Motor structure

Abstract

The invention relates to a motor structure. The motor structure includes a rotor core, a permanent magnet inserted into the rotor core, and a holder mounted to support the permanent magnet in a radial direction of the rotor core.

Description

Technical Field

[0001] The present invention relates to a motor structure for improving the torque density in the motor. Background Art

[0002] Electric vehicles are driven by the torque generated by the installed motor. Therefore, the higher the torque density of the motor, the better the power performance and fuel efficiency of the vehicle.

[0003] The motor installed in electric vehicles is generally a permanent magnet embedded motor. The amount of magnetic flux leakage varies depending on the state of the permanent magnet embedded in the rotor. In order to improve the torque density of the motor, it is necessary to reduce the amount of magnetic flux leakage as much as possible.

[0004] The above description as a related art of the present invention is only used to help understand the background art of the present invention and should not be construed as being included in the related art known to a person of ordinary skill in the art. Summary of the invention

[0005] The present invention is proposed to solve the above problems. The present invention aims to provide a motor structure which reduces the magnetic flux leakage of a rotor with embedded permanent magnets and improves the torque density of the motor.

[0006] The technical problems of the present invention are not limited to the problems mentioned above. A person skilled in the art should more clearly understand other problems not mentioned herein from the following description.

[0007] In order to achieve the objective of the present invention, a motor structure is provided, which includes a rotor core, a permanent magnet, and a retainer, wherein the permanent magnet is inserted into the rotor core; and the retainer is installed to support the permanent magnet in the radial direction of the rotor core.

[0008] The permanent magnet may be provided with a protruding end portion protruding from the rotor core. The retainer may be installed to constrain and support the protruding end portion of the permanent magnet.

[0009] The protruding end portion of the permanent magnet may be formed to protrude from each end of the rotor core in the axial direction. The retainer may be provided at each end of the rotor core in the axial direction.

[0010] The holder may be provided with a disk portion in a disk shape having a plurality of insertion portions, and the protruding end portions of the permanent magnet may be fitted into the plurality of insertion portions.

[0011] The insertion portion of the disk portion may be provided in the form of an insertion hole penetrating through the disk portion.

[0012] The inserting portion of the disc portion may be provided in the form of an inserting groove partially recessed in the disc portion.

[0013] In the disc portion of the holder, the insertion portion may be provided at a position such that centrifugal forces of the plurality of permanent magnets provided in the rotor core cancel each other.

[0014] In order to achieve the purpose of the present invention, a motor structure includes: a stator, a rotor core, a plurality of permanent magnets and a retainer; the rotor core is rotatably inserted into the stator; the plurality of permanent magnets are inserted parallel to the rotation axis of the rotor core; the retainer fixes the end of the rotor core, and the permanent magnet protrudes from the end.

[0015] The retainer may be formed to restrict the permanent magnet from moving in a radial direction relative to the rotor core.

[0016] The permanent magnets may be arranged along a circumferential direction of the rotor core. The holder may be provided in a disk shape so that ends of the permanent magnets are inserted into ends of the rotor core.

[0017] The permanent magnets may be inserted to protrude from opposite ends of the rotor core. A retainer may be installed at each end of the rotor core.

[0018] The holder may be provided with a plurality of insertion holes into which ends of the permanent magnets are inserted.

[0019] The holder may be provided at a surface facing the rotor core with a plurality of insertion grooves into which ends of the permanent magnets are inserted.

[0020] In the holder, ends of the permanent magnets may be inserted into insertion portions provided in the holder at positions symmetrical to each other around a rotation axis of the rotor core to offset the centrifugal force of the permanent magnets provided in the rotor core.

[0021] The present invention effectively reduces the magnetic flux leakage of a rotor embedded with permanent magnets, thereby improving the torque density of the motor and ensuring sufficient durability of the motor.

