Rotating electric machine and vehicle-mounted motor system

Abstract

This invention can suppress the increase of magnetic reluctance and the decrease of torque, and reduce rotor inertia. The rotary electric machine includes: a stator on which coils are wound; and a rotor rotatably supported by a shaft on the inner circumference of the stator, the rotor having: an iron core formed of a soft magnetic metal; and a magnet mounted on the iron core, the iron core having: a magnet insertion hole on which a magnet is mounted; a first magnet fixing portion disposed in the magnet insertion hole on the q-axis side of the magnet; a magnet receiving portion disposed between the first magnet fixing portions on both sides of the magnet insertion hole; a first space portion communicating with the magnet insertion hole; a second space portion formed on the inner circumference of the magnet at a distance less than the thickness of the magnet, with a long radial length at the center of the magnetic pole; and a third space portion convex in shape toward the inner circumference of the magnet on the q-axis, formed between the second space portion and the magnet.

Description

Technical Field

[0001] This invention relates to a rotary motor, and more particularly to a permanent magnet brushless motor suitable for an electric variable valve timing device for automobiles. Background Technology

[0002] In recent years, with the shift from hydraulic to electric systems in the automotive industry and the expansion of the market for hybrid and electric vehicles, the electrification of variable valve timing (eVTC) systems—which adjust the opening and closing timing of the engine's intake and exhaust valves to optimal values ​​based on engine speed and load—is underway. This is because electrification of the variable valve timing system eliminates the operational difficulties caused by reduced oil flow or decreased oil pressure in hydraulic engines when cold, thereby improving output and fuel efficiency.

[0003] When controlling the opening and closing timing of the engine's intake and exhaust valves based on engine speed and load, the faster the eVTC responds, the easier it is to implement optimal control. Therefore, the motor used for eVTC requires high responsiveness.

[0004] Prior art for brushless motors requiring high responsiveness includes Patent Document 1. The invention described in Patent Document 1 relates to an electrical device having a rotor and a stator rotatably supported about a rotational axis, the rotor having at least one permanent magnet. The rotor body has alternating magnetic field focusing regions and magnetic field-free regions parallel to the rotational axis.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2007 / 57412 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] The brushless motor disclosed in Patent Document 1 leaves much room for improvement in terms of response speed. In this invention, a motor is provided that can reduce rotor inertia and suppress increases in magnetic reluctance and decreases in torque.

[0010] Technical means to solve the problem

[0011] A representative example of the invention disclosed in this application is as follows. Specifically, a rotary electric motor is characterized by having a stator with coils wound around it and a rotor rotatably supported on the inner circumference of the stator. The rotor has an iron core made of a soft magnetic metal and magnets mounted on the iron core. The iron core has: a magnet insertion hole for mounting the magnet; a first magnet fixing portion disposed in the magnet insertion hole on the q-axis side of the magnet; a magnet receiving portion disposed between the first magnet fixing portions on both sides of the magnet insertion hole; a first space portion communicating with the magnet insertion hole; a second space portion formed on the inner circumference of the magnet at a distance less than the thickness of the magnet and a radial length longer than the center of the magnetic pole; and a third space portion convex in shape toward the inner circumference of the magnet on the q-axis side, formed between the second space portion and the magnet.

[0012] The effects of the invention

[0013] According to the present invention, it is possible to suppress the increase in magnetic reluctance and the decrease in torque, and to reduce rotor inertia. The following description of embodiments will clarify the issues, configurations, and effects beyond those described above. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the rotating plane of the permanent magnet rotary motor of the first embodiment.

[0015] Figure 2 yes Figure 1 An enlarged view of one-quarter of the rotation of the rotary motor shown.

[0016] Figure 3 This is a cross-sectional view of the permanent magnet rotary motor in the second embodiment, showing one-quarter of the rotational plane.

[0017] Figure 4A It is a cross-sectional view of the rotation plane of a permanent magnet rotary motor having a first space section and a slot space section, covering 1 / 4 of the circumference.

[0018] Figure 4B It is a cross-sectional view of the rotation plane of a permanent magnet rotary motor having a first space section, a slot space section and a second space section, at 1 / 4 of its circumference.

[0019] Figure 4C This is a cross-sectional view of the rotating plane of the permanent magnet rotary motor of the second embodiment, which is provided with a first space portion, a slot space portion, a second space portion and a third space portion, at 1 / 4 circumference.

[0020] Figure 5 It is a graph showing the change in inertia relative to the rotor radius.

[0021] Figure 6 This is a graph showing the change in torque when the rotor radius is constant due to the presence or absence of the spatial section.

[0022] Figure 7 It is a graph showing the change of rotor radius relative to inertia.

[0023] Figure 8 It is a graph showing the change in torque with a constant inertia caused by the presence or absence of a spatial part.

[0024] Figure 9A This is a cross-sectional view of the permanent magnet rotary motor in the second embodiment, showing one-quarter of the rotational plane.

[0025] Figure 9B Is to make Figure 9A The diagram shows a cross-sectional view of the rotation plane of a permanent magnet rotary motor with a thickness H of 1.5 times that of the umbrella-shaped iron core, at 1 / 4 of the circumference.

