JP6490993B2 - Multi-channel rotary joint - Google Patents

Description

  The present invention allows two or more fluids to flow between relative rotating members in a rotating device (for example, a CMP apparatus (a semiconductor wafer surface polishing apparatus using a CMP (Chemical Mechanical Polishing) method)) used in the semiconductor field or the like. The present invention relates to a multi-channel rotary joint.

  As a conventional rotary joint of this type, as disclosed in Patent Document 1, a case body is provided between opposing circumferential surfaces of a cylindrical case body and a rotating shaft body concentrically connected to the rotary shaft body. 4 or more mechanical seals configured to seal by a relative rotational sliding contact action of a sealing end surface which is an opposing end surface of a stationary sealing ring provided on the rotating shaft and a rotating sealing ring provided on the rotating shaft body. A plurality of passage connection spaces arranged in tandem in the direction and sealed by adjacent mechanical seals, and fluid passages communicating with each other through the passage connection spaces are formed on both bodies. A multi-channel rotary joint that is configured to cause two or more fluids to flow through a series of a plurality of channels formed by connecting both fluid channels in a channel connection space between them is well known.

  Thus, in such a multi-channel rotary joint (hereinafter referred to as “conventional rotary joint”), at least one rotary seal ring of a mechanical seal and a rotary seal ring of a mechanical seal adjacent thereto are provided at both end faces. Since this is also used as a single rotary sealing ring having a sealing end face, as disclosed in Patent Document 2, the rotary sealing ring of all mechanical seals is an independent member having only one end face as a sealing end face. Compared to the multi-channel rotary joint, the axial length of the rotary joint (the length of both bodies in the direction of the rotational axis) can be shortened, and the size of the mechanical seal can be reduced by reducing the number of parts. The structure, that is, the structure of the rotary joint can be simplified.

JP 2002-174379 A JP 2002-005380 A

  However, in the conventional rotary joint, the above-mentioned rotary sealing ring that is also used as the above-mentioned both ends of the sealing end face generates heat due to relative rotational sliding contact with the stationary sealing ring, so only one end face is sealed end face. As compared with the case, the thermal seal is likely to occur in the rotary seal ring.

  Further, a relative rotational sliding contact portion between one sealing end surface of the rotary sealing ring and a sealing end surface of the stationary sealing ring, and a relative rotational sliding contact portion between the other sealing end surface of the rotational sealing ring and the sealing end surface of the stationary sealing ring. The calorific value may be different. For example, if there is a pressure difference in the fluid flowing in each passage connection space sealed by two mechanical seals that also serve as a rotary seal ring, or if the pressure of each fluid fluctuates, both seals in one mechanical seal When the contact pressure at the end face is different from the contact pressure at the both sealed end faces of the other mechanical seal, the amount of heat generated at the relative rotational sliding contact portions of the two sealed rings in both mechanical seals is different. In such a case, a large temperature difference may occur between the two sealing end faces of the rotary sealing ring, and a large thermal strain may occur on the sealing end face that adversely affects the sealing function of the mechanical seal (hereinafter referred to as “mechanical sealing function”). There is.

  As described above, in the conventional rotary joint, since the rotary seal ring of the adjacent mechanical seal is also used, the relative rotation sliding contact with the stationary seal ring is not properly performed due to thermal strain generated in the sealed end face, The mechanical seal function is not exhibited well, and there is a possibility that fluid leaks from the passage connection space.

  The present invention solves the above-mentioned problem caused by sharing a rotating seal ring of adjacent mechanical seals, and can cause two or more fluids to flow well without causing leakage. The purpose is to provide a joint.

  In the present invention, a stationary seal ring provided on the case body and a rotary seal ring provided on the rotary shaft body are opposed to each other between the opposed peripheral surfaces of the cylindrical case body and the rotary shaft body connected to the rotary shaft body. A plurality of four or more mechanical seals configured to be sealed by the relative rotational sliding contact action of the sealing end surface, which is an end surface, are arranged in tandem in the rotation axis direction of both bodies and sealed by adjacent mechanical seals. A plurality of passage connection spaces, fluid passages communicating with each other through the passage connection spaces, and at least one rotary seal ring of the mechanical seal and a rotary seal ring of the mechanical seal adjacent thereto are formed. In order to achieve the above object, in a multi-channel rotary joint that is shared by a single rotary seal ring having both end faces as sealed end faces, in particular, both end faces and inner and outer peripheral faces of the double rotary seal ring that are also used One of the Rolling than the constituting material of the seal ring suggest to be formed into a series of coating layers consisting of thermal conductivity and hardness greater material.

