JP2008092743A - Rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotating electric machine capable of mechanically achieving variability in a torque constant. <P>SOLUTION: This rotating electric machine 19 includes a stator 12 wound by a winding wire and a rotor 14 having magnets 22, 24 of which different polarities are alternately located in a circumferential direction. The two magnets 22, 24 are provided side by side in an axial direction and so as to be relatively rotatable in the circumferential direction. A rotor 14 is installed with a spring 16 for urging the magnet 24 so that the polarity of the magnets 24 is deviated in the circumferential direction from the same polarity of the magnet 22 adjacent to each other in the axial direction. When current flowing through the winding wire is at a predetermined value or more, the magnet 24 is rotated so that the deviation in the circumferential direction between the polarity of the magnet 24 and the same polarity of the magnet 22 adjacent to each other in the axial direction becomes relatively smaller against energizing force by the spring 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary electric machine, and more particularly, to a rotary electric machine including a stator around which a winding is wound and a rotor having field magnets in which different polarities are alternately arranged in a circumferential direction.

2. Description of the Related Art Conventionally, a rotating electrical machine including a stator around which a winding is wound and a rotor having field magnets in which different polarities are alternately arranged in the circumferential direction is known (see, for example, Patent Document 1). ). In this rotating electrical machine, two field magnets of the rotor are arranged side by side in the direction of the rotation axis and are relatively rotatable in the circumferential direction. In such a rotating electrical machine, when functioning as an electric motor, the same poles of the field magnets are aligned in the rotation axis direction, and when functioning as a generator, the same poles are shifted in the rotation axis direction. That is, the magnetic pole center of the field magnet is changed according to the torque direction of the rotor. In order to realize this function, an electromagnetic servo mechanism is provided on the rotor side.
JP 2001-69609 A

  By the way, in order to obtain a high torque constant in the low rotation region and to obtain a low torque constant in the high rotation region, it is necessary to vary the torque constant of the rotating electrical machine according to the rotation region. However, if the electromagnetic servo mechanism is provided as described above or the field weakening by the control is performed to vary the torque constant, the structure becomes complicated and there is a problem that wasteful power is consumed.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a rotating electrical machine that mechanically realizes variable torque constants.

  The above object is a rotating electrical machine comprising a stator around which a winding is wound and a rotor having field magnets in which different polarities are alternately arranged in the circumferential direction, and the field magnet Are arranged side by side in the rotation axis direction and can be rotated relative to each other in the circumferential direction, and at least one of the field magnets on the rotor has the same polarity as that of the field magnet adjacent in the rotation axis direction. This is achieved by a rotating electrical machine provided with an urging means for urging each other so as to be displaced in the circumferential direction.

  In this aspect of the invention, at least one of the two field magnets arranged in the direction of the rotation axis and capable of relative rotation in the circumferential direction is attached such that the same polarity as the adjacent magnet is displaced in the circumferential direction. It is energized by the energizing means. If the same poles of two adjacent field magnets are displaced in the circumferential direction by the urging force of the urging means, the amount of magnetic flux linked between the rotor side and the stator side is relatively small, A field weakening effect can be obtained. On the other hand, if the same poles of two adjacent field magnets are arranged adjacent to each other in the rotational axis direction against the biasing force of the biasing means, the rotor side and the stator side are linked. The amount of magnetic flux becomes relatively large, and a high torque constant can be obtained. Therefore, the variable torque constant can be realized mechanically.

  In this case, in the rotating electric machine described above, the urging means may be provided corresponding to each field magnet.

  Further, in the rotating electrical machine described above, the field magnet biased by the biasing means resists the biasing force by the biasing means when the current flowing through the winding is equal to or greater than a predetermined value. What is necessary is just to rotate so that the shift | offset | difference of the circumferential direction of the same pole as the said field magnet adjacent to a rotating shaft direction may become small.

  In the rotating electric machine described above, a deviation angle detecting means for detecting a circumferential deviation angle generated between the two field magnets, and the deviation angle detecting means detected when the rotor rotates. If current control means for correcting the current flowing through the winding according to the deviation angle is provided, current control can be performed in consideration of deviation between the magnetic pole centers of the two field magnets.

  Further, in the rotating electric machine described above, a deviation angle detection means for detecting a circumferential deviation angle generated between the two field magnets, and the deviation angle detected by the deviation angle detection means is a predetermined angle or more. If there is an abnormality determination means for determining that an abnormality has occurred at a certain time, the motor disconnection or the deviation of the magnetic pole center between the two detected field magnets exceeds a desired range. It is possible to detect abnormalities in various sensors and separation abnormalities of the field magnet from the rotor.

  According to the present invention, the variable torque constant can be mechanically realized.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  1 and 2 each show a configuration diagram of a rotating electrical machine 10 according to a first embodiment of the present invention. FIG. 1 shows a situation when a small torque acts on the rotor, and FIG. 2 shows a situation when a large torque acts on the rotor. In this embodiment, the rotating electrical machine 10 is an electric motor that is used in, for example, an electric power steering device mounted on a vehicle, a vehicle power device, or the like and outputs a high torque at a low rotation and a low torque at a high rotation.

  As shown in FIG. 1, the rotating electrical machine 10 includes a stator (stator) 12 fixed to a housing, and a rotor (rotor) 14 that can rotate with respect to the stator 12. The stator 12 includes a stator core formed in a substantially cylindrical shape, and windings (stator windings) wound around the stator core. For example, a three-phase alternating current having a phase difference of 120 ° is supplied to the stator winding from the control unit.

  In addition, the rotor 14 is disposed on the inner peripheral side of the stator 12 so as to be rotatable about a rotation axis via a gap. The rotor 14 is fixed to a rotatable shaft 16 and is provided so as to surround the outer periphery of the shaft 16. The shaft 16 includes a shaft main body portion 16a and two flange portions 16b and 16c. The shaft main body 16a extends in the direction of the rotation axis in the shape of a round bar, and is rotatably supported by bearing devices at both ends in the axial direction. Each of the flange portions 16b and 16c is integrally fixed to the shaft main body portion 16a, protrudes in the radial direction from the shaft main body portion 16a, is formed in a disk shape, and has a predetermined thickness in the rotation axis direction. Have. The two flange portions 16b and 16c are separated from each other by a predetermined distance in the axial direction.

