Driving device for vehicles

Abstract

To attain downsizing while including a rotation stop function regarding a fastening structure between a power line and a wiring member.SOLUTION: A driving device for vehicles comprises: a rotary electric machine which is operated by power of a plurality of phases and includes a power line for each phase; a phase-basis wiring member which is formed from a conductor and electrically connected between the rotary electric machine and a power source; and a fastening member which fastens the power line and the wiring member for each phase. The wiring member integrally includes a rotation stopper which locks rotation of the power line in a rotation direction of the fastening member during fastening.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] A known technique is to provide a hexagonal prism-shaped anti-rotation portion at the end of the power line (power line terminal) of a rotating electric machine, and to provide a through hole in the terminal block that fits with the anti-rotation portion. In this technique, the terminal block is fixed with a bolt to a duct including a guide wall portion that has a through hole that fits with the anti-rotation portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-037063 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in a configuration in which a power line is joined to a wiring member (e.g., an inverter terminal) by screw fastening, if the friction between the screw groove and the thread is large, there is a risk that the power line will rotate together with the rotation of the fastening member when fastening. In this regard, in the conventional technology described above, a rotation prevention portion is provided to prevent the power line from being stopped from rotating when the screw is fastened, so that torque is transmitted to the power line and it does not twist. However, in the conventional technology described above, a rotation prevention portion (terminal block) is provided separately from the wiring member, which poses a problem in that it is likely to lead to an increase in the number of parts and an increase in the physical size of the configuration related to screw fastening.

[0005] Therefore, in one aspect, the present disclosure has an object to provide a fastening structure between a power line and a wiring member that is compact while providing an anti-rotation function. [Means for solving the problem]

[0006] In one aspect, a rotating electric machine that operates on a multi-phase power and has a power line for each phase; a wiring member for each phase, the wiring member being formed of a conductor and electrically connected between the rotating electric machine and a power source; a fastening member for fastening the power line and the wiring member for each phase, The wiring member has an integral anti-rotation portion that prevents the power line from rotating in a rotation direction of the fastening member when fastened, thereby providing a vehicle drive device. Effect of the Invention

[0007] According to one aspect, the present disclosure makes it possible to reduce the size of a fastening structure between a power line and a wiring member while providing an anti-rotation function. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a vehicle drive device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a portion corresponding to part Q2 in FIG. [Diagram 3] FIG. 3 is an exploded perspective view of the portion shown in FIG. 2. [Figure 4] FIG. 4 is a perspective view showing an end structure of one power line. [Diagram 5] FIG. 2 is a perspective view showing an end (the end on the power line side) of the bus bar module. [Figure 6] 2 is a cross-sectional view of a wiring structure related to a portion Q2 in FIG. 1, the cross-sectional view passing through the center of one power line. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Each embodiment will be described in detail below with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples and are not limiting, and shapes and the like in the drawings may be partially exaggerated for the sake of explanation. In addition, in the drawings, for ease of viewing, reference symbols may be given to only some of the parts that exist in a plurality of parts with the same attribute.

[0010] 1 is a schematic cross-sectional view of a vehicle drive device 100 according to this embodiment. In the following description, the Z direction corresponds to the up-down direction when the vehicle drive device 100 is in use, that is, the up-down direction when the vehicle drive device 100 is oriented in the use state. The Z1 side and the Z2 side correspond to the upper side and the lower side along the Z direction.

[0011] The vehicle to which the vehicle drive device 100 is applied may be any vehicle equipped with the rotating electric machine 1 as a drive source, and may be an electric vehicle, a hybrid vehicle, or the like.

[0012] 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, and the like. However, although the case 2 houses the rotating electric machine 1, the power conversion device 70 may be provided externally.

[0013] The case 2 may be formed by combining a plurality of 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.

[0014] The case 2 includes a motor case portion 21 and an inverter case portion 24 in an integrated form. Here, "integrated form" means a form integrated by integral molding (for example, casting, etc.). In this case, the motor case portion 21 and the inverter case portion 24 are one piece and may have a common partition portion 29.

[0015] In a modified example, other driving elements may be housed in the case 2. For example, a reduction mechanism, a differential gear device, and the like that may be disposed between the rotating electric machine 1 and the wheels may be housed in the case 2.

