JP2006320143A - Electrically assisted turbocharger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrically assisted turbocharger capable of suppressing a vibration of a rotation system and capable of maintaining stable operation using a motor that can be driven at a low power supply voltage. <P>SOLUTION: A compressor 2, an assist motor 6, and a second bearing mechanism 7, are sequentially arranged to a first bearing mechanism 4 connected to a turbine rotator 3a. A compressor wheel 2a and a motor rotor 6a are supported by the first and second bearing mechanisms 4 and 7 from both sides. A lead wire connected to a stator coil of the motor 6 extends in a rotational axis direction to the outside wall of the motor 6 with a protruding part from the outside wall used as a feeder terminal. A power converter 11 can be attached to the outside wall of the motor for consolidated structure. By using an induction machine as the motor 6, the power converter 11 can be gated-off when no assistance is required, or only an excitation current is supplied to the motor 6 to enter into a standby state. If engine braking is required, the motor 6 is operated in a regenerative mode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrically assisted turbocharger that assists a compressor drive of a turbocharger with an electric motor when accelerating an automobile engine.

  In recent years, in an automobile engine using a turbocharger (supercharger), when the engine is accelerated, the compressor (compressor) that drives the turbine wheel of the turbocharger does not increase in speed, and sufficient air is sent to the engine. Therefore, the development of technology for purifying exhaust gas by improving the horsepower and air-fuel ratio of the engine at low speed by sending sufficient air to the engine by assisting the compressor drive with an electric motor is being developed. . In this way, the turbocharger that assists the compressor drive with an electric motor has a direct drive method using an electric motor directly connected to the compressor, and the direct drive method requires the motor to be rotated at a high speed of 50,000 rpm or more. There is.

In this type of conventional technology, for example, as shown in Patent Document 1, an assist motor is provided between a turbine of a turbocharger and a compressor.
Japanese translation of PCT publication No. 2004-512453

  In such a conventional electric assist type turbocharger, as shown in FIG. 1, an assist electric motor AM and a compressor CM are attached to the turbine housing TH via a bearing portion BH. A rotating shaft RX that connects the turbine wheel TW to the motor rotor MR and the compressor wheel CW via a bearing member BE in the bearing portion BH is supported at two points by the two bearings B1 and B2 of the bearing member BE, and the motor rotor. MR and compressor wheel CW overhang from bearings B1, B2. In addition, the motor rotor MR coupled to the rotation shaft RX is constituted by a permanent magnet.

  As described above, the conventional system has a bearing structure with one-side two-point support in which the rotation system of the electric motor AM and the compressor CM overhangs from the turbine housing TH and the bearing portion BR. For this reason, since the eccentricity, spring characteristics, deflection, etc. of the motor rotor MR increase during high-speed rotation, the high-speed operation of the motor AM may not be maintained.

  In the conventional motor AM, the drive voltage supplied to the terminal TM is about several tens of volts [V]. Therefore, in order to drive with a low power supply voltage such as an automobile power supply (usually 12 V), a power supply is required. The voltage must be boosted, and permanent magnets are used for the rotor MR (synchronous motor). Therefore, electromagnetic or mechanical characteristics such as demagnetization and loss are noticeably deteriorated under high speed rotation. It cannot be put into practical use.

  In view of such circumstances, the present invention provides an electrically assisted turbocharger that can suppress vibration of a rotating system and can maintain stable operation using an electric motor that can be driven with a low power supply voltage. With the goal.

  According to one aspect of the present invention, the first bearing mechanism (4) connected to the turbine rotating part (3a) driven by the exhaust gas (Ex) of the engine (1) and the pressurized air to the engine (1). A compressor (2) having a rotating part (2a: 5) for feeding (Arp), one end of the rotating part (2a: 5) supported by the first bearing mechanism (4), and a compressor (2) The assist motor (6) having one end of the drive shaft (6a: 5) connected to the other end of the rotating portion (2a: 5) and the other end of the drive shaft (6a: 5) of the assist motor (6) are supported. An electrically assisted turbocharger comprising a second bearing mechanism (7) is provided. The parentheses are reference symbols or terms used in the embodiments for the sake of understanding.

  In this electrically assisted turbocharger, the lead wire (6e) connected to the stator coils (ac) of the assist motor (6) is connected to the outer wall of the assist motor (6) in the axial direction of the rotating portion (6a: 5). 6d, 11c), and an end portion (6f) protruding from the outer wall (6d, 11c) of the lead wire (6e) is formed as a power feeding terminal (claim 2). .

  Further, in this electrically assisted turbocharger, a power converter (11) for driving the assist motor (6) is attached to the end surface of the outer wall (11c) of the assist motor (6). It can be constituted as follows.

  According to another feature of the present invention, the rotating part connected to the turbine rotating part (3a) driven by the exhaust gas (Ex) of the engine (1) and for sending pressurized air (Arp) into the engine (1). A compressor (2) having (2a: 5), and an assist motor (6; FIG. 6) having an induction machine structure in which a drive shaft (6a: 5) is connected to a rotating part (2a: 5) of the compressor (2) And an electric power converter (11) for driving the assist electric motor (6). The electric power converter (11) is configured such that the assist electric motor (6) is forcibly rotated by the turbine rotating portion (3a) to generate a driving torque. When not required, an electrically assisted turbocharger (Claim 4) is provided that gates off and disconnects the assist motor (6) from the power source (B12).

  According to still another aspect of the present invention, the rotation for feeding pressurized air (Arp) to the engine (1) is connected to the turbine rotating part (3a) driven by the exhaust gas (Ex) of the engine (1). Compressor (2) having a portion (2a: 5) and an assist motor (6; FIG. 6) having an induction machine structure in which a drive shaft (6a: 5) is connected to a rotating portion (2a: 5) of the compressor (2) And an electric power converter (11) for driving the assist electric motor (6). The electric power converter (11) is configured such that the assist electric motor (6) is forcibly rotated by the turbine rotating part (3a) and the driving torque. When the motor is not required, an electric assist type turbocharger that applies to the assist motor (6) a voltage (Vm) that gives only the excitation current (if) at the same frequency as the rotation frequency (fr) of the assist motor (6). ] It is provided.

  According to another aspect of the present invention, the rotating part connected to the turbine rotating part (3a) driven by the exhaust gas (Ex) of the engine (1) and for sending pressurized air (Arp) into the engine (1). A compressor (2) having (2a: 5), an assist motor (6) in which a drive shaft (6a: 5) is connected to a rotating part (2a: 5) of the compressor (2), and an assist motor (6). A power converter (11) to be driven, and when the engine brake is required, the power converter (11) operates the assist motor (6) in a regeneration mode (B4, B5: sf2). A turbocharger is provided.

