JP2015126609A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress opening of electromagnetic steel plates constituting a rotor core while suppressing deterioration of magnetic characteristic of the rotor core in a variable magnetic field type rotary electric machine.SOLUTION: In an axial direction, an electromagnetic steel plate constituting a main rotor core 46 is sandwiched between a non-magnetic restraining plate 61 and a restraining plate 62 which are fixed to a main rotor shaft 26, and an electromagnetic steel plate constituting a sub rotor core 54 is sandwiched between a non-magnetic restraining plate 63 and a restraining plate 64 which are fixed to a sub rotor shaft 52. The restraining plate 61 and the restraining plate 63 are brought into contact and friction lowering treatment is applied to contact surfaces of the restraining plate 61 and the restraining plate 63.

Description

  The present invention relates to a variable field type rotating electrical machine.

  In the variable field type rotating electrical machine disclosed in Patent Document 1 below, the rotor includes first and second rotor elements that are axially divided and rotatable relative to each other, and changes the phase relationship between the first and second rotor elements. Thus, the magnetic field flux of the rotor acting on the stator is changed. Each of the first and second rotor elements includes a rotor core in which a plurality of electromagnetic steel plates are laminated in the axial direction and a magnet disposed in the rotor core, and a plurality of rivets that are spaced apart from each other in the circumferential direction. Each of these penetrates through the electromagnetic steel sheet, so that a plurality of laminated electromagnetic steel sheets are fixed.

JP 2011-83145 A JP 2011-188567 A JP 2013-46440 A

  In Patent Document 1, the electromagnetic steel sheet constituting the rotor cores of the first and second rotor elements is subjected to a force to open outward in the axial direction by the mutual repulsive action of the magnetic flux in the same direction. In patent document 1, although the opening to the axial direction outer side of an electromagnetic steel plate is suppressed by the some rivet, since each rivet has penetrated the electromagnetic steel plate, there exists a possibility that the magnetic characteristic of a rotor core may deteriorate.

  An object of this invention is to suppress the opening of the electromagnetic steel plate which comprises a rotor core, suppressing the deterioration of the magnetic characteristic of the rotor core of a 1st and 2nd rotor element.

  The rotating electrical machine according to the present invention employs the following means in order to achieve the above-described object.

  A rotating electrical machine according to the present invention includes a stator in which a stator coil is disposed, and a rotor including first and second rotor elements arranged to face the stator in an axially aligned state, and the first rotor element Rotates with the first rotor shaft, the second rotor element rotates with the second rotor shaft rotatable relative to the first rotor shaft, and the first rotor elements have polarities arranged alternately in the circumferential direction. A plurality of different first magnets and a first rotor core in which a plurality of electromagnetic steel plates are laminated in the axial direction, and the second rotor element includes a plurality of second magnets having different polarities arranged alternately in the circumferential direction A second rotor core in which a plurality of electromagnetic steel plates are laminated in the axial direction, and the first rotor element is fixed between the nonmagnetic first restraint plate and the second restraint plate fixed to the first rotor shaft in the axial direction. Sandwiched between the second rotor An element is sandwiched between a non-magnetic third restraint plate and a fourth restraint plate fixed to the second rotor shaft in the axial direction, the first restraint plate and the third restraint plate are in contact, and the first restraint plate and the third restraint plate The gist is that the contact surface of the restraint plate is subjected to a low friction treatment.

  According to the present invention, in a variable field type rotating electrical machine that changes the field magnetic flux of the rotor acting on the stator by changing the phase relationship between the first and second rotor elements, the first and second rotor elements While suppressing the deterioration of the magnetic properties of the rotor core, it is possible to suppress the opening of the electrical steel sheet constituting the rotor core.

It is a figure which shows the structural example of the rotary electric machine which concerns on embodiment of this invention. It is a figure equivalent to the AA cross section of FIG. It is a figure explaining the force which is going to open to the axial direction outer side which acts on an electromagnetic steel plate by the mutual repulsive effect by the same direction magnetic flux of a permanent magnet. It is a functional block diagram which shows the structural example of a control apparatus. In FIG. 2, it is the figure which looked at the 1st rotor element and the 2nd rotor element from the outer diameter side. FIG. 6 is a schematic view of the rotor of FIG. 5 viewed in the axial direction, viewed from the second rotor element side to the first rotor element side. In FIG. 5, it is a schematic diagram which shows a mode that a stator magnetic field is produced | generated so that the phase between rotors may be changed. It is a figure which shows the relationship between the phase (theta) e between rotors, and the inter-rotor magnet torque which acts between rotor elements. It is a figure which shows the positive direction of the magnet torque between rotors of FIG. In FIG. 2, it is a figure which shows the state which changes to a polarity same state from a polarity reversal state. FIG. 11 is a diagram corresponding to FIG. 10, as viewed from the outer diameter side of the rotor, in a state where the polarity reverse state is changed to the same polarity state. It is a figure which shows the relationship between rotor phase (theta) e and stability of rotor phase relationship. In FIG. 2, it is a figure which shows the state which changes to a polarity reversal state from the same polarity state. FIG. 14 is a view corresponding to FIG. 13, as seen from the outer diameter side of the rotor, in a state where the state is changed from the same polarity state to the polarity reverse state. It is a figure which shows the structural example of a detent mechanism. It is a figure which shows the relationship between the torque to generate | occur | produce in a 2nd rotor element with a stator magnetic field, the magnet torque between rotors, and the phase (theta) e between rotors.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

