Inverter unit

Abstract

The inverter unit (1) comprises: a switching element unit (30), a control substrate (50), a cooler (64), and an inverter housing (60). The inverter housing (60) is fixed integrally with a rotating electrical machine housing (9). The cooler (64) is arranged in a manner connected to the switching element unit (30) on the side opposite to the rotating electrical machine side. The control substrate (50) is arranged on the rotating electrical machine side relative to the switching element unit (30).

Description

Technical Field

[0001] The invention relates to a frequency converter unit. Background Art

[0002] A hybrid vehicle is used that uses both an internal combustion engine and a rotating electric machine as a driving force source for wheels. In a drive device for such a hybrid vehicle, an inverter unit for controlling the rotating electric machine is provided. The inverter unit may be provided separately from a rotating electric machine housing that accommodates the rotating electric machine, but is preferably integrated with the rotating electric machine housing in order to shorten the wiring length.

[0003] An example of a drive unit in which a rotating electrical machine housing and an inverter unit are integrated is disclosed in Japanese Patent Publication No. 2011-182480 (Patent Document 1). In the device of Patent Document 1, a refrigerant flow path (cooling passage 37) is formed in the rotating electrical machine housing (outer cover 10, inner cover 11), and the switching element unit (power module 23) and the like are cooled by the refrigerant flowing in the refrigerant flow path. In addition, starting from the rotating electrical machine housing side where the refrigerant flow path is formed, the switching element unit, the first control substrate (gate drive substrate 22), the capacitor (smoothing capacitor 21), and the second control substrate (motor control substrate 20) are arranged in the order described.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2011-182480

[0005] However, in the device of Patent Document 1, a refrigerant flow path is formed in the rotating electrical machine housing, so the switch element unit must be assembled in the rotating electrical machine housing at first. The rotating electrical machine housing that accommodates the rotating electrical machine is often relatively large, and handling of the rotating electrical machine housing during assembly becomes a major problem, resulting in poor assembly performance.

[0006] Therefore, in the inverter unit integrated with the rotating electrical machine case, it is desired to improve the assemblability with respect to the rotating electrical machine case. Summary of the invention

[0007] The inverter unit disclosed in the present invention is used to control a rotating motor, and the inverter unit is characterized in that it comprises: a switching element unit, which comprises a switching element that forms an inverter circuit; a control substrate, which controls the switching action of the switching element; a cooler, which comprises a refrigerant flow path for circulating the refrigerant inside; and an inverter housing, which accommodates the switching element unit, the control substrate, and the cooler, the inverter housing being integrally fixed relative to a rotating motor housing that accommodates the rotating motor, the cooler being arranged in a manner connected to the switching element unit on the side opposite to the rotating motor side relative to the switching element unit, and the control substrate being arranged on the rotating motor side relative to the switching element unit.

[0008] According to this structure, the switch element unit is arranged in a state of being connected to the cooler, so that the switch element can be efficiently cooled. In addition, the control substrate is arranged on the rotating motor side that is the same side as the switch element unit relative to the cooler, so that the switch element and the control substrate can be easily connected at a short distance. As a result, the performance as a frequency converter unit can be properly ensured. In addition, the switch element unit, the control substrate, and the cooler can be handled uniformly in a state where they are accommodated in the frequency converter housing. In addition, the assemblability of the frequency converter unit to the rotating motor housing can be improved by fixing the frequency converter housing that accommodates the switch element unit, the control substrate, and the cooler integrally relative to the rotating motor housing.

[0009] Other features and advantages of the technology disclosed herein will become more apparent from the following description of illustrative and non-limiting embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a schematic diagram of a drive unit according to an embodiment.

[0011] Figure 2 This is the circuit diagram of the inverter unit.

[0012] Figure 3 This is a perspective view of the drive unit.

[0013] Figure 4 This is an exploded perspective view of the inverter unit.

[0014] Figure 5 This is a schematic configuration diagram of the inverter unit.

[0015] Figure 6 This is a schematic diagram of the drive unit viewed from the axial direction.

[0016] Figure 7 yes Figure 6 Section view VII-VII in the figure.

