TWI513918B - Static pressure gas bearings and the use of the static pressure gas bearing linear motion guide device - Google Patents

Description

Hydrostatic gas bearing and linear motion guiding device using the same

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

In a precision working machine or a semiconductor exposure apparatus, it is required to accurately position a workpiece such as a processing tool or a substrate. Therefore, a linear motion guiding device using a static pressure gas bearing which is almost free from friction with a positioning device of a mounting table of a workpiece is used. In the linear motion guiding device, a lubricating film of compressed air is present between the movable pedestal of the mounting table as the workpiece and the guide rail as the guiding member, and the movable pedestal is configured to move the guide rail non-contact.

The throttling form of the air ejection port of the static pressure gas bearing used in the linear motion guiding device includes a porous throttling, a surface throttling, an orifice throttling, a self-throttle, and the like, and has such a throttling form. The static pressure gas bearing is used while adjusting the load capacity and bearing rigidity for each application.

For example, Patent Document 1 proposes a static pressure gas bearing pad which is fixed to either a supported body or a support, and which supports the support body by freely pressurized air supplied to the bearing surface via the bearing member. Among them, as the bearing member, a carbon graphite-based material in which the diameter of the material particles is substantially uniform and the uniformity of the open pores can be obtained is used.

Further, Patent Document 2 proposes a static pressure gas bearing which includes a base material including a porous body and which is bonded to the base material and adjusts a diameter of the through hole so as to have a predetermined air permeability. The surface throttling layer of the porous plate produced by distribution, via the table The surface throttling layer ejects gas and supports the supported body by its static pressure.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 63-231020

[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 pressure gas bearing can realize ultra-low friction, ultra-high precision and ultra-high-speed motion, high-strength metal or ceramic is mainly used as a bearing material, and it is necessary to implement high precision on a bearing surface containing the bearing material. There is a problem that the grinding process and the like are inevitably expensive.

However, even if it is not required to perform the above-described ultra-low friction, ultra-high-precision, and ultra-high-speed motion, for example, a static-pressure gas bearing is used for the purpose of non-contact conveying of a liquid crystal screen or the like, or for horizontally moving the article without causing temperature change. Although it has the advantages of simplification of the device configuration, on the contrary, since the static pressure gas bearing itself is expensive, the actual situation has not been widely used for this purpose.

In view of the above, in order to provide a low-cost static-pressure gas bearing that can be utilized in various fields, the applicant has originally proposed a static-pressure gas bearing (Patent Document 3) which integrates a synthetic resin bearing member with a bearing base. The bearing member is a plurality of air ejection ports having a self-throttle shape or an orifice throttling shape on the upper surface, and has an air supply groove communicating with the plurality of air ejection ports on the lower surface, the bearing base The system is joined to the lower surface of the bearing member in such a manner as to cover the aforementioned air supply groove, and has a gas supply port communicating with the air supply groove.

According to the static pressure gas bearing described in Patent Document 3, a synthetic resin bearing member constituting a static pressure gas bearing can be formed by injection molding using a mold, and no machining is required. Further, the structure of the bearing base can be assembled only by the air supply port that communicates with the bearing body, and the static pressure gas bearing can be assembled only by joining the bearing body and the bearing base, and can be mass-produced at low cost.

However, since the air discharge port of the static pressure gas bearing described in Patent Document 3 is formed by injection molding using a mold, it has a self-forming throttle or orifice throttle shape having a large diameter of about 0.2 to 0.4 mm. Since the amount of air blown from the air ejection port is too large, self-excited vibration is generated, and the supported body is unstable by the static pressure gas bearing, and improvement is still required in practical use.

The present invention has been made in view of the above points, and an object thereof is to provide a low-cost static pressure gas bearing capable of stably supporting a supported body without generating self-excited vibration, and a linear motion guiding device using the static pressure gas bearing.

The static pressure gas bearing of the present invention includes: a synthetic resin bearing body having an annular recess formed on one surface thereof on one surface, and an annular groove formed on the other surface and having the other surface opened thereon, and having a plurality of air ejection holes having one end open in the annular groove and the other end opening in the annular concave portion as a self-throttle; the bearing base having one end open on one side facing the bearing body and The one end is connected to the annular recess, and the other end is supplied with a gas supply passage and integrated with the bearing body; and a self-excited vibration damping mechanism; the self-excited vibration damping mechanism is formed on the bearing body or the bearing base The air chamber has at least one orifice open at one end of the other side of the bearing body and open at the other end to the air chamber.

According to the static pressure gas bearing of the present invention, the self-excited vibration damping mechanism having the air chamber and the at least one orifice opening at the center of the other end of the bearing body and the other end opening in the air chamber can suppress the self-excited vibration. Produced, so support for the supported body can be stabilized.

In a preferred embodiment of the present invention, the annular recessed portion is defined by the outer surface of the inner side small diameter of the annular shape, and the outer diameter of the inner side of the outer diameter of the inner small diameter The circumferential surface and the inner peripheral edge are connected to the lower edge of the outer peripheral surface of the inner small diameter, and the outer peripheral edge is connected to the upper edge of the inner large diameter outer peripheral surface. At this time, the static pressure gas bearing of the present invention can be further An annular seal member that is disposed in an annular recess and that is in elastic contact with one of the bearing bases in contact with the inner large-diameter outer peripheral surface and the annular step, and that is provided with the annular seal member for high airtightness The bearing body and the bearing body are integrated.

