Permanent magnet assembly and method for manufacturing same

Abstract

The present invention relates to a permanent magnet assembly that enables magnetic powder, which is difficult to be bulked, to be manufactured in the form of a bulk permanent magnet while maintaining magnetic properties thereof, and to a method for manufacturing same. To this end, the present invention may comprise: an outer frame having an accommodation space of which at least an upper side is opened so that magnetic powder is accommodated therein; a tube-shaped inner frame disposed on an inner central axis line of the outer frame, the inner frame having an insertion hole formed to penetrate therethrough in an axial direction; a cover coupled to an upper opening of the outer frame to seal the accommodation space, the cover having a through-hole communicating with the insertion hole; and a pressing rod having a predetermined length, slidably coupled to the insertion hole through the through-hole of the cover, the pressing rod expanding the inner frame in a radial direction when slidably coupled to the insertion hole, thereby compressing the magnetic powder accommodated in the accommodation space.

Description

Permanent magnet assembly and method of manufacturing the same

[0001] The present invention relates to a permanent magnet assembly capable of manufacturing magnetic powder in the form of a bulk permanent magnet and a method for manufacturing the same.

[0002]

[0003] Generally, to manufacture bulk permanent magnets, the process involves placing magnetic powder in a mold, applying a magnetic field to align the magnetic field, and then applying pressure with a press.

[0004] However, when manufacturing bulk permanent magnets using magnetic powder with good magnetic properties, there are cases where the magnetic properties are reduced depending on the type of magnetic powder.

[0005] In other words, it may be difficult to manufacture into a bulk permanent magnet form if the sintered magnet bulk form is not well formed, or if the magnetic properties in the powder state are greater than when sintered into a bulk form, such as Sm-Fe-N.

[0006] Accordingly, there is a need for a permanent magnet manufacturing technology that allows magnetic powder, which is difficult to manufacture in bulk form as described above, to be compressed and utilized in the form of a bulk permanent magnet, while maintaining the high magnetic properties of the powder state.

[0007]

[0008] The present invention aims to solve the aforementioned problems and provides a permanent magnet assembly and a method for manufacturing the same, which enables magnetic powder that does not easily bulk to be manufactured into a bulk permanent magnet form while maintaining its magnetic properties.

[0009]

[0010] A permanent magnet assembly according to a first embodiment of the present invention for implementing the purpose described above may comprise: an outer frame having a receiving space that is open at least at the top so as to accommodate magnetic powder inside; an inner frame in the shape of a tube disposed on the inner central axis of the outer frame and having an insertion hole formed through it in the axial direction; a cover coupled to the upper opening of the outer frame to seal the receiving space and having a through hole communicating with the insertion hole; and a pressure rod of a predetermined length that is slidably coupled to the insertion hole through the through hole of the cover and, when slidably coupled to the insertion hole, expands the inner frame in the radial direction to compress the magnetic powder stored in the receiving space.

[0011] In this case, the lower central axis of the outer frame may include a lower through hole so that the pressure rod can be slidably coupled into the insertion hole of the inner frame and then penetrate.

[0012] In addition, the above outer frame may include a portion where the magnetic field flows when the magnetic powder is aligned with a soft magnetic material, and the other portions formed of a non-magnetic material.

[0013] In addition, the pressure rod may include one formed with an outer diameter larger than the inner diameter of the insertion hole.

[0014] In addition, the inner frame may be formed of a flexible metal material so that the inner frame can expand when the pressure rod is slidably coupled.

[0015] In addition, the above pressure rod may include a rotating shaft when the above permanent magnet assembly is used as a rotor of a motor.

[0016] In addition, the magnetic powder may include using a bulk (Green body) that has been compressed and molded in advance before being stored in the receiving space.