  In the conventional one-sided support, the electromagnetic force of the assist motor is increased by the “leverage ratio” due to eccentricity, the influence of the negative spring constant of the magnetic spring, the increase of the magnetic force due to the swing of the rotor, etc. While the vibration sensitivity is increased and the amplitude of the third-order vibration mode in the high speed range is increased and the high speed operation cannot be continued, the electrically assisted turbocharger according to the present invention (claim 1) uses a compressor ( 2) and the structure in which both shaft ends of the rotating system (5) of the assist motor (6) are supported by the first and second bearing mechanisms (4, 7), especially the tertiary in the high-speed rotation region. The vibration amplitude at the time of high speed operation can be solved by sufficiently dampening the vibration amplitude of the mode. Further, the first bearing mechanism (4) can use a two-point support bearing that is usually used for a turbocharger (without electric assist), so that it is not necessary to make a significant design change, which is advantageous in terms of productivity. It is.

  In low-voltage, high-speed motors, such as turbocharger assist motors, the motor inductance is very small, so according to the conventional structure that connects the stator coil end of each phase of the motor to the terminal for power feeding on the peripheral surface with a lead wire, Impedance difference occurs, current becomes unbalanced, and problems such as rotational vibration occur. In the electrically assisted turbocharger according to the present invention (claim 2), each phase feeding terminal (6f) of the assist motor (6) Since the lead wire (6e) connected to is parallel to the axial direction, the length of the electric path connecting each phase stator coil can be made equal in the motor, and various problems due to current imbalance between the phases can be solved. Can be solved.

  In the turbocharger assist motor, the voltage of the automotive battery power supply used is as low as 12V, so the motor current is large, and because it is driven at high speed, the power supply frequency (2 to 3kHz) increases and the impedance drop is ignored during operation. It becomes an impossible value. On the other hand, in the electrically assisted turbocharger according to the present invention (Claim 3), the power converter (11) is directly attached to the assist motor (6) and has an integral structure. The distance can be minimized and the impedance drop can be extremely small. Further, since the direct current is fed to the power supply line (12) to the power converter (11), there is no influence of the impedance drop due to the frequency, and the number of direct current power supply lines is one or two, and the narrow engine In addition to being easy to mount in the room, it is also advantageous in terms of radiation noise.

  Since the assist motor of a turbocharger generally has a low load factor (the load time for one time is several seconds and the total load factor is 20% or less), the motor-assisted turbocharger according to the present invention has an induction machine structure. By using the assist induction machine (6; FIG. 6), the inverter (11A) of the power converter (11) is gated off (B12) when driven by the turbocharger turbine (3). (6) can be cut off from the frequency power supply (11A), and the compressor (2) can be put on standby when loaded to assist driving. In this way, when the assist is unnecessary, the assist motor is cut off from the power source and kept in a standby state, so that the rotor temperature can be prevented from rising without causing the rotor loss of the assist motor. Further, it is possible to prevent unstable rotational vibration due to a rise in rotor temperature and improve system efficiency.

  Further, in the electrically assisted turbocharger according to the present invention (Claim 5), by using the assist motor (6; FIG. 6) having an induction machine structure, when the driving torque is not required, the inverter (11A as described above) is used. ) Is not turned off, a voltage having the same frequency as the motor rotation frequency (fr) is applied to the assist motor (6), and only the excitation current (if) is allowed to enter a standby state, and only when torque is required. Control which gives a torque command (sf) to an assist electric motor (6) can be performed. That is, when the compressor (2) is assisted and re-loaded, since the motor excitation is established during standby, the motor torque is immediately raised by the torque command (sf), and a quick response can be realized. Furthermore, since an induction machine is used for assist, there is almost no torque reduction due to a control delay at high speed as in the case of using a synchronous machine.

  In the electrically assisted turbocharger according to the present invention (Claim 6), when the engine brake is required, the assist motor is operated in the regeneration mode, so that the engine brake performance is improved and the energy is regenerated to the power source side. By doing so, fuel consumption can be improved.

[System Overview]
FIG. 2 is a system outline diagram showing an outline of a system including an electrically assisted turbocharger according to one embodiment of the present invention. The engine 1 has a fuel injection valve 1a. The fuel component injected by the fuel injection valve 1a is mixed with the pressurized air Arp from the compressor 2 and passed through the manifold. And the mixed gas is burned in the cylinder to generate power. Exhaust gas Ex after combustion is supplied to the turbine 3 and then discharged to the outside. When the engine 1 rotates at high speed, a part of the exhaust gas Ex is discharged as it is through the wastegate valve 1b.

  A turbine wheel (impeller) 3a of the turbine 3 is connected to a compressor wheel (impeller) 2a of the compressor 2 via two bearings (bearings) 4a and 4b (shaded portions) of the first bearing portion 4 (hereinafter referred to as “the following”). The bearings 4a and 4b are referred to as “first bearing” and “second bearing”, respectively, and the rotor 6a of the electric motor 6 is connected to the compressor wheel 2a. That is, the turbine wheel 3a, the compressor wheel 2a, and the rotor 6a of the electric motor 6 are coupled to each other, and the axis of the rotating system to which these are coupled is indicated by the rotating shaft 5. The rotating shaft 5 further extends from the motor rotor 6a to the outer wall of the motor housing 6b (where "outer" or "outer" indicates the axial direction opposite to the turbine 3), and is provided near the outer wall. The end of the rotating shaft 5 is supported by the bearing (bearing) 7a (shaded portion) of the two-bearing portion 7.

  A rotation sensor 8 is provided at the end of the rotation shaft 5, and the rotation sensor 8 can send a rotation detection signal Nr representing the rotation state of the rotation shaft 5 to the signal line 9. The motor 6 is supplied with high frequency power from a power converter (inverter) 11 through an AC power supply line 10, and the power converter 11 is supplied from a power supply unit 13 including a 12 V battery power supply through a DC power supply line 12. DC power is supplied.

  With such a configuration, the rotation system of the turbine 3, the compressor 2 and the electric motor 6 are connected to each other. Therefore, the compressor wheel 2a to which power from the turbine wheel 3a rotated by the exhaust gas Ex of the engine 1 is applied is further provided. The power from the motor rotor 6a generated by the power supply from the power converter 11 is applied, and the pressurized air Arp to the engine can be pressurized more than when driven by the turbine 3 alone. Therefore, the function of the supercharging mechanism that sends the pressurized air Arp obtained by pressurizing the external air Ar by the rotation of the compressor wheel 2a from the compressor 2 to the engine 1 can be made efficient.

