KR20130034818A - Electro-magnetic linear actuator - Google Patents

Abstract

The electromagnetic linear actuator according to the present invention is an electromagnetic linear actuator comprising a stator and a mover provided to linearly move with respect to the stator, the mover comprising: a shaft; A plurality of first permanent magnets mounted on the shaft, the plurality of first permanent magnets being disposed at predetermined intervals along the longitudinal direction of the shaft and having a magnetization direction in a thickness direction; And a second permanent magnet mounted on the shaft and inserted between two first permanent magnets adjacent to each other, and having a magnetization direction in a radial direction. According to the present invention, the magnetic flux density acting between the stator and the mover can be greatly increased, and as a result, it is possible to provide a structure of a linear actuator capable of improving the thrust performance of the actuator and miniaturizing and reducing the weight.

Description

Electromagnetic linear actuator

The present invention relates to an electromagnetic preceding actuator, and more particularly to a structure of an electromagnetic linear actuator for increasing the thrust generated between the stator and the mover.

In general, hydraulic actuators are frequently used for fatigue endurance testing of automobile parts. Hydraulic actuator is a thrust (Thrust force) is generated by the hydraulic pressure, there is an advantage that the thrust is large, but there are problems due to leakage and vibration noise and the vibration frequency is low, the efficiency of fatigue test is low.

For this reason, in recent years, electromagnetic linear actuators (or linear motors) have replaced hydraulic actuators. Electromagnetic linear actuators have the advantages of no leakage, low vibration noise, smaller volume, better control accuracy and relatively high vibration frequency compared to hydraulic actuators. However, the conventional electromagnetic linear actuator has a problem that the thrust is relatively small compared to the hydraulic actuator, the situation is required to research and development to increase the thrust of the electromagnetic linear actuator.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic linear actuator capable of improving the thrust performance of an actuator and miniaturizing / lightening.

The object is, according to the present invention, an electromagnetic linear actuator comprising a stator and a mover arranged to linearly move with respect to the stator, the mover comprising: a shaft; A plurality of first permanent magnets mounted on the shaft, the plurality of first permanent magnets being disposed at predetermined intervals along the longitudinal direction of the shaft and having a magnetization direction in a thickness direction; And a second permanent magnet mounted on the shaft and inserted between the two first permanent magnets adjacent to each other and having a magnetization direction in a radial direction. have.

The second permanent magnet may be provided in a structure in which a plurality of permanent magnet split bodies magnetized in a radial direction are assembled with each other.

The second permanent magnet may further include a bracket for coupling the plurality of permanent magnet split bodies to each other.

Each of the first permanent magnets and the second permanent magnets may be provided in a ring shape surrounding the shaft.

The bracket may include a central portion provided in a ring shape and supporting an inner circumferential surface of the permanent magnet split body; And a joint extending radially from the central portion and interconnecting sides of the two permanent magnet partitions adjacent to each other.

The bracket may be made of silicon steel.

The permanent magnet split body may be provided in a 'C' shape.

The first permanent magnet and the second permanent magnet may have a Halbach array.

Radially extending first and second flange portions are formed at both ends of the shaft, and the first permanent magnet and the second permanent magnet are formed between the first flange portion and the second flange portion. It can be stored in the space.

The mover may include: a first cover member made of pure iron interposed between the first permanent magnet adjacent to the first flange portion and the first flange portion; And a second cover member made of pure iron, which is interposed between the first permanent magnet body adjacent to the second flange portion and the second flange portion.

The stator, the yoke is provided in a hollow shape to accommodate the mover; And a magnetic coil part provided to surround the mover in the yoke.

In the electromagnetic actuator including a stator and a mover, a mover having a structure in which a second permanent magnet in which the magnetization direction is radial is inserted and disposed between the first permanent magnets in which the magnetization direction is the thickness direction. By including, the magnetic flux density acting between the stator and the mover can be significantly increased as compared with the general electromagnetic linear actuator having a structure in which pure iron is inserted between the permanent magnets, and as a result, the thrust of the actuator It is possible to provide a structure of a linear actuator capable of improving performance and miniaturizing / lightening.

In addition, the present invention provides a structure in which a plurality of permanent magnet splitters in which the second permanent magnets having a magnetization direction in the radial direction are magnetized in the radial direction are assembled with each other, whereby the operation of magnetizing the second permanent magnets in the radial direction is relatively performed. Since it is easier to manufacture, it is possible to improve the convenience of manufacturing for the second permanent magnet having a magnetization direction in the radial direction.

