Drive unit

Abstract

Contact or short circuits could occur between adjacent power lines. [Solution] The drive device comprises a plurality of power lines connected to coils attached to a stator core, a plurality of first terminals provided at each end of the plurality of power lines opposite to the side connected to the coils, a terminal block, a plurality of second terminals supported by the terminal block at a distance from each other, a plurality of fastening members that fasten the plurality of first terminals and the plurality of second terminals one-to-one and fix them to the terminal block, and one or more partition walls made of insulators located between adjacent power lines.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a driving device.

Background Art

[0002] Patent Document 1 discloses a driving device including a motor, an inverter that controls a current supplied to the motor, and a plurality of plate-shaped busbars that electrically connect the motor and the inverter. Each busbar is arranged to overlap in a row in the plate thickness direction. Further, according to Patent Document 1, three connection coil lines corresponding to the U-phase, V-phase, and W-phase extend from the end of the coil of the motor. Each connection coil line is connected to each of the three busbars at the crimp terminal at the tip.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The distance between a plurality of conductors that electrically connect the inverter and the coil of the motor is narrow, and there is a risk of short-circuiting due to foreign matter or the like, or contact due to vibration. This specification provides a technology for avoiding such contact and short-circuit.

Means for Solving the Problems

[0005] The drive device disclosed herein comprises a plurality of power lines connected to coils attached to a stator core, a plurality of first terminals provided at each end of the plurality of power lines opposite to the side connected to the coils, a terminal block, a plurality of second terminals supported by the terminal block at a distance from each other, a plurality of fastening members that fasten the plurality of first terminals and the plurality of second terminals one-to-one and fix them to the terminal block, and one or more partitions made of insulators located between adjacent power lines.

[0006] According to the above configuration, the partition wall can prevent contact or short circuits between adjacent power lines. [Brief explanation of the drawing]

[0007] [Figure 1] A simplified diagram showing the configuration of the drive unit. [Figure 2] This figure shows cross-sections of the first and second terminals along the line II-II in Figure 1. [Figure 3] A diagram illustrating a configuration according to the first embodiment, showing a simplified configuration including a terminal block from a viewpoint facing the side of the terminal block. [Figure 4] A diagram illustrating a configuration according to the second embodiment, showing a simplified configuration including the terminal block from a viewpoint facing the side of the terminal block. [Figure 5] This diagram shows a simplified representation of the configuration shown in Figure 4, from a viewpoint opposite the support surface. [Figure 6] A diagram illustrating a configuration according to the third embodiment, showing a simplified configuration including a terminal block from a viewpoint facing the side of the terminal block. [Figure 7] This diagram shows a simplified representation of the configuration shown in Figure 6, from a viewpoint opposite the support surface. [Figure 8] This figure shows the configuration according to the fourth embodiment from the same viewpoint as in Figure 2. [Figure 9] This figure shows the configuration according to the fourth embodiment from the same viewpoint as in Figure 3. [Figure 10] This figure shows the configuration according to the fourth embodiment from the same viewpoint as in Figure 5. [Modes for carrying out the invention]

[0008] The main features of the embodiments described below are listed below. According to the drive device disclosed herein, each of the plurality of power lines may comprise a flexible conductor and an insulating film covering the conductor. According to the above configuration, even if the insulating film is damaged and the conductors used as power lines are exposed, contact between such conductors is prevented by the partition wall.

[0009] According to the drive device disclosed herein, the partition wall may be integrally molded with the terminal block. According to the above configuration, the partition wall, which is integrally molded with the terminal block, can prevent adjacent power lines from coming into contact with each other.

[0010] According to the drive device disclosed herein, the terminal block may include a support surface that supports the second terminal and to which the fastening member is fixed, and a side surface facing the side from which the power line extends from the first terminal, and the partition wall may include a first partition wall portion that protrudes from the side surface and separates adjacent power lines, and a second partition wall portion that protrudes from the support surface and separates adjacent first terminals. According to the above configuration, the first and second partitions prevent contact between adjacent power lines and between adjacent first terminals.

