TWI522544B - Static pressure gas bearing and its manufacturing method - Google Patents

Description

Static pressure gas bearing and manufacturing method thereof

The present invention relates to a static pressure gas bearing and a method of manufacturing the same.

As a bearing that can achieve ultra-low friction, ultra-high precision and ultra-high speed operation, the hydrostatic gas bearing is used for ultra-precision machining or ultra-precision measurement for conveying and horizontal movement of articles. As the orifice of the air outlet of the static pressure gas bearing, there are a porous orifice, a surface orifice, an orifice orifice, a self-forming orifice, etc., and the load capacitance and the bearing are adjusted according to the application side. Use one side of rigidity.

For example, Patent Document 1 proposes a gas bearing device which is a gas bearing device which maintains a relatively high rigidity on the one hand and achieves high attenuation, and is formed between two bearing faces which are substantially parallel to each other and between the two bearing faces. The bearing gap has at least one gas conduit for supplying gas through the orifice.

Further, Patent Document 2 proposes a static pressure gas bearing which is provided with a base material including a porous body and which is bonded to the base material and which has a diameter and a distribution which are adjusted so as to have a predetermined amount of air permeation. The surface of the perforated plate is an orifice layer, and the gas is ejected through the surface orifice layer, and the supported member is supported by the static pressure.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2006-510856

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2001-56027

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-82449

Although the above-mentioned static gas bearing can achieve ultra-low friction, ultra-high precision and ultra-high speed operation, it is inevitable that high-strength metal or ceramic is used as the bearing material, and it is necessary to perform high-precision finishing processing. There are problems that lead to high prices.

However, ultra-low friction, ultra-high precision, and ultra-high-speed operation are not required, for example, when a liquid crystal screen or the like is conveyed non-contactly, or when the article is moved horizontally without causing a temperature change, if a static pressure gas bearing is used, The composition of the device is relatively simple and the like, but on the other hand, since the static pressure gas bearing itself is expensive, the actual situation is not widely used for this purpose.

In view of the above-mentioned actual circumstances, in order to provide a low-cost static pressure gas bearing which can be utilized in various fields, the applicant has previously proposed a hydrostatic gas bearing which has a resin bearing member which has a self-contained upper surface. a plurality of air ejection ports having an orifice shape or an orifice shape, having a gas supply groove communicating with the plurality of air ejection ports on a lower surface; and a base body attached to a lower surface of the resin bearing member to cover the above The gas supply groove is joined to each other and has a gas supply port that communicates with the gas supply groove (Patent Document 3).

According to the static pressure gas bearing disclosed in Patent Document 3, a resin bearing member constituting a static pressure gas bearing can be formed by injection molding using a mold, and machining can be performed without requiring mechanical processing, and the structure of the base body can be formed only by resin. The gas supply port through which the bearing member communicates is coupled with the resin bearing member and the base body to assemble the static pressure gas bearing, and mass production of the static pressure gas bearing can be realized, thereby providing a low-cost static pressure gas bearing.

However, since the air ejection port of the static pressure gas bearing disclosed in Patent Document 3 has a self-forming orifice shape or an orifice shape having a diameter of about 0.2 to 0.4 mm, there is an excessive amount of air ejection from the air ejection port. The self-excited vibration is still in need of improvement for practical use.

The present invention has been made in view of the above points, and an object thereof is to provide a static pressure gas bearing which can be mass-produced and which is inexpensive and which does not generate self-excited vibration, and a method of manufacturing the same.

The static pressure gas bearing of the present invention includes: a bearing base made of synthetic resin and a bearing body made of synthetic resin, the bearing base having: a base; an annular projection integrally protruding from one surface of the base; One end of the annular protruding portion is open at the protruding end surface, and the other end is open at the outer peripheral surface of the base portion, and is provided at the annular protruding portion and the air supply passage of the base portion; the bearing body is formed on one surface facing the base portion And an annular recess that receives the annular projection of the bearing base; an annular groove that opens on the other side; and a self-forming section that communicates with the annular groove at one end and opens at the other end of the annular recess a plurality of air ejection holes of the flow holes; and the bearing body is welded and joined to the outer circumferential surface and the inner circumferential surface of the annular protruding portion on the outer circumferential surface and the inner inner circumferential surface of the bearing body defining the annular concave portion, and Integrating 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; the air ejection hole has a diameter of at least 30 μm at one end thereof; and the annular recess is formed between the annular groove Into the orifice.

According to the static pressure gas bearing of the present invention, the annular projection of the bearing body made of synthetic resin is housed in the annular recess of the bearing body made of synthetic resin, and The outer peripheral surface and the inner peripheral surface of the annular projecting portion are welded and joined to the inner peripheral surface and the inner inner peripheral surface of the outer side of the bearing body defining the annular recessed portion, so that the synthetic resin bearing body and the bearing base body are firmly integrated, and Since the synthetic resin bearing body has an annular groove opened on the other surface, and a plurality of air ejection holes that communicate with the annular groove at one end and open at the other end with the annular recess, the annular groove has at least With a width of 0.3 mm and a depth of at least 0.01 mm, the air ejection hole has a diameter of at least 30 μm at one end thereof, and a self-forming orifice is formed between the annular recess and the annular groove, so that the air is ejected from the air. The hole ejects a large amount of air, thereby suppressing self-excited vibration due to a large amount of air ejection from the air ejection port.

In a preferred embodiment, the annular groove has a width of 0.3 to 1.0 mm or 0.3 to 0.7 mm and a depth of 0.0.1 to 0.05 mm or 0.01 to 0.03 mm. The air ejection hole has 30 to 120 μm at one end thereof. The diameter.

Each of the annular groove and the plurality of air ejection holes is preferably formed by laser processing. As a processing laser, it is selected from a carbon dioxide laser, a YAG laser, a UV laser, an excimer laser, and the like.

When each of the annular groove and the plurality of air ejection holes is formed by laser processing, it can be formed instantaneously in comparison with machining such as cutting, and the like, not only can be mass-produced, but also can be produced at low cost. .

In the static pressure gas bearing of the present invention, in a preferred embodiment, the outer circumferential surface of the annular projection of the bearing base has a cylindrical outer wall surface; and the outer wall surface of the cylinder is continuous and gradually faces outward from the outer wall of the cylinder. An outer diameter frustoconical outer wall surface of the enlarged diameter; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical cone and connected to one side of the base portion and having a larger diameter than the outer wall surface of the cylinder; bearing base The inner peripheral surface of the annular protruding portion of the body includes: a cylindrical inner wall surface; and an annular frustoconical inner wall surface continuous with the inner wall surface of the cylinder and gradually decreasing in diameter from the inner wall of the cylinder; and a cylindrical inner wall surface continuous with the inner wall surface of the truncated cone and connected to one surface of the base portion and having a smaller diameter than the inner wall surface of the cylinder; and the inner circumferential surface of the outer side of the annular concave portion of the bearing body is provided with a predetermined annular shape An outer cylindrical inner wall surface of the outer circumference of the outer edge of the open end of the concave portion; the inner circumferential surface of the annular concave portion defining the annular concave portion includes an annular shape having an inner edge defining an open end of the annular concave portion The inner cylindrical inner wall surface of the peripheral edge; the bearing body is fitted to the outer cylindrical inner wall surface of the outer circumferential surface of the annular protruding portion, and the inner cylindrical inner wall surface is fitted to the inner circumference of the annular protruding portion The cylindrical inner wall surface of the surface is provided with an annular outer peripheral surface of the outer circumferential surface of the annular protruding portion, which is defined by the outer edge of the outer edge of the opening end of the annular concave portion, so as to define The inner circumference of the inner edge of the open end of the annular recess The peripheral edge of the inner wall surface of an annular contact with the inner wall surface of the frusto-conical inner circumferential surface of the annular projecting portion; the bearing body by ultrasonic welding and the weld joining portion in contact with each other, the substrate integrated with the bearing.