  The rotor 14 includes a first rotor 18 and a second rotor 20 that are divided into two substantially equally in the rotation axis direction. The first and second rotors 18 and 20 are disposed between the two flange portions 16 b and 16 c of the shaft 16. The first and second rotors 18 and 20 are each formed such that the sum of the axial thicknesses of the first and second rotors 18 and 20 is slightly shorter than the linear distance connecting the two flange portions 16b and 16c in the axial direction. Has been.

  The first rotor 18 is fixed to the flange portion 16 b of the shaft 16, and can rotate integrally with the shaft 16. The main body portion 16a of the shaft 16 is formed with a male screw on the outer peripheral surface (particularly on the flange portion 16c side). The second rotor 20 is formed with an internal thread that is engaged with the external thread of the shaft main body portion 16a on the inner peripheral surface thereof. That is, the second rotor 20 is screwed into the main body portion 16a of the shaft 16, and can be displaced in the direction of the rotation axis while rotating around the shaft main body portion 16a. The second rotor 20 can be displaced between the state in contact with the flange portion 16c of the shaft 16 and the state in contact with the first rotor 18 in the direction of the rotation axis.

  The first rotor 18 is attached with magnets 22 in which magnetic poles having different polarities (N pole and S pole) are alternately arranged at predetermined angles (for example, 90 °) in the circumferential direction. In addition, the second rotor 20 is provided with magnets 24 in which magnetic poles having different polarities (N pole and S pole) are alternately arranged at predetermined angles (for example, 90 °) in the circumferential direction. These two magnets 22 and 24 are provided so as to be aligned in the rotation axis direction and relatively rotatable in the circumferential direction. The attachment of the magnets 22 and 24 may be an adhesive fixing to the outer peripheral surfaces of the rotors 18 and 20 by an adhesive, or may be embedded in the rotors 18 and 20. The predetermined angle in the magnet 22 and the predetermined angle in the magnet 24 are the same.

  In the flange portion 16 c of the shaft 16, a groove 26 vacated in the direction of the rotation axis is formed on the side facing the second rotor 20. The groove 26 is provided in a cylindrical shape, and is formed only at one position at a position offset from the axis center. A spring spring 28 that can expand and contract in the direction of the rotation axis is disposed in the groove 26. One end of the spring spring 28 is fixed to the bottom surface of the groove 26. A spherical ball 30 having a certain weight is fixed to the other end of the spring spring 28. The ball 30 is displaced in the direction of the rotation axis in accordance with the expansion and contraction of the spring spring 28 in the direction of the rotation axis.

  Further, the second rotor 20 is formed with a groove 32 vacant in the direction of the rotation axis. The groove 32 is provided so as to face the flange portion 16c, and is formed at one position at a position offset from the axis center so as to face the groove 26 of the flange portion 16c. The groove 32 has a width about the diameter of the ball 30 described above in the radial direction and a length longer than the diameter of the ball 30 in the circumferential direction. The groove 32 is formed so that the depth in the direction of the rotation axis varies depending on the circumferential position, and gradually becomes deeper (linearly) as the rotor 14 rotates.

  The ball 30 is fitted in the groove 32 so as to be relatively rotatable. The position of the ball 30 is regulated in the groove 32. The spring spring 28 is configured such that the length in the direction of the rotation axis is shorter than the natural length even when the ball 30 is positioned at the deepest portion of the groove 32.

  The angle at which the ball 30 and the groove 32 relatively rotate and the distance by which the second rotor 20 is displaced in the direction of the rotation axis correspond to each other, and the ball 30 fitted in the groove 32 moves from one end of the groove 32 to the other end. 2, the second rotor 20 is displaced in the rotational axis direction from the state in which the second rotor 20 abuts on the flange portion 16 c or the first rotor 18 of the shaft 16 to the state in which the second rotor 20 abuts on the first rotor 18 or the flange portion 16 c. (See FIGS. 1 and 2).

  Note that the maximum angle (from one end to the other end) at which the ball 30 and the groove 32 can rotate relative to each other (hereinafter referred to as the maximum deviation angle) is an angle that can effectively reduce the torque pulsation of the rotating electrical machine 10 (for example, 15 °). Further, the magnet 22 of the first rotor 18 and the magnet 24 of the second rotor 20 have a relatively small circumferential shift between the same poles when the ball 30 is located at the shallowest portion of the groove 32. The same poles are arranged to face each other in the direction of the rotation axis (see FIG. 2). On the other hand, when the ball 30 is located at the deepest portion of the groove 32, the same poles are in the circumferential direction. Therefore, the maximum deviation angle is shifted (see FIG. 1).

  Next, operation | movement of the rotary electric machine 10 of a present Example is demonstrated.

  In the rotating electrical machine 10 of the present embodiment, the spring spring 28 is configured so that the length in the direction of the rotation axis is shorter than the natural length even when the ball 30 is positioned at the deepest portion of the groove 32 as described above. Therefore, an elastic force that causes the ball 30 to be positioned at the deepest portion of the groove 32 is generated. This spring force is a force that causes the second rotor 20 in which the groove 32 is formed to be displaced to the flange portion 16c side of the shaft 16 to come into contact therewith, and shifts the same poles of the magnet 22 and the magnet 24 in the circumferential direction. It becomes power. When the same poles of the magnets 22 and 24 are arranged to face each other so as to be adjacent to each other in the rotation axis direction, a large repulsive force acting in the rotation axis direction acts between the N poles. Since the repulsive force is a force that separates the magnet 24 from the magnet 22 in the direction of the rotation axis, the second rotor 20 is displaced to the flange portion 16c side of the shaft 16 and comes into contact therewith. This is the force that shifts the same poles in the circumferential direction.

  If no current is supplied to the windings of the stator 12 from the control unit, a rotating magnetic field that rotates the rotor 14 is not generated between the stator 12 and the rotor 14, so that the shaft 16 does not rotate. In this case, the spring force by the spring spring 28 or the force against the repulsive force between the N poles of the magnets 22 and 24 does not act on the second rotor 20 to which the magnet 24 is attached. Due to the force, the second rotor 20 abuts against the flange portion 16 c of the shaft 16. At the time of this contact, the first rotor 18 and the second rotor 20 are in a state where the same poles of the magnets 22 and 24 are displaced in the circumferential direction (FIG. 1).

