JP2013221529A - Aerostatic gas bearing and linear motion guiding device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aerostatic gas bearing which is capable of curbing the generation of a self-exited vibration and stably supporting an object to be supported and is low in cost, and to provide a linear motion guiding device using the aerostatic gas bearing.SOLUTION: An aerostatic gas bearing 1 comprises a bearing basal body 2 which is opened at an annular protrusion 6 provided integrally with one surface of a basal portion 4 and protrudingly from the basal portion 4 and at a protruding end face of the annular protrusion 6 in one end, and at the same time includes an air supply passage 11 opened on an outer circumferential surface of the basal portion 4 in the other end, a bearing body 3 with a plurality of air ejection holes 38 communicating with an annular depression that receives the annular protrusion 6 of the bearing basal body 2 and an annular depressed groove 33 and a self-exciting vibration damping mechanism A for damping the self-exciting vibration caused by the air ejection from the air ejection holes 38 via the annular depressed groove 33.

Description

    The present invention relates to a static pressure gas bearing and a linear motion guide device using the static pressure gas bearing.

  In precision machine tools, semiconductor exposure apparatuses, and the like, it is required to position a workpiece such as a processing tool or a substrate with high accuracy. For this reason, a linear motion guide device using a static pressure gas bearing with little friction is used for a positioning device for a work table. In such a linear motion guide device, a lubricating film of compressed air is interposed between a movable table as a work table and a guide rail as a guide member. It is configured to be moved by contact.

  As the throttle type of the air outlet of the static pressure gas bearing used in this linear motion guide device, there are a porous throttle, a surface throttle, an orifice throttle, a self-contained throttle, etc., and a static pressure gas bearing equipped with these throttle types Are used while adjusting the load capacity, bearing rigidity, etc. according to the respective applications.

  For example, in Patent Document 1, a static body is fixed to either a supported body or a support body, and the support body is movably supported by pressurized air supplied to the bearing surface via the bearing member. In a pressurized gas bearing pad, as a bearing member, a type of carbon graphite-based material has been proposed in which the diameter of material particles is substantially uniform and the uniformity of open pores can be obtained.

  Patent Document 2 discloses a porous material produced by adjusting the diameter and distribution of through-holes so that a desired amount of air permeation can be obtained by joining a porous material and a preform on the preform. There has been proposed a static pressure gas bearing that includes a surface constriction layer made of a plate, ejects gas through the surface constriction layer, and supports the supported body by the static pressure.

JP 63-23310 A JP 2001-56027 A JP 2008-82449 A

  Although the above-mentioned conventional static pressure gas bearings can realize ultra-low friction, ultra-high accuracy and ultra-high-speed motion, high-strength metals and ceramics are mainly used as bearing materials, and bearing surfaces made of these bearing materials are used. There is a problem that it is inevitably expensive because it is necessary to perform a high-precision grinding finish or the like.

  However, although the above-described ultra-low friction, ultra-high accuracy, and ultra-high-speed motion are not required, for example, an article such as a liquid crystal screen is transported in a non-contact manner, or the article is moved horizontally without causing a temperature change. In applications, the use of static pressure gas bearings has the advantage of simplifying the configuration of the apparatus, but the static pressure gas bearings themselves are expensive and are not widely used in such applications. .

  In view of the above situation, in order to provide an inexpensive static pressure gas bearing that can be used in various fields, the present applicant has firstly provided a plurality of air outlets having a self-contained throttle shape or an orifice throttle shape on the upper surface, and a lower surface. Synthetic resin bearing members each having an air supply groove communicating with the plurality of air outlets, and an air supply connected to the lower surface of the bearing member so as to cover the air supply groove and communicating with the air supply groove A hydrostatic gas bearing in which a bearing base having a mouth is integrated has been proposed (Patent Document 3).

  According to the hydrostatic gas bearing described in Patent Document 3, a synthetic resin bearing member that forms the hydrostatic gas bearing can be formed by injection molding using a mold, and machining is unnecessary. In addition, the structure of the bearing base also forms an air supply port communicating with the bearing body, and the static pressure gas bearing can be assembled by simply joining the bearing body and the bearing base. This enables mass production of bearings and provides an inexpensive static pressure gas bearing.

  However, since the air outlet in the static pressure gas bearing described in Patent Document 3 is formed by injection molding using a mold, its diameter is about 0.2 to 0.4 mm. There is a risk that it will be in the shape of an orifice or orifice, and there is a risk that self-excited vibration will occur due to the excessive amount of air supply from the air outlet, and the support of the supported body by the hydrostatic gas bearing will become unstable and will also be put to practical use. There is a need for improvement.

  The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an inexpensive static pressure gas that can suppress the occurrence of self-excited vibration and can stably support a supported body. An object of the present invention is to provide a bearing and a linear guide device using the static pressure gas bearing.

  The hydrostatic gas bearing of the present invention has a base, an annular protrusion integrally projecting from one surface of the base, and one end opening at the projecting end surface of the annular protrusion, while the other end of the base A bearing base made of a synthetic resin having an air supply passage provided in the base and the annular projecting portion and opening on the outer peripheral surface, and a bearing base formed on one surface facing one surface of the base A plurality of air as a self-contained aperture that communicates with the annular recess at one end and the annular recess at one end and opens into the annular recess at the other end. A bearing body made of a synthetic resin each having a blowout hole, and a self-excited vibration damping mechanism that attenuates self-excited vibration caused by blowing air from the air blowout hole through the annular groove, Rings on the outer and inner circumferential surfaces of the bearing body that define the annular recess The self-excited vibration damping mechanism is formed on the bearing base or the bearing body or by the cooperation of the bearing base and the bearing body. The air chamber includes at least one throttle hole that communicates with the air chamber at one end and opens at the other surface of the bearing body at the other end.

  According to the static pressure gas bearing of the present invention, the annular protrusion of the synthetic resin bearing base is received in the annular recess of the synthetic resin bearing body, and the outer peripheral surface and inner peripheral surface of the annular protrusion are Since it is welded and joined to the outer inner peripheral surface and the inner inner peripheral surface of the bearing body that defines the annular recess, the synthetic resin bearing body and the bearing base are firmly integrated, and the bearing base or An air chamber formed in the bearing body or by the cooperation of the bearing base and the bearing body, and at least one throttle hole that communicates with the air chamber at one end and opens at the other surface of the bearing body at the other end. The self-excited vibration damping mechanism can suppress the generation of self-excited vibration due to air blowing from the air blowing hole through the annular concave groove, so that the supported body is stably supported by the static pressure gas bearing. Can be made.

In the hydrostatic gas bearing of the present invention, the annular groove is at least 0.3 mm wide, preferably 0.3-0.1 mm wide and at least 0.01 mm deep, preferably 0.01-0. The air outlet hole has a diameter of at least 30 μm at one end thereof,
Preferably it has a diameter of 30-120 μm.

  At least one of the annular concave groove, the air blowing hole, and the throttle hole is preferably formed by laser processing with a processing laser laser selected from a carbon dioxide laser, a YAG laser, a UV laser, an excimer laser, and the like. Yes.

  When at least one of the annular groove, air blowing hole and throttle hole is formed by laser processing, these can be formed instantaneously compared to machining such as cutting, and mass production becomes possible, It can be manufactured at low cost.

