JP7003009B2 - Rotary joint - Google Patents

Description

The present invention relates to a rotary joint for flowing a fluid between relative rotating members in a rotating device used in the semiconductor field or the like (for example, a CMP device (for example, a surface polishing device for a semiconductor wafer by a CMP (Chemical Mechanical Polishing) method)). Is.

As a conventional rotary joint of this type, as disclosed in FIG. 6 of Patent Document 1, between the facing peripheral surfaces of the tubular case body and the rotating shaft body concentrically connected to the tubular case body so as to be relatively rotatable. , 6 pieces configured to exert the sealing function by relatively rotating the opposite end faces of the fixed sealing ring fixed to the case body and the movable sealing ring held on the rotating shaft body so as to be movable in the axial direction in a contact state. Mechanical seals are arranged in tandem in the axial direction to form a passage connection space sealed by adjacent mechanical seals, and a series of flow paths communicating with both bodies via the passage connection space are formed ( Hereinafter referred to as "conventional rotary joint") is well known.

Thus, in such a conventional rotary joint, as shown in FIG. 6 of Patent Document 1, both ends of a fixed sealing ring of two sets of adjacent mechanical seals excluding the mechanical seals located at both ends of the mechanical seal group. Since one fixed sealing ring whose surface is in contact with the movable sealing ring (hereinafter referred to as "combined fixed sealing ring") is also used, as disclosed in FIG. 1 of Patent Document 1, all mechanical seals are used. The axial length of the rotary joint (the length in the relative rotation axis direction of both bodies) can be shortened as compared with the rotary joint in which the fixed sealing ring has only one end surface as the contact surface with the movable sealing ring as an independent member. The size can be reduced, and the mechanical seal configuration, that is, the rotary joint configuration can be simplified by reducing the number of parts.

Japanese Patent Application Laid-Open No. 2003-42374

However, in the conventional rotary joint, since both end faces of the above-mentioned combined fixed sealing ring generate heat due to contact with the movable sealing ring, compared to the case where only one end face comes into contact with the movable sealing ring. Large thermal strain is likely to occur in the combined fixed sealing ring due to thermal expansion. Moreover, due to a pressure difference between the fluids flowing in the respective passage connection spaces sealed by the two mechanical seals using the combined fixed sealing ring, or the pressure of the fluid fluctuating, the combined fixed sealing ring If the contact pressure with the movable sealing ring on both end faces is different, the calorific value, that is, the thermal strain at the contact portion on both end faces of the combined fixed sealing ring is different, and the thermal strain generated in the combined fixed sealing ring is in the circumferential direction. It tends to be non-uniform.

Therefore, in the conventional rotary joint, such non-uniform and large thermal strain is likely to occur in the circumferential direction of the combined fixed sealing ring, so that the combined fixed sealing ring and the movable sealing ring are not properly contacted with each other, and the combined fixed sealing ring is not properly contacted. There was a risk that the sealing function of the passage connection space by the mechanical seal using the above would not be exhibited well.

An object of the present invention is to solve the above-mentioned problems in mechanical sealing using such a combined fixed sealing ring, and to provide a rotary joint capable of satisfactorily sealing a passage connection space.

In the present invention, in order to achieve the above object, a fixed sealing ring fixed to one of the two bodies is provided between a tubular case body and a rotating shaft body concentrically connected to the tubular case body so as to be relatively rotatable. Four or more mechanical seals that exert a sealing function by relative rotation in contact with the movable sealing ring held so as to be movable in the axial direction on the other side of both bodies are arranged in a vertical row in the axial direction. , A passage connection space sealed with an adjacent mechanical seal is formed, and a series of flow paths communicating with each other via the passage connection space are formed in the two bodies, and the space formed between the two bodies. It is configured to supply the quenching liquid to the quenching space partitioned from the passage connection space by the mechanical seal, and both ends of the fixed sealing ring of at least one set of adjacent mechanical seals come into contact with the movable sealing ring. A plurality of fixed sealing rings (hereinafter referred to as "combined fixed sealing rings") are also used, and a contact portion with an end surface of the movable sealing ring is opened in the quenching space on both end faces of the combined fixed sealing ring. A lubrication groove is formed, and each lubrication groove formed on one end surface of the combined fixed sealing ring and each lubricating groove formed on the other side are arranged so as not to overlap in the circumferential direction of the combined fixed sealing ring. We propose a rotary joint that is characterized by its lubrication.

