Rotors and rotating electric machines

Abstract

The magnetic properties of the rotor can be changed without requiring a large current in the stator windings. [Solution] According to the embodiment, the rotor 100 comprises a first rotor shaft 111, a first rotor core 112 including a flux barrier band which is a region in which a substantially convex shape toward the rotational axis and in which nonmagnetic regions and bridges are formed continuously, a first rotor comprising two first rotor permanent magnets 113 and two end plates, a second rotor 130 having a second rotor shaft 131 and a second rotor core 132 at each magnetic pole 110p, a rotation support portion 140 having two bearings 141 supported by the two end plates to rotatably support the second rotor 130 and at least one elastic body 142 which generates a spring torque in the opposite direction to the rotational torque acting on the second rotor 130.

Description

Technical Field

[0001] Embodiments of the present invention relate to a rotor and a rotating electrical machine.

Background Art

[0002] A permanent magnet motor incorporating a permanent magnet in the rotor has excellent characteristics such as high efficiency, high torque, and small size.

[0003] On the other hand, in the case of a permanent magnet motor, it is also known that the induced voltage increases as the rotational speed increases. In order to be able to drive beyond the upper limit of the output voltage of the inverter that drives the permanent magnet motor, a technology of rotating at high speed while maintaining a certain output by field weakening control has been put into practical use.

[0004] Field weakening control causes an increase in copper loss due to an increase in current, leading to a decrease in motor efficiency, because it flows a field weakening current component that does not contribute to the output. Also, in both the low to medium torque region and the medium to high speed region, iron loss may increase due to the large permanent magnet flux, and there were also design problems such as causing a decrease in motor efficiency. It was necessary to mount the permanent magnet in an amount necessary to ensure the permanent magnet flux for obtaining high torque. That is, there was a problem that it was impossible to achieve both high efficiency in the high torque region and low speed region and high efficiency in the low to medium torque region and medium to high speed region.

[0005] As a method for solving this problem, a variable flux motor (memory motor) is known, which uses a variable magnetic force magnet having a relatively low coercive force, instantaneously applies a magnetic field to the magnet, and actively changes the magnetization state. [[ID=二十六]]

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] When using a memory motor, a large current is required to increase or decrease the magnetization of the variable magnet, which presents the challenge of increasing the current capacity of the inverter.

[0008] Therefore, the present invention aims to provide a rotor and a rotating electric machine that enable changes in the magnetic properties of the rotor without requiring a large current in the stator winding. [Means for solving the problem]

[0009] To achieve the above objective, the rotor according to the embodiment includes a first rotor shaft extending axially along the rotational center axis, a first rotor core attached to the first rotor shaft and having electromagnetic steel plates stacked in the axial direction, and including a flux barrier band which is a region in which nonmagnetic regions and bridges are continuously arranged in a substantially convex shape toward the rotational center axis when viewed with respect to one magnetic pole sandwiched between two q-axis extending from the rotational center axis in a cross-section perpendicular to the axial direction, and within the flux barrier band, two front The rotor is characterized by comprising: two first rotor permanent magnets arranged to sandwich the d-axis, which is electrically central to the q-axis; two end plates provided to sandwich the electromagnetic steel plate in the axial direction; a second rotor shaft extending in the axial direction, with a pivot axis disposed within the flux barrier band; a second rotor core attached to the second rotor shaft; a second rotor bearing supported by the two end plates to allow the second rotor shaft to rotate around the pivot axis; and an elastic body that generates a spring torque corresponding to the rotation angle. [Brief explanation of the drawing]

[0010] [Figure 1] This is a longitudinal cross-sectional view showing an example of the overall configuration of a rotating electric machine according to the first embodiment. [Figure 2] This is a cross-sectional view showing an example of the overall configuration of a rotor according to the first embodiment. [Figure 3] This is a partial cross-sectional view showing an example of the configuration of a rotating electric machine according to the first embodiment. [Figure 4] This is a partial longitudinal cross-sectional view showing an example of the configuration of a rotating electric machine according to the first embodiment. [Figure 5] This is a partial longitudinal cross-sectional view showing an example of the configuration of the rotation drive unit for the second rotor of a rotating electric machine according to the first embodiment. [Figure 6] This is an explanatory diagram illustrating the conceptual state of magnetic flux in the first state of the second rotor in a rotating electric machine according to the first embodiment. [Figure 7] This is an explanatory diagram illustrating the conceptual state of magnetic flux in the second state of the second rotor in a rotating electric machine according to the first embodiment. [Figure 8] This is an explanatory diagram illustrating the conceptual state of magnetic flux in the third state of the second rotor in a rotating electric machine according to the first embodiment. [Figure 9] This is a conceptual graph illustrating the relationship between the rotational torque of the second rotor and the rotational angle of the second rotor in a rotating electric machine according to the first embodiment. [Figure 10] This is a cross-sectional view showing the configuration of a second rotor according to a first example in a rotating electric machine according to the first embodiment. [Figure 11] This is a cross-sectional view showing the configuration of a second rotor according to a second example in a rotating electric machine according to the first embodiment. [Figure 12] This is a cross-sectional view showing the configuration of a second rotor according to a third example in a rotating electric machine according to the first embodiment. [Figure 13] This is a cross-sectional view showing the configuration of a second rotor according to a fourth example in a rotating electric machine according to the first embodiment. [Figure 14] This is a cross-sectional view showing the configuration of a second rotor according to a fifth example in a rotating electric machine according to the first embodiment. [Figure 15] This is a cross-sectional view showing the configuration of a second rotor according to a sixth example of a rotating electric machine according to the first embodiment. [Figure 16] This is a cross-sectional view showing the configuration of the second rotor according to a seventh example in a rotating electric machine according to the first embodiment. [Figure 17]It is a cross-sectional view showing the configuration of a second rotor according to an eighth example in the rotating electrical machine according to the first embodiment. [Figure 18] It is a cross-sectional view showing the configuration of a second rotor according to a ninth example in the rotating electrical machine according to the first embodiment. [Figure 19] It is a partial cross-sectional view showing a configuration example of a rotating electrical machine according to a second embodiment. [Figure 20] It is a partial cross-sectional view showing a configuration example of a rotating electrical machine according to a third embodiment. [Figure 21] It is a partial cross-sectional view showing a configuration example of a rotating electrical machine according to a fourth embodiment. [Figure 22] It is a partial cross-sectional view showing a configuration example of a rotating electrical machine according to a fifth embodiment. [Figure 23] It is a partial cross-sectional view showing a configuration example of a rotating electrical machine according to a sixth embodiment. [Figure 24] It is an explanatory view showing a conceptual situation of magnetic flux in a third state in which the second rotor is rotated in the rotating electrical machine according to the sixth embodiment.