In the above example, since the contact portion between the bearing base and the bearing body is a so-called common joint, the joint is welded and joined by ultrasonic waves, and the airtightness is good, and a very strong welding strength can be obtained. A static pressure gas bearing that is firmly integrated with the bearing body and the bearing base is provided.

Further, in the static pressure gas bearing of the present invention, in a preferred embodiment, the outer peripheral surface of the annular projecting portion of the bearing base body includes: a cylindrical outer wall surface; and the outer wall surface of the cylinder is continuous and faces outward from the outer wall of the cylinder The square gradually expands the diameter of the ring a frustoconical outer wall surface; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical cone and connected to one side of the base portion and having a larger diameter than the outer wall surface of the cylinder; the inner circumferential surface of the annular projection of the bearing base body The inner wall surface of the cylinder; the annular frustoconical inner wall surface continuous with the inner wall surface of the cylinder and gradually decreasing in diameter from the inner wall of the cylinder; and the inner wall surface of the truncated cone is continuous with the base a cylindrical inner wall surface which is connected to one side and has a smaller diameter than the inner wall surface of the cylinder; and the inner circumferential surface of the outer side of the annular concave portion of the bearing body is provided with: an outer cylindrical inner wall surface; and an outer cylinder inner wall surface An outer frustoconical inner wall surface having a diameter that gradually enlarges an outer circumference of an opening end of the annular recess; wherein the inner circumferential surface of the annular recess defines an inner inner cylinder a wall surface; and an inner frustoconical inner wall surface that gradually decreases in diameter from the inner cylinder inner wall surface and has an annular outer edge defining an inner edge of the annular end of the annular recess; the bearing body respectively causes the outer cylinder inner wall surface Embedding into the annular protrusion The cylindrical outer wall surface of the outer peripheral surface is such that the inner cylindrical inner wall surface is fitted to the inner cylindrical surface of the inner peripheral surface of the annular projecting portion, and the outer frustoconical inner wall surface is in contact with the outer surface of the frustoconical outer side, so that the inner side The inner wall surface of the frustoconical cone contacts the inner wall surface of the truncated cone; the bearing body is welded and joined to the bearing base body by ultrasonic welding at the portions in contact with each other.

In another example of the above, since the portion of the bearing base body and the bearing body that are in contact with each other is so-called engagement, the same thermal energy can be obtained by the ultrasonic wave at the engagement portion, and a large welding area can be obtained. Therefore, the airtightness is good, and a very strong welding strength can be obtained, thereby providing a static pressure gas bearing in which the bearing body and the bearing base body are more firmly integrated.

In the static pressure gas bearing of the present invention, the bearing body has, in addition to the annular groove, a large-diameter annular groove that surrounds the annular groove on the outer side of the annular groove; one end is in the ring shape a plurality of first radial grooves having a groove opening and opening at the other end of the large-diameter annular groove; a small-diameter annular groove formed on the inner side of the annular groove; and one end portion being annularly concave a plurality of second radial grooves having a slot opening and opening at the other end of the small-diameter annular groove; the large-diameter annular groove, the small-diameter annular groove, and the first and second radial grooves It can be formed on one side of the bearing body.

In the static pressure gas bearing of the present invention, the bearing body is preferably formed of a thermoplastic synthetic resin such as a polyacetal resin, a polyamide resin, or a polyphenylene sulfide resin, and the bearing substrate is preferably a polyacetal resin. A thermoplastic synthetic resin such as a polyamide resin or a polyphenylene sulfide resin, or a thermoplastic synthetic resin containing a reinforcing filler of 30 to 50% by mass of glass fiber, glass powder, carbon fiber or inorganic filler in the thermoplastic synthetic resin. form. The bearing body and the bearing base may be formed by machining a synthetic resin material, or may be formed by injection molding using a mold.

A method for manufacturing a hydrostatic gas bearing comprising a synthetic resin-made bearing base and a synthetic resin bearing body welded to the bearing base of the present invention comprises the steps of: (a) preparing a synthetic resin-made bearing base, which The bearing base body includes: a base portion; an annular protruding portion integrally protruding from one surface of the base portion; and an opening end surface of the annular protruding portion at one end, and an outer peripheral surface of the base portion at the other end, and is disposed at the outer ring a gas supply passage of the protrusion and the base; the outer circumferential surface of the annular protrusion has a cylindrical outer wall surface; and the outer wall surface of the cylinder is continuous and gradually increases in diameter from the outer wall surface of the cylinder An annular frustoconical outer wall surface; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical cone and connected to one side of the base portion and having a larger diameter than the outer wall surface of the cylinder; the inner circumferential surface of the annular protruding portion The inner wall surface of the cylinder; the annular frustoconical inner wall surface continuous with the inner wall surface of the cylinder and gradually decreasing in diameter from the inner wall of the cylinder; and the inner wall surface of the truncated cone is continuous with the base a cylindrical inner wall surface which is connected to one side and has a smaller diameter than the inner wall surface of the cylinder; (b) a step of preparing a synthetic resin bearing body having an annular concave portion formed on one side and opening on the other side And an annular air groove; and a plurality of air ejection holes that communicate with the annular groove at one end and open at the other end of the annular concave portion; and the outer circumferential inner surface of the annular concave portion is defined to have the annular concave portion An outer cylindrical inner wall surface of the outer circumference of the annular outer edge of the open end; the inner inner circumferential surface of the annular concave portion is defined to have an inner inner cylinder having an annular outer periphery defining an inner edge of the open end of the annular concave portion Wall surface; (c) one side of the bearing body facing the base On one side, the annular projecting portion of the bearing base is housed in the annular recessed portion of the bearing body, and the annular peripheral edge of the outer cylindrical inner wall surface defining the outer edge of the open end of the annular recessed portion is in contact with the annular projecting portion. The frustoconical outer wall surface of the outer peripheral surface is formed such that an annular peripheral edge of the inner cylindrical inner wall surface defining the inner edge of the open end of the annular recess contacts the frustoconical inner wall surface of the inner peripheral surface of the annular projecting portion, thereby forming a step of assembling the bearing body and the bearing base; (d) pressing the welding head against the bearing body in the assembly, applying a pressure of 0.098 to 0.60 MPa, a vibration amplitude of 20 to 80 μm, and a vibration time of 0.1 to 1.5 seconds. Ultrasonic vibration imparted under a welding condition of a holding time of 0.5 to 1.0 seconds, wherein the bearing body is fusion-bonded to the bearing base at the contact portion; and (e) formed to have a width of at least 0.3 mm and at least 0.01 mm An annular groove having a depth and a plurality of air ejection holes which are open to the annular groove at one end and open at the other end and have a diameter of at least 30 μm at one end as a self-forming orifice In the manner of irradiating the laser to the other side of the bearing body that is welded to the bearing base.

