JP6593863B2 - Rotary joint - Google Patents

Description

  The present invention relates to a rotary joint that allows fluid to flow between relative rotating members in a rotating device (for example, a CMP (Chemical Mechanical Polishing) semiconductor wafer surface polishing apparatus) used in the semiconductor field or the like. It is.

  As a conventional rotary joint of this type, as disclosed in Patent Document 1, a hard material such as silicon carbide fixed to a rotating shaft body between a case body and a rotating shaft body relatively rotatably connected thereto. At the opposite end face of the fixed sealing ring made of silicon and the movable sealing ring made of a hard material such as silicon carbide held movably in the rotation axis direction of both bodies while being pressed and biased to the fixed sealing ring by the case body An end face contact type mechanical seal configured to seal by a relative rotational sliding action of a certain sealing end face, wherein the sealing end face of the movable sealing ring has a pointed shape with a small radial width (hereinafter referred to as “knife edge”). A series of flow formed by connecting a case body side passage formed in the case body and a shaft body side passage formed in the rotary shaft body through a flow passage space sealed with a knife edge seal. Shape the road The thing (hereinafter referred to as "conventional rotary joint") is well known.

  According to such a conventional rotary joint, even when the fluid flowing in the flow path is a slurry fluid or a high-viscosity fluid containing solid particles, a solidifying component, etc., these flow paths are sealed with a knife edge seal. It can be made to flow well without causing leakage. That is, in a knife edge seal in which one of the two sealing end faces (sealing end face of the movable sealing ring) that makes relative rotational sliding contact has a fine point shape with a radial surface width, the contact surface pressure of both sealing end faces is a general end face. Since it is higher than that of contact type mechanical seals, it is possible to prevent the entry of slurry components such as solid particles and high-viscosity fluid between sealed end faces as much as possible. Can be well sealed.

JP 2001-141149 A

  However, in the conventional rotary joint, since the contact surface pressure of both sealing end faces in the knife edge seal is high, both sealing rings are combined with the fact that both sealing rings are made of a hard material such as silicon carbide. High heat is generated by the relative rotational sliding contact between the end faces, and the relative rotational sliding contact portions of both sealed end faces may be worn. In particular, the sealing end face of the movable sealing ring has a pointed shape, and heat and friction are concentrated locally, so that thermal distortion and wear are likely to occur. Therefore, in the long-term use, the seal end portion of the flow path has a large thermal strain or wear that adversely affects the sealing function by the mechanical seal (hereinafter referred to as “mechanical sealing function”) on the sealing end surface of the movable sealing ring. There is a risk of fluid leakage from the (flow path space), and there is a problem in reliability and durability as a rotary joint.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary joint that solves the above-mentioned problems caused by using a knife edge seal and can perform fluid flow in a flow path satisfactorily over a long period of time.

  The present invention forms a flow path space sealed with a mechanical seal between a case body and a rotary shaft connected to the case body so as to be relatively rotatable, and the flow path is partitioned from the flow path space by the mechanical seal. A series of outer space is formed, and a case body side fluid passage formed in the case body and a shaft body side fluid passage formed in the rotating shaft body are connected to each other through the passage space. A flow path is formed, and the mechanical seal is movable in the direction of the rotation axis of the two bodies through a fixed sealing ring fixed to one of the case body and the rotary shaft body and an O-ring to the other of the two bodies. A holding movable seal ring and a spring that urges the movable seal ring to press and contact the fixed seal ring, and the flow path space by the relative rotational sliding action of the seal end faces that are the opposite end faces of both seal rings. Shielding the space outside the flow path In the rotary joint which is an end surface contact type mechanical seal (knife edge seal) configured to have a pointed shape in which the sealing end surface of the movable sealing ring has a small radial surface width. In particular, the fluid in the flow path space or the fluid in the space outside the flow path is a liquid that can always contact the movable seal ring and function as a cooling liquid, and at the surface portion of the movable seal ring. A constant diameter O-ring contact surface that contacts the O-ring, a sealing end surface of the movable sealing ring, and a surface portion of the movable sealing ring that extends from the sealing end surface to the O-ring contact surface, and is in contact with the liquid Furthermore, it is proposed to form a series of coating layers made of a material having a larger thermal conductivity coefficient and hardness than the constituent material of the sealing ring.

  In a preferred embodiment of such a rotary joint, when the space outside the flow path is closed with an oil seal and the coolant is circulated and supplied to the space outside the flow path, the space contacts the coolant. In the case where the surface portion of the movable sealing ring is a liquid contact surface forming the coating layer, and the fluid in the flow path space is a liquid that can always contact the movable sealing ring and function as a cooling liquid, A surface portion of the movable sealing ring that comes into contact with the liquid is a liquid contact surface that forms the coating layer. In any case, diamond is the most suitable material for the coating layer.

  In the rotary joint of the present invention, a coating layer (hereinafter referred to as “sealing end surface coating layer”) made of a material having a hardness higher than that of the constituent material of the sealing ring is provided on the sealing end surface of the movable sealing ring having a pointed shape. Since it is formed, wear and heat generation due to relative rotational sliding contact with the sealing end face of the mating sealing ring (fixed sealing ring) are suppressed as much as possible.

  Further, since the sealing end face of each movable sealing ring has a pointed shape, the heat generated by the relative rotational sliding contact with the sealing end face of the mating sealing ring concentrates and becomes locally hot. In the joint, on the O-ring contact surface and the liquid contact surface of the movable sealing ring, a coating layer of the same material connected to the sealing end surface coating layer (hereinafter referred to as “O-ring contact surface”) is formed. Since the coating layer formed on the wetted surface is called the “wetted surface coating layer”), the heat generated at the sealing end face of the movable sealing ring is effective from the coating layer with a high thermal conductivity coefficient. Thus, heat is released and cooled, and generation of high local heat at the sealed end face is prevented as much as possible. That is, the sealing end surface coating layer, the liquid contact surface coating layer, and the O-ring contact surface coating layer are a series of materials, and are made of a material having a large thermal conductivity coefficient compared to the constituent material of the movable sealing ring. The heat generated at the sealing end face of the sealing ring is transferred from the sealing end face coating layer to the liquid contact surface coating layer, and further from the liquid contact face coating layer to the O-ring contact face coating layer. The heat of the layer is dispersed throughout the coating layer including the sealed end face coating layer, and the temperature of the sealed end face coating layer is lowered. Moreover, a part of the liquid contact surface coating layer and the O ring contact surface coating layer (the O ring contact surface coating formed on the O ring contact surface portion from the portion sealed by the O ring on the O ring contact surface to the liquid contact surface) In the layer portion), the heat radiation and cooling from the coating layer are effectively performed by heat exchange with a liquid that is always in contact with these layers and can function as a cooling liquid. As a result, even if the sealing end face of the movable sealing ring has a small pointed shape with a radial width and the contact surface pressure with the sealing end face of the other sealing ring (fixed sealing ring) is high, the relative rotational sliding of both sealing end faces is possible. The amount of wear and heat generation due to contact is drastically reduced, and the occurrence of thermal strain that adversely affects the sealing function (mechanical sealing function) of the knife edge seal is prevented as much as possible. Also, the relative movement between the movable sealing ring and the O-ring is smoothly performed by the O-ring contact surface coating layer made of a material having a smaller friction coefficient than that of the constituent material of the movable sealing ring. The followability is improved, and in combination with the above, the mechanical seal function is exhibited well. Such an effect is particularly prominent when the coating layer is made of diamond.