  On the other hand, when a current flows through the winding of the stator 12 from the control unit, a rotating magnetic field is generated between the stator 12 and the rotor 14 to rotate the rotor 14 in the direction of the arrow shown in FIG. Rotate to. At this time, since the second rotor 20 does not restrict the relative rotation of the ball 30 on the flange portion 16c side in the groove 32, the second rotor 20 resisted the spring force by the spring spring 28 and the repulsive force by the N poles of the magnets 22 and 24. A force (torque) acts to rotate relative to the shaft body 16a in the circumferential direction. In this case, since the ball 30 moves from the deepest portion side to the shallowest portion side in the groove 32 to a position where each force is balanced, the second rotor 20 performs relative rotation with respect to the shaft main body portion 16a with the above-described spring force and An amount corresponding to the magnitude of the force resisting the repulsive force is realized while being separated from the flange portion 16c side toward the first rotor 18 side.

  When the current flowing through the stator 12 is not so large, the rotating magnetic field generated between the stator 12 and the rotor 14 is relatively small, so that the ball 30 cannot move in the groove 32 to the shallowest portion. In this case, the second rotor 20 is not so far away from the flange portion 16c, and the relative rotation amount with respect to the shaft main body portion 16a is not so large. On the other hand, when the current flowing through the stator 12 reaches a predetermined value and is relatively large, the rotating magnetic field generated between the stator 12 and the rotor 14 is relatively large, so that the ball 30 reaches the shallowest portion in the groove 32. Moving. In this case, the second rotor 20 is greatly separated from the flange portion 16 c, the relative rotation amount with respect to the shaft main body portion 16 a is increased, and the second rotor 20 is in contact with the first rotor 18. At the time of this contact, the first rotor 18 and the second rotor 20 are arranged so that the circumferential displacement between the same poles of the magnets 22 and 24 is small and the same poles face each other in the rotation axis direction. (Figure 2).

  Further, when the current flowing through the stator 12 disappears, the second rotor 20 loses the spring force due to the spring spring 28 or the force against the repulsive force due to the N poles of the magnets 22 and 24. As a result, the ball 30 moves in the groove 32 to the deepest portion. At this time, the second rotor 20 moves away from the first rotor 18 while rotating in the opposite direction relative to the shaft main body portion 16a, and then comes into contact with the flange portion 16c. At the time of this contact, the first rotor 18 and the second rotor 20 are in an original state in which the same poles of the magnets 22 and 24 are displaced in the circumferential direction (FIG. 1).

  When the same poles of the magnet 22 of the first rotor 18 and the magnet 24 of the second rotor 20 are arranged adjacent to each other in the rotational axis direction as shown in FIG. The amount of magnetic flux interlinked is relatively large, and the torque constant is relatively large. On the other hand, when the same poles of the magnet 22 and the magnet 24 are shifted in the circumferential direction as shown in FIG. 1, the amount of magnetic flux linked between the rotor 14 and the stator 12 is relatively small, and the torque constant is compared. The smaller it is, the smaller it becomes.

  The current exceeding the predetermined value flows through the stator 12 when the rotating electrical machine 10 is in a region where it rotates at a low speed such as at the start, while the current less than the predetermined value flows through the stator 12. Is when the rotating electrical machine 10 is in a region rotating at high speed. Therefore, according to the rotating electrical machine 10 of the present embodiment, in a low rotation region such as at the time of start-up, the torque constant is increased by flowing a current equal to or greater than the predetermined value to the stator 12, so that A large torque can be output. Further, in the high rotation region, a current less than the predetermined value described above is caused to flow through the stator 12, so that the torque constant is reduced, so that a field-weakening effect can be obtained, and the high speed of the rotating electrical machine 10 can be increased. Rotation can be realized.

  Thus, according to the configuration of the present embodiment, the torque constant of the rotating electrical machine 10 can be varied. The rotor 14 is divided into the first rotor 18 and the second rotor 20, and the rotors 18 and 20 are configured to be relatively rotatable by a screw mechanism and a spring spring 28. Can be realized by a mechanical operation accompanying current control in accordance with the rotation range of the rotating electrical machine 10. In this respect, according to the present embodiment, it is not necessary to provide an electromagnetic servomechanism on the rotor 14 side, and it is not necessary to perform field weakening by control, so that the structure of the rotating electrical machine 10 is complicated. In addition to being able to avoid this, it is possible to avoid wasting power.

  In the first embodiment, the magnets 22 and 24 are used for the “field magnet” described in the claims, and the spring spring 28 is used for the “biasing means” described in the claims. It corresponds.

  In the first embodiment described above, the torque constant is varied when the rotor 14 rotates in one direction, but the torque constant is unchanged when it rotates in the other direction. On the other hand, in the second embodiment of the present invention, the torque constant is variable when the rotor 14 rotates in any direction.

  FIG. 3 to FIG. 5 each show a configuration diagram of a rotating electrical machine 100 that is a second embodiment of the present invention. 3 shows the situation when a small torque acts on the rotor, FIG. 4 shows the situation when a large torque acts on the rotor in one direction of rotation, and FIG. 5 shows the situation when the rotor acts on the rotor. The situation when a large torque acts in the other rotational direction is shown respectively. Further, in FIGS. 3 to 5, the same components as those shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  The rotating electrical machine 100 according to the present embodiment includes a stator 12 and a rotor 14 as with the rotating electrical machine 10 according to the first embodiment described above. The rotor 14 is fixed to a shaft 102 that can rotate, and is provided so as to surround the outer periphery of the shaft 102. The shaft 102 includes a shaft main body portion 102a and two flange portions 102b and 102c. The shaft main body 102a extends in the direction of the rotation axis in the shape of a round bar, and is rotatably supported by a bearing device at both ends in the axial direction. Each of the flange portions 102b and 102c is integrally fixed to the shaft main body portion 102a, protrudes in the radial direction from the shaft main body portion 102a, is formed in a disk shape, and has a predetermined thickness in the rotation axis direction. Have. The two flange portions 102b and 102c are separated from each other by a predetermined distance in the axial direction.

