Actuator and robot

Abstract

This actuator includes: a fixing member; a movable member that rotates relative to the fixing member; a hollow hole that passes through the actuator; a pipe member that is inserted into the hollow hole; at least one wire body that passes through the inside of the pipe member; and a sealing part that seals at least one end of the pipe member.

Description

Actuators and Robots

[0001] The present disclosure relates to an actuator and a robot.

[0002] Industrial robots, particularly articulated robots, include at least one joint where two links are connected to each other. The joint is equipped with an actuator that drives the link, and requires at least a power line and a signal line to drive the actuator. In addition, signal lines, air tubes, coaxial cables, and high-speed communication signal lines are also required to drive the end effector at the tip of the industrial robot. In this specification, these power lines, air tubes, coaxial cables, and various signal lines are collectively referred to as "fibers."

[0003] In JP 2017-159397 A, the actuator has a fixed member and a movable member that rotate relative to each other, and at least one filament is inserted into a pipe member disposed in a through-hole of the actuator, and the filament is fixed to the fixed member and the movable member by a first fixing portion and a second fixing portion, respectively.

[0004] Japanese Patent Application Laid-Open No. 2017-159397

[0005] When the robot is operating, the wire may come into contact with the inner wall of the pipe member, generating dust. If the fixed member includes an encoder, dust may adhere to the rotary disk of the encoder, reducing the encoder's detection accuracy or causing detection errors. If the rotary disk and other components are tightly enclosed with a casing to prevent dust from adhering, this increases manufacturing costs. Furthermore, if an amplifier board is located behind the encoder, the wire leading from the relay connector on the amplifier board must also be tightly enclosed, requiring a corresponding sealing structure and cost.

[0006] Furthermore, even if the fixed member does not include an encoder, dust generated in the same manner may enter various parts of the robot and reduce the performance of the robot.

[0007] Therefore, there is a demand for an inexpensive and highly reliable actuator and robot that does not allow dust generated inside the pipe-shaped member to leak to the outside.

[0008] According to a first aspect of the present disclosure, there is provided an actuator comprising: a fixed member; a movable member that rotates relative to the fixed member; a hollow hole that passes through the actuator; a pipe member that is inserted into the hollow hole; at least one filament that passes through the inside of the pipe member; and a sealing portion that seals at least one end of the pipe member.

[0009] The objects, features, and advantages of the present disclosure will become more apparent from the following description of the embodiments taken in conjunction with the accompanying drawings.

[0010] 1 is a perspective view of a robot including an actuator according to the present disclosure; FIG. 2 is an axial cross-sectional view of an actuator according to a first embodiment; FIG. 3 is a view showing a variation of FIG. 2A; FIG. 4 is a partially enlarged view showing another variation of FIG. 2A; FIG. 5 is a partially enlarged view showing yet another variation of FIG. 2A; FIG. 6 is an axial cross-sectional view of an actuator according to a second embodiment; FIG. 7 is an axial cross-sectional view of an actuator according to a third embodiment; FIG. 8 is an axial cross-sectional view of an actuator according to a fourth embodiment; FIG. 9 is an axial cross-sectional view of an actuator according to a fifth embodiment; FIG. 10 is an axial cross-sectional view of an actuator in the prior art; FIG. 11 is a partially cutaway perspective view of another example of the actuator shown in FIG. 7A; FIG. 12 is a perspective view of a sealing portion in another embodiment; FIG. 13 is a partially exploded perspective view of an actuator shown in FIG. 14A;

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Corresponding components are designated by common reference numerals throughout the drawings. FIG. 1 is a perspective view of a robot equipped with actuators based on the present disclosure. Each of the multiple joints of a robot 1, for example, a vertical articulated robot, is equipped with actuators 5a to 5f. The actuators 5a to 5f may be incorporated into a machine other than the robot 1, for example, a machine tool. While the following describes actuator 5-1, etc., it is assumed that the actuators 5a to 5f shown in FIG. 1 also have a similar configuration.

[0012] 2A is an axial cross-sectional view of an actuator according to the first embodiment. The actuator 5-1 is mainly composed of a fixed member 21 and a movable member 22 that rotates relative to the fixed member 21. Specifically, the fixed member 21 includes a motor 10, such as a servo motor, that is composed of a stator and a rotor, a reducer 20 connected to a motor shaft 13 of the motor 10, and an encoder E that detects the rotation of the motor shaft 13. The fixed member 21 may further include an amplifier board 52 for driving the motor 10. The movable member 22 includes an output shaft 23 of the reducer 20, a force sensor S coupled to the output shaft 23, and a pipe member 23a, which will be described later.

