JP2017009012A - Rotary joint - Google Patents

Abstract

Provided is a rotary joint that can be reduced in size with respect to the rotation center direction and can be reduced in size.
SOLUTION: A fixed body 20, a rotating body 10 mounted so as to be relatively rotatable around a rotation center with respect to the fixed body, and one and the other annular sealed spaces S1 defined by the fixed body and the rotating body. , S2 and S3, and one and the other sealing members R1, R2, and R3, and communication paths P1 and P2 communicating the one and the other annular sealing spaces, and one annular sealing space and A rotary joint with a different distance from the center of rotation is different from the other annular sealed space.
[Selection] Figure 3

Description

  The present invention relates to a rotary joint for supplying a fluid between relative rotating members in an industrial robot such as a semiconductor manufacturing apparatus or a confectionery manufacturing apparatus.

  Conventionally, various rotary joints have been proposed. For example, Patent Document 1 discloses a rotary joint for causing a plurality of different fluids to flow between relative rotating members through different routes. In this rotary joint, an annular space is provided between the joint body, that is, the inner peripheral surface of the fixed body and the outer peripheral surface of the rotating body, and a plurality of communication spaces that are closed together are formed in the annular space. . The fixed body includes a fluid path forming member provided with a second fluid path extending in the radial direction. Further, the rotating body is provided with a first fluid path extending in the direction of the rotation center.

  The fluid enters the rotary joint from the second fluid path, flows through the communication space provided in the annular space, and flows to the first fluid path provided in the rotating body.

  The fluid path forming member includes a channel groove that defines the second fluid path and a pair of O-ring grooves that are spaced apart from the channel groove with respect to the rotation center direction and seal the communication space. Is formed. As described above, the fluid path forming member attached to the fixed body extends the wall section that defines the second fluid path and the wall section that defines the recessed section in which the pair of O-rings are respectively disposed. It is a configuration.

  Moreover, the structure as shown, for example in patent document 2 also exists in a rotary joint. Patent Document 2 discloses a fixed joint that can rotate relative to each other and a rotary joint for transferring a plurality of types of fluid between rotating shafts. As for this rotary joint, the outer cylinder with respect to a rotating shaft is comprised from the several outer cylinder unit.

  The outer cylinder unit includes an inner sleeve and a fixed cylinder body fitted through a bearing so as to be rotatable relative to the inner sleeve, and the inner sleeve is fixed to the rotation shaft. The outer cylinder unit of the said structure formed for every kind of fluid is a structure fitted by the outer peripheral surface of a single rotating shaft.

  The fluid from the fixed body side passes through the external port and the flow path for fluid to be communicated with the external port provided in the fixed cylinder and the groove and the hole provided in the inner sleeve, and is on the rotating shaft side. To the corresponding flow path provided in

JP 2001-141150 A Japanese Utility Model Publication No. 06-69590

  As described above, the rotary joint of Patent Document 1 is configured to include the wall portion that defines the second fluid path and the wall portion that defines the pair of concave portions for the O-ring. In particular, it is difficult to reduce the size in the direction of the rotation center.

  Moreover, in the rotary joint of patent document 2, as above-mentioned, the outer cylinder unit prepared for every kind of fluid is fitted by the single rotating shaft, and several types of fluid is transferred between a fixed body and a rotating shaft. It is a configuration. Therefore, when the number of fluids passing through the rotary joint is changed, it is necessary to prepare a rotating shaft having a number of flow paths corresponding to the number of the fluids, and it is difficult to improve the versatility of the rotary joint.

The present invention has been made in view of such circumstances. That is, it aims at providing the rotary joint which can shorten the dimension regarding a rotation center direction and can implement | achieve size reduction.
It is also preferable to provide a rotary joint that can cope with changes in the number of fluids exchanged between a rotating body and a stationary body that rotate relative to each other.

  In order to solve the above-described problems and achieve the object, a first aspect of the rotary joint of the present invention includes a fixed body, and a rotating body that is attached to the fixed body so as to be relatively rotatable around a rotation center. One and the other sealing members arranged in one and the other annular sealing space defined by the fixed body and the rotating body, and a communication path communicating the one and the other annular sealing space, One annular sealing space and the other annular sealing space are characterized in that the distance from the rotation center is different.

  According to another aspect of the present invention, in the above-described invention, the fixed body is provided with one fixed step portion and the other fixed step portion, and the one fixed step portion and the other fixed step portion have a rotation center. The rotating body is provided with one rotating step portion and the other rotating step portion, and the one rotating step portion and the other rotating step portion have different distances from the rotation center. One annular step space is formed by one rotating step portion facing one fixed step portion, and the other annular step space is formed by the other rotating step portion facing the other fixed step portion. It is preferable that a sealed space is formed.

  Further, according to another aspect of the present invention, in the above-described invention, a communication path is formed by one fixed cylindrical surface constituting one annular sealed space and the other rotating cylindrical surface constituting the other annular sealed space. Is preferably defined.

  In another aspect of the present invention, in the above-described invention, it is preferable that the radial dimension of the communication path is within the range of the inner diameter dimension and the outer diameter dimension of the cross section of one sealing member.

  In another aspect of the present invention, in the above-described invention, it is preferable that the rotating body includes a through-hole penetrating in a direction in which the rotation center extends.

  In another aspect of the present invention, in the above-described invention, it is preferable that the fluid pipe is attached to the rotating body and communicated with the communication path, and the fluid pipe extends into the through hole.

