Rotating electric machine

Abstract

To provide a rotary electric machine which simultaneously realizes a rotation operation and a lock function of a rotor without increasing size of a motor system.SOLUTION: A rotary electric machine comprises: a first rotor 16; a second rotor 18 which is divided from the first rotor 16 along an axial direction of a revolving shaft 14 and relatively rotatable to the first rotor 16 centering on the revolving shaft 14; a rotary lock shaft 38 which can be driven in the axial direction in a hollow region provided in the revolving shaft 14; and a transmission plate 34 which can be driven along a radial direction of the revolving shaft 14 by being interlocked with a motion of the rotary lock shaft 38 and switches a state between a lock state in which the revolving shaft 14 and the second rotor 18 integrally rotate and a rotation state in which the second rotor 18 is relatively rotated to the revolving shaft 14, wherein rotary torque of the second rotor 18 is supported by a load given to the transmission plate 34 by the rotary lock shaft 38, and / or the load to the transmission plate 34 is supported by the rotary torque of the second rotor 18.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rotating electric machine.

Background Art

[0002] For drive motors of moving bodies such as automobiles, miniaturization and high efficiency are required simultaneously, along with a wide operating range. In order to reduce the size due to an increase in torque at low speeds, the magnetomotive force of the rotor is increased, such as by using a strong magnet in the rotor. However, when a rotor with a high magnetomotive force is used, weakening flux control is necessary during high-speed driving, and there is concern that the motor efficiency may decrease due to an increase in current associated with this control.

[0003] Therefore, in order to make the magnetomotive force of the rotor variable according to the operating situation, a motor structure in which the rotor is divided in the axial direction has been proposed (Patent Documents 1 to 5). When torque is required at low speeds, the directions of the magnetic poles in the axial direction are aligned (the same poles: the state where N poles and N poles and S poles and S poles are aligned), and the magnetomotive force is increased. When it is desired to suppress the magnetomotive force at high speeds, the directions of the magnetic poles in the axial direction are changed (opposite poles: the state where N poles and S poles are aligned). Hereinafter, the state where the magnetic poles are aligned is referred to as "same poles", and the state where the magnetic poles are in opposite directions is referred to as "opposite poles". In such a motor structure, a rotating operation for twisting the axially divided rotor to switch between the same poles and the opposite poles, and a locking function for holding each rotor state in order to drive as a motor in the same poles and the opposite poles are required.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

[0005] In the technologies described in Patent Documents 1 to 3 above, rotational movement and locking function are realized using the same power source (actuator and oil pump). Therefore, it is necessary to add a dedicated external actuator or high-pressure oil pump, which increases the size of the motor system. In particular, the force (torque) required for rotational movement is greater than that required for locking, so additional components are needed to accommodate this. Furthermore, if a spring is used to realize or assist the locking mechanism, the force required for rotational movement increases. Consequently, the force (torque) required for rotational movement increases even further, leading to the problem of an even larger motor system.

[0006] Furthermore, in the technology described in Patent Document 4, the rotational movement is performed by an electric current supplied to the stator winding, and the locking function is performed by a small electromagnetic clutch. In addition, in the technology described in Patent Document 5, the rotational movement is performed by an electric current supplied to the stator winding, and a limiter (stopper) function is added to the locking function. In these conventional technologies, by separating the power sources for the rotational movement and the locking function, the motor system can be made smaller compared to other conventional structures. However, an additional mechanism for locking is provided on the outside of the motor structure, so there is still a problem that the overall motor system is large. Furthermore, in the configuration in which a limiter function is added to realize the locking function, an additional position detection sensor is required. In addition, if the responsiveness of the lock control is poor, there is a possibility that locking will not be possible. [Means for solving the problem]

[0007] One aspect of the present invention is a rotating electric machine comprising a stator and a rotor disposed opposite to the stator, wherein the rotor comprises a first rotor fixed to a rotating shaft, a second rotor separated from the first rotor along the axial direction of the rotating shaft and rotatable relative to the first rotor with the rotating shaft as the center of rotation, a rotating lock shaft provided on the rotating shaft and rotatable in the axial direction, and a transmission plate rotatable along the radial direction of the rotating shaft in conjunction with the movement of the rotating lock shaft, and switching between a locked state in which the rotating shaft and the second rotor rotate together and a rotating state in which the second rotor rotates relative to the rotating shaft, wherein the rotation torque of the second rotor is assisted by the load applied to the transmission plate by the rotating lock shaft, and / or the load on the transmission plate is assisted by the rotation torque of the second rotor.

[0008] Furthermore, it is preferable to have a locking assist structure that includes a slope whose height changes radially along the circumferential direction of the second rotor, and in which the transmission plate and the slope come into contact.

[0009] Furthermore, it is preferable to have a groove that rotates together with the second rotor and into which the transmission plate fits, thereby locking the second rotor and the rotating shaft into the locked state.

