Motor Control Device

Abstract

To provide a motor control device capable of further reducing the difference in the length of current paths of three phases between a power supply terminal connection portion and a motor terminal connection portion.SOLUTION: A motor control device includes a board provided at the end of a motor having two winding groups. The board has two areas separated by a boundary line passing through the center of the motor when viewed in the axial direction of the motor. Each of the two areas are provided with a power terminal connection portion, an inverter circuit, and a motor terminal connection portion. Three-phase motor terminals arranged in a line along the periphery of the end of the motor are connected to the motor terminal connection portion. When viewed from the axial direction of the motor, the power terminal connection portion, the inverter circuit, and the motor terminal connection portion are arranged in this order along the boundary line. The motor terminal connection portion is provided at an angle such that the boundary line forms an acute angle with a straight line perpendicular to the direction in which the motor terminals are arranged, which is also the extension direction of the motor terminal connection portion.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a motor control device. [Background technology]

[0002] Conventionally, as described in Patent Document 1, there is a motor having two power supply systems. The motor has two winding groups, each of which has three phases. The motor control device has a single power supply terminal connection section, a single ground terminal connection section, two drive circuits, two current detection circuits, two motor current cutoff circuits, and two motor terminal connection sections. The power supply terminal connection section is a section to which DC power is supplied from an external power supply. The ground terminal connection section is a section connected to the ground. The drive circuit converts the DC power supplied to the power supply terminal connection section into AC power supplied to the winding group of the corresponding system. The motor current cutoff circuit is a circuit for cutting off the power supply to the winding group of the corresponding system. The current detection circuit detects the current supplied from the drive circuit of the corresponding system to the motor of the corresponding system. The motor terminal connection section individually supplies the AC power generated by the drive circuit of the corresponding system to the winding group of the corresponding system.

[0003] The control device has a substrate. The substrate is divided into a first region and a second region. The first region is provided with a power supply terminal connection portion, a first drive circuit, a first current detection circuit, a first motor current interruption circuit, and a first motor terminal connection portion. The power supply terminal connection portion, the first drive circuit, the first current detection circuit, the first motor current interruption circuit, and the first motor terminal connection portion are arranged along the boundary line between the first region and the second region. The second region is provided with a ground terminal connection portion, a second drive circuit, a second current detection circuit, a second motor current interruption circuit, and a second motor terminal connection portion. The ground terminal connection portion, the second drive circuit, the second current detection circuit, the second motor current interruption circuit, and the second motor terminal connection portion are also arranged along the boundary line between the first region and the second region. The connection portions and circuits of each system are provided in pairs with the boundary line between them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-068542 A Summary of the Invention [Problem to be solved by the invention]

[0005] By arranging the drive circuits, current detection circuits, and motor current interruption circuits of each system in an orderly manner on a board, as in the control device of Patent Document 1, it may indeed be possible to reduce to a certain extent the variation in the length of the current path from the drive circuit in each system to the motor terminal connection part of each phase.

[0006] However, the control device of Patent Document 1 has the following concerns. That is, the drive circuit of each system is configured by connecting three legs in parallel, each corresponding to one of the three phases. Each leg is configured by connecting two switching elements in series. The three legs are arranged in a direction perpendicular to the boundary between the first area and the second area. The DC power supplied to the power supply terminal connection part is branched and supplied to these three legs. Therefore, depending on the positional relationship between the drive circuit and the power supply terminal connection part, there is a risk that a difference will occur in the length of the current path of each of the three phases that branches off from the power supply branch point for the leg of each phase.

[0007] For example, when considering the positional relationship between the power supply terminal connection part provided in the first region of the substrate and the second drive circuit provided in the second region of the substrate, it is considered that the current path from the power supply terminal connection part to the leg of each phase bends from a direction perpendicular to the boundary between the first region and the second region to a direction along the boundary. In this case, the current path from the power supply terminal connection part to the leg of each phase is divided into a first current path that is closest to the power supply terminal connection part, a second current path that is farthest from the power supply terminal connection part, and a third current path that is located between the current path that is closest to the power supply terminal connection part and the current path that is farthest from the power supply terminal connection part in the direction perpendicular to the boundary between the first region and the second region.

[0008] Therefore, in the direction perpendicular to the boundary between the first region and the second region, a difference in length is likely to occur between the current path passing through the side closer to the power supply terminal connection part and the current path passing through the side farther from the power supply terminal connection part. Similarly, there is a risk that a difference in length of the current path from the power supply terminal connection part to the legs of each phase of the first drive circuit will occur between the current path passing through the side closer to the power supply terminal connection part and the current path passing through the side farther from the power supply terminal connection part. Thus, in the control device of Cited Document 1, there is room to further reduce the difference in the total length of the current path between the power supply terminal connection part and the motor terminal connection part. [Means for solving the problem]

[0009] The motor control device that can solve the above problem is a motor control device including a board that is provided at an end of a motor having two winding groups and that controls the power supply to the winding groups independently for each system. The board has two regions that are divided by a boundary line that passes through the center of the motor when viewed from the axial direction of the motor. The two regions are provided with components corresponding to each system, including a power supply terminal connection part to which DC power is supplied from an external DC power supply, an inverter circuit that converts the DC power supplied from the power supply terminal connection part into three-phase AC power, and a motor terminal connection part that is a group of connection parts to which three-phase motor terminals are connected that are arranged in a row along the periphery of the end of the motor, the connection parts for each of the three phases are arranged in the same position as the motor terminals for each of the three phases, and supplies the three-phase AC power supplied from the inverter circuit to the winding group of the corresponding system. When viewed from the axial direction of the motor, the power supply terminal connection part, the inverter circuit, and the motor terminal connection part are arranged in this order along the boundary line. The motor terminal connection portion is provided so that a straight line perpendicular to an arrangement direction of the motor terminals forms an acute angle with the boundary line.

[0010] The following layout may be adopted as the layout of the board. For example, the power supply terminal connection parts and inverter circuits of each system are provided along the boundary between the two regions as in the above configuration, while the motor terminal connection parts of each system are provided so that their extension direction is parallel to the boundary. In this case, the current paths of each of the three phases from the power supply terminal connection parts to the motor terminal via the inverter circuit must be significantly bent from the direction along the boundary to a direction perpendicular to the boundary. This makes it easy for differences to occur in the lengths of the current paths of each of the three phases from the power supply terminal connection parts to the motor terminal.

[0011] In this respect, according to the above configuration, the power supply terminal connection parts, the inverter circuit, and the motor terminal connection parts of each system are aligned along the boundary line between the two regions, and the motor terminal connection parts of each system are inclined so that a straight line perpendicular to the arrangement direction of the motor terminals forms an acute angle with the boundary line. The degree of bending of the current paths of each of the three phases from the power supply terminal connection parts to the motor terminals via the inverter circuit can be made gentler by the amount of inclination of the motor terminal connection parts with respect to the boundary line. In other words, the current paths of each of the three phases can be made more linear between the power supply terminal connection parts and the motor terminal connection parts. Therefore, the difference in length of the current paths of each of the three phases between the power supply terminal connection parts and the motor terminals can be made smaller.

[0012] In the above motor control device, the power supply terminal connection portion, the inverter circuit, and the motor terminal connection portion of each system provided in the two regions may be arranged symmetrically about the boundary line as an axis of symmetry when viewed in the axial direction of the motor.

[0013] According to this configuration, the power supply terminal connections for the two systems, the inverter circuits, and the motor terminal connections can be arranged more regularly on the board. In the above motor control device, the inverter circuit may be located inside the motor terminal connection part, on the side toward the center of the motor with the motor terminal connection part as a reference, when viewed in the axial direction of the motor.

[0014] Depending on the product specifications, the above-mentioned layout can be adopted as the board layout. In the above motor control device, the inverter circuit may be located outside the motor terminal connection portion, on a side away from the center of the motor with the motor terminal connection portion as a reference, when viewed in the axial direction of the motor.

[0015] Depending on the product specifications, the above-mentioned layout can be adopted as the board layout. In the motor control device, the inverter circuit may have three legs corresponding to three phases in which a power supply side switching element and a ground side switching element are connected in series, and the three legs may be aligned along an extension direction of the motor terminal connection part. In this case, a current path from the power supply terminal connection part to the three legs may be branched into three linear current paths starting from a power supply branch point for the three legs.

[0016] According to this configuration, the current paths between the power supply branch point and the three legs are linearly arranged, so that the difference in length of the current paths from the power supply branch point to the three legs can be made smaller, and thus the difference in the total length of the current paths for each of the three phases from the power supply terminal connection part to the motor terminal connection part can be made smaller.

[0017] In the motor control device, the substrate may be configured such that the power supply terminal connection portion of one of the two regions is omitted. In this case, the power supply terminal connection portion of the other of the two regions is omitted. Before The power supply branch points for the three legs of the inverter circuit each They may be connected.

[0018] Depending on the product specifications, the above-mentioned layout can be adopted as the board layout. In the above motor control device, the power supply terminal connection portion may be provided toward the center of the substrate when viewed in the axial direction of the motor.

[0019] With this configuration, the electrical distance between the power supply terminal connection part and the inverter circuit is shorter by the amount that the power supply terminal connection part is closer to the center of the board than when the power supply terminal connection part is located closer to the end of the board opposite the motor terminal connection part relative to the inverter circuit, and therefore the electrical resistance between the power supply terminal connection part and the inverter circuit is smaller.

[0020] In the above motor control device, a filter may be provided in a current path between the power supply terminal connection portion and the inverter circuit on the substrate. According to this configuration, the filter provided on the board removes noise superimposed on the DC power supplied from the power supply terminal connection to the inverter circuit. In addition, it is also possible to provide the filter outside the board, but compared to the case of adopting this configuration, the electrical distance from the power supply terminal connection to the inverter circuit via the filter is shorter. Therefore, the electrical resistance between the power supply terminal connection and the inverter circuit is smaller.

