from the opening direction case side), X2: opening direction second side (opening direction case side), Y: opening surface direction (direction along the opening surface), Ya: specific opening surface direction (first direction), Ya1: specific opening surface direction first side (first direction first side)

Claims (5)

an inverter module for controlling the drive of a rotating electric machine that serves as a driving force source for the wheels;
a case for accommodating the inverter module;
a cover that closes an opening of the case;
A refrigerant module that configures a refrigerant circuit that circulates a refrigerant for an on-vehicle air conditioner,
The refrigerant module includes a refrigerant flow path that is a flow path of the refrigerant in the refrigerant circuit, and a plurality of functional components that are connected to each other by the refrigerant flow path to configure the refrigerant circuit,
The coolant flow path is formed inside the cover,
A direction perpendicular to an opening surface of the opening is defined as an opening direction, and a side on which the case is disposed with respect to the cover in the opening direction is defined as an opening direction case side,
the cover includes a protruding portion protruding from the case toward either side in a direction along the opening surface,
A vehicle-mounted inverter unit, wherein a specific functional part which is at least a part of the plurality of functional parts is attached to a surface of the protrusion which faces the opening direction case side and is connected to the refrigerant flow path. The case includes a peripheral wall portion that surrounds the opening and extends along the opening direction,
Among the directions along the opening surface, a specific direction is defined as a first direction,
the protruding portion protrudes from the case toward a first side in the first direction,
The vehicle-mounted inverter unit according to claim 1 , wherein the specific functional component is disposed at a position overlapping with the peripheral wall portion when viewed in a first direction along the first direction. An in-vehicle inverter unit according to claim 1 or 2;
The rotating electric machine;
An output member drivingly connected to the wheels;
a power transmission mechanism that transmits a driving force between the rotating electric machine and the output member,
the case includes a first housing chamber that houses the inverter module and a second housing chamber that houses the rotating electric machine and the power transmission mechanism,
The first storage chamber and the second storage chamber are arranged to be aligned in the opening direction,
The specific functional part is arranged at a position overlapping with a portion of the case that surrounds the second housing chamber when viewed in the opening direction along the opening direction. An in-vehicle inverter unit according to claim 1 or 2;
The rotating electric machine;
An output member drivingly connected to the wheels;
a power transmission mechanism that transmits a driving force between the rotating electric machine and the output member,
the case includes a first housing chamber that houses the inverter module and a second housing chamber that houses the rotating electric machine and the power transmission mechanism,
The engine further includes an oil cooler for cooling the oil accommodated in the second accommodation chamber, and a cooling water circuit module for configuring a cooling water circuit that circulates cooling water through a path passing through the oil cooler and an on-vehicle radiator,
The specific functional parts include a refrigerant heat exchanger for cooling the refrigerant by heat exchange between the refrigerant and the cooling water. the functional component includes a control valve that controls a flow rate or a flow path of the refrigerant in the refrigerant circuit;
The specific functional component includes an accumulator for separating the refrigerant into a liquid and a gas,
The control valve is attached to a surface of the cover facing away from the opening case,
The vehicle drive device according to claim 4 , wherein the refrigerant heat exchanger and the accumulator are arranged side by side along a wall portion surrounding the first housing chamber of the case.

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