Rotary motor

Abstract

In the rotor of the rotary motor of the present invention, the rotor is configured to open in a V-shape towards the outer periphery, and the magnet slot into which the permanent magnet is inserted has a two-layer structure in the radial direction. Each magnet slot is composed of a pair of slots formed between a central bridge located in the center and each of the two outer diameter bridges located between the magnet slot and the outer surface of the rotor. When the magnetic flux generated by each permanent magnet is defined as the effective magnetic flux after removing the magnetic flux that saturates each bridge, the effective magnetic flux generated by the permanent magnet on the outer diameter side is less than half of the effective magnetic flux generated by the permanent magnet on the inner diameter side.

Description

Technical Field

[0001] This application relates to rotating electrical machines. Background Technology

[0002] As a type of high-torque rotary motor, a well-known example is the permanent magnet embedded synchronous rotary motor, in which permanent magnets are embedded in the rotor core. In a permanent magnet embedded synchronous rotary motor, torque is increased through the magnetic flux generated by the armature windings of the stator, the magnetic torque generated by the attraction and repulsion of the magnetic flux generated by the permanent magnets in the rotor, and the reluctance torque generated by the magnetic flux polarity of the rotor. When embedding permanent magnets in the rotor, there are techniques that increase torque by arranging magnets in multiple layers, thereby increasing not only the magnetic torque but also the reluctance torque.

[0003] Patent Document 1 discloses a technique for increasing reluctance torque by arranging two layers of permanent magnets inside a rotor core. Patent Document 2 discloses a technique in which the width of the magnet located inside the magnetic pole is narrower and the thickness is greater than that of the magnet located outside the magnetic pole in a two-layer permanent magnet structure inside the rotor core.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-223836

[0007] Patent Document 2: Japanese Patent Application Publication No. 2007-274798 Summary of the Invention

[0008] The technical problem that the invention aims to solve

[0009] In the rotating electric motors disclosed in Patent Documents 1 and 2, since the leakage flux in the bridging components between the magnetic poles is not considered, the gap flux density generated by the rotor magnetomotive force of the permanent magnets configured in two layers contains a large number of high-order harmonic components. As torque pulsation increases, there is a problem of increased vibration and noise.

[0010] This application aims to solve the above-mentioned problems by reducing vibration and noise by suppressing torque pulsation.

[0011] Technical means for solving technical problems

[0012] The rotary motor disclosed in this application includes: a stator having multiple teeth on its cylindrical inner surface and coils wound in coil slots between adjacent teeth; and a rotor, which is cylindrical, with its outer surface spaced apart from the inner surface of the stator, and the rotor being rotatably arranged about a rotational central axis. In the rotor, magnet slots arranged in a V-shape opening from the rotational central axis to the outer periphery are formed in a double-layer structure in the radial direction. Each layer of magnet slots consists of a pair of slots formed between a central bridge located in the center and two outer diameter bridges located between the magnet slots and the outer surface of the rotor. Permanent magnets are inserted into each slot. In the permanent magnets inserted into the magnet slots on the outer diameter side (i.e., the first layer of permanent magnets), the permanent magnets (i.e., the first layer of permanent magnets) are treated with... The magnetic flux generated by the magnetic width obtained after saturating the central bridge (i.e., the first-layer central bridge) corresponding to the first-layer magnet slot and the magnetic width obtained after saturating the outer diameter bridge (i.e., the first-layer outer diameter bridge) corresponding to the first-layer magnet slot, which is the first-layer effective magnetic flux, is defined as the first-layer effective magnetic flux. In the permanent magnet (i.e., the second-layer permanent magnet) inserted into the magnet slot on the inner diameter side (i.e., the second-layer magnet), the magnetic flux generated by removing the magnetic width obtained after saturating the central bridge (i.e., the second-layer central bridge) corresponding to the second-layer magnet slot and the magnetic width obtained after saturating the outer diameter bridge (i.e., the second-layer outer diameter bridge) corresponding to the second-layer magnet slot, which is the second-layer effective magnetic flux, is defined as the second-layer effective magnetic flux. The first-layer effective magnetic flux is less than half of the second-layer effective magnetic flux.

[0013] Invention Effects

[0014] According to the rotating electric motor disclosed in this application, by reducing the higher harmonic components of the rotor magnetomotive force and suppressing torque pulsation, the vibration and noise generated by the rotating electric motor can be reduced. Attached Figure Description

[0015] Figure 1 This is an external view showing a simplified structure of the rotary electric machine according to Embodiment 1.

[0016] Figure 2 This is a cross-sectional view perpendicular to the rotation center axis, showing a simplified structure of the rotary electric machine according to Embodiment 1.

[0017] Figure 3 This is an enlarged cross-sectional view showing the structure of one pole of the rotor of the rotary electric machine according to Embodiment 1.

[0018] Figure 4 This is an enlarged schematic diagram showing the state of magnetic flux generated by the permanent magnet of the rotor of the rotary electric machine according to Embodiment 1.

[0019] Figure 5This is an enlarged schematic diagram showing the detailed dimensions of the magnet slots and permanent magnets of the rotor of the rotary electric motor according to Embodiment 1.

[0020] Figure 6 This is a cross-sectional view used to illustrate the magnetic pole arc angle of the rotor of the rotary electric machine in Embodiment 1.

[0021] Figure 7 It is used to illustrate the magnetic pole arc angle of the rotor of the rotating electric machine in Embodiment 1. Figure 6 Enlarged sectional view.

[0022] Figure 8 This is a schematic diagram illustrating the rotor magnetomotive force generated by the effective magnetic flux of the rotor of the rotating electric machine in Embodiment 1.

[0023] Figure 9 This is a diagram illustrating the effective magnetic flux when the high-order harmonic content (THD) of the rotor magnetomotive force of the rotating electric machine in Embodiment 1 is minimized.

[0024] Figure 10 Figure 1 shows the relationship between the magnetic pole arc angle and the high harmonic content (THD) of the rotor magnetomotive force of the rotating electric machine in Embodiment 1.