[0026] Figure 10 It means Figure 9A and Figure 9B A diagram showing the changes in torque and inertia in the composition.

[0027] Figure 11A This diagram shows the configuration where the magnet and the third spatial part are located at close range.

[0028] Figure 11B This diagram shows the configuration where the magnet and the third spatial part are located at a great distance.

[0029] Figure 12 This is a graph showing the changes in torque and inertia caused by the distance between the magnet and the third spatial part.

[0030] Figure 13 This diagram illustrates the situation where the third spatial section becomes a shape that obstructs the flow of magnetic flux.

[0031] Figure 14 It means Figure 9A and Figure 13 A diagram showing the changes in torque and inertia in the composition.

[0032] Figure 15 This is a diagram showing the configuration where the magnet is far from the second space section.

[0033] Figure 16 It means Figure 9A and Figure 15 A diagram showing the changes in torque and inertia in the composition.

[0034] Figure 17 This is a cross-sectional view of the permanent magnet rotary motor in the third embodiment, showing one-quarter of the rotational plane.

[0035] Figure 18 This is a cross-sectional view of the permanent magnet rotary motor in the fourth embodiment, showing one-quarter of the rotational plane.

[0036] Figure 19 This is a graph showing the changes in average torque and two amplitudes caused by the radius of the magnetic pole arc in the fourth embodiment.

[0037] Figure 20 This is a diagram showing the change in minimum torque caused by the radius of the magnetic pole arc in the fourth embodiment.

[0038] Figure 21 This is a cross-sectional view of the inner 1 / 4 circumference of the rotating surface of the linear embedded permanent magnet rotary motor of the first embodiment. Detailed Implementation

[0039] Embodiments of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same reference numerals are used to denote the same constituent elements, and descriptions are omitted.

[0040] (First Embodiment) Use Figure 1 and Figure 2 This describes the configuration of a permanent magnet rotary motor 1 equipped with the rotor core 200 of the first embodiment of the present invention. Figure 1 This is a cross-sectional view of the permanent magnet rotary motor 1 of the first embodiment within the plane of rotation. Figure 2 yes Figure 1 An enlarged view of one-quarter of the rotation of the rotary motor shown.

[0041] like Figure 1 As shown, the permanent magnet rotary motor 1 is a permanent magnet rotary motor with an 8-pole, 12-slot concentrated winding, consisting of a generally annular stator (stator) 10 on the outer periphery and a generally cylindrical rotor (rotor) 20 on the inner periphery. An air gap 30 is provided between the stator 10 and the rotor 20. The stator 10 has a stator core 100, a core back member 110, and multiple windings 140, and is arranged opposite to the rotor 20 across the air gap 30.

[0042] The stator 10 is manufactured as follows: First, in a stator core laminate consisting of an integrally stamped core material of stacked electromagnetic steel plates or soft magnetic metal plates, a plurality of radial teeth 130 are formed on the inner circumference side. Next, wires are provided on each tooth 130 to form a winding 140, and then the winding 140 is heat-pressed or pressed into a housing (not shown) to form an integral unit. The stator 10 is thus manufactured.

[0043] Furthermore, the rotor 20 has a rotor core 200, which is a core of a soft magnetic metal plate such as an electromagnetic steel plate, and a shaft 300, which serves as a rotation axis. The outer periphery of the rotor core 200 is a perfect circle, and an 8-pole magnetic pole portion 220 is provided on the outer periphery of the rotor core 200 in the circumferential direction. Each pole of the magnetic pole portion 220 has a magnet insertion hole 201 that is elongated in the circumferential direction. Magnet fixing portions 211 are formed on the inner periphery of both ends of the magnet insertion hole 201, and magnet receiving portions are formed in the magnet insertion holes 201 between the magnet fixing portions 211, with a magnet 210 disposed in each magnet receiving portion.

[0044] In addition, such as Figure 2 As shown, the rotor 20 has a first space portion 213 on the outer periphery of the magnet fixing portion 211, which communicates with the magnet insertion hole 201, and a bridge portion 242 on the outer periphery of the first space portion 213. Additionally, an umbrella-shaped iron core 230 is formed on the outer periphery of the magnet receiving portion. Furthermore, a second space portion 261 is formed closer to the magnet 210, the distance between the second space portion 261 and the magnet 210 being less than or equal to the thickness of the magnet 210, and the radial length at the center of the magnetic pole portion 220 is the longest. Additionally, a third space portion 262 is formed closer to the inner periphery of the magnet 210, located between the second space portion 261 and the magnet 210, and convex in shape towards the inner periphery of the q-axis 250.

[0045] In this embodiment, the outer periphery of the magnetic pole portion 220 is cylindrical, and its radius is the same as that of the rotor 20. The magnet 210 is short in distance from the magnets of adjacent magnetic poles and long in the circumferential direction, making it easy to obtain a shape with high torque. Therefore, the response can be improved by using high torque.

