JP2013108557A - Aerostatic bearing and linear motion guiding device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive aerostatic bearing and a linear motion guiding device using the same without generating self-excited vibration.SOLUTION: The aerostatic bearing 1 includes: a bearing substrate 2 formed of a thermoplastic synthetic resin or a reinforcing filler-containing thermoplastic synthetic resin comprising 30-50 mass% of glass fiber, glass powder, carbon fiber or an inorganic filler in the thermoplastic synthetic resin, or aluminum or an aluminum alloy; and a synthetic resin bearing body 3 which is glued and united with the bearing substrate 2 using an adhesive and formed of a thermoplastic synthetic resin.

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 and semiconductor exposure apparatuses, 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 is used in which a static pressure gas bearing with little friction is mounted on a positioning device for a work tool or a work table. In such a linear motion guide device, a pressurized fluid is interposed between a movable table as a work table and a guide rail as a guide member, and the movable table is not in contact with the guide rail. It is configured to be moved.

  The form of the air outlet of the static pressure gas bearing mounted on this linear motion guide device includes a porous throttle, a surface throttle, an orifice throttle, and a self-contained throttle. It is used while adjusting the rigidity.

  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 the pressure bearing pad, as a bearing member, a carbon graphite-based material of a type in which the diameter of material particles is almost uniform and the uniformity of open pores is obtained is described.

  Further, in Patent Document 2, as a gas bearing device that realizes a high damping property while maintaining a relatively high rigidity, an orifice is provided between two opposed substantially parallel bearing surfaces and a bearing gap between both bearing surfaces. A gas bearing device having at least one gas duct for supplying gas through is proposed.

  Furthermore, Patent Document 3 discloses a porous material prepared by adjusting the diameter and distribution of through holes so that a base material made of a porous body is bonded to the base material and a desired air permeation amount is obtained in advance. There has been proposed a static pressure gas bearing including a surface constriction layer made of a plate, jetting gas through the surface constriction layer, and supporting a supported member by the static pressure.

JP 63-23310 A JP 2006-510856 A JP 2001-56027 A JP 2008-82449 A

  Although the above-mentioned conventional static pressure gas bearings can achieve ultra-low friction, ultra-high precision, and ultra-high-speed motion, high-strength metals and ceramics are mainly used as bearing materials, and high-precision grinding There is a problem that it is inevitably expensive because finishing or the like is necessary.

  However, ultra-low friction, ultra-high accuracy, and ultra-high-speed motion are not required, but for example, when an article such as a liquid crystal screen is transported in a non-contact manner or when the article is moved horizontally without causing a temperature change. However, the use of a static pressure gas bearing has the advantage that the configuration of the apparatus is simplified. On the other hand, since the static pressure gas bearing itself is expensive, it is not widely used for this purpose.

  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. A resin bearing member having an air supply groove communicating with the plurality of air outlets, and an air supply port connected to the lower surface of the resin bearing member so as to cover the air supply groove and communicating with the air supply groove. The hydrostatic gas bearing provided with the base | substrate which has is proposed (patent document 4).

  According to the hydrostatic gas bearing described in Patent Document 4, the resin bearing member constituting the hydrostatic gas bearing can be formed by injection molding using a mold, and mechanical processing is unnecessary. In addition, the structure of the base also forms an air supply port communicating with the resin bearing member, and the static pressure gas bearing can be assembled simply by joining the resin bearing member and the base. Mass production of gas bearings is possible, and an inexpensive static pressure gas bearing can be provided.

  However, since the air outlet in the static pressure gas bearing described in Patent Document 4 is formed by injection molding, a self-contained throttle or orifice shape having a relatively large diameter of about 0.2 to 0.4 mm. Therefore, there is a risk that the amount of air supply from the air outlet will be too large and cause self-excited vibration.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a static pressure gas bearing that can be mass-produced and is inexpensive, and a linear motion guide device that uses the static pressure gas bearing. is there.

