Rotating Table Device
The rotary table device achieves a compact size and stable quality by integrating the scale directly onto the table's outer peripheral surface, reducing the need for additional scale members and simplifying assembly, thus enhancing precision and stability.
Patent Information
- Application Number
- JP2021155406
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-09-24
- Publication Date
- 2025-12-03
- Estimated Expiration
- 2041-09-24
AI Technical Summary
Existing rotary table devices face challenges in achieving a compact size while maintaining stable quality and efficient torque, particularly in the installation of a scale, which requires a rational process and has not been rational process.
A rotary table device with a scaleless design and a rational process.
The rotary table device is a rotary table device with a scaleless design and a rational process.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to a rotary table device. [Background technology]
[0002] A known rotary table device includes a bed serving as a fixed part, a disk-shaped rotary table, and bearings disposed between them, and is driven to rotate by a linear motor. The linear motor is composed of an armature coil consisting of a flat, annularly wound, three-phase coreless coil, and a field magnet consisting of multiple plate-shaped magnets. For example, in the rotary table device disclosed in Patent Document 1, the coil is fixed to the bed, and the magnet is fixed to the rotary table, with the coil and magnet facing each other. In this rotary table device, a tape-like scale is adhered to the outer surface of the table in an area corresponding to the rotation angle of the table. The position of the table is detected by reading the scale with an optical sensor disposed on the bed.
[0003] Known rotary table devices include infinitely rotating table devices in which the rotation of the table is not limited to a fixed rotation angle, but can rotate 360° or more. For example, Patent Document 2 discloses a rotary table device that rotates the table infinitely relative to the bed. The rotary table device in Patent Document 2 describes a ring-shaped scale fitted into the shaft of the table. A ring member with a scale provided around its entire circumference is inserted into the outer periphery of the shaft of the table and fixed to the table with screws. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-72960 [Patent Document 2] Japanese Patent Publication No. 2020-120430 Summary of the Invention [Problem to be solved by the invention]
[0005] There is a need for a small-sized rotary table device that can be manufactured through a rational process and has stable quality. Therefore, one of the objectives is to provide a small-sized rotary table device that can be manufactured through a rational process and has stable quality. [Means for solving the problem]
[0006] A rotary table device according to the present disclosure includes a base, a bearing, a table rotatably supported relative to the base via the bearing, and a motor that rotates the table in the rotational direction of the bearing. The motor includes a coil array fixed to the base, in which a plurality of flat, annularly wound three-phase coreless coils are arranged side by side, and a magnet array fixed to the table, facing the coil array, in which a plurality of plate-shaped magnets are arranged circumferentially of the table with alternating magnetic poles. A scale is printed around the entire outer peripheral surface of the table. A sensor for reading the scale is disposed on the base. [Effects of the Invention]
[0007] According to the above-described rotary table device, a rotary table device that is small in size, can be manufactured through a rational process, and has stable quality is provided. [Brief explanation of the drawings]
[0008] [Figure 1] FIG. 1 is a perspective view showing a rotary table device according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the rotary table device according to the first embodiment. [Figure 3] FIG. 3 is an enlarged partial cross-sectional view showing the rotary table device according to the first embodiment. [Figure 4] FIG. 4 is a perspective view showing a bed of the rotary table device according to the first embodiment. [Figure 5]FIG. 5 is a plan view showing a bed of the rotary table device according to the first embodiment and members fixed to the bed. [Figure 6] FIG. 6 is a perspective view showing a bed of the rotary table device according to the first embodiment and members fixed to the bed. [Figure 7] FIG. 7 is a plan view showing a table of the rotary table device according to the first embodiment. [Figure 8] FIG. 8 is a cross-sectional perspective view showing the table of the rotary table device according to the first embodiment. [Figure 9] FIG. 9 is a plan view showing the table and magnet array of the rotary table device according to the first embodiment. [Figure 10] FIG. 10 is a perspective view showing a rotating body and a bearing according to the second embodiment. [Figure 11] FIG. 11 is a cross-sectional perspective view showing a rotating body and a bearing according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional perspective view showing a rotating body according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0009] [Outline of the embodiment] First, embodiments of the present disclosure will be described. A rotary table device according to the present disclosure includes a base, a bearing, a table rotatably supported relative to the base via the bearing, and a motor that rotates the table in the rotational direction of the bearing. The motor includes a coil array fixed to the base, in which a plurality of flat, annularly wound three-phase coreless coils are arranged side by side, and a magnet array fixed to the table, facing the coil array, in which a plurality of plate-shaped magnets are arranged in a circumferential direction of the table with alternating magnetic poles. A scale is printed around the entire outer peripheral surface of the table. A sensor for reading the scale is disposed on the base.