[0046] On the other hand, the third space portion 262 is convex towards the inner periphery of the q-axis 250 to avoid obstructing the flow of magnetic flux between the two magnets 210 connected to the two adjacent magnetic pole portions 220, thereby suppressing the increase in magnetic reluctance of the rotor core 200 and suppressing the torque reduction caused by the increase in magnetic reluctance. Therefore, the sum of the minimum width of the core from the third space portion 262 to the outer periphery and the minimum width of the core between the third space portion 262 and the second space portion 261 is approximately 0.57 times the magnet width / 2. This ratio is preferably 0.5 times or more.

[0047] Furthermore, the presence of the first spatial section 213, the second spatial section 261, and the third spatial section 262 reduces inertia and improves responsiveness. The effects of each spatial section will be explained in the second embodiment.

[0048] (Second Embodiment) Next, using Figure 3 The permanent magnet rotary motor 1 of the second embodiment of the present invention will be described. Figure 3This is a cross-sectional view of the permanent magnet rotary motor 1 of the second embodiment, taken within 1 / 4 of its rotational plane, compared to the view described in the first embodiment. Figure 2 Corresponding. Additionally, some descriptions of parts common to the first embodiment are omitted.

[0049] exist Figure 3 In this context, if the angle of the estimated center of the magnetic pole section 220 is defined as the magnetic pole spacing angle, then the radial thickness of the umbrella-shaped iron core 230 is less than the radius of rotation × (1 - cos(magnetic pole spacing angle / 2)) × 0.55 + bridge width. Here, the intersection of a straight line parallel to the center line of the magnetic pole section from the point closest to the center of the magnetic pole section of the magnet fixing section and the inner circumference of the umbrella-shaped iron core 230 is defined as point R. Furthermore, the same point opposite to point R of the adjacent magnetic pole is defined as point R'. If the central angle formed by point R and point R' opposite to the adjacent magnet receiving section is defined as C, then C / (magnetic pole spacing angle / 2) ≒ 2 / 3.

[0050] Furthermore, if we define point Q as the point where the angle between the line connecting the first spatial section 213 and the rotation center is the smallest with respect to the q-axis, then let D be the angle between the line connecting point Q and the center of the first spatial section and the line connecting point R and the center. D / (pole spacing angle / 2) ≒ 2 / 9. Within a range of D / 2 closer to point R than point Q, the bridge width remains approximately constant. Additionally, a slot space 222 is provided on the outer periphery of the q-axis, opening towards the outer periphery of the rotor and widening towards the outer periphery. The slot space 222 reduces inertia without reducing torque.

[0051] In this second embodiment, the outer periphery of the magnetic pole portion 220 is cylindrical within a range of D / 2 closer to point R than point Q, and its radius is the same as the radius of the rotor 20. The estimated center angle of the magnet 210 is approximately (pole spacing angle × 2 / 3), resulting in a shape that makes the magnet 210 closer to the stator 10 compared to the first embodiment. In the second embodiment... Figure 3 In the shape, the radial thickness-bridge width of the umbrella-shaped iron core 230 is 0.45 times the radius of rotation × (1-cos(pole spacing angle / 2)), which is greater than that of the first embodiment. Figure 2 It is 0.68 times smaller than the shape.

[0052] Here, if the motor characteristics are evaluated using a three-dimensional magnetic field analytical simulation, the torque / magnet usage is 1.1 times that of the first embodiment. This is because the reduction in torque is more gradual than the reduction in magnet width, the umbrella-shaped core 230 is thinner, and the torque is greater when the magnet 210 is close to the stator 10. While the torque decreases due to the increased thickness of the umbrella-shaped core 230, if the radial thickness-bridge width of the umbrella-shaped core 230 is within 0.55 times the radius of rotation × (1 - cos(pole spacing angle / 2)), then relative to... Figure 3The shape is reduced by no more than 1.5%, therefore the radial thickness-bridge width of the preferred umbrella-shaped core 230 is within 0.55 times the radius of rotation × (1 - cos(pole spacing angle / 2)). Three-dimensional magnetic field analytical simulation is used in the following evaluation of motor characteristics.

[0053] In the second embodiment, besides increasing the size of the first space portion 213 and adding a slot space portion 222, the magnet width is reduced and the magnet 210 is closer to the stator 10, and the second space portion 261 increases outward circumferentially, thus the rotor core 200 is thinned, especially on the outer circumferential side. Therefore, compared to the first embodiment, the inertia ratio is reduced by 5.1% based on the condition that there are no space portions on the cylindrical rotor core 200 other than the magnet 210. The positional relationship and shape of the second space portion 261 and the third space portion 262 are the same as in the first embodiment. The effects of each space portion will be explained below.