  In the hydrostatic gas bearing of the present invention, in a preferred example, the outer peripheral surface of the annular projecting portion of the bearing base gradually expands outward from the cylindrical outer wall surface continuously to the cylindrical outer wall surface. An annular frustoconical outer wall surface and a cylindrical outer wall surface that is continuous with the outer wall surface of the frustoconical cone and continuous with one surface of the base and has a larger diameter than the cylindrical outer wall surface. An inner peripheral surface of the projecting portion includes a cylindrical inner wall surface, an annular frustoconical inner wall surface that is continuous with the cylindrical inner wall surface and gradually reduces inward from the cylindrical inner wall surface, and the frustoconical inner wall surface A cylindrical inner wall surface continuously connected to one surface of the base portion and having a smaller diameter than the cylindrical inner wall surface, and an outer inner peripheral surface defining the annular recess of the bearing body is An outer cylindrical inner wall surface having an annular periphery defining an outer edge of the open end, and defining an annular recess of the bearing body The inner inner peripheral surface has an inner cylindrical inner wall surface having a peripheral edge that defines the inner edge of the opening end of the annular recess, and the bearing body has an outer cylindrical inner wall surface that is a cylinder of the outer peripheral surface of the annular protrusion. The inner cylindrical inner wall surface is fitted to the outer cylindrical wall surface of the inner peripheral surface of the annular protrusion, and the annular peripheral edge of the outer cylindrical inner wall surface that defines the outer edge of the opening end of the annular recess is annular protruding portion. The outer peripheral surface of the outer peripheral surface of the annular recess is brought into contact with the inner peripheral surface of the inner peripheral surface of the annular protrusion, and the inner peripheral surface of the inner surface of the inner circular cylinder defining the inner edge of the opening of the annular recess. In addition, it is welded and joined to the annular projecting portion by ultrasonic welding at a portion in contact with the annular projecting portion and integrated with the bearing base.

  In such an example, since the part where the bearing base and the bearing body contact each other is a so-called shear joint, the joint is ultrasonically welded at the shear joint, which is airtight and has a very strong welding strength. Thus, a static pressure gas bearing in which the bearing body and the bearing base are firmly integrated can be provided.

  In another preferred example of the hydrostatic gas bearing of the present invention, the outer peripheral surface of the annular projection of the bearing base is gradually expanded outward from the cylindrical outer wall surface continuously with the cylindrical outer wall surface. An annular frusto-conical outer wall surface having a diameter, a cylindrical outer wall surface continuous with the outer wall surface of the frusto-cone and connected to one surface of the base and having a diameter larger than that of the cylindrical outer wall surface. The inner peripheral surface of the annular protrusion is formed by connecting a cylindrical inner wall surface, an annular frustoconical inner wall surface that is continuous with the cylindrical inner wall surface and gradually shrinks inward from the cylindrical inner wall surface, A cylindrical inner wall surface continuous with the wall surface and connected to one surface of the base and having a diameter smaller than that of the cylindrical inner wall surface, and an outer inner circumferential surface defining the annular recess of the bearing body is an outer cylindrical surface An inner wall and an annular periphery that gradually expands from the inner wall of the outer cylinder and that defines the outer edge of the open end of the annular recess. And an inner inner peripheral surface defining the annular recess of the bearing body is gradually reduced in diameter from the inner cylindrical inner wall surface and the inner cylindrical inner wall surface. And an inner frustoconical inner wall surface having an annular peripheral edge defining an inner edge of the opening end of the annular recess, and the bearing body has an outer cylindrical inner wall surface that is connected to the outer circumferential surface of the annular protrusion. Fit the inner cylindrical inner wall surface to the inner cylindrical inner wall surface of the annular protrusion, and the outer frustoconical inner wall surface to the outer truncated cone outer wall surface, and the inner truncated conical inner wall surface It is brought into contact with the inner wall surface of the head cone, and is welded and joined to the annular projecting portion by ultrasonic welding at a portion in contact with the annular projecting portion and integrated with the bearing base.

  In such another example, since the portions of the bearing base and the bearing body that contact each other are so-called scarf joints, uniform heat generation is obtained by ultrasonic waves at the scarf joints, and a large welding area is obtained. Therefore, it is possible to provide a static pressure gas bearing in which the airtightness is good, a very strong welding strength is obtained, and the bearing body and the bearing base are more firmly integrated.

  The air chamber has one surface of the base portion, one surface of the bearing body facing the one surface of the base portion, a frustoconical inner wall surface of the inner peripheral surface of the annular projecting portion of the bearing base, and a small-diameter cylinder. It may be provided with a space defined by the inner wall surface and formed by the cooperation of the bearing base and the bearing body. Instead, one surface of the base portion and one surface of the base portion face each other. A space defined by one surface of the bearing body and a small cylindrical inner wall surface of the bearing base and formed by the cooperation of the bearing base and the bearing body. The hole may open to a void at one end.

  The air chamber may be open at one surface of the bearing body and may have a recess formed in the bearing body. In this case, the throttle hole opens at the recess at one end. Good.

  In the static pressure gas bearing of the present invention, the bearing body is formed on the other surface in addition to the annular groove, and a large-diameter annular groove surrounding the annular groove outside the annular groove, A plurality of first radial grooves, one end of which opens into the annular groove and the other end of which opens into the large-diameter groove, and the other side of the annular groove. A small-diameter annular groove surrounded by the annular groove on the inner side of the groove, and a plurality of second radial grooves whose one end opens into the annular groove and the other end opens into the small-diameter groove. A groove having at least one of the large-diameter annular groove, the first radial groove, the small-diameter annular groove, and the second radial groove, as described above. It may be formed by processing.

  The static pressure gas bearing of the present invention may further include a sphere receiving means provided on the bearing base and having a sphere receiving recess, and the sphere receiving means opens on the other surface of the base. Even if it has a truncated conical recess formed in the base as a sphere receiving recess, it may have a hemispherical recess formed in the bearing base as an opening in the other surface of the base as a sphere receiving recess. And a piece having a truncated cone concavity that is open and fitted in a cylindrical recess formed on the other surface of the base and fitted in a cylindrical recess formed in the base. And a piece having a hemispherical recess opened as a sphere receiving recess that is open and fitted in a cylindrical recess formed in the base and opened on the other surface of the base. Good.

  In the static pressure gas bearing provided with such a sphere receiving means, for example, the sphere of the ball stud may be slidably disposed in contact with the base or the piece in the sphere receiving recess, and in such a case, An automatic centering function around the sphere is added to the static pressure gas bearing.

  The static pressure gas bearing to which such an automatic alignment function is added is suitable for use in a linear motion guide device as a positioning device for a work table.

  The linear motion guide device of the present invention includes a guide member having an upper surface guide surface and both side guide surfaces, a pair of upper plates disposed on the outer side of the guide member and facing the upper surface guide surface, and facing both side guide surfaces. A movable table provided with a side plate, a ball stud standing on at least one of a lower surface of the upper plate of the movable table and an inner surface of each of the pair of side plates with a sphere facing the guide member, and the ball stud And the above-mentioned hydrostatic gas bearing having a sphere-receiving means and a movable table other than the at least one surface, and a movable table other than the at least one surface. Between the lower surface of the upper plate and the inner surfaces of the pair of side plates and the upper surface guide surface and the both side guide surfaces facing the lower surface of the upper plate of the movable table other than the at least one surface and the inner surfaces of the pair of side plates. And the above-mentioned static pressure gas bearing that does not necessarily have a sphere receiving means, and the ball stud sphere has a ball bearing centered on the sphere. At least one of the static pressure gas bearings that are received in each of the sphere receiving portions of the sphere receiving means of the static pressure gas bearing so as to be swingable with respect to the stud and do not necessarily have the sphere receiving means. The base portion of the bearing base of the hydrostatic gas bearing is fixed to the lower surface of the upper plate of the movable table and the inner surfaces of the pair of side plates other than the at least one surface.

  According to the linear motion guide device of the present invention, the bearing gap between the other surface of the bearing body and the guide surface is obtained by injecting compressed air from the plurality of air blowing holes of the bearing body onto the guide surface of the guide member. The movable table can be held in a non-contact state with respect to the guide surface by an air lubrication film formed on the order of several μm to several tens of μm. Since the air chamber communicating with the bearing gap between the other surface of the bearing body and the guide surface via the throttle hole exerts a vibration damping action, the occurrence of self-excited vibration can be suppressed, and the other of the bearing body Even if the bearing gap between the bearing surface and the guide surface is uneven and a pressure difference occurs in the bearing gap, the static pressure gas bearing is automatically aligned in the direction in which the bearing gap becomes uniform due to the pressure difference. Because the other surface of the bearing body is kept parallel to the guide surface, The accuracy of parts such as parallelism and perpendicularity of the members and movable table can be made relatively coarse, and an inexpensive linear motion guide device can be provided in addition to the low cost of the static pressure gas bearing itself.