  1 and 2 are diagrams showing a schematic configuration of a rotating electrical machine according to an embodiment of the present invention. FIG. 1 shows a cross-sectional view seen from a direction orthogonal to the axial direction of the rotating electrical machine, and FIG. 2 shows a view corresponding to the AA cross-section of FIG. The rotating electrical machine includes a stator 24 fixed to a casing, and a rotor 28 that is opposed to the stator 24 in the radial direction with a predetermined gap (magnetic gap) and is rotatable relative to the stator 24. In the example of FIG. 1, the rotor 28 is disposed so as to face the stator 24 at a position on the inner peripheral side (radially inner side) of the stator 24.

  The stator 24 includes a stator core 36 and three-phase stator coils 38u, 38v, and 38w of U phase, V phase, and W phase, which are a plurality of phases disposed on the stator core 36 along the circumferential direction thereof. When a three-phase alternating current flows through the three-phase stator coils 38u, 38v, and 38w, a rotating magnetic field that rotates in the circumferential direction of the stator is generated in the stator 24.

  The rotor 28 includes a main rotor (first rotor element) 40 and a sub-rotor (second rotor element) 42 that are arranged in the axial direction so as to face the stator 24 in the radial direction. The main rotor 40 and the sub-rotor 42 are arranged to face each other with a magnetic gap in the axial direction. In the example of FIG. 1, the main rotor 40 is disposed on one axial side (left side in the figure) of the sub-rotor 42, and the main rotor 40 faces one axial part (left part in the figure) of the stator core 36 in the radial direction. The sub-rotor 42 faces the other axial side portion (right side portion in the figure) of the stator core 36 in the radial direction.

  The main rotor 40 includes a main rotor core 46 in which a plurality of electromagnetic steel plates are laminated in the axial direction, and a plurality of main permanent magnets 48n and 48s disposed on the main rotor core 46 at equal intervals along the circumferential direction. . In FIG. 2, the main permanent magnets 48n and 48s of the main rotor 40 are shown through. In the example of FIG. 2, the main permanent magnets 48 n and 48 s are embedded in a V shape as a pair at a plurality of locations in the circumferential direction of the main rotor core 46, but are not necessarily arranged in a V shape. The main permanent magnet 48n has an N pole on the outer peripheral side, the main permanent magnet 48s has an S pole on the outer peripheral side, and the main permanent magnet 48n and the main permanent magnet 48s are alternately arranged in the circumferential direction, whereby the main permanent magnet 48n, The polarity of 48s is alternately different in the circumferential direction.

  The sub-rotor 42 includes a sub-rotor core 54 in which a plurality of electromagnetic steel plates are laminated in the axial direction, and a plurality of sub-permanent magnets 56n and 56s disposed on the sub-rotor core 54 at equal intervals along the circumferential direction. . In the example of FIG. 2, the sub permanent magnets 56 n and 56 s are embedded in a V shape as a pair at a plurality of locations in the circumferential direction of the sub rotor core 54, but are not necessarily arranged in a V shape. The secondary permanent magnet 56n has an N pole on the outer peripheral side, the secondary permanent magnet 56s has an S pole on the outer peripheral side, and the secondary permanent magnet 56n and the secondary permanent magnet 56s are alternately arranged in the circumferential direction, whereby the secondary permanent magnet 56n, The polarity of 56s is alternately different in the circumferential direction. The circumferential interval between the sub permanent magnets 56n and 56s is equal to the circumferential interval between the main permanent magnets 48n and 48s.

  Nonmagnetic restraint plates 61 and 62 are fixed to the main rotor shaft 26 by being joined by welding or the like, for example. As the nonmagnetic material of the restraining plates 61 and 62, for example, stainless steel or the like can be used. The restraint plates 61 and 62 are arranged at intervals in the axial direction, the restraint plate 62 is placed on one axial side of the restraint plate 61, and the main rotor 40 (main rotor core 46) is connected to the restraint plate 61 in the axial direction. It is sandwiched between the restraining plates 62. Further, the main rotor 40 (main rotor core 46) is engaged with the main rotor shaft 26 by, for example, a keyway or a spline, so that the main rotor 40 rotates together with the main rotor shaft 26 and the restraining plates 61 and 62. To do. Alternatively, the main rotor 40 (main rotor core 46) and the main rotor shaft 26 can be assembled by press fitting such as shrink fitting.