According to the manufacturing method, since the common joint is formed at the contact portion between the bearing body and the bearing base of the assembly, the airtightness of the common joint is better by ultrasonic welding, and a very strong welding strength can be obtained. Thereby, the bearing body and the bearing base are firmly joined and integrated.

Another manufacturing method of the hydrostatic gas bearing comprising the synthetic resin-made bearing base and the synthetic resin bearing body welded to the bearing base of the present invention comprises the following steps: (a) preparing a synthetic resin-made bearing base The bearing base body includes: a base portion; an annular protruding portion integrally protruding from one surface of the base portion; and an opening end surface of the annular protruding portion at one end, and a peripheral surface opening at the other end of the base portion, and is disposed a gas supply passage for the annular projecting portion and the base portion; the outer peripheral surface of the annular projecting portion includes: a cylindrical outer wall surface; and an annular cross section continuous with the outer wall surface of the cylinder and gradually increasing in diameter from the outer wall surface of the cylinder a head conical outer wall surface; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical cone and connected to one side of the base portion and having a larger diameter than the outer wall surface of the cylinder; the inner peripheral surface of the annular protruding portion is provided in the cylinder a wall-shaped frustoconical inner wall surface continuous with the inner wall surface of the cylinder and gradually decreasing in diameter from the inner wall of the cylinder; and continuous with the inner wall surface of the frustoconical cone and connected to one side of the base portion a cylindrical inner wall surface having a smaller diameter than the inner wall surface of the cylinder; (b) a step of preparing a synthetic resin bearing body having: an annular concave portion formed on one surface; and an annular groove opened on the other surface; And in a plurality of air ejection holes that are open to the annular groove at one end and open to the annular recess at the other end; and an inner circumferential surface of the outer side of the annular recess is provided with: an outer cylindrical inner wall surface; and the outer cylindrical inner wall An outer frustoconical inner wall surface having a diameter gradually increasing in diameter and having an outer circumference defining an outer edge of the open end of the annular recess; wherein the inner inner peripheral surface of the annular recess is provided with an inner cylindrical inner wall surface; The inner cylinder inner wall surface is gradually reduced in diameter, and has an inner frustoconical inner wall surface defining an annular outer edge of the inner end of the annular recess; (c) one surface of the bearing body faces one side of the base portion, and The annular protruding portion of the bearing base is received in the annular concave portion of the bearing body, and the inner frustoconical inner wall surface is in contact with the outer surface of the frustoconical outer wall, so that the inner frustoconical inner wall surface contacts the inner wall surface of the truncated cone, thereby forming a step of assembling the bearing body and the bearing base; (d) pressing the welding head against the bearing body in the assembly, applying a pressure of 0.098 to 0.60 MPa, a vibration amplitude of 20 to 80 μm, and a vibration time of 0.1 to 1.5 seconds. Keep it Ultrasonic vibration imparted under 0.5 to 1.0 second welding conditions, wherein the bearing body is fusion-bonded to the bearing base at the contact portion; and (e) formed to have a width of at least 0.3 mm and a depth of at least 0.01 mm a groove, and a plurality of air ejection holes which are open to the annular groove at one end and open at the other end and have a diameter of at least 30 μm at one end as a self-forming orifice, the fusion bonding The step of illuminating the laser on the other side of the bearing body of the bearing base.

According to another manufacturing method described above, since the joint portion of the bearing body and the bearing base of the assembly is formed to have a surface contact with a frustoconical surface (inclined surface), so-called engagement, the same can be obtained by ultrasonic waves. The heat is generated, and a larger welding area is obtained, and the airtight portion of the joint is better, and a non-available The welding strength of Changqiang is so that the bearing body and the bearing base are firmly joined and integrated.

Further, since the annular groove and the plurality of air ejection holes are formed by laser in any of the manufacturing methods, it is possible to obtain a low-cost static pressure gas bearing without requiring machining or the like.

In any of the above manufacturing methods, the step of irradiating the other side of the bearing body welded to the bearing base may be formed to have a width of 0.3 to 1.0 mm or 0.3 to 0.7 mm and 0.01 to 0.05 mm or 0.01 to 0.03. An annular groove having a depth of mm and a plurality of air ejection holes that communicate with the annular groove at one end and open at the other end with an annular recess and have a diameter of 30 to 120 μm at one end thereof.

According to the present invention, it is possible to provide a static pressure gas bearing which can generate a large amount and which is inexpensive and which does not generate self-excited vibration, and a method of manufacturing the same.

Next, the present invention will be described in more detail based on examples of preferred embodiments shown in the drawings. Furthermore, the invention is not limited to the examples.

In FIGS. 1 to 4, the static pressure gas bearing 1 preferably includes a synthetic resin bearing base 2 made of a thermoplastic synthetic resin such as a polyacetal resin, a polyamide resin, or a polyphenylene sulfide resin, or The thermoplastic synthetic resin contains 30 to 50% by mass of glass fiber, glass powder, carbon fiber or inorganic filler, and a thermoplastic synthetic resin containing a reinforcing filler; and a synthetic resin bearing body 3 which is an integrally welded joint. For the bearing base 2, and preferably by a polyacetal resin, a polyamide resin, a polyphenylene sulfide resin or the like Plastic synthetic resin is formed.

In particular, as shown in FIGS. 5 to 8, the bearing base 2 includes: a base portion 4; an annular projecting portion 6 integrally formed from one circular surface 5 of the base portion 4; and a circular shape at one end 7 at the annular projecting portion 6 The protruding end surface 8 is open, and on the other hand, the other end 9 is opened at the cylindrical outer peripheral surface 10 of the base portion 4, and is provided in the annular protrusion portion 6 and the air supply passage 11 of the base portion 4; and is formed on the base portion 4 A bottomed cylindrical bore 13 of the other circular face 12.

The annular projecting portion 6 includes an outer annular protruding portion 15 having an outer peripheral surface 14 and an inner annular protruding portion 17 having an inner peripheral surface 16 .

In particular, as shown in Fig. 7, the outer peripheral surface 14 of the outer annular projecting portion 15 includes a cylindrical outer wall surface 18, and an annular cross section which is continuous with the outer cylindrical wall surface 18 and gradually enlarged in diameter from the outer cylindrical outer wall surface 18. a head conical outer wall surface 19; and a cylindrical outer wall surface 20 continuous with the frustoconical outer wall surface 19 and connected to one surface 5 of the substrate 4 and having a larger diameter than the cylindrical outer wall surface 18.