[0021] In the above motor control device, a control circuit for controlling an operation of the inverter circuit may be provided in each of the two regions of the substrate as a configuration corresponding to each system.

[0022] According to this configuration, the control device only needs to be provided with a single board, and there is no need to provide the control device with two boards, for example, a power board on which power system components are mounted and a control board on which control system components are mounted.

[0023] In the motor control device, the two regions may be partitioned into a power circuit region that corresponds to the motor in a direction along the boundary line when viewed from the axial direction of the motor, and a control circuit region that is separated from the motor. In this case, power system components including the motor terminal connection portion and the inverter circuit may be provided in the power circuit region, while control system components including the control circuit may be provided in the control circuit region.

[0024] This configuration allows the power system to be located closer to the motor, making it easier to connect the motor terminal connectors to the motor terminals, and also makes it possible to shorten and simplify the current path between the inverter circuit and the motor terminals. Effect of the Invention

[0025] According to the motor control device of the present invention, the difference in length of the current paths of each of the three phases between the power supply terminal connection part and the motor terminal connection part can be further reduced. [Brief description of the drawings]

[0026] [Figure 1] 1 is a partial cross-sectional view of a motor device on which a first embodiment of a motor control device is mounted. [Diagram 2] 1 is an exploded perspective view of a motor control device according to a first embodiment. [Diagram 3] 1 is a circuit diagram of a motor control device according to a first embodiment. [Figure 4] FIG. 2 is a plan view of the power board according to the first embodiment. [Diagram 5] FIG. 4 is a schematic diagram showing current paths for each of three phases from a power supply terminal connection part to a motor terminal connection part in a comparative example. [Figure 6] 3 is a schematic diagram showing current paths for each of three phases from a power supply terminal connection part to a motor terminal connection part in the first embodiment. FIG. [Figure 7] FIG. 11 is a plan view of a bus bar module according to a second embodiment. [Figure 8] FIG. 11 is a wiring diagram of a motor coil according to a second embodiment. [Figure 9] FIG. 4 is a plan view of a bus bar module according to a comparative example. [Figure 10] FIG. 13 is a plan view of a power board according to a third embodiment. [Figure 11] FIG. 13 is a schematic diagram showing current paths for each of three phases from a power supply terminal connection portion to a motor terminal connection portion in a third embodiment. [Figure 12] FIG. 13 is an exploded perspective view of a motor control device according to a fourth embodiment. [Figure 13] FIG. 13 is a plan view of a substrate according to a fourth embodiment. [Figure 14] FIG. 13 is a schematic diagram showing current paths for each of three phases from a power supply terminal connection portion to a motor terminal connection portion in a fourth embodiment. [Figure 15] FIG. 4 is a plan view showing the arrangement of four regions of a substrate in a comparative example. [Figure 16]FIG. 13 is a plan view of a substrate according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] <First embodiment> A first embodiment in which the motor control device is embodied in a motor device will be described below. As shown in Fig. 1, motor device 11 has motor 12 and control device 13. For example, a three-phase brushless motor is used as motor 12. Motor 12 has two winding groups. Control device 13 is provided at an end of motor 12. Control device 13 controls the power supply to the two winding groups in motor 12 independently for each system. Control device 13 corresponds to a motor control device.

[0028] The motor 12 has a cylindrical case 21 with a bottom, and a lid 22 that closes the opening of the case 21. Inside the case 21, a stator 23, a bus bar module 24, and a rotor 25 are provided.

[0029] The stator 23 is fixed in a state fitted into the inner circumferential surface of the case 21. The stator 23 has a cylindrical core 31, two insulators 32 and 33, and a plurality of windings 34. The insulator 32 is provided at a first end of the core 31, and the insulator 33 is provided at a second end of the core 31. The plurality of windings 34 are wound around the core 31 via the insulators 32 and 33.

[0030] The busbar module 24 is provided at the end of the stator 23 on the lid 22 side. The busbar module 24 has a cylindrical holder 35 and a plurality of busbars 36. The holder 35 is made of a synthetic resin material and has a cylindrical shape. Each busbar 36 is held by the holder 35. Both ends of each winding 34 are appropriately connected to each busbar 36. Three-phase AC power is supplied to each winding 34 via each busbar 36.

[0031] The rotor 25 is inserted through the stator 23 and the busbar module 24. The rotor 25 has a stepped cylindrical rotating shaft 37 and a cylindrical rotor magnet 38 fixed to the outer circumferential surface of the rotating shaft 37. The rotating shaft 37 is rotatably supported via two bearings 39A, 39B provided on the inner bottom of the case 21 and the lid 22, respectively. A first end of the rotating shaft 37 penetrates the bottom wall of the case 21 and protrudes to the outside. A second end of the rotating shaft 37 extends toward the control device 13.

[0032] Next, the control device 13 will be described. 2, the control device 13 has a heat sink 41, two boards 42 and 43, and a cover 44. The heat sink 41, the boards 42 and 43, and the cover 44 are assembled as a subassembly. The control device 13 as a subassembly is attached to the end of the motor 12.

[0033] The heat sink 41 is fixed to an end of the motor 12. The heat sink 41 is made of a metal material with excellent thermal conductivity, such as aluminum. The heat sink 41 is provided with a first board accommodating portion 41A and a second board accommodating portion 41B. The first board accommodating portion 41A opens toward the side opposite the motor 12 (upper side in FIG. 2). The second board accommodating portion 41B opens toward the motor 12 side (lower side in FIG. 2).

[0034] The substrate 42 is accommodated in the first substrate accommodating portion 41A of the heat sink 41. The substrate 42 is provided with electronic components for controlling the power supply to the motor 12. The electronic components include two microcomputers 51, 61 and an IC (integrated circuit) group corresponding to the two winding groups. The two microcomputers 51, 61 are chip-type integrated circuits. The IC group is responsible for inputting and outputting, to the microcomputers 51, 61, electric signals required for power supply control of the motor 12. The electric signals include, for example, electric signals generated by a rotation angle sensor described later. The substrate 42 is a so-called control substrate.

[0035] The substrate 43 is accommodated in the second substrate accommodating portion 41B of the heat sink 41. The substrate 43 is fixed to the inner bottom of the second substrate accommodating portion 41B. The substrate 43 is provided with electronic components for supplying power to the motor 12 through the control of the substrate 42. The electronic components include two inverter circuits 52, 62 corresponding to the two winding groups. The inverter circuit 52 has a plurality of FETs (Field Effect Transistors) 53, and the inverter circuit 62 has a plurality of FETs 63. These FETs 53, 63 are switching elements and are provided on the surface of the substrate 43 opposite to the motor 12. The substrate 43 is also provided with two motor terminal connection parts 54, 64, two power supply terminal connection parts 55, 65, and two ground terminal connection parts 56, 66 corresponding to the two winding groups. A rotation angle sensor (not shown) for detecting the rotation of the motor 12 is provided on the surface of the substrate 43 facing the motor 12. The substrate 43 is a so-called power substrate.

[0036] The cover 44 is attached to the surface of the heat sink 41 opposite to the motor 12. The cover 44 is made of a synthetic resin material and is provided as a single unit. The cover 44 covers and closes the first board accommodating portion 41A of the heat sink 41. The board 42 is fixed to the inner bottom of the cover 44.

[0037] Two connector fitting portions 57, 67 corresponding to the two winding groups are provided on the side of cover 44 opposite to heat sink 41. These connector fitting portions 57, 67 each have a rectangular tubular shape and open on the side opposite to heat sink 41. A plug connector is fitted into each of the two connector fitting portions 57, 67. The plug connector is provided at a second end of a wire whose first end is connected to a DC power source such as a battery.

[0038] A power supply terminal and a ground terminal (not shown) are provided inside each of the two connector fitting portions 57, 67. The power supply terminal of the connector fitting portion 57 penetrates the board 42 and the heat sink 41 in a non-contact state and is connected to the power supply terminal connection portion 55 of the board 43. The ground terminal of the connector fitting portion 57 penetrates the board 42 and the heat sink 41 in a non-contact state and is connected to the ground terminal connection portion 56 of the board 43. Similarly, the power supply terminal of the connector fitting portion 67 is connected to the power supply terminal connection portion 65. Moreover, the ground terminal of the connector fitting portion 67 is connected to the ground terminal connection portion 66.

[0039] To the board 43, DC power is supplied from a DC power source via power terminals of the two connector fitting portions 57 and 67. To the board 42, for example, the DC power supplied to the board 43 is supplied via an inter-board connector.

[0040] Motor terminals 36A for each of the three phases corresponding to the first winding group of motor 12 and motor terminals 36B for each of the three phases corresponding to the second winding group of motor 12 are provided to protrude from end face 12a of motor 12 on the side where control device 13 is attached. These motor terminals 36A, 36B are part of bus bars 36 for each of the three phases, and are provided by leading the ends of bus bars 36 to the outside of motor 12.

[0041] The three motor terminals 36A are arranged in a row along the periphery of the cylindrical portion of the case 21, more specifically along the inner circumferential surface of the cylindrical portion, and are connected to the motor terminal connection parts 54 of the substrate 43. The motor terminal connection parts 54 are a group of connection parts to which the three motor terminals 36A corresponding to each of the three phases are connected. The connection parts for each of the three phases constituting this group of connection parts are disposed in the same positions as the three motor terminals 36A.

[0042] The three motor terminals 36B are also arranged in a row along the periphery of the cylindrical portion of the case 21, more specifically along the inner circumferential surface of the cylindrical portion, and are connected to the motor terminal connection parts 64 of the substrate 43. The motor terminal connection parts 64 are a connection part group to which the three motor terminals 36B corresponding to each of the three phases are connected. The connection parts for each of the three phases constituting this connection part group are disposed in the same positions as the three motor terminals 36B.

