JP2004135447A - Motor integrated with inverter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor integrated with an inverter that allows the motor and the inverter efficiently to cool by a single cooling member. <P>SOLUTION: The motor 15 comprises a cylindrical housing 20 with its one end open, a stator 18 and a rotor 27 that are housed in the housing, the single cooling member 30 installed on a rotating shaft 26 in the vicinity of the opening of the housing, and a lid member 20 that covers the cooling member and closes the opening of the housing. The inverter 35 includes substrates 36, 44 that are arranged in a plane orthogonal to the rotating shaft and fixed to the lid member, a switching element 37 and a smoothing capacitor 38 that are installed on the substrates, and a protection cover 50 that covers the substrates. The single cooling member 30 cools the switching element 37 or the like and the stator 18 or the like, thus improving cooling efficiency. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an inverter-integrated electric motor in which an inverter and an electric motor are integrated.
[0002]
[Prior art]
In some cases, DC power is converted into AC power by an inverter to drive an electric motor. For example, in an electric vehicle, a DC power of a vehicle-mounted battery is converted into AC power by an inverter to drive an electric motor.
[0003]
FIG. 5 shows a general electric system in an electric vehicle. DC power is supplied from the DC power supply 70 to the inverter (power converter) 73 via the DC power supply wiring 71, and the switching element 75 of the inverter 73 converts the power to AC power of a predetermined frequency. The AC power is supplied to the electric motor 78 via the three-phase AC wiring 77. The inverter 73 cools a heat source such as a switching element by a cooling means 74, and the electric motor 78 cools a heat source such as a rotor by a cooling means 79.
[0004]
In order to simplify the cooling means for cooling the inverter and the electric motor, in a conventional inverter-integrated electric motor (see Patent Document 1), as shown in FIG. Both are cooled by one cooling fan 88 provided.
[0005]
Specifically, on a housing 86 having a stator and a rotor (not shown), a casing 83 having a built-in switching element (not shown) and provided with cooling fins 82 on its lower surface is mounted. Then, a short wiring (not shown) extending from the electric motor 85 is connected to the inverter 81. Further, a cooling fan 88 is attached to an output shaft 87 of the electric motor 85, and air is sent rearward (rightward) (see arrow x) to cool the cooling fins 82. The air (see arrow y) sent rearward by the cooling fan 88 also collides with the cooling fins 82 when flowing through the gap between the electric motor 85 and the inverter 81, and cools the capacitors and the like in the inverter 81.
[0006]
[Patent Document 1]
JP-A-6-30547
[Problems to be solved by the invention]
However, first, in the conventional example, it is difficult to say that the cooling efficiency of the inverter 81 is sufficient. The switching elements and the like mounted on the board are cooled by causing air to collide with the cooling fins 82 in the gap between the electric motor 85 and the inverter 81. This heat radiation action is merely transmitted from the switching element via the cooling fan 82 and is indirect.
[0008]
Second, the inverter 81 and the electric motor 85 are integrated while each having basic components. Therefore, the number of parts is large, the structure is complicated, and the dimensions are large.
[0009]
The present invention has been made in view of the above circumstances, and provides an inverter-integrated electric motor in which an electric motor and an inverter can be efficiently cooled by one cooling member, and the structure is simplified and an increase in size is suppressed. The purpose is to:
[0010]
[Means for Solving the Problems]
The inventor of the present application has earnestly studied a method of directly cooling a switching element or the like mounted on a substrate by a cooling member of the motor without increasing the dimensions of the motor and the inverter. As a result, when integrating the inverter and the electric motor, the present invention was completed by thinking of attaching the inverter to a lid member that covers an opening of the housing of the electric motor.
[0011]
According to a first aspect of the present invention, there is provided an inverter-integrated motor according to the first aspect of the present invention, wherein a cylindrical housing having one end opened, a stator and a rotor housed in the housing, and rotation of the rotor near the opening of the housing. An electric motor including one cooling member mounted on the shaft, a lid member covering the cooling member and closing an opening of the housing; a substrate disposed in a plane intersecting the rotation axis and fixed to the lid member; An inverter including a switching element and a smoothing capacitor mounted thereon, and a protective cover for covering the substrate.
[0012]
In this inverter-integrated electric motor, a substrate or the like is fixed on a lid member that covers a cooling member in the motor, and a switching element or the like on the substrate is close to the cooling member. Therefore, the switching element and the like in the inverter are directly cooled by one cooling member in addition to the stator and the like in the electric motor.
