JP2008206899A - Rotary joint and rotating device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary joint, capable of surely holding a treatment object, and a rotating device using the same. <P>SOLUTION: The rotary joint 50 is formed of polytetrafluoroethylene (PTFE). The rotary joint 50 includes a cylindrical joint body 51 having upper and lower openings. A rotary shaft 2 is disposed to be inserted into the joint body 51. Two or more (four in Fig.2) fins 52 are provided on the inner circumferential surface of the joint body 51 along the circumferential direction thereof to be protruded at predetermined intervals. The fin parts 52a, 52b, 52c and 52d are disposed respectively to be directed obliquely upward. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary joint and a rotary device using the rotary joint.

  2. Description of the Related Art Conventionally, a rotating device that develops a processing object such as grinding or cutting while rotating the processing object has been developed. In such a rotating device, the following configuration has been proposed to hold a rotating substrate. For example, in the spinner jig described in Patent Document 1, a plurality of vacuum chuck holes are formed in the substrate holding portion. These vacuum chuck holes are used for adsorbing the substrate to the upper surface of the substrate holding portion by vacuum suction. With such a configuration, the substrate that is rotated while being held by the substrate holding portion is held.

  Said board | substrate holding part is comprised from the rotating plate (turntable) holding a board | substrate, and a hollow rotating shaft. The plurality of vacuum chuck holes provided in the substrate holding part communicate with the rotating shaft. And this rotating shaft is connected to the exhaust pipe via the joint.

Here, in order to securely hold the object to be processed with a strong suction force, it is important to prevent air from leaking between the rotating shaft as a rotating body and the joint as a fixed body. For example, in a suction hose for a vacuum cleaner, an elastic substance is used to connect a rotatable joint (rotary body) and a hose (fixed body) with a locking portion and prevent air leakage at the connecting portion. A structure in which the formed hollow bellows-like airtight packing is mounted has been proposed (see, for example, Patent Document 2).
JP 2002-299204 A Japanese Utility Model Publication No. 48-28771

  However, the configuration described in Patent Document 1 has the following problems. That is, air may leak from a joint connecting the rotating shaft and the exhaust pipe. As a result, the substrate may not be sucked well, and the substrate may not be reliably sucked and held on the rotating plate.

  Moreover, since the structure of the said patent document 2 does not prevent an air leak when the rotary body (joint) is rotating, it is 100 rpm / 500 rpm, for example. It is difficult to prevent air leakage in a rotating rotating body.

  In view of the above problems, an object of the present invention is to provide a rotary joint that can reliably hold a processing object and a rotary device using the rotary joint.

The gist of the rotary joint according to the first aspect of the invention is used in a rotating device that rotates a rotating object having a hollow region by sucking the rotating object while holding the rotating object while holding the rotating object. A rotary joint,
A joint body that surrounds a part of the rotating body and is formed in a cylindrical shape;
One or more fin portions provided continuously in the circumferential direction of one or both of the inner peripheral surface of the joint body and the outer peripheral surface of the rotating body,
When the suction is performed, the fin portion is bent by the suction force so that the outer peripheral surface of the rotating body, the inner peripheral surface of the joint body, or the axial direction is opposed to each other. It is in close contact with the fin part.

  In the rotary joint, a plurality of the fin portions may be provided in multiple stages in the axial direction of the rotating body.

  In the rotary joint, the joint body and the fin portion may be made of polytetrafluoroethylene.

  In the rotary joint, the fin portion may be removable.

The gist of the rotating device according to the second invention is that the object to be processed is held on the rotating body by being sucked through the hollow area while rotating the object to be processed by the rotating body having the hollow area. A rotating device,
A rotary joint according to the first invention;
And suction means for sucking the processing object through the hollow region of the rotating body.

  The rotating device may further include processing means for performing a cutting process, a grinding process, or a polishing process on the processing object.

  According to the present invention, when the suction operation is started by a suction device such as a vacuum pump, the fin portion is drawn downward and bent. Thereby, the peripheral part of a fin part closely_contact | adheres to the outer peripheral surface of a rotating shaft. Therefore, air can be prevented from leaking from between the fin portion and the rotating shaft. Therefore, it is possible to reliably hold the processing object when the processing object is processed. Thereby, a process target object can be processed with high precision.

