JP2004312960A - Motor integrating inverter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor integrating an inverter in which the motor and the inverter can be cooled efficiently, and an increase in overall dimensions is suppressed. <P>SOLUTION: The motor integrating an inverter comprises a motor 15 including a tubular housing 16 having one open end, a stator 18 fixed to the housing, a rotor 27 fixed to a rotating shaft 26 supported by the housing and facing the stator, a cover member 21 covering the opening of the housing, and a first cooling member 30 fixed onto the rotating shaft in the vicinity of the opening of the housing, and an inverter 35 including a protective cover 50 fixed to the cover member, power converting elements 44 and 46 secured to the cover member or the protective cover, and a second cooling member 55 fixed and the protective cover. <P>COPYRIGHT: (C)2005,JPO&NCIPI

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 motor, in a conventional inverter-integrated 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, 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]
In addition, 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 external dimensions are large.
[0009]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inverter-integrated electric motor in which an electric motor and an inverter can be efficiently cooled and an increase in external dimensions is suppressed.
[0010]
[Means for Solving the Problems]
The inventor of the present application completed the present invention by thinking that the electric motor and the inverter are integrated in the axial direction of the electric motor, and then the electric motor and the inverter are provided with cooling members respectively.
[0011]
According to a first aspect of the present invention, there is provided an inverter-integrated electric motor having a cylindrical housing having an open end, a stator mounted on the housing, and a stator mounted on a rotating shaft supported by the housing. An electric motor including an opposing rotor, a cover member covering an opening of the housing, and a first cooling member mounted near an opening of the housing on a rotating shaft; a protective cover attached to the cover member; An inverter including a power conversion element fixed to the protective cover and a second cooling member mounted between the lid member on the rotating shaft and the protective cover.
[0012]
In this inverter-integrated electric motor, the electric motor and the inverter are arranged side by side in the axial direction and integrated, and the rotating shaft and the cover member are both constituent members. The first cooling member rotates together with the rotor of the electric motor, and the second cooling member rotates together with the first cooling member.
[0013]
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.
[0014]
In the inverter-integrated electric motor according to claim 2, in claim 1, the second cooling member has a lower cooling capacity than the first cooling member. According to a third aspect of the present invention, there is provided the inverter-integrated electric motor according to the second aspect, wherein the lid member and / or the protective cover have a ventilation hole.
[0015]
According to a fourth aspect of the present invention, in the inverter-integrated electric motor, a magnetic pole sensor is further mounted between the power conversion element on the rotating shaft and the protective cover. According to a fifth aspect of the present invention, in the inverter integrated motor of the fourth aspect, a magnet is attached to the second cooling member.
[0016]
According to a second aspect of the present invention, there is provided an inverter-integrated electric motor, comprising an electric motor, an inverter integrated with the electric motor at one axial end of the electric motor, and a first cooling member disposed in the electric motor. , And a second cooling member disposed in the inverter.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
In terms of structure, the inverter-integrated electric motor of the present invention is roughly classified into an electric motor having a cooling member and an inverter having a cooling member. Functionally, it is roughly divided into an electric motor, an inverter, and a cooling unit.
<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.
[0018]
The motor includes a housing, a stator, a rotating shaft, a rotor, a lid member, and a first cooling member. The housing has a bottomed cylindrical shape with one end closed and the other end open, and includes a bottom and a cylindrical portion. A stator is attached to the inner peripheral surface of the cylindrical portion, and one end of the stator is fixed to a rotating shaft supported by the bottom. An intermediate portion of the rotation shaft is supported by the lid member.
[0019]
The lid member may have a container shape including a bottom portion and a peripheral wall portion, the peripheral wall portion covering the first cooling member, and the bottom portion closing an opening of the housing. In addition, a vent hole that allows air to flow is formed at the bottom.
<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 power conversion element, a protective cover, and a second cooling member.
[0020]
The power conversion element includes a base and a switching element. The substrate is arranged in a plane orthogonal to the rotation axis of the rotor, is fixed to a cover member or a protective cover, and has a switching element, a smoothing capacitor, and the like mounted close to the periphery of the through hole. The number of substrates may be one or two or more. The sizes of the plurality of substrates may be the same or different.