  Non-magnetic restraint plates 63 and 64 are fixed to the sub-rotor shaft 52 by, for example, welding. As the nonmagnetic material of the restraining plates 63 and 64, for example, stainless steel or the like can be used. The restraint plates 63 and 64 are arranged at an interval in the axial direction, the restraint plate 63 is placed on one axial side of the restraint plate 64, and the sub-rotor 42 (sub-rotor core 54) is in the axial direction with the restraint plate 63. It is sandwiched between the restraining plates 64. Further, the sub-rotor 42 (sub-rotor core 54) is engaged with the sub-rotor shaft 52 by, for example, a keyway or a spline, so that the sub-rotor 42 rotates together with the sub-rotor shaft 52 and the restraining plates 63 and 64. To do. Alternatively, the sub-rotor 42 (sub-rotor core 54) and the sub-rotor shaft 52 can be assembled by press fitting such as shrink fitting. The auxiliary rotor shaft 52 is supported by the bearing 50 so as to be rotatable relative to the main rotor shaft 26, so that the auxiliary rotor 42 is rotatable relative to the main rotor 40. However, since the axial movement of the sub-rotor shaft 52 with respect to the main rotor shaft 26 is restricted, the axial movement of the sub-rotor 42 with respect to the main rotor 40 is restricted.

  In the present embodiment, nonmagnetic restraint plates 61 and 63 that are rotatable relative to each other are provided between the main rotor 40 and the sub-rotor 42 in the axial direction, and the restraint plate 61 and the restraint plate 63 are in contact with each other. Further, a low friction process is applied to the contact surface between the restraint plate 61 and the restraint plate 63. That is, the contact surface of the restraint plate 61 with the restraint plate 63 and the contact surface of the restraint plate 63 with the restraint plate 61 are coated with the low friction material. As the low friction material, for example, DLC (diamond-like carbon), polyamide-imide resin, fluorine resin, or the like can be used. The constraining plates 61, so that the axial magnetic gap between the main rotor 40 and the sub-rotor 42 is smaller than twice the radial magnetic gap between the stator 24 and the rotor 28 (the main rotor 40 and the sub-rotor 42). The total axial thickness of 63 is set to be smaller than twice the radial magnetic gap between the stator 24 and the rotor 28. On the other hand, in order to make the restraint plates 62 and 64 difficult to bend in the axial direction, the axial thickness of the restraint plates 62 and 64 is preferably sufficiently thicker than the axial thickness of the restraint plates 61 and 63.

  In the rotating electrical machine according to the present embodiment, the amount of effective magnetic flux, which is the amount of field magnetic flux of the rotor 28 acting on the stator 24, changes as the phase relationship between the main rotor 40 and the sub-rotor 42 changes. The “effective magnetic flux amount” refers to a magnetic flux amount that substantially acts on the stator 24 by the combined magnetic flux of the main rotor 40 and the sub-rotor 42. For example, this is effective when the main permanent magnet 48n and the sub permanent magnet 56n (the main permanent magnet 48s and the sub permanent magnet 56s) having the same polarity in the main rotor 40 and the sub rotor 42 are arranged in the same phase in the circumferential direction. The amount of magnetic flux is maximized. In this case, the effective magnetic flux amount is 100%. In addition, when the amount of effective magnetic flux is expressed by%, the case of the same polarity state is defined as 100%, and the ratio of the amount of effective magnetic flux with respect to it is said. On the other hand, the sub-rotor 42 rotates relative to the main rotor 40 and the main rotor 40 and the sub-rotor 42 have the same polarity in the circumferential direction of the main permanent magnet 48n and the sub-permanent magnet 56n (the main permanent magnet 48s and the sub-permanent magnet 56s). When the positional deviation occurs, the effective magnetic flux amount decreases. For example, the main permanent magnet 48n and the sub permanent magnet 56n (the main permanent magnet 48s and the sub permanent magnet 56s) having the same polarity in the main rotor 40 and the sub rotor 42 are displaced by 180 degrees in electrical angle, and the main permanent magnet 48n having the opposite polarity When the sub permanent magnet 56s (the main permanent magnet 48s and the sub permanent magnet 56n) are disposed in the same phase in the circumferential direction, the effective magnetic flux amount is zero. Thus, the rotating electrical machine according to the present embodiment functions as a variable field type rotating electrical machine that changes the amount of field magnetic flux of the rotor 28 that acts on the stator 24. A method of rotating the main rotor 40 and the sub-rotor 42 relative to each other will be described later.

