JP2024072436A - Vehicle drive device and method for manufacturing the same - Google Patents

Abstract

[Problem] To reduce the size of a vehicle drive device in relation to the arrangement of a current sensor, and to reduce the number of parts related to the arrangement structure of the current sensor. [Solution] A vehicle drive device is disclosed that includes a rotating electric machine, a case in which a first accommodation chamber in which the rotating electric machine is arranged and a second accommodation chamber in which a power conversion device is arranged are integrally formed while being partitioned by a partition, and a terminal block device attached to the partition, the terminal block device being a form in which a bus bar and a current sensor that detects a current flowing through the bus bar are integrated by an insulating material, and one end of the bus bar is connected to the rotating electric machine in the first accommodation chamber, and the other end is connected to the power conversion device in the second accommodation chamber. [Selected Figure] Figure 2

Description

This disclosure relates to a vehicle drive device and a method for manufacturing a vehicle drive device.

In a vehicle drive device in which a rotating electric machine and a power conversion device are arranged in two adjacent housings, a technology is known in which a current sensor is arranged in a through hole in the case together with a bus bar that electrically connects between the power conversion device and the rotating electric machine.

JP 2021-182827 A

However, while the above-mentioned conventional technology can reduce the size of the vehicle drive device in relation to the arrangement of the current sensor, it is difficult to reduce the number of parts related to the arrangement structure of the current sensor.

Therefore, in one aspect, the present disclosure aims to reduce the size of a vehicle drive device in relation to the arrangement of a current sensor, as well as the number of parts related to the arrangement structure of the current sensor.

In one aspect, a rotating electric machine;
a case in which a first accommodation chamber in which the rotating electric machine is disposed and a second accommodation chamber in which a power conversion device is disposed are integrally formed while being partitioned by a partition part;
a terminal block device attached to the partition wall and electrically connecting the rotating electric machine to the power conversion device,
the terminal block device is configured such that a bus bar for each phase and a current sensor for each phase, which detects a current flowing through the bus bar for each phase, are integrated with each other using an insulating material;
The bus bar for each phase has one end connected to the rotating electric machine in the first housing chamber and the other end connected to the power conversion device in the second housing chamber, thereby providing a vehicle drive device.

In one aspect, the present disclosure makes it possible to miniaturize the vehicle drive device in relation to the arrangement of the current sensor, while also reducing the number of parts related to the arrangement structure of the current sensor.

1 is a schematic cross-sectional view of a vehicle drive device according to an embodiment of the present invention. 2 is a cross-sectional view of a portion relating to a wiring structure in a vehicle drive device. FIG. 11 is a cross-sectional view of a portion relating to a wiring structure according to another embodiment. 4 is a schematic flowchart showing a method for manufacturing a vehicle drive device according to the present embodiment. 7A to 7C are explanatory diagrams of an assembly method for a vehicle drive device according to a comparative example.

Each embodiment will be described in detail below with reference to the attached drawings. Note that the dimensional ratios in the drawings are merely examples and are not limiting. Also, shapes in the drawings may be partially exaggerated for the sake of explanation.

Figure 1 is a schematic cross-sectional view of a vehicle drive device 100 according to this embodiment. In the following description, the Y direction corresponds to the up-down direction of the vehicle drive device 100 when in use, that is, the up-down direction when the vehicle drive device 100 is oriented in the direction in which it is in use. The Y1 side and the Y2 side correspond to the upper and lower sides along the Y direction.

The vehicle to which the vehicle drive device 100 is applied may be any vehicle equipped with a rotating electric machine 1 as a drive source, such as an electric vehicle or a hybrid vehicle.

The vehicle drive device 100 includes a case 2 that houses various components. In this embodiment, the case 2 houses the rotating electric machine 1, the power conversion device 70, etc.

The case 2 may be formed by combining multiple case members. In the following description, as an example, the case 2 is formed by joining a case member 200, a cover member 201, and an inverter cover member 203. The joining method may be fastening with bolts or the like.

