JP2021097457A - Rotator of rotary electric machine and rotary electric machine - Google Patents

Abstract

To suppress reduction of a torque at a heavy current.SOLUTION: A rotator of a rotary electric machine comprises: a rotator core provided with a magnet housing part; and a permanent magnet housed in the magnet housing part. The permanent magnet forms one pole with combination of a rotation side magnet and a reverse rotation side magnet in a V-shape. A region between the rotation side magnet and the reverse-rotation side magnet is separated into a first region opposite a main flux surface of the reverse rotation side magnet and a second region opposite a main flux surface of the rotation side magnet. A penetration hole penetrating the rotator core penetrates in an axial direction is formed in the second region, the penetration hole being formed from a position crossing a central normal line of the main flux surface of the rotation side magnet to a position in the proximity of the magnet between the rotation side magnet and the reverse rotation side magnet arranged in a V-shape.SELECTED DRAWING: Figure 6

Description

The present invention relates to a rotor of a rotary electric machine.

Permanent magnet type rotary electric machines are used for rotary electric machines for automobiles in order to obtain a small size and high output. In particular, an embedded magnet type rotary electric machine that can utilize both the magnet torque generated by the magnetic flux of the magnet and the reluctance torque generated by the magnetic flux of the armature and the salient pole of the core is mainly used.

The following prior arts are the background technologies in this technical field. Patent Document 1 (International Publication No. 2019/64801) provides a permanent magnet type rotary electric machine capable of improving the final torque of the sum of the magnet torque and the reluctance torque. The rotor provided in the permanent magnet type rotary electric machine is provided in a core region which is a region between a rotor core, a plurality of magnets embedded in the rotor core, and a magnet forming a magnetic pole of one pole among the plurality of magnets and a gap. The magnetic permeability is lower than the magnetic permeability of the core region, and the end near the outer circumference of the rotor is the force in the circumferential direction applied to the rotor by energizing the coil rather than the magnetic pole center of the one pole. The end portion provided in the core region on the same direction as the direction and close to the center of the rotation axis of the rotor has a magnetic slit provided on the center of the magnetic pole or in the core region on the side opposite to the direction of the force from the center of the magnetic pole. The permanent magnet type rotating electric machine that is used is described (see summary).

International Publication No. 2019/64801

In the above-mentioned embedded magnet type rotary electric machine, larger magnetic saturation may occur in the core on the rotor surface side and the rotation direction side with respect to the magnet, and the magnet magnetic flux may be tilted in the counter-rotation direction to reduce the torque. .. In particular, there is a problem that the torque decreases at the time of a large current in which magnetic saturation occurs remarkably, and the maximum torque in the specifications cannot be obtained.

A typical example of the invention disclosed in the present application is as follows. That is, it is a rotor of a rotating electric machine including a rotor core provided with a stone storage portion and a permanent magnet housed in the magnet storage portion, and the permanent magnets are a rotating side magnet and a counter-rotating side magnet. Are combined in a V shape to form one pole, and the region between the rotating side magnet and the counter-rotating side magnet is a first region facing the main magnetic flux surface of the counter-rotating side magnet and the rotating side. It is divided into a second region facing the main magnetic flux surface of the magnet, and a through hole that penetrates the rotor core in the axial direction is formed in the second region, and the through hole is the main of the rotating magnet. It is characterized in that the magnet is formed from a position intersecting the central normal line of the magnetic flux surface to a position close to the rotating magnet and the counter-rotating magnet arranged in a V shape.

According to one aspect of the present invention, the torque of the rotary electric machine can be improved. Issues, configurations and effects other than those mentioned above will be clarified by the description of the following examples.

It is a schematic diagram which shows the whole structure of the rotary electric machine which concerns on embodiment of this invention. It is an axial sectional view which shows the stator and the rotor of this Example. It is an axial sectional view which shows one pole part of the rotor of Example 1. FIG. It is a figure explaining the effect of Example 1. FIG. It is a figure which shows the magnetic flux of the conventional rotor core. It is a figure which shows the magnetic flux of the rotor core of Example 1. It is an axial sectional view which shows one pole part of the rotor of Example 2. FIG.

