JP2019091677A - Rotation drive device - Google Patents

Abstract

To provide a rotation drive device which enables a mirror to be fixed to a fly wheel with adhesives and can inhibit distortion of the mirror caused by hardening of the adhesive.SOLUTION: A rotation drive device rotates while reflecting light emitted from a light source and includes: a motor; a fly wheel 8 supported by a rotation part of the motor; and a plate-like mirror 61. The mirror 61 is fixed to the fly wheel 8 by multiple adhesives. The multiple adhesives are located at corner parts 611 of the mirror 61 and disposed at intervals along an end side 612 of the mirror.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rotary drive.

Conventionally, various devices having optical components are known. For example, Japanese Patent Application Laid-Open No. 2010-021105 describes an optical device provided with a light guide member 4 and a rod base 3 for supporting the light guide member 4. In the publication, illumination light emitted from the LED is reflected by the reflection prism of the light guide member 4. Also, the rod base 3 has a roughened contact surface for supporting the light guide member 4.
JP, 2010-021105, A

  In JP 2010-021105 A, no adhesive is used for fixing the light guide member 4 to the rod base 3.

  On the other hand, in recent years, as an apparatus used for optical position recognition and the like in a three-dimensional space, a demand for a rotational drive apparatus for rotating a mirror has been increasing. In this type of rotary drive device, it is necessary to firmly fix the mirror with an adhesive in order to prevent misalignment or removal of the mirror due to centrifugal force. However, with adhesives, the stresses that occur on curing of the adhesive cause minor distortion in the mirror. Due to this distortion, the direction of the reflected light may change.

  An object of the present invention is to provide a structure capable of fixing a mirror with an adhesive and suppressing distortion of the mirror accompanying curing of the adhesive in a rotational drive device.

  An exemplary first invention of the present application is a rotary drive device that rotates while reflecting light emitted from a light source, comprising: a motor having a rotary portion that rotates around a central axis extending up and down; A flywheel supported, a plate-like mirror having a plurality of corners and a plurality of end sides, and an adhesive for fixing the mirror to the flyhole, wherein a part of the adhesive is the mirror And are spaced along the edge of the mirror.

  According to the first exemplary invention of the present application, the mirror can be fixed to the flywheel with an adhesive, and distortion of the mirror caused by the curing of the adhesive can be suppressed.

FIG. 1 is a perspective view of a rotary drive, a light source, and a housing. FIG. 2 is a longitudinal sectional view of the rotary drive. FIG. 3 is a perspective view of a mirror. FIG. 4 is a perspective view of a flywheel and a mirror. FIG. 5 is a view showing the relationship between the application position of the adhesive to the mirror and the amount of deformation of the reflected light reflected by the mirror. FIG. 6 is a view showing how the mirror is fixed to the mirror accommodating portion. FIG. 7 is a perspective view of a mirror according to a modification.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the central axis of the motor to be described later is referred to as “axial direction”, a direction orthogonal to the central axis of the motor is “radial direction”, and a direction along an arc centered on the central axis of the motor is referred to It is referred to as “direction”. Further, in the present application, the shape and the positional relationship of each part will be described with the axial direction as the vertical direction and the light source side up with respect to the motor. However, there is no intention to limit the use direction of the rotary drive according to the present invention based on the definition in the vertical direction. Further, in the present application, the “parallel direction” also includes a substantially parallel direction. Further, in the present application, the “orthogonal direction” also includes a substantially orthogonal direction.

<1. Configuration of Rotational Drive>
FIG. 1 is a perspective view of a rotary drive 1, a light source 6, and a housing 7 according to one embodiment. The rotational drive device 1 is a device that rotates while reflecting the incident light 60 incident from the light source 6 in the radial direction (first radial direction D1), and emits the reflected light 62 to the outside of the rotational drive device 1. The light source 6 mounted on the housing 7 is disposed above the rotary drive 1. The optical axis of the light source 6 is located on the central axis 9 of the motor 10 described later. The housing 7 is fixed to a housing of a device in which the rotary drive 1 is mounted. From the light source 6, incident light 60 traveling downward along the central axis 9 is emitted. The light source 6 and the housing 7 of the present embodiment are provided outside the rotary drive device 1. However, the light source 6 and the housing 7 may be included in the rotary drive 1.

