Rotary joint

Abstract

To provide a rotary joint capable of expanding a rotation range of a rotary member.SOLUTION: A rotary joint 30 includes: a fixing member 31 having a peripheral wall 34; a rotary member 32 rotating along the peripheral wall 34; and a stopper mechanism 50 for regulating the rotation range of the rotary member 32. The stopper mechanism 50 has an interlocking member 51, a stopper 52, two engagement parts 63 and a lever 54. The interlocking member 51 is connected to the rotary member 32 in an axial direction X and is rotated interlocked with the rotary member 32. The stopper 52 is disposed in the interlocking member 51. The two engagement parts 63 are arranged so as not to be relatively movable to the peripheral wall 34. The lever 54 is swingably supported by a support shaft 56 incapable of being relatively movable to the peripheral wall 34. The lever 54 swings by being pushed by the stopper 52, and the range of the swing is regulated by a gap between the two engagement parts 63.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a rotary joint. [Background technology]

[0002] In a device having two members that rotate relative to one another, one of the members is connected to the other member via a rotary joint. The rotary joint has a fixed member with a peripheral wall and a rotary member that is rotatably held along the peripheral wall relative to the fixed member. The rotary member is connected to one of the members, and the fixed member is connected to the other member. The rotary joint connects the one member and the other member so that they can rotate relative to one another. For example, as disclosed in Patent Document 1, in a rotary joint, the rotary member is rotatable along the peripheral wall inside the fixed member.

[0003] Generally, a rotary joint has a stopper that protrudes toward the rotating member from the inside of the peripheral wall. The rotary joint defines a rotation range for the rotating member by engaging a portion of the outer circumferential surface of the rotating member with the stopper by protruding the protruding portion. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-062943 Summary of the Invention [Problem to be solved by the invention]

[0005] When the rotation range of the rotating member is defined by a portion of the rotating member and a stopper, the rotation range is limited by the width of the portion of the rotating member and the stopper in the rotation direction. In a rotary joint, it is desirable to expand the rotation range of the rotating member. [Means for solving the problem]

[0006] a stopper mechanism that defines a rotation range of the rotating member, the stopper mechanism comprising: an interlocking member that is aligned with the rotating member in the axial direction of the rotation axis and that rotates in conjunction with the rotating member outside the fixed member; a stopper provided on the circumferential surface of the interlocking member; two engaging portions that are arranged immovably relative to the circumferential wall and are aligned in the rotation direction of the rotating member; and a lever that is swingably supported by a support shaft that is immovable relative to the circumferential wall and is configured to be able to abut against the two engaging portions; the lever swings when pressed by the stopper, and the range of swing is defined by the distance between the two engaging portions.

[0007] In the above rotary joint, the stopper mechanism may have a stopper housing having a retaining inner surface facing the interlocking member and fixed to the outer peripheral surface of the peripheral wall, the two engagement portions being provided on the retaining inner surface, and the lever being supported by the stopper housing so as to be able to swing along the retaining inner surface.

[0008] In the above rotary joint, the engagement portion may have an inclined surface that comes into surface contact with the lever. The above rotary joint may have a brake mechanism that restricts rotation of the rotating member relative to the fixed member, and the brake mechanism may include a brake disc that is interposed between the rotating member and the interlocking member and rotates in conjunction with the rotating member outside the fixed member, and a brake device that is provided on the peripheral wall and restricts rotation of the rotating member by clamping a portion of the brake disc near the edge, and the stopper housing may have a first housing portion that faces the portion near the edge and is fixed to the peripheral wall, and a second housing portion that has the retaining inner surface, and the second housing portion may hold the lever radially outward of the brake disc.

[0009] In the above rotary joint, the peripheral wall may have a plurality of pairs of mounting holes that open on the outer circumferential surface and are aligned circumferentially of the peripheral wall, the brake device may have a pair of brake device holes that are at the same pitch and have the same diameter as the pair of mounting holes, and may be fixed to the peripheral wall by mounting members that are inserted through the brake device holes and the mounting holes, and the first housing portion may have a pair of housing holes that are the same pitch and have the same diameter as the pair of mounting holes, and may be fixed to the peripheral wall by the housing holes and the mounting members that are inserted through the mounting holes. [Effects of the Invention]

[0010] According to the present invention, the rotation range of the rotating member can be expanded. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing an arm-type assistive device. [Figure 2] FIG. 2 is a schematic diagram showing the operation of the arm-type assist device. [Figure 3] FIG. 3 is a perspective view showing a rotary joint. [Figure 4] FIG. 4 is a cross-sectional view showing a rotary joint. [Figure 5] FIG. 5 is an exploded perspective view showing the rotary joint. [Figure 6] FIG. 6 is a side view showing a rotary joint. [Figure 7] FIG. 7 is a partial cross-sectional view showing the operation of the lever and the stopper. [Figure 8] FIG. 8 is a schematic diagram showing the operation of a rotary joint. DETAILED DESCRIPTION OF THE INVENTION

[0012] An embodiment of the rotary joint will now be described with reference to Figures 1 to 8. In this embodiment, the rotary joint is mounted on an arm-type assistive device. <Overall image of the arm-type assistive device> 1 and 2, the arm-type assist device 10 has a base B, an arm 11, a load holding unit 12, a control device 13, and an air supply source 14. The arm-type assist device 10 also has a rotary joint 30. The arm-type assist device 10 assists a worker (not shown) in transporting an object W.

[0013] The base B is columnar. However, the base B does not have to be columnar. For example, the base B may be a low platform. The shape of the base B is arbitrary. The arm 11 has a first rotating portion 21 , a first supporting portion 22 , a first arm member 23 , a second supporting portion 24 , a second rotating portion 25 , a connecting arm 26 , and a second arm member 27 .

[0014] The first rotating part 21 is provided on the upper end surface of the base B. The first rotating part 21 is rotatable relative to the base B about a first vertical axis L1 that extends in the vertical direction. The first support part 22 is provided on the upper surface of the first rotating part 21. The first support part 22 is supported by the base B via the first rotating part 21. The first support part 22 has a columnar shape extending in the vertical direction. The first support part 22 is rotatable together with the first rotating part 21 around a first vertical axis L1 as the central axis. The first support part 22 is supported by the first rotating part 21 so as to be rotatable relative to the base B.

