Rotor core, rotor assembly and motor

Abstract

The invention relates to a rotor core, a rotor assembly and a motor. The rotor iron core comprises an iron core body; the shaft hole is formed in the axis of the iron core body in the axial direction; the containing groove is formed in the iron core body in the axial direction; and the magnetic isolation bridge is defined and formed by a part between the radial outer side edge of the accommodating groove and the peripheral edge of the iron core body. Wherein a part of magnetic isolation bridges in a part of punching sheets in the rotor iron core are cancelled, so that the magnetic isolation bridges are provided with gaps in the axial direction. According to the utility model, magnetic flux leakage of the rotor iron core at the position can be reduced through the magnetic isolation bridges without the number of parts of the punching sheets, and the overall air gap magnetic flux is increased, so that the performance of the motor is improved, or the size of the rare earth magnetic steel can be reduced under the same performance requirement to save the cost. All the punching sheets are connected and fixed by adopting a unified buckling point riveting, welding or gluing mode, so that the mechanical strength of the rotor iron core can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a rotor core, a rotor assembly and a motor. Background Art

[0002] The motor includes a rotor and a stator, wherein the rotor includes a rotating shaft, a rotor core and a permanent magnet. In the related art, the rotor core can be formed by a plurality of laminations. Each lamination has a magnetic isolation bridge. The smaller the thickness of the magnetic isolation bridge, the better it can prevent the flow of magnetic lines of force and the better the motor performance. However, in terms of mechanical strength, if the thickness of the magnetic isolation bridge is too small, the structural strength of the rotor core will be reduced. In particular, when the motor is rotating at high speed, due to the effect of centrifugal force, if the thickness of the magnetic isolation bridge is too small, its structure will be weak and prone to breakage. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a rotor core, a rotor assembly and a motor.

[0004] The rotor core provided by the embodiment of the present invention comprises: a core body, which is formed by a plurality of punching sheets coaxially stacked in the axial direction; an axial hole, which is opened in the axial center of the core body in the axial direction; a receiving groove, which is opened in the axial direction on the core body; and a magnetic isolation bridge, which is defined and formed by the portion between the radial outer side of the receiving groove and the outer peripheral edge of the core body. Part of the magnetic isolation bridge is eliminated so that the magnetic isolation bridge has a gap in the axial direction. The plurality of punching sheets include at least one first punching sheet and at least one second punching sheet stacked axially; the first punching sheet has all of the magnetic isolation bridges, and the second punching sheet eliminates part of the magnetic isolation bridges.

[0005] According to some embodiments of the present invention, among the plurality of punches, the 2n-1th punch is the first punch, and the 2nth punch is the second punch, where n is a positive integer.

[0006] According to some embodiments of the present invention, among the multiple punches, the 3n-2th punch is the first punch, and the 3n-1th punch is the second punch, where n is a positive integer; or, the 3n-2th and 3n-1th punch are the first punch, and the 3nth punch is the second punch, where n is a positive integer.

[0007] According to some embodiments of the present invention, each of the punching sheets is provided with a plurality of magnetic isolation bridge positions, wherein the magnetic isolation bridges of some magnetic isolation bridge positions in each of the punching sheets are cancelled, and the magnetic isolation bridges of another part of the magnetic isolation bridge positions are retained. The plurality of punching sheets are relatively rotated by a certain angle in the circumferential direction so that the magnetic isolation bridge positions where the magnetic isolation bridges are cancelled and the magnetic isolation bridge positions where the magnetic isolation bridges are retained are arranged correspondingly in the axial direction.

[0008] According to some embodiments of the present invention, two adjacent punching sheets are rotated relative to each other by a certain angle in the circumferential direction so that the magnetic isolation bridge position of one of the two adjacent punching sheets where the magnetic isolation bridge is canceled and the magnetic isolation bridge position of the other one where the magnetic isolation bridge is retained are arranged alternately in the axial direction correspondingly.

[0009] According to some embodiments of the present invention, a groove structure recessed toward the radial inside is provided on the radial outer edge of the punching sheet; and a plurality of punching sheets in the rotor core are welded at the groove structure.

[0010] According to some embodiments of the present invention, the plurality of punching sheets are fixedly connected by at least one of riveting, welding and gluing.

[0011] According to some embodiments of the present invention, the magnetic isolation bridges are evenly arranged in the circumferential direction.

[0012] An embodiment of the present invention further provides a rotor assembly, comprising the rotor core, permanent magnets and rotor shaft as described above, wherein the rotor core is sleeved on the rotor shaft through the shaft hole; and the permanent magnets are arranged in the accommodating grooves.