The annular recess can also be defined by a frustoconical surface that is gradually enlarged from one of the bearing bodies facing the other.

In the static pressure gas bearing of the present invention, the annular groove preferably has a width of at least 0.3 mm, more preferably a width of 0.3 to 0.1 mm, preferably a depth of at least 0.01 mm, more preferably 0.01~. At a depth of 0.05 mm, the air ejection hole preferably has a diameter of at least 30 μm at one end, more preferably 30 to 120 μm, and may form a self-throttle between the annular recess and the annular groove.

In the static pressure gas bearing of the present invention, the air chamber may be formed on the bearing body or may be formed on the bearing base. In the preferred embodiment, the air chamber is provided on one side of the bearing body and formed on the bearing body. a recess, the opening on one side of the bearing body of the recess is closed on one side of the bearing base facing one side of the bearing body. In this case, the recess may also be a truncated cone which gradually enlarges from the other side of the bearing body Formed into a mortar shape.

The at least one orifice preferably has a diameter of 0.8 to 1.2 mm, more preferably has a diameter of 1 mm, and in the case where the self-excited vibration damping mechanism has a plurality of orifices, each of the plurality of orifices may also have The diameter of 50 to 65 μm, and the self-excited vibration damping mechanism may have at least one orifice having a diameter of 0.8 to 1.2 mm and at least one orifice having a diameter of 50 to 65 μm.

The annular groove, the air ejection hole, and the orifice are preferably formed by laser processing using processing lasers selected from carbon dioxide gas lasers, YAG lasers, UV lasers, and excimer lasers.

When the annular grooves, the air ejection holes, and the plurality of orifices are formed by laser processing, they can be formed instantaneously compared with machining such as cutting, and can be produced not only in large quantities but also at low cost.

In the static pressure gas bearing of the present invention, the bearing body may further include: a large-diameter annular groove formed on the other surface, and surrounding the annular groove on the outer side of the annular groove; a radial groove having one end open at the annular groove and the other end opening in the large-diameter annular groove; a small-diameter annular groove formed on the other side and inside the annular groove Surrounded by the annular groove; a plurality of second radial grooves, one end of which is open in the annular groove, and the other end is open in the small-diameter annular groove; the first radial groove and the second Radial grooves can also each be formed by laser processing.

The static pressure gas bearing of the present invention may further include a spherical body receiving mechanism provided on the bearing base and having a spherical receiving concave portion, and the spherical receiving mechanism may have a frustoconical opening formed on the other side of the bearing base and formed on the bearing base. The concave portion or the hemispherical concave portion may be a spherical body receiving portion, or may have a cylindrical concave portion that is opened on the other surface of the bearing base and formed in the bearing base body, and has a frustoconical concave portion that is open on one surface as a spherical body receiving concave portion, and is fitted a wedge fixed to the cylindrical recess; or a cylindrical recess formed on the other surface of the bearing base and formed on the bearing base, and a hemispherical recess opened on one side as a spherical receiving recess and fitted and fixed to the cylindrical recess wedge.

In the static pressure gas bearing including the spherical body receiving mechanism, for example, the ball of the ball screw can be slidably connected to the bearing base or the wedge, and disposed in the spherical receiving concave portion, and the automatic rotation of the spherical body is added to the static pressure gas bearing at this time. Core function.

The static pressure gas bearing to which the automatic aligning function is added is preferably used as a linear motion guiding device for a positioning device of a mounting table of a workpiece.

A linear motion guiding device including a static pressure gas bearing according to the present invention includes: a guiding member having an upper surface guiding surface and both side guiding surfaces; and a movable pedestal disposed on an outer side of the guiding member and having an upper surface guiding surface One pair of upper plate and facing side guide faces a side plate; a ball screw, the ball body facing the guiding member being erected on at least one of a lower surface of the movable pedestal upper plate and each of the inner surfaces of the pair of side plates; the static pressure gas bearing disposed on the ball snail a spherical body facing the at least one surface upper surface guiding surface and the two side guiding surfaces, and having a spherical receiving mechanism; the static pressure gas bearing disposed on the lower surface of the movable pedestal above the at least one surface And the inner surface of the pair of side plates and the lower surface of the upper surface of the movable pedestal facing the at least one surface and the upper surface of the inner surface of the pair of side plates and the guiding surfaces of the two sides, and do not necessarily have a spherical receiving mechanism The ball body of the ball screw is swayed by the ball base as a center of the ball bearing body of the static pressure gas bearing having the ball receiving mechanism, and is accommodated in each ball receiving portion of the ball receiving mechanism of the static pressure gas bearing The bearing base of the at least one static gas bearing of the static pressure gas bearing that does not necessarily have the ball receiving mechanism is fixed on the movable pedestal other than the at least one surface. And each of the inner surfaces of the pair of side plates.

According to the linear motion guiding device of the present invention, the compressed air is ejected from the plurality of air ejection holes of the bearing body to the guiding surface of the guiding member, and the lubricating film formed of the air between the one surface of the bearing body and the guiding surface can be used. The movable pedestal maintains a non-contact state with respect to the guide surface. At this time, the static pressure gas bearing communicates with the air chamber between the one surface of the bearing body and the guide surface via the orifice to exhibit vibration damping, thereby suppressing the occurrence of self-excited vibration. Further, even if the bearing gap between the one surface of the bearing body and the guide surface (about several μm to several tens of μm) is uneven, a pressure difference is generated in the bearing gap, and the bearing body is automatically aligned to the bearing by the pressure difference. The gap is in a uniform direction and maintains a state parallel to the guiding surface. Therefore, the accuracy of the parts such as the parallelism and the straight angle of the guiding member and the movable pedestal can be made coarser, and the low-pressure static gas bearing itself can be provided. Low-cost linear motion guides are available.