[0043] In addition, the motor terminal connection parts 54, 64 may be, for example, rectangular parallelepiped terminal blocks. The three motor terminals 36A and the three motor terminals 36B may be arranged in an arc shape along the inner circumferential surface of the cylindrical part of the case 21.

[0044] Next, the electrical configuration of the motor device 11 will be described. As shown in FIG. 3, the motor device 11 has a first winding group 34A of the motor 12, an inverter circuit 52, and a microcomputer 51 as components of a first system.

[0045] The inverter circuit 52 is configured by connecting three legs, each of which is a pair of two FETs 53, 53 connected in series, in parallel between a power supply terminal connection portion 55 and a ground terminal connection portion 56. More specifically, the three legs of the inverter circuit 52 are connected between the power supply terminal connection portion 55 and the ground terminal connection portion 56 via a filter 58. The filter 58 includes a coil provided in series with the power supply line and a capacitor connected between the power supply line and the ground line. The connection path between the filter 58 and the inverter circuit 52 branches into three paths at a power supply branch point on the way to the power supply side and the ground side, respectively, and these branched paths are connected to the power supply side end and the ground side end of the three legs. The configuration of the filter 58 itself and the method of connecting the filter 58 to the inverter circuit 52 are publicly known techniques, so detailed description thereof will be omitted. The power supply terminal connection portion 55 is connected to the + terminal of a DC power supply, and the ground terminal connection portion 56 is connected to the - terminal of the DC power supply. Filter 58 applies filtering to the DC power supplied from power supply terminal connection portion 55 to remove noise superimposed on the DC power.

[0046] The first winding group 34A includes a U-phase winding, a V-phase winding, and a W-phase winding that are, for example, star-connected. The ends of the windings of each phase opposite the neutral point are connected to the midpoints of the legs of each phase in the inverter circuit 52 via motor terminals 36A.

[0047] The microcomputer 51 functions as a control circuit that controls the operation of the inverter circuit 52. The microcomputer 51 generates switching commands for each FET 53 of the inverter circuit 52 based on the rotation angle of the motor 12 detected by a rotation angle sensor. Each FET 53 of the inverter circuit 52 switches based on the switching commands generated by the microcomputer 51, thereby converting DC power supplied from a DC power source into three-phase AC power. The AC power generated by the inverter circuit 52 is supplied to the first winding group 34A of the motor 12 via the motor terminal 36A.

[0048] The motor device 11 has a second winding group 34B of the motor 12, an inverter circuit 62, and a microcomputer 61 as components of a second system. The inverter circuit 62 is configured by connecting three legs, each of which is a pair of two FETs 63, 63 connected in series, in parallel between a power supply terminal connection portion 65 and a ground terminal connection portion 66. More specifically, the three legs of the inverter circuit 62 are connected between the power supply terminal connection portion 65 and the ground terminal connection portion 66 via a filter 68. The connection path between the filter 68 and the inverter circuit 62 branches into three paths at a power supply branch point on the way to the power supply side and the ground side, respectively, and these branched paths are connected to the power supply side end and the ground side end of the three legs. The power supply terminal connection portion 65 is connected to the + terminal of the DC power supply, and the ground terminal connection portion 66 is connected to the - terminal of the DC power supply. The filter 68 removes noise superimposed on the DC power by filtering the DC power supplied from the power supply terminal connection portion 65.

[0049] The second winding group 34B is formed by, for example, star-connecting a U-phase winding, a V-phase winding, and a W-phase winding. The ends of the windings of each phase opposite the neutral point are connected to the midpoint of the leg of each phase in the inverter circuit 62 via motor terminals 36B.

[0050] The microcomputer 61 functions as a control circuit that controls the operation of the inverter circuit 62. The microcomputer 61 generates switching commands for each FET 63 of the inverter circuit 62 based on the rotation angle of the motor 12 detected by the rotation angle sensor. Each FET 63 of the inverter circuit 62 switches based on the switching commands generated by the microcomputer 61, thereby converting DC power supplied from the DC power supply into three-phase AC power. The AC power generated by the inverter circuit 62 is supplied to the second winding group of the motor 12 via the motor terminal 36B.

[0051] Next, the layout of the components provided on the substrate 43 will be described. As shown in FIG. 4, the substrate 43 has a hexagonal plate shape when viewed in the direction along the axis O of the motor 12. When viewed in the direction along the axis O of the motor 12, the substrate 43 has oblique sides 43A, 43B provided at two adjacent corners in the direction of the short side of the rectangle. The substrate 43 is divided into a first area A1 and a second area A2 by a boundary line BL. The boundary line BL extends along the long side of the substrate 43. When viewed in the direction along the axis O of the motor 12, the boundary line BL passes through the axis O, which is the center of the motor 12.

[0052] The first area A1 of the substrate 43 is provided with a motor terminal connection portion 54, an inverter circuit 52, a filter 58, a power supply terminal connection portion 55, and a ground terminal connection portion 56. These components are arranged in the following order from the first end portion to the second end portion of the substrate 43: motor terminal connection portion 54, inverter circuit 52, filter 58, power supply terminal connection portion 55, and ground terminal connection portion 56. The first end portion is the end portion on the side where the oblique side 43A of the substrate 43 is provided. The second end portion is the end portion on the opposite side to the first end portion in the direction along the boundary line BL of the substrate 43.

[0053] The motor terminal connection portion 54 and the inverter circuit 52 are closer to the first end of the substrate 43 when viewed from the direction along the axis O of the motor 12. Furthermore, on the substrate 43, the motor terminal connection portion 54 and the inverter circuit 52 are approximately contained within an area on the first end side based on a straight line NL that is perpendicular to the boundary line BL and passes through the axis O of the motor 12. The power supply terminal connection portion 55, the ground terminal connection portion 56, and the filter 58 are contained within an area on the second end side based on the straight line NL.

[0054] The motor terminal connection portion 54 is inclined along the oblique side 43A of the substrate 43. The motor terminal connection portion 54 is also inclined with respect to the boundary line BL. The three motor terminals 36A of the first system connected to the motor terminal connection portion 54 are arranged at an incline along the motor terminal connection portion 54. The angle θ1 between the boundary line BL and a straight line NL1 that is perpendicular to the arrangement direction of the three motor terminals 36A and passes through the axis O of the motor 12 is set to an acute angle that is less than 90°. Desirably, the three motor terminals 36A are arranged so that the straight line NL1 passes through the center of the central terminal among the three motor terminals 36A. When the three motor terminals 36A are arranged in an arc shape along the inner circumferential surface of the cylindrical portion of the case 21, the arrangement direction of the three motor terminals 36A is the direction connecting the terminals at both ends.

[0055] The inverter circuit 52 is located inside the motor terminal connection part 54 when viewed from the direction along the axis O of the motor 12. The inside of the motor terminal connection part 54 refers to the side facing the axis O, which is the center of the motor 12, with the motor terminal connection part 54 as a reference when viewed from the direction along the axis O of the motor 12. The three FETs 53 on the power supply side and the three FETs 53 on the ground side (legs for each of the three phases) in the inverter circuit 52 are aligned along the extension direction of the motor terminal connection part 54, i.e., along the alignment direction of the three motor terminals 36A. In the inverter circuit 52, the ground side FET 53 is located on the motor terminal connection part 54 side, and the power supply side FET 53 is located on the opposite side to the motor terminal connection part 54 with the ground side FET 53 as a reference.

[0056] In addition, in the substrate 43, the power supply terminal connection portion 55 and the ground terminal connection portion 56 are provided in an area on the second end side of the substrate 43, which is based on a straight line NL that is perpendicular to the boundary line BL and passes through the axis O of the motor 12. The power supply terminal connection portion 55 and the ground terminal connection portion 56 are aligned along the boundary line BL. The power supply terminal connection portion 55 is located on the first end side of the substrate 43 (the left side in FIG. 4), and the ground terminal connection portion 56 is located on the second end side of the substrate 43 (the right side in FIG. 4).

[0057] The current path between the power supply terminal connection portion 55 and each motor terminal 36A is set based on the viewpoint of connecting the power supply terminal connection portion 55 and each motor terminal 36A with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. In addition, the current path between the ground terminal connection portion 56 and each FET 53 on the ground side of the inverter circuit 52 is also set based on the viewpoint of connecting the ground terminal connection portion 56 and each FET 53 on the ground side with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43.

[0058] A motor terminal connection portion 64, an inverter circuit 62, a filter 68, a power supply terminal connection portion 65, and a ground terminal connection portion 66 are provided in the second area A2 of the substrate 43. The motor terminal connection portion 64, the inverter circuit 62, the filter 68, the power supply terminal connection portion 65, and the ground terminal connection portion 66 are provided in positions that are symmetrical with respect to the motor terminal connection portion 54, the inverter circuit 52, the filter 58, the power supply terminal connection portion 55, and the ground terminal connection portion 56 in the first area A1, with the boundary line BL being the axis of symmetry.

[0059] The motor terminal connection portion 64 is inclined along the oblique side 43B of the substrate 43. The motor terminal connection portion 64 is also inclined with respect to the boundary line BL. The three motor terminals 36B of the second system connected to the motor terminal connection portion 64 are arranged at an incline along the motor terminal connection portion 64. The angle θ2 between the boundary line BL and a straight line NL2 that is perpendicular to the arrangement direction of the three motor terminals 36B and passes through the axis O of the motor 12 is set to an acute angle that is an angle less than 90°. The angle θ2 is set to the same angle as the above angle θ1. However, the angle θ2 may be set to an angle different from the angle θ1. The angle between the two straight lines NL1 and NL2 is set to an angle less than 180°. Preferably, the three motor terminals 36B are arranged so that the straight line NL2 passes through the center of the terminal located in the middle among the three motor terminals 36B. When the three motor terminals 36B are arranged in an arc shape along the inner surface of the cylindrical portion of the case 21, the arrangement direction of the three motor terminals 36B is the direction connecting the terminals at both ends.