The case 2 includes a motor case section 21 and an inverter case section 24 in an integrated form. Here, "integrated form" means a form integrated by integral molding (e.g., casting, etc.). In this case, the motor case section 21 and the inverter case section 24 are one piece and have a common partition section 29.

In a modified example, the case 2 may house other driving elements. For example, a reduction mechanism or a differential gear device that may be disposed between the rotating electric machine 1 and the wheels may be housed in the case 2.

The motor case portion 21 forms a motor housing chamber S1 that houses the rotating electric machine 1. The motor case portion 21 may be cylindrical (e.g., circular or polygonal in cross section) corresponding to the outer shape of the rotating electric machine 1. The rotating electric machine 1 functions as a driving source for the vehicle. The rotating electric machine 1 may be, for example, a three-phase motor and may be of an inner rotor type. The rotating electric machine 1 may have, for example, an outer peripheral surface of the stator core 12 (see FIG. 2) abutting radially against an inner peripheral surface of the motor case portion 21.

The motor case section 21 does not need to have the entire cylindrical outer periphery closed. For example, in a configuration in which a reduction gear mechanism or a differential gear device (not shown) is arranged inside the case 2, the space inside the motor case section 21 may communicate with the space in which the output shaft between the wheels and the differential gear device is arranged.

The inverter case section 24 is disposed on the upper part of the motor case section 21. The inverter case section 24 forms an inverter housing chamber S4 that houses the power conversion device 70.

The power conversion device 70 is electrically connected between the rotating electric machine 1 and a power source (not shown). The power conversion device 70 may be in the form of a module, and may be fixed to the partition wall 29 between the inverter case section 24 and the motor case section 21 by bolts or the like. The power conversion device 70 may include a plurality of switching elements (power semiconductor elements, not shown) that constitute an inverter circuit, a control board (not shown) on which a control device that controls the inverter circuit is mounted, a smoothing capacitor, etc.

In this way, in this embodiment, the case 2 integrally forms the motor housing chamber S1 in which the rotating electric machine 1 is arranged and the inverter housing chamber S4 (second housing chamber) in which the power conversion device 70 is arranged, while being partitioned by the partition wall 29.

The rotating electric machine 1 and the power conversion device 70 are electrically connected via a wiring structure 9. Details of the wiring structure 9 will be described later.

Next, with reference to Figure 2 onwards, we will explain the water cooling structure 80 along with details of the wiring structure 9.

Figure 2 is a cross-sectional view of a portion related to the wiring structure 9 in the vehicle drive device 100. Figure 3 is a cross-sectional view of a portion related to the water-cooling structure 80A according to another embodiment. Note that Figures 2 and 3 correspond to cross-sectional views of a portion corresponding to part Q2 in Figure 1.

In this embodiment, the wiring structure 9 includes a terminal block device 90, an inverter side bus bar 92, and a power line 94. The power line 94 is drawn out from the stator coil 14 of the rotating electric machine 1 for each phase, or is joined to the end of the stator coil 14 of the rotating electric machine 1.

The terminal block device 90 is configured by integrating the terminal block bus bar 910 and the current sensor 920 with an insulating material. That is, the terminal block device 90 includes the terminal block bus bar 910, the current sensor 920, and an insulating material section 930. The insulating material section 930 may be a resin section formed by, for example, resin molding. In a modified example, the terminal block device 90 may be configured by integrating other electronic components (e.g., a noise filter, etc.) with an insulating material in addition to the terminal block bus bar 910 and the current sensor 920.

A terminal block bus bar 910 is provided for each of the three phases. The terminal block bus bar 910 is, for example, in the form of a plate-shaped conductor, and the upper end is joined to the inverter side bus bar 92 and the lower end is joined to the power line 94. Each joint may be realized by fastening with bolts BT1, BT2, etc.