In the rotary joint of the present invention, the plurality of lubricating grooves formed on one of both end faces of the combined fixed sealing ring and the plurality of lubricating grooves formed on the other side are respectively the combined fixed sealing. It is preferably formed at equal intervals in the circumferential direction of the ring. Further, each lubrication groove formed on one of both end faces of the combined fixed sealing ring is an adjacent lubricating groove formed on the other end surface of the combined fixed sealing ring in the circumferential direction of the combined fixed sealing ring. It is preferably located in the middle of the space.

Further, in all the mechanical seals except the mechanical seals located at both ends of the mechanical seal group in which the four or more mechanical seals are arranged in parallel in the axial direction, or in all the mechanical seals of the mechanical seal group. In the above, it is preferable that the fixed sealing ring of the adjacent mechanical seal is also used by the one combined fixed sealing ring.

Further, in the rotary joint of the present invention, in each of the mechanical seals, the fixed sealing ring is fixed to the rotating shaft body and the movable sealing ring is held by the case body so as to be movable in the axial direction. It is possible that the fixed sealing ring is fixed to the case body and the movable sealing ring is held by the rotating shaft body so as to be movable in the axial direction.

In the rotary joint of the present invention, since a plurality of lubricating grooves are formed on both end faces of the combined fixed sealing ring, the rotary joint is cooled by the quenching liquid that has entered the lubricating groove, and a large amount of heat is generated in the combined fixed sealing ring. No distortion occurs. Moreover, on each end surface of the dual-purpose fixed sealing ring, the cooling effect is high and the thermal strain is small at the portion where the lubricating groove that the quenching liquid comes into direct contact with is formed, and conversely, the lubricating groove that the quenching liquid does not come into direct contact with. The cooling effect is low and the thermal strain is large in the portion where In the circumferential direction of the dual-purpose fixed sealing ring, the cooling effect is high and the thermal strain is small (lubrication). The portion where the groove is formed) and the portion where the cooling effect is low and the thermal strain is large (the portion where the lubrication groove is not formed) on the other end surface are at the same position or substantially the same position in the circumferential direction of the combined fixed sealing ring. It becomes. As a result, the thermal strain generated in the combined fixed sealing ring becomes uniform in the circumferential direction, and the contact between each end surface of the combined fixed sealing ring and the end surface of the movable sealing ring is properly performed.

As described above, in the rotary joint of the present invention, since the thermal strain generated in the combined fixed sealing ring is small and the thermal strain becomes uniform in the circumferential direction of the combined fixed sealing ring, it is movable with the combined fixed sealing ring. Proper contact with the sealing ring is performed, and the sealing function of the passage connection space by the mechanical seal using the combined fixed sealing ring is well exhibited, and the fluid rotates with the case body that rotates relative to each other regardless of its properties. It can flow well without causing leakage in the flow path formed between the shaft and the shaft.

FIG. 1 is a cross-sectional view showing an example of a rotary joint according to the present invention. FIG. 2 is a cross-sectional view of the rotary joint crossed at a position different from that of FIG. FIG. 3 is a detailed cross-sectional view showing an enlarged main part of FIG. FIG. 4 is a cross-sectional view of a main part along the line IV-IV of FIG. FIG. 5 is a cross-sectional view of a main part along the VV line of FIG. FIG. 6 is a cross-sectional view of a main part corresponding to FIG. 3 showing a modified example of the rotary joint according to the present invention. FIG. 7 is a schematic cross-sectional view showing another modified example of the rotary joint according to the present invention. FIG. 8 is a cross-sectional view of a main part along the line VIII-VIII of FIG. FIG. 9 is a schematic cross-sectional view corresponding to FIG. 7 showing still another modification of the rotary joint according to the present invention. FIG. 10 is a cross-sectional view of a main part along the XX line of FIG. FIG. 11 is a schematic cross-sectional view corresponding to FIG. 7 showing still another modification of the rotary joint according to the present invention. FIG. 12 is a cross-sectional view of a main part along the line XII-XII of FIG.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an example of a rotary joint according to the present invention, FIG. 2 is a cross-sectional view of the rotary joint crossed at a position different from that of FIG. 1, and FIG. 3 is an enlarged view of a main part of FIG. It is a detailed cross-sectional view shown, FIG. 4 is a cross-sectional view of a main part along the line IV-IV of FIG. 3, and FIG. 5 is a cross-sectional view of the main part along the line VV of FIG. In the following description, the top and bottom refer to the top and bottom in FIGS. 1 to 3.

