JP2010265915A - Multi-passage rotary joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economical and practical multi-passage rotary joint which can be reduced in size as much as possible in any of the axial and radial directions. <P>SOLUTION: The multi-passage rotary joint connects a rotating side case 2 attached to a rotary shaft 1 of rotating equipment or a rotating side member including the same while being fitted or inserted into the rotary shaft 1, and a stationary side case 3 attached to a stationary side member of the rotary equipment in a relatively rotatable state via a bearing 4 around the rotary shaft. Between both the cases 2, 3, first and second passages 14, 15 are formed to communicate with first and second connection spaces 8, 9 sectioned and sealed by first to third mechanical seals 5, 6, 7 disposed in parallel coaxially with the rotary shaft 1. The bearing 4 is composed of an upper side bearing 4a and a lower side bearing 4b, and disposed inside of the first mechanical seal 5 with the minimum diameter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is mounted on a rotating device such as a semiconductor manufacturing apparatus, a stirrer, a medical device, and a food device in a state where the rotating shaft is fitted or inserted into the rotating device, and between the relative rotating members of the rotating device (the rotating side member and the stationary member). The present invention relates to a multi-channel rotary joint for causing a plurality of fluids (same or different types of liquids and gases) to flow in different routes without being mixed with each other.

  This type of multi-channel rotary joint is attached to a rotating side member including a rotating shaft of a rotating device and attached to a rotating side case fitted to or inserted through the rotating shaft and a stationary member of the rotating device. The stationary side case is connected by a bearing so as to be relatively rotatable around the rotation axis, and a plurality of flow flows communicated between the cases via a plurality of connection spaces that are partitioned and sealed by three or more mechanical seals. In the one in which the path is formed, three or more mechanical seals are arranged in tandem in the axial direction of the rotating shaft (hereinafter referred to as “first conventional joint”; for example, refer to Patent Document 1) and three or more mechanical seals. Are arranged in parallel in the radial direction of the rotating shaft (hereinafter referred to as “second conventional joint”, for example, see Patent Document 2 or Patent Document 3). It is well known.

JP 2001-141150 A JP 2003-04373 A JP 2004-183901 A

  However, the mechanical seal is configured to rotate relatively in a state where the fixed sealing ring fixed to one of the two cases and the movable sealing ring held to the other side so as to be movable in the axial direction are pressed and contacted by the spring member. Therefore, in the first conventional joint in which a plurality of mechanical seals are arranged in tandem in the axial direction, the moving space of the movable sealing ring and the installation space of the spring member are required in addition to the installation space of both sealing rings. The direction dimension becomes long. The axial dimension increases as the number of flow paths increases, that is, as the number of mechanical seals increases. Therefore, a large installation space is required in the axial direction, and applicable rotary devices are greatly limited. In addition, in order for the sealing function by the mechanical seal to be satisfactorily exhibited, the seal rings need to be in proper contact with each other, and it is necessary to reliably prevent the occurrence of vibration and shaft runout between the two cases. Since the dimension in the axial direction is long, it is difficult to reliably prevent the shaft from touching.

  On the other hand, the second conventional joint in which a plurality of mechanical seals are arranged in parallel in the radial direction does not have the above-described problem, but the bearing that connects both cases is arranged outside the maximum diameter mechanical seal, so Compared to this, a bearing having a very large diameter is required. Moreover, it is not necessary to increase the bearing diameter even if the number of flow paths, that is, the number of mechanical seals is increased in the first conventional joint, but in the second conventional joint, the bearing diameter increases as the number of mechanical seals increases. It will be. Accordingly, since the radial dimension becomes longer and a large installation space is required in the radial direction, coupled with the fact that the large-diameter bearing is expensive, the applicable rotary equipment is greatly limited. Application to a rotating device having a large diameter is greatly limited in terms of both cost and installation space. Furthermore, it is difficult to ensure good lubrication over a long period of time with a large-diameter bearing of the shield type or seal type that is generally used (with the bearing filled with a lubricant such as grease). Durability and life are reduced.

  The present invention has been made in view of the above points, and can solve the above-described problems in the first and second conventional joints to realize the miniaturization as much as possible in both the axial direction and the radial direction. An object of the present invention is to provide an economical and practical multi-channel rotary joint that can be used.

  The present invention includes a rotating side case that is attached to a rotating shaft of a rotating device or a rotating side member that includes the rotating shaft while being fitted or inserted into the rotating shaft, and a stationary case that is attached to a stationary side member of the rotating device. The bearings are connected so that they can rotate relative to each other around the rotation axis. The two cases communicate with each other through a plurality of connection spaces that are partitioned and sealed by three or more mechanical seals arranged concentrically with the rotation axis. In order to achieve the above object, in the multi-channel rotary joint in which a plurality of channels are formed, in particular, it is proposed to arrange a bearing inside a mechanical seal having a minimum diameter.