A current sensor 920 is provided for each of the three phases. Each current sensor 920 detects the current flowing through the terminal block bus bar 910 of the corresponding phase. The current sensor 920 may be, for example, a coreless type current sensor. The coreless type current sensor 920 can be made smaller since it does not have a magnetic core, which contributes to the miniaturization of the terminal block device 90. The current sensor 920 may be, for example, a form in which a primary conductor, a magnetic sensor, and an IC (e.g., an ASIC: application specific integrated circuit) are packaged with an insulating material (e.g., a part of the insulating material portion 930).

The insulating material portion 930 is joined to each terminal block bus bar 910 and each current sensor 920, integrating them. The insulating material portion 930 holds each terminal block bus bar 910 while ensuring the necessary insulation distance between each terminal block bus bar 910. Note that in FIG. 2, only one terminal block bus bar 910 is visible, and three terminal block bus bars 910 are overlapped in the direction perpendicular to the paper surface. The insulating material portion 930 covers each terminal block bus bar 910 in such a manner that only the upper and lower ends of each terminal block bus bar 910 are exposed.

The terminal block device 90 is attached to the partition wall 29. Specifically, a through hole 290 is formed in the partition wall 29 to allow communication between the motor housing chamber S1 and the inverter housing chamber S4, and the terminal block device 90 is fitted into the through hole 290.

The terminal block device 90 is fixed to the surface of the inverter housing chamber S4 in the partition wall 29 by a fastener BT3 such as a bolt. The fastener may be fastened in a manner that threads in a direction perpendicular to the axial direction (e.g., in the up-down direction). In this case, the terminal block device 90 can be easily assembled by utilizing the inverter housing chamber S4.

In this way, the terminal block device 90 including the current sensor 920 is disposed in the bulkhead portion 29 together with the terminal block bus bar 910, so that a more efficient arrangement can be realized compared to a configuration in which the current sensor 920 is disposed separately from the terminal block device (for example, a configuration in which a current sensor is provided separately between the terminal block device and the power conversion device 70). This allows the vehicle drive device 100 to be made smaller in size in relation to the arrangement of the current sensor 920.

In addition, since the terminal block device 90 includes the current sensor 920 as an integral part, the number of parts can be reduced compared to when the current sensor 920 is separate from the terminal block device 90. In relation to the arrangement of the current sensor 920, the vehicle drive device 100 can be made smaller, and the number of parts related to the arrangement structure of the current sensor 920 can be reduced.

The terminal block device 90 is preferably attached to the partition wall 29 in such a manner that the current sensor 920 overlaps the partition wall 29 when viewed in the axial direction. In this case, the thickness of the partition wall 29 can be utilized to ensure mounting space for the current sensor 920, making it possible to miniaturize the terminal block device 90. As a result, the vehicle drive device 100 can be further miniaturized in relation to the placement of the current sensor 920.

The terminal block device 90 has a seal member 940 that fits tightly against the side wall portion 292 of the through hole 290. The seal member 940 is, for example, in the form of an O-ring, and seals between the motor housing chamber S1 and the inverter housing chamber S4. This configuration is particularly suitable when oil flows in the motor housing chamber S1 (i.e., when the rotating electric machine 1 is oil-cooled). In this case, it is possible to prevent the oil in the motor housing chamber S1 from entering the inverter housing chamber S4. The seal member 940 may be positioned relative to the current sensor 920, for example, so as to surround the current sensor 920.

In the example shown in FIG. 2, the water-cooling structure 80 has a water passage 294 formed in the partition 29 through which cooling water passes. The cooling water circulates, for example, via a water pump and dissipates heat via a radiator (not shown), thereby removing heat from each object to be cooled.

The stator core 12 of the rotating electric machine 1 abuts against the partition wall 29 in the radial direction. The power conversion device 70 (e.g., a power module of the power conversion device 70) is also arranged in the partition wall 29, either directly or via a member 40 having relatively high thermal conductivity (e.g., a sheet member having relatively high thermal conductivity). The terminal block device 90 is also coupled to the partition wall 29 as described above. In this way, according to the configuration shown in FIG. 2, the stator core 12 of the rotating electric machine 1, the power conversion device 70, and the terminal block bus bar 910 of the terminal block device 90 can be cooled by the partition wall 29.