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 base is composed of a polyacetal resin and a polyamide resin. , thermoplastic synthetic resin such as polyphenylene sulfide resin, and the like The thermoplastic synthetic resin containing 30 to 50% by mass of glass fiber, glass powder, carbon fiber or inorganic filler is preferably formed of a reinforced filler-containing thermoplastic synthetic resin or aluminum or an aluminum alloy. The synthetic resin bearing body and the bearing base 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 a static pressure gas bearing which can suppress the generation of self-excited vibration and which can be mass-produced and inexpensive, and a linear motion guiding device using the static pressure gas bearing.

1‧‧‧Static gas bearing

2‧‧‧ bearing body

2a‧‧‧ bearing material

3‧‧‧ fastening members

4‧‧‧ bearing base

5‧‧‧Aperture sealing member

6‧‧‧Self-excited vibration attenuation mechanism

11‧‧‧ Face

12‧‧‧Round recess

13‧‧‧ Face

14‧‧‧ annular groove

15‧‧‧End

16‧‧‧The other end

17‧‧‧Air venting holes

18‧‧‧Female threaded holes

21‧‧‧Circular inner diameter outer peripheral surface

22‧‧‧Circular inner large diameter outer peripheral surface

23‧‧‧Circular step surface

24‧‧‧ top

25‧‧‧Frustum

26‧‧‧Rings

27‧‧‧ring face

28‧‧‧Cylinder

31‧‧‧End

32‧‧‧ Face

33‧‧‧The other end

34‧‧‧ outer perimeter

35‧‧‧ gas supply path

36‧‧‧End

37‧‧‧The other end

38‧‧‧The other side

39‧‧‧Bolt insertion hole

41‧‧‧ longitudinal air supply hole

42‧‧‧End

43‧‧‧Horizontal air supply holes

44‧‧‧Female thread

46‧‧‧Ring step

51‧‧‧Air room

52‧‧‧End

53‧‧‧The other end

54‧‧‧ orifice

55‧‧‧ recess

56‧‧‧round top

57‧‧‧Frustum

61‧‧‧Assembly

65‧‧‧ Large diameter annular groove

66‧‧‧One end

67‧‧‧Other end

68‧‧‧ Radial grooves

69‧‧‧Small diameter annular groove

70‧‧‧ one end

71‧‧‧Other end

72‧‧‧radial grooves

75‧‧‧Frustum conical recess

76‧‧‧Sphere receiving mechanism

81‧‧‧round top

82‧‧‧Frustum

85‧‧‧ Ball screw

86‧‧‧ sphere

90‧‧‧ concave spherical

91‧‧‧hemispherical recess

95‧‧‧Cylindrical recess

96‧‧‧ side

97‧‧‧Frustum conical recess

98‧‧‧The other side

99‧‧‧Cylindrical recess

100‧‧‧ wedge

101‧‧‧round top

102‧‧‧Cylindrical surface

103‧‧‧Frustum

104‧‧‧End

105‧‧‧The other end

106‧‧‧Cylindrical outer surface

110‧‧‧hemispherical recess

111‧‧‧ concave spherical surface

120‧‧‧Line motion guide

121‧‧‧Upper surface guide surface

122‧‧‧Lead side guides

123‧‧‧Guiding components

124‧‧‧Upper board

125‧‧‧ side panels

126‧‧‧ cross section Glyph movable pedestal

127‧‧‧ lower surface

128‧‧‧ inside

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 the example shown in Fig. 1.

Fig. 3 is a bottom view showing an example of Fig. 1.

Figure 4 is a bottom plan view of the bearing body shown in Figure 2.

Fig. 5 is a cross-sectional explanatory view of the V-V line of the bearing body shown in Fig. 4.

Fig. 6 is a partially enlarged cross-sectional explanatory view showing a bearing body shown in Fig. 2;

Figure 7 is a bottom plan view of the bearing base shown in Figure 2.

Fig. 8 is a cross-sectional explanatory view taken along the line VIII-VIII of the bearing base shown in Fig. 7.

Fig. 9 is a cross-sectional explanatory view for explaining an assembly of a bearing body material and a bearing base body in the manufacturing method of the example shown in Fig. 1.

Fig. 10 is a plan explanatory view showing another preferred embodiment of the embodiment of the present invention.

Fig. 11 is a cross-sectional explanatory view taken along the line XI-XI of the example shown in Fig. 10.

Fig. 12 is a cross-sectional explanatory view for explaining an assembly of a bearing body material and a bearing base body in the manufacturing method of the example shown in Fig. 10.

Fig. 13 is a plan view showing a preferred embodiment of the embodiment of the present invention.

Fig. 14 is a bottom plan view showing a preferred embodiment of another embodiment of the bearing base.

Fig. 15 is a cross-sectional explanatory view showing the XV-XV line of the bearing base of the example shown in Fig. 14.

