JP5330296B2 - Electric turbocharger - Google Patents

Description

  The present invention relates to an electric supercharger in which an electric motor is built in a supercharger using exhaust gas from an engine.

  In a supercharger using exhaust gas from an engine, an electric supercharger with a built-in electric motor has been proposed in order to assist a supercharging force at low speed rotation where efficiency is reduced. As such an electric supercharger, there is one in which a device for electrically controlling a motor is configured in a donut shape or a U shape and is fixed to a compressor discharge side of the electric supercharger via a heat insulating material. (For example, refer to Patent Document 1).

Japanese Patent Laying-Open No. 2007-46479 (first page, FIG. 1)

  In the conventional electric supercharger as described above, since the wiring between the motor and the control device passes through the inside of the compressor, it is necessary to keep the air tight so that air does not leak, and the structure becomes complicated. In addition, since the rotational speed of the electric supercharger reaches 100,000 to 200,000 rpm and its control is also performed at a high frequency, the wiring becomes longer by passing through the compressor portion as described above, and the wiring inductance increases. Loss increases. In addition, in control devices, the temperature rise due to heat generation of semiconductor elements and capacitors becomes significant, and the time for which the lifetime of the elements can be guaranteed is shortened. There was a problem. Further, since it is necessary to increase the carrier frequency for driving the inverter to, for example, a switching frequency several times higher than that of a normal inverter device in response to high-speed rotation, there is a problem that switching loss increases.

  The present invention has been made to solve the above-described problems of the prior art. The structure is simple and the wiring can be shortened, and the temperature rise is suppressed by increasing the cooling effect and the loss is reduced. The purpose is to provide an electric supercharger.

An electric supercharger according to the present invention is provided coaxially between a turbine device and a compressor device, and an electric motor in which wiring from a stator is drawn out to an outer peripheral portion of a housing in a radial direction and a connection portion is provided at an end thereof. Installed on the outer periphery of the housing via heat insulation means, provided on the opposite side of the heat insulation means to the connection means with the connection portion, a control circuit for driving the motor, and the control circuit. And a control device having a heat radiating portion, and a plurality of sets of the turbine device, the electric motor, and the compressor device, wherein the plurality of electric motors are arranged in parallel with their rotation axes parallel to each other. Rutotomoni, in that the control device is a common thing to a plurality of the electric motor, and arranged over the common of the control device to a plurality of housing of the electric motor, The outer diameter of the housing in the electric motor is made equal to the outer diameter of the housing in the compressor device, and the control device arranged on the outer periphery of the housing of the electric motor is biased toward the housing side of the compressor device. In addition, the connecting means for connecting the connecting portion and the control device is provided on the compressor device side of the motor .

In the present invention, the wiring from the stator is drawn out in the radial direction, while the control device is installed on the outer periphery of the housing via the heat insulating means, and the common control device is straddled across the housings of the plurality of electric motors. Since they are arranged, the wiring between the motor and the control device can be easily shortened with a simple configuration. For this reason, loss due to an increase in wiring inductance is reduced, and the cooling effect can be easily enhanced in terms of layout. And since the outer diameter of the housing in the electric motor is made equal to the outer diameter of the housing in the compressor device, the length of the wiring can be further shortened, loss can be further reduced, and the control device can be used as the compressor device. Since the control device and the wiring can be provided at a relatively low temperature, the cooling effect can be further enhanced.