[0017] Figure 8 This is a schematic diagram of the configuration of another inverter unit. DETAILED DESCRIPTION

[0018] The embodiment of the inverter unit is described with reference to the accompanying drawings. The inverter unit 1 of this embodiment controls the rotating electric machine 83 provided in the vehicle drive device 8 and is used in an integrated manner with the drive device housing 9 of the vehicle drive device 8. In this embodiment, the drive unit 100 is configured to include: the vehicle drive device 8 and the inverter unit 1 integrated therewith (refer to Figure 3 ).

[0019] like Figure 1As shown, the vehicle drive device 8 includes an input member 81 drivingly connected to the internal combustion engine EG, an engagement device 82, a rotary electric machine 83, a transmission 84, and an output member 85 drivingly connected to the wheels W. In addition, the vehicle drive device 8 includes a gear mechanism 86 and a differential gear device 87. The input member 81, the engagement device 82, the rotary electric machine 83, the transmission 84, the output member 85, the gear mechanism 86, and the differential gear device 87 are provided in the order described from the internal combustion engine EG side on the power transmission path connecting the internal combustion engine EG and the wheels W.

[0020] In addition, the input member 81, the engagement device 82, the rotary motor 83, the speed changer 84, and the output member 85 are arranged on a common first axis X1. The gear mechanism 86 is arranged on a second axis X2 different from the first axis X1. The differential gear device 87 is arranged on a third axis X3 different from the first axis X1 and the second axis X2. The first axis X1, the second axis X2, and the third axis X3 are parallel to each other, and the direction parallel to these axes is the axial direction L.

[0021] The input component 81 is drivingly connected to the internal combustion engine EG. The internal combustion engine EG is a prime mover (gasoline engine, diesel engine, etc.) that is driven by the combustion of fuel inside the engine to extract power. The input component 81 is drivingly connected to the internal combustion engine output shaft (crankshaft, etc.) that is the output shaft of the internal combustion engine EG so as to rotate integrally. In addition, the input component 81 and the internal combustion engine output shaft can be directly connected or connected via other components such as a damper. The input component 81 is drivingly connected to the rotary motor 83 via the engagement device 82.

[0022] The engagement device 82 selectively connects the input member 81 (internal combustion engine EG) and the rotary electric machine 83. In other words, the engagement device 82 is provided in a manner capable of releasing the connection between the input member 81 (internal combustion engine EG) and the rotary electric machine 83. In the present embodiment, the engagement device 82 is a friction clutch, and for example, a wet multi-plate clutch or the like can be used.

[0023] The rotating electric machine 83 is a stator fixed to the drive device housing 9 as a non-rotating member, and a rotor rotatably supported on the radial inner side of the stator. The rotating electric machine 83 is electrically connected to the DC power supply B via the inverter unit 1 (see Figure 2 The rotating electric machine 83 receives and supplies electric power from the DC power supply B, or supplies and stores electric power generated by the torque of the internal combustion engine EG, the inertia force of the vehicle, etc. to the DC power supply B. The rotor of the rotating electric machine 83 is drivingly connected to the transmission 84.

[0024] The transmission 84 of the present embodiment is configured as a stepped automatic transmission. The transmission 84, for example, includes a planetary gear mechanism and a plurality of gear-changing engagement devices (not shown). The gear-changing engagement devices include one or more clutches and one or more brakes. They are friction clutches and friction brakes, and for example, wet multi-plate clutches and wet multi-plate brakes can be used. The transmission 84 can selectively form any one of a plurality of gears in accordance with the respective engagement states of the gear-changing engagement devices. The transmission 84 changes the speed of the input rotation based on the gear ratio corresponding to the formed gear and outputs it from the output component 85.

[0025] The output member 85 is drivingly connected to a pair of left and right wheels W via a gear mechanism 86 and a differential gear device 87. The torque output from the output member 85 is distributed and transmitted to the left and right wheels W via the gear mechanism 86 and the differential gear device 87. Thus, the vehicle drive device 8 can transmit the torque of one or both of the internal combustion engine EG and the rotary electric machine 83 to the wheels W to drive the vehicle.