In particular, as shown in FIG. 8, the inner peripheral surface 16 of the inner annular projecting portion 17 includes a cylindrical inner wall surface 22, and an annular shape which is continuous with the inner wall surface 22 of the cylinder and gradually decreases in diameter from the inner wall surface 22 of the cylinder. The frustoconical inner wall surface 23; and the cylindrical inner wall surface 24 continuous with the frustoconical inner wall surface 23 and connected to one surface 5 of the substrate 4 and having a smaller diameter than the cylindrical inner wall surface 22.

The air supply passage 11 disposed in the bearing base 2 includes: a bottomed annular recess 32 having an annular opening 31 opening at one end 7 at the protruding end surface 8 and disposed on the annular projection 6 and a base portion 4; and a pair of air supply ports 33, which are disposed at the base portion 4, and communicate with the annular recess portion 32 at one end, and on the other end of the other end 9 of the air supply passage 11 at the base portion 4 Round The cylindrical outer peripheral surface 10 is open.

The annular recess 32 is defined by the outer cylindrical inner wall surface 35 of the base portion 4, the inner cylindrical inner wall surface 36 facing the base portion 4 of the outer cylindrical inner wall surface 35, and the annular bottom wall surface 37 of the base portion 4, each of which is defined. One end of the air supply port 33 is opened to the outer cylindrical inner wall surface 35 to communicate with the annular recess 32.

In particular, as shown in FIGS. 9 and 10, the bearing body 3 includes an annular recess 42 formed in a circular surface 41 facing one surface 5 of the base portion 4 and accommodating the annular projection 6 of the bearing base 2; An annular groove 44 having a circular face 43 opening; a plurality of air ejection holes 47 communicating with the annular groove 44 at one end 45 and opening at the other end 46 in the annular recess 42; and a cylindrical outer circumferential surface 48 .

The annular groove 44 defined by the annular surface 49 of the bearing body 3 and the cylindrical surface 50 opposed to each other has a width W of at least 0.3 mm and a depth d of at least 0.01 mm, and the air ejection hole 47 is at one end 45 thereof. In this example, there is a diameter D of at least 30 μm from one end 45 across the other end 46, thereby forming a self-forming orifice between the annular recess 42 and the annular groove 44.

The annular recessed portion 42 is an annular top surface 51 from which the other end 46 of the air ejection hole 47 is open, an inner peripheral surface 52 connected to the outer edge of the outer surface of the top surface 51, and an inner edge connected to the top surface 51. The inner inner peripheral surface 53 is defined.

The outer peripheral surface 52 of the outer annular portion 42 is provided with an annular frustoconical outer wall surface 61 having a small diameter edge connected to the outer edge of the top surface 51; and a large diameter edge connected to the outer wall 61 of the frustoconical shape a small-diameter edge, and an annular stepped wall surface 63 facing the protruding end surface 8 of the outer annular projecting portion 15 with a gap 62; and a peripheral edge having a large diameter edge connected to the stepped wall surface 63, and having a regulation An annular peripheral edge 65 of the outer edge of the circular open end 64 of the annular recess 42 The outer cylinder inner wall surface 66.

The inner inner peripheral surface 53 of the annular recessed portion 42 is provided with an annular frustoconical inner wall surface 71 having a large diameter edge connected to the inner edge of the top surface 51; and a small diameter edge connected to the frustoconical inner wall surface 71 a large-diameter edge, and an annular stepped wall surface 73 facing the projecting end surface 8 of the inner annular projecting portion 17 with a gap 72; and a peripheral edge having a small-diameter edge connected to the stepped wall surface 73, and having a predetermined The inner cylindrical inner wall surface 76 of the annular peripheral edge 75 of the inner edge of the circular open end 64 of the annular recess 42.

In the bearing body 3, the outer cylindrical inner wall surface 66 is brought into contact with the cylindrical outer wall surface 18 of the outer circumferential surface 14 of the outer annular protruding portion 15, and the inner cylindrical inner wall surface 76 is brought into contact with the inner annular protruding portion 17 The cylindrical inner wall surface 22 of the inner circumferential surface 16 and the annular peripheral edge 65 of the outer cylindrical inner wall surface 66 outside the outer edge of the open end 64 of the predetermined annular recess 42 are in contact with the outer circumferential surface 14 of the outer annular projection 15 The frustoconical outer wall surface 19 is such that the annular peripheral edge 75 of the inner cylindrical inner wall surface 76 of the inner edge of the open end 64 of the predetermined annular recess 42 contacts the truncated inner peripheral surface 16 of the inner annular projection 17. Conical inner wall surface 23; and the contact portion of the bearing body 3 in contact with each other, that is, the contact portion between the peripheral edge 65 and the frustoconical outer wall surface 19 and the contact portion between the peripheral edge 75 and the frustoconical inner wall surface 23, by ultrasonic welding, so-called Shear-type welding, except for the contact portion between the peripheral edge 65 and the frustoconical outer wall surface 19 and the contact portion between the peripheral edge 75 and the frustoconical inner wall surface 23, the contact portion between the outer cylindrical inner wall surface 66 and the cylindrical outer wall surface 18 And the contact portion between the inner cylindrical inner wall surface 76 and the inner wall surface 22 of the cylinder is welded and joined. Thereby integrated with the bearing base 2.

In the static pressure gas bearing 1, the shaft can be formed instantaneously by, for example, a laser An annular groove 44 having a width W of at least 0.3 mm and a depth d of at least 0.01 mm in the face 43 of the body 3 is open to the annular groove 44 at one end 45 and to the annular recess 42 at the other end 46. a plurality of air ejection holes 47 having a diameter of at least 30 μm and having the shape of an orifice.

In the above static pressure gas bearing 1, the contact portion of the bearing body 3 with the frustoconical outer wall surface 19 at the peripheral edge 65, the contact portion of the peripheral edge 75 with the frustoconical inner wall surface 23, the outer cylindrical inner wall surface 66 and the cylinder The contact portion between the outer wall surface 18 and the contact portion between the inner cylindrical inner wall surface 76 and the inner cylindrical surface 22 of the cylinder are welded to the bearing base 2 in an airtight manner by ultrasonic welding, so that it can be mass-produced. Make the price lower.

