JP2003042374A - Rotary joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower working accuracy for mounting and to improve treatment responsiveness by constituting one passage for use of both of flowing in and out as well as by prevent uneven abrasion at a sealing ring of a rotary joint. SOLUTION: A seal surface 11A at a moving tip of a non-rotating sealing ring 11 having a back surface to which a sealed fluid actuates is held on a seal surface 12A of a rotating sealing ring 12 sprung so that the sealing surface 11A can be freely pressed and moved. An area of a second pressure receiving back surface 12D of the rotating sealing ring 12 at the inside diameter side is almost equal to an area of a first pressure receiving back surface 11D of the non-rotating sealing ring 11 at the inside diameter side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint used, for example, in a fluid supply device such as a semiconductor manufacturing apparatus for a connecting portion of a multi-passage supplied from the fluid supply device to a rotating body.

[0002]

2. Description of the Related Art Regarding the use of a rotary joint according to the present invention, for example, a semiconductor wafer used for a substrate of an integrated circuit is obtained by slicing a cylindrical ultra-pure crystal such as silicon into a disk having a constant thickness. After that, grinding is performed, and further flattening and mirror finishing of the surface are performed. Further, with the progress of high integration of semiconductor devices, further higher precision in flatness and mirror finishing precision is required.

The polishing process for super flattening and mirror-finishing such a semiconductor wafer is performed by, for example, a polishing apparatus (CMP apparatus). This type of polishing apparatus has a structure in which a turntable for holding a semiconductor wafer on its upper surface, a top ring having a polishing surface provided facing the top thereof, and a polishing surface of the top ring are arranged on the turntable. A driving device that rotates the top ring while making horizontal movement while contacting the semiconductor wafer, and a polishing liquid (pure water + slurry), air, pure water + between the polishing surface of the top ring and the surface to be polished of the semiconductor wafer. And a device for intermittently supplying slurry, air and the like.

Polishing of a semiconductor wafer by the CMP apparatus constructed as described above is performed by bringing the top ring into contact with the surface to be polished of the semiconductor wafer and rotating it while supplying a polishing liquid or the like. Therefore, the connection passage between the rotating top ring and the non-rotating polishing liquid supply device is connected via a multi-channel rotary joint.

FIG. 6 is a cross-sectional view of a conventional rotary joint capable of connecting a connection passage for supplying the fluid from the fluid supply device to the rotating processing device. In FIG. 6, a rotary joint 100 has a body 101 provided with an inner peripheral surface, and a rotor 102 rotatably inserted in the inner peripheral surface of the body 101. Further, the body 101 is provided with a large number of fluid supply passages 103. Further, a large number of fluid passages 104 corresponding to the rotor 102 are also provided. A large number of mechanical seals 105 are arranged between the body 101 and the rotor 102 in the axial direction.

In this mechanical seal 105, a fixed seal ring 105A and a rotary seal ring 105B are arranged to face each other. Then, the fluid passages 103 and 104 are formed between the mechanical seals 105. Since the fluid passages 103 and 104 are configured as reciprocating passages, the stationary sealing ring 105A is held by the body block 110. The stationary seal ring 105A is made of carbon or ceramic. The fluid supply passage 103 and the fluid passage 104 are communicated with each other through each seal chamber 106 formed between the mechanical seals 105. In each of these seal chambers 106, liquid + slurry, gas, and vacuum state are alternately supplied according to the program of the operating processing device. Therefore, the fluid supply passage 103 serves as a reciprocating supply / discharge passage for supplying and discharging the fluid.

[0007]

As described above, the rotary joint 100 has a large number of passages 104 formed in the main body 101 and the rotor 102. In general, the mechanical seal 105 is configured to seal the fluid flowing from only one side. Therefore, when a reciprocating passage is required, each mechanical seal is provided for each of the forward and backward passages according to the sealing direction of the mechanical seal 105. 105 must be provided. In this case, since the double passage and the mechanical seal 105 must be provided, the structure of the rotary joint 100 becomes larger in size with this increase. Therefore, both side surfaces of the fixed seal ring 105A of the mechanical seal 105 are clamped and fixed by the body blocks 110 that form the body 101.

However, since the fixing sealing ring 105A is made of carbon or the like, if it is sandwiched from both sides, the sealing sliding surface is slightly deformed and its flatness is impaired. If this flatness is impaired, uneven wear is promoted and the sealing ability is reduced. In addition, the fixed sealing ring 105A has a problem that the sealing sliding surface is deformed due to the thermal effect of the temperature change because the heat generation of the sliding surface and the temperature change at the fixed position occur. In particular, when the sealed fluid is a fluid containing slurry or water, air, vacuum, etc. alternately flow,
This adverse effect is further increased and the sealing ability is reduced.

Further, the acceleration of wear of the stationary seal ring causes uneven wear of the rotary seal ring 105B and reduces the durability of the mechanical seal 105. Further, the fixing of the fixing seal ring by the body block 110 requires the processing accuracy of the body to be higher than necessary, resulting in high cost. Furthermore, the size of the body 101 is also increased.
Further, if the body 101 becomes large-sized, the mounting location of the device becomes a problem.