[0013] In the present application, the reducer 20 is defined as being disposed in front of the motor 10, and the motor 10 is defined as being disposed behind the reducer 20. In principle, the "radial direction" in the present application means the radial direction of the actuator 5-1, etc., and the "axial direction" means the axial direction of the actuator 5-1, etc.

[0014] The motor shaft 13 of the motor 10 is connected to a reducer 20. The tip of the output shaft 23 of the reducer 20 is connected to a link 2 (not shown) via a force sensor S. Therefore, the actuator 5-1 controls the positioning of the link 2 (not shown) by rotating it relative to the actuator 5-1 within a predetermined operating range. The reduction ratio of the reducer 20 is, for example, 1:50.

[0015] The motor shaft 13 is, for example, a hollow shaft. A pipe member 23a is connected to the output shaft 23 of the reducer 20 as an extension, and this pipe member 23a extends through the hollow motor shaft 13 toward the motor 10. The output shaft 23 of the reducer 20 and the pipe member 23a may be formed integrally. In other words, the pipe member 23a may be a part of the output shaft 23. Therefore, the pipe member 23a rotates integrally with the output shaft 23 of the movable member.

[0016] The encoder E is provided on the rear end side of the motor 10. The encoder E includes a rotary disk 51 for detecting the rotation speed of the motor shaft 13 and the rotation speed of the pipe member 23a by a known method. Furthermore, a hollow amplifier board 52 for driving the motor 10 is provided at the rear end of the encoder E. The rotary disk 51 is attached to the outer peripheral surface of the motor shaft 13 and rotates integrally with the motor shaft 13. In FIG. 2A, the rotary disk 51 is generally surrounded by the casing 50, but it does not have to be completely sealed.

[0017] The force sensor S is composed of a torque sensor or the like that detects the force acting around the axis of the actuator 5-1. As is well known, the force sensor S has a strain detection unit that connects two concentrically arranged sensor components. When a force acts around the axis of the actuator 5-1, the rigid strain detection unit elastically deforms in a slight elongation direction, and the force acting around the axis can be detected through the amount of deformation of the strain detection unit. The force sensor S may be a strain gauge type, a capacitance type, a magnetic type, an optical encoder type, or the like.

[0018] As shown in the figure, the force sensor S, reducer 20, and motor 10, which are coaxially connected to one another, share a common hollow hole 29. In FIG. 2A , a through hole 52a is also formed in the center of the amplifier board 52, and the through hole 52a also forms a hollow hole 29. The hollow holes 29 of the force sensor S, reducer 20, and motor 10 preferably have a common inner diameter. The inner diameter of the through hole 52a of the amplifier board 52 may be larger than the inner diameter of the hollow hole 29. This allows for easy placement of the pipe member 23a, for example, a resin pipe member. In other words, the actuator 5-1 has a hollow hole 29 formed in the axial direction that penetrates the entire actuator 5-1. The hollow hole 29 shown in FIG. 2A is formed by the inner circumferential surface of the amplifier board 52, the inner circumferential surface of the motor 10, the inner circumferential surface of the reducer 20, the inner circumferential surface of the force sensor S, and the inner circumferential surface of the amplifier board 52. Therefore, the hollow hole 29 includes the pipe member 23a and the motor shaft 13, which is located outside the pipe member 23a. As shown in the figure, the pipe member 23a extends beyond the rear end of the motor shaft 13 to partway along the amplifier board 52. The pipe member 23a is preferably shorter than the overall length of the actuator 5. At least one wire L, such as a signal line, air tube, coaxial cable, or high-speed communication signal line, passes through the inside of the pipe member 23a. Note that although multiple wires L normally pass parallel to each other, for the sake of simplicity, only one wire L is shown in the drawing. The numerous small circles shown around the wire L represent dust that is generated when the wire L comes into contact with the pipe member 23a.

[0019] 2A , a portion of the filament L is fixed to the fixed member 21 side by a first fixing portion 31. In addition, another portion of the filament L is fixed to the movable member 22 side by a second fixing portion 32.

