JP2015077006A - Motor generator and engine unit including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor generator in which magnetic flux of a permanent magnet can be prevented from leaking from a rotor in an unloaded state.SOLUTION: A motor generator 2 includes a stator 5, a rotor 6, and permanent magnets 62a to 62d. The rotor 6 is rotated around a rotation axis. The stator 5 is disposed in the outer periphery of the rotor 6. The permanent magnets 62a to 62d are disposed in the rotor 6 and are magnetized in a radial direction of the rotor 6. The rotor 6 includes magneto-resistance parts 63 which are disposed on one side of the permanent magnets 62a to 62d in a circumferential direction of the rotor 6 and reach the outer periphery of the rotor 6. In an unloaded state, the magnetic flux of the permanent magnets 62a to 62d is short-circuited on the other side of the permanent magnets 62a to 62d. In a loaded state, magnetic flux resulting from combination of the magnetic flux of the permanent magnets 62a to 62d and magnetic flux generated in the stator 5 is greater than saturated magnetic flux in the rotor 6.

Description

  The present invention relates to a motor generator and an engine unit including the motor generator, and more particularly to a motor generator using a permanent magnet and an engine unit including the motor generator.

  Engines such as aircraft and automobiles are provided with a starter generator. The starter generator supplies power to the engine when the engine is started. Further, when it is necessary to charge the battery of the aircraft, the starter generator generates power according to the rotation of the engine. The starter generator includes a motor generator in order to realize the above function.

  As a motor generator used for a starter generator, there is a salient pole winding type synchronous generator.

  In the salient pole winding type synchronous generator, the windings are wound around the rotor and the stator, respectively. The rotor windings are used as field windings. The magnetomotive force is generated by supplying a direct current (field current) to the rotor winding. However, salient-pole-synchronous synchronous motors have a low reliability because of the increased number of components such as slip rings, brushes, and rotary transformers. In addition, salient-pole winding synchronous motors are difficult to miniaturize because the winding is wound around the rotor.

  In order to solve these problems, it has been proposed to use a permanent magnet type synchronous generator for the starter generator.

  In the permanent magnet type synchronous generator, the winding is wound around the teeth of the stator, and the permanent magnet is provided on the rotor. Since the field is formed by the permanent magnet, it is not necessary to supply a field current.

  However, the permanent magnet type synchronous generator cannot adjust the field. The magnetic flux of the permanent magnet leaks from the rotor and links with the stator regardless of the unloaded state and the loaded state. As a result, even in a no-load state, a voltage corresponding to the engine speed is generated, causing iron loss in the stator (so-called pulling loss) and lowering the engine efficiency. For this reason, when a permanent magnet type synchronous generator is used as a starter generator, the magnetic flux of the permanent magnet must be adjusted so that the magnetic flux of the permanent magnet does not leak from the rotor in a no-load state.

  Patent Document 1 discloses a rotating electrical machine that can short-circuit the magnetic flux of a permanent magnet within a rotor in an unloaded state. The rotor of this rotating electrical machine is provided with a two-layer flux barrier that is convex toward the center. A plurality of sets of two-layer flux barriers are provided, and each set is arranged at a position that is rotationally symmetric. A permanent magnet is mounted in each flux barrier. A bridge part is provided between the rotor outer peripheral side end of the flux barrier and the rotor outer periphery. In the no-load state, the magnetic flux of the permanent magnet passes through the bridge portion and is short-circuited in the rotor. In the load state, the bridge portion is saturated by the magnetic flux from the stator. As a result, the magnetic flux of the permanent magnet interlinks with the stator.

JP 2008-136298 A

  The objective of this invention is providing the motor generator which can prevent that the magnetic flux of a permanent magnet leaks from a rotor in a no-load state.

  A motor generator according to the present invention includes a rotor that rotates about a rotation axis, a stator that is disposed to face the rotor, a rotor that is disposed in the rotor, and that is attached in a radial direction of the rotor. The rotor is disposed on one side of the first permanent magnet in the circumferential direction of the rotor, and the magnetic flux of the first permanent magnet is the first permanent magnet. Including a first magnetoresistive portion that prevents the permanent magnet from passing through one side of the permanent magnet, and in the no-load state, the magnetic flux of the first permanent magnet is short-circuited in the rotor, and in the loaded state, the first The magnetic flux obtained by combining the magnetic flux of one permanent magnet and the magnetic flux generated by the stator is equal to or greater than the saturation magnetic flux of the rotor.

  According to the above configuration, in the no-load state, the magnetic flux of the first permanent magnet is short-circuited not on one side of the first permanent magnet but on the other side. Therefore, the magnetic flux of the first permanent magnet can be prevented from leaking from the rotor. In the loaded state, the synthesized magnetic flux is saturated in the rotor and linked to the stator, so that the motor generator can function as an electric motor or a generator. Further, when the motor generator operates as either an electric motor or a generator, not only the magnet torque but also a reluctance torque generated due to the presence of the magnetoresistive portion can be used.

  The motor generator is further disposed via the first magnetoresistive portion at a position different from the position of the first permanent magnet in the circumferential direction in the rotor, and is attached in the radial direction of the rotor. A second permanent magnet to be magnetized, wherein the rotor is disposed on one side of the second permanent magnet in a circumferential direction of the rotor, and the magnetic flux of the second permanent magnet is the second permanent magnet. A second magnetoresistive portion that prevents passage through one side of the permanent magnet is included.

  According to said structure, since a 1st magnetoresistive part exists between a 1st permanent magnet and a 2nd permanent magnet, the magnetic flux of a 1st permanent magnet passes a 2nd permanent magnet. It is short-circuited without. Since the magnetic flux of the first permanent magnet and the magnetic flux of the second permanent magnet are not synthesized in the no-load state, saturation of the magnetic flux in the rotor can be suppressed.