1 is a perspective view showing an electromagnetic linear actuator according to an embodiment of the present invention with the stator and the mover separated from each other.
2 and 3 are perspective views illustrating a portion of the electromagnetic linear actuator of FIG. 1 taken along the axial direction.
4 is a perspective view of a first permanent magnet having a magnetization direction in a thickness direction in the electromagnetic linear actuator of FIG. 1.
5 is a perspective view of a second permanent magnet having a radial magnetization direction in the electromagnetic linear actuator of FIG. 1.
6 is a perspective view illustrating an electromagnetic linear actuator according to another embodiment of the present invention with the stator and the mover separated from each other.
FIG. 7 is a perspective view illustrating a portion of the electromagnetic linear actuator of FIG. 6 taken along the axial direction.
FIG. 8 is a perspective view of a second permanent magnet having a radial magnetization direction in the electromagnetic linear actuator of FIG. 6.

In order to fully understand the present invention, operational advantages of the present invention, and objects achieved by the practice of the present invention, reference should be made to the accompanying drawings and the accompanying drawings which illustrate preferred embodiments of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in order to avoid unnecessary obscuration of the present invention.

1 is a perspective view showing an electromagnetic linear actuator according to an embodiment of the present invention in a state where the stator and the mover are separated from each other, and FIGS. 2 and 3 illustrate a portion of the electromagnetic linear actuator of FIG. 1 along an axial direction. It is a perspective view shown in the state which was cut off. 4 is a perspective view of a first permanent magnet having a magnetization direction in the thickness direction of the electromagnetic linear actuator of FIG. 1, and FIG. 5 is a perspective view of a second permanent magnet having a magnetization direction in the electromagnetic linear actuator of FIG. 1. to be.

1 to 5, the electromagnetic linear actuator 100 according to the present embodiment may include a stator 110 and a mover 120 provided to linearly move with respect to the stator 110. That is, the electromagnetic preceding actuator 100 is configured such that the mover 120 reciprocates linearly with respect to the stator 110 by a thrust force generated by an electromagnetic action between the stator 110 and the mover 120. Can be configured.

On the other hand, the electromagnetic linear actuator 100 according to the present embodiment is provided as a linear actuator for performing a fatigue endurance test for automobile parts, etc., the present invention is not limited to this, but not only for the compressor (compressor) but also for transport or control Since the present invention can be sufficiently applied to a linear motor system, it can be applied to industrial fields such as factory automation equipment and semiconductor equipment.

The stator 110 may include the yoke 111 and the magnetic coil unit 113 as shown in FIGS. 1 to 3.

The yoke 111 may be provided in a hollow shape to accommodate the mover 120. In the present embodiment, the yoke 111 is provided in a cylindrical shape, but the shape of the yoke 111 may be appropriately changed according to the appearance of the mover 120 accommodated therein. The magnetic coil unit 113 may be provided to surround the circumference of the mover 120 in the yoke 111. In this case, the magnetic coil unit 113 may be provided in a state of being attached to the inner circumferential surface of the yoke 111. When a predetermined voltage is applied to the magnetic coil unit 113, the mover 120 accommodated in the yoke 111 may be straight in the front and rear direction with respect to the stator 110 by electromagnetic interaction with the magnetic coil unit 113. It will reciprocate. In the present embodiment, the magnetic coil unit 113 includes fifteen magnetic coils wound in a ring type inside the yoke 111, and these magnetic coils are grouped by three and connected in parallel to each other. However, the number and connection structure of the magnetic coils constituting the magnetic coil unit 113 are not limited to the matters disclosed in the present embodiment and may be appropriately changed.

The mover 120 may include a shaft 121, a first permanent magnet 123, and a second permanent magnet 125 as shown in FIGS. 1 to 5.

