Rotor of synchronous reluctance motor and synchronous reluctance motor

Abstract

The present invention relates to a rotor of a synchronous reluctance motor and the synchronous reluctance motor. The rotor comprises: a plurality of magnetic flux guide groups arranged in the circumferential direction, each magnetic flux guide group comprising a plurality of arc-shaped rotor blocks spaced apart and independent from each other in the radial direction, wherein the plurality of rotor blocks are fixed by casting a non-magnetic material and form an integral rotor together with the cast non-magnetic material, and the non-magnetic material located radially between the plurality of rotor blocks constitutes magnetic barrier portions of the rotor. According to the present invention, the non-magnetic material is cast around the discrete rotor blocks to form the integral rotor, thereby improving the torque density and efficiency of the motor while enhancing the mechanical strength, simplifying the manufacturing process, reducing the cost, and improving the recyclability and environmental performance.

Description

Synchronous reluctance motor rotor and synchronous reluctance motor Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a synchronous reluctance motor rotor and a synchronous reluctance motor. Background Technology

[0002] With the continuous development of motor technology, the requirements for motor cost and reliability are increasing. Synchronous Reluctance Motors (SRMs), due to their rotor's elimination of permanent magnets or insulated windings, have become a promising solution. The rotor of a SRM typically uses magnetic barriers to guide the magnetic flux path, increasing the difference in reluctance between the direct and quadrature axes, thereby improving the motor's torque output and efficiency. Magnetic barriers are non-magnetic regions in the rotor designed to guide the magnetic flux path, typically composed of air or non-magnetic materials.

[0003] Patent CN219458765U discloses a typical synchronous reluctance motor rotor plate, which includes multiple magnetic barrier regions and magnetic barrier connecting bridges (such as 301, 401, 501). The magnetic barrier regions are air slots formed by stamping on a complete circular rotor plate. The magnetic barrier connecting bridges are used to connect the magnetic barrier regions to ensure the strength of the rotor plate. However, the presence of these magnetic flux connecting bridges brings about obvious magnetic leakage problems, resulting in a low torque density of the synchronous reluctance motor.

[0004] To overcome this technical problem, several improvements have been proposed in related technologies. For example, patent CN118801599A increases torque density by filling some air slots with permanent magnet material. Patent CN118783716A further enhances the motor's torque density by adding additional permanent magnets. However, while these solutions improve torque density to some extent, the introduction of permanent magnets not only makes the rotor structure more complex, increasing the manufacturing difficulty and cost of the motor, but also may lead to problems such as low reliability and short lifespan due to permanent magnet demagnetization.

[0005] Therefore, there is an urgent need for a new type of synchronous reluctance motor rotor structure. Summary of the Invention

[0006] To overcome the problems existing in the related technologies, this disclosure provides a synchronous reluctance motor rotor and a synchronous reluctance motor, which can effectively reduce magnetic flux leakage, increase torque density, simplify rotor structure, and reduce manufacturing costs without relying on permanent magnets.

[0007] According to a first aspect of the present disclosure, a synchronous reluctance motor rotor is provided, comprising: a plurality of flux guiding groups arranged circumferentially, each flux guiding group comprising a plurality of radially spaced and mutually independent arc-shaped rotor blocks; wherein the plurality of rotor blocks are fixed by casting a non-magnetic material and form an integral rotor with the non-magnetic material, the cast non-magnetic material constituting a magnetic barrier portion of the rotor.

[0008] In some embodiments, the flux guiding group includes multiple layers of rotor blocks along the axial direction, with adjacent layers of rotor blocks fixedly connected and separated by connecting columns.

[0009] In some embodiments, the flux guiding group includes at least a first rotor block, a second rotor block, and a third rotor block in the radial direction, wherein the first rotor block, the second rotor block, and the third rotor block are arranged from the radially outer side to the radially inner side, and the arc length gradually increases.

[0010] In some embodiments, the third rotor block consists of two blocks symmetrically distributed along the cross axis of the rotor.

[0011] In some embodiments, the synchronous reluctance motor rotor further includes a rotor cylinder arranged at the center of the plurality of flux guide groups, and the rotor cylinder is fixed to the plurality of flux guide groups by casting material.

[0012] In some embodiments, the radial outer wall of the rotor cylinder is uniformly arranged with axially extending connecting ribs along the circumferential direction.

[0013] In some embodiments, the two third rotor blocks form a circumferential gap, and a portion of the connecting rib of the rotor cylinder is inserted into the gap formed by the third rotor blocks.

[0014] In some embodiments, the circumferential ends of the plurality of rotor blocks are not connected, and after the non-magnetic material is cast, the non-magnetic material covers the axial end face and the circumferential end face of the rotor blocks.

