Inverter

Abstract

To reduce a size of an inverter disposed in a motor housing.SOLUTION: An inverter disposed inside a motor housing is provided. This inverter includes an electron substrate formed of a plurality of layers orthogonal to a motor shaft and disposed opposite to a motor shaft end part, and a plurality of power semiconductor elements provided on an outer periphery of the electron substrate. The layers of the electron substrate include a first layer having a P pattern and an N pattern, at least one of a P relay pattern connecting to the P pattern and an N relay pattern connecting to the N pattern, and a second layer including a U pattern, a V pattern, and a W pattern connecting to a U phase, a V phase, and a W phase of the motor, respectively. The P pattern is connected to a positive electrode side line and a power semiconductor element directly or through the P relay pattern. The N pattern is connected to a negative electrode side line and the power semiconductor element directly or through the N relay pattern. The P pattern and the N pattern are connected to the U pattern, the V pattern, and the W pattern through the power semiconductor element.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an inverter. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in order to reduce the size of a motor system, a structure in which an inverter is disposed on an end of a motor shaft inside a motor housing is known.

[0003] Patent Document 1 discloses an inverter module in which a multi-phase inverter circuit is disposed on the shaft end of a cylindrical motor. In this inverter module, the inverter circuits for each phase are disposed in the circumferential direction of the motor shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-116840 A Summary of the Invention [Problem to be solved by the invention]

[0005] The inverter module described in Patent Document 1 has a structure in which the bus bars for the U, V, and W phases are taken out from around the motor shaft, and the three bus bars are stacked on top of each other. This requires space for the thickness of the bus bars and the insulation material or insulation distance between the bus bars. In other words, even if the inverter is placed on the end of the motor shaft, the inverter becomes large due to the high-voltage wiring that connects the inverter to each phase of the motor, and there is a risk that the motor system cannot be sufficiently miniaturized.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to reduce the size of an inverter arranged inside a motor housing. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided an inverter connected to a power source and a motor and disposed within a motor housing that accommodates the motor. The inverter includes an electronic board that is made up of multiple layers perpendicular to the motor shaft of the motor and disposed facing an end of the motor shaft of the motor, and multiple power semiconductor elements provided on the outer periphery of the electronic board. The multiple layers of the electronic board include a first layer that includes a P pattern for connecting a positive line of the power source to the power semiconductor elements and an N pattern for connecting a negative line of the power source to the power semiconductor elements, and a second layer that includes at least one of a P relay pattern connected to the P pattern and an N relay pattern connected to the N pattern, and a U pattern, a V pattern, and a W pattern that are respectively connected to the U phase, V phase, and W phase of the motor. The P pattern is connected to the positive side line and to a first terminal of the power semiconductor element constituting the upper arm directly or via a P relay pattern, the N pattern is connected to the negative side line and to a second terminal of the power semiconductor element constituting the lower arm directly or via an N relay pattern, and the P pattern and N pattern are connected to the U pattern, V pattern and W pattern via the second terminal of the power semiconductor element constituting the upper arm and the first terminal of the power semiconductor element constituting the lower arm. Effect of the Invention

[0008] According to the present invention, the multiple layers of the electronic board arranged to face the motor shaft end include a first layer having a P pattern for connecting the positive line of the power supply and the power semiconductor element, and an N pattern for connecting the negative line of the power supply and the power semiconductor element, and a second layer having at least one of a P relay pattern connected to the P pattern and an N relay pattern connected to the N pattern, and a U pattern, a V pattern, and a W pattern connected to the U phase, the V phase, and the W phase of the motor, respectively. In addition, the P pattern and the N pattern are connected to the U pattern, the V pattern, and the W pattern via the second terminal of the power semiconductor element constituting the upper arm and the first terminal of the power semiconductor element constituting the lower arm. In this way, the P pattern and the N pattern are arranged on the first layer of the electronic board, and at least one of the P relay pattern and the N relay pattern, and the U pattern, the V pattern, and the W pattern are arranged on the second layer of the electronic board, so that the space of the electronic board can be effectively utilized to connect wiring vertically within the electronic board. This allows each phase of the motor and the inverter to be connected on two layers of the electronic board, making it possible to reduce the size of the inverter placed inside the motor housing. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a circuit diagram of a motor system including an inverter common to all of the embodiments. [Diagram 2] FIG. 2 is a diagram for explaining the arrangement of the inverters. [Diagram 3] FIG. 3 is a diagram showing a first layer and a second layer of an electronic board. [Figure 4] FIG. 4 is a diagram showing an example of a flow direction when a current flows through an inverter. [Diagram 5] FIG. 5 is a diagram showing an example of a flow direction when a current flows through an inverter. [Figure 6] FIG. 6 is a diagram showing a first layer and a second layer of an electronic substrate in an inverter according to a modified example of the first embodiment. [Figure 7] FIG. 7 is a diagram showing a first layer and a second layer of an electronic board in the second embodiment. [Figure 8]FIG. 8 is a diagram showing an example of a flow direction when a current flows through an inverter. [Figure 9] FIG. 9 is a diagram showing an example of a flow direction when a current flows through an inverter. [Figure 10] FIG. 10 is a diagram showing a first layer and a second layer of an electronic board in the third embodiment. [Figure 11] FIG. 11 is a diagram showing a first layer and a second layer of an electronic substrate in a modified example of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] [First embodiment] 1 is a circuit diagram of a motor system 100 including an inverter 1 common to each embodiment of the present invention. As will be described later, the inverter 1 is disposed in a motor housing 21 that accommodates a motor 2 (FIG. 2).