  In a preferred embodiment of such a multi-channel type rotary joint, a cylindrical rotary side bearing portion in which the rotary side case is fitted or inserted into the rotary shaft, and a disk-like rotary side mechanical member protruding from the outer peripheral direction therefrom. A seal holding part, and a stationary side case having a cylindrical stationary side bearing part surrounding the rotating side bearing part and a disk-like stationary side mechanical seal holding part projecting in the outer peripheral direction therefrom The bearing is loaded between the opposed peripheral surfaces of both bearing parts, and each mechanical seal can move in the axial direction to the fixed seal ring fixed to one mechanical seal holding part and the other mechanical seal holding part And a spring member that urges the movable seal ring to be brought into pressure contact with the fixed seal ring.

  Further, the multi-channel rotary joint of the present invention is preferably used for a rotating device having a vertical rotation axis. In such a usage mode, it is preferable to further configure as follows.

  That is, the bearing is composed of an upper bearing and a lower bearing arranged at a predetermined interval in the vertical direction, and the bearing loading space formed between the opposed peripheral surfaces of both bearing portions is filled with a bearing lubricant, and It is preferable to seal the lower end of the loading space. In such a case, the lower bearing is preferably a parallel combination angular contact ball bearing.

  In addition, the rotation-side mechanical seal holding portion and the stationary-side mechanical seal holding portion face each other vertically, and each fixed seal ring is positioned at the upper position (the rotation-side mechanical seal holding portion or the stationary-side mechanical seal holding portion). Are fixed and held in a suspended state by frictional engagement force by an O-ring interposed between them, and the mechanical seal holding portion positioned at the upper position is provided with each fixed holding sealing ring at the time of mechanical seal assembly. It is preferable that a temporary fixing means for temporarily fixing to the hanging support is detachably provided. In addition, the rotating side mechanical seal holding part and the stationary side mechanical seal holding part are vertically opposed to each other, and the stationary side mechanical seal holding part is positioned between the stationary side bearing part and the smallest diameter mechanical seal. It is preferable to form a drain passage opening in the drain space to be formed. The rotating side mechanical seal holding part and the stationary side mechanical seal holding part are vertically opposed to each other, and the sealing ring of the maximum diameter mechanical seal held by the stationary side mechanical seal holding part is provided on the lower side. It is preferable that a surrounding cylindrical drain wall is provided, and that a drain passage opening to a drain space formed between the maximum diameter mechanical seal and the drain wall is formed. Moreover, it is preferable that the upper end of a stationary side bearing part and / or a drain wall is located higher than the relative rotational sliding contact surface of a fixed sealing ring and a movable sealing ring. Furthermore, the upper mechanical seal holder (rotary side mechanical seal holder or stationary side mechanical seal holder) is suspended downward from the relative rotational sliding contact surface of the fixed seal ring and the movable seal ring and has a maximum diameter. A dustproof cover having a cylindrical dustproof wall surrounding the mechanical seal is preferably provided.

  The multi-channel rotary joint of the present invention has a plurality of mechanical seals arranged in parallel in the radial direction, and a bearing is arranged inside the mechanical seal having the smallest diameter. While maintaining the same, it is possible to eliminate fatal defects in the second conventional joint, and it is economical and practical to be able to realize the miniaturization as much as possible in both the axial direction and the radial direction. It has excellent properties.

  That is, by arranging the bearing inside the mechanical seal having the smallest diameter, the bearing having the smallest diameter corresponding to the rotational shaft diameter can be used regardless of the increase or decrease in the number of flow paths, that is, the number of mechanical seals. Compared to joints, the radial dimension can be greatly shortened, and it can be applied not only to the axial installation space but also to rotating equipment with a small radial installation space. Can be achieved. In addition, since a bearing with a larger diameter than necessary is not required, the cost required for the bearing and thus the manufacturing cost of the rotary joint can be reduced as much as possible to improve the life, durability and reliability of the rotary joint. be able to.

FIG. 1 is a longitudinal sectional view showing an example of a multi-channel rotary joint according to the present invention. FIG. 2 is a longitudinal sectional view of the rotary joint cut at a position different from that in FIG. FIG. 3 is a longitudinal sectional view of the rotary joint cut at a position different from that in FIGS. 1 and 2. FIG. 4 is a longitudinal sectional view corresponding to FIG. 3, and shows a state during the assembly of the rotary joint.

  Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings. 1 is a longitudinal sectional view showing an example of a multi-channel rotary joint according to the present invention, FIG. 2 is a longitudinal sectional view of the rotary joint cut at a position different from FIG. 1, and FIG. FIG. 4 is a longitudinal sectional view of the rotary joint cut at a position different from that in FIG. 2, and FIG. 4 is a longitudinal sectional view corresponding to FIG. 3, showing a state during the assembly of the rotary joint.

  In this embodiment, a rotating side member (for example, a rotating table driven horizontally by a rotating shaft) and a stationary side member of a rotating device (for example, a polishing apparatus that uses a rotating table) having a rotating shaft whose axis is vertical. (For example, a device body that supports and drives a rotating shaft) A first and second fluid (same type or different type of liquid, gas) can flow between the different routes without being mixed with each other. The present invention relates to an example in which the present invention is applied to a rotary joint.

  That is, as shown in FIGS. 1 and 2, the multi-channel rotary joint in this embodiment includes a rotating side case 2 attached to the rotating side member while being inserted through the rotating shaft 1 extending in the vertical direction, and a stationary side. The stationary case 3 attached to the member, the bearing 4 for connecting the cases 2 and 3 so as to be rotatable relative to each other around the rotation shaft 1, and the rotation shaft 1 between the cases 2 and 3 are arranged in parallel. First and second connection spaces 8, 9 formed between the first to third mechanical seals 5, 6, 7 and the adjacent mechanical seals 5, 6, 6, 7 formed between the cases 2, 3. The first and second rotation-side passages 10 and 11 formed in the rotation-side case 2 and opening into the first and second connection spaces 8 and 9, and the first and second connections formed in the stationary-side case 3. First stationary passage 1 opening in the spaces 8 and 9 , 13, and a series of first and second flow paths formed by connecting the rotation-side passages 10, 11 and the stationary-side passages 12, 13 through the connection spaces 8, 9 between the cases 2, 3. 14 and 15 are formed.

  As shown in FIGS. 1 to 3, the rotation-side case 2 is a disk-shaped rotation-side mechanical seal that projects horizontally in the outer peripheral direction from the vertical cylindrical rotation-side bearing portion 16 inserted through the rotation shaft 1 and its upper end portion. And holding unit 17. The rotation-side bearing portion 16 is divided into three parts (first to third parts) 16a, 16b, and 16c in the vertical direction, and is connected by an appropriate number of bolts 18a and 18b as shown in FIG. Yes. The rotation side mechanical seal holding portion 17 is integrally formed with a first portion 16 a that is an upper end portion of the rotation side bearing portion 16. Concentric annular first and second convex portions 17 a and 17 b centering on the case axis are formed on the lower surface portion of the rotation-side mechanical seal holding portion 17. The rotating side case 2 is attached to the rotating side member of the rotating device. In this example, the upper end portion of the rotating portion 1 is rotated, with the bearing portion 16 fitted or inserted into the rotating shaft 1, that is, the upper end portion of the first portion 16a. It is attached to the table.

  As shown in FIGS. 1 to 3, the stationary case 3 has a disk-like shape that extends horizontally in the outer circumferential direction from a vertical cylindrical stationary bearing 19 that concentrically surrounds the rotating bearing 16 and a lower end thereof. It is an integral structure comprising a stationary side mechanical seal holding portion 20 and a vertical cylindrical drain wall 21 rising upward from an outer peripheral edge thereof. The length in the axial direction of the stationary side bearing portion 19 is slightly higher than the upper end of the second portion 16b that is an intermediate portion of the rotating side bearing portion 16 and whose upper end is close to the lower surface of the rotating side mechanical seal holding portion 17. Is set to be located. Concentric annular first and second convex portions 20 a and 20 b centering on the case axis are formed on the upper surface portion of the stationary side mechanical seal holding portion 20 in the vertical direction. It is formed at a position facing the convex portions 17a and 17b. The stationary side case 2 is attached to the stationary side member of the rotating device. In this example, the stationary side mechanical seal holding portion 20 is attached to the apparatus main body that supports and drives the rotating shaft 1.