[0011] According to the drive device disclosed herein, the second partition wall may comprise a plurality of pairs of walls corresponding to each of the plurality of first terminals, and the pairs of walls may be positioned to sandwich the corresponding first terminals in the direction in which the plurality of first terminals are aligned. According to the above configuration, rotation of each of the multiple first terminals is suppressed, and contact between the first terminals can be prevented.

[0012] According to the drive device disclosed in this specification, there is provided a cover attached to the terminal block, the cover being made of an insulator that covers a range including the power line, the first terminal, the second terminal, and the fastening member, and the partition wall may be a part of the cover. According to the above configuration, by attaching a cover to the terminal block, the partition wall can prevent adjacent power lines from coming into contact with each other.

[0013] Embodiments will be described with reference to the drawings. Each drawing is merely illustrative, and the present embodiments are not limited to the illustrated content. Also, since each drawing is illustrative, a part thereof may be omitted.

[0014] FIG. 1 schematically shows the configuration of a drive device 10. The drive device 10 includes, for example, all or part of the configuration shown in the drawing. The drive device 10 may be referred to as, for example, a motor unit. According to FIG. 1, the drive device 10 generally includes a motor 20, an inverter 50, and a wiring 70 that electrically connects the motor 20 and the inverter 50. The wiring 70 includes a power line 30, a first terminal 32, a second terminal 42, and a bus bar 60, which will be described later. The drive device 10 is mounted on, for example, an electric vehicle. The motor 20 is a driving motor for the electric vehicle and is a prime mover that drives at least one wheel of the electric vehicle.

[0015] The drive device 10 is housed in a common casing 80. Inside the casing 80, for example, a chamber for housing the motor 20 and a chamber for housing the inverter 50 may be partitioned by a partition wall 82. Alternatively, the casing 80 for housing the motor 20 and the casing 80 for housing the inverter 50 may be separate housings.

[0016] Power is supplied to the motor 20 from a battery (not shown) via an inverter 50. The inverter 50 converts the DC power supplied from the battery into, for example, three-phase AC power. Accordingly, the inverter 50 includes a plurality of inverter busbars 60. The plurality of inverter busbars 60 includes inverter busbars 6*U*, inverter busbars 6*V*, and inverter busbars 6*W* corresponding to the U-phase, V-phase, and W-phase, respectively.

[0017] The motor 20 includes a shaft 28, a rotor 26, a stator core 22, and coils 24. The shaft 28 extends along the central axis C of the motor 20. The rotor 26 has a generally cylindrical shape. The rotor 26 is fixed to the shaft 28. The rotor 26 rotates together with the shaft 28 about the central axis C as the rotation center. A direction parallel to the direction in which the central axis C faces is referred to as the axial direction. In FIG. 1, the motor 20 is illustrated from a viewpoint facing an end face 22*a*, which is a face of the stator core 22 facing one side in the axial direction.

[0018] The stator core 22 has a generally cylindrical shape. The radial direction of the stator core 22 and the circumferential direction of the stator core 22 are simply referred to as the radial direction and the circumferential direction, respectively. The stator core 22 is disposed radially outside the rotor 26. Coils 24 are attached to the stator core 22. The stator core 22 and the coils 24 are collectively referred to as the stator. The coils 24 include a plurality of coils 24*U*, 24*V*, and 24*W* corresponding to the U-phase, V-phase, and W-phase, respectively. In the motor *20*, the rotor 26 and the shaft 28 rotate when three-phase AC power of the U-phase, V-phase, and W-phase is input to the coils 24*U*, 24*V*, and 24*W* of the stator through the wiring 70 from the inverter 50.

[0019] Without going into detail, each of the coils 24U, 24V, and 24W extends circumferentially by being mounted across multiple slots formed in the stator core 22. Each of the coils 24U, 24V, and 24W is constructed by connecting multiple conductor wires having a rectangular cross-section, for example, called a segment coil. The specific configuration of coils 24U, 24V, and 24W is not particularly limited. For example, coils 24U, 24V, and 24W may have a concentrated winding configuration or a distributed winding configuration.