[0012] As shown in Fig. 1, inverter 1 is connected between power source 3 such as a battery and motor 2 by a high-voltage line, and includes multiple parallel circuits each consisting of power semiconductor elements 11, which are switching elements, and diodes D. A smoothing capacitor 4 is provided in parallel between inverter 1 and power source 3. Inverter 1 performs mutual conversion between DC power and AC power by the switching operation of power semiconductor elements 11.

[0013] The power semiconductor elements 11 are provided between a positive high-voltage line (positive-side line) 31 connected to the positive electrode of the power source 3, and a negative high-voltage line (negative-side line) 32 connected to the negative electrode. The power semiconductor elements 11 include power semiconductor elements 11UP, 11UN connected to the U-phase of the motor 2, power semiconductor elements 11VP, 11VN connected to the V-phase, and power semiconductor elements 11WP, 11WN connected to the W-phase. The power semiconductor elements 11 are configured with two arms, upper and lower, for each phase. That is, the power semiconductor elements 11UP, 11VP, 11WP form an upper arm, and the power semiconductor elements 11UN, 11VN, 11WN form a lower arm.

[0014] In this embodiment, the power semiconductor element 11 is a MOSFET having a drain terminal (first terminal) which is a high potential side terminal, a source terminal (second terminal) which is a low potential side terminal, and a gate terminal (third terminal) which is a control terminal, but is not limited to this and may be, for example, an IGBT, etc. A control signal is input to the gate terminal from a control circuit (not shown), and conduction between the drain terminal and the source terminal is performed or cut off in response to the control signal.

[0015] FIG. 2 is a diagram for explaining the arrangement of the inverter 1, and is a schematic diagram of the motor 2 as viewed from the axial direction.

[0016] As shown in FIG. 2, the inverter 1 is disposed in a motor housing 21 that accommodates the motor 2. The inverter 1 also includes an electronic board 12 made of multiple layers perpendicular to the motor shaft of the motor 2. The electronic board 12 is made of a copper board having a conductive layer made of copper foil several hundred μm thick, but is not limited to this. The electronic board 12 is disposed opposite the motor shaft end of the motor 2. That is, the inverter 1 is disposed on the motor shaft end of the motor 2 within the motor housing 21. In this embodiment, the electronic board 12 has a regular hexagonal shape, but is not limited to this.

[0017] A plurality of power semiconductor elements 11 (11UP, 11VP, 11WP, 11UN, 11VN, 11WN) are arranged on the outer periphery of the electronic board 12. Terminals 151, 161, 171 connected to the U-phase, V-phase, and W-phase of the motor 2 protrude from the outer periphery of the electronic board 12. As will be described later, the electronic board 12 is formed with patterns 13 and 14 connected to the power source 3 and patterns 15, 16, and 17 connected to each phase of the motor 2, and the terminals 151, 161, and 171 form part of the U-pattern 15, V-pattern 16, and W-pattern 17 connected to each phase of the motor 2 (FIG. 3).

[0018] The motor housing 21 has a coolant flow path (not shown) inside through which a coolant such as cooling water flows. The power semiconductor elements 11 (11UP, 11VP, 11WP, 11UN, 11VN, 11WN) arranged on the outer periphery of the electronic board 12 are in contact with the coolant flow path. This allows the power semiconductor elements 11 to be efficiently cooled.

[0019] As described above, the inverter 1 is disposed on the end of the motor shaft inside the motor housing 21. This allows the motor system 100 including the inverter 1 and the motor 2 to be made compact.

[0020] However, even in a structure in which the inverter is placed inside the motor housing, high-voltage wiring is required to connect the inverter and each phase of the motor, which may result in the inverter becoming larger. For example, in a structure in which the inverter is placed on the end of the motor shaft, if the bus bars for the U, V, and W phases are taken out from around the motor shaft and the three bus bars are stacked, space is required for the thickness of the bus bars and the insulating material or insulation distance between the bus bars, making it impossible to make the inverter smaller.