  As shown in FIG. 3, the electromagnetic steel sheet constituting the main rotor core 46 is subjected to a force to open outward in the axial direction by the mutual repulsive action by the same direction magnetic flux of the main permanent magnets 48n and 48s. Similarly, the magnetic steel sheet constituting the auxiliary rotor core 54 is also subjected to a force to open outward in the axial direction by the mutual repulsive action of the auxiliary permanent magnets 56n and 56s by the same direction magnetic flux. When the electromagnetic steel plate constituting the main rotor core 46 and the electromagnetic steel plate constituting the sub rotor core 54 are opened outward in the axial direction, the magnetic flux hardly acts between the main rotor 40 and the sub rotor 42, and the rotor 28 acting on the stator 24 The controllability of the effective magnetic flux amount is reduced.

  On the other hand, according to the present embodiment, in the axial direction, the electrical steel sheet constituting the main rotor core 46 is sandwiched between the restraint plate 61 and the restraint plate 62, and the electrical steel sheet constituting the sub-rotor core 54 contacts the restraint plate 61. By being sandwiched between the restraining plate 63 and the restraining plate 64, the electromagnetic steel plate constituting the main rotor core 46 and the electromagnetic steel plate constituting the sub rotor core 54 can be prevented from opening outward in the axial direction. As a result, the controllability of the effective magnetic flux amount of the rotor 28 acting on the stator 24 can be improved. In that case, the opening of the electromagnetic steel sheet can be suppressed without using a plurality of rivets penetrating the electromagnetic steel sheet as in Patent Document 1, and leakage flux to the constraining plates 61, 62, 63, 64, which are nonmagnetic materials. There are few. Therefore, the magnetic characteristics of the main rotor core 46 and the sub rotor core 54 are not deteriorated. Furthermore, the number of parts and the rivet processing steps can be reduced without using a plurality of rivets, and the opening of the electromagnetic steel sheet is suppressed not over the entire area of the rotor core as in the case of the rivet. It can be surely suppressed.

  Further, according to the present embodiment, the contact surface between the restraint plate 61 and the restraint plate 63 is subjected to a low friction process, so that the effective magnetic flux amount of the rotor 28 acting on the stator 24 is changed. The resistance force (friction force) when the rotor 40 and the sub-rotor 42 are rotated relative to each other can be reduced. Furthermore, since the suction force between the main rotor 40 and the sub-rotor 42 acts on the entire contact surface between the restraint plate 61 and the restraint plate 63, the surface pressure of the contact surface between the restraint plate 61 and the restraint plate 63 can be reduced. The wear resistance of the restraining plates 61 and 63 can be improved. Further, since the restraining plates 61 and 63 are joined by welding or the like, it is not necessary to provide a space for a head such as a bolt or a rivet.

  Next, a method of rotating the main rotor (first rotor element) 40 and the sub rotor (second rotor element) 42 relative to each other in order to change the field magnetic flux of the rotor 28 acting on the stator 24 will be described. In order to rotate the first rotor element 40 and the second rotor element 42 relative to each other, for example, a hydraulic mechanism disclosed in Patent Document 1, a magnetic flux varying device disclosed in Patent Document 2, a hub and a slider disclosed in Patent Document 3, and the like may be applied. Although possible, here, a method of rotating the first rotor element 40 and the second rotor element 42 relative to each other by current control of the stator coils 38u, 38v, 38w without using an external actuator will be described.

  A one-way clutch is provided between the second rotor element 42 (sub rotor shaft 52) and the first rotor element 40 (main rotor shaft 26). The one-way clutch here allows only rotation in the direction opposite to the arrow α in FIGS. 1 and 2, which is one direction of the second rotor element 42 relative to the first rotor element 40, and prevents rotation in the direction of arrow α. To do. The direction of arrow α is the direction of positive torque generation of the main rotor shaft 26.

  In the control device 70 of FIG. 4, the inter-rotor phase acquisition unit 72 determines the second rotor relative to the first rotor element 40 from the rotation angle of the first rotor element 40 and the rotation angle of the second rotor element 42 acquired from the rotation angle sensor. The inter-rotor phase θe, which is the difference between the relative phases of the elements 42, is acquired (see FIG. 2). The difference in relative phase means positive and negative as will be described later, and the direction of deviation is also distinguished.

  The effective magnetic flux amount setting unit 74 sets the effective magnetic flux amount according to a predetermined condition set in advance. For example, when the rotational speed of the rotor 28 is high, if the effective magnetic flux amount is too high, the counter electromotive voltage acting on the stator coils 38u, 38v, 38w increases from the rotor 28, which may cause a decrease in output. Can be suppressed to a desired value set in advance, so that a decrease in output can be suppressed.