Sectional drawing which shows typically the principal part structure of the electric supercharger which concerns on Embodiment 1 of this invention. Sectional drawing which shows typically the principal part structure of the 1st modification of the electric supercharger shown in FIG. Sectional drawing which shows typically the principal part structure of the 2nd modification of the electric supercharger shown in FIG. FIG. 2 is a cooling path diagram schematically showing a cooling path when the electric supercharger shown in FIG. 1 is provided with cooling means. The cooling route figure which shows the 1st modification of the cooling means shown in FIG. FIG. 5 is a cooling path diagram showing a second modification of the cooling means shown in FIG. 4. FIG. 5 is a cooling path diagram showing a third modification of the cooling means shown in FIG. 4. Sectional drawing which shows typically the principal part structure of the electric supercharger which concerns on Embodiment 2 of this invention. Sectional drawing which shows typically the principal part structure of the electric supercharger which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram schematically showing a main configuration of an electric supercharger according to Embodiment 1 of the present invention. In the figure, an electric supercharger 100 includes an electric motor 2 provided at a central portion of a common rotating shaft 1, a turbine device 3 connected to one side of the rotating shaft 1, and the other side of the rotating shaft 1. The compressor apparatus 4 connected and the control apparatus 6 which controls the electric motor 2 fixed to the outer peripheral part of the housing 5 are provided. The turbine device 3 includes a turbine impeller 31 fixed to the rotary shaft 1 and a turbine housing 32 formed so as to surround the turbine impeller 31. The turbine impeller 31 is rotated by wind power of exhaust gas from an internal combustion engine (engine) (not shown) guided to the turbine housing 32.

The compressor device 4 includes a compressor impeller 41 fixed to the rotating shaft 1 common to the turbine impeller 31 and a compressor housing 42 formed so as to surround the compressor impeller 41. The air is compressed by the rotational force of the electric motor 2 to be described later, and the air is compressed and supercharged to the internal combustion engine.
The electric motor 2 includes a motor rotor 21 fixed to a common rotating shaft 1, a stator 23 having a stator coil (not shown) disposed so as to surround the motor rotor 21, and a motor housing that holds the stator 23. 22, a wiring 24 drawn out from the stator 23 through the motor housing 22 in the radial direction downward in the figure, and an electrical connection portion 25 with the control device 6 provided at the tip of the wiring 24. Have.

  The control device 6 converts DC power supplied from a battery (not shown) as a power source into AC power, and rotates the rotating shaft 1 by applying AC power to the stator 23 of the motor 2. In the example of FIG. 1, the internal combustion engine is fixed to the vertical lower portions of the outer peripheral portions of the turbine housing 32 and the compressor housing 42 via the heat insulating means 7. The turbine housing 32, the compressor housing 42, and the motor housing 22 may be formed as a whole integrally, or may be formed by connecting a plurality of formed products. If there is no particular need for distinction, here, for the sake of convenience, it is simply referred to as the housing 5.

  The control device 6 includes a connecting means 61 for connecting to the connecting portion 25 provided in the motor 2, a control circuit 62 for driving the motor 2, and a heat radiating portion provided on the opposite side of the heat insulating means 7 with respect to the control circuit 62. 63. The control circuit 62, not shown in detail, includes a power circuit (not shown) having a power semiconductor or the like, and a device of a power circuit that generates particularly large heat is connected to the heat dissipation portion 63. The control circuit 62 is housed in an outer box (not shown), and the material thereof may be a metal having excellent heat resistance and heat dissipation, and the heat insulating means 7 may be a forced cooling system such as a liquid cooling system. In the case of adopting it, a resin material may be used because the required heat resistance can be lowered by improving the heat dissipation. Since the housing 5 becomes hot during operation, the control device 6 is installed on the lower side of the housing 5, so that the heat of the housing 5 is transferred to the control device 6 by convection and the temperature of the control device 6 rises. Can be suppressed.

  The wiring 24 from the stator 23 can be most miniaturized in terms of the structure of the stator core by arranging the terminal end of the wiring at the axial end of the stator 23. For this reason, it is preferable that the wiring 24 be housed in a plane portion including the end portion of the stator 23 in the axial direction because the size can be minimized. The wiring 24 passes through the motor housing 22 of the electric motor 2, and the connection portion 25 is provided at the tip end portion of the wiring 24 drawn to the outside of the motor housing 22. In addition, it is preferable to project the wiring 24 from between the electric motor 2 and the compressor device 4 because the temperature in the housing 5 is relatively low.

  The connection part 25 can select a structure and a system suitably according to a connection mechanism with the connection means 61. For example, the connecting portion 25 is composed of the end of the wiring 24 itself or a ring processed end, or one of the connectors connected to the end of the wiring 24 when the connecting mechanism is a male and female connector. Further, it includes an insulator that holds the end of the wiring 24 or constitutes a connector. The connecting portion 25 is electrically and mechanically connected to the connecting means 61 of the control device 6 when the control device 6 is attached.