  In the motor generator, the first magnetoresistive portion is formed of a slit or a notch that opens to the outer periphery of the rotor.

  According to said structure, a 1st magnetoresistive part is realizable with a simple structure.

  In the motor generator, the stator is disposed on the outer peripheral side of the rotor. In the first permanent magnet, the area of the surface on the stator side is equal to or larger than the area of the surface on the opposite side to the stator. The rotor further includes a bridge portion that is formed between the stator side surface and the permanent magnet and allows the magnetic flux of the first permanent magnet to pass therethrough.

  According to said structure, since the distance from the outer periphery of a rotor to a 1st permanent magnet can be enlarged conventionally, the intensity | strength of a rotor can be increased.

  The engine unit of the present invention includes the motor generator of the present invention and an engine including a rotation shaft connected to the rotation shaft of the rotor.

  According to said structure, a motor generator can be operated as a generator using rotation of an engine, or an engine can be started by using a motor generator as a motor.

  According to the present invention, since the magnetic flux of the first permanent magnet is short-circuited in the rotor when it is in an unloaded state, it is possible to prevent the magnetic flux from leaking from the rotor.

It is a functional block diagram which shows the structure of the starter generator provided with the motor generator which concerns on the 1st Embodiment of this invention. It is sectional drawing of the motor generator shown in FIG. It is a table which shows an example of the slot combination of the motor generator shown in FIG. FIG. 3 is an enlarged cross-sectional view of a stator and a rotor shown in FIG. 2. It is a figure explaining the position of the permanent magnet in the rotor shown in FIG. It is a figure which shows the magnetic path in the load state formed in the stator and rotor shown in FIG. It is a figure which shows the other structural example of the rotor shown in FIG. It is a figure which shows the other structural example of the rotor shown in FIG. It is a figure which shows the other structural example of the rotor shown in FIG. It is sectional drawing of the motor generator which concerns on the 2nd Embodiment of this invention. FIG. 10 is an enlarged cross-sectional view of the stator and the rotor shown in FIG. 9. It is a figure explaining the position of the permanent magnet in the rotor shown in FIG. It is sectional drawing of the motor generator which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the stator shown in FIG. FIG. 13 is a connection diagram of the main winding and the auxiliary winding shown in FIG. 12. It is a figure which shows the magnetic path formed in the stator and rotor shown in FIG. 12 in a no-load state. It is a figure which shows the magnetic path formed in the stator and rotor which are shown in FIG. 12 in a load state. It is sectional drawing of the motor generator which concerns on the 4th Embodiment of this invention. In the motor generator shown in FIG. 17, it is a figure which shows the magnetic path formed at the time of an unloaded state. FIG. 18 is a diagram showing a magnetic path formed in a load state in the motor generator shown in FIG. 17.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[First Embodiment]
{1. Configuration of starter generator}
FIG. 1 is a functional block diagram showing a configuration of an engine unit 200 using the motor generator 2 according to the first embodiment of the present invention. As shown in FIG. 1, the engine unit 200 includes an engine 1 and a starter generator 100. The starter generator 100 includes a motor generator 2, a controller 3, and an inverter 4. The starter generator 100 is attached to the engine 1.

  The engine 1 is a power source of an aircraft or an automobile (not shown). The rotating shaft of the motor generator 2 is connected to the rotating shaft of the engine 1. The motor generator 2 supplies power when the engine 1 starts driving. The motor generator 2 generates power in accordance with the rotation of the rotating shaft of the engine 1 and supplies the generated power to a battery and a load (not shown). The rotating shaft of the motor generator 2 may be indirectly connected to the rotating shaft of the engine 1 through a gear or the like.

The controller 3 controls the operation of the motor generator 2 based on the input torque command 41 and speed command 42. The controller 3 supplies the inverter 4 with a torque command 41, a speed command 42, and a control signal 43 corresponding to the rotational position θ of the rotor described later. Further, the controller 3 receives the currents i _u and i _w supplied to the motor generator 2 from the inverter 4 and adjusts the control signal 43 using the received current.

The inverter 4 supplies a drive current or an excitation current corresponding to the control signal 43 from the controller 3 to the motor generator 2. In FIG. 1, the current supplied to the motor generator 2 is denoted as i _u , i _v , and i _w without distinguishing between the drive current and the excitation current.

{2. Configuration of motor generator}
FIG. 2 is a cross-sectional view of the motor generator 2. As shown in FIG. 2, the motor generator 2 includes a stator 5 and a rotor 6. The rotor 6 rotates about the rotation axis A. The stator 5 is disposed on the outer periphery of the rotor 6.

  The stator 5 includes a stator core 51, a winding 52, and 24 teeth 53. In FIG. 2, a part of the winding 52 and a part of the teeth 53 are not shown.

  The stator core 51 has a hollow cylindrical shape, and is formed of a magnetic material such as an electromagnetic steel plate, a dust material, or an amorphous material. Twenty-four teeth 53 are provided on the inner peripheral side of the stator core 51. The slot 54 is a space between two adjacent teeth 53 and 53. Winding 52 is wound around teeth 53. The winding method of the winding 52 may be either concentrated winding or distributed winding. Alternatively, the winding 52 may be wound around the tooth 53 using a ring coil.

  Rotor 6 includes a rotor core 61, four permanent magnets 62 a to 62 d, and four magnetoresistive portions 63. The rotor core 61 has a cylindrical shape and rotates about the rotation axis A. The rotor core 61 is formed of a magnetic material such as an electromagnetic steel plate, a dust material, or an amorphous material.

  The permanent magnets 62 a to 62 d are disposed in the rotor core 61 and are magnetized in the radial direction of the rotor 6. Hereinafter, the permanent magnets 62a to 62d are collectively referred to as “permanent magnet 62”.