  The rotation drive device 1 has a motor 10, a flywheel 8, a mirror 61 described later, a lens 63 described later, and an adhesive 100 described later.

<2. Motor configuration>
First, the configuration of the motor 10 will be described. FIG. 2 is a longitudinal sectional view of the rotary drive device 1.

  As shown in FIG. 2, the motor 10 has a stationary portion 2 having a stator 22 and a rotating portion 3 having a magnet 34. The stationary unit 2 is stationary relative to the housing 7. In addition, the rotating portion 3 is rotatably supported with respect to the stationary portion 2 via a bearing portion 23 centering on a central axis 9 extending in the vertical direction.

  When a drive current is supplied to the coil 42 included in the stator 22, magnetic flux is generated in the plurality of teeth 412 that are the magnetic cores of the coil 42. Then, due to the action of the magnetic flux between the teeth 412 and the magnet 34, circumferential torque is generated between the stationary unit 2 and the rotating unit 3. As a result, the rotating unit 3 rotates around the central axis 9 with respect to the stationary unit 2. Thereby, the flywheel 8 supported by the rotating portion 3 rotates around the central axis 9 together with the rotating portion 3.

  For example, a fluid dynamic pressure bearing is used for the bearing portion 23. When a fluid dynamic bearing is used, the stationary unit 2 and the rotating unit 3 face each other through a gap in which the lubricating oil is present. When the motor 10 is driven, fluid dynamic pressure is induced in the lubricating oil. In addition, the bearing of other structures, such as a rolling bearing, may be used for the bearing part 23. FIG.

<3. Flywheel, mirror and lens configuration>
Subsequently, configurations of the flywheel 8, the mirror 61, and the lens 63 will be described.

  The flywheel 8 is located below the light source 6 and above the motor 10. The flywheel 8 is supported by the rotating portion 3 of the motor 10. The flywheel 8 is fixed to the upper surface of the rotating portion 3 by, for example, an engagement or an adhesive. For example, a resin is used as a material of the flywheel 8. The flywheel 8 supports the mirror 61 and the lens 63, respectively. The mirror 61 has a reflecting surface to be described later. Incident light 60 incident from the light source 6 is reflected by the reflection surface of the mirror 61 to change its direction. The lens 63 transmits the reflected light 62 reflected by the mirror 61. For the material of the mirror 61 and the lens 63, for example, glass is used.

  As shown in FIG. 2, the flywheel 8 has a cylindrical wall portion 81, a hollow portion 82, a barrel portion 83, and a lower support portion 84. The cylindrical wall portion 81, the barrel portion 83, and the lower support portion 84 are formed as a single member by injection molding of a resin. However, these may be separate members.

  The cylindrical wall portion 81 is a cylindrical portion surrounding the center axis 9. The hollow portion 82 is a hollow provided inside the cylindrical wall portion 81. The cylindrical wall portion 81 has a through hole 810 in a part in the circumferential direction. The through hole 810 penetrates the cylindrical wall portion 81 in the first radial direction D1. The lens 63 is fitted into the through hole 810 and fixed to the cylindrical wall 81. The barrel portion 83 extends in a cylindrical shape radially inward from the peripheral portion of the through hole 810.

  The lower support 84 extends perpendicularly to the central axis 9 at the lower part of the flywheel 8. The lower support 84 has a mirror support 841. The mirror support 841 protrudes upward from the upper surface of the lower support 84. The mirror 61 is fixed to a mirror support 841.

