Rotary table device

Abstract

To provide a rotary table device with a small diameter and high positioning accuracy.SOLUTION: A rotary table device includes: a housing having a cylindrical inner peripheral wall; a shaft which penetrates the housing and extends in an axial direction common to the axial direction of the inner peripheral wall; a first bearing mechanism which supports a first end side of the shaft so as to be able to move directly with respect to the housing; a motor mechanism which reciprocates the shaft in an axial direction of the shaft; and a rotary body connected to the shaft through a ball screw mechanism provided on a second end side which is an end on an opposite side of the first end side of the shaft. The rotary body is rotatably fixed to the housing via a second bearing mechanism and includes a ball screw nut and a table, which are mutually fixed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rotary table device.

Background Art

[0002] As a rotary table device, there is known a rotary table device including a bed as a fixed part, a rotary table, and a bearing disposed between them, and being rotationally driven by a linear motor. For example, in the rotary table device of Patent Document 1, a plurality of magnets are arranged along the circumferential direction of the table on the lower surface of the table, and a plurality of coils are arranged along the upper surface of the bed so as to face the magnets. The rotary table device of Patent Document 1 is a direct drive device that rotates the table by the thrust obtained from the magnetic flux of the magnet and the current flowing through the coil.

[0003] On the other hand, a linear actuator combining a ball screw and a motor is known. The linear actuator of Patent Document 2 includes a shaft, a motor unit, a ball screw nut, and a ball spline nut. The motor unit includes a stator including a coil fixed to the motor exterior and a rotor provided on the outer peripheral portion of a rotor holding shaft pivotally supported on the motor exterior via a bearing. The rotor holding shaft is a ball screw nut, and a rotor composed of a magnet and an iron core is formed on the outer peripheral portion of the ball screw nut, and a ball screw groove is formed on the inner peripheral portion of the ball screw nut, and the shaft is supported via balls. The ball spline nut is fixedly and non-rotatably attached to the motor exterior, and a ball rolling groove is formed on the inner peripheral side thereof, and the shaft is supported via balls.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] In rotary table devices, there is a demand for devices with smaller diameters and higher positioning accuracy. Therefore, one of the objectives of the present invention is to provide a rotary table device that is both small in diameter and highly accurate in positioning. [Means for solving the problem]

[0006] A rotary table apparatus according to this disclosure is: A housing having a cylindrical inner circumferential wall, A shaft that penetrates the housing and extends in an axial direction common to the axial direction of the inner circumferential wall, A first bearing mechanism supports the first end of the shaft so that it can move in a straight line relative to the housing, A motor mechanism that causes the shaft to reciprocate in the axial direction of the shaft, A rotating body connected to the shaft is provided via a ball screw mechanism located on the second end, which is the opposite end of the shaft to the first end, Equipped with, The rotating body is rotatably supported relative to the housing via a second bearing mechanism and includes a ball screw nut fixed to each other and a table. [Effects of the Invention]

[0007] According to the above configuration, a rotary table device is provided that is small in diameter and has high positioning accuracy. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a perspective view of the rotary table device 1 according to Embodiment 1. [Figure 2] Figure 2 is a cross-sectional view of the rotary table device 1, showing the section along line II-II in Figure 1. [Figure 3] Figure 3 is a cross-sectional view showing the cross-sectional view of Figure 2 with some additional components. [Figure 4] Figure 4 is a cross-sectional perspective view showing the II-II section of the rotary table device 1 in Figure 1. [Figure 5] Figure 5 is a cross-sectional view of the rotary table device 101 according to Embodiment 2. [Figure 6] Figure 6 is a cross-sectional view of the rotary table device 201 according to Embodiment 3. [Figure 7] Figure 7 is a cross-sectional view of the rotary table device 301 according to Embodiment 4. [Modes for carrying out the invention]

[0009] [Summary of the Embodiment] First, the embodiments of this disclosure will be listed and described.

[0010] The rotary table device according to this disclosure comprises a housing having a cylindrical inner wall, a shaft extending axially through the housing and in a direction common to the axial direction of the inner wall, a first bearing mechanism supporting the first end of the shaft so as to be linearly movable relative to the housing, a motor mechanism causing the shaft to reciprocate in the axial direction of the shaft, and a rotating body connected to the shaft via a ball screw mechanism provided at the second end, which is the end opposite to the first end of the shaft. The rotating body is rotatably supported relative to the housing via a second bearing mechanism. The rotating body includes a ball screw nut and a table fixed to each other.