  Hereinafter, a rotary joint according to an embodiment of the present invention and a rotary device using the rotary joint will be described with reference to the drawings.

  (1) First embodiment

  FIG. 1 is a schematic diagram showing an appearance of a rotating device 100 according to the present embodiment. 1A is a top view of the rotating device 100, and FIGS. 1B and 1C are side views of the rotating device 100. FIG.

  As shown in FIG. 1, the rotating device 100 includes a base 101. A cover 102 is fixed on the base 101 by a plurality of bolts 102a. The upper surface of the cover 102 penetrates, and the rotating body 3 is provided so as to protrude from the penetration portion. On the rotating body 3, the top plate 1 is fixed by a plurality of bolts 103a. The details of the top plate 1 and the rotating body 3 will be described later.

  A motor 4 connected to a later-described gear box 5 (FIG. 2) disposed in the cover 102 is disposed outside the cover 102. An exhaust pipe 104 is arranged from the inside to the outside of the cover 102, and a suction port 105 is attached to the exhaust pipe 104.

  The rotating device 100 according to the present embodiment is provided with a brake (not shown) that stops the rotation of the rotating body 3. When the rotating body 3 is used while being rotated, a rectangular processing object can be processed into a circular shape, a polishing process, or the like can be performed. Cutting such as dividing the object can be performed.

  FIG. 2 is a schematic diagram showing a configuration inside the cover 102 of the rotating device 100 of FIG. In FIG. 2, a part of the configuration is shown in cross section for easy understanding. The object to be processed W is sucked and held on the top plate 1 fixed to the upper surface of the rotating body 3.

  The rotator 3 has a flat plate portion 3a and a cylindrical portion 3b through which a central portion passes. A hollow rotating shaft 2 is fixed at the center of the lower surface of the top plate 1. The rotating shaft 2 is arranged so as to be accommodated in the cylindrical portion 3b through a penetrating portion of the flat plate portion 3a. The top plate 1 and the rotating shaft 2 are made of metal, alloy (for example, stainless steel) or the like. Thereby, the mechanical strength, chemical resistance, heat resistance, etc. of the top plate 1 and the rotating shaft 2 can be improved.

  A gear box 5 is connected to the rotating body 3 via a connecting means 5 a made of a gear, and a motor 4 is attached to the gear box 5. The rotating body 3 is rotated around the rotating shaft 2 by the motor 4, the gear box 5, and the connecting means 5a. Thereby, the top plate 1 attached to the rotating body 3 also rotates around the rotation shaft 2. Therefore, a predetermined process (a cutting process, a grinding process, a polishing process, etc.) is performed using the processing means 200 disposed so as to be movable up and down above the processing target object W while rotating the processing target object W. be able to.

  The top plate 1 has a plurality of suction holes 6 for sucking the processing object W. These suction holes 6 are arranged on a plurality of concentric circles when the top plate 1 is viewed from above. In addition, a communication region 6 a is formed inside the top plate 1 so that the plurality of suction holes 6 communicate with each other. The center of the lower surface of the top plate 1 penetrates, and the communication region 6 a communicates with the hollow region of the rotating shaft 2.

  Next, the rotary joint in the present embodiment will be described. The rotary joint 50 is made of a material having a low friction coefficient such as resin (for example, polytetrafluoroethylene (PTFE)). In the present embodiment, polytetrafluoroethylene is used for the rotary joint 50 because the polytetrafluoroethylene has low wear, non-adhesiveness, chemical resistance, and the like. In particular, in the present embodiment, as will be described later, the fin portion 52 of the rotary joint 50 is in close contact with the rotating rotary shaft 2, so that the material of the rotary joint 50 has low wear such as polytetrafluoroethylene. Is preferably used.

  The rotary joint 50 has a cylindrical joint body 51 having upper and lower portions opened. The rotating shaft 2 is arranged so as to be inserted into the joint body 51. On the inner peripheral surface of the joint body 51, a plurality of (four in FIG. 2) fin portions 52 are provided continuously in the circumferential direction of the joint body 51 so as to protrude at predetermined intervals. . For convenience of explanation, the plurality of fin portions 52 are defined as fin portions 52a, fin portions 52b, fin portions 52c, and fin portions 52d from the lower side in FIG. These fin portions 52a, 52b, 52c, and 52d are arranged so as to face the upward oblique direction, respectively.