  In the hydrostatic gas bearing of the present invention, the bearing body is preferably formed from a thermoplastic synthetic resin such as polyacetal resin, polyamide resin, polyphenylene sulfide resin, and the bearing base is composed of polyacetal resin, polyamide resin, polyphenylene. It is formed from a thermoplastic synthetic resin such as a sulfide resin, or a thermoplastic synthetic resin containing reinforcing filler containing 30-50% by mass of glass fiber, glass powder, carbon fiber or inorganic filler in these thermoplastic synthetic resins. Is preferred. These synthetic resin bearing bodies and bearing bases may be formed by machining a synthetic resin material or by injection molding using a mold.

  According to the present invention, the generation of self-excited vibration can be suppressed, and mass production capable of stably supporting a supported body is possible, and an inexpensive static pressure gas bearing and this static pressure gas bearing are used. A linear motion guide device can be provided.

FIG. 1 is an explanatory plan view of a preferred example of an embodiment of the present invention. 2 is a cross-sectional explanatory view taken along the line II-II in FIG. FIG. 3 is a partially enlarged cross-sectional explanatory view of FIG. FIG. 4 is an explanatory plan view of the bearing base. FIG. 5 is a cross-sectional explanatory view taken along the line V-V in FIG. 4. 6 is a partially enlarged cross-sectional explanatory view of FIG. FIG. 7 is a partially enlarged cross-sectional explanatory view of FIG. FIG. 8 is an explanatory bottom view of the bearing body. 9 is a cross-sectional explanatory view taken along line IX-IX in FIG. FIG. 10 is an explanatory plan view of the assembly of the bearing body and the bearing base. 11 is a cross-sectional explanatory view taken along the line XI-XI in FIG. FIG. 12 is a partially enlarged cross-sectional explanatory view of FIG. FIG. 13 is a cross-sectional explanatory view of a preferred example of another embodiment of the bearing body. FIG. 14 is a cross-sectional explanatory view of the assembly of the bearing body element and the bearing base body shown in FIG. FIG. 15 is a partially enlarged cross-sectional explanatory view of FIG. FIG. 16 is a bottom view for explaining a preferred example of another embodiment of the bearing body. 17 is a cross-sectional explanatory view taken along line XVII-XVII in FIG. 18 is an explanatory cross-sectional view of the assembly of the bearing body element and the bearing base body shown in FIG. FIG. 19 is a cross-sectional explanatory view of a preferred example of another embodiment of the present invention. FIG. 20 is an explanatory bottom view of a preferable example of another embodiment of the bearing body. 21 is a cross-sectional explanatory view taken along the line XXI-XXI in FIG. FIG. 22 is an explanatory plan view of the assembly of the bearing body element and the bearing base body shown in FIG. 23 is a cross-sectional explanatory view taken along line XXIII-XXIII in FIG. FIG. 24 is an explanatory plan view of a preferred example of another embodiment of the present invention. 25 is a cross-sectional explanatory view taken along the line XXV-XXV in FIG. FIG. 26 is an explanatory plan view of a preferred example of another embodiment of the bearing body. FIG. 27 is a cross-sectional explanatory view of a preferable example of the piece. FIG. 28 is a cross-sectional explanatory view of a preferred example of another embodiment of the present invention using the bearing base to which the piece shown in FIG. 27 is fitted and fixed. FIG. 29 is a cross-sectional explanatory view of a static pressure gas bearing in which an automatic alignment function is added to the example shown in FIG. FIG. 30 is a cross-sectional explanatory view of another preferred example of the piece. FIG. 31 is a cross-sectional explanatory view of a preferred example of another embodiment of the present invention using the bearing base to which the piece shown in FIG. 30 is fitted and fixed. FIG. 32 is a cross-sectional explanatory view of a static pressure gas bearing obtained by adding an automatic alignment function to the example shown in FIG. FIG. 33 is a cross-sectional explanatory view of a preferred example of an embodiment of a linear motion guide device using a static pressure gas bearing.

  Next, the present invention will be described in more detail based on an example of a preferred embodiment shown in the drawings. Note that the present invention is not limited to these examples.

  1 to 9, the static pressure gas bearing 1 is preferably made of a thermoplastic synthetic resin such as polyacetal resin (POM), polyamide resin (PA), polyphenylene sulfide resin (PPS), or a thermoplastic synthetic resin such as glass. A synthetic resin bearing base 2 formed from a thermoplastic synthetic resin containing reinforcing filler containing 30 to 50% by mass of fiber, glass powder, carbon fiber, or inorganic filler, and integrally welded to the bearing base 2 And a bearing body 3 made of a synthetic resin, preferably made of a thermoplastic synthetic resin such as a polyacetal resin, a polyamide resin, or a polyphenylene sulfide resin.

  As shown in FIGS. 4 to 7, the bearing base 2 has a base portion 4, an annular projecting portion 6 integrally projecting from one circular surface 5 of the base portion 4 in plan view, and an annular shape at one end 7. The protrusion 6 is open at the circular protrusion end surface 8 in plan view, while the other end 9 is open at the flat surface portion 10 of the cylindrical outer peripheral surface of the base 4 and is provided at the base 4 and the annular protrusion 6. An air passage 11 and an opening surface 13 having a circular shape in plan view are provided at the central portion of the other surface 12 of the base portion 4 having a circular shape in plan view. A cylindrical recess 15 is provided.

  The annular protrusion 6 includes an outer annular protrusion 17 having an outer peripheral surface 16 and an inner annular protrusion 19 having an inner peripheral surface 18.

  As shown in FIG. 6 in particular, the outer peripheral surface 16 of the outer annular protrusion 17 has a cylindrical outer wall surface 20 and an annular wharf that is continuous with the cylindrical outer wall surface 20 and gradually expands outward from the cylindrical outer wall surface 20. It has a conical outer wall surface 21 and a cylindrical outer wall surface 22 that is continuous with the frustoconical outer wall surface 21 and is continuous with one surface 5 of the base 4 and has a larger diameter than the cylindrical outer wall surface 20.

  As shown in FIG. 7 in particular, the inner peripheral surface 18 of the inner annular projecting portion 19 is a cylindrical inner wall surface 23 and an annular flange gradually reducing the diameter inward from the cylindrical inner wall surface 23 continuously to the cylindrical inner wall surface 23. The head cone inner wall surface 24 and the frustoconical inner wall surface 24 are connected to one surface 5 of the base 4 and have a cylindrical inner wall surface 25 having a smaller diameter than the cylindrical inner wall surface 23.

  The air supply passage 11 provided in the bearing base 2 opens at the projecting end surface 8 at one end 7 of the annular shape as the annular opening 26 and has a bottomed circle provided at the base 4 and the annular projecting portion 6. An annular recess 27 is provided in the base 4 and communicates with the annular recess 27 at one end, and at the other end which is also the other end 9 of the air supply passage 11 at the flat surface portion 10 of the cylindrical outer peripheral surface of the base 4. And an air supply opening 28 which is open.

  The annular recess 27 is defined by an outer cylindrical inner wall surface 29 of the base portion 4, an inner cylindrical inner wall surface 30 of the base portion 4 facing the outer cylindrical inner wall surface 29, and an annular bottom wall surface 31 of the base portion 4. The air supply port 28 is opened at one end by an outer cylindrical inner wall surface 29 and communicates with the annular recess 27.

  As shown in FIGS. 3, 8, and 9, the bearing body 3 is formed on one surface 32 having a circular shape in a plan view facing the one surface 5 of the base portion 4, and the annular shape of the bearing base 2. An annular recess 33 that receives the protrusion 6, an annular recess 35 that opens on the other surface 34 that is circular in plan view, an end 36 that communicates with the annular recess 35, and an annular recess 33 at the other end 37. And a plurality of air blowing holes 38 that are open to the outside and a cylindrical outer peripheral surface 39.