[0015] In some embodiments, the rotor block has a plurality of axially extending and parallel concave grooves on its radial inner wall and / or radial outer wall.

[0016] According to a second aspect of the present disclosure, the present disclosure provides a synchronous reluctance motor, including a synchronous reluctance motor rotor as described in the first aspect.

[0017] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0018] By fixing independent and discrete rotor blocks with cast non-magnetic material to form a single rotor structure, the magnetic barrier connecting bridge in related technologies, where air slots serve as magnetic barriers, is eliminated. This optimizes the magnetic flux path, avoids magnetic leakage problems, and significantly improves the motor's torque density. Furthermore, the magnetic barrier section is cast from non-magnetic material, eliminating the need for permanent magnets, simplifying the rotor structure, reducing manufacturing costs, and avoiding reliability issues caused by permanent magnet demagnetization, thus extending the motor's lifespan. The magnetic flux guiding section is formed from discrete rotor blocks, avoiding material waste in traditional integral stamping processes, significantly improving material utilization, reducing manufacturing costs, and increasing the rotor block recycling rate, further reducing costs. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0020] Figure 1 is a schematic diagram of the arrangement of rotor blocks according to a first exemplary embodiment;

[0021] Figure 2 is a schematic diagram of the three-dimensional structure of the pre-injection rotor block according to the first exemplary embodiment;

[0022] Figure 3 is a schematic diagram of the three-dimensional structure of the injection-molded rotor block according to the first exemplary embodiment;

[0023] Figure 4 is a longitudinal sectional view of the rotor and shaft assembly shown in Figure 3;

[0024] Figure 5 is a cross-sectional view of the rotor and shaft assembly shown in Figure 3.

[0025] Figure 6 is a schematic diagram of the rotor block arrangement according to a second exemplary embodiment;

[0026] Figure 7 is a schematic diagram of the three-dimensional structure of the pre-injection rotor block according to the second exemplary embodiment;

[0027] Figure 8 is a schematic diagram of the three-dimensional structure of the injection-molded rotor block according to the second exemplary embodiment;

[0028] Figure 9 is a longitudinal sectional view of the rotor and shaft assembly shown in Figure 8;

[0029] Figure 10 is a cross-sectional view of the rotor and shaft in Figure 8. Detailed Implementation

[0030] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0031] In this invention, unless otherwise specified, axial A, radial R, and circumferential W refer to the axial A, radial R, and circumferential W of the rotor, respectively; radial outer side refers to the side of the rotor's outer circumference that is radially away from the central axis O in Figures 2 and 7, and radial inner side refers to the side radially close to the central axis O. "Torsion-resistant connection" refers to a connection between two components that can transmit torque, and the methods for achieving this torque-resistant connection can include interference fits and bolted connections, etc.

[0032] To address the aforementioned technical problems, this disclosure provides a synchronous reluctance motor rotor 100 for use in a synchronous reluctance motor. As shown in Figures 1 and 6, the rotor 100 structure includes multiple flux guide groups 101 arranged circumferentially W. Each flux guide group 101 includes multiple radially spaced and independent arc-shaped rotor blocks 10. The multiple rotor blocks 10 are fixed by casting non-magnetic material 20 and form an integral rotor with the non-magnetic material 20. The non-magnetic material 20 located radially between the rotor blocks constitutes the magnetic barrier portion of the rotor.

[0033] The rotor block 10 is formed by stacking multiple layers of electrical steel sheets of the same shape. The stacked rotor block 10 has a certain thickness, and the arc-shaped rotor block 10 includes a radial inner wall, a radial outer wall, and two circumferential ends. The multiple rotor blocks 10 are independent of each other, meaning that there is a certain interval between each rotor block 10 in the radial direction R, and there is no connection between the circumferential ends of each rotor block 10 in the circumferential direction W. The rotor block 10 is a completely independent arc-shaped structure, which allows the electrical steel sheets constituting the rotor block 10 to be manufactured using stamping processes of metal sheets of any shape. As shown in Figures 1, 2, 6, and 7, in the casting process of the non-magnetic material 20, multiple independent and discrete rotor blocks 10 first need to be precisely positioned and arranged according to requirements, and then the non-magnetic material 20 is cast integrally (as shown in Figures 3 and 8).

[0034] This invention fixes multiple rotor blocks 10 together to form an integrated rotor structure by casting non-magnetic material 20, eliminating the magnetic barrier connecting bridge in the traditional technology where air slots are used as magnetic barrier parts. This not only enhances the mechanical strength of the rotor 100 and optimizes the magnetic flux path, but also avoids magnetic leakage problems and significantly improves the torque density of the motor.

