Rotary electric machine assembly

Abstract

To provide a rotary electric machine assembly to which a neutral point boost circuit is added while restraining an increase in the size of a housing.SOLUTION: A rotary electric machine assembly includes a rotary electric machine, an inverter having a neutral point boost circuit connected to a neutral point of the rotary electric machine, a rotary electric machine housing that houses the rotary electric machine, an electrical equipment housing to be fixed to the rotary electric machine housing on an anti-load side of the rotary electric machine, and an electrical equipment cover that is attached to the anti-load side of the electrical equipment housing to block the opening portion of the electrical equipment housing and form a storage section for the inverter together with the electrical equipment housing. Elements of the neutral point boost circuit and a voltage terminal and a control board of the inverter are attached to the electrical equipment housing. The gate board, a semiconductor module, and a smoothing capacitor of the inverter are attached to the electrical equipment cover.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] In recent years, from the perspective of reducing environmental impact, the development and popularization of electric vehicles equipped with a motor as a power source, which is an example of a rotating electrical machine, have been progressing. In motors for electric vehicles, in order to improve the vehicle assembly workability and save space, it has been proposed to integrate a motor and an inverter for controlling the motor to form a modularized rotating electrical machine assembly (for example, Patent Document 1, etc.).

[0003] In addition, inverters applied to the control of electric vehicles are known to include a neutral point boost circuit having a function of boosting the voltage connected to an external DC voltage terminal using the coils of the motor to charge the battery (for example, Patent Document 2, etc.). Examples of the elements of the neutral point boost circuit include a relay for switching between the battery charging operation and the motor driving operation, a boost capacitor, and a charging harness.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[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 side and an element attached to a second housing closing the first housing, and may be laid out in the space formed by the first housing and the second housing. When adding the function of a neutral point boosting circuit to the inverter, it is necessary to additionally arrange elements of the neutral point boosting circuit inside the housing, which may lead to an increase in the size of the housing.

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

Means for Solving the Problems

[0007] A rotating electrical machine assembly according to one aspect includes a rotating electrical machine, an inverter having a neutral point boosting circuit connected to the neutral point of the rotating electrical machine, a rotating electrical machine housing that houses the rotating electrical machine, an electrical equipment housing fixed to the rotating electrical machine housing on the anti-load side in the axial direction of the rotating electrical machine, and an electrical equipment cover attached to the anti-load side of the electrical equipment housing to close the opening of the electrical equipment housing and forming a housing portion of the inverter together with the electrical equipment housing. Elements of the neutral point boosting circuit, voltage terminals of the inverter, and a control board are attached to the electrical equipment housing. A gate board, a semiconductor module, and a smoothing capacitor of the inverter are attached to the electrical equipment cover.

[0008] In the above aspect, the elements of the neutral point boosting circuit may be arranged in the housing portion while being displaced in position from the semiconductor module and the smoothing capacitor on a plane orthogonal to the axial direction.

[0009] In the above aspect, the elements of the neutral point boosting circuit may be arranged while being displaced in position from the control board on the electrical equipment housing. Further, the control board may be arranged in the housing portion such that at least a part thereof overlaps with the gate board on a plane orthogonal to the axial direction and is spaced apart from the gate board in the axial direction.

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

[0011] In one aspect described above, at least one of the boosting capacitor and the relay may be disposed at a position adjacent to the voltage terminal on the electrical equipment housing.

[0012] In one aspect described above, 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 and the rotating electrical machine may be further attached to the electrical equipment housing. Also, the relay may be disposed between the voltage terminal and the terminal block on the electrical equipment housing.

Advantages of the Invention

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

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, for the sake of easy understanding, the structures and elements other than the main part of the present invention will be described in a simplified or omitted manner. Also, in the drawings, the same reference numerals are assigned to the same elements. Note that the shapes, dimensions, etc. of the elements shown in the drawings are schematically shown and do not represent actual shapes, dimensions, etc.

[0016] In the following description, the direction parallel to the extension direction of the rotation axis Ax is referred to as the axial direction, the circumferential direction centered on the rotation axis Ax is simply referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax is simply referred to as the radial direction. Also, in the following description, "extending in the axial direction" includes not only the case of strictly extending in the axial direction but also the case of extending in a direction inclined within a range of less than 45° with respect to the axial direction. Also, "extending in the radial direction" includes not only the case of strictly extending in the radial direction, that is, in a direction perpendicular to the axial direction, but also the case of extending in a direction inclined within a range of less than 45° with respect to the radial direction. Also, "parallel" includes not only the case of being strictly parallel but also the case of being inclined at an angle of less than 45° with respect to each other.