[0010] Conventionally, there are known rotary table devices that are used to rotate a workpiece or other component attached to a table. One such rotary table device is driven by a direct drive servo motor. For example, there are known rotary table devices that reciprocate within a fixed rotation angle range, such as 60° or 150°. There are also known infinite rotary table devices that rotate 360° or more. In either case, a position detection mechanism is often provided, in which a sensor fixed to a base reads the graduations on a scale attached to the table to detect the position of the table.
[0011] Known methods for attaching a scale to a table include adhering a tape bearing a scale to the outer periphery of the table and fitting a ring bearing a scale (ring scale) to the outer periphery of the table. In an infinitely rotating table device, the scale must be provided around the entire periphery of the table. When using a tape-type scale in an infinitely rotating table device, precise adjustments must be made to the vertical and horizontal positions, phase, origin position, and other parameters for attaching the tape to each table device, requiring considerable man-hours and skill. Furthermore, the formation of seams in the tape is unavoidable. For this reason, it has been proposed to attach a ring scale bearing a scale to the table of an infinitely rotating table device (see, for example, Patent Document 2).
[0012] On the other hand, ring scales have a radial thickness of several millimeters to approximately 10 mm. Therefore, particularly in small infinitely rotating table devices, providing installation space for a ring scale means that the installation space for the magnet and coil module becomes relatively small, making it difficult to obtain sufficient torque. After extensive research under these circumstances, the idea of printing the scale directly on the entire outer periphery of the table was conceived.
[0013] The rotary table device according to the present disclosure does not require installation space for a scale member, is compact, does not require tape attachment, and provides a rotary table device with stable quality through a streamlined manufacturing process. Furthermore, by printing the scale on the outer peripheral surface of the table, the number of parts can be reduced, assembly is simplified, and errors due to the accumulation of part tolerances are reduced, resulting in excellent stability of quality. Furthermore, by not using a scale member, eccentricity of the rotating part is suppressed, maintaining precision and stable quality.
[0014] In the rotary table device, the coil array may be a coil array in which a plurality of the coreless coils are arranged to form a part of a circle, and the magnet array may be a circular magnet array in which the magnets are arranged around the entire circumference of the table. With this configuration, an infinite rotary table device whose rotation angle is not limited to within a certain range can be obtained.
[0015] In the rotary table device, the table may include a disk-shaped mounting portion having a flat upper surface and a shaft portion located below the mounting portion and having a smaller diameter than the mounting portion. The scale may be printed on the outer peripheral surface of the shaft portion, and an encoder head including the sensor may be disposed on the base portion so that the entire encoder head is located below the mounting portion. With this configuration, the entire rotary table device can be made compact while ensuring the size of the table mounting portion.
[0016] In the rotary table device, each of the graduations constituting the scale may be a recess formed on the outer circumferential surface of the shaft, with a length of 0.2 mm to 10 mm and a depth of 0.1 to 100 μm. Such a scale graduation can be produced by a general-purpose manufacturing technique such as laser processing, and has sufficient sensor reading accuracy.
[0017] In the rotary table device, the table and the outer ring of the bearing may be configured as an integrated part. By configuring the table and the outer ring of the bearing as an integrated part and printing a scale on the outer peripheral surface of the table, the number of parts is further reduced and assembly adjustments are unnecessary. Furthermore, machining of the raceway surface of the outer ring of the bearing and machining of the outer peripheral surface of the table can be performed in one chuck, resulting in a highly accurate rotary table device through a streamlined manufacturing process.