[0025] Figure 11 Figure 2 shows the relationship between the magnetic pole arc angle and the high harmonic content (THD) of the rotor magnetomotive force of the rotating electric machine in Embodiment 1.

[0026] Figure 12 This is a diagram illustrating the dimensions of the inter-tooth arc angle of the stator of the rotary electric motor in Embodiment 1.

[0027] Figure 13 This is an enlarged cross-sectional view showing the structure of one pole of the rotor of the rotary electric machine according to Embodiment 2.

[0028] Figure 14 This is an enlarged schematic diagram showing the detailed dimensions of the permanent magnet and bridging member of the rotor of the rotary electric motor in Embodiment 2.

[0029] Figure 15 This is an enlarged cross-sectional view showing another structure of one pole of the rotor of the rotary electric machine according to Embodiment 2.

[0030] Figure 16 This is an enlarged cross-sectional view showing the structure of one pole of the rotor of the rotary electric machine according to Embodiment 3. Detailed Implementation

[0031] Implementation method 1.

[0032] Figure 1 This is an external view showing a simplified structure of the rotary electric machine according to Embodiment 1. Figure 2This is a cross-sectional view perpendicular to the rotation center axis, showing a simplified structure of the rotary electric machine according to Embodiment 1. (Example) Figure 1 As shown, the rotary electric motor consists of a stator 1 and a rotor 2. The cylindrical stator 1 is composed of a stator core 10 and coils 11 stacked along the rotation axis. The rotor 2 is formed with its outer surface spaced apart from the inner surface of the stator 1, and is rotatably arranged about the central axis of rotation. The rotor 2 consists of a rotor core 20 stacked along the rotation axis and permanent magnets 22 inserted into magnet slots 21. Figure 2 As shown, the stator core 10 includes an annular core back 12 and teeth 13 protruding inwards. A coil 11 is wound in a coil slot 14 between the teeth. Each pole of the rotor 2 has two layers of magnet slots 21 along the radial direction, the magnet slots 21 being configured in a V-shape opening from the rotational central axis to the outer periphery, and a permanent magnet 22 is inserted into the two layers of magnet slots 21.

[0033] Figure 3 This is an enlarged cross-sectional view of a section perpendicular to the rotation center axis, showing the structure of one pole of the rotor of the rotary electric machine according to Embodiment 1. Additionally, Figure 3 The subsequent diagrams illustrating the structure are also sectional views perpendicular to the axis of rotation. The rotor includes: a rotor core having two layers of V-shaped magnet slots; and permanent magnets inserted into the two layers of magnet slots. The two layers of magnet slots consist of a first layer of magnet slots 31 on the outer diameter side of the rotor and a second layer of magnet slots 41 on the inner diameter side of the rotor. Each layer of magnet slots consists of a pair of slots formed between a central bridge located in the center and each of the two outer diameter bridges located between the magnet slot and the outer surface of the rotor 2, with permanent magnets inserted into each slot. That is, the first layer of magnet slots 31 consists of a pair of slots formed between a central bridge 33 located in the center and two first outer diameter bridges 34 located between the first layer of magnet slots 31 and the outer surface of the rotor. The second layer of magnet slots 41 consists of a pair of slots formed between a central bridge 43 located in the center and two second outer diameter bridges 44 located between the second layer of magnet slots 41 and the outer surface of the rotor. The first layer of permanent magnets 32 is inserted into the first layer of magnet slot 31, and the second layer of permanent magnets 42 is inserted into the second layer of magnet slot 41.

[0034] Figure 4 This is an enlarged schematic diagram showing the magnetic flux generated by a permanent magnet, dividing the magnetic flux into effective flux and leakage flux. As mentioned above, each magnet slot in the first and second layers consists of a pair of slots arranged in a V-shape, but in... Figure 4 In the middle, the first layer of magnet slots and the second layer of magnet slots are in Figure 4The diagram only shows a portion of one side of a pair of slots. The first layer of permanent magnets 32 on the rotor outer diameter side is divided into three regions by the magnetic flux it generates: the first layer outer diameter bridge-side magnet 321, the first layer effective magnet 322, and the first layer central bridge-side magnet 323. The magnetic flux generated by the first layer outer diameter bridge-side magnet 321 surrounds the first layer outer diameter bridge 34, saturating the first layer outer diameter bridge 34. Therefore, the magnetic flux generated by the first layer outer diameter bridge-side magnet 321 becomes leakage flux that does not contribute to the gap flux between the stator and rotor. The magnetic flux generated by the first layer central bridge-side magnet 323 surrounds the first layer central bridge 33, saturating the first layer central bridge 33. Therefore, the magnetic flux generated by the first layer central bridge-side magnet 323 becomes leakage flux that does not contribute to the gap flux between the stator and rotor. The magnetic flux generated by the first layer of effective magnets 322 is directed toward the gap between stator 1 and rotor 2, thus becoming an effective magnetic flux that contributes to the gap magnetic flux between stator 1 and rotor 2.

[0035] The second layer of permanent magnets 42 on the inner diameter side of the rotor is divided into three regions by the magnetic flux it generates: the second layer outer diameter bridge-side magnet 421, the second layer effective magnet 422, and the second layer central bridge-side magnet 423. The magnetic flux generated by the second layer outer diameter bridge-side magnet 421 surrounds the second layer outer diameter bridge 44, saturating the second layer outer diameter bridge 44. Therefore, the magnetic flux generated by the second layer outer diameter bridge-side magnet 421 becomes leakage flux that does not contribute to the gap flux between the stator and rotor. The magnetic flux generated by the second layer central bridge-side magnet 423 surrounds the second layer central bridge 43 and saturates the second layer central bridge 43. Therefore, the magnetic flux generated by the second layer central bridge-side magnet 423 becomes leakage flux that does not contribute to the gap flux between the stator 1 and rotor 2. The magnetic flux generated by the second layer of effective magnets 422 is divided into magnetic flux toward the first layer of effective magnets 322 and magnetic flux passing through the gap between the first layer of magnet slots 31 and the second layer of magnet slots 41 and toward the gap between the stator 1 and the rotor 2. At this time, the magnetic flux generated by the second layer of effective magnets 422 is divided into magnetic flux toward the first layer of effective magnets 322 and magnetic flux passing through the gap between the first layer of magnet slots 31 and the second layer of magnet slots 41 and toward the gap between the stator 1 and the rotor 2, according to the ratio of the width of the first layer of effective magnets 322 to the width of the second layer of effective magnets 422.