[0010] Furthermore, it is preferable that the transmission plate is positioned in a through hole provided radially through the rotation axis of the second rotor. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a rotating electric machine that achieves rotor rotation and locking function without increasing the size of the motor system. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows the configuration of a rotating electric machine system in an embodiment of the present invention. [Figure 2] This is a cross-sectional view showing the configuration of the rotor in an embodiment of the present invention. [Figure 3] This is a cross-sectional perspective view showing the configuration of the rotor in an embodiment of the present invention. [Figure 4] This is a cross-sectional view explaining the operation of the rotor in an embodiment of the present invention. [Figure 5] This is a cross-sectional perspective view explaining the operation of the rotor in an embodiment of the present invention. [Figure 6] This is a diagram showing the configuration of the transmission plate in an embodiment of the present invention. [Figure 7] This is a cross-sectional view explaining the operation of the rotor in an embodiment of the present invention. [Figure 8] This is a cross-sectional perspective view showing a modified example of the configuration of the rotor in an embodiment of the present invention. [Figure 9] This is a diagram showing the change in the back electromotive force ratio and torque ratio with respect to the rotational speed in an embodiment of the present invention. [Figure 10] This is a diagram showing the time change of the characteristics during the rotation operation in an embodiment of the present invention. [Figure 11] This is a diagram for explaining the switching timing from the same-pole state to the opposite-pole state in an embodiment of the present invention. [Figure 12] This is a diagram for explaining the switching timing from the opposite-pole state to the same-pole state in an embodiment of the present invention. [Figure 13] This is a diagram for explaining the rotation control in an embodiment of the present invention. [Figure 14] This is a diagram for explaining the preferable rotation control in an embodiment of the present invention. [Figure 15] This is a flowchart showing the transition control from the same-pole state to the opposite-pole state in an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0013] As shown in Figure 1, the rotating electric machine system 100 in an embodiment of the present invention comprises a rotating electric machine 102, a drive circuit 104, a power supply 106, and a control device 108. The rotating electric machine system 100 is installed in, for example, hybrid vehicles, electric vehicles, fuel cell vehicles, etc. The rotating electric machine system 100 can be used as a motor that generates driving force, and can also be used as a motor generator that has the functions of both a generator, a motor, and a power generator.

[0014] The rotating electric machine 102 is composed of a housing 10, a stator 12, a rotating shaft 14, a first rotor 16, a second rotor 18, a locking mechanism 20, a bearing 22, and a locking drive mechanism 24. Alternatively, the bearing 22 may be omitted, and the second rotor 18 may slide relative to the rotating shaft 14.

[0015] The rotating electric machine 102 generates a driving force on the rotating shaft 14 using power supplied from the power supply 106 via a drive circuit 104 controlled by a control device 108. Furthermore, the rotational energy applied to the rotating shaft 14 is converted into electricity by the drive circuit 104 and regenerated back to the power supply 106. The drive circuit 104 may include an inverter that converts the power from the power supply 106 into alternating current. The power supply 106 may include, for example, an energy storage system including a secondary battery.

[0016] The housing 10 is configured to mechanically support the rotating electric machine 102. The stator 12, rotating shaft 14, first rotor 16, second rotor 18, locking mechanism 20, bearings 22, and locking drive mechanism 24 are housed inside the housing 10.

[0017] The stator 12 comprises a stator core and stator coils. The stator core is a hollow cylindrical member made of a laminate formed by stacking electromagnetic steel sheets in the axial direction of the rotating shaft 14. However, the material constituting the stator core is not limited to electromagnetic steel sheets, but can be a magnetic material such as amorphous metal, nanocrystalline soft magnetic material, or compacted magnetic core. The stator coils are coils arranged in a plurality of slots provided on the inner circumferential surface of the stator core. By supplying current from the power supply 106 to the stator coils via the drive circuit 104, a magnetic field can be generated in the stator coils.

[0018] The first rotor 16 and the second rotor 18 are arranged on the rotating shaft 14 at intervals along the axial direction. In the rotating electric machine system 100 of this embodiment, the second rotor 18 is positioned between the two divided first rotors 16a and 16b. However, the first rotor 16 and the second rotor 18 are not limited to a three-part structure, but can be any structure that is divided in the axial direction and can rotate relative to each other.

[0019] The first rotors 16a and 16b are fixed to the rotating shaft 14. The second rotor 18 is installed so as to be movable in the rotational direction relative to the rotating shaft 14. That is, the second rotor 18 is rotatable relative to the rotating shaft 14. For example, the second rotor 18 is attached to the rotating shaft 14 via a bearing 22, and the bearing 22 allows it to rotate relative to the rotating shaft 14.

[0020] The first rotor 16 (16a, 16b) comprises a base fixed to the rotating shaft 14 and a laminate formed by axially stacking electromagnetic steel sheets on the outer circumference of the base. However, the material constituting the laminate is not limited to electromagnetic steel sheets, but can be an amorphous metal, a nanocrystalline soft magnetic material, a compacted magnetic core, or other magnetic material.

[0021] The second rotor 18 comprises a laminate formed by stacking electrical steel sheets in the axial direction. However, the materials constituting the laminate are not limited to electrical steel sheets, but can be magnetic materials such as amorphous metals, nanocrystalline soft magnetic materials, or compacted magnetic cores.

[0022] In this embodiment, as shown in the schematic cross-sectional view of Figure 2, magnets 30 are arranged at equal intervals along the circumferential direction on the first rotor 16 and the second rotor 18. For example, eight magnets 30 are arranged such that the north and south poles alternate at 45° intervals. Note that Figure 2 shows the second rotor 18 as a representative example, and the direction of the magnetic poles of the magnets 30 is indicated by arrows pointing from the south pole to the north pole. The arrangement of the magnets 30 is similar for the first rotor 16. However, the schematic cross-sectional view of Figure 2 is just one example of the arrangement of the magnets 30, and the arrangement of the magnets 30 is not limited to this.

[0023] Furthermore, the second rotor 18 is provided with a locking mechanism 20 so that it can be fixed to the rotating shaft 14. In this embodiment, the locking mechanism 20 is provided between the second rotor 18 and the rotating shaft 14. The locking mechanism 20 is driven by a locking drive mechanism 24 provided inside the rotating shaft 14.