Figure 16 is a view showing an embodiment of the present invention in which the automatic aligning function is added to the example shown in Figure 14; Sectional illustration.

Fig. 17 is a bottom plan view showing a preferred embodiment of the bearing base and further embodiments.

Fig. 18 is a cross-sectional explanatory view showing the XVIII-XVIII line of the bearing base of the example shown in Fig. 17.

Fig. 19 is a cross-sectional explanatory view showing an embodiment of the present invention in which the automatic aligning function is added to the example shown in Fig. 17.

Fig. 20 is a bottom plan view showing a preferred embodiment of the bearing base and further embodiments.

Fig. 21 is a cross-sectional explanatory view showing the XXI-XXI line of the bearing base of the embodiment shown in Fig. 20.

Figure 22 is a perspective view of the bearing base shown in Figure 20.

Fig. 23 is a cross-sectional explanatory view showing a preferred embodiment of the wedge embodiment.

Fig. 24 is a cross-sectional explanatory view showing a preferred example of a bearing base to which the wedge shown in Fig. 23 is fitted and fixed.

Fig. 25 is a cross-sectional explanatory view showing another preferred example of the static pressure gas bearing of the present invention in which the automatic aligning function is added as shown in Fig. 20.

Fig. 26 is a cross-sectional explanatory view showing a preferred embodiment of another embodiment of the wedge.

Fig. 27 is a cross-sectional explanatory view showing a preferred example of a bearing base to which the wedge shown in Fig. 26 is fitted and fixed.

Fig. 28 is a cross-sectional explanatory view showing another preferred example of the static pressure gas bearing of the present invention in which the automatic aligning function is added as shown in Fig. 27.

Fig. 29 is a cross-sectional explanatory view showing a preferred example of a linear motion guiding device using a static pressure gas bearing.

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

In the first embodiment, the static pressure gas bearing 1 includes a synthetic resin bearing body 2, a bearing base 4 integrally joined to the bearing body 2 by the fastening member 3, and a bearing body that prevents the compressed air (gas) from being integrally joined. 2 and the gap between the bearing base 4 is leaked out and mounted on the bearing body 2 The annular sealing member 5 and the self-excited vibration damping mechanism 6.

As shown in FIG. 4 to FIG. 6 , the bearing body 2 has an annular recess 12 formed on one surface 11 of the bearing body 2 having a circular shape in plan view, and is formed on the other side of the circular bearing body 2 in a plan view. 13 has an annular groove 14 formed on the surface 13 and has one end 15 open in the annular groove 14, and the other end 16 is formed in the annular recess 12 and arranged at equal intervals in the circumferential direction R. A plurality of air ejection holes 17 which are self-throttled, and a plurality of female screw holes 18 which are opened on the surface 11 and are arranged at equal intervals in the circumferential direction R.

The annular recessed portion 12 has an annular inner-diameter outer peripheral surface 21 of the bearing body 2 and an annular inner large-diameter outer peripheral surface 22 of the bearing body 2 which is expanded in diameter with respect to the inner small-diameter outer peripheral surface 21, and the inner peripheral edge is connected to the inner side. a ring-shaped step surface 23 of the bearing body 2 whose outer peripheral edge is connected to the upper edge of the inner large-diameter outer peripheral surface 22, and a bearing whose outer peripheral edge is connected to the upper edge of the inner small-diameter outer peripheral surface 21 The top surface 24 of the body 2 and the frustoconical surface 25 of the bearing body 2 whose upper edge is connected to the inner circumference of the top surface 24 and gradually expands from the surface 11 to the surface 13 and extends to the upper edge is defined by the ring The recessed portion 12 is defined by a frustoconical surface 25 which is formed by gradually expanding from the surface 11 to the surface 13 and can increase the annular recessed portion without forming the annular thin portion 26 formed between the surface 11 and the top surface 24 in the radial direction. Since the volume is 12, the bearing body 2 having the annular thin portion 26 is not deteriorated in strength.

As shown in FIG. 6, the annular groove 14 defined by the annular surface 27 of the bearing body 2 and one of the bearing bodies 2 facing each other has a width W of at least 0.3 mm, and at least 0.01 mm. The depth d, the one end 15 of the air ejection hole 17 has a diameter D of at least 30 μm from the one end 15 to the other end 16 in this example, and forms a self-throttle between the annular groove 14 and the annular recess 12.

In particular, as shown in FIGS. 7 and 8, the bearing base 4 is provided with an air supply passage 35 whose one end 31 opens in a circular circular surface 32 of the bearing base 4 facing the surface 11, and the one end 31 communicates with the annular recess 12, The other end 33 is open on the outer peripheral surface 34 of the bearing base 4, and the other end 33 is supplied with compressed air (gas); and a plurality of bolt insertion holes 39, one end 36 of which is on one side 32 is open, and the other end 37 is open on the other side 38 of the bearing base 4, and is formed at equal intervals along the circumferential direction R.

The air supply passage 35 is provided with a longitudinal air supply hole 41 having one end 31, a lateral air supply hole 43 communicating with the one end 42 and the longitudinal air supply hole 41, and having the other end 33, and a bearing base body 4 of the lateral air supply hole 43 on the other end 33 side. A female screw 44 that is screwed to a gas supply plug (not shown) is formed.