[0021] Therefore, in the inverter 1 of this embodiment, the multiple layers of the electronic board 12 arranged to face the motor shaft end of the motor 2 include a first layer 12A having a P pattern 13 for connecting the positive electrode side line 31 of the power source 3 to the power semiconductor element 11, an N pattern 14 for connecting the negative electrode side line 32 of the power source 3 to the power semiconductor element 11, and a second layer 12B having an N relay pattern 18 connected to the N pattern 14, and a U pattern 15, a V pattern 16, and a W pattern 17 respectively connected to the U phase, V phase, and W phase of the motor 2. The P pattern 13 and the N pattern 14 are connected to the U pattern 15, the V pattern 16, and the W pattern 17 via second terminals (source terminals) of the power semiconductor elements 11UP, 11VP, and 11WP constituting the upper arm and first terminals (drain terminals) of the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm. In this way, the P pattern 13 and the N pattern 14 are arranged on the first layer 12A of the electronic board 12, and the N relay pattern 18, the U pattern 15, the V pattern 16, and the W pattern 17 are arranged on the second layer 12B of the electronic board 12, so that the space of the electronic board 12 can be effectively utilized to connect wiring from above and below within the electronic board 12. This allows each phase of the motor 2 and the inverter 1 to be connected on two layers of the electronic board 12, and the inverter 1 arranged within the motor housing 21 can be made smaller.

[0022] Hereinafter, the arrangement of each pattern formed on the electronic substrate 12 will be described in detail with reference to Fig. 3. The electronic substrate 12 includes a first layer 12A and a second layer 12B.

[0023] FIG. 3 is a top view (view from one side in the axial direction of the motor 2) of the first layer 12A ((a) of FIG. 3) and the second layer 12B ((b) of FIG. 3) of the electronic board 12. As described above, the electronic board 12 is disposed on the motor shaft end of the motor 2 so as to face the motor shaft end of the motor 2, and a plurality of power semiconductor elements 11 (11UP, 11VP, 11WP, 11UN, 11VN, 11WN) are disposed on the outer periphery of the electronic board 12 so as to surround the electronic board 12. In this embodiment, the second layer 12B is disposed on the side closer to the motor 2 (lower layer side) than the first layer 12A, but is not limited to this. In addition, the motor shaft end on the other side in the axial direction of the motor 2 (the side not provided with the electronic board 12) is connected to a gear box (not shown).

[0024] 3(a), a P pattern 13 and an N pattern 14 are formed of copper foil on a first layer 12A of an electronic substrate 12. First to third terminals of a power semiconductor element 11 are placed on the outer periphery of the first layer 12A. The first to third terminals of the power semiconductor element 11 on the outer periphery of the first layer 12A are electrically connected to first to third terminals of the power semiconductor element 11 on the outer periphery of a second layer 12B (described later) by through holes or the like.

[0025] The P pattern 13 is a wiring for electrically connecting the positive line (high voltage line) 31 of the power source 3 and the power semiconductor element 11. The P pattern 13 is connected to the positive line 31 of the power source 3 at a terminal 131. The P pattern 13 is formed from the terminal 131 toward three directions of the power semiconductor elements 11UP, 11VP, and 11WP constituting the upper arm, and is connected to the first terminals (drain terminals) of the power semiconductor elements 11UP, 11VP, and 11WP on the outer periphery of the first layer 12A. In this way, the P pattern 13 is directly connected to the positive line 31 of the power source 3 and the power semiconductor elements 11UP, 11VP, and 11WP constituting the upper arm. The connection portion between the P pattern 13 and the power semiconductor elements 11UP, 11VP, and 11WP is located on the outer periphery of the electronic substrate 12 (first layer 12A).

[0026] The N pattern 14 is a wiring for electrically connecting the negative line (high voltage line) 32 of the power source 3 and the power semiconductor element 11. The N pattern 14 is connected to the negative line 32 of the power source 3 at a terminal 141. The N pattern 14 is also connected from the terminal 141 to second terminals (source terminals) of the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm on the outer periphery of the first layer 12A via an N relay pattern 18 formed on the second layer 12B of the electronic substrate 12 described later. In this manner, the N pattern 14 is connected to the negative line 32 of the power source 3 and the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm via the N relay pattern 18. The connection portion between the N pattern 14 and the power semiconductor elements 11UN, 11VN, and 11WN is located on the outer periphery of the electronic substrate 12 (first layer 12A).

[0027] On the other hand, as shown in FIG. 3(b), an N relay pattern 18, a U pattern 15, a V pattern 16, and a W pattern 17 are formed on the second layer 12B of the electronic board 12 by copper foil. The U pattern 15, the V pattern 16, and the W pattern 17 are arranged circumferentially on the outer diameter side of the electronic board 12 (second layer 12B) from the N relay pattern 18, and the N relay pattern 18 is arranged on the inner diameter side of the electronic board 12 (second layer 12B) from the U pattern 15, the V pattern 16, and the W pattern 17. In addition, the first to third terminals of the power semiconductor element 11 are placed on the outer periphery of the second layer 12B. The first to third terminals of the power semiconductor element 11 on the outer periphery of the second layer 12B and the first to third terminals of the power semiconductor element 11 on the outer periphery of the first layer 12A are electrically connected to each other by through holes or the like.

[0028] The N relay pattern 18 located on the inner diameter side of the second layer 12B is electrically connected to a terminal 141 in the N pattern 14 formed on the first layer 12A and a portion connected to the second terminals of the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm by a through hole or the like. That is, the N relay pattern 18 connects the terminal 141 of the N pattern 14 connected to the negative pole line 32 of the power source 3 and the second terminals of the power semiconductor elements 11UN, 11VN, and 11WN.