[0026] The input member 81, the engagement device 82, the rotating electric machine 83, the speed changer 84, the output member 85, the gear mechanism 86, and the differential gear device 87 are accommodated in the drive device housing 9. In this embodiment, the drive device housing 9 is equivalent to the "rotating electric machine housing". Figure 3 As shown, the drive device housing 9 includes: a first housing portion 91, and a second housing portion 92. The first housing portion 91 and the second housing portion 92 are engaged in a state of being in contact with each other in the axial direction L. In addition, the drive device housing 9 includes: an end wall portion 93 covering an end portion on one side (the transmission 84 side) in the axial direction L, and a peripheral wall portion 94 covering the periphery of the rotating electric machine 83, the transmission 84, the gear mechanism 86, and the differential gear device 87.

[0027] The peripheral wall portion 94 includes a large diameter portion 94A and a small diameter portion 94B having a smaller diameter than the large diameter portion 94A (see Figure 7 In addition, the drive device housing 9 includes a protruding wall portion 95 protruding from the peripheral wall portion 94 toward the outer peripheral side. The protruding wall portion 95 is generally arranged in a vertical direction ( Figure 3 The protruding wall portion 95 is formed so as to protrude upward (in the vertical direction). The protruding wall portion 95 is used as a base, and the inverter unit 1 is integrally fixed to the upper part of the protruding wall portion 95.

[0028] like Figure 2 As shown, the rotary electric machine 83 is electrically connected to a DC power supply B via the inverter unit 1 . The DC power supply B is a secondary battery (battery) such as a nickel-hydrogen battery or a lithium-ion battery, an electric double layer capacitor, etc. The DC power supply B and the inverter unit 1 are electrically connected via a power supply terminal 14 .

[0029] The inverter unit 1 includes: a positive bus 11, a negative bus 12, a capacitor 20, a switching element unit 30, a three-phase bus 36, a current sensor 42, and a control substrate 50. The positive bus 11 is connected to the positive electrode of the DC power supply B. The negative bus 12 is connected to the negative electrode of the DC power supply B. The capacitor 20 is connected to the positive bus 11 and the negative bus 12, and smoothes the voltage between the positive and negative electrodes. In this embodiment, the capacitor 20 includes a plurality of capacitor elements 21 (see Figure 5 ).

[0030] The switching element unit 30 includes a plurality of switching elements 31. An inverter circuit 32 is formed by these plurality of switching elements 31. The inverter circuit 32 is composed of a bridge circuit having arms corresponding to a plurality of phases. In the present embodiment, the rotating motor 83 is a three-phase AC rotating motor, and the inverter circuit 32 is composed of a bridge circuit having arms corresponding to the U phase, V phase, and W phase of the stator coil of the rotating motor 83. The arms of each phase are composed of two switching elements 31 connected in series between the positive and negative poles, and they are connected in parallel to form the inverter circuit 32 (bridge circuit).

[0031] In addition, as the switching element 31, power semiconductor elements such as IGBT (insulated gate bipolar transistor), power MOSFET (metal oxide semiconductor field effect transistor), SiC-MOSFET (silicon carbide-metal oxide semiconductor field effect transistor), and SiC-SIT (silicon carbide electrostatic induction transistor) can be used. In addition, a freewheeling diode is connected in parallel to each switching element 31. Moreover, in the present embodiment, the inverter circuit 32 configured as a three-phase arm having a switching element 31 and a freewheeling diode is unitized as a switching element unit 30.

[0032] The three-phase bus 36 connects the inverter circuit 32 to the rotating electric machine 83. The three-phase bus 36 plays a part in the function of electrically connecting the middle point of the two switching elements 31 constituting the arm of each phase to the stator coil of each phase of the rotating electric machine 83. In the present embodiment, the three-phase bus 36 electrically connects the middle point of the two switching elements 31 constituting the arm of each phase to the three-phase terminal 38. The three-phase bus 36 is connected to the stator coil of each phase of the rotating electric machine 83 via the three-phase terminal 38 and the three-phase cable connected to the three-phase terminal 38. In the present embodiment, the three-phase bus 36 corresponds to the "wiring component".

