Rotary electrical machine assembly

Abstract

This rotary electrical machine assembly comprises: a rotary electrical machine; an inverter that has a neutral point booster circuit connected to a neutral point of the rotary electrical machine; a rotary electrical machine housing that accommodates the rotary electrical machine; an electrical equipment housing that is fixed to the rotary electrical machine housing on the anti-load side of the rotary electrical machine; and an electrical equipment cover that is attached to the anti-load side of the electrical equipment housing to seal off an opening of the electrical equipment housing, and that forms, together with the electrical equipment housing, an accommodation portion for the inverter. An element of the neutral point booster circuit, and a control board and a voltage terminal of the inverter are attached to the electrical equipment housing. A smoothing capacitor, a semiconductor module, and a gate substrate of the inverter are attached to the electrical equipment cover.

Description

Rotating electric machine assembly

[0001] The present invention relates to a rotating electrical machine assembly.

[0002] In recent years, from the viewpoint of reducing environmental impact, electric vehicles equipped with motors as a power source as an example of rotating electric machines have been developed and popularized. For motors for electric vehicles, in order to improve the ease of assembly of vehicles and to save space, it has been proposed to integrate the motor and an inverter for controlling the motor into a modular rotating electric machine assembly (for example, see Patent Document 1).

[0003] Furthermore, inverters used to control electric vehicles are known to include a neutral point boost circuit that uses a motor coil to boost the voltage connected to an external DC voltage terminal and charge the battery (see, for example, Patent Document 2). Elements of the neutral point boost circuit include, for example, a relay that switches between charging the battery and driving the motor, a boost capacitor, and a charging harness.

[0004] JP 2023-100188 A JP 2012-200139 A

[0005] In this type of rotating electrical machine assembly, the inverter may be divided into an element attached to a first housing facing the motor and an element attached to a second housing that closes the first housing, and these elements may be laid out in the space formed by the first and second housings. If the inverter is to have the function of a neutral point boost circuit, it is necessary to place the element of the neutral point boost circuit inside the housing, but this may result in an increase in the size of the housing.

[0006] The present invention has been made in view of the above circumstances, and has an object to provide a rotating electrical machine assembly to which a neutral point boost circuit is added while suppressing an increase in the size of the housing.

[0007] A rotating electric machine assembly according to one aspect includes a rotating electric machine, an inverter having a neutral point boost circuit connected to a neutral point of the rotating electric machine, a rotating electric machine housing that houses the rotating electric machine, an electrical equipment housing fixed to the rotating electric machine housing on the axially opposite load side of the rotating electric machine, and an electrical equipment cover attached to the opposite load side of the electrical equipment housing to close an opening of the electrical equipment housing and to form an accommodation section for the inverter together with the electrical equipment housing. Elements of the neutral point boost circuit, voltage terminals and a control board for the inverter are attached to the electrical equipment housing. A gate board, semiconductor module and smoothing capacitor for the inverter are attached to the electrical equipment cover.

[0008] In the above aspect, the elements of the neutral point boost circuit may be disposed in the housing portion so as to be offset from the semiconductor module and the smoothing capacitor on a plane perpendicular to the axial direction.

[0009] In the above aspect, the elements of the neutral point boost circuit may be positioned on the electrical housing at a position offset from the control board. Also, the control board may be positioned in the accommodation portion so as to overlap at least a portion of the gate board in a plane perpendicular to the axial direction and be spaced apart from the gate board in the axial direction.

[0010] In one aspect of the above, the elements of the neutral point boost circuit may include a charging terminal to which an external voltage is applied for boosting the neutral point, a charging harness connecting the charging terminal and the neutral point, a relay arranged between the charging terminal and the neutral point for switching between charging the battery and driving the motor, and a boost capacitor connected to one of the charging terminal and the voltage terminal.

[0011] In the above aspect, at least one of the boost capacitor and the relay may be disposed adjacent to the voltage terminal on the electrical component housing.

[0012] In the above-described embodiment, a power supply line may be connected to the AC terminal of the semiconductor module, and a terminal block for connecting the power supply line to the rotating electric machine may be further attached to the electrical housing. Also, the relay may be disposed on the electrical housing between the voltage terminal and the terminal block.

[0013] According to one aspect, it is possible to provide a rotating electrical machine assembly to which a neutral point boost circuit is added while suppressing an increase in the size of the housing.