  The connection mechanism and connection method between the connection part 25 and the connection means 61 are not particularly limited, and may be, for example, a fitting type or a screwing type. Moreover, the connection part 25 may comprise a part or all of the connection mechanism. For example, the end portion itself of the wiring 24 may constitute the connection portion 25, or the connection portion 25 and the connection means 61 may constitute one connection mechanism. In addition, a terminal block (not shown) is provided as the connecting means 61, while the connecting portion of the wiring 24 is configured by a through hole, and a screw (not shown) inserted into the through hole is used as a terminal block that forms the connecting means 61. Screwing may be used. In this example, it is configured by screwing, but the connection mechanism may be configured by male and female connectors, for example. Moreover, you may reverse the structure of the connection part 25 and the connection means 61. FIG.

  Moreover, as what can be preferably used as the said heat insulation means 7, what sprayed the ceramic membrane | film | coat to metals, such as a ceramic and iron whose heat conductivity is not so high, the raw material which shape | molded glass wool, etc. are mentioned, for example. However, it is not limited to these. The material of the heat radiating portion 63 is preferably a heat good conductor such as general aluminum or copper. Air cooling may be used, or liquid cooling may be used for downsizing. In addition, it is preferable that the motor rotor 21 (the electric motor 2) be arranged offset to the compressor impeller 41 side because the heat resistance with respect to the turbine impeller 31 that becomes a high temperature can be increased and the amount of heat received can be reduced.

Moreover, in order to reduce the heat conduction from the housing 24 transmitted from the wiring 24, the connecting portion 25, and the connecting means 61 to the control device 6, metal-related materials used for the wiring 24, the connecting portion 25, and the connecting means 61 are used. The thermal conductivity is preferably lower than copper, for example, aluminum or iron.
In the first modification of the first embodiment shown in FIG. 2, the attachment position of the control device 6 is installed close to the compressor housing 42 side where the temperature is likely to be lower in the housing 5. .

  In the second modification of the first embodiment shown in FIG. 3, the outer diameter of the motor housing 22 is enlarged so as to be equal to or larger than that of the turbine housing 32 or the compressor housing 42, and the control device 6 is changed to the electric motor 2. On the other hand, the wiring 24 is provided on the side facing the compressor device 4. In the second modification, the diameter of the motor rotor 21 is increased, whereby the length of the wiring 24 can be further shortened, and the loss can be further reduced.

  Further, the wiring 611 constituting the connecting means 61 of the control device 6 may be insert-molded on the wall surface of the control circuit 62 portion, and connected to the insert-molded portion by cutting a screw hole. In that case, it can connect simply by screwing the conductor edge part which comprises the connection part 25 of the wiring 24 of the electric motor 2 directly. That is, with this arrangement, the inductance of the wires 24 and 611 can be minimized while reducing the thermal interference from the turbine in the control device 6.

Furthermore, FIGS. 4 to 7 use a method of forcibly cooling the circulating means 8 by circulating a liquid as the cooling means 8 in order to reliably suppress the temperature rise of the control device 6 within the allowable temperature. A plurality of configuration examples when the motor 2 is cooled as an essential cooling target are shown. The liquid used may be water or oil. The cooling means 8 may be a system using a heat pipe and a cooling fan, for example.
In FIG. 4, the cooling means 8 is configured by a radiator 81, a circulation pump 82, a heat radiating portion 63, a housing 5, an electric motor 2, and a circulation path 80 that connects these portions in series so that liquid flows in the order of description. is there.

  Here, the radiator 81 and the circulation pump 82 are configured such that what is provided in a vehicle equipped with a general water-cooled engine is used as it is and bypassed to the circulation path 80 (not shown). . The radiator 81 and the circulation pump 82 may be separately prepared. In addition, the heat radiating unit 63, the housing 5, and the electric motor 2 that are to be cooled require a flow path for allowing the coolant to flow, and these are conventional metal pipes that allow the liquid to flow, for example. And a method of mechanically and thermally coupling the object to be cooled with a joining means such as brazing or a method of forming a flow path for allowing a liquid to flow through the heat radiating portion 63 or the like. it can. Here, since there is no particular limitation, the flow structure and the cooling structure are not shown for convenience, and the cooling object interposed in the circulation path 80 is shown as a block.