  In the multi-channel rotary joint of the present invention, a pair of oil seals are disposed on both sides of the mechanical seal group arranged in a column in the direction of the rotation axis of the two bodies, It is preferable to form a cooling fluid space in which cooling fluid is circulated and supplied between both surfaces with oil seals, or mechanical seals arranged in tandem in the rotational axis direction of the two bodies A pair of cooling fluid space mechanical seals having the same structure as the mechanical seals on both sides of the group, and a space sealed between the opposing peripheral surfaces of the two bodies by the cooling fluid space mechanical seals. It is preferable to form a cooling fluid space in which the cooling fluid is circulated and supplied. Further, the rotary sealing ring of each of the cooling fluid space mechanical seals and the rotary sealing ring of the mechanical seal adjacent thereto are used as one rotary sealing ring having both end faces as sealing end faces, It is preferable to form a series of coating layers made of a material having a higher thermal conductivity coefficient and hardness than the constituent material of the rotary seal ring on one of the surface and the inner and outer peripheral surfaces. Furthermore, it is preferable that the radial width of the sealing end face of each stationary sealing ring that is in relative rotational sliding contact with the combined rotary sealing ring is set smaller than the radial width of the sealing end face of the rotary sealing ring. Also, a coating made of a material having a higher thermal conductivity coefficient and hardness than the constituent material of the sealing ring on the sealing end face of each rotary sealing ring and / or the sealing end face of each stationary sealing ring excluding the combined rotary sealing ring It is preferable to form a layer. In any case, the coating layer is preferably made of diamond.

  In the rotary joint of the present invention, the sealing end face which is the both end faces of the rotating seal ring also used as an adjacent mechanical seal (hereinafter referred to as “combined rotation seal ring”) is compared with the constituent material of the rotary seal ring. Since the coating layer made of a material with high hardness is formed, the amount of wear and heat generated at the relative rotational sliding contact part with the mating sealing ring (stationary sealing ring) on both sealing end faces of the dual-purpose rotating sealing ring is as much as possible. Can be reduced. Moreover, the coating layer is made of a material having a large thermal conductivity coefficient compared to the constituent material of the dual-use rotary seal ring, and this coating layer is also formed in series on the outer peripheral surface and / or inner peripheral surface of the dual-use rotary seal ring. Therefore, the heat generated in the coating layers formed on both sealing end faces of the dual-purpose rotary sealing ring is transferred to each other via the coating layer formed on the outer peripheral surface and / or the inner peripheral surface, and the Both sealed end faces of the dual-purpose rotary seal ring have a uniform temperature. As a result, a large temperature difference does not occur on both sealed end faces of the dual-use rotary seal ring, and a large thermal strain that adversely affects the mechanical seal function does not occur on the both sealed end faces. Such an effect is particularly prominent when the coating layer is made of diamond.

  Therefore, according to the present invention, it is possible to prevent, as much as possible, wear, heat generation at the relative rotational sliding contact portion between the dual-use rotary seal ring and each stationary seal ring, and generation of thermal strain at both sealed end faces of the dual-use rotary seal ring. A mechanical seal function can be satisfactorily exhibited over a long period of time, and an extremely practical multi-channel rotary joint that is superior in durability and reliability compared to conventional rotary joints can be provided.

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

  FIG. 1 is a cross-sectional view showing an example of a multi-channel rotary joint according to the present invention, FIG. 2 is a cross-sectional view of the multi-channel rotary joint taken along a position different from FIG. 1, and FIG. FIG. 4 is an enlarged detailed cross-sectional view showing an essential part of FIG. 1, and FIG. 4 is an enlarged detailed cross-sectional view showing an essential part of FIG. 1 different from FIG. In the following description, “upper and lower” refers to the upper and lower sides in FIGS.

  1 and 2 includes a cylindrical case body 1 and a rotating shaft body 2 concentrically connected to the rotary shaft body 2 so as to be relatively rotatable. Between the peripheral surfaces, four or more mechanical seals 3 are arranged in a row in the direction of the rotation axis of both bodies 1 and 2 (hereinafter simply referred to as “axial direction”), that is, in the vertical direction, and adjacent mechanical seals 3 and 3 are arranged. A plurality of passage connection spaces 4 sealed by 3 and a space defined by the passage connection space 4 and the mechanical seal 3, and a cooling fluid space 6 sealed by a pair of oil seals 5, 5. And a series of a plurality of flow paths R (see FIG. 2) formed by communicating the fluid passages 7 and 8 through the passage connection space 4 between the two bodies 1 and 2. Yes, two or more types of flow between relative rotating members of rotating equipment such as CMP equipment It is intended to flow to each other by each channel R to F.

