Coreless linear motor and movable element

Abstract

To provide a small-sized coreless linear motor which utilizes a gap in a center of a coreless coil, and has a cooling performance.SOLUTION: A coreless linear motor 1 has a stator 2 and a mover 3 moved in a longitudinal direction of the stator 2, wherein the mover 3 has a coreless coil 32 in which a gap part 33 is provided in a center of a wound coil, and a resin-made coil mold part 30 where the coreless coil 32 is embedded, and a heat radiation part 84 integral with the coil mold part 30 is provided in the gap part 33.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a coreless linear motor and a mover.

Background Art

[0002] A coreless linear motor basically includes a stator having a permanent magnet and a mover having a coil. In general, the form of the coreless linear motor is such that the mover is movably inserted into the groove of a U-shaped stator.

[0003] In general, in order to increase the speed of a conveying device, the energizing current flowing through the coil of a coreless linear motor tends to increase. Therefore, the amount of heat generated by the coil unit increases, and there is a risk that peripheral members will be thermally deformed.

[0004] Patent Document 1 discloses a linear motor provided with cooling fins on the surface of a coil unit in order to efficiently release heat generated from the coil unit. Patent Document 2 discloses a linear motor provided with through holes on the periphery of a coil unit in order to efficiently release heat generated from the coil unit.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the case of a linear motor using a coreless coil, the cooling fins disclosed in Reference 1 and the through-holes disclosed in Reference 2 do not allow for effective utilization of the dead space in the center of the coreless coil. Therefore, it is difficult to miniaturize a coreless linear motor with cooling capabilities.

[0007] The present invention aims to provide a compact coreless linear motor with cooling capabilities. [Means for solving the problem]

[0008] A coreless linear motor according to one aspect of the present invention is A coreless linear motor having a stator and a movable element that moves in the longitudinal direction of the stator, The movable element has a coreless coil with a void in the center of the wound wires, and a resin coil molded part into which the coreless coil is embedded. A heat dissipation section, which is integrated with the coil mold section, is provided in the aforementioned gap.

[0009] Furthermore, the movable element according to one aspect of the present invention is A movable element that moves in the longitudinal direction of a coreless linear motor, A coreless coil has an air gap in the center of the wound wires, The coreless coil has a resin coil mold portion in which it is embedded, A heat dissipation section, which is integrated with the coil mold section, is provided in the aforementioned gap. [Effects of the Invention]

[0010] According to the present invention, by effectively utilizing the void in the center of the coreless coil, a compact coreless linear motor with cooling capabilities can be provided. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view of a coreless linear motor according to an embodiment of the present invention. [Figure 2] This is a perspective view showing the movable element of a coreless linear motor. [Figure 3] This is a front view of the coil mold section that constitutes the movable element. [Figure 4] Figure 3 is a cross-sectional perspective view of BB. [Figure 5] Figure 3 is a cross-sectional perspective view of BB according to another embodiment. [Figure 6] This is a diagram illustrating the manufacturing process of the coil mold section. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. For the sake of clarity, the description of components having the same reference numeral as those already described in the description of the embodiments will be omitted. Furthermore, the dimensions of the components shown in these drawings may differ from the actual dimensions of the components for the sake of clarity.

[0013] Figure 1 is a perspective view showing an example of a coreless linear motor according to an embodiment of the present invention. As shown in Figure 1, the coreless linear motor 1 comprises a stator 2 and a movable element 3 that is movable relative to the stator 2.

[0014] The stator 2 has a yoke 21 and a permanent magnet 22 attached to the yoke 21. The yoke 21 is composed of a pair of side plate yokes 21a and 21b formed in a flat plate shape and a bottom plate yoke 21c connecting the pair of side plate yokes 21a and 21b. The yoke 21 is formed of a metallic material, such as iron or the like. The pair of side plate yokes 21a and 21b are arranged to face each other. One end of the side plate yokes 21a and 21b in a direction orthogonal to the longitudinal direction of the stator 2 (the direction indicated by arrow A in FIG. 1) is connected by the bottom plate yoke 21c. The side plate yokes 21a, 21b and the bottom plate yoke 21c are fixed, for example, by bolts 23. When the side plate yokes 21a, 21b and the bottom plate yoke 21c are connected, a groove portion extending in the longitudinal direction A is formed between the side plate yokes 21a, 21b and the bottom plate yoke 21c. The yoke 21 is configured to have a substantially U-shaped cross-section when viewed along the longitudinal direction A.