[0015] The first arm member 23 has a first end connected to the first support portion 22. The first arm member 23 is capable of swinging relative to the first support portion 22 in the vertical direction. The second support part 24 is connected to a second end part of the first arm member 23. The second support part 24 is columnar and extends in the vertical direction. The first arm member 23 is capable of swinging in the vertical direction relative to the second support part 24.

[0016] The first arm member 23 has a built-in actuator (not shown). The actuator is an air cylinder. The actuator is connected to the air supply source 14 via the control device 13. The actuator is driven by air supplied from the air supply source 14. As the actuator is driven by the control device 13, the first arm member 23 moves vertically relative to the first support portion 22.

[0017] The second rotating portion 25 is provided on the upper surface of the second support portion 24. The second rotating portion 25 is rotatable relative to the second support portion 24 about a second vertical axis L2 that extends in the vertical direction.

[0018] The connecting arm 26 extends horizontally. A first end of the connecting arm 26 is connected to the second rotating portion 25. The connecting arm 26 is supported by the second support portion 24 via the second rotating portion 25. In other words, the connecting arm 26 is supported by the second rotating portion 25 so as to be rotatable relative to the second support portion 24.

[0019] The second arm member 27 extends in the vertical direction. A first end of the second arm member 27 is connected to a second end of the connecting arm . The load holding portion 12 is provided at the second end of the second arm member 27 via a rotary joint 30 and a holding plate 55. The second arm member 27, rotary joint 30, holding plate 55, and load holding portion 12 are aligned vertically. The load holding portion 12 is configured to be able to hold an object W. The load holding portion 12 has an adsorption portion 12a extending downward. The load holding portion 12 holds the object W by adsorbing it to the adsorption portion 12a. However, the configuration of the load holding portion 12 is not limited to this. For example, the load holding portion 12 may have a hook, and hold the object W by hanging it from the hook.

[0020] The load holding unit 12 has a built-in load detection device (not shown). The load detection device detects the load of the object W held by the load holding unit 12 and transmits a signal related to the load to the control unit 13.

[0021] The second arm member 27 has a built-in actuator (not shown). The actuator is connected to the air supply source 14 via the control device 13. The actuator is driven by air supplied from the air supply source 14. The second arm member 27 raises and lowers the load holding portion 12 by driving the actuator.

[0022] The arm-type assist device 10 houses a plurality of pipes and a plurality of cables (not shown) inside the arm 11. The plurality of pipes connect, for example, each actuator to an air supply source 14. The plurality of cables connect, for example, a load detection device built into the load holding portion 12 to the control device 13.

[0023] <Rotational joint> As shown in FIGS. 1 and 2, the rotary joint 30 is provided at the second end of the second arm member 27. The rotary joint 30 connects the second arm member 27 and the load holding unit 12 via a holding plate 55. The rotary joint 30 connects the load holding unit 12 to the second arm member 27 so that the load holding unit 12 can rotate relative to the second arm member 27 around a third vertical axis L3 serving as a rotation axis. Hereinafter, the direction in which the third vertical axis L3 extends will be referred to as the axial direction X. In this embodiment, the axial direction X is the vertical direction.

[0024] As shown in Fig. 3, the rotary joint 30 has a connection hole 30a extending in the axial direction X. The connection hole 30a is open at both end faces in the axial direction X. Fig. 3 shows only one of the end faces where the connection hole 30a opens. A plurality of wires and a plurality of cables (not shown) are inserted into the connection hole 30a.

[0025] 3 and 4, the rotary joint 30 has a fixed member 31, a rotary member 32, a brake mechanism 40, and a stopper mechanism 50. In the rotary joint 30, the fixed member 31 and the rotary member 32 are aligned in the axial direction X. In other words, the rotary joint 30 is formed by aligning the fixed member 31 and the rotary member 32 in the axial direction X. The stopper mechanism 50 defines the rotation range of the rotary member 32.

[0026] <Fixing material> The fixed member 31 is connected to the second arm member 27. The fixed member 31 has an end wall 33 connected to the second end of the second arm member 27, and a peripheral wall 34 extending from the end wall 33.

[0027] The end wall 33 is disk-shaped. The thickness direction of the end wall 33 coincides with the axial direction X. The end wall 33 has an end wall hole 33a. The end wall hole 33a forms a part of the connection hole 30a. The end wall 33 has four connecting members 331 on one of its end faces in the thickness direction for connecting to the second arm member 27. The connecting members 331 protrude from that end face of the end wall 33.

[0028] The peripheral wall 34 is connected to the edge of the end wall 33 and extends in the thickness direction of the end wall 33. In other words, the peripheral wall 34 stands upright on one of the end faces in the thickness direction of the end wall 33. Specifically, the peripheral wall 34 stands upright on the end face of the end wall 33 from which the connecting member 331 does not protrude.

[0029] The peripheral wall 34 is cylindrical with the third vertical axis L3 as its central axis. In other words, the peripheral wall 34 is cylindrical with a thickness direction perpendicular to the third vertical axis L3. The peripheral wall 34 has an outer peripheral surface 341 and an inner peripheral surface 342. The peripheral wall 34 has a plurality of peripheral wall holes 34a. The plurality of peripheral wall holes 34a are arranged at equal intervals in the circumferential direction of the peripheral wall 34. Each peripheral wall hole 34a penetrates the peripheral wall 34 in the thickness direction. In other words, each peripheral wall hole 34a opens at the outer peripheral surface 341 and the inner peripheral surface 342. Although not used in this embodiment, each peripheral wall hole 34a is provided for attaching a rotation restricting member (not shown) for restricting the rotation range of the rotating member 32.

[0030] The peripheral wall has two mounting surfaces 35. The two mounting surfaces 35 are formed on an outer circumferential surface 341 of the peripheral wall and face in opposite directions to each other in the radial direction of the peripheral wall . The peripheral wall 34 has multiple pairs of mounting holes 34b. In this embodiment, the peripheral wall 34 has two pairs of mounting holes 34b, so the peripheral wall 34 has four mounting holes 34b. The pairs of mounting holes 34b are formed in the mounting surface 35. The pair of mounting holes 34b sandwich one peripheral wall hole 34a and are provided between the peripheral wall holes 34a that are adjacent to the one peripheral wall hole 34a in the circumferential direction of the peripheral wall 34. Each mounting hole 34b opens at the outer peripheral surface 341. Of the two pairs of mounting holes 34b, one pair is provided on the opposite side of the other pair on the outer peripheral surface 341. A female thread is formed on the inner surface that defines each mounting hole 34b.