Next, an example of a method of manufacturing the static pressure gas bearing 1 shown in FIGS. 1 to 4 will be described. First, the bearing base 2 made of synthetic resin shown in FIGS. 5 to 8 is prepared, and the annular groove 44 and the plural are not formed. As shown in FIGS. 11 to 13 , the air ejection hole 47 has a bearing body 3 made of synthetic resin as shown in FIGS. 9 and 10, and one surface 41 of the bearing body 3 faces the surface 5 of the base portion 4, and the bearing is made. The annular projecting portion 6 of the base body 2 is housed in the annular recessed portion 42 of the bearing body 3, and the annular peripheral edge 65 of the outer cylindrical inner wall surface 66 of the outer edge of the open end 64 of the predetermined annular recessed portion 42 is in contact with the outer ring. The frustoconical outer wall surface 19 of the outer peripheral surface 14 of the projecting portion 15 contacts the annular peripheral edge 75 of the inner cylindrical inner wall surface 76 of the inner edge of the open end 64 of the predetermined annular recess 42 to the inner annular projection 17 The frustoconical inner wall surface 23 of the inner peripheral surface 16 forms an assembly 81 of the bearing body 3 and the bearing base 2.

The horn (not shown) is pressed against the surface 43 of the bearing body 3 of the assembly 81, and the welding pressure is 0.098 to 0.60 MPa, the vibration amplitude is 20 to 80 μm, and the vibration time is obtained. Under the welding condition of 0.1 to 1.5 seconds and holding time of 0.5 to 1.0 seconds, ultrasonic vibration is applied, and the contact portion between the peripheral edge 65 and the frustoconical outer wall surface 19 and the joint portion of the peripheral edge 75 and the frustoconical inner wall surface 23 are connected. In the middle, the welding allowance X in the radial direction and the welding allowance Y in the entering direction are welded and joined, so that the bearing base 2 and the bearing body 3 are joined and integrated.

Here, the diameter of the cylindrical outer wall surface 20 of the outer annular projecting portion 15 of the bearing base 2 formed of the polyphenylene sulfide resin containing 30% by mass of the glass fiber is set to D1, and the diameter of the outer cylindrical wall surface 18 is set to D2, the diameter of the cylindrical inner wall surface 22 of the inner annular protruding portion 17 is D3, the diameter of the cylindrical inner wall surface 24 is D4, and the outer circumference of the annular concave portion 42 of the bearing body 3 formed of polyphenylene sulfide resin is rounded. The diameter of the inner wall surface 66 of the cylinder is set to d1, and the diameter of the inner cylindrical inner wall surface 76 of the annular recessed portion 42 is set to d2. For the case of ultrasonic welding under the following welding conditions, the bearing base 2 of the following dimensional specifications will be described. The assembly 81 of the bearing body 3.

<size specification>

D1 (diameter of the outer wall surface 20 of the cylinder) Φ41 mm (tolerance +0.1, 0)

D2 (diameter of the outer wall surface 18 of the cylinder) Φ40 mm (tolerance 0, -0.05)

D3 (diameter of the inner wall surface 22 of the cylinder) Φ20 mm (tolerance 0.05, 0)

D4 (diameter of the inner wall surface 23 of the cylinder) Φ19 mm (tolerance 0, -0.1)

D1 (diameter of the outer cylinder inner wall surface 66) Φ40 mm (tolerance +0.10, +0.05)

D2 (diameter of inner cylinder inner wall surface 76) Φ20 mm (tolerance -0.05, -0.10)

<fusion condition>

Welding pressure: 0.1 MPa Vibration amplitude: 40 μm Vibration time: 0.5 second Holding time: 0.5 second

It has been confirmed that the assembly 81 of the bearing base 2 and the bearing body 3 which is ultrasonically welded under the above-mentioned dimensional specifications and welding conditions, the joint portion of the peripheral edge 65 and the frustoconical outer wall surface 19, and the peripheral edge 75 and the frustoconical inner wall surface 23 The joint portion is preferably welded and joined to be airtight, and is joined and integrated with a firm weld strength.

An annular groove having a width W of 0.3 to 1.0 mm and a depth d of 0.01 to 0.05 mm is formed by irradiating a laser to a surface 43 of the bearing body 3 of the assembly 81 which is integrally joined by the laser. 44, the diameter of the opening from the annular surface 49 on the annular surface 49 of the predetermined annular groove 44 and the opening of the annular surface 42 in the top surface 51 is at least 30 μm and preferably 30 to 120 μm. A plurality of air ejection holes 47 in the shape of an orifice.

As the processing laser used, it is selected from a carbon dioxide laser, a YAG laser, a UV laser or an excimer laser, and it is preferable to use a carbon dioxide laser.

An annular groove 44 centered on a circular arc with a diameter of 30 mm and a width of 0.5 mm and a depth of 0.05 mm can be used with a laser output of 9.5 W of carbon dioxide laser at a scanning speed of 1000 mm/s, additional printing times, processing After 2 seconds, it is formed and processed on the surface 43 of the bearing body 3 formed of a polyphenylene sulfide resin, and penetrates the bearing body 3 from the annular surface 49 on the annular surface 49 of the annular groove 44. The air ejection hole 47 of the top surface 51 having a diameter of 0.065 mm and having an opening of the annular recess 42 can be processed by a laser output of 14 W, a processing time of 15 seconds, and an equidistant distance of 10 in the circumferential direction.

In the above-described example, the outer peripheral surface 52 of the outer side of the bearing body 3 includes the frustoconical outer wall surface 61, the stepped wall surface 63, and the outer cylindrical inner wall surface 66, and the inner inner peripheral surface 53 of the bearing body 3 has the frustoconical inner wall surface. 71. The step wall surface 73 and the inner cylinder inner wall surface 76. Alternatively, as shown in FIGS. 14 to 16, the outer inner peripheral surface 52 except the frustoconical outer wall surface 61, the stepped wall surface 63, and the outer cylindrical inner wall surface Further, in addition to 66, the outer peripheral surface of the frustoconical outer peripheral surface of the outer peripheral side of the outer cylindrical inner wall surface 66, which is gradually enlarged in diameter from the one end and having the outer edge of the open end 64 of the predetermined annular recessed portion 42, is provided. 86. The inner inner peripheral surface 53 has a frustoconical inner wall surface 71, a stepped wall surface 73, and an inner cylindrical inner wall surface 76, and further has one end connected to the inner cylindrical inner wall surface 76, and has a diameter gradually reduced from the one end. The inner frustoconical inner wall surface 88 of the annular periphery 87 of the inner edge of the open end 64 of the annular recess 42 is formed by the outer side of the bearing body 3 in the static pressure gas bearing 1 shown in Figs. 14 to 16 The inner wall surface 66 of the cylinder is fitted to the outer circumference of the outer annular projection 15 The cylindrical outer wall surface 18 of the 14 is such that the inner cylindrical inner wall surface 76 is fitted to the cylindrical inner wall surface 22 of the inner circumferential surface 16 of the inner annular projection 17, and the outer frustoconical inner wall surface 86 is in contact with the truncated cone The outer wall surface 19 brings the inner frustoconical inner wall surface 88 into contact with the frustoconical inner wall surface 23, and the bearing body 3 is in contact with the frustoconical outer wall surface 19 by the mutually contacting portion, that is, the outer frustoconical inner wall surface 86. Ultrasonic welding of the contact portion between the inner portion and the inner frustoconical inner wall surface 88 and the frustoconical inner wall surface 23, so-called engagement (axial welding allowance X, welding direction allowance Y in the direction of entry), in the outer frustoconical The contact portion between the wall surface 86 and the frustoconical outer wall surface 19 and the contact portion between the inner frustoconical inner wall surface 88 and the frustoconical inner wall surface 23 are welded and joined to the bearing base 2.