[0024] During normal operation of the rotating electric machine system 100, the locking mechanism 20 prevents the second rotor 18 from rotating relative to the rotation shaft 14, so that both the first rotor 16 (16a, 16b) and the second rotor 18 contribute to the rotation of the rotation shaft 14. On the other hand, during field adjustment, the locking mechanism 20 is released, allowing the second rotor 18 to rotate around the rotation shaft 14 as the center of rotation. By rotating the second rotor 18 relative to the first rotor 16 (16a, 16b) and adjusting its circumferential position, the field of the entire rotor can be adjusted.

[0025] In this configuration, with the locking mechanism 20 engaged, the first rotor 16 (16a, 16b) and the second rotor 18 do not rotate relative to the rotating shaft 14 (normal operation state). By passing current through the stator coil of the stator 12 to form a rotating magnetic field, an output torque can be generated that rotates the rotating shaft 14 relative to the stator 12. Conversely, the rotational energy of the rotating shaft 14 can be converted into current flowing through the stator coil of the stator 12 for regeneration.

[0026] Furthermore, by releasing the locking mechanism 20 and controlling the current flowing through the stator coil of the stator 12 in a state where the second rotor 18 can rotate relative to the rotating shaft 14 (adjusted state), it is possible to generate output torque from the first rotor 16 (16a, 16b) to the rotating shaft 14 while adjusting the relative phase angle (skew angle) of the magnetic poles between the first rotor 16 (16a, 16b) and the second rotor 18. It is preferable to use so-called vector control for the current flowing through the stator coil of the stator 12.

[0027] Hereinafter, the state in which the north poles of the first rotor 16a and first rotor 16b and the north pole of the second rotor 18 are aligned along the axial direction, and the south poles of the first rotor 16a and first rotor 16b and the south pole of the second rotor 18 are aligned along the axial direction is referred to as same pole. Conversely, the state in which the north poles of the first rotor 16a and first rotor 16b and the south pole of the second rotor 18 are aligned along the axial direction, and the south poles of the first rotor 16a and first rotor 16b and the north pole of the second rotor 18 are aligned along the axial direction is referred to as opposite pole.

[0028] The locking mechanism 20 and the locking drive mechanism 24 will be described with reference to Figures 3 to 6. The locking mechanism 20 consists of a pin 32, a transmission plate 34, and a hub 36. The locking drive mechanism 24 consists of a rotating locking shaft 38.

[0029] The rotating shaft 14 has a hollow region 14a that extends in the axial direction of rotation of the first rotor 16 and the second rotor 18. The rotating lock shaft 38 has a cylindrical shape and a pin hole 38a into which a pin 32 included in the lock mechanism 20 is inserted. The rotating lock shaft 38 is positioned in the hollow region 14a of the rotating shaft 14, in the region corresponding to the inner circumference of the second rotor 18. The rotating lock shaft 38 is provided so as to be movable in the axial direction of the rotating shaft 14 (in the direction of the arrow in Figure 3) by an external driving force such as an actuator.

[0030] The pin 32 is inserted into a pin hole 38a provided in the rotating lock shaft 38. When the rotating lock shaft 38 is moved in the axial direction of the rotation axis 14, the pin 32 moves axially along with the rotating lock shaft 38.

[0031] The transmission plate 34 is a component provided to lock the rotating shaft 14 and the second rotor 18, and to transmit power between the rotating shaft 14 and the second rotor 18. As shown in Figure 6, the transmission plate 34 is a plate-shaped component. The transmission plate 34 is positioned within a through hole 38b that extends radially through the central axis of the rotation lock shaft 38. The transmission plate 34 is movable within the through hole 38b in the radial direction of the rotating shaft 14 (rotation lock shaft 38).

[0032] The radial length of the transmission plate 34 is made larger than the outer diameter of the rotating shaft 14. Specifically, the radial length of the transmission plate 34 is made larger than the outer diameter of the rotating shaft 14 to such an extent that when one end of the transmission plate 34 is fitted into the hub groove 36a, the other end can contact the inclined surface 36d. Furthermore, the radial length of the transmission plate 34 is made large enough so that it does not come into contact with the inner circumferential surface of the hub groove 36c during rotational operation of the rotating electric system 100 from the same pole to the opposite pole or from the opposite pole to the same pole.

[0033] As shown in Figure 6, the transmission plate 34 is provided with a guide hole 34a for passing the pin 32 through. The guide hole 34a is provided in a direction oblique to both the axial and radial directions of the rotation axis 14 when the transmission plate 34 is positioned in the through hole 38b of the rotation lock shaft 38. When the pin 32 moves axially with the rotation lock shaft 38 while the pin 32 is passed through the guide hole 34a, the transmission plate 34 is guided in the direction of movement indicated by the arrow in Figure 6.

[0034] The hub 36 is a cylindrical component. The hub 36 is positioned between the rotating shaft 14 and the core of the second rotor 18. The outer circumference of the hub 36 is configured to engage with the inner circumference of the second rotor 18, and the hub 36 rotates integrally with the second rotor 18.

[0035] The inner circumferential surface of the hub 36 is provided with hub grooves 36a into which both ends of the transmission plate 34 can be fitted. The hub grooves 36a are provided at positions where one end of the transmission plate 34 fits when the second rotor 18 is the same polarity as the first rotor 16a and first rotor 16b, and at positions where the other end of the transmission plate 34 fits when the second rotor 18 is the opposite polarity as the first rotor 16a and first rotor 16b.

[0036] A hub groove 36b is provided on the inner circumferential surface of the hub 36 to further restrict the range of rotation. A projection (key portion) 14c provided on the outer circumference of the rotating shaft 14 fits into the hub groove 36b, and the range of rotation of the second rotor 18 relative to the rotating shaft 14 is restricted to the extent that the projection 14c can move within the hub groove 36b.