[0060] The inverter circuit 62 is located inside the motor terminal connection part 64 when viewed from the direction along the axis O of the motor 12. The inside of the motor terminal connection part 64 refers to the side toward the axis O, which is the center of the motor 12, with the motor terminal connection part 64 as a reference when viewed from the direction along the axis O of the motor 12. The legs of each of the three phases in the inverter circuit 62, more specifically, the three FETs 63 on the power supply side and the three FETs 63 on the ground side are aligned along the extension direction of the motor terminal connection part 64, that is, along the alignment direction of the three motor terminals 36B. In the inverter circuit 62, the ground side FET 63 is located on the motor terminal connection part 64 side, and the power supply side FET 63 is located on the opposite side of the motor terminal connection part 64 with the ground side FET 63 as a reference.

[0061] The current path between the power supply terminal connection portion 65 and each motor terminal 36B is set based on the viewpoint of connecting the power supply terminal connection portion 65 and each motor terminal 36B with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. In addition, the current path between the ground terminal connection portion 66 and each FET 63 on the ground side of the inverter circuit 62 is also set based on the viewpoint of connecting the ground terminal connection portion 66 and each FET 63 on the ground side with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43.

[0062] Next, a comparative example of the layout of the substrate 43 will be described with reference to this embodiment. In the comparative example, the two motor terminal connection parts 54, 64 are provided at positions that are symmetrical with respect to the boundary line BL. However, the two motor terminal connection parts 54, 64 are located on opposite sides of the axis O of the motor 12 in the direction along the straight line NL.

[0063] As shown in Fig. 5, the current path from the power supply terminal connection part 55 to the motor terminal connection part 54 in the first system is bent in an L shape. The inverter circuit 52 and the motor terminal connection part 54 are aligned in a direction perpendicular to the boundary line BL. The inverter circuit 52 is provided at a position closer to the boundary line BL than the motor terminal connection part 54 in the direction perpendicular to the boundary line BL. The power supply terminal connection part 55 is provided at a position closer to the boundary line BL than the inverter circuit 52 in the direction perpendicular to the boundary line BL. The power supply terminal connection part 55 is provided on the side of the inverter circuit 52 (to the right in Fig. 5) in the direction along the boundary line BL.

[0064] When this layout is adopted, the current path from the power supply terminal connection part 55 to the leg of each phase of the inverter circuit 52 is provided so as to bend, for example, from a direction along the boundary line BL to a direction perpendicular to the boundary line BL. In this case, the current path CP from the power supply terminal connection part 55 to the leg of each phase of the inverter circuit 52 (the FET 53 on the power supply side) branches into three current paths CP1, CP2, and CP3 along the way. The current path CP1 is the current path closest to the power supply terminal connection part 55 in the direction along the boundary line BL. The current path CP2 is the current path farthest from the power supply terminal connection part 55 in the direction along the boundary line BL. The current path CP3 is a current path located between the current path CP1 and the current path CP2 in the direction along the boundary line BL.

[0065] Therefore, in the direction along the boundary line BL, a difference in the length of the current path occurs between current path CP1 passing through the side closer to power supply terminal connection portion 55 and current path CP2 or current path CP3 passing through the side farther from power supply terminal connection portion 55. Also, a difference in the length of the current path occurs between current path CP2 passing through the side closer to power supply terminal connection portion 55 and current path CP3 passing through the side farther from power supply terminal connection portion 55.

[0066] Incidentally, as with the first system, a difference occurs in the length of the current path from the power supply terminal connection part 65 to the legs of each phase (the power supply side FETs 63) of the inverter circuit 62 in the second system between the current path passing through the side closer to the power supply terminal connection part 65 and the current path passing through the side farther from the power supply terminal connection part 65. Also, a difference occurs in the length of the current path between each ground side FET 53 and the ground terminal connection part 56 in the first system, and the length of the current path between each ground side FET 63 and the ground terminal connection part 66 in the second system.

[0067] The difference in the lengths of the three-phase current paths causes a difference in the electrical resistance of the three-phase current paths. This difference in electrical resistance in the three-phase current paths is one of the causes of torque ripple in the motor 12.

[0068] Therefore, in this embodiment, the following layout is adopted as the layout of the board 43. As shown in FIG. 6, in the first area A1 of the substrate 43, the motor terminal connection portion 54, the inverter circuit 52, the filter 58, and the power supply terminal connection portion 55 are arranged in this order along the boundary line BL. The direction in which the motor terminal connection portion 54 and the inverter circuit 52 are arranged side by side is inclined with respect to the boundary line BL. The inverter circuit 52 is provided at a position closer to the boundary line BL than the motor terminal connection portion 54 in a direction perpendicular to the boundary line BL. The filter 58 and the power supply terminal connection portion 55 are provided on the side of the inverter circuit 52 in the direction along the boundary line BL. By arranging the motor terminal connection portion 54 and the inverter circuit 52 so that the arrangement direction is inclined with respect to the boundary line BL, it is possible to make the motor terminal connection portion 54, the inverter circuit 52, the filter 58, and the power supply terminal connection portion 55 closer to a state in which they are arranged in a line along the boundary line BL.

[0069] The current path between the power supply terminal connection part 55 and each motor terminal 36A is set based on the viewpoint of connecting the power supply terminal connection part 55 and each motor terminal 36A with a path that is as straight or as close to straight as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. The current path CP from the power supply terminal connection part 55 to the leg of each phase (the FET 53 on the power supply side) of the inverter circuit 52 is provided so as to bend from the direction along the boundary line BL toward the direction intersecting with the boundary line BL in accordance with the degree of inclination of the inverter circuit 52.

[0070] A current path CP from the power supply terminal connection part 55 to the leg of each phase of the inverter circuit 52 branches into three current paths CP11, CP12, and CP13, starting from a power supply branch point BP for the leg of each phase. Current path CP11 is the current path farthest from the boundary line BL. Current path CP12 is the current path closest to the boundary line BL. Current path CP13 is a current path located between current path CP11 and current path CP12. Each of these three current paths CP11, CP12, and CP13 is a single path, and it is desirable that the path be as straight as possible. A filter 58 is arranged between the power supply terminal connection part 55 and the power supply branch point BP in the current path CP.

[0071] 6, for ease of explanation, the motor terminals 36A of each phase connected to the motor terminal connection portion 54 and the legs of the inverter circuit 52 for each phase correspond to each other in the arrangement direction of the motor terminals 36A of each phase. Three current paths from the legs of each phase to the motor terminals 36A of each phase are provided linearly. Furthermore, the lengths of the three current paths from the inverter circuit 52 to the motor terminals 36A of each phase at the motor terminal connection portion 54 are set to be approximately the same.

[0072] Therefore, by providing the motor terminal connection part 54 and the inverter circuit 52 at an incline with respect to the boundary line BL, the motor terminal connection part 54, the inverter circuit 52, the filter 58, and the power supply terminal connection part 55 approach a state of being aligned in a line along the boundary line BL. Therefore, compared with the L-shaped current path of the comparative example shown in FIG. 5, the degree of bending of the current path from the power supply terminal connection part 55 to the legs of each phase of the inverter circuit 52 becomes gentler by the amount of the inclination of the motor terminal connection part 54 and the inverter circuit 52 at an acute angle. In addition, by providing the current path between each motor terminal 36A and the power supply branch point BP from the viewpoint of approaching a straight line, the difference in the length of the current path between each motor terminal 36A and the power supply branch point BP for each phase leg becomes smaller. In addition, the difference in the total length of the current path from the power supply terminal connection part 55 to the motor terminal 36A of each phase becomes smaller.

[0073] Incidentally, when the motor terminals 36A of each phase and the legs of the inverter circuit 52 are arranged to be shifted from each other in the arrangement direction of the motor terminals 36A of each phase, the current paths between the motor terminals 36A of each phase and the power feed branch point BP are provided as follows. That is, the current paths between the motor terminals 36A of each phase and the power feed branch point BP are provided based on the viewpoint of connecting the motor terminals 36A of each phase and the power feed branch point BP with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the board 43. In this way, the difference in length of the current paths between the motor terminals 36A and the power feed branch point BP for the legs of the inverter circuit 52 of each phase can be made smaller.

[0074] Although not shown in the drawings, the current paths between the ground terminal connection portion 56 and each of the FETs 53 on the ground side of the inverter circuit 52 are set based on the viewpoint of connecting the ground terminal connection portion 56 and each of the FETs 53 on the ground side with a path that is as straight or as close to straight as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. This makes it possible to further reduce the difference in the length of the current paths between the ground terminal connection portion 56 and each of the FETs 53 on the ground side of the inverter circuit 52.

[0075] The current paths in the second system from the power supply terminal connection part 65 to the legs of each phase of the inverter circuit 62 are similar to those in the first system. That is, by providing the current paths between each motor terminal 36B and the power supply branch point BP with a view to making them closer to a straight line, the difference in the length of the current paths between each motor terminal 36B and the power supply branch point BP for the legs of each phase of the inverter circuit 62 becomes smaller. As a result, the difference in the total length of the current paths from the power supply terminal connection part 65 to the motor terminals 36B of each phase becomes smaller.

[0076] Moreover, the current paths between the ground terminal connection portion 66 and each of the FETs 63 on the ground side of the inverter circuit 62 are set based on the viewpoint of connecting the ground terminal connection portion 66 and each of the FETs 63 on the ground side with a path that is as straight or as close to straight as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. This makes it possible to further reduce the difference in the length of the current paths between the ground terminal connection portion 66 and each of the FETs 63 on the ground side of the inverter circuit 62.