  The arrows in the permanent magnets 62a to 62d indicate the magnetization direction. That is, in the permanent magnets 62 a and 62 c, the N pole is located on the outer peripheral side of the rotor core 61 and the S pole is located on the inner peripheral side of the rotor core 61. In the permanent magnets 62 b and 62 d, the N pole is located on the inner peripheral side of the rotor core 61, and the S pole is located on the outer peripheral side of the rotor core 61. That is, in the two permanent magnets adjacent to each other in the circumferential direction, the directions of the magnetic poles are opposite.

  The cross-sectional shape of the permanent magnet 62 is an arc shape. The permanent magnet 62 is disposed along the outer periphery of the rotor core 61. A neodymium magnet, a samarium cobalt magnet, a ferrite core, or the like can be used as the permanent magnet 62.

  The magnetoresistive portion 63 is disposed on one side of the permanent magnet 62 in the circumferential direction of the rotor 6 and reaches the outer periphery of the rotor 6. The magnetoresistive portion 63 is formed by a notch 64 provided on the outer periphery of the rotor 6. One side surface of the permanent magnet 62 in the circumferential direction of the rotor 6 is exposed to the outside of the rotor core 61 by the magnetic resistance portion 63. The magnetoresistive portion 63 is not disposed on the other side of the permanent magnet 62. Therefore, the magnetic flux of the permanent magnet 62 is short-circuited on the other side of the permanent magnet 62 in a no-load state, as will be described later.

  An example of the slot combination of the motor generator 2 is shown in FIG. In FIG. 3, P indicates the number of poles of the rotor 6 and is a multiple of two. q represents the number of slots per phase for each station, and is a natural number. The slot combination of the motor generator 2 is not limited to the example shown in FIG.

{3. Change in magnetic path of motor generator 2}
Hereinafter, the permanent magnet 62a is taken as an example, and the magnetic path in the motor generator 2 having the configuration shown in FIG. 2 will be described separately for the no-load state and the load state. The load state is a state in which current is supplied to the stator 5 when the rotor 6 is rotating. The no-load state is a state in which no current is supplied to the stator 5 when the rotor 6 is rotating. The magnetic path in the loaded state is different from the magnetic path in the unloaded state.

{3.1. No load condition}
FIG. 4 is an enlarged cross-sectional view of the motor generator 2 in the vicinity of the permanent magnet 62 a and the magnetoresistive portion 63. In FIG. 4, the detailed structure (winding 52, teeth 53, slot 54) of the stator 5 is not shown.

In the no-load state, the rotor 6 is rotated by driving the engine 1, but the stator 5 is not excited. That is, the inverter 4 does not supply the currents i _u , i _v, and i _w to the winding 52. In this state, the magnetic flux of the permanent magnet 62 a is short-circuited in the rotor core 61. The magnetic path of the magnetic flux of the permanent magnet 62a is indicated by an arrow 67 in FIG. Hereinafter, the magnetic path indicated by the arrow 67 is referred to as a “magnetic path 67”.

  The magnetoresistance of the magnetoresistive portion 63 is larger than the magnetoresistance of the region opposite to the magnetoresistive portion 63 (hereinafter referred to as “short-circuit region”) with the permanent magnet 62a as the center. In addition, the magnetic resistance of the air gap (the space between the stator 5 and the rotor 6) is larger than the magnetic resistance of the rotor core 61. Therefore, the magnetic flux of the permanent magnet 62a is emitted from the N pole, passes through the bridge portion 65 and the short circuit region, and reaches the S pole. The bridge portion 65 is a portion of the rotor core 61 that is radially outward from the outer peripheral surface of the permanent magnet 62a.

  It is desirable that the region 66 between the left end of the permanent magnet 62a and the outer periphery of the rotor core 61 has a sufficient thickness so as not to be saturated by the magnetic flux of the permanent magnet 62a when in a no-load state. This is because all the magnetic flux emitted from the N pole is concentrated in the region 66 in the no-load state.

  Hereinafter, the position of the permanent magnet 62a for preventing magnetic saturation from occurring in the region 66 in the no-load state will be described.

  FIG. 5 is a view for explaining the position of the permanent magnet 62 a in the rotor core 61. As shown in FIG. 5, the circumferential length of the outer peripheral surface of the permanent magnet 62a is an arc Lm. The length from the circumferential end of the permanent magnet 62a to the outer peripheral surface of the rotor core 61 is defined as a passage width Lc. That is, the passage width Lc indicates the width in the radial direction of the rotor 6 in the region 66. The magnetic flux density of the N pole of the permanent magnet 62a is Br. The magnetic flux density in the region 66 is BL.

  In order for the magnetic flux of the permanent magnet 62a to be short-circuited in the rotor core 61 without saturating in the region 66, the arc Lm, the passage width Lc, the magnetic flux density Br, and the BL are expressed by the following formula (1). Should be satisfied.

BL × Lc ≧ Br × Lm (Formula 1)
In (Formula 1), the left side corresponds to a magnetic flux in which magnetic saturation occurs in the region 66, and the right side corresponds to a magnetic flux of N pole. When the value on the left side is larger than the value on the right side, the N-pole magnetic flux can pass through the region 66. When (Equation 1) is solved for the passage width Lc, the passage width Lc is expressed by (Equation 2).

Lc ≧ (Br × Lm) / BL (Expression 2)
The magnetic flux density BL is a value that varies depending on the material forming the rotor core 61. Preferably, the magnetic flux density BL is 1.4 to 1.6 (Tesla). Specifically, in the BH curve of the material forming the rotor core 61, the magnetic flux density in a region where the tangential slope changes gently can be used as the magnetic flux density BL.