  The hydrostatic gas bearing according to the present invention has a base, a cylindrical projecting portion projecting from the outer peripheral edge of one surface of the base, and an opening at one surface of the base at one end, and an outer periphery of the base at the other end. A bearing base having an air supply passage that opens on the surface, an annular recess formed on one surface facing one surface of the base, an annular groove opened on the other surface, and an annular groove on one end And a synthetic resin bearing body having a plurality of air blowing holes as a self-contained aperture opened at the annular bottom surface of the annular recess at the other end. The outer peripheral surface adjacent to one surface is fitted to the inner surface of the cylindrical protrusion of the base, and is bonded to the fitting portion and integrated with the bearing base, and the annular groove is at least 0.3 mm. Having a width and a depth of at least 0.01 mm, and the air blowing hole at one end thereof Have a diameter of 30μm even without, characterized in that it forms a self-formed aperture between the annular recess and the annular groove.

  According to the hydrostatic gas bearing of the present invention, the synthetic resin bearing body is fitted with the outer peripheral surface adjacent to one surface to the inner surface of the cylindrical protruding portion of the base, and is bonded with an adhesive at the fitting portion. The synthetic resin bearing body is connected to the annular concave groove opened at the other surface and the annular concave groove at one end and opened to the annular concave portion at the other end. A plurality of air blowing holes, 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; A self-contained throttle is formed between the annular recess and the annular groove, and the annular recess and the plurality of air blowing holes are formed without machining, so that mass production is possible. It is possible and inexpensive to manufacture.

  In a preferred example, the annular groove has a width of 0.3 to 1.0 mm or 0.3 to 0.7 mm and a depth of 0.01 to 0.05 mm or 0.01 to 0.03 mm. The air blowing hole has a diameter of 30 to 120 μm at one end thereof.

  Each of the annular concave groove and the air blowing hole is preferably formed by laser processing. The processing laser is selected from a carbon dioxide laser, a YAG laser, a UV laser, an excimer laser, and the like.

  If each of the annular concave groove and the air blowing hole is formed by laser processing, these can be formed instantaneously compared with machining such as cutting, which enables mass production and can be manufactured at low cost. it can.

  In the static pressure gas bearing of the present invention, a spherical pressure receiving recess may be formed on the other surface of the bearing base. The spherical pressure receiving concave portion is a frustoconical concave portion or a concave spherical portion opened on the other surface, and these spherical pressure receiving concave portions may be directly formed on the other surface of the bearing base.

  In the static pressure gas bearing of the present invention, the other surface of the bearing base is formed with a cylindrical recess that opens on the other surface, and a piece is fitted and fixed to the cylindrical recess. The spherical body pressure-receiving recess may open on one surface of the piece on the other surface side of the bearing base and have a truncated conical surface formed on the piece.

  In the static pressure gas bearing of the present invention, the other surface of the bearing base is formed with a cylindrical recess that opens on the other surface, and a piece is fitted and fixed to the cylindrical recess. The spherical body pressure-receiving recess may open on one surface of the piece on the other surface side of the bearing base and have a concave spherical surface formed on the piece.

  In a static pressure gas bearing having a spherical pressure receiving recess on the other surface of the bearing base, a ball stud sphere, for example, is placed in sliding contact with the spherical pressure receiving recess, so that the static pressure gas bearing is moved around the sphere. An automatic alignment function may be added.

  In the hydrostatic 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 a small-diameter annular formed inside the annular groove. And a plurality of second radial grooves having one end opening into the annular groove and the other end opening into the small-diameter annular groove. The groove, the small-diameter annular groove, and the first and second radial grooves are preferably formed on the other surface of the bearing body.

  The static pressure gas bearing to which the automatic alignment function is added is suitable for use in a linear motion guide device as a positioning device for a work table. That is, the linear motion guide device having the static pressure gas bearing according to the present invention has a pair of an upper plate facing the upper guide surface and a pair of opposite guide surfaces on the outer side of the guide member having the upper guide surface and the both side guide surfaces. A U-shaped movable table with a side plate is arranged, and ball studs are erected on the lower surface of the upper plate of the movable table and the inner surfaces of the side plates, with the sphere facing inward. Between the ball stud and the upper guide surface and both guide surfaces of the guide member, the static pressure gas bearing slides the spherical pressure receiving recess into the ball stud sphere, and the bearing member is connected to the guide member. It is good to be arranged facing the upper guide surface and the both side guide surfaces.