[0033] The current sensor 42 detects the current flowing in the three-phase bus 36. The current sensor 42 can independently detect the current flowing in each of the three-phase bus 36 corresponding to the three-phase stator coils of the rotating motor 83, or can detect only the current of the two-phase portion and obtain the current of the remaining one-phase portion through calculation.

[0034] The control substrate 50 controls the switching action of the switching element 31. An inverter control unit (controller) is constructed on the control substrate 50 using a logic circuit such as a microcomputer as a core component. The current flowing in the three-phase bus 36 respectively detected by the current sensor 42 is input to the control substrate 50 (inverter control unit). In addition, the magnetic pole position and rotation speed of the rotor of the rotating motor 83 at each moment are detected by a rotation sensor 44 such as a rotary transformer, and the information of the detection result is also input to the control substrate 50 (inverter control unit). Based on this information and the required torque of the vehicle, the control substrate 50 (inverter control unit) performs current feedback control such as using a vector control method to control the on / off of each switching element 31.

[0035] like Figure 4 and Figure 5 As shown, the capacitor 20, the switching element unit 30, the three-phase busbar 36, the current sensor 42, and the control substrate 50 are accommodated in the inverter case 60 fixed integrally with the drive device case 9. Here, the inverter case 60 includes: a case body 61, and a case cover 68 mounted on the case body 61. The case body 61 includes: a peripheral wall portion 62 surrounding the periphery of the accommodating space of the switching element unit 30 and the like, and a flange portion 63 provided at the lower end portion and serving as a portion mounted on the drive device case 9 (protruding wall portion 95).

[0036] In addition, the housing body 61 is provided with a radiator portion 64 in its middle region. A refrigerant flow path 65 for circulating the refrigerant is formed inside the radiator portion 64. In the present embodiment, the radiator portion 64 is equivalent to a "cooler". The radiator portion 64 provided with the refrigerant flow path 65 may be either an air-cooled type or a water-cooled type, but is preferably a water-cooled type from the point of view of cooling efficiency. In addition, as in the present embodiment, even in a structure in which a part of the housing body 61 constituting the inverter housing 60 is the radiator portion 64, it can be considered that the radiator portion 64 is accommodated in the inverter housing 60.

[0037] In the present embodiment, the internal space of the housing body 61 is divided into two spaces (a first accommodation space P1 and a second accommodation space P2) with the heat sink portion 64 as a boundary. The first accommodation space P1 is a space located closer to the drive device housing 9 side (rotating motor 83 side) than the heat sink portion 64. The second accommodation space P2 is a space located closer to the outside (opposite to the drive device housing 9 and the rotating motor 83 side) than the heat sink portion 64. Moreover, in the present embodiment, the switching element unit 30, the three-phase bus 36, the current sensor 42, and the control substrate 50 are accommodated in the first accommodation space P1, and the capacitor 20 is accommodated in the second accommodation space P2.

[0038] In the first accommodation space P1, the switching element unit 30 is arranged in contact with the surface of the heat sink 64 on the drive device housing 9 side (rotating motor 83 side). If the heat sink 64 is viewed as a main body, the heat sink 64 is arranged in contact with the switching element unit 30 on the side opposite to the drive device housing 9 side (rotating motor 83 side) with respect to the switching element unit 30.

[0039] The current sensor 42 is arranged slightly apart from the surface of the heat sink 64 on the drive device housing 9 side (rotating motor 83 side). In addition, the current sensor 42 is arranged so as to include the same position as the switching element unit 30 in the direction (stacking direction S) in which the components constituting the inverter unit 1 are stacked, and is located on the drive device housing 9 side (rotating motor 83 side). In addition, the current sensor 42 is arranged at a position adjacent to the switching element unit 30 so as not to overlap with the switching element unit 30 when viewed along the stacking direction S.