According to the static pressure gas bearing 1 shown in Figs. 14 to 16, the contact portion between the outer frustoconical inner wall surface 86 and the frustoconical outer wall surface 19 and the inner frustoconical inner wall surface 88 and the frustoconical inner wall surface 23 Since the contact portion is formed with so-called engagement including surface contact (inclined contact), the same heat can be obtained by surface contact (slope contact) in the ultrasonic welding, and a large welding area can be obtained, and as a result, the engagement portion is obtained. The airtightness is good, and a very strong welding strength can be obtained, so that the bearing body 3 and the bearing base 2 are firmly integrated.

In order to manufacture the static pressure gas bearing 1 shown in FIGS. 14 to 16, a bearing base 2 made of synthetic resin shown in FIGS. 5 to 8 and a bearing body 3 shown in FIG. 14 are prepared, as shown in FIGS. 15 and 16. It is shown that one surface 41 of the bearing body 3 faces one surface 5 of the base portion 4, and the annular projecting portion 6 of the bearing base 2 is received in the annular recessed portion 42 of the bearing body 3, and the outer frustoconical inner wall surface 86 is respectively brought into contact with the cut surface. The head conical outer wall surface 19 is such that the inner frustoconical inner wall surface 88 is in contact with the frustoconical inner wall surface 23 to form the assembly 81 of the bearing body 3 and the bearing base 2, and the ultrasonic vibration is applied to the thunder in the same manner as described above. Irradiation, the contact portion between the outer frustoconical inner wall surface 86 and the frustoconical outer wall surface 19, and the fusion joint of the inner frustoconical inner wall surface 88 and the frustoconical inner wall surface 23, and the annular groove 44 and The formation of a plurality of air ejection holes 47.

Further, the bearing body 3 of the above-described static pressure gas bearing 1 is provided with an annular groove 44, but in addition to the annular groove 44, as shown in FIG. 17, the bearing body 3 may be provided with a large-diameter annular groove. 91, which is formed on one surface 43 of the bearing body 3, and surrounds the annular groove 44 on the outer side of the annular groove 44, and is concentric with the annular groove 44; a plurality of radial grooves 92, one end of which is The annular groove 44 is open, and the other end is open in the large-diameter annular groove 91; the small-diameter annular groove 93, which is formed on the inner side of the annular groove 44 and concentric with the annular groove 44; and a plurality of radial grooves 94 having one end at the mouth of the annular groove 44 and the other end at the small diameter The annular groove 93 is open.

In the static pressure gas bearing 1 having the bearing body 3 shown in Fig. 17, the air supplied to the annular groove 44 is supplied to the large-diameter annular groove 91 and the small through the radial grooves 92 and 94. The annular groove 93 is provided so that the supply area is large, so that stable suspension can be performed, for example, in the suspension of the article.

As described above, since the bearing body and the bearing base system are formed by injection molding using a mold, there is no need for machining, and the synthetic resin bearing body allows the inner and outer peripheral surfaces of the annular groove to be inserted into the ring of the bearing base body, respectively. The inner and outer peripheral surfaces of the protruding portion are firmly integrated with the bearing base body at the contact portion, and the annular groove having a width of at least 0.3 mm and a depth of at least 0.01 mm is formed in the bearing body, and the diameter is at least 30 μm of a plurality of air ejection holes in the shape of an orifice, so that it is possible to suppress a large amount of air ejected from the air ejection hole and suppress self-excited vibration caused by a large amount of air ejected from the air ejection hole, thereby Not only a mass-produced and low-cost static pressure gas bearing and a method of manufacturing the same.

1‧‧‧Static gas bearing

2‧‧‧ bearing base

3‧‧‧ bearing body

4‧‧‧ base

5‧‧‧ Face

6‧‧‧ annular protrusion

7‧‧‧End

8‧‧‧Outstanding end face

9‧‧‧The other end

10‧‧‧ outer perimeter

11‧‧‧ gas supply channel

12‧‧‧ Face

13‧‧‧ hole

14‧‧‧ outer perimeter

15‧‧‧Outer annular projection

16‧‧‧ inner circumference

17‧‧‧Inside annular projection

18‧‧‧Cylinder outer wall

19‧‧‧Front-cone outer wall

20‧‧‧Cylinder outer wall

22‧‧‧Cylinder inner wall

23‧‧‧Front-cone inner wall

24‧‧‧Cylinder inner wall

31‧‧‧ openings

32‧‧‧Round recess

33‧‧‧ gas supply port

35‧‧‧Outer cylinder inner wall

36‧‧‧ inner cylinder inner wall

37‧‧‧ bottom wall

41‧‧‧ Face

42‧‧‧ annular recess

43‧‧‧ Face

44‧‧‧ annular groove

45‧‧‧End

46‧‧‧The other end

47‧‧‧Air venting holes

48‧‧‧ outer perimeter

49‧‧‧ annular surface

50‧‧‧Cylinder

51‧‧‧ top surface

52‧‧‧Outer inner peripheral surface

53‧‧‧ inside inner circumference

61‧‧‧Front-cone outer wall

62‧‧‧ gap

63‧‧‧ step wall

64‧‧‧Open end

65‧‧‧ Periphery

66‧‧‧Outer cylinder inner wall

71‧‧‧ frustoconical inner wall

72‧‧‧ gap

73‧‧‧ step wall

75‧‧‧ Periphery

76‧‧‧ inner cylinder inner wall

81‧‧‧Assembly

85‧‧‧ Periphery

86‧‧‧Outer frustoconical inner wall

87‧‧‧ Periphery

88‧‧‧Internal frustoconical inner wall

91‧‧‧ Large diameter annular groove

92‧‧‧radial grooves

93‧‧‧ Small diameter annular groove

94‧‧‧radial grooves

D‧‧‧depth

D1‧‧‧Diameter of the outer cylinder inner wall surface 66

D1‧‧‧Diameter of the outer wall 20 of the cylinder

D2‧‧‧Diameter of inner cylinder inner wall surface 76

D2‧‧‧Diameter of the outer wall 18 of the cylinder

D3‧‧‧Diameter of the inner wall 22 of the cylinder

D4‧‧‧Diameter of the inner wall 23 of the cylinder

W‧‧‧Width

X‧‧‧ axial weld allowance

Y‧‧‧welding margin in the direction of entry

Fig. 1 is a plan view showing a preferred embodiment of the embodiment of the present invention.

Fig. 2 is a cross-sectional explanatory view taken along line II-II of Fig. 1.

Figure 3 is a partially enlarged cross-sectional explanatory view of Figure 2.

Figure 4 is a cross-sectional perspective view of Figure 2.

Figure 5 is a top plan view of the bearing base.