  In particular, as shown in FIG. 3, the annular groove 35 defined by the annular bottom surface 43 of the bearing body 3 and the pair of cylindrical surfaces 44 facing each other has a width W of at least 0.3 mm and a width of at least 0.01 mm. The air blowing hole 38 has a diameter D of at least 30 μm from one end 36 to the other end 37 in this example, and has an annular recess 33 and an annular groove 35. A self-contained diaphragm is formed between

  The annular recess 33 is connected to an annular ceiling surface 45 where the other end 37 of the air blowing hole 38 opens, an outer inner peripheral surface 46 connected to the outer edge of the ceiling surface 45, and an inner edge of the ceiling surface 45. The inner inner peripheral surface 47 is defined.

  An outer inner peripheral surface 46 defining the annular recess 33 is formed on an annular frustoconical outer wall surface 48 having a small-diameter edge connected to an outer edge of the ceiling surface 45, and a large-diameter edge of the frustoconical outer wall surface 48. An annular step wall surface 50 having a small-diameter edge that is connected and facing the protruding end surface 8 of the outer annular protrusion 17 with a gap 49, and a large-diameter edge of the step wall surface 50. And an outer cylindrical inner wall surface 53 having an annular peripheral edge 52 that defines the outer edge of the circular open end 51 of the annular recess 33.

  An inner inner peripheral surface 47 defining the annular recess 33 is formed on an annular frustoconical inner wall surface 54 having a large-diameter edge connected to the inner edge of the ceiling surface 45, and a small-diameter edge of the frustoconical inner wall surface 54. An annular step wall surface 56 having a large-diameter edge that is connected and facing the protruding end surface 8 of the inner annular protrusion 19 with a gap 55, and a small-diameter edge of the step wall surface 56. And an inner cylindrical inner wall surface 58 having an annular peripheral edge 57 that defines the inner edge of the circular open end 51 of the annular recess 33.

  The static pressure gas bearing 1 further includes a self-excited vibration damping mechanism A that attenuates self-excited vibration caused by blowing air from the air blowing hole 38 through the annular concave groove 35. The air chamber B formed by the cooperation of the bearing base 2 and the bearing body 3 and the one end 40 open to the center of one surface 32 and communicate with the air chamber B, and the other surface 41 has the other surface 34. It is preferable that the throttle hole 42 has a diameter of about 1 mm.

  The air chamber B includes one surface 5 of the base 4, one surface 32 of the bearing body 3 facing the surface 5, a frustoconical inner wall surface 24 of the inner peripheral surface 18 of the annular protrusion 6 of the bearing base 2, and The space C is defined by the small-diameter cylindrical inner wall surface 25 and formed by the cooperation of the bearing base 2 and the bearing body 3, and the throttle hole 42 opens into the space C at one end 40. .

  The bearing body 3 has an outer cylindrical inner wall surface 53 on the outer cylindrical surface 20 of the outer annular projection 17 and an inner cylindrical inner wall surface 58 on the inner cylindrical surface 23 of the inner annular projection 19. The annular peripheral edge 52 of the outer cylindrical inner wall surface 53 that fits the contact and defines the outer edge of the opening end 51 of the annular recess 33 is formed on the frustoconical outer wall surface 21 of the outer peripheral surface 16 of the outer annular protrusion 17. The annular peripheral edge 57 of the inner cylindrical inner wall surface 58 that defines the inner edge of the opening end 51 of the 33 is brought into contact with the frustoconical inner wall surface 24 of the inner peripheral surface 18 of the inner annular protrusion 19, respectively. The peripheral edge 52 is formed by ultrasonic welding, that is, a so-called shear joint, at a portion where the peripheral edge 52 and the frustoconical outer wall surface 21 are in contact with each other and a portion where the peripheral edge 57 and the frustoconical inner wall surface 24 are in contact with each other. Contact with outer cone wall 21 In addition to the portion that contacts the inner wall surface 24 of the frustoconical portion of the peripheral edge 57 and the portion that contacts the outer cylindrical wall surface 53 of the outer cylindrical inner wall surface 53 and the inner wall surface 23 of the inner cylindrical inner wall surface 58 It is welded and joined to the bearing base 2 at a part to be integrated with the bearing base 2.

  The bearing body 3 is welded and joined to the outer peripheral surface 16 and the inner peripheral surface 18 of the annular protrusion 6 at the outer inner peripheral surface 46 and the inner inner peripheral surface 47 that define the annular recess 33, and is integrated with the bearing base 2. As a result, one surface 5 of the shaft base 4, one surface 32 of the bearing body 3 facing the one surface 5, and the frustoconical inner wall surface 24 of the inner peripheral surface 18 of the inner annular protrusion 19 of the bearing base 2. And the void C of the air chamber B defined by the small-diameter cylindrical inner wall surface 25 is formed.

  In the hydrostatic gas bearing 1, the annular groove 35 having a width W on the surface 34 of the bearing body 3 of at least 0.3 mm and a depth d of at least 0.01 mm, and the one end 36 open to the annular groove 35. At the other end 37, a plurality of self-drawing air blowing holes 38 having a diameter of at least 30 μm that open into the annular recess 33 may be formed instantaneously by, for example, laser processing.

  In the hydrostatic gas bearing 1 described above, the bearing body 3 includes a portion where the peripheral edge 52 and the frustoconical outer wall surface 21 are in contact, a portion where the peripheral edge 57 and the frustoconical inner wall surface 24 are in contact, and an outer cylindrical inner wall surface 53. Mass production is possible because the portion in contact with the cylindrical outer wall surface 20 and the portion in contact with the inner cylindrical inner wall surface 58 and the cylindrical inner wall surface 23 are welded and bonded to the bearing base 2 instantaneously and hermetically by ultrasonic welding. In addition, it can be made inexpensive.

  Next, an example of a manufacturing method of the hydrostatic gas bearing 1 shown in FIGS. 1 to 3 will be described. First, a synthetic resin bearing base 2 as shown in FIGS. 4 to 7 and a central portion of one surface 32 are used. One throttle hole 42 that is opened and opened at the center of the other surface 34 is formed in advance, but the annular concave groove 35 and the plurality of air blowing holes 38 are not formed. Such a synthetic resin-made bearing body element 3a is prepared. As shown in FIGS. 10 to 12, one surface 5 of the base 4 is made to face one surface 32 of the bearing body 3 and the bearing base 2 is annular. The protrusion 6 is received in the annular recess 33 of the bearing body 3, and the annular peripheral edge 52 of the outer cylindrical inner wall surface 53 that defines the outer edge of the opening end 51 of the annular recess 33 is connected to the outer peripheral surface 16 of the outer annular protrusion 17. An inner wall defining the inner edge of the open end 51 of the annular recess 33 on the outer wall 21 of the truncated cone The annular rim 57 of the cylindrical inner wall surface 58 to the truncated conical inner wall surface 24 of the inner peripheral surface 18 of the inner annular protrusion 19 is respectively in contact to form an assembly 59 of the bearing element body 3a and the bearing base 2.

  A tool horn (not shown) is pressed against the surface 34 of the bearing body 3a in the assembly 59, the applied pressure is 0.098 to 0.60 MPa, the vibration amplitude is 20 to 80 μm, and the transmission time is 0.1 to 1.5 seconds. The ultrasonic vibration is applied under a welding condition of a hold time of 0.5 to 1.0 seconds, and the contact portion between the peripheral edge 52 and the frustoconical outer wall surface 21 and the contact portion between the peripheral edge 57 and the frustoconical inner wall surface 24 are The shear joint is welded and joined with a welding allowance X in the radial direction and a welding allowance Y in the entry direction, and the bearing base 2 and the bearing body 3a are joined and integrated.