[0054] Here, use Figure 4A , Figure 4B , Figure 4C and Figures 5-8 Explain the effect of the presence or absence of the third space section 262 and the slot space section 222 on the rotor inertia and torque. Figure 4A This is a cross-sectional view of the permanent magnet rotary motor 1, which has a first space section 213 and a slot space section 222, within 1 / 4 of its rotational plane. Figure 4B This is a cross-sectional view of the permanent magnet rotary motor 1, which is provided with a first space section 213, a slot space section 222, and a second space section 261, at one-quarter of its rotational circumference. Figure 4C This is a cross-sectional view of the permanent magnet rotary motor 1, which is provided with the first space portion 213, the slot space portion 222, the second space portion 261 and the third space portion 262 of the second embodiment, within 1 / 4 of the rotation plane. Figure 5 It is a graph showing the change in inertia relative to the rotor radius. Figure 6 This is a graph showing the change in torque with a fixed rotor radius caused by the presence or absence of the spatial section. Figure 7 It is a graph showing the change of rotor radius relative to moment of inertia. Figure 8 It is a graph showing the change in torque with a constant inertia caused by the presence or absence of a spatial part.

[0055] Figure 5This diagram illustrates the effect of the presence or absence of a space portion when the cylindrical rotor core 200 has no space portion other than the magnet 210 as the vertical axis, and the rotor radius / reference radius as the horizontal axis. As the rotor radius increases, the inertia tends to decrease relatively due to the presence of the first space portion 213 and the slot space portion 222, but the change in the relative ratio is small. Conversely, if a second space portion 261 is present, the inertia ratio decreases further as the radius increases. This is because the radial length of the second space portion 261 increases since the magnet 210 is located on the outer periphery. If a third space portion 262 is present, the inertia ratio decreases further; the larger the radius, the lower the inertia ratio. The inertia ratio decreases to 65% near the reference radius, which can increase the response speed. On the other hand, as... Figure 6 As shown, the torque ratio near the reference radius has little effect on torque due to the presence or absence of the space portion. Even with the second space portion 261 present, the torque reduction can be ignored because the magnetic flux flow between adjacent magnets is wide. Furthermore, even with the third space portion 262 present, the configuration of the second embodiment ensures the magnetic circuit width and suppresses the increase in magnetic reluctance, so the torque reduction is small and suppressed to 0.4%. In this way, the torque reduction can be suppressed to a small extent, and the inertia can be reduced by 10% with the third space portion 262 alone, thus increasing the response speed.

[0056] Figure 7 The horizontal axis represents the ratio of inertia to the reference radius, taken as the inertia of the cylindrical rotor core 200 when there are no spaces other than the magnet 210. The vertical axis represents the influence of the presence or absence of spaces, with the rotor radius / reference radius (i.e., rotor radius with spaces / rotor radius without spaces / slots) as the inertia ratio. In other words, it represents the ratio by which the rotor radius can be increased when the inertia is varied based on the inertia of a certain model, with or without spaces / slots, compared to the form without spaces / slots. As shown by the thick dashed line, even with an increased inertia ratio, the rotor radius increases slightly due to the presence of the first space 213 and the slot space 222. Conversely, as shown by the thin dashed line, when the second space 261 is present, the rotor radius increases if the inertia ratio increases. This is because, since the magnet 210 is located on the outer periphery, the radial length of the second space 261 increases, making it easier to reduce the inertia and, for the same inertia, to increase the rotor radius. As shown by the solid line, if a third spatial section 262 exists, the rotor radius increases further; the greater the inertia ratio, the more significantly the radius increases. Increasing the rotor radius by 17% when it approaches the reference radius can increase the torque.

[0057] Figure 8 Therefore Figure 4AThe diagram illustrates the increase in torque caused by the presence of a spatial portion, based on the existing structure, under the same moment of inertia. Due to the presence of the spatial portion, the rotor radius can be increased for the same moment of inertia, and this increase in rotor radius leads to an increase in torque. Therefore, the torque increase is as follows: Figure 8 As shown. From Figure 8 It can be seen that the torque can be increased by 9% under the same inertia through the second space section 261, and the torque can be further increased by 7% under the same inertia through the third space section 262. As a result, the response speed can be increased.

[0058] Thus, from the use Figures 4A to 8 As can be seen from the description, a high response speed can be achieved by using a third space portion 262, which is located on the inner periphery of the magnet 210, between the second space portion 261 and the magnet 210, and has a convex shape on the inner periphery of the q-axis 250.

[0059] Here, compared to the first embodiment, the second embodiment increases torque due to reduced inertia, thus improving response speed. Furthermore, it is known that the reduction in inertia caused by the third spatial portion 262 is greater based on the difference in inertia between the first and second embodiments, therefore the effect caused by the configuration of this embodiment is more significant.

[0060] Next, use Figure 9A , Figure 9B , Figure 10 This explains the effect of the thickness of the umbrella-shaped iron core 230. Figure 9A This is a cross-sectional view of the permanent magnet rotary motor 1 of the second embodiment, taken at 1 / 4 of its rotational plane. Figure 9B Is to make Figure 9A The diagram shows a cross-sectional view of the rotating plane of a permanent magnet rotary motor 1 with a thickness H of 1.5 times that of the umbrella-shaped iron core 230. Figure 10 It means Figure 9A and Figure 9B A graph showing the changes in torque and inertia in the composition, to Figure 9A Based on.