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

(Overall configuration of rotary electric machine)
The rotary electric machine according to the present embodiment is a rotary electric machine suitable for use in running an automobile. Here, the so-called electric vehicles that use a rotating electric vehicle include a hybrid type electric vehicle (HEV) that has both an engine and a rotating electric vehicle, and a pure electric vehicle (EV) that runs only on the rotating electric vehicle without using an engine. However, the rotary electric machines described below can be used for both types.

FIG. 1 is a schematic view showing the overall configuration of the rotary electric machine 100 according to the embodiment of the present invention, and shows the inside of the rotary electric machine 100 with a part of the rotary electric machine 100 as a cross section. The rotary electric machine 100 is arranged inside the case 10, a housing 112, a stator 130 having a stator core 132 fixed to the housing 112, and a rotor 150 rotatably arranged in the stator 130. And have. The case 10 may be composed of an engine case or a transmission case.

The rotary electric machine 100 is a three-phase synchronous motor with a built-in permanent magnet.

The rotary electric machine 100 of this embodiment operates as an electric machine for rotating the rotor 150 by supplying a three-phase AC current to the stator coil 138 wound around the stator core 132. Further, when the rotary electric machine 100 is driven by an engine, it operates as a generator and outputs three-phase alternating current generated power. That is, the rotary electric machine 100 has both a function as an electric motor that generates rotational torque based on electric energy and a function as a generator that generates electric power based on mechanical energy, and is described above depending on the running state of the automobile. Functions can be used selectively.

The stator 130 is fixed to the housing 112. The stator 130 is fixed and held in the case 10 by fastening a flange 115 provided at one end in the axial direction of the housing 112 to the case 10 by bolts 12. The housing 112 is formed in a cylindrical shape by drawing a steel plate (high-strength steel plate or the like) having a thickness of about 2 to 5 mm. The flange 115 is integrally formed with the housing 112 by drawing. The stator 130 may be directly fixed to the case 10 without providing the housing 112. The rotor 150 fixed to the rotating shaft 118 is supported by bearings 14A and 14B of the case 10 and is rotatably held inside the stator core 132.

FIG. 2 is an axial sectional view showing the stator 130 and the rotor 150 of this embodiment.

The stator 130 is fixed to the inner peripheral side of the housing 112. Inside the stator 130, the rotor 150 is pivotally supported via a gap at a distance where the stator 130 and the rotor 150 do not come into contact with each other.

The stator 130 has a cylindrical stator core 132 and a stator coil 138 mounted on the stator core 132. The stator core 132 is formed by laminating a plurality of electromagnetic steel sheets formed by punching or etching, for example, having a thickness of about 0.05 to 1.0 mm. The laminated electromagnetic steel sheets are connected and fixed by welding, caulking, laminated adhesion, or the like, and deformation of the electrical steel sheets due to the tightening force when attached to the housing 112 is suppressed.

The stator core 132 is formed with a plurality of slots 420 extending in the axial direction at equal intervals in the circumferential direction. The number of slots 420 is, for example, 72 in this embodiment. The stator coil 138 is housed in the slot 420. The slot 420 is an open slot, and an opening is formed on the inner peripheral side of the stator core 132. The width of the opening in the circumferential direction may be substantially equal to or slightly smaller than the coil mounting portion of each slot 420 in which the stator coil 138 is mounted.

Insulating paper (so-called slot liner) is arranged in each slot 420. The insulating paper is, for example, an insulating sheet of heat-resistant polyamide paper, and has a thickness of about 0.1 to 0.5 mm. The insulating paper is arranged in the slot 420 and the coil end. By arranging the insulating paper in the slot 420, it is arranged between the stator coils 138 inserted into the slot 420 and between the stator coil 138 and the inner surface of the slot 420, and between the stator coils 138. The withstand voltage between the stator coil 138 and the inner surface of the slot 420 is improved.

Teeth 430 are formed between the slots 420, and each tooth 430 is integrally formed with an annular core back 440. The stator core 132 is an integrated core in which each tooth 430 and a core back 440 are integrally formed. The teeth 430 guides the rotating magnetic field generated by the stator coil 138 to the rotor 150 and generates a rotational torque in the rotor 150.

<Example 1>
FIG. 3 is an axial sectional view showing one pole of the rotor 150 according to the first embodiment of the present invention.