  According to the above linear motion guide device, the compressed air is injected from the plurality of air blowing holes of the bearing body onto the upper guide surface and the both side guide surfaces of the guide member, whereby the bearing body and the upper guide surface and the both side guide surfaces are separated. The movable table can be held in a non-contact state with respect to the upper guide surface and the both side guide surfaces by the air lubrication film formed therebetween. If the bearing gaps between the bearing body and the upper guide surface and both side guide surfaces are not uniform, a pressure difference will occur in each part of the bearing gap. The pressurized gas bearing is automatically aligned, and a state parallel to the upper guide surface and the both side guide surfaces is maintained. Therefore, the accuracy of parts such as the parallelism and perpendicularity of the guide member and movable table can be made relatively coarse, and in addition to the low cost of the static pressure gas bearing itself, an inexpensive linear motion guide device is provided. can do.

  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 made of polyacetal resin, polyamide resin, polyphenylene sulfide. Reinforced filler-containing thermoplastic synthetic resin or aluminum or aluminum alloy containing 30-50% by mass of glass fiber, glass powder, carbon fiber or inorganic filler in thermoplastic synthetic resin such as resin or these thermoplastic synthetic resins It is preferable. 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, it is possible to provide an inexpensive static pressure gas bearing capable of mass production and a linear motion guide device using the static pressure gas bearing.

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 an explanatory bottom view of FIG. FIG. 4 is an explanatory bottom view of the bearing body of FIG. FIG. 5 is an enlarged cross-sectional explanatory diagram of a main part of FIG. FIG. 6 is an explanatory plan view of the bearing base. 7 is a cross-sectional explanatory view taken along line VII-VII in FIG. FIG. 8 is an explanatory plan view of the bearing body. 9 is a cross-sectional explanatory view taken along line IX-IX in FIG. FIG. 10 is an explanatory bottom view of FIG. FIG. 11 is a cross-sectional explanatory view of an assembly of a bearing body and a bearing base. FIG. 12 is an explanatory plan view of another embodiment of the bearing body. FIG. 13 is an explanatory bottom view of another embodiment of the bearing base. 14 is a cross-sectional explanatory view taken along the line XIV-XIV in FIG. 13. FIG. 15 is a cross-sectional explanatory view of an assembly of a bearing body and a bearing base. FIG. 16 is a cross-sectional explanatory view of a static pressure gas bearing to which an automatic alignment function is added. FIG. 17 is an explanatory bottom view of still another embodiment of the bearing base. 18 is a cross-sectional explanatory view taken along line XVIII-XVIII in FIG. FIG. 19 is a cross-sectional explanatory view of an assembly of a bearing body and a bearing base. FIG. 20 is a cross-sectional explanatory view of a static pressure gas bearing to which an automatic alignment function is added. FIG. 21 is an explanatory view of the bottom surface of another embodiment of the bearing base. 22 is a cross-sectional explanatory view taken along the line XXII-XXII in FIG. FIG. 23 is a cross-sectional explanatory diagram of the piece. FIG. 24 is a cross-sectional explanatory view of a bearing base to which a piece is fitted and fixed. FIG. 25 is a cross-sectional explanatory view of an assembly of a bearing body and a bearing base. FIG. 26 is a cross-sectional explanatory view of a static pressure gas bearing to which an automatic alignment function is added. FIG. 27 is a cross-sectional explanatory view of another embodiment of the piece. FIG. 28 is a cross-sectional explanatory view of the bearing base with the pieces fitted and fixed. FIG. 29 is a cross-sectional explanatory view of an assembly of a bearing body and a bearing base. FIG. 30 is a cross-sectional explanatory view of a static pressure gas bearing to which an automatic alignment function is added. FIG. 31 is a cross-sectional explanatory view of the linear motion guide device.

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

  1 to 5, 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 these thermoplastic synthetic resins. Glass fiber, glass powder, carbon fiber or bearing filler 2 made of reinforcing filler-containing thermoplastic synthetic resin containing 30 to 50% by mass or aluminum or aluminum alloy, and adhesive to bearing substrate 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. 6 and 7, in particular, the bearing base 2 is integrally protruded upward in the axial direction Y at the outer periphery of the base 4 and the circular surface 5 of one of the bases 4 in plan view. A cylindrical projection 6, the other circular surface 7 of the base 4 in plan view, and an air supply hole 10 having a circular opening 9 that is open at one end 8 on the circular surface 5 of the base 4 in plan view. The one end 11 communicates with the air supply hole 10, and the other end includes an air supply passage 13 that opens at the outer peripheral surface 12 of the base 4.