[0029] The U pattern 15, V pattern 16, and W pattern 17 located circumferentially on the outer diameter side of the second layer 12B are connected to the power semiconductor elements 11UP, 11UN, the power semiconductor elements 11VP, 11VN, and the power semiconductor elements 11WP, 11WN, respectively. Specifically, the U pattern 15 is connected to the second terminal of the power semiconductor element 11UP constituting the upper arm and the first terminal of the power semiconductor element 11UN constituting the lower arm on the outer periphery of the electronic substrate 12 (second layer 12B). The V pattern 16 is connected to the second terminal of the power semiconductor element 11VP constituting the upper arm and the first terminal of the power semiconductor element 11VN constituting the lower arm on the outer periphery of the electronic substrate 12 (second layer 12B). The W pattern 17 is connected to the second terminal of the power semiconductor element 11WP constituting the upper arm and the first terminal of the power semiconductor element 11WN constituting the lower arm on the outer periphery of the electronic substrate 12 (second layer 12B).

[0030] The U pattern 15, the V pattern 16, and the W pattern 17 each have terminals 151, 161, and 171 protruding from the outer periphery of the electronic board 12. The terminal 151 of the U pattern 15 is joined to a bus bar connected to the U phase of the motor 2, the terminal 161 of the V pattern 16 is joined to a bus bar connected to the V phase of the motor 2, and the terminal 171 of the W pattern 17 is joined to a bus bar connected to the W phase of the motor 2 by fastening members such as screws. As a result, the power semiconductor elements 11UP and 11UN are electrically connected to the U phase of the motor 2, the power semiconductor elements 11VP and 11VN are electrically connected to the V phase of the motor 2, and the power semiconductor elements 11WP and 11WN are electrically connected to the W phase of the motor 2. In this way, the terminals 151, 161, and 171 protruding from the outer periphery of the electronic board 12 are joined to the bus bars connected to the windings of the motor 2. That is, terminals 151, 161, 171 of U pattern 15, V pattern 16, and W pattern 17 are connected to bus bars connected to motor 2 near power semiconductor element 11 on the outer periphery of electronic board 12, thereby shortening the high-voltage lines and reducing impedance.

[0031] The terminals 151, 161, 171 are configured by drawing the thick copper foils that constitute the U pattern 15, V pattern 16, and W pattern 17 to the outside of the electronic board 12, and constitute a part of the U pattern 15, V pattern 16, and W pattern 17. In other words, the terminals 151, 161, 171 are the same parts as the U pattern 15, V pattern 16, and W pattern 17. By configuring the terminals 151, 161, 171 from the same parts as the thick copper foils that constitute the U pattern 15, V pattern 16, and W pattern 17 in this way, it is possible to connect the inverter 1 to the U phase, V phase, and W phase of the motor 2 without increasing the number of parts, and it is possible to save space for the wiring that connects the inverter 1 and the motor 2.

[0032] As described above, the P pattern 13 on the first layer 12A connects the positive line 31 of the power source 3 to the first terminals of the power semiconductor elements 11UP, 11VP, and 11WP constituting the upper arm, and the N pattern 14 and the N relay pattern 18 on the second layer 12B connect the negative line 32 of the power source 3 to the second terminals of the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm. In addition, the U pattern 15 on the second layer 12B connects the power semiconductor elements 11UP and 11UN to the U phase of the motor 2, the V pattern 16 connects the power semiconductor elements 11VP and 11VN to the V phase of the motor 2, and the W pattern 17 connects the power semiconductor elements 11VP and 11VN to the V phase of the motor 2. As a result, each phase of the motor 2 can be connected to the inverter 1 using two layers: the first layer 12A having the P pattern 13 and the N pattern 14, and the second layer 12B having the N relay pattern 18, the U pattern 15, the V pattern 16, and the W pattern 17, making it possible to miniaturize the inverter 1.

[0033] In addition, in the first layer 12A, the connection portions between the P pattern 13 and the N pattern 14 and the power semiconductor element 11 are located on the outer periphery of the electronic board 12, and in the second layer 12B, the connection portions between the U pattern 15, the V pattern 16 and the W pattern 17 and the power semiconductor element 11 are located on the outer periphery of the electronic board 12. This allows the power semiconductor element 11 to be in contact with the refrigerant flow path inside the motor housing 21, improving the cooling efficiency of the power semiconductor element 11.

[0034] Figures 4 and 5 are diagrams showing an example of the flow direction when current flows through the inverter 1. Figure 4 is a circuit diagram of a motor system 100 including the inverter 1, and Figures 5 (a) and (b) are top views of the first layer 12A and second layer 12B of the electronic board 12, respectively.

[0035] 4, the third terminals (gate terminals) of the power semiconductor elements 11UP, 11VN, and 11WN are conductive (ON), and the third terminals (gate terminals) of the power semiconductor elements 11VP, 11WP, and 11UN are cut off (OFF). As a result, a current flows from the positive pole line 31 of the power source 3 to the U phase of the motor 2 via the power semiconductor element 11UP, and a current flows from the V phase and W phase of the motor 2 to the negative pole line 32 of the power source 3 via the power semiconductor elements 11VN and 11WN.