[0015] The permanent magnet 22 is attached to each of the opposing surfaces of the side plate yokes 21a, 21b. The permanent magnet 22 has permanent magnets 22a and 22b with different polarities. The permanent magnets 22a, 22b are each formed in a long and thin flat plate shape extending along the side plate yokes 21a, 21b in a direction orthogonal to the longitudinal direction A from the bottom plate yoke 21c. The permanent magnets 22a, 22b are arranged in parallel in the longitudinal direction A on the opposing surfaces of the side plate yokes 21a, 21b. The permanent magnets 22a, 22b are attached to the side plate yokes 21a, 21b with the ends on the bottom plate yoke 21c side being separated from the bottom plate yoke 21c by a predetermined distance. For this reason, there are regions on the bottom plate yoke 21c side of the side plate yokes 21a, 21b where the permanent magnets 22a, 22b are not provided.

[0016] The permanent magnets 22a and 22b are arranged such that adjacent magnets have different polarities from each other, and opposing magnets also have different polarities from each other. That is, as shown in FIG. 1, for example, a permanent magnet 22a having a north pole and a permanent magnet 22b having a south pole are arranged adjacent to and opposing each other. The mover 3 moves along the longitudinal direction A within a groove portion 24 between side plate yokes 21a and 21b to which the permanent magnets 22a and 22b are attached. The distance between the opposing permanent magnets 22a and 22b (the width of the groove portion 24a) is configured to be slightly larger than the thickness of the coil molded portion 30 of the mover 3 that moves within the groove portion 24. Also, the distance between the side plate yokes 21a and 21b in a region where the permanent magnets 22a and 22b are not provided on the side of the bottom plate yoke 21c of the side plate yokes 21a and 21b (the width of the groove portion 24b) is configured to be larger than the groove portion 24a by the thickness of the permanent magnets 22a and 22b.

[0017] FIG. 2 is a perspective view showing the mover 3. As shown in FIG. 2, the mover 3 has a coil molded portion 30, a connection portion decorative plate 50, a power line cable 60, and a heat dissipation portion 35.

[0018] The coil molded portion 30 is a plate-like member in which a plurality of coils are integrally molded with resin, and has a pair of opposing surfaces 37 and 38 that oppose the permanent magnet 22 of the stator 2. The connection portion decorative plate 50 is attached to one end (the upper side in FIG. 2) in the direction orthogonal to the longitudinal direction A of the coil molded portion 30 (the vertical direction in FIG. 2).

[0019] The power line cable 60 is provided so as to protrude from the connection portion decorative plate 50. The power line cable 60 is a cable that supplies power to the coils of the coil molded portion 30. A circuit connection connected to the coils of the coil molded portion 30 is connected to the power line cable 60. The circuit connection connected to the coils of the coil molded portion 30 is housed in a space formed by the connection portion decorative plate 50.

[0020] The heat dissipation section 35 is formed integrally with the coil mold section 30 by providing a fence-like structure of thin, plate-shaped resin.

[0021] The movable element 3 is positioned such that the portion of the coil molded section 30 to which the connection section decorative plate 50 is not attached is located within the groove 24 of the stator 2, and the portion of the coil molded section 30 to which the connection section decorative plate 50 is attached is located outside the groove 24 of the stator 2 (see Figure 1).

[0022] Figure 3 is a front view of the coil mold section 30. Figure 4 is a cross-sectional perspective view of BB in Figure 3. As shown in Figures 3 and 4, the coil molded section 30 is a rectangular plate-shaped member formed by molding a plurality of coils (three in the illustrated example) arranged in parallel with a resin section 31, and has a plurality of heat dissipation sections 35a, 35b, and 35c arranged in parallel. The coil is composed of coreless coils 32a, 32b, and 32c having air gaps 33. The three coreless coils 32a, 32b, and 32c are arranged along the direction of movement of the movable element 3 (the same direction as the longitudinal direction A), and the heat dissipation sections 35a, 35b, and 35c are arranged in each air gap 33. In the illustrated example, the three coreless coils 32a, 32b, and 32c are composed of a U-phase coil, a V-phase coil, and a W-phase coil. The resin portion 31 that molds the coreless coils 32a, 32b, and 32c is also poured into the gaps 33 between the coreless coils 32a, 32b, and 32c, forming the heat dissipation portions 35a, 35b, and 35c.