[0013]
According to a second aspect of the present invention, there is provided an inverter-integrated electric motor according to the first aspect, wherein the lid member includes a bottom portion having a ventilation hole, and an outer peripheral wall portion covering the cooling member, and the substrate is fixed to the bottom portion. According to a third aspect of the present invention, there is provided an inverter-integrated motor according to the first aspect, wherein the substrate has a through-hole at the center of which the rotation shaft passes therethrough, and the switching element and the smoothing capacitor are mounted around the through-hole. According to a fourth aspect of the present invention, in the inverter integrated type electric motor according to the first aspect, the protective cover includes a bottom portion having a ventilation hole, and an outer peripheral wall covering the substrate. According to a fifth aspect of the present invention, in the inverter integrated motor of the first aspect, the cooling member circulates external air from the inverter to the electric motor. According to a sixth aspect of the present invention, in the first aspect, the substrate is disposed in a plane orthogonal to the axis of the rotating shaft.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
<Electric motor>
The electric motor functions as a motor generator (MG) in an electric vehicle or a hybrid vehicle. The MG has a motor function, an alternator and a function, is driven by three-phase alternating current, and assists in starting the engine and smoothly starting and stopping the vehicle. Also, the output of the engine and the rotational energy of the axle are converted into electric energy and stored in a DC power supply.
[0015]
One end of the housing that houses the rotor and the stator is open, and one cooling member such as a cooling fan is attached near the opening on the rotation axis of the rotor, and rotates with the rotor. The lid member may have a container shape including a bottom portion and a circumferential wall portion, the circumferential wall portion covering the cooling member, and the bottom portion closing an opening of the housing. In addition, a ventilation hole that allows air to flow from the switching element or the like to the stator or the like is formed. The motor has a three-phase AC input / output unit.
<Inverter>
The inverter converts a direct current of a direct current power supply into an alternating current such as a three-phase alternating current, and includes a substrate, a switching element mounted on the substrate, a smoothing capacitor and a control circuit, and a protective cover.
[0016]
The substrate is arranged in a plane (vertical plane) orthogonal to the rotation axis of the rotor, and is fixed to the lid member by a fixing member. The substrate has a through hole at the center for allowing the rotating shaft of the electric motor to penetrate therethrough in order to enable the substrate to be orthogonal to the rotating shaft, and a switching element, a smoothing capacitor, and the like are mounted in the vicinity of the through hole. Therefore, the inverter has a vertically long shape as a whole. The number of substrates may be one or two or more. In the case of a plurality of substrates, the size of each substrate may be the same or different.
[0017]
The protective cover may have a container shape including a bottom portion and a circumferential wall portion, and an opening is closely attached to the lid member. Therefore, the protective cover does not require a lid member that covers the opening.
[0018]
An air flow gap is formed between the substrate and a circumferential wall that covers the substrate, and a vent hole for introducing air is formed at the bottom. The inverter has a three-phase power input / output unit.
<Relationship between inverter and motor>
The bottom portion of the cover member of the electric motor covers the opening of the housing, serves as a fixed member of the inverter substrate, and further serves as a cover member of the protective cover. In addition, the cooling member of the electric motor circulates the air taken in from the protective cover side toward the bottom side, thereby cooling the switching elements of the inverter and the stator of the electric motor. Furthermore, the three-phase AC input / output unit of the inverter and the three-phase AC input / output unit of the electric motor are connected to each other by terminals or by short wiring.
[0019]
Regardless of the name of the invention (inverter-integrated electric motor, electric motor-integrated inverter device), the present invention includes those that satisfy the relationship between the configuration of the electric motor and the inverter and the relation between the inverter and the electric motor.
[0020]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Example>
(Constitution)
3 and 4 show the electric system of the hybrid vehicle. The electric system includes a DC power supply 61, an inverter-integrated electric motor 10, a transmission 62, and a gasoline engine 63.