  As shown in FIGS. 1 and 2, 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. 1 and 2, the rotary shaft body 2 includes a columnar shaft body 21 having an axial line extending in the vertical direction, and a plurality of shafts fitted and fixed in a vertical row at a predetermined interval in the vertical direction. It comprises a sleeve 22... And a bottomed cylindrical bearing receiver 23 fitted and fixed to the upper end of the shaft main body 21, and between the bearing receiver 23 and the upper end of the case body 1 and 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 of the case and the lower end of the case body 1 are concentrically opposed to the inner periphery of the case body 1. It is supported rotatably. 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. 1, each mechanical seal 3 includes a rotary seal ring 31 fixed to the rotary shaft body 2, a stationary seal ring 32 held opposite to the rotary seal ring 31 and movable in the axial direction on the case body 1. And a spring 33 that presses and contacts the sealing ring 31, and a relative rotational sliding contact action of the sealing end surfaces 31 a and 32 a that are opposite end surfaces of the sealing rings 31 and 32, in an inner peripheral side region of the relative rotational sliding contact portion. It is an end surface contact type mechanical seal configured to seal a certain passage connection space 4 and a cooling fluid space 6 that is an outer peripheral side region thereof. In this example, as shown in FIG. 1 and FIG. 2, the four mechanical seals 3 are arranged in such a manner that all the sealing rings 31... 32 are arranged in the direction of the rotation axis and at both ends of the sealing ring groups 31. It arrange | positions in the state in which the rotation sealing rings 31 and 31 are located. 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 stationary seal rings 32 and 32 are located between the rotary seal rings 31 and 31 are arranged in tandem in the axial direction.

  Each rotary seal ring 31 is an annular body having a square cross section that is concentric with the rotation axes (hereinafter simply referred to as “axis lines”) of both bodies 1 and 2, and as shown in FIGS. 3 and 4, the stationary seal ring 32. The end face which contacts is configured as a sealed end face 31a which is a smooth annular plane perpendicular to the axis. In this example, one rotary seal ring 31 of one mechanical seal 3 and a rotary seal ring 31 of a mechanical seal 3 adjacent thereto are provided as a single end with sealed end faces 31a and 31a as shown in FIG. The rotary seal ring 31 (hereinafter referred to as “combined rotary seal ring 31A”) is also used. That is, both end faces of the rotary seal ring (combined rotary seal ring) 31A are sealed except for the rotary seal rings 31 and 31 positioned at both ends (upper and lower ends) of the rotary seal ring group 31 vertically aligned. It is comprised in the end surfaces 31a and 31a.

  As shown in FIGS. 1 and 2, each rotary seal ring 31, 31 </ b> A is fitted and fixed to the shaft main body 21 of the rotary shaft body 2 in a state where the interval between the adjacent rotary seal rings 31 is regulated by the sleeve 22. ing. That is, as shown in FIG. 1, each rotary seal ring 31, 31 </ b> A is provided between the bearing receiver 21 a and the bearing receiver 23 via the sleeve 22 by fastening the bearing receiver 23 to the shaft body 21 with the bolt 24. Are fixed to the rotary shaft body 2 in a tandem state at equal intervals in the axial direction. As shown in FIG. 3, an O-ring 25 that seals the fitting portion between the shaft main body 21 and the rotary seal rings 31 and 31A is loaded between the inner peripheral portions of both ends of each sleeve 22 and the shaft main body 21. ing.

  As shown in FIG. 3, each stationary sealing ring 32 is an annular body having a substantially L-shaped cross section concentric with the axis, and a sealing end face 32a which is a smooth annular plane whose end face is perpendicular to the axis. It is configured. The sealing end surface 32a of the stationary sealing ring 32 has a radial surface width (sealing surface width) smaller than the radial surface width of the sealing end surface 31a of the rotary sealing rings 31 and 31A, and the inner and outer peripheral portions of the sealing end surface 31a. In contact with the sealed end face 31a. That is, the inner diameter of the sealing end face 32a of the stationary sealing ring 32 is set larger than the inner diameter of the sealing end face 31a of the rotary sealing rings 31 and 31A and the outer diameter thereof is set smaller than the outer diameter of the sealing end face 31a of the rotary sealing rings 31 and 31A. Yes. As shown in FIGS. 1 and 3, each stationary sealing ring 32 is fitted and held in an annular wall 11 protruding from the inner peripheral portion of the case body 1 so as to be movable in the axial direction via an O-ring 32b. As shown in FIG. 1, by engaging a drive pin 32c protruding in the axial direction from the annular wall 11 with an engaging recess formed in the outer peripheral portion thereof, relative movement in the axial direction is allowed within a predetermined range. The case body 1 is held in a relatively non-rotatable manner. In this example, as shown in FIG. 1, all the drive pins 32c are also used as drive bars that are supported by the annular walls 11 and 11 in the axial direction.