[0036] Figure 5This is an enlarged schematic diagram showing the detailed dimensions of the magnet slots and permanent magnets. The width of the first-layer outer diameter bridge 34 on the rotor outer diameter side is set as 'a', the width of the first-layer central bridge 33 is set as 'b', the width of the second-layer outer diameter bridge 44 on the rotor inner diameter side is set as 'c', and the width of the second-layer central bridge 43 is set as 'd'. Regarding the width of each bridge, when the widths of the bridges are not uniform, the narrowest part of the bridge is taken as the width of each bridge. The width of the first-layer permanent magnet 32 ​​on the rotor outer diameter side is set as 'W1', the width of the second-layer permanent magnet 42 on the rotor inner diameter side is set as 'W2', and the width of the first-layer outer diameter bridge-side magnet 321 used to saturate the first-layer outer diameter bridge is set as 'W'. 1a The width of the first-layer central bridge side magnet 323 used to saturate the first-layer central bridge magnet is set to W. 1b The width of the second-layer outer diameter bridge-side magnet 421, used to saturate the second-layer outer diameter bridge magnet, is set to W. 2c The width of the second-layer central bridge side magnet used to saturate the second-layer central bridge magnet is set to W. 2d Here, as Figure 5 As shown, the width of the magnet is the dimension from the outer diameter bridge-side end of each permanent magnet towards the central bridge-side end. Assume the saturation magnetic flux density of the rotor core is B. s The magnetic flux density of the first layer of magnets is set to B. m1 The magnetic flux density of the second layer magnet is set to B. m2 At that time, the width W of the first layer outer diameter bridge side magnet 321 1a The width W of the first layer central bridge side magnet 323 1b The width W of the second-layer outer diameter bridge-side magnet 421 2c The width W of the second-layer central bridge side magnet 423 2d The width of the magnet described above, whether in the first or second layer, represents the width of the permanent magnet inserted into one of a pair of slots.

[0037] [Mathematical Expression 1]

[0038]

[0039] [Mathematical Expression 2]

[0040]

[0041] [Mathematical Expression 3]

[0042]

[0043] [Mathematical Expression 4]

[0044]

[0045] Surrounding the central bridge 33 on the first level are not only those from Figure 5 The leakage flux of the first layer permanent magnet 32 ​​shown, and the magnetic flux relative to the first layer central bridge 33 arranged in Figure 5 The leakage flux of the permanent magnet on the opposite side of the first layer permanent magnet 32 ​​is shown. Therefore, the first layer central bridge side magnet 323 is used to achieve magnetic saturation at half the width of the first layer central bridge 33. Similarly, there are also magnets arranged relative to the second layer central bridge 43 around the second layer central bridge 43. Figure 5 The leakage flux of the permanent magnet on the opposite side of the second layer permanent magnet 42 is shown. Therefore, the second layer central bridge side magnet 423 is used to achieve magnetic saturation at half the width of the second layer central bridge 43. The saturation flux density B of the rotor core when using laminated electromagnetic steel plates... s The magnetic flux density of the first layer magnet is 2T. m1 The magnetic flux density B of the second layer magnet m2 When the value is 1T, the width W of the first-layer outer diameter bridge-side magnet 321 is... 1a The width W of the first layer central bridge side magnet 323 1b The width W of the second-layer outer diameter bridge-side magnet 421 2c The width W of the second-layer central bridge side magnet 423 2d Calculate using equations (5) to (8).

[0046] [Mathematical Expression 5]

[0047]

[0048] [Mathematical Expression 6]

[0049]

[0050] [Mathematical Expression 7]

[0051]

[0052] [Mathematical Expression 8]

[0053]

[0054] If the width of the first layer of effective magnets 322 is set to W 1e The width of the second layer of effective magnets 422 is set to W. 2e Then the width W of the first layer of effective magnets 322 1e It is the width W1 of the first layer of magnets minus the width W of the first layer outer diameter bridge-side magnet 321. 1a The width W of the first layer central bridge side magnet 323 1b The obtained value is the width W of the second layer of effective magnet 422. 2e It is the width W2 of the second layer magnet minus the width W of the second layer outer diameter bridge side magnet 421. 2cThe width W of the second-layer central bridge side magnet 423 2d The obtained value. Therefore, the width W of the first layer of effective magnets 322. 1e The width W of the second layer of effective magnet 422 2e The calculation is performed using equations (1) to (4) and equations (9) to (10).

[0055] [Mathematical Expression 9]

[0056]

[0057] [Mathematical Expression 10]

[0058]

[0059] The width W of the first layer of effective magnet 322 calculated by equation (9) 1e and the width W of the second layer of effective magnet 422 calculated by equation (10) 2e It is the width of the magnet that contributes to the rotor magnetomotive force. The width W of the first layer of effective magnets 322 calculated by equation (9) is... 1e Multiplied by the magnetic flux density B of the first layer of magnets m1 The value obtained is the effective magnetic flux of the first layer. The width W of the second layer of effective magnet 422 calculated by equation (10) 2e Multiplied by the magnetic flux density B of the second layer magnet m2 The value obtained is the effective magnetic flux of the second layer. In equations (5) to (10), the saturation magnetic flux density B of the rotor core when using laminated electromagnetic steel plates is... s Let T be 2T, and the magnetic flux density B of the first layer of magnets be... m1 The magnetic flux density B of the second layer magnet m2 Given a current of 1T and with an electromagnetic steel plate, what is the saturation magnetic flux density B of the rotor core? s Typically, in the case of neodymium magnets, the magnetic flux density B is in the range of 1.5T to 2.0T. m Typically, the range is between 1.0T and 1.4T. The first and second layers of magnets can be the same magnet or different magnets.