[0036] In this case, as shown in Fig. 5(a), a current is supplied from the positive line 31 of the power source 3 to the terminal 131 of the P pattern 13 on the first layer 12A of the electronic substrate 12. The current supplied to the terminal 131 flows through the first terminal (drain terminal) of the power semiconductor element 11UP, and further flows from the second terminal (source terminal) of the power semiconductor element 11UP to the U pattern 15 on the second layer 12B of the electronic substrate 12, as shown in Fig. 5(b). The current flowing through the U pattern 15 is supplied from the terminal 151 of the U pattern 15 to the U phase of the motor 2.

[0037] On the other hand, the currents from the V-phase and W-phase of the motor 2 flow through the V-pattern 16 and the W-pattern 17 via the terminal 161 of the V-pattern 16 and the terminal 171 of the W-pattern 17 on the second layer 12B of the electronic board 12, respectively, as shown in Fig. 5(b). The currents flowing through the V-pattern 16 and the W-pattern 17 flow through the first terminals (drain terminals) of the power semiconductor elements 11VN and 11WN, and then flow through the N-pattern 14 from the second terminals (source terminals) of the power semiconductor elements 11VN and 11WN on the first layer 12A of the electronic board 12 (Fig. 5(a)). The current flowing through the N-pattern 14 further flows through the N-relay pattern 18 on the second layer 12B of the electronic board 12, and then flows through the terminal 141 of the N-pattern 14 to the negative-side line 32 of the power source 3.

[0038] Note that the current flow in Figures 4 and 5 is just an example, and by using the P pattern 13, N pattern 14, U pattern 15, V pattern 16, W pattern 17, N relay pattern 18 and power semiconductor element 11 of this embodiment, power can be supplied from the power source 3 to each phase of the motor 2.

[0039] In addition, in the present embodiment, the second layer 12B of the electronic substrate 12 has the N relay pattern 18 connected to the N pattern 14, but is not limited to this. For example, the second layer 12B may have a P relay pattern connected to the P pattern 13. In this case, the P pattern 13 is connected to the positive electrode side line 31 and the first terminal of the power semiconductor element 11 via the P relay pattern. In addition, in this case, the second layer 12B may not have the N relay pattern 18. That is, the N pattern 14 may be directly connected to the negative electrode side line 32 and the second terminal of the power semiconductor element 11. In this way, the second layer 12B only needs to have at least one of the P relay pattern connected to the P pattern 13 and the N relay pattern 18 connected to the N pattern 14.

[0040] In the present embodiment, the electronic board 12 and the power semiconductor element 11 (that is, the inverter 1) are arranged inside the motor housing 21. However, the smoothing capacitor 4 may also be arranged inside the motor housing 21.

[0041] According to the inverter 1 of the above-described first embodiment, the following effects can be obtained.

[0042] The inverter 1 is disposed in a motor housing 21, and the multiple layers of the electronic board 12 include a first layer 12A having a P pattern 13 for connecting the positive electrode side line 31 and the power semiconductor element 11, and an N pattern 14 for connecting the negative electrode side line 32 and the power semiconductor element 11, and a second layer 12B having at least one of a P relay pattern connected to the P pattern 13 and an N relay pattern 18 connected to the N pattern 14, and a U pattern 15, a V pattern 16, and a W pattern 17 respectively connected to the U phase, V phase, and W phase of the motor 2. The P pattern 13 and the N pattern 14 are connected to the U pattern 15, the V pattern 16, and the W pattern 17 via second terminals (source terminals) of the power semiconductor elements 11UP, 11VP, and 11WP constituting the upper arm and first terminals (drain terminals) of the power semiconductor elements 11UN, 11VN, and 11WN constituting the lower arm. In this way, the P pattern 13 and the N pattern 14 are arranged on the first layer 12A of the electronic board 12, and the N relay pattern 18, the U pattern 15, the V pattern 16, and the W pattern 17 are arranged on the second layer 12B of the electronic board 12, so that the space of the electronic board 12 can be effectively utilized to connect wiring from above and below within the electronic board 12. This allows each phase of the motor 2 and the inverter 1 to be connected on two layers of the electronic board 12, and the inverter 1 arranged within the motor housing 21 can be made smaller.

[0043] In the inverter 1, a plurality of power semiconductor elements 11 are provided on the outer periphery of an electronic board 12, and the U pattern 15, V pattern 16, and W pattern 17 have terminals 151, 161, and 171 connected to the U phase, V phase, and W phase of the motor 2 protruding from the outer periphery of the electronic board 12. As a result, the terminals 151, 161, and 171 of the U pattern 15, V pattern 16, and W pattern 17 are connected to the wiring of each phase of the motor 2 near the power semiconductor elements 11 on the outer periphery of the electronic board 12, so that the high-voltage lines are shortened and impedance can be suppressed.

