Rotor for LSPM, and motor comprising same

Abstract

The present invention relates to a rotor for an LSPM, and a motor comprising same. The rotor for an LSPM, according to the present invention, comprises: an iron core having a circular cross section, and including a rotary shaft insertion hole, a plurality of permanent magnet insertion holes, and a plurality of conductor bar insertion holes within the cross section; permanent magnets inserted into the permanent magnet insertion holes; and conductor bars inserted into the conductor bar insertion holes, wherein the permanent magnet is disposed only in a partial section of the iron core along the longitudinal direction.

Description

Rotor for LSPM and motor including the same

[0001] The present invention relates to a rotor for an LSPM and a motor including the same, and more specifically, to a rotor for an LSPM and a motor including the same that has superior starting characteristics compared to a conventional LSPM.

[0002] In the field of industrial electric motors, developing motors with high efficiency and excellent starting characteristics is an important task.

[0003] Conventional induction motors (IMs) have the advantage of generating high torque during starting, but they have the disadvantage of low power efficiency during rated operation.

[0004] On the other hand, permanent magnet synchronous motors (PMSMs) provide high efficiency during rated operation, but suffer from reduced starting performance and a problem of insufficient starting torque.

[0005] To address this, a Line Start Permanent Magnet Motor (LSPM) was developed that combines the advantages of IM and PMSM. The LSPM has the characteristic of achieving high efficiency during rated operation by inserting permanent magnets into the rotor, while also being able to obtain high torque during starting like an IM.

[0006] However, existing LSPMs also have several problems. For example, in existing LSPMs, the magnetic force of the permanent magnet interferes with the induction of current in the squirrel-cage during startup. Consequently, unlike IMs, the current required for startup is not sufficiently induced, which can lead to degraded startup characteristics compared to IMs. This problem makes it difficult to apply LSPMs, particularly in industrial environments handling heavy loads.

[0007] [Prior Art Literature]

[0008] [Patent Literature]

[0009] (Patent Document 1) KR10-2666330 B1

[0010] Accordingly, the objective of the present invention is to solve such conventional problems by providing a rotor for an LSPM with superior starting characteristics compared to existing LSPMs and a motor including the same.

[0011] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0012] The above objective is achieved by a rotor for an LSPM according to the present invention, comprising: an iron core having a circular cross-section, wherein the cross-section includes a rotation shaft insertion hole, a plurality of permanent magnet insertion holes, and a plurality of conductor bar insertion holes; a permanent magnet inserted into the permanent magnet insertion hole; and a conductor bar inserted into the conductor bar insertion hole; wherein the permanent magnet is positioned only in a portion of the longitudinal section of the iron core.

[0013] The above permanent magnet insertion hole may be characterized by being formed along the entire longitudinal section of the iron core.

[0014] In the longitudinal direction of the above-mentioned permanent magnet insertion hole, a fixed structure may be disposed in the section where the permanent magnet is not disposed.

[0015] The above permanent magnet insertion hole may be characterized by being formed only in a portion of the longitudinal section of the iron core.

[0016] The above iron core may be characterized by being formed in multiple stages along the longitudinal direction, with the permanent magnet insertion hole formed in some stages.

[0017] The above iron core may be formed in three sections along the longitudinal direction, and the permanent magnet insertion hole may be formed at the ends of both longitudinal sections or at the middle section of the iron core.

[0018] The above conductor bar insertion hole may be characterized by being formed only in a portion of the longitudinal section of the iron core.

[0019] The adjacent surfaces of each stage of the above iron core may be characterized by having protrusions and indentations formed for interlocking.

[0020] According to another embodiment of the present invention, a motor including the rotor for the LSPM described above is provided.

[0021] According to the rotor for LSPM according to the present invention, since permanent magnets are formed only in a portion of the longitudinal direction of the iron core, high efficiency can be achieved during rated operation while minimizing interference with current induction during motor startup.

[0022] When permanent magnet insertion holes are formed along the entire length of the iron core, the flexibility of rotor manufacturing can be increased, and in this case, the fixed structure fills the empty space of the permanent magnet insertion holes, thereby preventing the problem of reduced mechanical rigidity of the iron core caused by the empty space.

[0023] If the iron core is formed in multiple stages along the longitudinal direction, the ease of manufacturing the rotor can be improved.