[0014] The present invention relates to a rotary electric machine assembly, a rotary electric machine assembly including a rotary electric machine housing, a rotary electric machine cover, and a rotary electric machine assembly having a rotary electric machine cover, and a rotary electric machine assembly having a rotary electric machine cover and a rotary electric machine cover.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, in order to make the description easier to understand, structures and elements other than the main parts of the present invention will be described in a simplified or omitted manner. In addition, the same elements will be given the same reference numerals in the drawings. Note that the shapes, dimensions, etc. of each element shown in the drawings are shown schematically and do not represent the actual shapes, dimensions, etc.

[0016] In the following description, the direction parallel to the extension direction of the rotation axis Ax will be referred to as the axial direction, the circumferential direction centered on the rotation axis Ax will be simply referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax will be simply referred to as the radial direction. In the following description, "extending in the axial direction" includes not only extending strictly in the axial direction but also extending in a direction tilted by less than 45° with respect to the axial direction. Furthermore, "extending in the radial direction" includes not only extending strictly in the radial direction, i.e., in a direction perpendicular to the axial direction, but also extending in a direction tilted by less than 45° with respect to the radial direction. Furthermore, "parallel" includes not only strictly parallel but also tilted by an angle of less than 45° relative to each other.

[0017] In addition, in the drawings, an XYZ coordinate system is shown as a three-dimensional Cartesian coordinate system as appropriate. In the XYZ coordinate system, the Z direction is the axial direction. The X direction is a direction perpendicular to the Z direction and corresponds to the depth direction on the paper surface of Fig. 1. The Y direction is a direction perpendicular to both the X direction and the Z direction and corresponds to the up-down direction in Fig. 1.

[0018] Fig. 1 is an axial cross-sectional view showing an example of a rotating electrical machine assembly according to this embodiment. Fig. 2 is a diagram showing an example of a circuit configuration of the rotating electrical machine assembly according to this embodiment. Fig. 3 is a diagram showing an example of an arrangement of circuit elements on the electrical housing side. Fig. 4 is a diagram showing an example of an arrangement of circuit elements on the electrical cover side.

[0019] The rotating electric machine assembly of this embodiment is applied to, for example, a drive unit of an electric vehicle. As shown in Figure 1, the rotating electric machine assembly 1 includes a motor 2, an inverter 3, a motor cover 4a, a motor housing 4b, an electrical component housing 4c, and an electrical component cover 4d. The motor cover 4a, the motor housing 4b, the electrical component housing 4c, and the electrical component cover 4d are all formed by, for example, casting, and together form a housing 4.

[0020] The motor housing 4b is an example of a rotating electric machine housing. The motor housing 4b is a housing that is open on one and the other axial sides (Z direction) and has a cylindrical space inside that can accommodate the motor 2. The opening on one side (left side in FIG. 1 ) of the motor housing 4b, which is the load side of the motor 2, is closed by the motor cover 4a. The opening on the other side (left side in FIG. 1 ), which is the anti-load side of the motor 2, is closed by the electrical equipment housing 4c. As a result, a first housing section 5 that faces the motor housing 4b, motor cover 4a, and electrical equipment housing 4c and accommodates the motor 2 is formed in the rotating electric machine assembly.

[0021] The motor 2 is an example of a rotating electric machine, and is an inner rotor type motor having a rotor 11 , a shaft 12 and a stator 13 .

[0022] A shaft 12 is fitted into the rotor 11 along the rotation axis Ax. The rotor 11 may be any of a magnet-embedded rotor, a surface magnet rotor, a squirrel-cage rotor, a wound rotor, and the like. A stator 13 is arranged concentrically around the outer periphery of the rotor 11 with a small air gap between them. U-phase, V-phase, and W-phase coils (not shown) are wound around the stator 13 with phases shifted in the circumferential direction.

[0023] In the motor 2, the magnetic field of the stator 13 is switched in sequence by controlling the current of the coils of each phase, thereby forming a rotating magnetic field in the stator 13. As a result, the rotor 11 and the shaft 12 rotate about the rotation axis Ax due to the attractive or repulsive force with the magnetic field of the rotor 11.

[0024] The shaft 12 is rotatably supported by a load-side bearing 14a disposed in the motor cover 4a and a counter-load-side bearing 14b disposed on the electrical housing 4c side. One side of the shaft 12, which is the load side, passes through the motor cover 4a and protrudes outward, and is connected to a reduction gear mechanism and a drive shaft (neither of which are shown). A resolver (not shown) that detects the rotation angle of the shaft 12 is attached to the other side, which is the counter-load side, of the shaft 12. The speed on the output side (vehicle speed) can be detected by determining the rotation angle per unit time from the resolver output.

[0025] The electrical housing 4c is a box-shaped enclosure that is open on the other axial side. The electrical housing 4c is attached and fixed to the other side (anti-load side) of the motor housing 4b and also serves to close the opening on the other side of the motor housing 4b.