Fig. 6 is a cross-sectional explanatory view taken along line VI-VI of Fig. 5;

Figure 7 is a partially enlarged cross-sectional explanatory view of Figure 6.

Figure 8 is a partially enlarged cross-sectional explanatory view of Figure 6.

Fig. 9 is a bottom view of the bearing body.

Fig. 10 is a cross-sectional explanatory view taken along line X-X of Fig. 9.

Fig. 11 is a plan explanatory view of an assembly of a bearing body and a bearing base.

Fig. 12 is a cross-sectional explanatory view taken along line XII-XII of Fig. 11;

Figure 13 is a partially enlarged cross-sectional explanatory view of Figure 12.

Fig. 14 is a cross-sectional explanatory view showing another embodiment of the bearing body.

Fig. 15 is a cross-sectional explanatory view showing another preferred embodiment of the embodiment of the present invention.

Figure 16 is a partially enlarged cross-sectional explanatory view of Figure 15.

Fig. 17 is a plan explanatory view showing another embodiment of the bearing body.

1‧‧‧Static gas bearing

3‧‧‧ bearing body

43‧‧‧ Face

44‧‧‧ annular groove

47‧‧‧Air venting holes

Claims (8)

A static pressure gas bearing comprising: a bearing base made of synthetic resin and a bearing body made of synthetic resin, the bearing base having: a base; an annular projection integrally protruding from one side of the base; and The protruding end surface of the annular protruding portion is open, and the other end is open to the outer peripheral surface of the base portion, and is provided at the annular protruding portion and the air supply passage of the base portion; the bearing body is formed on one surface facing the base portion, And an annular recess for receiving the annular protrusion of the bearing base; an annular groove that opens on the other side; and a self-forming orifice that communicates with the annular groove at one end and opens at the other end of the annular recess a plurality of air ejection holes; and the bearing body is welded to the outer circumferential surface and the inner circumferential surface of the outer circumferential surface of the bearing body defining the annular recess, and is welded to the outer circumferential surface and the inner circumferential surface of the annular projection, and the bearing The base body is integrated; the annular groove has a width of at least 0.3 mm and a depth of at least 0.01 mm; the air ejection hole has a diameter of at least 30 μm at one end thereof; and a self-formed section is formed between the annular recess and the annular groove a flow hole; the outer peripheral surface of the annular projection of the bearing base includes: a cylindrical outer wall surface; and an annular frustoconical outer wall surface continuous with the outer wall surface of the cylinder and gradually increasing in diameter from the outer wall of the cylinder; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical portion and connected to one surface of the base portion and having a larger diameter than the outer wall surface of the cylinder; the inner circumferential surface of the annular protruding portion of the bearing base body has a cylindrical inner wall surface; The inner wall surface of the cylinder is continuous and gradually reduces the diameter of the annular frustoconical inner wall surface from the inner wall of the cylinder; and is continuous with the inner wall surface of the frustoconical cone and is connected to one side of the base portion, and is relatively cylindrical Inner wall surface of a smaller diameter inner wall; and the specification of the bearing body The inner peripheral surface on the outer side of the annular recessed portion is provided with an outer cylindrical inner wall surface having an annular outer periphery defining an outer edge of the open end of the annular recessed portion; and the inner peripheral surface of the inner peripheral surface defining the annular recessed portion of the bearing body is provided An inner cylindrical inner wall surface defining an annular outer periphery of an inner edge of the open end of the annular recess; the bearing body fitting the outer cylindrical inner wall surface to a cylindrical outer wall surface of the outer circumferential surface of the annular protruding portion, The inner cylinder inner wall surface is fitted to the cylindrical inner wall surface of the inner circumferential surface of the annular projecting portion, and the annular outer peripheral edge of the outer cylindrical outer wall surface defining the outer end of the annular recessed portion is in contact with the ring. a frustoconical outer wall surface of the outer peripheral surface of the protruding portion, such that a circumferential periphery of an inner cylindrical inner wall surface defining an inner edge of the open end of the annular concave portion contacts a truncated cone of an inner circumferential surface of the annular protruding portion The inner wall surface; the bearing body is welded and joined to the bearing base body by ultrasonic welding at the portions in contact with each other. A static pressure gas bearing comprising: a bearing base made of synthetic resin and a bearing body made of synthetic resin, the bearing base having: a base; an annular projection integrally protruding from one side of the base; and The protruding end surface of the annular protruding portion is open, and the other end is open to the outer peripheral surface of the base portion, and is provided at the annular protruding portion and the air supply passage of the base portion; the bearing body is formed on one surface facing the base portion, And an annular recess for receiving the annular protrusion of the bearing base; an annular groove that opens on the other side; and a self-forming orifice that communicates with the annular groove at one end and opens at the other end of the annular recess a plurality of air ejection holes, wherein the bearing body is welded to the outer circumferential surface and the inner circumferential surface of the annular protruding portion, and is welded and joined to the outer circumferential surface and the inner circumferential surface of the annular protruding portion. And integrating 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; the air ejection hole has a diameter of at least 30 μm at one end thereof; and is formed between the annular recess and the annular groove Self-forming orifice; the outer peripheral surface of the annular projection of the bearing base includes: a cylindrical outer wall surface; and a circular frustocone which is continuous with the outer wall surface of the cylinder and gradually increases in diameter from the outer wall of the cylinder a wall surface; and a cylindrical outer wall surface continuous with the outer surface of the frustoconical portion and connected to one side of the base portion and having a larger diameter than the outer wall surface of the cylinder; the inner circumferential surface of the annular protruding portion of the bearing base body is provided in the cylinder a wall-shaped frustoconical inner wall surface continuous with the inner wall surface of the cylinder and gradually decreasing in diameter from the inner wall of the cylinder; and continuous with the inner wall surface of the frustoconical cone and connected to one side of the base portion, and a cylindrical inner wall surface having a smaller diameter than the inner wall surface of the cylinder; and the inner circumferential surface of the outer side of the annular concave portion of the bearing body is provided with: an outer cylindrical inner wall surface; and a diameter gradually increasing from the outer cylindrical inner wall surface, and Having the opening of the annular recess An outer frustoconical inner wall surface of the outer circumference of the annular outer edge; the inner circumferential surface of the inner annular surface of the annular concave portion is provided with an inner cylindrical inner wall surface; and the inner cylindrical inner wall surface is gradually reduced An inner frustoconical inner wall surface having a diameter and a circumferential periphery defining an inner edge of the open end of the annular recess; the bearing body respectively fitting the outer cylindrical inner wall surface to the outer circumference of the annular projection The inner wall surface of the cylinder is such that the inner wall surface of the inner cylinder is fitted to the inner wall surface of the inner circumferential surface of the annular projecting portion, and the inner wall surface of the outer frustoconical shape is respectively brought into contact with the outer wall surface of the truncated cone, so that the inner frustoconical inner surface The wall surface is in contact with the inner wall surface of the truncated cone; the bearing body is welded and joined by ultrasonic welding at the mutually contacting