[0031] The fixed member 31 has a rotation chamber 31a defined by an end wall 33 and a peripheral wall 34. One end of the rotation chamber 31a in the axial direction X is defined by the end wall 33, and the other end opens to the outside of the fixed member 31. The rotation chamber 31a communicates with the outside of the fixed member 31 through an end wall hole 33a. The rotation chamber 31a opens to the outside of the fixed member 31 through a plurality of peripheral wall holes 34a in a direction perpendicular to the third vertical axis L3.

[0032] Of the end faces in the thickness direction, end wall 33 faces a second end portion of second arm member 27 at a surface on which peripheral wall 34 is not erected, and is connected to the second end portion by connecting member 331. Since end wall 33 is fixed to second arm member 27, fixing member 31 cannot move relative to second arm member 27.

[0033] <Rotating parts> The rotating member 32 is cylindrical with the third vertical axis L3 as its central axis. The rotating member 32 has a rotation hole 32a extending in the axial direction X. The rotation hole 32a penetrates the rotating member 32 in the axial direction X. The rotation hole 32a opens at the center of both end faces in the axial direction X. The rotating member 32 has a rotation block 321 in a portion in the circumferential direction. The rotation block 321 is fixed to the rotating member 32.

[0034] A portion of the rotating member 32 in the axial direction X is accommodated in the rotating chamber 31a of the fixed member 31. More specifically, the portion of the rotating member 32 accommodated in the rotating chamber 31a is accommodated in the rotating chamber 31a so that a first end thereof faces the end wall 33 in the axial direction X and faces an inner circumferential surface 342 of the peripheral wall 34 in a direction perpendicular to the axial direction X. Furthermore, a portion of the rotating member 32 closer to its second end is located outside the fixed member 31. A portion of the rotating member 32 is accommodated in the rotating chamber 31a so that the rotation hole 32a and the end wall hole 33a are aligned in the axial direction X. In other words, the rotation hole 32a communicates with the outside of the rotating chamber 31a via the end wall hole 33a. The rotation hole 32a constitutes a part of the connecting hole 30a. The rotating block 321 is accommodated in the rotating chamber 31a between the peripheral wall 34 and the rotating member 32. The rotating member 32 is accommodated in the rotating chamber 31a so that the rotating block 321 is aligned with the inner peripheral surface 342 of the peripheral wall 34 and so that the rotating member 32 is rotatable about the third vertical axis L3 relative to the fixed member 31. Note that the rotating member 32 does not necessarily have to have the rotating block 321. It is sufficient that the rotating member 32 is accommodated in the rotating chamber 31a so that the rotating member 32 is rotatable about the third vertical axis L3.

[0035] A bearing (not shown) is provided on the second end side of the rotating member 32. The bearing is interposed between the peripheral wall 34 and the rotating member 32. The rotating member 32 is inserted into the bearing. The rotating member 32 is attached to the fixed member 31 via the bearing. The bearing of this embodiment has an inner ring and an outer ring. The inner ring of the bearing is connected to the rotating member 32. The outer ring of the bearing is connected to the peripheral wall 34.

[0036] The rotary joint 30 has an annular pressing member 322. The pressing member 322 is provided at an end of the peripheral wall 34 that is not connected to the end wall 33. The pressing member 322 supports a bearing and is fixed to the peripheral wall 34. More specifically, the pressing member 322 supports the outer ring of the bearing. That is, the pressing member 322 holds the bearing between the peripheral wall 34 and the rotating member 32. In the rotation chamber 31a, the movement of the rotating member 32 in the axial direction X is restricted by the end wall 33, the bearing, and the pressing member 322. That is, the rotating member 32 is held by the fixed member 31. Therefore, the rotating member 32 is held by the fixed member 31 so as to be rotatable about the third vertical axis L3 while moving along the inner peripheral surface 342 of the peripheral wall 34.

[0037] A retaining plate 55 is fixed to the rotating member 32 via the brake mechanism 40 and the stopper mechanism 50. In other words, the retaining plate 55 is configured to be rotatable in conjunction with the rotating member 32. The retaining plate 55 is aligned with the rotating member 32 in the axial direction X via the brake mechanism 40 and the stopper mechanism 50. The retaining plate 55 is flat, with the axial direction X as its thickness direction. One of the end faces of the retaining plate 55 in the thickness direction faces the rotating member 32 via the brake mechanism 40 and the stopper mechanism 50, and the other face is connected to the load holding portion 12. In other words, the retaining plate 55 holds the load holding portion 12 so as to be rotatable relative to the fixed member 31.

[0038] The retaining plate 55 has a through-hole (not shown) that penetrates in the thickness direction. The through-hole is provided in the center of the retaining plate 55. The through-hole of the retaining plate 55 is aligned with the end wall hole 33a and the rotation hole 32a in the axial direction X. The through-hole of the retaining plate 55 forms a part of the connection hole 30a.

[0039] <Brake mechanism> 3 and 6, the brake mechanism 40 includes a brake disc 41, a disc fixing portion 42, and a brake device 43. The brake mechanism 40 regulates the rotation of the rotating member 32 relative to the fixed member 31.

[0040] The brake disc 41 is disk-shaped and has a through-hole (not shown) that penetrates through it in the thickness direction. The outer diameter of the brake disc 41 is larger than the outer diameter of the peripheral wall 34. The thickness direction of the brake disc 41 is the axial direction X. The brake disc 41 is aligned with the rotating member 32 in the axial direction X. The brake disc 41 faces a second end of the rotating member 32 in the axial direction X. The brake disc 41 rotates in conjunction with the rotating member 32 outside the fixed member 31. The brake disc 41 is connected to the rotating member 32 with its central axis aligned with the third vertical axis L3.

[0041] The through hole of the brake disc 41 is provided in the center of the brake disc 41. The through hole is aligned with the rotation hole 32a in the axial direction X. The through hole constitutes a part of the connection hole 30a.

[0042] The disc fixing portion 42 is cylindrical. The central axis of the disc fixing portion 42 coincides with the third vertical axis L3. The disc fixing portion 42 faces the surface of the brake disc 41 in the thickness direction opposite the surface facing the second end of the rotating member 32. In other words, the brake disc 41 is interposed between the disc fixing portion 42 and the rotating member 32. The disc fixing portion 42 is connected to the second end of the rotating member 32 via the brake disc 41. The disc fixing portion 42 is connected to the rotating member 32 with the brake disc 41 interposed therebetween, thereby fixing the brake disc 41 to the rotating member 32.