The rotary joint shown in FIGS. 1 and 2 (hereinafter referred to as “first rotary joint R1”) includes a tubular case body 1 and a rotating shaft body 2 concentrically connected thereto and connected so as to be relatively rotatable. , Four or more mechanical seals 3 are arranged vertically between the facing peripheral surfaces of both bodies 1 and 2 in the axial direction (relative rotation axis direction of both bodies 1 and 2), that is, in the vertical direction, and adjacent mechanical seals are arranged. A plurality of passage connection spaces 4 sealed by 3 and 3 are formed, and a quenching space 5 partitioned by the passage connection space 4 and the mechanical seal 3 is formed, and between the two bodies 1 and 2. It is a vertical type in which a plurality of series of flow paths 6 (see FIG. 2) communicated with each other through the passage connection space 4 are formed, and an appropriate fluid is used between relative rotating members of a rotating device such as a CMP device. (For example, a liquid, a gas, or a slurry fluid) F is flown separately by each flow path 6.

As shown in FIGS. 1 and 2, the case body 1 has a circular inner peripheral portion extending in the vertical direction, and has a tubular structure divided into a plurality of annular portions in the vertical direction. The case body 1 is attached to a fixed side member of a rotating device (for example, a device body of a CMP device).

As shown in FIGS. 1 and 2, the rotary shaft body 2 includes a columnar shaft body 21 extending in the vertical direction and a plurality of sleeves 22 fitted therein in a vertical row at predetermined intervals. It is composed of a bottomed tubular bearing receiver 23 fitted to the upper end portion of the shaft main body 21, and is located between the bearing receiver 23 and the upper end portion of the case body 1 and at the lower end portion of the shaft main body 21. Bearings 24 and 25 loaded between the formed large-diameter bearing receiving portion 21a and the lower end portion of the case body 1 form concentric bearings on the inner peripheral portion of the case body 1 and are supported so as to be relatively rotatable. The rotating shaft body 2 is attached to a rotating side member of a rotating device (for example, a top ring or a turntable of a CMP device) at the lower end of the shaft main body 21.

As shown in FIGS. 1 and 3, each mechanical seal 3 has a fixed sealing ring 31 fixed to one of both bodies 1 and 2 (rotating shaft body 2 in this example) and both bodies 1 and 2 facing the fixed sealing ring 31. On the other hand (in this example, the case body 1) is provided with a movable sealing ring 32 held so as to be movable in the axial direction and a spring 33 for pressing and contacting the movable sealing ring 32 with the fixed sealing ring 31, and facing end faces of both sealing rings 31 and 32. By relatively rotating the sealed end faces 31a and 32a in a contact state, the passage connection space 4 which is the inner peripheral side region of the contact portion S (see FIG. 3) of the sealed end faces 31a and 32a and the quench which is the outer peripheral side region thereof. It is an end face contact type mechanical seal configured to seal the ching space 5.

As shown in FIGS. 1 and 2, each fixed sealing ring 31 is an annular body having a rectangular cross section concentric with the axes (relative rotation axes) of both bodies 1 and 2, and the fixed sealing rings 31 and 31 adjacent to each other. It is fitted and fixed to the shaft body 21 of the rotating shaft body 2 with the mutual spacing regulated by the sleeve 22. That is, as shown in FIG. 1, the fixed sealing ring 31 tightens the bearing receiver 23 to the shaft body 21 by the bolt 26, and between the bearing receiver 23 and the bearing receiver 23 of the shaft body 21 via the sleeve 22. The bearings are fixed to the rotating shaft body 2 in a columnar state at equal intervals in the axial direction. As shown in FIGS. 1 to 3, between the upper end portion of each sleeve 22 (upper and lower end portions of the lowermost sleeve 22) and the shaft main body 21, the shaft main body 21 and each fixed sealing ring 31 are provided. An O-ring 27 that seals the fitting portion is loaded.

As shown in FIG. 3, each movable sealing ring 32 is an annular body having a substantially L-shaped cross section concentric with the rotating shaft body 2, and the end face is completely in contact with the sealing end surface 31a of the fixed sealing ring 31. It is configured on the end face 32a. That is, the inner diameter of the sealed end face 32a of the movable sealed ring 32 is set to be larger than the inner diameter of the sealed end face 31a of the fixed sealed ring 31, and the outer diameter thereof is smaller than the outer diameter of the sealed end face 31a. As shown in FIGS. 1 and 3, each movable sealing ring 32 is held by an annular holding wall 11 projecting from the inner peripheral portion of the case body 1 so as to be movable in the axial direction via an O-ring 34. As shown in FIGS. 1 and 3, each movable sealing ring 32 has an engaging recess formed in the outer peripheral portion thereof engaged with a drive bar 35 penetratingly supported by the holding wall 11 in the axial direction. The case body 1 is held so as to be non-rotatable in a state where the relative movement of the above is permitted within a predetermined range.