  Therefore, according to the present invention, the flow path seal by the knife edge seal can be satisfactorily demonstrated over a long period of time, and it is an extremely practical rotary joint that is superior in durability and reliability compared to conventional rotary joints. Can be provided.

FIG. 1 is a sectional view showing an example of a rotary joint according to the present invention. FIG. 2 is a detailed cross-sectional view showing an enlarged main part of FIG. FIG. 3 is a sectional view showing a modification of the rotary joint according to the present invention. 4 is a cross-sectional view of the rotary joint taken along a position different from that in FIG. FIG. 4 is a detailed cross-sectional view showing an enlarged main part of FIG. 3. FIG. 6 is a cross-sectional view of the main part corresponding to FIG. 2 showing another modification of the rotary joint according to the present invention. FIG. 7 is a cross-sectional view of a main part corresponding to FIG. 2 showing still another modification of the rotary joint according to the present invention. FIG. 8 is a cross-sectional view of a main part corresponding to FIG. 2 showing still another modification of the rotary joint according to the present invention. FIG. 9 is a cross-sectional view of a main part corresponding to FIG. 2 showing still another modification of the rotary joint according to the present invention. FIG. 10 is a cross-sectional view of a main part corresponding to FIG. 2 showing still another modification of the rotary joint according to the present invention. FIG. 11 is a cross-sectional view of a main part corresponding to FIG. 5 showing still another modification of the rotary joint according to the present invention. FIG. 12 is a cross-sectional view of the main part corresponding to FIG. 5 showing still another modification of the rotary joint according to the present invention. FIG. 13 is a cross-sectional view of the main part corresponding to FIG. 5 showing still another modification of the rotary joint according to the present invention. FIG. 14 is a cross-sectional view of the main part corresponding to FIG. 5 showing still another modification of the rotary joint according to the present invention.

  FIG. 1 is a sectional view showing a first embodiment of a rotary joint according to the present invention, and FIG. 2 is a detailed sectional view showing an essential part of FIG. 3 is a cross-sectional view showing a second embodiment of the rotary joint according to the present invention, FIG. 4 is a cross-sectional view of the rotary joint taken along a position different from FIG. 3, and FIG. It is detail sectional drawing which expands and shows the principal part. In the following description, “upper and lower” refers to the upper and lower sides in FIGS.

  As shown in FIG. 1, there is one rotary joint (hereinafter referred to as “first rotary joint”) according to the first embodiment between a case body 101 and a rotary shaft body 102 that is relatively rotatably connected thereto. Forming a flow path space 104 sealed with the mechanical seal 103 and forming a space outside the flow path 106 that is separated from the flow path space 104 by the mechanical seal 103 and sealed with the oil seal 105, A case body side fluid passage 107 formed in the case body 101 and a shaft body side fluid passage 108 formed in the rotating shaft body 102 are connected to each other via the flow passage space 104 between the bodies 101 and 102. A series of flow paths R1 is formed, and the relative rotation of the rotating device in a rotating device (for example, a CMP apparatus) used in the semiconductor field or the like. It is intended to flow the fluid F1 by the passage R1 between members.

  As shown in FIG. 1, the case body 101 has a bottomed cylindrical structure whose center line extends in the vertical direction. The case body 101 is a disk-like shape that is attached to the cylindrical peripheral wall 101a and closes the upper end opening of the peripheral wall 101a. And is attached to a fixed side member (for example, an apparatus main body of a CMP apparatus) of a rotating device.

  As shown in FIG. 1, the rotating shaft body 102 has a cylindrical shape extending in the vertical direction, and a pair of bearings 109 a interposed between a lower end side portion thereof and a lower end portion of the peripheral wall 101 a of the case body 101, 109b is concentrically connected to the case body 101 so as to be freely rotatable. The rotating shaft body 102 is attached to a rotating side member (for example, a top ring or a turntable of a CMP apparatus) of the rotating device.

  The mechanical seal 103 includes a fixed seal ring 131 fixed to one of the two bodies 101 and 102 (in this example, the rotating shaft body 102) and the other (case body 101 in this example) facing the fixed seal ring 131. A movable sealing ring 132 held so as to be movable in the rotational axis direction of the bodies 101 and 102 (hereinafter simply referred to as “axial direction”), and a spring that urges the movable sealing ring 132 to press and contact the fixed sealing ring 101 133, and by the relative rotational sliding contact action of the sealing end surfaces 131a and 132a which are upper and lower opposing end surfaces of both sealing rings 131 and 132, the inner peripheral side region of the relative rotational sliding contact portion (inside of both sealing rings 131 and 132). An end surface contact type mechanical seal configured to shield and seal the flow path space 104 which is a peripheral side region) and the external flow space 106 which is an outer peripheral side region thereof. Sealing end face 131a, a knife edge seal configured to small apex shape at one radial face width 132a.

  That is, as shown in FIGS. 1 and 2, the fixed sealing ring 131 includes an annular main body part 131b and a cylindrical fixing part 131c integrally formed at the lower end thereof, and the fixing part 131c is connected to the main body part 131b. With the base end face (lower end face) concentric with the rotation axis (hereinafter simply referred to as “axis line”) of both bodies 101 and 102 and abutting the tip end face (upper end face) of the rotary shaft body 102, The rotary shaft body 102 is fitted and fixed to the distal end portion (upper end portion). The front end surface (upper end surface) of the main body 131b is configured as a sealed end surface 131a that is a smooth annular plane that is orthogonal to the axis. The fitting portion between the fixed portion 131c and the rotary shaft body 102 is made relatively non-rotatable by the key 131d and is sealed (secondary seal) by an O-ring 131e engaged with the outer peripheral portion of the rotary shaft body 102. .