  A female screw 15 is formed on the inner peripheral surface 14 of the end of the air supply passage 13 that opens to the outer peripheral surface 12 of the base 4, and the male screw of the air supply plug 16 is screwed into the female screw 15. Is fixed to the outer peripheral surface 12 of the base 4 of the bearing base 2.

  As shown in FIGS. 8 to 10, the bearing body 3 particularly has an annular recess 18 formed on one planar surface 17 facing the one circular surface 5 of the base 4 facing the planar surface 5. And an annular groove 20 opened on the other circular surface 19 in plan view, and a plurality of one end 21 communicating with the annular groove 20 and the other end 22 opening on the annular bottom surface 24 of the annular recess 18. Air blowing holes 25 and an outer peripheral surface 23 adjacent to one circular surface 17 in plan view.

  The annular groove 20 is defined by an annular bottom surface 26 and a cylindrical side surface 27 facing each other, and the annular groove 20 has a width W of at least 0.3 mm and a depth d of at least 0.01 mm. The air blowing hole 25 has a diameter D of at least 30 μm at one end 21 in this example from the one end 21 to the other end 22, and between the annular recess 18 and the annular recess 20. A self-contained diaphragm is formed.

  The annular recess 18 is connected to the annular bottom surface 24 where the other end 22 of the air blowing hole 25 opens, the outer peripheral surface 28 connected to the outer edge of the annular bottom surface 24, and the inner edge of the annular bottom surface 24. The outer peripheral surface 28 and the inner peripheral surface 29 are formed on the frustoconical surfaces 31 and 32 that extend from the annular bottom surface 24 toward the opening 30 of the annular recess 18, respectively. Has been.

  In the bearing body 3, the outer peripheral surface 23 adjacent to one surface 17 is fitted to the inner surface of the cylindrical protruding portion 6 of the bearing base 2, and is bonded to the bearing base 2 by an adhesive at the fitting portion. The

  In the hydrostatic gas bearing 1, an annular groove 20 having a width W on the surface 19 of the bearing body 3 of at least 0.3 mm and a depth d of at least 0.01 mm and an annular groove 20 at one end 21 are opened. At the other end 22, a plurality of self-drawn air blowing holes 25 having a diameter D of at least 30 μm that open to the annular bottom surface 24 of the annular recess 18 may be formed instantaneously by, for example, laser processing.

  In the above-described hydrostatic gas bearing 1, since the bearing body 3 is integrated with the bearing base 2 with an adhesive, its manufacture is easy and the cost can be reduced. Further, the air blowing hole 25 has a diameter of at least 30 μm and a very small diameter, and can suppress the occurrence of self-excited vibration caused by a large amount of air injection from the air blowing hole 25.

  Next, an example of a manufacturing method of the hydrostatic gas bearing 1 shown in FIGS. 1 to 5 will be described. First, a bearing base 2 made of synthetic resin containing reinforcing filler or aluminum or aluminum alloy shown in FIGS. 8 to FIG. 10, a bearing body 3 made of synthetic resin, which does not have the annular groove 20 and the air blowing hole 25, is prepared. As shown in FIG. 11, the bearing body 3a is prepared. The annular recess 18 is communicated with the opening 9 of the air supply hole 10 of the bearing base 2, and the outer peripheral surface 23 adjacent to the one surface 17 of the bearing body 3 a is connected to the cylindrical protrusion of the bearing base 2. 6 is fitted to the inner surface of 6, and the fitting portion is bonded with an adhesive to form an assembly 33 in which the bearing base 2 and the bearing body 3a are integrated.

  The other surface 19 of the bearing body 3a in the assembly 33 thus integrated is irradiated with laser by a laser processing machine, the width W is 0.3 to 1.0 mm, and the depth d is 0.01 to 0.00. An annular groove 20 of 05 mm and an annular bottom surface 26 defining the annular groove 20 have a diameter D of at least 30 μm, preferably penetrating the bearing body 3a from the annular bottom surface 26 and opening to the annular bottom surface 24 of the annular recess 18. Forms a plurality of self-drawn air blowing holes 25 of 30 to 120 μm to produce a static pressure gas bearing 1.