[0017] Also, in the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal 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 of 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 vertical direction of FIG. 1.

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

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

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

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

[0022] The shaft 12 is fitted into the rotor 11 along the rotation axis Ax. The rotor 11 may have any configuration, such as an embedded magnet type rotor, a surface magnet type rotor, a cage type rotor, or a wound type rotor. Also, the stator 13 is arranged concentrically with the rotor 11 with a slight air gap between them on the outer periphery of the rotor 11. Coils (not shown) of U phase, V phase, and W phase are wound around the stator 13 with a phase shift in the circumferential direction.

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

[0024] The shaft 12 is rotatably supported by a load-side bearing 14a disposed on the motor cover 4a and a non-load-side bearing 14b disposed on the electrical equipment housing 4c side. Also, one side of the shaft 12, which is the load side, protrudes outside through the motor cover 4a, and a speed reduction mechanism and a drive shaft (both not shown) are connected thereto. Further, a resolver (not shown) for detecting the rotation angle of the shaft 12 is attached to the other side of the shaft 12, which is the non-load side. By obtaining the rotation angle per unit time from the output of the resolver, it becomes possible to detect the speed (vehicle speed) on the output side.

[0025] The electrical equipment housing 4c is a box-shaped housing with an opening on the other axial side. The electrical equipment housing 4c is attached and fixed to the other side (non-load side) of the motor housing 4b and also functions to close the opening on the other side of the motor housing 4b.

[0026] The opening on the other side of the electrical equipment housing 4c is closed by an electrical equipment cover 4d. As a result, a second accommodation portion 6 is formed in the rotating electric machine assembly 1, which faces the electrical equipment housing 4c and the electrical equipment cover 4d and is located on the non-load side in the axial direction of the first accommodation portion 5. An inverter 3 including a neutral point boost circuit is disposed in the second accommodation portion 6. Note that the second accommodation portion 6 is partitioned from the first accommodation portion 5 by the electrical equipment housing 4c, and the internal atmosphere of the second accommodation portion 6 is isolated from the internal atmosphere of the first accommodation portion 5 where the motor 2 is disposed.

[0027] The inverter 3 is a controller for controlling the motor 2. The inverter 3 functions to convert the DC voltage from a battery (not shown) into AC and supply it to the coil of the motor 2 during power running, and to convert the AC from the motor 2 into a DC voltage to the battery during regeneration. Also, the neutral point boost circuit functions to boost the voltage connected to the DC voltage terminal using the coil of the motor 2 and charge the battery.

[0028] In the rotating electric machine assembly 1, as shown in FIG. 2, the motor 2 is housed in the first housing portion 5 facing the motor housing 4b, and the elements of the inverter 3 and the neutral point boosting circuit are housed in the second housing portion 6 facing the electrical equipment housing 4c and the electrical equipment cover 4d. Further, voltage terminals 21P and 21N and a charging terminal 21C are provided in the second housing portion 6. The voltage terminals 21P and 21N are respectively connected to the battery. Also, 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-phase, V-phase, and W-phase, a gate board 22, a smoothing capacitor 23, and a control board 24. The gate board 22 is connected to the gate terminals of the high-speed switching elements of the semiconductor module 20 and outputs a gate signal (on / off command signal) to the gate terminals. The smoothing capacitor 23 and the semiconductor module 20 of the inverter 3 are respectively connected to the voltage terminals 21P and 21N. Then, the semiconductor module 20 supplies the AC voltages of the U-phase, V-phase, and W-phase switched by the IGBTs to the motor 2 respectively.

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

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

[0032] Here, during the driving operation of the motor 2, the relay 33 is in an off state according to an instruction from the control board 24, and the control board 24 controls the switching operation of the IGBT via the board - to - board connectors 25a, 25b and the gate board 22. Thereby, the AC voltages of the U - phase, V - phase, and W - phase are supplied from the inverter 3 to the coils of the motor 2, and the motor 2 rotates and drives. On the other hand, during the charging operation of the battery, the relay 33 is in an on state according to an instruction from the control board 24. At this time, the inverter 3 boosts the external DC voltage connected to the charging terminal 21C and the voltage terminal 21N using the coils of the motor 2, and charges the battery connected to the voltage terminals 21P, 21N.