[0035] The magnetic barrier section is cast from non-magnetic material 20, eliminating the need for permanent magnets, simplifying the rotor structure, and reducing manufacturing costs. At the same time, it avoids reliability issues caused by permanent magnet demagnetization, extending the motor's lifespan.

[0036] The flux guiding assembly 101 is composed of multiple discrete rotor blocks 10, which avoids material waste in the traditional integral stamping process, significantly improves material utilization, and reduces manufacturing costs. In addition, during the recycling process, the non-magnetic material 20 connecting the rotor blocks 10 can be melted at high temperature to separate the rotor blocks 10, eliminating the need for re-stamping to obtain the rotor blocks 10, further improving the recycling rate and reducing recycling costs.

[0037] As shown in Figures 1, 2, 5, 6, 7, and 10, the rotor 100 in this embodiment specifically employs a design with four flux guide groups 101. It should be noted that the number of flux guide groups 101 can be flexibly configured according to actual magnetic circuit guidance requirements. Those skilled in the art can select an appropriate number of flux guide groups 101 based on specific application scenarios; this embodiment does not impose specific limitations in this regard.

[0038] In some embodiments, each flux guiding group 101 includes at least a first rotor block 11, a second rotor block 12 and a third rotor block 13 in the radial direction, and the first rotor block 11, the second rotor block 12 and the third rotor block 13 are arranged sequentially from the radially outer side to the radially inner side, and the arc length of the first rotor block 11, the second rotor block 12 and the third rotor block 13 gradually increases.

[0039] As shown in Figures 5 and 10, the non-magnetic material 20 on the radially outer side of the first rotor block 11 is defined as the first magnetic barrier 21, the second magnetic barrier 22 is defined between the first rotor block 11 and the second rotor block 12, and the third magnetic barrier 23 is defined between the second rotor block 12 and the third rotor block 13.

[0040] It should be noted that the number of rotor blocks 10 in the radial direction R is only exemplary. In other embodiments, in order to enable the motor to better adapt to diverse operating conditions, the number, shape or distribution of rotor blocks 10 can be reasonably changed to maximize the use of magnetic flux, reduce magnetic leakage, optimize the magnetic flux path distribution, and further improve the torque density of the motor.

[0041] Furthermore, in some embodiments, the rotor block 10 can be a single unit in the axial direction A. For example, the axial length of a single first rotor block 11, second rotor block 12, or third rotor block 13 is substantially equal to the axial length of the final rotor 100. Also, since each flux guide group 101 is spaced in the circumferential direction W, i.e., at the direct axis (D-axis) of the rotor 100, in this embodiment, the cast non-magnetic material 20 is only connected to each other at the direct axis (D-axis) of the rotor, while within the arc length of the rotor block 10 (i.e., between the magnetic barrier portions), the non-magnetic material 20 is radially isolated by the rotor block 10.

[0042] Since the non-magnetic material 20 is only connected at the direct axis (D-axis) and when the non-adhesive non-magnetic material 20 is used, the formed rotor 100 will be subjected to the dual effects of centrifugal force and thermal expansion during high-speed rotation, which may cause the interface between the non-magnetic material 20 and the rotor block 10 to separate, thereby affecting the structural integrity and operational stability of the rotor 100.

[0043] In some embodiments, a non-magnetic material 20 with adhesive properties is used for casting. This type of non-magnetic material 20 can form a strong adhesive interface with the surface of the rotor block 10 after cooling, thereby significantly improving the overall stability and operational reliability of the rotor structure. However, while the use of adhesive non-magnetic material 20 solves the structural stability problem, it also brings the disadvantage of increased material costs, which poses a challenge to the cost control of the rotor.

[0044] To this end, while reducing costs and increasing rotor strength, the present invention provides another embodiment in which the flux guiding assembly 101 may include multiple layers of rotor blocks 10 along the axial direction A. Adjacent rotor blocks 10 are fixed and axially separated by connecting posts 30. For example, as shown in Figures 2 and 7, the first rotor block 11, the second rotor block 12, and the third rotor block 13 of the flux guiding assembly 101 each include three layers of rotor blocks 10 along the axial direction A, and two connecting posts 30 are provided between two axially adjacent rotor blocks 10.

[0045] The connecting column 30 fixes the two adjacent rotor blocks 10 along the axial direction A and ensures that the axial spacing between the two adjacent rotor blocks 10 is equal, thereby ensuring the uniformity and stability of the structure of the finally formed rotor 100.