  The housing 5 and the electric motor 2 are provided on the downstream side of the circulation path 80 because the temperature rise is remarkably high and the necessity for liquid cooling is high. In this case, it is preferable that the circulation path constituting the circulation path 80 is in order of increasing upper limit temperature, and the heat radiation part 63, the housing 5, and the electric motor 2 are arranged in this order, thereby eliminating the need to unnecessarily increase the heat dissipation. Because it is economical. Further, when the cooling part of the electric motor 2 is divided into a plurality of parts, the cooling may be performed by alternately passing through the housing 5 and the cooling part of the electric motor 2. However, this order is not necessarily required depending on restrictions on mounting in the engine room, but there is a need to increase the size of the radiator 81. Furthermore, the cooling system of the radiator 81, the circulation pump 82, and the like can be reduced by making the cooling method of the heat radiation part 63, the housing 5 and the electric motor 2 the same as those mounted on the vehicle, and also using the radiator 81 and the circulation pump 82 of the circulation path 80. Without increasing, the cooling effect can be enhanced and the size can be reduced.

  The first modification of the cooling means shown in FIG. 5 is obtained by adding a heat insulating means 7 to the configuration of FIG. 4 for miniaturization. As in the case of FIG. 4, the cooling method of the heat insulating means 7, the heat radiating portion 63, and the housing 5 is made the same, and the circulation path 80 is unified, so that the cooling effect can be further enhanced and the size can be reduced. Further, the size can be further reduced by integration with the housing 5. Also in this case, it is preferable that the cooling path of the circulation path 80 is in order of increasing upper limit temperature, and as shown in the schematic diagram of FIG. 5, the order of the heat radiating portion 63, the heat insulating means 7, the housing 5, and the electric motor 2 is preferable.

  The second modification of the cooling means shown in FIG. 6 is the control circuit 62 portion by liquid-cooling the connecting means 61, the wiring 611, the connecting portion 25, and the wiring 24 instead of the heat insulating means 7 in the configuration of FIG. The heat transfer to is further reduced. In this case, it is better that the cooling path passes from the side where the upper limit temperature is low. As shown in FIG. The order of the housing 5 and the electric motor 2 is preferable.

  On the other hand, in the third modification of the cooling means shown in FIG. 7, the connection means 61, the wiring 611, the connection portion 25, and the wiring 24 are liquid-cooled to the control circuit 62 portion in addition to the configuration of FIG. The heat transfer is further reduced. In this case, as shown in FIG. 7, the cooling path includes the heat radiating portion 63, the heat insulating means 7, the connecting means 61 and the wiring 611 of the control device 6, the connecting portion 25 and the wiring 24 of the electric motor 2, the housing 5 and the electric motor 2. The order is preferred. As a cooling method of the wirings 611 and 24, the cooling water pipe may be made of an insulating material and run along the wiring, or a through hole may be provided in the wiring and the cooling water may be passed through the through hole. In addition, according to the test conducted by the present inventors, it was confirmed that the cooling performance was improved by passing cooling water through the through hole.

  In the first embodiment configured as described above, the wiring 24 from the stator 23 projects in the radial direction downward in FIG. 1 (vertically downward) and faces the connection portion 25 provided at the end thereof. By installing the connection means 61 of the control device 6 as described above, the wiring 24 of the electric motor 2 is only passed through the portion that penetrates the motor housing 22, so that the wiring length can be easily shortened with a simple structure. For this reason, wiring inductance and resistance can be reduced even at high frequencies, and loss can be reduced. In switching at a high carrier frequency, which is a problem in the electric supercharger, the inductance is reduced by reducing the wiring length. As a result, the surge voltage at the time of switching is reduced and the switching loss can be reduced, which is very effective in reducing the loss.