[0020] 2A , the first fixed part 31 is fixed to the rear end surface of the amplifier board 52, and the second fixed part 32 is fixed to a portion of the front end surface close to the inner periphery of the sensor S that does not affect the detection of the sensor S. However, when the actuator 5-1 is an actuator 5d mounted on the robot 1, the first fixed part 31 may be fixed to the arm member 62 on the fixed (rotating) side of the arm, and the second fixed part 32 may be fixed to another arm member 61 on the rotating side of the arm. In the following, it is assumed that the first fixed part 31 is fixed to the rear end surface of the fixed member 21, the fixed member 21 is connected to the arm member 62, the second fixed part 32 is fixed to the front end surface of the movable member 22, and the movable member 22 is connected to the arm member 61. Note that with regard to the mounting orientation of the actuator, the force sensor S may be connected to the arm member 62 on the fixed (non-rotating) side of the arm, and the fixed member 21 may be connected to the arm member 61 on the rotating side of the arm.

[0021] 2A , the first fixing portion 31 includes a generally L-shaped member having two long portions that are perpendicular to each other. One of the long portions is fixed to an end of the fixing member 21, for example, the rear end of the amplifier board 52, and the other long portion extends from one end of the hollow hole 29 toward the inside of the hollow hole 29. The first fixing portion 31 includes at least one gripping portion 43 a. A portion of the filament L is gripped by the other long portion with the at least one gripping portion 43 a.

[0022] Similarly, the second fixing part 32 also includes a generally L-shaped member having two long parts that are perpendicular to each other. One long part is fixed to an end of the movable member 22, for example, the front end of S, and the other long part extends from the other end of the hollow hole 29 toward the inside of the hollow hole 29. The second fixing part 32 has at least one gripping part 43b. The other part of the filament L is gripped by the other long part with the at least one gripping part 43b.

[0023] The other long portion of the first fixing portion 31 and the second fixing portion 32 may be located outside the hollow hole 29. Furthermore, the gripping portions 43a and 43b may be, for example, binding bands.

[0024] 2A, the motor shaft 13 extends from inside the motor 10 and terminates just before the amplifier board 52. The pipe member 23a extends beyond the end of the motor shaft 13 on the reducer 20 side and terminates inside the amplifier board 52. The end of the motor shaft 13 on the reducer 20 side is engaged with the input portion of the reducer 20.

[0025] 2A , a gripping portion 63 perpendicular to one long portion of the first fixed portion 31 extends toward the outside of the fixed member 21. The gripping portion 63 may be, for example, a plate having a surface along which at least one filament L passes and along which the filament L is aligned. Furthermore, an extension portion 64 perpendicular to one long portion of the first fixed portion 31 extends toward the inside of the fixed member 21. A rotary seal mechanism 59 is provided at the tip of the extension portion 64 and engages with the outer peripheral surface of the pipe member 23 a. The extension portion 64 is preferably made of a rigid metal and has a structure that keeps the rotary seal mechanism 59 immovable at a predetermined position relative to the first fixed portion 31.

[0026] Furthermore, the sealing portion 70, which is a bag-shaped member, covers and seals the rotary seal mechanism 59, the extension portion 64, and a portion of the first fixed portion. The rotary seal mechanism 59 can be a rotary seal member such as a sealed bearing or an oil seal. The sealing portion 70 is preferably an elastic body. A typical sealing portion 70 is formed of, for example, a rubber material. The gripping portion 63 is, for example, a cable tie. The end of the sealing portion 70 is tied and sealed with the cable tie to prevent dust inside the sealing portion 70 from diffusing to the outside. Even if a gap occurs between the sealing portion 70 and the gripping portion 63, the rubber material portion of the sealing portion 70 elastically deforms and wraps around the gap, creating a seal without any gaps.

[0027] The sealing portion 70 sealably surrounds the region between the gripping portion 63 and the rotary seal mechanism 59. One open end of the sealing portion 70 is attached to the gripping portion 63 so as to circumferentially surround at least one filament L passing through the gripping portion 63. The other open end of the sealing portion 70 is attached to the outer surface of the extension portion 64 and the outer peripheral surface of the rotary seal mechanism 59. Therefore, the cylindrical sealing portion 70 is curved to follow the filament L.

[0028] With this configuration, when the actuator 5-1 is driven, the pipe member 23a can rotate relative to the sealing portion 70. Therefore, even if at least one filament L comes into contact with the inner wall of the pipe member 23a and generates dust when the actuator 5-1 is driven, the dust will remain inside the hollow hole 29 and the sealing portion 70 and will not leak out from one end of the hollow hole 29. Furthermore, for the same reason, the dust will not leak out to the outer circumferential surface of the pipe member 23a.