[0061] like Figure 10 As shown, the torque decreases by 5% due to a 1.5-fold increase in the thickness of the umbrella-shaped iron core 230. This is because as the thickness of the umbrella-shaped iron core 230 increases, the distance between the magnet 210 and the stator 10 increases, leading to increased magnetic flux leakage inside the rotor. Additionally, the inertia increases by 3.4%. This is due to the increased outer circumferential rotor core size caused by the increased thickness of the umbrella-shaped iron core 230, and the retraction of the second space portion 261 and the third space portion 262 towards the inner circumferential side. Therefore, to balance high torque and low inertia, it is preferable to position the magnet closer to the stator 10.

[0062] in addition, Figure 9BThe thickness-bridge width of the umbrella-shaped iron core 230 is 0.77 times the radius of rotation × (1 - cos(pole spacing angle / 2)). Therefore, if the thickness-bridge width of the umbrella-shaped iron core is 0.55 times the radius of rotation × (1 - cos(pole spacing angle / 2)), the torque is reduced to about 1.5% through proportional distribution.

[0063] In this invention, the rotary motor is intended for small-scale, low-output applications, so the temperature rise caused by magnetic eddy currents due to the thinness of the umbrella-shaped iron core 230 is not a problem. Therefore, a thin umbrella-shaped iron core 230 can be used.

[0064] Next, use Figure 11A , Figure 11B as well as Figure 12 Explain the effect of the distance between the third space section 262 and the magnet 210. Figure 11A This diagram shows the configuration where the magnet 210 and the third space portion 262 are at close range D3. Figure 11B This diagram shows the configuration where magnet 210 and the third space portion 262 are at a distance of D3×5.9. The distance between magnet 210 and the third space portion 262 is... Figure 11A 5.9 times. Figure 12 This is a diagram showing the changes in torque and inertia caused by the distance between magnet 210 and the third space portion 262. Figure 12 The distance / D3 between magnet 210 and the third space portion 262 is set as the horizontal axis. Figure 11A Using this as a reference, the torque ratio and inertia ratio are expressed. For example... Figure 12 As shown, when the distance / D3 between the magnet 210 and the third space portion 262 increases, and the third space portion 262 moves inward, the torque increases slightly by 0.3%, while the inertia increases by nearly 4%. Therefore, it can be seen that when the third space portion 262 is located as far as possible on the outer periphery, the inertia decreases, resulting in a high response.

[0065] Next, use Figure 9A , Figure 13 and Figure 14 Explain the influence of the orientation of the convex direction on the q-axis of the third spatial part 262. Figure 13 It indicates that it has the ability to make Figure 9A The diagram shows a configuration where the third space portion 262 has its shape reversed on the inner and outer sides, and the distance between the second space portion 261 and the third space portion 262 is reduced by this reversal. Additionally, Figure 13 This diagram illustrates the situation where the third spatial section becomes a shape that obstructs the flow of magnetic flux. Figure 14 It means Figure 9A and Figure 13 A graph showing the changes in torque and inertia in the composition, to Figure 9ABased on this, the change in torque and inertia is indicated by whether the convex direction of the q-axis of the third spatial section 262 is oriented towards the inner or outer circumference. For example... Figure 14 As shown, by reversing the convex direction of the q-axis in the third spatial portion 262, the torque is significantly reduced by 13%. This is because the magnetic path width between the second spatial portion 261 and the third spatial portion 262 decreases, increasing the magnetic reluctance. Furthermore, the inertia only increases by 0.8%. This is because the outer periphery of the third spatial portion 262 moves inward. Therefore, to achieve high torque and low inertia, the third spatial portion 262 should protrude inward toward the inner periphery of the q-axis 250 instead of protruding outward.

[0066] Here, the sum of the minimum width of the iron core from the third space portion 262 to the outer periphery and the minimum width of the iron core between the third space portion 262 and the second space portion 261 is 0.36 times the magnet width / 2. Figure 9A In the case of 0.53 times, the ratio is 0.53 times. Therefore, if the ratio is 0.5 times, the torque is reduced by about 2% through proportional distribution. Thus, the ratio is preferably 0.5 times or higher.

[0067] Next, use Figure 9A , Figure 15 , Figure 16 This explains the effect of the distance between the second space section 261 and the magnet 210. Figure 15 This diagram shows the configuration when the magnet 210 is far from the second space portion 261, relative to... Figure 9A The distance between the second space section 261 and the magnet 210 is 0.75 times the thickness of the magnet, and Figure 15 It is 1.75 times. Figure 16 It means Figure 9A and Figure 15 A graph showing the changes in torque and inertia in the structure.

[0068] like Figure 16 As shown, if the distance between the second space portion 261 and the magnet 210 is large, the torque change can be ignored, but the inertia increases by 10%. This is because the outer periphery of the second space portion 261 contracts inward. Therefore, to achieve low inertia, the distance between the second space portion 261 and the magnet 210 should be as small as possible. In the configuration of the present invention, due to the presence of the third space portion 262, the inertia can be reduced and the circumferential width of the outer periphery of the second space portion 261 can be decreased, thus reducing the distance between the second space portion 261 and the magnet 210 without reducing the torque. Therefore, the distance between the second space portion 261 and the magnet 210 can be less than the width of the magnet 210, thereby reducing the inertia. Furthermore, the distance between the second space portion 261 and the magnet 210 is preferably less than the width of the magnet 210.