  The engine control unit 14 performs various operations such as the throttle signal Th based on the operation of the accelerator pedal 15, the engine speed Ne, the crank angle signal Ae, the manifold signal Mn, the engine brake signal Eb, various temperature sensor signals Tm, and the vehicle speed signal Sp. To process these signals. Then, the fuel control signal Fc, the wastegate valve control signal Wc, and the converter control signal Ic are output to the fuel injection valve 1a, the wastegate valve 1b, and the power converter 11, respectively, to control the operation of these control devices. . The power converter 11 controls power supply to the electric motor 6 based on the converter control signal Sc from the engine control unit 14 and the rotation detection signal Nr from the rotation sensor 8.

  Here, the characteristic functions of the electrically assisted turbocharger according to one embodiment of the present invention will be described in brief with reference to FIG. 2 as follows: In this electrically assisted turbocharger, the turbine rotation The compressor 2, the assist motor 6 and the second bearing mechanism 7 are sequentially arranged with respect to the first bearing mechanism 4 connected to the portion 3a, and the compressor wheel 2a and the motor rotor 6a include the first and second bearing mechanisms 4, 7 respectively. Is supported from both sides. The lead wire connected to the stator coil of the electric motor 6 extends to the outer wall of the electric motor 6 in the direction of the rotation axis, and a protruding portion from the outer wall of the electric motor is used as a power feeding terminal. A power converter (inverter) 11 can be attached to the outer wall of the electric motor to form an integral structure. By using an induction machine for the assist motor 6, when the assist is unnecessary, the power converter 11 can be gated off or only the excitation current can be supplied to the motor 6 to be in a standby state. When engine braking is necessary, the electric motor 6 is operated in the regeneration mode.

[Structural example of main part]
In the electrically assisted turbocharger according to one embodiment of the present invention, a compressor is attached to the first bearing portion of the two-point support type that is attached to the turbine housing in order to suppress vibration of the rotating system. The assist motor and the second bearing portion are sequentially attached to the outside. That is, by supporting the rotating system including the compressor wheel and the electric motor rotor by the two bearings of the first bearing portion and the bearing of the second bearing portion, it is possible to sufficiently suppress vibration during high-speed rotation. 3 and 4 show a front sectional view of the main part of the electrically assisted turbocharger according to one embodiment of the present invention as seen from a direction orthogonal to the axis and a side view as seen from the axial direction of the electric motor side.

  As the first bearing portion 4 interposed between the turbine 3 and the compressor 2, a two-point support type bearing structure used as a standard can be used as in the prior art of FIG. 1. That is, the first and second bearings 4a and 4b accommodated in the bearing housing 4c support the connection shaft 4d between the turbine wheel 3a of the turbine 3 and the compressor wheel 2a of the compressor 2 at two points. Further, the lubricating oil supplied from the oil supply port 4e lubricates both the bearings 4a and 4b, and then is discharged from the oil discharge port 4f. The outer periphery of both ends of the connecting portion between the turbine wheel 3a and the compressor wheel 2a, and the bearing housing 4c An oil seal ring (small black portion) is provided between the inner periphery of both side walls on the turbine 3 side and the compressor 2 side.

  The compressor 2 includes a compressor wheel 2a in the compressor housing 2b. The compressor housing 2b has an outer wall 2c on the electric motor 6 side, both of which are an air introduction port 2d and a pressurization that are oriented in a direction orthogonal to the rotation shaft 5. An air output port 2e (see FIG. 4) is provided. The electric motor 6 includes a stator 6c and a rotor 6a, which are main elements of the electric motor, in a space surrounded by the outer wall 2c of the compressor 2 and the electric motor housing 6b. The stator 6c is fixed to be inserted through the compressor outer wall 2c. The member (screw) is attached to the side surface portion of the motor housing 6b. It should be noted that the direction of the compressor wheel 2a may be opposite to that illustrated.

  With the structure of the compressor 2 and the electric motor 6 as described above, the first electric assist assembly 20 including the compression mechanism and the electric mechanism is configured in the compressor housing 2b and the electric motor housing 6b.

  The motor housing 6b has a projecting portion 6d projecting from the side surface portion to which the stator 6c is attached to the side opposite to the compressor 2, and a lead wire 6e of the stator coil of the motor 6 is inserted into the outer wall of the projecting portion 6d. Each of these lead wires 6e is connected to a power feeding terminal 6f provided outside the outer wall. The rotating shaft of the motor rotor 6a has one end connected to the compressor wheel 2a and the other end supported by the bearing 7a of the second bearing portion 7 (hereinafter, the bearing 7a is referred to as "third bearing"). Call it.)

  As described above, the rotation system including the compressor wheel 2a and the electric motor rotor 6a includes the first and second bearings 4a and 4b (first bearing part 4) and the third bearing 7a (second bearing part 7) at both ends of the rotation system. ) And a structure that does not overhang can be sufficiently suppressed to vibrate during high-speed rotation.

  As described above, in the prior art shown in FIG. 1, when the one-side bearing structure in which the electric motor (AM) and the compressor (CM) are overhanged from the turbine housing (TH) and the bearing portion (BR), high-speed rotation is achieved. As a result, the eccentricity, spring characteristics, runout, etc. of the motor rotor (MR) increase, so that the operation of the motor (AM) cannot be maintained. This is because when the motor rotor rotates at a high speed like a turbocharger, even if the motor rotor is slightly decentered, the displacement of the electromagnetic force increases or the influence of the negative spring constant of the magnetic spring on the electromagnetic force becomes significant. In addition, since the electromagnetic force of the motor increases at the “leverage ratio”, such as an increase in the magnetic force due to the vibration of the motor rotor, the vibration sensitivity is increased, especially in the third-order vibration mode in the high-speed operation range. This is because the amplitude of the signal becomes extremely large and high speed operation becomes difficult.

  FIG. 5 is a vibration characteristic diagram showing the relationship between the rotational speed and vibration amplitude of the rotating system corresponding to the bearing structure. In FIG. 5, the vibration characteristic according to the prior art of FIG. 1 has an overhang from the bearing (BR), and therefore, as represented by the curve A, a large peak Pk3 is generated in the vibration of the third-order mode (also referred to as a bending mode). coming out. In contrast, the electrically assisted turbocharger according to one embodiment of the present invention exhibits good vibration characteristics as represented by curve B.

  That is, in this turbocharger, the compressor wheel 2a and the motor rotor 6a are supported by the first and second bearings 4a, 4b and the third bearing 7a located at both ends, and do not have an overhang from the bearing portion 4. Therefore, as shown in the vibration characteristic curve B of FIG. 5, the third-order vibration mode can be sufficiently damped by reducing the influence of the magnetic force of the motor in the high-speed operation region, and the vibration problem at the time of high-speed rotation is solved. be able to. Moreover, since the bearing assembly used for the standard turbocharger (without electric assistance) can be used for the 1st bearing part 4 without a big structural change, it is advantageous also in productivity.