The present invention has been made in view of the above problems, and its technical problem is to provide a mechanical seal between mechanical seals without fixing a sealing ring for fixing the mechanical seals. One of the passages is surely sealed, and the passage between the mechanical seals is configured as a reciprocating fluid passage. In addition, the sealing sliding surface is prevented from being deformed by the pressure of the fluid to be sealed, and the sealing sliding surface is prevented from being thermally deformed by heat generated by sliding, and the sealing sliding surface of the mechanical seal is biased. The purpose is to prevent the occurrence of wear. Furthermore, it is to improve the sealing ability even if the assembly accuracy of the mechanical seal in the rotary joint is reduced. Furthermore,
The purpose is to reduce the sliding resistance of the mechanical seal and reduce the consumption of power energy due to the sliding resistance.

[0011]

The present invention has been made to solve the above-mentioned technical problem, and the technical solution means is configured as follows.

In the rotary joint of the present invention according to claim 1, a main body having a first passage penetrating into the inner peripheral surface and an inner peripheral surface and an outer peripheral surface of the main body are fitted to each other and are rotatably arranged. A rotor having a second passage penetrating the outer peripheral surface and communicating with the first passage, and the first passage and the second passage between the inner peripheral surface of the main body and the outer peripheral surface of the rotor. And mechanical seals arranged on both sides of a space portion of the main body to form a communication passage of the first passage and the second passage, and the mechanical seal is axially movable to the first holding portion of the main body. A non-rotating sealing ring having a first sealing surface at one end and a first back surface at the other end on which a sealed fluid can act, and a second holding portion of the rotor movably held in the axial direction. Second seal closely contacting the first sealing surface facing each other A non-rotating sealing ring having a surface and a second back surface on which the sealed fluid can act, the non-rotating sealing ring from the inner diameter side to the first sealing surface side by the pressure of the sealed fluid. The non-rotating seal has a first pressure receiving rear surface that is pressed, and the rotating sealing ring also has a second pressure receiving rear surface that is pressed from the inner diameter side to the first sealing surface side by the pressure of the sealed fluid. One of the ring and the rotary sealing ring is pressed toward the sealing surface side by the elastic means.

In the rotary joint according to the first aspect of the present invention, the fluid is generally supplied from the passage on the main body side to the passage on the rotor side via the passage penetrating the sliding surface. At the same time, the mechanical seal that seals the connection path between these two passages is also configured to seal only the fluid flowing from the main body side to the rotor side. For this reason, when flowing back and forth through a passage that penetrates the sliding surface, for example, when the fluid supplied from the main body side is sucked from the rotor side to the main body side, or when the fluid is supplied to the main body side passage through the rotor side passage, If fluid is supplied to the mechanical seal, the mechanical seal is not so configured, resulting in incomplete sealing of the fluid and leakage. However, even if the fluid to be sealed acts from the inner peripheral side against the sealing sliding surfaces of the non-rotating sealing ring and the rotating sealing ring, the fluid pressures acting on both sealing rings are pressed against each other. Therefore, the first sealing surface of the stationary sealing ring does not incline, and the sealing fluid can be reliably sealed even when the sealed fluid flows in and out of the communication passage formed between the mechanical seals. Become possible

The non-rotating seal ring is not slidably held in the axial direction but is fixed by pressing the body blocks into which the main body is divided, as in the conventional case. It is possible to prevent uneven wear by ensuring that the joint surfaces of the surfaces are always in close contact with each other and to exert the sealing ability. Further, since the non-rotating seal ring is not fixed but is held so as to be movable in the axial direction, the close contact of the first sealing surface can be achieved even if the non-rotating seal ring is not precisely processed. It becomes possible to exert the sealing ability.

According to a second aspect of the present invention, in the rotary joint of the present invention, the holding portion has an inner peripheral surface in the inner periphery in the direction of the sealing ring for rotation and protrudes in a ring shape, and the free end has the first supporting end surface. The first fitting guide portion is formed, and the non-rotating sealing ring is fitted into the first fitting guide portion in a sealed manner to form the first fitting guide portion.
It has a first pressure receiving back surface facing the supporting end surface, and the second holding portion has an inner peripheral surface toward the non-rotating sealing ring side and projects in a ring shape to form the second supporting end surface at the free end. A second fitting guide portion, the rotation sealing ring having the second pressure receiving rear surface forming an O-ring mounting groove between the rotation sealing ring and the second support end surface, and The area of the first pressure receiving back surface and the area of the second pressure receiving back surface of the rotary seal ring are configured to be substantially equal.

In the rotary joint according to the second aspect of the present invention, the body is movably fitted via the seal ring to the first fitting surface of the first fitting guide portion which has a ring shape and projects in the axial direction. Since they are matched, it is possible to improve the sealing ability without precisely processing the mounting accuracy of the holding portion of the non-rotating seal ring. Further, even when the pressure of the sealed fluid acts from the inner peripheral side of the mechanical seal, the pressure received on the first pressure receiving rear surface of the non-rotating sealing ring and the pressure received on the second pressure receiving rear surface of the rotating sealing ring are almost the same. Sealing sliding surfaces are brought into close contact with each other by the equal force balance, and at the same time, optimally pressed by the spring means, so that the sealing ability is exhibited. For this reason, even if the fluid to be sealed reciprocates and flows in the communication passages connected in the two passages, it is possible to reliably seal the fluid.