  The joint body 51 includes a tapered portion 51a and a tubular exhaust portion 51b below the joint body 51. The exhaust part 51 b is connected to the exhaust pipe 104 via the connection part 7. A vacuum pump (not shown) is connected to the suction port 105 attached to the exhaust pipe 104. With this configuration, each suction hole 6 of the top plate 1 is connected to the vacuum pump via the communication region 6 a of the top plate 1, the internal space of the rotary shaft 2, the internal space of the joint body 51, and the internal space of the exhaust pipe 104. It communicates with the inside.

  In the present embodiment, when processing such as grinding is performed on the processing target W, the processing target W is sucked and held on the top plate 1. The method for adsorbing and holding the processing object W is as follows.

  When the suction operation is started at a vacuum pressure (for example, −80 MPa) by the vacuum pump, the processing object W is placed on the top plate through the exhaust pipe 104, the joint body 51, the rotary shaft 2, and the suction holes 6 of the top plate 1. 1 is adsorbed on. Thereby, the processing object W can be sucked and held on the top plate 1.

  Among the plurality of suction holes 6, the sheet 9 is covered on the suction holes 6 that are not blocked by the processing object W. Thereby, air can be prevented from leaking from the suction hole 6, and the object to be processed W can be reliably adsorbed.

  Here, when the suction operation is started by the vacuum pump, the processing object W is sucked by the suction holes 6 and sucked and held on the top plate 1 as described above, and the fin portion 52 of the joint body 51 is also sucked. Is done. The detailed operation is as follows.

  FIG. 3 is an explanatory diagram for explaining a state in which the fin portion 52a of the joint body 51 is sucked. As shown in FIG. 3, some of the peripheral portions of the fin portions 52 a, 52 b, 52 c, 52 d are in contact with the outer peripheral surface of the rotating shaft 2 in a normal state (a state where vacuum suction is not performed by a vacuum pump).

  When the suction operation is started by the vacuum pump, the pressure in the region X below the fin portion 52a becomes negative. Since the pressure in the region Y above the fin portion 52a is atmospheric pressure, the fin portion 52a is drawn downward and bent by the differential pressure. Thereby, as shown by a dotted line in FIG. 3, the peripheral edge portion of the fin portion 52 a is in close contact with the outer peripheral surface of the rotating shaft 2. Therefore, air can be prevented from leaking from between the fin portion 52a and the rotating shaft 2. Therefore, when the processing target object W is processed, the processing target object W can be reliably held. Thereby, the processing target object W can be processed with high accuracy.

  Even when the rotary joint 50 is in close contact with the rotating rotary shaft 2, the rotary joint 50 is made of polytetrafluoroethylene having a small friction coefficient, and therefore the degree of wear of the rotary joint 50 is small. When the fin portion 52a is in close contact with the rotating shaft 2 for a long time, the degree of wear increases, and even when the fin portion 52a is not in close contact with the rotating shaft 2, the upper fin portion 52b is sucked. Thereby, the fin part 52b closely_contact | adheres to the outer peripheral surface of the rotating shaft 2. FIG. Therefore, it is possible to prevent air from leaking between the fin portion 52b and the rotary shaft 2. As described above, even when one fin portion is worn, it is possible to prevent air leakage by the other fin portion provided above the fin portion.

  (2) Second embodiment

  FIG. 4 is a cross-sectional view showing another configuration of the rotary joint 50 and the rotary shaft 2. In FIG. 4, the illustration of the same configuration as in FIG. 2 is omitted. Below, a different point from the structure of the rotary joint 50 of FIG. 2 is demonstrated.

  As shown in FIG. 4, in the present embodiment, the joint body 51 has fin portions 52a, 52b, 52c, and 52d projecting in a diagonally downward direction at predetermined intervals on the inner peripheral surface of the joint body 51. 51 are provided continuously in the circumferential direction. In addition, a plurality of convex portions 2 a that are continuous in the circumferential direction of the rotating shaft 2 are provided on the outer peripheral surface of the rotating shaft 2.