  3 and 4, the rotor 6a of the electric motor 6 is integrated with the electric motor rotating shaft, and the electric motor rotating portion integrated with the rotor 6a is supported by the first and second bearings 4a and 4b. A rotating shaft 5 is configured by being coupled to a rotating shaft connected to a connecting portion between 3a and the compressor wheel 2a. Further, since the outer wall of the compressor housing 2b has a common structure shared as a part of the electric motor housing 6b, the axial length of the rotating system between the turbocharger bearings 4b and 7a can be shortened. The second bearing portion 7 is mounted in the overhang portion 6d of the electric motor housing 6b, and a rotation sensor 8 is provided at the end of the rotating shaft 5 protruding from the second bearing portion 7. And the signal wire | line 9 connected to the rotation sensor 8 is taken out outside from the overhang | projection part 6d of the motor housing 6b.

  In this example, a bar conductor having a bar shape is used for the stator coil mounted on the electric motor stator 6c, and the bar-shaped conductor serving as an end of each phase stator coil is directly in the direction of the rotation axis. It protrudes on the outer surface of the outer wall of the motor housing 6b. The portion of the bar-shaped conductor from the stator 6c to the outer wall functions as a lead wire 6e, and the end protruding from the outer surface of the outer wall is used as a power feeding terminal (also referred to as a lead wire) 6f. In the illustrated example, three power supply terminals 6 f are provided, and three-phase high-frequency power is supplied from the power converter 11 through the three-phase AC power supply line 10.

  Although not shown in FIGS. 3 and 4, the end portions other than the feeding end of the bar-shaped conductor forming each phase stator coil are provided on the end surface of the motor stator 6 c and function as a crossover plate shape. They are connected by connecting bodies, and these plate-like connecting bodies are formed so that the lengths of the electric circuits are equal in each phase (see FIG. 6).

  When the assist motor 6 is driven at a high speed with a low voltage (for example, a 12V power supply for automobiles), the frequency is high and the motor current is very large, so that the impedance difference between the phases appears remarkably. When power is supplied to each phase of the motor with a structure provided on the motor side surface, it becomes difficult to balance the impedance between the phases, and an imbalance occurs between the phase impedances, resulting in an unbalanced phase current. Problems such as rotational vibration occur. For this reason, usually, a method of driving the power converter (inverter) after once boosting the power supply voltage (for example, 72 V or more) is adopted, but this method requires a booster circuit and an inductance component is required in the electric circuit. As a result, the size of the power converter is increased and the loss is also increased.

  On the other hand, in the assist motor of this electrically assisted turbocharger, the lead wire 6e connected to the power feeding terminal 6f is taken out in parallel to the rotation axis direction from the stator coil of the stator 6c as described above, and in each phase. Drives at low voltage and high speed by making the lengths equal to each other and by connecting the bar-shaped conductors forming each phase stator coil to each other with equal-length plate-like connectors in each phase. However, the variation between the impedances of the respective phases inside the motor can be reduced, and the impedance difference between the phases can be reduced, so that the above-mentioned problems can be solved all at once.

[Configuration example of assist motor]
In the electrically assisted turbocharger according to one embodiment of the present invention, various types of multiphase motors can be used as the assist motor. In particular, an induction motor is preferably used. FIG. 6 shows an example of the configuration of an induction motor used in an electrically assisted turbocharger according to one embodiment of the present invention.

  In FIG. 6, the stator 6c has a structure called a “closed slot stator”, and is a fully closed and deep groove coil slot S1 to S6 in the vicinity of the inner periphery (reference symbols S2, S4, and S6 are not shown). Are provided, the inner circumferential side cross section of each slot is tapered, and the interval between adjacent slots of the stator 6c is widened. A wide portion of each slot S1 to S6 on the outer periphery side of the stator is called a slot bottom and has a circular cross section (may be rectangular). At the bottom of the slot, bar conductors ai to ck having a bar shape as a whole and having a circular cross section (may be rectangular) are incorporated. As a result, the coil occupation ratio in each of the slots S1 to S6 can be increased, the current capacity can be increased, the magnetic flux density of the air gap can be increased, and a high torque can be obtained.

  In this example, the A-phase to C-phase stator coils include first and second bar conductors ai, ak; bi, bk; ci, ck, and first bar conductors ai, bi serving as end portions of the respective phase stator coils. , Ci protrudes at an equal length from one end face of the stator 6c, and these protruding portions function as the lead wire 6e and the power supply terminal (lead wire) 6f described in FIG. Each end face of the stator 6c is provided with a common connection n serving as a neutral point and inter-conductor connection bodies aj to cj for connecting the phase conductors with an insulating spacer sp interposed therebetween. One end of each of the bar conductors ak, bk, ck is commonly connected to one end surface of the stator 6c by a common connector n, and the other ends of the first and second bar conductors ai, ak; bi, bk; ci, ck of each phase. Is connected to the other end of the second and first bar conductors ak, ai; bk, bi; ck, ci of the same phase by interconductor connectors aj; bj; cj on the other end surface of the stator 6c.

  The neutral point common connection body n and the interconductor connection bodies aj to cj are arc-shaped plates, and the distances to the connection points with the bar conductors are equal. As a result, the end portions (coil ends) of the bar conductors ai to ck can be made short except for the lead wire and the power supply terminal, and the shaft length can be shortened to be suitable for high-speed driving. . Further, since the interconductor connecting bodies aj to cj are provided on the end face of the stator 6c without rotating the outer periphery of the stator 6c, not only the manufacture is facilitated but also the impedance reduction of the interconductor connecting element can be contributed. it can.

  Further, the length between the conductor connection points in the interconductor connection bodies aj to cj and the length of the protruding portion of the first bar conductors ai, bi, ci of each phase are made equal in each phase, and the neutral point common connection body Since the shape of n can also be made circular and the length between the conductor connection points can be made equal, for example, the crossover length of the stator coil can be easily adjusted for each phase. Will be very easy.

  The rotor 6a may be a squirrel-cage rotor, but it is preferable to use a cylindrical solid rotor having a high permeability and low resistance on the stator side so as to reduce slip and increase operating efficiency. In the case of a solid rotor, the strength against centrifugal force due to high-speed rotation can be increased by using a portion close to the axis X as a high-strength steel component or by integrating with a rotating shaft.