[0060] like Figure 5 As shown, the closest distance between the first layer magnet slot 31 and the second layer magnet slot 41 is set as L. The maximum width W of the second layer effective magnet 422 passing through the first layer magnet slot 31 and the second layer magnet slot 41 is [missing information]. 2e Half of the magnetic flux and the width W of the second-layer outer diameter bridge-side magnet 421 2c The magnetic flux. If we assume the saturation magnetic flux density of rotor core 20 is B. s The magnetic flux density of the second layer magnet is B.m2 In order to prevent magnetic saturation between the first magnet slot 31 and the second magnet slot 41, the relationship in equation (11) needs to hold.

[0061] [Mathematical Expression 11]

[0062]

[0063] Substitute equation (10) into the left side of equation (11) to calculate equation (12).

[0064] [Mathematical Expression 12]

[0065]

[0066] Therefore, the relation in equation (11) becomes equation (13).

[0067] [Mathematical Expression 13]

[0068]

[0069] If magnetic saturation occurs between the first magnet slot 31 and the second magnet slot 41, the gap magnetic flux density also decreases, resulting in a decrease in torque. Furthermore, due to magnetic saturation at the point where effective magnetic flux passes, the higher harmonic components of the gap magnetic flux density increase, leading to increased vibration and noise. By preventing magnetic saturation between the first magnet slot 31 and the second magnet slot 41, the decrease in gap magnetic flux density and the decrease in torque can be suppressed. Moreover, by preventing magnetic saturation at the point where effective magnetic flux passes, the higher harmonic components of the gap magnetic flux density can be reduced, thereby reducing vibration and noise.

[0070] Figure 6 This is a cross-sectional view showing the dimensions of the magnetic pole arc angles of the first and second layers. The rotor's rotation center axis is set to O. The points forming the inner V-shaped angles in the side of the first layer magnet slot 31 that connects to the outer diameter bridge 34 are X and X', respectively. m11 and X m12 The first layer of magnetic poles has an arc angle θ. m1 Defined as connecting the rotation center axes O and X m11 The line connecting the rotation center axis O and X m12 The angle formed by the lines. The points that form the inner V-shaped angle in the side of the second magnet slot 41 that connects to the outer diameter bridge 44 are X... m21 and X m22 The second layer of magnetic poles has an arc angle θ. m2 Defined as connecting the rotation center axes O and X m21 The line connecting the rotation center axis O and X m22 The angle formed by the lines. Figure 7 It is shown more clearly in the enlarged sectional view. Figure 6 X inm11 and X m21 The first layer of magnetic poles has an arc angle θ. m1 It is the range of magnetomotive force generated by half the width of the first layer of effective magnets and half the width of the second layer of effective magnets, and extends from the second layer magnetic pole arc angle θ. m2 The first layer of magnetic pole angle θ was removed. m1 The range thereafter is the range of magnetomotive force generated by half the width of the second layer of effective magnets. Furthermore, the magnetic pole arc angle corresponding to the electrical angle is calculated by multiplying the magnetic pole arc angle corresponding to the mechanical angle by the number of pole pairs.

[0071] Figure 8 This is a schematic diagram illustrating the rotor magnetomotive force generated by the effective magnetic flux due to the effective magnet width. At the first layer of magnetic pole arc angle θ... m1 Within a certain range, the magnitude of the magnetomotive force is generated by half of the effective magnetic flux of the first layer and the second layer, at the second layer magnetic pole arc angle θ. m2 The first layer of magnetic pole angle θ was removed. m1 Within the obtained range, the magnitude of the magnetomotive force is generated by half of the effective magnetic flux of the second layer. Since the gap magnetic flux density is calculated by multiplying the rotor magnetomotive force by the permeability between the rotor and stator, reducing the higher harmonic components of the rotor magnetomotive force to reduce the higher harmonic components of the gap magnetic flux density is effective. If F1 is the magnitude of the fundamental component of the rotor magnetomotive force within one period of the electrical angle, F... n If is the magnitude of the nth-order component of the rotor magnetomotive force, then the higher harmonic content rate (THD), which is used as an index to represent the higher harmonic content rate of the rotor magnetomotive force, is defined as Equation (14).

[0072] [Mathematical Expression 14]

[0073]

[0074] The smaller the THD, the closer the rotor magnetomotive force is to a sine wave, and therefore the closer the gap magnetic flux density is to a sine wave, which can reduce vibration and noise.

[0075] Figure 9 This is a graph showing the relationship between the effective magnetic flux and the rotor magnetomotive force (THD) at its minimum. The first layer of magnetic pole arc angle θ... m1 Second layer magnetic pole arc angle θ m2 The magnitude corresponds to the electrical angle. θ is the arc angle of the second magnetic pole. m2 Plot the three angles of 140°, 120°, and 100°, and show the angles when passing through the second layer of magnetic poles at arc angles θ. m2 Change the first layer magnetic pole arc angle θ m1 The rotor magnetomotive force has the lowest THD. Because this structure has a second layer of magnet slots, the second layer magnetic pole arc angle θ m2The maximum value is 140 degrees. The first layer magnetic pole arc angle θ m1 Second layer magnetic pole arc angle θ m2 Under various conditions, the effective magnetic flux of the first layer Divide by the second layer of effective magnetic flux Received The rotor magnetomotive force THD is minimized when it is below 0.5. That is, by configuring the first layer of effective magnetic flux... Second layer effective magnetic flux By reducing the magnet width to less than half, the THD of the rotor magnetomotive force can be minimized. Furthermore, the amount of magnet can be reduced because the additional magnet width, which increases higher harmonic components, can be minimized.