In the rotary joy of the present invention according to claim 3, the rotary joint is used as a multi-channel rotary joint for a semiconductor manufacturing apparatus.

In the rotary joy of the present invention according to claim 3, the multi-channel rotary joint for the semiconductor manufacturing apparatus has a multi-channel structure, and the fluid continuously flows in and out of the multi-channel of the rotary joint. Although the outflow is repeated, the rotary joint for such an application exhibits an excellent effect because the fluid can be reciprocated in one working flow passage. In other words, the configuration in which the working fluid flows in and out through the single flow passage as in the present invention improves the responsiveness of the working fluid and can reduce the configuration of the communication passage by the mechanical seal in multiple flow passages. Become. Furthermore, since the number of passages through which the fluid reciprocates can be reduced, the rotary joint can be made compact and the manufacturing cost can be reduced. Moreover, the control device for controlling the flow of the working fluid becomes easy, and it becomes possible to eliminate the malfunction such as flowing the wrong working fluid.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a rotary joint according to the present invention will be described below with reference to FIGS. 1, 2 and 3. FIG. 1 is a sectional view of a rotary joint used as a multi-channel rotary joint for a polishing apparatus of a semiconductor manufacturing apparatus according to a first embodiment of the present invention. 2 is a front view thereof. Further, FIG. 3 is a cross-sectional view of a main part of a rotary joint in which a communication passage of a first passage and a second passage is formed by a mechanical seal. Furthermore, FIG. 4 is a half cross-sectional view showing a mechanical seal in the rotary joint of the second embodiment. It should be noted that, for unclear points in the reference numerals in FIGS. 1 and 3, it is regarded as an enlarged view of FIG. 1 and refer to FIG.

FIG. 1 is a sectional view of a multi-channel rotary joint for a polishing apparatus of a semiconductor manufacturing apparatus. In FIG. 1, 1A is a rotary joint. The main body 2 of the rotary joint 1A has a substantially cylindrical shape and is provided with an inner peripheral surface 6, and the inner peripheral surface 6 is provided with space portions 3 having annular grooves that are equidistantly arranged in the axial direction. There is. The main body 2 has a large number of first perforations extending from the outer periphery to the inner peripheral surface 6.
A passage 4 is formed. A pipe screw is formed in the opening of the first passage 4, and a pipe (not shown) is screwed into the pipe screw. Further, the main body 2 is integrally formed by connecting the blocks 2A with bolts 32 via O-rings 37 (6 places) so that the mechanical seal 10 can be easily attached.

Inside the inner peripheral surface 6 of the main body 2, a rotor 20 provided with an outer peripheral surface 28 is arranged so as to be relatively rotatable via a bearing 33. The rotor 20 is provided with a second passage 24 corresponding to the first passage 4 at a position where the second passage 24 penetrates the outer peripheral surface 28 and faces the rotor 20. The second passage 24 is orthogonal to the inside of the rotor 20 and penetrates one end face in the axial direction. The arrangement status is as shown in FIG. As is clear from FIG. 2, as the number of second passages 24 provided in the rotor 20 increases, the diameter of the rotor 24 also increases. Further, a mounting jig 21 is mounted on the axially opening side of the second passage 24 of the rotor 20. Then, the rotary joint 1A can be connected to the actuating device by the mounting jig 21.

A connecting passage 30 is formed through a mechanical seal 10 between the coupling between the first passage 4 and the second passage 24 during the fitting between the main body 2 and the rotor 20 thus configured. The two pair of mechanical seals 10 are arranged on both sides of the second passage 24 in the space 3 of the main body 2 to form a communication passage 30. A mechanical seal 10 seals the connection between the two passages 4 and 24 so that the sealed fluid does not flow out.

FIG. 3 is an enlarged view of the arrangement of the pair of mechanical seals 10 on the lower side of FIG. In FIG.
In the mechanical seal 10, the non-rotating seal ring 11 and the rotating seal ring 12 are opposed to each other, and the first and second sealing surfaces 1
They are arranged so that 1A and 12A are in close contact with each other. The non-rotating sealing ring 11 is movable in the axial direction to the first fitting surface 5B on the outer periphery of the first fitting guide portion 5R formed in the holding portion 5 of the main body 2 and extending in the axial direction. To fit. The free end of the first fitting guide portion 5R is formed on the first support end surface 5A, and the O-ring mounting groove 5C is formed on the first fitting surface 5B. A first retaining pin 9 is provided on the first holding portion 5 of the main body 2.