[0046] As shown in Figures 2 and 7, after the non-magnetic material 20 is poured, the axial gap between adjacent rotor blocks 10, which were originally separated by the connecting column 30, is completely filled by the non-magnetic material 20. This filling material connects the magnetic barrier portions located on the radially inner and radially outer sides of the rotor block 10 in the radial direction, forming a radial connecting bridge structure. Specifically, the radial connecting bridge that passes radially through the first rotor block 11 achieves the radial connection between the first magnetic barrier portion 21 and the second magnetic barrier portion 22, while the radial connecting bridge that passes radially through the second rotor block 12 connects the second magnetic barrier portion 22 and the third magnetic barrier portion 23.

[0047] Thus, when the rotor 100 is running at high speed, even if radial separation occurs between the surface of the rotor block 10 and the non-magnetic material 20 due to centrifugal force and thermal expansion, the radial connecting bridge can still effectively maintain the structural integrity of the magnetic barrier section and prevent the rotor block 10 from radially detaching. This achieves the radial confinement effect of the non-magnetic material 20 at the magnetic barrier section, significantly improving the overall strength and operational stability of the rotor 100.

[0048] Taking a structure with three axially arranged rotor blocks 10 as an example, after the casting of the non-magnetic material 20, two radial connecting bridges are formed between the three rotor blocks 10. To further enhance the mechanical strength of the rotor, in this embodiment, as shown in Figures 3 and 4, the non-magnetic material 20 not only fills the axial gaps between the rotor blocks 10 but also completely covers the axial and circumferential end faces of the rotor blocks 10. The non-magnetic material 20 forms two additional end-face connecting bridges at the axial end faces of the rotor, resulting in a total rotor structure with four radial connecting bridges. These two additional end-face connecting bridges significantly enhance the overall mechanical strength of the rotor, enabling it to better withstand the centrifugal force and vibration generated during high-speed operation, thereby effectively improving the rotor's operational stability, reliability, and service life.

[0049] In addition, the complete coverage of the circumferential end face of the rotor block 10 by the non-magnetic material 20 ensures the continuity of the non-magnetic material 20 in the circumferential direction. The continuous non-magnetic material further enhances the overall structural strength of the rotor, providing a reliable guarantee for the stable operation of the rotor under high-speed rotation.

[0050] Structurally, the cooled and solidified non-magnetic material 20 forms a monolithic structure, in which multiple independent and discretely distributed rotor blocks 10 are firmly embedded. This invention differs fundamentally from related technologies that simply embed or inject magnetic barriers into a complete rotor plate.

[0051] Furthermore, in some embodiments, the rotor block 10 has multiple axially extending and parallel concave grooves 14 on its radial inner wall and / or radial outer wall. The concave grooves 14 can be formed simultaneously during the stamping of electrical steel sheets, or they can be machined after the electrical steel sheets are stacked to form the rotor block 10.

[0052] The concave groove 14 significantly increases the contact area between the non-magnetic material 20 and the rotor block 10, providing a stronger mechanical interlocking effect. After the non-magnetic material 20 is poured and solidified, it will fully fill the concave groove 14, forming a mechanical interlock similar to a "mortise and tenon" structure, effectively preventing relative displacement or separation between the non-magnetic material 20 and the surface of the rotor block 10 under high-speed rotation or thermal expansion conditions.

[0053] In some embodiments, the third rotor block 13 consists of two blocks symmetrically distributed along the cross axis of the rotor, i.e., the Q axis. Dividing the third rotor block 13 into two blocks avoids the problem of excessive length of a single third rotor block 13, making the layout of the stamped sheet more compact, maximizing material utilization, reducing waste of scrap material, and thus significantly reducing raw material costs.

[0054] In addition, the reduced length of the third rotor block 13 lowers the difficulty of the stamping process and avoids stamping deformation or precision reduction caused by excessive length of rotor block 10, thereby improving the production efficiency and quality of the rotor block.

[0055] In an optional embodiment, as shown in Figures 6 to 10, the synchronous reluctance motor rotor may further include a rotor cylinder 40, which is arranged in the central region formed by multiple flux guide groups 101. The rotor cylinder 40 is fixed to the surrounding multiple flux guide groups 101 by casting a non-magnetic material 20. As shown in Figure 6, before the casting process of the non-magnetic material 20, the rotor cylinder 40 has been accurately positioned at the center of the flux guide group 101. As shown in Figure 9, the rotor cylinder 40 is used to achieve a torsional connection with the rotor shaft.

[0056] The rotor cylinder 40 serves as the central support structure, which helps to improve the overall rigidity of the rotor. The direct connection between the rotor cylinder 40 and the rotor shaft enables a more efficient torque transmission path and improves transmission efficiency.