  Each convex portion 2a is arranged below each of the fin portions 52a, 52b, 52c, and 52d. Moreover, the thickness of each convex part 2a is set larger than the thickness of fin part 52a, 52b, 52c, 52d.

  In such a configuration, when the suction operation is started by the vacuum pump, the fin portion 52a is drawn downward as in the first embodiment described above. Thereby, the fin part 52a closely_contact | adheres to the convex part 2a. Therefore, air can be prevented from leaking from between the fin portion 52a and the rotating shaft 2. Therefore, when the processing target object W is processed, the processing target object W can be reliably held. Thereby, the processing target object W can be processed with high accuracy.

  In the present embodiment, the fin portions 52a, 52b, 52c, and 52d are made of a resin material, and the convex portion 2a of the rotating shaft 2 is made of stainless steel. However, the present invention is not limited to this, and the fin portions 52a and 52b. , 52c, 52d and the convex portion 2a may be made of a resin material. As a result, wear due to contact between the fin portions 52a, 52b, 52c, 52d and the convex portion 2a can be reduced, and the rotary shaft 2 can be easily inserted and arranged in the rotary joint 50. However, when the suction operation is performed by the vacuum pump, the convex portion 2a needs to have rigidity (strength) that does not bend by the suction force.

  (3) Third embodiment

  FIG. 5 is a cross-sectional view showing still another configuration of the rotary joint 50 and the rotary shaft 2. In FIG. 5, illustration of the same components as those in FIG. 2 is omitted. Below, a different point from the structure of the rotary joint 50 of FIG. 2 is demonstrated.

  As shown in FIG. 5, in the present embodiment, a plurality of convex portions 2 a that are continuous in the circumferential direction of the rotating shaft 2 are provided on the outer peripheral surface of the rotating shaft 2. Each convex portion 2a is arranged below each of the fin portions 52a, 52b, 52c, and 52d. Moreover, the thickness of each convex part 2a is set larger than the thickness of fin part 52a, 52b, 52c, 52d.

  In such a configuration, when the suction operation is started by the vacuum pump, the fin portion 52a is drawn downward as in the first embodiment described above. Thereby, the fin part 52a closely_contact | adheres to the convex part 2a of the rotating shaft 2. FIG. Therefore, air can be prevented from leaking from between the fin portion 52a and the rotating shaft 2. Therefore, when the processing target object W is processed, the processing target object W can be reliably held. Thereby, the processing target object W can be processed with high accuracy.

  (4) Fourth embodiment

  FIG. 6 is a cross-sectional view showing still another configuration of the rotary joint 50 and the rotary shaft 2. 6, the illustration of the same configuration as in FIG. 2 is omitted. Below, a different point from the structure of the rotary joint 50 of FIG. 2 is demonstrated.

  As shown in FIG. 6, in this embodiment, the joint body 51 of the rotary joint 50 is not provided with fin portions. A removable cylindrical leakage preventing means 20 is attached to the outer peripheral surface of the rotating shaft 2 by adhesion or the like. On the outer peripheral surface of the leakage preventing means 20, a plurality of fin portions 21 are provided continuously in the circumferential direction of the leakage preventing means 20 so as to protrude obliquely upward at predetermined intervals. Instead of using the leakage prevention means 20 described above, a removable leakage prevention means having a fin portion may be provided on the inner peripheral surface of the joint body 51.

  In such a configuration, when the suction operation is started by the vacuum pump, the lowermost fin portion 21 is drawn downward as in the first embodiment. Thereby, the fin portion 21 is in close contact with the inner peripheral surface of the joint body 51. Therefore, air can be prevented from leaking from between the fin portion 21 and the joint body 51. Therefore, when the processing target object W is processed, the processing target object W can be reliably held. Thereby, the processing target object W can be processed with high accuracy.

  In the present embodiment, even when the fin portion 21 of the leakage preventing means 20 is worn, the leakage preventing means 20 can be removed from the rotating shaft 2 and replaced. Therefore, maintainability can be improved.