[0011] Conventionally, a rotary table device is known that has a magnet array on the underside of the rotary table and a coil array on the upper surface of the bed, opposite to the magnet array (for example, Patent Document 1). The rotary table device of Patent Document 1 enables precise positioning. On the other hand, since the magnet array that constitutes the motor is attached to the table, the smaller the diameter of the table, the smaller the magnet array becomes, and as a result the motor output decreases. For this reason, there has been a limit to how much the diameter of the rotary table device can be reduced.

[0012] On the other hand, shaft motors are known in which a movable element reciprocates along a shaft. A shaft motor consists of a shaft containing multiple magnets arranged axially with alternating magnetic poles, and a movable element containing a cylindrical coil surrounding the shaft. In a shaft motor, thrust is generated by passing an electric current through the coil, causing the movable element to move linearly along the shaft. Conventionally, the use of the linear motion of a shaft motor to rotate a table in a rotary table device had not been considered.

[0013] Furthermore, a linear actuator is known that combines a ball screw and a ball spline, with a motor incorporated inside the ball screw nut (for example, Patent Document 2). The linear actuator in Patent Document 2 converts the rotational motion of the ball screw nut into the linear motion of the shaft. In the linear actuator of Patent Document 2, it is also possible to make the shaft rotate or spiral by incorporating a motor inside the ball spline nut as well. However, the linear actuator in Patent Document 2 cannot be applied to applications that rotate a table held in a fixed position.

[0014] The rotary table device according to the present disclosure applies a shaft motor to reciprocate a shaft in the axial direction. Further, a ball screw mechanism is provided at one end of the shaft. The ball screw nut in this ball screw mechanism is rotatably attached to the housing of the shaft motor via a bearing. Therefore, the ball screw nut is immovable in the axial direction and only rotational movement is allowed. With these configurations, the linear motion of the shaft is converted into the rotational motion of the ball screw nut, and the table fixed to the ball screw nut rotates. Since no motor components are attached to the table in the rotary table device of the present disclosure, it is easy to reduce the diameter of the table. Further, the base that was conventionally formed in a rectangular shape in the rotary table device becomes unnecessary, and the size of the rotary table device in the planar direction can be made smaller. Further, since the linear motion of the shaft is converted into the rotational motion of the table by the ball screw mechanism, the rotation can be reliably controlled. Therefore, the positioning accuracy is high. Furthermore, the rotation speed can be controlled by controlling the output of the motor. Also, since the lead of the ball screw and the rotation angle of the table are correlated, a rotary table device having a desired rotation angle can be obtained by using a general-purpose and established method of setting and forming the lead of the ball screw.

[0015] In the rotary table device, the motor mechanism may include a coil fixed to the inner peripheral wall of the housing and a field magnet fixed to an outer peripheral surface of the shaft at a position facing the coil. By providing a linear motor as the motor mechanism, the control of the movement amount of the shaft, that is, the rotation amount of the rotary table, can be made more reliable and easier. Therefore, a rotary table device with more excellent positioning accuracy can be obtained.

[0016] In the rotary table device, the first bearing mechanism may be a ball spline mechanism, a ball spline nut may be fixed to the housing, and a spline groove may be formed on an outer peripheral surface of the first end side of the shaft. By supporting the end (the first end side) of the shaft on the side opposite to the side (the second end side) where the rotary table is provided with a ball spline bearing, the allowable range for the load can be made larger.

[0017] In the rotary table device, the second bearing mechanism is a cross roller bearing, and a bearing outer ring of the cross roller bearing is fixed to the housing, and the bearing outer ring, the ball screw nut, and a bearing inner ring fixed to the table may be connected via rollers. In this rotary table device, the cross roller bearing enables acceptance of loads from all directions. Therefore, it is suitable not only for applications where an object is placed and rotated, but also for wider applications such as being applied to, for example, the tip of a manipulator.