[0018] [Specific example of embodiment] Next, an example of a specific embodiment of the rotary table of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.
[0019] (Embodiment 1) FIG. 1 is a schematic perspective view showing the structure of a rotary table device 1 in embodiment 1. In FIG. 1, the Z-axis direction is the direction in which the rotation axis (rotation axis of the bearing) R of the table of the rotary table device extends. FIG. 2 is a cross-sectional view of the rotary table device 1, taken along line II-II in FIG. 1. FIG. 3 is an enlarged cross-sectional view of FIG. 2 with some members omitted.
[0020] First, the general configuration of the rotary table device 1 will be described. 1, a rotary table device 1 in the first embodiment includes a base unit 10, which is a fixed unit, and a table 20 that is rotatable relative to the base unit 10. The base unit 10 includes a bed 11. A cover 61 is fixed to the bed 11. The cover 61 is a cover that covers an encoder head 82 (FIG. 2). The cover 61 ensures the reading accuracy of the optical sensor of the encoder head 82 and also prevents dust from entering the sensor portion.
[0021] The table 20 is rotatable around a rotation axis R. The table 20 includes a mounting portion 21, which is a hollow disk-shaped portion, and a shaft portion 22 located below the mounting portion 21. The outer diameter of the shaft portion 22 is smaller than the outer diameter of the mounting portion 21. The upper surface of the mounting portion 21 is formed flat. The mounting portion 21 and the shaft portion 22 are formed as a single, integral part. A scale 81 is printed around the entire outer peripheral surface 22a of the shaft portion 22.
[0022] The mounting portion 21 is formed with a plurality of screw holes 9 that penetrate the mounting portion 21 in the thickness direction (Z-axis direction). The screw holes 9 are used to attach a workpiece, which is an external component. In the rotary table device 1, eight screw holes 9 are provided at equal intervals in the circumferential direction, but this number is not particularly limited. The mounting portion 21 is also formed with a plurality of screw holes 16 that penetrate the mounting portion 21 in the thickness direction. Screws 46 are inserted into the screw holes 16.
[0023] Mounting portion 21 is provided with mounting hole 18, into which a reference mark for generating an origin signal can be attached. Mounting portion 21 also has mounting hole 19, into which a sensor dog for a pre-origin sensor or the like can be attached. In the rotary table device of the present disclosure, the reference mark and pre-origin sensor are not essential components, so mounting holes 18, 19 do not have to be used. Also, mounting holes 18, 19 do not have to be provided on the mounting portion.
[0024] Referring to FIG. 2, the rotary table device 1 includes a bearing 70. The bearing 70 is, for example, a cross roller bearing. In FIG. 2, the rolling elements of the bearing 70 are omitted. An outer ring 71 of the bearing 70 is fixed to the bed 11. A screw 47 is inserted into a threaded hole 17 that penetrates the bed 11 from the underside in the thickness direction. The screw 47 fixes the bed 11 and the outer ring 71. The inner ring 72 is fixed to the table 20. The screw 46 fixes the table 20 and the inner ring 72. In other words, the table 20 is rotatably supported relative to the base unit 10 via the bearing 70.
[0025] A magnet 51 is attached to the underside of table 20. A coil 52, which is a coreless coil, is attached to bed 11 in a position facing magnet 51. A plurality of magnets 51 are arranged in the circumferential direction of table 20 to form magnet array 56 (FIG. 9). A plurality of coils 52 are arranged in positions corresponding to magnet array 56 to form coil array 57 (FIG. 5). When current flows through coil 52, motor 50, which is composed of magnet 51 and coil 52, functions to generate torque, causing table 20 to rotate.