[0017]

[0018] A method for manufacturing a permanent magnet assembly according to a first embodiment of the present invention may include: a step of arranging an inner frame on an inner central axis line of an outer frame; a step of storing magnetic powder in a receiving space between the outer frame and the inner frame; a step of sealing the receiving space in which the magnetic powder is stored by attaching a cover to an upper opening of the outer frame; a step of aligning the magnetic field by applying a magnetic field to the stored magnetic powder; and a step of compressing the magnetic powder stored in the receiving space by slidingly connecting the pressure rod into the insertion hole of the inner frame through the upper through hole of the cover to expand the inner frame in a radial direction.

[0019] In this case, the method may further include a step of injecting a polymer into the received magnetic powder after receiving the magnetic powder in the receiving space or after aligning the magnetic field of the received magnetic powder, so that the polymer permeates the received magnetic powder; and a heat treatment step of compressing the magnetic powder using the pressure rod and then heat-treating at a temperature at which the polymer hardens to fix the position of the compressed magnetic powder.

[0020]

[0021] A permanent magnet assembly according to a second embodiment of the present invention may include: a frame having a plurality of receiving spaces, at least one of which is open at the top, so as to accommodate magnetic powder inside; and a cover coupled to the upper opening of the frame to seal the receiving space and having a plurality of corresponding pressure protrusions so as to compress the magnetic powder stored in the receiving space when coupled to the upper opening.

[0022] In this case, the frame may include an insertion hole on the central axis line into which a rotation shaft is inserted so that the permanent magnet assembly can be used as a rotor of a motor.

[0023]

[0024] In addition, a method for manufacturing a permanent magnet assembly according to a second embodiment of the present invention may include: a step of storing magnetic powder in a plurality of receiving spaces through an upper opening of the frame; a step of aligning the magnetic field by applying a magnetic field to the stored magnetic powder while a cover is placed on the upper opening of the frame; and a step of compressing the magnetic powder stored in the receiving spaces by pressing the cover in the axial direction of the frame.

[0025] In this case, the method may further include a step of injecting a polymer into the received magnetic powder after receiving the magnetic powder in the receiving space, or after compressing the received magnetic powder, while the cover is open; and a heat treatment step of fixing the position of the compressed magnetic powder by heat treating at a temperature at which the polymer hardens after closing the cover.

[0026]

[0027] The permanent magnet assembly according to the present invention having the above configuration and the method for manufacturing the same can easily manufacture magnetic powder that does not easily bulk into a bulk permanent magnet form while maintaining its magnetic properties.

[0028] In addition, the permanent magnet assembly according to the present invention can be used permanently as a motor rotor without the cumbersome process of inserting permanent magnets into a frame or attaching permanent magnets to the outer surface of a frame, as is the case with conventional motor rotors.

[0029]

[0030] FIG. 1 is a perspective view of a permanent magnet assembly according to a first embodiment of the present invention,

[0031] FIG. 2 is an exploded perspective view of a permanent magnet assembly according to a first embodiment of the present invention,

[0032] FIG. 3 is a side cross-sectional view of a permanent magnet assembly according to a first embodiment of the present invention,

[0033] FIGS. 4a to 4e are drawings showing the manufacturing process of a permanent magnet assembly according to a first embodiment of the present invention,

[0034] FIG. 5 is a perspective view of a permanent magnet assembly according to a second embodiment of the present invention,

[0035] FIG. 6 is an exploded perspective view of a permanent magnet assembly according to a second embodiment of the present invention,

[0036] FIGS. 7a to 7e are drawings showing the manufacturing process of a permanent magnet assembly according to a second embodiment of the present invention.