  According to another aspect of the present invention, in the above-described invention, the rotary joint according to the above-described invention includes a plurality of rotary joints and fastening means for connecting the plurality of rotary joints to each other. It is preferable that the fluid pipe attached to the rotary body of the rotary joint is inserted into the through hole of one rotary joint and the through holes of the other rotary joints among the plurality of rotary joints.

  In the present specification, positive pressure means pressure higher than atmospheric pressure, negative pressure means pressure lower than atmospheric pressure, and fluid means gas or liquid.

  According to the rotary joint according to the present invention, it is possible to shorten the dimension with respect to the rotation center direction, thereby realizing miniaturization.

(A) is a top view which shows the rotary joint which concerns on 1st Embodiment, (b) is a front view which shows the rotary joint which concerns on 1st Embodiment, (c) is FIG. It is a reverse view of a). It is sectional drawing along line II-II of Fig.1 (a). It is an expanded sectional view which shows the III section of FIG. It is a schematic diagram for demonstrating the relationship between a fixed body, a rotary body, and an O-ring, (a) shows the state in which the negative pressure is supplied to a connection path, (b) is a positive pressure to a connection path. Indicates a state in which is supplied. (A) is a top view which shows the rotary joint which concerns on 2nd Embodiment, (b) is sectional drawing along line VV of Fig.5 (a), (c) is a figure. It is a back view of 5 (a). It is sectional drawing which shows the state in which the slip ring is integrated in the rotary joint which concerns on 1st Embodiment similarly to FIG. It is a front view which shows the state with which the rotary joint which concerns on 1st Embodiment shown by FIG. 1 and the rotary joint which concerns on 2nd Embodiment shown by FIG. 6 were connected.

  Hereinafter, a rotary joint according to an embodiment of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

[First Embodiment]
1A is a plan view showing the rotary joint 1 according to the first embodiment, and FIG. 1B is a front view showing the rotary joint 1 according to the first embodiment. (C) is a back view of FIG. 1 (a), FIG. 2 is sectional drawing along line II-II of FIG. 1 (a), FIG. 3 is an enlarged view showing the III part of FIG. It is sectional drawing.

  The rotary joint 1 according to the first embodiment mainly includes a rotating body 10, a fixed body 20, and O-rings R1 to R6. The rotating body 10 is mounted so as to be rotatable relative to the fixed body 20. The rotary joint 1 includes an O-ring that is one and the other sealing member disposed in one and the other annular sealing space defined by the fixed body and the rotating body, and one and the other annular sealing space. The one annular sealing space and the other annular sealing space have different distances from the rotation center. Below, each component of the rotary joint 1 which concerns on embodiment is explained in full detail.

〔Rotating body〕
The rotating body 10 has a cylindrical shape, and one end side of the discharge path 11 is opened on the upper surface 10a. The discharge path 11 is formed so as to penetrate the rotary body 10 along the axial direction of the rotary body 10, and the other end side of the discharge path 11 is opened at the lower surface 10b. In addition, as shown in FIG. 2, screw hole portions 111 and 112 are provided on one end side and the other end side of the discharge passage 11, respectively. Among them, the screw portion 31 of the hose joint 30 is screwed into the screw hole portion 111.

  In the configuration shown in FIG. 1A, four discharge paths 11 are provided at equal intervals in the circumferential direction of the rotating body 10, and screw holes 14 for fastening components are provided in the discharge paths 11. ing. A hose joint 30 is attached to the four discharge paths 11. However, the number of discharge passages 11 and the number of hose joints 30 are not particularly limited. In the following description, the first discharge path 11a, the second discharge path 11b, the third discharge path 11c, and the discharge path 11 to which the hose joint 30 is attached need to be distinguished. This is referred to as a fourth discharge path 11d.

  Further, the discharge path 11 may not be configured to be provided at equal intervals in the circumferential direction of the rotating body 10. Further, the hose joint 30 and the hose joint 40 described later may be included in the components of the rotary joint 1, but may not be included in the components of the rotary joint 1.

  In addition, a rotation mechanism (not shown) to which the rotary joint 1 is mounted can be mounted on the inner peripheral surface 10 c side of the rotating body 10. That is, as shown in FIG. 2, the inner peripheral surface 10 c of the rotating body 10 defines a through hole 12 that penetrates the rotating body 10 in the axial direction. The through hole 12 is located closer to the center side in the radial direction than the discharge path 11. The rotating body 10 includes a branch path 13 extending in the radial direction of the rotary joint 1 (left and right direction in FIG. 2). In the following description, when it is necessary to distinguish the branch path 13, they are referred to as a first branch path 13a, a second branch path 13b, a third branch path 13c, and a fourth branch path 13d. . One end of each of the first to fourth branch paths 13 a to 13 d is connected to the first to fourth discharge paths 11 a to 11 d, and the other end is opened on the outer peripheral surface of the rotating body 10. Yes.

  Four branch paths 13 are provided corresponding to the number of discharge paths 11. Note that the number of branch paths 13 may be perforated by the number required for the rotating body 10 corresponding to the number of ports. Further, the number of branch paths 13 may be larger than the number of ports. In that case, the unused branch paths 13 may be blocked with a separate blocking member.

  Further, as shown in FIG. 2, the outer peripheral surface of the rotating body 10 has a symmetrical step shape in a cross-sectional view including the axial center line L, and the diameter on the central side of the axial center line L. Although the size is large, the size is gradually reduced toward the upper surface 10a and the lower surface 10b. In FIG. 2, the outer circumferential cross section of the rotating body 10 is vertically symmetrical with respect to the diametrical direction passing through the midpoint between the upper surface 10 a and the lower surface 10 b of the rotating body 10. The configuration will be described below using three rotation stage portions D1, D2, and D3.