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

  As shown in FIG. 2, fluid passages 7 and 8 communicating with the passage connection spaces 4 are formed in both bodies 1 and 2. In this example, both fluid passages 7 and 8 are disposed between the bodies 1 and 2. And the passage connection space 4 form two flow paths R and R for allowing the fluid F to flow separately in the direction of the arrow (solid or broken line) between the bodies 1 and 2. Each fluid passage 7 of the case body 1 is formed so as to penetrate the case body 1 in the radial direction. One end of the fluid passage 7 opens into the passage connection space 4 on the inner peripheral surface of the annular wall 11 and the other end is a rotating device. Connected to a fluid passage formed in the stationary side member. Each fluid passage 8 formed in the rotary shaft body 2 includes an annular header space 8a formed between opposed peripheral surfaces of the shaft body 21 and the sleeve 22, and a header space 8a penetrating the sleeve 22 in the radial direction. A plurality of communication holes 8b that communicate with the passage connection space 4, and a fluid passage body 8c that penetrates the shaft body 21 in the axial direction from the lower end thereof and opens into the header space 8a. The lower end portion of the 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, 31A, 32 is selected according to rotary joint use conditions, such as the property of the fluid F which flows through the flow path R, and generally ceramics, such as silicon carbide, or a cemented carbide (tungsten carbide). Etc.

  As shown in FIGS. 1 and 2, the 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. Rings made of an elastic material such as rubber that are fixed to the inner peripheral part of the rotary seal rings 31 and 31 and the outer peripheral surfaces of the rotary seal rings 31 and 31 positioned at both ends (upper and lower ends) of And a seal member 51. The annular seal member 51 is a well-known member, and as shown in FIG. 4, a main body portion in which a reinforcing metal fitting 51 a made of a metal material (SUS304 or the like) is embedded and fixed to the inner peripheral portion of the case body 1 is rotated. The lip seal portion is tightly bound to and pressed against the outer peripheral surface of the seal ring 31 by a garter spring 51b and exhibits a seal function (oil seal function).

  Between the opposing peripheral surfaces of both bodies 1 and 2, communication is formed on 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 annular wall 11 that partitions the outer peripheral side region. A cooling fluid space 6 which is a space constituted by the holes 11a and is sealed by both oil seals 5 and 5 is formed, and an appropriate cooling fluid C is circulated and supplied to the cooling fluid space 6. . In this example, a liquid such as room temperature water is used as the cooling fluid C. That is, as shown in FIG. 1, the case body 1 is formed with a cooling fluid supply passage 6 a and a cooling fluid discharge passage 6 b that are opened at the upper and lower ends of the cooling fluid space 6 to supply and discharge the cooling fluid C, The cooling fluid C is circulated and supplied to the cooling fluid space 6. As shown in FIG. 1, 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.

  Thus, according to the present invention, one of the sealed end faces 31a, 31a and the inner and outer peripheral surfaces of the dual-use rotary seal ring 31A has a large thermal conductivity coefficient and hardness as compared with the constituent material of the dual-use rotary seal ring 31A, and friction. Coating layers 10a, 10a, 10b made of a material having a small coefficient are formed in series. In this example, as shown in FIGS. 1 to 3, a series of coating layers 10 a, 10 a, and 10 b are formed on both sealed end faces 31 a and 31 a and the outer peripheral surface of the combined rotary seal ring 31 </ b> A. That is, the coating layer has a sealing end face coating layer 10a, 10a that covers the entire end faces 31a, 31a of the dual-purpose rotary seal ring 31A and an outer periphery that covers the outer peripheral face of the rotary seal ring 31A. And a surface coating layer 10b. 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, 10a, and 10b, no matter what the constituent material of the dual-purpose rotary seal ring 31A (the constituent material of the seal ring base material) is any seal ring constituent material such as ceramics or cemented carbide. Diamonds having a high thermal conductivity coefficient and hardness and a small friction coefficient are used. The diamond coating layers 10a and 10b 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. .

  In the rotary joint configured as described above, both the sealing end faces 31a and 31a of the dual-use rotary seal ring 31A are made of a material having a hardness higher than that of the constituent material (the constituent material of the seal ring base material) and a small friction coefficient. Since the sealing end face coating layers 10a and 10a are formed, when the sealing end face of the rotary sealing ring and the sealing end face of the stationary sealing ring directly rotate relative to each other like a conventional rotary joint, the sealing ring base materials are directly The amount of wear and heat generated at the relative rotational sliding contact portion between each sealing end surface 31a and the mating sealing end surface (sealing end surface of the stationary sealing ring 32) 32a is smaller than in the case of relative rotational sliding contact. In particular, when each coating layer 10a is made of diamond as described above, diamond is the hardest solid substance existing in nature, and the friction coefficient is higher than that of any sealing ring constituent material such as silicon carbide. (In general, the coefficient of friction of diamond is 0.03 (μ), which is 10% or more lower than PTFE (polytetrafluoroethylene) having a much lower coefficient of friction than all seal ring components). Therefore, wear and heat generated by relative rotational sliding contact between each sealed end face 31a covered with the sealed end face coating layer 10a in the dual-use rotary seal ring 31A and the sealed end face 32a of the counterpart seal ring (stationary seal ring) 32. Are very few.