The rotor 150 includes a rotor core (rotor core) 152 that is fixed by laminating and welding a plurality of molded electromagnetic steel plates, and a permanent magnet 154 that is held in a magnet storage portion 153 formed in the rotor core 152. And have.

The rotor core 152 is provided with a plurality of magnet storage portions 153. Two magnet housing units 153 are arranged in a V shape at a predetermined angle with respect to the magnetic pole center axis (d axis) in one pole, and one permanent magnet 154 is housed in each and fixed with an adhesive or the like. There is. In the permanent magnet 154, the rotating side permanent magnet 154A located in the rotation direction of the rotor 150 and the counter-rotating side permanent magnet 154B located in the counter-rotating direction of the rotor 150 are combined in a V shape to form one pole. ing. Magnet stoppers are provided on both sides of the inner circumference of the magnet accommodating portion 153, and the position of the permanent magnet 154 in the magnet accommodating portion 153 is determined by the convex portion of the magnet stopper. The width of the magnet accommodating portion 153 in the circumferential direction is formed to be larger than the width of the permanent magnet 154 in the circumferential direction, and magnetic gaps are provided on both sides of the permanent magnet 154. The magnetic void may be embedded with an adhesive, or may be integrally solidified with the permanent magnet 154 with a resin. A thin outer bridge is provided on the outer peripheral side of the magnet storage portion 153. By forming the outer bridge thinly, the magnetic resistance of the portion is increased, and the leakage of the magnetic flux generated from the permanent magnet 154 to the adjacent magnetic pole is suppressed. The permanent magnet 154 forms the field pole of the rotor 150. As the permanent magnet 154, a neodymium-based or samarium-based sintered magnet, a ferrite magnet, a neodymium-based bonded magnet, or the like can be used, and it is desirable that the residual magnetic flux density Br = 0.2T or more.

The rotor core 152 between the two magnet housing portions 153 constituting one pole is provided with a through hole 155 that penetrates the rotor core 152 in the axial direction. The through hole 155 intersects the central axis 1542 of the normal line of the main magnetic flux surface 1541 of the rotating permanent magnet 154A in the rotor core 152 in the second region 158 facing the main magnetic flux surface 1541 of the rotating permanent magnet 154A. It is formed from the position where the magnet is stored to the position of the inner bridge 156 between the two magnet housing portions 153 (for example, on the inner peripheral side from the closest position of the permanent magnet 154). The through hole 155 has a lower magnetic permeability than the rotor core 152, and functions as a magnetic resistor that magnetically insulates the through hole 155. The through hole 155 is formed by a vertical portion 155A extending in the radial direction between the two magnet housing portions 153 and an oblique portion 155B extending to a position intersecting the central axis 1542 of the main magnetic flux surface 1541 of the rotating side permanent magnet 154A. It is formed. The width of the through hole 155 may be determined by the strength of the permanent magnet 154, the arrangement of the permanent magnets 154, the current flowing through the stator coil 138, and the specifications (torque, rotation speed, etc.) of the rotary electric machine 100. For example, the width of the through hole 155 is preferably about 0.5 mm in the vertical portion 155A and about 0.5 mm to 3.5 mm in the diagonal portion 155B. When the width of the through hole 155 is wide, the magnetic resistance of the rotor core 152 of the portion is increased, and the direction of the magnetic flux of the magnet can be easily controlled.

When the three-phase AC current is supplied to the stator coil 138, the rotating magnetic field generated in the stator 130 acts on the permanent magnet 154 to generate magnet torque. In addition to this magnet torque, the above-mentioned reluctance torque is generated in the rotor 150. Therefore, both the above-mentioned magnet torque and the above-mentioned reluctance torque act as the rotation torque in the rotor 150, and a large rotation torque is applied to the rotor 150. Obtainable.

The effects of the present invention will be described with reference to FIGS. 4, 5, and 6. In this embodiment, as shown in FIG. 4, the magnetic flux 1543 generated by the permanent magnet 154A on the rotating side is generated by forming the through hole 155 between the magnets arranged in a V shape in the first region 157 on the counter-rotating side. I try not to flow to. Further, the through hole 155 is formed at a position where the q-axis current magnetic flux 1545 is kept in the first region 157 and does not flow into the second region 158. Therefore, the q-axis current magnetic flux 1545 passes through a path that flows in from the vicinity of the outer bridge of the counter-rotating side magnet and flows out from the vicinity of the through hole. Then, magnetic saturation is generated in the first region 157 by the combination of the magnetic flux 1544 generated by the anti-rotating side permanent magnet 154B and the q-axis current magnetic flux 1545, and the magnetic flux 1543 generated by the rotating side permanent magnet 154A causes the second region 158. Magnetic saturation occurs.