  The current vector control unit 76 controls the stator coil current by current vector control according to the effective magnetic flux amount set by the effective magnetic flux amount setting unit 74. In this case, the current vector control unit 76 can generate a magnetic field with an arbitrary effective magnetic flux amount corresponding to the positional relationship between the magnets 48n, 48s, 56n, 56s of the rotor elements 40, 42. In this case, the current vector control unit 76 generates a torque for rotating the second rotor element 42 with respect to the first rotor element 40 so as to shift the inter-rotor phase θe between the two rotor elements 40 and 42. The stator coil current is vector controlled so as to generate a stator magnetic field. The “inter-rotor phase θe” represents the relative phase difference of the second rotor element 42 with respect to the first rotor element 40 in electrical angle. The inter-rotor phase θe is obtained when the first rotor element 40 is viewed in the axial direction from the second rotor element 42 side with reference to the position where the N-pole magnet or S-pole magnet of the first rotor element 40 is disposed. The case where the N-pole magnet or the S-pole magnet having the same polarity as the reference magnet of the 2-rotor element 42 is displaced in the counterclockwise direction in FIG. On the other hand, the case where the N-pole magnet or S-pole magnet of the second rotor element 42 is displaced in the clockwise direction in FIG. 2 is negative. When the rotor phase θe is 0 °, the same polarity state is established, and when the phase is shifted 180 degrees in either positive or negative direction, the polarity reverse state is established. The current vector control unit 76 changes the effective magnetic flux amount of the rotor 28 by the transition of the inter-rotor phase θe. Next, the concept of current vector control for controlling the effective magnetic flux amount and its control method will be described.

  FIG. 5 shows the first rotor element 40 and the second rotor element 42 as viewed from the outer diameter side in FIG. 2. FIG. 6 is a schematic view of the rotor 28 of FIG. 5 as viewed in the axial direction, as viewed from the second rotor element 42 side to the first rotor element 40 side. In FIG. 6, the magnets 48 n and 48 s on the first rotor element 40 side arranged on the rear side of the second rotor element 42 are indicated by (N) and (S). Further, in FIG. 6, the number of magnets 48n, 48s, 56n, 56s is shown in a simplified manner smaller than the actual number. 5 and 6 show a polarity reversal state in which the phases in the circumferential direction of the opposite polarity magnets 48n, 48s, 56n, 56s of the rotor elements 40, 42 coincide with each other. In FIG. 5 and FIG. 7 to be described later, the attraction force acts with arrows in directions away from each other, and the repulsion force acts with arrows in directions toward each other. In this case, as shown in FIG. 5, attraction force acts between the magnets 48n, 48s, 56n, and 56s of the two rotor elements 40 and 42, which are opposite in polarity to each other in the axial direction. In contrast, a repulsive force acts between magnets of the same polarity that face each other in an inclined direction. However, since the attractive force between the opposite polarity magnets facing each other in the axial direction is strong, as a result, the rotor phase relationship which is the phase relationship between the rotor elements 40 and 42 in the polarity reversal state is the most stable state.

  Next, in this state, apparent N-pole and S-pole poles are arranged at positions in the d-axis direction shown in FIG. 6 as control for changing the rotor phase relation between the rotor elements 40 and 42 to a different phase relation. Consider a stator magnetic field. In this case, since the S pole is located on the upper left side in the drawing of the second rotor element 42, the second rotor element 42 rotates in the β direction by the magnetic attraction force by the stator magnetic flux. On the other hand, in the first rotor element 40, since the S pole is located on the lower right side in the figure, the first rotor element 40 rotates in the γ direction by the magnetic attraction force by the stator magnetic flux. In this case, since both rotor elements 40 and 42 rotate in opposite directions, torque that does not contribute to rotation acts on the entire rotor 28. From such an idea, the control device 70 generates torque in a direction in which the first rotor element 40 and the second rotor element 42 are rotated in directions opposite to each other, and generates torque that does not contribute to rotation for the entire rotor 28. Thus, the stator coil current is vector-controlled. For example, the stator coil current is vector-controlled so as to generate a stator magnetic field so as to generate a magnetic flux at a position where such torque is generated. With this configuration, the second rotor element 42 rotates with respect to the first rotor element 40. In this case, the stator magnetic field is determined so that the stator magnetic flux is generated in the d-axis direction of FIG. Generate torque to rotate. Such a stator magnetic field can be determined by current vector control that determines a current command in the dq coordinate system. FIG. 6 shows a case where the d-axis magnetic flux is generated but the q-axis magnetic flux is not generated, and only the d-axis current is generated. However, when the rotor 28 is rotated in the α direction in FIGS. 1 and 2, which is the positive direction of the rotor 28, a q-axis current for generating a q-axis magnetic flux can be generated in accordance with the d-axis current.