  Further, both sealed end face coating layers 10a, 10a formed on the dual-use rotary seal ring 31A are connected by an outer peripheral surface coating layer 10b formed on the outer peripheral surface of the seal ring 31A, and the coating layers 10a, 10a, 10b are connected. Since it is made of a material having a higher thermal conductivity than the constituent material of the dual-use rotary seal ring 31A, as described at the beginning, one sealed end face 31a of the dual-use rotary seal ring 31A and the sealed end face 32a of the stationary seal ring 32 Even when the amount of heat generated between the relative rotational sliding contact portion and the relative rotational sliding contact portion between the other sealing end surface 31a of the combined rotary sealing ring 31A and the sealing end surface 32a of the stationary sealing ring 32 is different, both sealed end surface coating layers are used. The heat generated in 10a and 10a is transferred to and uniformed through the outer peripheral surface coating layer 10b. Therefore, both the sealing end face coating layers 10a, 10a have a uniform temperature, that is, both end faces 31a, 31a of the sealing ring base material in the dual-purpose rotary sealing ring 31A have the same temperature, and are caused by relative rotational sliding contact with the mating sealing end faces 32a, 32a. Even when the amount of generated heat is different, generation of thermal strain in the dual-use rotary seal ring 31A is effectively prevented, and the two sealing end faces 31a and 31a of the dual-use rotary seal ring 31A have a large adverse effect on the mechanical seal function. Thermal strain does not occur.

  Moreover, since the radial end face width of the sealed end face 32a of the stationary seal ring 32 that contacts the radial end face width of each sealed end face 31a of the combined rotary seal ring 31A is small, the sealed end face of the stationary seal ring 32 The heat generated in 32a is transferred to and absorbed by the sealed end surface coating layer 10a having a high thermal conductivity formed on the mating sealed end surface 31a, and the temperature of the sealed end surface 32a decreases. On the other hand, in each sealed end face coating layer 10a formed on the dual-use rotary seal ring 31A, a portion of the stationary seal ring 32 that protrudes from the contact portion with the seal end face 32a toward the inner and outer peripheral sides passes through the flow path R. F and the cooling fluid C that is circulated and supplied to the cooling fluid space 6 are in contact with each other, so that the heat generated by the relative rotational sliding contact with the sealed end surface 32a is caused by the fluid F and the cooling fluid C from the protruding portion. The heat is dissipated and cooled by the fluid F and the cooling fluid C. Such heat radiation and cooling are performed more effectively by the fact that both sealed end surface coating layers 10a and 10a are connected by the outer peripheral surface coating layer 10b and the contact area with the cooling fluid C is increased.

  The coating layer 10a, 10a, 10b is made of diamond as described above in order to make the both end faces 31a, 31a of the dual-use rotary seal ring 31A uniform temperature, and to dissipate and cool by contact with the fluid F and the cooling fluid C. As a result, diamond has the highest thermal conductivity among all solid materials, and has extremely high thermal conductivity compared to sealing ring components such as ceramics and cemented carbide (for example, thermal conductivity of silicon carbide). The rate is 70 to 120 W / mK, whereas the thermal conductivity of diamond is 1000 to 2000 W / mK).

  Therefore, the dual-purpose rotary seal ring 31A has both end surfaces 31a and 31a that generate heat due to relative rotational sliding contact with the mating seal rings 32 and 32, but the heat generation amounts at the both end surfaces 31a and 31a are different. It is possible to prevent wear, heat generation and thermal distortion as much as possible in each of the sealed end faces 31a, 31a, and to exhibit a good mechanical seal function over a long period of time.

  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 the dual-use rotary seal ring 31A, a coating layer 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 seal ring base material is as shown in FIG. Can be formed. That is, in the one shown in FIG. 5, the coating layers 10a, 10a, and 10c are formed in series on both end surfaces 31a and 31a and the inner peripheral surface of the dual-purpose rotary seal ring 31A. Also in this case, as shown in FIG. 3, both the sealing end surfaces 31a and 31a are at a uniform temperature, as in the case where the both sealing end surface coating layers 10a and 10a are connected by the outer peripheral surface coating layer 10b. Thermal distortion is prevented as much as possible.

