Tangential motor rotor structure and motor

Abstract

This invention provides a tangential motor rotor structure and a motor. The tangential motor rotor structure includes a rotor core (1) and permanent magnets (2). The rotor core (1) is provided with magnetic slots (5) and auxiliary slots (4). The permanent magnets (2) are disposed within the magnetic slots (5). The auxiliary slots (4) are circumferentially spaced between adjacent magnetic slots (5) and located on the outer edge of the rotor core (1). The auxiliary slots (4) between two adjacent magnetic slots (5) are symmetrical about the d-axis. The auxiliary slots (4) open towards the outer circle of the rotor core (1), and the maximum pole arc coefficient of the opening is b. The pole arc coefficient between the sidewalls of two adjacent permanent magnets (2) near the d-axis is c, where 0.01 ≤ b / c ≤ 0.03. According to the tangential motor rotor structure of this invention, leakage flux and torque pulsation of the tangential motor can be suppressed, improving the output torque quality of the motor without reducing its torque output capability.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to a tangential motor rotor structure and a motor. Background Technology

[0002] With the improvement of motor energy efficiency standards, higher requirements are placed on the energy efficiency level of motors. For permanent magnet motors, it is necessary to further improve the efficiency and torque density of the motors.

[0003] In existing permanent magnet motors, when the magnets are magnetized tangentially, there is a relatively serious magnetic leakage phenomenon, which reduces the air gap magnetic flux density of the motor and reduces the quality of the output torque. Summary of the Invention

[0004] The main objective of this invention is to provide a tangential motor rotor structure and motor that can suppress leakage flux and torque pulsation in tangential motors, thereby improving the output torque quality of the motor without reducing its torque output capability.

[0005] To achieve the above objectives, according to one aspect of the present invention, a tangential motor rotor structure is provided, comprising a rotor core and permanent magnets. The rotor core is provided with magnetic slots and auxiliary slots. The permanent magnets are disposed within the magnetic slots. The auxiliary slots are circumferentially spaced between adjacent magnetic slots and located at the outer edge of the rotor core. The auxiliary slots between two adjacent magnetic slots are symmetrical about the d-axis. The auxiliary slots open on the side facing the outer circle of the rotor core, and the maximum pole arc coefficient of the opening is b. The pole arc coefficient between the sidewalls of two adjacent permanent magnets near the d-axis is c, where 0.01 ≤ b / c ≤ 0.03.

[0006] Furthermore, b / c = 0.02.

[0007] Furthermore, the width of the opening is not equal in the radial outward direction along the rotor core; and / or, in a cross-section perpendicular to the central axis of the rotor core, the opening is symmetrical about the radial line of the rotor core.

[0008] Furthermore, the width of the opening decreases radially outward from the rotor core.

[0009] Furthermore, in the cross-section perpendicular to the central axis of the rotor core, the depth of the opening is h1, where h1 is the minimum distance between the auxiliary slot and the outer circle of the rotor core along the radial direction of the rotor core, and the outer diameter of the rotor core is D, 0.006≤h1 / D≤0.02.

[0010] Furthermore, 0.01≤h1 / D≤0.015.

[0011] Furthermore, in the cross-section perpendicular to the central axis of the rotor core, the tangential edge of the auxiliary slot opening extending tangentially from the outer circle of the rotor core to the shaft hole of the motor rotor structure is a straight line, a curve, or a combination of a straight line and a curve. The angle between the tangent line of the tangent edge at the outer circle of the rotor core and the tangent line of the rotor core at the outer circle of the rotor core is e, where 90°≤e≤180°.

[0012] Furthermore, 100°≤e≤130°.

[0013] Furthermore, in the cross section perpendicular to the central axis of the rotor core, the polar arc coefficient of the angle between the radial lines containing the centers of two adjacent auxiliary slots is α, where 0.07 ≤ α / c ≤ 0.16.

[0014] Furthermore, 0.09 ≤ a / c ≤ 0.16.

[0015] Furthermore, within a cross-section perpendicular to the central axis of the rotor core, the auxiliary slot is shaped as a regular polygon, circle, or ellipse that is symmetrical about the radial line passing through the center of the auxiliary slot.