Mode for Carrying Out the Invention

[0011] Hereinafter, referring to the drawings, the rotor and the rotating electrical machine according to the embodiments of the present invention will be described. Here, the same or similar parts are denoted by common reference numerals, and overlapping descriptions are omitted.

[0012] [First Embodiment] FIG. is a longitudinal sectional view showing an overall configuration example of a rotating electrical machine 1 according to the first embodiment.

[0013] The rotating electrical machine 1 includes a rotor 100, a stator 10 disposed radially outside the rotor 100, two bearings 2 that rotatably support the rotor 100, a bearing bracket 3 that statically supports each bearing 2, and a housing 4 that surrounds the outside in the radial direction of the stator 10 and statically supports the bearing bracket 3.

[0014] The stator 10 has a substantially cylindrical stator core 11 and stator windings 12 wound around the stator core 11. The stator windings 12 have a portion inside the stator core 11 and coil ends 12a protruding from both sides of the stator core 11 in the axial direction.

[0015] Power, such as three-phase AC power, is supplied to the stator winding 12 by the power supply unit 200 via the power cable 201.

[0016] The rotor 100 has a first rotor 110 and a second rotor 130. Details of the rotor 100 will be explained with reference to Figures 2 to 4.

[0017] Here, we define the directions. The axial direction is the direction parallel to the direction in which the rotational axis CL extends. The radial direction is the direction away from the rotational axis CL. For the first rotor 110, the circumferential direction is the direction in which the part of interest moves (direction of rotation) when the first rotor 110 is rotating. For the second rotor 130, the circumferential direction is the direction in which the part of interest moves (direction of rotation) when the second rotor 130 is rotating.

[0018] Figure 2 is a cross-sectional view showing an example of the overall configuration of the rotor 100 according to the first embodiment.

[0019] In Figure 2, the area enclosed by the fan-shaped dashed line represents one magnetic pole 110p. Each magnetic pole 110p of the rotor 100 is equipped with two first rotor permanent magnets 113. At adjacent magnetic poles 110p, the magnetic flux directions from the two first rotor permanent magnets 113 alternate between radially outward and radially inward.

[0020] Each magnetic pole 110p of the first rotor core 112 has a second rotor housing hole 112h for housing the second rotor 130 and a magnet housing section 112m for housing the first rotor permanent magnet 113. In Figure 2, the lead line of the magnet housing section 112m indicates the space in which the first rotor permanent magnet 113 is housed. An outer flux barrier 112b for the magnet housing section is formed adjacent to the radially outer side of the magnet housing section 112m. In addition, an inner flux barrier 112c for the magnet housing section is formed adjacent to the radially inner side of the magnet housing section 112m.

[0021] In the first rotor core 112, a top bridge 112a is formed by the outer flux barrier 112b of the magnet housing and the outer circumferential surface 112s of the first rotor core. In addition, an inner bridge 112d is formed by the second rotor housing hole 112h and the inner flux barrier 112c of the magnet housing.

[0022] From one point on the outer surface 112s of the first rotor core to the second rotor housing hole 112h, the top bridge 112a, the outer flux barrier 112b of the magnet housing, the magnet housing 112m, the inner flux barrier 112c of the magnet housing, and the inner bridge 112d are arranged continuously. Furthermore, from the second rotor housing hole 112h to another point on the outer surface 112s of the first rotor core, the inner bridge 112d, the inner flux barrier 112c of the magnet housing, the magnet housing 112m, the outer flux barrier 112b of the magnet housing, and the top bridge 112a are arranged continuously. Note that the two sides flanking the second rotor housing hole 112h do not need to be symmetrical with respect to each other in the cross-section shown in Figure 2.

[0023] The outer flux barrier 112b of the magnet housing, the magnet housing 112m, and the inner flux barrier 112c of the magnet housing are non-magnetic regions. Furthermore, the top bridge 112a and the inner bridge 112d are areas of high magnetic resistance. That is, including the second rotor housing hole 112h, a region that obstructs the passage of magnetic flux is continuously formed from one point on the outer surface 112s of the first rotor core to another point on the outer surface 112s of the first rotor core. Therefore, this continuously formed region is collectively referred to as the flux barrier band.

[0024] The center of the second rotor housing hole 112h is located on the flux barrier band. In other words, the pivot axis CX of the second rotor 130 is located at the circumferential center of each flux barrier band. The second rotor 130 is supported by the second rotor bearing 141 so as to be rotatable around the pivot axis CX. With the second rotor 130 positioned in this way, as will be described later, the rotation of the second rotor 130 makes it possible to effectively change the path of the magnetic flux within the first rotor 110.

[0025] The second rotor 130 includes a second rotor shaft 131, a second rotor core 132, and a second rotor permanent magnet 133.

[0026] Figure 3 is a partial cross-sectional view showing an example of the configuration of the rotating electric machine 1 according to the first embodiment. Figure 4 is a partial longitudinal cross-sectional view showing an example of the configuration of the rotating electric machine 1 according to the first embodiment. Figure 4 is a partial cross-sectional view taken along the line AA in Figure 3.