[0076] Half of the magnetic flux of the second layer of effective magnets 422 is directed towards the first layer of effective magnets 322, and the remaining half passes between the slots of the first and second layers of magnets and towards the gap. Therefore, when the first layer of effective magnetic flux generated by the first layer of effective magnets 322 is greater than half of the second layer of effective magnetic flux generated by the second layer of effective magnets 422, the rotor magnetomotive force at the first layer magnetic pole arc angle θ m1 Within this range, the magnetomotive force increases, and the higher harmonic components increase. Therefore, as... Figure 9 As shown, by making the first layer of effective magnetic flux For the second layer of effective magnetic flux less than half, that is This minimizes the THD of the rotor magnetomotive force, thereby reducing vibration and noise.

[0077] As described above, the first layer of effective magnetic flux The width W of the first layer of effective magnet 322 is calculated by equation (9). 1e Multiplied by the magnetic flux density B of the first layer of magnets m1 The obtained value, and the second layer effective magnetic flux The width W of the second layer of effective magnet 422 is calculated by equation (10). 2e Multiplied by the magnetic flux density B of the second layer magnet m2 The value obtained is therefore determined by satisfying the following formula.

[0078] [Mathematical Expression 15]

[0079]

[0080] Figure 10 and Figure 11 This is a graph showing the relationship between the pole arc angle and the THD of the rotor magnetomotive force. For example... Figure 10 As shown, when the second layer magnetic pole arc angle θ m2 When the angle is 140 degrees, the first layer of magnetic pole arc angle θ m1 With the second layer of magnetic poles arc angle θm2 The ratio θ m1 / θ m2 The THD of the rotor magnetomotive force is minimized when the value is 80 / 140, or 0.57. The first layer of magnetic pole arc angle θ m1 Second layer magnetic pole arc angle θ m2 Due to manufacturing tolerances, deviations will occur. In a four-pole motor, when there is a tolerance of ±1° for the mechanical angle, a deviation of ±4° will occur for the electrical angle. At this time, the first layer of magnetic pole arc angle θ... m1 With the second layer of magnetic poles arc angle θ m2 The ratio θ m1 / θ m2 The convergence occurs within the range of 0.53 to 0.62, therefore, when the second layer magnetic pole arc angle θ... m2 When the angle is 140 degrees, the first layer of magnetic pole arc angle θ m1 With the second layer of magnetic poles arc angle θ m2 The ratio θ m1 / θ m2 The THD of the rotating magnetomotive force is lowest in the range of 0.53 to 0.62.

[0081] like Figure 11 As shown, when the second layer magnetic pole arc angle θ m2 When the angle is 120 degrees, the first layer of magnetic pole arc angle θ m1 With the second layer of magnetic poles arc angle θ m2 The ratio θ m1 / θ m2 The THD of the rotor magnetomotive force is minimized when the value is 60 / 120, or 0.50. The first layer of magnetic pole arc angle θ m1 Second layer magnetic pole arc angle θ m2 Due to manufacturing tolerances, deviations will occur. In a four-pole motor, a tolerance of ±1° for the mechanical angle will result in a deviation of ±4° for the electrical angle. At this time, the first layer of magnetic pole arc angle θ... m1 With the second layer of magnetic poles arc angle θ m2 The ratio θ m1 / θ m2 The convergence occurs within the range of 0.45 to 0.55, therefore, when the second layer magnetic pole arc angle θ... m2 When the angle is 120 degrees, the first layer of magnetic pole arc angle θ m1 With the second layer of magnetic poles arc angle θ m2 The ratio θ m1 / θ m2 The THD of the rotating magnetomotive force is lowest within the range of 0.45 to 0.55. (Refer to...) Figure 10 and Figure 11 At that time, at the second magnetic pole arc angle θ m2 θ is in the range of 120deg to 140deg m1 / θ m2When the value is above 0.45 and below 0.62, the THD of the rotor magnetomotive force is almost minimal.

[0082] Figure 12 This is a cross-sectional view showing the arc angle between the teeth when there are 2 slots per pole per phase in the stator. Each tooth has a raised flange at its front end, widening the tooth width. The rotor's rotation center axis is set to O. The stator teeth are opposite each other on the extension line of the line connecting the inner V-shaped corner of the first layer of magnet slots (which are arranged in a V-shape) to the outer diameter bridge and the rotation center axis. At the same time, the stator teeth are opposite each other on the extension line of the line connecting the inner V-shaped corner of the second layer of magnet slots (which are arranged in a V-shape) to the outer diameter bridge and the rotation center axis. Because the effective magnetic flux generated by the first and second layers of magnets links with the opposing stator teeth, the magnetic flux is not disturbed, and the high-order harmonic components of the gap magnetic flux density are reduced.

[0083] In the flange 151 of tooth 131, which is counterclockwise adjacent to tooth 130 located on the central axis of the magnetic pole, the protruding front end located on the side of tooth 130 is designated as X. s11 The front end of the protrusion located on the side furthest from tooth 130 is designated as X. s21 In the flange 153 of tooth 133, which is clockwise adjacent to tooth 130 located on the central axis of the magnetic pole, the protruding front end on the side of tooth 130 is designated as X. s12 The front end of the protrusion located on the side furthest from tooth 130 is designated as X. s22 The inner arc angle θ of the two teeth 131 and 133, which are separated by tooth 130 located on the central axis of the magnetic pole, is... S1 Defined as consisting of the axis of rotation O and X. s11 The line connecting the rotation center axis O and X s12 The angle formed by the line, the outer arc angle θ S2 Defined as consisting of the axis of rotation O and X. s21 The line connecting the rotation center axis O and X s22 The angle formed by the line. In the flange 152 of the third tooth 132, which is circumferentially counterclockwise from the tooth 130 located on the central axis of the magnetic pole, the front end of the protrusion located on the side of the tooth 130 is set as X. s31 The front end of the protrusion located on the side furthest from tooth 130 is designated as X. s41 In the flange 154 of the third tooth 134 circumferentially clockwise from the tooth 130 located on the central axis of the magnetic pole, the front end of the protrusion located on the side of the tooth 130 is set as X. s32 The front end of the protrusion located on the side furthest from tooth 130 is designated as X. s42 The inner arc angle θ of the two teeth 132 and 134 located circumferentially from the central axis of the magnetic pole, that is, the two teeth 132 and 134 located three teeth 130, 131 and 133, centered on the tooth 130 located on the central axis of the magnetic pole. s3 Defined as consisting of the axis of rotation O and X.s31 The line and the connection between the rotation center axis O and X s32 The angle formed by the line, the outer arc angle θ s4 Defined as consisting of the axis of rotation O and X. s41 The line and the connection between the rotation center axis O and X s42 The angle formed by the lines. When the first layer of permanent magnets is positioned opposite the second circumferential tooth 131, the effective magnetic flux of the first layer can link with the stator without obstruction. That is, Figure 6 The first layer of magnetic pole arc angle θ shown m1 Satisfying θ s1 ≤θ m1 ≤θ s2 When the second layer of permanent magnets is positioned opposite the third circumferential tooth 132, the effective magnetic flux of the second layer can link with the stator without obstruction. That is, Figure 6 The second layer magnetic pole arc angle θ shown m2 Satisfying θ s3 ≤θ m2 ≤θ s4 This structure links the effective magnetic flux of the first and second permanent magnet layers without concentrating it on any particular tooth, thus reducing the high-harmonic components of the gap flux density and lowering vibration and noise. Furthermore, when flux is concentrated on a particular tooth, magnetic saturation occurs, preventing an increase in gap flux density and torque. This structure mitigates flux concentration on specific teeth and allows for torque increase.