In addition, according to the configuration shown in FIG. 2, the water channel 294 in the partition 29 is provided in common for the power conversion device 70 and the rotating electric machine 1, so there is no need to form a separate water channel in the power conversion device 70, and an efficient water-cooling structure 80 can be realized.

In another embodiment shown in FIG. 3, the water-cooled structure 80A includes a water channel forming member 810A disposed in the inverter housing chamber S4. The water channel forming member 810A has a water channel 294A formed therein. The water channel forming member 810A is, for example, in the form of a plate, and the water channel 294A is formed therein. In this case, the water channel forming member 810A may be connected to the power conversion device 70 directly or via a member 40 having relatively high thermal conductivity (for example, a sheet member having relatively high thermal conductivity). This allows the power conversion device 70 to be efficiently cooled by the water channel forming member 810A.

The water channel forming member 810A is preferably thermally connected to the terminal block device 90. For example, the water channel forming member 810A may have a tip (the tip on the terminal block device 90 side in the axial direction) connected to the terminal block device 90 via a member 42 having relatively high thermal conductivity (e.g., a sheet member having relatively high thermal conductivity). This allows the terminal block device 90 to be efficiently cooled by the water channel forming member 810A.

Next, a method for manufacturing the vehicle drive device 100 according to this embodiment will be described with reference to FIG.

Figure 4 is a schematic flowchart showing a method for manufacturing a vehicle drive device 100 according to this embodiment.

This manufacturing method includes a process (step S30) of preparing a rotating electric machine 1, a power conversion device 70, a case 2, and a terminal block device 90.

Next, the manufacturing method includes a step (step S31) of assembling the rotating electric machine 1 inside the case 2. At this stage, the case 2 is in the form of the case member 200, and the cover member 201 and the inverter cover member 203 may be joined to the case member 200 after step S36, which will be described later.

Next, the manufacturing method includes a step (step S32) (an example of an installation step) of assembling the terminal block device 90 inside the case 2. As described above, the terminal block device 90 can be assembled from inside the inverter housing chamber S4 of the case 2. Furthermore, the terminal block device 90 can be fastened inside the inverter housing chamber S4 by the fastener BT3.

Next, the manufacturing method includes a process of assembling the power conversion device 70 inside the case 2 (step S33).

Next, in this manufacturing method, the upper end of the terminal block bus bar 910 of the terminal block device 90 is fastened to the inverter side bus bar 92 from the power conversion device 70 with a bolt BT1, and the lower end of the terminal block bus bar 910 of the terminal block device 90 is fastened to the power line 94 from the stator coil 14 of the rotating electric machine 1 with a bolt BT2 (step S34).

In this way, according to this manufacturing method, the current sensor 920 can be assembled by assembling the terminal block device 90 to the case 2. Furthermore, according to this manufacturing method, the terminal block device 90 and the power conversion device 70 can be assembled independently to the case 2.

Next, the effect of this embodiment will be further explained by comparing it with the comparative example shown in Figure 5.

Figure 5 is an explanatory diagram of an assembly method for a vehicle drive device 100' according to a comparative example.

The vehicle drive device 100' according to the comparative example differs from the vehicle drive device 100 according to the present embodiment in that the case 2' is different, specifically, the inverter case section 24' that houses the power conversion device 70 is separate from the motor case section 21' that houses the rotating electric machine 1. In this case, in a sub-assembly state in which the terminal block bus bar 910' and the like are assembled to the inverter case section 24', the assembly is completed by fastening the inverter case section 24' to the motor case section 21'.

In addition, in this comparative example, unlike this embodiment, the terminal block bus bar 910', the cover member 940', and the current sensor 920' are separate. Therefore, this comparative example is disadvantageous in that the number of parts is greater than in this embodiment.

In such a comparative example, the positioning accuracy between the terminal block bus bar 910' and the power line 94 is likely to decrease due to the positioning and assembly of the inverter case part 24' relative to the motor case part 21'. In other words, the positioning accuracy between the lower end of the terminal block bus bar 910' and the power line 94 is affected by the positioning accuracy of the inverter case part 24' relative to the motor case part 21', and the positioning accuracy between the lower end of the terminal block bus bar 910' and the power line 94 is likely to decrease.