[0069] Thus, according to use Figures 4A to 8As can be seen from the description, a high response speed can be achieved by having a third space portion 262 that is convex toward the inner periphery of the q-axis 250, located at a position closer to the inner periphery than the magnet 210 and between the second space portion 261 and the magnet 210. Furthermore, from... Figure 9A , Figure 13 , Figure 14 It can be seen that, compared to a convex shape on the outer periphery of the q-axis, a convex shape on the inner periphery is required, necessitating a magnetic circuit width of at least 0.5 times the magnet width / 2. Furthermore, from... Figure 9A , Figure 9B , Figure 10 It can be seen that the thinner the umbrella-shaped iron core 230, the greater the effect. Furthermore, from... Figure 11A , Figure 11B , Figure 12 It can be seen that the effect is greater when the third space section 262 is closer to the magnet 210. Furthermore, from... Figure 9A , Figure 15 , Figure 16 It can be seen that the closer the second space section 261 is to the magnet 210, the greater the effect.

[0070] Therefore, it can be seen that the high response speed can be effectively achieved through the configuration of the present invention.

[0071] Furthermore, if the permanent magnet rotary motor 1 of this embodiment is used in eVTC, optimal control of the opening and closing timing of the engine's intake and exhaust valves can be easily achieved based on engine speed and load. This improves engine output and fuel efficiency. Moreover, the use of the permanent magnet rotary motor 1 of this embodiment is not limited to the automotive field; it can also be applied to rotary motors used in industries requiring responsiveness.

[0072] (Third embodiment) Next, using Figure 17 The permanent magnet rotary motor 1 of the third embodiment of the present invention will be described. Figure 17 This is a cross-sectional view of the permanent magnet rotary motor 1 of the third embodiment, taken within 1 / 4 of the rotation plane, compared to the view described in the first embodiment. Figure 2 Corresponding. Additionally, some descriptions of parts common to the first embodiment are omitted.

[0073] The permanent magnet rotary motor 1 described in the first embodiment is an embedded permanent magnet type rotary motor, but the permanent magnet rotary motor 1 in this embodiment is a surface permanent magnet type rotary motor.

[0074] The rotor core 200 has the following on its outer periphery: a magnet 210; magnet fixing portions 211 on both sides of the magnet 210 in the circumferential direction; a non-magnetic metal tube 235 that covers the outer periphery of the magnet 210 and is continuous in the circumferential direction; a first space portion 213 located on the outer periphery of the magnet fixing portion 211 and divided by the magnet 210 and the metal tube 235; a second space portion 261 located inside the magnet 210, at a distance from the magnet 210 less than the magnet thickness, and with the longest radial length at the center of the magnetic pole; and a third space portion 262 located on the inner periphery of the rotor core 200, between the second space portion 261 and the magnet 210, and convex in shape toward the inner periphery of the q-axis 250.

[0075] In this embodiment, the magnet 210 has a shape referred to as a D-shape in the cross-section within the plane of rotation. In this embodiment, it has a large circumferential length with a straight inner circumference and an arc outer circumference. This shape results in a higher torque than the second embodiment because it uses approximately 60% more magnets. However, the torque / magnet usage ratio is 30% lower than in the second embodiment. Furthermore, due to the thickness of the magnet 210, the second space portion 261 and the third space portion 262 move inwards. Therefore, based on the moment of inertia ratio when there are no other spaces in the cylindrical rotor core 200 besides the magnet 210, it is 3.4% larger than in the second embodiment.

[0076] The positional relationship and shape of the second space portion 261 and the third space portion 262 are the same as in the first embodiment. Therefore, even in a surface permanent magnet type rotary motor, the third space portion 262 allows for connection with... Figures 4A to 16 The same explanation applies to reducing inertia.

[0077] (Fourth embodiment) Next, using Figure 18 The embedded permanent magnet rotary motor 1 of the fourth embodiment of the present invention is described. Figure 18 This is a cross-sectional view of the permanent magnet rotary motor 1 of the fourth embodiment, taken within 1 / 4 of its rotational plane, compared to the view described in the first embodiment. Figure 2 Corresponding. Additionally, some descriptions of parts common to the first embodiment are omitted.

[0078] like Figure 2 As shown, the permanent magnet rotary motor 1 of the first embodiment is a linear embedded permanent magnet rotary motor 1 with a magnet 210 in the magnetic pole section 220, while the permanent magnet rotary motor 1 of the fourth embodiment is as follows... Figure 18 As shown, the embedded permanent magnet rotary motor 1 has two magnets 210A and 210B in the magnetic pole section 220, and the angle formed by the outer peripheral sides of the two magnets 210A and 210B is greater than 180 degrees.