[0044] In inverter 1, terminals 151, 161, 171 connected to the U phase, V phase, and W phase of motor 2 are the same components as U pattern 15, V pattern 16, and W pattern 17. By configuring terminals 151, 161, 171 from the same components as U pattern 15, V pattern 16, and W pattern 17 in this way, it is possible to connect inverter 1 to the U phase, V phase, and W phase of motor 2 without increasing the number of components, and it is also possible to save space for wiring connecting inverter 1 and motor 2.

[0045] In the inverter 1, the connection portions between the P pattern 13 and the N pattern 14 and the power semiconductor elements 11 are located on the outer periphery of the electronic board 12, and the connection portions between the U pattern 15, the V pattern 16 and the W pattern 17 and the power semiconductor elements 11 are located on the outer periphery of the electronic board 12. This allows the power semiconductor elements 11 to be in contact with the refrigerant flow path inside the motor housing 21, thereby improving the cooling efficiency of the power semiconductor elements 11.

[0046] In this embodiment, the terminals 151, 161, 171 connected to the U-phase, V-phase, and W-phase of the motor 2 simply protrude from the outer periphery of the electronic board 12, but this is not limited to this. For example, the terminals 151, 161, 171 may be bent on the outer periphery of the electronic board 12 and joined to bus bars connected to the U-phase, V-phase, and W-phase of the motor 2. This can further reduce the space required for the motor system 100.

[0047] Furthermore, the terminals 151, 161, and 171 do not necessarily have to protrude from the outer periphery of the electronic board 12. For example, the terminals 151, 161, and 171 may be exposed inside the electronic board 12 and joined to bus bars connected to the U-phase, V-phase, and W-phase of the motor 2.

[0048] As in this embodiment, the connection portions between the P pattern 13 and the N pattern 14 and the power semiconductor element 11, and the connection portions between the U pattern 15, the V pattern 16, and the W pattern 17 and the power semiconductor element 11 are preferably located on the outer periphery of the electronic substrate 12, but are not necessarily limited to this. For example, the terminals of the power semiconductor element 11 may be made longer, and the P pattern 13 and the N pattern 14 and the power semiconductor element 11, and the U pattern 15, the V pattern 16, and the W pattern 17 and the power semiconductor element 11 may be connected at positions that are not on the outer periphery of the electronic substrate 12.

[0049] [Modification of the first embodiment] An inverter 1 according to a modified example of the first embodiment will be described with reference to Fig. 6. Note that the same elements as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted.

[0050] 6 is a top view (viewed from one axial side of the motor 2) of a first layer 12A (FIG. 6(a)) and a second layer 12B (FIG. 6(b)) of an electronic board 12 in an inverter 1 according to a modification of the first embodiment. In this modification, the positions of a terminal 131 of the P pattern 13 and a terminal 141 of the N pattern 14 are different from those of the first embodiment.

[0051] As shown in FIG. 6, in this modification, a terminal 131 of the P pattern 13 connected to the positive line 31 and a terminal 141 of the N pattern 14 connected to the negative line 32 protrude from the outer periphery of the electronic substrate 12 (first layer 12A).

[0052] Even with this configuration, the same effects as in the first embodiment can be obtained.

[0053] [Second embodiment] The inverter 1 of the second embodiment will be described with reference to Figures 7 to 9. Note that the same elements as those in the other embodiments are given the same reference numerals, and the description thereof will be omitted.

[0054] 7 is a top view (viewed from one axial side of the motor 2) of a first layer 12A (FIG. 7(a)) and a second layer 12B (FIG. 7(b)) of an electronic board 12 in an inverter 1 according to a second embodiment. This embodiment differs from the other embodiments in that the electronic board 12 includes a P relay pattern 19.

[0055] As shown in (a) of Figure 7, in this embodiment, the terminal 131 of the P pattern 13 connected to the positive side line 31 and the power semiconductor element 11UP are directly connected by the P pattern 13 in the first layer 12A, but the terminal 131 and the power semiconductor elements 11VP, 11WP are not directly connected.

[0056] Further, while the terminal 141 of the N pattern 14 and the power semiconductor elements 11VN, 11WN are not directly connected on the first layer 12A, the terminal 141 of the N pattern 14 and the power semiconductor element 11UN are directly connected by the N pattern 14.

[0057] On the other hand, the second layer 12B is provided on the inner diameter side with first to third P relay patterns 19A, 19B, and 19C and N relay patterns 18A, 18B, and 18C, respectively.

[0058] The first P relay pattern 19A is electrically connected to the portion of the P pattern 13 formed on the first layer 12A that is connected to the power semiconductor element 11UP and the portion that is connected to the power semiconductor element 11VP by through holes or the like. The second P relay pattern 19B is electrically connected to the portion of the P pattern 13 formed on the first layer 12A that is connected to the power semiconductor element 11VP and the portion that is connected to the power semiconductor element 11WP by through holes or the like. The third P relay pattern 19C is electrically connected to the portion of the P pattern 13 formed on the first layer 12A that is connected to the power semiconductor element 11WP and the portion that is connected to the power semiconductor element 11UP by through holes or the like. As a result, the respective portions of the P pattern 13 formed on the first layer 12A are electrically connected to each other via the P relay pattern 19 on the second layer 12B.