In contrast, according to the present embodiment, the terminal block device 90 can be assembled to the case 2 separately from the power conversion device 70, so that the positional accuracy of the upper and lower ends of the terminal block bus bar 910 of the terminal block device 90 can be improved. That is, the positional accuracy of the upper and lower ends of the terminal block bus bar 910 of the terminal block device 90 can be managed, for example, based on the fastening portion of the terminal block device 90 (fastening portion by the fastener BT3). In this case, the positional relationship between the fastening portion of the terminal block device 90 and the upper and lower ends of the terminal block bus bar 910 can be managed with high precision, so that the positional accuracy of the upper and lower ends of the terminal block bus bar 910 of the terminal block device 90 can be improved. As a result, the positioning accuracy between the terminal block bus bar 910 and the inverter side bus bar 92 and the power line 94 can be improved, and inconveniences that may occur when the positioning accuracy is not good (for example, stress concentration at the fastening portion) can be prevented.

In addition, in the comparative example shown in FIG. 5, a water channel structure (not shown) is required to connect the water channel 294A' for the power conversion device 70' and the water channel 294' for the rotating electric machine 1, which is disadvantageous in terms of the number of parts and manufacturability. In this regard, according to the present embodiment shown in FIG. 2, the water channel 294 can be shared, reducing such inconveniences.

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.

1: rotating electric machine, 2: case, 29: bulkhead, 290: through hole, 294: water channel, 70: power converter, 810A: water channel forming member, 90: terminal block device, 910: terminal block bus bar (bus bar), 920: current sensor, 930: insulating material part (insulating material), 940: sealing member, 100: vehicle drive device, S1: motor housing (first housing), S4: inverter housing (second housing), BT3: fastener

Claims (6)

A rotating electric machine;
a case in which a first accommodation chamber in which the rotating electric machine is disposed and a second accommodation chamber in which a power conversion device is disposed are integrally formed while being partitioned by a partition part;
a terminal block device attached to the partition wall and electrically connecting the rotating electric machine to the power conversion device,
the terminal block device is configured such that a bus bar for each phase and a current sensor for each phase, which detects a current flowing through the bus bar for each phase, are integrated with each other using an insulating material;
The bus bar of each phase has one end connected to the rotating electric machine in the first housing chamber and the other end connected to the power conversion device in the second housing chamber. A water passage through which cooling water passes is formed in the partition wall,
The vehicle drive device according to claim 1 , wherein the rotating electric machine, the power conversion device, and the bus bars of each phase are cooled by the partition portion. The cooling water supply system further includes a plate-shaped water channel forming member disposed in the second storage chamber and having a water channel through which the cooling water passes.
The water channel forming member is thermally connected to the terminal block device,
The vehicle drive device according to claim 1 , wherein the power conversion device and the bus bars of each phase are cooled by the water channel forming member. the partition portion has a through hole that communicates between the first accommodating chamber and the second accommodating chamber and into which the terminal block device is fitted,
The vehicle drive device according to claim 1 , wherein the terminal block device has a seal member that is in close contact with a side wall of the through hole. The vehicle drive device according to claim 1, wherein the terminal block device is fixed to the second storage chamber side of the partition wall by a fastener. preparing a rotating electric machine and a power conversion device;
preparing a case that integrally forms a first accommodation chamber in which the rotating electric machine is disposed and a second accommodation chamber in which the power conversion device is disposed, the first accommodation chamber being partitioned by a partition wall;
preparing a terminal block device in which bus bars for each phase and current sensors for each phase, which detect currents flowing through the bus bars for each phase, are integrated with each other using an insulating material;
a mounting step of mounting the terminal block device to the bulkhead portion;
a step of assembling the power conversion device to the case so that the power conversion device fits into the second housing chamber, the step being performed separately from the mounting step;
and electrically connecting the bus bars of each phase to the power conversion device.