As shown in FIGS. 1 and 3, the spring 33 is held in the axial through hole 51 formed in the holding wall 11 in the adjacent mechanical seals 3 and 3, and is located on both the upper and lower sides of the holding wall 11. Both movable sealing rings 32 and 32 are used as a common member for pressing and biasing each fixed sealing ring 31.

As shown in FIGS. 1 to 3, between the facing peripheral surfaces of both bodies 1 and 2, loading is performed between the facing peripheral surfaces of the fixed sealing rings 31 and 31 located at both ends of the fixed sealing ring group 31 and the case body 1. It is a space sealed by the annular seal member (known oil seal or the like) 52, 53, and a quenching space 5 partitioned by a passage connection space 4 and a mechanical seal 3 is formed. The quenching space 5 is formed by communicating the outer peripheral side region of the contact portion S of each of the two sealing rings 31 and 32 through the through hole 51 of each holding wall 11, and is formed in the case body 1. An appropriate quenching liquid (cooling liquid) Q is circulated and supplied through the water supply / drainage passages 54 and 55. That is, as shown in FIG. 1, the liquid supply passage 54 is communicated with the lower part of the quenching space 5 (the through hole 51 of the holding wall 11 at the lowermost end), and the drainage passage 55 is connected to the upper part of the quenching space 5 (upper ring). The quenching liquid Q supplied from the liquid supply passage 54 to the quenching space 5 by communicating with the space portion between the seal member 52 and the uppermost movable sealing ring 32 passes through the quenching space 5 (each). It passes through the outer peripheral side region of the contact portion S of both the sealing rings 31 and 32 in sequence) and is discharged from the drainage passage 55. The pressure of the quenching liquid Q supplied to the quenching space 5 is lower than the pressure of the fluid F flowing in each flow path 6, and clean water, pure water, or the like at room temperature is used as the quenching liquid Q. .. As shown in FIG. 1, the case body 1 is formed with a drain 56 that communicates with the space between the lower annular seal member 53 and the bearing 25.

Thus, as shown in FIG. 3, the fixed sealing rings 31, 31 of at least one set of adjacent mechanical seals 3, 3 in the mechanical seal group 3 have both end faces of the movable sealing rings 32, 32, and the sealing end faces 32a, It is also used as one fixed sealing ring 31 (hereinafter referred to as "combined fixed sealing ring 31A") having the sealing end faces 31a and 31a with which 32a is in contact. In this example, in all the mechanical seals 3 except the mechanical seals 3 and 3 located at both ends (upper and lower end portions) of the mechanical seal group 3 parallel to each other in the vertical direction, the fixed sealing rings 31 of the adjacent mechanical seals 3 and 3 are 31. , 31 are also used by one dual-purpose fixed sealing ring 31A. That is, all the fixed sealing rings 31 are used as the combined fixed sealing ring 31A except for the fixed sealing rings 31 and 31 located at both ends (upper and lower end portions) of the fixed sealing ring group 31 parallel to each other in the vertical direction.

As shown in FIG. 2, each flow path 6 communicates the case-side passage 61 formed in the case body 1 and the shaft-side passages 62, 63, 64 formed in the rotary shaft body 2 via the passage connection space 4. It is a series of things. Each case-side passage 61 is formed so as to penetrate the case body 1 in the radial direction without intersecting the through hole 51 of the holding wall 11, and one end thereof is formed as a passage connecting space 4 on the inner peripheral surface of the holding wall 11. The other end is connected to the flow path formed in the fixed side member of the rotating device. Each of the shaft-side passages 62, 63, 64 is an annular space formed by closing the annular recess formed on the inner peripheral surface of the sleeve 22 with the shaft main body 21, and is between the facing peripheral surfaces of the sleeve 22 and the shaft main body 21. The formed header space 62, a plurality of communication holes 63 that penetrate the sleeve 22 in the radial direction and communicate the header space 62 and the passage connection space 4, and the shaft body 21 penetrate in the axial direction from the lower end thereof. It is composed of a connection passage 64 communicating with the header space 62, and the lower end portion of the connection passage 64 is connected to a flow path formed in a rotation side member of the rotating device.