  As shown in FIGS. 1 and 2, the movable sealing ring 132 includes a cylindrical main body portion 132b and an annular flange portion 132c that integrally projects in the outer diameter direction from the vicinity of the tip (near the bottom). The base end portion (upper end portion) of the main body portion 132b is fitted to the holding hole 101c formed in the end wall 101b of the case body 101 via the O-ring 132d, so that the case body 101 is concentric with the fixed sealing ring 131. In addition, it is held so as to be movable in the axial direction (movable in the vertical direction) in a vertically opposed manner. As shown in FIG. 2, the movable sealing ring 132 has a truncated conical surface whose diameter gradually expands downward on the inner peripheral surface of the lower end portion of the main body 132b, and the distal end of the main body 132b that protrudes downward from the flange 132c. (The lower end) has a pointed shape, and the front end surface (lower end surface) of the main body portion 132b is a smooth flat surface perpendicular to the axis and has a minute sealing end surface 131a having a radial surface width (seal surface width). It is composed. That is, the sealing end surface 132a of the movable sealing ring 132 is concentrically in contact with the substantially central portion in the radial direction of the sealing end surface 131a of the fixed sealing ring 131, and its radial surface width is 0.1 to 0. .8 mm (more preferably 0.4 to 0.7 mm). The O-ring 132d is engaged and held in an O-ring groove 101d formed on the inner peripheral surface of the holding hole 101c of the case body 101. The O-ring 132d is an outer peripheral surface of the main body 132b of the movable sealing ring 132 and has a constant diameter O-ring contact. The surface 132e is press-contacted (elastically contacted) so as to be relatively movable in the axial direction. That is, the movable sealing ring 103 is held by the case body 101 so as to be movable in the axial direction while being sealed (secondary seal) with the O-ring 132d between the movable sealing ring 103 and the case body 101. As shown in FIG. 2, the movable sealing ring 132 engages a drive pin 132g planted at the lower end of the end wall 101b of the case body 101 with an engagement recess 132f formed on the outer periphery of the flange 132c. Thus, relative rotation with respect to the case body 101 is prevented in a state where movement in the axial direction (movement in the vertical direction) is allowed within a predetermined range.

  As shown in FIGS. 1 and 2, the spring 133 is loaded between the flange 132c of the movable sealing ring 132 and the end wall 101b of the case body 1, and the movable sealing ring 132 is connected to both sealing end surfaces 131a, The fixed seal ring 131 is pressed and urged so that the 132a can be brought into press contact with each other.

  As shown in FIGS. 1 and 2, the oil seal 105 is disposed between the opposing peripheral surfaces of the case body 101 and the fixed sealing ring 131, and the outer peripheral portion of an annular seal member 105a made of an elastic material such as rubber is used as the case. The outer peripheral side region of the relative rotational sliding contact portion of both the sealing rings 131 and 132 of the knife edge seal 3 is fixed to the body 101 and its inner peripheral part (lip seal part) is brought into elastic contact with the fixed sealing ring 131. The space outside the flow path 106 is sealed. The annular seal member 105a is a well-known member, and as shown in FIG. 2, a main body portion in which a reinforcing metal fitting 105b made of a metal material (SUS304 or the like) is embedded and is fitted and fixed to the inner peripheral portion of the peripheral wall 101a of the case body 101. And a lip seal portion that is tightly bound and pressed against the outer peripheral surface of the rotary seal ring 131 by a garter spring 105c to exert a sealing function.

  As shown in FIG. 1, a cooling liquid supply passage 106 a and a cooling liquid discharge passage 106 b for supplying and discharging the cooling liquid C <b> 1 to the outer space 106 closed and sealed with the oil seal 105 are formed on the peripheral wall 101 a of the case body 101. In addition, the coolant C1 is circulated and supplied to the space 106 outside the flow path, and the coolant C1 is always in contact with the movable sealing ring 132. A liquid such as room temperature water is used as the cooling liquid C1. A drain 113a is formed on the peripheral wall 101a of the case body 101 so as to open between the opposing peripheral surfaces of the two bodies 101 and 102 between the oil seal 105 and the bearing 109a.

  As shown in FIG. 1, the case body-side fluid passage 107 penetrates the end wall 101 b of the case body 1 to the holding hole 101 c and communicates with the flow path space 4 that is the inner peripheral portion of the movable sealing ring 132. , Connected to a fluid passage formed in the stationary side member of the rotating device. As shown in FIG. 1, the shaft body side fluid passage 108 passes through the central portion of the rotating shaft body 102 and communicates with the flow path space 104 that is the inner peripheral portion of the fixed sealing ring 131. It is connected to a fluid passage formed in the side member. Accordingly, the fluid F1 can flow between the two bodies 101 and 102 through a series of flow paths R1 formed by connecting both the fluid passages 107 and 108 through the flow path space 104 as shown in FIG. In this example, the fluid F1 is a slurry fluid having substantially the same temperature as the coolant C1 (for example, a liquid containing a slurry component such as solid particles such as a polishing liquid), and this fluid flows in the direction of the solid arrow in FIG. At the same time, vacuum suction is performed in the direction of the broken line arrow.

  Meanwhile, the balance ratio κ of the mechanical seal 3 is determined by the inner and outer diameters of the sealing end surface 132a of the movable sealing ring 132 and the outer diameter of the main body 132b of the movable sealing ring 132 (the diameter of the O-ring contact surface 132e). In general, 0 ≦ κ ≦ 0.6 so that the contact pressure of the sealed end faces 131a and 132a is properly maintained even when the flow path R1 has a negative pressure (when the fluid F1 is vacuumed). Is set to In this example, κ = 0.5 is set.

  Thus, according to the present invention, in the movable sealing ring 132 in which the sealing end surface 132a is configured to have a fine point shape with a radial width, the O-ring contact is made from the O-ring contact surface 132e, the sealing end surface 132a, and the sealing end surface 132a. The surface portion of the movable seal ring 132 that reaches the surface 132e, and is in contact with the liquid contact surface 132h that is in contact with the coolant C1 that is the fluid in the space outside the flow path 106, as compared with the constituent material of the seal ring 132. Coating layers 10a, 10b and 10c made of a material having a large coefficient and hardness and a small friction coefficient are formed in series. As shown in FIG. 2, the liquid contact surface 132h, which is the surface portion of the movable sealing ring 132 extending from the sealing end surface 132a to the O-ring contact surface 132e, is the tip of the main body portion 132b connected to the outer peripheral edge of the sealing end surface 132a. The outer peripheral surface of the main body portion 132b protruding from the portion 132c, the distal end surface (lower end surface) of the flange portion 132c connected to the base end edge (upper edge), and the outer peripheral surface of the flange portion 132c connected to the outer peripheral edge thereof. (In the portion where the engagement recess 132f is formed, the inner peripheral surface of the engagement recess 132f is included) and the base end edge (upper edge) of the engagement recess 132f is connected to the distal end edge (lower end edge) of the O-ring contact surface 132e. It consists of the base end surface (upper end surface) of the collar part 132c which reaches.