The one non-rotating seal ring 11 constituting the mechanical seal 10 is configured to be held by the first holding portion 5 so as to be movable in the axial direction. This non-rotating seal ring 1
A first seal surface 11A is formed on the end surface in the axial direction of 1, and a first rear surface 11H having a radial width B is formed on the surface opposite to the first seal surface 11A. The first rear surface 11H has a first locking groove 11 that engages with the first stop pin 9.
B is provided. In addition, the non-rotating seal ring 11 is provided with a first guide surface 11C that slidably fits and slides on the first fitting surface 5B, and is in contact with the first support end surface 5A in the radial direction. A faceable first pressure receiving back surface 11D is provided, and this surface is formed as a step surface that is orthogonal to each other. Then, the sealed fluid that enters between the fitting surfaces is sealed by the first O-ring 35 mounted in the O-ring mounting groove 5C of the first fitting surface 5B. The non-rotating seal ring 11 is made of silicon carbide, but may be made of other materials such as carbon material.

The first position is at a position symmetrical to the non-rotating seal ring 11.
A rotary seal ring 12 provided with a second seal surface 12A that is in close contact with the seal surface 11A is arranged. The second sealing surface 12A is provided on the convex sealing portion, but there is an example in which the convex portion is not formed. Then, this rotating seal ring 1
2 is also formed in a shape similar to the non-rotating sealing ring 11. That is, the second back surface 12H having the radial width dimension B is formed on the surface opposite to the second seal surface 12A. The area B of the first back surface 11H and the area of the second back surface 12H are the dimensions B that are preferably formed to be substantially the same. And this second back surface 1
A locking groove 12B that engages with the second stop pin 29 is also formed in 2H. In addition, the rotary sealing ring 12 has a second guide surface 12C that slidably fits and slides with the second fitting surface 25B.
Is provided, and the second support end surface 25A and the second pressure receiving rear surface 12D are formed at an interval that forms the O-ring mounting groove 13. The second O-ring 36 seals the space between the rotor 20 and the rotary seal ring 12 from the sealed fluid. The rotary seal ring 12 is made of carbon, but other materials such as
It is composed of a silicon carbide material or the like.

Between the two symmetrical rotary seal rings 12, a passage ring 26 is fitted on the rotor 20 as shown in FIG. 3, and is fixed by a set screw 39.
The passage ring 26 has the second passage 24 of the rotor 20.
A connection passage 24A that communicates with is provided. Further, the connection passage 24A is arranged at a position corresponding to the first passage 4. Then, the second holding portions 25 are formed on both side surfaces of the passage ring 26, respectively. Second retaining pins 29 are provided on the second holding portions 25, respectively. Further, the second ring portions 25R projecting from both side surfaces are also received on both sides. A second fitting surface 25B is provided on the outer peripheral surface of the second fitting guide portion 25R, and a second support end surface 25A is formed at the free end. The radial width dimension A of the second support end surface 25A is preferably substantially the same as the width dimension A of the first support end surface 5A.

Further, the passage ring portion 26 is provided with through grooves in the axial direction at equal intervals. The coil springs (resilient means) 38 are respectively received through the through grooves. The coil spring 38 elastically presses the rotating seal ring 12 toward the non-rotating seal ring 11. The pair of mechanical seals 10 configured as described above are arranged for each of the passages 4 and 24 on both sides of the connection passage 24A in the space 3 as shown in FIG.

The rotary joint 1A according to the first embodiment having the above-described structure has a passage in the space 3 when the sealed fluid, which is the working fluid, flows from the first passage 4 into the second passage 24 through the pipe. It acts on the mechanical seals 10 arranged on both sides of. Then, the sealed fluid acts on the first back surface 11H of the non-rotating sealing ring 11 that constitutes the mechanical seal 10. Further, the sealed fluid also acts on the back surface 12H of the rotary seal ring 2. At the same time, the sealed fluid acts as a force in the opposite direction on each of these front surfaces. The pressure-receiving areas on both front surfaces corresponding to the both back surfaces 11H and 12H are preferably configured to be substantially the same (the pressure-receiving areas may not be the same depending on the design of the spring means 38). It will be balanced to erase each other. As a result, the rotary seal ring 12 is pressed toward the non-rotary seal ring 11 side by the pressure acting on the second O-ring and the force acting by the spring means 38.
1A and the sealing surface 12A are in parallel close contact with each other to form a communication passage 30 that seals the first passage 4 and the second passage 24.

When the sealed fluid, which is the working fluid, flows from the second passage 24 of the rotor 20 to the first passage 4, the pressure of the sealed fluid is the first pressure receiving rear surface 1 of the non-rotating seal ring 11.
Acts on 1D. At the same time, it is preferable that the second pressure receiving rear surface 12D of the rotary seal ring 12 has substantially the same area as the first pressure receiving rear surface 11D, so that the pressure of the sealed fluid is uniform.
It acts on A and 12A. Then, the first sealing surface 11A of the non-rotating sealing ring 11 and the second sealing surface 12A of the rotating sealing ring 12 are in close contact with each other. In that state, the spring means 38
Presses the rotary seal ring 12 toward the first seal surface 11A, so that the seal surfaces 11A and 12A strengthen the sealing contact,
A communication passage 30 is formed by sealing the connection between the first passage 4 and the second passage 24.