  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 20 having a width of 0.5 mm and a depth of 0.05 mm centered on an arc having a diameter of 30 mm uses a carbon dioxide laser with a laser output of 9.5 W, a scanning speed of 1000 mm / s, and the number of overprints once. It can be formed and processed on the surface 19 of the bearing body 3a formed from polyphenylene sulfide resin in a processing time of 2 seconds, and passes through the bearing body 3a from the annular bottom surface 26 to the annular bottom surface 26 of the annular groove 20. Ten self-drawn air blow holes 25 having a diameter of 0.06 mm opened at the annular bottom surface 24 of the annular recess 18 are machined at 10 equally spaced positions in the circumferential direction with a laser output of 14 W and a machining time of 15 seconds. We were able to.

  The bearing body 3 of the static pressure gas bearing 1 includes one annular groove 20. In addition to the annular groove 20, the bearing body 3 includes a bearing body 3 as shown in FIG. 12. A large-diameter annular groove 34 that is formed on the other surface 19 and surrounds the annular groove 20 outside the annular groove 20 and is concentric with the annular groove 20, and one end 35 is the annular groove 20. And a plurality of radial grooves 37 whose other end 36 opens into the large-diameter annular groove 34 and a small-diameter annular groove formed inside the annular groove 20 and concentric with the annular groove 20. The groove 38 and a plurality of radial grooves 41 whose one end 39 opens into the annular groove 20 and whose other end 40 opens into the small-diameter annular groove 38 may be provided.

  In the hydrostatic gas bearing 1 having the bearing body 3 shown in FIG. 12, the compressed air supplied to the annular groove 20 passes through the radial grooves 37 and 41 and the large diameter annular groove 34 and the small diameter annular groove 38. Therefore, the supply area is increased, and stable levitation can be performed, for example, when the article is levitated.

  FIGS. 13 to 16 show another embodiment of the static pressure gas bearing 1, and the center portion of the other circular surface 7 of the bearing base 2 has a circular opening on the surface 7. A spherical pressure receiving recess 43 having 42 is formed, and the spherical pressure receiving recess 43 is a truncated cone defined by a circular bottom surface 44 in plan view and a truncated cone surface 45 extending from the bottom surface 44 to the opening 42 in a divergent manner. A recess 46 is provided.

  The bearing base 2 including the spherical pressure receiving recess 43 having the truncated conical recess 46 is similar to the static pressure gas bearing 1 in that the opening 9 of the air supply hole 10 is replaced with the opening 30 of the annular recess 18 of the bearing 3. The outer peripheral surface 23 adjacent to the one surface 17 of the bearing body 3 is fitted to the inner surface of the cylindrical protruding portion 6 of the bearing base 2, and then the fitting portion is bonded with an adhesive. An assembly 47 in which the base body 2 and the bearing body 3 are integrated is formed.

  The other surface 19 of the bearing body 3 in the assembly 47 integrated in this way is irradiated with laser by a laser processing machine, and the width W is 0.3 to 1.0 mm and the depth d is 0.01 to 0.00. An annular groove 20 having a diameter of 05 mm and an annular bottom surface 26 defining the annular groove 20 have a diameter D of at least 30 μm, preferably penetrating the bearing body 3 from the annular bottom surface 26 and opening at the annular bottom surface 24 of the annular recess 18. Forms a plurality of self-drawn air blowing holes 25 of 30 to 120 [mu] m to produce a static pressure gas bearing 1.

  In the static pressure gas bearing 1 formed in this way, as shown in FIG. 16, a sphere 49 of a ball stud 48 is arranged in sliding contact with a frustoconical surface 45 of a sphere pressure receiving recess 43 of the bearing base 2. Thus, an automatic alignment function is added.

  FIGS. 17 to 20 show still another embodiment of the static pressure gas bearing 1. In the center portion of the other circular surface 7 in the plan view of the bearing base 2, a circular opening in the plan view is formed in the surface 7. A spherical pressure receiving recess 43 having a portion 42 is formed, and the spherical pressure receiving recess 43 has a concave spherical portion 51 defined by a circular bottom surface 44 and a concave spherical surface 50 extending from the bottom surface 44 to the opening 42. doing.

  The bearing base 2 provided with the spherical pressure receiving recess 43 having the concave spherical portion 51 has the opening 9 of the air supply hole 10 as the opening 30 of the annular concave portion 18 of the bearing body 3, as in the static pressure gas bearing 1. The outer peripheral surface 23 adjacent to the one surface 17 of the bearing body 3 is fitted to the inner surface of the cylindrical projecting portion 6 of the bearing base 2 and then the fitting portion is adhered with an adhesive. 2 and the bearing body 3 are integrated.