[0016] Furthermore, the center of the auxiliary slot is located on the first circumference, and multiple auxiliary slots are arranged at intervals along the circumference of the first circumference. The diameter of the first circumference is D1, and the outer diameter of the rotor core is D, where 0.8≤D1 / D≤0.95.

[0017] Furthermore, 0.85≤D1 / D≤0.92.

[0018] Furthermore, in the cross-section perpendicular to the central axis of the rotor core, along the circumferential direction of the rotor core, the maximum width of the auxiliary slot is d1, (z1*d1) / (π*D)≤0.6, where z1 is the number of auxiliary slots in the circumferential direction of the rotor core, and D is the outer diameter of the rotor core.

[0019] Furthermore, in the cross-section perpendicular to the central axis of the rotor core, the depth of the opening is h1, and the depth of the auxiliary slot along the radial direction of the rotor core is h3, where 0.1≤h1 / h3≤0.2.

[0020] Furthermore, the rotor core includes multiple core blocks, and the tangential motor rotor structure also includes a bushing with a shaft hole. The core blocks are arranged at intervals along the circumference of the bushing and are fixedly connected to the bushing.

[0021] Furthermore, in the cross-section perpendicular to the central axis of the rotor core, the cross-sectional area of ​​the rotor core is S1. The area between the circle containing the point farthest from the center of the shaft hole and the inner wall of the shaft hole forms the first region. The overlapping area between the cross-section of the rotor core and the first region is S2, where S2≤S1*20%.

[0022] Furthermore, the maximum distance between the edge of the bushing that contacts the rotor core and the outer circle of the rotor core is L1, and the height of the magnet slot along the radial direction of the rotor core is L3, 0.8≤L1 / L3≤1.1.

[0023] Furthermore, the maximum outer diameter of the bushing is D2, the minimum outer diameter of the bushing is D3, and 1.02≤D2 / D3≤1.2.

[0024] Furthermore, the length of the side of the bushing that contacts the rotor core is L4, and the circumferential width of the magnet slot is L2, with 0.1≤L4 / L2≤3.1.

[0025] Furthermore, part of the magnetic steel slot is located on the rotor core and part is located on the bushing. The magnetic steel slots located on the rotor core and the magnetic steel slots located on the bushing are located in the same radial direction and together form a complete magnetic steel slot.

[0026] Furthermore, the maximum outer diameter D2 of the bushing is the area of ​​the projection of the circle on the rotor core in the axial direction and the projection of the permanent magnet on the rotor core in the axial direction, which overlaps with the area of ​​the circle on the rotor core in the axial direction. The total projected area of ​​the permanent magnet on the rotor core in the axial direction is S4, and S3 / S4≤30%.

[0027] Furthermore, the distance between the edge of the permanent magnet near the outer circle of the rotor core and the shaft hole of the tangential motor rotor structure is greater than the radius of the circle where the center of the auxiliary slot is located; and / or, the auxiliary slot is filled with a conductive but non-magnetic material.

[0028] Furthermore, the height of the permanent magnet along the radial direction of the rotor core is h, and the width in the circumferential direction is L2, where 2.0≤h / L2≤2.5.

[0029] According to another aspect of the present invention, an electric motor is provided, including a tangential motor rotor structure, which is the tangential motor rotor structure described above.