Generally, in an embedded magnet type rotary electric machine, magnetic saturation occurs in the core on the outer diameter side of the permanent magnet 154A on the rotating side when the stator coil 138 is energized. As a result, as shown in FIG. 5, the magnetic flux 1546 generated by the rotating side permanent magnet 154A when the coil is energized flows to the counter-rotating side (first region 157 facing the main magnetic flux surface of the counter-rotating side permanent magnet 154B). In order to suppress such magnetic saturation, in this embodiment, as shown in FIG. 6, a through hole 155 (vertical portion 155A) is provided in the inner bridge 156 between the permanent magnets 154 arranged in a V shape to rotate. The magnetic flux 1543 of the side permanent magnet 154A blocks the leakage path of the first region 157 on the counter-rotating side, and suppresses the flow of the magnetic flux 1546 to the counter-rotating side.

Therefore, the path through which the magnetic flux 1543 generated by the rotating permanent magnet 154A leaks to the counter-rotating side can be completely blocked without hindering the magnetic flux generated by the rotating permanent magnet 154A and the counter-rotating permanent magnet 154B. Therefore, when the stator coil 138 is energized, the inclination of the magnet magnetic flux due to the bias of magnetic saturation generated on the rotating side and the counter-rotating side can be reduced. Therefore, the influence of magnetic saturation can be reduced and the utilization rate of the magnet magnetic flux can be improved. Then, the magnetic flux in the direction of suppressing rotation is reduced, and the torque can be improved.

Further, since the width of the narrowly formed inner bridge 156 is further narrowed by the through hole 155, the generation of short-circuit magnetic flux can be suppressed.

<Example 2>
FIG. 7 is an axial sectional view showing one pole of the stator core 132 of the second embodiment of the present invention.

In the second embodiment, unlike the first embodiment, the inner peripheral side end portion of the through hole 155 is located on the inner peripheral side from the closest position of the magnet accommodating portion 153. The inner peripheral side end of the through hole 155 may be located closer to the inner peripheral side than the inner peripheral side end position of the permanent magnet 154. More preferably, the inner peripheral side end portion of the through hole 155 may be located at the same position as the inner peripheral side end portion of the magnet accommodating portion 153 or on the inner peripheral side. Since the other configurations are the same as those in the first embodiment described above, their description will be omitted.

In the second embodiment, by extending the through hole 155 through the inner bridge 156 to the inner peripheral side from the magnet storage portion 153, the short-circuit magnetic flux passing through the inner bridge 156 can be suppressed, and the utilization rate of the magnetic flux generated by the magnet is further improved. Then, a larger torque can be obtained.

Further, in the second embodiment, the outer peripheral side of the rotor core 152 is magnetically divided by the through hole 155, and the width of the inner bridge 156 is narrowed by the through hole 155. Therefore, the magnetic flux 1543 of the rotating side permanent magnet 154A. Leakage to the first region 157 on the counter-rotating side of the magnet can be suppressed.

As described above, in the rotor 150 of the rotary electric machine 100 of the present embodiment, a through hole 155 penetrating the rotor core 152 in the axial direction is formed in the second region 158 facing the permanent magnet 154A on the rotating side. The through hole 155 is a position where the permanent magnets 154A and 154B are close to each other between the permanent magnets 154A and 154B arranged in a V shape from the position intersecting the central normal line of the main magnetic flux surface 1541 of the rotating side permanent magnet 154A. Of the magnetic flux generated by the permanent magnet 154A on the rotating side, the magnetic flux leaking to the first region 157 on the counter-rotating side through between the permanent magnets 154A and 154B and the through hole 155 can be suppressed. Therefore, it is possible to suppress a decrease in torque.