[0043] The disc fixing portion 42 has a through-hole (not shown) that extends along the third vertical axis L3. The through-hole penetrates the disc fixing portion 42 in the direction of extension of the third vertical axis L3. The through-hole communicates with the end wall hole 33a via the through-hole of the brake disc 41 and the rotation hole 32a, and forms part of the connection hole 30a. The outer diameter of the disc fixing portion 42 is smaller than the outer diameter of the brake disc 41.

[0044] The brake device 43 is provided on the outer peripheral surface 341 of the peripheral wall 34. In other words, the brake device 43 is provided on the peripheral wall 34. The brake device 43 has a pair of brake device holes 43a and a restricting portion 43b. The pitch and diameter of the pair of brake device holes 43a match the pitch and diameter of the pair of mounting holes 34b. In other words, the brake device 43 has a pair of brake device holes 43a that have the same pitch and diameter as the pair of mounting holes 34b. The restricting portion 43b is configured to be able to press the brake disc 41 from both end faces in the thickness direction. In other words, the restricting portion 43b clamps the brake disc 41.

[0045] The brake device 43 is disposed such that a pair of brake device holes 43a face a pair of mounting holes 34b on one mounting surface 35, and a portion of the brake disc 41 near the edge and the restricting portion 43b are aligned in the thickness direction of the brake disc 41. The brake device 43 is fixed to the mounting surface 35 of the peripheral wall 34 by mounting members 80 that are inserted into the brake device holes 43a and the mounting holes 34b. For example, the mounting members 80 are bolts that are fixed to the peripheral wall 34 by being threaded into female threads formed on the inner surface that defines the mounting holes 34b.

[0046] The brake device 43 is connected to the air supply source 14 via piping (not shown). The brake device 43 is configured such that, when air is supplied from the air supply source 14, the restricting portion 43b presses the brake disc 41 from both end surfaces in the thickness direction.

[0047] <Stopper mechanism> As shown in FIGS. 3 and 5, the stopper mechanism 50 includes an interlocking member 51, a stopper 52, a stopper housing 53, a lever 54, and two engagement portions 63.

[0048] <Interlocking member and stopper> The interlocking member 51 is disk-shaped and has a through-hole (not shown) that penetrates through it in the thickness direction. The thickness direction of the interlocking member 51 coincides with the axial direction X. The interlocking member 51 is aligned with the rotating member 32 in the axial direction X. The interlocking member 51 is aligned with the disc fixing portion 42 in the axial direction X. The interlocking member 51 faces the opposite surface of the end of the disc fixing portion 42 in the axial direction X to the surface that faces the brake disc 41. The interlocking member 51 is provided outside the fixed member 31. The interlocking member 51 is connected to the rotating member 32 via the disc fixing portion 42 and the brake disc 41. In other words, the brake disc 41 is interposed between the rotating member 32 and the interlocking member 51. The interlocking member 51 rotates in conjunction with the rotating member 32 outside the fixed member 31.

[0049] The interlocking member 51 is connected to the disc fixing portion 42 with its central axis aligned with the third vertical axis L3. The outer diameter of the interlocking member 51 is smaller than the outer diameter of the brake disc 41. One end face of the interlocking member 51 in the axial direction X faces the disc fixing portion 42, and the other end face faces the holding plate 55. The holding plate 55 is connected to the disc fixing portion 42 with the interlocking member 51 interposed therebetween. Movement of the interlocking member 51 in the axial direction X is restricted by the connection between the holding plate 55 and the disc fixing portion 42. In other words, the interlocking member 51 is fixed to the disc fixing portion 42 by the holding plate 55.

[0050] The through hole of the interlocking member 51 is aligned with the through hole of the retaining plate 55 in the axial direction X. The through hole of the interlocking member 51 is also aligned with the through hole of the disc fixing portion 42 in the axial direction X, and forms a part of the connecting hole 30a. The connecting hole 30a is formed by aligning the end wall hole 33a, the rotation hole 32a, and the through holes of the brake disc 41, the disc fixing portion 42, the interlocking member 51, and the retaining plate 55 in the axial direction X.

[0051] The interlocking member 51 has a peripheral surface, i.e., an interlocking outer peripheral surface 511. An insertion hole 51a is provided in the interlocking outer peripheral surface 511. A female screw is formed on the inner surface defining the insertion hole 51a.

[0052] The stopper 52 is cylindrical. The stopper 52 is made of resin. The stopper 52 is provided on the interlocking outer peripheral surface 511. The stopper 52 protrudes from the interlocking outer peripheral surface 511 with the direction in which the central axis extends aligned with the radial direction of the interlocking member 51. The stopper 52 is arranged so as to be aligned with the insertion hole 51a in the radial direction of the interlocking member 51.

[0053] The stopper 52 is fixed to the interlocking member 51 by a stopper fixing device 52a. The stopper fixing device 52a is cylindrical and extends radially of the interlocking member 51, with a flange formed near one end and a male thread formed near the other end. The stopper fixing device 52a is inserted through the stopper 52, and the male thread is threaded into the female thread of the insertion hole 51a. The stopper fixing device 52a is fastened to the interlocking member 51, thereby fixing the stopper 52 to the interlocking member 51.

[0054] The sum of the outer diameter of the interlocking member 51 and the length from the base end to the tip end of the stopper 52 is slightly larger than the outer diameter of the brake disc 41. In other words, the tip end of the stopper 52 is slightly outward from the edge of the brake disc 41 in the radial direction of the brake disc 41.

[0055] <Stopper housing and engagement portion> The stopper housing 53 is provided on the outer peripheral surface 341 of the peripheral wall 34. The stopper housing 53 is provided at a position on the outer peripheral surface 341 that faces the mounting holes 34b of the mounting surface 35 to which the brake device 43 is not attached. In other words, the stopper housing 53 faces a pair of mounting holes 34b. The stopper housing 53 is fixed to the outer peripheral surface 341 of the peripheral wall 34.

[0056] The stopper housing 53 has a first housing portion 61 attached to the peripheral wall 34 and a second housing portion 62 extending from the first housing portion 61. The first housing portion 61 is block-shaped. The first housing portion 61 has a first housing inner surface 611 and a first housing outer surface 612. The first housing inner surface 611 faces the outer peripheral surface 341. The first housing outer surface 612 is the opposite surface of the first housing inner surface 611.