The shaft 121 provides an axis in which the mover 120 moves in the front-rear direction with respect to the stator 110. The shaft 121 is disposed inside the yoke 111 to coincide with the virtual center axis of the yoke 111. It is desirable to be. In addition, the shaft 121 may provide a space in which the first and second permanent magnets 123 and 125 are mounted. To this end, radially extending first flange portions 121a and second flange portions 121b may be formed at both ends of the shaft 121. The first and second permanent magnets 123 and 125 may be accommodated between the first flange portion 121a and the second flange portion 121b. Accordingly, the first and second permanent magnets 123 and 125 are stably stored in the space formed by the first flange portion 121a and the second flange portion 121b, and at the same time, the first flange portion 121a and the first permanent magnet bodies 123 and 125 are formed. It can be firmly supported by the two flange portion 121b. In addition, although not shown in the accompanying drawings, one end of the shaft 121 may be provided with a rod (Rod) for transmitting a linear reciprocating motion of the mover 120 to the object.

Meanwhile, as illustrated in FIGS. 1 to 3, the first permanent magnet 123 adjacent to the first flange portion 121a of the shaft 121 (the first disposed magnet in the uppermost part of the first permanent magnets in the drawings). The first cover member 131 made of pure iron may be interposed between the first permanent magnet and the first flange portion 121a. Similarly, the first permanent magnet 123 (the first permanent magnet disposed at the bottom of the first permanent magnets in the drawings) and the second flange portion adjacent to the second flange portion 121b of the shaft 121. A second cover member 132 made of pure iron may be interposed between the 211. In this case, each of the first and second cover members 131 and 132 may be provided in a ring shape surrounding the shaft 210.

The first permanent magnet 123 is magnetized or magnetized in the thickness direction (or vertical direction) as indicated by the arrows in FIGS. 2 and 3. Specifically, the first permanent magnet 123 is magnetized in the thickness direction toward the upper side or the thickness direction toward the lower side. For reference, the first permanent magnet 123 illustrated in FIG. 4 indicates magnetization in the thickness direction toward the upper side. The first permanent magnet 123 may be provided as a rare earth sintered magnet such as an NdFeB-based sintered magnet which is pressed in a magnetic field so that the magnetization direction thereof becomes a thickness direction.

A plurality of first permanent magnets 123 are provided, and the plurality of first permanent magnets 123 are arranged at predetermined intervals along the longitudinal direction of the shaft 121 as shown in FIGS. 1 to 3. Can be deployed. In the present embodiment, the first permanent magnets 123 are provided as four first permanent magnets 123 having a ring shape surrounding the shaft 121 as shown in FIG. 4. The magnet body 123 is sequentially mounted to the shaft 121. At this time, the four first permanent magnets 123 may be arranged such that the magnetization direction is "↑ ↓ ↑ ↓" from above, as shown in FIGS. 2 and 3. However, the number, shape and mounting structure of the first permanent magnets 123 are not limited to those disclosed in the present embodiment and may be appropriately changed.

The second permanent magnet 125 is magnetized or magnetized in the radial direction as indicated by the arrows in FIGS. 2 and 3. Specifically, the second permanent magnet 125 is magnetized in the inner radial direction or the outer radial direction. For reference, the second permanent magnet 125 shown in FIG. 5 indicates magnetization in the outer radial direction. The second permanent magnet 125 may be provided as a rare earth sintered magnet such as NdFeB-based sintered magnet magnetically molded so that the magnetization direction is a radial direction.

The second permanent magnets 125 are mounted on the shaft 121 like the first permanent magnets 123, but two first permanent magnets 123 neighboring each other as shown in FIGS. 1 to 3. Can be placed between each insertion. In the present embodiment, since the first permanent magnets 123 are provided as four as described above, the second permanent magnets 125 are inserted between two neighboring first permanent magnets 123. Is provided in three. The second permanent magnet 125 is provided in a ring shape surrounding the shaft 121, as shown in FIG. 5, similar to the first permanent magnet 123 described above. In this case, the three second permanent magnets 125 may be arranged such that the magnetization direction becomes “← → ←” from above, as shown in FIGS. 2 and 3. Meanwhile, the second permanent magnet 125 may have a thickness smaller than that of the first permanent magnet 123 as shown in FIGS. 1 to 3. For example, the thickness of the second permanent magnets 125 may be selected to be 1/2 of the thickness of the first permanent magnets 123. However, the number, shape and mounting structure of the second permanent magnets 125 are not limited to those disclosed in this embodiment and may be appropriately changed.

As a result, the four first permanent magnets 123 and the three second permanent magnets 125 have a magnetization direction of ↑ ← ↓ → ↑ ← ↓ from the top, as shown in FIGS. 2 and 3. It may be arranged so as to constitute a so-called 'Halbach array'. Accordingly, since the magnetic force generated in the magnetic coil portion 113 of the stator 110 and the magnetic force generated in the permanent magnets 123 and 125 of the mover 120 are made more active, the stator 110 is more active. And the thrust generated between the mover 120 may increase.