  As shown in FIGS. 1 to 3, the bearing 4 is loaded in a cylindrical bearing loading space 22 formed between the opposed peripheral surfaces of both bearing portions 16, 19. It is connected so that relative rotation is possible about the axis of The bearing 4 is composed of an upper bearing 4a and a lower bearing 4b which are arranged vertically at a predetermined interval. The upper bearing 4 a is a radial ball bearing that is loaded between the upper end portions of the second portion 16 b of the rotating side bearing portion 16 and the stationary side bearing portion 19, and the lower bearing 4 b is the second portion 16 b of the rotating side bearing portion 16. And a parallel combination angular contact ball bearing loaded between the upper end portions of the stationary bearing portion 19. The lower end surface of the inner diameter ring of the lower bearing 4b is supported by an annular recess 16d formed on the outer peripheral upper end surface of the third portion 16c, which is the lower end portion of the rotation side bearing portion 16, and the lower end surface of the outer diameter ring is The stationary bearing 19 is supported by an annular ring 24 that is fitted in a recess formed at the lower end of the inner periphery of the stationary bearing 19 and is secured by a suitable number of bolts 23 (see FIG. 3).

  As shown in FIGS. 1 to 3, the lower end portion of the rotation side bearing portion 16 (the lower end portion of the third portion 16 c) is in pressure contact with the annular ring 23, and the lower end portion of the bearing loading space 22 (below the lower bearing 4 b). An annular seal member (in this example, a lip seal) 25 that seals the portion) is provided. The bearing loading space 22 sealed by the lip seal 25 is filled with an appropriate bearing lubricant 26 for lubricating the bearing 4 so that the bearing 4 (particularly, the lower bearing 4b) can be lubricated satisfactorily. It is devised so that it can be done. As the bearings 4a and 4b, ultra-thin type members are used.

  As shown in FIG. 1, the mechanical seals 5, 6, 7 are axially connected to the stationary sealing rings 5 a, 6 a, 7 a fixed to the upper rotation-side mechanical seal holding portion 17 and the lower stationary-side mechanical seal holding portion 20. Movable sealing rings 5b, 6b, 7b held movably in the (vertical direction) and spring members 5c, 6c, 7c urged upward to press contact the fixed sealing rings 5a, 6a, 7a. And an end face contact type mechanical seal that exhibits a sealing function by a relative rotational sliding contact action between the fixed sealing rings 5a, 6a, and 7a and the movable sealing rings 5b, 6b, and 7b.

  The fixed sealing rings 5a, 6a, and 7a and the movable sealing rings 5b, 6b, and 7b are arranged concentrically as shown in FIGS. 1 to 3, and the inner first mechanical seal (the smallest diameter mechanical seal) The seal rings 5a and 5b of the seal 5 have a smaller diameter than the seal rings 6a and 6b of the intermediate second mechanical seal, and the seal rings 6a and 6b are sealed by the outer third mechanical seal (maximum diameter mechanical seal) 7. It has a smaller diameter than the rings 7a and 7b.

As shown in FIGS. 1 to 3, each of the fixed sealing rings 5 a, 6 a, and 7 a has an inner peripheral portion or an outer peripheral portion on the first or second convex portion 17 a or 17 b of the rotation side mechanical seal holding portion 17 and an O-ring 5 d. , 6d, and 7d are fixedly held on the rotating case 2 in a suspended manner by the frictional engagement force of the O-rings 5d, 6d, and 7d. That is, the fixed seal ring 5a having the smallest diameter is fitted and held in the first convex portion 17a via the O-ring 5d, and the fixed seal ring 6a having the intermediate diameter is externally attached to the first convex portion 17b via the O-ring 6d. The fixed sealing ring 7a having the largest diameter is fitted and held on the second convex portion 17b via an O-ring 7d. Further, the relative rotation of each stationary seal ring 5a, 6a, 7a with respect to the rotation side case 2 is applied to the lower surface portion of the rotation side mechanical seal holding portion 17 in the concave portion formed in the inner peripheral portion or the outer peripheral portion as shown in FIG. By engaging the drive pins 5e, 6e, 7e planted in a hanging shape, they are devised to prevent them.

As shown in FIGS. 1 to 3, each movable sealing ring 5b, 6b, 7b has an inner peripheral portion or an outer peripheral portion connected to the first or second convex portion 20a, 20b of the stationary mechanical seal holding portion 20 and an O-ring 5f. , 6f, and 7f are fitted and held so as to be movable in the axial direction (vertical direction). That is, the small-diameter movable seal ring 5b is fitted and held in the first convex portion 20a through the O-ring 5f so as to be movable in the axial direction, and the intermediate-diameter movable seal ring 6b is first-projected through the O-ring 6f. The movable seal ring 7b having the maximum diameter is externally fitted and held on the second convex portion 20b via the O-ring 7f so as to be movable in the axial direction.

  Further, as shown in FIG. 2, each movable seal ring 5b, 6b, 7b is a drive which is installed upright on the upper surface portion of the stationary mechanical seal holding portion 30 in a recess formed in the inner peripheral portion or the outer peripheral portion thereof. By engaging the pins 5g, 6g, and 7g, relative rotation with respect to the stationary case 3 is prevented while allowing movement in the axial direction.