[0020] Multiple power lines 30 are connected to each of the coils 24. The multiple power lines 30 include power lines 30U, 30V, and 30W corresponding to the U-phase, V-phase, and W-phase, respectively. One end 24Ua, 24Va, and 24W of each coil 24U, 24V, and 24W are connected one-to-one with the power lines 30U, 30V, and 30W, for example, by welding. In Figure 1, the power lines 30U, 30V, and 30W are shown connected to the input ends 24Ua, 24Va, and 24W of each coil 24U, 24V, and 24W, respectively. However, these power lines 30U, 30V, and 30W may also be understood as being connected to the other output ends of each coil 24U, 24V, and 24W. The other ends of each coil 24U, 24V, and 24W may be connected to a so-called neutral wire. Multiple power lines 30 and neutral lines can be considered as part of the wiring 70, and the features of this embodiment can be understood to apply to these wirings 70.

[0021] The drive unit 10 further includes a terminal block 40, a plurality of second terminals 42, a plurality of fastening members 46, and one or more partition walls 44. The terminal block 40 and partition walls 44 are formed of an insulator such as resin. The terminal block 40 is fixed to the casing 80. For example, a hole is formed in a part of the partition wall 82 to connect a chamber housing the motor 20 and a chamber housing the inverter 50, and the terminal block 40 is fixed to this hole. The terminal block 40 supports a plurality of metal second terminals 42 spaced apart from each other. A plurality of metal first terminals 32 are provided at each end of the plurality of power lines 30 on the side opposite to the side connected to the coil 24. Power line 30U has a first terminal 32U. Similarly, power line 30V has a first terminal 32V, and power line 30W has a first terminal 32W.

[0022] Multiple fastening members 46 fasten multiple first terminals 32 and multiple second terminals 42 in one-to-one pairs and fix them to the terminal block 40. The fastening members 46 are, for example, metal bolts. According to Figure 1, the first terminal 32U and the second terminal 42U are fastened together by the fastening members 46. Similarly, the first terminal 32V and the second terminal 42V are fastened together by the fastening members 46, and the first terminal 32W and the second terminal 42W are fastened together by the fastening members 46. The partition walls 44 are located between adjacent power lines 30. According to Figure 1, partition walls 44 are located between adjacent power lines 30U and 30V, and between adjacent power lines 30V and 30W.

[0023] As shown in Figure 1, multiple inverter busbars 60 and multiple second terminals 42 are connected one-to-one. Inverter busbar 60U is connected to second terminal 42U. Similarly, inverter busbar 60V is connected to second terminal 42V, and inverter busbar 60W is connected to second terminal 42W. The method of connecting the inverter busbars 60 and second terminals 42 is not particularly limited. The second terminals 42 may be part of the inverter busbar 60, i.e., terminals of the inverter busbar 60. In the terminal block 40, by connecting multiple first terminals 32 and multiple second terminals 42 one-to-one, wiring 70 corresponding to the U phase, V phase, and W phase, which electrically connect the inverter 50 and the coils 24U, 24V, and 24W of the motor 20, is realized.

[0024] Figure 2 shows cross-sections of the first terminal 32 and the second terminal 42 along the line II-II in Figure 1. In Figure 2, for clarity, hatching is applied to show the cross-sections only on the first terminal 32, the second terminal 42, and the fastening member 46. Figure 2 shows the first terminal 32V and the second terminal 42V as an example of a combination of the first terminal 32 and the second terminal 42 that are fastened together. The terminal block 40 is provided with a support surface 40b that supports the second terminal 42. In the example in Figure 2, the second terminal 42 is supported by the support surface 40b with at least a portion of the second terminal 42 embedded in a recess formed in the support surface 40b. The first terminal 32 contacts the second terminal 42 in an overlapping state, and the fastening member 46 is passed through the through holes formed in the first terminal 32 and the second terminal 42, thereby fastening the first terminal 32 and the second terminal 42 together. One end of a fastening member 46, which passes through through holes formed in the first terminal 32 and the second terminal 42 respectively, is fixed to the terminal block 40. If the fastening member 46 is a bolt, one end of the fastening member 46 may be fastened to a screw hole formed in the terminal block 40, or to a nut fixed to the terminal block 40. Alternatively, one end of the fastening member 46 may be fixed to the terminal block 40 by fastening to a nut fixed to the second terminal 42.