  That is, the sealing end surface coating layer 10a is formed on the sealing end surface 132a, the liquid contact surface coating layer 10b connected to the sealing end surface coating layer 10a is formed on the liquid contact surface 132h, and the liquid contact surface coating layer 10b is formed on the O-ring contact surface 132e. An O-ring contact surface coating layer 10c is formed in a row. In the following description, when it is necessary to distinguish between a sealing ring and a coating layer formed thereon, the former is referred to as a sealing ring base material.

  As a constituent material of the coating layers 10a, 10b, and 10c, no matter what the constituent material of the movable sealing ring 132 (the constituent material of the sealing ring base material) is any of the sealing ring constituent materials such as ceramics and cemented carbide. Diamonds having a high conductivity coefficient and hardness and a small friction coefficient are used. The diamond coating layers 10a, 10b, and 10c are formed by a coating method such as a hot filament chemical vapor deposition method, a microwave plasma chemical vapor deposition method, a high frequency plasma method, a direct current discharge plasma method, an arc discharge plasma jet method, or a combustion flame method. Done.

  Further, as shown in FIGS. 3 and 4, the rotary joint of the second embodiment (hereinafter referred to as “second rotary joint”) is concentrically connected to the cylindrical case body 1 so as to be relatively rotatable. The rotating shaft body 2 is provided, and four or more mechanical seals 3 are arranged between the opposing peripheral surfaces of the both bodies 1 and 2 in the rotational axis direction of the both bodies 1 and 2 (hereinafter simply referred to as “axial direction”). That is, a plurality of flow path spaces 4 are arranged in a vertical line in the vertical direction and sealed by the adjacent mechanical seals 3 and 3, and the space defined by the flow path space 4 and the mechanical seal 3 Thus, a space 6 outside the flow path sealed with a pair of oil seals 5, 5 is formed, and formed between the two bodies 1, 2 in the case body side fluid passage 7 formed in the case body 1 and the rotary shaft body 2. The shaft body side fluid passage 8 communicates with the passage space 4 through the passage space 4. A series of a plurality of flow paths R2 (see FIG. 4) are formed, and two or more kinds of fluids F2 flow between the relative rotation members of a rotating device such as a CMP apparatus, respectively, through the flow paths R2. It is something to be made.

  As shown in FIGS. 3 and 4, the case body 1 has a circular inner peripheral portion whose center line extends in the vertical direction, and forms a cylindrical structure that is divided into a plurality of annular portions in the vertical direction. The case main body 1 is attached to a fixed side member (for example, an apparatus main body of a CMP apparatus) of a rotating device.

  As shown in FIGS. 3 and 4, the rotary shaft body 2 includes a cylindrical shaft body 21 having an axial line extending in the vertical direction, and a plurality of sleeves 22 inserted in a vertical row at a predetermined interval in the vertical direction. ... and a bottomed cylindrical bearing receiver 23 fitted and fixed to the upper end portion of the shaft main body 21, and between the bearing receiver 23 and the upper end portion of the case body 1 and of the shaft main body 21. A pair of upper and lower bearings 9a and 9b loaded between a large-diameter bearing receiving portion 21a formed at the lower end portion and the lower end portion of the case body 1 are concentric with the inner peripheral portion of the case body 1 for relative rotation. It is supported freely. The rotating shaft body 2 is attached to a rotating side member (for example, a top ring or a turntable of a CMP apparatus) at a lower end portion of the shaft main body 21.

  As shown in FIG. 3, each mechanical seal 3 includes a fixed sealing ring 31 fixed to the rotating shaft 2, a movable sealing ring 32 that is opposed to the movable sealing ring 32, and is held movably in the axial direction. And a spring 33 that presses and contacts the fixed sealing ring 31, and the inner peripheral side of the relative rotational sliding contact portion by the relative rotational sliding contact action of the sealing end surfaces 31 a, 32 a that are opposite end surfaces of the both sealing rings 31, 32. An end face contact type mechanical seal configured to seal the flow path space 4 as a region and the outer flow path space 6 as an outer peripheral side region thereof, and the sealing end surface 32a of the movable sealing ring 32 is arranged in the radial direction. It is a knife edge seal constructed in the shape of a minute tip with a small width.

  In this example, as shown in FIGS. 3 and 4, the four mechanical seals 3 are arranged in such a manner that all the sealing rings 31, 32... The fixed sealing rings 31 and 31 are located at the end). That is, two sets of mechanical seal units composed of a pair of mechanical seals 3 and 3 in a double seal arrangement in which the movable seal rings 32 and 32 are located between the fixed seal rings 31 and 31 are arranged in tandem in the axial direction.

  Each fixed sealing ring 31 is an annular body having a square cross section that is concentric with the rotation axis (hereinafter simply referred to as “axis”) of both bodies 1 and 2, and as shown in FIGS. 3 and 4, the movable sealing ring 32. The end face that is in contact with each other is configured as a sealed end face 31a that is a smooth annular plane perpendicular to the axis. In this example, the fixed sealing ring 31 of one mechanical seal 3 and the fixed sealing ring 31 of the mechanical seal 3 adjacent to this are both sealed end faces 31a and 31a as shown in FIGS. One fixed sealing ring 31 is also used. That is, both end surfaces of the fixed sealing ring 31 are configured as sealing end surfaces 31a and 31a except for the fixed sealing rings 31 and 31 positioned at both ends (upper and lower ends) of the fixed sealing ring group 31 in the vertical direction. It is.

  As shown in FIGS. 3 and 4, each fixed sealing ring 31 is fitted and fixed to the shaft main body 21 of the rotating shaft body 2 with the interval between the fixed sealing rings 31 being restricted by the sleeve 22. . That is, as shown in FIG. 3, each fixed sealing ring 31 is sandwiched between the bearing receiver 21 a and the bearing receiver 23 via the sleeve 22 by tightening the bearing receiver 23 to the shaft body 21 with the bolt 24. It is pressure-fixed, and is fixed to the rotating shaft body 2 in a tandem state at equal intervals in the axial direction. An O-ring 25 for sealing the fitting portion between the shaft main body 21 and the fixed sealing ring 31 is loaded between the inner peripheral portions of both ends of each sleeve 22 and the shaft main body 21 as shown in FIGS. Has been.