  As shown in FIG. 3, the first rotating step portion D1 is connected to the first rotating cylindrical surface D1a extending in the axial direction and the first rotating cylindrical surface D1a and extends in the radial direction. 1 rotation annular surface D1b. Similarly, the second rotating step portion D2 includes a second rotating cylindrical surface D2a extending in the axial direction and a second rotating annular surface connecting to the second rotating cylindrical surface D2a and extending in the radial direction. D2b. Further, the third rotating step portion D3 is connected to the third rotating cylindrical surface D3a extending in the axial direction, and the third rotating annular surface D3b extending in the radial direction, connected to the third rotating cylindrical surface D3a. It is comprised by.

  Further, the first rotating annular surface D1b constituting the first rotating step portion D1 and the second rotating cylindrical surface D2a constituting the second rotating step portion D2 are connected, and the second rotating step portion D2 is connected. Are connected to the third rotating annular surface D2b that constitutes the third rotating step portion D3. Further, the radius of curvature with respect to the center line L of the first rotating cylindrical surface D1a is dimensioned smaller than the radius of curvature with respect to the center line L of the second rotating cylindrical surface D2a, and is related to the center line L of the second rotating cylindrical surface D2a. The radius of curvature is dimensioned smaller than the radius of curvature with respect to the center line L of the third rotating cylindrical surface D3a.

  As is clear from FIG. 2, three rotation step portions D4, D5, and D6 are also provided on the upper side of the rotating body 10. The fourth rotation step portion D4 is vertically symmetrical with the third rotation step portion D3, and has a fourth rotation cylindrical surface D4a and a fourth rotation annular surface D4b. The fifth rotation step portion D5 is vertically symmetrical with the second rotation step portion D2, and has a fifth rotation cylindrical surface D5a and a fifth rotation annular surface D5b. The sixth rotation step portion D6 is vertically symmetrical with the first rotation step portion D1, and has a sixth rotation cylindrical surface D6a and a sixth rotation annular surface D6b. Since these are vertically symmetric, a detailed description thereof will be omitted.

  Further, as shown in FIG. 3, a first branch path 13a is opened in the second rotating cylindrical surface D2a. 3, the lower right portion of FIG. 2 has been described, but the upper right portion of FIG. 2 has the same configuration as the lower right portion, except for the branch path 13. That is, the fourth rotation stage D4, the fifth rotation stage D5, and the sixth rotation stage D6, which are located above the third rotation stage D3 in the axial direction, are respectively the first rotation stage. The distance (outside diameter dimension) from the center line L is the same as D1, the second rotation step portion D2, and the third rotation step portion D3. As described above, the upper right portion and the lower right portion in FIG. 2 are vertically symmetrical with respect to the diameter passing through the midpoint between the upper surface 10a and the lower surface 10b of the rotating body 10.

  In addition, the first branch path 13a extends in the radial direction, but the outer diameter side of the first branch path 13a opens at the second rotation step portion D2 (second rotation cylindrical surface D2a). On the other hand, the inner diameter side communicates with the first discharge path 11a. In addition, the outer diameter side of the second branch path 13b opens at the third rotation step portion D3 (third rotation cylindrical surface D3a), and the inner diameter side communicates with the second discharge path 11b. Further, the outer diameter side of the third branch path 13c opens at the fourth rotation step portion D4, and the inner diameter side communicates with the third discharge path 11c. Further, the outer diameter side of the fourth branch path 13d opens at the fifth rotation step portion D5, and the inner diameter side communicates with the fourth discharge path 11d.

[Fixed body]
As shown in FIG. 1, the above-described rotating body 10 is mounted concentrically via rolling bearings B <b> 1 and B <b> 2 (see FIGS. 2 and 3) so as to be relatively rotatable on the inner cylinder side of the fixed body 20. ing. The outer peripheral surface 20a of the fixed body 20 is provided with a planar region 21 that is a surface orthogonal to the radial direction, and the planar region 21 is formed by cutting the outer peripheral surface 20a in a tangential direction. Further, a supply path 22 passes through the fixed body 20 from the inner cylinder side toward the outer peripheral side, and an end portion on the outer peripheral side of the supply path 22 is opened in the planar region 21. However, screw hole portions 221 are provided on the outer peripheral side of the supply path 22. A screw portion 41 of the hose joint 40 can be screwed into the screw hole portion 221. In the following description, when it is necessary to distinguish the supply path 22, the first supply path 22a, the second supply path 22b, the third supply path 22c, and the fourth supply path 22d Call it.

  Here, in the planar region 21, the four supply paths 22 are not arranged on the same straight line in the axial direction, but the two supply paths 22 are arranged on two straight lines along two different axial directions. In addition, the supply paths 22 are arranged on different straight lines alternately from the lower surface 10b to the upper surface 10a so that the first supply path 22a is on one straight line and the second supply path 22b is on another straight line. ing.

  As shown in FIG. 2, the fixed body 20 includes an upper fixed half piece 20A and a lower fixed half piece 20B. Note that the shapes of the upper fixed half piece 20A and the lower fixed half piece 20B are the same except for the configuration of the supply path 22, and so on, and the configuration will be described with reference mainly to the lower fixed half piece 20B.