[0025] The terminal block 40 has a side surface 40a that is different from the support surface 40b and faces the side from which the power lines 30 extend from the first terminals 32. Figure 3 shows a simplified view of the configuration including the terminal block 40 from a viewpoint facing the side surface 40a. In Figure 3, direction D1 is the direction in which multiple power lines 30 are lined up, and is also the direction in which multiple first terminals 32 are lined up. The partition wall 44 shown in Figure 2 is a partition wall 44 provided at a position separating adjacent power lines 30V and power lines 30U, as can be seen by referring to Figures 1 and 3. As shown in Figure 1, the partition wall 44 also extends between adjacent first terminals 32. According to Figure 2, the partition wall 44 includes a first partition wall portion 44a that protrudes from the side surface 40a and separates adjacent power lines 30, and a second partition wall portion 44b that protrudes from the support surface 40b and separates adjacent first terminals 32. According to Figure 2, the partition wall 44 has a roughly L-shape, with a first partition wall portion 44a extending along the side surface 40a and a second partition wall portion 44b extending along the support surface 40b connected together.

[0026] Each of the multiple power lines 30 may be a plate-shaped conductor like a busbar, but in the example in Figures 2 and 3, each of the multiple power lines 30 comprises a flexible conductor and an insulating film covering the conductor. The flexible conductor is, for example, braided wire. Braided wire is made by bundling and braiding multiple strands together, and is excellent in flexibility and pliability. As an example, a cable in which such braided wire is covered with a resin tube (a type of insulating film) is used as the power line 30 (30U, 30V, 30W).

[0027] For example, the partition wall 44 is integrally molded with the terminal block 40. That is, the partition wall 44 is part of the terminal block 40 and is integrally molded with the terminal block 40 from a common material. This simplifies the assembly of the drive unit 10, including the partition wall 44 and the terminal block 40. However, the partition wall 44 may be manufactured separately from the terminal block 40 and fixed to the terminal block 40 directly or indirectly. Alternatively, the partition wall 44 does not need to be connected to the terminal block 40 as long as it is located in a position that separates adjacent power lines 30. The partition wall 44 may also be fixed to an object other than the terminal block 40, such as the casing 80.

[0028] As described above, according to this embodiment, the drive unit 10 can prevent contact and short circuits between adjacent power lines 30 by providing a partition wall 44. For example, if the power lines 30 are flexible conductors such as braided wire, contact between the power lines 30 is likely to occur due to the effects of vibration, etc. However, according to this embodiment, contact between the power lines 30 is prevented by the partition wall 44. Even if the insulating film covering the flexible conductor in the power line 30 is damaged and a part of the conductor is exposed, contact between the conductors is prevented by the partition wall 44.

[0029] The first terminal 32 can rotate around the fastening member 46 when it is fastened by the fastening member 46. The first terminal 32 can also rotate around the fastening member 46 due to vibration, loosening of the fastening member 46, etc. In this embodiment, the partition wall 44 includes a second partition wall portion 44b in addition to the first partition wall portion 44a. Therefore, even if the first terminal 32 rotates, the second partition wall portion 44b prevents contact between adjacent first terminals 32.

[0030] For convenience, the embodiment described so far with reference to Figures 1-3 will be referred to as the First Embodiment. Below, each embodiment other than the First Embodiment will be described. For each of the following embodiments, the differences from the First Embodiment will be described, and explanations common to both embodiments will be omitted.