[0026] The opening on the other side of the electrical housing 4c is closed by an electrical cover 4d. As a result, a second housing portion 6 is formed in the rotating electrical machine assembly 1, facing the electrical housing 4c and the electrical cover 4d and located on the axially opposite load side of the first housing portion 5. The inverter 3 including a neutral point boost circuit is disposed in the second housing portion 6. The second housing portion 6 is separated from the first housing portion 5 by the electrical housing 4c, and the internal atmosphere of the second housing portion 6 is isolated from the internal atmosphere of the first housing portion 5 in which the motor 2 is disposed.

[0027] The inverter 3 is a controller for controlling the motor 2. During power running, the inverter 3 converts DC voltage from a battery (not shown) into AC voltage and supplies it to the coil of the motor 2, and during regeneration, it converts AC from the motor 2 into DC voltage for the battery. In addition, the neutral point boost circuit boosts the voltage connected to the DC voltage terminal using the coil of the motor 2, thereby charging the battery.

[0028] As shown in FIG. 2 , in the rotating electrical machine assembly 1, the motor 2 is housed in the first housing portion 5 facing the motor housing 4b, and the inverter 3 and neutral point boost circuit elements are housed in the second housing portion 6 facing the electrical equipment housing 4c and electrical equipment cover 4d. The second housing portion 6 is also provided with voltage terminals 21P, 21N and a charging terminal 21C. The voltage terminals 21P, 21N are each connected to a battery. An external DC voltage for neutral point boosting is applied to the charging terminal 21C and the voltage terminal 21N.

[0029] The inverter 3 includes a semiconductor module 20 including high-speed switching elements (IGBTs) corresponding to the U, V, and W phases, a gate substrate 22, a smoothing capacitor 23, and a control substrate 24. The gate substrate 22 is connected to the gate terminals of the high-speed switching elements of the semiconductor module 20 and outputs gate signals (on / off command signals) to the gate terminals. The smoothing capacitor 23 and the semiconductor module 20 of the inverter 3 are connected to voltage terminals 21P and 21N, respectively. The semiconductor module 20 supplies the U-, V-, and W-phase AC voltages switched by the IGBTs to the motor 2, respectively.

[0030] The control board 24 controls the operation of the motor 2 and the inverter 3 in response to instructions from an external instruction device (e.g., an ECU, not shown). The control board 24 is connected to the gate board 22 within the second housing portion 6 via inter-board connectors 25a and 25b, and communicates with the instruction device via a communication harness 26 disposed within the second housing portion 6. The control board 24 is also connected to a relay 33 (described below) via a control signal line 27, and receives a signal from a resolver within the first housing portion 5 via a motor harness 28.

[0031] Furthermore, a boost capacitor 31 disposed in the second housing section is connected between the charging terminal 21C and the voltage terminal 21N. Furthermore, the charging terminal 21C is connected to the neutral point of the motor 2 via a charging harness 32 and a relay 33. The relay 33 is disposed in the second housing section 6 and has the function of switching between charging the battery and driving the motor 2. The charging terminal 21C, the boost capacitor 31, the charging harness 32, and the relay 33 are examples of elements of a neutral point boost circuit.

[0032] Here, when motor 2 is being driven, relay 33 is turned off in response to a command from control board 24, and control board 24 controls the switching operation of the IGBTs via inter-board connectors 25a and 25b and gate board 22. As a result, U-phase, V-phase, and W-phase AC voltages are supplied from inverter 3 to the coil of motor 2, driving motor 2 to rotate. On the other hand, when the battery is being charged, relay 33 is turned on in response to a command from control board 24. At this time, inverter 3 uses the coil of motor 2 to boost the external DC voltage connected to charging terminal 21C and voltage terminal 21N, and charges the battery connected to voltage terminals 21P and 21N.

[0033] As shown in FIGS. 3 and 4, the inverter 3 and the elements of the neutral point boost circuit are arranged in the second accommodation section 6 as follows.

[0034] 3, the electrical housing 4c is fitted with voltage terminals 21P, 21N, charging terminal 21C, boost capacitor 31, relay 33, charging harness 32, communication harness 26, control board 24, and terminal block 34. Terminal block 34 is provided to electrically connect U-phase, V-phase, and W-phase output wires (not shown) on the motor 2 side to U-phase, V-phase, and W-phase power supply wires 36 (see FIG. 4) on the semiconductor module 20 side.