[0026] A support base 12 is fixed to the bed 11 with screws 48. An encoder head 82 is fixed onto the support base 12. The encoder head 82 is disposed below the lower surface 21b of the mounting portion 21, which is the portion of the mounting portion 21 of the table 20 that protrudes outward beyond the shaft portion 22. The encoder head 82 is covered with a cover 61. Note that "outward" here means the direction away from the rotation axis R of the table 20.
[0027] Referring to Figure 3, the bed 11 is provided with a first annular portion 102 that is coaxial with the rotation axis R (Figure 2). The first annular portion 102 is a portion that is relatively thick compared to its surroundings. The outer peripheral surface 71b of the outer ring 71 of the bearing 70 is in close contact with the inner peripheral surface 102b of the first annular portion 102. The outer ring 71 is spigot-fitted to the bed 11.
[0028] A scale 81 is printed on the outer peripheral surface 22a of the shaft portion 22 of the table 20. An encoder head 82 is disposed opposite the scale 81. A gap 35 is formed between the scale 81 and the encoder head 82, allowing the sensor of the encoder head 82 to read the scale graduations. The width of the gap 35 is substantially constant regardless of the size of the entire device or the arrangement of each component, so that the scale graduations can be read. For example, in a rotary table device in which the outer diameter of the mounting portion 21 of the table 20 is 65 mm, the size of the bed 11 can be approximately 65 mm to 75 mm x 75 mm to 85 mm. The back surface 82c of the encoder head 82 does not protrude outward from the outer peripheral surface 21a of the mounting portion 21. In other words, the encoder head 82 is accommodated below the mounting portion 21. The rotary table device 1 does not have a ring scale; the scale 81 is printed directly on the table. This allows the table and the sensor to be disposed in close proximity. This configuration allows the rotary table device to be made more compact. Furthermore, the accuracy of reading the sensor can be expected to improve. Furthermore, by accommodating the encoder head 82 under the mounting portion 21, it is possible to obtain a rotary table device that is compact overall while still ensuring the area of the mounting portion 21.
[0029] Next, the base 10 of the rotary table device 1, which is the fixed side of the rotary table device, and the members fixed to the base 10 will be described in detail. Fig. 4 is a perspective view of the bed 11 that constitutes the base 10. Fig. 5 is a plan view showing the bed 11 and the members fixed to the bed 11. Fig. 6 is a perspective view showing the bed 11 and the members fixed to the bed 11.
[0030] Referring to FIG. 4, bed 11 is an integral member made entirely of steel plate. Roughly speaking, bed 11 has a hole 103 formed in the center thereof, the hole 103 being centered on rotation axis R. A first recess 101, which is an annular recess, is formed concentrically with hole 103. A second recess 105 is formed continuous with first recess 101. Second recess 105 is a recess that reaches end face 11e of bed 11. Screw holes 13 that penetrate bed 11 in the thickness direction (Z-axis direction) are formed in four locations on bed 11. The screw holes 13 can be used to fix bed 11 to an external member.
[0031] The diameter of the hole 103 is approximately equal to the diameter of the inner peripheral surface of the outer ring 71 (FIG. 3) of the bearing 70. A second annular portion 104 is located on the periphery of the hole 103. A plurality of screw holes 17 are formed in the second annular portion 104 at equal intervals around the periphery, penetrating the bed 11 in the thickness direction (Z-axis direction). A first annular portion 102 is located along the outer peripheral edge of the second annular portion 104. The outer ring 71 (FIG. 3) of the bearing 70 is spigot-fitted onto a step formed by the inner peripheral surface 102b of the first annular portion 102 and the upper surface 104a of the second annular portion 104.
[0032] FIG. 5 shows some of the components fixed to the bed 11. Referring to FIG. 5, a first insulator 53, which is an insulating film corresponding to the shape of the first recess 101, is disposed on the upper surface 101a of the first recess 101. A coil 52 is disposed on the first insulator 53. Each of the coils 52 is a flat, coreless coil wound in an annular shape. Fifteen coils 52 constitute a coil array 57 forming a part of an annular ring. The coils 52 are three-phase coils, and in the coil array 57, the coils are arranged in the order of U-phase, V-phase, and W-phase from one end. Note that, although the coil array includes 15 coils in the first embodiment, the number and arrangement of coils included in the coil array can be changed depending on the size of the motor and the desired torque. The number of coils 52 may be increased by three to form an annular coil array arranged around the entire circumference of the first recess 101. The coil 52 is fixed to the bed 11 together with the substrate 14 (FIG. 6) via a collar 42 by screws 41.