[0031] A second embodiment will now be described. Figure 4 shows a simplified configuration including the terminal block 40 according to the second embodiment from the same viewpoint as in Figure 3. Figure 5 shows a simplified configuration including the terminal block 40 shown in Figure 4 from a viewpoint facing the support surface 40b. According to the second embodiment, the second partition wall portion 44b of the partition wall 44 comprises a plurality of "pairs of wall portions 44b1, 44b2" corresponding to each of the plurality of first terminals 32. The pairs of wall portions 44b1, 44b2 are positioned to sandwich the corresponding first terminals 32 in the direction D1 in which the plurality of first terminals 32 are lined up.

[0032] The pair of wall sections 44b1 and 44b2 exist in proportion to the number of first terminals 32. According to Figure 5, the first terminal 32U is sandwiched between a pair of wall sections 44b1 and 44b2, which correspond to the second partition wall section 44b. Similarly, the first terminal 32V is sandwiched between a pair of wall sections 44b1 and 44b2, which correspond to the second partition wall section 44b, and the first terminal 32W is also sandwiched between a pair of wall sections 44b1 and 44b2, which correspond to the second partition wall section 44b. According to Figures 4 and 5, the second embodiment can also be described as having two partition walls 44, each comprising a first partition wall section 44a and a second partition wall section 44b, arranged between adjacent power lines 30.

[0033] In the direction D1 where multiple first terminals 32 are lined up, the distance between the pair of wall portions 44b1 and 44b2 that form a pair on either side of the first terminal 32 is equal to or approximately equal to the width of the first terminal 32. As can be seen from Figures 4 and 5, the pair of wall portions 44b1 and 44b2 that sandwich the first terminal 32 are in contact with or approximately in contact with the first terminal 32 they are sandwiching. Therefore, each of the multiple first terminals 32 is effectively immobile by the pair of wall portions 44b1 and 44b2 that sandwich it. Because the first terminals 32 are immobile in this way, contact between adjacent first terminals 32 and contact between adjacent power lines 30 are reliably prevented.

[0034] A third embodiment will now be described. Figure 6 shows a simplified configuration including the terminal block 40 according to the third embodiment from the same viewpoint as in Figures 3 and 4. Figure 7 shows a simplified configuration including the terminal block 40 shown in Figure 6 from the same viewpoint as in Figure 5. In the third embodiment, as in the second embodiment, the second partition portion 44b of the partition wall 44 comprises multiple pairs of wall portions 44b1, 44b2 corresponding to each of the multiple first terminals 32. The third embodiment differs from the second embodiment in that, as in the first embodiment, one first partition portion 44a of the partition wall 44 is placed between adjacent power lines 30. In other words, instead of placing two partition walls 44 including the first partition portion 44a between adjacent power lines 30, two second partition portions 44b may be placed between adjacent first terminals 32, thereby realizing a configuration in which each first terminal 32 is sandwiched between second partition portions 44b (pairs of wall portions 44b1, 44b2). According to the third embodiment, the total amount of material required to form the partition wall 44 can be reduced compared to the second embodiment, while achieving the same effects as the second embodiment.

[0035] A fourth embodiment will be described. The drive unit 10 may include a cover 90 that is attached to the terminal block 40. Figure 8 shows the configuration including the cover 90 from the same viewpoint as in Figure 2. Figures 9 and 10 show the configuration including the cover 90 from the same viewpoint as in Figures 3 and 5, respectively. In Figures 8 to 10, the general shape of the cover 90 is shown by a dashed line. The cover 90 is made of an insulator such as resin. The cover 90 covers the area including the power line 30, the first terminal 32, the second terminal 42, and the fastening member 46. The cover 90 covers part or all of the area including the power line 30, the first terminal 32, the second terminal 42, and the fastening member 46.