[0077] Therefore, according to the first embodiment, the following effects can be obtained. (1) The difference in the length of the current path between the motor terminal 36A of each phase in the first system and the power supply branch point BP for the leg of each phase of the inverter circuit 52, and therefore the difference in the total length of the current path from the power supply terminal connection part 55 to the motor terminal 36A of each phase, is reduced. Therefore, the difference in the electrical resistance from the power supply terminal connection part 55 to the motor terminal 36A of each phase is also reduced. That is, the electrical resistance from the power supply terminal connection part 55 to the motor terminal 36A of each phase is made more uniform. The second system is similar to the first system. Therefore, the torque ripple, which is the amount of fluctuation in the torque generated by the motor 12, is reduced.

[0078] (2) The motor terminal connection portion 54 of the first system is provided along the oblique side 43A of the substrate 43. Therefore, by providing the motor terminal connection portion 54 closer to the oblique side 43A of the substrate 43, it is possible to reduce the dead space on the substrate 43. It is also possible to further shorten the length in the direction along the boundary line BL that extends along the long side of the substrate 43.

[0079] <Second embodiment> Next, a second embodiment of the motor control device will be described. This embodiment basically has the same configuration as the first embodiment shown in Figs.

[0080] 8, the motor 12 has windings 34 numbered 1 to 12. The windings 34 numbered 1, 2, 5, 6, 9, and 10 constitute a first winding group 34A. The windings 34 numbered 3, 4, 7, 8, 11, and 12 constitute a second winding group 34B. Each winding 34 is connected to a motor terminal 36A, 36B of each phase via a bus bar 36 of each phase in the bus bar module 24.

[0081] In the motor 12, a so-called double winding is used as the winding 34. A double winding is a winding in which two adjacent windings 34, 34 in the circumferential direction of the core 31 of the motor 12 are connected in series. In Fig. 8, "x" indicates the end of each winding 34, and "black circles" indicate the connection points between each winding 34 and the busbar 36 of each phase.

[0082] Next, a method for connecting the first winding group 34A will be described. A first end of the first winding 34 is connected to a U-phase (U1) motor terminal 36A of the first system via a bus bar 36. A second end of the first winding 34 is connected to a first end of the second winding 34. A second end of the second winding 34 is connected to a W-phase (W1) motor terminal 36A of the first system via a bus bar 36.

[0083] A first end of the fifth winding 34 is connected to a V-phase (V1) motor terminal 36A of the first system via a bus bar 36. A second end of the fifth winding 34 is connected to a first end of the sixth winding 34. A second end of the sixth winding 34 is connected to a U-phase (U1) motor terminal 36A of the first system via a bus bar 36.

[0084] A first end of the 9th winding 34 is connected to a W-phase (W1) motor terminal 36A of the first system via a bus bar 36. A second end of the 9th winding 34 is connected to a first end of the 10th winding 34. A second end of the 10th winding 34 is connected to a V-phase (V1) motor terminal 36A of the first system via a bus bar 36.

[0085] Next, a method for connecting the second winding group 34B will be described. A first end of the third winding 34 is connected to a V-phase (V2) motor terminal 36B of the second system via the bus bar 36. A second end of the third winding 34 is connected to a first end of the fourth winding 34. A second end of the fourth winding 34 is connected to a W-phase (W2) motor terminal 36B of the second system via the bus bar 36.

[0086] A first end of the seventh winding 34 is connected to a W-phase (W2) motor terminal 36B of the second system via the bus bar 36. A second end of the seventh winding 34 is connected to a first end of the eighth winding 34. A second end of the eighth winding 34 is connected to a U-phase (U2) motor terminal 36B of the second system via the bus bar 36.

[0087] A first end of the 11th winding 34 is connected to a U-phase (U2) motor terminal 36B of the second system via the bus bar 36. A second end of the 11th winding 34 is connected to a first end of the 12th winding 34. A second end of the 12th winding 34 is connected to a V-phase (V2) motor terminal 36B of the second system via the bus bar 36.

[0088] In this manner, a so-called double winding is used as the winding 34 of the motor 12, in which two adjacent windings 34, 34 are connected in series in the circumferential direction of the core 31. This makes it possible to reduce the number of connections between each winding 34 of the motor 12 and the bus bars 36 of each phase.

[0089] For example, when a single coil is used as the windings 34 of the motor 12, there will be a total of 24 connections between each winding 34 and each bus bar 36, as shown by the black circles in Fig. 9. This is because the two ends of each single coil must be connected to the bus bar 36. In contrast, when a double coil is used as the windings 34 of the motor 12, there will be a total of 12 connections between each winding 34 and each bus bar 36, as shown by the black circles in Fig. 7. In other words, when a double coil is used, the number of connections between each winding 34 and each bus bar 36 is half that when a single coil is used.

[0090] Therefore, according to the second embodiment, the following effects can be obtained. (3) A double winding is used as the winding 34 of the motor 12. This allows for a reduction in the number of connections between each winding 34 of the motor 12 and each bus bar 36, compared to when a single winding is used as the winding 34 of the motor 12. This improves the freedom of installation of the motor terminals 36A, 36B. This also improves the freedom of arrangement of the motor terminal connection parts 54, 64. This makes it easier to provide the motor terminal connection parts 54, 64 at an angle with respect to the boundary line BL.

[0091] (4) Furthermore, as shown by the dashed line in Fig. 9, when a single winding is used as the winding 34 of the motor 12, the distance over which the ends of the winding 34 are routed becomes longer, and there is a risk that the ends of the winding 34 may cross over. In this regard, when a double winding is used as the winding 34 of the motor 12, the number of connection points between each winding 34 of the motor 12 and each bus bar 36 is reduced, thereby improving the degree of freedom in arranging the motor terminal connection parts 54, 64. For this reason, the ends of the winding 34 are prevented from crossing over as shown in Fig. 7. This ensures the insulation performance of the motor 12.

[0092] <Third embodiment> Next, a motor control device according to a third embodiment will be described. This embodiment differs from the first embodiment in the layout of the components provided on the substrate 43.

[0093] 10, as in the first embodiment, the substrate 43 is shaped like a hexagonal plate with oblique sides 43A, 43B at two corners of a rectangle when viewed in a direction along the axis O of the motor 12. The substrate 43 is divided into a first area A1 and a second area A2 by a boundary line BL. The boundary line BL extends along the long side of the substrate 43. When viewed in a direction along the axis O of the motor 12, the boundary line BL passes through the axis O, which is the center of the motor 12.

[0094] The first area A1 of the substrate 43 is provided with a motor terminal connection 54, an inverter circuit 52, a filter 58, a power terminal connection 55, and a ground terminal connection 56. The motor terminal connection 54, the inverter circuit 52, the filter 58, the power terminal connection 55, and the ground terminal connection 56 are located in a region on the second end side (the right side in FIG. 10) based on a straight line NL that is perpendicular to the boundary line BL and passes through the axis O of the motor 12. The motor terminal connection 54, the inverter circuit 52, the filter 58, the power terminal connection 55, and the ground terminal connection 56 are arranged in this order from the first end to the second end. Incidentally, the first end is the end on the side where the oblique side 43A of the substrate 43 is provided. The second end is the end opposite to the first end in the direction along the boundary line BL of the substrate 43.

[0095] The inverter circuit 52 is located outside the motor terminal connection part 54 when viewed from the direction along the axis O of the motor 12. The outside of the motor terminal connection part 54 refers to the side away from the axis O, which is the center of the motor 12, with the motor terminal connection part 54 as the reference when viewed from the direction along the axis O of the motor 12. Although not shown in the figure, in the inverter circuit 52, the ground side FET 53 is located on the motor terminal connection part 54 side, and the power supply side FET 53 is located on the opposite side to the motor terminal connection part 54 with the ground side FET 53 as the reference.

[0096] The motor terminal connection part 54 is inclined along a tangent direction to the contour of the motor 12 shown by a two-dot chain line in FIG. 10 when viewed from the direction along the axis O of the motor 12. The three motor terminals 36A of the first system connected to the motor terminal connection part 54 are arranged at an incline along a tangent direction to the contour of the motor 12. An angle θ1 between a line NL1 that is perpendicular to the arrangement direction of the three motor terminals 36A and passes through the axis O of the motor 12 and a boundary line BL is set to an acute angle that is less than 90°. Desirably, the three motor terminals 36B are arranged so that the line NL1 passes through the center of the central terminal among the three motor terminals 36B. Incidentally, although not shown in the figure, the three FETs 53 on the power supply side and the three FETs 53 on the ground side (legs of each of the three phases) in the inverter circuit 52 are arranged at an incline along the extension direction of the motor terminal connection part 54, i.e., the tangent direction to the contour of the motor 12.

[0097] The power supply terminal connection portion 55 and the ground terminal connection portion 56 are provided near the second end portion of the substrate 43. The power supply terminal connection portion 55 and the ground terminal connection portion 56 are aligned along the short side of the substrate 43. The ground terminal connection portion 56 is provided at a position closer to the boundary line BL than the power supply terminal connection portion 55.

[0098] The current path between the power supply terminal connection portion 55 and each motor terminal 36A is set based on the viewpoint of connecting the power supply terminal connection portion 55 and each motor terminal 36A with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. In addition, the current path between the ground terminal connection portion 56 and each FET 53 on the ground side of the inverter circuit 52 is also set based on the viewpoint of connecting the ground terminal connection portion 56 and each FET 53 on the ground side with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43.