  (5) Fifth embodiment

  FIG. 7 is a cross-sectional view showing still another configuration of the rotary joint 50 and the rotary shaft 2. In FIG. 7, illustration of the same components as those in FIG. 2 is omitted. Below, a different point from the structure of the rotary joint 50 of FIG. 2 is demonstrated.

  As shown in FIG. 7, in the present embodiment, the joint body 51 of the rotary joint 50 is not provided with a fin portion. Further, the outer peripheral surface of the rotating shaft 2 is provided with a plurality of concave portions 2b formed continuously in the circumferential direction of the outer peripheral surface.

  A plurality of rings 22 are fitted in the respective recesses 2b so as to contact the inner peripheral surface of the joint body 51. When the suction operation is started by the vacuum pump, each ring 22 is brought into close contact with the inner peripheral surface of the joint body 51 by bending in the axial direction of the rotary shaft 2. Therefore, it is possible to prevent air from leaking from between each ring 22 and the joint body 51. Therefore, when the processing target object W is processed, the processing target object W can be reliably held. Thereby, the processing target object W can be processed with high accuracy.

  In the present embodiment, even when the ring 22 is worn, the ring 22 can be easily replaced. Therefore, maintainability can be improved.

  (6) Other embodiments

  In each of the above embodiments, the four fin portions 52 are provided. However, the present invention is not limited to this, and the number may be less than four, or five or more.

  In the fourth embodiment, the example in which the removable leakage preventing means 20 is attached to the rotating shaft 2 has been described. However, the present invention is not limited to this, and the leakage preventing means 20 is attached to the joint body 51. It is also possible to adopt a configuration.

  As mentioned above, although each aspect of the rotary joint 50 which concerns on this invention was demonstrated, this invention can be implemented in the aspect which added various improvement, correction, or deformation | transformation based on the knowledge of those skilled in the art within the range which does not deviate from the meaning. All of these aspects belong to the technical scope of the present invention.

  The rotary joint according to the present invention can be used to prevent gas leakage in various rotating devices such as a lathe.

It is a schematic diagram which shows the external appearance of a rotating apparatus. It is a schematic diagram which shows the structure in the cover of the rotating apparatus of FIG. It is explanatory drawing for demonstrating the state by which the fin part of a coupling main body is attracted | sucked. It is sectional drawing which shows the other structure of a rotary joint and a rotating shaft. It is sectional drawing which shows the further another structure of a rotary joint and a rotating shaft. It is sectional drawing which shows the further another structure of a rotary joint and a rotating shaft. It is sectional drawing which shows the further another structure of a rotary joint and a rotating shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top plate 2 Rotating shaft 2a Convex part 2b Concave part 3 Rotary table 4 Motor 5 Gear box 6 Suction hole 9 Sheet | seat 20 Leak prevention means 21 Fin part 22 Ring 50 Rotary joint 51 Joint main body 52, 52a, 52b, 52c, 52d Fin part 100 Rotating device 104 Exhaust pipe

Claims (6)

A rotary joint used in a rotating device that rotates a rotating object while holding the rotating object by suction through the hollow area in a rotating body having a hollow area,
A joint body that surrounds a part of the rotating body and is formed in a cylindrical shape;
One or more fin portions provided continuously in the circumferential direction of one or both of the inner peripheral surface of the joint body and the outer peripheral surface of the rotating body,
When the suction is performed, the fin portion is bent by the suction force so that the outer peripheral surface of the rotating body, the inner peripheral surface of the joint body, or the axial direction is opposed to each other. A rotary joint that is in close contact with the fin portion. The rotary joint according to claim 1, wherein a plurality of the fin portions are provided in multiple stages in the axial direction of the rotating body. The rotary joint according to claim 1 or 2, wherein the joint body and the fin portion are made of polytetrafluoroethylene. The rotary joint according to claim 1, wherein the fin portion is removable. A rotating device that holds the object to be processed by the rotating body by rotating the object to be processed by the rotating body having a hollow area and sucking the object through the hollow area,
The rotary joint according to any one of claims 1 to 4,
A rotating device comprising: suction means for sucking the processing object through the hollow region of the rotating body. The rotating device according to claim 5, further comprising processing means for performing a cutting process, a grinding process, or a polishing process on the processing object.

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