[0040] The three-phase busbar 36 is arranged in contact with the surface of the switch element unit 30 on the drive device housing 9 side (rotating electric machine 83 side). In addition, the three-phase busbar 36 is arranged in a state surrounded by the current sensor 42. Figure 4 ) does not extend outside the internal space enclosed by the inverter case 60 and the drive device case 9, but is only arranged in the internal space enclosed by the inverter case 60 and the drive device case 9. In addition, in the present embodiment, the three-phase busbar 36 is only arranged in the space on the inverter case 60 side.

[0041] The control substrate 50 is arranged on the drive device housing 9 side (rotating motor 83 side) with respect to both the switch element unit 30 and the current sensor 42. In other words, the control substrate 50 is arranged closest to the drive device housing 9 side (rotating motor 83 side) among the components constituting the inverter unit 1 in the stacking direction S. In addition, the control substrate 50 is arranged slightly apart from the current sensor 42, which is located closer to the drive device housing 9 side (rotating motor 83 side) among the switch element unit 30 and the current sensor 42, along the stacking direction S. The control substrate 50 is formed to be of the same size as the heat sink portion 64 and is arranged in parallel with the heat sink portion 64.

[0042] In this way, the switching element unit 30 and the current sensor 42 are disposed adjacent to each other in a direction orthogonal to the stacking direction S between the heat sink portion 64 and the control substrate 50 which are disposed in parallel with each other at a predetermined interval in the stacking direction S. If this is viewed mainly from the current sensor 42, the current sensor 42 is disposed on the switching element unit 30 side relative to the control substrate 50.

[0043] In addition, if Figure 6As shown, when viewed along the axial direction L, the control substrate 50 is tangentially connected to the point closest to the control substrate 50 in the rotary motor 83 (in Figure 6 In this embodiment, the tangent direction of the rotating motor 83 at the point closest to the control substrate 50 is viewed along the axial direction L relative to the vertical direction ( Figure 6 In contrast, the control substrate 50, the switching element unit 30, and the heat sink 64 are arranged in a substantially horizontal direction (a direction orthogonal to the vertical direction). As a result, the control substrate 50 can be arranged closest to the drive device housing 9 among the components constituting the inverter unit 1 as described above, and heat is difficult to be transferred to the control substrate 50.

[0044] The control board 50 and the like are arranged to include a region between the first axis X1 where the rotary motor 83 and the like are arranged and the third axis X3 where the differential gear device 87 is arranged, as viewed in the axial direction L. This makes it difficult for heat to be transmitted to the control board 50 and suppresses an increase in the overall size of the drive unit 100.

[0045] like Figure 7 As shown, in the control substrate 50, various circuit components 51 for constructing a logic circuit are mounted on the surface of the control substrate 50 on the drive device housing 9 side (rotating motor 83 side). And, the most protruding component 51h having the highest protruding height from the control substrate 50 (protruding height toward the drive device housing 9 side) among the plurality of circuit components 51 is arranged on the small diameter portion 94B of the large diameter portion 94A and the small diameter portion 94B of the peripheral wall portion 94 of the drive device housing 9. In this way, by making the outer shape of the drive device housing 9 (peripheral wall portion 94) complementary to the approximate shape of the control substrate 50 also including the circuit components 51, the inverter unit 1 as a whole can be arranged as close to the drive device housing 9 as possible. As a result, the overall miniaturization of the drive unit 100 can be achieved.

[0046] The capacitor 20 is arranged in the second accommodation space P2 relative to the heat sink portion 64, and the second accommodation space P2 is formed on the opposite side to the side arranged in the first accommodation space P1. The capacitor 20 is arranged in the groove-shaped second accommodation space P2 in a resin-molded state. The capacitor 20 is arranged on the opposite side to the switching element unit 30 side relative to the heat sink portion 64. In other words, the capacitor 20 is arranged at the outermost position (away from the drive device housing 9) among the components constituting the inverter unit 1 in the stacking direction S. For the capacitor 20, there are many cases in which a plurality of capacitor elements 21 are assembled to form it, and the configuration freedom is higher than that of other components. Therefore, by arranging the capacitor 20 at the outermost position, the freedom of the outer shape of the inverter unit 1 can be increased.