[0099] A motor terminal connection portion 64, an inverter circuit 62, a filter 68, a power supply terminal connection portion 65, and a ground terminal connection portion 66 are provided in the second area A2 of the substrate 43. The motor terminal connection portion 64, the inverter circuit 62, the filter 68, the power supply terminal connection portion 65, and the ground terminal connection portion 66 are provided in positions that are symmetrical with respect to the motor terminal connection portion 54, the inverter circuit 52, the power supply terminal connection portion 55, and the ground terminal connection portion 56 in the first area A1, with the boundary line BL being the axis of symmetry.

[0100] The motor terminal connection part 64 is inclined along a tangent direction to the contour of the motor 12 shown by a two-dot chain line in FIG. 10 when viewed from the direction along the axis O of the motor 12. The three motor terminals 36B of the second system connected to the motor terminal connection part 64 are arranged at an incline along a tangent direction to the contour of the motor 12. The angle θ2 between the boundary line BL and a straight line NL2 that is perpendicular to the arrangement direction of the three motor terminals 36B and passes through the axis O of the motor 12 is set to an acute angle that is an angle less than 90°. The angle θ2 is set to the same angle as the above angle θ1. However, the angle θ2 may be set to an angle different from the angle θ1. The angle between the two straight lines NL1 and NL2 is set to an angle less than 180°. Preferably, the three motor terminals 36B are arranged so that the straight line NL2 passes through the center of the central terminal among the three motor terminals 36B. Incidentally, although not shown in the figure, the three FETs 63 on the power supply side of the inverter circuit 62 and the three FETs 63 on the ground side (legs for each of the three phases) are arranged at an angle along the extension direction of the motor terminal connection portion 64, i.e., the tangent direction to the contour of the motor 12.

[0101] The power supply terminal connection portion 65 and the ground terminal connection portion 66 are provided near a second end portion of the substrate 43. The power supply terminal connection portion 65 and the ground terminal connection portion 66 are aligned along the short side of the substrate 43. The ground terminal connection portion 66 is provided at a position closer to the boundary line BL than the power supply terminal connection portion 65.

[0102] The current path between the power supply terminal connection portion 65 and each motor terminal 36B is set based on the viewpoint of connecting the power supply terminal connection portion 65 and each motor terminal 36B with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. In addition, the current path between the ground terminal connection portion 66 and each FET 63 on the ground side of the inverter circuit 62 is also set based on the viewpoint of connecting the ground terminal connection portion 66 and each FET 63 on the ground side with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43.

[0103] As shown in FIG. 11, in the first area A1 of the substrate 43, the motor terminal connection portion 54, the inverter circuit 52, the filter 58, and the power supply terminal connection portion 55 are arranged in this order along the boundary line BL. The direction in which the motor terminal connection portion 54 and the inverter circuit 52 are arranged side by side is inclined with respect to the boundary line BL. This makes it possible to approximate a state in which the motor terminal connection portion 54, the inverter circuit 52, the filter 58, and the power supply terminal connection portion 55 are arranged in a line along the boundary line BL. The motor terminal connection portion 54 is provided at a position closer to the boundary line BL than the inverter circuit 52 in a direction perpendicular to the boundary line BL. The power supply terminal connection portion 55 is provided on the side of the inverter circuit 52 (to the right in FIG. 11) in the direction along the boundary line BL.

[0104] The current path between the power supply terminal connection part 55 and each motor terminal 36A is set based on the viewpoint of connecting the power supply terminal connection part 55 and each motor terminal 36A with a path that is as straight or as close to straight as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. The current path CP from the power supply terminal connection part 55 to the leg of each phase (the FET 53 on the power supply side) of the inverter circuit 52 is provided so as to bend from the direction along the boundary line BL toward the direction intersecting with the boundary line BL in accordance with the degree of inclination of the inverter circuit 52.

[0105] A current path CP from the power supply terminal connection part 55 to the leg of each phase of the inverter circuit 52 branches into three current paths CP11, CP12, and CP13, starting from a power supply branch point BP for the leg of each phase. Current path CP11 is the current path farthest from the boundary line BL. Current path CP12 is the current path closest to the boundary line BL. Current path CP13 is a current path located between current path CP11 and current path CP12. Each of these three current paths CP11, CP12, and CP13 is a single path, and it is desirable that the path be as straight as possible.

[0106] 11, for ease of explanation, the motor terminals 36A of each phase connected to the motor terminal connection portion 54 and the legs of the inverter circuit 52 for each phase correspond to each other in the arrangement direction of the motor terminals 36A of each phase. Three current paths from the legs of each phase to the motor terminals 36A of each phase are provided linearly. Furthermore, the lengths of the three current paths from the inverter circuit 52 to the motor terminals 36A of each phase at the motor terminal connection portion 54 are set to be the same.

[0107] Therefore, by providing the motor terminal connection part 54 and the inverter circuit 52 at an incline with respect to the boundary line BL, the motor terminal connection part 54, the inverter circuit 52, the filter 58, and the power supply terminal connection part 55 are closer to being aligned in a line along the boundary line BL. Therefore, compared to the L-shaped current path of the comparative example shown in FIG. 5, the degree of bending of the current path from the power supply terminal connection part 55 to the legs of each phase of the inverter circuit 52 is more gentle by the amount that the inverter circuit 52 is inclined at an acute angle. In addition, by providing the current path between each motor terminal 36A and the power supply branch point BP from the viewpoint of making it closer to a straight line, the difference in the length of the current path between each motor terminal 36A and the power supply branch point BP for each phase leg is smaller. In addition, the difference in the total length of the current path from the power supply terminal connection part 55 to the motor terminal 36A of each phase is smaller.

[0108] Incidentally, when the motor terminals 36A of each phase and the legs of the inverter circuit 52 are arranged to be shifted from each other in the arrangement direction of the motor terminals 36A of each phase, the current paths between the motor terminals 36A of each phase and the power feed branch point BP are provided as follows. That is, the current paths between the motor terminals 36A of each phase and the power feed branch point BP are provided based on the viewpoint of connecting the motor terminals 36A of each phase and the power feed branch point BP with a path that is as straight or as close to a straight line as possible within the range allowed from the viewpoint of the configuration layout of the board 43. In this way, the difference in length of the current paths between the motor terminals 36A and the power feed branch point BP for the legs of the inverter circuit 52 of each phase can be made smaller.

[0109] Although not shown in the drawings, the current paths between the ground terminal connection portion 56 and each of the FETs 53 on the ground side of the inverter circuit 52 are set based on the viewpoint of connecting the ground terminal connection portion 56 and each of the FETs 53 on the ground side with a path that is as straight or as close to straight as possible within the range allowed from the viewpoint of the configuration layout of the substrate 43. This makes it possible to further reduce the difference in the length of the current paths between the ground terminal connection portion 56 and each of the FETs 53 on the ground side of the inverter circuit 52.

[0110] The current paths between the power supply terminal connection part 65 and each FET 63 on the power supply side of the inverter circuit 62 in the second system are similar to those in the first system. That is, by providing the current paths between each motor terminal 36B and the power supply branch point BP with a view to making them closer to a straight line, the difference in the length of the current paths between each motor terminal 36B and the power supply branch point BP for each phase leg of the inverter circuit 62 becomes smaller. As a result, the difference in the total length of the current paths from the power supply terminal connection part 65 to the motor terminal 36B of each phase becomes smaller.

[0111] The current paths in the second system between the ground terminal connection part 66 and each FET 63 on the ground side of the inverter circuit 62 are also similar to those in the first system. That is, by providing the current paths between the ground terminal connection part 56 and each FET 53 on the ground side of the inverter circuit 62 with a view to making them closer to a straight line, the difference in length of the current paths between the ground terminal connection part 56 and each FET 53 on the ground side becomes smaller.

[0112] Therefore, according to the third embodiment, it is possible to obtain the same effect as that of the first embodiment (1). Depending on the product specifications, the layout of the board 43 may be the layout of the third embodiment shown in FIG.

[0113] <Fourth embodiment> Next, a fourth embodiment of the motor control device will be described. This embodiment basically has the same configuration as the first embodiment shown in Figures 1 to 4. However, this embodiment differs from the first embodiment mainly in that the two boards 42 and 43 are integrated into a single board.

[0114] As shown in FIG. 12, the motor device 11 has a motor 12 and a control device 13. The control device 13 has a single board 71 and a cover 44. The board 71 has the functions of both of the two boards 42, 43 in the first embodiment. The board 71 has an outer shape similar to the two boards 42, 43 when viewed from the direction along the axis O of the motor 12. The board 71 is accommodated inside the housing section 21A provided at the end of the case 21 of the motor 12. The housing section 21A has a box shape that opens in the axial direction of the motor 12. The inner shape of the housing section 21A corresponds to the outer shape of the board 71. The lid 22 and the motor terminals 36A, 36B are exposed inside the housing section 21A. The cover 44 is attached to the housing section 21A in a form that covers the opening of the housing section 21A with the board 71 accommodated inside the housing section 21A.

[0115] Motor device 11 has, as components of a first system, a motor terminal connection part 54, an inverter circuit 52, a filter 58, a power supply terminal connection part 55, a ground terminal connection part 56, and a microcomputer 51. Motor device 11 has, as components of a second system, a motor terminal connection part 64, an inverter circuit 62, a filter 68, a power supply terminal connection part 65, a ground terminal connection part 66, and a microcomputer 61. As filters 58 and 68, for example, LC filters formed of an inductor and a capacitor are used.

[0116] 13, as in the first embodiment, the substrate 71 is divided into a first region A1 and a second region A2 by a boundary line BL1 when viewed from the direction along the axis O of the motor 12. The boundary line BL1 extends along the long side of the substrate 71. Moreover, when viewed from the direction along the axis O of the motor 12, the boundary line BL1 passes through the axis O that is the center of the motor 12.