  FIG. 3 is a perspective view of the mirror 61. As shown in FIG. As shown in FIG. 3, the mirror 61 of the present embodiment is plate-like and has a rectangular outer shape. The mirror 61 has four corners 611 and four sides 612. The corner portion 611 is a portion corresponding to a vertex of a rectangle. The end side 612 is a portion extending linearly between adjacent corner portions 611. The central portion of the mirror 61 is located on the central axis 9. The surface 610 (reflection surface) of the mirror 61 is inclined at 45 ° with respect to the axial direction and the first radial direction D1. For the mirror 61, for example, a total reflection mirror is used. The incident light 60 is incident on the central portion of the mirror 61.

  The lens 63 has a disk-like outer shape. The lens 63 is located in the through hole 810 and is disposed perpendicular to the first radial direction D1. Further, the lens 63 is fixed to the flywheel 8 by adhesion, engagement or the like. The mirror 61, the hollow portion 82, and the lens 63 overlap in the first radial direction D1. The above-described reflected light 62 is transmitted through the central portion of the lens 63 and emitted to the outside of the flywheel 8. The lens 63 may be fixed to the lens frame held by the flywheel 8.

  An opening 80 is formed on the upper surface of the flywheel 8. The reflective surface of the mirror 61 is exposed to the opening 80. The incident light 60 emitted from the light source 6 enters the mirror 61 through the opening 80. Then, as described above, the incident light 60 becomes the reflected light 62 by being reflected by the mirror 61. The reflected light 62 further travels in the hollow portion 82 in the first radial direction D 1 and is emitted to the outside of the rotary drive 1 through the lens 63 fitted in the through hole 810 of the cylindrical wall portion 81.

  The mirror 61 reflects the incident light 60 while rotating about the central axis 9 together with the rotating portion 3 of the motor 10. Thereby, the direction of the reflected light 62 (first radial direction D1) is rotated.

<4. Mounting structure of mirror to flywheel>
Then, the attachment structure of the mirror 61 to the flywheel 8 is demonstrated.

  FIG. 4 is a perspective view of the flywheel 8 and the mirror 61. As shown in FIG. The mirror support portion 841 of the flywheel 8 has a concave mirror housing portion 840 in which the mirror 61 is fitted. The arrangement surface 842 which is the bottom surface of the mirror housing portion 840 is inclined at 45 ° with respect to the axial direction and the first radial direction D1. The placement surface 842 is rectangular. The vertical and horizontal dimensions of the arrangement surface 842 are slightly larger than the vertical and horizontal dimensions of the back surface of the mirror 61.

  FIG. 6 is a view showing how the mirror 61 is fixed to the mirror housing portion 840. As shown in FIG. As shown in FIG. 6, when the mirror 61 is fixed to the mirror accommodating portion 840, the mirror 61 is first fitted on the above-mentioned arrangement surface 842 to fit the mirror 61 into the mirror accommodating portion 840. Thereby, the mirror 61 is accurately positioned at a predetermined position of the flywheel 8.

  Next, as shown in FIGS. 3 to 6, the adhesive 100 is applied to the four corner portions 611 of the mirror 61 disposed in the mirror housing portion 840 and the vicinity of the four corner portions 611. The four corners 611 are covered with the adhesive 100, respectively. In FIGS. 3 and 4, the application area 614 of the adhesive 100 is indicated by a dashed circle. In each application area 614, the adhesive 100 contacts both the corner 611 and the flywheel 8. Thereby, the mirror 61 is fixed to the flywheel 8 with sufficient strength. As a result, the mirror 61 can be prevented from coming off, falling off, or scattering from the flywheel 8.

  The adhesive 100 of the present embodiment is an ultraviolet curable resin. For this reason, the time to cure is shorter compared to a thermosetting or anaerobic adhesive. Therefore, it is possible to suppress the displacement of the position due to the flow of the adhesive 100 after the application of the adhesive 100 until the curing. Further, since the curing time of the adhesive 100 is short, the production efficiency of the rotary drive device 1 can be improved.