[0057] The first housing portion 61 has a pair of housing holes 61a. Each housing hole 61a opens to the first housing inner surface 611 and the first housing outer surface 612. That is, each housing hole 61a penetrates the first housing portion 61. The pair of housing holes 61a are provided in positions of the first housing portion 61 facing the pair of mounting holes 34b. In the first housing portion 61, the pitch and diameter of the pair of housing holes 61a match the pitch and diameter of the pair of mounting holes 34b. In other words, the first housing portion 61 has a pair of housing holes 61a that have the same pitch and diameter as the pair of mounting holes 34b. Furthermore, the pitch and diameter of the pair of housing holes 61a match the pitch and diameter of the pair of brake device holes 43a.

[0058] The second housing portion 62 is plate-shaped. The second housing portion 62 extends from a portion of the first housing portion 61 closer to the first housing outer surface 612. The thickness direction of the second housing portion 62 coincides with the direction in which the first housing inner surface 611 and the first housing outer surface 612 are aligned. In other words, the thickness direction of the second housing portion 62 is a direction perpendicular to each of the first housing inner surface 611 and the first housing outer surface 612.

[0059] The second housing portion 62 has a retaining inner surface 621, a retaining outer surface 622, and a connecting surface 613 in the thickness direction. That is, the stopper housing 53 has the retaining inner surface 621. The retaining inner surface 621 faces the same direction as the first housing inner surface 611. The retaining outer surface 622 faces the same direction as the first housing outer surface 612. The connecting surface 613 connects the retaining inner surface 621 and the first housing inner surface 611. The connecting surface 613 is a surface perpendicular to both the first housing inner surface 611 and the retaining inner surface 621. The retaining outer surface 622 forms a single surface together with the first housing outer surface 612. In other words, the stopper housing 53 has a surface consisting of the first housing outer surface 612 and the retaining outer surface 622.

[0060] The second housing portion 62 has two engagement portions 63 on the retaining inner surface 621. In other words, the two engagement portions 63 are provided on the retaining inner surface 621. The engagement portions 63 are rectangular prism-shaped and extend along the retaining inner surface 621. The engagement portions 63 protrude from the retaining inner surface 621 in the thickness direction of the second housing portion 62, and protrude from the connection surface 613 in the thickness direction of the first housing portion 61. The engagement portions 63 are erected on the connection surface 613. The two engagement portions 63 are provided on the retaining inner surface 621, spaced apart in a direction parallel to the connection surface 613 and the retaining inner surface 621. Each engagement portion 63 has an inclined surface 64 at its tip in the erecting direction from the connection surface 613. The inclined surface 64 faces away from the connection surface 613 and in the direction in which the two engagement portions 63 are aligned. The two inclined surfaces 64 are aligned in the direction in which the two engagement portions 63 are aligned. The inclined surfaces 64 are inclined so that the distance between the two inclined surfaces 64 increases as the distance from the connecting surface 613 increases.

[0061] The second housing portion 62 has a support hole 62a in a portion closer to the first housing portion 61. The support hole 62a is a through hole that opens in each of the retaining inner surface 621 and the retaining outer surface 622. The support hole 62a is provided between the two engagement portions 63. A support shaft 56 is inserted into the support hole 62a, and the support shaft 56 is fixed to the stopper housing 53. The support shaft 56 is disposed so as to be immovable relative to the peripheral wall 34.

[0062] <Lever> Lever 54 has a long plate shape. Lever 54 has, in the thickness direction, a first lever surface 541 and a second lever surface 542. Lever 54 has two lever side surfaces 543 that connect first lever surface 541 and second lever surface 542 and are parallel to the longitudinal direction of lever 54.

[0063] The lever 54 has a lever hole 54a that opens at the first lever surface 541 and the second lever surface 542. The lever hole 54a penetrates the lever 54 in the thickness direction. The lever hole 54a is provided in a portion of the lever 54 near the first end.

[0064] The support shaft 56 inserted into the support hole 62a of the stopper housing 53 is inserted into the lever hole 54a. The support shaft 56 supports the lever 54 relative to the stopper housing 53. In other words, the lever 54 is supported by the stopper housing 53 via the support shaft 56. The lever 54 is disposed in a position where the lever hole 54a and the support hole 62a are aligned in the thickness direction of the lever 54, with the second lever surface 542 facing the retaining inner surface 621. In other words, the lever 54 is supported by the stopper housing 53 so as to be swingable along the retaining inner surface 621.

[0065] The portion of the lever 54 near the first end is attached to the second housing part 62 by the support shaft 56, and the portion near the second end is swingable around the support shaft 56. In other words, the lever 54 is swingably supported by the support shaft 56, which is immovable relative to the peripheral wall 34. The lever 54 is provided in the stopper housing 53 so as to be swingable between the two engagement parts 63 around the support shaft 56 as the swing center.

[0066] The lever 54 is provided in the stopper housing 53 so that the lever side surface 543 and each engagement portion 63 are spaced apart. When the lever 54 is pivoting, one of the two lever side surfaces 543 approaches the opposing engagement portion 63, while the other moves away from the opposing engagement portion 63. The lever 54 is configured so that a portion near the second end can come into contact with the two engagement portions 63 as it pivots. In other words, the lever 54 is configured so that it can come into contact with the two engagement portions 63. When the lever 54 is in contact with one engagement portion 63, it is spaced apart from the other engagement portion 63. When the lever 54 comes into contact with the engagement portions 63, the lever side surface 543 comes into surface contact with the inclined surface 64. In other words, the engagement portion 63 has an inclined surface 64 that comes into surface contact with the lever 54.

[0067] <Installing the stopper housing> The stopper housing 53 is provided on the peripheral wall 34 at a position where the brake device 43 is not attached and where the pair of housing holes 61a and the pair of mounting holes 34b face each other. The stopper housing 53 is provided on the fixing member 31 by being fixed to the peripheral wall 34 with the first housing inner surface 611 of the first housing portion 61 facing the mounting surface 35. The first housing portion 61 is fixed to the peripheral wall 34 by mounting members 80 inserted into the pair of housing holes 61a and the pair of mounting holes 34b. In other words, the first housing portion 61 is fixed to the peripheral wall 34 by the mounting members 80 inserted into the housing holes 61a and the mounting holes 34b. The first housing portion 61 is provided on the peripheral wall 34 so as to face the brake disc 41 in the axial direction X. More specifically, the first housing portion 61 faces a portion of the brake disc 41 near the edge and is fixed to the peripheral wall 34.