A plurality of communication holes 63 in each shaft-side passage are formed at the central portion of the sleeve 22 in the axial direction at equal intervals in the circumferential direction of the sleeve 22, and are adjacent to each sleeve 22 with the combined fixed sealing ring 31 interposed therebetween. The sleeve 22 is a state in which the communication hole 63 formed in one sleeve 22 and the communication hole 63 formed in the other sleeve 22 are inconsistent (non-overlapping state) in the circumferential direction of the sleeve 22. It is fitted to. In this example, as shown in FIG. 5, five communication holes 63 are formed in each sleeve 22, and the adjacent sleeves 22 and 22 are each communication hole formed in one sleeve 22 (solid line in the figure). (Communication hole) 63 is fitted to the shaft body 21 in a state where the communication hole 63 is located in the middle of the circumferential direction of the adjacent communication holes (communication holes shown by the broken lines in the figure) 63 and 63 formed in the other sleeve 22. There is.

As shown in FIG. 3, a part (outer peripheral side portion) of the contact portion S of the movable sealed ring 32 with the sealed end surface 32a is opened in the quenching space 5 in each end surface (sealed end surface) 31a of each combined fixed sealing ring 31A. A plurality of lubrication grooves 31b are formed. Each lubrication groove 31b is a concave groove generally called a hydrocut, and in this example, as shown in FIG. 4, three lubrication grooves 31b are provided on each sealed end surface 31a of the combined fixed sealing ring 31A in the circumferential direction of the sealed end surface 31a. A straight line passing through the outer peripheral side portion of the contact portion S on the sealed end surface 31a (the portion overlapping the outer peripheral portion of the sealed end surface 32a of the movable sealing ring 32) and the outside of the sealed end surface 31a. It has a rectangular cross section formed by cutting out a fan-shaped portion surrounded by a peripheral edge to a predetermined depth.

Thus, the plurality of lubrication grooves 31b formed on one of the sealed end faces 31a of each combined fixed sealing ring 31A and the same number of lubricating grooves 31b formed on the other sealed end face 31a are the same number of lubricating grooves 31b of the combined fixed sealing ring 31. It is formed so as to be inconsistent (do not overlap) in the circumferential direction. In this example, as shown in FIG. 4, the formation position of each lubrication groove 31b on both sealed end faces 31a and 31a of each combined fixed sealing ring 31A is set to each lubrication groove formed on one of the sealed end faces 31a (solid line in the figure). (Lubrication groove) 31b is set to be located in the middle of the circumferential direction with the adjacent lubrication grooves (lubrication grooves shown by the broken line in the figure) 31b and 31b formed on the other sealed end surface 31a. That is, in both the sealed end faces 31a and 31a of each dual-purpose fixed sealing ring 31A, the lubrication grooves 31b formed on one of the sealed end faces 31a and the lubrication grooves 31b formed on the other sealed end face 31a are equally spaced in the circumferential direction. It is set to be located alternately at a distance.

By the way, the constituent materials of the constituent members constituting the rotary joint are selected according to the functions required for the constituent members, the mechanical strength and the like, and also according to the properties of the fluid F flowing in the flow path 6 and the purpose of use. In general, it is preferable to select a fluid that is inert to the fluid F. The constituent material that is inert to the fluid F is determined in relation to the properties of the fluid F and the conditions of use (avoidance of metal contamination, etc.). For example, the fluid F is used for processing a semiconductor wafer. When metal contamination should be avoided, such as polishing liquids and cleaning liquids, ceramics and plastics (for example, PEEK, which do not elute metal components or generate metal powder due to contact with fluids). PES, PC, etc.) is used. That is, each sealed ring 31, 31A, 32 is generally composed of ceramics such as silicon carbide, cemented carbide (tungsten carbide), etc., but in this example, each sealed ring 31, 31A, 32 is composed of silicon carbide. At the same time, the constituent members (shaft body 21, each sleeve 22, etc.) of the case body 1 and the rotating shaft body 2 are made of PEEK.

In the first rotary joint R1 configured as described above, the lubrication grooves 31b and 31b as described above are formed on both the sealing end faces 31a and 31a of the dual-purpose fixed sealing ring 31A. Such a problem does not occur.

That is, since each sealed end surface 31a of the combined fixed sealing ring 31 is cooled by the quenching liquid Q that has entered each of the lubricating grooves 31b, it is compared with the conventional rotary joint in which the lubricating groove is not formed in the combined fixed sealing ring 31. Therefore, a large thermal strain due to a large thermal expansion does not occur in the combined fixed sealing ring 31.