[0047] When the drive unit 100 is installed in the vehicle according to the specifications of the vehicle, for example, Figure 8 As shown, there is a case where obstacles OB such as vehicle-mounted components and a vehicle body frame interfere with the upper area of ​​the inverter unit 1. In such a case, as shown in the figure, a part of the plurality of capacitor elements 21 constituting the capacitor 20 is moved to a position where it does not interfere with the obstacle OB, and the inverter housing 60 is formed into a shape corresponding to the configuration of this case. In this way, the outer shape of the inverter unit 1 can be appropriately changed according to the specifications of the vehicle side, so the range of vehicles that can be installed can be expanded.

[0048] Furthermore, the configuration structure of each of the above components is also along the flow of power of "capacitor 20 → switching element unit 30 → current sensor 42 → rotating motor 83" in the inverter unit 1. As a result, the length of the three-phase bus 36 extending from the switching element unit 30 to the rotating motor 83 side can be suppressed as short as possible.

[0049] When the inverter unit 1 is integrated with the drive device housing 9, an assembly method can be adopted in which the inverter housing 60 is fixed to the drive device housing 9 in a state where each component has been fixed to the inverter housing 60. In this case, the switch element unit 30, the three-phase bus 36, the current sensor 42, and the control substrate 50 are fixed to the first accommodation space of the inverter housing 60 and fixed to P1, and the positive bus 11, the negative bus 12, and the capacitor 20 are fixed to the second accommodation space and fixed to P2. Moreover, the inverter housing 60 to which each component is fixed can be finally fixed to the drive device housing 9. Only the inverter unit 1 is assembled separately and finally fixed to the drive device housing 9, so the assemblability of the inverter unit 1 to the drive device housing 9 can be improved.

[0050] [Other implementation methods]

[0051] (1) In the above-mentioned embodiment, the capacitor 20 is arranged on the side opposite to the switching element unit 30 side with respect to the heat sink 64. However, the present invention is not limited to such a structure, and the capacitor 20 may be arranged on the switching element unit 30 side (drive device housing 9 and rotary motor 83 side) with respect to the heat sink 64.

[0052] (2) In the above-mentioned embodiment, the current sensor 42 is arranged on the switch element unit 30 side relative to the control board 50. However, the current sensor 42 may be arranged on the opposite side of the switch element unit 30 side (the drive device housing 9 and the rotating electric machine 83 side) relative to the control board 50 without being limited to such a structure.

[0053] (3) In the above-mentioned embodiment, the control substrate 50 is arranged in a direction intersecting with the tangent direction at the point closest to the control substrate 50 in the rotary motor 83 when viewed in the axial direction L. However, the present invention is not limited to such a structure, and the control substrate 50 may be arranged in a direction parallel to the tangent direction when viewed in the axial direction L.

[0054] (4) In the above embodiment, a part of the case body 61 constituting the inverter case 60 is described as the heat sink 64. However, the present invention is not limited to such a structure, and the heat sink 64 may be completely independent from the case body 61.

[0055] (5) In the above-mentioned embodiment, the structure in which the three-phase busbar 36 is arranged only in the inverter housing 60 is described as an example. However, it is not limited to such a structure, and at least a part of the three-phase busbar 36 may be arranged outside the inverter housing 60. For example, the three-phase busbar 36 may be arranged so as to span the space on the inverter housing 60 side and the space on the drive device housing 9 side. Alternatively, at least a part of the three-phase busbar 36 may be arranged outside the internal space surrounded by the inverter housing 60 and the drive device housing 9.

[0056] (6) In the above-mentioned embodiment, the structure in which the most protruding component 51h among the plurality of circuit components 51 mounted on the control substrate 50 is arranged on the small diameter portion 94B of the peripheral wall portion 94 of the drive device housing 9 is described as an example. However, the structure is not limited to that, and the most protruding component 51h may be arranged on the large diameter portion 94A of the peripheral wall portion 94. In addition, the peripheral wall portion 94 of the drive device housing 9 may not originally include the large diameter portion 94A and the small diameter portion 94B. In this way, the outer shape of the drive device housing 9 (peripheral wall portion 94) and the general shape of the control substrate 50 which also includes the circuit components 51 may not necessarily complement each other.