[0030] According to the technical solution of the present invention, the tangential motor rotor structure includes a rotor core and a permanent magnet. The rotor core is provided with magnetic steel slots and auxiliary slots. The permanent magnets are disposed in the magnetic steel slots. The auxiliary slots are arranged circumferentially between adjacent magnetic steel slots and are located on the outer edge of the rotor core. The auxiliary slots between two adjacent magnetic steel slots are symmetrical about the d-axis. The auxiliary slots open on the side facing the outer circle of the rotor core, and the maximum pole arc coefficient of the opening is b. The pole arc coefficient between the sidewalls of two adjacent permanent magnets near the d-axis is c, and 0.01≤b / c≤0.03. The auxiliary slots are arranged evenly on the outer edge of the rotor, and the auxiliary slots between every two magnet slots are symmetrical about the d-axis to ensure that the symmetry of the rotor magnetic field is not affected by the slotting. The maximum pole arc coefficient of the auxiliary slot opening is limited to b, which prevents the auxiliary slots from becoming too large and reducing the mechanical strength of the rotor. The range of the ratio b / c between the maximum pole arc coefficient of the auxiliary slot opening and the pole arc coefficient c of the included angle between the iron cores of two adjacent permanent magnets can effectively reduce cogging torque and reduce torque pulsation. By slotting the outer edge of the rotor iron core, the harmonic content of the air gap magnetic flux density of the motor is reduced, the sinusoidality of the back electromotive force of the permanent magnet synchronous motor is increased, the harmonic loss problem of the permanent magnet motor under the drive of the frequency converter is improved, the motor loss is reduced, and the motor efficiency is improved. Through the design of the auxiliary slots and magnet slots, the leakage flux and torque pulsation of the tangential motor are suppressed, and the output torque quality of the motor is improved without reducing the torque output capability. Attached Figure Description

[0031] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0032] Figure 1 A structural diagram of a tangential motor rotor structure according to an embodiment of the present invention is shown;

[0033] Figure 2 A structural diagram of a tangential motor rotor structure according to an embodiment of the present invention is shown;

[0034] Figure 3 A schematic diagram of the auxiliary slot of a tangential motor rotor structure according to an embodiment of the present invention is shown;

[0035] Figure 4 An exploded structural diagram of a tangential motor rotor structure according to an embodiment of the present invention is shown;

[0036] Figure 5 A comparison diagram of the output torque of the motor of an embodiment of the present invention and a motor of related technologies is shown;

[0037] Figure 6 A dimensional structural diagram of a tangential motor rotor structure according to an embodiment of the present invention is shown.

[0038] The above figures include the following reference numerals:

[0039] 1. Rotor core; 2. Permanent magnet; 3. Rotor laminations; 4. Auxiliary slots; 5. Magnet slots; 6. Shaft sleeves; 7. Shaft holes. Detailed Implementation

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] See also Figures 1 to 6 As shown, according to an embodiment of the present invention, the tangential motor rotor structure includes a rotor core 1 and a permanent magnet 2. The rotor core 1 is provided with a magnetic steel slot 5 and an auxiliary slot 4. The permanent magnet 2 is disposed in the magnetic steel slot 5. The auxiliary slot 4 is circumferentially spaced between adjacent magnetic steel slots 5 and located on the outer edge of the rotor core 1. The auxiliary slot 4 between two adjacent magnetic steel slots 5 is symmetrical about the d-axis. The auxiliary slot 4 opens on one side facing the outer circle of the rotor core 1, and the maximum pole arc coefficient of the opening is b. The pole arc coefficient between the side walls of two adjacent permanent magnets 2 near the d-axis is c, and 0.01≤b / c≤0.03.

[0042] The auxiliary slots 4 are evenly arranged on the outer edge of the rotor, and the auxiliary slots 4 between every two magnet slots 5 are symmetrical about the d-axis to ensure that the symmetry of the rotor magnetic field is not affected by the slotting. The maximum pole arc coefficient of the opening of the auxiliary slot 4 is limited to b, which can prevent the auxiliary slot 4 from being too large and thus prevent the reduction of the rotor's mechanical strength. The range of the ratio b / c between the maximum pole arc coefficient of the opening of the auxiliary slot 4 and the pole arc coefficient c of the included angle between the iron cores of two adjacent permanent magnets 2 can effectively reduce the cogging torque and reduce torque pulsation. By slotting the outer edge of the rotor iron core 1, the harmonic content of the air gap magnetic flux density of the motor is reduced, the sinusoidality of the back electromotive force of the permanent magnet synchronous motor is increased, the harmonic loss problem of the permanent magnet motor under the drive of the frequency converter is improved, the motor loss is reduced, and the motor efficiency is improved. Through the design of the auxiliary slots 4 and magnet slots 5, the leakage flux and torque pulsation of the tangential motor are suppressed, and the output torque quality of the motor is improved without reducing the torque output capability.

[0043] In one embodiment, b / c = 0.02 can more effectively reduce cogging torque and further reduce torque pulsation.