  Here, the diameter of the cylindrical outer wall surface 22 of the outer annular projection 17 of the bearing base 2 formed of polyphenylene sulfide resin containing 30% by mass of glass fiber is D1, the diameter of the cylindrical outer wall surface 20 is D2, and the inner annular projection. The diameter of the cylindrical inner wall surface 23 of the portion 19 is D3, the diameter of the cylindrical inner wall surface 25 is D4, and the diameter of the outer cylindrical inner wall surface 53 of the annular recess 33 of the bearing body 3a formed of polyphenylene sulfide resin is d1, Assuming that the diameter of the inner cylindrical inner wall surface 58 of the annular recess 33 is d2, the assembly 59 of the bearing base 2 and the bearing body 3a having the following dimensions is integrated by ultrasonic welding under the following welding conditions. An example will be described.

<Dimensions>
D1 (diameter of cylindrical outer wall surface 22) φ41 mm (tolerance +0.1, 0)

D2 (diameter of cylindrical outer wall surface 20) φ40 mm (tolerance 0, -0.05)

D3 (diameter of cylindrical inner wall surface 23) φ20 mm (tolerance 0.05, 0)

D4 (diameter of cylindrical inner wall surface 25) φ19 mm (tolerance 0, -0.1)

d1 (diameter of outer cylindrical inner wall surface 53) φ40 mm (tolerance +0.10, +0.05)

d2 (diameter of inner cylindrical inner wall surface 58) φ20 mm (tolerance -0.05, -0.10)

<Welding conditions>
Applied pressure: 0.1 MPa Vibration amplitude: 40 μm Oscillation time: 0.5 seconds Hold time: 0.5 seconds

  The assembly 59 of the bearing base body 2 and the bearing body 3a ultrasonically welded under the above-mentioned dimensions and welding conditions is a joint between the peripheral edge 52 and the frustoconical outer wall surface 21 and the frustoconical part with the peripheral edge 57. It was confirmed that the joint portion with the inner wall surface 24 was welded and joined with good airtightness and joined and integrated with strong welding strength.

  The surface 34 of the bearing body 3a in the assembly 59 thus joined and integrated is irradiated with a laser by a laser processing machine, and has a width W of 0.3 to 1.0 mm and a depth of d 0.01 to 0.05 mm. The diameter of the annular groove 35 and the annular bottom surface 43 defining the annular groove 35 through the bearing body 3 from the annular bottom surface 43 and opening to the annular recess 33 at the ceiling surface 45 is preferably at least 30 μm, preferably 30 to 120 μm. A plurality of self-drawing air blowing holes 38 are formed.

  The processing laser to be used is selected from a carbon dioxide laser, a YAG laser, a UV laser, an excimer laser, and the like. Preferably, a carbon dioxide laser is used.

  An annular groove 35 having a diameter at the center of 30 mm, a width of 0.5 mm, and a depth of 0.05 mm uses a carbon dioxide laser with a laser output of 9.5 W. It can be formed and processed on the surface 34 of the bearing body 3a made of polyphenylene sulfide resin with a processing time of 2 seconds, and the bearing body element can be formed on the annular bottom surface 43 of the annular groove 35 from the annular bottom surface 43. The self-drawn air blow hole 38 having a diameter of 0.065 mm (65 μm) that penetrates the body 3a and opens to the annular recess 33 at the ceiling surface 45 has a laser output of 14 W and a processing time of 15 seconds, and is 10 in the circumferential direction. Ten pieces could be processed at evenly spaced positions.

  In the above example, the outer inner peripheral surface 46 includes the frustoconical outer wall surface 48, the stepped wall surface 50, and the outer cylindrical inner wall surface 53, and the inner inner peripheral surface 47 is the frustoconical inner wall surface 54, the stepped wall. The inner wall surface 56 and the inner cylindrical inner wall surface 58 are provided. Instead, as shown in FIGS. 13 to 15, the outer inner circumferential surface 46 includes a frustoconical outer wall surface 48, a stepped wall surface 50 and In addition to the outer cylindrical inner wall surface 53, an annular peripheral edge 60 which is connected to one end of the outer cylindrical inner wall surface 53 and gradually increases in diameter from the one end and which defines the outer edge of the opening end 51 of the annular recess 33 is provided. The inner inner circumferential surface 47 further includes a frustoconical inner wall surface 54, a stepped wall surface 56, and an inner cylindrical inner wall surface 58, and an inner cylindrical inner wall surface 58. It is connected to one end and gradually decreases in diameter from the one end, and the annular recess 33 is opened. An inner frustoconical inner wall surface 63 having an annular peripheral edge 62 defining the inner edge of the end 51 may be further provided, and the assembly of the bearing body 3a and the base 4 shown in FIGS. 64, the bearing body 3 has the outer cylindrical inner wall surface 53 as the cylindrical outer wall surface 20 of the outer circumferential surface 16 of the outer annular projection 17 and the inner cylindrical inner wall surface 58 as the cylindrical inner wall surface of the inner circumferential surface 18 of the inner annular projection 19. 23, and the outer frustoconical inner wall surface 61 is fitted to the outer frustoconical outer wall surface 21 of the outer circumferential surface 16 of the outer annular projection 17 and the inner frustoconical inner wall surface 63 is fitted to the inner circumferential surface of the inner annular projection 19. 18, the bearing element bodies 3a are in contact with each other, that is, the portion where the outer frustoconical inner wall surface 61 and the frustoconical outer wall surface 21 are in contact with each other, and the inner side. The frustoconical inner wall surface 63 and the frustoconical inner wall surface 24 come into contact with each other. Of the outer frustoconical inner wall surface 61 to the outer frustoconical outer wall surface 21 and the inner corrugation by ultrasonic welding at the position, so-called scarf joint (welding margin X in the axial direction, welding margin Y in the penetration direction). The head cone inner wall surface 63 is welded and joined to the bearing base 2 at a portion where it comes into contact with the frustoconical inner wall surface 24, and is integrated with the bearing base 2.

  In the assembly 64 shown in FIGS. 13 to 15, the air chamber B includes one surface 5 of the base portion 4, one surface 32 of the bearing body 3 facing the one surface 5, and an inner annular protrusion of the bearing base 2. The space C is defined by the small-diameter cylindrical inner wall surface 25 of the inner peripheral surface 18 of the portion 19 and is formed by the cooperation of the bearing base 2 and the bearing body 3a.

  According to the assembly 64 shown in FIGS. 13 to 15, the portion where the outer frustoconical inner wall surface 61 and the outer frustoconical outer wall surface 21 are in contact with each other, and the inner frustoconical inner wall surface 63 and the frustoconical inner wall surface 24. Since a so-called scarf joint consisting of surface contact (slope contact) is formed at the contacted part, uniform heat generation is obtained by surface contact in ultrasonic welding, and a large welding area is obtained. The airtightness is good, a very strong welding strength is obtained, and the bearing base 2 and the bearing body 3a are firmly integrated.

  In order to manufacture the assembly 64 of the bearing body 3a and the bearing base 2 shown in FIGS. 14 and 15, the synthetic resin bearing base 2 shown in FIGS. 4 to 7 and the synthetic resin bearing shown in FIG. 14 and 15, as shown in FIGS. 14 and 15, one surface 32 of the bearing body 3a faces one surface 5 of the base 4, and the annular protrusion 6 of the bearing base 2 is connected to the bearing body 3a. Receiving in the annular recess 33, the outer frustoconical inner wall surface 61 is brought into contact with the outer frustoconical outer wall surface 21 and the inner frustoconical inner wall surface 63 is brought into contact with the inner frustoconical wall surface 24, respectively. Then, welding and joining are performed on a portion where the outer frustoconical inner wall surface 61 and the frustoconical outer wall surface 21 are in contact and a portion where the inner frustoconical inner wall surface 63 and the frustoconical inner wall surface 24 are in contact.

  The surface 34 of the bearing body 3a in the assembly 64 thus joined and integrated is irradiated with a laser by a laser processing machine in the same manner as described above, and the width W is 0.3 to 1.0 mm and the depth d 0.01 to 0. .05 mm annular groove 35 and an annular bottom surface 43 defining the annular groove 35 through the bearing body 3 from the annular bottom surface 43 and having a diameter of at least 30 μm and preferably 30 μm. The static pressure gas bearing 1 similar to the above is formed by forming a plurality of self-drawn air blowing holes 38 of ~ 120 μm.