[0024] FIG. 1 is a perspective view of a rotor for an LSPM according to a first embodiment of the present invention,

[0025] FIG. 2 is a cross-sectional view of a rotor for an LSPM according to a first embodiment of the present invention,

[0026] FIG. 3 is a perspective view of a rotor for an LSPM according to a second embodiment of the present invention,

[0027] FIG. 4 is a cross-sectional view of a rotor for an LSPM according to a second embodiment of the present invention,

[0028] FIG. 5 is a perspective view of a rotor for an LSPM according to a third embodiment of the present invention,

[0029] FIG. 6 is a cross-sectional view of a rotor for an LSPM according to a third embodiment of the present invention,

[0030] FIG. 7 is a perspective view of a rotor for an LSPM according to a fourth embodiment of the present invention,

[0031] FIG. 8 is a cross-sectional view of a rotor for an LSPM according to a fourth embodiment of the present invention.

[0032] In order to clarify the features and advantages of the means for solving the problem of the present invention, the present invention will be described in more detail with reference to specific embodiments of the present invention illustrated in the attached drawings.

[0033] However, detailed descriptions of known functions or configurations that may obscure the essence of the invention are omitted in the following description and the attached drawings. Additionally, it should be noted that identical components throughout the drawings are indicated by the same reference numerals whenever possible.

[0034] Terms and words used in the following description and drawings should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the invention and do not represent all aspects of the technical spirit of the invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0035] Furthermore, the terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. Additionally, terms such as “comprising” or “having” described in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0036] Additionally, terms such as "part," "unit," and "module" as described in the specification refer to a unit that processes at least one function or operation, which may be implemented in hardware, software, or a combination of hardware and software. Furthermore, "one (a or an)," "one," "the," and similar related terms may be used in the context describing the invention (particularly in the context of the following claims) in a sense that includes both singular and plural forms, unless otherwise indicated in the specification or clearly contradicted by the context.

[0037] In addition to the terms described above, specific terms used in the following description are provided to aid in understanding the present invention, and the use of such specific terms may be modified in other forms without departing from the technical spirit of the present invention.

[0038]

[0039] Hereinafter, a rotor (1) for LSPM according to the present invention and a motor (not shown) including the same will be described.

[0040]

[0041] FIGS. 1 and FIGS. 2 illustrate an explanatory diagram of one embodiment of a rotor (1) for an LSPM according to the present invention.

[0042] The rotor (1) for LSPM according to the present invention comprises an iron core (10), a permanent magnet (20), and a conductor bar (30).

[0043] The iron core (10) is a body part that plays a structural role in the rotor (1) for the LSPM according to the present invention, and is formed in a column shape having a circular cross-section. A rotation shaft insertion hole (11) is formed at the center of the cross-section (transverse cross-section) of the iron core (10) so that a rotation shaft (not shown) of the motor can be inserted. Within the cross-section of the iron core (10), a plurality of permanent magnet insertion holes (12) are spaced apart along one circumference, and a plurality of conductor bar insertion holes (13) are spaced apart along another circumference. On the radius of the iron core (10), the conductor bar insertion holes (13) can be formed on the outer side of the permanent magnet insertion holes (12).

[0044] The permanent magnets (20) are each inserted into the permanent magnet insertion holes (12) of the iron core (10), and can increase the efficiency of the motor by forming a magnetic field during rated operation of the motor.

[0045] The conductor bar (30) is inserted into the conductor bar insertion hole (13) of the iron core (10) and serves to transmit current for the rotational movement of the motor. The conductor bar (30) may be made of a metal material with relatively high conductivity, such as aluminum or copper. A relatively large current is induced in the conductor bar (30) when the motor starts, which can generate the high torque required for initial starting.

[0046] In the rotor (1) for LSPM according to the present invention, the permanent magnet (20) is characterized by being placed only in a portion of the longitudinal direction of the iron core (10).

[0047] By arranging the permanent magnets (20) in this way, it is possible to significantly improve the starting characteristics by reducing interference with current induction during the starting of the motor. Specifically, in the section where the permanent magnets (20) are not arranged, current induction through the conductor bar (30) is not hindered, so current flows freely and it is possible to generate a larger starting torque. This is particularly effective in situations where initial starting is difficult due to heavy loads, etc.

[0048] In addition, during rated operation, the motor can achieve excellent efficiency due to the section where the permanent magnet (20) is arranged.

[0049] That is, the rotor (1) for LSPM according to the present invention has excellent starting characteristics and is also advantageous in terms of rated operating efficiency.

[0050]

[0051] As shown in FIG. 2, the permanent magnet insertion hole (12) can be formed along the entire longitudinal section of the iron core (10). That is, the permanent magnet insertion hole (12) is formed along the entire longitudinal section of the iron core (10), but the permanent magnet (20) can be formed only in a part of the permanent magnet insertion hole (12).

[0052] These permanent magnet insertion holes (12) can increase flexibility when manufacturing the rotor (1) for LSPM according to the present invention. Specifically, permanent magnet insertion holes (12) are formed along the entire length of the iron core (10), and permanent magnets (20) can be placed as needed during the subsequent manufacturing process.