[0044] In this embodiment, the rotor core is formed by stacking rotor laminations 3, and the rotor laminations 3 are provided with auxiliary slots 4 and magnet slots 5.

[0045] Within a cross-section perpendicular to the central axis of rotor core 1, the opening is symmetrical about the radial line of rotor core 1, which can further improve the sinusoidal nature of the back electromotive force of the permanent magnet synchronous motor and improve motor performance.

[0046] In one embodiment, the width of the opening is unequal in the radial outward direction along the rotor core 1. Limiting the unequal width of the opening of the auxiliary slot 4 facing the air gap along the radial direction of the rotor core 1 can increase the imbalance of the air gap between the stator and rotor and reduce air gap harmonics.

[0047] In one embodiment, the width of the opening decreases radially outward along the rotor core 1, which allows the change in opening width to match the change in magnetic field density. This can further reduce magnetic leakage and further reduce harmonic losses in permanent magnet motors driven by frequency converters, thereby reducing motor losses and improving motor efficiency.

[0048] In one embodiment, within a cross-section perpendicular to the central axis of the rotor core 1, the auxiliary slot 4 is shaped as a regular polygon, a circle, or an ellipse that is symmetrical about the radial line passing through the center of the auxiliary slot 4.

[0049] The shape of the auxiliary groove 4 is restricted to a regular polygon, a circle, or an ellipse, which can ensure that the magnetic field is symmetrical about the d-axis and reduce the difficulty of processing.

[0050] In one embodiment, the depth of the opening in the cross section perpendicular to the central axis of the rotor core 1 is h1, where h1 is the minimum distance between the auxiliary slot 4 and the outer circle of the rotor core 1 along the radial direction of the rotor core 1, and the outer diameter of the rotor core 1 is D, 0.006≤h1 / D≤0.02.

[0051] In one embodiment, 0.01 ≤ h1 / D ≤ 0.015.

[0052] Limiting the range of the ratio between the outer diameter of the rotor core 1 and the opening depth of the auxiliary slot 4 can optimize torque pulsation, increase the mechanical strength of the rotor, limit the slot depth, ensure that the magnetic bridges on both sides of the slot opening can better utilize saturation to reduce leakage flux, and reduce the harmonic content of the air gap magnetic flux density.

[0053] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 1, the opening of the auxiliary slot 4 extends from the outer circle of the rotor core 1 toward the shaft hole 7 of the motor rotor structure by a straight line, a curve, or a combination of a straight line and a curve. The angle between the tangent of the tangent at the outer circle of the rotor core 1 and the tangent of the rotor core 1 at the outer circle of the rotor core 1 is e, where 90°≤e≤180°.

[0054] In one embodiment, 100°≤e≤130°.

[0055] The angle between the tangent of the opening at the outer circle of the rotor core 1 extending tangentially to the shaft hole 7 of the motor rotor structure and the tangent at the outer circle of the rotor core 1 can better optimize the torque pulsation of the motor without reducing the output torque of the motor.

[0056] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 1, the polar arc coefficient of the angle between the radial lines containing the centers of two adjacent auxiliary slots 4 is α, where 0.07 ≤ α / c ≤ 0.16.

[0057] In one embodiment, 0.09 ≤ a / c ≤ 0.16.

[0058] The polar arc coefficient 'a', which limits the angle between the center diameters of two adjacent auxiliary slots 4, can improve the mechanical strength of the motor and prevent rotor deformation caused by excessive slotting, thus avoiding accidents during high-speed operation.

[0059] In one embodiment, the center of the auxiliary slot 4 is located on the first circumference, and multiple auxiliary slots 4 are arranged at intervals along the circumference of the first circumference. The diameter of the first circumference is D1, and the outer diameter of the rotor core 1 is D, where 0.8≤D1 / D≤0.95.

[0060] By limiting the diameter range of the trajectory where the center of the auxiliary slot 4 is located, it can be determined that the area of ​​the auxiliary slot 4 will not be too large, which would reduce the radial distance of the rotor core 1, cause oversaturation, and reduce the motor's output torque.

[0061] In one embodiment, 0.85 ≤ D1 / D ≤ 0.92.