  The bearing body 3a shown in FIGS. 16 to 18 may be used to form the static pressure gas bearing 1 shown in FIG. 19, and the self-excited vibration damping mechanism A in the static pressure gas bearing 1 shown in FIG. In addition to C, a concave portion D formed in the bearing body 3 having a circular opening end 66 in a plan view at the center of one surface 32 of the bearing body 3 and communicating with the void C at the opening end 66 is provided. Further, the air chamber B and the one end 68 are opened at a ceiling surface 69 having a circular shape in plan view defining the recess D and communicated with the recess D, while the other end 70 is opened at the center of the other surface 34. One throttle hole 42 having a diameter of about 1 mm is provided.

  A concave portion D formed in the bearing body 3 by opening at the center of one surface 32 is defined by a circular ceiling surface 69 in plan view and a truncated conical surface 71 extending from the ceiling surface 69 to the surface 32 in a divergent manner. It is formed in a mortar shape.

  In order to manufacture the static pressure gas bearing 1 shown in FIG. 19, first, as shown in FIG. 18, the one end 5 of the base portion 4 of the bearing base 2 has an opening end 66 at the center of the one surface 32. 16 and FIG. 17 provided with the concave portion D are made to face one face 32 and the annular protrusion 6 of the bearing base body 2 is received in the annular recess 33 of the bearing body element 3a. The annular peripheral edge 52 of the outer cylindrical inner wall surface 53 that defines the outer edge of the opening end 51 of the recess 33 is formed on the frustoconical outer wall surface 21 of the outer peripheral surface 16 of the outer annular protrusion 17, and the opening end 51 of the annular recess 33 is formed. An assembly of the bearing body 3a and the bearing base 2 by bringing the annular peripheral edge 57 of the inner cylindrical inner wall surface 58 defining the inner edge into contact with the frustoconical inner wall surface 24 of the inner peripheral surface 18 of the inner annular projection 19 respectively. 65, and in the same manner as described above, the peripheral edge 52 and the frustoconical outer wall surface 21 In addition to the contact portion and the contact portion between the peripheral edge 57 and the frustoconical inner wall surface 24, the contact portion between the outer cylindrical inner wall surface 53 and the cylindrical outer wall surface 20 and the inner cylindrical inner wall surface 58 and the cylindrical inner wall surface 23 The contact portions are welded and joined, and the bearing body 3a and the bearing base 2 are integrated to form an assembly 65.

  The surface 34 of the bearing body 3a in the assembly 65 thus joined and integrated is irradiated with a laser by a laser processing machine in the same manner as described above, and the width W is 0.3 to 1.0 mm and the depth is d0.01. An annular groove 35 of 0.05 mm and an annular bottom surface 43 defining the annular groove 35 from the annular bottom surface 43 through the bearing body 3a and opening to the annular recess 33 on the ceiling surface 45 are at least 30 μm. Preferably, a plurality of self-drawn air blowing holes 38 of 30 to 120 μm are formed to form a static pressure gas bearing 1 as shown in FIG.

  Such a static pressure gas bearing 1 shown in FIG. 19 includes one surface 5 of the base 4, one surface 32 of the bearing body 3 facing the one surface 5, and the inner peripheral surface 18 of the annular protrusion 6 of the bearing base 2. In addition to the space C surrounded by the inner wall surface 24 of the truncated cone and the inner wall surface 25 of the cylinder, a concave portion D is formed on one surface 32 of the bearing body 3 in communication with the air chamber C at the opening end 66. A self-excited vibration damping mechanism A comprising the air chamber B and a single throttle hole 42 opened in the recess D of the air chamber B is provided.

  Further, the hydrostatic gas bearing 1 shown in FIGS. 24 and 25 is the bearing element body 3a shown in FIGS. 16 and 17 but having the bearing element body 3a shown in FIGS. May be manufactured.

  When the hydrostatic gas bearing 1 shown in FIGS. 24 and 25 is manufactured using the bearing body 3a shown in FIGS. 20 and 21, as shown in FIGS. 22 and 23, the base 4 of the bearing base 2 is formed. Of the outer cylindrical inner wall surface 53 that defines the outer edge of the opening end 51 of the annular recess 33 by allowing the one surface 32 of the bearing base 2 to face the one surface 5 and receiving the annular protrusion 6 of the bearing base 2 in the annular recess 33. An annular peripheral edge 52 is formed on the frustoconical outer wall surface 21 of the outer peripheral surface 16 of the outer annular protrusion 17, and an annular peripheral edge 57 of the inner cylindrical inner wall surface 58 that defines the inner edge of the opening end 51 of the annular recess 33 is formed on the inner annular protrusion. The inner peripheral surface 18 of the portion 19 is brought into contact with the frustoconical inner wall surface 24, respectively, and the portion where the peripheral edge 52 and the frustoconical outer wall surface 21 are in contact with each other, and the peripheral edge 57 and the inner surface of the frustoconical cone. In addition to the portion in contact with the wall surface 24, the outer cylindrical inner wall surface 53 and the cylinder The contact sites between the sites and the inner cylindrical inner wall surface 58 and the cylindrical inner wall surface 23 in contact with the wall surface 20 by fusion bonded to form an assembly 72 formed by integrating the bearing base 2 and the bearing element body 3a.

  As shown in FIGS. 22 and 23, the surface 34 of the bearing body 3a in the assembly 72 joined and integrated is irradiated with a laser by a laser processing machine in the same manner as described above, and the width W is 0.3 to 1.0 mm. An annular groove 35 having a depth d of 0.01 to 0.05 mm and an annular bottom surface 43 defining the annular groove 35 are passed through the bearing body 3 from the annular bottom surface 43 and opened to the annular recess 33 on the ceiling surface 45. A plurality of self-drawn air blowing holes 38 having a diameter of at least 30 μm, preferably 30 to 120 μm, and a plurality of 50 to 65 μm in diameter at the center of the surface 34 corresponding to the ceiling surface 69 defining the recess D Preferably, 4 to 24 throttle holes 42 are formed, and the static pressure gas bearing 1 as shown in FIGS. 24 and 25 is formed.

  Such a hydrostatic gas bearing 1 shown in FIGS. 24 and 25 includes one surface 5 of the bearing base 2, one surface 32 of the bearing body 3 facing the one surface 5, and the annular protrusion 6 of the bearing base 2. In addition to the cavity C surrounded by the inner wall surface 21 and the cylindrical inner wall surface 22 of the inner peripheral surface 18, the cavity C communicates with the cavity C and has a recess D formed on one surface 32 of the bearing body 3. A self-excited vibration damping mechanism A comprising the air chamber B and a plurality of throttle holes 42 opened in the recess D of the air chamber B is provided.

  Further, the bearing body 3 of the static pressure gas bearing 1 includes one annular groove 35. In addition to the annular groove 35, as shown in FIG. A large-diameter annular groove 73 that is formed concentrically with the annular groove 35 on the surface 34 and surrounds the annular groove 35 outside the annular groove 35, and one end 74 opens into the annular groove 35. The other end 75 opens into the large-diameter annular groove 73 and a plurality of radial grooves 76 arranged at equal intervals in the circumferential direction, and the other surface 34 of the bearing body 3 is concentric with the annular groove 35. A small-diameter annular groove 77 surrounded by the annular groove 35 inside the annular groove 35, one end 78 opens into the annular groove 35, and the other end 79 has a small-diameter annular shape. And a plurality of radial grooves 80 that are open in the grooves 77 and arranged at equal intervals in the circumferential direction. It may be.

  In the static pressure gas bearing 1 having the bearing body 3 shown in FIG. 26, the air supplied to the annular groove 35 is supplied to the large diameter annular groove 73 and the small diameter annular groove 77 via the radial grooves 76 and 80. Therefore, the supply area is increased, and stable levitation can be performed, for example, when the supported body is floated.

  The large-diameter annular groove 73, the radial groove 76, the small-diameter annular groove 77, and the radial groove 80 may be formed by laser processing together with the formation of the annular groove 35.