[0037] Furthermore, a hub groove 36c is provided on the inner circumferential surface of the hub 36. The hub groove 36c is provided along the circumferential direction of the hub 36 so as to communicate with the hub groove 36a. The radial depth of the hub groove 36c is set to a depth such that the end of the transmission plate 34 does not structurally interfere with the inner circumferential surface of the hub 36 during rotational movement transitioning from the same pole to the opposite pole or from the opposite pole to the same pole. In addition, at the end of the hub groove 36c opposite to the side where the hub groove 36a is provided, a slope 36d is provided whose height changes so that the depth of the hub groove 36c gradually decreases radially along the circumferential direction of the hub 36.

[0038] The operation of the locking mechanism 20 and the locking drive mechanism 24 in this embodiment will be explained below with reference to Figures 4 to 7. Here, the operation of the locking mechanism 20 and the locking drive mechanism 24 when changing the rotating electric machine system 100 from like polarity to opposite polarity will be explained.

[0039] Figure 4 shows a cross-section of the second rotor 18 in a plane perpendicular to the axial direction of the rotating shaft 14. Figure 4(a) shows the locked state with the same polarity, Figure 4(b) shows the rotation from the same polarity to the opposite polarity, and Figure 4(c) shows the locked state with the opposite polarity. Figure 5 is a partial cross-sectional perspective view showing the internal structure of the second rotor 18. Figure 5(a) shows the locked state with the same polarity, Figure 5(b) shows the rotation from the same polarity to the opposite polarity, and Figure 5(c) shows the locked state with the opposite polarity. Figure 6 is a diagram showing the configuration of the transmission plate 34. Figure 7 shows an enlarged cross-section of the transmission plate 34, rotation lock shaft 38, rotating shaft 14, and hub 36 in a plane perpendicular to the axial direction of the rotating shaft 14. Figure 7(a) shows the locked state with the same polarity, Figures 7(b) and 7(c) show the rotation from the same polarity to the opposite polarity, and Figure 7(d) shows the locked state with the opposite polarity. Figures 7(a) to 7(c) show enlarged sections of region A1, and Figure 7(d) shows enlarged sections of region A2.

[0040] As shown in Figures 4(a), 5(a), and 7(a), when the rotating electric machine system 100 is of the same polarity, an external force is applied to the rotation lock shaft 38 such that the pin 32 is positioned at one end of the guide hole 34a (the lower end in Figure 5(a)). The pin 32, which passes through the guide hole 34a, pushes one end of the transmission plate 34 upward toward the inner circumferential surface of the hub 36 (upward in Figures 4, 5, and 7).

[0041] In addition, the rotating electric machine system 100 is further subjected to an upward force on the transmission plate 34 by the inclined surface 36d. In the like-polarity locked state, as shown in Figure 7(a), a rotational torque is applied to the transmission plate 34 in a counterclockwise direction relative to the rotating shaft 14 and the rotation lock shaft 38. In this state, one end of the transmission plate 34 (the lower end in Figures 4(a), 5(a), and 7(a)) comes into contact with the inclined surface 36d, and the rotational torque of the transmission plate 34 applies a force perpendicular to the inclined surface 36d to the transmission plate 34. Then, as a component of the force perpendicular to the inclined surface 36d, a force F1 is applied that pushes the transmission plate 34 upward along the radial direction.

[0042] In the locked state with the same polarity, the transmission plate 34 is pressed against the inner circumferential surface of the hub 36, causing one end of the transmission plate 34 (the upper end in Figures 4(a), 5(a), and 7(a)) to fit into the hub groove 36a of the hub 36. In addition, the projection 14c provided on the rotating shaft 14 comes into contact with one end of the hub groove 36b of the hub 36.

[0043] When the rotating electric machine system 100 is operating as a motor, the first rotor 16 and the second rotor 18 rotate in the forward direction (CCW direction in Figure 4(a)) and output torque in that forward direction. During the motor operation in the same-pole locked state, the motor torque of the second rotor 18 is transmitted to the rotating shaft 14 by a projection 14c of the rotating shaft 14 that abuts against one end of the hub groove 36b of the hub 36. In other words, in the motor operation state, no motor torque is applied to the end of the transmission plate 34. On the other hand, when the rotating electric machine system 100 is operating as a generator in a regenerative state, the first rotor 16 and the second rotor 18 rotate in the forward direction and output regenerative torque in the reverse direction (opposite direction to the CCW direction in Figure 4(a)). In this regenerative operation state, the regenerative torque of the second rotor 18 is transmitted to the rotating shaft 14 by the end of the transmission plate 34 fitted into the hub groove 36a provided in the hub 36.

[0044] Next, the second rotor 18 is rotated to change from the same polarity to the opposite polarity. When the rotation lock shaft 38 is moved by an external force (in the direction of the arrow in Figure 5(a)), the pin 32 also moves along with the rotation lock shaft 38, and the transmission plate 34 is pushed down according to the slope of the guide hole 34a (downward in Figures 4, 5, and 7). As a result, the end of the transmission plate 34 disengages from the hub groove 36a, and the lock between the second rotor 18 and the rotating shaft 14 is released. Therefore, the increase in rotational torque required for the rotation of the second rotor 18 can be suppressed.

[0045] In this state, the current flowing through the stator coil of the stator 12 is controlled to provide the torque (rotational torque) necessary to rotate the second rotor 18. As a result, the rotation of the second rotor 18 begins, as shown in Figure 7(b).