[0018] In the rotary table device, the field magnet may include a magnet array in which a plurality of ring-shaped permanent magnets inserted into the shaft are arranged in the axial direction. Further, the shaft is provided with a flange portion that contacts the field magnet at one end of a portion where the field magnet is disposed, and the field magnet may be clamped and fixed by the flange portion and a nut inserted into the shaft. With such a configuration, while suppressing the number of components constituting the rotary table device, assembly is easy, eccentricity and rattling of the shaft are prevented, and a highly accurate rotary table device can be realized.

[0019] The rotary table device further includes an encoder, and the encoder may include a scale attached to the outer peripheral surface of the rotating body and an encoder head attached to the housing and facing the scale. By directly detecting the rotation of the rotating body, higher-precision rotation control can be realized.

[0020] [Specific Example of Embodiment] Next, an example of a specific embodiment of the rotary table device of the present disclosure will be described while referring to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals and their description will not be repeated.

[0021] (Embodiment 1) Figure 1 is an external perspective view showing the structure of a rotary table device 1, which is a rotary table device in one embodiment of the present disclosure. Figure 2 is a cross-sectional view of the rotary table device 1 showing the section II-II in Figure 1. Figure 3 is a diagram showing the cross-sectional view of Figure 2 with some components added. Figure 4 is a cross-sectional perspective view of the rotary table device 1 showing the section II-II in Figure 1. Note that Figures 1 to 4 are all schematic diagrams, and some of the components constituting the rotary table device are not shown, nor are the detailed configurations of each component.

[0022] Referring to Figure 1, the rotary table device 1 has an overall cylindrical appearance. The rotary table device 1 comprises an outer cylinder 11 as a housing, a shaft 21 passing through the outer cylinder 11, and a table 31 which is a rotary table. In the rotary table device 1, the side from which the shaft 21 protrudes is referred to as the first end, and the side to which the table 31 is provided is referred to as the second end.

[0023] The outer cylinder 11 has a cylindrical outer surface that extends in the axial direction. The housing 12 is fixed to the first end of the outer cylinder 11. The housing 12 also constitutes the enclosure of the rotary table device 1. The outer diameter of the housing 12 is the same as that of the outer cylinder 11. The outer bearing ring 13 is fixed to the second end of the outer cylinder 11. The outer diameter of the outer bearing ring 13 is the same as that of the outer cylinder 11. However, the outer shapes of the outer cylinder 11, housing 12, and outer bearing ring 13 shown in Figure 1 are examples and are not limited thereto. For example, the outer cylinder 11, housing 12, and outer bearing ring 13 may have different outer diameters. Also, the shape of the outer surface of the outer cylinder 11 and housing 12 is not limited to a cylindrical shape, but may be a rectangular tube shape. Furthermore, there may be a housing section for accommodating sensors and various cords, a mounting section for other members, etc.

[0024] The outer cylinder 11, housing 12, and bearing outer ring 13 are fixed to each other. The outer cylinder 11, housing 12, and bearing outer ring 13 constitute the fixed part 10 of the rotary table device 1. In contrast, the shaft 21 reciprocates in the axial direction by a motor mechanism 40 (Figure 2) provided inside the outer cylinder 11. The shaft 21 constitutes the linear motion part 20 of the rotary table device 1. The table 31 rotates in conjunction with the reciprocating motion of the shaft 21. The table 31 constitutes the rotating part 30 of the rotary table device 1. In other words, the rotary table device 1 includes the fixed part 10, the linear motion part 20, and the rotating part 30.

[0025] The fixing part 10 will now be described. Referring to Figure 2, the outer cylinder 11 has a cylindrical inner circumferential wall 11a. A coil 41 is fixed to the inner circumferential wall 11a. The coil 41 is wound multiple times in a spiral shape along the inner circumferential wall 11a and extends as a whole in the axial direction of the inner circumferential wall 11a. The coil 41 may be directly fixed to the inner circumferential wall 11a or it may be attached via a support member.

[0026] A ball spline nut 51 is fixed to the inner circumference of the housing 12, which is fixed to the first end of the outer cylinder 11. The ball spline nut 51 constitutes a ball spline 50 (Figure 3) as the first bearing mechanism. The ball spline nut 51 supports the first end of the shaft 21 so that it can move linearly in the axial direction via the balls 53 (Figure 3). A bearing outer ring 13 is fixed to the second end of the outer cylinder 11. The bearing outer ring 13 faces the bearing inner ring 32.