[0016] The motor case portion 21 forms a motor housing chamber S1 that houses the rotating electric machine 1. The motor case portion 21 may have a cylindrical shape (e.g., a circular or polygonal cross section) corresponding to the outer shape of the rotating electric machine 1. The rotating electric machine 1 functions as a drive 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 a stator core (not shown) abutting against an inner peripheral surface of the motor case portion 21 in the radial direction.

[0017] It is not necessary that the cylindrical outer periphery of motor case 21 is completely closed. For example, in a configuration in which a reduction gear mechanism or a differential gear device (not shown) is disposed inside case 2, the space inside motor case 21 may communicate with a space in which an output shaft between the wheels and the differential gear device is disposed.

[0018] The inverter case 24 is disposed on the upper part of the motor case 21. The inverter case 24 forms an inverter accommodating chamber S4 that accommodates the power conversion device 70. As described above, the power conversion device 70 may be provided outside the case 2, away from the case 2, and in this case, the inverter accommodating chamber S4 may be provided in another location.

[0019] 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 configure an inverter circuit, a control board (not shown) on which a control device that controls the inverter circuit is mounted, a smoothing capacitor, and the like.

[0020] Note that a water channel or the like for cooling the power conversion device 70 may be formed in the case 2, or a water channel forming member (not shown) for forming a water channel for cooling the power conversion device 70 may be provided separately. Note that the coolant for cooling the power conversion device 70 may be something other than cooling water.

[0021] The rotating electric machine 1 and the power conversion device 70 are electrically connected via a wiring structure 9.

[0022] Next, the details of the wiring structure 9 related to the portion Q2 in FIG. 1 will be described with reference to FIG. 2 and subsequent figures.

[0023] FIG. 2 is a perspective view of a portion corresponding to the portion Q2 in FIG. 1. FIG. 3 is an exploded perspective view of the portion shown in FIG. 2, and FIG. 4 is a perspective view showing an end structure of one power line 94. Note that FIGS. 3 and 4 are perspective views seen from the same direction as FIG. 2. FIG. 5 is a perspective view showing an end (the end on the power line 94 side) of the bus bar module 90. FIG. 6 is a cross-sectional view of the wiring structure 9 related to the portion Q2 in FIG. 1, and is a cross-sectional view passing through the center of one power line 94. Note that in FIGS. 2 to 6, the fastening bolt BT shown in FIG. 1 is omitted. Also, in FIGS. 2, 3, etc., only a portion of the case 2 is shown diagrammatically in the form of a rectangular parallelepiped.

[0024] 2 to 6, the X, Y, and Z directions are shown in a three-axis Cartesian coordinate system (right-handed coordinate system). The positive side of the Z direction corresponds to the Z1 side in FIG.

[0025] The power lines 94 may be in the form of three-phase terminals drawn from a stator coil (not shown) of the rotating electric machine 1. The power lines 94 are drawn from the stator coil of the rotating electric machine 1 or joined to the ends of the stator coil of the rotating electric machine 1 for each phase. The power lines 94 may be formed from the same coil wire as the stator coil. In this embodiment, the power lines 94 have cylindrical ends, which are fitted into the ends (recesses 913) of three-phase bus bars 910 of the bus bar module 90 described later.

[0026] The power line 94 extends from the motor accommodating chamber S1 of the case 2 to the inverter accommodating chamber S4 through the insertion hole 290 of the partition wall 29. That is, the partition wall 29 of the case 2 has the insertion hole 290 in the Z direction, and the power line 94 extends through the insertion hole 290 from the motor accommodating chamber S1 on the rotating electric machine 1 side to the inverter accommodating chamber S4 on the power conversion device 70 side.

[0027] As shown in FIG. 3 and the like, a cylindrical seal member 80 is provided on the power line 94. The seal member 80 may be made of a rubber material or the like. The seal member 80 has a Z-direction through hole 82 (see FIG. 4) into which the power line 94 is fitted. The seal member 80 may be attached to the power line 94 in such a manner that the inner periphery of the seal member 80 is in close contact with the outer periphery of the power line 94. As shown in FIG. 6, the seal member 80 fills the gap between the insertion hole 290 of the case 2 and the power line 94. That is, the seal member 80 seals the periphery of the power line 94 passing through the insertion hole 290 of the case 2. This can prevent oil in the motor housing chamber S1 of the case 2 from entering the inverter housing chamber S4. Note that other refrigerants such as cooling water may be used instead of oil. In this case, the seal member 80 can prevent other refrigerants in the motor housing chamber S1 of the case 2 from entering the inverter housing chamber S4.