By the way, since the quenching liquid Q comes into direct contact with the portion of each sealed end surface 31a of the combined fixed sealing ring 31A where the lubricating groove 31b is formed, the cooling effect of the quenching liquid Q is enhanced, which is generated by thermal expansion. The amount of thermal strain to be applied becomes smaller. On the other hand, in the portion of each sealed end surface 31a where the lubricating groove 31b is not formed, the quenching liquid Q does not come into direct contact, so that the cooling effect of the quenching liquid Q is small and the amount of thermal strain generated by thermal expansion is large. Become. Therefore, in each of the sealed end faces 31a, a portion having a small thermal strain (a portion in which the lubrication groove 31b is formed) and a portion having a large thermal strain (a portion in which the lubrication groove 31b is not formed) alternate in the circumferential direction. It will be present, and each of the sealed end faces 31a will have a swell-like thermal strain in the circumferential direction.

However, in the combined fixed sealing ring 31A, as shown in FIG. 4, the lubricating groove 31b formed on one sealed end surface 31a and the lubricating groove 31b formed on the other sealed end surface 31a do not overlap in the circumferential direction. In the circumferential direction, the portion where the lubrication groove 31b is formed on one of the sealed end faces 31a becomes the portion where the lubrication groove 31b is not formed on the other sealed end face 31a, and conversely, the one of the sealed end faces is not formed. Since the portion of the 31a where the lubrication groove 31b is not formed is the portion where the lubrication groove 31b is formed on the other sealed end face 31a, the ridges of the waviness-like thermal strain are formed on both the sealed end faces 31a and 31a. The part where the thermal strain is large) and the valley part of the waviness-like thermal strain (the part where the thermal strain is small) overlap. As a result, the thermal strain generated in the combined fixed sealing ring 31A becomes uniform in the circumferential direction, and the amount of the thermal strain becomes small. As shown in FIG. 4, the effect is that the lubrication groove 31b formed on one of the sealed end faces 31a and the lubrication groove 31b formed on the other sealed end face 31a on both sealed end faces 31a and 31a of the combined fixed sealing ring 31A are formed. It is more prominently exhibited by devising so that the positions are alternately arranged at equal intervals in the circumferential direction.

Therefore, according to the first rotary joint R1, the combined fixed sealing ring 31A has each sealing end surface 31a and the movable sealing ring of the combined fixed sealing ring 31a as compared with the conventional rotary joint in which the thermal strain is non-uniform in the circumferential direction. The 32a is properly contacted with the sealed end surface 32a, and the sealing function of the mechanical seal 3 using the combined fixed sealing ring 31A is satisfactorily exhibited.

Further, in the first rotary joint R1, the quenching liquid Q in which the contact portion S between each sealed end surface 31a of the combined fixed sealing ring 31A and the sealing end surface 32a of the movable sealing ring 32 has entered from the plurality of lubricating grooves 31b. Since it is lubricated by the above, the combined fixed sealing ring 31 and the movable sealing rings 32 and 32 on both sides thereof are smoothly brought into contact with each other. As a result, when the fluid F flowing in the passage connection space 4 is a liquid, of course, when the fluid F is a gas, wear in the contact portion S is prevented as much as possible, and the fluid F wears. There is no risk of being contaminated by powder. Moreover, since the pressure of the quenching liquid Q is lower than the pressure of the fluid F flowing in the passage connection space 4, leakage of the fluid F from the connection portion S is prevented as much as possible. In the first rotary joint R1, the mechanical seals 3 and 3 located at both ends of the mechanical seal group 3 also form a lubrication groove similar to the lubrication groove 31b on the sealed end surface 31a of each fixed sealing ring 31. In this way, even in the mechanical seals 3 and 3, the sealing at the contact portion between each fixed sealing ring 31 and the movable sealing ring 32 can be performed better.

By the way, in the first rotary joint R1, the space between the combined fixed sealing rings 31A and 31A is regulated by the sleeve 22 made of plastic (made of PEEK), and the sleeve 22 is subjected to the axial pressing force by tightening the bolt 26. , The combined fixing sealing ring 31A is fixed by the frictional engagement force with the sleeve 22, but since the sleeve 22 is made of plastic (made of PEEK in the above example) and is not a rigid body, it is also fixed by the sleeve 22. The pressing force on the sealing ring 31A may not be uniform in the circumferential direction of the sleeve 22, and the combined fixed sealing rings 31, 31A may be greatly distorted. As the number of the combined fixed sealing rings 31A increases, the strain becomes extremely large as a whole of the combined fixed sealing ring groups 31 and 31A, and there is a possibility that the sealing function of the mechanical sealing group 3 is adversely affected.