[0027] The linear motion section 20 will now be described. Referring to Figure 2, the shaft 21 is an axial member that extends through the inside of the outer cylinder 11. The axial direction of the shaft 21 is the same as the axial direction of the inner circumferential wall 11a of the outer cylinder 11. In other words, the shaft 21 extends in the same axial direction as the inner circumferential wall 11a of the outer cylinder 11. The field magnet 42 is fixed near the center of the shaft 21 in the axial direction. The field magnet 42 consists of multiple ring-shaped permanent magnets inserted into the shaft 21 and arranged in the axial direction. As is well known, the multiple permanent magnets are arranged with alternating N poles and S poles. The field magnet 42 is positioned opposite the coil 41. The shaft 21 has a flange portion 22, which is a flange-like portion that protrudes outward. The field magnet 42 is clamped and fixed by the flange portion 22 and a nut 23, which is a bearing nut. The field magnet 42 and the nut 23 are fixed to the shaft 21. The coil 41 and the field 42 constitute the motor mechanism 40.

[0028] The second end of the shaft 21 is supported by a ball screw nut 61 via a ball 63 (Figure 3). The second end of the shaft 21 penetrates the hollow portion of the inner circumference of the bearing inner ring 32 and reaches the hollow portion of the inner circumference of the table 31. As the shaft 21 moves linearly in the axial direction, it is preferable that the design ensures that the shaft 21 does not protrude from the main surface 31a of the table 31 when the shaft 21 is moved to its maximum extent toward the second end.

[0029] The rotating part 30 will now be described. Referring to Figure 2, the rotating part 30 includes a ball screw nut 61, a bearing inner ring 32, and a table 31, all of which are fixed to each other. As previously mentioned, the ball screw nut 61 is connected to the shaft 21 via a ball 63 (Figure 3). The bearing inner ring 32 is rotatably connected to the bearing outer ring 13 via a roller 33 (Figure 3). The rotating part 30 is rotatable, but at the same time, it is immobile in the axial direction because it is connected to the bearing outer ring 13 which constitutes the fixed part 10.

[0030] Referring to Figure 3, the structure connecting the fixed part 10, the linear motion part 20, and the rotating part 30 will be described. A ball spline 50, which serves as the first bearing mechanism, is configured between the fixed part 10 and the shaft 21 that constitutes the linear motion part 20. A spline groove 52 extending in the axial direction is formed on the outer circumferential surface of the first end of the shaft 21. A ball 53 is inserted into a raceway formed between a ball spline nut 51 and the spline groove 52. Note that the ball spline 50 shown in Figure 3 is a schematic diagram conceptually illustrating the configuration and does not necessarily reflect the actual dimensions or shape. In addition, although the example shown in Figure 3 is equipped with a ball spline 50 as the first bearing mechanism, any mechanism that can support the desired load and allow axial movement of the shaft 21 is acceptable, and is not limited to a ball spline. For example, a sliding bearing may be used instead of a ball spline. When using a ball spline, it has the advantage of being able to receive the rotational reaction force received from the rotating part 30 and suppressing the free rotation of the shaft.

[0031] Referring to Figure 3, a ball screw mechanism 60 is configured between the shaft 21 constituting the linear motion section 20 and the rotating section 30. A helical ball screw groove 62 is formed on the outer circumferential surface of the second end of the shaft 21. A ball 63 is inserted into a raceway formed between the ball screw nut 61 and the ball screw groove 62. Note that the ball screw mechanism 60 shown in Figure 3 is a schematic diagram conceptually illustrating the configuration and does not necessarily reflect the actual dimensions or shape. By connecting the linear motion section 20 and the rotating section 30 with a ball screw mechanism, energy loss is reduced, and the linear motion of the linear motion section 20 can be efficiently converted into the rotational motion of the rotating section 30. In addition, the rotational speed and amount of rotation of the rotating section 30 can be designed by selecting the lead. Furthermore, rigidity can be increased and backlash can be reduced by selecting the ball size. It may also be possible to utilize existing knowledge about ball screws regarding durability, etc.