[0028] In this embodiment, the wiring structure 9 includes a bus bar module 90 and the power line 94 described above.

[0029] The busbar module 90 is electrically connected between the power conversion device 70 and the rotating electric machine 1, and may be provided separately from the power conversion device 70. In a modified example, a part or the whole of the busbar module 90 may be integrated with the power conversion device 70.

[0030] The bus bar module 90 may be supported by the partition wall portion 29 of the case 2. For example, the bus bar module 90 may be fastened to the partition wall portion 29 by bolts or the like.

[0031] The busbar module 90 has a three-phase busbar 910 and a current sensor 920 integrated with an insulating material. That is, the busbar module 90 includes the three-phase busbar 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. Note that in a modified example, the busbar module 90 may have other electronic components (for example, a noise filter, etc.) integrated with an insulating material in addition to the three-phase busbar 910 and the current sensor 920.

[0032] A three-phase bus bar 910 is provided for each of the three phases. The three-phase bus bar 910 is, for example, in the form of a plate-shaped conductor, and one end on the Y-direction positive side is joined to the power conversion device 70, and the other end on the Y-direction negative side is joined to the power line 94. The three-phase bus bar 910 is joined to the power line 94 for each phase.

[0033] A current sensor 920 is provided for each of the three phases. One current sensor 920 detects a current flowing through the three-phase 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, and can contribute to the miniaturization of the bus bar module 90. The current sensor 920 may be in a form in which, for example, a primary conductor, a magnetic sensor, and an IC (for example, an ASIC: application specific integrated circuit) are packaged by an insulating material (for example, a part of the insulating material portion 930).

[0034] As described above, in this embodiment, the busbar module 90 integrally includes the current sensor 920, and therefore the number of parts can be reduced compared to a case where the current sensor 920 is separate from the busbar module 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.

[0035] 5 and 6, the insulating material portion 930 is joined to and integrates each of the three-phase bus bars 910 and each of the current sensors 920. The insulating material portion 930 holds each of the three-phase bus bars 910 while ensuring a necessary insulation distance between the three-phase bus bars 910.

[0036] Here, the fastening structure between the bus bar module 90 and the power line 94 of this embodiment will be described in detail with reference to Figs.

[0037] In this embodiment, as shown in FIG. 1, the busbar module 90 and the power lines 94 are fastened to each other by screws. Specifically, the busbar module 90 and the power lines 94 are fastened to each other by fastening bolts BT. Note that FIG. 1 shows only one fastening bolt BT for fastening one power line 94 to one three-phase busbar 910, but the three-phase busbars 910 of the busbar module 90 and the power lines 94 are fastened to each other by fastening bolts BT for each phase. That is, in FIG. 1, only one three-phase busbar 910 and one power line 94 are visible, and three three-phase busbars 910 and three power lines 94 are overlapped in the direction perpendicular to the paper surface.

[0038] Specifically, the three-phase bus bar 910 is disposed in a manner that it abuts in the Z direction against an end (an end on the positive side in the Z direction) of the power line 94 that passes through the insertion hole 290 of the case 2 and extends toward the inverter accommodating chamber S4. The three-phase bus bar 910 is provided with a through hole 9130 in the Z direction. A screw hole 942 is provided at the end of the power line 94 in a manner that it is recessed toward the negative side in the Z direction. In this case, the fastening bolt BT passes through the through hole 9130 and is screwed into the screw hole 942. Note that, during fastening, the fastening bolt BT advances to the negative side in the Z direction while being rotated around an axis along the Z axis. In this case, the extension direction (axial direction) of the shaft portion of the fastening bolt BT is a direction parallel to the Z axis. Note that the head of the fastening bolt BT has a larger diameter than the through hole 9130 of the three-phase bus bar 910. Therefore, when fastened, the bearing surface of the fastening bolt BT comes into contact with the periphery of the through hole 9130 on the surface of the three-phase bus bar 910 on the positive side in the Z direction (Z1 side).

[0039] In this embodiment, as described above, the three-phase bus bar 910 is provided with the sealing member 80. The sealing member 80 fits snugly into the insertion hole 290 of the case 2 (see FIG. 6), preventing rattling or misalignment of the power line 94 relative to the case 2. That is, in addition to the sealing function described above, the sealing member 80 can also perform a function of positioning the power line 94 relative to the case 2 (and therefore the three-phase bus bar 910) during assembly.