  As shown in FIG. 5, each movable sealing ring 32 is an annular body that is concentric with the axis and has a substantially L-shaped cross section in which the inner diameter of the distal end portion 32b is smaller than the inner diameter of the base end portion 32c. The distal end side inner peripheral surface is a frustoconical surface gradually reducing the diameter in the proximal direction, and the outer peripheral surface of the distal end portion 32b is a frustoconical surface gradually expanding in the proximal direction, whereby the distal end has a pointed shape. It is what. Each movable sealing ring 32 is configured such that the end face (tip face) of the tip end portion 32b is a sealed end face 32a that is a smooth annular plane having a small radial width and orthogonal to the axis. The inner and outer peripheral portions of the sealing end surface 31a of the fixed sealing ring 31 are in concentric contact with the sealing end surface 31a in a state of protruding in the radial direction. The radial width of the sealing end surface 32a of the movable sealing ring 32 is 0.1 to 0.8 mm (more preferably 0.4 to 0.7 mm), similar to the sealing end surface 132a of the movable sealing ring 132 in the first rotary joint. ) Is set. As shown in FIG. 5, each movable sealing ring 32 is fitted and held in an annular wall 11 projecting from the inner peripheral portion of the case body 1 with its base end portion 32c movably in the axial direction via an O-ring 32d. Yes. That is, as shown in FIG. 5, an O-ring engaging portion 11a having an outer diameter larger than the inner diameter of the distal end portion 32b of the movable sealing ring 32 and smaller than the inner diameter of the base end portion 32c is formed on the inner peripheral portion of the annular wall 11. And an O-ring holding portion 11b whose outer diameter is smaller than the inner diameter of the tip end portion 32b of the movable sealing ring 32 are integrally formed so as to project, and the O-ring 32d is an O-ring locking portion of the annular wall 11. Opposing peripheral surfaces of the base end portion 32c of the movable sealing ring 32 and the O-ring holding portion 11b of the annular wall 11 in a state in which the axial movement is restricted between the opposing end surfaces of the portion 11a and the distal end portion 32b of the movable sealing ring 32 It is loaded in between. Therefore, the movable sealing ring 32 is formed on the case body 1 by the O-ring 32d that presses (elastically contacts) the O-ring contact surface 32e having a constant diameter with the O-ring contact surface 32e in the axial direction so as to be relatively movable in the axial direction. In a state of sealing (secondary seal) with the (annular wall 11), the case body 1 is held so as to be relatively movable in the axial direction. As shown in FIG. 3, the movable seal ring 32 is moved relative to the axial direction by engaging a drive pin 32f protruding in the axial direction from the annular wall 11 with an engaging recess formed in the outer peripheral portion thereof. It is held in the case body 1 so as not to be rotatable relative to a predetermined range.

  As shown in FIG. 1, in each mechanical seal unit, the spring 33 is loaded in a communication hole 11 c penetrating the annular wall 11 in the axial direction, and the movable seal rings 32, 32 positioned on both sides of the annular wall 11 are mounted. It is a common member that presses and urges each fixed sealing ring 31.

  As shown in FIG. 4, fluid passages 7 and 8 communicating with the respective flow passage spaces 4 are formed in both bodies 1 and 2. In this example, both fluid passages 7 and 8 are disposed between both bodies 1 and 2. And the flow path space 4 form two flow paths R2 and R2 for allowing the fluid F2 to flow separately between the two bodies 1 and 2. As shown in FIG. 4, each case-side fluid passage 7 of the case body 1 is formed so as to penetrate the case body 1 in the radial direction, and one end thereof is formed in the flow path space 4 on the inner peripheral surface of the annular wall 11. While opening, the other end is connected to a fluid passage formed in the stationary member of the rotating device. As shown in FIG. 4, each shaft body side fluid passage 8 formed in the rotating shaft body 2 has an annular header space 8 a formed between the opposed peripheral surfaces of the shaft main body 21 and the sleeve 22, and the sleeve 22 in the radial direction. A plurality of communication holes 8b (only one is shown) that communicate with the header space 8a and the flow path space 4 and the shaft main body 21 from the lower end thereof in the axial direction and open into the header space 8a. The lower end of the fluid passage main body 8c is connected to a fluid passage formed in the rotation side member of the rotating device. In addition, the constituent material of each sealing ring 31 and 32 is selected according to rotary joint use conditions, such as the property of the fluid F2 which flows through the flow path R2, and is generally comprised with hard materials, such as ceramics, such as silicon carbide, and a cemented carbide. Is done.

  As shown in FIGS. 3 and 4, the two oil seals 5 and 5 are disposed at both ends of the mechanical seal group 3 between the bearings 9a and 9b, and the seal ring groups 31 and 32 arranged in parallel in the axial direction. Annular ring made of an elastic material such as rubber that is fixed to the inner peripheral portion of the case body 1 and is in pressure contact with the outer peripheral surface of the fixed sealing ring 31, 31. It consists of seal members 51, 51. Each annular seal member 51 is a well-known member having the same structure as that of the annular seal member 105a. As shown in FIG. 5, a reinforcing metal fitting 51a made of a metal material (SUS304 or the like) is embedded in the inner periphery of the case body 1. And a lip seal portion which is tightly bound and pressed against the outer peripheral surface of the fixed sealing ring 31 by a garter spring 51b and exerts a sealing function.

  Between the opposing peripheral surfaces of both bodies 1 and 2, communication is formed in an annular wall 11 that partitions the outer peripheral side region of the relative rotational sliding contact portion of both sealed end surfaces 31 a and 32 a of each mechanical seal 3 and the outer peripheral region. A space outside the flow path 6 that is a space formed by the holes 11c and is sealed by both oil seals 5 and 5 is formed. In this example, a cooling liquid C2 such as room temperature water is provided in the space 6 outside the flow path. Is circulated and supplied so that the coolant C2 is always in contact with the movable sealing ring 32. That is, as shown in FIG. 3, the case body 1 is formed with a coolant supply passage 6a and a coolant discharge passage 6b that are opened at the upper and lower ends of the outer space 6 to supply and discharge the coolant C2. The coolant C2 is circulated and supplied to the space 6 outside the flow path. As shown in FIG. 3, the case body 1 is formed with drains 13a and 13b that are opened between the opposing peripheral surfaces of the bodies 1 and 2 between the oil seals 5 and the bearings 9a and 9b.

  By the way, in this example, the fluid F2 flowing through each flow path R2 is a slurry fluid that is substantially the same as the coolant C1 (for example, a liquid containing a slurry component such as solid particles such as a polishing liquid). It is made to flow in the direction of the solid line arrow 4 and to be vacuum-sucked in the direction of the broken line arrow. For this reason, each mechanical seal 3 has a structure that can cope with fluctuations in positive and negative pressures in the flow path space 4 (in the flow path R2). That is, the balance ratio κ of each mechanical seal 3 is determined by the inner and outer diameters of the sealing end surface 32a of the movable sealing ring 32 and the inner diameter (the diameter of the O-ring contact surface 32e) of the base end portion 32c of the movable sealing ring 32. However, in general, 0 ≦ κ ≦ 0.6 so that the contact pressure of the sealed end faces 31a and 32a is properly maintained even when the flow path R2 has a negative pressure (when the fluid F2 is vacuumed). It is set to be. In this example, κ = 0.5 is set.