[0084] Implementation method 2.

[0085] Figure 13This is an enlarged cross-sectional view showing the structure of one pole of the rotor of the rotary electric machine according to Embodiment 2. Similar to Embodiment 1, the rotor includes: a rotor core having two layers of magnet slots arranged in a V-shape; and permanent magnets inserted into the two layers of magnet slots. The two layers of magnet slots consist of a first layer of magnet slots 31 on the outer diameter side of the rotor and a second layer of magnet slots 41 on the inner diameter side of the rotor. Each layer of magnet slots consists of a pair of slots formed between a central bridge located in the center and each of the two outer diameter bridges located between the magnet slot and the outer surface of the rotor 2, and a permanent magnet is inserted into each slot. That is, the first layer of magnet slots 31 is a pair of slots formed between the first layer of central bridge 33 located in the center and the first layer of outer diameter bridge 34 located on the outer diameter side of the rotor. The second layer of magnet slots 41 is a pair of slots formed between the second layer of central bridge 43 located in the center and the second layer of outer diameter bridge 44 located on the outer diameter side of the rotor. The first layer of permanent magnets 32 is inserted into the first layer of magnet slots 31, and the second layer of permanent magnets 42 is inserted into the second layer of magnet slots 41. The first layer of permanent magnets 32 is divided into the first layer outer magnet 35 on the side of the first layer outer diameter bridge 34 and the first layer central magnet 36 on the side of the first layer central bridge 33. The second layer of permanent magnets 42 is divided into the second layer outer magnet 45 on the side of the second layer outer diameter bridge 44 and the second layer central magnet 46 on the side of the second layer central bridge 43. That is, the permanent magnets in each layer are permanently magnets that are physically divided along the long side of each magnet slot.

[0086] Figure 14 This is an enlarged cross-sectional view showing the detailed dimensions of the permanent magnets and bridging components of the rotor of the rotary electric motor according to Embodiment 2. The width of the first layer outer diameter bridge 34 on the rotor outer diameter side is *a*, the width of the first layer central bridge 33 is *b*, the width of the second layer outer diameter bridge 44 on the rotor inner diameter side is *c*, and the width of the second layer central bridge 43 is *d*. Regarding the width of each bridge, when the widths of the bridges are not uniform, the narrowest part of the bridge is taken as the width of each bridge. The width of the first layer outer magnet 35 on the rotor outer diameter side after division is set as W. 1L The width of the central side magnet 36 in the first layer is set to W. 1M The width of the second outer magnet 45 on the inner diameter side of the rotor is set to W. 2L The width of the central side magnet 46 in the second layer is set to W. 2M Furthermore, the width of the first-layer outer diameter bridge-side magnet 351 used to magnetically saturate the first-layer outer diameter bridge 34 is set to W. 1a The width of the first-layer central bridge side magnet 361 used to saturate the first-layer central bridge magnet is set to W. 1b The width of the second-layer outer diameter bridge side magnet 451, used to magnetically saturate the second-layer outer diameter bridge 44, is set to W. 2c The width of the second-layer central bridge side magnet 461 used to magnetically saturate the second-layer central bridge 43 is set to W. 2d Let the saturation magnetic flux density of the rotor core be B.s The magnetic flux density of the first layer of magnets is set to B. m1 The magnetic flux density of the second layer of magnets is B. m2 At that time, the width W of the first layer outer diameter bridge side magnet 351 1a The width W of the first layer central bridge side magnet 361 1b The width W of the second-layer outer diameter bridge-side magnet 451 2c The width W of the second-layer central bridge side magnet 461 2d The same calculations are performed using equations (1) to (4) as in Implementation Method 1.

[0087] If the width of the effective magnet 352 on the outer side of the first layer is W 1Le The width of the effective magnet 362 on the inner side of the first layer is W. 1Me The width of the second outer effective magnet 452 is W. 2Le The width of the effective magnet 462 on the inner side of the second layer is W. 2Me Then the width of the first layer of effective magnets is the width W of the outermost effective magnet 352 of the first layer. 1Le The width W of the effective magnet 362 on the inner side of the first layer 1Me The sum of the widths of the second layer of effective magnets is the width W of the outermost effective magnet of the second layer (452). 2Le The width W of the effective magnet 462 on the inner side of the second layer 2Me The sum. The width of the effective magnet 352 on the outer side of the first layer is the width W of the outer magnet 35 on the outer side of the first layer. 1L Subtract the width W of the first layer outer diameter bridge side magnet 351 1a The obtained value is the width W of the effective magnet 362 on the inner side of the first layer. 1Me It is the width W of the inner magnet 36 of the first layer. 1M Subtract the width W of the first-layer central bridge side magnet 361 1b The obtained value is the width W of the second outer effective magnet 452. 2Le It is the width W of the outer magnet 45 of the second layer. 2L Subtract the width W of the second-layer outer diameter bridge-side magnet 451 2c The obtained value is the width W of the effective magnet 462 on the inner side of the second layer. 2Me It is the width W of the inner magnet 46 of the second layer. 2M Subtract the width W of the second-layer central bridge side magnet 461 2d The obtained value is the width W of the effective magnet 352 on the outer side of the first layer. 1Le The width W of the effective magnet 362 on the inner side of the first layer 1Me The width W of the second outer effective magnet 452 2Le The width W of the effective magnet 462 on the inner side of the second layer 2MeCalculate using formulas (16) to (19).