[0117] Each of the first region A1 and the second region A2 is further divided into two regions with the boundary line BL2 as the boundary. That is, the substrate 43 is divided into four regions by the two boundary lines BL1 and BL2 that are perpendicular to each other. The boundary line BL2 extends in a direction perpendicular to the boundary line BL1 when viewed from the direction along the axis O of the motor 12. Moreover, the boundary line BL2 passes through the vicinity of the center of the substrate 71 in the direction along the boundary line BL1 when viewed from the direction along the axis O of the motor 12.

[0118] The first area A1 is divided into a first power circuit area A11 and a first control circuit area A12. The second area A2 is divided into a second power circuit area A21 and a second control circuit area A22. The first power circuit area A11 and the second power circuit area A21 correspond to the motor 12 when viewed in a direction along the axis O of the motor 12. The first control circuit area A12 and the second control circuit area A22 are separated from the motor 12 when viewed in a direction along the axis O of the motor 12.

[0119] The inverter circuit 52 and the microcomputer 51, which are components of the first system, are provided on the surface of the substrate 43 on the motor 12 side. The inverter circuit 52 is provided in the first power circuit area A11 when viewed from the direction along the axis O of the motor 12. Each FET 53 of the inverter circuit 52 is maintained in contact with the lid 22 of the case 21 via heat dissipation grease. The lid 22 is made of a metal material with excellent thermal conductivity, such as aluminum. The lid 22 functions as a bearing holder that holds the bearing 39A and as a heat sink that promotes heat dissipation. The microcomputer 51 is provided in the first control circuit area A12 when viewed from the direction along the axis O of the motor 12.

[0120] The inverter circuit 62 and the microcomputer 61, which are components of the second system, are also provided on the surface of the substrate 43 facing the motor 12. The inverter circuit 62 is provided in the second power circuit area A21 when viewed from the direction along the axis O of the motor 12. Each FET 63 of the inverter circuit 62 is maintained in contact with the lid 22 of the case 21 via heat dissipation grease. The microcomputer 61 is provided in the second control circuit area A22 when viewed from the direction along the axis O of the motor 12.

[0121] The two filters 58, 68 are each provided on the surface of the substrate 71 opposite to the motor 12. The filter 58, which is a component of the first system, is provided in the first power circuit area A11 when viewed from the direction along the axis O of the motor 12. The filter 68, which is a component of the second system, is provided in the second power circuit area A21 when viewed from the direction along the axis O of the motor 12.

[0122] As shown in FIG. 14, the filter 58 of the first system is provided in the current path CP between the power supply terminal connection part 55 and the inverter circuit 52. More specifically, the filter 58 is located between the power supply terminal connection part 55 and the power supply branch point BP in the current path CP. The filter 58 applies a filtering process to the DC power supplied from the power supply terminal connection part 55, thereby removing noise superimposed on the DC power. Although not shown in the figure, the filter 68 of the second system is provided in the current path between the power supply terminal connection part 65 and the inverter circuit 62. The filter 68 applies a filtering process to the DC power supplied from the power supply terminal connection part 65, thereby removing noise superimposed on the DC power.

[0123] 13, the power supply terminal connection portion 55 and the ground terminal connection portion 56 of the first system are provided near the center of the substrate 71. The power supply terminal connection portion 55 and the ground terminal connection portion 56 are provided at one of the four corners formed by the intersection of the two boundary lines BL1 and BL2, which corresponds to the first control circuit area A12. The power supply terminal connection portion 65 and the ground terminal connection portion 66 of the second system are also provided near the center of the substrate 71. The power supply terminal connection portion 65 and the ground terminal connection portion 66 are provided at one of the four corners formed by the intersection of the two boundary lines BL1 and BL2, which corresponds to the second control circuit area A22.

[0124] The two filters 58, 68 are also provided near the center of the substrate 71. The first filter 58 is provided at one of the four corners formed by the intersection of the two boundary lines BL1, BL2, which corresponds to the first power circuit area A11. The second filter 68 is provided at one of the four corners formed by the intersection of the two boundary lines BL1, BL2, which corresponds to the second power circuit area A21. The two filters 58, 68 are provided at positions that are symmetrical to each other with the boundary line BL as an axis of symmetry. The first filter 58 is provided as close to the power supply terminal connection part 55 as possible in the direction along the boundary line BL1 within a range that is permissible from the viewpoint of the configuration layout of the substrate 71. The second filter 68 is provided as close to the power supply terminal connection part 65 as possible in the direction along the boundary line BL1 within a range that is permissible from the viewpoint of the configuration layout of the substrate 71.

[0125] Therefore, according to the fourth embodiment, in addition to the advantages (1) and (2) of the first embodiment, the following advantages can be obtained. (5) The power supply terminal connection portion 55 and the ground terminal connection portion 56 of the first system are provided near the center of the substrate 71. Therefore, for example, the electrical distance between the power supply terminal connection portion 55 and the inverter circuit 52 (the power supply side FET 53) is smaller than when the power supply terminal connection portion 55 is provided near the end of the substrate 71 opposite to the motor terminal connection portion 54 in the direction along the boundary line BL1. Also, the electrical distance between the ground terminal connection portion 56 and the inverter circuit 52 (the ground side FET 53) is smaller. Therefore, the electrical resistance between the power supply terminal connection portion 55 and the inverter circuit 52, and the electrical resistance between the ground terminal connection portion 56 and the inverter circuit 52 are smaller. The same can be said about the second system as about the first system. Therefore, the current is supplied to the motor 12 more suitably. The output of the motor 12 is also improved.

[0126] (6) The filter 58 of the first system is provided on the substrate 71. More specifically, the filter 58 is provided in the vicinity of the power supply terminal connection portion 55 in the current path CP between the power supply terminal connection portion 55 and the inverter circuit 52. This provides the following effects. That is, for example, it is conceivable to adopt a configuration in which the filter 58 is incorporated in the cover 44 as the motor device 11. Compared to the case of adopting this configuration, the electrical distance from the power supply terminal connection portion 55 through the filter 58 to the inverter circuit 52 is shorter. Therefore, the electrical resistance between the power supply terminal connection portion 55 and the inverter circuit 52 is smaller. The same can be said about the second system as about the first system. Therefore, the current is more suitably supplied to the motor 12. The output of the motor 12 is also improved.

[0127] (7) The substrate 71 has four regions, namely, a first power circuit region A11, a second power circuit region A21, and a first control circuit region A12, and a second control circuit region A22. The first power circuit region A11 and the second power circuit region A21 are regions corresponding to the motor 12 when viewed from the axial direction of the motor 12. The power circuit regions (A11, A21) are provided with power system components for supplying power to the motor 12, such as the inverter circuits (52, 62) and the motor terminal connectors (54, 64). The control circuit regions (A12, A22) are regions outside the motor 12 when viewed from the axial direction of the motor 12. The control circuit regions (A12, A22) are provided with inverter circuits, such as the microcomputers (51, 61), and ultimately with a control system configuration for controlling the operation of the motor 12.

[0128] According to this configuration, the power system configuration can be provided closer to the motor 12. Therefore, the motor terminal connection parts 54, 64 and the motor terminals 36A, 36B can be more easily connected. Also, the current path between the inverter circuits 52, 62 and the motor terminals 36A, 36B can be made shorter and simpler. Therefore, the power system configuration and the control system configuration can be arranged more efficiently on a single board 71. This is particularly suitable for a board 71 on which multiple circuits with a larger number of electronic components are provided.

[0129] Incidentally, as shown in FIG. 15, if the positions of the second power circuit area A21 and the second control circuit area A22 are set in the opposite positions to those shown in FIG. 13 in the direction along the boundary line BL1, the following concerns arise. That is, it becomes difficult to provide the configuration of the power system closer to the motor 12. This makes it more difficult to connect the motor terminal connection part 64 and the motor terminal 36B. In addition, the current path between the inverter circuit 62 and the motor terminal 36B may become longer and more complicated. Incidentally, the same concerns arise when the positions of the first power circuit area A11 and the first control circuit area A12 are set in the opposite positions to those shown in FIG. 13 in the direction along the boundary line BL1.

[0130] <Fifth embodiment> Next, a fifth embodiment of the motor control device will be described. As with the fourth embodiment, this embodiment differs from the first embodiment mainly in that the two boards 42, 43 are integrated into a single board 71. This embodiment basically has the same configuration as the fourth embodiment shown in FIG. 12. However, this embodiment differs from the fourth embodiment in the layout of the components provided on the board 71.

[0131] As shown in FIG. 16, the substrate 71 is divided into a first region A1 and a second region A2 with a boundary line BL1 as a boundary when viewed from the direction along the axis O of the motor 12, as in the previous first embodiment. The boundary line BL1 extends along the long side of the substrate 71 and passes through the axis O of the motor 12. The first region A1 and the second region A2 are each further divided into two regions with a boundary line BL2 as a boundary. That is, the substrate 43 is divided into four regions by the two boundary lines BL1 and BL2 that are perpendicular to each other. The boundary line BL2 is perpendicular to the boundary line BL1 when viewed from the direction along the axis O of the motor 12 and passes through the axis O of the motor 12.

[0132] The first area A1 is divided into a first power circuit area A11 and a first control circuit area A12. The second area A2 is divided into a second power circuit area A21 and a second control circuit area A22. The first power circuit area A11 and the second power circuit area A21 protrude to the side of the motor 12 when viewed in a direction along the axis O of the motor 12. The first control circuit area A12 and the second control circuit area A22 generally overlap the motor 12 when viewed in a direction along the axis O of the motor 12.

[0133] As shown in Fig. 16, the layout of the components provided on the substrate 71 is basically the same as that of the third embodiment shown in Fig. 10 and Fig. 11, except for the microcomputers 51 and 61. However, the boundary line BL1 corresponds to the boundary line BL in the third embodiment shown in Fig. 10. The boundary line BL2 corresponds to the straight line NL in the third embodiment shown in Fig. 10.