[0032] Referring to Figure 3, a cross roller bearing 70 is provided as a second bearing mechanism between the stationary part 10 and the rotating part 30. The cross roller bearing 70 includes a bearing outer ring 13 that constitutes the stationary part 10, a bearing inner ring 32 that constitutes the rotating part 30, and a roller 33 inserted into a raceway formed between the bearing outer ring 13 and the bearing inner ring 32. Note that the cross roller bearing 70 shown in Figure 3 is a schematic diagram that conceptually shows the configuration and does not necessarily reflect the actual dimensions and shape. In addition, although the example shown in Figure 3 is provided with a cross roller bearing 70 as the second bearing mechanism, any mechanism that can support the desired load and support the rotational motion of the table 31 is acceptable and is not limited to a cross roller bearing. For example, an angular contact bearing or a normal ball bearing may be used instead of a cross roller bearing, and a sliding bearing may also be used depending on the application and dimensions. When a cross roller bearing is used, high rigidity can be achieved. Furthermore, the cross roller bearing 70 is preferable because it can receive both the axial load from the shaft 21 and the radial load from the table 31. Furthermore, positioning accuracy can be further improved by using high-precision cross-roller bearings together with the encoder.

[0033] Referring to Figure 4, the operation of the rotary table device 1 will be described. The rotary table device 1 includes a motor mechanism 40. The motor mechanism 40 includes a coil 41 fixed to the inner circumferential wall 11a of the outer cylinder 11, and a field magnet 42 fixed to the outer circumferential surface of the shaft 21 at a position opposite to the coil 41. The field magnet 42 consists of ring-shaped magnets inserted into the shaft 21 and arranged in multiple axial directions. When current flows through the coil 41, which is the stator of the motor mechanism 40, an axial thrust is generated and the shaft 21 moves in the axial direction. By switching the direction of the current flowing through the coil 41, the shaft 21 can be made to reciprocate. In addition, by changing the amount of current, the output of the motor 40 can be controlled, and the moving speed of the shaft 21 can be controlled.

[0034] The linear motion of the shaft 21 is transmitted to the ball screw nut 61. Since the axial movement of the ball screw nut 61 is restricted, only rotational motion occurs. Since the table 31 is fixed to the ball screw nut 61, the table 31 rotates together with the ball screw nut 61. The amount of rotation of the table 31 correlates with the amount of movement of the shaft 21. The rotation angle of the table 31 depends on the lead of the ball screw groove 62 (Figure 3). In the rotary table device 1, a rotary table device with any rotation angle can be obtained by the lead of the ball screw groove 62. For example, it may be a rotary table device that reciprocates within a fixed angle such as 60°, 120°, or 250°, or it may be a rotary table device that rotates 360° or more.

[0035] The rotary table device 1 may further include an encoder for detecting the amount of movement. Figure 5 is a cross-sectional view of the rotary table device 101 according to Embodiment 2. Figure 6 is a cross-sectional view of the rotary table device 201 according to Embodiment 3. Figure 7 is a rotary table device 301 according to Embodiment 4. The rotary table devices 101, 201, and 301 each include an encoder, but the positions in which the encoder is installed differ. In Figures 5 to 7, components similar to those in the rotary table device 1 are denoted by the same reference numerals, and some of the explanations are omitted.

[0036] Referring to Figure 5, the rotary table device 101 is equipped with a rotary scale 81 on the outer circumferential surface of the shaft portion of the table 31. Opposite the rotary scale 81 is an encoder head 82. The encoder head 82 is fixed to the outer cylinder 11 via a bracket 83. The rotary scale 81 and the encoder head 82 constitute the encoder 80. With this arrangement, the rotation of the table 31 can be detected directly, allowing for more accurate control of rotation and positioning.

[0037] Referring to Figure 6, the rotary table device 201 is equipped with a rotary scale 81 on the outer circumferential surface of the shaft portion of the ball screw nut 61. Opposite the rotary scale 81 is an encoder head 82. The encoder head 82 is fixed to the outer cylinder 11. The rotary scale 81 and the encoder head 82 constitute the encoder 80. With this configuration, the rotation of the ball screw nut 61, which rotates together with the table 31, can be detected, allowing for more accurate control of rotation and positioning. Furthermore, since the detection parts of the rotary scale 81 and the encoder head 82 are housed inside the outer cylinder 11, dust accumulation is prevented, resulting in excellent durability and operational stability.