[0068] The second housing portion 62 is spaced from the peripheral wall 34 and has a thickness direction perpendicular to the axial direction X. The stopper housing 53 is provided such that the second housing portion 62 faces the brake disc 41, the disc fixing portion 42, and the interlocking member 51. That is, the retaining inner surface 621 faces the interlocking member 51. In the second housing portion 62, the lever 54 and the two engaging portions 63 are aligned in the rotational direction of the rotating member 32. Therefore, the two engaging portions 63 are disposed so as not to move relative to the peripheral wall 34 and are aligned in the rotational direction of the rotating member 32. The second housing portion 62 supports each of the engaging portions 63 and the lever 54 so as not to come into contact with the brake disc 41. In other words, the second housing portion 62 holds the lever 54 radially outward of the brake disc 41. The second housing portion 62 supports the lever 54 at a position where a portion of the lever 54 near the second end can abut against the stopper 52. That is, the stopper housing 53 has the lever 54 at a position where it abuts against the stopper 52 without coming into contact with the brake disc 41 .

[0069] <Arm-type assistive device and rotary joint operation> The operation of the arm-type assistive device 10 and the rotary joint 30 will now be described. 1 and 2, the arm-type assist device 10 holds an object W by means of the load holding portion 12. The worker holds the object W by means of the load holding portion 12 by attracting the object W to the suction portion 12a.

[0070] In the process of operating the arm-type assist device 10, for example, when changing the orientation of the held object W, the worker rotates the load holding part 12 around the third vertical axis L3 as the center of rotation. The rotation of the load holding part 12 by the worker induces the rotation of the holding plate 55. The rotation of the holding plate 55 induces the rotation of the interlocking member 51, the disc fixing part 42, the brake disc 41, and the rotating member 32. The rotating member 32 rotates relative to the fixing member 31. In other words, the load holding part 12 rotates relative to the second arm member 27 by the rotary joint 30.

[0071] When the load retaining portion 12 is rotated by an operator, the stopper 52 moves in the rotational direction. The stopper 52 moves relative to the second arm member 27 and the fixed member 31. In other words, the stopper 52 moves relative to the stopper housing 53 and the lever 54.

[0072] Next, the operation of the stopper mechanism 50 in association with the rotation of the load holding portion 12 will be described with reference to Figure 7. Figure 7 shows how the lever 54 swings in association with the rotation of the stopper 52. The two-dot chain line in Figure 7 indicates a state in which the stopper 52 and the lever 54 are spaced apart. Furthermore, the solid line in Figure 7 indicates a state in which the stopper 52 and the lever 54 are in contact with each other.

[0073] The stopper 52 moves relative to the lever 54 from the state indicated by the two-dot chain line in FIG. 7 to a position where it abuts against a portion of the lever 54 near the second end. In other words, the stopper 52 abuts against the lever 54 as the rotating member 32 rotates relative to the fixed member 31. The stopper 52, while abutting against the lever 54, further moves in the rotational direction, causing the lever 54 to swing. In other words, the lever 54 swings when pushed by the stopper 52. The lever 54 is pushed in the rotational direction by the stopper 52, and the lever side surface 543 that is not abutting against the stopper 52 approaches the inclined surface 64 that faces the lever side surface 543. The stopper 52 swings the lever 54 until the lever 54 abuts against the engagement portion 63, as indicated by the solid line in FIG. 7. When the lever 54 and the engaging portion 63 are in contact with each other, movement of the stopper 52 in a direction that would cause the lever 54 to swing further is restricted by the engaging portion 63. In other words, the stopper 52 can move in the rotational direction until the lever 54 and the engaging portion 63 come into contact with each other. In other words, the range of swing of the lever 54 is determined by the distance between the two engaging portions 63. When the lever 54 and the engaging portion 63 are in contact with each other, the lever side surface 543 and the inclined surface 64 are in surface contact with each other.

[0074] When the rotation of the rotating member 32 causes the stopper 52 and the lever 54 to come into contact with each other and the lever 54 to come into contact with the engaging portion 63, the rotating member 32 is restricted from further rotation relative to the fixed member 31. In other words, the rotating member 32 will rotate relative to the fixed member 31 until it is restricted by the stopper mechanism 50. In other words, the stopper mechanism 50 defines the rotation range of the rotating member 32.

[0075] Next, the range of movement of the stopper 52 due to rotation of the load retaining portion 12 will be described with reference to FIG. 8. FIG. 8 schematically illustrates the movement of the lever 54 accompanying the movement of the stopper 52 in the rotational direction. The lever 54 oscillated by the stopper 52 moving in the first direction D1 is shown by a solid line. The central axis of the stopper 52, which is restricted from further rotation in the first direction D1, is depicted as a first reference axis LS. That is, when the central axis of the stopper 52 is located at the position of the first reference axis LS, the lever 54 abuts the engaging portion 63. In the state shown by the solid line in FIG. 8, the lever 54 abuts the engaging portion 63 as a result of swinging in the first direction D1. In this state, the stopper 52 can move in the opposite direction to the first direction D1. This opposite direction is referred to as a second direction D2. In FIG. 8, the second direction D2 is shown by a two-dot chain line.

[0076] When the stopper 52 moves in the second direction D2 from a state in which its central axis is on the first reference axis LS, the lever 54 swings in a direction away from the engagement portion 63 with which it was in contact. The stopper 52 moves in the second direction D2 and makes a full revolution around the third vertical axis L3, thereby approaching the lever 54 again. As a result, the stopper 52 comes into contact with the lever 54. At this time, the lever side surface 543 that comes into contact with the stopper 52 is different from the lever side surface 543 that was in contact with the stopper 52 before it started moving in the second direction D2.

[0077] The stopper 52, which has moved in the second direction D2 and abutted against the lever 54, swings the lever 54 in the second direction D2. This swinging causes the lever 54 to move the lever side surface 543, which is not abutting against the stopper 52, closer to the inclined surface 64. The stopper 52 swings the lever 54 in the second direction D2 until the lever 54 abuts against the engagement portion 63. In FIG. 8 , the lever 54 abutting against the engagement portion 63 due to the stopper 52 moving in the second direction D2 is indicated by a two-dot chain line. The lever 54 abutting against the engagement portion 63 is restricted from further movement in the second direction D2 by the lever 54 abutting against the engagement portion 63. In FIG. 8 , the central axis of the stopper 52, whose movement in the second direction D2 is restricted, is depicted as the second reference axis LE. That is, the stopper 52 moves in the second direction D2 from a position where its central axis coincides with the first reference axis LS to a position where its central axis coincides with the second reference axis LE. As described above, the stopper 52 is configured to be able to rotate once around the third vertical axis L3 as the load holding portion 12 rotates.