  Further, as shown in FIG. 1, each movable seal ring 5b, 6b, 7b is pressed upward by spring members 5c, 6c, 7c interposed between the lower end portion thereof and the stationary side mechanical seal holding portion 20. The urging force presses the fixed sealing rings 5a, 6a and 7a. Each of the spring members 5c, 6c, and 7c is a plurality of coil springs arranged in parallel at an appropriate interval in an annular region centered on the case axis.

  Thus, annular connection spaces 8 and 9 sealed by adjacent mechanical seals are defined between the upper and lower opposing end surfaces of the mechanical seal holding portions 17 and 20. That is, as shown in FIGS. 1 to 3, a first connection space 8 is formed between the first and second mechanical seals 5, 6, and a second connection space 9 is formed between the second and third mechanical seals 6, 7. It is formed. In addition, the sealing surfaces (relative rotational sliding contact surfaces of the fixed sealing rings 5a, 6a, and 7a and the movable sealing rings 5b, 6b, and 7c) in the mechanical seals 5, 6, and 7 are located on the same horizontal plane.

Further, as shown in FIG. 1, the rotation-side case 2 is formed with a first rotation-side passage 10 having one end portion opened to the upper end surface of the rotation-side bearing portion 16 and the other end portion opened to the first connection space 8. In addition, as shown in FIG. 2, a second rotation-side passage 11 having one end opened to the upper end surface of the rotation-side bearing portion 16 and the other end opened to the first connection space 8 is formed. Both the rotation side passages 10 and 11 are formed without crossing each other, and one end portions thereof are respectively connected to rotation side fluid passages 27 and 28 provided on a rotation side member (rotation table) of the rotary device. .

  Further, as shown in FIG. 1, the stationary case 3 has a first stationary side passage 12 having one end opened to the outer peripheral surface of the stationary mechanical seal holder 20 and the other end opened to the first connection space 8. As shown in FIG. 2, a second stationary side passage 13 having one end opened on the outer peripheral surface of the stationary side mechanical seal holding portion 20 and the other end opened on the second connection space 9 is formed. Yes. Both stationary side passages 12 and 13 are formed without crossing each other, and one end portions thereof are respectively connected to stationary side fluid passages 29 and 30 provided in a stationary side member (device main body) of the rotating device. .

  Therefore, a series of first and second flow paths 14 and 15 formed by connecting the rotation side passages 10 and 11 and the stationary side passages 12 and 13 through the connection spaces 8 and 9 are provided between the cases 2 and 3. The first and second fluids 31 and 32, such as liquids, are formed through these flow paths 14 and 15 from the stationary fluid passages 29 and 30 to the rotation fluid passages 27 and 28 via different routes ( Alternatively, the fluid can flow from the rotation side fluid passages 27, 28 to the stationary side fluid passages 29, 30).

  Further, as shown in FIG. 3, the stationary case 3 communicates with a first drain space 33 that is an inner peripheral region of the first mechanical seal 5 and a second drain space 34 that is an outer peripheral side region of the third mechanical seal 7. The first fluid 31 and the third mechanical seal 7 leaking from the seal surface of the first mechanical seal 5 to the first drain space 33 are formed. The second fluid 32 leaking from the sealing surface to the second drain space 34 is designed to be discharged from the drain passage 35. And as shown in FIG. 3, the stationary side bearing part 19 located inside the 1st mechanical seal 5, and the drain wall 21 located outside the 3rd mechanical seal 7 have those upper ends mechanical seals 5, 6, and 7 as shown in FIG. The height is such that it is located above the sealing surface. Accordingly, the first fluid 31 leaked from the sealing surface of the first mechanical ball 5 is prevented from entering the bearing loading space 22 by the stationary bearing portion 19, and the function and durability of the bearing 4 are hindered by the leaked fluid 31. There is no such thing. Further, the drain wall 21 prevents the second fluid 32 leaking from the sealing surface of the third mechanical ball 7 from directly leaking out of the rotary joint.

  Further, as shown in FIGS. 1 to 3, the upper rotation side mechanical seal holding portion 17 surrounds the third mechanical seal 7 having the maximum diameter and has a sealing surface (relative rotational sliding contact between both seal rings 7a and 7b). A dust-proof cover 36 having a cylindrical dust-proof wall 36a that hangs downward from the surface) is attached to prevent dust from adhering to and entering the sealing surface of the mechanical seal. In this example, the dust-proof wall 36 a surrounds the upper end portion of the drain wall 21.