[0037] ※Explanation of symbols※

[0038] M : Magnetic powder 100, 200 : Permanent magnet assembly

[0039] 110 : External frame 110a : Soft magnet

[0040] 110b : Non-magnetic S : Accommodation space

[0041] 111 : Opening 113 : Lower penetration hole

[0042] 120 : Inner frame 121 : Insertion hole

[0043] 130 : Cover 131 : Upper penetration hole

[0044] 140: Pressure rod 150: Permanent magnet for magnetic field alignment

[0045] 210 : Frame 211 : Opening

[0046] 213 : Insertion hole 220 : Cover

[0047] 221 : Pressure projection 223 : Through hole

[0048] 230: Permanent magnet for magnetic field alignment

[0049]

[0050] The configuration and operation of a specific embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0051] Here, it should be noted that when assigning reference numerals to the components of each drawing, identical components are denoted by the same numeral whenever possible, even if they are shown on different drawings.

[0052]

[0053] <First Example>

[0054] FIG. 1 is a perspective view of a permanent magnet assembly according to a first embodiment of the present invention, and FIG. 2 is an exploded perspective view of a permanent magnet assembly according to a first embodiment of the present invention.

[0055] Referring to FIGS. 1 and 2, a permanent magnet assembly (100) according to a first embodiment of the present invention may include an outer frame (110), an inner frame (120), a cover (130), and a pressure rod (140).

[0056] The configuration of the present invention is described in detail as follows.

[0057]

[0058] First, the outer frame (110) forms the main body of the permanent magnet assembly (100), and a receiving space (S) can be provided with at least an upper opening (111) so that magnetic powder (M) can be stored inside.

[0059] In this case, the outer frame (110) can be formed in a cylindrical shape so that the permanent magnet assembly (100) can be directly used as a rotor for the motor.

[0060] In addition, the outer frame (110) may be formed with a soft magnetic (110a) material in the part where the magnetic field flows and a non-magnetic (110b) material (see FIG. 4d) in the other part so that the loss of magnetic force can be minimized when the magnetic powder (M) is aligned using a permanent magnet (150) to be described later.

[0061] In addition, the magnetic powder (M) stored in the internal receiving space (S) of the outer frame (110) may be in a powder state requiring a magnetic field alignment process.

[0062] As another example, the magnetic powder (M) may be used as a bulk (Green body) that has been pre-compressed through a magnetic field molding process before being received in the receiving space (S). In this case, the magnetic field alignment process described later is not additionally required. In the present invention, an example is provided for the case where the magnetic powder (M) is received in the receiving space (S) in a powder state.

[0063]

[0064] The inner frame (120) is positioned on the inner central axis of the outer frame (110), and the inner frame (120) may be formed in a tube shape with an insertion hole (121) penetrating it in the axial direction. Preferably, the inner frame (120) may be cylindrical in shape.

[0065] In this case, the height of the inner frame (120) can be formed to correspond to the inner receiving space (S) of the outer frame (110) so that the receiving space (S) of the outer frame (110) and the inner space of the insertion hole (121) can be partitioned.

[0066] In addition, the inner frame (120) may be formed of a flexible metal material so that when the pressure rod (140), which will be described later, is slidably coupled within the insertion hole (121), the outer surface of the inner frame (120) can be expanded radially. For example, the inner frame (120) may be formed of a material such as aluminum or copper.

[0067] The inner frame (120) may be formed integrally within the outer frame (110) or formed separately and assembled, and is not specifically limited in the present invention.

[0068]

[0069] Referring to FIG. 3, the cover (130) can be coupled to the upper opening (111) of the outer frame (110) to seal the receiving space (S), and the cover (130) can prevent magnetic powder (M) stored in the receiving space (S) from leaking out. This cover (130) can be formed of the same material as the outer frame (110) and can be sealed by methods such as bolt fastening or welding.

[0070] In this case, an upper through hole (131) communicating with the insertion hole (121) of the inner frame (120) is provided on the central axis of the cover (130), and a lower through hole (113) communicating with the insertion hole (121) can be provided on the lower central axis of the outer frame (110).

[0071]

[0072] The above pressure rod (140) is slidably coupled within the insertion hole (121) of the inner frame (120) through the upper through hole (131) of the cover (130), and can be formed in the shape of a cylinder of a predetermined length.