[0029] 2A, there is no need to completely cover both the rotating disk 51 and the amplifier board 52 with the casing 50, and dust will not adhere to the rotating disk 51 and / or the amplifier board 52. This also applies when a simple raised structure using spacers is used instead of the casing 50 that surrounds the rotating disk 51.

[0030] Furthermore, in the present disclosure, the sealing portion 70 does not seal the entire actuator 5-1 or the entire arm 61 that houses the actuator 5-1, but rather seals only one end of the hollow hole 29 and its surrounding area. In other words, the sealing portion 70 seals only the minimum number of locations. As a result, in the present disclosure, the actuator 5-1 can be manufactured inexpensively. Furthermore, because the sealing portion 70 is not exposed to the outside of the robot 1, the sealing portion 70 does not affect the operation of the robot 1 or peripheral devices, and does not detract from the aesthetic appearance of the robot 1 itself.

[0031] Here, the pipe member 23a rotates integrally with the output portion 23 of the reducer 20. Therefore, the pipe member 23a rotates at an extremely slower speed than the motor shaft 13 according to the reduction ratio of the reducer 20. Therefore, the risk of dust generation in the present disclosure is smaller to begin with than in the absence of the reducer 20. Furthermore, compared to the case where the rotary seal mechanism 59 is attached to the motor shaft 13, the risk of dust generation due to wear of the seal portion of the rotary seal mechanism caused by high-speed rotation can be reduced.

[0032] FIG. 6 is an axial cross-sectional view of an actuator according to the prior art. In FIG. 6, a sealing portion 70 is not provided. Therefore, dust generated inside the pipe member 23a can leak from one end of the pipe member 23a through the through-hole 52a of the amplifier board 52 to the outside. Furthermore, some of the dust may move toward the rotating disk 51 through the through-hole 52a of the amplifier board 52. This can result in dust adhering to the rotating disk 51 and / or the amplifier board 52, reducing the detection accuracy of the encoder E and / or interfering with the operation of the amplifier board 52.

[0033] In contrast, in the present disclosure, the sealing portion 70 extends from the grip portion 63, passes through the through-hole 52a of the amplifier board 52, and terminates at one end of the pipe member 23a. Therefore, dust generated inside the pipe member 23a does not move through the through-hole 52a toward the rotating disk 51. Therefore, in the present disclosure, the risk of dust adhering to the rotating disk 51 and / or the amplifier board 52 can be eliminated.

[0034] Furthermore, the arm of the robot 1 is configured by engaging a first arm cover and a second arm cover with each other. The back surfaces of these arm covers are provided with protrusions 71 and 72 that protrude toward the inside of the arm.

[0035] 2A, these protrusions 71, 72 are engaged with and fixed to the rear end of the reducer 20. Therefore, even if dust leaks from the other end of the hollow hole 29 located on the force sensor S side, the dust will not reach the rotating disk 51 and / or amplifier board 52. In other words, when the actuator 5 is housed in the arm of the robot 1 as shown in FIG. 2A, providing the sealing part 70 at only one end of the hollow hole 29 will prevent dust from reaching the rotating disk 51 and / or amplifier board 52.

[0036] Figure 2B shows a variation of Figure 2A. In the actuator 5-2 shown in Figure 2B, an additional sealing portion 70' is provided to seal the other end of the hollow hole 29. The additional sealing portion 70' is preferably a bag-shaped member made of the same material as described above.

[0037] An extension 35 extending in a direction away from the force sensor S is attached to the second fixing portion 32, and a gripping portion 36 similar to the gripping portion 63 is provided at the tip of the extension 35. One end of the additional sealing portion 70' is attached to the end of the force sensor S on the inner ring side, and the other end is attached to the gripping portion 36. The additional sealing portion 70' is preferably attached to the force sensor S and the gripping portion 36 with an adhesive or a fastener. The gripping portion 36 may be, for example, a cable tie. Because the filament L is a non-moving portion at this location, the extension 35 may be omitted.