[0134] The inverter circuit 52 and the microcomputer 51, which are components of the first system, are provided on the surface of the substrate 43 facing the motor 12. The inverter circuit 52 is provided in a first power circuit area A11 when viewed from the direction along the axis O of the motor 12. The microcomputer 51 is provided in a first control circuit area A12 when viewed from the direction along the axis O of the motor 12. The filter 58, which is a component of the first system, is provided on the surface of the substrate 71 opposite to the motor 12. The filter 58 is provided in the first power circuit area A11 when viewed from the direction along the axis O of the motor 12.

[0135] The inverter circuit 62 and the microcomputer 61, which are components of the second system, are also provided on the surface of the substrate 43 facing the motor 12. The inverter circuit 62 is provided in the second power circuit area A21 when viewed from the direction along the axis O of the motor 12. The microcomputer 61 is provided in the second control circuit area A22 when viewed from the direction along the axis O of the motor 12. A filter 68, which is a component of the second system, is provided on the surface of the substrate 71 opposite to the motor 12. The filter 68 is provided in the second power circuit area A21 when viewed from the direction along the axis O of the motor 12.

[0136] Therefore, according to the fifth embodiment, the same effect as that of the first embodiment (1) can be obtained by laying out the components other than the microcomputers 51 and 61 on the board 71 in the same manner as in the third embodiment shown in Figures 10 and 11. Also, depending on the product specifications, the layout of the fifth embodiment shown in Figure 16 can be adopted as the layout of the board 71.

[0137] <Other embodiments> The first to fifth embodiments may be modified as follows. The size of the boards 42, 43, 71 may be changed as appropriate depending on the product specifications. For example, in the first embodiment, the length of the boards 42, 43 in the direction along the boundary line BL may be set to be approximately the same as the length of the short side of the boards 42, 43. In this case, the power supply terminal connection portion 55 and the ground terminal connection portion 56, as well as the power supply terminal connection portion 65 and the ground terminal connection portion 66, are provided closer to the axis O of the motor 12 in the direction along the boundary line BL.

[0138] The substrates 42, 43, and 71 may have a configuration in which the two oblique sides 43A and 43B are omitted. In this case, the substrates 42, 43, and 71 may have a rectangular shape when viewed from the direction along the axis O of the motor 12. Also, the first end of the substrates 42, 43, and 71 where the two oblique sides 43A and 43B were provided may be provided in the shape of an arc surface centered on the axis of the motor 12 when viewed from the direction along the axis O of the motor 12.

[0139] A motor relay may be provided in the current path of each phase between the inverter circuit 52, 62 and the motor terminal connection part 54, 64. The opening and closing of the motor relay is controlled by the microcomputer 51, 61. The motor relay is maintained in the on state during normal operation when no abnormality occurs in the inverter circuit 52, 62. When an abnormality such as an open circuit or a short circuit occurs in the inverter circuit 52, 62, the motor relay is switched from the on state to the off state. When the motor relay is turned off, the current path between the inverter circuit 52, 62 and the motor terminal connection part 54, 64 is interrupted, and the power supply from the inverter circuit 52, 62 to the winding group of the motor 12 is interrupted. Incidentally, a FET (field effect transistor) may be used as the motor relay.

[0140] In each embodiment, the number of connector fittings connected to DC power sources such as batteries (here, two) is the same as the number of systems, but only one may be provided. For example, when only the connector fittings 57 of the first system are provided, the power supply terminal connection portion 65 and the ground terminal connection portion 66 of the second system may be omitted from the boards 43 and 71. In this case, the power supply terminal connection portion 55 of the first system is connected to a power supply branch point for each leg (FET 63 on the power supply side) of the inverter circuit 62 of the second system via a current path provided as a wiring pattern on the boards 43 and 71. Also, the ground terminal connection portion 56 of the first system is connected to a connection branch point for each leg (three FETs 63 on the ground side) of the inverter circuit 62 of the second system via a current path provided as a wiring pattern on the boards 43 and 71. However, even when this configuration is adopted, the current paths between the power supply terminal connection portion 55 and each motor terminal 36B, and the current paths between the ground terminal connection portion 56 and each motor terminal 36B are set based on the viewpoint of making them as close to a straight line as possible within the range allowable from the viewpoint of the configuration layout of the boards 43 and 71.

[0141] In each embodiment, the motor terminal connection portion 54 and the inverter circuit 52 (legs of each of the three phases) of the first system are inclined with respect to the boundary lines BL and BL1, but it is sufficient that at least the motor terminal connection portion 54 is inclined with respect to the boundary lines BL and BL1. Even in this case, it is possible to make the degree of curvature of the current path of each of the three phases from the power supply terminal connection portion 55 through the inverter circuit 52 to the motor terminal 36A more gentle by the amount that the motor terminal connection portion 54 is inclined with respect to the boundary lines BL and BL1. In other words, it is possible to make the current path of each of the three phases between the power supply terminal connection portion 55 and the motor terminal connection portion 54 more linear. Incidentally, it is sufficient that at least the motor terminal connection portion 64 of the second system and the inverter circuit 62 are inclined with respect to the boundary line BL, as in the first system.

[0142] The motor device 11 may be used as a drive source for an electric power steering device, for example. In this case, the motor 12 functions as an assist motor that generates a steering assist force. The control device 13 controls the motor 12 as an assist motor. The motor device 11 may also be used as a drive source for a reaction mechanism or a turning mechanism in a steer-by-wire steering device. In this case, the motor 12 functions as a reaction motor that generates a steering reaction force, or a turning motor that generates a turning force for turning the steered wheels of a vehicle. The control device 13 controls the motor 12 as a reaction motor or a turning motor. Whether the motor device 11 is applied to an electric power steering device or a steer-by-wire steering device, the torque ripple of the motor 12 is reduced by the motor device 11. This makes it possible to suppress the discomfort caused by the torque pulsation felt by the driver through the steering wheel.

[0143] The application of the motor device 11 is not limited to an in-vehicle device, but may also be used as a drive source for a machine tool such as a machining center. [Explanation of symbols]

[0144] 11...Motor device 12…Motor 13...Control device (motor control device) 34A…First winding group 34B…Second winding group 36A, 36B...Motor terminals 43,71…Substrate 51, 61...Microcomputer (control circuit) 52, 62...Inverter circuit 55,65…Power terminal connection 53, 63...FET (switching element) 54,64…Motor terminal connection 58,68…Filter A1: First area A2: Second area A11, A21…Power circuit area A12, A22…Control circuit area BL,BL1…Boundary line BP: Power supply branch point CP, CP11, CP12, CP13...Current path

Claims

1. A motor control device including a board provided at an end of a motor having two systems of winding groups and controlling power supply to the winding groups independently for each system, The substrate has two regions defined by a boundary line passing through the center of the motor as viewed in the axial direction of the motor, and the two regions are each configured to correspond to one of the systems, as follows: a power supply terminal connection portion to which DC power is supplied from an external DC power supply; an inverter circuit for converting DC power supplied from the power supply terminal connection portion into three-phase AC power; a group of connection parts to which three-phase motor terminals are connected, the connection parts being arranged in a row along the periphery of an end of the motor, the connection parts for each of the three phases being arranged in the same position as the motor terminals for each of the three phases, and a motor terminal connection part for supplying three-phase AC power supplied from the inverter circuit to the winding group of a corresponding system, When viewed in the axial direction of the motor, the power supply terminal connection portion, the inverter circuit, and the motor terminal connection portion are arranged in this order along the boundary line, The motor terminal connection portion is arranged so that a straight line perpendicular to an arrangement direction of the motor terminals forms an acute angle with the boundary line.

2. 2. The motor control device according to claim 1, wherein the power supply terminal connection portions, the inverter circuit, and the motor terminal connection portions of each system provided in the two regions are arranged symmetrically about the boundary line as an axis of symmetry when viewed in the axial direction of the motor.

3. 3. The motor control device according to claim 1, wherein the inverter circuit is located inside the motor terminal connection part, on the side toward the center of the motor with the motor terminal connection part as a reference, when viewed in the axial direction of the motor.

4. 3. The motor control device according to claim 1, wherein the inverter circuit is located outside the motor terminal connection portion, on a side away from the center of the motor with respect to the motor terminal connection portion, when viewed in the axial direction of the motor.

5. the inverter circuit has three legs corresponding to three phases, each of which has a power supply side switching element and a ground side switching element connected in series, the three legs being aligned along an extension direction of the motor terminal connection portion, The motor control device according to any one of claims 1 to 4, wherein a current path from the power supply terminal connection portion to the three legs branches into three linear current paths starting from a power supply branch point for the three legs.

6. The substrate is configured such that the power supply terminal connection portion in one of the two regions is omitted, The motor control device according to claim 5 , wherein the power supply terminal connection portion of the other of the two regions is connected to the power supply branch points for the three legs of the inverter circuit in the two regions, respectively.

7. 7. The motor control device according to claim 1, wherein the power supply terminal connection portion is provided toward the center of the substrate when viewed in the axial direction of the motor.

8. 8. The motor control device according to claim 1, wherein a filter is provided in a current path between the power supply terminal connection portion and the inverter circuit on the substrate.

9. The motor control device according to any one of claims 1 to 8, wherein a control circuit for controlling the operation of the inverter circuit is provided in each of the two regions of the substrate as a configuration corresponding to each system.

10. The two regions are divided into a power circuit region that corresponds to the motor in a direction along the boundary line when viewed from the axial direction of the motor, and a control circuit region that is away from the motor, 10. The motor control device according to claim 9, wherein power system components including the motor terminal connection portion and the inverter circuit are provided in the power circuit area, while control system components including the control circuit are provided in the control circuit area.

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