[0033] Also, as shown in FIGS. 3 and 4, the elements of the inverter 3 and the neutral point boosting circuit are arranged in the second housing portion 6 as follows.

[0034] As shown in FIG. 3, in the electrical equipment housing 4c, the voltage terminals 21P, 21N, the charging terminal 21C, the boosting capacitor 31, the relay 33, the charging harness 32, the communication harness 26, the control board 24, and the terminal block 34 are respectively attached. The terminal block 34 is provided to electrically connect the outgoing lines of the U - phase, V - phase, and W - phase on the motor 2 side (not shown) and the power supply lines 36 of the U - phase, V - phase, and W - phase on the semiconductor module 20 side (see FIG. 4).

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

[0036] Also, in FIG. 3, the control board 24 is arranged at a position approximately in the middle of the electrical equipment housing 4c below the terminal block 34. That is, the charging terminal 21C, the boost capacitor 31, the charging harness 32, and the relay 33, which are elements of the neutral point boost circuit, are arranged on the electrical equipment housing 4c with a displacement from the control board 24. The control board 24 is provided with a board-to-board connector 25a facing the other side. By arranging the control board 24 on the electrical equipment housing 4c side, the wiring length of the motor harness 28 connecting the control board 24 and the resolver can be shortened, and the connectivity of the motor harness 28 during assembly can be improved.

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

[0038] Also, the gate terminal of the semiconductor module 20 protrudes in the Z direction. Further, a gate substrate 22 is arranged so as to cover the upper part (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 hardly visible, hidden by the gate substrate 22, and only the vicinity of the DC terminal and the vicinity of the AC terminal of the semiconductor module 20 are visible. Note that a cooler (not shown) is provided on the surface of the semiconductor module 20 opposite to the gate substrate 22 side.

[0039] Also, the gate substrate 22 and the semiconductor module 20 on the electrical equipment cover 4d are arranged at positions corresponding to the control substrate 24 on the electrical equipment housing 4c side. Thereby, the control substrate 24 overlaps at least partially with the gate substrate 22 and the semiconductor module 20 on the XY plane orthogonal to the axial direction, and in the second housing portion 6, the control substrate 24, the gate substrate 22, and the semiconductor module 20 are arranged in parallel with a space in the axial direction. Further, on the gate substrate 22, an inter-board connector 25b is provided toward one side at a position corresponding to the inter-board connector 25a of the control substrate 24. By coupling the opposing inter-board connectors 25a and 25b in the control substrate 24 and the gate substrate 22, the control substrate 24 arranged in the electrical equipment housing 4c and the gate substrate 22 arranged in the electrical equipment cover 4d are electrically connected.

[0040] Therefore, the charging terminal 21C, the boosting capacitor 31, the charging harness 32, and the relay 33, which are elements of the neutral point boosting circuit, are arranged in the second housing portion 6 with positions shifted from the gate substrate 22, the semiconductor module 20, and the smoothing capacitor 23 respectively on the XY plane orthogonal to the axial direction.

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

[0042] As described above, the rotating electric machine assembly 1 of the present embodiment includes a motor 2, an inverter 3 having a neutral point boosting circuit connected to the neutral point of the motor 2, a motor housing 4b that houses the motor 2, an electrical equipment housing 4c that is fixed to the motor housing 4b on the anti-load side in the axial direction of the motor 2, and an electrical equipment cover 4d that is attached to the anti-load side of the electrical equipment housing 4c to close the opening of the electrical equipment housing 4c and forms the second housing portion 6 of the inverter 3 together with the electrical equipment housing 4c. Elements of the neutral point boosting circuit, voltage terminals 21P and 21N of the inverter 3, and a control board 24 are attached to the electrical equipment housing 4c. Further, a gate board 22, a semiconductor module 20, and a smoothing capacitor 23 of the inverter 3 are attached to the electrical equipment cover 4d. With the above configuration, since the elements of the neutral point boosting circuit are arranged on the side of the electrical equipment housing 4c where the gate board 22, the semiconductor module 20, and the smoothing capacitor 23 are not arranged, the elements of the neutral point boosting circuit can be mounted in the empty space in the second housing portion 6. Therefore, in the present embodiment, it is possible to provide the rotating electric machine assembly 1 with the added neutral point boosting circuit while suppressing an increase in the size of the housing 4.