  Further, when the surface of the dual-use rotary seal ring 31A is coated with the coating layers 10a, 10b or 10a, 10c as shown in FIG. 3 or 5, the seal end face 31a of each rotary seal ring 31 other than the dual-use rotary seal ring 31A is provided. As shown in FIG. 6, the coating layer 10d is formed 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 seal ring base material of the rotary seal ring 31. Can be kept. In this way, wear, heat generation, and thermal distortion due to the relative rotational sliding contact between the rotary sealing ring 31 and the mating sealing ring 32 are prevented as much as possible, and all the mechanical elements constituting the multi-channel rotary joint are configured. The mechanical seal function by the seal 3 can be exhibited well, and the flow of the fluid F through the flow path R can be performed well over a long period of time. When the coating layers 10a and 10d are formed on the sealing end surfaces 31a of all the rotary sealing rings 31 including the dual-purpose rotary sealing ring 31A in this way, the stationary end surfaces 32a of all the stationary sealing rings 32 have the stationary If a coating layer made of a material (diamond is most suitable) having a large thermal conductivity coefficient and hardness and a small friction coefficient as compared with the constituent material of the sealing ring 32, the above-described effect can be exhibited more remarkably.

  Further, as shown in FIG. 7, the surface of each stationary seal ring 32 that is in contact with the cooling fluid C including the sealed end face 32 a is heated as compared with the constituent material of the seal ring base material of the stationary seal ring 32. The coating layer 10e made of a material having a large conduction coefficient and hardness and a small friction coefficient (optimized by diamond) can be formed. If it does in this way, each stationary sealing ring 32 will be cooled effectively by the cooling fluid C, and the wear and heat generation | occurrence | production in a relative rotation sliding contact part with the other party sealing rings 31 and 31A will be prevented more effectively. Is done. Therefore, as shown in FIG. 3 or FIG. 5, the coating layer 10d is formed on the sealing end face 31a of the rotary sealing ring 31 as shown in FIG. In any case, wear, heat generation and thermal distortion due to relative rotational sliding contact between the sealing end faces 31a and 32a of each mechanical seal 3 are prevented as much as possible, and a good mechanical seal function is exhibited over a long period of time. be able to. Of course, when the coating layer is not formed on the rotating sealing ring 31 other than the dual-purpose rotating sealing ring 31A, the wear and heat generation with the mating sealing end surface 31a is limited to the sealing end surface 32a of the stationary sealing ring 32 as described above. It can prevent effectively also by covering.

  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 through the flow path of the rotary joint is ultrapure water or pure water, erosion / corrosion occurs in the sealing ring due to contact with the fluid. May occur. In such a case, as shown in FIG. 8, the surface portions of the respective sealing rings 31, 31A, 32 that come into contact with the fluid F flowing in the flow path R include the sealing end surfaces 31a, 32a to have electrical insulation. In addition, it is preferable to form a series of chemically and physically stable diamond coating layers 10a, 10d, and 10f. In the example shown in FIG. 8, the surface portion in contact with the fluid F in each of the rotary sealing rings 31 and 31A is only the end surface (sealed end surface) 31a. By doing so, carbonization that may cause erosion / corrosion due to contact with cemented carbide or the like that may cause metal ions to elute from the sealing rings 31, 31A, 32, ultrapure water, or pure water. It can be made of silicon or the like, and the constituent material selection range of the sealing rings 31, 31A, 32 is not limited. In this case, the surface or part of the rotary joint member other than the sealing rings 31, 31A, 32 that contacts the fluid F in the member constituting the flow path R is made of plastic (for example, fluororesin or polyether ether ketone (PEEK)). Or an engineering plastic such as polyphenylene sulfide (PPS). With such a configuration, the above-described problem does not occur even when the fluid F flowing in the flow path R is ultrapure water or pure water, or when the fluid F dislikes elution of metal ions.

  In addition, even when the fluid F flowing through the flow path R is not a fluid that dislikes elution of ultrapure water or pure water or metal ions, the fluid F has a cooling function superior to the cooling fluid C (for example, the fluid F When F is a liquid having a temperature lower than that of the cooling fluid C), the cooling effect by the fluid F can be further expected. Therefore, the surface portion of each stationary sealing ring 32 that contacts the fluid F as shown in FIG. It is preferable to coat the coating layer 10f including the sealing end face 32a. When the two types of fluids that contact the stationary seal ring 32 are different-phase fluids (one of the fluid F and the cooling fluid C in the flow path R is a liquid and the other is a gas), The cooling function includes the case where the temperature is the same or substantially the same, and the liquid is superior to the gas. Therefore, the sealing end face 32a is included in the surface of the stationary sealing ring 32 and in contact with the fluid which is a liquid. It is preferable to coat the coating layer 10e shown in FIG. 8 or the coating layer 10f shown in FIG.