[0088] [Mathematical Expression 16]

[0089]

[0090] [Mathematical Expression 17]

[0091]

[0092] [Mathematical Expression 18]

[0093]

[0094] [Mathematical Expression 19]

[0095]

[0096] At this time, due to the width W of the first layer outer effective magnet 352 1Le The width W of the effective magnet 362 on the inner side of the first layer 1Me The sum is the width of the first layer of effective magnets, and the width W of the second layer of outer effective magnets 452. 2Le The width W of the effective magnet 462 on the inner side of the second layer 2Me The sum is the width of the second layer of effective magnets, therefore the effective magnetic flux of the first layer is... For (W) 1Le +W 1Me )×B m1 Second layer effective magnetic flux For (W) 2Le +W 2Me )×B m2 At this point, by making the first layer of effective magnetic flux... For the second layer of effective magnetic flux By dividing the magnet by less than half, the high-order harmonic components of the rotor magnetomotive force can be reduced. Furthermore, dividing the magnet reduces the eddy currents generated within it, suppressing temperature rise and preventing demagnetization. Additionally, the eddy currents generated in the magnet become high-order harmonic flux, leading to high-order harmonic components in the gap flux density; therefore, dividing the magnet also helps reduce vibration and noise.

[0097] Figure 15 This is a cross-sectional view showing another structure of one pole of the rotor of the rotary electric machine according to Embodiment 2. The permanent magnet 42 inserted into the second layer of magnet slots can be segmented magnets, such that gaps exist between the magnets. Even... Figure 15 In the rotating motor with the structure shown, by setting the effective magnetic flux of the first layer to less than half of the effective magnetic flux of the second layer, the high-order harmonic components of the rotor magnetomotive force can be reduced, and vibration and noise can be reduced.

[0098] Implementation method 3.

[0099] Figure 16 This is a cross-sectional view showing one pole of the rotor of the rotary electric machine according to Embodiment 3. Similar to Embodiment 1, the rotor consists of a rotor core having two layers of V-shaped magnet slots and permanent magnets inserted into the two layers of magnet slots. The two layers of magnet slots consist of a first layer of magnet slot 31 on the outer diameter side of the rotor and a second layer of magnet slot 41 on the inner diameter side of the rotor. The first layer of magnet slot 31 is held by a first layer of central bridge 33 located in the center and a first layer of outer diameter bridge 34 located on the outer diameter side of the rotor. The second layer of magnet slot 41 is held by a second layer of central bridge 43 located in the center and a second layer of outer diameter bridge 44 located on the outer diameter side of the rotor. The types of the first layer of permanent magnets 32 inserted into the first layer of magnet slot 31 and the second layer of permanent magnets 42 inserted into the second layer of magnet slot 41 are different. Figure 16 The magnetic flux density B of the second layer magnet is shown. m2 Greater than the magnetic flux density B of the first layer of magnets m1 The situation.

[0100] At this point, by setting the effective magnetic flux generated by the width of the first layer of effective magnets to less than half of the effective magnetic flux generated by the width of the second layer of effective magnets, the effect of minimizing the THD of the rotor magnetomotive force can also be achieved. When the magnetic flux density of the second layer of magnets is greater than that of the first layer of magnets, the width of the second layer outer diameter bridge side magnet and the width of the second layer central bridge side magnet used to magnetically saturate the second layer outer diameter bridge 44 and the second layer central bridge 43 are reduced. When the width of the first layer magnet 32 ​​on the rotor outer diameter side is W1, the width of the second layer magnet 42 on the rotor inner diameter side is W2, and the saturation magnetic flux density of the rotor core is B... s When the width of the first layer outer diameter bridge 34 on the outer diameter side of the rotor is a, the width of the first layer central bridge 33 is b, the width of the second layer outer diameter bridge 44 on the inner diameter side of the rotor is c, and the width of the second layer central bridge 43 is d, by forming the relationship of the above formula (15), the first layer effective magnetic flux generated by the width of the first layer effective magnet is less than half of the second layer effective magnetic flux generated by the width of the second layer effective magnet.

[0101] By using a magnet with a second magnet having a higher magnetic flux density than the first magnet, the width of the second magnet can be reduced. This allows for minimizing the THD of the rotating motor's magnetomotive force using a small number of magnets, thereby reducing vibration and noise.

[0102] While this application describes various exemplary embodiments and examples, the various features, methods, and functions described in one or more embodiments are not limited to the application of a particular embodiment and can be applied to the embodiments individually or in various combinations. Therefore, it can be considered that numerous variations not illustrated are also included within the scope of the technology disclosed in this application. For example, this includes cases where at least one constituent element is modified, added to, or omitted, and cases where at least one constituent element is extracted and combined with constituent elements of other embodiments.

[0103] Label Explanation

[0104] 1. Stator, 2. Rotor, 10. Stator core, 11. Coil, 130, 131, 132, 133, 134 teeth, 14. Coil slots, 151, 152, 153, 154 flanges, 21. Magnet slot, 22. Permanent magnet, 31. First layer magnet slot, 32. First layer permanent magnet, 321. First layer outer diameter bridge-side magnet, 322. First layer effective magnet, 323. First layer central bridge-side magnet, 33. First layer central bridge, 34. First layer outer diameter bridge, 35. First layer outer magnet, 36. First layer inner magnet, 41. Second layer magnet slot, 42. Second layer permanent magnet, 421. Second layer outer diameter bridge-side magnet, 422. Second layer effective magnet, 423. Second layer central bridge-side magnet, 43. Second layer central bridge, 44. Second layer outer diameter bridge, 45. Second layer outer magnet, 46. Second layer inner magnet.