Each of the bolt insertion holes 39 is reduced in diameter at one end 36 side via the annular step portion 46, and is expanded in diameter at the other end 37 side, and a fastening member that is screwed to the female screw hole 18 is inserted into each of the bolt insertion holes 39. The hexagonal socket head bolt of 3, the bearing base 4 is integrally joined with the bearing body 2 by the hexagonal socket head bolt.

The O-ring as the annular sealing member 5 which is disposed in contact with the inner large-diameter outer peripheral surface 22 and the annular step surface 23 and has a pressing margin so as to protrude from the surface 11 is, for example, As shown in Fig. 2, it is pressed and elastically pressed into contact with the face 32 to seal the gap between the faces 11 and 32.

The self-excited vibration damping mechanism 6 includes an air chamber 51 formed by the interlocking of the bearing body 2 and the bearing base 4, and a section 1 mm in diameter with the one end 52 opened at the center of the surface 13 and the other end 53 opened at the air chamber 51. Flow hole 54.

The air chamber 51 is provided with a mortar-like recess 55 formed in the bearing body 2, and the opening of the surface 11 of the bearing body 2 of the recess 55 is closed by the surface 32 facing the surface 11.

The recess 55 opened in the central portion of the surface 11 is defined by a top surface 56 of the bearing body 2 which is circular in plan view, and a frustoconical surface 57 which is connected to the outer edge of the top surface 56 and which gradually expands from the surface 13 to the surface 11. In the form of a mortar, the other end 53 of the orifice 54 is opened to the recess 55 at the top surface 56, and communicates with the outside and the air chamber 51.

Next, an example of a method of manufacturing the static pressure gas bearing 1 shown in Figs. 1 to 8 will be described. First, the bearing body material 2a which is the same as the synthetic resin bearing body 2 shown in FIGS. 4 and 5 but does not have the annular groove 14 and the air ejection hole 17 is prepared, and the bearing shown in FIGS. 7 and 8 base As shown in FIG. 9, the body 4 is sandwiched by an O-ring as an annular seal member 5 disposed in the annular recess 12 so that the open end of the annular recess 12 of the bearing body material 2a and the longitudinal direction of the bearing base 4 are formed. One end 31 of the air supply hole 41 is aligned, and the open end of the female screw hole 18 of the bearing body material 2a is aligned with one end 36 of the bolt insertion hole 39 of the bearing base 4, and then inserted into the bolt insertion hole 39 as a fastening member. A hexagonal socket head bolt of 3, and a male screw portion of the hexagon socket head bolt is screwed and fixed to the female screw hole 18 of the bearing body material 2a, and an assembly body 61 for fastening and integrating the bearing base 4 and the bearing body material 2a is formed.

Next, the surface 13 of the bearing body material 2a of the assembly 61 shown in FIG. 9 is irradiated with a laser by a laser processing machine to form 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. 14. The diameter D of the annular thin portion 26 that penetrates the bearing body material 2a from the annular surface 27 of the predetermined annular groove 14 and the opening of the top surface 24 of the predetermined annular recess 12 is at least 30 μm, preferably 30. A plurality of self-throttled air ejection holes 17 of 120 μm are obtained, whereby the static pressure gas bearing 1 shown in Figs. 1 to 8 including the bearing body 2 and the bearing base 4 is obtained.

The processing laser used is selected from a carbonate gas laser, a YAG laser, a UV laser, and an excimer laser, and is preferably a carbon dioxide gas laser.

In the static pressure gas bearing 1 manufactured as described above, the bearing body 2 and the bearing base 4 are integrated by the hexagonal socket head bolt as the fastening member 3 via the O-ring as the annular sealing member 5, and thus the bearing body 2 is included. The gap between the joint faces of the faces 11 and 32 of the bearing base 4 is such that the annular recess 12, the air supply passage 35 and the air chamber 51 are strongly sealed, and the annular groove 14 formed on the surface 13 of the bearing body 2 and the plurality The air ejection holes 17 of the self-throttle shape are formed by laser processing, so that the manufacturing price thereof is remarkably lowered, and the self-excited vibration damping mechanism 6 can suppress the generation of self-excited vibration, so that the static pressure gas can be stably supported. The supported body of the bearing 1.

In the above example, the self-excited vibration damping mechanism 6 includes the air chamber 51 and one of the orifices 54, but instead of, as shown in Figs. 10 and 11, the air chamber 51 and the one end 52 are in the center of the surface 13 The portion and the central portion are open to the outside and open to the air chamber 51 at the other end 53 The plurality of, specifically, 4 to 24 orifices 54 each having a diameter of 50 μm to 65 μm.

As shown in Fig. 12, the bearing body material 2a and the bearing which are the same as the synthetic resin bearing body 2 shown in Figs. 4 and 5 but have no orifice 54 other than the annular groove 14 and the air ejection hole 17 are provided. The base 4 is fastened to the integrated assembly 61 by the fastening member 3, and when the annular groove 14 and the air ejection hole 17 are formed by the laser processing machine on the surface 13 of the bearing body material 2a, the orifices are formed. 54 can also be formed by the same laser processing machine.

The static pressure gas bearing 1 shown in Figs. 10 and 11 including the bearing body 2 having a plurality of orifices 54 and the bearing base 4 includes a gap between the bearing body 2 and the joint faces of the faces 11 and 32 of the bearing base 4. The annular recess 12, the air supply passage 35, and the air chamber 51 are also strongly sealed, and the manufacturing cost thereof is remarkably lowered, and the supported body using the static pressure gas bearing 1 can be stably supported.