[0022] The effects of the present invention are not limited to the above-mentioned effects. A person skilled in the art should more clearly understand other effects not mentioned herein from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram showing the structure of a motor according to the present invention;

[0024] Figure 2 It shows the removal Figure 1 A schematic diagram of the state of the retainer in;

[0025] Figure 3 is a schematic diagram showing a rotor core and permanent magnets;

[0026] Figure 4 It is along Figure 3A cross-sectional view of the rotor core and the permanent magnet taken along line IV-IV; and

[0027] Figure 5 It is along Figure 1 A cross-sectional view of the motor structure taken along line V-V. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. In all the drawings, the same or similar components are given the same reference numerals, and description is not repeated in each drawing.

[0029] Terms such as “module” and “unit” used for components in the following description are used for convenience of description only and have no distinct meanings or functions.

[0030] In the following description, in the case where it has been determined that the detailed description of known technologies related to the present invention will make the subject matter of the embodiments described herein unclear, the detailed description of these technologies is omitted. In addition, the drawings are provided only to help understand the embodiments disclosed in the specification. The technical spirit disclosed in the specification is not limited by the drawings. All modified embodiments, equivalent embodiments and alternative embodiments of the disclosed embodiments should be understood to be included in the spirit and scope of the present invention.

[0031] Terms including ordinal numbers such as "first", "second", etc. may be used to describe various components, but these components should not be construed as being limited by these terms. These terms are only used to distinguish one component from another.

[0032] It should be understood that when an element is referred to as being “connected to” or “engaged to” another element, the element may be directly connected to or directly engaged to the other element, or may be connected to or engaged to the other element with other elements interposed therebetween. On the other hand, it should be understood that when an element is referred to as being “directly connected to” or “directly engaged to” another element, the element may be connected to or engaged to the other element without any elements interposed therebetween.

[0033] Unless the context clearly indicates otherwise, the singular form is intended to include the plural form. When a component, device, element, etc. of the present invention is described as having a purpose or performing an operation, function, etc., the component, device or element should be considered herein as being "configured to" meet the purpose or perform the operation or function.

[0034] It should be further understood that the terms "comprises", "includes" or "having" or their variations used in this specification indicate the presence of the features, steps, operations, components, parts or combinations thereof. These terms do not exclude the presence or addition of one or more other features, values, steps, operations, components, parts or combinations thereof.

[0035] Figure 1 is a schematic diagram showing the structure of a motor according to the present invention. Figure 1 There are shown a stator core 5 in which a coil 1 is wound to form the stator 3 , permanent magnets 9 constituting the rotor 7 , and a holder 11 that constrains the permanent magnets 9 .

[0036] Figure 2 It shows the removal Figure 1 Schematic diagram of the state of the retainer 11 in FIG. Figure 2 The structure of the rotor core 13 and the permanent magnets 9 inserted into the rotor core 13 constituting the rotor 7 is shown. The portion shown corresponds to one eighth (1 / 8) of the entire rotor 7.

[0037] Figure 3 Shown from different angles Figure 2 The rotor core 13 and the permanent magnet 9 are provided. Figure 4 It is along Figure 3 A cross-sectional view of the rotor core 13 taken along line IV-IV.

[0038] Figure 5 It is along Figure 1 A cross-sectional view of the motor structure taken along line V-V. Figure 5 In FIG. 1 , the coil 1 is shown wound on the stator core 5 .

[0039] refer to Figures 1 to 5 , shows a motor structure according to an embodiment of the present invention. The motor structure includes a rotor core 13, permanent magnets 9 inserted into the rotor core 13, and a holder 11 installed to support the permanent magnets 9 in the radial direction of the rotor core 13.

[0040] The stator core 5 constituting the stator 3 is provided outside the rotor core 13. The coil 1 for generating a magnetic field is wound around the stator core 5.