  Further, since the control device 6 for driving the electric motor 2 is provided on the outer peripheral portion of the housing 5 through the heat insulating means 7 made of a high heat resistance and low heat conductive material, the heat conduction from the housing 5 can be reduced. In addition, since the heat dissipating part 63 made of a high heat conductive material is provided on the opposite side of the heat insulating means 7 of the control device 6, the heat dissipation can be enhanced, so that the temperature rise of the control device 6 can be suppressed. . For this reason, since the temperature rise of semiconductor elements (not shown), such as a switching element mounted in the control apparatus 6, is suppressed, the time which can guarantee a lifetime can be lengthened.

In addition, since the control device 6 is biased to the outer peripheral portion of the housing 5 on the compressor device 4 side where the temperature is low and installed via the heat insulating means 7, the cooling effect can be further enhanced.
Moreover, since the installation position of the wiring 24, the connection part 25, and the connection means 61 from the electric motor 2 is provided on the compressor device 4 side from the electric motor 2, the temperature rise is suppressed and the cooling effect can be enhanced.
In addition, since any or all of the wiring 24, the connecting portion 25, and the connecting means 61 from the electric motor 2 are made of a heat conductive material that is at least lower than copper, it is difficult to transfer the heat of the housing 5 to the control device 6.

  Further, a liquid cooling type cooling means 8 is attached to the heat radiating section 63, the housing 5, and the electric motor 2 (FIG. 4), or a liquid cooling type cooling means 8 is added to the heat dissipation means 7 added thereto (FIG. 4). 5), or a liquid cooling type cooling means 8 is added to the configuration shown in FIG. 4 to which the connection means 61 of the control device 6, the wiring 611, the connection portion 25 of the motor 2 and the wiring 24 are added (FIG. 6). In addition, since the liquid cooling type cooling means 8 is added to the structure shown in FIG. 6 to which the heat insulating means 7 is further added (FIG. 7), the temperature rise of the control device 6 is further reliably suppressed, so The property is further improved.

Further, the cooling means 8 can be unified with the vehicle equipment in the cooling path by interposing the radiator 81 and the circulation pump 82 in the circuit and connected in series by one circulation path 80. The number of devices such as the circulating pump 82 can be reduced, and the size and cost can be reduced.
Further, since the cooling path is cooled in order from the side with the lower allowable temperature upper limit, such as the heat radiating portion 63 and the housing 5, the cooling path can be efficiently cooled.
Further, since the control device 6 is arranged vertically below the center of the housing 5, the heat of the higher temperature housing 5 can be prevented from being transmitted to the control device 6 by natural convection, so that the cooling effect is enhanced. Can do.

Embodiment 2. FIG.
FIG. 8 is a diagram schematically showing a main configuration of the electric supercharger according to the second embodiment of the present invention. In the figure, the electric supercharger 100 is made into a twin turbine, and two housings 5A and 5B are arranged in parallel with the rotation shafts 1A and 1B in parallel. The control device 6 is fixed to a vertically lower portion across the outer peripheral portions of the two housings 5A and 5B via heat insulating means 7, and the control device 6 and the two housings 5A and 5B It arrange | positions symmetrically so that it may become. In addition, the turbine impeller, the electric motor 2, and the compressor impeller are provided in each housing 5A and 5B similarly to what is shown in FIGS. Further, the wires 24 from the stators 23A and 23B are drawn obliquely downward from the lower portions of the housings 5A and 5B, respectively, and an integrated connection portion 25 is provided at the tip thereof. Other configurations are substantially the same as those of the first embodiment.

  In Embodiment 2 configured as described above, since the electric turbocharger is converted into a twin turbine, the number of housings becomes two and heat is also dispersed, so the temperature rise of the housings 5A and 5B is reduced. The temperature rise of the control device 6 due to heat transfer from the housings 5A and 5B can be reduced. In particular, an example in which the control device 6 and the two housings 5A and 5B are positioned in an isosceles triangle has been shown, but the size can be minimized while minimizing inductance and ensuring heat dissipation from the control device 6. . However, the isosceles triangle does not necessarily have to be located depending on the constraints in the engine room. In FIG. 8, the control device 6 is unified into one and fixed across the outer peripheral bottoms of the two housings 5 </ b> A and 5 </ b> B. However, the control device 6 may be attached to each turbine.