[0062] In one embodiment, in a cross-section perpendicular to the central axis of the rotor core 1, along the circumferential direction of the rotor core 1, the maximum width of the auxiliary slot 4 is d1, (z1*d1) / (π*D)≤0.6, where z1 is the number of auxiliary slots 4 in the circumferential direction of the rotor core 1, and D is the outer diameter of the rotor core 1.

[0063] Limiting the maximum outer diameter of the auxiliary slot 4 serves two purposes: firstly, to ensure that the rotor does not deform under high-speed operation; and secondly, to ensure that the distance between the auxiliary slots 4 is not too small, which would reduce the main magnetic flux and decrease the motor's torque output capability.

[0064] In one embodiment, the depth of the opening in the cross-section perpendicular to the central axis of the rotor core 1 is h1, and the depth of the auxiliary groove 4 in the radial direction of the rotor core 1 is h3, where 0.1≤h1 / h3≤0.2.

[0065] Limiting the width and depth of the auxiliary slot 4 can ensure the mechanical strength of the rotor, and on the other hand, it can ensure that the magnetic bridge on the outer circle of the rotor core 1 can function and reduce magnetic leakage.

[0066] In one embodiment, the rotor core 1 includes multiple core blocks, and the tangential motor rotor structure also includes a bushing 6 with a shaft hole 7. The core blocks are arranged at intervals along the circumference of the bushing 6 and are fixedly connected to the bushing 6.

[0067] In this embodiment, the rotor structure adopts a design that combines the iron core segments with the bushing 6 for assembly. This design enhances the rotor's deformation during manufacturing and reduces the difficulty of the process.

[0068] During the processing, the rotor laminations 3 can be stacked to form multiple core blocks, and then the assembled core blocks can be joined together and spliced ​​into a complete core structure using bushings 6. The core blocks and bushings 6 can be fixedly connected together by means of adhesive bonding or other methods.

[0069] The magnetic steel groove 5 is formed by the interval arrangement of adjacent iron core blocks. The magnetic steel groove 5 is an open groove. The inner wall surface of the magnetic steel groove 5 is coated with adhesive. After the permanent magnet 2 is installed in the magnetic steel groove 5, it is fixed in the magnetic steel groove 5 by adhesive.

[0070] In one embodiment, in a cross section perpendicular to the central axis of the rotor core 1, the cross-sectional area of ​​the rotor core 1 is S1. The area between the circle containing the point farthest from the center of the shaft hole 7 of the bushing 6 and the inner wall of the shaft hole 7 forms a first region. The overlapping area between the cross section of the rotor core 1 and the first region is S2, where S2 ≤ S1 * 20%.

[0071] In this embodiment, the cross-sectional area of ​​the rotor core 1 is the projected area of ​​the rotor core on a plane perpendicular to the central axis of the rotor core 1, and the area of ​​the first region is the projected area of ​​the circle formed by the maximum outer diameter D2 of the bushing 6 on a plane perpendicular to the central axis of the rotor core 1. By limiting the proportional relationship between the overlapping area of ​​the projected area of ​​the circle formed by the maximum outer diameter D2 of the bushing 6 and the projected area of ​​the rotor core 1 and the projected area of ​​the rotor core 1, it can be ensured that the area of ​​the bushing 6 on the axial end face is not too large, so as not to affect the magnetic field distribution and torque output capability of the rotor.

[0072] In one embodiment, the maximum distance between the edge of the bushing 6 that contacts the rotor core 1 and the outer circle of the rotor core 1 is L1, and the height of the magnet slot 5 along the radial direction of the rotor core 1 is L3, where 0.8≤L1 / L3≤1.1.

[0073] Limiting the distance between the edge of the bushing 6 that contacts the rotor core 1 and the outer circle of the rotor core 1 allows the bushing 6 to better perform its fixing function and improves the mechanical strength of the rotor.

[0074] In this embodiment, the bushing 6 is a regular polygon, and the number of sides of the bushing 6 is the same as the number of permanent magnets 2. The magnetic groove 5 is located at the intersection of adjacent sides of the bushing 6. The adjacent sides of the bushing 6 are cut at the intersection, so that the adjacent sides of the bushing 6 form a plane at the mating position with the permanent magnet 2, which makes it easier to install and fix the permanent magnet 2.