[0040] However, in the case of such a fastening method, if the friction between the fastening bolt BT and the screw hole 942 is large, the power line 94 may rotate together with the rotation of the fastening bolt BT during fastening, which may cause torsional deformation in the power line 94. In response to this, in this embodiment, a rotation prevention structure, which will be described in detail below, is provided so that torque is transmitted to the power line 94 during fastening and twisting is prevented.

[0041] Specifically, the end of the power line 94 has a non-circular shape when viewed in the Z direction. In this embodiment, the end of the power line 94 has two flat portions 944 with a normal line perpendicular to the Z direction. In this embodiment, the two flat portions 944 are provided at diagonal positions, but may be arranged in other ways. In a modified example, the non-circular shape when viewed in the Z direction may be a polygonal shape such as a hexagon. The same applies to a recess 913 of a three-phase bus bar 910 described later.

[0042] Furthermore, three-phase busbar 910 has two side wall portions 9134 corresponding to the two flat portions 944 in recess 913 that receives an end of power line 94. That is, recess 913 has a non-circular shape when viewed in the Z direction, and in this embodiment, recess 913 has two side wall portions 9134 whose normal line is a direction perpendicular to the Z direction. The two side wall portions 9134 are provided at diagonal positions, but may be arranged in any other manner as long as they are arranged in the same manner as the two flat portions 944.

[0043] During assembly, the three-phase busbar 910 receives the end of the power line 94 with the two flat surfaces 944 mated to the two side wall surfaces 9134 (see FIG. 6). In this case, if either the three-phase busbar 910 or the screw hole 942 attempts to rotate around an axis along the Z axis relative to the other, the rotation is prevented via the side wall surfaces 9134 and the flat surfaces 944. In this way, the end of the power line 94 is substantially unable to rotate around an axis along the Z axis relative to the three-phase busbar 910. Note that "substantially" means that slight rotation due to play that may occur due to tolerances, etc. is permitted.

[0044] In this manner, in this embodiment, an anti-rotation structure can be realized at the fastening portion between the end of the power line 94 and the three-phase bus bar 910. Specifically, the power line 94 and the three-phase bus bar 910 are locked against rotation relative to each other about an axis along the Z axis. As a result, even if the friction between the fastening bolt BT and the screw hole 942 is large, it is possible to prevent a relatively large torque from being transmitted to the power line 94 during fastening.

[0045] In the present embodiment, three-phase busbar 910 has recess 913, which has two side walls 9134 for preventing rotation. That is, three-phase busbar 910 integrally has recess 913 having two side walls 9134. This reduces the number of parts and the size of the fastening structure, compared to a case in which a rotation prevention portion is provided separately from three-phase busbar 910.

[0046] In this embodiment, the end of the three-phase busbar 910 on the negative side in the Y direction is formed to be thicker than other portions in order to form the recess 913. In this case, the three-phase busbar 910 may be formed by integrating two or more pieces of members. That is, the end of the three-phase busbar 910 on the negative side in the Y direction may be formed of two or more pieces. In this embodiment, the recess 913 is formed of the same conductive material as the other portions of the three-phase busbar 910 and forms a current path, but in a modified example, the recess 913 may be formed of another material such as a resin material.

[0047] In this embodiment, the recess 913 has a bottom surface portion 9132 around the through hole 9130 as shown in Fig. 5. An end face 946 (an end face on the positive side in the Z direction) of the end of the power line 94 abuts against the bottom surface portion 9132 in the Z direction as shown in Fig. 6. This ensures a necessary current path (cross-sectional area) even in the fastening portion between the power line 94 and the three-phase bus bar 910. That is, a necessary contact area can be ensured between the end face 946 of the end of the power line 94 and the bottom surface portion 9132 around the through hole 9130.

[0048] In the present embodiment, as described above, since three-phase busbar 910 has two side walls 9134 integrally formed therewith for preventing rotation, the number of parts and the size of the busbar can be reduced. However, when the anti-rotation function functions, the busbar receives a relatively large force via side walls 9134. That is, when the anti-rotation function functions during fastening, three-phase busbar 910 receives a rotational torque about a rotation axis parallel to the Z direction via two side walls 9134. If sensor arrangement portion 918 (see FIG. 6 ), in which current sensor 920 of three-phase busbar 910 is arranged, is deformed by such a rotational torque, the reliability of current information obtained via current sensor 920 may be reduced.