[0059] Similarly, the first N relay pattern 18A is electrically connected to the portion of the N pattern 14 formed on the first layer 12A that is connected to the power semiconductor element 11UN and the portion that is connected to the power semiconductor element 11VN by through holes or the like. The second N relay pattern 18B is electrically connected to the portion of the N pattern 14 formed on the first layer 12A that is connected to the power semiconductor element 11VN and the portion that is connected to the power semiconductor element 11WN by through holes or the like. The third N relay pattern 18C is electrically connected to the portion of the N pattern 14 formed on the first layer 12A that is connected to the power semiconductor element 11WN and the portion that is connected to the power semiconductor element 11UN by through holes or the like. As a result, the respective portions of the N pattern 14 formed on the first layer 12A are electrically connected to each other via the N relay pattern 18 of the second layer 12B.

[0060] As described above, in this embodiment, the second layer 12B includes the P relay pattern 19 and the N relay pattern 18. The positive electrode side line 31 and the power semiconductor element 11 are connected via the P pattern 13, or the P pattern 13 and the P relay pattern 19, and the negative electrode side line 32 and the power semiconductor element 11 are connected via the N pattern 14, or the N pattern 14 and the N relay pattern 18. In this way, even if the second layer 12B is configured to include both the P relay pattern 19 and the N relay pattern 18, it is possible to obtain the same effects as in the first embodiment.

[0061] Figures 8 and 9 are diagrams showing an example of the flow direction when a current flows through the inverter 1 in the second embodiment. Figure 8 is a circuit diagram of a motor system 100 including the inverter 1, and Figures 9 (a) and (b) are top views of the first layer 12A and second layer 12B of the electronic board 12, respectively.

[0062] 8, the third terminals (gate terminals) of the power semiconductor elements 11UP, 11VN, and 11WN are conductive (ON), and the third terminals (gate terminals) of the power semiconductor elements 11VP, 11WP, and 11UN are cut off (OFF). As a result, a current flows from the positive pole line 31 of the power source 3 to the U phase of the motor 2 via the power semiconductor element 11UP, and a current flows from the V phase and W phase of the motor 2 to the negative pole line 32 of the power source 3 via the power semiconductor elements 11VN and 11WN.

[0063] In this case, as shown in (a) of Fig. 9, a current is supplied from the positive line 31 of the power source 3 to the terminal 131 of the P pattern 13 on the first layer 12A of the electronic substrate 12. The current supplied to the terminal 131 flows through the first terminal (drain terminal) of the power semiconductor element 11UP, and further flows from the second terminal (source terminal) of the power semiconductor element 11UP to the U pattern 15 on the second layer 12B of the electronic substrate 12, as shown in (b) of Fig. 9. The current flowing through the U pattern 15 is supplied from the terminal 151 of the U pattern 15 to the U phase of the motor 2.

[0064] On the other hand, the currents from the V-phase and W-phase of the motor 2 flow through the V pattern 16 and the W pattern 17 via the terminal 161 of the V pattern 16 and the terminal 171 of the W pattern 17 on the second layer 12B of the electronic board 12, respectively, as shown in (b) of Fig. 9. The currents flowing through the V pattern 16 and the W pattern 17 flow through the first terminals (drain terminals) of the power semiconductor elements 11VN and 11WN, and then flow through the N pattern 14 from the second terminals (source terminals) of the power semiconductor elements 11VN and 11WN on the first layer 12A of the electronic board 12 ((a) of Fig. 9). The current flowing through the N pattern 14 further flows through the first N relay pattern 18A and the third N relay pattern 18 on the second layer 12B of the electronic board 12, and then flows from the terminal 141 of the N pattern 14 to the negative pole line 32 of the power source 3.

[0065] Note that the current flow in Figures 8 and 9 is just an example, and by using the P pattern 13, N pattern 14, U pattern 15, V pattern 16, W pattern 17, P relay pattern 19, N relay pattern 18 and power semiconductor element 11 of this embodiment, power can be supplied from the power source 3 to each phase of the motor 2.

[0066] [Third embodiment] The inverter 1 of the third embodiment will be described with reference to Fig. 10. Note that the same elements as those in the other embodiments are given the same reference numerals, and the description thereof will be omitted.

[0067] 10 is a top view (viewed from one side in the axial direction of the motor 2) of a first layer 12A (FIG. 10(a)) and a second layer 12B (FIG. 10(b)) of an electronic substrate 12 in an inverter 1 according to a third embodiment. In this modification, the shape of the electronic substrate 12 and the arrangement of the power semiconductor elements 11 are different from those of the other embodiments.