  The passing width Lc is a distance from the outer peripheral surface of the rotor core 61 to the circumferential end of the permanent magnet 62a, and is a parameter indicating the position of the permanent magnet 62. Therefore, by arranging the permanent magnet 62a at a position satisfying (Equation 2) in the rotor core 61, the magnetic flux of the permanent magnet 62a can be short-circuited in the rotor 6 in a no-load state. Therefore, the magnetic flux of the permanent magnet 62a is prevented from leaking from the rotor 6 in the no-load state.

  Since the magnetic path 67 similar to that of the permanent magnet 62a is formed with respect to the permanent magnet 62c, the magnetic flux of the permanent magnet 62c is short-circuited in the rotor 6 in a no-load state. Regarding the permanent magnets 62b and 62d, a magnetic path opposite to the magnetic path 67 shown in FIG. 4 is formed. However, the magnetic flux of the permanent magnets 62b and 62d is short-circuited in the rotor 6 in an unloaded state. It is the same.

  In addition, as shown in FIG. 2, a magnetoresistive portion 63 is interposed between two permanent magnets adjacent to each other. Therefore, as shown in FIG. 4, all the magnetic fluxes of the permanent magnets 62 are short-circuited through the bridge portion 65 and the short-circuit region, and do not pass through the other permanent magnets 62. Since the magnetic fluxes of the permanent magnets 62 are not synthesized in the rotor 6, magnetic saturation does not occur in the rotor 6 in a no-load state.

{3.2. Loaded magnetic path}
FIG. 6 is a diagram illustrating a magnetic path in the motor generator 2 in a loaded state. When the inverter 4 supplies current to the winding 52, the motor generator 2 shifts from the no-load state to the load state. Due to the transition to the load state, the magnetic path in the motor generator 2 changes from the path shown in FIG. Hereinafter, the magnetic path in the loaded state will be described using the permanent magnet 62a as an example.

  As described above, the load state is a state in which no current is supplied to the winding 52, and includes a case where the motor generator 2 operates as a motor and a case where the motor generator 2 operates as a generator. The magnetic path formed in the load state is common in both cases.

When the motor generator 2 operates as a motor, the controller 3 uses the inverter 4 to supply three-phase alternating current to the stator 5 as in the conventional case. That is, the inverter 4 supplies the currents i _u , i _v and i _w to the winding 52.

Even when the motor generator 2 operates as a generator, the controller 3 supplies three-phase alternating current to the stator 5. However, the direction of the current supplied to the stator 5 is opposite to the direction of the current supplied when the motor generator 2 operates as a motor. That is, the current supplied to the windings 52 _becomes -i u, -i _v and -i _w. The magnitude of the current supplied to the stator 5 is smaller than the current supplied when the motor generator 2 operates as a motor. The reason for this will be described later.

The controller 3 controls the amounts of currents i _u , i _v and i _w flowing through the winding 52. The inverter 4 supplies currents i _u , i _v and i _w corresponding to the control signal 43 from the controller 3 to the winding 52. Magnetic flux is newly generated in the stator 5 by the current supplied from the inverter 4. The newly generated magnetic flux is combined with the magnetic flux of the permanent magnet 62 a in the rotor 6. The synthesized magnetic flux is saturated in the region 66 in the rotor 6.

  When magnetic saturation occurs in the region 66, the magnetic resistance of the air gap becomes smaller than the magnetic resistance of the region 66. As a result, the synthesized magnetic flux passes through the air gap and passes through the stator 5. Finally, the synthesized magnetic flux passes through the stator 5 and the rotor 6 and passes through the magnetic path indicated by the arrow 68a. Hereinafter, the magnetic path indicated by the arrow 68a is referred to as “magnetic path 68a”.

  When the motor generator 2 operates as an electric motor, the rotor 6 is rotated by magnet torque and reluctance torque.

  The magnetic flux passing through the magnetic path 68a is stretched in the vicinity of the air gap in accordance with the rotation of the rotor 6. As a result, reluctance torque is generated by contracting the stretched magnetic flux back to the original length.

  The magnetic pole of the tooth 53 (the salient pole) changes depending on the direction of the current flowing through the winding 52. Therefore, magnet torque is generated by the repulsive force acting between the permanent magnet 62 and the salient pole magnetic pole, and the attractive force acting between the permanent magnet 62a and the salient pole magnetic pole.

  The above description in the loaded state holds true for the permanent magnet 62c as well. In addition, the above description is similarly applied to the permanent magnets 62b and 62d except that a magnetic path 68b having a different direction from the magnetic path 68a is formed.

  Thus, when the motor generator 2 operates as a motor, the rotor 6 can be rotated using the reluctance torque and the magnet torque. As a result, since the torque of the rotor 6 can be increased, the rated output as a motor can be increased.

  On the other hand, when the motor generator 2 operates as a generator, the motor generator 2 does not need to generate torque. If the magnetic paths 68a and 68b are formed, the motor generator 2 generates power using the magnet torque and the reluctance torque. Therefore, the controller 3 may supply the winding 52 with a current that causes the combined magnetic flux to be equal to or greater than the saturation magnetic flux in the region 66. As a result, the current supplied to the winding 52 when the motor generator 2 operates as a generator is smaller than the current supplied to the winding 52 when the motor generator 2 operates as a motor.

  As described above, by controlling the current supplied to the winding 52, the magnetic flux can be saturated or short-circuited in the rotor. Therefore, the magnetic path in the motor generator 2 can be adjusted. That is, in the no-load state, the magnetic flux of the permanent magnet 62 is short-circuited without passing through other permanent magnets in the rotor core 61, and passes through the stator 5 and the rotor 6 in the loaded state. Therefore, the field generated by the permanent magnet 62 can be adjusted in the loaded state and the unloaded state.