  The other surface 19 of the bearing body 3 in the assembly 52 integrated in this way is irradiated with laser by a laser processing machine, the width W is 0.3 to 1.0 mm, and the depth d is 0.01 to 0.00. An annular groove 20 having a diameter of 05 mm and an annular bottom surface 26 defining the annular groove 20 have a diameter D of at least 30 μm, preferably penetrating the bearing body 3 from the annular bottom surface 26 and opening at the annular bottom surface 24 of the annular recess 18. Forms a plurality of self-drawn air blowing holes 25 of 30 to 120 [mu] m to produce a static pressure gas bearing 1.

  In the static pressure gas bearing 1 formed in this way, as shown in FIG. 20, the spherical body 49 of the ball stud 48 is arranged in sliding contact with the concave spherical surface 50 of the spherical body pressure-receiving concave portion 43 of the bearing base 2. An automatic alignment function is added.

  21 to 26 show another embodiment of the static pressure gas bearing 1 to which an automatic alignment function is added. A cylindrical recess 55 having a circular bottom surface 54 opened at the surface 7 is formed at the center of the other circular surface 7 of the bearing base 2 in plan view. As shown, a cylindrical body 56, a circular hole 59 that opens at one surface 58 of the cylindrical body 56 at one end 57, and the other surface 60 of the cylindrical body 56 from the other end 60 are connected to the other end 60 of the circular hole 59. A piece 64 provided with a recess 63 having a frustoconical surface 62 extending toward the end 61 and opening at the other surface 61 has one surface 58 directed toward the bottom surface 54 of the cylindrical recess 55 and the other The surface 61 is flush with and fixed to the other surface 7 of the bearing base 2. The spherical pressure receiving recess 43 has such a truncated conical surface 62.

  The bearing base 2 to which the piece 64 is fitted and fixed communicates the opening 9 of the air supply hole 10 to the opening 30 of the annular recess 18 of the bearing body 3 and the bearing body, as in the static pressure gas bearing 1. 3 is fitted to the inner surface of the cylindrical protrusion 6 of the bearing base 2 and the fitting part is bonded with an adhesive to bond the bearing base 2 and the bearing body 3 to each other. To form an integrated assembly 65.

  The other surface 19 of the bearing body 3 in the assembly 65 integrated in this way is irradiated with a laser by a laser processing machine, the width W is 0.3 to 1.0 mm, and the depth d is 0.01 to 0.00. An annular groove 20 having a diameter of 05 mm and an annular bottom surface 26 defining the annular groove 20 have a diameter D of at least 30 μm, preferably penetrating the bearing body 3 from the annular bottom surface 26 and opening at the annular bottom surface 24 of the annular recess 18. Forms a plurality of self-drawn air blowing holes 25 of 30 to 120 [mu] m to produce a static pressure gas bearing 1.

  As shown in FIG. 26, the static pressure gas bearing 1 formed in this way has a ball stud 48 on the truncated conical surface 62 of the recess 63 of the piece 64 fitted and fixed to the cylindrical recess 55 of the bearing base 2. The spherical body 49 is arranged so as to be in sliding contact with each other, whereby an automatic alignment function is added.

  27 to 30 show still another embodiment of the static pressure gas bearing 1 to which an automatic alignment function is added. As shown in FIG. 22, a cylindrical recess 55 having a circular bottom surface 54 opened at the surface 7 is formed at the center of the other circular surface 7 in plan view of the bearing base 2. 27, a cylindrical body 56, a circular hole 59 opened at one end 58 of the cylindrical body 56 at one end 57, and the other end 60 of the circular hole 59 are connected to each other. A piece 64 having a concave portion 63 having a concave spherical surface 66 that opens at the other surface 61 toward the other surface 61 of 56 has one surface 58 directed toward the bottom surface 54 of the cylindrical concave portion 55 and the other surface. 61 is fitted and fixed to be flush with the other surface 7 of the bearing base 2. The spherical pressure receiving recess 43 has such a concave spherical surface 66.

  The bearing base 2 to which the piece 64 is fitted and fixed communicates the opening 9 of the air supply hole 10 to the opening 30 of the annular recess 18 of the bearing body 3 and the bearing body, as in the static pressure gas bearing 1. 3 is fitted to the inner surface of the cylindrical protrusion 6 of the bearing base 2 and the fitting part is bonded with an adhesive to bond the bearing base 2 and the bearing body 3 to each other. Is formed as an integrated body 67.