[0021]
As shown in FIGS. 1 and 2, the inverter-integrated electric motor 10 includes an electric motor (MG) 15 and an inverter 35. The MG 15 includes a housing 16, a stator 18, a cover member 20 covering an opening of the housing, a rotating shaft 26, a rotor 27 fixed to the rotating shaft 26, and a cooling fan 30. The housing 16 has a closed-end cylindrical shape with the other end (left end) closed and one end (right end) opened. The lid member 20 includes a circular bottom portion 21 and a circumferential wall portion 22 rising at right angles from the periphery thereof. The circumferential wall portion 22 covers a cooling fan 30 described later, and the bottom portion 21 covers an opening of the housing 16. . A plurality of ventilation holes 21a are formed in the bottom 21.
[0022]
Stator 18 is fixed to the inner peripheral surface of housing 16. The rotating shaft 26 is rotatably supported at both ends by the housing 16 and the cover member 20, and a rotor 27 fixed to the rotating shaft 26 faces the stator 18. A cooling fan 30 is fixed on the rotation shaft 26 between the rotor 27 and the lid member 20, and rotates with the rotor 27.
[0023]
The inverter 35 includes two substrates 36 and 44, a switching element 37 mounted thereon, and the like, and the protective cover 50. The disc-shaped first substrate 36 fixed to the bottom 21 of the lid member 20 by the fixing member 34 has a through hole 36a formed in the center thereof, and a switching element 37, a smoothing capacitor 38, and a control circuit 39 are formed therearound. Is installed.
[0024]
The disk-shaped first substrate 36 is disposed in a plane orthogonal to the rotation shaft 26, and the rotation shaft 26 passes through the through hole 36a. An air flow gap is formed between the rotation shaft 26 and the inner peripheral edge of the through hole 36a.
[0025]
The disk-shaped second substrate 44 fixed to the first substrate 36 and the lid member 20 by the fixing member 34 also has a through-hole 44a at the center thereof, and a switching element 46 is mounted around the through-hole 44a. The rotating shaft 26 is arranged in parallel with the first substrate 36 and passes through the through hole 44a. An air gap is formed between the rotation shaft 26 and the inner peripheral edge of the through hole 44a.
[0026]
The protective cover 50 includes a circular bottom portion 51 and an outer peripheral wall portion 52 that rises at a right angle from a peripheral edge thereof. The opening of the outer peripheral wall 52 is in close contact with the bottom 21 of the lid member 20, and the outer peripheral wall 52 and the bottom 51 cover the substrates 36 and 44. A plurality of ventilation holes 51 a are formed in the bottom portion 51, and an air flow gap is formed between the outer peripheral edge 36 b of the first substrate 36 and the outer peripheral edge 44 b of the second substrate 44 and the outer peripheral wall portion 52.
[0027]
A three-phase AC input / output unit (not shown) of the inverter 35 is connected to the three-phase AC input / output unit (not shown) of the MG 15 via short wiring (not shown). The inverter 15 and the DC power supply are connected by a DC power supply wiring 71 (see FIG. 5).
(Effect)
3 and 4, the MG 15 drives the vehicle at the start of the vehicle and before the engine 63 starts after the vehicle starts. During normal running, the engine 63 drives the wheels 64 via the transmission 62 and also drives the MG 15. The power generated by MG 15 is charged to DC power supply 61 via inverter 35. During regenerative braking, MG 15 is driven by wheels 64, and the generated regenerative energy is stored in DC power supply 61.
[0028]
When the vehicle is stopped, the engine 63 is automatically stopped (idle stop). When the engine 63 is restarted after the idle stop, the DC power of the DC power supply 61 is converted into AC power by the inverter 15, and the MG 15 rotates.
[0029]
According to this embodiment, the following effects can be obtained.
[0030]
1 and 2, first, the cooling fan 30 effectively cools the switching elements 37 and 46 of the inverter 35 and the stator 18 in the MG 15. The cooling fan 30 takes in the air outside the protective cover 50 from the vent hole 51 a of the bottom 51, and circulates the air flow gap between the substrates 36 and 44 and the outer peripheral wall 52 in the inverter 35 in the axial direction. At that time, the switching elements 37 and 46 mounted on the substrates 36 and 44 are directly cooled by the air flowing through the inverter 35. Therefore, the cooling efficiency of the switching elements 37 and 46 is good.
[0031]
The air that has flowed in the inverter 35 flows into the MG 15 through the ventilation hole 21a in the bottom 21 of the lid member 20, and flows in the MG 15 in the axial direction. At this time, the stator 18 and the rotor 27 are directly cooled by the flowing air. Therefore, the cooling efficiency of the stator 18 and the like is good.