  FIG. 7 shows a schematic diagram corresponding to FIG. 5 when the stator magnetic field is generated in this way. As shown by the broken line frame in FIG. 7, a common apparent N pole is formed on the outer diameter side between the NS of the first rotor element 40 and the outer diameter side between the SNs of the second rotor element 42, and the circumferential direction The stator magnetic field is generated so that apparent S poles are formed on the outer diameter sides on both sides. As a result, the first rotor element 40 is displaced in the γ direction, which is the upper part of FIG. 7, and the second rotor element 42 is displaced in the β direction, which is the lower part of FIG. The controller 70 causes the rotor phase relationship to transition from the polarity reversal state to the same polarity state by generating this torque. In this case, the rotor phase θe (FIG. 2) transitions.

  For example, as shown in FIG. 8, the rotor phase relationship includes a polarity reversal state and a polarity identical state. The same polarity state is a state in which the phases in the circumferential direction match between the magnets of the same polarity of the rotor elements 40 and 42. When the rotor phase relationship is between the polarity reversal state and the same polarity state, the control device 70 generates torque in the direction in which the rotor elements 40 and 42 are rotated in opposite directions to rotate with respect to the entire rotor 28. The stator coil current is controlled by vector control so as to generate torque that does not contribute to. For example, the stator coil current is vector-controlled so as to generate a stator magnetic field in which magnetic flux is generated at a position where such torque is generated. In this case, the control device 70 performs vector control on the stator coil current so that the rotor phase θe transitions from the polarity reversal state toward the same polarity state.

  FIG. 8 shows the relationship between the rotor phase θe and the rotor magnet torque acting between the rotor elements 40 and 42. The “rotor magnet torque” defines the positive direction as shown in FIG. As shown in FIG. 8, when the inter-rotor phase θe is −180 ° <θe <0 °, the inter-rotor magnet torque is “negative”, and the N-pole magnets 48n and 56n between the rotor elements 40 and 42 and the S Due to the attractive force between the polar magnets 48 s and 56 s, negative torque, that is, torque in the direction toward θe = −180 °, acts on the rotor elements 40 and 42. In this case, torque acts on the rotor elements 40 and 42 in the direction opposite to the direction shown in FIG. Therefore, when θe is changed in the forward direction, it is necessary to generate torque in the direction of the arrow in FIG.

  On the other hand, when the inter-rotor phase θe is 0 ° <θe <180 °, the inter-rotor magnet torque becomes “positive”, and the N-pole magnets 48n and 56n and the S-pole magnets 48s and 56s between the rotor elements 40 and 42 Is exerted between the rotor elements 40 and 42 in the positive direction, that is, in the direction toward θe = + 180 °. In this case, torque acts on each rotor element 40 and 42 in the same direction as the direction shown in FIG. For this reason, when θe is changed in the positive direction, if θe> 0 ° is at least temporarily changed from the state of θe = 0 °, the drive torque is not applied from the outside by the positive inter-rotor magnet torque. = + 180 ° can be changed.

  First, control for changing the rotor phase relationship so that θe changes in the positive direction when −180 ° ≦ θe <0 ° will be described. FIGS. 10 and 11 (a) to (d) show the positive transition of θe when −180 ° ≦ θe ≦ 0 °. In the polarity reversal state of θe = −180 °, the stator coil current, which is the current flowing through the three-phase stator coils 38u, 38v, and 38w, is vector-controlled so as to generate a stator magnetic field that forms a magnetic pole in a predetermined direction. In this case, the phase is θe with reference to the first magnet 48s of the first rotor element 40, with the circumferential interval between the magnets 48s and 56s of the same polarity of the first rotor element 40 and the second rotor element 42 divided into two equal parts. A stator magnetic field is generated in such a way that a magnetic flux in the same direction as that of the reference magnet 48s is generated in the shifted direction. As a result, a magnetic attraction force is generated between the stator magnetic field and the magnet magnetic flux of each rotor element 40, 42, and the positive direction is a torque that brings the magnets 48s, 56s of the same polarity between each rotor element 40, 42 closer to each other. Torque can be generated. In the above description, the stator magnetic flux corresponding to the magnets 48s and 56s has been described. However, the stator magnetic flux corresponding to the magnets 48n and 56n is the same except that the direction is reversed. In FIG. 10, the attractive force is generated by the bidirectional arrow δ shown to act between the magnetic flux indicated by the arrows N and S generated by the stator magnetic field and the magnets 48n, 48s, 56n and 56s of the rotor 28. Show.

  With the torque in the positive direction, θe can be shifted in the positive direction. At this time, since the magnetic flux direction of the stator magnetic field generated by the vector control needs to be controlled in synchronization with the transition of θe, the detection values of the two rotation angle sensors for detecting the rotation angles of the rotor elements 40 and 42 are used as needed. The control device 70 obtains, that is, receives, and controls so that a stator magnetic field that generates magnetic flux in a direction corresponding to the detected value is generated.