[0068] As shown in Fig. 10, in this embodiment, the surface shape of the multiple layers (first layer 12A, second layer 12B) of the electronic board 12 is rectangular. The multiple power semiconductor elements 11 are provided on the outer periphery of the electronic board 12, but do not surround the electronic board 12. Specifically, the power semiconductor elements 11 are not provided on one side of the rectangle of the electronic board 12. As a result, a space is generated between the outer periphery of the side on which the power semiconductor elements 11 are not provided and the inner wall of the motor housing 21, and components such as the smoothing capacitor 4 can be easily accommodated in the space. In other words, it is possible to further save space.

[0069] In this embodiment, the terminals 131, 141 of the P pattern 13 and the N pattern 14 protrude from the outer periphery of the electronic substrate 12 (first layer 12A). The P pattern 13 has a portion connected to the power semiconductor elements 11UP, 11VP and a portion connected to the power semiconductor element 11WP, and the two portions are electrically connected via the P relay pattern 19 of the second layer 12B. The N pattern 14 has a portion connected to the power semiconductor elements 11VN, 11WN and a portion connected to the power semiconductor element 11UN, and the two portions are electrically connected via the N relay pattern 18 of the second layer 12B.

[0070] [Modification of the third embodiment] An inverter 1 according to a modified example of the third embodiment will be described with reference to Fig. 11. Note that elements similar to those in the other embodiments are given the same reference numerals and descriptions thereof will be omitted.

[0071] 11 is a top view (viewed from one side in the axial direction of the motor 2) of a first layer 12A (FIG. 11(a)) and a second layer 12B (FIG. 11(b)) of an electronic board 12 in an inverter 1 according to a modification of the third embodiment. In this modification, the shape of the electronic board 12 differs from that of the other embodiments.

[0072] As shown in FIG. 11, in this embodiment, the surface shape of the multiple layers (first layer 12A, second layer 12B) of the electronic board 12 is trapezoidal. As in the third embodiment, the multiple power semiconductor elements 11 are provided on the outer periphery of the electronic board 12, but do not surround the electronic board 12. Specifically, the power semiconductor elements 11 are not provided on one side of the trapezoid of the electronic board 12. As a result, a space is generated between the outer periphery of the side on which the power semiconductor elements 11 are not provided and the inner wall of the motor housing 21, and components such as the smoothing capacitor 4 can be accommodated in the space. That is, as in the third embodiment, further space saving is possible.

[0073] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments.

[0074] Although the above-described embodiments have been described as separate embodiments, they may be combined as appropriate. [Explanation of symbols]

[0075] 1: inverter, 11: power semiconductor element, 12: electronic board, 12A: first layer, 12B: second layer, 13: P pattern, 14: N pattern, 15: U pattern, 16: V pattern, 17: W pattern, 18: N relay pattern, 19: P relay pattern, 2: motor, 21: motor housing, 3: power supply, 31: positive line, 32: negative line, 4: smoothing capacitor, 100: motor system

Claims

1. An inverter connected to a power source and a motor and disposed within a motor housing that accommodates the motor, an electronic board that is made up of a plurality of layers perpendicular to a motor shaft of the motor and that is disposed opposite an end of the motor shaft of the motor; a plurality of power semiconductor elements provided on an outer periphery of the electronic substrate; The layers of the electronic substrate include: a first layer including a P pattern for connecting a positive line of the power supply and the power semiconductor element, and an N pattern for connecting a negative line of the power supply and the power semiconductor element; a second layer including at least one of a P relay pattern connected to the P pattern and an N relay pattern connected to the N pattern, and a U pattern, a V pattern, and a W pattern connected to a U phase, a V phase, and a W phase of the motor, respectively; The P pattern is connected to the positive electrode side line and a first terminal of the power semiconductor element constituting the upper arm directly or via the P relay pattern, The N pattern is connected to the negative side line and a second terminal of the power semiconductor element constituting the lower arm directly or via the N relay pattern, the P pattern and the N pattern are connected to the U pattern, the V pattern, and the W pattern via a second terminal of the power semiconductor element constituting the upper arm and a first terminal of the power semiconductor element constituting the lower arm, Inverter.

2. 2. The inverter according to claim 1, The U pattern, the V pattern, and the W pattern have terminals connected to the U phase, the V phase, and the W phase of the motor protruding from the outer periphery of the electronic board. Inverter.

3. 3. The inverter according to claim 2, The electronic substrate is a copper substrate, The terminals connected to the U-phase, V-phase, and W-phase of the motor are the same parts as the U-pattern, the V-pattern, and the W-pattern. Inverter.

4. 4. The inverter according to claim 1, The motor housing has a refrigerant flow path through which a refrigerant flows, In the first layer, connection portions between the P pattern and the N pattern and the power semiconductor element are located on an outer periphery of the electronic substrate, the second layer has the U pattern, the V pattern, and the W pattern positioned circumferentially on the outer diameter side of the electronic substrate, the P relay pattern and the N relay pattern positioned on the inner diameter side of the electronic substrate relative to the U pattern, the V pattern, and the W pattern, and connection portions between the U pattern, the V pattern, and the W pattern and the power semiconductor element are positioned on the outer circumferential edge of the electronic substrate, The power semiconductor element is in contact with the coolant flow path. Inverter.

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