[0027] Figure 3 shows one magnetic pole 110p, which is a fan-shaped region sandwiched between two radially extending q-axes. The electrically central axis between the two q-axes is called the d-axis.

[0028] As described above, the stator 10 has a stator core 11 and stator windings 12. As shown in Figure 3, a plurality of teeth 11t are formed on the inner circumferential surface of the stator core 11 at intervals in the circumferential direction. In addition, a yoke 11y is formed in the outer portion of the area where the teeth 11t are formed. Stator slots 11s are formed by adjacent teeth 11t.

[0029] The portion of the stator winding 12 inside the stator core 11 is housed in the stator slot 11s and connected to the coil end 12a (Figure 4). The stator winding 12 is also connected to the power supply unit 200 via the power cable 201, as shown in Figure 1.

[0030] Next, the first rotor 110 and the second rotor 130 of the rotor 100 will be described.

[0031] The first rotor 110, as shown in Figure 4, includes a first rotor shaft 111, a first rotor core 112, a first rotor permanent magnet 113 (Figure 3), end plates 114 and 115, a flange 116, and a nut 117.

[0032] The first rotor shaft 111 extends along the rotational axis CL. The first rotor shaft 111 is also rotatably supported on both sides in the longitudinal direction (axial direction) by bearings 2 (Figure 1).

[0033] The first rotor core 112 is mounted radially outward of the first rotor shaft 111 and is cylindrical in shape. The first rotor core 112 has a plurality of electrical steel sheets 112p stacked in the axial direction.

[0034] As shown in Figure 3, the flux barrier band of the first rotor core 112 extends in a substantially convex shape towards the rotational axis CL at its circumferential center.

[0035] First rotor permanent magnets 113 are housed in the magnet housings 112m on both sides of the circumferential direction, straddling the d-axis. Each first rotor permanent magnet 113 is oriented such that the side closer to the q-axis is the south pole, and the side opposite the q-axis, i.e., closer to the d-axis, is the north pole. Note that for adjacent magnetic poles 110p, the relationship between the north and south poles is reversed.

[0036] Furthermore, the first rotor core 112 has a pivot center at the circumferential center of the flux barrier and a second rotor housing hole 112h for housing the second rotor 130 is formed therein.

[0037] An unbalance-forming hole 132h is formed in the second rotor core 132. As shown in Figure 2, when the N pole of the second rotor permanent magnet 133 is radially outward and the S pole is radially inward, the unbalance-forming hole 132h is formed on the d-axis and in the radially outward region of the second rotor core 132. In other words, the unbalance-forming hole 132h is formed in the region outside the N pole of the second rotor permanent magnet 133. Due to the unbalance-forming hole 132h, in a cross section perpendicular to the axial direction of the second rotor 130, the center of gravity of the second rotor 130 is shifted from the geometric center of the second rotor 130, that is, the center of gravity of the second rotor 130 is eccentric. As a result, the centrifugal force applied to the center of gravity of the second rotor 130 by the rotation of the first rotor 110 becomes the driving force that rotates the second rotor 130.

[0038] As shown in Figure 3, when the unbalance forming hole 132h is not formed, there are two axes of symmetry that are symmetrical. From the viewpoint of maximizing the rotation angle of the second rotor 130 and the second rotor core 132, it is preferable that the unbalance forming hole 132h be formed on one of the axes of symmetry. The shape of the unbalance forming hole 132h is not limited to a circle, but may be an ellipse, polygon, or other shape. It is preferable that the width of the unbalance forming hole 132h be small in the circumferential direction so as not to narrow the magnetic path of the magnetic flux linkage between the rotor 100 and the stator 10. Alternatively, the unbalance forming hole 132h may be positioned radially outward at the rotation angle in which the magnetic flux linkage between the rotor 100 and the stator 10 is smallest.

[0039] End plates 114 and 115 are provided on both sides of the first rotor core 112 in the axial direction, sandwiching the first rotor core 112. The end plates 114 and 115 are attached to the radially outer side of the first rotor shaft 111 and are annular in shape. End plate internal spaces 114h and 115h are formed in each of the end plates 114 and 115, respectively, to house a portion of the second rotor 130. The end plate internal spaces 114h and 115h are formed as recessed circular holes in the surface, opposite the second rotor housing hole 112h.

[0040] As shown in Figure 4, flanges 116 and nuts 117 are provided on the axially outer side of end plate 114 (opposite side of the first rotor core 112) and on the axially outer side of end plate 115 (opposite side of the first rotor core 112), respectively. Flange 116 is integrally formed with the first rotor shaft 111, and the nut 117 has an internal thread that screws into the radially outer surface of the first rotor shaft 111. These flanges 116 and nuts 117 clamp end plate 114, first rotor core 112, and end plate 115 in the axial direction, fixing them to the first rotor shaft 111.

[0041] Next, the second rotor 130 and the rotation drive unit 140 of the rotor 100 will be described, mainly with reference to Figure 4.

[0042] The second rotor 130 and the rotation drive unit 140 are located within the second rotor drive region 120.

[0043] The second rotor 130 includes a second rotor shaft 131 extending in the axial direction, a second rotor core 132, a second rotor permanent magnet 133 (Figure 3), and a closing plate 136.

[0044] The second rotor shaft 131 passes through the center of the cross-section of the second rotor core 132. Both axial ends of the second rotor shaft 131 are rotatably supported by the second rotor bearings 141. Here, the second rotor bearings 141 are annular in shape and are housed in the end plate internal spaces 114h and 115h, respectively, and are statically supported by the end plates 114 and 115. Here, the support portion of the second rotor shaft 131 of the second rotor bearing 141 (the contact portion with the second rotor shaft 131) may be a bearing such as a roll bearing or a ball bearing, or it may be a sliding member such as a bushing.