  Note that torque is generated between the rotor elements 40 and 42 by the stator magnetic field, but the stator magnetic field is a composite phase of the two rotor elements 40 and 42, which is the phase center of the magnetic flux of the same polarity magnet of the two rotor elements 40 and 42. Since only the magnetic field in the d-axis direction of the magnetic flux is present, no torque that acts outside via the main rotor shaft 26 is generated.

  By performing the “positive torque generation operation” in which the rotor phase relationship is shifted in the positive direction of θe by the above method, the stator magnetic field is set to 0 in a state where the effective magnetic flux amount of the rotor 28 becomes a desired value. For example, the stator current may be vector controlled so that only the d-axis magnetic flux among the d-axis magnetic flux and the q-axis magnetic flux generated by the stator magnetic field is zero. In this case, the rotor inter-rotor magnet torque in FIG. 8 acts between the rotor elements 40 and 42 as the torque to return to the state of θe = −180 °. However, with the function of the one-way clutch provided between the second rotor element 42 and the main rotor shaft 26, the rotor phase θe is kept constant as “phase fixing operation” without changing θe in the negative direction. The rotor phase relationship can be maintained.

  FIG. 12 conceptually shows the relationship between the rotor phase θe and the stability of the rotor phase relationship. Control is performed so that the stator magnetic field that generates the d-axis magnetic flux is generated as described above when the inter-rotor phase θe transitions in the positive direction from the polarity reversal state at the point P1 toward the same polarity state at the point P2. Thus, the inter-rotor phase θe and the stability change in the direction of the arrow Q1. In this case, if the stator magnetic field is set to 0 with a desired value of the effective magnetic flux amount, negative rotor magnet torque that moves in the R direction, which is the phase stabilization direction, acts. However, it can be held in a desired state, for example, at the points P3 and P4, by the function of the one-way clutch. In this state, the effective magnetic flux amount of the rotor 28 increases from the effective magnetic flux 0 state in the polarity reversal state.

  When the effective magnetic flux amount is further increased, the positive torque generation operation and the phase fixing operation are repeated. By the above operation, the phase between the rotors can be changed from the magnetic flux 0% state to the magnetic flux 100% state.

  Next, control for changing the rotor phase relationship so that θe changes in the positive direction when 0 ° ≦ θe <+ 180 ° will be described. FIGS. 13 and 14 (a) to 14 (c) show the positive direction transition of θe when 0 ° ≦ θe ≦ + 180 °. When transitioning from the same polarity state of θe = 0 ° to the positive direction, at least at the initial driving stage of the second rotor element 42, the phase difference between the rotor elements 40, 42, that is, the positive inter-rotor phase θe is set. The stator coil current is vector-controlled so as to generate a stator magnetic field to be generated. In this case, in the initial driving of the second rotor element 42, the stator coil current is vector-controlled so as to generate a stator magnetic field that increases the phase difference between the magnets of the same polarity of the two rotor elements 40 and 42. For example, the stator magnetic field is generated so as to generate a q-axis magnetic flux having a predetermined magnitude that gives torque to the rotor 28 in the direction of arrow β (FIG. 13) temporarily at the beginning of driving.

  In this case, the stator coil current is vector-controlled so that a stator magnetic field that generates magnetic flux in a predetermined direction is formed. In this stator magnetic field, as shown in FIGS. 13 and 14 (a), the stator magnetic flux in the same direction as the magnetic flux of the magnets of the same polarity of the two rotor elements 40 and 42 having the same phase is the phase between the rotors. A position shifted in the positive direction of θe, for example, a position indicated by an arrow N in FIG. As a result, the stator magnetic field generates a torque in the β direction having the same magnitude in each of the rotor elements 40 and 42, but the first rotor element 40 integrally formed with the main rotor shaft 26 has a large rotational inertia, The second rotor element 42 that is not a monolithic structure has a lower rotational inertia than the first rotor element 40. For this reason, the second rotor element 42 can be rotated in the β direction with respect to the first rotor element 40 by the positive torque in FIG. 9 acting on the second rotor element 42.

  With this torque in the positive direction, the phase between the rotors can be shifted toward a state where θe = + 180 °.

  In this case, in FIG. 12, the rotor phase θe and the stability change in the direction of the arrow Q2 by controlling the stator magnetic field to be generated as described above in the same polarity state at the point P2. In this case, since the positive rotor-to-rotor magnet torque of FIG. 8 always acts in the range of 0 ° <θe <+ 180 °, transition to the polarity reversal state, which is the phase stable state, is not applied from the outside. Can do.