[0023] Each heat dissipation section 35a, 35b, and 35c has a pair of heat dissipation base sections 35Ba, 35Bb, and 35Bc located at both ends in the direction Y perpendicular to the longitudinal direction A, and heat dissipation fins 35Fa, 35Fb, and 35Fc extending in the direction Y. The heat dissipation fins 35Fa, 35Fb, and 35Fc extend from one opposing surface 37 to the other opposing surface 38, and the slit portion, which is the space between each heat dissipation fin 35Fa, 35Fb, and 35Fc penetrates from one opposing surface 37 to the other opposing surface 38. In this way, the heat dissipation sections 35a, 35b, and 35c are formed in the gaps 33 of each coreless coil 32a, 32b, and 32c, thereby providing a uniform cooling effect throughout the entire movable element.

[0024] Next, the manufacturing process of the coil mold section 30 will be described with reference to Figure 6. In step S1 of Figure 6, a first movable mold 80 for manufacturing the coil molded portion 30 is prepared. The first movable mold 80 has a recess 81 formed in it that corresponds to the size of the coil molded portion 30. The depth of the recess 81 is formed to be approximately half the thickness of the coil molded portion 30. Positioning blocks 82a, 82b, and 82c for determining the position of the coreless coils 32a, 32b, and 32c to be molded are provided in the recess 81. The positioning blocks 82a, 82b, and 82c are formed such that their length L corresponds to the length of the gap 33 of the coreless coils 32a, 32b, and 32c, their width W corresponds to the width of the gap 32, and their thickness H is the same as the depth of the recess 81 and approximately half the thickness of the coreless coils 32a, 32b, and 32c. Positioning holes 83 for determining the position of the first movable mold 80 are also provided in the recess 81.

[0025] In step S2 of Figure 6, the coreless coils 32a, 32b, and 32c are set in the first movable mold 80. The coreless coils 32a, 32b, and 32c are set so that the positioning blocks 82a, 82b, and 82c of the first movable mold 80 are fitted into the gap 32.

[0026] In step S3 of Figure 6, a fixed mold 90 for manufacturing the coil mold portion 30 is prepared. The fixed mold 90 has a recess 91 formed in it that corresponds to the size of the coil mold portion 30. The depth of the recess 91 is formed to be slightly deeper than half the thickness of the coil mold portion 30. In addition, a plurality of fence-like blocks 84a, 84b, 84c for forming the heat dissipation portions 35a, 35b, 35c and a positioning pin 92 for determining the position of the fixed mold 90 relative to the first movable mold 80 are provided within the recess 91. The height of the plurality of fence-like blocks 84a, 84b, 84c is approximately the same as the depth of the recess 91 and is set to form a slit portion that penetrates one of the opposing surfaces 37. The positioning pin 92 is provided to correspond to the positioning hole 83 of the first movable mold 80.

[0027] In step S4 of Figure 6, the fixed mold 90 is attached to the first movable mold 80 in which the coreless coils 32a, 32b, and 32c are set. The fixed mold 90 is attached to the first movable mold 80 by fitting the positioning pins 92 of the fixed mold 90 into the positioning holes 83 of the first movable mold 80. After the fixed mold 90 is attached to the first movable mold 80, the first resin molding is performed. In the first resin molding, half the thickness of the coreless coils 32a, 32b, and 32c on the side of the fixed mold 90 is molded with resin.

[0028] In step S5 of Figure 6, after the first resin molding, the first movable mold 80 is removed from the fixed mold 90. Slit portions 93 corresponding to the positioning blocks 82a, 82b, 82c of the first movable mold 80 are formed in the gap portions 32 of the coreless coils 32a, 32b, 32c.

[0029] In step S6 of Figure 6, a second movable mold 85 for manufacturing the coil mold portion 30 is prepared. The second movable mold 85 has a recess 86 formed in it that corresponds to the size of the coil mold portion 30. The depth of the recess 86 is formed to be slightly deeper than half the thickness of the coil mold portion 30. Inside the recess 81, there are a plurality of fence-like blocks 88a, 88b, 88c for forming the heat dissipation portions 35a, 35b, 35c, and a positioning hole 87 for determining the position of the second movable mold 85. The height of the plurality of fence-like blocks 88a, 88b, 88c is approximately the same as the sum of the depths of the recess 86 and the recess 91, and is set to form a slit portion that penetrates one opposing surface 37 and the other opposing surface 38.

[0030] In step S7 of Figure 6, the second movable mold 85 is attached to the fixed mold 90, which has the coreless coils 32a, 32b, and 32c installed. The second movable mold 85 is attached to the fixed mold 90 by fitting the positioning pin 92 of the fixed mold 90 into the positioning hole 87 of the second movable mold 85. After attaching the fixed mold 90 to the second movable mold 85, a second resin molding is performed. The second resin molding causes the portion of the coreless coils 32a, 32b, and 32c on the second movable mold 85 side to be molded with resin, with half the thickness remaining.