[0045] The second rotor core 132 is cylindrical and mounted radially outward from the second rotor shaft 131. The second rotor core 132 is, for example, a laminated structure of electromagnetic steel sheets that are magnetic. The second rotor core 132 has housing holes formed on both sides of the second rotor shaft 131, each housing a second rotor permanent magnet 133 and penetrating axially. As shown in Figure 3, an unbalance-forming hole 132h is formed in one of the two regions of the second rotor core 132 where the two second rotor permanent magnets 133 are not present. In Figure 3, the eccentric through-hole 132a is shown as circular as an example, but is not limited to this. That is, it may be of any other shape, such as a notch, as long as it is formed so that a weight imbalance exists between the two regions of the second rotor core 132 where the two second rotor permanent magnets 133 are not present.

[0046] In the state shown in Figure 3, each of the two second rotor permanent magnets 133 is arranged such that the radially inner side is the south pole and the radially outer side is the north pole. As will be explained later, this state is called the first state.

[0047] As shown in Figure 4, the closing plates 136 are provided on both sides in the axial direction of the second rotor core 132 to prevent the second rotor permanent magnets 133 from protruding from the second rotor core 132.

[0048] Figure 5 is a partial longitudinal cross-sectional view showing an example of the configuration of the rotation drive unit 140 of the rotor 100 of the rotating electric machine 1 according to the first embodiment. Figure 5 is a transverse cross-sectional view of the portion of the second rotor 130 as seen by the arrow XX in Figure 4. Figure 5 is also a view of the closing plate 136 side from a plane perpendicular to the second rotor shaft 131 at the position between the closing plate 136 and the second rotor bearing 141 in the end plate internal space 114h. Note that the rotation direction of the rotor 100 is assumed to be counterclockwise in Figure 5.

[0049] The rotation drive unit 140 includes a second rotor bearing 141 (Figure 4), an elastic body 142, an arm 143, and stoppers 144a and 144b. The eccentric through hole 132a formed in the second rotor core 132 also plays a part in the function of the rotation drive unit 140.

[0050] As shown in Figure 5, the elastic body 142 is a coil spring wound around the second rotor shaft 131. The first end of the elastic body 142 engages with the end plate 114. The second end of the elastic body 142 engages with the closing plate 136, or further through the closing plate 136, with the second rotor core 132 (Figure 4). As a result, a rotational force (rotational torque) acts on the elastic body 142 of the second rotor 130 depending on the rotation angle of the second rotor 130. Here, the rotation angle refers to the angle (circumferential angle in the cross-section) at which the second rotor 130 rotates around the second rotor shaft 131. For example, it is the angle from the first state, which will be described later.

[0051] In Figure 5, an example is shown where the elastic body 142 is a coil spring wound around the second rotor shaft 131, but the elastic body is not limited to this. The elastic body 142 may be a coil spring not wound around the second rotor shaft 131, or a leaf spring, as long as it has a similar function.

[0052] The arm 143 is attached to the second rotor shaft 131 and extends away from the second rotor shaft 131. The arm 143 pivots circumferentially in response to the rotation of the second rotor 130.

[0053] The stoppers 144a and 144b are connected to the closing plate 136, or further through the closing plate 136 to the second rotor core 132. The stoppers 144a and 144b protrude perpendicularly from the closing plate 136 toward the second rotor bearing 141.

[0054] As shown in Figure 5, stopper 144a is provided in the radially inner region of the second rotor shaft 131, and stopper 144b is provided in the radially outer region of the second rotor shaft 131. Stoppers 144a and 144b are stoppers that restrict the movement of the arm 143, thereby limiting the rotation angle of the second rotor 130 to a predetermined range. Figure 5 shows the case where the upper limit of the rotation angle is 180 degrees.

[0055] Within a predetermined range of the rotation angle, the elastic body 142 is in a compressed state. Hereinafter, the force exerted by the arm 143 on the second rotor 130 will be referred to as the spring force, and the torque due to the spring force will be referred to as the spring torque.

[0056] Here, the state in which the arm 143 shown in Figure 5 is in contact with the stopper 144a, that is, the state in which the eccentric through hole 132a is radially outward of the second rotor shaft 131, is referred to as the first state. Alternatively, as explained with reference to Figure 3, the state in which the second rotor permanent magnet 133 has the south pole on the radially inward side and the north pole on the radially outward side is also referred to as the first state.

[0057] Furthermore, the state in which the arm 143 is in contact with the stopper 144b, that is, the state in which the eccentric through hole 132a is radially inward of the second rotor shaft 131, is referred to as the third state. Alternatively, the state in which the second rotor permanent magnet 133 has the radially inward side as the north pole and the radially outward side as the south pole is also referred to as the third state.

[0058] <effect> In the second rotor 130 and rotation drive unit 140 configured as described above, when the rotor 100 is stopped or the rotational speed of the rotor 100 is below a predetermined value, the arm 143 is pressed against the stopper 144a by the spring force of the elastic body 142, and the system is in the first state.

[0059] On the other hand, when the rotational speed of the rotor 100 exceeds a predetermined value, the centrifugal force acting on the unbalanced second rotor core 132 overcomes the spring torque of the elastic body 142, causing the arm 143 to move away from the stopper 144a and towards the stopper 144b. If the rotational speed of the rotor 100 increases further, the arm 143 will eventually reach the stopper 144b, and the rotation will stop. That is, it will transition to the third state.

[0060] Thus, the rotation angle of the second rotor 130 is determined by the balance between the spring torque of the elastic body 142 and the rotational torque due to the centrifugal force caused by the rotation of the rotor 100. As a result, the rotation of the second rotor 130 within the first rotor 110 changes the magnetic properties of the rotor 100. <effect>

[0061] Figure 6 is a conceptual diagram illustrating the magnetic flux conditions in the first state of the second rotor 130 in the rotating electric machine 1 according to the first embodiment. Figure 7 is a conceptual diagram illustrating the magnetic flux conditions in the second state of the second rotor 130 in the rotating electric machine 1 according to the first embodiment. Figure 8 is a conceptual diagram illustrating the magnetic flux conditions in the third state of the second rotor 130 in the rotating electric machine 1 according to the first embodiment. The curves in the figures represent the magnetic flux at each position.