[0035] The elements attached to the electrical housing 4c are arranged toward the upper side in Fig. 3. Specifically, the voltage terminals 21P, 21N and the charging terminal 21C are arranged at the upper left side in Fig. 3, and the terminal block 34 is arranged at the upper right side in Fig. 3. The boost capacitor 31 and the relay 33 are arranged adjacent to the voltage terminals 21P, 21N and the charging terminal 21C on the electrical housing 4c. The relay 33 is also arranged between the voltage terminals 21P, 21N and the charging terminal 21C and the terminal block 34 on the electrical housing 4c.

[0036] 3, the control board 24 is disposed below the terminal block 34 and approximately in the middle of the electrical housing 4c. In other words, the elements of the neutral point boost circuit, namely the charging terminal 21C, boost capacitor 31, charging harness 32, and relay 33, are disposed on the electrical housing 4c at positions offset from the control board 24. The control board 24 is provided with an inter-board connector 25a facing the other side. Note that by disposing the control board 24 on the electrical housing 4c side, the wiring length of the motor harness 28 that connects the control board 24 and the resolver can be shortened and the connectivity of the motor harness 28 can be improved during assembly.

[0037] On the other hand, as shown in Fig. 4, the electrical cover 4d is equipped with the smoothing capacitor 23, the gate board 22, the semiconductor module 20, and bus bars 35P and 35N connected to the voltage terminals 21P and 21N, respectively. The smoothing capacitor 23 occupies a relatively large volume compared to the other components. Therefore, the smoothing capacitor 23 on the electrical cover 4d is positioned at a lower position in Fig. 4 to avoid interference with elements on the electrical housing 4c side.

[0038] The gate terminal of the semiconductor module 20 protrudes in the Z direction. A gate substrate 22 is disposed so as to cover the upper portion (Z direction) of the semiconductor module, and the pattern in the gate substrate 22 and the gate terminal of the semiconductor module 20 are connected by soldering. Therefore, in FIG. 4 , the main body of the semiconductor module 20 is hidden by the gate substrate 22 and is almost invisible, with only the vicinity of the DC terminal and the vicinity of the AC terminal of the semiconductor module 20 being visible. A cooler (not shown) is provided on the surface of the semiconductor module 20 opposite the gate substrate 22 side.

[0039] Furthermore, the gate board 22 and semiconductor module 20 on the electrical cover 4d are disposed in a position corresponding to the control board 24 on the electrical housing 4c side. As a result, the control board 24 at least partially overlaps with the gate board 22 and semiconductor module 20 on the XY plane perpendicular to the axial direction, and the control board 24, gate board 22, and semiconductor module 20 are disposed in parallel with a gap in the axial direction within the second accommodating section 6. Furthermore, the gate board 22 is provided with an inter-board connector 25b facing one side at a position corresponding to the inter-board connector 25a of the control board 24. By coupling the opposing inter-board connectors 25a, 25b on the control board 24 and gate board 22, the control board 24 disposed in the electrical housing 4c and the gate board 22 disposed in the electrical cover 4d are electrically connected.

[0040] Therefore, the elements of the neutral point boost circuit, namely the charging terminal 21C, the boost capacitor 31, the charging harness 32, and the relay 33, are positioned within the second storage section 6, offset from the gate substrate 22, the semiconductor module 20, and the smoothing capacitor 23, respectively, on the XY plane perpendicular to the axial direction.

[0041] The AC terminals of the semiconductor module 20 are connected to U-, V-, and W-phase power supply lines 36 arranged at positions corresponding to the terminal block 34 on the electrical housing 4c side. By further connecting the power supply lines 36 to the terminal block 34, voltages of each phase can be supplied from the semiconductor module 20 arranged in the electrical cover 4d to the coil of the motor 2 in the first housing section 5.

[0042] As described above, the rotating electric machine assembly 1 of this embodiment includes the motor 2, the inverter 3 having a neutral point boost circuit connected to the neutral point of the motor 2, the motor housing 4b that accommodates the motor 2, the electrical housing 4c that is fixed to the motor housing 4b on the axially opposite load side of the motor 2, and the electrical cover 4d that is attached to the opposite load side of the electrical housing 4c to close the opening of the electrical housing 4c and, together with the electrical housing 4c, form the second housing section 6 for the inverter 3. The electrical housing 4c is equipped with elements of the neutral point boost circuit, as well as voltage terminals 21P, 21N and a control board 24 of the inverter 3. The electrical cover 4d is also equipped with the gate board 22, semiconductor module 20 and smoothing capacitor 23 of the inverter 3. With the above configuration, the elements of the neutral point boost circuit are arranged on the side of the electrical housing 4c where the gate board 22, semiconductor module 20 and smoothing capacitor 23 are not arranged, allowing the elements of the neutral point boost circuit to be installed in the available space within the second housing section 6. Therefore, in this embodiment, it is possible to provide a rotating electrical machine assembly 1 to which a neutral point boost circuit is added while suppressing an increase in size of the housing 4 .