  In the present embodiment, the example in which the notch 64 is used as the magnetoresistive portion 63 has been described, but the present invention is not limited to this.

  For example, as shown in FIG. 7A, a plurality of slits 69 extending in the circumferential direction of the rotor 6 may be arranged in the radial direction of the rotor 6 instead of the notches 64. When no load is applied, the magnetic flux of the permanent magnet 62 may be saturated in this space when passing through the space between the two adjacent slits 69. Thereby, the magnetic flux of the permanent magnet 62 is short-circuited through the short-circuit region. The same applies when the magnetic flux of the permanent magnet 62 passes between the outer peripheral surface of the rotor core 61 and the slit 69.

  As shown in FIG. 7B, a slit 69 extending in the radial direction of the rotor 6 may be provided in the rotor core 61 instead of the notch 64. In this case, when the magnetic flux of the permanent magnet 62 passes through the space between the outer peripheral surface of the rotor core 61 and the slit 69, it may be saturated in this space.

  In the present embodiment, the example in which the permanent magnet 62 is exposed by the notch 64 has been described. However, the present invention is not limited to this. The permanent magnet 62 may not be exposed to the outside of the rotor core 61 by the notch 64, and may not be in contact with the magnetoresistive portion 63. Specifically, the magnetoresistive portion 63 may be disposed on one side of the permanent magnet 62 in the circumferential direction of the rotor 6.

  For example, as shown in FIG. 8, a rotor core 61 may be interposed between the permanent magnet 62 and the magnetic resistance portion 63. When no load is applied, the magnetic flux of the permanent magnet 62 passes through the space between the permanent magnet 62 and the magnetoresistive portion 63, but it is only necessary to be saturated in this space. Thereby, the magnetic flux of the permanent magnet 62 is short-circuited through the short-circuit region.

  In the present embodiment, the example in which the permanent magnet 62 has an arc shape and is disposed along the circumferential direction of the rotor core 61 has been described. However, the present invention is not limited thereto. For example, the permanent magnet 62 may have a shape on a flat plate. That is, in the permanent magnet 62, the area of the outer peripheral surface may be equal to or larger than the area of the inner peripheral surface. By using the permanent magnet 62 that satisfies this condition, the distance from the outer periphery of the rotor core 61 to the permanent magnet 62 can be made larger than the distance from the outer periphery of the rotor described in Patent Document 1 to the flux barrier. it can. As a result, the strength of the entire rotor 6 can be increased, and destruction of the rotor 6 due to centrifugal force can be prevented.

  That is, the magnetoresistive portion 63 is disposed on one side of the permanent magnet 62 in the circumferential direction of the rotor 6 and prevents the magnetic flux of the permanent magnet 62 from passing on one side of the permanent magnet 62 in the circumferential direction. That's fine.

  In addition, as illustrated in FIGS. 2, 4, and 5, the example in which the magnetoresistive portion 63 is disposed on the clockwise direction side of the permanent magnet 62 in the circumferential direction of the rotor 6 has been described. However, the magnetoresistive portion 63 may be arranged on the counterclockwise direction side of the permanent magnet 62.

[Second Embodiment]
{1. Configuration of motor generator}
In the motor generator 2 according to the second embodiment, the configuration of the rotor is different from that of the rotor 6 shown in FIG. Hereinafter, in the present embodiment, description will be made focusing on the configuration of the rotor.

  FIG. 9 is a cross-sectional view of the motor generator 2 according to the present embodiment. The motor generator 2 shown in FIG. 9 includes a stator 5 and a rotor 7. The rotor 7 includes a rotor core 71 and a permanent magnet 62. Unlike the rotor 6 shown in FIG. 2, the rotor 7 does not include the magnetoresistive portion 63. That is, the notch 64 is not formed on the outer peripheral surface of the rotor core 71.

{2. Change in magnetic path of motor generator 2}
FIG. 10 is an enlarged cross-sectional view of the vicinity of the permanent magnet 62a of the motor generator 2 according to the second embodiment. In FIG. 10, the detailed structure (winding 52, teeth 53, slot 54) of the stator 5 is not shown.

  Hereinafter, the magnetic path in the motor generator 2 having the configuration shown in FIG. 10 will be described using the permanent magnet 62a as an example. However, since the magnetic path formed in the motor generator 2 in the load state is the same as that in the first embodiment, the detailed description thereof is omitted.

  In the no-load state, no current is supplied to the stator 5. For this reason, the magnetic flux of the permanent magnet 62a is short-circuited in the rotor core 61 as in the above embodiment. The magnetic path of the magnetic flux of the permanent magnet 62a is indicated by an arrow 73 in FIG. Hereinafter, the magnetic path indicated by the arrow 73 is referred to as a “magnetic path 73”. As shown in FIG. 10, the magnetic path 73 is formed on both sides of the permanent magnet 62 a in the circumferential direction of the rotor 7.

  Here, it is desirable that the regions 72a and 72b between both ends of the permanent magnet 62a and the outer periphery of the rotor core 71 have a sufficient thickness so that the magnetic flux of the permanent magnet 62a is not saturated. This is because the magnetic flux generated from the N pole passes through one of the regions 72a and 72b in the no-load state.

  FIG. 11 is a diagram for explaining the position of the permanent magnet 62 a in the rotor core 61. Similarly to the above embodiment, the arc Lm and the magnetic flux densities Br and BL are defined. Further, passage widths Lc1 and Lc2 are defined. The passage width Lc1 is a distance from one end of the permanent magnet 62a in the circumferential direction of the rotor 7 to the outer peripheral surface of the rotor core 61. The passage width Lc2 is a distance from the other end to the outer peripheral surface of the rotor core 61. The passage widths Lc1 and Lc2 correspond to the radial widths of the regions 72a and 72b, respectively.