FIG. 4 is a half sectional view showing a main part of a rotary joint 1B according to a second embodiment of the present invention.

In FIG. 4, one non-rotating seal ring 11 constituting the mechanical seal 10 is held by the holding portion 5 so as to be movable in the axial direction. A sliding seal surface 11A is formed on an axial end surface of the non-rotating seal ring 11, and a first rear surface 11H having a radial width B is formed on a surface opposite to the sliding seal surface 11A. Has been done. The first rear surface 11H is provided with a first locking groove 11B that engages with the first pin 9. Further, the non-rotating seal ring 11 has a first guide surface 11C slidably fitted and slidably fitted to the first fitting surface 5B.
Is provided, and a first pressure receiving surface 11D having a radial dimension A capable of contacting the first support end surface 5A having a radial width dimension A is provided. Then, the sealed fluid that enters between the fitting surfaces is sealed by the first O-ring 35 mounted in the O-ring mounting groove 5C of the fitting surface 5B. Therefore, when the sealed fluid acts between the first support end surface 5A and the first pressure receiving rear surface 11D, the non-rotating seal ring 11 moves in the direction of the rotating seal ring 12 by the force P. The non-rotating seal ring 11 is made of silicon carbide, but may be made of other materials such as carbon material.

At one position symmetric to the non-rotating seal ring 11, the inner diameter D is larger than the outer diameter d of the rotor 20, and the first seal is provided in the seal portion 12S whose inner peripheral side projects to form a step. Surface 1
A rotary seal ring 12 having a second sealing surface 12A that is in close contact with 1A is arranged. Then, this rotating seal ring 1
2 is also formed in a shape similar to the non-rotating sealing ring 11. Since the second sealing ring 11 has a second rear surface 12H having a radial width B on the surface opposite to the sealing surface 12A, it has substantially the same area as the first rear surface 11H of the non-rotating sealing ring 11. ing. Further, the front surface on the second seal surface 12A side is also formed to have substantially the same radial width. And
A locking groove 12B that engages with the second stop pin 29 is also formed on the second rear surface 12H. Further, the rotary seal ring 12 is provided with a second guide surface 12C that slidably fits and slides on the second fitting surface 25B, and the second guiding surface 12C is provided between the second fitting surface 25B and the second supporting end surface 25A. Second spacing for placing ring 36
A pressure receiving back surface 12D is provided. An O-ring mounting groove 13 is formed between the second pressure receiving rear surface 12D and the second supporting surface 25A in this gap. The radial width dimension A of the second pressure receiving rear surface 12D is substantially the same as the radial width dimension A of the first pressure receiving rear surface 11D. Furthermore, the O-ring mounting groove 5 of the first fitting surface 5B
The first O-ring 35 attached to C seals the sealed fluid entering between the fitting surfaces. This rotating sealing ring 12
Is made of carbon, but is made of another material such as a silicon carbide material.

Two symmetrical sealing rings 12, 12 which are symmetrical
The passage ring 26 is fitted to the rotor 20 and is fixed by the set screw 39 between them. The passage ring 26 is provided with a connection passage 24A that communicates with the second passage 24 of the rotor 20. Also, the connection passage 24A
Are arranged at positions corresponding to the first passage 4. Then, the second holding portions 25 are formed on both side surfaces of the passage ring 26, respectively. The second holding portion 25 is provided with a second stop pin 29. Further, second fitting guide portions 25R projecting from both side surfaces in the axial direction are also received on both sides. A second fitting surface 25B is provided on the outer peripheral surface of the second fitting guide portion 25R, and a second supporting end surface 25A is formed at the free end. A second O-ring 36 is mounted in the O-ring mounting groove 13 formed between the second support end surface 25A and the second pressure receiving rear surface 12D of the rotary seal ring 12. The O-ring 36 seals between the rotary seal ring 12 and the rotor 20. This O
The sealed fluid acts on the ring 36 from the gap 22 between the rotor 20 and the mechanical seal 10. On the contrary,
The sealed fluid also acts from the second support end face 25A side.

Further, the passage ring 26 is provided with through grooves in the axial direction at equal intervals. The coil springs (resilient means) 38 are respectively received through the through grooves. With this coil spring 38, the sealing ring for rotation 1
2 is elastically pressed toward the non-rotating seal ring 11.
The mechanical seal 10 configured as described above is arranged on both sides of the passage in the space 3 as shown in FIG. 1 for each passage to form the communication passage 30.

The second embodiment of the second embodiment configured as described above
The rotary joint 1B includes a mechanical seal 10 arranged on both sides of each of the passages 4 and 24 in the space 3 when the sealed fluid, which is a working fluid, flows into the second passage 24 from the first passage 4 through the pipe. Pressure acts on. Then, the non-rotating seal ring 1 that constitutes the mechanical seal 10
It acts on the first first rear surface 11H. At the same time, substantially the same total pressure acts on the front surface of the non-rotating sealing ring 11. Further, the pressure also acts on the second rear surface 12H of the rotary seal ring 2. At the same time, substantially the same total pressure acts on the front surface of the rotary seal ring 12 as well. Since the pressure receiving areas of the two back surfaces 11H and 12H are substantially the same as those of the both front surfaces, the total pressures of these both face each other in the sealing rings 11 and 12, so that the forces are balanced. The rotating seal ring 12 is pressed toward the non-rotating seal ring 11 side by the unbalanced acting force of the forces acting on the second O-ring and the force of the spring means 38. The sealing surface 12A is in close parallel contact with each other to form a communication passage 30 connecting the first passage 4 and the second passage 24.