  Thus, according to the present invention, in each movable sealing ring 32 in which the sealing end surface 32a is formed in a fine point shape with a radial surface width, the O-ring contact surface 32e, the sealing end surface 32a, and the sealing end surface 32a to the O-ring. The surface portion of the movable seal ring 32 that reaches the contact surface 32e, and is in contact with the liquid contact surface 32g that contacts the coolant C2 that is the fluid in the space 6 outside the flow path, as compared with the constituent material of the seal ring 32. Coating layers 10d, 10e, and 10f made of a material having a large conduction coefficient and hardness and a small friction coefficient are formed in series. As shown in FIG. 5, a liquid contact surface 32g, which is a surface portion of the movable sealing ring 32 from the sealing end surface 32a to the O-ring contact surface 32e, has a distal end portion 32b and a proximal end portion 32c that are continuous with the outer peripheral edge of the sealing end surface 32a. And an end surface (base end surface) of the base end portion 32c that continues to the base end edge and reaches the base end edge of the O-ring contact surface 32e.

  That is, the sealing end surface coating layer 10d is formed on the sealing end surface 32a, the liquid contact surface coating layer 10e connected to the sealing end surface coating layer 10d is formed on the liquid contact surface 32g, and the liquid contact surface coating layer 10e is formed on the O-ring contact surface 32e. An O-ring contact surface coating layer 10f that is continuous with the above is formed. In the following description, when it is necessary to distinguish between a sealing ring and a coating layer formed thereon, the former is referred to as a sealing ring base material.

  As a constituent material of the coating layers 10d, 10e, and 10f, no matter what the constituent material of the movable seal ring 32 (the constituent material of the seal ring base material) is any of the seal ring constituent materials such as ceramics and cemented carbide. Diamonds having a high conductivity coefficient and hardness and a small friction coefficient are used. The diamond coating layers 10d, 10e, and 10f are formed by a coating method such as a hot filament chemical vapor deposition method, a microwave plasma chemical vapor deposition method, a high frequency plasma method, a direct current discharge plasma method, an arc discharge plasma jet method, or a combustion flame method. Done.

  In the first and second rotary joints configured as described above, the sealing end faces 32a and 132a of the movable sealing rings 32 and 132 have a hardness greater than that of the constituent material (the constituent material of the sealing ring base material) and Since the sealing end face coating layers 10a and 10d made of a material having a small friction coefficient are formed, the case where the sealing end face of the fixed sealing ring and the sealing end face of the movable sealing ring directly rotate relative to each other like a conventional rotary joint, that is, Compared with the case where the sealing ring base materials are directly in relative rotational sliding contact with each other, the relative rotational sliding contact portions between the respective sealing end surfaces 32a and 132a and the mating sealing end surfaces (sealing end surfaces of the fixed sealing rings 31 and 131) 31a and 131a. Less wear and heat generation. In particular, when each of the sealing end face coating layers 10a and 10d is made of diamond as described above, diamond is the hardest solid substance existing in nature, and any sealing ring structure such as silicon carbide having a friction coefficient. Very low compared to the material (generally, the friction coefficient of diamond is 0.03 (μ), which is 10 times higher than PTFE (polytetrafluoroethylene), which has a much lower coefficient of friction than any seal ring component. %), The sealing end faces 31a and 132a of the movable sealing rings 32 and 132 covered with the sealing end face coating layers 10a and 10d and the sealing end faces 31a of the mating sealing rings (fixed sealing rings) 31 and 131, respectively. , 131a causes very little wear and heat generation due to the relative rotational sliding contact with 131a.

  Further, since the sealing end faces 32a and 132a of the movable sealing rings 32 and 132 are pointed, heat generated by relative rotational sliding contact with the sealing end faces 31a and 131a of the mating sealing rings 31 and 131 is concentrated. There is a possibility that heat distortion that may cause high heat locally and adversely affect the mechanical seal function may occur on the sealed end faces 32a and 132a. However, in the first and second rotary joints, such sealed end faces 32a, Generation of thermal strain in 132a is prevented as much as possible.

  That is, the liquid contact surface coating layers 10b and 10e connected to the sealing end surface coating layers 10a and 10d are formed on the liquid contact surfaces 32g and 132h of the movable seal rings 32 and 132, and the O ring contact surfaces of the movable seal rings 32 and 132 are formed. O-ring contact surface coating layers 10c and 10f connected to the liquid contact surface coating layers 10b and 10e are formed on 32e and 132e, and the sealed end surface coating layers 10a and 10d, the liquid contact surface coating layers 10b and 10e, and the O ring. Since the contact surface coating layers 10c and 10f are a series and are made of a material having a larger thermal conductivity coefficient than the constituent material of the movable sealing rings 32 and 132, the sealing of the movable sealing rings 32 and 132 is performed. The heat generated at the end faces 32a and 132a is wetted from the sealed end face coating layers 10a and 10d. 10b, then heated to 10e Den, further wetted surface coating layer 10b, O-ring contact surface coating layer 10c from 10e, are heated to 10f Den. Therefore, the heat of the sealing end surface coating layers 10a and 10c is dispersed throughout the coating layer including the sealing end surface coating layers 10a and 10c, and the temperature of the sealing end surface coating layers 10a and 10c is greatly reduced. In addition, a part of the wetted surface coating layers 10b and 10e and the O-ring contact surface coating layers 10c and 10f (the O-rings from the contact points of the O-rings 32d and 132d on the O-ring contact surfaces 32e and 132e to the wetted surfaces 32g and 132h). In the O-ring contact surface coating layers 10c and 10f formed on the ring contact surfaces 32e and 132e), the liquid contact surface coating layer 10b is exchanged by heat exchange with the coolants C1 and C2 that are always in contact with and circulate. , 10e and part of the O-ring contact surface coating layers 10c, 10f are effectively radiated and cooled. As a result, since the sealing end faces 32a and 132a of the movable sealing rings 32 and 132 have a minute tip shape with a radial width, the contact surfaces of the mating sealing rings (fixed sealing rings) 31 and 131 with the sealing end faces 31a and 131a. Even when the pressure is high, the amount of wear and heat generated by the relative rotational sliding contact between both sealed end faces is drastically reduced, and thermal strain that can adversely affect the knife edge seal function (mechanical seal function) is possible. It is prevented as much as possible. In addition, the relative movement between the movable seal rings 32 and 132 and the O-rings 32d and 132d is smoothly performed by the low friction coefficient O-ring contact surface coating layers 10c and 10f, and the followability of the movable seal rings 32 and 132 is improved. In addition, in combination with the above, the mechanical seal function is exhibited well. Such an effect is achieved when the coating layers 10a, 10b, 10c and 10d, 10e, 10f are made of diamond as described above, so that diamond has the highest thermal conductivity among all solid substances, and ceramics or carbide Thermal conductivity is extremely higher than that of sealed ring components such as alloys (for example, the thermal conductivity of silicon carbide is 70 to 120 W / mK, whereas the thermal conductivity of diamond is 1000 to 2000 W. / MK).