  Further, the sizes of the turbines may be different from each other. In this case, it is possible to efficiently perform supercharging in each rotation region by dividing into a turbine operating at a low speed and a turbine operating at a high speed. In other words, characteristics such as a turbine with a small moment of inertia boosting the boost pressure first and a boost pressure of the turbine with a large moment of inertia rising later are obtained, and as a result, the boost characteristics of the boost pressure are improved. Can also be obtained.

  Furthermore, in order to improve the efficiency at low speed, the size can be reduced by using only the turbine operating at low speed as the electric supercharger. Furthermore, at high speed, the supply of exhaust gas to the turbine operating at low speed is stopped, and only the turbine operating at high speed is operated, whereby the temperature rise of the housing of the turbine operating at low speed can be reduced. The number of housings 5, that is, the number of turbines may be three or more. Moreover, it is the same as that of Embodiment 1 that the cooling means 8 illustrated in FIGS. 4 to 7 can be provided.

Embodiment 3 FIG.
FIG. 9 is a diagram schematically showing a main configuration of the electric supercharger according to the third embodiment of the present invention. In the figure, the wiring 24 of the electric motor 2 is projected radially from the stator 23 at an equal angle of 120 ° for each phase, and the connection portion 25 is provided at three positions on the outer peripheral portion of the housing 5 at an equal angle corresponding to the wiring 24. Are distributed. The control device 6 is also divided into three parts corresponding to each phase, and is installed at a position corresponding to the connecting portion 25 on the housing 5 with the heat insulating means 7 interposed therebetween. , Mechanically connected to the connecting portion 25. Further, the heat insulating means 7 may be fixed directly to the outer peripheral portion of the housing 5 or may be fixed via the connecting portion 25. In addition, although one of the protruding directions of the wiring 24 is directly above, it may have a configuration in which the top and bottom are inverted so as to be directly below. Other configurations are the same as those of the first embodiment.

  In the third embodiment configured as described above, the wiring 24 from the stator 23 is projected radially from the stator 23 at an equal angle of 120 ° for each phase, and the control device 6 is also configured corresponding to each phase. In this way, the length of the wirings 24 and 611 can be further shortened by dividing them into three and providing them at the corresponding positions on the housing 5, so that the loss can be further reduced. In addition, since the heat radiating portions 63 are also distributed and disposed, the heat interference is reduced, and even with a smaller heat radiating device, sufficient heat radiation can be ensured, so that the size of the heat radiating device can also be reduced.

  DESCRIPTION OF SYMBOLS 1 Rotating shaft, 2 Electric motor, 21 Motor rotor, 22 Motor housing, 23 Stator, 24 Wiring, 25 Connection part, 3 Turbine apparatus, 31 Turbine impeller, 32 Turbine housing, 4 Compressor apparatus, 41 Compressor impeller, 42 Compressor housing, 5, 5A, 5B housing, 6 control device, 61 connection means, 611 wiring, 62 control circuit, 63 heat radiating part, 7 heat insulation means, 8 cooling means, 80 circulation path, 81 radiator, 82 circulation pump, 100 electric supercharger.

Claims (2)

An electric motor installed coaxially between the turbine device and the compressor device, wherein the wiring from the stator is drawn out to the outer peripheral portion of the housing in the radial direction and a connection portion is provided at the end thereof, and is insulated from the outer peripheral portion of the housing Means for connecting to the connecting portion, a control circuit for driving the motor, and a control device having a heat radiating portion provided on the opposite side of the heat insulating means with respect to the control circuit. A plurality of sets of the turbine device, the electric motor, and the compressor device, wherein the plurality of electric motors are arranged in parallel with their rotation axes parallel to each other, and the electric motor as a common, in that arranged over the common of the control device to a plurality of housing of the electric motor, the housing of the electric motor The control device disposed on the outer peripheral portion of the housing of the electric motor is biased toward the housing side of the compressor device such that the outer diameter is equal to the outer diameter of the housing in the compressor device, and An electric supercharger characterized in that the connecting means between the connecting portion and the control device is provided on the compressor device side of the electric motor. Shall constitute a plurality of the electric motor in the first motor and the second electric motor, disposed equidistant said connection means of said control device from the said first electric motor housing and the second motor housing The electric supercharger according to claim 1.

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