[0062] Here, the first state is when the flux linkage between the stator 10 and the rotor 100 is at its maximum, and the rotation angle of the second rotor is 0 degrees. The second state is when the rotation angle is 90 degrees, and the third state is when the rotation angle is 180 degrees.

[0063] As shown in Figures 6 to 8, as the rotation angle increases, that is, as the system transitions from the first state to the second state and then to the third state, the density of the magnetic flux passing through the rotor 100 and the stator 10, i.e., the flux linkage, decreases. In other words, the field weakening effect increases. Thus, the rotation of the second rotor 130 changes the magnetic properties of the rotor 100.

[0064] Figure 9 is a conceptual graph illustrating the relationship between the rotation angle of the second rotor 130 and the rotational torque of the second rotor for a rotating electric machine according to the first embodiment.

[0065] In Figure 9, the horizontal axis represents the rotation angle [degree] of the second rotor 130, and the vertical axis represents the relative torque [pu] due to the centrifugal force acting on the second rotor 130.

[0066] Curves M1 through M4 each show the dependence of the torque due to centrifugal force acting on the second rotor 130 on the rotation angle. As the curves progress from M1 to M4, the rotational speed of the rotor 100 increases. The dashed line A0 shows the restoring torque (spring force) due to the elastic body 142.

[0067] The intersection points S1, S2, S3, and S4, which are the points where curves M1 through M4 intersect with straight line A0, represent the equilibrium points at their respective rotational speeds. In other words, the system stabilizes at the rotational angle of each equilibrium point.

[0068] Thus, as the rotational speed of rotor 100 increases, the equilibrium point shifts from S1 to S4. As a result, the flux linkage decreases in the high-speed region. In this way, the variable flux effect of flux weakening and strengthening can be obtained by the second rotor 130.

[0069] <First example of a second rotor> Figure 10 is a cross-sectional view showing the configuration of the second rotor 151 in a first example of a rotating electric machine 1 according to the first embodiment.

[0070] The second rotor 151 has two second rotor cores 151a and two second rotor permanent magnets 151b.

[0071] Figure 10 shows the case where the second rotor permanent magnet 151b is in the first state, with the radially inner side being the south pole and the radially outer side being the north pole. Also, the unbalance forming hole 132h is formed so that it is radially outer in the first state. Therefore, as the rotational speed of the rotor 100 increases, it transitions from the first state to the third state, and the flux linkage decreases. The same applies to the second example shown in Figure 11 to the ninth example shown in Figure 18, which will be described later.

[0072] The cross-sectional shape of the second rotor permanent magnet 151b is approximately rectangular. Here, "approximately rectangular" includes cases where, for example, the corners of the rectangular shape are partially chamfered.

[0073] In Figure 10, the opening width of the second rotor core 151a is equal to the storage width D0, which is the width of the storage portion of the second rotor core 151a that houses the second rotor permanent magnet 151b.

[0074] The second rotor core 151a and the second rotor permanent magnet 151b are firmly bonded together with an adhesive or the like. The second rotor core 151a and the second rotor shaft 131 are also firmly bonded together with an adhesive or the like.

[0075] <Second example of the second rotor> Figure 11 is a cross-sectional view showing the configuration of a second rotor 152 in a second example of a rotating electric machine 1 according to the first embodiment.

[0076] The second rotor 152 has a second rotor core 152a and two second rotor permanent magnets 152b.

[0077] The second rotor 152 is formed as a single unit via an inner bridge 152c. The second rotor core 152a and the second rotor permanent magnet 152b are fixed together with adhesive or the like. Because the second rotor core 152a is formed as a single unit, the number of parts is reduced, and positioning and assembly are easier. In addition, the second rotor core 152a and the second rotor shaft 131 can be fitted together by press-fitting or shrink-fitting. Compared to the first example shown in Figure 11, the second rotor core 152a and the second rotor permanent magnet 152b can withstand centrifugal force more effectively.

[0078] To suppress the reduction in magnet width and reduce leakage flux, it is preferable to minimize the width of the inner bridge 152c as much as is structurally feasible.

[0079] <Third example of a second rotor> Figure 12 is a cross-sectional view showing the configuration of a second rotor 153 according to a third example in a rotating electric machine according to the first embodiment.

[0080] The second rotor 153 has a second rotor core 153a and two second rotor permanent magnets 153b.

[0081] The second rotor core 153a has retaining protrusions 153c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 153b. In other words, the opening width d0 of the opening 153z of the second rotor core 153a is formed to be smaller than the storage width D0, which is the width of the magnet storage portion.

[0082] While the rotor 100 is rotating, centrifugal force acts on the second rotor permanent magnet 153b radially outward, that is, towards the outer circumference of the second rotor. If the second rotor permanent magnet 153b protrudes radially outward and comes into contact with the first rotor core 112, it will hinder the rotation of the second rotor 130. The retaining projection 153c is shaped and sized to withstand centrifugal force and prevents the second rotor permanent magnet 153b from flying out radially.

[0083] <Fourth example of a second rotor> Figure 13 is a cross-sectional view showing the configuration of a second rotor 154 in a fourth example of a rotating electric machine according to the first embodiment.

[0084] The second rotor 154 has two second rotor cores 154a and two second rotor permanent magnets 154b.

[0085] The second rotor core 154a has retaining protrusions 154c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 154b.

[0086] A chamfered portion 154d is formed on the portion of the second rotor permanent magnet 154b that faces the retaining projection 154c. Here, the chamfered portion 154d is a portion that has been processed into a flat or curved surface with an angle at the corner. It is preferable that the chamfered portion 154d and the retaining projection 154c have the same angle.