[0041] In other words, the motor of the present invention is composed of a stator 3 including a stator core 5 and a coil 1, and a rotor including a rotor core 13, a permanent magnet 9 and a retainer 11. The permanent magnet 9 is inserted into the rotor core 13 and is configured so that its movement in the radial direction of the rotor core 13 is constrained by the retainer 11.

[0042] The ribs 15 between the permanent magnets 9 and the outer peripheral surface of the rotor core 13 are made as thin as possible. Since the retainer 11 stably constrains the permanent magnets 9 against the centrifugal force caused by the rotation of the rotor 7, the stable embedding state of the permanent magnets 9 in the rotor core 13 is continuously maintained. Therefore, the durability required for the rotor 7 can be ensured. In addition, due to the thinner ribs 15 as described above, the magnetic flux leakage of the rotor 7 is reduced, and the torque density of the motor is finally improved.

[0043] In other words, the present invention maximizes the effect of reducing magnetic flux leakage by reducing the thickness of the rib 15 of the rotor core 13. This is achieved while allowing the retainer 11 to effectively restrain the radial movement of the permanent magnet 9. Therefore, the structural durability required of the rotor 7 is fully ensured.

[0044] The permanent magnet 9 is provided at a first end with a first protruding end portion 17 protruding from one end of the rotor core 13. The retainer 11 may be considered as a first retainer 11 installed to constrain and support the first protruding end portion 17 of the permanent magnet 9.

[0045] The protruding end portions 17 (i.e., the first and second protruding end portions 17) of the permanent magnets 9 may be formed to protrude in the axial direction from each end (i.e., one end and the other end) of the rotor core 13. The retainers 11 (i.e., the first and second retainers 11) may be provided at each end of the rotor core 13 in the axial direction, respectively.

[0046] The retainers 11 restrain the permanent magnets 9 from moving outward in the radial direction of the rotor core 13 due to the centrifugal force generated when the rotor 7 rotates, at opposite sides of the rotor core 13. Therefore, the retainers 11 firmly support the permanent magnets 9. Therefore, the ribs 15 of the rotor core 13 can be made thinner, which has the effect of reducing the magnetic flux leakage of the rotor 7.

[0047] In one embodiment, each holder 11 has a disk portion 21 in a disk shape having a plurality of insertion portions 19 into which the respective protruding ends 17 of the permanent magnets 9 are inserted.

[0048] In one embodiment, a plurality of permanent magnets 9 are arranged in a predetermined pattern along the circumferential direction of rotor core 13. In disk portion 21 of holder 11 as described above, centrifugal forces acting on permanent magnets 9 act symmetrically around the rotation axis of rotor core 13 and cancel each other.

[0049] Accordingly, the rotation axes of the rotor core 13 and the holder 11 are constantly kept in a concentric state, thereby preventing unnecessary vibration from occurring.

[0050] As shown in the drawings, each insertion portion 19 of the disk portion 21 may be provided in the form of an insertion hole 23 penetrating the disk portion 21 , or in the form of an insertion groove (not shown) partially recessed in the disk portion 21 .

[0051] When the insertion portion 19 is provided in the form of an insertion groove, the permanent magnet 9 is not exposed to the surface of the holder 11. Therefore, when the holder 11 rotates at a high speed, unnecessary resistance, noise and vibration are relatively advantageously prevented from occurring.

[0052] On the other hand, when the insertion portion 19 is provided in the form of an insertion hole, the manufacture and assembly of the holder 11 can be performed more easily.

[0053] The motor structure of the present invention as described above can be implemented as follows.

[0054] The motor structure of the present invention includes: a stator 3; a rotor core 13 which is rotatably inserted into the stator 3; a plurality of permanent magnets 9 which are inserted parallel to the rotation axis of the rotor core 13; and a retainer 11 which fixes the end of the rotor core 13 from which the permanent magnets 9 protrude.

[0055] The retainer 11 is configured to constrain the permanent magnet 9 from moving in the radial direction relative to the rotor core 13 .