[0078] The brake device 43 is configured to press a portion of the brake disc 41 that is not aligned with the stopper housing 53 in the axial direction X. The brake device 43 restricts the rotation of the rotating member 32 by clamping a portion of the brake disc 41 near the edge. The brake device 43 restricts the rotation of the load holding unit 12 that has been rotated by the worker by a desired angle relative to the second arm member 27. In this way, the worker can move the object W while restricting the load holding unit 12 from rotating relative to the second arm member 27 beyond the desired angle.

[0079] [Operation of this embodiment] The operation of this embodiment will be described. The rotation of the rotating member 32 relative to the fixed member 31 is accompanied by the rotation of the interlocking member 51. As the interlocking member 51 rotates, the stopper 52 moves in the rotational direction. As the stopper 52 moves in the rotational direction, it approaches the lever 54 and then abuts against it. After abutting against the lever 54, the stopper 52 moves in the rotational direction accompanied by the swinging of the lever 54. The movement of the stopper 52 ends when the lever 54 abuts against the engaging portion 63. The rotating member 32 rotates relative to the fixed member 31 within a range up to the point where the stopper 52 abuts against the lever 54, in addition to a range up to the point where the lever 54, swung by the stopper 52, abuts against the engaging portion 63.

[0080] [Effects of this embodiment] The effects of this embodiment will be described. (1) The rotating member 32 can rotate relative to the fixed member 31 not only in the range where the stopper 52 and the lever 54 do not come into contact with each other, but also in the range where the stopper 52 comes into contact with the lever 54 but the lever 54 does not come into contact with the engaging portion 63. Therefore, the rotating joint 30 allows the rotating member 32 to rotate relative to the fixed member 31 over a wider range than when, for example, the member coming into contact with the stopper 52 does not swing. As described above, the rotating joint 30 can expand the rotation range of the rotating member 32.

[0081] (2) The rotary joint 30 has the stopper mechanism 50 outside the fixed member 31. For example, when replacing the stopper 52 or the lever 54, the rotary joint 30 can facilitate the replacement work compared to when the stopper 52 or the lever 54 is provided inside the fixed member 31. In other words, the rotary joint 30 can improve maintainability while expanding the rotation range of the rotating member 32.

[0082] (3) In the stopper mechanism 50, the two engaging portions 63 and the lever 54 are integrated by the stopper housing 53. Furthermore, the stopper mechanism 50 is provided to the fixed member 31 by attaching the stopper housing 53 to the peripheral wall 34. In other words, in the rotary joint 30, the stopper mechanism 50 is easier to attach to the fixed member 31 than, for example, when the two engaging portions 63 and the lever 54 are separate and attached to the peripheral wall 34 individually.

[0083] (4) In the stopper mechanism 50, the engaging portion 63 and the lever 54 come into contact with each other through surface contact between the inclined surface 64 and the lever side surface 543. For example, if the engaging portion 63 does not have the inclined surface 64, the engaging portion 63 and the lever 54 come into contact with each other through a corner of the engaging portion 63 and the lever side surface 543. In other words, the stopper mechanism 50 can reduce wear on the lever 54 when the engaging portion 63 and the lever 54 come into contact with each other, compared to when the engaging portion 63 does not have the inclined surface 64.

[0084] (5) In the rotary joint 30, the stopper housing 53 and the brake device 43 are provided in different positions. Furthermore, the stopper housing 53 supports the lever 54 and the engaging portion 63 relative to the peripheral wall 34 at a position away from the brake disc 41 by means of the first housing portion 61 and the second housing portion 62. Therefore, the rotary joint 30 can introduce the stopper mechanism 50 without interfering with the brake disc 41. With the above configuration, the rotary joint 30 can be equipped with both the brake mechanism 40 and the stopper mechanism 50.

[0085] (6) The pair of housing holes 61a and the pair of brake device holes 43a have the same pitch and the same hole diameter. The rotary joint 30 having the brake device 43 has a pair of mounting holes 34b in the peripheral wall 34 whose pitch and hole diameter match those of the pair of brake device holes 43a. In other words, in the rotary joint 30, the stopper housing 53 can be mounted to the peripheral wall 34 using the pair of mounting holes 34b without providing new holes in the peripheral wall 34 for mounting the stopper housing 53. As a result, the stopper mechanism 50 can be installed in the rotary joint 30 without additional machining of the peripheral wall 34.

[0086] (7) The range over which the lever 54 can swing is determined by the distance between the two engagement portions 63. Each engagement portion 63 has an inclined surface 64 aligned in the direction in which the two engagement portions 63 are aligned, and therefore the distance between the two engagement portions 63 is increased at the position of the inclined surface 64 in the axial direction X. In other words, the stopper mechanism 50 increases the range over which the lever 54 can swing without changing the distance between the two engagement portions 63 in the rotational direction of the rotating member 32, because the engagement portions 63 have inclined surfaces 64. Therefore, by providing the inclined surfaces 64 in each engagement portion 63, the rotary joint 30 can increase the rotation range of the rotating member 32 while minimizing the size of the stopper mechanism 50.

[0087] (8) By providing the rotary joint 30, the arm-type assist device 10 can rotate the load holding unit 12 around the third vertical axis L3 relative to the second arm member 27. Therefore, the arm-type assist device 10 can face the entire circumference to a worker who performs work such as processing on the object W from a predetermined position, without the need to perform an action such as re-holding the object W. An example of processing the object W is the attachment of a nameplate to the object W held by the load holding unit 12. As described above, the arm-type assist device 10 can improve work efficiency.

[0088] [Example of change] The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0089] The peripheral wall 34 may have three or more pairs of mounting holes 34b. The pair of housing holes 61a do not have to have the same pitch and diameter as the pair of mounting holes 34b. In this case, new holes having the same pitch and diameter as the pair of housing holes 61a are provided in the peripheral wall 34, and the first housing part 61 is mounted to the peripheral wall 34 through these holes. In this case, the first housing part 61 is mounted to the peripheral wall 34 using a mounting member of a different type than the mounting member 80.

[0090] The brake device 43 does not have to be fixed to the peripheral wall 34. For example, the brake device 43 may be supported by the retaining plate 55 and may be capable of pressing the brake disc 41 in the thickness direction by the restricting portion 43b. In short, the brake device 43 may be configured so that the restricting portion 43b can restrict the rotation of the brake disc 41.