[0053] Accordingly, by selecting and arranging the insertion section of the permanent magnet (20) according to the required starting performance or rated operating efficiency, it is possible to easily manufacture electric motors with various performances.

[0054]

[0055] When a permanent magnet insertion hole (12) is formed along the entire length of the iron core (10) and a permanent magnet (20) is formed only in a portion of the permanent magnet insertion hole (12), a fixed structure (40) may be placed in the portion of the length of the permanent magnet insertion hole (12) where the permanent magnet (20) is not placed.

[0056] The fixed structure (40) may have a cross-section of the same size and shape as the permanent magnet (20) so that it can be inserted into the permanent magnet insertion hole (12), for example, and may be made of a lightweight, high-strength material such as high-strength plastic. Alternatively, it may be made of the same material as the iron core (10).

[0057] For example, the permanent magnet (20) may be placed in the middle section along the longitudinal direction of the permanent magnet insertion hole (12), and the fixed structure (40) may be placed at both ends.

[0058] This fixed structure (40) prevents the permanent magnet (20) from moving in the longitudinal direction within the permanent magnet insertion hole (12) and can prevent the problem of the mechanical strength of the iron core (10) being reduced by the empty space of the iron core (10).

[0059] Accordingly, this can increase the stability of motor operation and enhance the durability of the motor.

[0060] And if the fixed structure (40) is made of a lightweight, high-strength material, the total weight of the rotor (1) is reduced, so it is possible to further improve the starting characteristics and efficiency of the electric motor.

[0061]

[0062] It is also possible for the permanent magnet insertion hole (12) to be formed only in a portion of the longitudinal direction of the iron core (10). That is, the permanent magnet insertion hole (12) can also be formed only in a portion of the longitudinal direction of the iron core (10) in accordance with the arrangement of the permanent magnet (20).

[0063] Figures 3, 4, 5, 6, 7, and 8 illustrate explanatory diagrams for such cases.

[0064] In this case, the mechanical strength of the iron core (10) can be prevented from being reduced by the permanent magnet insertion hole (12) in which the permanent magnet (20) is not inserted.

[0065]

[0066] In the case where the permanent magnet insertion hole (12) is formed only in a portion of the longitudinal direction of the iron core (10), the iron core (10) may be formed in multiple sections along the longitudinal direction, and the permanent magnet insertion hole (12) may be formed only in some sections.

[0067] In this case, when manufacturing the rotor (1) for LSPM according to the present invention, the inconvenience of having to form permanent magnet insertion holes (12) throughout the entire longitudinal direction of the iron core (10) can be avoided.

[0068] The iron core (10) can be easily manufactured by separately manufacturing a section with a permanent magnet insertion hole (12) and a section without one, and then stacking them in the longitudinal direction.

[0069]

[0070] For example, as shown in FIGS. 3, 4, 5 and 6, the iron core (10) is formed in three sections along the longitudinal direction, and the permanent magnet insertion hole (12) may be formed at the ends of both longitudinal sections of the iron core (10) or at the middle section.

[0071] The lengths of the ends at both ends and the middle end of the iron core (10) in the longitudinal direction can have a length ratio of, for example, about 1:2.

[0072] For example, depending on which is relatively important between starting performance and efficiency during rated operation in the motor, the permanent magnet insertion hole (12) may be formed at both ends in the longitudinal direction of the iron core (10) or at the middle end.

[0073] The iron core (10) may be formed into two or four or more sections in the longitudinal direction depending on the performance or operating conditions required by the motor.

[0074]

[0075] When the iron core (10) is formed in multiple stages, as shown in FIGS. 7 and 8, not only the permanent magnet insertion hole (12) but also the conductor bar insertion hole (13) may be formed only in a portion of the longitudinal section of the iron core (10). In this case, it is natural that the section where the permanent magnet insertion hole (12) is formed and the section where the conductor bar insertion hole (13) is formed are opposite each other along the longitudinal section of the iron core (10).

[0076] In this case, the section where the conductor bar (30) is placed and the section where the permanent magnet (20) is not placed can be aligned to reduce factors that hinder current induction during starting. As a result, the starting torque of the motor increases, and smoother starting becomes possible.

[0077] When the conductor bar insertion hole (13) is formed only in a portion of the longitudinal section of the iron core (10), the iron core (10) may be formed in two sections, for example, such that the conductor bar insertion hole (13) is formed in one section and the permanent magnet insertion hole (12) is formed in the other section. The lengths of the two sections may be formed to be nearly the same.