[0033] A support base 12 and a cover 61 are fixed to the bed 11. A central end face 61b of the cover 61 is formed in an arc shape that faces the outer peripheral face 21a of the mounting portion 21 of the table 20 with a small gap between them. Components (not shown) such as signal lines and power lines of the encoder are housed inside the cover 61.
[0034] Fig. 6 is a perspective view showing the addition of substrate 14 to Fig. 5. Referring to Fig. 6, upper surface 14a of substrate 14 is configured to be at approximately the same height as upper surface 11a of bed 11 and upper surface 102a of first annular portion 102. An insulator such as an insulating film may be attached to upper surface 14a of substrate 14.
[0035] Next, the table 20 of the rotary table device 1, which is the rotating side of the rotary table device, and the members fixed to the table 20 will be described in detail. Fig. 7 is a plan view showing the table 20 and bearing 70. Fig. 8 is a cross-sectional perspective view of the table 20 and bearing 70 shown in Fig. 7. Fig. 9 shows the underside of the table 20. Fig. 9 is a plan view showing the table 20 and the members fixed to the table 20.
[0036] Referring to FIG. 7, a scale 81 is printed on the entire outer peripheral surface 22a of the shaft portion 22 of the table 20. Here, "printed" means that a detection target portion detectable by a sensor is printed, and includes marks formed by laser processing, etching, printing, transferring, writing, or the like. The scale 81 is a collection of numerous graduations 83. The scale 81 is printed directly on the outer peripheral surface 22a. "Directly printed" means that the graduations 83 are formed directly on the surface of the outer peripheral surface 22a without using a sticker, ribbon, or the like. Preferably, the graduations 83 are minute recesses (slits) formed on the outer peripheral surface 22a by laser processing or etching. For example, the graduations 83 may be recesses having a length of 0.2 mm to 10 mm and a depth of 0.1 to 100 μm formed on the outer peripheral surface 22a. The intervals between the graduations 83 may be, for example, 1 to 100 μm. The graduations 83 may be formed at equal intervals, or may have portions with varying intervals. The markings on the scale 83 may all be the same around the entire circumference. Alternatively, for example, reference marks indicating the origin position or specific positions may be formed as part of the scale 83 or in addition to the scale 83. Alternatively, the length or width of the markings at regular intervals may be different from other markings, making it possible to distinguish the markings from one another.
[0037] Referring to FIG. 8 , the center of the table 20 is hollow. The inner peripheral surface 20c of the table 20 is flush with the mounting portion 21 and the shaft portion 22. By making the center of the table 20 hollow and providing the scale 81 directly on the outer peripheral surface 22a of the shaft portion 22, the rotating portion can be made lighter. The underside 20d of the table 20 is formed with a first annular portion 23 and a second annular portion 24, which are annular recesses extending along the circumferential direction of the table 20. The bearing 70 is disposed in the first annular portion 23. The bearing 70 is disposed so that the inner peripheral surface 23a defining the first annular portion 23 is in contact with the inner peripheral surface 72a of the inner ring 72 of the bearing 70. The magnet 51 is disposed in the second annular portion 24. The thickness of the magnet 51 and the depth of the second annular portion 24 are approximately equal. The magnet 51 is almost entirely contained within the second annular portion 24, and protrudes only slightly from the lower surface 20d of the table 20.