  When generating a stator magnetic field that forms a magnetic pole in a predetermined direction with the same polarity as described above, the control device 70 causes the stator coil current to rotate in the same direction in both the two rotor elements 40 and 42. The second rotor element 42 may be rotated with respect to the first rotor element 40 by vector control. For example, the stator coil current may be vector controlled so as to generate a stator magnetic field in which a magnetic flux is generated in a pulse shape at a position where both of the two rotor elements 40 and 42 are rotated in the same direction.

  Instead of (or in addition to) the one-way clutch, for example, a detent mechanism 96 as shown in FIG. 15 can be provided. The detent mechanism 96 maintains the same polarity when the effective magnetic flux amount is 100% and the phase between the rotors of the first rotor element 40 and the second rotor element 42 is in the same polarity state. The detent mechanism 96 applies a spring force to the ball with a spring so that the ball engages with a recess provided on the axial side surface of the main rotor shaft 26 and a recess on the axial side surface of the sub-rotor shaft 52. The phase between the two rotor elements 40, 42 is maintained. The detent mechanism 96 generates a predetermined fixing force so that the lock is not released by the inter-rotor magnet torque but the lock is released by the driving force for shifting the rotor phase relationship by the stator magnetic field. The control device 70 vector-controls the stator coil current so that the phase between the rotors is maintained only in one of two switching states of a polarity reversal state and an identical polarity state of 0% of the effective magnetic flux amount. .

  In addition, the first rotor element 40 and the second rotor element 42 can be rotated relative to each other by the following method. FIG. 16 shows the relationship between the torque generated in the second rotor element 42 by the stator magnetic field, the inter-rotor magnet torque, and the inter-rotor phase θe. The control device 70 is configured so that the rotor phase θe is maintained only in one of two switching states of a polarity reversal state where the effective magnetic flux amount is 0% and an effective magnetic flux amount is 100%. Stator coil current is vector controlled. In this case, when the phase θe between the rotors is changed from the polarity reversal state to the same polarity state, the vector control is performed so as to generate energy that can be changed to θe = 0 ° in the state of θe = −180 °. In this case, the attraction force energy commensurate with the attraction force energy generated by the inter-rotor magnet torque acting on the rotor 28 in the entire transition from θe = −180 ° to θe = 0 ° and the inertia energy for rotating the second rotor element 42. Is momentarily applied at the initial driving of the second rotor element 42, and the stator coil current is vector-controlled. Further, when the polarity is changed from the same polarity state to the polarity reverse state, the stator coil current is vector-controlled so that both the two rotor elements 40 and 42 are rotated in the same direction. For example, the stator coil current is vector-controlled so as to generate a stator magnetic field in which magnetic flux is generated in the form of a rectangular wave or triangular wave pulse at a position where both of the two rotor elements 40 and 42 are rotated in the same direction. In this case, the torque generated by the stator magnetic field can be made smaller than the torque applied when the polarity is reversed. According to the above configuration, it is not necessary to perform vector control for generating a stator magnetic flux based on the inter-rotor phase θe in the entire transition operation region of the rotor phase relationship.

  As mentioned above, although the form for implementing this invention was demonstrated, this invention is not limited to such embodiment at all, and it can implement with a various form in the range which does not deviate from the summary of this invention. Of course.

  24 stator, 26 main rotor shaft, 28 rotor, 36 stator core, 38u, 38v, 38w stator coil, 40 main rotor (first rotor element), 42 sub rotor (second rotor element), 46 main rotor core, 48n, 48s main Permanent magnet, 50 bearing, 52 subrotor shaft, 54 subrotor core, 56n, 56s subpermanent magnet, 61, 62, 63, 64 constraining plate, 70 control device, 72 rotor phase acquisition unit, 74 effective magnetic flux amount setting unit, 76 Current vector controller, 96 detent mechanism.

Claims (1)

A stator provided with a stator coil;
A rotor including first and second rotor elements disposed opposite to the stator in an axially aligned state;
With
The first rotor element rotates with the first rotor shaft;
The second rotor element rotates with a second rotor shaft rotatable relative to the first rotor shaft;
The first rotor element has a plurality of first magnets having different polarities arranged alternately in the circumferential direction, and a first rotor core in which a plurality of electromagnetic steel plates are laminated in the axial direction,
The second rotor element has a plurality of second magnets having different polarities arranged alternately in the circumferential direction, and a second rotor core in which a plurality of electromagnetic steel plates are laminated in the axial direction,
The first rotor element is sandwiched between a non-magnetic first restraint plate and a second restraint plate fixed to the first rotor shaft in the axial direction;
The second rotor element is sandwiched between a non-magnetic third restraining plate and a fourth restraining plate fixed to the second rotor shaft in the axial direction;
A rotating electrical machine in which the first restraining plate and the third restraining plate are in contact with each other, and the contact surface between the first restraining plate and the third restraining plate is subjected to a low friction process.

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