[0073] Specifically, when the pressure rod (140) is slidably coupled to the insertion hole (121) of the inner frame (120), it can expand the outer surface of the inner frame (120) in a radial direction to compress the magnetic powder (M) stored in the receiving space (S) of the outer frame (110). Accordingly, the magnetic powder (M) in powder form stored in the receiving space (S) of the outer frame (110) can be prevented from moving.

[0074] That is, by compressing the magnetic powder (M) contained through the pressure rod (140) so that the magnetic powder (M) cannot move within the receiving space (S), it can be utilized as a 'bulk permanent magnet' even if it is not a sintered or bonded magnet. At this time, the compression of the magnetic powder (M) using the pressure rod (140) within the receiving space (S) of the outer frame (110) can be permanent.

[0075] In this case, the pressure rod (140) is formed with an outer diameter (d2) (see FIG. 4c) larger than the inner diameter (d1) of the insertion hole (121), so that the inner frame (120) can be expanded radially.

[0076] In addition, the pressure rod (140) may be provided with an inclined surface on the tip edge in the direction of insertion so that it can be smoothly inserted into the insertion hole (121).

[0077] This pressure rod (140) can be slidably coupled within the insertion hole (121) and then protrude outward by a predetermined length through the lower through hole (113) at the bottom of the outer frame (110). Accordingly, when the permanent magnet assembly (100) is used as a rotor of a motor, the pressure rod (140) protruding to a predetermined length can serve as a rotation axis.

[0078] Meanwhile, it is preferable that the components of the inner frame (120), cover (130), and pressure rod (140) be formed from a non-magnetic material. That is, if the components (120, 130, 140) are formed from a non-magnetic material, the magnetic powder (M) stored inside the outer frame (110) can be aligned well in one direction when an external magnetic field is applied, and as a result, the magnetic field that the permanent magnet can produce can be maximized. If the external magnetic field applied to the components (120, 130, 140) flows too strongly, the alignment of the magnetic powder (M), which is actually important, may not be properly achieved.

[0079]

[0080] Then, the manufacturing process of the permanent magnet assembly (100) according to the present invention as described above will be explained with reference to FIGS. 4a to 4e.

[0081] First, an inner frame (120) is placed on the inner central axis of the outer frame (110) (see FIG. 4a).

[0082] Magnetic powder (M) is stored in the receiving space (S) between the outer frame (110) and the inner frame (120) (see FIG. 4b).

[0083] Then, a cover (130) is attached to the upper opening (111) of the outer frame (110) to seal the receiving space (S) in which the magnetic powder (M) is stored. At this time, the magnetic powder (M) stored in the receiving space (S) is loose enough to move even with the cover (130) attached.

[0084] Then, the N pole and S pole of the magnetic field alignment permanent magnet (150) are placed facing each other with an outer frame (110) in between so that a magnetic field can be applied to the magnetic powder (M) stored in the above-mentioned receiving space (S) to align the magnetic field (see FIG. 4c).

[0085] In this case, the outer frame (110) is formed as a combination of two materials, such as soft magnetic (110a) and non-magnetic (110b), so that when a magnetic field is aligned using a permanent magnet (150), the magnetic field can be more concentrated and pass through the magnetic powder (M). Accordingly, the loss of magnetic force can be minimized (see FIG. 4d).

[0086] In this state, a pressure rod (140) is slidably coupled into the insertion hole (121) of the inner frame (120) through the upper through hole (131) of the cover (130). Accordingly, the outer surface of the inner frame (120) can be expanded radially to compress the magnetic powder (M) stored in the receiving space (S). At this time, by coupling the pressure rod (140) so as to penetrate the lower through hole (113) of the outer frame (110), the pressure rod (140) can be used as a rotation axis for the motor rotor (see FIG. 4e).

[0087] Preferably, here, a process of storing magnetic powder (M) in the receiving space (S) or, after aligning the magnetic field of the magnetic powder (M) stored in the receiving space (S), a process of introducing a polymer to permeate the stored magnetic powder (M) may be further performed.