  The inner peripheral surface of the lower fixed half 20B of the fixed body 20 has a symmetrical step shape in cross-sectional view including the axial center line L, similar to the outer peripheral surface of the rotating body 10 described above. The radial dimension (diameter dimension) of the surface is such that the diameter dimension of the upper surface 20B1 is large and gradually decreases toward the lower surface 20B2 side. The inner peripheral surface includes a first fixed step portion F1, a second fixed step portion F2, and a third fixed step portion F3. As shown in FIG. 3, the first fixed step portion F1 is connected to the first fixed cylindrical surface F1a extending in the axial direction and the first fixed cylindrical surface F1a, and extends in the radial direction. 1 fixed annular surface F1b. Similarly, the second fixed step portion F2 includes a second fixed cylindrical surface F2a extending in the axial direction and a second fixed annular surface connected to the second fixed cylindrical surface F2a and extending in the radial direction. F2b. Further, the third fixed step portion F3 is connected to the third fixed cylindrical surface F3a extending in the axial direction and the third fixed cylindrical surface F3b connected to the third fixed cylindrical surface F3a and extending in the radial direction. It is comprised by.

  Further, the first fixed cylindrical surface F1a constituting the first fixed step portion F1 is connected to the second fixed annular surface F2b constituting the second fixed step portion F2, and the second fixed step portion F2 is connected to the second fixed step portion F2. The 2nd fixed cylindrical surface F2a to comprise is connected to the 3rd stationary annular surface F3b which comprises the 3rd stationary step part F3. Further, the radius of curvature with respect to the center line L of the first fixed cylindrical surface F1a is dimensioned smaller than the radius of curvature with respect to the center line L of the second fixed cylindrical surface F2a, and is related to the center line L of the second fixed cylindrical surface F2a. The radius of curvature is dimensioned smaller than the radius of curvature with respect to the center line L of the third fixed cylindrical surface F3a.

  In addition, as shown in FIG. 3, the first supply path 22a extends in a direction orthogonal to the planar region 21, and the inner peripheral end thereof opens at the first fixed cylindrical surface F1a. Similarly, the second supply path 22b extends in the radial direction, and an inner peripheral end thereof opens at a second fixed cylindrical surface F2a that constitutes a second fixed step portion F2.

  As is apparent from FIG. 2, the upper fixed half piece 20A is also provided with three fixed step portions F4, F5, and F6, similarly to the above-described lower fixed half piece 20B. The fourth fixed step portion F4 is vertically symmetrical with the third fixed step portion F3, and has a fourth fixed cylindrical surface F4a and a fourth fixed annular surface F4b. The fifth fixed step portion F5 is vertically symmetrical with the second fixed step portion F2, and has a fifth fixed cylindrical surface F5a and a fifth fixed annular surface F5b. The sixth fixed step portion F6 is vertically symmetrical with the first fixed step portion F1, and has a sixth fixed cylindrical surface F6a and a sixth fixed annular surface F6b. Since these are vertically symmetric, a detailed description thereof will be omitted.

  The upper fixed half piece 20A is also provided with a third supply path 22c and a fourth supply path 22d, as in the above-described lower fixed half piece 20B. However, these are the same as in the case of the above-described lower fixed half piece 20B, and therefore, detailed description thereof is omitted.

  In a state where the rotating body 10 and the fixed body 20 configured as described above are fixed via the rolling bearings B1 and B2 so as to be relatively rotatable with each other, the rotation body 10 and the fixed body 20 are defined by the first rotation step portion D1 and the first fixed step portion F1. The first O-ring R1 is disposed in the first annular sealing space S1 having a substantially square shape in cross section. Further, the second O-ring R2 is accommodated in a second annular sealing space S2 defined by the second rotating step portion D2 and the second fixed step portion F2 and having a substantially square shape in cross section. Similarly, the third O-ring R3 is accommodated in a third annular sealing space S3 that is defined by the third rotating step portion D3 and the third fixed step portion F3 and has a substantially square shape in cross section. The

  Note that, on the upper fixed half piece 20A side, as in the above-described lower fixed half piece 20B, the fourth annular sealed space S4, the fifth annular sealed space S5, and the sixth annular sealed space S6 are provided. Is provided. Among these, the fourth annular sealing space S4 is vertically symmetrical with the third annular sealing space S3, and is defined by the fourth rotation step portion D4 and the fourth fixed step portion F4, and inside thereof. A fourth O-ring R4 is accommodated. Further, the fifth annular sealing space S5 is vertically symmetrical with the second annular sealing space S2, is defined by the fifth rotation step portion D5 and the fifth fixed step portion F5, and has a fifth inside. The O-ring R5 is housed. The sixth annular sealing space S6 is vertically symmetrical with the first annular sealing space S1, is defined by the sixth rotation step portion D6 and the sixth fixed step portion F6, and has a sixth inside. O-ring R6 is housed. Since these are vertically symmetric, a detailed description thereof will be omitted.

  Further, the radius of curvature of the second rotating cylindrical surface D2a of the second rotating step portion D2 is sized smaller than the radius of curvature of the first fixed cylindrical surface F1a of the first fixed step portion F1. The lower surface 10b side of the second rotating cylindrical surface D2a and the upper surface 10a side of the first fixed cylindrical surface F1a are in close proximity to each other. Hereinafter, this proximity facing portion is referred to as a first communication path P1. The flow of the fluid flowing through the first communication path P1 is regulated by the first O-ring R1 and the second O-ring R2. Therefore, the fluid entering from the hose joint 40 is rotated from the hose joint 30 through the first supply path 22a, the first communication path P1, the first branch path 13a, and the first discharge path 11a. Supplied to the mechanism.