  As shown in FIGS. 27 and 28, the static pressure gas bearing 1 may further include a sphere receiving means F provided on the bearing base 2 and having a sphere receiving recess E, and the sphere receiving means. F has a piece 81 which is open on the other surface 12 of the base 4 and is in close contact with the bottom 14 in a cylindrical recess 15 formed in the base 4 and is fitted and fixed to the base 4. The piece 81 communicates with a circular hole 84 opened at one surface 83 at one end 82 and the other end 85 of the circular hole 84 and opened at the other surface 86 at one end and from the other end 85 to the surface 86. It has a mortar-shaped truncated cone conical recess 88 as a sphere receiving recess E defined by a truncated cone surface 87 that gradually expands in diameter.

  In the hydrostatic gas bearing 1 shown in FIGS. 27 and 28, as shown in FIG. 29, the mortar-shaped frustoconical recess 88 of the piece 81 and the outer surface of the sphere 91 of the ball stud 90 to the frustoconical surface 87 are provided. An automatic alignment function is added by arranging the sphere 91 in sliding contact.

  30 and 31, the spherical body receiving means F communicates with a circular hole 84 opened at one surface 83 at one end 82 and the other end 85 of the circular hole 84 and at the other surface at the other end. And a hemispherical concave portion 88 as a sphere receiving portion E defined by a hemispherical concave surface 92 which is opened at 86 and gradually increases in diameter from the other end 85 toward the surface 86, and at the bottom surface 14 in the cylindrical concave portion 15. You may comprise the piece 81 which fits and was fixed to the base 4 in close contact.

  Also in the static pressure gas bearing 1 shown in FIGS. 30 and 31, as shown in FIG. 32, the outer surface of the sphere 91 of the ball stud 90 is in sliding contact with the hemispherical concave surface 92 against the hemispherical recess 88 of the piece 81. Is provided, an automatic alignment function is added.

  By forming the piece 81 with a material having excellent slidability, for example, a thermoplastic synthetic resin such as polyacetal resin, polyamide resin, polyester resin, or copper or copper alloy, the truncated conical surface 87 or hemispherical concave surface of the piece 81 The sliding contact between 92 and the outer surface of the sphere 91 can be performed more smoothly.

  The spherical body receiving means F is an example having a piece 81, but does not have such a piece 81, and opens at the other surface 12 of the base portion 4 and is directly formed in the base portion 4. 88 or hemispherical recess 88 may be provided as the sphere receiving recess E.

  The static pressure gas bearing 1 may be used in a linear motion guide device 120 as shown in FIG. 33. The linear motion guide device 93 shown in FIG. 33 includes an upper surface guide surface 94 and both side guide surfaces as guide surfaces. A guide member 96 having 95, an upper plate 97 facing the upper surface guide surface 94 and a pair of side plates 98 facing both side guide surfaces 95. The movable table 99 having a U-shaped cross section, the lower surface 100 of the upper plate 97 of the movable table 99 and the inner surface 101 of each of the side plates 98, in this example, the inner surface 101 of each of the side plates 98 are spherical. The ball stud 90 fixed to the guide member 96 toward the guide member 96, and both guide surfaces 9 facing the inner surface 101 of each of the spheres 91 of the ball stud 90 and the side plate 101 which is the at least one surface. 29 between the hydrostatic gas bearing 1 shown in FIG. 29 and the lower surface 100 of the upper plate 97 other than the at least one surface and the upper surface guide surface 94 facing the lower surface 100. The hydrostatic gas bearing 1 shown in FIG. 2 is provided.

  In the linear motion guide device 93, each of the spheres 91 of the ball stud 90 receives the sphere so that each base portion 4 of the static pressure gas bearing 1 can swing with respect to the ball stud 90 around the sphere 91. The respective frustoconical recesses 88 of the means F are received in sliding contact with the frustoconical surface 87.

  The base 4 of the bearing gas 2 of the static pressure gas bearing 1 shown in FIG. 2 arranged between the lower surface 100 of the upper plate 97 and the upper surface guide surface 94 facing the lower surface 100 is the lower surface of the upper plate 97 of the movable table 99. 100 is fixed.

  According to such a linear motion guide device 93, compressed air supplied to the air supply passage 11 is compressed air from the plurality of air blowing holes 38 of the bearing body 3 to the upper surface guide surface 94 and the both side guide surfaces 95 of the guide member 96. , The movable table 99 is moved to the upper and lower guide surfaces 94 and 95 by a lubricating film of air formed in the bearing gap between the surface 34 of the bearing body 2 and the upper and lower guide surfaces 94 and 95. Can be kept in a non-contact state. Further, according to the linear motion guide device 93, the air pressure in the bearing gap between the surface 34 of the bearing body 2 and the upper surface guide surface 94 and both side guide surfaces 95 can be transmitted to the air chamber B through the throttle hole 42. The self-excited vibration in the static pressure gas bearing 1, particularly the static pressure gas bearing 1 to which an automatic alignment function is added, can be suppressed, and the movable table 99 as a supported body can be supported stably. If the bearing gaps between the surface 34 of the bearing body 3 and the upper guide surface 94 and the both side guide surfaces 95 are not uniform, a pressure difference is generated in each part of the bearing gap. The hydrostatic gas bearing 1 with a function is automatically aligned in a direction that makes the bearing gap uniform, and is maintained parallel to the guide surfaces 95 on both sides. The accuracy of parts such as angles can be made relatively coarse, and in addition to the low cost of the static pressure gas bearing 1 itself, the manufacture of the linear motion guide device 93 and the cost can be reduced.

  In the linear motion guide device 93, the static pressure gas bearing 1 shown in FIG. 32 may be used as the static pressure gas bearing 1 to which the automatic alignment function is added, and the automatic alignment function is not added. As the static pressure gas bearing 1, each of the above static pressure gas bearings 1 may be used.

DESCRIPTION OF SYMBOLS 1 Static pressure gas bearing 2 Bearing base body 3 Bearing body 4 Base 5 Surface 6 Annular protrusion 11 Supply air passage 17 Outer annular protrusion 19 Inner annular protrusion 20 Cylindrical outer wall surface 21 Frustum cone outer wall surface 22 Cylindrical outer wall surface 23 In cylinder Wall surface 24 Inner wall surface of truncated cone 25 Inner wall surface of cylinder 33 Annular recess 35 Annular groove 38 Air blowing hole 42 Restriction hole B Air chamber 90 Ball stud 93 Linear motion guide device

Claims (19)