[0057] (7) In the above-mentioned embodiment, the circuit component 51 is mounted on the surface of the control substrate 50 on the drive device case 9 side (rotating motor 83 side). However, the present invention is not limited to such a structure, and the circuit component 51 may be mounted on the surface of the control substrate 50 on the heat sink portion 64 side (the side opposite to the drive device case 9 and the rotating motor 83 side).

[0058] (8) The structures disclosed in the above-mentioned embodiments (including the above-mentioned embodiments and other embodiments; the same applies hereinafter) can also be applied in combination with structures disclosed in other embodiments as long as no contradiction occurs. Regarding other structures, the embodiments disclosed in this specification are illustrative in all points and can be appropriately changed within the scope of the main purpose of the present disclosure.

[0059] [Outline of Implementation Method]

[0060] To summarize the above, the inverter unit (1) of the present disclosure preferably has the following structures.

[0061] A frequency converter unit (1) for controlling a rotating electric machine (83), the frequency converter unit (1) being characterized in that it comprises: a switching element unit (30) comprising a switching element (31) forming a frequency converter circuit (32); a control substrate (50) controlling the switching action of the switching element (31); a cooler (64) comprising a refrigerant flow path (65) inside thereof for circulating a refrigerant; and a frequency converter housing (60) accommodating the frequency converter housing (60), the switching element unit (30), the control substrate (50), and the cooler (64), the frequency converter housing (60) being integrally fixed to a rotating electric machine housing (9) accommodating the rotating electric machine (83), the cooler (64) being arranged in a manner connected to the switching element unit (30) on the side opposite to the rotating electric machine (83) side relative to the switching element unit (30), and the control substrate (50) being arranged on the rotating electric machine (83) side relative to the switching element unit (30).

[0062] According to this structure, the switch element unit (30) is arranged in a state of being connected to the cooler (64), so that the switch element (31) can be efficiently cooled. In addition, the control substrate (50) is arranged on the rotating motor (83) side that is on the same side as the switch element unit (30) relative to the cooler (64), so that the switch element (31) and the control substrate (50) can be easily connected at a short distance. As a result, the performance of the inverter unit (1) can be properly ensured. In addition, the switch element unit (30), the control substrate (50), and the cooler (64) can be handled uniformly in a state where they are accommodated in the inverter housing (60). In addition, the inverter housing (60) accommodating the switch element unit (30), the control substrate (50), and the cooler (64) can be fixed integrally to the rotating motor housing (9), thereby improving the assemblability of the inverter unit (1) to the rotating motor housing (9).

[0063] As one embodiment, it is preferred that: there is also a current sensor (42) that detects the current flowing in the wiring component (36) connecting the above-mentioned inverter circuit (32) and the above-mentioned rotating motor (83), and the above-mentioned current sensor (42) is arranged on the side of the above-mentioned switching element unit (30) relative to the above-mentioned control substrate (50).

[0064] According to this structure, the wiring component (36) connecting the inverter circuit (32) and the rotating electric machine (83) can be arranged along a reasonable path, thereby reducing the total length of the wiring component (36).

[0065] As one embodiment, it is preferred that the wiring member (36) is arranged only in an internal space surrounded by the inverter case (60) and the rotating electrical machine case (9).

[0066] According to this structure, the wiring component (36) is only arranged in the internal space surrounded by the inverter case (60) and the rotating electrical machine case (9) and does not protrude to the outside, so the total length of the wiring component (36) can be further shortened.

[0067] As one embodiment, it is preferred that: a capacitor (20) is further provided which is electrically connected between the DC power supply and the inverter circuit (32), and the capacitor (20) is arranged on the side opposite to the switching element unit (30) side with respect to the cooler (64).

[0068] According to this structure, the heat from the switching element unit (30) side can be difficult to be transferred to the capacitor (20) side by the cooler (64), or the capacitor (20) can be cooled by the cooler (64). In addition, by arranging the capacitor (20) with a high degree of configuration freedom at a position farthest from the rotating electrical machine housing (9), it is easy to change the overall outer shape of the integrated inverter unit (1) and the rotating electrical machine housing (9).