The bearing body 2 of the static pressure gas bearing 1 is provided with an annular groove 14, but in addition to the annular groove 14, as shown in FIG. 13, it may be provided that the surface 13 is formed concentrically with the annular groove 14. And a large-diameter annular groove 65 surrounding the annular groove 14 outside the annular groove 14; one end portion 66 is open to the annular groove 14 and the other end portion 67 is opened at the large-diameter annular groove 65, along A plurality of radial grooves 68 formed in the surface 13 at equal intervals in the circumferential direction R; small diameter rings formed concentrically on the surface 13 and the annular groove 14 and surrounded by the annular groove 14 inside the annular groove 14 a groove 69; the one end portion 70 is open in the annular groove 14 and the other end portion 71 is opened in the small-diameter annular groove 69, and a plurality of radial grooves 72 formed in the face 13 are arranged at equal intervals along the circumferential direction R. .

When the annular groove 14 is formed by the laser processing machine, the large-diameter annular groove 65 and the small-diameter annular groove 69 and the radial grooves 68 and 72 can also be formed by the same laser processing machine.

In the static pressure gas bearing 1 having the bearing body 2 shown in Fig. 13, the air supplied to the annular groove 14 is also supplied to the large-diameter annular groove 65 and the small-diameter ring via the radial grooves 68 and 72. With the groove 69, for example, the supply area of the air to the supported body becomes large, and the supported body can be stably floated, and the gap between the bearing surface 2 and the joint faces of the faces 11 and 32 of the bearing base 4 is borrowed. The annular recessed portion 12, the air supply passage 35, and the air are formed by the annular seal member 5. The chamber 51 is strongly sealed, and if the annular groove 14, the radial grooves 68 and 72, and the large-diameter annular groove 65 and the small-diameter annular groove 69 are formed by the laser processing machine, the manufacturing price thereof can be It is remarkably lowered, and the supported body using the static pressure gas bearing 1 is stably supported by the self-excited vibration damping mechanism 6 having the orifice 54.

As shown in FIGS. 14 and 15 , the static pressure gas bearing 1 may further include a ball receiving mechanism 76 formed on the bearing base 4 on the surface 38 of the bearing base 4 and having a spherical receiving recess as the ball bearing body 4 . The mortar-shaped frustoconical recess 75 is open at the center of the face 38.

The frustoconical recess 75 is defined by a top surface 81 of the bearing base 4 that is circular in plan view and a frustoconical surface 82 that extends progressively from the top surface 81 to the surface 38.

As shown in FIG. 16, the spherical body 86 having the ball screw 85 having a smaller diameter than the opening diameter of the truncated conical recess 75 is slidably coupled to the frustoconical surface 82, and is disposed in the frustoconical recess 75. The static pressure gas bearing 1 having the ball receiving mechanism 76 is provided with an automatic core adjustment function.

The spherical body receiving mechanism 76 may have a hemispherical concave portion 91 as a spherical body receiving concave portion instead of the frustoconical concave portion 75. The hemispherical concave portion 91 is opened at a central portion of the surface 38 of the bearing base 4, and is formed therein. The face 38 of the bearing base 4 is defined by a concave spherical surface 90.

The static pressure gas bearing 1 having the spherical body receiving mechanism 76 having the hemispherical concave portion 91 as the spherical body receiving concave portion is also provided with the same diameter as the opening diameter of the hemispherical concave portion 91 or smaller than the opening diameter of the hemispherical concave portion 91 as shown in Fig. 19 . The ball 86 of the ball sill 85 is slidably attached to the concave spherical surface 90, and is disposed in the hemispherical recess 91, and an automatic aligning function is added.

The ball receiving mechanism 76 may also replace the frustoconical recess 75 or the hemispherical recess 91 having the surface 38 formed directly on the bearing base 4 as a spherical receiving recess, as shown in Figs. 20 to 24, having an opening 38 on the surface of the bearing base 4. a cylindrical recess 95 formed in the bearing base 4, and a frustoconical recess 97 having a spherical receiving recess opened on one surface 96 and a cylindrical recess 99 opening in the other surface 98 and fitted and fixed to the cylindrical recess 95 Wedge 100.

The cylindrical recess 95 is defined by a top surface 101 formed in a circular shape in the plan view of the bearing base 4, and a cylindrical surface 102 formed on the top surface 101 and formed on the bearing base 4, and a frustoconical recess 97 is formed on the wedge 100. Further, the frustoconical surface 103 which is enlarged in diameter from the surface 98 toward the surface 96 defines that the one end 104 of the cylindrical recess 99 is open at the surface 98, and the other end 105 communicates with the frustoconical recess 97, and has a cylindrical shape. The wedge 100 of the outer peripheral surface 106 is such that the outer peripheral surface 106 is in contact with the cylindrical surface 102, the surface 98 is in contact with the top surface 101, and the surface 96 and the surface 38 are fitted and fixed to the cylindrical recess 95.

As shown in Fig. 25, the hydrostatic gas bearing 1 having the frustoconical concave portion 97 formed in the wedge 100 as a spherical body receiving concave portion is provided, and has a smaller diameter than the opening diameter of the truncated conical concave portion 97 as described above. The ball 86 of the ball screw 85 is slidably coupled to the frustoconical surface 103 and disposed in the frustoconical recess 97, and an automatic core adjustment function is added.