[0079] exist Figure 18In the rotor core 200, there are: a magnet insertion hole 201 extending circumferentially; a magnet receiving portion disposed between two magnet fixing portions 211 at both ends of the magnet insertion hole 201; and an umbrella-shaped core 230 on the outer periphery of the magnet receiving portion. The radius of the magnetic pole arc 219 of the umbrella-shaped core 230 is smaller than the rotation radius 218 of the rotor 20. Two magnets 210A and 210B are disposed in the magnet insertion hole 201, forming an inverted V-shaped arrangement in which the angle between the outer periphery sides of the two magnets 210A and 210B is greater than 180 degrees. In addition, the rotor core 200 has a magnet fixing portion B215 on the inner periphery of the center of the umbrella-shaped core 230 and a first space portion B214 on the inner periphery of the magnet fixing portion B215.

[0080] In this embodiment, the smaller radius of curvature of the magnetic pole portion 220 compared to the rotation radius of the rotor 20 may be a major cause of torque reduction. However, torque is increased by extending the magnet width to the magnetic pole end portion. Furthermore, by making the radius of curvature of the magnetic pole portion 220 smaller than the rotation radius of the rotor 20, torque pulsation can be reduced, thus increasing the minimum value of pulsating torque.

[0081] During startup, if no torque is generated to make the rotor 20 rotate against the load, the motor will not start rotating. Therefore, the minimum value of the pulsating torque needs to be greater than the required starting torque. The inventors discovered that by making the radius of the arc of the magnetic pole portion 220 smaller than the radius of rotation of the rotor 20, the minimum value of the pulsating torque can be increased. That is, with this configuration, the response from startup can be made faster.

[0082] Furthermore, the positional relationship and shape of the second space portion 261 and the third space portion 262 are the same as in the first embodiment. Therefore, in the embedded permanent magnet type rotary motor of the fourth embodiment, due to the presence of the third space portion 262, the... Figures 4A to 16 The explanation also states that it can reduce inertia.

[0083] Here, use Figures 19-21 This illustrates how the configuration of this embodiment can increase the minimum value of the pulsating torque. Figure 19 This is a graph showing the changes in average torque and two amplitudes caused by the magnetic pole arc radius in the fourth embodiment. Average torque / (average torque under magnetic pole arc radius) and two amplitudes / average torque are set on the vertical axis, and magnetic pole arc radius / radius of rotation is set on the horizontal axis. Figure 19 In this context, the ratio of the two amplitudes (two amplitudes / average torque) represents the magnitude of the torque ripple. Figure 20This is a graph showing the change in minimum torque caused by the radius of the magnetic pole arc in the fourth embodiment. The vertical axis is set as minimum torque / maximum minimum torque, and the horizontal axis is set as magnetic pole arc radius / radius of rotation. Here, when the magnetic pole arc radius and the radius of rotation are equal, the angle formed by the outer peripheral surfaces of the two magnets 210A and 210B is 180 degrees, therefore... Figure 21 The linear embedded permanent magnet type rotary motor shown is the same.

[0084] like Figure 19 As shown, when the radius of the magnetic pole arc decreases, the average torque decreases. At the same time, the torque pulsation decreases, and the ratio of the magnetic pole arc radius to the radius of rotation is 0.57, resulting in the minimum amplitude ratio.

[0085] In contrast, such as Figure 20 As shown, the minimum torque increases as the radius of the magnetic pole arc decreases, reaching its maximum when the ratio of magnetic pole arc radius to rotation radius = 0.75. If the magnetic pole arc radius decreases further, the minimum torque decreases. The amplitude ratio at magnetic pole arc radius / rotation radius = 0.5 is approximately 0.2 (refer to...). Figure 19 ).

[0086] The fourth embodiment is the same as the second embodiment except for the rotor structure. However, comparing the fourth embodiment, which uses more magnets, with the second embodiment, the average torque in the fourth embodiment is greater than that in the second embodiment when the magnetic pole radius / rotation radius is 0.6 or more. Furthermore, when the minimum torque / maximum minimum torque is 0.91 or more, the minimum pulsating torque is greater than that in the second embodiment. Therefore, the fourth embodiment outperforms the second embodiment in terms of magnetic pole radius / rotation radius between 0.6 and 0.95. However, since the amount of magnets used increases by approximately 29%, the second space portion 261 and the third space portion 262 move inwards. Therefore, based on the inertia ratio when there are no space portions in the cylindrical rotor core 200 other than magnets 210A and 210B, the inertia increases by 8.2%. Therefore, it is preferable to use... Figure 20 The range of magnetic pole radius / rotation radius is 0.65 to 0.9, which is within 3% of the maximum center distance and can obtain large torque.

[0087] As explained above, the configurations of the various embodiments of the present invention are superior to conventional configurations in suppressing torque reduction, reducing inertia, and achieving high responsiveness, and thus demonstrate effectiveness. Specifically, the construction of the permanent magnet rotary motor 1 described in the various embodiments is effective for high responsiveness.

[0088] Furthermore, if the permanent magnet rotary motor 1 of this embodiment is used in eVTC, optimal control of the opening and closing timing of the engine's intake and exhaust valves can be easily achieved based on engine speed and load. This improves output and fuel efficiency. Moreover, the use of the permanent magnet rotary motor 1 of this embodiment is not limited to the automotive field, but can also be applied to rotary motors used in industries requiring responsiveness.