[0032]
Second, the structure of the inverter 35 is simplified and the thickness is reduced. The bottom portion 21 of the cover member 20 of the MG 15 also functions as a member to be attached to the substrates 36 and 44 of the inverter 35 and a cover member of the protective cover 50. As a result, it is not necessary to provide fixing members for the boards 36 and 44 in the inverter 35, and the number of components is reduced. In addition, it is unnecessary to provide a dedicated cover member for the protective cover 50, and the thickness is reduced.
[0033]
Third, since the substrates 36 and 44 are arranged in a plane orthogonal to the axis of the rotating shaft 26, the thickness of the inverter 35 can be reduced. When the substrates 36 and 44 are provided at positions not orthogonal to the rotation shaft 26, for example, at positions deviated to the right from the right end of the rotation shaft 26, the thickness of the inverter 35 increases accordingly.
[0034]
Fourth, since the length of the three-phase AC wiring connecting the inverter 35 and the MG 15 is short, adverse effects such as noise on peripheral devices are reduced. Further, in the inverter 35, since the smoothing capacitor 38 is arranged near the switching element 37, the surge generated by the switching operation of the switching element 37 is absorbed near the generation source, and radiation of noise can be prevented. Further, since the control circuit 39 is arranged near the switching element 37, the wiring length to the switching element is shortened, and noise on the control signal for driving the switching element 37 can be prevented.
[0035]
【The invention's effect】
As described above, according to the present invention, the cooling member is provided near the opening of the housing of the electric motor, and the inverter board and the like are fixed in the lid member covering the opening. As a result, the substrate approaches the cooling member, the switching elements and the stator on the substrate are efficiently cooled by the cooling member, and an increase in the axial dimension of the inverter can be suppressed.
[0036]
According to the second aspect, the lid member can function as a covering means for the cooling member and a means for fixing the substrate. According to the third aspect, the substrate can be brought close to the cooling member without increasing the axial dimension of the inverter. According to the fourth aspect, one cooling member in the electric motor allows air to flow from the inverter to the electric motor, thereby efficiently cooling the switching element and the like and the stator.
[0037]
According to the fifth aspect, the substrate and the like are protected, and the dimension of the protective cover in the axial direction can be reduced. According to claim 6, an increase in the thickness of the inverter can be suppressed.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing an embodiment of the present invention.
FIG. 2 is a perspective view showing a substrate of the embodiment.
FIG. 3 is an explanatory diagram of an electric system including the embodiment.
FIG. 4 is an explanatory diagram of a main part in FIG. 3;
FIG. 5 is an explanatory diagram of a conventional electric system.
FIG. 6 is a front view showing a conventional example.
[Explanation of symbols]
10: Inverter type electric motor 15: MG
16: Housing 18: Stator 20: Lid 21: Bottom 22: Circular wall 26: Rotating shaft 27: Rotor 30: Cooling fan 35: Inverter 36, 44: Substrate 37, 46: Switching element 38: Smoothing capacitor 50: Protective cover 51: bottom 52: circumferential wall

Claims (6)

A cylindrical housing having one end opened, a stator and a rotor housed in the housing, one cooling member mounted on the rotation shaft of the rotor near the opening of the housing, and An electric motor including a lid member closing an opening of the housing,
An inverter including a substrate disposed in a plane intersecting the rotation axis and fixed to the lid member, a switching element and a smoothing capacitor mounted on the substrate, and a protective cover covering the substrate;
An inverter-integrated electric motor characterized by comprising: 2. The inverter-integrated electric motor according to claim 1, wherein the lid member includes a bottom having a ventilation hole, and an outer peripheral wall that covers the cooling member, and the substrate is fixed to the bottom. 3. 2. The inverter-integrated electric motor according to claim 1, wherein the substrate has a through hole through which the rotating shaft passes at the center thereof, and the switching element and the smoothing capacitor are mounted around the through hole. 3. 2. The inverter-integrated electric motor according to claim 1, wherein the protective cover includes a bottom portion having a vent hole, and an outer peripheral wall that covers the substrate. 3. The inverter-integrated electric motor according to claim 1, wherein the cooling member allows external air to flow from the inverter toward the electric motor. 2. The inverter-integrated electric motor according to claim 1, wherein the substrate is disposed in a plane orthogonal to an axis of the rotation shaft.

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