  The rotor 14 includes a first rotor 104 and a second rotor 106 that are divided into two substantially equally in the rotation axis direction. The first and second rotors 104 and 106 are disposed between the two flange portions 102 b and 102 c in the shaft 102. Each of the first and second rotors 104 and 106 is formed such that the sum of the axial thicknesses of the first and second rotors 104 and 106 is slightly shorter than the linear distance connecting the two flange portions 102b and 102c. .

  A male thread is formed on the outer peripheral surface of the shaft main body 102a. Each of the first and second rotors 104 and 106 is formed with an internal thread that engages with an external thread of the shaft main body 102a on the inner peripheral surface thereof. That is, the first and second rotors 104 and 106 are screwed into the main body portion 102a of the shaft 102, respectively, and can be displaced toward the rotation axis while rotating around the shaft main body portion 102a. is there. The first rotor 104 can be displaced between the state in contact with the flange portion 102b of the shaft 102 and the state in contact with the second rotor 106 in the rotation axis direction. In addition, the second rotor 106 can be displaced between the state of contact with the flange portion 102 c and the state of contact with the first rotor 104 in the rotation axis direction.

  The first rotor 104 is attached with a magnet 22 in which magnetic poles having different polarities (N pole and S pole) are alternately arranged at predetermined angles (for example, 90 °) in the circumferential direction. Further, the second rotor 106 is attached with magnets 24 in which magnetic poles having different polarities (N pole and S pole) are alternately arranged at predetermined angles (for example, 90 °) in the circumferential direction.

  The flange portion 102b of the shaft 102 has a groove 110 vacated in the direction of the rotation axis on the side facing the first rotor 104, and the flange portion 102c rotates on the side facing the second rotor 106. Grooves 112 vacated in the axial direction are respectively formed. Each of the grooves 110 and 112 is provided in a columnar shape, and is formed at one position at a position offset from the axis center.

  In the grooves 110 and 112, spring springs 114 and 116 that can expand and contract in the direction of the rotation axis are disposed. One end of the spring spring 114 is fixed to the bottom surface of the groove 110, and one end of the spring spring 116 is fixed to the bottom surface of the groove 112. A spherical ball 118 having a certain weight is fixed to the other end of the spring spring 114, and a spherical ball 120 having a weight similar to that of the ball 118 is fixed to the other end of the spring spring 116, respectively. Yes. The balls 118 and 120 are displaced in the rotation axis direction in accordance with the expansion and contraction of the spring springs 114 and 116 in the rotation axis direction.

  Further, the first rotor 104 is formed with a groove 122 vacated in the direction of the rotation axis, and the second rotor 106 is formed with a groove 124 vacated in the direction of the rotation axis. The groove 122 is provided so as to face the flange portion 102b, and is formed at only one position at a position offset from the axial center so as to face the groove 110 of the flange portion 102b. Further, the groove 124 is provided so as to face the flange portion 102c, and is formed at only one position at a position offset from the axial center so as to face the groove 112 of the flange portion 102c.

  The grooves 122 and 124 have a width approximately equal to the diameter of the balls 118 and 120 in the radial direction and a length longer than the diameter of the balls 118 and 120 in the circumferential direction. Each of the grooves 122 and 124 has a depth in the rotation axis direction that varies depending on a circumferential position, and is formed so as to gradually become deeper (in a straight line) as the rotor 14 rotates in one direction. Note that the circumferential direction in which the depth of the groove 122 is deep and the circumferential direction in which the depth of the groove 124 is deep are opposite to each other and are different.

  The above-described ball 118 is fitted in the groove 122 so as to be relatively rotatable. Further, the above-described ball 120 is fitted in the groove 124 so as to be relatively rotatable. The positions of the balls 118 and 120 are restricted in the grooves 122 and 124. The spring springs 114 and 116 are configured such that the length in the direction of the rotation axis is shorter than the natural length even when the balls 118 and 120 are located at the deepest portions of the grooves 122 and 124.

  The angle at which the ball 118 and the groove 122 rotate relative to each other and the distance by which the first rotor 104 is displaced in the direction of the rotation axis correspond to each other. When the first rotor 104 rotates relative to the first rotor 104, the first rotor 104 is displaced in the rotational axis direction from a state where the first rotor 104 abuts against the flange portion 102b or the second rotor 106 of the shaft 102 to a state where the first rotor 104 abuts against the second rotor 106 or the flange portion 102b. (See FIGS. 3 and 5). Further, the angle at which the ball 120 and the groove 124 rotate relative to each other and the distance by which the second rotor 106 is displaced in the direction of the rotation axis correspond to each other. When the second rotor 106 rotates relative to the other end, the rotational direction of the second rotor 106 from the state in which the second rotor 106 abuts on the flange portion 102c or the first rotor 104 of the shaft 102 to the state in which the second rotor 106 abuts on the first rotor 104 or flange portion 102c. Displace (see FIGS. 3 and 4).

  Note that the maximum angle (from one end to the other end) at which the ball 118 and the groove 122 can rotate relative to each other and the maximum angle (from one end to the other end) at which the ball 120 and the groove 124 can rotate relative to each other (from the other end). Hereinafter, the maximum deviation or angle) is set to an angle (for example, 15 °) that can effectively reduce the torque pulsation of the rotating electrical machine 100. Further, the magnet 22 of the first rotor 104 and the magnet 24 of the second rotor 106 are configured such that the ball 118 is positioned at the shallowest portion of the groove 122 and the ball 120 is positioned at the deepest portion of the groove 124 (FIG. 5). ) And when the ball 118 is located at the deepest part of the groove 122 and the ball 120 is located at the shallowest part of the groove 124 (situation shown in FIG. 4), the circumferential shift between the same poles Becomes relatively small, and the same poles are arranged to face each other in the direction of the rotation axis (see FIGS. 4 and 5), while the ball 118 is located at the deepest portion of the groove 122 and the ball 120 Are located at the deepest part of the groove 124, the same poles are shifted in the circumferential direction by the maximum shift angle (see FIG. 3).

  Next, operation | movement of the rotary electric machine 100 of a present Example is demonstrated.