[0069] As one embodiment, the control substrate (50) is preferably arranged along a direction intersecting a tangent direction at a point closest to the control substrate (50) in the rotating electric machine (83) when viewed along the axial direction (L).

[0070] According to this structure, compared with a structure in which the control substrate (50) is arranged along the tangent direction at the closest point in the rotating motor (83), the separation distance of the control substrate (50) from the rotating motor (83) can be ensured to be larger. As a result, heat generated by driving the rotating motor (83) can be less likely to be transferred to the control substrate (50).

[0071] As one method, it is preferred that the rotating motor housing (9) comprises a large diameter portion (94A) and a small diameter portion (94B) having a smaller diameter than the large diameter portion (94A), and the most protruding component (51h) having the highest protruding height from the control substrate (50) among the circuit components (51) mounted on the control substrate (50) is arranged on the small diameter portion (94B).

[0072] According to this structure, the most protruding component (51h) on the control substrate (50) can be arranged as close as possible to the rotating electrical machine housing (9) by utilizing the recess of the small diameter portion (94B) of the rotating electrical machine housing (9). As a result, the overall miniaturization of the integrated inverter unit (1) and the rotating electrical machine housing (9) can be achieved.

[0073] The inverter unit of the present disclosure only needs to be able to achieve at least one of the above-mentioned effects.

[0074] Description of Reference Numerals

[0075] 1… inverter unit; 9… drive device housing (rotating motor housing); 20… capacitor; 30… switch element unit; 31… switch element; 32… inverter circuit; 36… three-phase bus (wiring component); 42… current sensor; 50… control substrate; 51… circuit component; 51h… most protruding component; 60… inverter housing; 64… radiator part (cooler); 65… refrigerant flow path; 83… rotating motor; 94A… large diameter part; 94B… small diameter part; B… DC power supply; L… axial direction.

Claims

1. A frequency converter unit for controlling a rotating electrical machine, the frequency converter unit comprising: a switching element unit including a switching element forming an inverter circuit; A control substrate, which controls the switching action of the switching element; a cooler having a refrigerant flow path therein through which the refrigerant flows; and an inverter housing, which accommodates the switch element unit, the control substrate, and the cooler, The inverter housing is integrally fixed to a rotating electrical machine housing that accommodates the rotating electrical machine. The cooler is arranged so as to be in contact with the switching element unit on the side opposite to the rotating electric machine side with respect to the switching element unit. The control substrate is arranged on the rotating electrical machine side relative to the switching element unit. The rotating electrical machine housing includes a large diameter portion and a small diameter portion having a smaller diameter than the large diameter portion. The circuit components mounted on the control substrate include a low protrusion component and a high protrusion component that protrudes higher from the control substrate than the low protrusion component, the high protrusion component is arranged to face the small diameter portion, and the low protrusion component is arranged to face the large diameter portion.

2. The frequency converter unit according to claim 1, characterized in that: A current sensor is further provided to detect a current flowing in a wiring member connecting the inverter circuit and the rotating electric machine. The current sensor is arranged on the switching element unit side with respect to the control substrate.

3. The frequency converter unit according to claim 2, characterized in that: The wiring member is arranged only in an internal space surrounded by the inverter case and the rotating electrical machine case.

4. The frequency converter unit according to any one of claims 1 to 3, characterized in that: A capacitor is also provided which is electrically connected between the DC power supply and the inverter circuit. The capacitor is arranged on the side opposite to the switching element unit side with respect to the cooler.

5. The frequency converter unit according to any one of claims 1 to 3, characterized in that: The control substrate is arranged along a direction intersecting a tangent direction at a point of the rotating electrical machine closest to the control substrate when viewed in the axial direction.

6. The frequency converter unit according to claim 4, characterized in that: The control substrate is arranged along a direction intersecting a tangent direction at a point of the rotating electrical machine closest to the control substrate when viewed in the axial direction.

Images