[0046] Furthermore, when the rotating electric machine system 100 is operating as a motor, if it is transitioned from the same-polarity locked state to the rotating state, the torque of the second rotor 18 is transmitted to the rotating shaft 14 by the projection 14c of the rotating shaft 14, and the transition to the rotating state can be made while torque is not being transmitted by the end of the transmission plate 34. In other words, when the lock is released, the transmission plate 34 is not pressed against the hub groove 36a of the hub 36, and the force required to release the lock is not increased. If it is pressed, friction occurs at the contact surface, and the force required to release the lock increases. Therefore, it is possible to suppress the increase in the external force required for the axial movement of the rotating lock shaft 38.

[0047] Furthermore, at the start of rotation from the same pole to the opposite pole, a rotational torque is applied to the hub 36 by the force pushing down on the transmission plate 34, causing the hub 36 to rotate relative to the rotation shaft 14. As shown in Figure 7(b), one end of the transmission plate 34 (the lower end in Figure 7(b)) is in contact with the inclined surface 36d, and the force pushing down on the transmission plate 34 is applied as a force perpendicular to the inclined surface 36d. Then, a rotational torque is applied to the transmission plate 34 by the component force F2 of this force. As a result, the speed at which the transmission plate 34 rotates relative to the rotation shaft 14 increases.

[0048] Furthermore, during the transition from the opposite pole to the same pole, as shown in Figure 7(a), a force F1 is applied from the inclined surface 36d to the transmission plate 34, pushing the transmission plate 34 upward, and the speed at which the transmission plate 34 engages with the hub groove 36a and locks increases.

[0049] As the rotation continues, the transmission plate 34 will come off the inclined surface 36d, as shown in Figures 4(b), 5(b), and 7(c). At this time, as shown in Figure 7(c), neither end of the transmission plate 34 will be in contact with the inner surface of the hub groove 36c provided in the hub 36, and there will be no mechanical resistance from the transmission plate 34 to the relative rotation between the rotating shaft 14 and the transmission plate 34.

[0050] As the rotation progresses further, the second rotor 18 rotates to the opposite pole position, and another hub groove 36a provided in the hub 36 moves to the position of the transmission plate 34. At the same time, the pin 32 moves together with the continuously pushed rotation lock shaft 38, and the pin 32 is positioned at one end of the guide hole 34a (the upper end in Figure 5(c)). That is, the pin 32, which passes through the guide hole 34a, pushes one end of the transmission plate 34 downwards toward the inner circumferential surface of the hub 36 (downward in Figures 4, 5, and 7).

[0051] In addition, in the rotating electric machine system 100, an additional force is applied by the inclined surface 36d to push down the transmission plate 34. In the reverse-pole locked state, as shown in Figure 7(d), a rotational torque is applied to the transmission plate 34 in a clockwise direction relative to the rotating shaft 14 and the rotation lock shaft 38. In this state, one end of the transmission plate 34 (the upper end in Figures 4(c), 5(c), and 7(d)) ​​comes into contact with the inclined surface 36d, and the rotational torque of the transmission plate 34 applies a force perpendicular to the inclined surface 36d to the transmission plate 34. Then, as a component of the force perpendicular to the inclined surface 36d, a force F3 is applied that pushes down the transmission plate 34 along the radial direction. This increases the speed at which one end of the transmission plate 34 engages with the hub groove 36a and locks into place.

[0052] In the reverse-polarity locked state, the transmission plate 34 is pressed against the inner circumferential surface of the hub 36, causing one end of the transmission plate 34 (the lower end in Figures 4(c), 5(c), and 7(d)) ​​to fit into the hub groove 36a of the hub 36. In addition, the projection 14c provided on the rotating shaft 14 comes into contact with the opposite end of the hub groove 36b of the hub 36 compared to the same-polarity locked state.

[0053] When the rotating electric machine system 100 is operating as a motor, the first rotor 16 and the second rotor 18 rotate in the forward direction (CCW direction in Figure 4(c)) and output torque in that forward direction. During powered operation in the reverse-pole locked state, the power torque of the second rotor 18 is transmitted to the rotating shaft 14 by the end of the transmission plate 34 fitted into the hub groove 36a provided in the hub 36. On the other hand, when the rotating electric machine system 100 is operating as a generator in a regenerative state, the first rotor 16 and the second rotor 18 rotate in the forward direction and output regenerative torque in the reverse direction (opposite direction to the CCW direction in Figure 4(c)). At this time, the regenerative torque of the second rotor 18 is transmitted to the rotating shaft 14 by the projection 14c of the rotating shaft 14 that abuts against one end of the hub groove 36b of the hub 36. In other words, in the regenerative operation state, no regenerative torque is applied to the end of the transmission plate 34.

[0054] Furthermore, when transitioning from the reverse polarity state to the same polarity state using the locking mechanism 20 and the locking drive mechanism 24, the reverse operation should be performed. In this case, if the rotational electric system 100 is transitioning from the reverse polarity locked state to the rotational state while it is in regenerative operation, torque is transmitted by the projection 14c of the rotating shaft 14 and the hub groove 36b of the hub 36, and the transition to the rotational state can be achieved while torque is not transmitted by the end of the transmission plate 34. In other words, the transmission plate 34 is not pressed by the hub groove 36a of the hub 36, and the force required to release the lock does not increase. If it is pressed, friction occurs at the contact surface, and the force required to release the lock increases. Therefore, it is possible to suppress the increase in the external force required for movement along the axial direction of the rotational lock shaft 38.