  In order for the magnetic flux of the permanent magnet 62a to be short-circuited in the rotor core 61 without being saturated in the regions 72a and 72b, the arc Lm, the passage widths Lc1 and Lc2, and the magnetic flux densities Br and BL are expressed by the following (formula 3). And the condition shown by (Formula 4) may be satisfied.

BL × Lc1 ≧ Br × Lm × {Lc1 / (Lc1 + Lc2)} (Expression 3)
BL × Lc2 ≧ Br × Lm × {Lc2 / (Lc1 + Lc2)} (Expression 4)
By solving (Equation 3) for the passage width Lc1, the passage width Lc1 is expressed by (Equation 5).

Lc1 = {(Br × Lm) / Bm} −Lc2 (Formula 5)
By solving (Equation 4) for the passage width Lc2, the passage width Lc1 is expressed by (Equation 6).

Lc2 = {(Br × Lm) / Bm} −Lc1 (Expression 6)
In this way, by arranging the permanent magnet 62a in the rotor core 71 so that the passage widths Lc1 and Lc2 satisfy (Expression 5) and (Expression 6), the magnetic flux of the permanent magnet 62a can be changed in the no-load state. A short circuit can be made in the rotor 7. Therefore, the magnetic flux of the permanent magnet 62a can be prevented from leaking from the rotor 7 in a no-load state. The above description holds true for the permanent magnet 62c. Further, the above description is similarly applied to the permanent magnets 62b and 62d except that the direction of the magnetic path is reversed.

[Third Embodiment]
FIG. 12 is a cross-sectional view of the motor generator 2 according to the third embodiment. As shown in FIG. 12, the motor generator 2 includes a stator 8 and a rotor 9 in the present embodiment.

  The rotor 9 includes a rotor core 91 and four permanent magnets 92a to 92b. The arrows in the permanent magnets 92a to 92d indicate the magnetization directions of the permanent magnets 92a to 92d. Hereinafter, the permanent magnets 92a to 92d are collectively referred to as “permanent magnet 92”. Unlike the above embodiment, the magnetic flux of the permanent magnet 92 leaks from the rotor 9 and links with the stator 8 in a no-load state.

  13 is a cross-sectional view of the stator 8 shown in FIG. The stator 8 cancels the induced voltage generated in the no-load state. As shown in FIG. 13, the stator 8 includes a stator core 81, main teeth 831 to 836, auxiliary teeth 841 to 846, main windings 851 to 856, and auxiliary windings 861 to 866.

  The widths of the main teeth 831 to 836 are wider than the widths of the auxiliary teeth 841 to 846. However, in FIG. 13, the ratio of the main teeth 831 to 836 and the auxiliary teeth 841 to 846 is exaggerated and the width of the auxiliary teeth 841 to 846 is greatly shown.

  A space between the adjacent main teeth and auxiliary teeth is not counted as a slot. A space formed between two main teeth adjacent via the auxiliary teeth is counted as one slot. Accordingly, the number of slots of the stator 8 is six.

  Main windings 851 to 856 are wound around each of main teeth 831 to 836 by concentrated winding. The auxiliary windings 861 to 866 are wound around each of the auxiliary teeth 841 to 846 by concentrated winding. The auxiliary windings 861 to 866 are wound in the opposite direction to the main windings 851 to 856.

  FIG. 14 is a connection diagram of the main winding and the auxiliary winding wound around the stator 8 shown in FIG. In the motor generator 2 including the stator 8, the number of parallel circuits is two. FIG. 14 shows one of the two parallel circuits.

  The circuit shown in FIG. 14 is a connection diagram of main windings 851, 853, 855 and auxiliary windings 861-866. Although a plurality of coils are shown as the main windings 851, 853, 855, each of the plurality of coils indicates a coil for one turn wound around the main teeth.

The auxiliary winding 861, the main winding 851, and the auxiliary winding 862 are connected in series. The auxiliary winding 861 is connected to the terminal 871. The current i _u is supplied from the inverter 4 to the terminal 871. The auxiliary winding 862 is grounded.

The auxiliary winding 863, the main winding 853, and the auxiliary winding 864 are connected in series. The auxiliary winding 863 is connected to the terminal 872. Current _{i v} is supplied from the inverter 4 to the terminal 872. The auxiliary winding 864 is grounded.

The auxiliary winding 865, the main winding 855, and the auxiliary winding 866 are connected in series. The auxiliary winding 865 is connected to the terminal 873. The current i _w is supplied from the inverter 4 to the terminal 873. The auxiliary winding 866 is grounded.

  FIG. 15 is a diagram illustrating a magnetic path generated when a magnetic flux leaking from the rotor 7 (leakage magnetic flux) is linked to the stator 5 in an unloaded state. In FIG. 15, of the main windings 851, one turn for the main teeth 831 is referred to as main windings 851 a and 851 b, and the main windings excluding the main windings 851 a and 851 b are not shown. Further, the auxiliary windings 861 and 862 show only one turn.

  Hereinafter, the reason why the induced voltage is canceled in the no-load state will be described using the permanent magnet 92a as an example with reference to FIGS.

  As described above, the magnetic flux of the permanent magnet 92a leaks from the rotor 9 and links with the stator 8 in a no-load state. Magnetic fluxes 87 and 88 passing through the stator 8 and the rotor 9 are formed by the leakage magnetic flux interlinking with the stator 8. The magnetic path 87 passes through the permanent magnet 92a, the main teeth 831, and the auxiliary teeth 841. The magnetic path 88 passes through the permanent magnet 92a, the main teeth 831, and the auxiliary teeth 842.

  The rotor 9 continues to rotate even in a no-load state. For this reason, an induced voltage is generated in the main winding 851 and the auxiliary windings 861 and 862 by forming the magnetic paths 87 and 88.