[0038] 2B, even if dust leaks from the other end of the hollow hole 29, the dust remains inside the additional sealing portion 70' and does not leak outside the additional sealing portion 70'. Therefore, dust leaking from the other end of the hollow hole 29 does not reach the rotating disk 51 and / or the amplifier board 52. This prevents detection errors and deterioration of detection accuracy of the encoder E, and also prevents interference with the operation of the amplifier board 52. Note that the movable member 22 does not have to include the force sensor S, in which case the additional sealing portion 70' is attached to the distal end of the output section 23.

[0039] FIG. 2C is a partially enlarged view showing another variation of FIG. 2A . In FIG. 2C , a metallic tubular sleeve 58 is fitted onto the outer peripheral surface of the rear end of the pipe member 23a. The outer peripheral surfaces of the sleeve 58 and the pipe member 23a are preferably flush with each other. Furthermore, an O-ring 57 is provided on the inner periphery of the sleeve 58 in the radial direction of the pipe member 23a. As shown in FIG. 2C , the sleeve 58 is positioned to correspond to a rotary seal mechanism 59. This configuration reduces friction between the rotary seal mechanism 59 and the sleeve 58 and prevents wear of the pipe member 23a, which can cause dust to be generated on the outer peripheral surface of the pipe member 23a. The O-ring 57 can be omitted by tightly fitting the sleeve 58 and utilizing the elastic deformation of the resin of the pipe member 23a for sealing.

[0040] In other words, the provision of sleeve 58 increases the hardness of the sealing surface for rotary seal mechanism 59. Therefore, even when rotary seal mechanism 59 is in close contact with sleeve 58, it is possible to significantly reduce dust generation from the outer peripheral surface of pipe member 23 a due to wear of pipe member 23 a.

[0041] Furthermore, Figure 2D is a partially enlarged view showing another modification of Figure 2A. In Figure 2D, a sealed bearing 59 is arranged as the rotary seal mechanism 59. It will be understood that a similar effect can be obtained with this configuration. In this case, there is also the advantage that the end of the long, thin-walled pipe member 23a can be supported.

[0042] FIG. 3 is an axial cross-sectional view of an actuator based on a second embodiment. For the sake of simplicity, protrusions 71 and 72 are omitted from the drawings following FIG. 3. In the actuator 5-3 shown in FIG. 3, the rotary seal mechanism 59 is not disposed between the sealing portion 70 and the pipe member 23a. Therefore, the sealing portion 70 is directly attached to the inner circumferential surface of the pipe member 23a near one end of the pipe member 23a. The sealing portion 70 and the pipe member 23a are attached to each other with adhesive, fasteners, or the like. Alternatively, the sealing portion 70 and the pipe member 23a may be formed from resin and integrally formed using a known heterogeneous joining molding technique.

[0043] The sealing portion 70 may be attached directly to the outer peripheral surface of the pipe member 23a near one end of the pipe member 23a, or may be attached to the inner peripheral surface of the pipe member 23a via a rotary seal mechanism 59. In either case, substantially the same effects as those described above can be obtained.

[0044] 3, the pipe member 23a has a flange 23b at a position corresponding to the output shaft 23 of the movable member 22. A support portion 65, such as a bearing, is provided between the output shaft 23 and the flange 23b of the pipe member 23a. The support portion 65 serves to support the pipe member 23a relative to the output shaft 23 so that the pipe member 23a can rotate freely.

[0045] Therefore, in the second embodiment, the pipe member 23a does not rotate, and only the output shaft 23 rotates. In other words, the sealing portion 70 and the pipe member 23a do not rotate relative to each other. As a result, in the third embodiment, the rotary seal mechanism 59 can be omitted. Furthermore, it is possible to prevent the pipe member 23a from wearing between the pipe member 23a and the rotary seal mechanism 59, which would otherwise cause dust to be generated on the outer circumferential surface of the pipe member 23a.

[0046] Furthermore, Figure 4 is an axial cross-sectional view of an actuator based on a third embodiment. In the actuator 5-4 shown in Figure 4, the surface of the sealing portion 70 is not smooth, but has a bellows-like structure. With this configuration, the sealing portion 70 in the third embodiment has the flexibility to follow the rotation of the pipe member 23a.

[0047] Furthermore, Figure 5A is an axial cross-sectional view of an actuator based on a third embodiment. The actuator 5-5 shown in Figure 5A does not include a sensor S. That is, the movable member 22 of the actuator 5-5 includes only the output portion 23. The second fixed portion 32 is fixed to the end face of the pipe member 23a, i.e., the end of the hollow hole 29. The fixed member 21 includes the reducer 20, the motor 10, and the encoder E. In this way, the case where the movable member 22 of the actuator does not include the sensor S is also included in the scope of the present disclosure.