  By the way, as shown in FIG. 4, the rotary joint is assembled with the bearing 4 by connecting the second and third portions 16 b and 16 c of the rotary bearing 16 and the stationary case 3 incorporating the movable sealing rings 5 b, 6 b and 7 b. The upper rotary joint member A, the first portion 16a of the rotation-side bearing portion 16 and the rotation-side mechanical seal holding portion 17 formed integrally therewith with the fixed sealing rings 5a, 6a, 7a incorporated therein. The members B and B are assembled separately, and then the upper rotary joint member B is lifted by a crane or the like, brought on the lower rotary joint member A, and both the members A and B are connected. In this case, in the upper rotary joint B, as described above, the fixed seal rings 5a, 6a, 7a are O-rings in a state where relative rotation is prevented by the drive pins 5e, 6e, 7e by the rotation-side mechanical seal holding portion 17. 4d, 6d, and 7d are fixed and held in a suspended manner, and their own weight is supported only by the frictional engagement force with the O-rings 5d, 6d, and 7d, so that they are lifted as shown in FIG. In some cases, the fixed sealing rings 5a, 6a, 7a may be detached and dropped downward, and there is a danger that the fixed sealing rings 5a, 6a, 7a may be dropped and damaged in an assembling operation. The occurrence of such trouble becomes more noticeable as the diameter of the rotary shaft 1 into which the rotation-side bearing portion 16 is fitted, that is, as the diameter of the fixed sealing rings 5a, 6a, 7a is increased and the weight is increased. .

  Therefore, in this example, in order to prevent the occurrence of such troubles, when the upper rotary joint member B is assembled, the fixed sealing rings 5a, 6a, 7a are fixed to the rotation side mechanical seal holding portion 17 with a fixture 37a such as a bolt. , 37b, 37c are devised so as to be temporarily fixed. For example, as shown in FIG. 4, the screw holes 5h, 6h, and 7h formed at the upper ends of the fixed sealing rings 5a, 6a, and 7a are inserted through the through holes 17c, 17d, and 17e formed in the rotation-side mechanical seal holding portion 17. The fixed bolts 37a, 37b, and 37c are screwed together, and the fixed sealing rings 5a, 6a, and 7a are fixed (temporarily fixed) to the rotation side mechanical seal holding portion 17 in a suspended state. In this temporarily fixed state, the upper rotary joint member B is suspended on the lower rotary joint member A, and the first portion 16a of the rotation-side bearing portion 16 is brought into contact with the second portion 16b. As shown in FIG. 3, the abutting positions of both the parts 16a and 16b are fitted into an annular convex part 16f formed in the central part of the upper surface of the second part 16b and an annular concave part 16e formed in the central part of the lower surface of the first part 16a. By positioning, it is positioned accurately. Then, after connecting the rotary joint members A and B, that is, after the rotation-side bearing portion 16 is integrated with the bolt 18a, the bolts 37a, 37b and 37c are removed and the fixed sealing rings 5a, 6a and 7a are temporarily fixed. Is released. In a state where the rotary joint members A and B are connected, the fixed sealing rings 5a, 6a and 7a are abutted and supported by the movable sealing rings 5b, 6b and 7b urged upward by the spring members 5c, 6c and 7c. Therefore, even if the temporary fixing is released, no problem occurs. A plurality of fixing tools (bolts) 37a, 37b, and 37c for temporarily fixing the fixed sealing rings 5a, 6a, and 7a are provided. The number of the fixing sealing rings 5a, 6a, and 7a is the weight of the fixed sealing rings 5a, 6a, and 7a. It sets suitably according to etc. After the temporary sealing of the fixed sealing rings 5a, 6a, 7a is released (before the dust cover 36 is attached), the through holes 17c, 17d, 17e are closed with blind plugs or the like as shown in FIG. Keep it. In this case, the through hole 17d communicating with the connection space 9 is required to be sealed as a closing means, but the through holes 17c and 17e not communicating with the connection space are covered with the dust-proof cover 36 without using a blind plug or the like. You can just leave it. Even when the joint is disassembled during maintenance work, the disassembly and maintenance work can be performed safely and efficiently by temporarily fixing the fixed sealing ring as shown in FIG.