  The arrows shown in FIG. 14 indicate directions of induced voltages generated in the main winding 851 and the auxiliary windings 861 and 862, respectively. Since the auxiliary windings 861 and 862 are wound in the opposite direction to the main winding 851, the direction of the induced voltage generated in the auxiliary windings 861 and 862 is opposite to the direction of the induced voltage generated in the main winding 851. It is. Since the main winding 851 and the auxiliary windings 861, 862 are connected in series, the induced voltage generated in the main winding 851 is canceled by the induced voltage generated in the auxiliary windings 861, 862.

  When the inside of the motor 2 is short-circuited due to a failure, the motor generator 2 needs to be shifted to a no-load state. Even in the no-load state, since it is possible to suppress the current caused by the induced voltage due to the leakage magnetic flux from being generated in the stator 8, the current is not short-circuited inside the motor generator 2. Heat generation and failure can be prevented.

  FIG. 16 is a diagram illustrating magnetic paths formed in the stator 8 and the rotor 9 in a loaded state. In the load state, the inverter 4 supplies current to the main winding 851 and the auxiliary windings 861 and 862. Since the auxiliary windings 861 and 862 are wound in the opposite direction to the main winding 851, the magnetic flux generated in the auxiliary windings 861 and 862 acts in a direction to cancel the magnetic flux generated in the main winding 851.

  However, since the widths of the auxiliary teeth 841 and 842 are smaller than the width of the main teeth 831, the auxiliary teeth 841 and 842 are saturated with the magnetic flux generated by the auxiliary teeth 841 and 842. Therefore, in the load state, the magnetic flux generated by combining the magnetic flux generated in the main winding 851 and the permanent magnet 92a cannot pass through the saturated auxiliary teeth 841 and 842. The synthesized magnetic flux passes through the magnetic path 89. The motor generator 2 can rotate the rotor 9 or generate electric power according to the rotation of the rotor 9 by the magnetic flux passing through the magnetic path 89.

  The reason why the induced voltage in the no-load state is canceled has been described by taking the main winding 851 and the auxiliary windings 861 and 862 as an example. However, the main winding 853 and the auxiliary windings 863 and 864 connected in series are also described. It is the same. The same applies to the main winding 855 and the auxiliary windings 865 and 866 connected in series. Further, the description of the synchronization holds true for the permanent magnets 92b to 92c as well. In the present embodiment, the rotors 6 and 7 may be used instead of the rotor 9.

[Fourth Embodiment]
In the above embodiment, the inner rotor type motor generator 2 has been described. However, the motor generator 2 may be an outer rotor type. Hereinafter, the outer rotor type motor generator 2 will be described focusing on differences from the above embodiment.

  FIG. 17 is a cross-sectional view of the motor generator 2 according to the present embodiment. The motor generator 2 shown in FIG. 17 is an outer rotor type, and includes a stator 15 and a rotor 16. The stator 15 is arranged coaxially with the rotation axis A. The rotor 16 is disposed on the outer periphery of the stator 15 and rotates about the rotation axis A.

  The stator 15 includes a stator core 151, a winding 152, and 24 teeth 153. In FIG. 17, a part of the winding 152 and a part of the teeth 153 are not shown.

  The stator core 151 has a cylindrical shape and is formed of the same material as that of the stator core 51. Teeth 153 is provided on the outer peripheral side of stator core 151. The slot 154 is a space between two adjacent teeth 153 and 153. Winding 152 is wound around teeth 153. The winding method of the winding 152 is the same as that of the winding 52.

  The rotor 16 includes a rotor core 161, four permanent magnets 162a to 162d, and four magnetoresistive portions 163. The rotor core 161 has a hollow cylindrical shape and rotates about the rotation axis A. The rotor core 161 is made of the same material as the rotor core 61.

  Permanent magnets 162 a to 162 d are arranged in the rotor core 161 and are magnetized in the radial direction of the rotor 16. Hereinafter, the permanent magnets 162a to 162d are collectively referred to as “permanent magnet 162”.

  The sectional shape of the permanent magnet 162 is an arc shape. The material of the permanent magnet 162 is the same as that of the permanent magnet 62. An arrow in the permanent magnet 162 indicates the magnetization direction. In the two permanent magnets adjacent to each other in the circumferential direction, the directions of the magnetic poles are opposite.

  The magnetoresistive portion 163 is disposed on one side of the permanent magnet 162 in the circumferential direction of the rotor 16 and reaches the inner periphery of the rotor 16. The magnetoresistive portion 163 is formed by a notch 164 provided on the inner periphery of the rotor 16. One side surface of the permanent magnet 162 in the circumferential direction of the rotor 16 is exposed to the outside of the rotor core 161 by the magnetoresistive portion 163. The magnetoresistive portion 163 is not disposed on the other side of the permanent magnet 162.

  Hereinafter, the change of the magnetic path in the motor generator 2 according to the present embodiment will be described.

  FIG. 18 is a diagram showing a magnetic path formed when the motor generator 2 shown in FIG. 17 is in a no-load state. As shown in FIG. 18, the magnetic flux of the permanent magnet 162 is short-circuited in the rotor core 161 in the no-load state. Arrows 167a to 167d indicate magnetic paths formed in the rotor core 161 by the magnetic fluxes of the permanent magnets 162a to 162d. Hereinafter, the arrows 167a to 167d are referred to as “magnetic paths 167a to 167d”.

  Hereinafter, the magnetic path 167a will be described. The description of the magnetic path 167a is similarly applied to the magnetic paths 167b to 167c.