  The other surface 19 of the bearing body 3 of the assembly 67 integrated in this way is irradiated with laser by a laser processing machine, and the width W is 0.3 to 1.0 mm and the depth d is 0.01 to 0.00. An annular groove 20 having a diameter of 05 mm and an annular bottom surface 26 defining the annular groove 20 have a diameter D of at least 30 μm, preferably penetrating the bearing body 3 from the annular bottom surface 26 and opening at the annular bottom surface 24 of the annular recess 18. Forms a plurality of self-drawn air blowing holes 25 of 30 to 120 [mu] m to produce a static pressure gas bearing 1.

  As shown in FIG. 30, the static pressure gas bearing 1 formed in this way has a spherical body of a ball stud 48 on a concave spherical surface 66 of a concave portion 63 of a piece 64 fitted and fixed to a cylindrical concave portion 55 of a bearing base 2. When 49 is placed in sliding contact, an automatic alignment function is added.

  The piece 64 fitted and fixed in the cylindrical recess 55 formed in the center of the other circular surface 7 of the bearing base 2 in a plan view has excellent sliding characteristics, for example, polyacetal resin, polyamide resin, polyester resin, etc. The self-lubricating thermoplastic synthetic resin, or copper or copper alloy is used to make the sliding contact between the truncated conical surface 62 or the concave spherical surface 66 of the concave portion 63 of the piece 64 and the sphere 49 of the ball stud 48. It can be performed smoothly.

  FIG. 31 shows a linear motion guide device 68 using the static pressure gas bearing 1 shown in FIG. 26. The linear motion guide device 68 includes an upper guide surface 69 and guide members 71 having both side guide surfaces 70 and 70. Further, a U-shaped movable table having a U-shaped cross section provided with an upper plate 72 facing the upper guide surface 69 and straddling the guide member 71 and a pair of side plates 73 and 73 facing both side guide surfaces 70 and 70. 74, a ball stud 48 erected on the lower surface 75 of the upper plate 72 of the movable table 74 and the inner surfaces 76 of the side plates 73 and 73 with the sphere 49 facing inward, and the ball stud 48 and the guide member 71 The truncated conical surface 62 of the piece 64 is slidably brought into contact with the spherical body 49 of the ball stud 48 between the guide surface 69 and the both side guide surfaces 70 and 70, and the other surface 19 of the bearing body 3 is guided upward of the guide member 71. Surface 69 and both side guide surfaces 0 and is opposed to 70 are formed from the provided a hydrostatic gas bearing 1 Tokyo.

  According to this linear motion guide device 68, compressed air is injected from the plurality of air blowing holes 25 of the bearing body 3 to the upper guide surface 69 and the both side guide surfaces 70 and 70 of the guide member 71, thereby The movable table 74 is not moved against the upper guide surface 69 and the both side guide surfaces 70 and 70 by an air lubrication film formed between the other surface 19 and the upper guide surface 69 and both side guide surfaces 70 and 70 of the guide member 71. It can be held in contact. If the bearing gap between the bearing body 3 and the upper guide surface 69 and the both side guide surfaces 70 and 70 is not uniform, a pressure difference is generated in each part of the bearing gap. The bearing gap is uniform due to the pressure difference. In this direction, the static pressure gas bearing 1 is automatically aligned, and a state parallel to the upper guide surface 69 and the both side guide surfaces 70 and 70 is maintained. For this reason, the accuracy of parts such as the parallelism and perpendicularity of the guide member 71 and the movable table 74 can be made relatively coarse, and in addition to the low cost of the static pressure gas bearing 1 itself, Manufacturing can be facilitated and cost can be reduced.

  In the linear motion guide device 68, the static pressure gas bearing 1 as shown in FIG. 26 is used as the static pressure gas bearing 1 to which the automatic alignment function is added. You may use the static pressure gas bearing 1 shown in FIG.