However, in the first rotary joint R1, a plurality of communication holes 63 parallel to each sleeve 22 are formed in the circumferential direction thereof, and the sleeve portion formed with the communication holes 63 forms a combined fixed sealing ring 31A. The pressing force is smaller than the pressing force on the dual-purpose fixed sealing ring 31A by the sleeve portion where the communication hole 63 is not formed. Further, since the plurality of communication holes 63, 63 formed in the adjacent sleeves 22, 22 are arranged so as not to overlap in the circumferential direction as shown in FIG. 5, the combined fixed sealing ring 31A is arranged in the circumferential direction. At the portion where a large pressing force acts on one end surface 31a, a small pressing force acts on the other end surface 31a, and on both end faces 31a and 31a of the combined fixed sealing ring 31, the portion where a large and small pressing force acts at the same time is peripheral. It will exist alternately in the direction.

Therefore, the strain due to the pressing force becomes uniform in the dual-purpose fixed sealing ring 31A in the circumferential direction of the sleeve 22, and it is possible to prevent large strain from occurring in the dual-purpose fixed sealing ring 31A. In combination with this, the sealing function of the mechanical seal 3 can be satisfactorily exhibited.

By the way, the present invention is not limited to the above-described embodiment, and can be appropriately improved or modified without departing from the basic principle of the present invention.

For example, the shape and number of the lubrication grooves 31b are arbitrary, and the cross-sectional shape of the lubrication grooves 31b is such that the depth of the lubrication grooves 31a is gradually increased in the inner peripheral direction of the sealed end surface 31a of the fixed sealing ring 31A. It can be made into a shallow triangular shape. When the cross-sectional shape of the lubrication groove 31b is a rectangular shape as shown in FIG. 4, it is generally necessary to form the lubrication groove 31b by a cutting step, and the step of forming the lubrication groove 31b after the molding step of the combined fixed sealing ring 31A. Although it is necessary to perform (cutting step), if the cross-sectional shape of the lubricating groove 31b is triangular as described above, the forming of the fixed sealing ring 31A and the forming of the lubricating groove 31b can be performed by the forming step of the fixed sealing ring 31A. This can be performed at the same time, facilitating the production of the dual-purpose fixed sealing ring 31A having the lubrication groove 31b, and further the mass production.

Further, the number of the fixed sealing rings 31 including the mechanical seal 3 and the combined fixed sealing ring 31A, and whether the sealing rings 31, 31A, 32 are provided in the case body 1 or the rotary shaft body 2 depends on the type of the fluid F to be flowed. , It can be set arbitrarily according to the properties and the rotating equipment equipped with the rotary joint. For example, the rotary joint according to the present invention can be configured as shown in FIG. 7, FIG. 9 or FIG.

That is, in the rotary joint shown in FIG. 7 (hereinafter referred to as “second rotary joint R2”), the rotary shaft body 2 is formed by attaching a plurality of sealed ring holders 28 to the outer peripheral portion of the shaft main body 21, and the fixed sealed ring. The point where the movable sealing ring 32 is fixed to the case body 1 and the movable sealing ring 32 is held by the sealing ring holding body 28 so as to be movable in the axial direction, and the passage connection space 4 is the contact between the fixed sealing ring 31, 31A and the movable sealing ring 32. The outer peripheral side region of the portion S, the point where the quenching space 5 is the inner peripheral side region of the contact portion S communicating through the through hole 57 formed in the sealed ring holder 28, and the shaft side passage is the shaft main body 21. A point consisting of a connection passage 64 formed in the above and a communication hole 65 formed in the sealing ring holder 28 to connect the connection passage 64 to the passage connection space 4, and as shown in FIG. 8, of the combined fixed sealing ring 31A. It has the same structure as the first rotary joint R1 except that a plurality of lubricating grooves 31b that open the contact portion S in the quenching space 5 are formed on the inner peripheral side portion of each sealed end surface 31a.

Further, in the rotary joint shown in FIG. 9 (hereinafter referred to as “third rotary joint R3”), the fixed sealing ring 31 in all the mechanical seals 3 is also used as the fixed sealing ring 31A, and the passage connecting space 4 is also used as the fixed sealing ring. It is an inner peripheral side region of the contact portion S between the 31A and the movable sealing ring 32, and is an outer peripheral side region of the contact portion S in which the quenching space 5 communicates through the through hole 58 formed in the combined fixed sealing ring 31A. Point, a point where a communication hole 66 for communicating the case side passage 61 and the passage connection space 4 is formed in the combined fixed sealing ring 31A, and a connection passage 64 formed in the shaft body 21 for the shaft side passage is connected to the passage connection space 4. And, as shown in FIG. 10, a plurality of lubrication grooves 31b for opening the contact portion S into the quenching space 5 are formed on the outer peripheral side portion of each sealed end surface 31a of the combined fixed sealing ring 31A. Therefore, it has the same structure as the second rotary joint R2.