  The adhesives 100 located at the four corners 611 of the mirror 61 are spaced from each other along the edge 612 of the mirror 61. For this reason, when the adhesive 100 is cured, stress from the adhesive 100 is not likely to be applied near the center of each end side 612 of the mirror 61. Therefore, distortion of mirror 61 accompanying hardening of adhesive 100 can be controlled. The adhesive 100 is preferably applied only in the vicinity of the corner portion 611. Specifically, the adhesive 100 is preferably in contact with half or less of each of the four end sides 612 of the mirror 61.

  FIG. 5 shows the relationship between the application position of the adhesive 100 to the mirror 61 and the amount of deformation of the reflected light 62 reflected by the mirror 61. The horizontal axis indicates the ratio (g / L) of the distance g of the adhesive applied to the corner of the edge to the length L of the edge of the mirror 61. The vertical axis represents the ratio (d / D) of the minor axis d to the major axis D of the cross section of the reflected light 62 cut in the direction perpendicular to the first radial direction D1. As shown in FIG. 5, as g / L approaches one, d / D approaches one. In other words, as the distance between adjacent adhesives is increased, the cross section of the reflected light 62 becomes closer to a perfect circle. That is, distortion of the mirror 61 can be suppressed. Therefore, when the adhesive is applied only to both ends of one end of the mirror 61, that is, near the corner portion 611 of the mirror 61, the distance g between the adjacent adhesives becomes wide, so g / L becomes close to 1 . As shown in FIG. 5, it is preferable that g / L is 0.5 or more, that is, the adhesive 100 contacts an area of half or less of each of the four end sides 612 of the mirror 61. Thus, distortion of the mirror 61 can be further suppressed by limiting the application range of the adhesive 100.

  Further, as described above, in the present embodiment, after the mirror 61 is disposed on the disposition surface 842 of the flywheel 8, the adhesive 100 is applied. Therefore, as shown in FIG. 6, the corner portion 611 of the mirror 61 is sandwiched between a part of the adhesive 100 and the arrangement surface 842 of the flywheel 8. Thereby, the mirror 61 can be firmly fixed to the flywheel 8. Further, temporarily, after the adhesive 100 is applied to the arrangement surface 842 or the mirror 61 in advance, when the mirror 61 is arranged on the arrangement surface 842, the adhesive 100 is spread when the mirror 61 is arranged. However, if the adhesive 100 is applied after the mirror 61 is arranged on the arrangement surface 842 as in the present embodiment, the adhesive 100 can not be spread. Therefore, the application range of the adhesive 100 can be easily managed. As a result, it is possible to suppress adhesion, dripping, scattering, etc. of the adhesive 100 to unintended locations.

  Further, in the present embodiment, the mirror 61 is disposed in a state of being inclined at 45 ° with respect to the central axis 9 and the first radial direction D1. Then, a part of the adhesive 100 comes in contact with the corner 611 located axially above the center of the mirror 61 among the four corners 611 of the mirror 61. Therefore, a part of the adhesive 100 contacts the upper end side 615 which is the end side 612 located on the most axial direction upper side of the mirror 61. As a result, the adhesive 100 before curing can be suppressed from drooping by gravity and spreading to an unintended location.

<5. Modified example>
Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.

  FIG. 7 is a perspective view of a mirror 61B according to a modification. The mirror 61B of FIG. 7 is plate-like and has a hexagonal outer shape. The mirror 61B has six corners 611B and six ends 612B. The mirror 61B is disposed in the mirror housing in a state of being inclined at 45 ° with respect to the axial direction and the first radial direction. The incident light 60B emitted from the light source is reflected by the surface 610B (reflecting surface) of the mirror 61B to become a reflected light 62B.

  When the mirror 61B is fixed to the mirror housing of the flywheel, the mirror 61B is first disposed on the arrangement surface of the mirror housing. Next, an adhesive is applied to the six corner portions 611B of the mirror 61B and the vicinity of the six corner portions 611B. The six corners 611 are covered with the adhesive 100, respectively. In FIG. 7, the application area 614B of the adhesive is indicated by a broken circle. In each application area 614B, the adhesive contacts both the corner 611B and the flywheel. Thereby, the mirror 61B is fixed with sufficient strength to the flywheel. As a result, the mirror 61B is prevented from coming off, falling off, or scattering from the flywheel.