[0043] Further, according to the present embodiment, if a portion for drawing out the charging harness 32 is added to the electrical equipment housing 4c, it is possible to substantially reuse the housing 4 of the rotating electric machine assembly 1 that does not have a neutral point boosting circuit. In this regard, the configuration of the present embodiment is also advantageous in that it can suppress the manufacturing cost of the housing 4.

[0044] Also, in the configuration of the present embodiment, the elements of the neutral point boosting circuit are arranged in the electrical equipment housing 4c adjacent to the motor housing 4b. Therefore, compared with the case where the elements of the neutral point boosting circuit are arranged on the side of the electrical equipment cover 4d, the wiring length of the charging harness 32 that connects the charging terminal 21C and the neutral point of the motor 2 can be shortened. When the wiring length of the charging harness 32 is shortened, the resistance thereof is reduced accordingly, and a decrease in the current during the charging operation is also suppressed, so that it is possible to improve the efficiency during the charging operation.

[0045] The present invention is not limited to the above-described embodiments, 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 case where the rotating electrical machine is the motor 2 has been described, but the rotating electrical machine may be a generator. Further, the configuration of the rotating electrical machine assembly 1 of the above embodiment is not limited to that for an electric vehicle, and can also be applied to rotating electrical machines for other uses.

[0047] Also, in the above embodiment, the control board 24 and the gate board 22 of the inverter 3 are connected by the inter-board connectors 25a and 25b, but the two may be connected by other connection means such as a harness. Further, in the above embodiment, the shapes and dimensions of the electrical equipment housing 4c and the electrical equipment cover 4d may be appropriately changed as necessary.

[0048] In addition, the embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0049] 1... Rotating electrical machine assembly, 2... Motor, 3... Inverter, 4... Motor cover, 4b... Motor housing, 4c... Electrical equipment housing, 4d... Electrical equipment cover, 5... First housing portion, 6... Second housing portion, 11... Rotor, 12... Shaft, 13... Stator, 14a, 14b... Bearings, 20... Semiconductor module, 21P, 21N... Voltage terminals, 21C... Charging terminal, 22... Gate board, 23... Smoothing capacitor, 24... Control board, 25a, 25b... Inter-board connectors, 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 electrical machine, an inverter having a neutral point boosting circuit connected to the neutral point of the rotating electrical machine, a rotating electrical machine housing that houses the rotating electrical machine, an electrical equipment housing fixed to the rotating electrical machine housing on the anti-load side in the axial direction of the rotating electrical machine, an electrical equipment cover attached to the anti-load side of the electrical equipment housing to close the opening of the electrical equipment housing and forming a housing portion of the inverter together with the electrical equipment housing, the electrical equipment housing has elements of the neutral point boosting circuit, voltage terminals of the inverter, and a control board attached thereto, the electrical equipment cover has a gate board, a semiconductor module, and a smoothing capacitor of the inverter attached thereto Rotating electrical machine assembly.

2. The elements of the neutral point boosting circuit are arranged in the housing portion with their positions shifted from the semiconductor module and the smoothing capacitor on a plane orthogonal to the axial direction. The rotating electrical machine assembly according to Claim 1.

3. The elements of the neutral point boosting circuit are arranged with their positions shifted from the control board on the electrical equipment housing, the control board is arranged in the housing portion with at least a part of it overlapping the gate board on a plane orthogonal to the axial direction and spaced apart from the gate board in the axial direction. The rotating electrical machine assembly according to Claim 1.

4. The elements of the neutral point boosting circuit include a charging terminal to which an external voltage is applied for neutral point boosting, a charging harness connecting the charging terminal and the neutral point, a relay arranged between the charging terminal and the neutral point to switch between the battery charging operation and the motor driving operation, a boosting capacitor connected to one of the charging terminal and the voltage terminal. The rotating electrical machine assembly according to any one of Claims 1 to 3.

5. At least one of the boosting capacitor and the relay is arranged at a position adjacent to the voltage terminal on the electrical equipment housing. The rotating electrical machine assembly according to Claim 4.

6. 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 electrical machine is further attached to the electrical equipment housing, the relay is arranged between the voltage terminal and the terminal block on the electrical equipment housing. The rotating electrical machine assembly according to Claim 4.

Images