[0056] The permanent magnets 9 are arranged along the circumferential direction of the rotor core 13. The holder 11 may be provided in a disk shape so that the ends of the permanent magnets 9 are inserted in the ends of the rotor core 13.

[0057] The permanent magnets 9 may be inserted to protrude from opposite ends of the rotor core 13. Therefore, the holder 11 may be installed at each of the opposite ends of the rotor core 13.

[0058] The holder 11 may be provided with a plurality of insertion holes 23 into which the ends of the permanent magnets 9 are inserted. Alternatively, the holder 11 may be provided with a plurality of insertion grooves on a surface facing the rotor core 13 into which the ends of the permanent magnets 9 are inserted.

[0059] Meanwhile, in the holder 11 , insertion portions into which ends of the permanent magnets 9 are inserted may be provided at positions symmetrical to each other about the rotation axis of the rotor core 13 to offset the centrifugal force of the permanent magnets 9 provided in the rotor core 13 .

[0060] Although the invention has been described above with respect to specific embodiments shown in the accompanying drawings, it will be apparent to those skilled in the art that the embodiments of the invention may be changed and modified in various ways without departing from the scope of the invention as provided in the appended claims.

Claims

1. A motor structure, comprising: Rotor core; a permanent magnet inserted into the rotor core; as well as A first holder is installed to support the permanent magnet in a radial direction of the rotor core.

2. The motor structure according to claim 1, wherein: The permanent magnet has a first protruding end portion protruding from one end of the rotor core, and the first holder is installed to constrain and support the first protruding end portion of the permanent magnet.

3. The motor structure according to claim 2, wherein: The second protruding end portion of the permanent magnet protrudes from the other end of the rotor core, the other end of the rotor core is provided with a second holder, and the first protruding end portion and the second protruding end portion protrude in the axial direction.

4. The motor structure according to claim 2, wherein: The first holder includes a disk portion in a disk shape having an insertion portion, and the first protruding end portion of the permanent magnet is mounted in the insertion portion.

5. The motor structure according to claim 4, wherein: The insertion portion of the disk portion is provided as an insertion hole penetrating through the disk portion.

6. The motor structure according to claim 4, wherein: The inserting portion of the disk portion is configured as an inserting groove partially recessed in the disk portion.

7. The motor structure according to claim 4, wherein: The permanent magnet includes a plurality of permanent magnets, and the insertion portion is provided in a disk portion of the holder at a position where centrifugal forces of the plurality of permanent magnets provided in the rotor core cancel each other.

8. A motor structure, comprising: stator; a rotor core rotatably inserted into the stator; a permanent magnet inserted parallel to the rotation axis of the rotor core and protruding from one end of the rotor core; as well as A retainer fixes one end of the rotor core.

9. The motor structure according to claim 8, wherein: The retainer constrains the permanent magnets from moving in a radial direction relative to the rotor core.

10. The motor structure according to claim 9, wherein: The permanent magnets are arranged along a circumferential direction of the rotor core, and the holder is provided in a disk shape so that an end of the permanent magnet is inserted into one end of the rotor core.

11. The motor structure according to claim 10, wherein: The permanent magnets are inserted to protrude from one end and the other end of the rotor core, and another holder is mounted on the other end of the rotor core.

12. The motor structure according to claim 10, wherein: The holder is provided with a plurality of insertion holes, and end portions of the permanent magnets are respectively inserted into the plurality of insertion holes.

13. The motor structure according to claim 10, wherein: The holder is provided with a plurality of insertion grooves at a surface facing the rotor core, and end portions of the permanent magnets are respectively inserted into the plurality of insertion grooves.

14. The motor structure according to claim 10, wherein: In the holder, ends of the permanent magnets are inserted into insertion portions provided at positions symmetrical to each other around a rotation axis of the rotor core to offset the centrifugal force of the permanent magnets provided in the rotor core.

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