When the sealed fluid flows from the second passage 24 of the rotor 20 to the first passage 4, the pressure of the sealed fluid acts on the first pressure receiving rear surface 11D of the non-rotating seal ring 11. At the same time, the pressure of the sealed fluid also acts on the second pressure receiving rear surface 12D of the rotary sealing ring 12. These acting forces balance each other in the non-rotating seal ring 11 and the rotating seal ring 12 regardless of the presence of the seal portion 12S. Then, the first sealing surface 11A of the non-rotating sealing ring 11
And the second sealing surface 12A of the rotary seal ring 12 are in close contact with each other on the same plane. In this state, the spring means 38 presses the rotary seal ring 12 toward the first seal surface 12A, so that the seal contact is made and the connection between the first passage 4 and the second passage 24 is sealed to form the communication passage 30. Form.

FIG. 5 shows a first embodiment of the present invention.
It is a block diagram which attached the rotary joint 1A and the 2nd rotary joint 1B to the semiconductor manufacturing apparatus. In FIG. 5, the first rotary joint 1 shown in FIG.
FIG. 4 is a side view of a configuration showing a state in which A is attached to a rotating unit in order to supply cooling water to a table 40 in a CMP apparatus that performs wafer polishing. The first rotary joint 1A attached to this CMP apparatus will be described below.

A first rotary shaft 41 driven by a motor (not shown) is provided below the rotary table 40. The first rotary shaft 41 has a cooling water supply passage 42.
And a recovery passage 43 for cooling water. Further, a first rotary joint 1A having the structure shown in FIG. 1 is provided below the first rotary shaft 41. Also, the first rotary shaft 4
No. 1 supply passage 42 and the first rotary joint 1A
The passage 4 (see FIG. 1) communicates with the recovery passage 43 and the first passages 4, 4, 4 (see FIG. 1). And
The first passage 4 of the body 2 of the first rotary joint 1A,
Second passages 24, 2 of the rotor 20 rotating with 4, 4, 4
4, 24 communicate with each other even in a rotating state via communication passages 30, 30, 30 formed between the mechanical seals 10.

Further, it becomes possible to supply the cooling water from the fluid supply pump 60 connected to the supply passage 42 to the cooling circuit 44 provided on the rotary table 40 regardless of the rotating or non-rotating state. . And turntable 4
The cooling water is sent to 0 to cool the silicon wafer S and the turntable 40.

These cooling waters must be sufficiently supplied to the cooling circuit 44 of the rotary table 40, but in the rotary joint 1A, which must be small in size for mounting as in the present invention, the cooling water is conventionally used. If the supply passage is enlarged, the rotor 20 becomes large both in the axial direction and in the radial direction. Further, since the recovery passage 43 also needs to have a flow cross-sectional area equal to or larger than that of the supply passage 42, the diameter is further increased. However, when the reciprocable passage is used as in the present invention, the cooling passage and the discharge passage can be used with a small number of passages, so that a multi-functional passage can be configured without increasing the diameter of the rotor 20. Furthermore, it exhibits an excellent sealing ability without causing uneven wear of the sealing ring.

Next, the second rotary joint 1B attached to the upper portion of the CMP apparatus shown in FIG. 4 will be described. In FIG. 4, reference numeral 40 denotes a rotary table on which the silicon wafer S is placed and processed. This turntable 40
Is connected to the first rotating shaft 41 and rotates in the P1 direction.
At the same time, the pad support 53 equipped with the second rotary joint 1B moves back and forth in the X direction shown. Further, a polishing pad 54 supported by the pad support 53 and rotated by a drive motor (not shown) is attached to the lower portion of the pad support 53. This polishing pad 54
Rotates in the P2 direction by the second rotation shaft 55 connected to the pad support 53 and the polishing pad 54. Then, the polishing pad 54 moves in the X direction on the silicon wafer while rotating to perform polishing processing.

The first supply / discharge passage 58 provided in the pad support 53 has a supply / discharge device 7 for sending the polishing liquid under pressure by piping.
It is in communication with 0. Further, the first supply / discharge passage 58 is
In addition to communicating with the first passage 4 of the second rotary joint 1B, it becomes possible to rotatably communicate with the second passage 24 via the communication passage 30 formed between the adjacent mechanical seals 10. Further, the first passage 4 of the second rotary joint 1B communicates with the second supply / discharge passage 56 provided in the second rotation shaft 55 and also with the injection passage 51 of the polishing pad 54.