  Further, as described above, the outer peripheral surface of the first communication path P1 is configured by the first fixed cylindrical surface F1a. Then, the inner peripheral surface of the first communication path P1 is configured by the second rotating cylindrical surface D2a, and the curvature radius of the second rotating cylindrical surface D2a is set to be equal to the inner diameter dimension of the cross section of the first O-ring R1. The diameter is within the range. That is, the second rotating cylindrical surface D2a is dimensioned so as to be larger than the curvature radius of the inner peripheral surface of the first O-ring R1 and smaller than the curvature radius of the outer peripheral surface in the cross-sectional view of FIG. With this configuration, for example, a flow path can be provided between the two O-rings R1 and R2, but in this case, it is necessary to form a groove as a flow path on the second rotating cylindrical surface D2a. Absent. Therefore, the axial dimension of the rotary joint 1 can be reduced.

  Similarly, the other connecting path P (second connecting path P2, third connecting path P3, fourth connecting path P4) includes two O-rings, a fixed cylindrical surface and a rotating cylindrical surface facing each other in the radial direction. It consists of. The fluid introduced from the hose joint 40 to the second supply path 22b is attached to the rotating body 10 from the second discharge path 11b via the second communication path P2 and the second branch path 13b. Is supplied to a rotating mechanism. Similarly, the fluid introduced from the hose joint 40 to the third supply path 22c passes from the third discharge path 11c to the rotating body 10 via the third communication path P3 and the third branch path 13c. Supplied to the mounted rotation mechanism. The fluid introduced from the hose joint 40 to the fourth supply path 22d is attached to the rotating body 10 from the fourth discharge path 11d via the fourth communication path P4 and the fourth branch path 13d. Is supplied to a rotating mechanism. Furthermore, the inner peripheral surface and outer peripheral surface of each communication path P (P1 to P4) and the related O-rings R1 to R6 have the above-described dimensional relationship.

  The first annular sealing space S1 corresponds to one annular sealing space, and the second annular sealing space S2 corresponds to the other annular sealing space. At this time, the first communication path P1 corresponds to the communication path, the first O-ring R1 corresponds to one sealing member, and the second O-ring R2 corresponds to the other sealing member. The first rotation stage D1 corresponds to one rotation stage, the second rotation stage D2 corresponds to the other rotation stage, and the first fixed stage F1 corresponds to one fixed stage. Correspondingly, the second fixed step portion F2 corresponds to the other fixed step portion.

  However, on the contrary, the first annular sealing space S1 may correspond to the other annular sealing space, and the second annular sealing space S2 may correspond to the one annular sealing space. At this time, the first O-ring R1 corresponds to the other sealing member, and the second O-ring R2 corresponds to one sealing member. The first rotation stage D1 corresponds to the other rotation stage, the second rotation stage D2 corresponds to one rotation stage, and the first fixed stage F1 corresponds to the other fixed stage. Correspondingly, the second fixed step portion F2 corresponds to one fixed step portion.

  Further, the second annular sealing space S2 may correspond to one annular sealing space, and the third annular sealing space S3 may correspond to the other annular sealing space, and the second communication path P2 May correspond to the connecting path. At this time, the second O-ring R2 corresponds to one sealing member, and the third O-ring R3 corresponds to the other sealing member. The second rotation stage D2 corresponds to one rotation stage, the third rotation stage D3 corresponds to the other rotation stage, and the second fixed stage F2 corresponds to one fixed stage. Correspondingly, the third fixed step portion F3 corresponds to the other fixed step portion.

  However, on the contrary, the second annular sealing space S2 may correspond to the other annular sealing space, and the third annular sealing space S3 may correspond to the one annular sealing space. At this time, the second O-ring R2 corresponds to the other sealing member, and the third O-ring R3 corresponds to the one sealing member. The second rotation stage D2 corresponds to the other rotation stage, the third rotation stage D3 corresponds to one rotation stage, and the second fixed stage F2 corresponds to the other fixed stage. Correspondingly, the third fixed step portion F3 corresponds to one fixed step portion.

  Further, the sixth annular sealing space S6 may correspond to one annular sealing space, and the fifth annular sealing space S5 may correspond to the other annular sealing space, and the fourth communication path P4. May correspond to the connecting path. At this time, the sixth O-ring R6 corresponds to one sealing member, and the fifth O-ring R5 corresponds to the other sealing member. Further, the sixth rotation step portion D6 corresponds to one rotation step portion, the fifth rotation step portion D5 corresponds to the other rotation step portion, and the sixth fixed step portion F6 corresponds to one fixed step portion. Correspondingly, the fifth fixed step portion F5 corresponds to the other fixed step portion.

  However, on the contrary, the sixth annular sealing space S6 may correspond to the other annular sealing space, and the fifth annular sealing space S5 may correspond to one annular sealing space. At this time, the sixth O-ring R6 corresponds to the other sealing member, and the fifth O-ring R5 corresponds to the one sealing member. Further, the sixth rotation step portion D6 corresponds to the other rotation step portion, the fifth rotation step portion D5 corresponds to one rotation step portion, and the sixth fixed step portion F6 corresponds to the other fixed step portion. Correspondingly, the fifth fixed step portion F5 corresponds to one fixed step portion.

  Further, the fifth annular sealing space S5 may correspond to one annular sealing space, and the fourth annular sealing space S4 may correspond to the other annular sealing space, and the third communication path P3. May correspond to the connecting path. At this time, the fifth O-ring R5 corresponds to one sealing member, and the fourth O-ring R4 corresponds to the other sealing member. In addition, the fifth rotation step portion D5 corresponds to one rotation step portion, the fourth rotation step portion D4 corresponds to the other rotation step portion, and the fifth fixed step portion F5 corresponds to one fixed step portion. Correspondingly, the fourth fixed step portion F4 corresponds to the other fixed step portion.