[Arrangement of motor control equipment]
In the electrically assisted turbocharger according to one embodiment of the present invention, by attaching an electric motor control device including a power converter directly in the vicinity of the assist electric motor, the impedance drop in the power feeding path is reduced, and the assist electric motor is operated at a low pressure. Even if it is rotated at high speed, it can be stably operated. FIG. 7 shows an electrically assisted turbocharger structure incorporating an electric motor control device according to one embodiment of the present invention, and FIG. 7 (1) shows a front view of the structure viewed from a direction orthogonal to the axis. 7 (2) shows a side view of the power converter side as viewed from the axial direction.

  The structure shown in FIG. 7 is simply the second electric assist assembly 30 by directly attaching the power converter 11 to the outside of the electric motor 6 with respect to the electric assist assembly 20 described in FIG. Is. The power converter 11 includes a converter board 11a and a converter housing 11b. A converter circuit and a control circuit member are mounted on the converter board 11a. The converter housing 11b has an intermediate wall 11c perpendicular to the axial direction. Have.

  A power conversion member is accommodated in the converter housing 11b outside the intermediate wall 11c, and a converter board 11a is installed on the outer surface side of the intermediate wall 11c. The converter board 11a has a power conversion element that is a main element of power conversion. A circuit element of a power conversion circuit including a switching element (FET transistor) and a control circuit for controlling the power conversion circuit are attached. A DC power supply terminal block 11d and an operation panel (not shown) are provided on the outer surface of the converter housing 11b. The positive (+) and negative (−) terminals 11e and 11f provided on the DC power supply terminal block 11d The terminal of the DC power supply line 12 connected to the unit 13 can be received.

  The intermediate wall 11c of the converter housing 11b has the same function as the outer wall of the motor housing 6b described in FIG. That is, the converter housing 11b on the electric motor side from the intermediate wall 11c has the same function as the overhanging portion 6d of the electric motor housing 6b, and accommodates the portion of the lead wire 6e of the motor 6 and the second bearing portion 7, and the lead wire 6e penetrates the intermediate wall 11c and the converter substrate 11a. Further, the leading end portion of the lead wire 6 e protruding from the converter substrate 11 a forms a power feeding terminal 6 f of the electric motor 6, and the power feeding terminal 6 f also functions as an output terminal of the power converter 11. The outer opening of the converter housing 11b is sealed with a converter cover 11g.

  In the structural example of FIG. 7, the compressor housing 2 b ′ in which the structure of the main part of the motor housing 6 b is integrated with the compressor housing 2 b described in FIG. 3 is provided. The compressor housing 2b ′ has an intermediate wall (not shown) having the function of the outer wall 2c of the compressor housing 2b, and the stator 6c and the rotor 6a of the electric motor 6 are placed in the space outside the intermediate wall (the left side in the drawing). A compressor wheel 6a is included in an inner space (right side in the figure). Similarly to FIG. 3, the compressor housing 2b ′ is attached to a bearing housing 4c provided in the turbine housing 3b. As shown in FIG. 7, the converter housing 11b is attached to the outside of the compressor housing 2b ′. .

  Due to the structure in which the compressor 2, the electric motor 6, and the power converter 11 are integrated as described above, the second electric assist assembly 30 including a compression mechanism, an electric function, and an electric power conversion mechanism in the compressor housing 2b ′ and the converter housing 11b. Is configured.

  In order to operate the motor at a low pressure and at a high speed, as described above, the method of boosting the power supply voltage to a high voltage DC voltage (72 V or more) and then supplying power to the motor through the power converter is adopted. It is normal. In this method, even if the fundamental frequency is high, the influence of the voltage drop (drop) is small, but since the booster circuit is provided, the size of the power converter increases. Furthermore, high-frequency current flows in the power supply wires connected from the power converter to the motor, so there is a problem of radiation noise, and the number of wires is the same as the number of phases, so wiring from the motor to the power converter is very difficult. There is also an implementation problem.

  In addition, since the turbocharger is mainly used for automobiles, weight reduction and high efficiency are required at the same time, but there is a restriction that a battery voltage as low as 12 V must be used for the power supply voltage. Further, when the power supply voltage is low, the current becomes large. For example, the capacity of the assist motor is generally about 2 kW, so the direct current has a large value of 167A. Since efficiency and weight reduction are required, the efficiency is reduced by boosting and the size of the power converter is increased (for example, an inductance is required, which makes it heavier and larger).

  On the other hand, since high frequency power of about 2 to 3 kHz is supplied to drive the assist motor for high speed operation, the impedance drop (drop) is a value that cannot be ignored. For example, if the power supply wire has a normal inductance value = 1 μH / m, the impedance is about 19 mΩ for a single line of 20 SQ at a power supply frequency = 3 kHz, and the voltage drop at 100 A is 1.9 V, so that the 12 V power supply The effect will be greater.

  On the other hand, when the power converter (including the control circuit) 11 is directly attached to the assist motor 6 as in the second electric assist assembly 30 described in FIG. 7, from the motor 6 to the power converter 11. Can be extremely shortened, and the influence of the drop in the circuit impedance between the motor 6 and the power converter 11 can be reduced to the maximum. Further, even if the distance between the power converter 11 and the power supply unit (battery power supply) 13 is somewhat longer, the current flowing through the power supply line 12 between them is a direct current. Since the number of power supply lines 12 connected to the battery power supply 11 is one (in the case of grounding on one side) or two, it is easy to mount in a narrow engine room.

[Drive assist motor]
An assist motor used in an electrically assisted turbocharger according to an embodiment of the present invention is driven by a power converter (DC / AC converter) using an inverter that outputs high-frequency AC power from a DC power supply. For the three-phase motor, for example, a power converter including a three-phase inverter 11A is used as in the electric motor drive circuit shown in FIG. That is, in the case of using a three-phase motor such as the assist motor described in FIG. , DC12V (volt)] is supplied, and the inverter 11A supplies high-frequency power of about 3 kHz to the three-phase stator coils ac of the assist motor 6.

  The inverter 11A includes switching elements T1 to T6 such as power FET transistors, and the control circuit 11B including the CPU performs these according to the converter control signal Sc from the engine control unit 14 and the rotation detection signal Nr from the rotation sensor 8. A gate control signal is sent to the switching elements T1 to T6 to control the voltage / current output from the inverter 11A to control the three-phase motor 6 to a desired speed.

  As the assist motor 6 of this electrically assisted turbocharger, an inverter 11A can be operated in a so-called “non-commutator motor” system using a synchronous machine structure having a permanent magnet rotor. However, for the reason described later, it is preferable to use the assist motor 6 having an induction machine structure. When an induction machine is used, the inverter 11A can be stably operated by a so-called “vector control” method, and as a practical method, the inverter 11A can also be operated by a so-called “slip frequency control” method. Regardless of the operation method used for any type of electric motor, the electric motor 6 is operated as a generator driven from the turbine 3 side due to a decrease in speed command value or the like when engine braking is required. Thus, regenerative braking can be performed and power can be controlled to be regenerated to the DC power source 13.