portions, and the shaft The base body is integrated. The static pressure gas bearing of claim 1 or 2, wherein 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, and the air ejection hole is at one end thereof. It has a diameter of 30 to 120 μm. A static pressure gas bearing according to claim 1 or 2, wherein each of the annular groove and the air ejection hole is formed by laser processing. The static pressure gas bearing of claim 1 or 2, wherein the bearing body has, in addition to the annular groove, a large diameter ring formed on one side thereof and surrounding the annular groove on the outer side of the annular groove a plurality of first radial grooves having one end opening in the annular groove and the other end opening in the large diameter annular groove; and a small diameter annular concave formed on the inner side of the annular groove a groove; and a plurality of second radial grooves having one end opening in the annular groove and the other end opening in the small-diameter annular groove. A method for manufacturing a static pressure gas bearing, comprising: (a) preparing a synthetic resin-made bearing base, the bearing base comprising: a base; an annular projection integrally protruding from one side of the base; and at one end a protruding end surface of the annular protruding portion is open, and the other end is open to the outer peripheral surface of the base portion, and is provided in the annular protruding portion and the air supply passage of the base portion; the outer peripheral surface of the annular protruding portion is provided with a cylindrical outer wall surface; An annular frustoconical outer wall surface continuous with the outer wall surface of the cylinder and gradually increasing in diameter from the outer wall of the cylinder; and continuous with the outer wall surface of the frustoconical cone and connected to one side of the base portion a cylindrical outer wall surface having a larger outer diameter; the inner circumferential surface of the annular projection has a cylindrical inner wall surface; and is continuous with the inner wall surface of the cylinder And an annular frustoconical inner wall surface which gradually decreases in diameter from the inner wall of the cylinder; and is continuous with the inner wall surface of the truncated cone and is connected to one side of the base portion, and has a smaller diameter than the inner wall surface of the cylinder (b) a step of preparing a synthetic resin bearing body, the bearing body having: an annular recess formed on one side; an annular groove opening on the other side; and communicating with the annular groove at one end And a plurality of air ejection holes that are open at the other end in the annular recess; and the outer peripheral surface of the outer side of the annular recess is defined to have an outer cylinder having a circumferential periphery defining an outer edge of the open end of the annular recess An inner wall surface; the inner inner circumferential surface of the annular recessed portion is provided with an inner cylindrical inner wall surface having an annular outer periphery defining an inner edge of the open end of the annular concave portion; (c) one surface of the bearing body faces the base portion And the annular protruding portion of the bearing base is received in the annular concave portion of the bearing body, and the annular peripheral edge of the outer cylindrical inner wall surface defining the outer edge of the open end of the annular concave portion is in contact with the annular protruding portion Frustum outer wall surface of outer peripheral surface The annular peripheral edge of the inner cylindrical inner wall surface defining the inner edge of the open end of the annular recess is brought into contact with the frustoconical inner wall surface of the inner peripheral surface of the annular projecting portion, thereby forming the assembly of the bearing body and the bearing base. Step of the body; (d) pressing the welding head against the bearing body in the assembly, the welding condition of the pressing force of 0.098 to 0.60 MPa, the vibration amplitude of 20 to 80 μm, the vibration time of 0.1 to 1.5 seconds, and the holding time of 0.5 to 1.0 second Ultrasonic vibration is applied to the step of welding the bearing body to the bearing base at the contact portion; (e) irradiating the other side of the bearing body welded to the bearing base to form a laser having a width of at least 0.3 mm An annular groove having a depth of at least 0.01 mm, and communicating with the annular groove at one end and opening the annular recess at the other end A plurality of air ejection holes having a diameter of at least 30 μm at one end as a self-forming orifice. A method for manufacturing a static pressure gas bearing, comprising: (a) preparing a synthetic resin-made bearing base, the bearing base comprising: a base; an annular projection integrally protruding from one side of the base; and at one end a protruding end surface of the annular protruding portion is open, and the other end is open to the outer peripheral surface of the base portion, and is provided in the annular protruding portion and the air supply passage of the base portion; the outer peripheral surface of the annular protruding portion is provided with a cylindrical outer wall surface; An annular frustoconical outer wall surface continuous with the outer wall surface of the cylinder and gradually increasing in diameter from the outer wall of the cylinder; and the outer wall surface of the frustoconical body is continuous with one side of the base portion and is relatively cylindrical a cylindrical outer wall surface having a larger outer wall surface; the inner circumferential surface of the annular protruding portion includes: a cylindrical inner wall surface; and an annular shape which is continuous with the inner wall surface of the cylinder and gradually decreases in diameter from the inner wall surface of the cylinder a frustoconical inner wall surface; and a cylindrical inner wall surface continuous with the inner surface of the frustoconical cone and connected to one side of the base portion and having a smaller diameter than the inner wall surface of the cylinder; (b) a step of preparing a synthetic resin bearing body , the bearing body has: shape An annular recess on one side; an annular groove opening on the other side; and a plurality of air ejection holes communicating with the annular groove at one end and opening at the other end of the annular recess; and defining the annular recess The outer inner peripheral surface includes: an outer cylindrical inner wall surface; and an outer frustoconical inner wall surface that gradually enlarges the diameter from the outer cylinder inner wall surface and has an annular outer periphery defining an outer edge of the annular end of the annular recess; The inner circumferential surface of the annular recessed portion is provided with an inner cylindrical inner wall surface, a ring-shaped diameter that gradually decreases in diameter from the inner cylindrical inner wall surface, and an inner edge that defines an open end of the annular concave portion. (c) one side of the bearing body faces the one surface of the base, and the annular protrusion of the bearing base is received in the annular recess of the bearing body, respectively contacting the inner frustoconical inner wall surface a frustoconical outer wall surface, the inner frustoconical inner wall surface contacting the inner wall surface of the frustoconical shape to form an assembly of the bearing body and the bearing base; (d) the bearing body pressing the welding head against the assembly body Ultrasonic vibration is applied under the welding condition of a pressure of 0.098 to 0.60 MPa, a vibration amplitude of 20 to 80 μm, a vibration time of 0.1 to 1.5 seconds, and a holding time of 0.5 to 1.0 seconds, and the bearing body is welded and joined to the bearing base at the contact portion. a step of (e) illuminating the other side of the bearing body welded to the bearing base to form an annular groove having a width of at least 0.3 mm and a depth of at least 0.01 mm, and an annular groove at one end A plurality of air ejection holes that are open at the other end and open at the annular recess and have a diameter of at least 30 μm at one end serve as a self-forming orifice. The method of manufacturing a static pressure gas bearing according to claim 6 or 7, comprising the steps of: illuminating the other side of the bearing body welded to the bearing base to form an annular groove having at least 0.3 mm; Or a width of 0.3 to 1.0 mm and a depth of at least 0.01 mm or 0.01 to 0.1 mm; and a plurality of air ejection holes which are connected at one end to the annular groove and at the other end to the annular recess and at one end It has a diameter of at least 30 μm or 30 to 120 μm.