[0013] An embodiment of the present invention further provides a motor, comprising the rotor assembly and the stator assembly as described above; wherein the rotor assembly and the stator assembly are coaxially arranged to be relatively rotatable.

[0014] An embodiment of the present invention also provides a vehicle transmission system, comprising a torque transfer device, an engine and a gearbox according to any one of the above embodiments; one axial end of the torque transfer device is connected to the engine, and the other axial end of the torque transfer device is connected to the gearbox.

[0015] In the field of motor technology, the present invention provides a rotor core, a rotor assembly and a motor. By eliminating a part of the magnetic isolation bridges in some of the punching sheets in the rotor core, the magnetic leakage of the rotor core can be reduced, the motor performance can be improved, or the use of rare earth magnets can be reduced to save costs under the same performance requirements.

[0016] In addition, the punching sheets without the magnetic isolation bridge and the punching sheets without the magnetic isolation bridge are arranged alternately to ensure the mechanical strength of the iron core to resist the rotating centrifugal force. At the same time, multiple punching sheets are connected by riveting, welding or gluing to ensure the overall mechanical strength of the rotor iron core. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 A three-dimensional schematic diagram of a rotor core according to an embodiment of the present invention is shown;

[0019] Figure 2 A front view of a first punching sheet according to an embodiment of the present invention is shown;

[0020] Figure 3 A partial enlarged schematic diagram of a first punching sheet according to an embodiment of the present invention is shown;

[0021] Figure 4 A front view of a second punching sheet according to an embodiment of the present invention is shown;

[0022] Figure 5 A partial enlarged schematic diagram of a second punching sheet according to an embodiment of the present invention is shown;

[0023] Figure 6 A partial side view of a rotor core according to an embodiment of the present invention is shown;

[0024] Figure 7 A partial enlarged schematic diagram of a rotor core according to an embodiment of the present invention is shown;

[0025] Figure 8 A partial side view of a punching sheet according to an embodiment of the present invention is shown;

[0026] Fig. 9 A partial schematic diagram showing a rotor core according to an embodiment of the present invention; and

[0027] Fig.10 A schematic structural diagram of a rotor assembly according to an embodiment of the present invention is shown.

[0028] It should be understood that the above drawings are merely schematic and are not drawn according to actual scale. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0030] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "include" or "comprises" and the like used in the embodiments of the present invention mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Up", "down", etc. are only used with respect to the orientation of the components in the drawings. These directional terms are relative concepts. They are used for description and clarification with respect to the components, and they may change accordingly according to the change of the orientation of the components in the drawings.

[0031] The purpose of the present invention is to minimize the magnetic isolation bridge in the field of motors to reduce the magnetic leakage of the rotor core in the motor, improve the motor performance or reduce the volume of the magnetic steel, while meeting the structural strength of the rotor core.

[0032] Figure 1 FIG. 2 shows a three-dimensional schematic diagram of a rotor core 10 according to an embodiment of the present invention. Figure 1 As shown, the rotor core 10 comprises: a core body 11, an axial hole 12, a receiving groove 13 and a magnetic isolation bridge 14. The core body 11 can be made of a soft magnetic material, such as silicon steel.

[0033] Specifically, the shaft hole 12 is opened along the axial direction at the axis of the core body 11, and the shaft hole 12 is used for the rotor shaft of the rotor assembly to pass therethrough. The receiving groove 13 is opened along the axial direction on the core body 11; the receiving groove 13 is used to accommodate permanent magnets; there can be multiple receiving grooves 13, which are evenly spaced around the center of the circle along the circumferential direction on the core body 11, so that a uniform rotor magnetic field can be generated, and the stator magnetic field works together to generate mechanical energy, so that the core 11 drives the rotation of the shaft in the shaft hole 12, and outputs the speed and torque to the outside. The magnetic isolation bridge 14 is defined and formed by the portion between the radial outer side of the receiving groove 13 and the outer peripheral edge of the core body 10.