  Further, the present invention is not limited to the vertical multi-channel rotary joint in which the rotation axes of both bodies 1 and 2 extend in the vertical direction as described above, but a horizontal multi-channel type in which the rotation axis extends in the horizontal direction. It can be suitably applied to a rotary joint. Further, the present invention is not limited to the multi-channel rotary joint having two channels R and R as described above, and is also suitable for a multi-channel rotary joint having three or more channels R. Can be applied. Furthermore, in the multi-channel rotary joint of the present invention, the number of the combined rotary seal rings 31A is not limited and is arbitrary. For example, three or more sets of mechanical seal units each including a pair of mechanical seals 3 and 3 having a double seal arrangement in which stationary seal rings 32 and 32 are positioned between the rotary seal rings 31 and 31 are arranged in tandem in the axial direction. In the case of forming the above flow paths R ..., the rotary seal ring 31 of each mechanical seal 3 and the mechanical seal 3 adjacent thereto are removed except for the mechanical seals 3, 3 located at both ends of the mechanical seal group 3 .... The rotary seal ring 31 can be shared by the dual-use rotary seal ring 31A. That is, the rotational seal ring 31 of all the mechanical seals 3 except the mechanical seals 3 and 3 located at both ends of the mechanical seal group 3.

  In the multi-channel rotary joint of the present invention, each oil seal 5 can be replaced with a mechanical seal. For example, as shown in FIG. 9 and FIG. 10, a pair of cooling fluid space mechanical seals 5a, 5a are arranged on both sides of the mechanical seal group 3 constituting the flow path R so that the opposing circumferences of both bodies 1, 2 are opposed to each other. A cooling fluid space 6 in which the cooling fluid C is circulated and supplied is formed between the two surfaces, which is a space sealed by both cooling fluid space mechanical seals 5a and 5a. In this example, as the cooling fluid C, a liquid such as room temperature water is used as described above.

  As shown in FIG. 11, each cooling fluid space mechanical seal 5a has the same structure as the mechanical seal 3, and is a flow path forming mechanical seal located at the end of the mechanical seal group 3. The rotary sealing ring 31 of No. 3 is configured such that the end surface opposite to the rotary sealing end surface 31a is formed as a sealing end surface 31b, and this is also used as a rotary sealing ring. That is, as shown in FIG. 9, each of the fluid space mechanical seals 5a is a stationary seal that is held by the case body 1 so as to be movable in the axial direction opposite to the rotary seal ring 31 fixed to the rotary shaft body 2. A ring 52 and a spring 53 that presses the ring 52 against the rotary sealing ring 31 are provided, and the relative rotational sliding contact portions of the sealing end surfaces 31b and 52a, which are the opposed end surfaces of the sealing rings 31 and 52, are provided. The cooling fluid space 6, which is the outer peripheral side region, and the bearing arrangement space, which is the inner peripheral side region, are sealed. In this case, as shown in FIG. 11, the constituent material of the seal ring base material of the rotary seal ring 31 on one of the both end faces 31a and 31b and the inner and outer peripheral surfaces of the rotary seal ring 31 of each cooling fluid space mechanical seal 5a. It is preferable to form a series of coating layers 10h made of a material (diamond is most suitable) having a large thermal conductivity coefficient and hardness and a small friction coefficient compared to the above. That is, the rotary seal rings 31 of all the mechanical seals (the mechanical seal 3 for the passage connection space and the mechanical seal 5a for the cooling fluid space) constituting the multi-channel rotary joint are used as the rotary seal rings 31A. It is preferable to form the coating layer described above on at least one of the surface and the inner and outer peripheral surfaces. Further, even in this case, it is preferable to form a coating layer on the stationary sealing rings 32 and 52 of all the mechanical seals as described above. For example, the coating layer shown in FIG. 7 includes a sealing end face 52a in a portion of the surface of the stationary sealing ring 52 of the mechanical seal 5a for cooling fluid space that contacts the cooling fluid C supplied to the cooling fluid space 6. Similarly to 10e, a coating layer made of a material (diamond is optimal) having a high thermal conductivity coefficient and hardness and a small friction coefficient as compared with the constituent material of the seal ring base material of the stationary seal ring 52 is formed. It is preferable. As described above, when the cooling fluid mechanical seal 5 a is used instead of the oil seal 5, the cooling fluid space 6 is more reliably sealed and supplied to the cooling fluid space 6 than when the oil seal 5 is used. It is possible to make the cooling fluid C to be of higher pressure. The multi-channel rotary joint shown in FIGS. 9 to 11 has the same structure as the multi-channel rotary joint shown in FIGS. 1 and 2 except for the above points. The same reference numerals as those used in FIG. 1 and FIG.