The spherical body receiving mechanism 76 shown in Figs. 20 to 25 is an example in which the frustoconical concave portion 97 is provided as a spherical body receiving concave portion in the wedge 100. Alternatively, as shown in Figs. 26 and 27, the spherical body receiving portion 76 may be provided on the wedge 100. The hemispherical concave portion 110 serves as a spherical body receiving concave portion, and the hemispherical concave portion 110 is defined by a concave spherical surface 111 formed in the central portion of the surface 96 of the wedge 100 and formed in the wedge 100, as described above.

The cylindrical recess 95 having the surface 38 of the bearing base 4 and formed in the bearing base 4, and the wedge 100 having the hemispherical recess 110 opened on the surface 96 as a spherical receiving recess and fitted and fixed to the cylindrical recess 95 In the static pressure gas bearing 1 of the spherical body receiving mechanism 76, as shown above, as shown in Fig. 28, the ball screw having the same diameter as the opening diameter of the hemispherical concave portion 110 or the smaller diameter than the opening diameter of the hemispherical concave portion 110 is used. The ball 86 of the cymbal 85 is slidably coupled to the concave spherical surface 111 and disposed on the hemispherical recess 110, and an automatic aligning function is added.

Thus, by using the wedge 100 which is a separate body from the bearing base 4, a spherical receiving recess is provided on the wedge 100, and a thermoplastic material such as polyacetal resin or polyamide resin or polyester resin is used as a material having good slidability. Or a copper or copper composite or the like forms the wedge 100, and the frustoconical surface 103 of the wedge 100 or the concave spherical surface 111 and the spherical body 86 of the ball screw 85 can be used. The sliding is smoother.

The above automatic aligning function can also be added to the static pressure gas bearing 1 shown in FIG.

The static pressure gas bearing 1 can also be used for the linear motion guiding device 120 shown in FIG. 29, and the linear motion guiding device 120 shown in FIG. 29 is provided with a guiding member 123 having a surface guiding surface 121 as a guiding surface and two Side guiding surface 122; cross section a movable movable pedestal 126 disposed on the outer side of the guiding member 123 across the guiding member 123, and having an upper surface facing the upper surface guiding surface 121 and a pair of side guiding surfaces 122 facing the side plate 125; 85, which fixes the ball 86 toward the guiding member 123 and is fixed on at least one of the lower surface 127 of the upper plate 127 of the movable pedestal 126 and the inner surface 128 of the side plate 125, in this case, the inner faces of the side plates 125. 128; the static pressure gas bearing 1 shown in FIG. 25 is disposed between each of the spheres 86 of the ball screw 85 and the two side guide faces 122 facing the inner faces 128 of the at least one face, that is, the side plates 125. And the static pressure gas bearing 1 shown in FIG. 2 is disposed between the lower surface 127 of the upper plate 124 and the upper surface guiding surface 121 facing the lower surface 127.

In the linear motion guiding device 120, the ball 86 of each ball screw 85 slides freely with the ball screw 86 as the center of each of the bearing bases 4 of the static pressure gas bearing 1, and slides freely with the frustoconical surface 103. The ground contacts and is received in each of the frustoconical recesses 97 of the ball receiving mechanism 76.

The bearing base 4 of the static pressure gas bearing 1 shown in FIG. 2 disposed between the lower surface 127 of the upper plate 124 and the upper surface guiding surface 121 facing the lower surface 127 is fixed to the lower surface 127 of the upper plate 124 of the movable pedestal 126. on.

According to the linear motion guiding device 120, the compressed air supplied to each of the air supply passages 35 is ejected from the plurality of air ejection holes 17 of the bearing body 2 to the upper surface guiding surface 121 of the guiding member 123 and the both side guiding surfaces 122. The movable pedestal 126 can maintain the non-upper surface guiding surface 121 and the two side guiding surfaces 122 by the air lubricating film formed on the bearing gap between the surface 13 of the bearing body 2 and the upper surface guiding surface 121 and the both side guiding surfaces 122. Contact status. Then, if When the bearing gap between the surface 13 of the bearing body 2 and the two side guiding surfaces 122 is not uniform, a pressure difference is generated in each part of the bearing gap, but the static pressure gas bearing 1 can be automatically adjusted to a uniform bearing gap by the pressure difference. The direction is maintained in a state in which the guide faces 122 are parallel to each other. Therefore, the accuracy of the components such as the parallelism and the straight angle of the guiding member 123 and the movable pedestal 126 can be relatively coarse, and the low cost of the static pressure gas bearing 1 itself can be The production of the linear motion guiding device 120 is facilitated and the cost is reduced.

Then, according to the linear motion guiding device 120, the air pressure of the bearing gap between the surface 13 of the bearing body 2 and the upper surface guiding surface 121 and the both side guiding surfaces 122 can be transmitted to the air chamber 51 via the orifice 54, thereby suppressing The self-excited vibration of the static pressure gas bearing 1 can stably support the movable pedestal 126 as a supported body.

In the linear motion guiding device 120, as the static pressure gas bearing to which the automatic aligning function is added, the static pressure gas bearing 1 shown in Figs. 16, 19, and 28 can be used, irrespective of whether or not the automatic aligning function is added. The static pressure gas bearing 1 shown in Fig. 11 can also be used in the static pressure gas bearing.