  As described above, after the outer peripheral surface adjacent to one surface of the bearing body is fitted to the inner surface of the cylindrical protruding portion of the bearing base, the fitting portion is bonded with an adhesive. Therefore, the joint surface between the bearing body and the bearing base is firmly sealed, and the width W is 0.3 to 1.0 mm and the depth d is 0 on one surface of the bearing body. An annular groove having a diameter of 0.01 to 0.05 mm, and an annular bottom surface defining the annular groove, a plurality of self having a diameter D of at least 30 μm that penetrates the bearing body from the annular bottom surface and opens at the annular bottom surface of the annular recess. An air blow hole having an aperture shape is formed, and the annular groove and the air blow hole can be formed without machining, so that not only an inexpensive static pressure gas bearing can be provided, but also the static pressure gas bearing Linear motion guide device that facilitates production and reduces costs It is possible to provide a.

DESCRIPTION OF SYMBOLS 1 Hydrostatic base bearing 2 Bearing base 3 Bearing body 4 Base part 6 Cylindrical protrusion part 13 Supply path 18 Annular recessed part 20 Annular recessed groove 23 Outer peripheral surface 25 Air blowing hole

Claims (10)

  A base, a cylindrical projecting portion projecting from the outer peripheral edge of one surface of the base, and an air supply passage opening at one end of the base at one end and opening at the outer peripheral surface of the base at the other end Bearing base, an annular recess formed on one surface facing one surface of the base, an annular groove opened on the other surface, and one end communicating with the annular groove and the other end A synthetic resin bearing body having a plurality of air blowing holes as a self-contained aperture opened at the annular bottom surface of the annular recess, and the bearing body is an outer peripheral surface adjacent to one surface Is fitted to the inner surface of the cylindrical protrusion of the base, and is bonded to the fitting portion to be integrated with the bearing base. The annular groove has a width of at least 0.3 mm and a depth of at least 0.01 mm. And the air outlet hole has a diameter of at least 30 μm at one end thereof. Have been, the externally pressurized gas bearing, characterized in that to form a self-formed aperture between the annular recess and the annular groove.   The annular groove has a width of 0.3 to 1.0 mm or 0.3 to 0.7 mm and a depth of 0.01 to 0.05 mm or 0.01 to 0.03 mm. The static pressure gas bearing according to claim 1, wherein the blowout hole has a diameter of 30 to 120 μm at one end thereof.   The static pressure gas bearing according to claim 1 or 2, wherein each of the annular concave groove and the air blowing hole is formed by laser processing.   The hydrostatic gas bearing according to any one of claims 1 to 3, wherein a spherical pressure receiving recess is formed on the other surface of the bearing base.   The hydrostatic gas bearing according to claim 4, wherein the spherical pressure receiving recess has a frustoconical recess that opens on the other surface of the bearing base.   The static pressure gas bearing according to claim 4, wherein the spherical pressure-receiving recess has a concave spherical portion that opens on the other surface of the bearing base.   The other surface of the bearing base is formed with a cylindrical recess that opens at the other surface, and a piece is fitted and fixed to the cylindrical recess, and the spherical pressure receiving recess is the other of the bearing base. The static pressure gas bearing according to claim 4, wherein the static pressure gas bearing has an truncated conical surface formed on the piece and opening on one surface of the piece on the surface side.   The other surface of the bearing base is formed with a cylindrical recess that opens at the other surface, and a piece is fitted and fixed to the cylindrical recess, and the spherical pressure receiving recess is the other of the bearing base. The hydrostatic gas bearing according to claim 4, wherein the static pressure gas bearing has an indented spherical surface formed in the piece and opening in one surface of the piece on the surface side.   The bearing body is formed on the other surface in addition to the annular groove, and has a large-diameter annular groove surrounding the annular groove on the outside of the annular groove, and one end portion of the annular groove. A plurality of first radial grooves having an opening in the groove and the other end opening in the large-diameter annular groove; a small-diameter annular groove formed inside the annular groove; The static pressure gas according to any one of claims 1 to 8, further comprising: a plurality of second radial grooves that open in the annular groove and have the other end opening in the small-diameter groove. bearing.   On the outside of the guide member having the upper guide surface and the both side guide surfaces, a U-shaped movable table having a U-shaped cross section having an upper plate facing the upper guide surface and a pair of side plates facing the both guide surfaces is arranged. In addition, ball studs are erected on the inner surfaces of the lower surface of the upper plate and the side plates of the movable table with the spheres facing inward, respectively. The static pressure gas bearing according to any one of claims 1 to 9 causes the spherical body pressure receiving recess to slide in contact with the spherical body of the ball stud, and the bearing body is connected to the upper guide surface of the guide member and A linear motion guide device, characterized in that it is arranged facing both side guide surfaces.

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