[0048] Furthermore, Figure 5B is an axial cross-sectional view of an actuator based on the fifth embodiment. The actuator 5-6 shown in Figure 5B does not include an encoder E or an amplifier board 52. In other words, the fixed member 21 of the actuator 5-6 includes only the motor 10 and the reducer 20. This case is also within the scope of the present disclosure. In this case, dust generated inside the pipe member 23a can be prevented from adhering to other parts of the robot 1 other than the actuator 5-6, such as other adjacent actuators (not shown), and interfering with the operation of those other parts.

[0049] Fig. 7A is a partial perspective view of another embodiment of the actuator shown in Fig. 2D, and Fig. 7B is a partially cutaway perspective view of Fig. 7A. These drawings mainly show the pipe member 23a, the first fixing portion 31, the umbilical member L, and related parts, and omit other parts. Furthermore, Fig. 7B omits the illustration of the sealing portion 70 and the like.

[0050] 7A and 7B, a connecting flange provided on pipe member 23a for connecting to output section 23 is provided at the end of pipe member 23a on the movable member 22 side. In contrast to this, in Figure 2A etc., a similar connecting flange is provided spaced apart from the end of pipe member 23a on the movable member 22 side.

[0051] 7A and 7B , near the distal end of the sealing portion 70, the first fixing portion 31, the filament L, and the sealing portion 70 are preferably tightly fixed together by a gripping portion 63. Similarly, near the proximal end of the sealing portion 70, the first fixing portion 31, the pipe member 23a, and the sealing portion 70 are preferably tightly fixed together by another gripping portion 63′.

[0052] A portion of the first fixing portion 31 extending perpendicular to the pipe member 23a has a flat surface 31a which faces an end face of the fixing member 21, for example, an end face of the amplifier board 52, and therefore the first fixing portion 31 and the fixing member 21 can be fixed to each other immovably.

[0053] Fig. 8A is a perspective view of a sealing portion in another embodiment, Fig. 8B is a partial perspective view of an actuator including the sealing portion shown in Fig. 8A, and Fig. 8C is a partial exploded perspective view of the actuator shown in Fig. 8B.

[0054] 8A , sealing portion 70 in another embodiment is a thin cover entirely made of an elastic material, such as rubber. Sealing portion 70 mainly includes a circular or polygonal cylindrical body 91 with one closed end, a flange 92 provided at the other end of cylindrical body 91, and an extension portion 93 provided on the outer circumferential surface of cylindrical body 91.

[0055] The flange 92 preferably has a plurality of through holes. The extension 93 extends perpendicularly or at a predetermined angle to the outer peripheral surface of the cylindrical body 91. A through hole of a size suitable for the passage of the filament L is formed inside the extension 93. This through hole is connected to the interior of the cylindrical body 91. Before attaching the sealing part 70 to the fixing member 21, the filament L extending through the pipe member 23a is inserted into the extension 93 of the sealing part 70 in advance. At this time, it is preferable to expand the diameter of the through hole of the extension 93 using elastic deformation of the rubber, and then pass a relay connector or the like, which is expected to have a diameter larger than the bundle of filaments L, through the through hole of the extension 93.

[0056] As shown in FIG. 8B , the sealing portion 70 with the filament L inserted into the extension portion 93 is fixed to the end face of the fixing member 21. Strictly speaking, in FIG. 8B , the sealing portion 70 is fixed to a cylindrical closing member 31b that closes the end face of the amplifier board 52. The end face of the closing member 31b has the same dimensions as the end face of the amplifier board 52. Preferably, multiple screws or bolts are inserted into multiple through holes in the flange 92 of the sealing portion 70. Alternatively, the flange 92 of the sealing portion 70 may be directly fixed to the end face of the closing member 31b using an adhesive.

[0057] The extension 93 and the filament L are then fixed by the gripping portion 63. The extension 93 is elastically deformable, so that the extension 93 and the filament L can be tightly fixed together. Furthermore, since the flange 92 is elastically deformed when fixed, the flange 92 and the closure member 31b can be fixed in a tightly contacting state. This prevents dust generated inside the pipe member 23a from leaking out of the actuator and to the outer circumferential surface of the pipe member 23a.