  However, on the contrary, the fifth annular sealing space S5 may correspond to the other annular sealing space, and the fourth annular sealing space S4 may correspond to one annular sealing space. At this time, the fifth O-ring R5 corresponds to the other sealing member, and the fourth O-ring R4 corresponds to one sealing member. The fifth rotation stage D5 corresponds to the other rotation stage, the fourth rotation stage D4 corresponds to one rotation stage, and the fifth fixed stage F5 corresponds to the other fixed stage. Correspondingly, the fourth fixed step portion F4 corresponds to one fixed step portion.

[Operation mechanism of rotary joint]
The operation mechanism of the rotary joint 1 having the above configuration will be described mainly with reference to FIG. FIG. 4 is a schematic diagram for explaining the relationship between the fixed body 20, the rotating body 10, and the O-rings R1 and R2. FIG. 4A shows a case where negative pressure is supplied to the first communication path P1. FIG. 4B shows a state in which positive pressure is supplied to the first communication path P1.

  When the rotating body 10 of the rotary joint 1 according to this embodiment rotates around the center line L that is the rotation center with respect to the lower fixed half piece 20B of the fixed body 20, the O-rings R1 and R2 together with the rotating body 10 Whether it rotates or is stationary with the fixed body 20 (lower fixed half piece 20B) is determined by the size of the contact area of the O-rings R1 and R2 with respect to the fixed step portions F1 and F2 and the rotation step portions D1 and D2.

  As shown in FIG. 4A, when negative pressure is supplied to the first communication path P1 through the first supply path 22a (see FIG. 3), the first annular sealed space S1 and the first In the two annular sealing spaces S2, the first O-ring R1 and the second O-ring R2 move in the direction of the first communication path P1. At this time, the first O-ring R1 includes the first rotating cylindrical surface D1a and the first rotating annular surface D1b of the first rotating step portion D1, and the first fixed cylindrical surface of the first fixed step portion F1. Contact F1a. On the other hand, the second O-ring R2 includes the second rotating cylindrical surface D2a of the second rotating step portion D2, the second fixed cylindrical surface F2a and the second fixed annular surface F2b of the second fixed step portion F2. Contact with.

  Accordingly, as shown in FIG. 4A, the contact area of the first O-ring R1 with respect to the first rotating step portion D1 is larger than the contact area with respect to the first fixed step portion F1, so that the first O-ring R1. Rotates together with the rotating body 10. As a result, the outer peripheral surface of the first O-ring R1 slides on the first fixed cylindrical surface F1a. On the other hand, since the contact area of the second O-ring R2 with respect to the second rotating step portion D2 is smaller than the contact area with respect to the second fixed step portion F2, the second O-ring R2 is fixed to the fixed body 20 (lower fixed half 20B). As a result, the inner peripheral surface of the second O-ring R2 slides on the second rotating cylindrical surface D2a.

  As shown in FIG. 4B, in a state where positive pressure is supplied to the first communication path P1 via the first supply path 22a (see FIG. 3), the first annular sealed space S1 and In the second annular sealing space S2, the first O-ring R1 and the second O-ring R2 move in a direction away from the first communication path P1. At this time, the first O-ring R1 includes the first rotating cylindrical surface D1a of the first rotating step portion D1, the first fixed cylindrical surface F1a and the first fixed annular surface of the first fixed step portion F1. Contact F1b. On the other hand, the second O-ring R2 includes the second rotating cylindrical surface D2a and the second rotating annular surface D2b of the second rotating step portion D2, and the second fixed cylindrical surface F2a of the second fixed step portion F2. Contact with.

  Therefore, as shown in FIG. 4B, the contact area of the first O-ring R1 with respect to the first rotation step portion D1 is smaller than the contact area with respect to the first fixed step portion F1, so that the rotating body 10 rotates. At this time, the first O-ring R1 stops together with the fixed body 20 (lower fixed half piece 20B). As a result, the inner peripheral surface of the first O-ring R1 slides on the first rotating cylindrical surface D1a. On the other hand, since the contact area of the second O-ring R2 with respect to the second rotating step portion D2 is larger than the contact area with respect to the second fixed step portion F2, the second O-ring R2 rotates together with the rotating body 10. As a result, the outer peripheral surface of the second O-ring R2 slides on the second fixed cylindrical surface F2a.

  As described above, the first and second Os when the rotating body 10 rotates in the case where the positive pressure is applied to the first communication path P1 and the case where the negative pressure is applied. Since the sliding surfaces of the rings R1 and R2 change, it is possible to prevent the amount of wear at the portions of the first and second O-rings R1 and R2 from being biased, and to improve the durability of the sealing member. The same operation is performed for the O-rings R2, R3, R4, R5, and R6 related to the other second, third, and fourth communication paths P2, P3, and P4.

[Second Embodiment]
Next, a rotary joint 1S according to the second embodiment will be described with reference to FIG. FIG. 5A is a plan view showing a rotary joint 1S according to the second embodiment, and FIG. 5B is a cross-sectional view taken along line V-V in FIG. 5 (c) is a back view of FIG. 5 (a).

  In the present embodiment, the same components as those of the rotary joint 1 according to the first embodiment described above will be described using the same reference numerals. Note that the rotary joint 1S according to the second embodiment is composed of the rotating body 10 and the fixed body 20 as in the first embodiment, and the annular sealed space is formed on the same principle as in the first embodiment. Form. Therefore, the configuration of each part is basically the same, and different parts will be described below.