[0078] At this time, in the section where the permanent magnet (20) is placed in the iron core (10), the permanent magnet (20) can be placed like a PMSM. That is, the permanent magnet (20) can be placed near the periphery in the cross-section (transverse section) of the iron core (10).

[0079]

[0080] When the iron core (10) is formed in multiple stages, an interlocking protrusion (not shown) may be formed on the adjacent surface of each stage of the iron core (10).

[0081] For example, a protruding part may be formed on the adjacent surface of one of the two adjacent sections of the iron core (10), and a groove capable of accommodating the protruding part may be formed on the adjacent surface of the other section.

[0082] When these interlocking structures interlock, no single stage shakes or slips relative to another, even under external forces or high rotor speeds. Consequently, it is possible to prevent performance degradation or durability issues that may arise from the relative movement of each stage during motor operation, and to ensure stable motor operation.

[0083] In addition, during the assembly process of the iron core (10), it is possible to easily and accurately combine each section.

[0084] Alternatively, by forming a matching hole (14) at the same position on the plane of each stage of the iron core (10) and inserting a matching rod (not shown) having a length greater than the total length of the iron core (10) into the matching hole (14), it may be possible to prevent each stage from moving relative to each other during the operation of the motor.

[0085]

[0086] The motor (electric motor) including the rotor (1) for LSPM according to the present invention described above has permanent magnets (20) formed only in a portion of the longitudinal section of the iron core (10), so it is possible to achieve high efficiency during rated operation while minimizing interference with current induction during motor startup.

[0087]

[0088] The scope of the present invention is not limited to the embodiments described above but may be implemented in various forms of embodiments within the scope of the appended claims. It is deemed that the scope of the claims of the present invention includes various modifications that are possible by anyone with ordinary knowledge in the technical field to which the invention pertains, without departing from the essence of the invention claimed in the claims.

[0089] [Explanation of the symbol]

[0090] 1 : Rotor for LSPM

[0091] 10 : Iron core

[0092] 11: Rotation shaft insertion hole

[0093] 12: Permanent magnet insertion hole

[0094] 13: Conductor bar insertion hole

[0095] 20 : Permanent magnet

[0096] 30 : Conductor bar

[0097] 40: Fixed structure

[0098]

[0099] This invention was carried out with the support of the following project.

[0100] [Project ID] 2410000706

[0101] [Project No.] RS-2024-00419152

[0102] [Ministry Name] Ministry of Trade, Industry and Energy

[0103] [Project Management (Specialized) Agency Name] Korea Institute of Energy Technology Evaluation and Planning

[0104] [Research Project Name] Development of Core Technologies for Energy Demand Management

[0105] [Research Project Title] Development of 5kW-Class Electrification Platform Technology for Industrial Logistics

[0106] [Name of Project Performing Organization] Hygen R&M Co., Ltd.

[0107] [Research Period] April 1, 2024 ~ March 31, 2028

Claims

1. An iron core having a circular cross-section, comprising a rotation shaft insertion hole, a plurality of permanent magnet insertion holes, and a plurality of conductor bar insertion holes within the cross-section; A permanent magnet inserted into the above permanent magnet insertion hole; and A conductor bar inserted into the conductor bar insertion hole; comprising, The above permanent magnet is, A rotor for LSPM characterized by being positioned only in a portion of the longitudinal section of the above iron core.

2. In Paragraph 1, The above permanent magnet insertion hole is, A rotor for LSPM characterized by being formed along the entire longitudinal section of the above-mentioned iron core.

3. In Paragraph 2, In the longitudinal direction of the above permanent magnet insertion hole, A rotor for an LSPM characterized by having a fixed structure placed in the section where the above-mentioned permanent magnet is not placed.

4. In Paragraph 1, The above permanent magnet insertion hole is, A rotor for LSPM characterized by being formed only in a portion of the longitudinal section of the above iron core.

5. In Paragraph 4, The above iron core is, It is formed in multiple layers along the length direction, A rotor for an LSPM characterized by having the above-mentioned permanent magnet insertion holes formed in some sections.

6. In Paragraph 5, The above iron core is, It is formed in three sections along the length, The above permanent magnet insertion hole is, A rotor for LSPM characterized by being formed at the ends of both longitudinal ends or at the middle end of the above iron core.

7. In Paragraph 5, The above conductor bar insertion hole is, A rotor for LSPM characterized by being formed only in a portion of the longitudinal section of the above iron core.

8. In Paragraph 5, On the adjacent surfaces of each section of the above iron core, A rotor for LSPM characterized by the formation of protrusions and indentations for interlocking.

9. A motor comprising a rotor for an LSPM according to any one of paragraphs 1 to 8.

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