[0038] Referring to FIG. 9, magnet 51 is a plate-shaped magnet having a substantially trapezoidal surface converging toward the center of rotation. 23 magnets 51 arranged adjacent to one another constitute magnet array 56. Magnets 51 are arranged around the entire circumference of second annular portion 24. Magnet array 56 is an annular magnet array. In magnet array 56, magnets 51 are arranged so that their north and south poles alternate. Note that the number and arrangement of magnets are not limited to this and can be changed appropriately depending on the size, performance, required torque, etc. of the magnets. Magnet 51 may be adhered to table 20 with an adhesive, for example, or may be fixed to table 20 solely by the magnetic force of magnet 51. Magnet array 56 is arranged to face coil array 57 (FIG. 5).
[0039] Next, the motor 50 of the rotary table device 1 will be described. 2, 5, and 9, the motor 50 is composed of a magnet array 56 including magnets 51 and a coil array 57 including coils 52. The table 20 also serves as a magnet yoke that forms a magnetic path for the magnet 51. Power is supplied to the coil 52 through power lines (not shown) from connection parts (not shown) corresponding to the three phases U, V, and W. In the rotary table device 1, the substrate 14 is disposed between the magnet 51 and the coil 52, so that heat generated in the coil 52 during power supply is less likely to be transmitted to the magnet 51. This configuration reduces the decrease in magnetic flux density due to a rise in temperature of the magnet 51, thereby suppressing a decrease in output power of the motor 50. Furthermore, airflow caused by the rotation of the table 20 can be expected to cool the magnet 51. The rotary table device 1 does not have a ring scale disposed on the outer periphery of the shaft portion. Therefore, the outer periphery 22a of the shaft portion 22 is exposed to the outside of the device, and the magnet 51 is also disposed close to the outside of the device, thereby enhancing the air-cooling effect.
[0040] Here, the size of the rotary table device will be explained. There are no particular restrictions on the size of the rotary table device 1, but by configuring the device so that the scale is printed directly on the outer peripheral surface of the table shaft, an infinitely small rotary table device that has not been available before can be obtained. For example, an infinitely small rotary table device can be configured in which the outer diameter of the table 20 is 100 mm and the bed size is 100 mm x 115 mm. Naturally, these sizes are not limited to these, and the outer diameter of the table can be approximately 10 to 1000 mm. The size of the bed can be approximately 10 to 1020 mm on one side.
[0041] (Variation) 10 to 12, a rotating body 200 is an example of an embodiment of a rotating part constituting a rotating table device according to the present disclosure. The configuration of the rotating table device other than the rotating body 200 can be applied by modifying the configuration of the above-described rotating table device 1 as necessary. The rotating body 200 is mainly different from the table 20 of the first embodiment in that the table and the outer ring of the bearing are integrated into one component. This difference will be mainly described. The same components as those in the first embodiment are given the same reference numerals, and description thereof will be omitted.
[0042] Fig. 10 is a perspective view showing the rotating body 200 and the inner ring 720. Fig. 11 is a cross-sectional view showing a cross section cut along line XI-XI in Fig. 10. Fig. 12 is a cross-sectional perspective view of the cross section XI-XI in Fig. 10, showing the inner ring 720 without the inner ring 720.
[0043] Referring to FIG. 10, the rotating body 200 includes a mounting portion 210, which is a hollow disk-shaped portion, and a shaft portion 220, which is located below the mounting portion 210 and has a smaller outer diameter than the mounting portion 210. The upper surface of the mounting portion 210 is formed flat. The mounting portion 210 and the shaft portion 220 are integrally formed as a single component. A scale 810 is printed around the entire outer periphery of the outer periphery 220a of the shaft portion 220. The scale 810 is composed of graduations 830 formed directly on the surface of the outer periphery 220a by laser processing, etching, or the like, similar to the scale 81 described above.
[0044] Referring to FIG. 11, raceway surfaces 710a and 710b, which are the rolling surfaces of rolling elements 91 in bearing 700, are formed on inner peripheral surface 200c of rotating body 200. In other words, rotating body 200 is a member in which a table of a rotary table device and an outer ring of a bearing are integrally constructed. Rotating body 200 includes outer ring 710 of the bearing. The inner peripheral side of shaft portion 220 functions as outer ring 710, which, together with inner ring 720 and rolling elements 91, constitutes bearing 700. Rolling elements 91 are cylindrical rollers. Bearing 700 is a cross roller bearing. Inner ring 720 is fixed to a bed (not shown) by screws (not shown) inserted into threaded holes 160.