[0049] Therefore, in this embodiment, three-phase busbar 910 has low-rigidity portion 919 between recess 913 and sensor arrangement portion 918. Low-rigidity portion 919 has lower rigidity than sensor arrangement portion 918 with respect to a force (rotational torque about a rotation axis parallel to the Z direction) that three-phase busbar 910 receives when the anti-rotation function functions during fastening. In this case, when three-phase busbar 910 receives a force when the anti-rotation function functions during fastening, low-rigidity portion 919 deforms before sensor arrangement portion 918. As a result, deformation of sensor arrangement portion 918 is prevented or reduced, and a decrease in the reliability of current information obtained via current sensor 920 can be prevented or reduced.

[0050] In this embodiment, as shown in Fig. 3 and Fig. 5, three-phase busbar 910 has low-rigidity portion 919 in the form of a constriction when viewed in the Z direction. That is, the dimension of three-phase busbar 910 in the X direction is locally minimum at low-rigidity portion 919. In this case, low-rigidity portion 919 can be easily formed, for example, by punching a sheet metal member. Note that low-rigidity portion 919 has a smaller thickness (dimension in the Z direction) than the end portion on the negative side in the Y direction of three-phase busbar 910 that forms recess 913, but may have the same thickness. Alternatively, low-rigidity portion 919 may be formed by a portion where the thickness (dimension in the Z direction) is locally minimum.

[0051] Although each embodiment has been described above in detail, the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the claims. In addition, it is also possible to combine all or a plurality of the components of the above-described embodiments.

[0052] For example, in the above-described embodiment, the end of the power line 94 is cylindrical including the screw hole 942, but may be in the form of a screw portion having a screw thread formed on the outer periphery. In this case, a nut may be used instead of the fastening bolt BT to achieve a similar fastening. In this case, a similar anti-rotation structure can be achieved by making the through hole (not shown) of the three-phase bus bar corresponding to the through hole 9130 of the recess 913 non-circular as viewed in the Z direction, and by making the portion of the end of the power line on the negative side in the Z direction from the screw thread portion non-circular as viewed in the Z direction. [Explanation of symbols]

[0053] DESCRIPTION OF SYMBOLS 1... rotating electric machine, 2... case, 290... insertion hole, 80... sealing member, 94... power line, 942... screw hole, 944... flat portion, 946... end face, 910... three-phase bus bar (wiring member), 913... recess, 9130... through hole, 9132... bottom portion, 9134... side wall portion (anti-rotation portion), 918... sensor placement portion (first portion), 919... low-rigidity portion (second portion), 920... current sensor, S1... motor housing chamber (housing space), S4... inverter housing chamber (outside), BT... fastening bolt (fastening member)

Claims

1. A rotating electric machine that operates on a multi-phase power and has a power line for each phase; a wiring member for each phase, the wiring member being formed of a conductor and electrically connected between the rotating electric machine and a power source; a fastening member for fastening the power line and the wiring member for each phase, The wiring member has an integral anti-rotation portion that prevents the power line from rotating in a rotation direction of the fastening member when fastened.

2. the wiring member has a recess for receiving an end of the power line, The recess has a through hole through which the fastening member passes, a bottom surface portion around the through hole, and a flat side wall portion forming the anti-rotation portion, 2. The vehicle drive device according to claim 1, wherein an end of the power line has a screw hole into which the fastening member is screwed, and an end face around the screw hole that abuts against the bottom portion of the recess in the axial direction of the fastening member, and a flat portion facing the side wall portion of the recess.

3. a current sensor provided in a first portion of the wiring member and configured to detect a current flowing through the first portion; The vehicle drive device according to claim 1 , wherein the wiring member has a second portion between the rotation prevention portion and the first portion, the second portion having a lower rigidity than the first portion against a force received when the rotation is locked.

4. The rotating electric machine further includes a case that defines an accommodation space for accommodating the rotating electric machine. The wiring member is disposed outside the accommodation space, the case has an insertion hole through which the power line extends from inside the accommodation space to the outside, The vehicle drive device according to claim 1 , further comprising a seal member that fills a gap between the insertion hole and the power line.

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