[0021]
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. The bottom can have vents.
<Cooling member>
The cooling member includes a first cooling member that mainly cools a rotor and the like of the electric motor, and a second cooling member that mainly cools a substrate and the like of the inverter, and both are fixed on a rotating member. The first cooling member is fixed inside the lid member near the opening of the housing, sucks air outside the lid member into the housing, and mainly cools the rotor and the stator.
[0022]
The second cooling member is fixed between the substrate and the like and the protective cover. The air outside the protective cover is sucked to cool mainly the substrate and the like. It should be noted that a vent (an inner peripheral portion) of the second cooling member other than the fan can be provided as necessary.
[0023]
There is no particular limitation on the outer diameter of the two cooling members, but it is desirable that the cooling capacity (particularly the outer diameter) of the second cooling member is smaller than that of the first cooling member.
<Magnetic pole sensor, magnet>
A magnetic pole sensor for detecting the phase in the rotation direction of the rotor can be attached to the other end (free end) of the rotating shaft. The magnetic pole sensor is housed in the protective cover and rotates with the rotation axis. Either the magnetic pole sensor or the second cooling member may be located on the tip side. The permanent magnet is fixed to the inner peripheral portion of the second cooling member. However, if the second cooling member is magnetized, it becomes unnecessary to attach the permanent magnet.
[0024]
【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. As shown in FIGS. 1 and 2, the inverter-integrated electric motor 10 is roughly divided into an electric motor (MG) 15 having a cooling fan and an inverter 35 having a cooling fan 46.
[0025]
More specifically, the MG 15 includes a housing 16, a stator 18, a lid member 20, a rotating shaft 26, a rotor 27, and a first cooling fan 30. The housing 16 has a bottomed cylindrical shape with the other end (left end) closed and one end (right end) opened. The cover member 20 includes a circular bottom portion 21 and a circumferential wall portion 22 rising at a right angle from the periphery thereof. The circumferential wall portion 22 covers the first cooling fan 30, and the bottom portion 21 covers the opening of the housing 16. . A plurality of ventilation holes 21a are formed in the bottom 21.
[0026]
Stator 18 is fixed to the inner peripheral surface of housing 16. The rotating shaft 26 is rotatably supported at one end and an intermediate portion by the housing 16 and the lid member 20, respectively. A rotor 27 fixed thereon faces the stator 18. A first cooling fan 30 is fixed on the rotation shaft 26 near the opening of the housing 16, that is, between the rotor 27 and the lid member 20, and rotates integrally with the rotation shaft 26, that is, the rotor 27.
[0027]
The inverter 35 includes a board 36, a switching element 37, and the like, a protective cover 50, a second cooling fan 55, a magnetic pole sensor 56, and the like. 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.
[0028]
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.
[0029]
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.
[0030]
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.
[0031]
A second cooling fan 55 having an outer diameter smaller than that of the first cooling fan 30 is attached to the other end (free end) of the rotating shaft 26 and is located between the substrate 44 and the like and the bottom 51 of the protective cover 50. 26 and rotate together.
[0032]
The magnetic pole sensor 56 is mounted at a position slightly retracted from the free end of the rotating shaft 26, that is, between the second cooling fan 55 and the substrate 44 or the like. A magnet 57 for determining the phase in the rotation direction of the rotor 27 in cooperation with the magnetic pole sensor 56 is attached to the inner peripheral portion of the side surface of the second cooling fan 55 facing the magnetic pole sensor 56.
[0033]
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).
(Action)
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. At the time of regenerative braking, MG 15 is driven by wheels 64, and the generated regenerative energy is stored in DC power supply 61.
[0034]
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.
(effect)
According to the present embodiment, the following effects can be obtained by integrating the motor 15 and the inverter 35 in the axial direction of the motor 15.
[0035]
First, 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.
[0036]
Further, since the substrates 36 and 44 are arranged in a plane perpendicular to the axis of the rotating shaft 26, the thickness of the inverter 35 can be reduced, and 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, since the smoothing capacitor 38 of the inverter 35 is arranged near the switching element 37, a surge generated by the switching operation of the switching element 37 is absorbed near the generation source, and radiation of noise can be prevented.