[0034] Furthermore, if Figure 1As shown, the thickness T of the magnetic isolation bridge 14 is the distance in the radial direction between the radial outer side of the accommodating groove 13 and the outer peripheral edge of the core body 10. Since the magnetic lines of force allowed to pass through the unit cross-sectional area of ​​the core are certain, that is, the electromagnetic density is certain, reducing the thickness T of the magnetic isolation bridge can reduce the magnetic lines of force flowing to the magnetic isolation bridge, and make this part of the reduced magnetic lines of force flow to the air gap direction, that is, the space between the inner diameter of the stator and the outer diameter of the rotor, and then flow to the inside of the stator core to complete the closure of the magnetic circuit. This will make more magnetic lines of force flow to the air gap, thereby strengthening the strength of the air gap magnetic field, which is beneficial to improving the efficiency of the motor. However, in terms of mechanical strength, if the thickness of the magnetic isolation bridge 14 is too small, it will reduce the structural strength of the rotor core 10. Therefore, in some embodiments of the present application, in order to reduce the rotor magnetic leakage of the motor, some magnetic isolation bridges in some punching sheets in the iron core are eliminated so that the magnetic isolation bridge 14 has a gap in the axial direction. In order to avoid strength problems caused by eliminating the magnetic isolation bridge, the punching sheets with the magnetic isolation bridge eliminated and the punching sheets with the magnetic isolation bridge not eliminated are stacked in a certain arrangement.

[0035] Specifically, in some embodiments of the present application, Figure 2 A front view of a first punching sheet 111a according to an embodiment of the present invention is shown; Figure 3 A partial enlarged schematic diagram of a first punching sheet 111a according to an embodiment of the present invention is shown; Figure 4 A front view of a second punching sheet 111b according to an embodiment of the present invention is shown; Figure 5 FIG. 2 shows a partially enlarged schematic diagram of a second punching sheet 111 b according to an embodiment of the present invention. Figure 1-5 As shown, the core body 11 is formed by a plurality of punching sheets 111 coaxially stacked in the axial direction. The plurality of punching sheets 111 include at least one first punching sheet 111a and at least one second punching sheet 111b. The first punching sheet 111a has the magnetic isolation bridge 14, and the second punching sheet 111b does not have the magnetic isolation bridge 14.

[0036] Further, Figure 6 A partial side view of a rotor core 10 according to an embodiment of the present invention is shown; Figure 7 FIG. 1 is a partial enlarged schematic diagram of a rotor core 10 according to an embodiment of the present invention. Figure 1-7 As shown, in some embodiments, among the plurality of punches 111 stacked in the axial direction, the 2n-1th punch 111 is the first punch 111a, and the 2nth punch 111 is the second punch 111b, where n is a positive integer. That is, the first punch 111a and the second punch 111b are alternately arranged. For example Figure 6As shown in , the positions of the magnetic isolation bridges 14 on each punching sheet 111 are aligned in the axial direction, and the side view of the rotor core 10 shows that the magnetic isolation bridges 14 and the gaps in which the magnetic isolation bridges 14 are eliminated are alternately arranged in the axial direction. In this way, eliminating the gaps in the magnetic isolation bridges 14 can reduce magnetic leakage and improve motor performance, and retaining a portion of the magnetic isolation bridges 14 can take into account the structural strength of the rotor core 10.

[0037] In other embodiments, the first punching sheet 111a and the second punching sheet 111b may also be stacked in other ways. For example, among the multiple punching sheets 111 stacked in the axial direction, the 3n-2 punching sheet 111 is the first punching sheet 111a, and the 3n and 3n-1 punching sheets 111 are the second punching sheets 111b, where n is a positive integer. Through such an arrangement, there is a first punching sheet 111a with the magnetic isolation bridge 14 in every three punching sheets 111, and there are two second punching sheets 111b without the magnetic isolation bridge 14, which can further improve the motor performance compared with the previous embodiment.

[0038] In some other embodiments, the first punching sheet 111a and the second punching sheet 111b may also be stacked in other ways. For example, among the multiple punching sheets 111 stacked in the axial direction, the 3n-2 and 3n-1 punching sheets 111 are the first punching sheets 111a, and the 3n-1 punching sheets 111 are the second punching sheets 111b, where n is a positive integer. Through such an arrangement, two of every three punching sheets 111 have the first punching sheets 111a of the magnetic isolation bridge 14, and one second punching sheet 111b without the magnetic isolation bridge 14. Compared with the previous embodiment, the structural strength of the rotor core 10 can be further improved.

[0039] Of course, the first punching sheet 111a and the second punching sheet 111b can also have other stacking arrangements, such as arranging more punching sheets 111 as a group in a cycle, and the ratio of the first punching sheet 111a and the second punching sheet 111b can also be flexibly adjusted as needed, which will not be repeated here. In practical applications, based on the actual situation, on the basis of meeting the structural strength of the rotor core 10, the magnetic isolation bridge 14 can be reduced as much as possible, that is, the second punching sheet 111b can be used as much as possible to reduce magnetic leakage and improve motor performance.