[0058] 8C , a portion of the first fixing portion 31 extending perpendicular to the pipe member 23a terminates at the inner circumferential surface of the cylindrical body 91. However, although not shown in the drawing, a portion of the first fixing portion 31 may extend at least partially into the extension portion 93.

[0059] At least one of the embodiments described above has the effect of preventing dust generated inside the pipe member 23a from leaking out to the outside of the actuator 5-1 and the like and to the outer peripheral surface side of the pipe member 23a.

[0060] Although the embodiments of the present disclosure have been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible to these embodiments without departing from the gist of the invention or the concept and spirit of the present invention derived from the content of the claims and their equivalents. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical formulas are used in the description of the above-described embodiments. Furthermore, appropriate combinations of several of the above-described embodiments are within the scope of the present disclosure.

[0061] The following supplementary notes are further disclosed regarding the above embodiments and variations. (Supplementary Note 1) An actuator comprising: a fixed member; a movable member rotatable relative to the fixed member; a hollow hole penetrating the actuator; a pipe member inserted into the hollow hole; at least one filament passing through the pipe member; and a sealing portion sealing at least one end of the pipe member. (Supplementary Note 2) The actuator according to Supplementary Note 1, further comprising: a first fixing portion fixing a portion of the filament; and a second fixing portion fixing another portion of the filament. (Supplementary Note 3) The actuator according to Supplementary Note 1 or 2, wherein the movable member includes an output shaft of a reducer, and the pipe member rotates integrally with the output shaft. (Supplementary Note 4) The actuator according to any one of Supplementary Notes 1 to 3, further comprising a rotary seal mechanism disposed between at least one end of the pipe member and the sealing portion. (Appendix 5) The actuator according to Appendix 4, wherein a metal sleeve is disposed on a peripheral surface of the pipe member corresponding to the rotary seal mechanism. (Appendix 6) The actuator according to any one of Appendixes 1 to 5, wherein the movable member has an output shaft and includes a support part that rotatably supports the pipe member relative to the output shaft. (Appendix 7) The actuator according to any one of Appendixes 1 to 6, wherein the sealing part is a bag-shaped member that surrounds at least one end of the pipe member. (Appendix 8) The actuator according to Appendix 7, wherein the bag-shaped member is formed from an elastic body. (Appendix 9) The actuator according to Appendix 8, wherein the bag-shaped member has elasticity that allows it to stretch to follow the rotation of the pipe member. (Appendix 10) A robot including the actuator according to any one of Appendixes 1 to 9.

[0062] REFERENCE SIGNS LIST 1 Robot 5-1 to 5-5 Actuator 10 Motor 13 Motor shaft 20 Reducer 21 Fixed member 22 Movable member 23 Output section 23a Pipe member 29 Hollow hole 31 First fixed section 32 Second fixed section 43a Grip section 43b Grip section 50 Casing 51 Rotating disk 52 Amplifier board 63 Grip section 64 Extension section 70, 70' Sealing section E Encoder L Wire body S Force sensor

Claims

1. An actuator comprising: a fixed member; a movable member that rotates relatively to the fixed member; a hollow hole that passes through the actuator; a pipe member that is inserted into the hollow hole; at least one filament that passes through the inside of the pipe member; and a sealing portion that seals at least one end of the pipe member.

2. The actuator according to claim 1, further comprising: a first fixing portion for fixing a portion of the filament; and a second fixing portion for fixing another portion of the filament.

3. The actuator according to claim 1, wherein the movable member includes an output shaft of a reducer, and the pipe member rotates integrally with the output shaft.

4. The actuator according to claim 3, further comprising a rotary seal mechanism disposed between at least one end of said pipe member and said sealing portion.

5. The actuator according to claim 4, wherein a metal sleeve is disposed on the peripheral surface of the pipe member corresponding to the rotary seal mechanism.

6. The actuator according to claim 1, wherein the movable member has an output shaft and includes a support portion that rotatably supports the pipe member relative to the output shaft.

7. The actuator according to claim 1, wherein the sealing portion is a bag-shaped member surrounding at least one end of the pipe member.

8. The actuator according to claim 7, wherein the bag-shaped member is made of an elastic material.

9. The actuator according to claim 8, wherein said bag-shaped member has elasticity to follow the rotation of said pipe member.

10. A robot comprising an actuator according to any one of claims 1 to 9.

Images