Then, the polishing liquid pressure-fed from the feeding / discharging device 70 is sent to the first passage 4 of the second rotary joint 1B through the first feeding / discharging passage 58, and is formed between the mechanical seals 10 by the second rotary joint 1B. Communication passage 30
Is supplied to the second passage 24 of the rotor 20 that rotates through the above, and is pressure-fed to the injection passage 51 of the polishing pad 54 through the second supply / discharge passage 56 of the second rotating shaft 55. Then, the polishing liquid is jetted from the jet passage 51 onto the upper surface of the silicon wafer S to perform surface polishing of the silicon wafer S.

At the same time, the first fluid passage 59 provided in the pad support 53 is connected to the pneumatic fluid supply device 75 by piping. Further, the first fluid passage 59 has a second
It communicates with the first passages 4, 4, 4 of the rotary joint 1B. The first passages 4, 4, 4 also communicate with the second passages 24, 24, 24 of the rotor 20 via the communication passages 30, 30, 30 between the mechanical seals 10 even in a rotating state.
Then, while communicating with the second fluid passage 57 of the second rotating shaft 55 rotating from the second passages 24, 24, 24, and communicating with the second injection passage 52 of the polishing pad 54 from the second fluid passage 57, the air pressure is increased. It has the function of uniformly spraying and spraying the polishing liquid sprayed from the first spray passage 51. At the same time, the polished polishing liquid is quickly removed from the silicon wafer S and the upper surface of the rotary table 40 and the like.

Since it is necessary to quickly and uniformly disperse the polishing liquid in these air pressure injections, the processing accuracy and quality depend on whether or not the air pressure is injected through a large number of first and second injection passages 51 and 52. . Further, the supply / drainage device 70 pressure-feeds the polishing liquid or the like to the first passages 4, ..., The communication passages 30, ..., The second passages 24 ,. Polishing pad 5 by joint 1B even in rotating state
The polishing liquid and the air pressure are supplied to the first injection passage 51 and the second injection passage 52 of No. 4, but these operations are performed by the supply / discharge device 70.
The positive pressure operation of the polishing pad 54 and the silicon wafer S
And the compressed air from the fluid supply device 75, a polishing liquid is jetted, and while the polishing pad portion 54 is rotated, the pad support 53 reciprocates the upper surface of the silicon wafer S to polish the silicon wafer S. It is a thing. The polishing pad portion 54 moves up and down in the Y direction for work before and after processing.

After the polishing is completed, the polishing pump of the supply / discharge device 70 is switched to the suction operation so that the polishing liquid remaining in the first injection passage 51 can be sucked and discharged through the same passage. Process it quickly so that it does not drip on the surface of. These require a large number of passages, but by making one passage reciprocable, the number of the passages is reduced to facilitate the processing control of the working fluid, and the rotor 2
The diameter of 0 is reduced to improve the operation control of the polishing pad 54 and the turntable. The first and second rotary joints 1A and 1B of the present invention can be configured as a passage that can reciprocate according to the working fluid, and can prevent uneven wear of the sliding seal surface of the mechanical seal 10 and improve durability. Play. Then, the rotary joints 1A, 1 of the present invention
B exhibits an excellent effect in such applications.

Further, after the polishing is completed, the polishing pump of the supply / discharge device 70 is switched to the suction operation so that the polishing liquid remaining in each passage is sucked and discharged through the reciprocating passage so as not to drop on the surface of the silicon wafer S. It can be processed quickly. These operations are made possible by reciprocating passages. Since the rotary joint 1 of the present invention can make a reciprocating passage, it exhibits an excellent effect in such an application. The through hole S that penetrates the rotor 20 in the axial direction shown in FIGS. 1 and 2 is used for a sensor, a control device, or the like.

[0048]

The rotary joint according to the present invention has the following effects.

According to the rotary joint of the first aspect of the present invention, even if the sealed fluid acts from the inner peripheral side on the sealing sliding surfaces of the non-rotating seal ring and the rotating seal ring, both seals are sealed. Since the fluid pressures acting on the respective pressure receiving back surfaces of the ring are configured to be pressed in balance with each other, the first sealing surface of the stationary sealing ring does not incline and the connection formed between both mechanical seals is prevented. A communication passage can be formed with respect to the passage to reliably seal even when the sealed fluid flows in and out.

Since the non-rotating seal ring is movably held only in the axial direction, the first seal surface always operates so as to be in close contact with the second seal surface to prevent uneven wear and to achieve sealing ability. Can be demonstrated. Further, the non-rotating seal ring is not fixed but is held so as to be movable in the axial direction. Therefore, even if the non-rotating seal ring is not processed with high precision, the second seal of the first sealing surface It can be expected that the sealing contact with the sealing surface is maintained and the sealing effect is achieved.

According to the rotary joint of the second aspect of the present invention, the main body is ring-shaped and is movable via the seal ring to the first fitting surface of the first fitting guide portion projecting in the axial direction. It is possible to expect the effect of improving the sealing ability without failing to precisely process the mounting accuracy of the non-rotating sealing ring holding part as in the conventional case, because it is fitted in the axial direction. .