[0075] In one embodiment, the maximum outer diameter of the bushing 6 is D2, the minimum outer diameter of the bushing 6 is D3, and 1.02≤D2 / D3≤1.2.

[0076] By limiting the maximum and minimum outer diameter of the bushing 6, the bushing 6 can better perform its fixing function and improve the mechanical strength of the rotor.

[0077] In this embodiment, the maximum outer diameter D2 of the bushing 6 is the circumscribed circle diameter of the bushing 6, and the minimum outer diameter of the bushing 6 is the inscribed circle diameter of the outer contour of the bushing 6.

[0078] In one embodiment, the length of the side of the bushing 6 that contacts the rotor core 1 is L4, and the circumferential width of the magnet slot 5 is L2, where 0.1≤L4 / L2≤3.1.

[0079] By limiting the length of the side of the bushing 6 that contacts the rotor core 1 and the width of the magnet slot 5, the bushing 6 can better fix the permanent magnet 2 and the rotor core 1.

[0080] In one embodiment, part of the magnetic slot 5 is located on the rotor core 1 and part is located on the bushing 6. The part of the magnetic slot 5 on the rotor core 1 and the part of the magnetic slot 5 on the bushing 6 are located in the same radial direction and together form a complete magnetic slot 5.

[0081] The two sides of the magnetic slot 5 are not limited to the rotor core 1; the rotor core 1 and the bushing 6 can also extend radially to form the magnetic slot 5. The diameter of the bushing 6 can be greater than the distance between the side of the permanent magnet 2 near the shaft hole 7 and the central axis of the shaft hole 7, so that part of the bushing 6 can be located between two adjacent permanent magnets 2. In this case, part of the end of the permanent magnet 2 near the shaft hole 7 is located inside the bushing 6, and the bushing 6 also forms part of the magnetic slot 5. This part of the magnetic slot 5 corresponds to the magnetic slot 5 formed by the rotor core 1 and cooperates to form a complete magnetic slot 5. The permanent magnet 2 is located in the magnetic slot 5 jointly formed by the bushing 6 and the rotor core 1, so that the bushing 6 can better play a fixing and magnetic isolation role without affecting the output torque capability.

[0082] In one embodiment, the overlapping area of ​​the projection of the circle with the maximum outer diameter D2 of the bushing 6 onto the axial direction of the rotor core 1 and the projection of the permanent magnet 2 onto the axial direction of the rotor core 1 is S3, and the total projected area of ​​the permanent magnet 2 onto the axial direction of the rotor core 1 is S4, where S3 / S4≤30%.

[0083] The area between the two magnet slots 5 is limited by the extension of the bushing 6, which can prevent the bushing 6 from obstructing the direction of the magnetic lines of force.

[0084] In one embodiment, the distance between the edge of the permanent magnet 2 near the outer circle of the rotor core 1 and the shaft hole 7 of the tangential motor rotor structure is greater than the radius of the circle containing the center of the auxiliary slot 4. The distance between the edge of the permanent magnet 2 near the outer circle of the rotor core 1 and the shaft hole 7 of the tangential motor rotor structure is the sum of the radial height h of the permanent magnet 2 and the distance h2 between the side of the permanent magnet 2 near the shaft hole 7 and the central axis of the shaft hole 7. This limitation ensures that (h+h2)>D1 / 2, thereby limiting the distance between the edge of the tangentially magnetized permanent magnet 2 near the outer circle of the rotor core 1 and the center of the auxiliary slot 4, thus suppressing radial magnetic leakage of the tangentially magnetized permanent magnet 2.

[0085] In one embodiment, the permanent magnet 2 has a height of h in the radial direction along the rotor core 1 and a width of L2 in the circumferential direction, where 2.0 ≤ h / L2 ≤ 2.5.

[0086] By limiting the ratio of the height h to the width L2 of the tangentially magnetized permanent magnet 2 to a suitable range, the utilization rate of the permanent magnet 2 can be improved.

[0087] In one embodiment, the auxiliary groove 4 is filled with a conductive but non-magnetic material. In one embodiment, the conductive but non-magnetic material is, for example, a copper strip or an aluminum strip.