  In the rotating electrical machine 100, the spring springs 114 and 116 are arranged such that when the balls 118 and 120 are located at the deepest portions of the grooves 122 and 124, the length in the rotation axis direction is shorter than the natural length, as described above. Since it is configured, an elastic force for generating the balls 118 and 120 at the deepest portions of the grooves 122 and 124 is generated. The spring force by the spring spring 114 is a force for displacing the first rotor 104 in which the groove 122 is formed toward the flange portion 102b side of the shaft 102, and the spring force by the spring spring 116 is the groove force. The second rotor 106 in which 124 is formed is displaced to the flange portion 102c side of the shaft 102 and comes into contact with each other. Both spring forces cause the same poles of the magnets 22 and 24 to move in the circumferential direction. It becomes the power to shift.

  When the same poles of the magnets 22 and 24 are arranged to face each other so as to be adjacent to each other in the rotation axis direction, a large repulsive force acting in the rotation axis direction acts between the N poles. Since the repulsive force is a force that separates the magnet 22 and the magnet 24 from each other in the rotation axis direction, the first rotor 104 is placed on the flange portion 102b side of the shaft 102 and the second rotor 106 is placed on the flange portion 102c side. Each force is displaced and brought into contact, and is a force that shifts the same poles of the magnets 22 and 24 in the circumferential direction.

  If no current is supplied to the windings of the stator 12 from the control unit, a rotating magnetic field that rotates the rotor 14 is not generated between the stator 12 and the rotor 14, so that the shaft 102 does not rotate. In this case, the spring force due to the spring spring 114 and the force against the repulsive force between the N poles of the magnets 22 and 24 do not act on the first rotor 104 to which the magnet 22 is attached. The first rotor 104 abuts on the flange portion 102b of the shaft 102 by force. Further, since the spring force due to the spring spring 116 and the force against the repulsive force due to the N poles of the magnets 22 and 24 do not act on the second rotor 106 to which the magnet 24 is attached, The second rotor 106 abuts on the flange portion 102 c of the shaft 102. At the time of this contact, the first rotor 104 and the second rotor 106 are in a state in which the same poles of the magnets 22 and 24 are displaced in the circumferential direction (FIG. 3).

  On the other hand, when a current for rotating the rotor 14 in the one rotation direction (specifically, the right rotation direction when the rotating electrical machine 100 shown in FIG. 3 is viewed from the right side) is supplied to the winding of the stator 12 from the control unit, Since a rotating magnetic field that rotates the rotor 14 in the rotation direction is generated between the stator 12 and the rotor 14, the shaft 102 rotates in that direction.

  At this time, the first rotor 104 restricts the relative rotation of the ball 118 on the flange portion 102b side in the groove 122, so that the spring force by the spring spring 114 and the repulsive force by the N poles of the magnets 22 and 24 are affected. The resisted force (torque) does not act and rotates integrally with the shaft body 102a, and does not rotate relative to the shaft body 102a. On the other hand, since the second rotor 106 does not restrict the relative rotation of the ball 120 on the flange portion 102c side in the groove 124, the second rotor 106 has a spring force by the spring spring 116 and a repulsive force by the N poles of the magnets 22 and 24. The resisted force (torque) acts to rotate relative to the shaft body 102a in the circumferential direction. In this case, since the ball 120 moves from the deepest portion side to the shallowest portion side in the groove 124 to a position where each force is balanced, the second rotor 106 performs relative rotation with respect to the shaft main body portion 102a with the above spring force and An amount corresponding to the magnitude of the force against the repulsive force is realized while being separated from the flange portion 102c side toward the first rotor 104 side.

  Further, the rotor of the stator 12 is wound in the other rotation direction opposite to the one rotation direction described above from the control unit (specifically, in the right rotation direction when the rotating electrical machine 100 shown in FIG. 3 is viewed from the left). When a current that rotates 14 is applied, a rotating magnetic field that rotates the rotor 14 in the rotation direction is generated between the stator 12 and the rotor 14, so that the shaft 102 rotates in that direction.

  At this time, the second rotor 106 restricts the relative rotation of the ball 120 on the flange portion 102c side in the groove 124, so that the spring force by the spring spring 116 and the repulsive force by the N poles of the magnets 22 and 24 are affected. The resisted force (torque) does not act and rotates integrally with the shaft body 102a, and does not rotate relative to the shaft body 102a. On the other hand, since the first rotor 104 does not restrict the relative rotation of the ball 118 on the flange portion 102b side in the groove 122, the first rotor 104 is not affected by the spring force by the spring spring 114 and the repulsive force by the N poles of the magnets 22 and 24. The resisted force (torque) acts to rotate relative to the shaft body 102a in the circumferential direction. In this case, since the ball 118 relatively moves from the deepest portion side to the shallowest portion side in the groove 122 to a position where each force is balanced, the first rotor 104 performs relative rotation with respect to the shaft main body portion 102a. And it implement | achieves, separating | separating from the flange part 102b side toward the 2nd rotor 106 side by the quantity according to the magnitude | size of the force resisting the repulsive force.

  When the current flowing through the stator 12 is not so large, the rotating magnetic field generated between the stator 12 and the rotor 14 is relatively small, so that the balls 118 and 120 move in the grooves 122 and 124 to the shallowest portion. Can not. In this case, the first or second rotor 104, 106 is not so far away from the flange portions 102b, 102c, and the amount of relative rotation with respect to the shaft main body portion 102a is not so large. On the other hand, when the current flowing through the stator 12 reaches a predetermined value and is relatively large, the rotating magnetic field generated between the stator 12 and the rotor 14 is relatively large, so that the balls 118 and 120 move in the grooves 122 and 124. Move to the shallowest part. In this case, the first or second rotor 104, 106 is largely separated from the flange portions 102b, 102c, the amount of relative rotation with respect to the shaft main body portion 102a is increased, and the first or second rotor 104, 106 is 2 or the first rotor 106, 104. At the time of this contact, the first rotor 104 and the second rotor 106 are arranged so that the circumferential displacement between the same poles of the magnets 22 and 24 is small and the same poles face each other in the rotation axis direction. It will be in a state (FIGS. 4, 5).

  Further, when the current flowing through the stator 12 is eliminated, the first or second rotor 104, 106 has no force to resist the spring force of the spring springs 114, 116 and the repulsive force of the N poles of the magnets 22, 24. The balls 118 and 120 move in the grooves 122 and 124 to the deepest portion by the spring force and the repulsive force. At this time, the first or second rotor 104 or 106 moves away from the second or first rotor 106 or 104 while rotating relative to the shaft main body portion 102a in the opposite direction, and then the flange portion 102b or 102c. At the time of this contact, the first rotor 104 and the second rotor 106 are in an original state in which the same poles of the magnets 22 and 24 are displaced in the circumferential direction (FIG. 3).