[0040] In some other embodiments, the punching sheet 111 can also be arranged to have multiple magnetic isolation bridge positions, and the magnetic isolation bridge positions are positions where the magnetic isolation bridge 14 is provided and positions where the magnetic isolation bridge 14 is cancelled. Among them, the magnetic isolation bridges 14 at some magnetic isolation bridge positions are cancelled, and the magnetic isolation bridges 14 at other magnetic isolation bridge positions are retained. Optionally, in the same punching sheet 111, the magnetic isolation bridge positions where the magnetic isolation bridge 14 is cancelled and the magnetic isolation bridge positions where the magnetic isolation bridge 14 is retained are arranged symmetrically and evenly spaced in the circumferential direction. The stacking arrangement of the multiple punching sheets 111 can be: the multiple punching sheets 111 are relatively rotated by a certain angle in the circumferential direction, so that the magnetic isolation bridge positions where the magnetic isolation bridge 14 is cancelled and the magnetic isolation bridge positions where the magnetic isolation bridge 14 is retained are arranged correspondingly in the axial direction. Taking two punching sheets 111 as a group of cyclic stacking arrangement as an example, two adjacent punching sheets 111 are relatively rotated by a certain angle in the circumferential direction so that the magnetic isolation bridge position of one of the two adjacent punching sheets 111 that cancels the magnetic isolation bridge 14 and the magnetic isolation bridge position of the other that retains the magnetic isolation bridge 14 are alternately arranged in a corresponding position in the axial direction. In this way, the rotor core 10 can also realize the magnetic isolation bridge position of the magnetic isolation bridge 14 being canceled and the magnetic isolation bridge position of the magnetic isolation bridge 14 being alternately arranged in a corresponding position in the axial direction.

[0041] It should be understood that the stacking arrangement of the multiple punching sheets 111 can also be: more punching sheets 111 are arranged in a cycle as a group, and in the axial direction at the same position, the ratio of the magnetic isolation bridge position where the magnetic isolation bridge 14 is cancelled and the magnetic isolation bridge position where the magnetic isolation bridge 14 is retained can also be flexibly adjusted as needed, which will not be repeated here.

[0042] In some embodiments of the present application, there may be multiple ways of fixing the plurality of punching sheets 111 . Figure 8 FIG. 2 shows a partial side view of a punch according to an embodiment of the present invention. Figure 8 As shown, one side of the punching sheet 111 in the axial direction has a protruding buckle point 112, and the other side of the punching sheet 111 in the axial direction has a recessed groove portion 113 at a position corresponding to the buckle point 112, and the multiple punching sheets 111 are fixedly connected by riveting the buckle point 112 and the groove portion 113.

[0043] In addition, the plurality of punching sheets 111 may be fixedly connected by welding. Fig. 9 FIG. 1 shows a partial schematic diagram of a rotor core 10 according to an embodiment of the present invention. Fig. 9As shown, a groove structure 114 recessed toward the radial inside is provided at the radial outer edge of the punching sheet 111. The multiple groove structures 114 of the multiple punching sheets 111 can be arranged correspondingly in the circumferential direction, which is conducive to welding all the punching sheets 111 in the rotor core 10 at the groove structures 114. Since the groove structure 114 is recessed toward the radial inside, it is possible to avoid the situation where the protrusions caused by welding cause the rotor assembly to interfere with the inner wall of the stator during rotation.

[0044] In addition, the plurality of punching sheets 111 may also be connected and fixed by gluing.

[0045] In some embodiments of the present application, the plurality of punching sheets 111 in the rotor core 10 may be fixedly connected by any one of riveting, welding and gluing, or may be fixedly connected by a combination of multiple methods. Fig. 9 The black line features are welding seams 115, the rectangular features in the rotor core 10 are buckle points 112 in riveting, and glue can be coated between each two adjacent punching sheets 111, so that the multiple punching sheets 111 cannot be separated from each other.

[0046] Some embodiments of the present application also provide a rotor assembly. Fig.10 FIG. 2 shows a schematic diagram of the structure of a rotor assembly according to an embodiment of the present invention. Fig.10 As shown, the rotor assembly includes a rotor core 10, a permanent magnet 20 and a rotor shaft 30 as described in any one of the above embodiments. The rotor core 10 is sleeved on the rotor shaft 30 through the shaft hole 12; and the permanent magnet 20 is disposed in the receiving groove 13.

[0047] Some embodiments of the present application further provide a motor, comprising a rotor assembly as described in the above embodiments, and a stator assembly; wherein the rotor assembly and the stator assembly are coaxially arranged to be relatively rotatable.