[0036] The cover 90 may have holes or notches at the necessary locations and sizes for passing power lines 30, inverter busbars 60, etc. The method of attaching the cover 90 to the terminal block 40 is not particularly limited. It is sufficient that the cover 90 is fixed to the terminal block 40 directly or indirectly. In the fourth embodiment, the partition wall 44 is part of the cover 90. That is, at least a part of the cover 90 functions as the partition wall 44 of this embodiment. Of the cover 90, the wall portion that is located between adjacent power lines 30 and separates the power lines 30 corresponds to the partition wall 44. By attaching the cover 90 to the terminal block 40 in this way, the same effect as in the first embodiment is achieved.

[0037] Figure 10 shows a pair of parallel ribs 92 inside a cover 90 that covers a set of power lines 30, a first terminal 32, a second terminal 42, and a fastening member 46 (a set of power lines 30U, a first terminal 32U, a second terminal 42U, and one fastening member 46). The pair of ribs 92 extend in a direction intersecting direction D1 and are spaced apart in direction D1. The pair of ribs 92 are part of the internal structure of the cover 90. The pair of ribs 92 correspond to the pair of wall portions 44b1, 44b2 described in the second and third embodiments. In other words, in the fourth embodiment, the pair of wall portions 44b1, 44b2 may be formed inside the cover 90. Although not shown in Figure 10, pairs of ribs 92 may be formed inside each of multiple covers 90. After fastening the first terminal 32 and the second terminal 42 with the fastening member 46, the cover 90 is attached to the terminal block 40, thereby preventing the first terminal 32 from rotating due to the pair of wall portions 44b1, 44b2, i.e., the pair of ribs 92.

[0038] In the examples in Figures 9 and 10, one cover 90 is attached to each set of power lines 30, first terminal 32, second terminal 42, and fastening member 46. In other words, in the examples in Figures 9 and 10, three covers 90 are attached to the terminal block 40 in the same way. However, these multiple covers 90 may be molded as a single unit.

[0039] The specific examples of the technologies disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of Symbols]

[0040] 10: Drive unit, 20: Motor, 22: Stator core, 24, 24U, 24V, 24W: Coil, 30, 30U, 30V, 30W: Power line, 32, 32U, 32V, 32W: First terminal, 40: Terminal block, 40a: Side, 40b: Support surface, 42, 42U, 42V, 42W: Second terminal, 44: Partition, 44a: First part of partition, 44b: Second part of partition, 44b1, 44b2: Wall section, 46: Fastening member, 50: Inverter, 60, 60U, 60V, 60W: Inverter busbar, 70: Wiring, 80: Casing, 90: Cover, 92: Rib

Claims

1. A coil attached to the stator core and multiple power lines connected to each of them, Multiple first terminals are provided at each end of the plurality of power lines on the side opposite to the side connected to the coil, Terminal block and Multiple second terminals supported by the terminal block at a distance from each other, A plurality of fastening members are used to fasten the plurality of first terminals and the plurality of second terminals in a one-to-one relationship and fix them to the terminal block, A drive device comprising one or more partitions made of insulators located between adjacent power lines.

2. The drive device according to claim 1, wherein each of the plurality of power lines comprises a flexible conductor and an insulating film covering the conductor.

3. The drive device according to claim 1, wherein the partition wall is integrally molded with the terminal block.

4. The terminal block comprises a support surface that supports the second terminal and to which the fastening member is fixed, and a side surface facing the side from which the power line extends from the first terminal, The drive device according to claim 1, wherein the partition wall comprises a first partition wall portion that protrudes from the side surface and separates adjacent power lines, and a second partition wall portion that protrudes from the support surface and separates adjacent first terminals.

5. The second partition wall comprises a plurality of pairs of wall portions corresponding to each of the plurality of first terminals, The drive device according to claim 4, wherein the pair of wall portions are arranged in a position that sandwiches the corresponding first terminals in the direction in which the plurality of first terminals are lined up.

6. A cover to be attached to the terminal block, comprising an insulator that covers an area including the power line, the first terminal, the second terminal, and the fastening member, The drive device according to claim 1, wherein the partition wall is part of the cover.

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