[0087] The formation of the chamfered portion 154d allows the radial outer surface of the second rotor permanent magnet 154b to be positioned further radially outward. That is, as shown in Figure 13, the second rotor permanent magnet 154b extends to the outer circumferential surface 154s of the second rotor core 154a. As a result, the radial width of the second rotor permanent magnet 154b can be increased, thereby increasing the magnetic force. In addition, by increasing the size of the chamfered portion 154d, the retaining projection 154c can be increased, thereby increasing its strength.

[0088] <Fifth example of the second rotor> Figure 14 is a cross-sectional view showing the configuration of the second rotor 155 in a fifth example of a rotating electric machine according to the first embodiment.

[0089] The second rotor 155 has a second rotor core 155a and two second rotor permanent magnets 155b.

[0090] In the fifth modification, the second rotor core 155a has retaining protrusions 155c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 155b. In addition, a chamfered portion 155d is formed on the portion of the second rotor permanent magnet 155b facing the retaining protrusions 155c. As a result, as shown in Figure 14, the second rotor permanent magnet 155b extends to the outer circumferential surface 155s of the second rotor core 155a.

[0091] On the other hand, the second rotor core 155a is not divided, but is integrated by the joint 155e.

[0092] The second rotor core 155a is not divided, but is integrated by a radially inward joint 155e, which ensures strength and facilitates positioning during assembly.

[0093] <Sixth example of the second rotor> Figure 15 is a cross-sectional view showing the configuration of a second rotor 156 in a sixth example of a rotating electric machine according to the first embodiment.

[0094] The second rotor 156 has a second rotor core 156a and two second rotor permanent magnets 156b.

[0095] In the sixth modification, the second rotor core 156a is not divided, but is integrated by a radially outer joint 156c.

[0096] The second rotor core 156a is not divided but is integrated by the joint 156c, which ensures strength and facilitates positioning during assembly.

[0097] <Seventh example of the second rotor> Figure 16 is a cross-sectional view showing the configuration of the second rotor 157 in a seventh example of a rotating electric machine according to the first embodiment.

[0098] The second rotor 157 has two second rotor cores 157a and two second rotor permanent magnets 157b.

[0099] The second rotor core 157a has retaining protrusions 157c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 157b. In addition, a chamfered portion 157d is formed on the portion of the second rotor permanent magnet 157b facing the retaining protrusions 157c. As a result, as shown in Figure 17, the second rotor permanent magnets 157b extend to the outer circumferential surface 157s of the second rotor core 157a.

[0100] On the other hand, in this modified example, the second rotor shaft 131 has axially extending planar portions 131f formed on opposite sides in the circumferential direction and facing the second rotor permanent magnet 157b.

[0101] Since two flat portions 131f are formed on the second rotor shaft 131, each flat portion 131f and the radially inner portion of the second rotor permanent magnet 157b can come into close contact with each other. As a result, the radial width of the second rotor permanent magnet 157b can be increased, thereby increasing the magnetic force.

[0102] <Example 8 of the second rotor> Figure 17 is a cross-sectional view showing the configuration of the second rotor 158 in an eighth example of a rotating electric machine according to the first embodiment.

[0103] The second rotor 158 has two second rotor cores 158a and two second rotor permanent magnets 158b.

[0104] The second rotor core 158a has retaining protrusions 158c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 158b. In addition, a chamfered portion 158d is formed on the portion of the second rotor permanent magnet 158b facing the retaining protrusions 158c. As a result, as shown in Figure 18, the second rotor permanent magnet 158b extends to the circumscribing surface 158x of the second rotor core 158a. Furthermore, the outer surface of the second rotor permanent magnet 158b extends outward so as to have the same radius of curvature as the outer circumferential surface 158s of the second rotor core 158a. In reality, the circumscribing surface 158x overlaps with the outer circumferential surface 158s, but for the sake of explanation, they are shown as circles of different diameters.

[0105] Furthermore, the second rotor shaft 131 has flat portions 131f extending in the axial direction formed at opposite positions in the circumferential direction.

[0106] Each of the planar portions 131f of the second rotor shaft 131 and the radially inward portion of the second rotor permanent magnet 158b are parallel planes and face each other via the coupling portion 158e of the second rotor core 158a. The coupling portion 158e functions as a shaft adjacent bridge with high magnetic resistance.

[0107] Since the second rotor core 158a is integrated with the joint 158e, strength is ensured and assembly is improved.

[0108] <Ninth example of the second rotor> Figure 18 is a cross-sectional view showing the configuration of the second rotor 159 in a ninth example of a rotating electric machine according to the first embodiment.

[0109] The second rotor 159 has a second rotor core 159a and two second rotor permanent magnets 159b.

[0110] The second rotor core 159a has retaining protrusions 159c formed so as to cover both sides in the circumferential direction of the radially outer portion of each second rotor permanent magnet 159b. In addition, a chamfered portion 159d is formed on the portion of the second rotor permanent magnet 159b facing the retaining protrusions 159c. As a result, as shown in Figure 19, the second rotor permanent magnet 159b extends to the circumscribing surface 159x of the second rotor core 159a. Furthermore, the outer surface of the second rotor permanent magnet 159b extends outward so as to have the same radius of curvature as the outer circumferential surface 159s of the second rotor core 159a. In reality, the circumscribing surface 159x overlaps with the outer circumferential surface 159s, but for the sake of explanation, they are shown as circles of different diameters.

[0111] Furthermore, the second rotor shaft 131 has flat portions 131f extending in the axial direction formed at opposite positions in the circumferential direction.

[0112] The planar portions 131f of the second rotor shaft 131 and the radially inward portions of the second rotor permanent magnet 159b are parallel planes and face each other via the coupling portion 159e of the second rotor core 159a. The coupling portion 159e functions as a shaft adjacent bridge. A recess 159h is formed in the middle of the coupling portion 159e in the metal direction.