[0088] Taking copper bars as an example, copper bars are inserted into auxiliary slots 4 that are evenly distributed circumferentially along the outer circumference of the rotor core 1. The copper bars in the auxiliary slots 4 need to be fixed in accordance with the dimensions of the auxiliary slots 4. This can be achieved by interference fit or by adhesive bonding. Adding copper bars can ensure that the area within the auxiliary slots 4 is non-magnetic and maintain the non-uniformity of the air gap, reducing torque pulsation and increasing the starting torque of the motor.

[0089] See also Figure 5 As shown, after adopting the rotor structure of this embodiment, compared with the prior art, the output torque of the motor of this embodiment remains basically unchanged, the torque pulsation is reduced by 8%, and the motor performance is significantly improved.

[0090] See also Figure 6 As shown, after adopting the rotor structure of this embodiment, compared with the prior art, the cogging torque of the motor of this embodiment is reduced by more than 70%, the harmonic content of the air gap magnetic flux density is significantly reduced, the torque pulsation of the motor is significantly suppressed, and the motor performance is significantly improved.

[0091] According to an embodiment of the present invention, the motor includes a tangential motor rotor structure, which is the tangential motor rotor structure described above.

[0092] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0093] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tangential motor rotor structure, characterized in that, The rotor core (1) includes a rotor core (1) and a permanent magnet (2). The rotor core (1) is provided with a magnetic steel slot (5) and an auxiliary slot (4). The permanent magnet (2) is disposed in the magnetic steel slot (5). The auxiliary slot (4) is disposed circumferentially between adjacent magnetic steel slots (5) and located on the outer edge of the rotor core (1). The auxiliary slot (4) between two adjacent magnetic steel slots (5) is symmetrical about the d-axis. The auxiliary slot (4) opens to the side facing the outer circle of the rotor core (1) and the maximum polar arc coefficient of the opening is b. The polar arc coefficient between the side walls of two adjacent permanent magnets (2) near the d-axis is c, and 0.01≤b / c≤0.

03. In the cross section perpendicular to the central axis of the rotor core (1), the depth of the opening is h1, where h1 is the minimum distance between the auxiliary groove (4) and the outer circle of the rotor core (1) along the radial direction of the rotor core (1), and the outer diameter of the rotor core (1) is D, 0.006≤h1 / D≤0.02; In a cross section perpendicular to the central axis of the rotor core (1), the opening of the auxiliary groove (4) extends from the outer circle of the rotor core (1) toward the shaft hole (7) of the tangential motor rotor structure. The tangent edge of the tangent edge at the outer circle of the rotor core (1) and the tangent of the rotor core (1) at the outer circle of the rotor core (1) is e, where 90°≤e≤180°.

2. The tangential motor rotor structure according to claim 1, characterized in that, b / c = 0.

02.

3. The tangential motor rotor structure according to claim 1, characterized in that, The width of the opening is not equal along the radial outward direction of the rotor core (1); and / or, in a cross section perpendicular to the central axis of the rotor core (1), the opening is symmetrical about the radial line of the rotor core (1).

4. The tangential motor rotor structure according to claim 3, characterized in that, The width of the opening decreases radially outward along the rotor core (1).

5. The tangential motor rotor structure according to claim 1, characterized in that, 0.01≤h1 / D≤0.

015.

6. The tangential motor rotor structure according to claim 1, characterized in that, 100°≤e≤130°。 7. The tangential motor rotor structure according to claim 1, characterized in that, In a cross section perpendicular to the central axis of the rotor core (1), the polar arc coefficient of the angle between the radial lines containing the centers of two adjacent auxiliary slots (4) is a, 0.07≤a / c≤0.

16.

8. The tangential motor rotor structure according to claim 7, characterized in that, 0.09≤a / c≤0.

16.

9. The tangential motor rotor structure according to claim 1, characterized in that, In a cross section perpendicular to the central axis of the rotor core (1), the auxiliary groove (4) is a regular polygon, a circle, or an ellipse that is symmetrical about the radial line passing through the center of the auxiliary groove (4).