  In the mirror 61B of this modification, half or more of the six sides 612B are positioned on the axial direction upper side than the center of the mirror 61B. Therefore, half or more of the six application areas 614B for applying the adhesive are located above the center of the mirror 61B in the axial direction. As a result, the adhesive 100 before curing can be suppressed from drooping by gravity and spreading to an unintended location. However, the number of corners and ends of the mirror is not limited to this. The mirror may have a plurality of corners and a plurality of edges.

  Note that the adhesive does not necessarily have to be provided at all corner portions of the mirror.

  Moreover, the mirror of said embodiment was a total reflection mirror. However, instead of the total reflection mirror, a half mirror that transmits part of incident light may be used. In this case, a through hole may be provided in the lower part of the mirror of the flywheel, and the shaft of the motor may be a cylindrical hollow shaft. Then, the transmitted light transmitted through the half mirror may pass through the inside of the flywheel and the hollow shaft to reach the lower side of the motor. In addition, a flywheel and a mirror may be further disposed below the motor. Then, the above-mentioned transmitted light may be reflected in the radial direction (second radial direction) by the mirror.

  Further, the shape of the detail of each part may be different from the shape shown in each drawing of the present application. In addition, the elements appearing in the above-described embodiment and modification may be combined as appropriate as long as no contradiction occurs.

  The present invention is applicable to a rotary drive.

DESCRIPTION OF SYMBOLS 1 rotation drive 2 stationary part 3 rotary part 6 light source 7 housing 8 flywheel 9 central axis 10 motor 22 stator 23 bearing 34 magnet 42 coil 60, 60 B incident light 61, 61 B mirror 62, 62 B reflected light 63 lens 80 opening 81 Tubular wall portion 82 Hollow portion 83 Lens barrel portion 84 Lower support portion 100 Adhesive 610, 610B Surface 611, 611B Corner portion 612, 612B End side 614, 614 B Coating area 615 Upper end side 810 Through hole 840 Mirror housing portion 841 Mirror Support portion 842 Arrangement surface 843 Inner surface D1 First radial direction

Claims (8)

A rotary drive device that rotates while reflecting light emitted from a light source,
A motor having a rotating portion that rotates about a central axis extending up and down;
A flywheel supported by the rotating portion;
A plate-like mirror having a plurality of corners and a plurality of edges;
A plurality of adhesives for securing the mirror to the flywheel;
Equipped with
A plurality of the adhesive agents are located at the corner of the mirror and are spaced apart along the edge of the mirror. The rotary drive according to claim 1, wherein
The rotary drive device wherein the adhesive contacts both the corner and the flywheel. The rotary drive according to claim 1 or 2, wherein
The flywheel has an arrangement surface on which the mirror is arranged,
A rotary drive in which the corner of the mirror is sandwiched between the arrangement surface and a part of the adhesive. The rotary drive device according to any one of claims 1 to 3, wherein
The rotary drive according to claim 1, wherein the plurality of adhesives contact an area of half or less of each of the plurality of end sides. The rotary drive device according to any one of claims 1 to 4, wherein
The mirror is inclined with respect to the central axis;
The rotational drive device according to claim 1, wherein a part of the plurality of the adhesive contacts a corner located axially above the center of the mirror among the plurality of corners. The rotary drive device according to any one of claims 1 to 5, wherein
The flywheel is
A rotary drive device having a mirror accommodating portion in which the mirror is fitted. The rotary drive device according to any one of claims 1 to 6, wherein
The mirror is in the form of a rectangular plate having four corners.
The rotary drive device wherein the adhesive covers at least four of the corners. The rotary drive device according to any one of claims 1 to 7, wherein
The adhesive is an ultraviolet curing type rotational drive device.

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