[0043] Furthermore, according to this embodiment, if a portion for leading out the charging harness 32 is added to the electrical housing 4c, it is possible to reuse the housing 4 of the rotating electrical machine assembly 1 that does not have a neutral point boost circuit almost as is. In this respect, the configuration of this embodiment is also advantageous in that it can reduce the manufacturing cost of the housing 4.

[0044] Furthermore, in the configuration of this embodiment, the elements of the neutral point boost circuit are located in the electrical equipment housing 4c adjacent to the motor housing 4b. This allows the wiring length of the charging harness 32 connecting the charging terminal 21C and the neutral point of the motor 2 to be shorter than when the elements of the neutral point boost circuit are located on the electrical equipment cover 4d side. A shorter wiring length of the charging harness 32 reduces resistance and suppresses a decrease in current during charging, thereby improving charging efficiency.

[0045] The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.

[0046] For example, in the above embodiment, the rotating electric machine is the motor 2, but the rotating electric machine may be a generator. Furthermore, the configuration of the rotating electric machine assembly 1 in the above embodiment is not limited to use in electric vehicles, but may also be applied to rotating electric machines for other purposes.

[0047] In the above embodiment, the control board 24 of the inverter 3 and the gate board 22 are connected by the board-to-board connectors 25a, 25b, but they may be connected by other connecting means such as a harness. In the above embodiment, the shapes and dimensions of the electrical housing 4c and the electrical cover 4d may be changed as needed.

[0048] Furthermore, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0049] DESCRIPTION OF SYMBOLS 1...Rotating electric machine assembly, 2...Motor, 3...Inverter, 4...Motor cover, 4b...Motor housing, 4c...Electrical equipment housing, 4d...Electrical equipment cover, 5...First accommodating section, 6...Second accommodating section, 11...Rotor, 12...Shaft, 13...Stator, 14a, 14b...Bearings, 20...Semiconductor module, 21P, 21N...Voltage terminal, 21C...Charging terminal, 22...Gate board, 23...Smoothing capacitor, 24...Control board, 25a, 25b...Inter-board connector, 26...Communication harness, 27...Control signal line, 28...Motor harness, 31...Boost capacitor, 32...Charging harness, 33...Relay, 34...Terminal block, 35P, 35N...Bus bars, 36...Power supply line

Claims

1. A rotating electric machine assembly comprising: a rotating electric machine; an inverter having a neutral point boost circuit connected to the neutral point of the rotating electric machine; a rotating electric machine housing that accommodates the rotating electric machine; an electrical equipment housing fixed to the rotating electric machine housing on the axial anti-load side of the rotating electric machine; and an electrical equipment cover attached to the anti-load side of the electrical equipment housing to close an opening of the electrical equipment housing and to form an accommodation section for the inverter together with the electrical equipment housing, wherein elements of the neutral point boost circuit and the voltage terminals and control board of the inverter are attached to the electrical equipment housing, and a gate board, semiconductor module and smoothing capacitor of the inverter are attached to the electrical equipment cover.

2. A rotating electric assembly as set forth in claim 1, wherein the elements of the neutral point boost circuit are arranged in the housing section at positions offset from the semiconductor module and the smoothing capacitor on a plane perpendicular to the axial direction.

3. A rotating electric assembly as described in claim 1, wherein elements of the neutral point boost circuit are positioned on the electrical housing at a position offset from the control board, and the control board is positioned within the accommodating section so as to overlap at least a portion of the gate board on a plane perpendicular to the axial direction and to be spaced apart from the gate board in the axial direction.

4. A rotating electric assembly as claimed in any one of claims 1 to 3, wherein the elements of the neutral point boost circuit include: a charging terminal to which an external voltage is applied for boosting the neutral point; a charging harness connecting the charging terminal and the neutral point; a relay arranged between the charging terminal and the neutral point for switching between battery charging operation and motor driving operation; and a boost capacitor connected to the charging terminal and one of the voltage terminals.

5. The rotating electrical machine assembly according to claim 4, wherein at least one of said boost capacitor and said relay is disposed adjacent to said voltage terminal on said electrical equipment housing.

6. A rotating electric machine assembly as described in claim 4, wherein a power supply line is connected to the AC terminal of the semiconductor module, a terminal block for connecting the power supply line and the rotating electric machine is further attached to the electrical housing, and the relay is disposed between the voltage terminal and the terminal block on the electrical housing.

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