  When the same poles of the magnet 22 of the first rotor 104 and the magnet 24 of the second rotor 106 are arranged adjacent to each other in the rotational axis direction as shown in FIG. 4 or FIG. 5, the rotor 14 and the stator 12 There is a relatively large amount of magnetic flux interlinked with and a relatively large torque constant. On the other hand, when the same poles of the magnet 22 and the magnet 24 are shifted in the circumferential direction as shown in FIG. 3, the amount of magnetic flux linked between the rotor 14 and the stator 12 is relatively small, and the torque constant is compared. The smaller it is, the smaller it becomes.

  The current exceeding the predetermined value flows through the stator 12 when the rotating electrical machine 100 is in a region where the rotating electrical machine 100 rotates at a low speed such as at the start, while the current less than the predetermined value flows through the stator 12. Is when the rotating electrical machine 100 is in a region rotating at high speed. Therefore, according to the rotating electrical machine 100 of the present embodiment, in a low rotation region such as at the time of start-up, the torque constant is increased by flowing a current equal to or greater than the predetermined value to the stator 12, thereby A large torque can be output. Further, in the high rotation region, a current less than the predetermined value described above is caused to flow through the stator 12, so that the torque constant is reduced. Thus, a field weakening effect can be obtained, and the high speed of the rotating electrical machine 100 can be obtained. Rotation can be realized.

  Thus, according to the configuration of the present embodiment, the torque constant of the rotating electrical machine 100 can be varied. The rotor 14 is divided into two parts, the first rotor 104 and the second rotor 106, and both the rotors 104, 106 are configured to be relatively rotatable by a screw mechanism and spring springs 114, 116, as described above. The variable torque constant can be realized by a mechanical operation accompanying current control according to the rotation range of the rotating electrical machine 100. In this regard, according to the present embodiment, it is not necessary to provide an electromagnetic servomechanism on the rotor 14 side, and it is not necessary to perform field weakening by control, so that the structure of the rotating electrical machine 100 is complicated. In addition to being able to avoid this, it is possible to avoid wasting power.

  Further, in this embodiment, the variable torque constant of the rotating electrical machine 100 is different from the rotating electrical machine 10 of the first embodiment, not only in one rotating direction but also in the rotating direction opposite to the rotating direction of one. Is also realized. Therefore, the rotating electrical machine 100 of this embodiment is not only applied to an electric motor that rotates only in one direction, but also applied to an electric motor that rotates in both directions (for example, an electric motor used in an electric power steering device). Is possible.

  In the second embodiment, the spring springs 114 and 116 correspond to “biasing means” described in the claims.

  In the first and second embodiments described above, the same poles of the magnets 22 and 24 of the first rotor 18 and 104 and the second rotor 20 and 106 are arranged opposite to each other in the rotational axis direction. In order to increase the torque constant, it is necessary to bring the first rotors 18 and 104 and the second rotors 20 and 106 into contact with each other. It implement | achieves when the 2nd rotors 20 and 106 approach relatively rotating. However, during such contact, the first rotor 18 and 104 and the second rotor 20 and 106 may be tightened like a double nut, and the same poles of the magnets 22 and 24 are displaced in the circumferential direction. When returning to the original state, a large force may be required to remove the fastening. Therefore, in order to prevent such a situation from occurring, an elastic body such as rubber or resin is inserted between the first rotors 18 and 104 and the second rotors 20 and 106. For example, an elastic body is attached to the contact surface of the first rotor 18 or 104 or the contact surface of the second rotor 20 or 106 by baking or the like. According to such a configuration, it is possible to avoid a situation in which the first rotors 18 and 104 and the second rotors 20 and 106 are tightened like a double nut, whereby the positional relationship between the magnets 22 and 24 is restored to the original. It becomes possible to return to the state smoothly.

  In the first and second embodiments, the maximum deviation angle at which the balls 30, 118, 120 and the grooves 32, 122, 124 can rotate relative to each other is effective for the torque pulsation of the rotating electrical machines 10, 100. Set to an angle that can be reduced.

  For example, in the rotating electrical machines 10 and 100 in which the number of poles of the rotor 14 is “4” and the number of slots of the stator 12 is “6”, cogging of “12” peaks occurs per revolution. In order to cancel out the components, the magnets 22 of the first rotor 18 and 104 and the magnet 24 of the second rotor 20 and 106 when the balls 30, 118 and 120 are located at the deepest part of the grooves 32, 122 and 124 are the same. The first rotors 18 and 104 and the second rotors 20 and 106 are arranged so that the deviation angle between the poles is 360/12/2 = 15 °. According to this configuration, the cogging component generated by the magnet 22 of the first rotor 18 and 104 and the cogging component generated by the magnet 24 of the second rotor 20 and 106 cancel each other, so that torque pulsation is effectively reduced. Can be reduced.

  By the way, in the first and second embodiments described above, the rotating electrical machines 10 and 100 are rotationally controlled by the control unit. In these rotating electrical machines 10 and 100, the magnets 22 and 24 of the rotor 14 divided into two are arranged in the same direction in the circumferential direction (state shown in FIG. 6A) and in the rotational axis direction. The center of the imaginary magnetic pole in the entire magnets 22 and 24 is changed (the state of X0 and X1 indicated by the one-dot chain line in FIG. 6). while). In this regard, since the phase relationship between the magnetic field and the rotation angle in the rotation angle sensor that detects the rotation angle by the magnetic field is deviated, the rotation angle on the rotor 14 side may be erroneously detected, and rotation control may not be performed properly. There is sex. Therefore, in order to appropriately control the rotation of the rotating electrical machines 10 and 100, when detecting the motor rotation angle on the rotor 14 side and performing feedback, the winding of the stator 12 is applied according to the deviation of the magnetic pole center. It is necessary to correct the flowing current.