Further, even when the fluid to be sealed flows from the inner peripheral side of the mechanical seal and the pressure acts, the pressure received by the first pressure receiving rear surface of the non-rotating seal ring and the second pressure of the rotating seal ring.
The sealing sliding surfaces are brought into close contact with each other by the balance of the force substantially the same as the pressure received by the pressure receiving rear surface, and at the same time, the spring means presses the sealing contact, so that the sealing effect is exhibited. Therefore, even if the fluid to be sealed reciprocates and circulates in the connected communication path that crosses the sliding surface, it is possible to reliably seal the fluid.

According to the rotary joint of the third aspect of the present invention, the multi-channel rotary joint for the semiconductor manufacturing apparatus has a multi-channel structure, and the fluid continuously flows through the multi-flow passage of the rotary joint. Although the inflow and outflow are repeated, the rotary joint for such an application exhibits an excellent effect because the fluid can be reciprocated in one working flow passage. That is, when the working fluid is caused to flow in and out through one flow passage as in the present invention, the responsiveness of the working fluid can be improved. Furthermore, since the passages through which the fluid reciprocates can be reduced, the rotary joint can be made compact, and the manufacturing cost can be reduced. In addition, the control device for controlling the flow of the working fluid becomes easy, and the erroneous operation of flowing the wrong working fluid is eliminated.

[Brief description of drawings]

FIG. 1 is a sectional view of a rotary joint showing a first embodiment according to the present invention.

FIG. 2 is a front view of the rotary joint shown in FIG.

FIG. 3 is an enlarged sectional view of a part of the rotary joint shown in FIG.

FIG. 4 is a cross-sectional view of a rotary joint showing a second embodiment according to the present invention.

FIG. 5: CM equipped with the rotary joint of the present invention
It is a side view of P apparatus.

FIG. 6 is a cross-sectional view of a conventional rotary joint.

[Explanation of symbols]

1 rotary joint 1A 1st rotary rejoint 1B 2nd rotary joint 2 body 2A block 3 space 4 first passage 5 First holding part 5A First support end face 5B First mating surface 5C O-ring mounting groove 5R 1st fitting guide 6 Inner surface 9 First stop pin 10 mechanical seal 11 Non-rotating sealed ring 11A 1st sealing surface 11B First locking groove 11C 1st guide surface 11D 1st pressure receiving back surface 11H 1st back 12 rotation seal ring 12A Second sealing surface 12B Second locking groove 12C Second guide surface 12D 2nd pressure receiving back 12H 2nd back 13 O-ring mounting groove 20 rotor 21 Mounting jig 22 Gap 24 Second passage 24A connection passage 25 Second holding unit 25A Second support end face 25B Second mating surface 25R Second fitting guide 26 Passage ring 28 outer peripheral surface 29 Second stop pin 30 passages 32 volts 33 bearings 34 Piping 35 1st O-ring 36 2nd O-ring 37 O-ring 38 spring means 39 set screw 60 fluid supply pump 65 Fluid recovery pump 70 Supply and discharge device 75 Fluid supply device

Claims (3)

[Claims] 1. A main body having a first passage penetrating into an inner peripheral surface, and an inner peripheral surface and an outer peripheral surface of the main body are fitted and rotatably arranged and penetrate through the outer peripheral surface. A rotor having a second passage that is capable of communicating with the first passage, and arranged on both sides of a space between the first passage and the second passage between the inner peripheral surface of the main body and the outer peripheral surface of the rotor. A mechanical seal that forms a communication path between the first passage and the second passage, the mechanical seal being axially movably held by the first holding portion of the main body and having a first sealing surface at one end. And a non-rotating seal ring having a first rear surface on the other end, on which the sealed fluid can act, and the first seal surface, which is held by the second holding portion of the rotor so as to be movable in the axial direction and is opposed to the first seal surface. Having a second sealing surface that allows the sealed fluid to act on the other end. A rotary sealing ring having two back surfaces, wherein the non-rotating sealing ring has a first pressure receiving back surface which is pressed from the inner diameter side to the first sealing surface side by the pressure of the sealed fluid, The ring also has a second pressure receiving back surface that is pressed from the inner diameter side to the first sealing surface side by the pressure of the sealed fluid, and one of the non-rotating sealing ring or the rotating sealing ring is formed by the elastic means. A rotary joint which is pressed toward the sealing surface side. 2. The holding portion has an inner peripheral surface on the inner periphery in the direction of the rotary sealing ring and projects in a ring shape at the first end at the free end.
The non-rotating sealing ring has a first pressure receiving rear surface facing the first support end surface by sealingly fitting the first fitting guide portion. Having the second
A second holding member having an inner peripheral surface on the non-rotating seal ring side and projecting in a ring shape with the second supporting end surface formed at a free end.
A first pressure receiving portion of the non-rotating seal ring having a fitting guide portion, the rotating seal ring having the second pressure receiving rear surface forming an O-ring mounting groove with the second support end face. 2. The rotary joint according to claim 1, wherein the area of the back surface and the area of the second pressure receiving back surface of the rotary seal ring are configured to be substantially equal. 3. The rotary joint according to claim 1 or 2, wherein the rotary joint is used as a multi-channel rotary joint for a semiconductor manufacturing apparatus.