DESCRIPTION OF SYMBOLS 1 Case body 2 Rotating shaft body 3 Mechanical seal 4 Passage connection space 5 Oil seal 5a Mechanical seal for cooling fluid space 6 Cooling fluid space 6a Cooling fluid supply passage 6b Cooling fluid discharge passage 7 Fluid passage 8 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 11 Annular wall 11a Communication hole 13a Drain 13b Drain 21 Shaft body 21a Bearing Sleeve 23 Bearing receiver 24 Bolt 25 O-ring 31 Rotating seal ring 31A Rotating seal ring for dual use (Rotating seal ring with both end faces as sealing end faces)
31a Sealing end face of the rotating sealing ring 31b Sealing end face of the rotating sealing ring 32 Stationary sealing ring 32a Sealing end face of the stationary sealing ring 32b O-ring 32c Drive pin 33 Spring 51 Ring seal member 51a Reinforcing metal fitting 51b Gutter spring 52 Stationary sealing ring 52a Stationary sealing Sealed end face of ring C Cooling fluid F Fluid R Channel

Claims (2)

A seal which is an opposing end face between a stationary seal ring provided on the case body and a rotary seal ring provided on the rotary shaft body, between opposed circumferential surfaces of the cylindrical case body and the rotary shaft body connected to the rotary shaft body in a relatively rotatable manner. Four or more mechanical seals configured to be sealed by the relative rotational sliding contact of the end faces are arranged in such a manner that all the sealing rings are arranged in the direction of the rotation axis of both bodies, and the rotating sealing rings are located at both ends of the sealing ring group. and disposed in state, thereby forming a plurality of passages connecting the space which is sealed by a mechanical seal adjacent, by disposing the pair of oil seals on both sides of the mechanical seal unit is sealed in both the oil seal A cooling fluid space in which cooling fluid is circulated and supplied ,
Forming a fluid passage communicating with both bodies via the passage connecting space;
Ri Thea also used in one rotary seal ring to the rotary seal ring and the seal end face both end faces of the rotary seal ring you adjacent thereto except rotary seal ring located at both ends of the seal ring group,
The passage connection space is an inner peripheral region of a relative rotational sliding contact portion of the sealing end faces of the two sealing rings;
The cooling fluid space is an outer peripheral side region of the relative rotational sliding contact portion,
The cooling fluid is room temperature water;
A coating layer made of diamond having a large thermal conductivity coefficient and hardness as compared with the constituent material of the rotary seal ring only on the both end faces and the outer peripheral surface in contact with the cooling fluid on the surface of each rotary seal ring that is also used. Are formed on the surface of each stationary sealing ring, and only on the sealing end face and the portion in contact with the cooling fluid, the diamond has a higher thermal conductivity coefficient and hardness than the constituent material of the stationary sealing ring. A multi-channel rotary joint characterized in that a series of coating layers are formed . A seal which is an opposing end face between a stationary seal ring provided on the case body and a rotary seal ring provided on the rotary shaft body, between opposed circumferential surfaces of the cylindrical case body and the rotary shaft body connected to the rotary shaft body in a relatively rotatable manner. Four or more mechanical seals configured to be sealed by the relative rotational sliding contact of the end faces are arranged in such a manner that all the sealing rings are arranged in the direction of the rotation axis of both bodies, and the rotating sealing rings are located at both ends of the sealing ring group. A plurality of passage connection spaces sealed with adjacent mechanical seals, and a pair of cooling fluid space mechanical seals having the same structure as the mechanical seals on both sides of the mechanical seal group. A cooling fluid space in which the cooling fluid is circulated and supplied, and is a space sealed by mechanical seals for both cooling fluid spaces,
Forming a fluid passage communicating with both bodies via the passage connecting space;
The rotary seal ring of each mechanical seal including the mechanical seal for the cooling fluid space and the rotary seal ring adjacent thereto are combined with one rotary seal ring having both end faces as sealed end faces,
The passage connection space is an inner peripheral region of a relative rotational sliding contact portion of the sealing end faces of the two sealing rings;
The cooling fluid space is an outer peripheral side region of the relative rotational sliding contact portion,
The cooling fluid is room temperature water;
A coating layer made of diamond having a large thermal conductivity coefficient and hardness as compared with the constituent material of the rotary seal ring only on the both end faces and the outer peripheral surface in contact with the cooling fluid on the surface of each rotary seal ring that is also used. Are formed on the surface of each stationary sealing ring, and only on the sealing end face and the portion in contact with the cooling fluid, the diamond has a higher thermal conductivity coefficient and hardness than the constituent material of the stationary sealing ring. multi passage shaped rotary joint you characterized in that the coating layer is formed into a series made.

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