  Therefore, the third embodiment of the present invention has a first feature in that the rotation control of the rotary electric machines 10 and 100 is shown in consideration of such points. Hereinafter, with reference to FIG. 7 and FIG. 8, the above-described features of the present embodiment will be described. Note that the rotation control of the rotating electrical machine 10 and the rotation control of the rotating electrical machine 100 have almost no difference except that the rotation direction is only one direction or bidirectional. Only will be described.

  FIG. 7 is a configuration diagram of a control device 200 that controls the rotation of the rotating electrical machine 100 according to the present embodiment. As shown in FIG. 7, the control device 200 of this embodiment includes a rotation angle sensor 202 and a control unit 204. The rotation angle sensor 202 has a magnet that is disposed on a rotor fixed to the shaft main body 102a of the shaft 102 of the rotating electrical machine 100, a resistance value that changes according to the strength of the magnetic field, and an output signal phase difference of 90. And two magnetic circuits arranged so as to be at 0 °. The rotation angle sensor 202 outputs a signal corresponding to the motor rotation angle of the shaft 102.

  The control unit 204 includes a command current calculation unit 206, an inverter control unit 208, a motor drive unit 210, and a current sensor 212. The command current calculation unit 206 calculates a current command value I * of the rotating coordinate system based on the output signal of a predetermined sensor attached to the vehicle, and outputs it to the inverter control unit 208. The current sensor 212 detects the current flowing through the windings of the U, V, and W phases and outputs the current detection signal to the inverter control unit 208. The output of the rotation angle sensor 202 described above is input to the inverter control unit 208.

  The inverter control unit 208 is configured to output a biaxial current command value I * based on the output of the current sensor 212 converted based on the rotation angle based on the output of the rotation angle sensor 202 and the command current calculation unit 206. The two-axis voltage command value is calculated based on the deviation between the two and a motor drive signal is generated and output to the motor drive unit 210. The motor drive unit 210 is composed of a power element such as an FET, and switches the power element based on the motor drive signal generated by the inverter control unit 208 to energize the rotating electrical machine 100 with a current corresponding to the current command value I *. To do.

  FIG. 8 shows a flowchart of an example of a control routine executed by the inverter control unit 208 of the control device 200 in the present embodiment. The inverter control unit 208 determines whether or not the rotation speed (motor rotation speed) of the shaft 102 based on the output of the rotation angle sensor 202 exceeds a predetermined rotation speed A (step 100). The predetermined rotational speed A is a motor rotational speed boundary value indicating whether or not the motor rotational angle can be detected from the back electromotive voltage of each phase.

  As a result of the above determination, when the motor rotation speed exceeds a predetermined rotation speed A, the motor rotation angle is obtained from the detected back electromotive force of each phase, and the voltage command value is calculated using the motor rotation angle. By outputting a motor drive signal to the motor drive unit 210, a process of applying a current corresponding to the current command value I * is performed (step 102).

  On the other hand, when the motor rotation speed does not exceed the predetermined rotation speed A, it is next determined whether or not the detected current value I based on the output of the current sensor 212 exceeds the predetermined current value B (step 104). ). The predetermined current value B is obtained when the magnet 22 of the first rotor 104 and the magnet 24 of the second rotor 106 on the rotor 14 side are shifted from each other in the circumferential direction to the maximum in the circumferential direction. Minimum current value that is judged to start to rotate relatively by the force against the spring force generated by the rotating magnetic field generated by the rotating magnetic field based on the current flow to the windings and the repulsive force caused by the N poles of the magnets 22 and 24 Value.

  As a result of the above determination, when the detected current value does not exceed the predetermined current value B, it can be determined that the same poles of the magnets 22 and 24 are shifted to the maximum in the circumferential direction. A voltage command value is calculated using the motor rotation angle of the shaft 102 detected based on the output of the sensor 202 as it is, and a process of applying a current corresponding to the current command value I * is performed (step 106).

  On the other hand, when the detected current value exceeds the predetermined current value B, it can be determined that the magnets 22 and 24 are rotating relative to each other in the circumferential direction from a state where the same poles are deviated to the maximum in the circumferential direction. In contrast, the motor rotation angle of the shaft 102 detected based on the output of the rotation angle sensor 202 is linearly interpolated (specifically, the motor rotation angle based on the output of the rotation angle sensor 202 is calculated by the following equation (1). The voltage command value is calculated using the motor rotation angle obtained by linear interpolation, and the current corresponding to the current command value I * is calculated. Processing to energize is performed (step 108).

Y = (X1-X0) / (maximum current Imax-B) × (detection current value IB) (1)
However, (X1-X0) is a state in which the same poles of the magnets 22 and 24 are displaced to the maximum in the circumferential direction (X0 indicated by a one-dot chain line in FIG. 6) and a state in which they are aligned in the rotation axis direction (one-dot chain line in FIG. And Imax is a current value to be passed through the stator necessary to align the same poles of the magnets 22 and 24 in the direction of the rotation axis from the state where they are shifted to the maximum in the circumferential direction. B is the minimum value of the current value at which it is determined that the magnets 22 and 24 start to rotate relatively, and I is the detected current value based on the output of the current sensor 212.

  According to this processing, the same poles of the magnets 22 and 24 of the rotor 14 divided into two (the first rotor 104 and the second rotor 106) are shifted in the circumferential direction and aligned in the rotation axis direction. Therefore, even when the center of the magnetic pole in the whole of the magnets 22 and 24 changes in position, the motor rotation angle based on the output of the rotation angle sensor 202 can be linearly interpolated following the change in position. Thus, the current flowing through the windings of the stator 12 can be corrected in accordance with the positional deviation of the magnetic pole centers of the magnets 22 and 24 described above. For this reason, according to the present embodiment, it is possible to accurately and appropriately perform the current control of the rotating electrical machine 100 corresponding to the positional deviation of the magnetic pole centers of the magnets 22 and 24 on the rotor 14 side.

  In the first and second embodiments described above, the same polarity of the magnets 22 and 24 of the rotor 14 divided into two parts of the rotating electrical machines 10 and 100 are aligned in the circumferential direction and aligned in the rotational axis direction. Although the position changes between states, the dimension of the maximum position change (maximum deviation angle) is defined in advance. In this regard, since the first rotor 104 and the second rotor 106 do not rotate relative to each other beyond the maximum deviation angle, it is detected that both the 104 and 106 rotate relative to each other beyond the maximum deviation angle. When the rotation angle sensor 202 is disconnected, it can be determined that a disconnection has occurred in the rotation angle sensor 202 or that the rotor 14 has run idle due to the magnets 22 and 24 coming off from the first or second rotor 104 or 106. Therefore, it is possible to detect an abnormality occurring in the rotating electrical machines 10 and 100 based on the relative rotation between the first rotor 104 and the second rotor 106.