[0088] Then, after undergoing a process of compressing the magnetic powder (M), the process of manufacturing the permanent magnet assembly (100) according to the first embodiment of the present invention is completed by undergoing a heat treatment process that fixes the position of the compressed magnetic powder (M) by heat treating it at a temperature at which the polymer hardens.

[0089]

[0090] <Second Embodiment>

[0091] FIG. 5 is a perspective view of a permanent magnet assembly according to a second embodiment of the present invention, and FIG. 6 is an exploded perspective view of a permanent magnet assembly according to a second embodiment of the present invention.

[0092] Referring to FIGS. 5 and 6, a permanent magnet assembly (200) according to a second embodiment of the present invention may include a frame (210) having a plurality of receiving spaces (S) that are at least open (211) at the upper side so as to receive magnetic powder (M) inside, and a cover (220) that is coupled to the upper opening (211) of the frame (210) and has a plurality of corresponding pressure protrusions (221) so as to seal the receiving space (S) and compress the magnetic powder (M) received in the receiving space (S).

[0093] In this case, the frame (210) can be formed entirely of a soft magnetic material.

[0094] In addition, the receiving space (S) provided in the frame (210) may be arranged radially at a predetermined angle apart from the central axis, and the pressure protrusion (221) provided in the cover (220) may also be arranged at corresponding positions and numbers.

[0095] In addition, an insertion hole (213) into which a rotation shaft is inserted may be provided on the central axis of the frame (210) so that the permanent magnet assembly (200) can be used as a rotor of the motor.

[0096]

[0097] Then, the manufacturing process of the permanent magnet assembly (200) according to the second embodiment of the present invention as described above will be explained with reference to FIGS. 7a to 7e.

[0098] First, magnetic powder (M) is stored in the receiving space (S) of the frame (210) (see FIG. 7a, FIG. 7b).

[0099] Then, with the cover (220) placed slightly on the upper opening (211) of the frame (210) (see FIG. 7c), a plurality of magnetic field alignment permanent magnets (230) are arranged around the outer circumference of the frame (210) to apply a magnetic field to the magnetic powder (M) stored in the receiving space (S) and align the magnetic field (see FIG. 7d).

[0100] Then, the cover (220) is pressed in the axial direction (C) of the frame (210) to compress the magnetic powder (M) contained in the receiving space (S) (see FIG. 7e).

[0101] Preferably, after storing magnetic powder (M) in the receiving space (S) of the frame (210), or after compressing the stored magnetic powder (M), the cover (220) may be opened, and a process of introducing a polymer to permeate the stored magnetic powder (M) may be further performed.

[0102] Then, after closing the cover (220), the manufacturing process of the permanent magnet assembly (200) according to the second embodiment of the present invention is completed by undergoing a heat treatment process to fix the position of the compressed magnetic powder (M) by heat treatment at a temperature at which the polymer hardens.

[0103]

[0104] A permanent magnet assembly (100) (200) with the above configuration can easily manufacture magnetic powder (M), which does not bulk well, into a bulk permanent magnet form while maintaining its magnetic properties.

[0105] In addition, the permanent magnet assembly (100)(200) according to the present invention can be used permanently as a motor rotor without the cumbersome process of inserting a permanent magnet into a frame or attaching a permanent magnet to the outer surface of a frame, as is the case with the rotor of a conventional motor.

[0106]

[0107] Although the present invention has been illustrated and described above with specific embodiments, the present invention is not limited to the embodiments described above, and it is understood that various changes and modifications are possible within the scope of the technical spirit of the present invention.