[0031] In step S8 of Figure 6, after the second resin molding, the fixed mold 90 and the second movable mold 85 are removed. The slits of the heat dissipation sections 35a, 35b, and 35c are formed, creating heat dissipation fins 35Fa, 35Fb, and 35Fc that extend from one opposing surface 37 to the other opposing surface 38. The coil mold portion 30 has a positioning hole 34a and a bolt hole 34b formed by the fitting of the positioning pin 92 of the fixed mold 90. Since the heat dissipation sections 35a, 35b, and 35c do not protrude from the pair of opposing surfaces 37 and 38, they do not obstruct the airflow path between the coil mold section 30 and the magnet rail of the stator 2. Because the ends of the heat dissipation fins 35Fa, 35Fb, and 35Fc face the airflow path, the cooling effect can be improved.

[0032] In the above-described embodiment, the heat dissipation fins 35Fa, 35Fb, and 35Fc are configured to extend in the direction Y perpendicular to the longitudinal direction A, but they may also be configured to extend in the longitudinal direction A. Furthermore, although the heat dissipation fins 35Fa, 35Fb, and 35Fc have slits that penetrate from one opposing surface 37 to the other opposing surface 38, as shown in Figure 5, a central base portion 35Ca, 35Cb, and 35Cc on the plate may be provided on the intermediate plane between one opposing surface 37 and the other opposing surface 38, and they may have non-penetrating slits from one opposing surface 37 to the other opposing surface 38.

[0033] Although embodiments of the present invention have been described above, it goes without saying that the technical scope of the present invention should not be interpreted as being limited by the description of these embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications to the embodiments are possible within the scope of the invention described in the claims. The technical scope of the present invention should be determined based on the scope of the invention described in the claims and the scope of its equivalents. [Explanation of Symbols]

[0034] 1 Coreless linear motor 2 Stator 3 Mover 21 York 21a, 21b Side plate yoke 21c Bottom plate yoke 22(22a,22b) Permanent magnet 23, 41, 51, 71 bolts 24(24a,24b) Groove 30 Coil mold section 31 Resin part 32a, 32b, 32c Coreless Coil 33(33a,33b,33c) Void 35(35a,35b,35c) Heat dissipation part 35Ba, 35Bb, 35Bc Heat dissipation base section 35Fa, 35Fb, 35Fc heat sink fins 37,38 Opposing surfaces 50 Wiring section decorative panel 60 Power line cables 84a, 84b, 84c Fence-like blocks 88a, 88b, 88c Fence-like blocks

Claims

1. A coreless linear motor having a stator and a movable element that moves in the longitudinal direction of the stator, The movable element has a coreless coil with a void in the center of the wound wires, and a resin coil molded part into which the coreless coil is embedded. A heat dissipation section, which is integrated with the coil mold section, is provided in the aforementioned gap. The heat dissipation section is integrally molded from the same resin material as the coil molded section in this coreless linear motor.

2. The coil mold portion has a plurality of coreless coils, The heat dissipation portion is provided in the air gap of each of the coreless coils. The coreless linear motor according to claim 1.

3. The coil mold portion has a pair of opposing surfaces that face each of the magnet portions of the stator, The coreless linear motor according to claim 1 or 2, wherein the heat dissipation portion does not protrude from the pair of opposing surfaces.

4. The heat dissipation section has a plurality of fins, A coreless linear motor according to any one of claims 1 to 3, wherein a slit is provided between adjacent fins.

5. The coil mold portion has a pair of opposing surfaces that face each of the magnet portions of the stator, The coreless linear motor according to claim 4, wherein the slit penetrates a pair of the opposing surfaces.

6. The coreless linear motor according to claim 1 or 2, wherein the heat dissipation section has a base portion extending in the longitudinal direction and fins protruding from the base portion.

7. The coreless linear motor according to claim 1 or 2, wherein the heat dissipation section has fins extending in the longitudinal direction.

8. The coreless linear motor according to claim 1 or 2, wherein the heat dissipation section extends in a direction perpendicular to the longitudinal direction.

9. The coreless linear motor according to any one of claims 4 to 6, wherein the heat dissipation section has a plurality of fins extending parallel to each other.

10. A movable element that moves in the longitudinal direction of a coreless linear motor, A coreless coil has an air gap in the center of the wound wires, The coreless coil has a resin coil mold portion in which it is embedded, A heat dissipation section, which is integrated with the coil mold section, is provided in the aforementioned gap. The heat dissipation section is a movable element integrally molded from the same resin material as the coil mold section.

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