[0038] Referring to Figure 7, the rotary table device 301 is equipped with a rotary scale 81 on the outer circumferential surface of the shaft 21. Opposite the rotary scale 81 is an encoder head 82. The encoder head 82 is fixed to the housing 12. The rotary scale 81 and the encoder head 82 constitute the encoder 80. With this configuration, the number of radially protruding members of the rotary table device 301 can be reduced, allowing for the construction of a smaller rotary table device.

[0039] The rotary table device according to this disclosure can have various configurations in place of or in addition to the specific embodiments described above. For example, the motor mechanism is not limited to a linear motor, as long as the desired accuracy and output can be obtained. For example, the shaft may be reciprocated in the axial direction by a hydraulic cylinder or the like. Also, the shape of the main surface of the table is not limited to an annular surface with an open center, but may be a disc shape without a hollow portion. Additional members may be attached to the main surface of the table. The main surface of the table is not limited to a flat surface, but may have protrusions or steps. In other words, the table may have other functions in addition to or instead of the function of placing and rotating an object. For example, the rotary table device according to this disclosure can be used as an end effector of a manipulator to rotate an end effector attached to the table. Furthermore, regarding the shape of the shaft, in the above embodiments, a spline groove was formed on the first end of the shaft, a flange portion was formed in the center, and a ball screw groove was formed on the second end, but the specific shape is not limited to this.

[0040] The rotary table apparatus according to this disclosure is particularly suitable as a small-diameter rotary table apparatus. While the specific dimensions are not particularly limited, for example, the outer diameter of the rotary table can be approximately 30 to 80 mm, and the outer diameter of the housing (fixed part) can be approximately the same.

[0041] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the invention is defined by the claims and not by the foregoing description, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of Symbols]

[0042] 1, 101, 201, 301 Rotary table device, 10 Fixed part, 11 Outer cylinder, 11a Inner circumferential wall, 12 Housing, 13 Bearing outer ring, 20 Linear motion part, 21 Shaft, 22 Flange part, 23 Nut, 30 Rotating part, 31 Table, 31a Main surface, 32 Bearing inner ring, 33 Roller, 40 Motor mechanism, 41 Coil, 42 Field, 50 Ball spline, 51 Ball spline nut, 52 Spline groove, 53, 63 Ball, 60 Ball screw mechanism, 61 Ball screw nut, 62 Ball screw groove, 70 Cross roller bearing, 80 Encoder, 81 Rotary scale, 82 Encoder head, 83 Bracket.

Claims

1. A housing having a cylindrical inner circumferential wall, A shaft that penetrates the housing and extends in an axial direction common to the axial direction of the inner circumferential wall, A first bearing mechanism supports the first end of the shaft so that it can move in line with respect to the housing, A motor mechanism that causes the shaft to reciprocate in the axial direction of the shaft, A rotating body connected to the shaft is provided on the second end, which is the end opposite to the first end of the shaft, via a ball screw mechanism that converts linear motion into rotational motion. Equipped with, The rotating body is rotatably supported in relation to the housing via a second bearing mechanism and includes a ball screw nut and a table fixed to each other. The motor mechanism is located inside the housing. The motor mechanism is A coil fixed to the inner circumferential wall of the housing, A field magnet fixed to the outer surface of the shaft at a position facing the coil, including, Rotary table device.

2. The first bearing mechanism is a ball spline mechanism, A ball spline nut is fixed to the aforementioned housing. A spline groove is formed on the outer circumferential surface of the first end of the shaft. The rotary table device according to claim 1.

3. The second bearing mechanism is a cross roller bearing, The outer ring of the cross roller bearing is fixed to the housing, The outer ring of the bearing and the inner ring of the bearing, which is fixed to the ball screw nut and the table, are connected via rollers. The rotary table device according to claim 1 or claim 2.

4. The aforementioned field includes a magnet array in which a plurality of annular permanent magnets are inserted into the shaft and arranged in the axial direction, The shaft has a flange portion at one end of the part where the field is arranged that contacts the field. The field is held and fixed by the flange portion and the nut inserted into the shaft. The rotary table device according to any one of claims 1 to 3.

5. Furthermore, it is equipped with an encoder, The encoder described above is A scale attached to the outer surface of the rotating body, An encoder head mounted on the aforementioned housing and facing the scale, including, A rotary table device according to any one of claims 1 to 4.

Images