[0089] Furthermore, the present invention is not limited to the embodiments described above, but includes various modifications and equivalent configurations within the spirit of the appended claims. For example, the above embodiments are detailed descriptions provided for ease of understanding of the invention, and the invention is not limited to possessing all the described configurations. Additionally, a portion of the configuration of one embodiment may be replaced with the configuration of another embodiment. Furthermore, the configuration of another embodiment may be incorporated into the configuration of one embodiment.

[0090] In addition, other components may be added, deleted, or replaced for a portion of the configuration of each embodiment.

[0091] Symbol Explanation

[0092] 1 Permanent magnet rotary motor

[0093] 10 stators

[0094] 20 rotors

[0095] 30 air gap

[0096] 100 stator core

[0097] 110 iron core back component

[0098] 130 teeth

[0099] 140 winding

[0100] 200 rotor core

[0101] 201 Magnet Insertion Hole

[0102] 210 magnet

[0103] 211 Magnet Fixing Part

[0104] 213 First Space Division

[0105] 214 First Space Division B

[0106] 215 Magnet Fixing Part B

[0107] 218 rotation radius

[0108] 219 magnetic pole arc

[0109] 220 magnetic pole section

[0110] 222 slot space section

[0111] 230 Umbrella-shaped Iron Core

[0112] 235 metal pipe

[0113] 242 Bridge Section

[0114] 261 Second Space Division

[0115] 262 Third Space Division

[0116] 250q axis

[0117] 300 axes.

Claims

1. A rotary electric motor, characterized in that, have: Stator, which contains coils; and The rotor, which is rotatably supported by a shaft on the inner circumferential side of the stator, The rotor has: The iron core, which is formed of a soft magnetic metal; and A magnet, which is mounted on the iron core, The iron core has: A magnet insertion hole, into which the magnet is installed; The first magnet fixing part is disposed in the magnet insertion hole on the q-axis side of the magnet; A magnet receiving portion is disposed between the first magnet fixing portions on both sides of the magnet insertion hole; The first spatial portion is connected to the magnet insertion hole; The second space portion is located at a distance from the magnet that is less than or equal to the thickness of the magnet. The second space portion has the longest radial length at the center of the magnetic pole and is formed on the inner circumference of the magnet. The third space portion is convex in shape toward the inner circumference of the q-axis of the magnet and is formed between the second space portion and the magnet; A bridge portion is disposed on the outer periphery of the first spatial portion; An umbrella-shaped iron core portion is disposed on the outer periphery of the magnet receiving portion; as well as The second magnet fixing part is disposed on the inner circumferential side of the center of the umbrella-shaped iron core part. The radius of the arc of the umbrella-shaped iron core is smaller than the radius of rotation of the rotor. The first space portion is formed on the inner peripheral side of the second magnet fixing portion. Two magnets are installed in the magnet insertion hole in an inverted V-shape with an angle greater than 180 degrees on the outer peripheral side.

2. The rotary motor according to claim 1, characterized in that, The magnet housing portion is elongated in the circumferential direction. The first space portion is formed on the outer periphery of the first magnet fixing portion on both sides of the magnet insertion hole.

3. The rotary motor according to claim 2, characterized in that, Point R is defined as the intersection of a straight line parallel to the center line of the magnetic pole portion, drawn from the point closest to the center of the first magnet fixing part, and the inner circumference of the umbrella-shaped iron core portion. Let the point opposite to the point R of the adjacent magnetic pole be the point R'. The point where the angle between the line connecting the first spatial part and the center of rotation and the q-axis is the smallest is taken as point Q. The radial thickness of the umbrella-shaped iron core is less than the rotor's rotation radius × (1 - cos(pole spacing angle / 2)) × 0.55 + the width of the bridge section. Let C be the central angle formed by the points R and R' of adjacent magnet receiving portions, and let C / (pole spacing angle / 2) be 2 / 3. Let D be the angle formed by the straight line connecting point Q and the center of the first spatial section and the straight line connecting point R and the center. D / (pole spacing angle / 2) is 2 / 9. The width of the bridge portion is constant within a range of D / 2 that is closer to point R than point Q. The magnet has a slot space on the outer periphery of its q-axis, which opens to the outer periphery of the iron core, and the circumferential width of the outer periphery is wide.

4. The rotary motor according to claim 1, characterized in that, The iron core has a metal tube that covers the outer periphery of the magnet and is continuous in the circumferential direction. The magnet is installed in the magnet insertion hole in such a way that it contacts the metal tube on the outer periphery of the iron core. The first space portion is formed on the outer periphery of the first magnet fixing portion between the magnet and the metal tube.

5. The rotary electric motor according to any one of claims 1 to 4, characterized in that, The rotary motor is a motor used in the electric variable valve timing device of automobiles.

6. A vehicle-mounted electric motor system, characterized in that, have: The rotary motor according to any one of claims 1 to 4, The rotary motor is used to control the electric variable valve timing device.

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