[0048] It should be understood that the shape structure, quantity and stacking arrangement of the punching sheets 111 described in the technical solution of the present invention can be changed in various ways and are not limited to the types described in the embodiments and shown in the drawings.

[0049] Although possible embodiments are described exemplarily in the above description, it should be understood that there are still a large number of variations of embodiments through all known and other technical features and embodiments that can be easily thought of by the skilled person. It should also be understood that the exemplary embodiments are only examples and such embodiments do not limit the scope of protection, application and construction of the present invention in any form. The above description is more to provide a technical guide for converting at least one exemplary embodiment to the skilled person, wherein various changes can be made, especially changes in the functions and structures of the components, as long as they do not depart from the scope of protection of the claims.

[0050] Reference numerals list

[0051] 10. Rotor core; 11. Core body; 111. Punching sheet; 111a. First punching sheet; 111b. Second punching sheet; 112. Buckle point; 113. Groove; 114. Groove structure; 115. Welding seam; 12. Shaft hole; 13. Accommodating groove; 14. Magnetic isolation bridge;

[0052] 20.Permanent magnet;

[0053] 30. Rotor shaft;

[0054] T. Thickness of the magnetic isolation bridge.

Claims

1. A rotor core, characterized in that: include: An iron core body (11) is formed by a plurality of punching sheets (111) coaxially stacked in an axial direction; An axial hole (12) is opened along the axial direction at the axis of the core body (11); a receiving groove (13) which is opened on the core body (11) along the axial direction; and A magnetic isolation bridge (14), which is defined and formed by the portion between the radial outer side of the accommodating groove (13) and the outer peripheral edge of the core body (11); Part of the magnetic isolation bridge (14) is removed so that the magnetic isolation bridge (14) has a gap in the axial direction; The plurality of punching sheets (111) include at least one first punching sheet (111a) and at least one second punching sheet (111b) stacked axially; wherein the first punching sheet (111a) has all of the magnetic isolation bridges (14), and the second punching sheet (111b) eliminates part of the magnetic isolation bridges (14).

2. The rotor core according to claim 1, characterized in that: Among the plurality of punches (111), the 2n-1th punch (111) is the first punch (111a), and the 2nth punch (111) is the second punch (111b), wherein n is a positive integer.

3. The rotor core according to claim 1, characterized in that: In the plurality of punching sheets (111), The 3n-2 th punch (111) is the first punch (111a), and the 3n and 3n-1 th punches (111) are the second punches (111b), wherein n is a positive integer; or The 3n-2nd and 3n-1st punching sheets (111) are the first punching sheets (111a), and the 3nth punching sheet (111) is the second punching sheet (111b), wherein n is a positive integer.

4. The rotor core according to claim 1, characterized in that: Each of the punching sheets (111) is provided with a plurality of magnetic isolation bridge positions, wherein the magnetic isolation bridges (14) at some of the magnetic isolation bridge positions in each of the punching sheets (111) are cancelled, and the magnetic isolation bridges (14) at another part of the magnetic isolation bridge positions are retained; The plurality of punching sheets (111) are relatively rotated by a certain angle in the circumferential direction so that the positions of the magnetic isolation bridges (14) that are eliminated and the positions of the magnetic isolation bridges (14) that are retained are arranged correspondingly in the axial direction.

5. The rotor core according to claim 4, characterized in that: Two adjacent punching sheets (111) are relatively rotated by a certain angle in the circumferential direction so that the magnetic isolation bridge position of one of the two adjacent punching sheets (111) where the magnetic isolation bridge (14) is cancelled and the magnetic isolation bridge position of the other where the magnetic isolation bridge (14) is retained are alternately arranged in a corresponding position in the axial direction.

6. The rotor core according to claim 1, characterized in that: A groove structure (114) recessed radially inward is provided on the radially outer edge of the punching sheet (111); and a plurality of punching sheets (111) in the rotor core (10) are welded at the groove structure (114).

7. The rotor core according to claim 1, characterized in that: The plurality of punching sheets (111) are fixedly connected by at least one of riveting, welding and gluing.

8. The rotor core according to claim 1, characterized in that: The magnetic isolation bridges (14) are evenly arranged in the circumferential direction.

9. A rotor assembly, comprising a rotor core (10), a permanent magnet (20) and a rotor shaft (30) according to any one of claims 1 to 8; wherein: The rotor core (10) is sleeved on the rotor shaft (30) through the shaft hole (12); and the permanent magnet (20) is arranged in the accommodating groove (13).

10. A motor, comprising the rotor assembly and the stator assembly according to claim 9; wherein: The rotor assembly and the stator assembly are coaxially arranged to be relatively rotatable.

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