[0055] As described above, in the rotating electric machine system 100, the lock state of the same polarity or opposite polarity can be released by moving the rotation lock shaft 38 in the axial direction, and the same polarity state and the opposite polarity state can be transitioned between each other by rotating the second rotor 18 relative to the rotating shaft 14 by energizing the stator 12. Furthermore, the locking function between the rotating shaft 14 and the second rotor 18 can be performed passively by continuously pressing the rotation lock shaft 38, without requiring any external mechanisms or additional sensors other than the lock mechanism 20 and the lock drive mechanism 24.

[0056] Furthermore, the simple configuration using the transmission plate 34 makes it possible to achieve both a locked state and an unlocked state. In addition, since the transmission plate 34 is positioned at the center of the second rotor 18 during rotation, the structure is less susceptible to the effects of centrifugal force caused by rotation.

[0057] Furthermore, in the rotating electric machine system 100, the locking mechanism 20 and the locking drive mechanism 24 are arranged inside the second rotor 18, and the rotational operation is performed by energizing the stator 12, so that the same-polarity and opposite-polarity states can be achieved without increasing the volume of the rotating electric machine system 100. In addition, there is no need for means to detect or control the skew angle for locking.

[0058] Furthermore, the interaction between the transmission plate 34 and the inclined surface 36d provided on the hub 36 allows the load applied to the transmission plate 34 by the rotation lock shaft 38 to be used to accelerate the rotation of the hub 36, thereby shortening the time required for the transition between like-pole and opposite-pole positions. Additionally, the rotational torque of the hub 36 can be used to accelerate the locking action of the transmission plate 34 against the hub 36, shortening the time required to achieve the like-pole and opposite-pole locked states.

[0059] As shown in Figure 8, an elastic body 40, such as a spring, may be provided in the hollow part of the rotating shaft 14 to continuously apply force to the rotating lock shaft 38 from one side along the axial direction. By providing an elastic body 40, it becomes possible to continuously apply an external force to the rotating lock shaft 38 from one side. This makes it possible to maintain a same-polarity locked state or a reverse-polarity locked state even when the actuator or the like that drives the rotating lock shaft 38 of the rotating electric machine system 100 from the outside is stopped.

[0060] The mechanism that applies external force to the rotating lock shaft 38 can be operated using, for example, the hydraulic pressure of the lubricating oil used in bearings or gears, without the need for a special actuator. In this case, since the existing lubricating oil pump can be used, there is no need to add an external driving force mechanism such as an actuator, and the entire system can be made smaller. [Control of Rotating Electrical Machine Systems]

[0061] Incidentally, when the field flux of the first rotor 16 and the second rotor 18 is increased to increase the torque of the rotating electric machine system 100, the induced voltage (back electromotive force) generated by the magnets (fields) increases. As a result, for example, if the rotating electric machine system 100 is driven by an inverter, the induced voltage may exceed the withstand voltage of the switching element, potentially damaging the switching element. Therefore, it is necessary to simultaneously increase the torque of the rotating electric machine system 100 and suppress the back electromotive force to below an upper limit.

[0062] In the following explanation, rotational speed refers to the number of rotations (rotational velocity) of the first rotor 16 or the second rotor 18 per unit time. For example, the unit of rotations per minute is rpm.

[0063] For example, by setting the axial division ratio between the first rotors 16a and 16b and the second rotor 18 to 4:1, and rotating the second rotor 18 at half the upper limit rotational speed, 1 / 4 of the magnetic poles are changed from like poles to opposite poles, causing the magnetic flux from the N pole and S pole to cancel each other out in the axial half. As a result, the field flux is halved, the back electromotive force is also halved, and control becomes possible without damaging the switching elements even at high rotational speeds. Figures 9(a) and 9(b) show the changes in the ratio of back electromotive force and torque ratio with respect to the rotational speed of the first rotor 16 and the second rotor 18 in this case. In the drivable range of the rotating electric machine system 100, the torque at low speeds can be increased compared to the comparison motor.

[0064] The rotational control of the second rotor 18 suitable for the rotating electric machine system 100 is as follows: Up to rotational speed N1, the first rotor 16 and the second rotor 18 are driven with the same poles and accelerated by the power torque.

[0065] When the rotational speed reaches rotational speed N1, the system switches to rotation control mode 1, which rotates the second rotor 18 from the same polarity to the opposite polarity. In rotation control mode 1, the system maintains the torque output to the rotating shaft 14 (output torque) while simultaneously outputting rotation torque to rotate the second rotor 18 relative to the first rotor 16 to perform the rotational operation. Specifically, in the same polarity state, both the first rotor 16 and the second rotor 18 output output torque, and during the rotational operation in rotation control mode 1, the system controls the current supplied to the stator coil of the stator 12 so that the output torque is maintained by the first rotor 16 while rotation torque is output by the second rotor 18.

[0066] In this manner, when the rotational speed exceeds N1, the rotating electric machine system 100 is driven with the second rotor 18 in the opposite polarity to the first rotor 16.

[0067] If braking or other actions are performed on the vehicle while it is being driven in the reverse polarity, deceleration occurs due to regenerative torque. When the rotational speed reaches N2 due to deceleration, the system switches to rotation control mode 2, which rotates the second rotor 18 from the reverse polarity to the same polarity. In rotation control mode 2, similar to rotation control mode 1, the system performs rotational operation by simultaneously outputting rotational torque while maintaining output torque. Specifically, in the reverse polarity, both the first rotor 16 and the second rotor 18 output output torque, and during rotational operation in rotation control mode 2, the current supplied to the stator coil of the stator 12 is controlled so that the first rotor 16 maintains output torque while the second rotor 18 outputs rotational torque.

[0068] Thus, when the rotational speed falls below N2, the rotating electric machine system 100 is driven with the second rotor 18 having the same pole as the first rotor 16.