  Unlike the first embodiment, the rotary joint 1 </ b> S according to the second embodiment is configured to include two discharge paths 11 and two supply paths 22.

  The two discharge paths 11 described above are provided at positions that are symmetrical with respect to the center line L. In this embodiment, the rotary joint 1S includes two branch paths 13 (a first branch path 13a and a second branch path 13b), and one ends of the first and second branch paths 13a and 13b are provided. These are connected to the first and second discharge paths 11 a and 11 b, respectively, and the other ends are opened at the outer peripheral surface of the rotating body 10.

  Further, the fixed body 20 of the present embodiment includes a lower half 20C constituting the first to third fixed steps F1 to F3 and an upper half 20D fixed to the lower half 20C in the axial direction. It is a component structure. However, it is also possible to configure the fixed body from one part.

  In addition, the fixed body 20 of the present embodiment has a cylindrical shape and includes two supply paths 22 (a first supply path 22a and a second supply path 22b) to which a fluid is supplied. A screw hole 221 is provided on the outer peripheral side. Then, the screw portion 41 of the hose joint 40 is screwed into the screw hole portion 221.

  By using the rotary joint 1S having such a configuration, fluid can be exchanged between elements (rotation mechanism and fixing mechanism) that rotate relative to each other. In addition, the rotary joint of this embodiment can change the number of the discharge paths 11 and the supply paths 22 arbitrarily.

  Needless to say, the functions and effects described in connection with the first embodiment can also be obtained in this embodiment.

[Third Embodiment]
A rotary joint 1T according to the third embodiment has a configuration in which a slip ring 301 is incorporated in the rotary joint 1 according to the first embodiment. A rotary joint 1T according to a third embodiment will be described with reference to FIG. FIG. 6 is a cross-sectional view showing a state in which the slip ring 301 is incorporated in the rotary joint 1T according to the first embodiment. In addition, the rotary joint 1T of this embodiment is used in a state where the rotary joint 1 shown in FIG. 2 is reversed and the hose joint 30 is mounted on the lower surface 20B2.

  The slip ring 301 is a mechanism for performing power feeding and data communication between components (rotating mechanism and fixing mechanism) that rotate relative to each other. The slip ring 301 used in the present embodiment includes a cylindrical slip ring main body 303, a rotation-side electric wire 305, a fixed-side electric wire 307, a fixed shaft fastening member 309, a shaft member 311, a main body fastening member 313, The shaft member 311 and the slip ring body 303 are supported at one end of the shaft member 311 in the slip ring body 303 so as to be relatively rotatable with each other.

  The slip ring main body 303 is disposed in the through hole 12 defined by the inner peripheral surface 10 c of the rotary joint 1 according to the first embodiment, and is fixed to the main body fastening member 313 by a screw member 315. The main body fastening member 313 is attached below the inner peripheral surface 10 c of the rotating body 10. On the other hand, the shaft member 311 is fixed to the fixed shaft fastening member 309 by a screw member (not shown) which is a fastening means. The fixed shaft fastening member 309 is fixed to 20A1 of the fixed body 20 by a screw member 91.

  In the above configuration, the slip ring main body 303 and the rotation-side electric wire 305 rotate with the rotation of a rotation mechanism (not shown) to which the rotating body 10 is attached. On the other hand, the shaft member 311 and the slip ring main body 303 are in a stationary state together with the fixed body 20. Accordingly, between the fixing mechanism (not shown) attached to the fixed body 20 and the rotating mechanism (not shown) attached to the rotating body 10, power is supplied via the fixed-side electric wire 307, the slip ring body 303, and the rotating-side electric wire 305. Information communication and the like can be performed. As described above, in the rotary joints 1, 1 </ b> S, and 1 </ b> T in which the rotating body 10 includes the through hole 12, devices used together with the rotary joint can be accommodated in the through hole 12. Can be reduced in size.

[Fourth Embodiment]
In the fourth embodiment, the rotary joints 1 and 1S according to the first and second embodiments are connected. A rotary joint 1F according to a fourth embodiment will be described with reference mainly to FIG. FIG. 7 is a front view showing a state where the rotary joint 1 according to the first embodiment shown in FIG. 1 and the rotary joint 1S according to the second embodiment shown in FIG. 6 are connected.

  As shown in FIG. 2, the lower surface 20B2 of the fixed body 20 of the rotary joint 1 is substantially flat. As shown in FIG. 5B, the lower surface 20b of the fixed body 20 of the rotary joint 1S is also substantially flat. Moreover, the diameter of the inner peripheral surface 10c of the rotating body 10 is dimensioned the same. Similarly, the outer peripheral surface 20a of the fixed body 20 is also dimensioned in the same manner. According to the rotary joints 1 and 1S having the above-described configuration, a plurality of rotary joints can be stacked by fastening the rotating bodies 10 with bolts and nuts which are known fastening means.

  Further, the rotary joint 1 </ b> F is configured to penetrate through the entire axial direction due to the presence of the through hole 12 of the rotating body 10. For example, when a fluid pipe 77 (77a, 77b) for supplying a fluid to a rotation mechanism (not shown) is attached to the hose joint 30 of the rotary joint 1S, the fluid pipe 77 passes through the through-hole 12 (FIG. 2). 5 (b)), the supply pipe (not shown) attached to the hose joint 40 of the fixed body 20 and the fluid pipe 77 do not interfere with each other. As a result, the versatility of the rotary joints 1 and 1S can be improved.