  Similar to the first embodiment, the magnetic resistance of the magnetoresistive portion 163 in contact with the permanent magnet 162a is larger than the magnetic resistance of the region 166 opposite to the magnetoresistive portion 163 with the permanent magnet 162a as the center. The region 166 corresponds to the region 66 (see FIG. 4 or FIG. 5) described in the first embodiment. The magnetic resistance of the air gap (the space between the stator 15 and the rotor 16) is larger than the magnetic resistance of the rotor core 161. Therefore, the magnetic flux of the permanent magnet 162a is emitted from the N pole, passes through the region 166, and reaches the S pole.

  In this case, it is desirable that the region 166 has a sufficient thickness so as not to be saturated by the magnetic flux of the permanent magnet 162a in a no-load state. The condition of this thickness is that the arc Lm described in the first embodiment is defined as the length in the circumferential direction on the inner circumferential surface of the permanent magnet 162a, and the passage width Lc is defined on the inner circumferential surface of the permanent magnet 162a. What is necessary is just to define with the length from the edge of the circumferential direction to the internal peripheral surface of the rotor core 161. As a result, a condition in which magnetic saturation does not occur in the rotor core 161 in the no-load state can be obtained.

  Next, the magnetic path formed in the motor generator 2 in the load state will be described using the permanent magnet 162a as an example.

FIG. 19 is a diagram showing a magnetic path formed when the motor generator 2 shown in FIG. 17 is in a load state. In the load state, currents i _u , i _v and i _w are supplied to the winding 152, so that magnetic flux is generated in the stator 5. The generated magnetic flux passes through the air gap and flows into the rotor 16, and is combined with the magnetic flux of the permanent magnet 162a. The synthesized magnetic flux is saturated in the region 166 in the rotor core 161.

  When magnetic saturation occurs in the region 166, the synthesized magnetic flux passes through the air gap and passes through the stator 5. Finally, the synthesized magnetic flux passes through the stator 15 and the rotor 16 and passes through the magnetic path indicated by the arrow 168a.

  The magnetic fluxes of the permanent magnets 162b to 162d are combined with the magnetic flux generated in the stator 5, similarly to the magnetic flux of the permanent magnet 162a. As a result, as shown in FIG. 19, magnetic paths indicated by arrows 168b to 168d are formed.

  As described above, the outer rotor type motor generator 2 also causes the magnetic flux of the permanent magnet to be short-circuited in the rotor core 61 without passing through other permanent magnets in the no-load state, as in the above embodiment. Can do. In the loaded state, the magnetic flux combined with the permanent magnet 162 is combined with the magnetic flux generated in the stator 5 and passes through the stator 5 and the rotor 6. Therefore, the field generated by the permanent magnet 162 can be adjusted in the loaded state and the unloaded state.

  The magnetoresistive portion 163 may be a plurality of slits arranged in the radial direction of the rotor 16 as in the first embodiment, or may be a slit extending in the radial direction of the rotor 6. May be. Further, the permanent magnet 162 may not be in contact with the magnetoresistive portion 63.

  As described above, the motor generator 2 may be an inner rotor type or an outer rotor type, and may be disposed to face the rotor. Permanent magnets magnetized in the radial direction of the rotor are arranged in the rotor. The magnetoresistive portion may be disposed on one side of the permanent magnet in the circumferential direction of the rotor to prevent the magnetic flux of the permanent magnet from passing through one side of the permanent magnet.

  While the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiment, and can be implemented by appropriately modifying the above-described embodiment without departing from the spirit thereof.

DESCRIPTION OF SYMBOLS 100 Starter generator 200 Engine unit 1 Engine 2 Motor generator 3 Controller 4 Inverters 5, 8, 15 Stator 6, 7, 9, 16 Rotor 51, 81, 151 Stator core 52 Winding 53 Teeth 54 Slots 61, 71 , 91, 161 Rotor cores 62a-62d, 92a-92d, 162a-162d Permanent magnets 63, 163 Magnetic resistance portions 64, 164 Notches 65 Bridge portions 831-836 Main teeth 841-846 Auxiliary teeth 851-856, 851a, 851b Main winding 861-866 Auxiliary winding

Claims (5)

A rotor that rotates about a rotation axis;
A stator disposed opposite the rotor;
A first permanent magnet disposed in the rotor and magnetized in a radial direction of the rotor,
The rotor is
A first magnetoresistor that is disposed on one side of the first permanent magnet in the circumferential direction of the rotor and prevents the magnetic flux of the first permanent magnet from passing through one side of the first permanent magnet. Part
In an unloaded state, the magnetic flux of the first permanent magnet is short-circuited in the rotor,
The motor generator in which a magnetic flux obtained by combining the magnetic flux of the first permanent magnet and the magnetic flux generated by the stator is greater than or equal to the saturation magnetic flux of the rotor in a loaded state. The motor generator according to claim 1, further comprising:
A second permanent magnet which is arranged via the first magnetoresistive portion at a position different from the position of the first permanent magnet in the circumferential direction in the rotor and is magnetized in the radial direction of the rotor. With
The rotor is
A second magnetoresistor disposed on one side of the second permanent magnet in the circumferential direction of the rotor and preventing magnetic flux of the second permanent magnet from passing through one side of the second permanent magnet. Motor generator including parts. The motor generator according to claim 1 or 2,
The first magnetoresistive portion is a motor generator formed of a slit or a notch that opens in a surface of the rotor on the stator side. The motor generator according to any one of claims 1 to 3,
The stator is disposed on the outer peripheral side of the rotor,
In the first permanent magnet, the area of the surface on the stator side is equal to or larger than the area of the surface on the opposite side of the stator,
The rotor further includes:
A motor generator including a bridge portion that is formed between the stator side surface and the permanent magnet and allows the magnetic flux of the first permanent magnet to pass therethrough. The motor generator according to any one of claims 1 to 4,
An engine unit including a rotation shaft coupled to the rotation shaft of the rotor.

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