Claims

1. An outer frame provided with a receiving space, at least on the upper side, open so that magnetic powder can be stored inside; A tube-shaped inner frame disposed on the inner central axis of the outer frame and having an insertion hole formed through it in the axial direction; A cover coupled to the upper opening of the outer frame to seal the receiving space and having a through hole communicating with the insertion hole; and A permanent magnet assembly comprising: a pressure rod of a predetermined length that is slidably coupled to the insertion hole through the through hole of the cover, and expands the inner frame radially to compress the magnetic powder stored in the receiving space when slidably coupled to the insertion hole.

2. In Paragraph 1, On the lower central axis of the above outer frame, A permanent magnet assembly comprising having a lower through hole so that the pressure rod can be slidably coupled within the insertion hole of the inner frame and then penetrate.

3. In Paragraph 1, The above external frame is, A permanent magnet assembly comprising a portion in which the magnetic field flows when the magnetic powder is aligned with the magnetic field, and the other portion is formed of a non-magnetic material.

4. In Paragraph 1, The above pressure rod is, A permanent magnet assembly comprising an outer diameter formed larger than the inner diameter of the insertion hole.

5. In Paragraph 4, The above inner frame is, A permanent magnet assembly comprising an inner frame formed of a flexible metal material so that it can expand when the pressure rod is slidably coupled.

6. In Paragraph 2, The above pressure rod is, A permanent magnet assembly comprising a rotating shaft when the above permanent magnet assembly is used as a rotor of a motor.

7. In Paragraph 1, The above magnetic powder is, A permanent magnet assembly comprising using a bulk (Green body) that has been compression-molded in advance before being stored in the above-mentioned receiving space.

8. A method for manufacturing a permanent magnet assembly of any one of claims 1 to 7, A step of placing the inner frame on the inner central axis of the outer frame; A step of storing magnetic powder in the receiving space between the outer frame and the inner frame; A step of sealing the receiving space containing the magnetic powder by attaching a cover to the upper opening of the outer frame; A step of applying a magnetic field to the stored magnetic powder to align the magnetic field; and A method for manufacturing a permanent magnet comprising the step of slidingly coupling the pressure rod into the insertion hole of the inner frame through the upper through hole of the cover, thereby expanding the inner frame radially to compress the magnetic powder contained in the receiving space.

9. In Paragraph 8, A step of injecting a polymer so that it permeates the stored magnetic powder after storing the magnetic powder in the above-mentioned receiving space, or after aligning the magnetic field of the stored magnetic powder; and A method for manufacturing a permanent magnet, further comprising: a heat treatment step of compressing the magnetic powder using the above-mentioned pressure rod, and then heat-treating at a temperature at which the polymer hardens to fix the position of the compressed magnetic powder.

10. A frame having a plurality of receiving spaces, at least the upper side of which is open, so that magnetic powder can be stored inside; and A permanent magnet assembly comprising: a cover coupled to an upper opening of the frame to seal the receiving space, and having a plurality of corresponding pressure protrusions to compress magnetic powder stored in the receiving space when coupled to the upper opening.

11. In Paragraph 10, On the central axis of the above frame, A permanent magnet assembly comprising an insertion hole into which a rotating shaft is inserted so that the above permanent magnet assembly can be used as a rotor of a motor.

12. A method for manufacturing a permanent magnet assembly according to claim 10 or 11, A step of storing magnetic powder in a plurality of receiving spaces through the upper opening of the above frame; A step of aligning the magnetic field by applying a magnetic field to the stored magnetic powder while the cover is placed on the upper opening of the frame; and A method for manufacturing a permanent magnet assembly comprising the step of compressing magnetic powder stored in the receiving space by pressing the cover in the axial direction of the frame.

13. In Paragraph 12, A step of injecting a polymer into the stored magnetic powder so that it permeates the stored magnetic powder while the cover is open, after storing the magnetic powder in the above-mentioned receiving space or after compressing the stored magnetic powder; and A method for manufacturing a permanent magnet, further comprising a heat treatment step of fixing the position of the compressed magnetic powder by heat treating at a temperature at which the polymer hardens after closing the cover.

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