  FIG. 9 is a block diagram showing an example of an assist motor drive control system when an induction motor is used as the assist motor and the operation is performed by the slip frequency control method. In this case, the induction motor may be a solid type rotor as described with reference to FIG. 6 or a normal type cage rotor. Note that the same operation can be performed even in the operation by the vector control method.

  The control circuit 11B in this system includes a control signal distribution circuit B1, a rotation detection circuit B2, a speed comparator B3, a slip frequency calculation circuit B4, a torque command control circuit B5, a first adder B6, an excitation voltage command circuit B7, and a current detection. A circuit B8, a voltage drop calculation circuit B9, a second adder B10, a gate control circuit B11, a forced gate-off command circuit B12, and the like are provided. Here, the rotation detection circuit B2 extracts a speed actual value nr representing the actual rotation speed of the electric motor 6 and a rotation frequency value fr corresponding to the actual rotation speed from the rotation detection signal Nr from the rotation sensor 8. In addition, a current sensor 16 for detecting the motor current Im flowing through the motor 6 is provided in the power supply path from the inverter 11A to the stator coil of the motor 6, and the current detection circuit B8 detects the motor current from the detection signal of the current sensor 16. The primary current value im representing the current Im is taken out, and the voltage drop calculation circuit B9 multiplies the primary resistance value Rm of the motor 6 acquired in advance by the primary current value im to cause a voltage drop due to the primary resistance of the motor 6. The value vd = im · Rm is calculated.

  The engine control unit 14 (see FIG. 2) receives various input signals such as a throttle signal Th, an engine speed signal Ne, a crank angle signal Ae, a manifold signal Mn, an engine brake signal Eb, a vehicle speed signal Sp, and the situation at that time Accordingly, the speed command value ns representing the optimum rotation speed of the compressor wheel 3a and the excitation current command value if of the assist motor are calculated, and the acceleration command ac, the deceleration command eb, the first and second assist disabling commands an1, an2 is generated, and these values and commands ns, if, ac, eb, an1, and an2 are transmitted to the control circuit 11B of the power converter 11 as the converter control signal Sc. The control signal distribution circuit B1 of the control circuit 11B determines the contents of the converter control signal Sc sent from the engine control unit 14, and determines the speed command value ns, the excitation current value if, the acceleration command ac, the deceleration command eb, The first and second assist disabling commands an1 and an2 are extracted and output to the corresponding control elements.

  In the normal operation control in which the above-mentioned commands ac, eb, an1, and an2 are not transmitted from the engine control unit 14, the speed command value ns and the excitation current command value if are respectively sent from the control signal distribution circuit B1 to the speed comparator B3. And the speed feedback system shown in the figure operates effectively as it is. The speed comparator B3 compares the speed command value ns from the converter signal distribution circuit B1 with the actual speed value nr from the rotation sensor 8, and generates a speed error ne. When the speed error ne = ns−nr is less than or equal to a predetermined value, the slip frequency calculation circuit B4 multiplies the speed error ne by a constant k1 to convert it to a slip frequency command value fs = k1ne, and the speed error ne is a predetermined value that is positive or negative. If it exceeds, a constant slip frequency command value fs = + sf0 / −sf0 = a constant value is output.

During normal driving, the torque command control circuit B5 adopts the slip frequency command value fs from the slip frequency calculation circuit B4 as it is as a torque command for the motor 6, and outputs it to the first adder B6. The first adder B6 adds the rotation frequency value fr from the rotation detector B2 to the slip frequency command value fs adopted as the torque command to generate a drive frequency command value fm = fr + fs for the inverter 11A. The excitation voltage command circuit B7 is a function generator that calculates the excitation voltage command value vf according to the following equation (1) based on the drive frequency command value fm and the excitation current command value if commanded from the converter signal distribution circuit B1. is there:
vf = (√2) · if · Xm · exp (j2πfmt) (1)
Here, Xm: excitation reactance of the electric motor 6, t: time.

  The second adder B10 adds the excitation voltage command value vf from the excitation voltage command circuit B7 and the primary resistance voltage drop value vd from the voltage drop calculation circuit B9 to generate a primary voltage command value vm = vf + vd. The primary voltage command value vm functions as a command value for the inverter output voltage Vm. Then, the gate control circuit B11 outputs a gate control signal gs to the switching element of the inverter 11A based on the primary voltage command value vm output from the second adder B10, and controls the input voltage Vm to the motor 6. .

  In the engine control unit 14, the operation mode of the control circuit 11B is set to the acceleration mode, the deceleration mode, the first assist disabled (unnecessary) mode and the second assist disabled (unnecessary) mode according to the user's request or automatically. can do. When each mode is set, the engine control unit 14 cannot perform the acceleration command ac, the deceleration command eb, or the first and second assists when the operating conditions of the mode are satisfied by analyzing various input signals. Commands an1 and an2 are generated, and each command is included in the converter control signal Sc and transmitted to the control signal distribution circuit B1 of the control circuit 11B. The control signal distribution circuit B1 outputs each command to the corresponding control element. Thus, the control circuit 11B operates in the acceleration mode, the deceleration mode, the first assist disabled (unnecessary) mode or the second assist disabled (unnecessary) mode, and the operation based on each command becomes the operation during the normal operation control. Prioritize.

  For example, when the acceleration mode is set, the engine control unit 14 accelerates the engine 1 by depressing the accelerator pedal 15 at the start of the vehicle from the throttle signal Th, the engine speed Ne, the vehicle speed signal Sb, and the like. If it is determined that the acceleration condition is satisfied, the acceleration command ac is output to the torque command control circuit B5, and the system is operated in the acceleration mode. The torque command control circuit B5 outputs the acceleration slip frequency command value having a positive constant value “sf1” as a torque command to the first adder B6 in preference to the slip frequency command value fs from the slip frequency calculation circuit B4. To do. Accordingly, the drive control system of FIG. 9 forcibly accelerates the motor 6 with a high acceleration torque based on the acceleration slip frequency command value sf1 regardless of the content of the slip frequency command value fs, so that the acceleration performance of the engine is improved. Can be up. When the acceleration condition is not satisfied because the accelerator pedal 15 is depressed or the vehicle speed is settled, the acceleration command ac is reset and returns to the original operation during normal operation control.