As such, in the electromagnetic linear actuator 100 according to the present exemplary embodiment, the second permanent magnet 125 having the magnetization direction in the radial direction is inserted and disposed between the first permanent magnets 123 having the magnetization direction in the thickness direction. By including a mover 120 having a structure that is, between the stator 110 and the mover 120, compared to the conventional electromagnetic linear actuator having a structure in which the pure iron (Pure iron) is inserted between the permanent magnets The effective magnetic flux density can be greatly increased, and as a result, it is possible to improve the thrust performance of the actuator and provide a structure of a linear actuator that can be miniaturized and lightened.

Hereinafter, an electromagnetic linear actuator according to another embodiment of the present invention will be described based on differences from the above-described embodiment.

FIG. 6 is a perspective view illustrating an electromagnetic linear actuator according to another embodiment of the present invention in a state where the stator and the mover are separated from each other, and FIG. 7 is a state in which a portion of the electromagnetic linear actuator of FIG. 6 is cut along the axial direction. 8 is a perspective view of a second permanent magnet having a radial magnetization direction in the electromagnetic linear actuator of FIG. 6.

6 to 8, the electromagnetic linear actuator 200 according to the present embodiment may include a stator 110 and a mover 120 provided to linearly move with respect to the stator 110. Here, the stator 110 includes the yoke 111 and the magnetic coil portion 113, the mover 120 is the shaft 121, the first permanent magnet 123 and the second permanent magnet 225 It may include. In addition, the mover 120 may further include first and second cover members 131 and 132 made of pure iron.

In other words, the electromagnetic linear actuator 200 according to the present embodiment is substantially identical to the configuration of the electromagnetic linear actuator 100 according to the above-described embodiment except for the configuration of the second permanent magnet 225 of the mover 120. Same as The same configuration is given the same reference numerals, and the description thereof will apply mutatis mutandis to the above-described embodiment.

Like the above-described embodiment, the second permanent magnets 225 may be mounted on the shaft 121 and inserted between two first permanent magnets 123 adjacent to each other. Here, unlike the above-described embodiment, the second permanent magnet 225 has a structure in which three permanent magnet split bodies 225a, 225b, and 225c are magnetized or magnetized in a radial direction as shown in FIG. 8. Can be provided. That is, the second permanent magnet 225 magnetizes three permanent magnet split bodies 225a, 225b, and 225c in the radial direction (inner radial direction or outer radial direction), and then the permanent magnet split bodies 225a and 225b. , 225c) may be constructed by assembling each other. In this case, each of the three permanent magnet splitters 225a, 225b, and 225c may be provided as rare earth sintered magnets such as NdFeB-based sintered magnets magnetically molded so that the magnetization direction thereof becomes radial. However, in the present invention, the number of permanent magnet partitions constituting the second permanent magnet is not limited to the three disclosed in the present embodiment and may be appropriately changed. Meanwhile, the assembled second permanent magnets 225 form a ring shape surrounding the shaft 121, and each of the permanent magnet splitters 225a, 225b, and 225c has a 'C' shape as shown in FIG. 8. It is preferable to provide.

In general, permanent magnets, such as rare earth sintered magnets, are difficult to manufacture in the radial direction compared to magnetization in the thickness direction or in the vertical direction. This difficulty in manufacturing may increase the size of the permanent magnets. The more serious it becomes.

In this aspect, the electromagnetic linear actuator 200 according to the present embodiment includes a plurality of permanent magnet split bodies 225a, 225b, and 225c in which the second permanent magnet 225 having the radial magnetization direction is magnetized in the radial direction. Is provided in a mutually assembled structure, so that the magnetization of the second permanent magnet 225 in the radial direction is relatively easy, thereby improving the convenience of manufacturing the second permanent magnet 225 in the magnetization direction. You can.

Meanwhile, in order to assemble the permanent magnet splitters 225a, 225b and 225c, the mover 120 couples the permanent magnet splitters 225a, 225b and 225c to each other as shown in FIGS. It may further include a bracket 226 for.