[0037]
Further, the second cooling fan 55 is a mounting member for the magnet 57 cooperating with the magnetic pole sensor 56, so that an increase in the axial dimension is suppressed.
[0038]
On the other hand, by providing the two cooling fans 30 and 55, the following effects can be obtained. 1 and 2, the first cooling fan 30 and the second cooling member 55 effectively cool the switching elements 37 and 46 of the inverter 35 and the stator 18 in the MG 15.
[0039]
More specifically, the first cooling fan 30 sucks the air outside the protective cover 50 into the housing 16 from the ventilation hole 51 a of the bottom 51. The sucked air flows into the MG 15 and flows inside the MG 15 in the axial direction. At that time, since the stator 18 and the rotor 27 are directly cooled, the cooling efficiency of the stator 18 and the like is good. The first cooling fan 30 also generates an air flow outside the lid member 21 to cool the substrate 44 and the like.
[0040]
On the other hand, the second cooling member 55 sucks the air outside the protective cover 50 of the inverter 35 from the vent 51 a of the bottom 51. The sucked air flows in the air flow gap between the substrates 36 and 44 and the outer peripheral wall 52 in the axial direction. At this time, the air flowing through the inverter 35 directly cools the switching elements 37 and 46 mounted on the substrates 36 and 44, and thus the cooling efficiency of the switching elements 37 and 46 is good. The second cooling fan 55 also generates an air flow inside the cover member 21 to cool the rotor 27 and the like.
[0041]
【The invention's effect】
As described above, according to the inverter-integrated electric motor of the first and second inventions, the electric motor and the inverter are integrated in the axial direction, and the rotary shaft and the lid member are both constituent elements. . As a result, an increase in the axial dimension is suppressed. In addition, the rotor and the stator are efficiently cooled by the first cooling member, and the power conversion element is efficiently cooled by the second cooling member.
[0042]
According to the inverter-integrated electric motor of the second aspect, the rotor and the stator, which are more likely to increase in temperature than the power conversion element, can be cooled by the first cooling member having a large outer diameter.
According to the inverter-integrated electric motor of the third aspect, the flow of air in the electric motor and the inverter becomes smooth.
[0043]
According to the inverter-integrated electric motor of the fourth aspect, it is possible to detect the rotational phase of the rotor and excite a predetermined coil of the stator at a predetermined time. According to the inverter-integrated electric motor of the fifth aspect, an increase in the axial dimension due to the attachment of the magnet 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 integrated motor 15: MG
16: Housing 18: Stator 20: Lid member 26: Rotating shaft 27: Rotor 30: First cooling fan 35: Inverter 36, 44: Substrate 37, 46: Switching element 38: Smoothing capacitor 50: Protective cover 55: Second Cooling fan 56: magnetic pole sensor

Claims (6)

A cylindrical housing having an open end, a stator mounted on the housing, a rotor mounted on a rotating shaft supported by the housing, facing the stator, a lid member covering an opening of the housing, and the rotating shaft; An electric motor comprising: a first cooling member mounted near an opening of the housing above;
A protective cover attached to the lid member, a power conversion element fixed to the lid member or the protective cover, and a second cooling member attached between the lid member and the protective cover on the rotating shaft. An inverter comprising:
An inverter-integrated electric motor characterized by comprising: The electric motor according to claim 1, wherein the second cooling member has a lower cooling capacity than the first cooling member. The inverter-integrated electric motor according to claim 2, wherein the cover member and / or the protective cover have a ventilation hole. 2. The inverter-integrated electric motor according to claim 1, further comprising a magnetic pole sensor mounted between the power conversion element on the rotating shaft and the protective cover. 3. The inverter-integrated electric motor according to claim 4, wherein a magnet is attached to the second cooling member. Electric motor,
An inverter integrated with the motor at one axial end of the motor;
A first cooling member disposed in the electric motor;
A second cooling member disposed in the inverter;
An inverter-integrated electric motor characterized by comprising:

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