  When the deceleration mode is set, when the deceleration condition that the engine brake signal Eb is generated or there is an extreme brake operation is satisfied, the deceleration command eb is output to the torque command control circuit B5 and the system is set to the deceleration mode. Operate with. The torque command control circuit B5 prioritizes the slip frequency command value fs and uses the deceleration slip frequency command value having a negative constant value “sf2” (| sf1 | ≈ | sf2 |) as a torque command to the first adder B6. Output. As a result, the drive control system of FIG. 9 operates the motor 6 in the regeneration mode regardless of the slip frequency command value fs, and decelerates the motor 6 with a high deceleration torque based on the acceleration slip frequency command value sf2. Since the performance is improved and the electric motor 6 is operated as a generator, the rotational energy of the rotating system of the electric assist type turbocharger can be regenerated in the power supply unit 13. When the deceleration condition is no longer satisfied, for example, when the engine brake is released or the vehicle speed is reduced, the deceleration command eb is reset and returns to the original normal operation control operation.

  As described above, when the operation in the deceleration mode is performed, the engine braking force can be increased when the engine brake is required, and the fuel efficiency can be improved by energy regeneration. In addition, when using engine braking, the driving force from the turbine 3 side is reduced by using the wastegate valve 1b attached to the turbocharger as necessary, and at the same time, the compressor air volume is controlled. Preferably it is done. The acceleration and regenerative operations in the acceleration mode and the deceleration mode can be realized in the same manner even in an operation using a non-commutator motor system using a synchronous machine.

  One of the first and second assist disabled modes can be selectively set. Here, when the first assist disabling mode is set, it is impossible to assist that the accelerator pedal 15 is weakly depressed or the vehicle speed changes little and the vehicle is stably traveling based on the throttle signal Th, the vehicle speed signal Sb, etc. (unnecessary). When the condition is satisfied, the first assist disabling command an1 is output to the torque command control circuit B5. The torque command control circuit B5 outputs to the first adder B6 as a torque command having a zero value “0” in preference to the slip frequency command value fs. That is, when the electrically assisted turbocharger does not require the drive torque of the electric motor 6, the drive control system of FIG. 9 sets the generated torque of the electric motor 6 to zero with no slip regardless of the slip frequency command value fs. And a voltage having the same frequency as the rotational frequency fr of the electric motor 6 is applied to the electric motor 6, and only the exciting current if is supplied to make the generated torque zero. When the accelerator pedal 15 is strongly depressed and the vehicle is in a state to be accelerated and the assist disabling condition is not satisfied, the first assist disabling command an1 is reset and returns to the original operation during normal operation control. When returning to the operation at the time of normal operation control, since the excitation voltage vf has already been established, a desired torque can be generated in response promptly.

  In addition, when the second assist disabling mode is set, when the assist disabling condition similar to that described above is satisfied, the second assist disabling command an2 is output to the forced gate-off command circuit B12. The forced gate-off command circuit B12 immediately turns off the gate control signal transmission from the gate control circuit B11 to the switching element of the inverter 11A based on the second assist disabling command an2, and stops the operation of the inverter 11A. That is, when the electrically assisted turbocharger does not require the driving torque of the electric motor 6, the operation of the inverter 11A can be stopped so that no electric current is supplied to the electric motor 6. Thus, the stator 6c of the electric motor 6 can be prevented. In addition, the loss of the rotor 6a can be reduced to increase the operating efficiency, and the temperature of the motor rotor 6a can be prevented from rising to prevent unstable vibrational rotation accompanying the temperature rise.

  Generally, in an electric motor having a synchronous machine structure using a permanent magnet, excitation is always performed by the permanent magnet, and the induced voltage increases in proportion to the increase in the rotational speed. In addition, as the induced voltage increases, the current component that generates torque in phase with the induced voltage decreases, and the torque also tends to decrease.In practice, field weakening control is performed, and a slow-phase current is supplied to the motor. The armature reaction generates a magnetic field in the opposite direction to the magnetic field of the permanent magnet, weakens the excitation as a whole, suppresses the induced voltage, and prevents the current component that generates torque from decreasing. Furthermore, in order to prevent the induced voltage from exceeding the power supply voltage even in the high-speed region where no drive torque is required, it is necessary to continue the slow-phase current and perform field weakening control, so the inverter is always maintained in the control state. There is a need to.

  For example, when a motor using a permanent magnet is used for the assist motor 6 and the inverter 11A is gated off as in the above-described second assist disabled mode, the field weakening control is performed at high speed. As a result, the induced voltage rises, causing a problem that a large current flows into the DC power supply 13 side through a diode connected in parallel with the switching element (active element) of the inverter 11A, and the DC power supply 13 side is opened. Even in this case, there is a disadvantage that the induced voltage rises and exceeds the breakdown voltage of the semiconductor switching element. For this reason, since it is difficult to turn off the power in the electric motor 6 using a permanent magnet, the no-load loss increases, and the output voltage of the inverter 11A includes many harmonics in addition to the basic sine wave. Since a wave voltage is included, a high frequency current flows through the electric motor 6 and a high frequency magnetic field is generated in the air gap. For this reason, a high-frequency current for canceling the high-frequency magnetic field flows on the surface of the permanent magnet rotor and the rotor temperature rises. As a result, the balance of the rotor is lost, the permanent magnet is demagnetized, and the loss on the stator side also increases. End up.

  Furthermore, the turbocharger assist motor has a high basic drive frequency, so the ratio of control delay (control delay is tens of microseconds or more as analog control) is very high. Is very bad and no torque is generated. For this reason, rotor unbalance occurs due to heat generated by the rotor due to increased loss, and the rotor cannot be stably rotated at a high speed. In addition, the rotor becomes longer, which makes it difficult to design the rotating shaft system.

  In addition, a sine wave output is desirable for the motor drive power supply, but the inverter output voltage of a static inverter that is generally used contains many high-frequency components in addition to the basic sine wave, which increases the motor loss. In the case of a high-speed electric motor, the volume output ratio of the electric motor is large, so that the heat generation process is a big problem. In particular, in the rotor where it is difficult to escape the heat generation, the problem becomes larger.

  The turbocharger assist motor, in particular, with respect to the load state in which the compressor assist drive is performed, for example, the overall load factor with respect to the total operation time of the turbocharger is 20% or less, and the load time for one time is several seconds. Thus, a relatively low value is shown. On the other hand, when an induction motor (for example, FIG. 6) is used for the assist motor 6 and is operated in the second assist-impossible mode as described in FIG. 9, it is driven by the turbocharger turbine 3. Can be put into a standby state in which the inverter 11A of the power converter 11 is gated off and the electric motor 6 waits for assistance. As a result, it is possible to prevent a loss of the rotor during standby, thereby preventing an increase in the temperature of the rotor, preventing unstable rotational vibration due to an increase in the rotor temperature, and improving the system efficiency. .