[0057] In some embodiments, the radial outer wall of the rotor cylinder 40 is uniformly provided with axially extending connecting ribs 41 along the circumferential direction. The arrangement of the connecting ribs 41 has a similar effect to the concave grooves 14 on the rotor block 10, increasing the contact area and mechanical interlocking effect between the non-magnetic material 20 and the rotor cylinder 40, and significantly improving the connection strength between the two. Specifically, the connecting ribs 41 form a series of regular protrusions in the radial direction. When the non-magnetic material 20 is poured, the non-magnetic material 20 will fully fill the gaps between the connecting ribs 41, forming a strong mechanical interlock after solidification.

[0058] In some embodiments, two third rotor blocks 13 form a gap 15 along the circumferential direction W, and a portion of the connecting rib 41 of the rotor cylinder 40 is inserted into the gap 15 formed by the third rotor blocks 13. The mutual engagement of the connecting rib 41 and the gap 15 of the third rotor blocks 13 effectively reduces the radial dimension of the rotor 100, achieving a more compact structural layout. In addition, the cooperation between the connecting rib 41 and the gap 15 provides a natural positioning reference for the assembly of the rotor 100, improving assembly accuracy and efficiency.

[0059] In addition, as shown in Figure 2, the radial inner walls of the adjacent circumferential ends of the two third rotor blocks 13 are set as planes 16, which can better fit with the surface of the rotor cylinder 40 or the rotor shaft 102, further maximizing the use of radial space.

[0060] Based on the same inventive concept, this disclosure provides a synchronous reluctance motor. The specific methods by which the functions of the synchronous reluctance motor in the above embodiments are implemented have been described in detail in the embodiments relating to the rotor, and will not be elaborated upon here.

[0061] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following scope of claims.

[0062] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A synchronous reluctance motor rotor (100), characterized in that, include: Multiple flux guide groups (101) are arranged circumferentially (W), each flux guide group (101) including multiple radially (R) spaced and independent arc-shaped rotor blocks (10); In this process, multiple rotor blocks (10) are fixed by casting non-magnetic material (20) and form an integral rotor (100) with the cast non-magnetic material 20. The non-magnetic material (20) located radially (R) between multiple rotor blocks (10) constitutes the magnetic barrier part of the rotor (100).

2. The synchronous reluctance motor rotor (100) according to claim 1, characterized in that, The flux guiding group (101) includes multiple layers of rotor blocks (10) along the axial direction (A), and adjacent layers of rotor blocks (10) are fixedly connected and separated by connecting columns (30).

3. The synchronous reluctance motor rotor (100) according to claim 1, characterized in that, The flux guiding group (101) includes at least a first rotor block (11), a second rotor block (12) and a third rotor block (13) along the radial direction (R), wherein the first rotor block (11), the second rotor block (12) and the third rotor block (13) are arranged from the radial outer side to the radial inner side, and the arc length gradually increases.

4. The synchronous reluctance motor rotor (100) according to claim 3, characterized in that, The third rotor block (13) consists of two blocks symmetrically distributed along the cross axis (Q) of the rotor (100).

5. The synchronous reluctance motor rotor (100) according to claim 4, characterized in that, The synchronous reluctance motor rotor (100) also includes a rotor cylinder (40), which is arranged in the central area surrounded by a plurality of magnetic flux guide groups (101). The rotor cylinder (40) is fixed to the plurality of magnetic flux guide groups (101) by the cast non-magnetic material (20).

6. The synchronous reluctance motor rotor (100) according to claim 5, characterized in that, The rotor cylinder (40) has connecting ribs (41) that extend axially (A) evenly arranged along the circumferential (W) direction on its radial outer wall.

7. The synchronous reluctance motor rotor (100) according to claim 6, characterized in that, The two third rotor blocks (13) form a gap (15) along the circumferential direction (W), and a portion of the connecting rib (41) of the rotor cylinder (40) is inserted into the gap (15) formed by the third rotor blocks (13).

8. The synchronous reluctance motor rotor (100) according to claim 1, characterized in that, The circumferential (W) ends of the multiple rotor blocks (10) are not connected. After the non-magnetic material (20) is poured, the non-magnetic material (20) covers the axial end face and the circumferential end face of the rotor block (10).

9. The synchronous reluctance motor rotor (100) according to claim 1, characterized in that, The rotor block (10) has multiple axially extending and parallel concave grooves (14) on its radial (R) inner wall and / or radial (R) outer wall.

10. A synchronous reluctance motor, characterized in that, Includes a synchronous reluctance motor rotor (100) as described in any one of claims 1-9.

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