Specifically, in consideration of the fact that the permanent magnet splitters 225a, 225b, and 225c are provided in a 'C' shape, the bracket 226 is provided in a ring shape and has a permanent magnet splitter as shown in FIG. 225a, 225b or 225c or 225c and 225a of the central portion 227 supporting the inner circumferential surface of the 225a, 225b and 225c and the two permanent magnet partitions 225a, 225b or 225b or 225c or 225a extending radially from the central portion 227 and neighboring each other. It may include a joint 228 that interconnects the sides. At this time, the permanent magnet dividers (225a, 225b, 225c) can be firmly fixed by the bolt (B) in the fitted state on both sides of the joint 228 of the bracket 226 as shown in FIG. . However, the structure of the bracket used to assemble the permanent magnet split bodies in the present invention is not limited to that disclosed in this embodiment and may be appropriately changed according to the shape of the permanent magnet split body. On the other hand, the bracket 226 is preferably made of silicon steel (Silicon steel) material, which is intended to be a strong magnet easily by the external magnetic field, so that the magnetic field can be returned to the absence of the magnetic soon.

As such, in the electromagnetic linear actuator 200 according to the present embodiment, the second permanent magnet 225 having the radial magnetization direction is inserted between the first permanent magnets 123 having the magnetization direction in the thickness direction. A plurality of permanent magnet split bodies 225a, 225b, and 225c, each of which includes a mover 220 having a structure in which the second permanent magnet 225 having a magnetization direction is radially magnetized in a radial direction. By providing the structure, the magnetization direction is radial, while still including the advantages of the electromagnetic preceding actuator 100 according to the above-described embodiment, such as increasing the thrust generated between the stator 110 and the mover 220. The convenience of fabrication for the second permanent magnet 225 can be improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, such modifications or variations are intended to fall within the scope of the appended claims.

100,200: Electromagnetic Linear Actuator
110: stator
111: yoke
113: magnetic coil part
120,220: mover
121: shaft
123: the first permanent magnet
125,225: second permanent magnet
225a, 225b, 225c: Permanent Magnet Splitter
226: Bracket

Claims (11)

An electromagnetic linear actuator comprising a stator and a mover provided to linearly move with respect to the stator.
shaft;
A plurality of first permanent magnets mounted on the shaft, the plurality of first permanent magnets being disposed at predetermined intervals along the longitudinal direction of the shaft and having a magnetization direction in a thickness direction; And
And a second permanent magnet mounted to the shaft, the second permanent magnet being inserted between two first permanent magnets adjacent to each other and having a magnetization direction in a radial direction.
The method of claim 1,
The second permanent magnet,
Electromagnetic linear actuator characterized in that the radially magnetized plurality of permanent magnet splitter is provided in a mutually assembled structure.
The method of claim 2,
The second permanent magnet,
Electromagnetic linear actuator further comprises a bracket for mutually coupling the plurality of permanent magnet split body.
The method of claim 3,
Each of the first permanent magnet and the second permanent magnet,
Electromagnetic linear actuator characterized in that it is provided in a ring shape surrounding the shaft.
The method of claim 3,
The bracket,
A central portion provided in a ring shape and supporting an inner circumferential surface of the permanent magnet split body; And
And a joint for radially extending from said central portion and interconnecting sides of said two permanent magnet segments adjacent to each other.
The method of claim 3,
The bracket,
Electromagnetic linear actuator, characterized in that made of silicon steel (Silicon steel) material.
The method according to claim 2 or 4,
The permanent magnet split body,
Electromagnetic linear actuator, characterized in that provided in the 'C' shape.
The method according to claim 1 or 2,
The first permanent magnet and the second permanent magnet,
Electromagnetic linear actuators characterized by forming a Halbach array.
The method according to claim 1 or 2,
Both ends of the shaft are formed with a first flange portion and a second flange portion extending radially,
And the first permanent magnet and the second permanent magnet are accommodated in a space between the first flange part and the second flange part.
10. The method of claim 9,
The mover,
A first cover member made of pure iron interposed between the first permanent magnet adjacent to the first flange portion and the first flange portion; And
And a second cover member made of pure iron interposed between the first permanent magnet body adjacent to the second flange portion and the second flange portion.
The method according to claim 1 or 2,
The stator comprises:
Yoke is provided in a hollow shape to accommodate the mover; And
Electromagnetic linear actuator, characterized in that it comprises a magnetic coil portion provided to surround the mover inside the yoke.

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