[0069] If rotational speeds N1 and N2 are the same, there is a risk of a chattering phenomenon occurring around that rotational speed, where rotational movements from the same pole to the opposite pole or from the opposite pole to the same pole are repeated. Therefore, it is preferable to set rotational speed N1 > rotational speed N2. In this way, by providing hysteresis between rotational speed N1, which is the reference speed for initiating rotational movement from the same pole to the opposite pole, and rotational speed N2, which is the speed for initiating rotational movement from the opposite pole to the same pole, the chattering phenomenon can be suppressed.

[0070] Furthermore, compared to rotation from the same pole to the opposite pole, the rotation torque that can be output while maintaining output torque is smaller in rotation from the opposite pole to the same pole, and the conditions under which rotation is possible are limited. Therefore, it is preferable to add a torque constraint in addition to the rotation speed constraint (rotation speed N2) as a condition for transitioning to rotation control mode 2 from the opposite pole to the same pole. That is, it is preferable to transition to rotation control mode 2 when the rotation speed of the first rotor 16 and the second rotor 18 is less than or equal to rotation speed N2, and the output torque is less than or equal to the reference torque T2.

[0071] In particular, when the rotating electric machine system 100 is in a regenerative state with the polarity reversed, and the rotational speeds of the first rotor 16 and the second rotor 18 are decreasing from rotational speed N1, the system is not switched to rotational control mode 2, and the rotating electric machine system 100 is driven in the polarity reversed state during regenerative operation. Subsequently, when re-acceleration occurs and the system transitions to a power state, or when the rotating electric machine system 100 stops, the output torque will become 0, or it will cross 0 and transition from negative regenerative torque to positive power torque. Therefore, it is preferable to switch to rotational control mode 2 and perform rotational operation when the output torque is 0 or close to it. Note that the closer the output torque is to 0, the greater the rotational torque that can be output, making it easier to rotate the second rotor 18 from the opposite polarity to the same polarity relative to the first rotor 16.

[0072] Figure 10 shows an example of the time evolution of rotational speed, phase difference angle, output torque, torque of the first rotor 16 (main rotor torque), and torque of the second rotor 18 (rotating rotor torque) during rotational operation in rotational control mode 1, which transitions from the same polarity to the opposite polarity. The torques (output torque, main rotor torque, and rotating rotor torque) are values ​​calculated by magnetic field analysis. These characteristics show the results when the maximum current is kept below the upper limit.

[0073] These results demonstrate that rotational operation can be achieved while maintaining the output torque at a predetermined value. Furthermore, by releasing the same-polarity lock state and switching the control of the current supplied to the stator coil of the stator 12, it is possible to switch to rotational control mode 1, and by changing the current control conditions according to the phase difference angle, the second rotor 18 can be rotated by the torque (rotational torque) of the second rotor 18 while maintaining the output torque (output torque) with the torque (main rotor torque) of the first rotor 16. In addition, after the rotational operation is completed, the reverse-polarity lock state is returned, and the control of the current supplied to the stator coil of the stator 12 is also changed at that time.

[0074] Figures 11 and 12 show examples of the change in rotational torque with respect to rotational speed from the same pole to the opposite pole and from the opposite pole to the same pole, while maintaining the output torque at a predetermined value, and the conditions (range) under which rotational operation is possible. In Figures 11 and 12, the conditions marked with an "x" indicate conditions suitable for switching to rotational operation. Symbol (1) indicates conditions suitable for transitioning to rotational control mode 1, and symbols (2) and (3) indicate conditions suitable for transitioning to rotational control mode 2. Symbol (2) indicates the condition when the rotational speed is less than or equal to rotational speed N2, and symbol (3) indicates the condition when the rotational speed is less than or equal to rotational speed N2, in addition to the torque being close to 0.

[0075] Furthermore, Figures 13 and 14 show a method for suppressing torque shock associated with the rotational operation of the second rotor 18. As shown in Figure 13, when increasing the rotational speed in the rotating electric machine system 100 when the output torque is at its maximum, transitioning from a same-polarity state to a reverse-polarity state at a predetermined rotational speed may cause a torque gap during the transition, potentially resulting in torque shock in the rotating electric machine system 100. Therefore, as shown in Figure 14, it is preferable to perform control to limit the drive range so as to reduce the output torque of the rotating electric machine system 100 before transitioning from a same-polarity state to a reverse-polarity state at a predetermined rotational speed. For example, the current to the stator coil of the stator 12 is controlled so that the output torque becomes the maximum torque in the reverse-polarity state, and then control is performed to transition from a same-polarity state to a reverse-polarity state. This prevents the occurrence of a torque gap during the transition from the same polarity to the reverse polarity, thereby suppressing torque shock in the rotating electric machine system 100.

[0076] As described above, in the rotating electric machine system 100, torque is transmitted by projections 14c provided on the rotating shaft 14 when the system is in a same-polarity state and in a powered state. In this state where torque is transmitted by projections 14c, no torque is applied to the locking mechanism 20, so the lock can be released by moving the locking drive mechanism 24 with an external force. At this time, since the output torque of the first rotor 16 and the second rotor 18 is transmitted by projections 14c, there is no decrease in output torque associated with the release of the lock. On the other hand, in the regenerative state where the output torque is in the opposite direction, torque is transmitted by the locking mechanism 20. In this state where torque is transmitted by the locking mechanism 20, torque is applied to the locking mechanism 20, so the lock cannot be released simply by moving the locking drive mechanism 24 with an external force. Therefore, the transition from the same-polarity state to the opposite-polarity state is performed when the rotating electric machine system 100 is in a powered state.