10. The tangential motor rotor structure according to claim 1, characterized in that, The center of the auxiliary groove (4) is located on the first circumference, and multiple auxiliary grooves (4) are arranged at intervals along the circumference of the first circumference. The diameter of the first circumference is D1, and the outer diameter of the rotor core (1) is D, 0.8≤D1 / D≤0.

95.

11. The tangential motor rotor structure according to claim 10, characterized in that, 0.85≤D1 / D≤0.

92.

12. The tangential motor rotor structure according to claim 1, characterized in that, In a cross section perpendicular to the central axis of the rotor core (1), along the circumferential direction of the rotor core (1), the maximum width of the auxiliary slot (4) is d1, (z1*d1) / (π*D)≤0.6, where z1 is the number of auxiliary slots (4) of the rotor core (1) in the circumferential direction, and D is the outer diameter of the rotor core (1).

13. The tangential motor rotor structure according to claim 1, characterized in that, In a cross section perpendicular to the central axis of the rotor core (1), the depth of the opening is h1, and the depth of the auxiliary groove (4) along the radial direction of the rotor core (1) is h3, 0.1≤h1 / h3≤0.

2.

14. The tangential motor rotor structure according to claim 1, characterized in that, The rotor core (1) includes multiple core blocks, and the tangential motor rotor structure also includes a bushing (6). The bushing (6) has a shaft hole (7). The core blocks are arranged at intervals along the circumference of the bushing (6) and are fixedly connected to the bushing (6).

15. The tangential motor rotor structure according to claim 14, characterized in that, In the cross section perpendicular to the central axis of the rotor core (1), the cross-sectional area of ​​the rotor core (1) is S1. The area between the circle where the farthest point of the bushing (6) from the center of the shaft hole (7) is located and the inner wall of the shaft hole (7) forms a first region. The overlapping area between the cross section of the rotor core (1) and the first region is S2, where S2 ≤ S1 * 20%.

16. The tangential motor rotor structure according to claim 14, characterized in that, The maximum distance between the side of the bushing (6) that contacts the rotor core (1) and the outer circle of the rotor core (1) is L1, and the height of the magnetic groove (5) along the radial direction of the rotor core (1) is L3, 0.8≤L1 / L3≤1.

1.

17. The tangential motor rotor structure according to claim 14, characterized in that, The maximum outer diameter of the bushing (6) is D2, and the minimum outer diameter of the bushing (6) is D3, where 1.02≤D2 / D3≤1.

2.

18. The tangential motor rotor structure according to claim 14, characterized in that, The length of the side of the bushing (6) that contacts the rotor core (1) is L4, and the circumferential width of the magnet slot (5) is L2, 0.1≤L4 / L2≤3.

1.

19. The tangential motor rotor structure according to claim 14, characterized in that, Part of the magnetic steel groove (5) is located on the rotor core (1) and part is located on the bushing (6). The part of the magnetic steel groove (5) on the rotor core (1) and the part of the magnetic steel groove (5) on the bushing (6) are located in the same radial direction and together form a complete magnetic steel groove (5).

20. The tangential motor rotor structure according to claim 19, characterized in that, The maximum outer diameter D2 of the bushing (6) is the circle whose projection on the rotor core (1) in the axial direction coincides with the projection of the permanent magnet (2) on the rotor core (1) in the axial direction. The total projected area of ​​the permanent magnet (2) on the rotor core (1) in the axial direction is S4, and S3 / S4≤30%.

21. The tangential motor rotor structure according to claim 1, characterized in that, The distance between the edge of the permanent magnet (2) near the outer circle of the rotor core (1) and the shaft hole (7) of the tangential motor rotor structure is greater than the radius of the circle where the center of the auxiliary groove (4) is located; and / or, the auxiliary groove (4) is filled with a conductive but non-magnetic material.

22. The tangential motor rotor structure according to claim 1, characterized in that, The permanent magnet (2) has a height of h in the radial direction along the rotor core (1) and a width of L2 in the circumferential direction, where 2.0 ≤ h / L2 ≤ 2.

5.

23. An electric motor, comprising a tangential motor rotor structure, characterized in that, The tangential motor rotor structure is the tangential motor rotor structure according to any one of claims 1 to 22.

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