  At the time of reloading to return to normal operation from the standby state in the second assist disabling mode due to unsatisfied assist disabling conditions, first, a voltage having the same frequency as the motor rotation frequency fr is applied to the assist motor 6 to raise the excitation current if. Subsequently, a voltage of frequency fm = fr + fs obtained by adding a slip frequency command value fs corresponding to the torque command to the motor rotation frequency fr is applied to the motor 6, and the motor 6 is driven by slip according to the torque command. Torque vibration due to excessive control during reloading can be avoided and torque vibration can be prevented.

  In contrast to such a second assist disabled mode, the operation in the first assist disabled mode is suitable when high responsiveness is required. In other words, in the operation in the first assist disabled mode, the voltage of the motor rotation frequency fr is applied even during standby, the excitation current if is kept flowing, and the motor drive frequency fm immediately corresponds to the torque command (fs) during re-loading. Since the control is performed so that the torque is increased by applying a voltage of frequency fm = fr + fs obtained by adding the slip frequency command value fs to the motor rotation frequency fr to the motor 6, it is possible to realize a quick response.

  As in the operation in the first assist disabled mode, when the driving torque is not required, the inverter 11A is not gated off, and a voltage having the same frequency as the motor rotation frequency fr is applied to the assist motor 6, and the excitation current command if When the control is performed in which only the excitation current is supplied to enter the standby state and the torque command is given only when the torque is required, there is a concern that the rotor loss may occur due to the excitation current flowing even during standby. The excitation reactance Xm of Fig. 6 is larger by one digit or more than the primary and secondary leakage reactances, the harmonic current flow component included in the excitation current if is suppressed and smoothed by the excitation reactance Xm, and the waveform of the excitation current if is sinusoidal. Since the waveform is close to a wave, the loss caused by the excitation current is one order of magnitude less than the loss caused during loading, and the temperature of the rotor 6 rises. There is no significant impact. Furthermore, since an induction machine is used, there is almost no reduction in torque due to a control delay at high speed as in the case of using a synchronous machine.

[Various Embodiments]
The preferred embodiments of the present invention have been described in detail above with reference to the drawings. However, these embodiments are merely examples, and various modifications can be made without departing from the spirit of the present invention. For example, the drive control system of FIG. 9 is configured to perform forced control in the acceleration mode, the deceleration mode, or the first and second assist-disabled modes in accordance with a command from the engine control unit. When the command (ns) is given to the system, the speed feedback system operates properly without giving an acceleration command or a deceleration command from the engine control unit, so the acceleration command (ac) is sent to the torque command control circuit (B5). And a function of responding to the deceleration command (eb) may not be provided.

  Similarly, when the ideal speed command (ns) is given to the system, it is not necessary to provide the first and second assist disabling commands (an1, an2) from the engine control unit. For example, in the first assist disabled mode, the torque command control circuit (B5) is omitted, and the slip frequency calculation circuit (B4) itself has a predetermined range near the speed error (ne) = 0 from the speed comparator (B3). By providing the “dead zone” characteristic in which the output value fs = 0, an excitation function based on the torque “zero” command can be realized instead of the first assist disabling command (an1). Similarly, in the second assist disabled mode, instead of the forced gate-off command circuit B12 of FIG. 9, the output value is within a predetermined range (including ne = 0) near the speed error ne = 0 from the speed comparator B3. It is also possible to use a circuit having a characteristic that becomes “1” and to gate off the gate control circuit (B11) with a signal of an output value “1” from this circuit.

It is a figure for demonstrating a prior art. 1 is a system outline diagram showing an outline of a system including an electrically assisted turbocharger according to an embodiment of the present invention. It is principal part sectional drawing of the electrically assisted turbocharger by one Example of this invention. It is a principal part side view of the electrically assisted turbocharger by one Example of this invention. It is a figure showing the vibration characteristic of a motor-assisted turbocharger rotating system. It is a figure showing the structural example of the induction motor used for the electrically assisted turbocharger by one Example of this invention. It is a figure showing the example of a structure of the electric assist type | mold turbocharger which attached the electric motor control apparatus by one Example of this invention. It is a figure showing the drive circuit applied to the assist electric motor of the electrically assisted turbocharger by one Example of this invention. 1 is a block diagram showing an assist motor drive control system of an electrically assisted turbocharger according to one embodiment of the present invention. FIG.

Explanation of symbols

2 a compressor provided with a compressor wheel 2a,
3 turbine provided with turbine wheel 3a,
4 1st bearing part provided with the 1st and 2nd bearings 4a and 4b of 2 point support,
5 Rotation system shaft (rotary shaft) of compressor 2 and assist motor 6,
6 an assist motor provided with a rotor 6a,
7 A second bearing portion including the third bearing 7a.

Claims (6)

A first bearing mechanism coupled to a turbine rotor driven by engine exhaust gas;
A compressor having a rotating part for sending pressurized air to the engine, one end of the rotating part being supported by a first bearing mechanism;
An assist motor having one end of a drive shaft connected to the other end of the rotating portion of the compressor;
An electrically assisted turbocharger comprising: a second bearing mechanism that supports the other end of the drive shaft of the assist motor. A lead wire connected to the stator coil of the assist motor extends to the outer wall of the assist motor in the axial direction of the rotating part,
The electrically assisted turbocharger according to claim 1, wherein an end portion protruding from the outer wall of the lead wire is formed as a power feeding terminal.   The electric assist type turbocharger according to claim 2, wherein a power converter for driving the assist motor is attached to an outer wall end surface of the assist motor. A compressor connected to a turbine rotating part driven by engine exhaust gas and having a rotating part for feeding pressurized air to the engine;
An induction motor having an induction machine structure in which a drive shaft is connected to a rotating part of the compressor;
A power converter for driving the assist motor,
The power converter is an electrically assisted turbocharger characterized in that when the assist motor is forcibly rotated by the turbine rotating part and does not require driving torque, the assist motor is turned off and the assist motor is disconnected from the power source. A compressor connected to a turbine rotating part driven by engine exhaust gas and having a rotating part for feeding pressurized air to the engine;
An induction motor having an induction machine structure in which a drive shaft is connected to a rotating part of the compressor;
A power converter for driving the assist motor,
The power converter is characterized in that when the assist motor is forcibly rotated by the turbine rotating part and does not require a driving torque, a voltage that gives only an excitation current at the same frequency as the rotation frequency of the assist motor is applied to the assist motor. Electric assist type turbocharger. A compressor connected to a turbine rotating part driven by engine exhaust gas and having a rotating part for feeding pressurized air to the engine;
An assist motor having a drive shaft coupled to the rotating part of the compressor;
A power converter for driving the assist motor,
The power converter is an electrically assisted turbocharger that operates an assist motor in a regenerative mode when engine braking is required.

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