[0045] 11 and 12, a first annular portion 230, which is a recess in an annular portion extending in the circumferential direction of the rotor 200, is formed on the lower surface 200d of the rotor 200. A plurality of plate-shaped magnets are arranged on the first annular portion 230. Raceway surfaces 710a, 710b are formed on the inner peripheral surface 200c. During manufacturing, the raceway surfaces 710a, 710b and the outer peripheral surface 220a can be machined in one chuck, enabling a streamlined manufacturing process.
[0046] Rotating body 200 has scale 810 printed directly on the outer peripheral surface of shaft 220, and furthermore, the table and the outer ring of the bearing in the rotary table device are integrated. With this configuration, a more compact rotary table device that is infinitely rotatable can be obtained through a streamlined manufacturing process.
[0047] (Other variations) In the rotary table device 1, the outer ring 71 of the bearing 70 is fixed to the bed, and the inner ring 72 is fixed to the table 20. Alternatively, the outer ring of the bearing may be fixed to the table, and the inner ring may be fixed to the bed. Furthermore, the rotating body 200 is a member that includes the outer ring 710 of the bearing 700. Alternatively, the table and the inner ring of the bearing may be integrated. These can be selected appropriately taking into consideration the layout of the parts, the size and mass of the device.
[0048] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]
[0049] 1 rotary table device, 10 base portion, 11 bed, 12 support base, 14 substrate, 20 table, 21, 210 mounting portion, 22, 220 shaft portion, 23, 230 first annular portion, 24 second annular portion, 35 gap, 41, 46, 47, 48 screw, 42 collar, 9, 13, 16, 17, 160 screw hole, 18, 19 mounting hole, 50 motor, 51 magnet, 52 coil, 53 first insulator, 56 magnet array, 57 coil array, 61 cover, 70, 700 bearing, 71, 710 outer ring, 72, 720 inner ring, 81, 810 scale, 82 encoder head, 83, 830 scale, 91 rolling element, 101 first recess, 102 first annular portion, 103 Hole, 104 second annular portion, 105 second recess, 200 rotating body.
Claims
1. A base portion; A bearing, a table rotatably supported on the base portion via the bearing; a motor that rotates the table in the rotation direction of the bearing, The motor a coil array including a plurality of flat, annularly wound, three-phase coreless coils arranged side by side and fixed to the base; a magnet array fixed to the table, the magnet array being arranged opposite the coil array and including a plurality of plate-shaped magnets arranged in a circumferential direction of the table with alternating magnetic poles; Including, A scale is printed on the outer peripheral surface of the table over the entire circumference, a sensor for reading the scale is disposed on the base portion; the table includes a disk-shaped mounting portion having a flat upper surface, and a shaft portion located below the mounting portion and having a smaller diameter than the mounting portion; The scale is printed on the outer peripheral surface of the shaft portion, an encoder head including the sensor is disposed on the base portion such that the entire encoder head is located below the placement portion; Rotating table device.
2. the coil array is a coil array in which a plurality of the coreless coils are arranged to form a part of a ring, The magnet array is an annular magnet array in which the magnets are arranged along the entire circumference of the table. The rotary table device according to claim 1 .
3. Each of the graduations constituting the scale is a recess having a length of 0.2 mm to 10 mm and a depth of 0.1 to 100 μm and formed on the outer peripheral surface of the shaft portion.
3. The rotary table device according to claim 1 or 2.
4. The table and the outer ring of the bearing are configured as an integrated part. The rotary table device according to any one of claims 1 to 3.
Citation Information
Patent Citations
Spindle bearing of CT (Computed Tomography) machine
CN102364135A
Alignment stage device containing linear motor
JP2004072960A
Rotary table device
JP2020120430A