  In the multi-channel rotary joint configured as described above, a plurality of fluids (first and second fluids in the above example) 31 and 32 are formed on the rotation-side member of the rotating device by the independent channels 14 and 15. The fluid passages 27 and 28 thus formed and the fluid passages 29 and 30 formed in the stationary side member of the rotating device can be favorably flowed. Then, the connection spaces 8 and 9, which are relative rotational connection portions of the flow paths 14 and 15, are sealed with mechanical seals 5, 6, and 7 arranged concentrically in parallel in a direction (radial direction) orthogonal to the rotation shaft 1. Therefore, the axial dimension of the rotary joint can be made extremely small as compared with the first conventional joint. That is, the dimension in the axial direction can be set to be equal to the case where one mechanical seal is provided in the first conventional joint, similarly to the second conventional joint. Regardless, it is constant. Furthermore, since the bearing 4 that couples the cases 2 and 3 so as to be relatively rotatable is disposed inside the smallest diameter mechanical seal (the innermost first mechanical seal) 5, compared to the second conventional joint. The radial dimension of the rotary joint can be reduced. That is, like the first conventional joint, the bearing 4 can always have the minimum diameter corresponding to the diameter of the rotary shaft 1 regardless of the increase or decrease in the number of flow paths, that is, the number of mechanical seals.

  In addition, since the bearing 4 having a minimum diameter corresponding to the diameter of the rotating shaft can be used, in combination with the use of a parallel combination type angular ball bearing having a high load capacity as the lower bearing 4b, Even if the bearings 4a and 4b are of an ultra-thin type, there is no problem in the connection strength and durability of the cases 2 and 3. Moreover, since the bearing lubricant 26 is filled in the bearing loading space 22 whose lower end is closed by the lip seal 25, a shield type or seal type filled with a lubricant such as grease inside the bearing is used. In comparison with this, the lubrication of the bearing 4, particularly the lubrication of the lower bearing 4 b, which handles a high load, can be satisfactorily exhibited over a long period of time. Further, since the bearing loading space 22 and the drain space 33 are partitioned by the stationary bearing portion 19 that is higher than the position of the seal surface by the sealing rings 5a and 5b, fluid leakage from the seal surface to the drain space 33 occurs. Even if it occurs, the leaked fluid overflows the stationary side bearing portion 19 and does not enter the bearing loading space 22 and is discharged to the drain path 35, so that the bearings 4a and 4b are soiled by the leaked fluid. There is nothing to do. For these reasons, the relative rotation by the bearings 4 of both cases 2 and 3 is performed reliably and reliably, and the life of the rotary joint and the reliability are improved.

  Even when fluid leakage occurs from the seal surface of the outermost third mechanical seal 7, the leaked fluid is discharged to the drain path 35 without leaking out of the rotary joint by the drain wall 21 higher than the seal surface. Therefore, the periphery of the rotary joint is not contaminated with leaking fluid.

  Further, since the mechanical seals 5, 6, and 7 are shielded from the outside by the dust-proof wall 36a of the dust-proof cover 36 and the drain wall 21 higher than the lower end position thereof, dust and the like are sealed from the outside of the rotary joint. The problem that the mechanical seal function deteriorates due to intrusion into the surface is surely prevented, and the reliability of the mechanical seal and thus the reliability of the rotary joint is ensured.

  Further, the fixed sealing rings 5a, 6a, 7a are incorporated into the mechanical seal holding part 17 by being fitted into the convex parts 17a, 17b of the rotation side mechanical seal holding part 17 with the O-rings 5d, 6d, 7d interposed therebetween. Therefore, the assembly work of the rotary joint can be easily performed. On the other hand, such fixed sealing rings 5a, 6a and 7a can be easily assembled by dropping the fixed sealing rings 5a, 6a and 7a held only by the frictional engagement force with the O-rings 5d, 6d and 7d by their own weight. However, such a risk can be prevented by devising the fixed sealing rings 5a, 6a, 7a so that they can be temporarily fixed to the rotary mechanical seal holding portion 17 as shown in FIG. be able to. Therefore, the assembly work of the rotary joint can be performed efficiently and safely.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be improved and changed as appropriate without departing from the basic principle of the present invention. For example, the number of flow paths, that is, the number of mechanical seals, can be arbitrarily set according to the rotating device to which the rotary joint is attached and the use conditions. In the case where four or more mechanical seals are arranged in parallel, the two seal spaces formed between one mechanical seal and the mechanical seals adjacent to both sides form a flow path. In addition to the connection space, one may be a connection space, and the other may be a drain space for fluid leaking from the connection space (a drain path is communicated). The rotary joint of the present invention can also be applied to a rotating device having a rotating shaft whose axis is not vertical. Furthermore, when applied to a rotating device having a rotating shaft whose axis is vertical, depending on the usage, each component of the rotary joint can be arranged upside down from the above embodiment. It is.