  Therefore, according to the first and second rotary joints, the relative sealing and sliding contact between the fixed sealing rings 31 and 131 and the movable sealing rings 32 and 132 in the mechanical seals 3 and 103 is appropriately performed, so 4,104 is sealed well over a long period of time, and a rotary joint function with excellent reliability and durability can be exhibited.

  The configuration of the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.

  For example, in each mechanical seal 3, 103, the sealing end faces 31 a, 131 a of the fixed sealing rings 31, 131 are compared with the constituent materials of the sealing ring base material of the sealing rings 31, 131 as shown in FIG. Thus, the coating layers 10g and 10h made of a material having a large thermal conductivity coefficient and hardness and a small friction coefficient (optimized by diamond) can be formed. If it does in this way, the heat which generate | occur | produces in each movable sealing rings 32 and 132 will be heat-transferred and distributed to the coating layers 10g and 10h of the other sealing rings 31 and 131, and the movable sealing rings 32 and 132 of the movable sealing rings 32 and 132 are carried out. Generation of thermal strain due to relative rotational sliding contact between the sealing end surfaces 32a and 132a and the sealing end surfaces 31a and 131a of the mating sealing rings 31 and 131 can be more effectively prevented, and the amount of wear due to the relative rotational sliding contact is drastically reduced. Can be made. Furthermore, in this case, as shown in FIG. 7 or FIG. 12, the coating layers 10g and 10h are formed on the sealing end faces 31a and 131a of the fixed sealing rings 31 and 131, and the cooling in the fixed sealing rings 31 and 131 is performed. It is preferable to form coating layers 10i and 10j of the same material connected to the coating layers 10g and 10h on the surface portions (outer peripheral surfaces) in contact with the liquids C1 and C2. If it does in this way, the said heat dissipation and cooling effect will be exhibited more effectively.

  Further, when the fluids F1 and F2 flowing through the flow path spaces 4 and 104 (flow paths R1 and R2) are liquids that are always in contact with the movable sealing rings 32 and 132 and can function as a cooling liquid, the space 6 outside the flow path. , 106 is a gas such as nitrogen gas, or when the fluid passage space 6, 106 is open to the atmosphere without the oil seals 5, 105, the cooling action by the fluids F1, F2 flows. Since it can be expected from the cooling action by the fluid (gas) in the outside space 6, 106, as shown in FIG. 8 or FIG. 13, the sealing end faces 32 a and 132 a and the O-ring contact faces 32 e and 132 e in the movable sealing rings 32 and 132. In addition, the surface portions of the movable sealing rings 32 and 132 extending from the sealing end surfaces 32a and 132a to the O-ring contact surfaces 32e and 132e, which are in contact with the fluids F1 and F2, respectively. Further, the coating layers 10a, 10c, 10k or 10d made of a material (diamond is optimal) having a large thermal conductivity coefficient and hardness and a small friction coefficient as compared with the constituent material of the sealing ring base material of the sealing rings 32 and 132. , 10f, 10m are preferably formed in series. That is, in the first rotary joint, as shown in FIG. 8, the inner peripheral surface of the main body portion 132b of the movable sealing ring 132 in which the liquid contact surface 132i continues to the inner peripheral edge of the sealed end surface 132a and the base end edge (upper end edge). ) To the base end edge (upper end edge) of the O-ring contact surface 132e and the base end face (upper end face) of the main body 132b of the movable sealing ring 132, and the sealed end face formed on the sealing end face 132a on the liquid contact surface 132i. A liquid contact surface coating layer 10k that connects the coating layer 10a and the O ring contact surface coating layer 10c formed on the O ring contact surface 132e is formed in advance. In the second rotary joint, as shown in FIG. 13, the inner periphery of the distal end portion 32b of the movable sealing ring 32 where the liquid contact surface 32h extends from the inner peripheral edge of the sealed end surface 32a to the distal end edge of the O-ring contact surface 32e. A wetted surface coating layer 10m is formed on the wetted surface 32h to connect the sealed end surface coating layer 10d formed on the sealed end surface 32a and the O-ring contact surface coating layer 10f formed on the O-ring contact surface 32e. Keep it. If it does in this way, the heat which generate | occur | produces in coating layer 10a, 10d of sealing end surface 32a, 132a will be heat-transferred and distributed to coating layer 10c, 10k or 10f, 10m which contacts fluid F1, F2, and fluid F1. , F2 is performed, and thermal strain does not occur on the sealed end faces 32a, 132a. Further, in this case, as shown in FIG. 9 or FIG. 14, the heat conduction between the sealing end faces 31 a and 131 a of the fixed sealing rings 31 and 131 is larger than that of the constituent material of the sealing ring base material of the sealing rings 31 and 131. It is preferable to form the coating layers 10g and 10h made of a material having a large coefficient and hardness and a small friction coefficient (diamond is optimal).

  By the way, in a rotating device used in the semiconductor field such as a CMP apparatus, ultrapure water, pure water, or a fluid that dislikes elution of metal ions is used, and these fluids are not contaminated by a rotary joint. Since it is necessary to make it flow, it has been proposed that the mechanical seal constituent member that comes into contact with the fluid flowing in the flow path of the rotary joint is made of silicon carbide or plastic that hardly generates particles or metal ions. For example, as disclosed in Japanese Patent Application Laid-Open No. 2003-200344, each sealing ring is made of silicon carbide, and a rotary joint constituent member other than the sealing ring that is in contact with the fluid flowing in the flow path is made of engineering plastic or the like. It is made of plastic. However, in such a rotary joint, the sealing ring cannot be made of a cemented carbide or the like that may elute metal ions, and the constituent material selection range of the sealing ring is greatly limited. Become. Further, when the sealing ring is made of silicon carbide and the fluid flowing in the flow path of the rotary joint is ultrapure water or pure water, erosion / corrosion is caused in the sealing ring by contact with the fluid. May occur. In such a case, when the fluids F1 and F2 flowing through the flow paths R1 and R2 are liquids that always contact the movable sealing rings 32 and 132 and can function as a cooling liquid, as shown in FIG. 10 or FIG. The surface portions of the respective sealing rings 31, 32 or 131, 132 that come into contact with the fluids F1, F2 include the sealing end surfaces 31a, 32a or 131a, 132a, and are electrically insulating and chemically and physically stable. It is preferable to form a series of diamond coating layers 10a, 10c, 10k, 10g, 10n or 10d, 10f, 10h, 10m. In this way, it is possible to prevent the occurrence of wear and thermal distortion at the sealing end faces 32a and 132a of the movable sealing rings 32 and 132 as much as possible, as well as the above-mentioned cases. , 132 can be made of cemented carbide or the like that may cause metal ions to elute, ultrapure water, silicon carbide that may cause erosion or corrosion due to contact with pure water, and the like. The component material selection range of 31, 32 or 131, 132 is not limited. In this case, the surfaces or portions of the rotary joint members other than the respective sealing rings 31, 32 or 131, 132 that make up the flow paths R1, R2 and in contact with the fluids F1, F2 are made of plastic (for example, fluororesin Or an engineering plastic such as polyetheretherketone (PEEK) or polyphenylene sulfide (PPS)). If configured in this way, the above-described problems are caused even when the fluids F1 and F2 flowing through the flow paths R1 and R2 are ultrapure water or pure water, or are fluids that dislike elution of metal ions. Does not occur.