Further, in the rotary joint shown in FIG. 11 (hereinafter referred to as “fourth rotary joint R4”), the fixed sealing ring 31 in all the mechanical seals 3 is also used as the fixed sealing ring 31A, and the passage connecting space 4 is also used as the fixed sealing ring. It is an outer peripheral side region of the contact portion S between the 31A and the movable sealing ring 32, and is an inner peripheral side region of the contact portion S in which the quenching space 5 communicates through the through hole 59 formed in the combined fixed sealing ring 31A. A point, a point in which the shaft-side passage is formed in the connection passage 64 formed in the shaft main body 21 and a communication hole 67 formed in the fixed sealing ring 31A and connecting the connection passage 64 to the passage connection space 4, and FIG. As shown, the first rotary joint R1 is formed except that a plurality of lubricating grooves 31b for opening the contact portion S into the quenching space 5 are formed on the inner peripheral side portion of each sealed end surface 31a of the combined fixed sealing ring 31A. It has the same structure as.

In the second to fourth rotary joints R2, R3, and R4 configured as described above, the contact portion S is lubricated and cooled by the quenching liquid Q that has penetrated into the lubricating groove 31b, similarly to the first rotary joint R1. Not to mention that it is performed well, the thermal strain generated in the combined fixed sealing ring 31A becomes uniform in the circumferential direction, the contact with the movable sealing ring 32 is properly performed, and the passage connection space 4 is well sealed. can.

1 Case body 2 Rotating shaft body 3 Mechanical seal 4 Passage connection space 5 Quenching space 6 Flow path 31 Fixed sealing ring 31A Combined fixed sealing ring (fixed sealing ring)
31a End face of fixed sealed ring (sealed end face)
31b Lubrication groove 32 Movable sealed ring 32a End face of movable sealed ring (sealed end face)
F Fluid Q Quenching liquid S Contact part

Claims (7)

Between the tubular case body and the rotating shaft body concentrically connected to the rotating shaft body, a fixed sealing ring fixed to one of the two bodies and an axially movable holding to the other of the two bodies. A passage connection space sealed by adjacent mechanical seals by arranging four or more mechanical seals that exhibit a sealing function by rotating relative to each other in a contact state with the movable sealing ring. Form and
A series of flow paths communicating with each other via the passage connection space are formed in both bodies.
It is configured to supply the quenching liquid to the quenching space formed between the two bodies and partitioned from the passage connection space by the mechanical seal.
The fixed sealing ring of at least one set of adjacent mechanical seals is also used as one fixed sealing ring whose both end surfaces are in contact with the movable sealing ring.
A plurality of lubrication grooves are formed on both end faces of the fixed sealing ring that is also used to open a contact portion with the end face of the movable sealing ring in the quenching space.
A rotary joint characterized in that each lubrication groove formed on one end surface of the fixed sealing ring and each lubrication groove formed on the other side are arranged so as not to overlap in the circumferential direction of the fixed sealing ring. .. A plurality of lubrication grooves formed on one end surface of the fixed sealing ring and a plurality of lubricating grooves formed on the other side are formed at equal intervals in the circumferential direction of the fixed sealing ring, respectively. The rotary joint according to claim 1, wherein the rotary joint is characterized by being Each lubrication groove formed on one of both end faces of the fixed sealing ring is located in the middle of the adjacent lubrication grooves formed on the other end face of the fixed sealing ring in the circumferential direction of the fixed sealing ring. The rotary joint according to claim 2, wherein the rotary joint is characterized in that. In all mechanical seals except the mechanical seals located at both ends of the mechanical seal group in which the four or more mechanical seals are arranged in parallel in the axial direction, the fixed sealing ring of the adjacent mechanical seal is one. The rotary joint according to any one of claims 1 to 3, wherein the rotary joint is also used as a fixed sealing ring. In all the mechanical seals of the mechanical seal group in which the four or more mechanical seals are arranged in parallel in the axial direction, the fixed sealing ring of the adjacent mechanical seal is also used as the one fixed sealing ring. The rotary joint according to any one of claims 1 to 3, wherein the rotary joint is characterized in that. According to any one of claims 1 to 5, in each of the mechanical seals, the fixed sealing ring is fixed to the rotating shaft body and the movable sealing ring is held by the case body so as to be movable in the axial direction. Rotary joint to describe. According to any one of claims 1 to 5, in each of the mechanical seals, the fixed sealing ring is fixed to the case body and the movable sealing ring is held by the rotating shaft body so as to be movable in the axial direction. Rotary joint to describe.

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