DESCRIPTION OF SYMBOLS 1 Rotating shaft 2 Rotating side case 3 Stationary side case 4 Bearing 4a Upper bearing 4b Lower bearing 5 First mechanical seal (mechanical seal of minimum diameter)
5a fixed seal ring 5b movable seal ring 5c spring member 5d O-ring 5e drive pin 6 second mechanical seal 6a fixed seal ring 6b movable seal ring 6c spring member 6d O-ring 6e drive pin 7 third mechanical seal 7a fixed seal ring 7b movable Seal ring 7c Spring member 7d O-ring 7e Drive pin 8 First connection space 9 Second connection space 10 First rotation side passage 11 Second rotation side passage 12 First stationary side passage 13 Second stationary side passage 14 First flow passage DESCRIPTION OF SYMBOLS 15 2nd flow path 16 Rotation side bearing part 17 Rotation side mechanical seal holding part 19 Stationary side bearing part 20 Stationary side mechanical seal holding part 21 Drain wall 22 Bearing loading space 23 Bolt 24 Annular ring 26 Bearing lubricant 31 1st fluid 32 Second fluid 33 First drain space 34 Second drain Down space 35 drain passage 36 dust-proof cover 36a dust-proof wall

Claims (10)

  Via a bearing, a rotating side case attached to the rotating shaft of the rotating device or a rotating side member including the rotating shaft in a state fitted to or inserted through the rotating shaft and a stationary case attached to the stationary side member of the rotating device via a bearing A plurality of joints that are connected to each other so as to be relatively rotatable around a rotation axis and communicated via a plurality of connection spaces that are partitioned and sealed by three or more mechanical seals arranged concentrically with the rotation axis between both cases. A multi-channel rotary joint having a channel, wherein a bearing is disposed inside a mechanical seal having a minimum diameter.   The rotating side case includes a cylindrical rotating side bearing portion that is fitted or inserted into the rotating shaft, and a disk-shaped rotating side mechanical seal holding portion that projects in the outer peripheral direction. A cylindrical stationary side bearing portion that surrounds the bearing portion and a disk-shaped stationary side mechanical seal holding portion that protrudes in the outer peripheral direction from the cylindrical stationary side bearing portion. The bearing is loaded between the opposed peripheral surfaces of both bearing portions. Each mechanical seal has a fixed sealing ring fixed to one mechanical seal holding part, a movable sealing ring held by the other mechanical seal holding part so as to be movable in the axial direction, and this is pressed against the fixed sealing ring. The multi-passage rotary joint according to claim 1, further comprising a spring member that is urged to be made.   The multi-channel rotary joint according to claim 2, wherein the multi-channel rotary joint is used for a rotary device having a vertical rotation axis.   The bearing is composed of an upper bearing and a lower bearing which are arranged at a predetermined interval in the vertical direction, and the bearing loading space formed between the opposed peripheral surfaces of both bearing portions is filled with a bearing lubricant, and the loading space The multi-passage rotary joint according to claim 3, wherein a lower end portion of the multi-path type is sealed.   The multi-passage rotary joint according to claim 4, wherein the lower bearing is a parallel combination angular contact ball bearing.   Friction engagement force by an O-ring interposed between the rotation-side mechanical seal holding part and the stationary-side mechanical seal holding part facing each other up and down, and each fixed seal ring positioned above the mechanical seal holding part The mechanical seal holder located in the upper position is detachably attached to the mechanical seal holder, which is located at the upper position, so that each fixed holding sealing ring can be temporarily fixed to a suspended support during mechanical seal assembly. The multi-channel rotary joint according to any one of claims 3 to 5, wherein the multi-channel rotary joint is provided.   The rotating side mechanical seal holding part and the stationary side mechanical seal holding part are vertically opposed to each other, and are formed between the stationary side bearing part and the smallest diameter mechanical seal on the lower side stationary mechanical seal holding part. A multichannel rotary joint according to any one of claims 3 to 6, wherein a drain passage opening in the drain space is formed.   The rotating side mechanical seal holding part and the stationary side mechanical seal holding part are vertically opposed to each other, and the stationary side mechanical seal holding part positioned at the lower side surrounds the sealing ring of the maximum diameter mechanical seal held by this. A drain path that opens into a drain space formed between the mechanical seal having the maximum diameter and the drain wall is formed while providing a cylindrical drain wall. Multi-channel rotary joint described in the above.   The upper end of the stationary side bearing portion and / or the drain wall is located higher than the relative rotational sliding contact surface between the fixed seal ring and the movable seal ring. Multi-channel rotary joint.   The upper mechanical seal holder is provided with a dustproof cover having a cylindrical dustproof wall that hangs downward from the relative rotational sliding contact surface of the fixed sealing ring and the movable sealing ring and surrounds the maximum diameter mechanical seal. The multi-channel rotary joint according to any one of claims 3 to 9, wherein