  A base, an annular protrusion integrally projecting from one surface of the base, and one end opening at the protruding end surface of the annular protrusion, while the other end opening at the outer peripheral surface of the base and the base and annular A synthetic resin bearing base provided with an air supply passage provided in the protrusion, and an annular recess formed on one surface facing one surface of the base and receiving the annular protrusion of the bearing base A synthetic resin having a plurality of air outlet holes as a self-contained throttle that opens to the annular recess at the other end and communicates with the annular recess at one end and the annular recess at the other end. And a self-excited vibration damping mechanism for attenuating self-excited vibration caused by blowing air from the air blowing hole through the annular concave groove, and the bearing body is a bearing body that defines the annular recess. Outer circumferential surface and inner circumferential surface of the annular protrusion on the outer circumferential surface and the inner circumferential surface The self-excited vibration damping mechanism includes an air chamber formed on the bearing base, the bearing body, or the cooperation of the bearing base and the bearing body, and the air chamber at one end. A hydrostatic gas bearing characterized in that it has at least one throttle hole that opens at the other surface of the bearing body at the other end.   The static groove according to claim 1, wherein the annular groove has a width of at least 0.3 mm and a depth of at least 0.01 mm, and the air blowing hole has a diameter of at least 30 μm at one end thereof. Pressure gas bearing.   The annular groove has a width of 0.3 to 1.0 mm and a depth of 0.01 to 0.05 mm, and the air blowing hole has a diameter of 30 to 120 μm at one end thereof. The static pressure gas bearing according to claim 1 or 2.   The hydrostatic gas bearing according to any one of claims 1 to 3, wherein at least one of the annular groove, the air blowing hole, and the throttle hole is formed by laser processing.   The outer peripheral surface of the annular projecting portion of the bearing base includes a cylindrical outer wall surface, an annular frustoconical outer wall surface that is continuous with the cylindrical outer wall surface and gradually expands outward from the cylindrical outer wall surface, and the truncated cone It has a cylindrical outer wall surface that is continuous with the outer wall surface and is continuous with one surface of the base and has a larger diameter than the cylindrical outer wall surface, and the inner peripheral surface of the annular projecting portion of the bearing base includes a cylindrical inner wall surface, An annular frustoconical inner wall surface that is gradually reduced inward from the inner wall surface of the cylinder continuously to the inner wall surface of the cylinder, and is connected to one surface of the base continuously to the inner wall surface of the frustocone and a cylinder A cylindrical inner wall surface having a smaller diameter than the inner wall surface, and the outer inner peripheral surface defining the annular recess of the bearing body has an annular peripheral edge defining the outer edge of the opening end of the annular recess. An inner cylindrical wall surface having an outer cylindrical surface and an inner inner circumferential surface defining the annular recess of the bearing body defines an inner edge of the opening end of the annular recess. The bearing body has an inner cylindrical inner wall surface with a peripheral edge, and the bearing body has an outer cylindrical inner wall surface on the outer cylindrical surface of the annular protrusion and an inner cylindrical inner wall surface on the inner peripheral surface of the annular protrusion. An annular peripheral edge of the outer cylindrical inner wall surface that is fitted to each cylindrical inner wall surface and defines an outer edge of the opening end of the annular recess is formed on the outer circumferential surface of the annular protrusion, and the opening of the annular recess is An annular peripheral edge of the inner cylindrical inner wall surface defining the inner edge of the end is brought into contact with the inner wall surface of the frustoconical cone on the inner peripheral surface of the annular projecting portion, and the annular projecting portion is formed by ultrasonic welding at a portion in contact with the annular projecting portion. The hydrostatic gas bearing according to any one of claims 1 to 4, wherein the hydrostatic gas bearing is integrated with the bearing base by being welded and joined to the portion.   The air chamber has one surface of the base portion, one surface of the bearing body facing the one surface of the base portion, a frustoconical inner wall surface of the inner peripheral surface of the annular projecting portion of the bearing base, and a small-diameter cylinder. The hydrostatic gas bearing according to claim 5, further comprising a void defined by an inner wall surface and formed by cooperation of a bearing base and a bearing body.   The outer peripheral surface of the annular projecting portion of the bearing base includes a cylindrical outer wall surface, an annular frustoconical outer wall surface that is continuous with the cylindrical outer wall surface and gradually expands outward from the cylindrical outer wall surface, and the truncated cone It has a cylindrical outer wall surface that is continuous with the outer wall surface and is continuous with one surface of the base and has a larger diameter than the cylindrical outer wall surface, and the inner peripheral surface of the annular projecting portion of the bearing base includes a cylindrical inner wall surface, An annular frustoconical inner wall surface that is gradually reduced inward from the inner wall surface of the cylinder continuously to the inner wall surface of the cylinder, and is connected to one surface of the base continuously to the inner wall surface of the frustocone and a cylinder A cylindrical inner wall surface having a smaller diameter than the inner wall surface, and an outer inner circumferential surface defining the annular recess of the bearing body gradually increases in diameter from the outer cylindrical inner wall surface and the outer cylindrical inner wall surface. And an outer frustoconical inner wall surface having an annular periphery defining an outer edge of the open end of the annular recess, and the shaft The inner inner peripheral surface that defines the annular recess of the body has an inner cylindrical inner wall surface and an annular peripheral edge that is gradually reduced in diameter from the inner cylindrical inner wall surface and that defines the inner edge of the opening end of the annular recess. An inner frustoconical inner wall surface, and the bearing body has an outer cylindrical inner wall surface as a cylindrical outer wall surface of the annular projecting portion and an inner cylindrical inner wall surface as an inner circumferential surface of the annular projecting portion. The inner wall surface of the outer truncated cone and the inner wall surface of the inner truncated cone are in contact with the inner wall surface of the truncated cone, respectively, and the annular protrusion is in contact with each other The hydrostatic gas bearing according to any one of claims 1 to 4, wherein the hydrostatic gas bearing is integrated with the bearing base by being welded and joined to the annular protrusion by ultrasonic welding.   The air chamber is defined by one surface of the base, one surface of the bearing body facing the one surface of the base, and a small cylindrical inner wall surface of the bearing base. The static pressure gas bearing according to claim 7, further comprising a void formed by operation.   The static pressure gas bearing according to any one of claims 1 to 8, wherein the air chamber is open on one surface of the bearing body and includes a recess formed in the bearing body.   The static pressure gas bearing according to claim 6 or 8, wherein the throttle hole is open to a void at one end.   The static pressure gas bearing according to claim 9, wherein the throttle hole is open to the recess at one end.   The bearing body is formed on the other surface and encloses the annular groove outside the annular groove, and one end opens into the annular groove and the other end. A plurality of first radial grooves, the portion of which is open to the large-diameter annular groove, and a small-diameter annular groove formed on the other surface and surrounded by the annular groove inside the annular groove And a plurality of second radial grooves having one end opened to the annular groove and the other end opened to the small-diameter annular groove. The static pressure gas bearing according to one item.   The hydrostatic gas bearing according to claim 12, wherein at least one of the large-diameter annular groove, the first radial groove, the small-diameter annular groove, and the second radial groove is formed by laser processing.   The hydrostatic gas bearing according to any one of claims 1 to 13, further comprising a sphere receiving means provided on the bearing base and having a sphere receiving recess.   The static pressure gas bearing according to claim 14, wherein the spherical body receiving means has a truncated conical concave portion that is opened on the other surface of the base portion and formed in the base portion as the spherical body receiving concave portion.   The static pressure gas bearing according to claim 14, wherein the spherical body receiving means has a hemispherical concave portion that is opened on the other surface of the base portion and formed in the base portion as the spherical body receiving concave portion.   The spherical body receiving means includes a piece that is open on the other surface of the base and is fitted and fixed to a cylindrical concave portion formed in the base and has a truncated conical concave portion that opens on one surface as a spherical receiving recess. The hydrostatic gas bearing according to claim 14.   The spherical body receiving means includes a piece that is opened and fixed on a cylindrical concave portion formed on the other surface of the base portion and has a hemispherical concave portion opened on one surface as a spherical body concave portion. The static pressure gas bearing according to claim 13. A guide member having an upper surface guide surface and both side guide surfaces, a movable table provided on the outside of the guide member and provided with an upper plate facing the upper surface guide surface and a pair of side plates facing both side guide surfaces; A ball stud erected on at least one surface of the lower surface of the upper plate of the movable table and the inner surfaces of the pair of side plates with the sphere facing the guide member, and the sphere of the ball stud and the at least one surface The static pressure gas bearing according to any one of claims 14 to 18, which is disposed between an upper surface guide surface and both side guide surfaces facing each other, and a lower surface and a pair of upper plates of a movable table other than the at least one surface. From the inner surface of each side plate, the lower surface of the upper plate of the movable table other than the at least one surface, and the upper surface guide surface and the both side guide surfaces facing each inner surface of the pair of side plates. The static pressure gas bearing according to any one of claims 1 to 3, wherein the ball stud sphere includes the ball bearing base of the static pressure gas bearing according to any one of claims 14 to 18. It is received in each of the sphere receiving portions of the sphere receiving means of the static pressure gas bearing according to any one of claims 14 to 18 so as to be swingable with respect to the ball stud as a center. Item 14. The base portion of the bearing base of at least one of the static pressure gas bearings according to any one of Items 1 to 13, the bottom surface of the upper plate of the movable table other than the at least one surface, and a pair of A linear motion guide device fixed to the inner surface of each side plate.

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