  In view of this, the present embodiment has a second feature in that an abnormality occurring in the rotating electrical machines 10 and 100 is detected in consideration of such points. Hereinafter, with reference to FIG. 9, the above-described features of the present embodiment will be described. The abnormality detection of the rotating electrical machine 10 and the abnormality detection of the rotating electrical machine 100 have almost no difference except that the rotation direction is only one direction or bidirectional. Only will be described.

  FIG. 9 shows a flowchart of an example of a control routine executed by the inverter control unit 208 of the control device 200 in the present embodiment. The inverter control unit 208 first determines the first rotor 104 and the second rotor based on the difference between the motor rotation angle obtained from the back electromotive voltage of each phase and the motor rotation angle obtained from the output of the rotation angle sensor 202. The relative deviation angle α from the initial state (X0) with 106 is calculated. The absolute value of the deviation angle α (considering left and right rotation) is the maximum between the first rotor 104 and the second rotor 106 that is defined in advance from the relationship between the balls 118 and 120 and the grooves 122 and 124. It is determined whether or not the absolute value of the shift angle βmax exceeds the predetermined value γ (step 200). The predetermined value γ is an angle error of the maximum deviation angle βmax that can occur in the structure of the rotor 14.

  If | α | − | βmax |> γ is not satisfied as a result of the above determination, the detected angular deviation of the first rotor 104 and the second rotor 106 from the initial position (X0) is specified. Assuming that no abnormality has occurred by not exceeding the value, the motor angle is detected as usual according to the routine shown in FIG. 8 and the current of the rotating electrical machine 100 is controlled to control its rotation (step 202).

  On the other hand, when | α | − | βmax |> γ is satisfied, the angle deviation from the initial state (X0) between the first rotor 104 and the second rotor 106 exceeds a specified value, and thus the rotation angle sensor. Processing for turning on the fail flag and canceling the current control of the rotating electrical machine 100 described above, assuming that an abnormality such as disconnection at 202 or peeling off of the magnets 22 and 24 from the first or second rotor 104 or 106 has occurred. (Step 204). In this case, for example, the generation of assist torque by the electric power steering device using the rotating electrical machine 100 is stopped, or information indicating that an abnormality has occurred in the rotating electrical machine 100 is provided to the user (vehicle driver or the like). The

  According to such processing, the magnets 22 and 24 of the rotor 14 divided into two parts have an abnormality that causes an angle shift exceeding a desired range from the initial state (for example, motor disconnection abnormality or sensor abnormality, magnets 22 and 24 separation abnormality, etc. ) Can be detected. For this reason, according to the present embodiment, it is possible to avoid current control of the rotating electrical machine 100 during an abnormality, and it is possible to appropriately perform the current control.

  In the third embodiment, the inverter control unit 208 calculates the deviation angle Y from the initial position of both magnets 22 and 24 by the above equation (1) at step 108 in the routine shown in FIG. Thus, the “deviation angle detection means” described in claim 4 of the claims calculates the voltage command value using the motor rotation angle obtained by linear interpolation in step 108, and responds to the current command value I *. By performing the process of energizing the current, the “current control means” described in the claims determines the difference between the motor rotation angle obtained from the back electromotive voltage and the motor rotation angle obtained from the output of the rotation angle sensor 202. On the basis of this, the relative deviation angle α from the initial state (X0) between the first rotor 104 and the second rotor 106 is calculated, and then, according to claim 5 of the claims. Re angle detecting means ", described in the claims by performing the processing routine in step 200 and 204 shown in FIG. 9," abnormality determining means "is realized, respectively.

It is a block diagram of the rotary electric machine which is 1st Example of this invention. It is a block diagram of the rotary electric machine of a present Example. It is a block diagram of the rotary electric machine which is 2nd Example of this invention. It is a block diagram of the rotary electric machine of a present Example. It is a block diagram of the rotary electric machine of a present Example. It is a figure showing the condition where the magnetic pole center of the rotary electric machine which is 3rd Example of this invention has shifted | deviated. It is a block diagram of the control apparatus which controls rotation of the rotary electric machine of a present Example. It is a flowchart of an example of the control routine performed in the control apparatus of a present Example. It is a flowchart of an example of the control routine performed in the control apparatus of a present Example.

Explanation of symbols

10,100 Rotating electric machine 12 Stator
14 Rotor
16, 102 Shaft 18, 104 First rotor 20, 106 Second rotor 22, 24 Magnet 28, 114, 116 Spring spring 30, 118, 120 Ball

Claims (5)

A rotating electrical machine comprising a stator around which a winding is wound and a rotor having field magnets in which different polarities are alternately arranged in the circumferential direction,
Two field magnets are provided side by side in the rotational axis direction and capable of relative rotation in the circumferential direction,
The rotor is provided with urging means for urging at least one of the field magnets so that the same poles of the field magnets adjacent in the rotation axis direction are displaced in the circumferential direction. Rotating electric machine.   The rotating electrical machine according to claim 1, wherein the urging means is provided corresponding to each field magnet.   The field magnets urged by the urging means have the fields adjacent to each other in the rotation axis direction against the urging force by the urging means when the current flowing through the winding is a predetermined value or more. The rotating electrical machine according to claim 1 or 2, wherein the rotating electric machine is rotated so that a deviation in a circumferential direction between the same poles as that of the magnet for magnet is reduced. A deviation angle detecting means for detecting a circumferential deviation angle generated between the two field magnets;
Current control means for correcting a current flowing in the winding according to the deviation angle detected by the deviation angle detection means when the rotor rotates;
The rotating electrical machine according to any one of claims 1 to 3, further comprising: A deviation angle detecting means for detecting a circumferential deviation angle generated between the two field magnets;
An abnormality determination unit that determines that an abnormality has occurred when the deviation angle detected by the deviation angle detection unit is equal to or greater than a predetermined angle;
5. The rotating electrical machine according to claim 1, further comprising:

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