[0077] Figure 15 shows a flowchart of the control for transitioning from a like-polarity state to a reverse-polarity state. The control for transitioning the rotating electric machine system 100 from a like-polarity state to a reverse-polarity state will be explained below with reference to this flowchart.

[0078] In step S10, normal drive control is performed in the same-polarity state. In step S12, it is determined whether the rotational speed is greater than or equal to rotational speed N1. If the rotational speed is greater than or equal to rotational speed N1, the process moves to step S14; otherwise, the process returns to step S12. In step S14, the lock drive mechanism 24 is driven. In step S16, it is determined whether the lock has been released. If the lock has been released, the process moves to step S18; otherwise, the process returns to step S14 and the drive of the lock drive mechanism 24 continues. The release of the lock can be detected using a sensor. For example, the position of the rotating lock shaft can be detected by a sensor, and the state of being locked or unlocked can be detected based on the position of the rotating lock shaft.

[0079] In step S18, the second rotor 18 is rotated relative to the first rotor 16. At this time, the lock drive mechanism 24 is kept running. In step S20, it is determined whether or not the lock has been completed. By continuing to drive the lock drive mechanism 24 while rotating the second rotor 18, the rotating electric machine system 100 enters a locked state in the reverse polarity state. If the lock has been completed, the process proceeds to step S22; otherwise, the process is repeated from step S18. In step S22, normal drive control is started in the reverse polarity state.

[0080] The transition from the reverse polarity state to the same polarity state can be controlled in the same way as described above. In this case, step S10 performs normal control in the reverse polarity state, and step S22 performs normal control in the same polarity state. Furthermore, the condition for the determination in step S12 is that the rotational speed is less than or equal to rotational speed N2. In addition, a condition that the torque is close to 0 may be added to this condition.

[0081] [Structure of the invention] [Configuration 1] A rotating electric machine comprising a stator and a rotor positioned opposite the stator, The rotor comprises a first rotor fixed to the rotating shaft, and a second rotor that is separated from the first rotor along the axial direction of the rotating shaft and is rotatable relative to the first rotor with the rotating shaft as the center of rotation. A rotating lock shaft that can be driven in the axial direction is provided within a hollow region on the rotating shaft, A transmission plate that can be driven along the radial direction of the rotating shaft in conjunction with the movement of the rotating lock shaft, and which switches between a locked state in which the rotating shaft and the second rotor rotate together, and a rotating state in which the second rotor rotates relative to the rotating shaft, Equipped with, A rotating electric machine characterized in that the rotational torque of the second rotor is assisted by the load applied to the transmission plate by the rotational lock shaft, and / or the load on the transmission plate is assisted by the rotational torque of the second rotor. [Configuration 2] The rotating electric machine described in Configuration 1, A rotating electric machine characterized by having a slope whose height changes radially along the circumferential direction of the second rotor, and having a locking assist structure in which the transmission plate and the slope come into contact. [Configuration 3] A rotating electric machine as described in configuration 1 or 2, A rotating electric machine characterized by having a groove that rotates together with the second rotor and into which the transmission plate fits, thereby locking the second rotor and the rotating shaft into the locked state. [Structure 4] A rotating electric machine as described in any one of items 1 to 3, The rotating electric machine is characterized in that the transmission plate is arranged in a through hole provided radially through the rotation axis of the second rotor. [Explanation of symbols]

[0082] 10 Housing, 12 Stator, 14 Rotating shaft, 14a Hollow region, 14c Projection (key part), 16 (16a, 16b) First rotor, 18 Second rotor, 20 Locking mechanism, 22 Bearing, 24 Locking drive mechanism, 30 Magnet, 32 Pin, 34 Transmission plate, 34a Guide hole, 36 Hub, 36a, 36b, 36c Hub groove, 36d Inclined surface, 38 Rotating locking shaft, 38a Pin hole, 38b Through hole, 40 Elastic body, 100 Rotating electric system, 102 Rotating electric machine, 104 Drive circuit, 106 Power supply, 108 Control device.

Claims

1. A rotating electric machine comprising a stator and a rotor positioned opposite the stator, The rotor comprises a first rotor fixed to the rotating shaft, and a second rotor that is separated from the first rotor along the axial direction of the rotating shaft and is rotatable relative to the first rotor with the rotating shaft as the center of rotation. A rotation lock shaft is provided within a hollow region on the rotating shaft, is drivable in the axial direction, and is used to switch between a locked state in which the rotation of the rotating shaft and the second rotor are locked to rotate together, and a rotation state in which the rotation of the second rotor is not locked to rotate relative to the rotating shaft. A transmission plate is provided that can be driven along the radial direction of the rotating shaft in conjunction with the axial movement of the rotating lock shaft, and which switches between the locked state and the rotating state. Equipped with, A rotating electric machine characterized in that, as the rotating lock shaft moves in the axial direction, a force is applied to the transmission plate, and the force applied to the transmission plate is decomposed into radial and circumferential forces of the second rotor by the contact between the transmission plate and an inclined surface provided on the inner circumferential surface of a hub that rotates together with the second rotor, and the circumferential force provides a rotational torque to the second rotor relative to the first rotor.

2. A rotating electric machine according to claim 1, The aforementioned slope is characterized in that its radial height changes along the circumferential direction of the second rotor.

3. A rotating electric machine according to claim 1 or 2, A rotating electric machine characterized in that the inner circumferential surface of the hub is provided with a groove into which the transmission plate fits, thereby locking the second rotor and the rotating shaft into the locked state.

4. A rotating electric machine according to claim 1, The rotating electric machine is characterized in that the transmission plate is arranged in a through hole provided radially through the rotating shaft.

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