[0113] Since the second rotor core 159a is integrated with the coupling portion 159e, strength is ensured and assembly is improved. In addition, since a recess 159h is formed in the coupling portion 159e, the magnetic resistance of the coupling portion 159e is increased. As a result, leakage flux is reduced, and the variable magnetic flux effect of the second rotor 130 is improved.

[0114] [Second Embodiment] Figure 19 is a partial cross-sectional view showing an example of the configuration of a rotating electric machine 1a according to the second embodiment.

[0115] This embodiment is a modification of the first embodiment. In the rotor 100a of the rotating electric machine 1a according to this embodiment, an outer flux barrier band is formed radially outside the flux barrier band. The rotor 100a also has two first rotor outer fixed permanent magnets 118 arranged in the region of the outer flux barrier band.

[0116] By providing the second layer of permanent magnets 118 fixed to the outside of the first rotor on the radially outer side, the maximum torque that the rotating electric machine 1a can exert can be increased, and by reducing the harmonic components of the linked flux waveform linked from the rotor 100a to the stator 10, it is possible to reduce losses.

[0117] Figure 19 shows the first state. In this state, the unbalance forming hole 132h is formed on the radially outer portion of the second rotor core 132. In other words, the unbalance forming hole 132h is formed on the outside of the N pole of the second rotor permanent magnet 133. In this embodiment as well, as in the first embodiment, as the rotational speed of the rotor 100a increases, the state transitions from the first state to the second state and then to the third state. As a result, the flux linkage decreases. This provides the same effect as in the first embodiment.

[0118] [Third Embodiment] Figure 20 is a partial cross-sectional view showing an example of the configuration of a rotating electric machine 1b according to the third embodiment.

[0119] This embodiment is a modification of the first embodiment. In the rotating electric machine 1b according to this embodiment, the second rotor 130b of the rotor 100b has a second rotor permanent magnet 133b instead of the second rotor permanent magnet 133 in the first embodiment. The second rotor permanent magnet 133b has different lengths on the right and left sides, with the second rotor shaft 131 in between. This causes a mass imbalance. Note that other methods, such as increasing the thickness, may also be used to cause a mass imbalance.

[0120] The second rotor shaft 131 may pass through the second rotor permanent magnet 133b, or, for example, the second rotor permanent magnet 133b may be housed in a magnetic housing and attached to the axial end of the second rotor permanent magnet 133b.

[0121] The second rotor shaft 131 may pass through the second rotor permanent magnet 133b, or, for example, the second rotor permanent magnet 133b may be housed in a magnetic housing and attached to the axial end of the second rotor permanent magnet 133b.

[0122] In this embodiment, as the rotational speed of the rotor 100b increases, it transitions from the first state to the second state. However, the state where it has rotated 90 degrees is the stable state at high speed. Therefore, as it transitions from the first state to the second state, the flux linkage decreases, resulting in a change in the magnetic properties of the rotor 100b. [Fourth Embodiment] Figure 21 is a partial cross-sectional view showing an example of the configuration of a rotating electric machine 1c according to the fourth embodiment.

[0123] This embodiment is a modification of the first embodiment. In the rotating electric machine 1c according to this embodiment, the second rotor 130c of the rotor 100c has a second rotor permanent magnet 133c instead of the second rotor permanent magnet 133 in the first embodiment. The second rotor permanent magnet 133c has a cylindrical shape.

[0124] An unbalance-forming hole 133h is formed on the north pole side of the second rotor permanent magnet 133c. Alternatively, a mass imbalance may be created by providing a notch on the north pole side instead of the unbalance-forming hole 133h.

[0125] The second rotor shaft 131 may pass through the second rotor permanent magnet 133c, or, for example, the second rotor permanent magnet 133c may be housed in a magnetic housing and attached to the axial end of the second rotor permanent magnet 133c.

[0126] The change in magnetic flux distribution is almost the same as the state shown in Figures 6 to 8 in the first embodiment, and thus produces the same effects as in the first embodiment.

[0127] [Fifth Embodiment] Figure 22 is a partial cross-sectional view showing an example of the configuration of a rotating electric machine 1d according to the fifth embodiment.

[0128] This embodiment is a modification of the first embodiment. In the rotating electric machine 1d according to this embodiment, the second rotor 130d of the rotor 100d has second rotor permanent magnets 133d and 133e instead of the second rotor permanent magnet 133 in the first embodiment. The second rotor permanent magnet 133d is arranged on the surface of the second rotor core 132.

[0129] The inner second rotor permanent magnet 133d is longer in the circumferential direction than the outer second rotor permanent magnet 133e. As a result, a mass imbalance occurs.

[0130] Furthermore, the second rotor shaft 131 passes through the second rotor core 132, similar to the first embodiment.

[0131] The change in magnetic flux distribution is almost the same as the state shown in Figures 6 to 8 in the first embodiment, and thus produces the same effects as in the first embodiment. [Sixth Embodiment] Figure 23 is a partial cross-sectional view showing an example of the configuration of the rotating electric machine 1e according to the sixth embodiment. Figure 24 is a conceptual diagram illustrating the magnetic flux situation in the third state in which the second rotor 130e is rotated in the rotating electric machine 1e according to the sixth embodiment. The dashed arrows conceptually represent the magnetic flux.

[0132] This embodiment is a modification of the first embodiment. In this embodiment, the second rotor 130e of the rotor 100e has a second rotor shaft 131 and a second rotor core 132. The second rotor core 132 has two slit-shaped gaps 135 that extend radially outward from the second rotor shaft 131 in opposite directions and penetrate axially.

[0133] An unbalance-forming hole 132h is formed in the radially outer portion of the second rotor core 132. As a result, the rotor transitions through a first state, a second state, and a third state as the rotational speed of the rotor 100e increases. Figure 23 shows the first state, and Figure 24 shows the second state.