Further, the through hole 155 is located closer to the rotating side permanent magnet 154A than the counter-rotating side permanent magnet 154B, and is the central normal line (central axis) 1542 and the rotor core of the main magnetic flux surface 1541 of the rotating side permanent magnet 154A. From the intersecting position in 152, the inner bridge 156 is formed. In the first region 157, magnetic saturation occurs in the vicinity of the through hole 155 due to the combination of the magnetic flux generated by the permanent magnet 154B on the counter-rotating side and the q-axis current magnetic flux 1545. In the second region 158, the path of the magnetic flux generated by the rotating side permanent magnet 154A is corrected to the rotating side by the through hole 155, and the magnetic flux generated by the rotating side permanent magnet 154A is in the second region 158 where the cross-sectional area near the gap is small. Magnetic saturation occurs because it is densely packed on the outer periphery. Therefore, since the difference in magnetic permeability between the first region 157 and the second region 158 becomes small, the phenomenon that the magnetic flux generated by the magnet tilts to the counter-rotation side is suppressed. Therefore, it is possible to suppress a decrease in torque.

Further, the through hole 155 is located closer to the rotating side permanent magnet 154A than the counter-rotating side permanent magnet 154B, and is the central normal line (central axis) 1542 and the rotor core of the main magnetic flux surface 1541 of the rotating side permanent magnet 154A. Since it is formed from the position where it intersects in 152, passes through the inner bridge 156, and extends from the closest position to the inner peripheral side of the magnet storage portion 153 that constitutes one pole, the short-circuit magnetic flux passing through the inner bridge 156 is suppressed and the magnet magnetic flux is suppressed. It is possible to improve the utilization rate of magnets and suppress the decrease in torque.

It should be noted that the present invention is not limited to the above-described examples, but includes various modifications and equivalent configurations within the scope of the appended claims. For example, the above-described examples have been described in detail in order to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to those having all the described configurations. Further, a part of the configuration of one embodiment may be replaced with the configuration of another embodiment. Further, the configuration of another embodiment may be added to the configuration of one embodiment. In addition, other configurations may be added / deleted / replaced with respect to a part of the configurations of each embodiment.

10 cases, 12 bolts, 14A, 14B bearings, 100 rotors, 112 housings, 115 flanges, 118 rotors, 130 stators, 132 stator cores, 138 stator coils, 150 rotors, 152 rotor cores, 153 magnets Storage, 154 permanent magnet, 154A rotating side permanent magnet, 154B counter-rotating side permanent magnet, 155 through hole, 155A through hole vertical part, 155B through hole diagonal part, 156 inner bridge, 157 first area, 158 second Region, 420 slots, 430 teeth, 440 core back, 1541 main magnetic flux surface, 1542 central axis, 1543 magnetic flux generated by rotating permanent magnet 154A, 1544 counter-rotating permanent magnet 154B generated magnetic flux, 1545 q-axis current magnetic flux

Claims (4)

A rotor of a rotating electric machine including a rotor core provided with a magnet storage portion and a permanent magnet housed in the magnet storage portion.
In the permanent magnet, a rotating magnet and a counter-rotating magnet are combined in a V shape to form one pole.
The region between the rotating side magnet and the counter-rotating side magnet is divided into a first region facing the main magnetic flux surface of the counter-rotating side magnet and a second region facing the main magnetic flux surface of the rotating side magnet. And
A through hole that penetrates the rotor core in the axial direction is formed in the second region.
The through hole extends from a position intersecting the central normal line of the main magnetic flux surface of the rotating magnet to a position where the magnet is close to the rotating magnet and the counter-rotating magnet arranged in a V shape. A rotor of a rotating electric machine, characterized in that it is formed. The rotor of the rotary electric machine according to claim 1.
A narrow inner bridge is formed between the rotating magnet and the counter-rotating magnet on the inner peripheral side of the rotor core.
The through hole is located closer to the rotating side magnet than the counter-rotating side magnet, and from a position where it intersects the central normal line of the main magnetic flux surface of the rotating side magnet in the rotor core, the inner bridge. Rotor of a rotating electric machine formed up to. The rotor of the rotary electric machine according to claim 1.
The through hole passes through the inner bridge from a position closer to the rotating side magnet than the counter-rotating side magnet and intersecting the central normal line of the main magnetic flux surface of the rotating side magnet in the rotor core. , A rotor of a rotating electric machine formed from the closest position to the inner peripheral side of the magnet housing portion forming one pole. A rotary electric machine having the rotor according to any one of claims 1 to 3.

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