Claims

1. A rotary electric motor, comprising: The stator has multiple teeth on its inner surface side in a cylindrical shape, and coils are wound in coil slots provided between adjacent teeth; as well as The rotor is cylindrical, with its outer surface spaced apart from the inner surface of the stator, and is rotatably arranged about a central axis of rotation. The rotary electric motor is characterized in that, In the rotor, the magnet slots, which open in a V-shape from the center of rotation to the outer periphery, are formed in a double-layer structure in the radial direction. Each layer of magnet slots consists of a central bridge located in the center and a pair of slots between two outer diameter bridges located between the magnet slot and the outer surface of the rotor. A permanent magnet is inserted into each slot. In the permanent magnets (i.e., the first layer of permanent magnets) inserted into the magnet slots (i.e., the first layer of magnets) on the outer diameter side, the magnetic flux generated by the magnetic width obtained after removing the magnet width used to magnetically saturate the central bridge (i.e., the first layer of central bridge) corresponding to the first layer of magnet slot and the magnet width used to magnetically saturate the outer diameter bridge (i.e., the first layer of outer diameter bridge) corresponding to the first layer of magnet slot, is defined as the first layer of effective magnetic flux. In the permanent magnet (i.e., the second layer permanent magnet) in the magnet slot (i.e., the second layer magnet) inserted on the inner diameter side, the magnetic flux generated by the magnetic width obtained after removing the magnet width used to magnetically saturate the central bridge (i.e., the second layer central bridge) corresponding to the second layer magnet slot and the magnet width used to magnetically saturate the outer diameter bridge (i.e., the second layer outer diameter bridge) corresponding to the second layer magnet slot, is defined as the second layer effective magnetic flux. The effective magnetic flux of the first layer is less than half of the effective magnetic flux of the second layer. The width of the first-layer permanent magnet inserted into one of the slots forming the first-layer magnet slot is defined as W1, the width of the first-layer outer diameter bridge is defined as a, and the width of the first-layer central bridge is defined as b. The width of the second-layer permanent magnet inserted into one of the slots forming the second-layer magnet slot is defined as W2, the width of the second-layer outer diameter bridge is defined as c, and the width of the second-layer central bridge is defined as d. The saturation magnetic flux density of the rotor core constituting the rotor is defined as B. s Let the magnetic flux density of the first layer of permanent magnets be B. m1 The magnetic flux density of the second layer of permanent magnets is set to B. m2 When the following formula is satisfied:

2. The rotary motor as described in claim 1, characterized in that, When the closest distance between the first layer of magnet slots and the second layer of magnet slots is set to L, the following formula is satisfied:

3. The rotary motor as described in claim 1, characterized in that, The angle formed by the inner V-shaped corner of the side connecting the first layer magnet slot to the outer diameter bridge of the first layer and the two lines of the rotation center axis is defined as the first layer magnetic pole arc angle θ. m1 , The angle formed by the inner V-shaped corner of the side connecting the second layer magnet slot to the outer diameter bridge of the second layer and the two lines of the rotation center axis is defined as the second layer magnetic pole arc angle θ. m2 hour, Satisfy the following formula: Where 120deg≤θ m2 ≤140deg.

4. The rotary motor as described in claim 1, characterized in that, The arc angle of the stator teeth is set as follows: When one tooth of the stator is located on the extension line of the line connecting the inner corner of the V-shape of the side of the first layer magnet slot that connects to the outer diameter bridge of the first layer and the axis of rotation, the other tooth of the stator is located on the extension line of the line connecting the inner corner of the V-shape of the side of the second layer magnet slot that connects to the outer diameter bridge of the second layer and the axis of rotation.

5. The rotary motor as described in claim 4, characterized in that, In the rotor, the angle formed by the inner V-shape of the side connecting the first layer of magnet slots to the outer diameter bridge and the two lines of the rotation center axis is defined as the first layer magnetic pole arc angle θ. m1 The angle formed by the inner V-shaped corner of the side connecting the second layer magnet slot to the outer diameter bridge and the two lines of the rotation center axis is defined as the second layer magnetic pole arc angle θ. m2 , The stator is a stator with 2 slots per pole per phase, and each tooth has a protruding flange at the front end of the tooth, the width of which increases. In two teeth separated by one tooth, the angle formed by the line connecting the front ends of the protrusions on the side of the one tooth that connects the flanges of the two teeth and the axis of rotation is denoted as θ. s1 Let θ be the angle formed by the line connecting the front ends of the protrusions on the side of the flanges of the two teeth away from the one tooth and the axis of rotation. s2 , In two teeth separated by three teeth with the aforementioned central tooth, the angle formed by the line connecting the front ends of the protrusions on the side of the aforementioned central tooth of the flanges of the two teeth and the axis of rotation is defined as θ. s3 Let θ be the angle formed by the line connecting the front ends of the protrusions on the side of the flanges of the two teeth away from the tooth and the axis of rotation. s4 When the following equation is satisfied: i s1 ≤θ m1 ≤θ s2 And the s3 ≤θ m2 ≤θ s4 。 6. The rotary electric motor as described in any one of claims 1 to 5, characterized in that, The first layer of permanent magnets and the second layer of permanent magnets are permanent magnets that are physically divided along the long side of each magnet slot.

7. The rotary electric motor as described in any one of claims 1 to 5, characterized in that, The magnetic flux density of the second permanent magnet layer is greater than that of the first permanent magnet layer.

8. The rotary motor as described in claim 6, characterized in that, The magnetic flux density of the second permanent magnet layer is greater than that of the first permanent magnet layer.

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