[0134] As a result, similar to the first embodiment, the rotor 100e transitions from the first state to the second state and then to the third state as its rotational speed increases. In this embodiment as well, the rotation of the second rotor 130e within the first rotor 110 changes the magnetic properties of the rotor 100e, thereby achieving the same effect as in the first embodiment. Furthermore, the second rotor 130e does not require permanent magnets, thus reducing costs.

[0135] According to the embodiments described above, it is possible to provide a rotor and a rotating electric machine that enable changes in the magnetic characteristics of the rotor without requiring a large current in the stator winding.

[0136] [Other embodiments] Although embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. Furthermore, the features of each embodiment may be combined. Moreover, the embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. Embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of symbols]

[0137] 1, 1a, 1b, 1c, 1d, 1e... Rotating electric machine, 2... Bearing, 3... Bearing bracket, 4... Housing, 10... Stator, 11... Stator core, 11s... Stator slot, 11t... Teeth section, 11y... Yoke section, 12... Stator winding, 12a... Coil end, 100, 100a, 100b, 100c, 100d, 100e... Rotor, 110... First rotor, 110p... Magnetic pole, 111... First rotor shaft, 112... First rotor core, 112a... Top bridge, 112b... Outer flux barrier of magnet housing, 112c... Inner flux barrier of magnet housing, 112d... Inner Side bridge, 112h... Second rotor housing hole, 112m... Magnet housing section, 112p... Electromagnetic steel sheet, 112s... Outer circumference of the first rotor core, 113... First rotor permanent magnet, 114... End plate, 114h... Space inside the end plate, 115... End plate, 115h... Space inside the end plate, 116... Flange, 117... Nut, 118... First rotor outer fixed permanent magnet, 118f... Outer flux barrier band, 120... Second rotor drive region, 130, 130b, 130c, 130d, 130e... Second rotor, 131... Second rotor shaft, 131f... Flat section, 132... Second rotor core, 132a... Eccentric crossbar Through hole, 132h... Unbalance forming hole, 133, 133b, 133c, 133d, 133e... Second rotor permanent magnet, 133h... Unbalance forming hole, 135... Slit-shaped gap, 136... Closing plate, 140... Rotary drive unit, 141... Second rotor bearing, 142... Elastic body, 143... Arm, 144a, 144b... Stopper, 151... Second rotor, 151a... Second rotor core, 151b... Second rotor permanent magnet, 152... Second rotor, 152a... Second rotor core, 152b... Second rotor permanent magnet, 152c... Inner bridge, 153... Second rotor, 153a... Second rotor core Core, 153b...Second rotor permanent magnet, 153c...Retaining projection, 153z...Opening, 154...Second rotor, 154a...Second rotor core, 154b...Second rotor permanent magnet, 154c...Retaining projection, 154d...Chamfered part, 154s...Outer surface, 155...Second rotor, 155a...Second rotor core, 155b...Second rotor permanent magnet, 155c...Retaining projection, 155d...Chamfered part, 155e...Connecting part, 155s...Outer surface, 156...Second rotor, 156a...Second rotor core, 156b...Second rotor permanent magnet, 156c...Connecting part, 157...Second rotor, 157a...Second rotor core,157b...Second rotor permanent magnet, 157c...Retaining projection, 157d...Chamfered part, 157s...Outer surface, 158...Second rotor, 158a...Second rotor core, 158b...Second rotor permanent magnet, 158c...Retaining projection, 158d...Chamfered part, 158e...Connecting part, 158s...Outer surface, 158x...Circumferential surface, 159...Second rotor, 159a...Second rotor core, 159b...Second rotor permanent magnet, 159c...Retaining projection, 159d...Chamfered part, 159e...Connecting part, 159h...Recess, 159s...Outer surface, 159x...Circumferential surface, 200...Power supply unit, 201...Power cable,

Claims

1. The first rotor shaft extends axially along the rotational axis, The first rotor core is attached to the first rotor shaft and has electromagnetic steel plates stacked in the axial direction, and when viewed with respect to one magnetic pole sandwiched between two q-axis extending from the rotational center axis in a cross-section perpendicular to the axial direction, it includes a flux barrier band which is a region in which non-magnetic regions and bridges are continuously arranged in a substantially convex shape toward the rotational center axis, Within the flux barrier band, two first rotor permanent magnets are arranged so as to sandwich the electrically central d-axis of the two q-axis, Two end plates are provided so as to sandwich the aforementioned electromagnetic steel sheet in the axial direction, A pivot axis is positioned within the flux barrier band, and a second rotor shaft extends in the axial direction, The second rotor core attached to the second rotor shaft, A second rotor bearing supported by the two end plates, which supports the second rotor shaft so that it can rotate around the pivot axis, An elastic body that generates a spring torque corresponding to the rotation angle, A rotor characterized by having the following features.

2. The rotor according to claim 1, characterized in that the second rotor core has a center of gravity that is eccentric from the geometric center.

3. The elastic body has a first end and a second end formed in the axial direction, and is a coil spring centered on the pivot axis. The first end engages with one of the end plates, The second end engages with the second rotor core. The rotor according to feature 1.

4. The rotor according to claim 1, characterized by having a second rotor permanent magnet.

5. The second rotor core has an opening formed on its radially outer side. The rotor according to claim 4, characterized in that the width of the opening is equal to or smaller than the storage width of the storage portion of the second rotor permanent magnet in the second rotor core.

6. A flat surface is formed on the portion of the second rotor shaft facing the second rotor permanent magnet. The second rotor permanent magnet is in contact with the flat portion, or is adjacent to the second rotor core via a shaft adjacent bridge formed therein. The rotor according to feature 4.

7. The rotor according to claim 1, A stator provided on the radially outer side of the rotor, A rotating electric machine characterized by having the following features.

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