  In addition, the present invention is not limited to the saddle type rotary joint in which the rotation axis of both bodies 1, 2, 101, 102 extends in the vertical direction as described above, but also to a horizontal rotary joint in which the rotation axis extends in the horizontal direction. It can be suitably applied. In addition, the present invention is not limited to the one having one flow path R1 as in the first rotary joint and the one having two flow paths R2 and R2 as in the second rotary joint. The present invention can also be suitably applied to a multi-channel rotary joint having a channel. Further, as disclosed in Japanese Patent Application Laid-Open No. 2002-005365, in the present invention, a plurality of mechanical seals are concentric between a case main body and a rotating shaft body, and a direction (diameter perpendicular to the rotating axis line of the two bodies is used. It can also be applied to a rotary joint that is arranged in parallel in the direction) and seals the flow path space with an adjacent mechanical seal. The present invention can also be applied to a rotary joint that uses a mechanical seal in which a fixed sealing ring is provided in a case body and a movable sealing ring is provided in a rotating shaft body. Each of the rotary joints shown in FIGS. 6 to 10 has the same structure as that of the first rotary joint shown in FIGS. 1 and 2 except for the points described above. The same reference numerals as those used in FIG. Moreover, since each rotary joint shown in FIGS. 11-14 has the same structure as the 2nd rotary joint shown in FIGS. 3-5 except the above-mentioned point, about the same component, FIG. The detailed description is abbreviate | omitted by attaching | subjecting the code | symbol same as the code | symbol used for FIG.

DESCRIPTION OF SYMBOLS 1 Case body 2 Rotating shaft body 3 Mechanical seal 4 Channel space 5 Oil seal 6 Outer channel space 6a Coolant supply passage 6b Coolant discharge passage 7 Case body side fluid passage 8 Shaft body side fluid passage 8a Header space 8b Communication hole 8c Fluid Passage body 9a Bearing 9b Bearing 10a Coating layer 10b Coating layer 10c Coating layer 10d Coating layer 10e Coating layer 10f Coating layer 10g Coating layer 10h Coating layer 10i Coating layer 10j Coating layer 10k Coating layer 10m Coating layer 10n Coating layer 11 O Ring layer 11 Ring locking portion 11b O-ring holding portion 11c Communication hole 13a Drain 13b Drain 21 Shaft body 21a Bearing receiving portion 22 Sleeve 23 Bearing Body 24 Bolt 25 O-ring 31 Fixed seal ring 31a Sealed end face of fixed seal ring 32 Movable seal ring 32a Sealed end face of movable seal ring 32b Tip of movable seal ring 32c Base end of movable seal ring 32d O-ring 32e O-ring contact Surface 32f drive pin 32g liquid contact surface 32h liquid contact surface 33 spring 51 annular seal member 51a reinforcing metal fitting 51b garter spring 101 case body 101a peripheral wall 101b end wall 101c holding hole 101d O-ring groove 102 rotating shaft body 103 mechanical seal 104 flow path Space 105 Oil seal 105a Annular seal member 105b Reinforcing bracket 105c Garter spring 106 Space outside flow path 106a Coolant supply path 106b Coolant discharge path 107 Case body side fluid path 108 Shaft body side fluid path 109a Bearing 109b Bearing 113a Drain 131 Fixed sealing ring 131a Sealing end surface of fixed sealing ring 131b Main body portion 131c Fixed portion 131d Key 131e O-ring 132 Movable sealing ring 132a Sealing end surface of movable sealing ring 132b Main body portion 132c Hut 132d O-ring 132e O-ring contact Surface 132f Engaging recess 132g Drive pin 132h Liquid contact surface 132i Liquid contact surface 133 Spring C1 Coolant C2 Coolant F1 Fluid F2 Fluid R1 Channel R2 Channel

Claims (1)

A plurality of flow path spaces, in which four or more mechanical seals are arranged in the axial direction between the opposing peripheral surfaces of the case body and the rotary shaft body connected to the case body so as to be relatively rotatable, and are sealed by adjacent mechanical seals. And a space outside the flow path partitioned from the flow path space by the mechanical seal, and between the two bodies, a case body side fluid passage formed in the case body and a shaft body side formed in the rotary shaft body A series of a plurality of flow paths formed by communicating and connecting fluid passages through the flow path space is formed,
Wherein the mechanical seal, times in a fixed stationary seal ring and the case body on the rolling shaft member via the O-ring movably retained movable seal in the direction of the rotation axis of the two body ring and this to the stationary seal ring And a spring energized so as to be in pressure contact with each other, and the flow path space which is the inner peripheral side region of the relative rotational sliding contact portion by the relative rotational sliding contact action of the sealing end surfaces which are the opposite end surfaces of both sealing rings; It is configured to shield and seal the space outside the flow path which is the outer peripheral side region, and the fixed sealing ring is an annular body having its end face entirely configured as a sealing end face, and the movable sealing ring In a rotary joint which is an end surface contact type mechanical seal configured in a pointed shape with a sealed end surface having a small radial width,
Flow of the flow path in the space is a liquid which can function as a coolant in constant contact with the movable seal ring, the fluid flow path out of the space is a gas,
A surface portion of each movable sealing ring, which is a surface portion of an O-ring contact surface having a constant diameter in contact with the O-ring, a sealing end surface of the movable sealing ring, and a movable sealing ring extending from the sealing end surface to the O-ring contact surface. A rotary joint characterized in that a coating layer made of diamond is formed in series only on the liquid contact surface in contact with the liquid, and a coating layer made of diamond is formed only on the sealing end face of each fixed sealing ring.

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