[0091] The rotary joint 30 does not necessarily have to have the brake mechanism 40. In this case, the interlocking member 51 is fixed to the rotary member 32. In this case, the peripheral wall 34 only needs to have one pair of mounting holes 34b.

[0092] The stopper housing 53 and the two engaging portions 63 may be separate bodies. For example, the engaging portion 63 may be manufactured separately from the stopper housing 53 and attached to the second housing portion 62 at a position where it can come into contact with the lever 54.

[0093] The stopper housing 53 does not have to be composed of the first housing portion 61 and the second housing portion 62. In other words, the shape of the stopper housing 53 is not limited to the shape described in the embodiment. The stopper housing 53 only needs to support the lever 54 and the two engaging portions 63 so as to prevent them from moving relative to the fixed member 31.

[0094] The engaging portion 63 does not have to have the inclined surface 64. In this case, the lever 54 abuts the lever side surface 543 against the corner of the engaging portion 63. The rotary joint 30 does not have to have the stopper housing 53. That is, in the stopper mechanism 50, the lever 54 and the two engagement portions 63 do not have to be integrated. In this case, the lever 54 and each of the two engagement portions 63 may be provided directly on the peripheral wall 34. In this case, the two engagement portions 63 are manufactured as two independent rectangular pillar-shaped members and then fixed to the peripheral wall 34. Furthermore, for example, the lever 54 may be supported by the support shaft 56 so as to be swingable relative to the peripheral wall 34.

[0095] The stopper 52 does not have to be made of resin. For example, the stopper 52 may be made of metal. The stopper 52 does not have to be fixed to the interlocking member 51 by the stopper fixing device 52a. For example, the stopper 52 may be formed in a columnar shape. The stopper 52 may also be fixed directly to the interlocking member 51. For example, the stopper 52 is provided on the interlocking member 51 so that a first end is inserted into the insertion hole 51a and a second end protrudes from the interlocking outer peripheral surface 511.

[0096] The rotary joint 30 does not have to have the retaining plate 55. In this case, the load retaining portion 12 is connected to the interlocking member 51. The arm-type assist device 10 may have a rotary joint 30 as the first rotating part 21. In this case, the rotary joint 30 has a fixed member 31 fixed to the base B and an interlocking member 51 fixed to the first support part 22. In other words, the rotary joint 30 connects the base B and the first support part 22 so that the first support part 22 can rotate relative to the base B around the first vertical axis L1.

[0097] The arm-type assist device 10 may have a rotary joint 30 as the second rotating part 25. In this case, the rotary joint 30 has a fixed member 31 fixed to the second support part 24 and an interlocking member 51 fixed to a first end of the connecting arm 26. In other words, the rotary joint 30 connects the second support part 24 and the connecting arm 26 so that the connecting arm 26 can rotate relative to the second support part 24 around the second vertical axis L2.

[0098] The rotary joint 30 does not have to be mounted on the arm-type assistive device 10. For example, the rotary joint 30 may be mounted on an industrial robot that is different from the arm-type assistive device 10 and is made up of multiple arm units. In this case, the rotary joint 30 rotatably connects the multiple arm units. [Explanation of symbols]

[0099] 30...rotary joint, 31...fixed member, 32...rotating member, 34...peripheral wall, 34b...mounting hole, 40...brake mechanism, 41...brake disc, 43...brake device, 43a...brake device hole, 50...stopper mechanism, 51...interlocking member, 52...stopper, 53...stopper housing, 54...lever, 56...support shaft, 61...first housing part, 61a...housing hole, 62...second housing part, 63...engaging part, 64...inclined surface, 80...mounting member, 341...outer surface, 342...inner surface, 511...interlocking outer peripheral surface as peripheral surface, 621...retaining inner surface, L3...third vertical axis as rotation axis, X...axial direction.

Claims

1. a fixed member having a peripheral wall; a rotating member held by the fixed member so as to be rotatable about a central axis line as a rotation axis while extending along an inner peripheral surface of the peripheral wall; a stopper mechanism that defines the rotation range of the rotary member, A rotary joint in which the fixed member and the rotary member are arranged in the axial direction of the rotary shaft, The stopper mechanism includes: an interlocking member that is aligned with the rotating member in the axial direction and rotates in conjunction with the rotating member outside the fixed member; a stopper provided on a peripheral surface of the interlocking member; two engaging portions arranged so as to be immovable relative to the peripheral wall and aligned in a rotational direction of the rotating member; a lever that is swingably supported by a support shaft that is immovable relative to the peripheral wall and that is configured to be able to abut against the two engaging portions, The rotary joint is characterized in that the lever swings when pressed by the stopper, and the range of the swing is determined by the distance between the two engaging portions.

2. the stopper mechanism includes a stopper housing having a holding inner surface facing the interlocking member and fixed to an outer peripheral surface of the peripheral wall, The two engaging portions are provided on the retaining inner surface, 2. The rotary joint according to claim 1, wherein the lever is supported by the stopper housing so as to be able to swing along the retaining inner surface.

3. 3. The rotary joint according to claim 1, wherein the engaging portion has an inclined surface that comes into surface contact with the lever.

4. a brake mechanism that restricts rotation of the rotating member relative to the fixed member, The brake mechanism includes: a brake disc interposed between the rotating member and the interlocking member and rotating in conjunction with the rotating member outside the fixed member; a brake device provided on the peripheral wall and configured to clamp a portion of the brake disc near an edge to restrict rotation of the rotating member, The stopper housing includes: a first housing portion facing the edge portion and fixed to the peripheral wall; a second housing portion having the retaining inner surface, The rotary joint according to claim 2 , wherein the second housing portion holds the lever radially outward of the brake disc.

5. The peripheral wall has a plurality of pairs of mounting holes that open at the outer circumferential surface and are aligned in the circumferential direction of the peripheral wall, the brake device has a pair of brake device holes that are arranged at the same pitch and have the same diameter as the pair of mounting holes, and is fixed to the peripheral wall by mounting members that are inserted through the brake device holes and the mounting holes, 5. The rotary joint according to claim 4, wherein the first housing portion has a pair of housing holes that are arranged at the same pitch and have the same diameter as the pair of mounting holes, and is fixed to the peripheral wall by the mounting members that are inserted through the housing holes and the mounting holes.

Images