  The fluid pipe 78 is connected to the hose joint 30 on the rotary joint 1 side. The fluid pipe 78 is a part that supplies a fluid to a rotation mechanism (not shown), similarly to the fluid pipe 77 described above.

  In 4th Embodiment, although it is the structure which couple | bonds the 1st and 2nd rotary joints 1 and 1S, it can also be set as the structure which connects only one of the 1st and 2nd rotary joints 1 and 1S. is there.

  In the rotary joints 1 and 1S of the first and second embodiments, the rotating body is configured to include a through hole penetrating in the rotation center direction, but the rotary joint of the present invention is not limited to this configuration. It is also possible to use a solid rotating body.

  The rotary joints 1 and 1S of the first to fourth embodiments are configured to use a gas as a fluid, but the rotary joint of the present invention can also be configured to flow a liquid between relative rotating members. . Further, in the rotary joints 1, 1 </ b> S, 1 </ b> T, and 1 </ b> F of the first to fourth embodiments, the member disposed on the outer peripheral side is the fixed body 20, and the member disposed on the inner peripheral side is relative to the fixed body 20. However, the present invention is not limited to this configuration. It is also possible to rotate the stationary body arranged on the inner circumferential side and use the rotating body arranged on the outer circumferential side as a stationary member that does not rotate.

  The rotary joint 1 of the first embodiment is configured to include four supply paths 22 and four discharge paths 11, and the rotary joint 1S of the second embodiment includes two supply paths 22 and two discharge paths. However, the rotary joint of the present invention is not limited to the above-described configuration, and an arbitrary number of discharge holes and supply holes can be provided.

DESCRIPTION OF SYMBOLS 1,1S, 1T, 1F ... Rotary joint, 10 ... Rotating body, 10a ... Upper surface, 10b ... Lower surface 10, 10c ... Inner peripheral surface, 11 ... Discharge path, 11a-11d ... 1st-4th discharge path, 12 DESCRIPTION OF SYMBOLS ... Through-hole, 13 ... Branch path, 13a-13d ... 1st-4th branch path, 20 ... Fixed body, 20a ... Outer peripheral surface, 20b ... Lower surface, 20A ... Upper fixed half piece, 20B ... Lower fixed half piece, 20B1 ... Upper surface, 20B2 ... Lower surface, 20C ... Lower half piece, 20D ... Upper half piece, 21 ... Planar region, 22 ... Supply path, 22a-22d ... First to fourth supply paths, 30 ... Hose joint, 31 ... Screw part, 40 DESCRIPTION OF SYMBOLS ... Hose coupling, 41 ... Screw part, 77, 78 ... Fluid pipe, 91 ... Screw member, 111, 112 ... Screw hole part, 301 ... Slip ring, 303 ... Slip ring main body, 305 ... Rotation side electric wire, 307 ... Fixed side Electric wire, 309 Fixed shaft fastening member, 311 ... Shaft member, 313 ... Main body fastening member, 315 ... Screw member, B1, B2 ... Rolling bearings, D1-D6 ... First to sixth rotation steps, D1a-D6a ... First-first 6 rotating cylindrical surfaces, D1b to D6b ... 1st to 6th rotating annular surfaces, F1 to F6 ... 1st to 6th fixed step portions, F1a to F6a ... 1st to 6th fixed cylindrical surfaces, F1b to F6b: 1st to 6th fixed annular surface, P1 to P4: 1st to 4th communication path, R1 to R6 ... 1st to 6th O-ring, S1 to S6 ... 1st to 6th annular seal Stop space

Claims (7)

A fixed body,
A rotating body mounted so as to be relatively rotatable around a rotation center with respect to the fixed body;
One and the other sealing members arranged in one and the other annular sealing space defined by the fixed body and the rotating body;
A communication path communicating with the one and the other annular sealing space,
The one annular sealing space and the other annular sealing space have different distances from the rotation center,
A rotary joint characterized by that. The rotary joint according to claim 1,
The fixed body is provided with one fixed step portion and the other fixed step portion, and the one fixed step portion and the other fixed step portion have different distances from the rotation center,
The rotating body is provided with one rotation step portion and the other rotation step portion, and the one rotation step portion and the other rotation step portion have different distances from the rotation center,
The one annular sealing space is formed by the one rotating stepped portion facing the one fixed stepped portion,
The other annular sealing space is formed by the other rotating stepped portion facing the other fixed stepped portion,
A rotary joint characterized by that. The rotary joint according to any one of claims 1 to 2,
The communication path is defined by one fixed cylindrical surface constituting the one annular sealed space and the other rotating cylindrical surface constituting the other annular sealed space.
A rotary joint characterized by that. The rotary joint according to any one of claims 1 to 3,
The dimension in the radial direction of the communication path is within the range of the inner diameter dimension and the outer diameter dimension of the cross section of the one sealing member.
A rotary joint characterized by that. The rotary joint according to any one of claims 1 to 4,
The rotating body includes a through hole penetrating in a direction in which the rotation center extends.
A rotary joint characterized by that. The rotary joint according to claim 5,
A fluid pipe that is attached to the rotating body and communicates with the communication path;
The fluid pipe extends into the through hole;
A rotary joint characterized by that. A plurality of rotary joints according to claim 6,
Fastening means for connecting the plurality of rotary joints to each other,
Fluid pipes attached to a rotary body of one rotary joint among the plurality of rotary joints are formed in a through hole of the one rotary joint and a through hole of another rotary joint of the plurality of rotary joints. A rotary joint that is inserted.

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