1‧‧‧Static gas bearing

2‧‧‧ bearing body

3‧‧‧ fastening members

4‧‧‧ bearing base

5‧‧‧Aperture sealing member

6‧‧‧Self-excited vibration attenuation mechanism

11‧‧‧ Face

12‧‧‧Round recess

13‧‧‧ Face

14‧‧‧ annular groove

17‧‧‧Air venting holes

18‧‧‧Female threaded holes

21‧‧‧Circular inner diameter outer peripheral surface

22‧‧‧Circular inner large diameter outer peripheral surface

23‧‧‧Circular step surface

24‧‧‧ top

25‧‧‧Frustum

26‧‧‧Circular thin wall

31‧‧‧End

32‧‧‧ Face

33‧‧‧The other end

34‧‧‧ outer perimeter

35‧‧‧ gas supply path

38‧‧‧The other side

39‧‧‧Bolt insertion hole

41‧‧‧ longitudinal air supply hole

43‧‧‧Horizontal air supply holes

46‧‧‧Ring step

51‧‧‧Air room

54‧‧‧ orifice

55‧‧‧ recess

Claims (18)

A static pressure gas bearing comprising: a synthetic resin bearing body having an annular recess formed on one surface thereof on one surface, and an annular groove formed on the other surface and having one end on the other surface a plurality of air ejection holes that are open at the annular groove and open at the other end in the annular recess; the bearing base has one end open on one side facing the bearing body and The one end is in communication with the annular recess, and the other end is supplied with a gas supply passage and integrated with the bearing body; and a self-excited vibration damping mechanism; the self-excited vibration damping mechanism has air formed in the bearing body or the bearing base a chamber, and at least one orifice opening at one end of the other side of the bearing body and opening at the other end of the bearing chamber; wherein the air chamber is provided with a recess formed on one side of the bearing body and formed on the bearing body, the recess The opening on one side of the bearing body is closed by one side of the bearing base facing one side of the bearing body. The static pressure gas bearing according to claim 1, wherein the annular recess is defined by the following surface: an annular outer diameter outer peripheral surface, and an annular inner large diameter outer circumference which is expanded with respect to the inner small diameter outer circumferential surface. The surface and the inner peripheral edge are connected to the lower edge of the outer peripheral surface of the inner small diameter, and the outer peripheral edge is connected to the upper edge of the inner large diameter outer peripheral surface; the static pressure gas bearing is further provided with the inner large diameter outer peripheral surface and the circle An annular sealing member that is disposed in an annular recess and that is in elastic contact with one of the surfaces of the bearing base. A hydrostatic gas bearing according to claim 1 or 2, wherein the annular recess is defined by a frustoconical surface which is gradually enlarged from one of the bearing bodies facing the other surface. A static pressure gas bearing according to claim 1 or 2, wherein 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, and is annularly concave and annular Self-forming throttling is formed between the grooves. The static pressure gas bearing of claim 1 or 2, wherein the annular groove has a width of 0.3 to 1.0 mm and a depth of 0.01 to 0.05 mm; and the air ejection hole has a diameter of 30 to 120 μm at one end. A static pressure gas bearing according to claim 1 or 2, wherein the recess is formed in a mortar shape by a frustoconical surface which is gradually enlarged from the other surface of the bearing body. The static pressure gas bearing of claim 1 or 2, wherein at least one of the orifices has a diameter of 0.8 to 1.2 mm. The static pressure gas bearing of claim 1 or 2, wherein the self-excited vibration damping mechanism has a plurality of orifices, each of which has a diameter of 50 to 65 μm. The static pressure gas bearing according to claim 1 or 2, wherein the self-excited vibration damping mechanism has at least one orifice having a diameter of 0.8 to 1.2 mm and at least one orifice having a diameter of 50 to 65 μm. The static pressure gas bearing of claim 1 or 2, wherein the annular groove, the air ejection hole and the orifice are each formed by laser processing. The static pressure gas bearing of claim 1 or 2, wherein the bearing body further comprises: a large-diameter annular groove formed on the other surface, and surrounding the annular groove on an outer side of the annular groove; a first radial groove having one end opening in the annular groove and the other end opening in the large diameter annular groove; a small diameter annular groove formed on the other surface and in the annular groove The inner side is surrounded by the annular groove; and the plurality of second radial grooves have one end open in the annular groove and the other end open in the small-diameter annular groove. The static pressure gas bearing of claim 11, wherein the first radial groove and the second radial groove are each formed by laser processing. A static pressure gas bearing according to claim 1 or 2, further comprising a spherical body receiving mechanism provided on the bearing base and having a spherical receiving recess. A static pressure gas bearing according to claim 13, wherein the ball receiving mechanism has a frustoconical recess opened on the other side of the bearing base and formed in the bearing base as a spherical receiving recess. A static pressure gas bearing according to claim 13, wherein the ball receiving mechanism has a hemispherical recess opened on the other side of the bearing base and formed in the bearing base as a spherical receiving recess. The static pressure gas bearing according to claim 13, wherein the ball receiving mechanism includes a cylindrical recess formed on the other surface of the bearing base and formed in the bearing base, and a frustoconical recess opened on one side as a spherical receiving recess and fitting A wedge fixed to the cylindrical recess. The static pressure gas bearing according to claim 13, wherein the ball receiving mechanism includes a cylindrical recess opened on the other surface of the bearing base and formed on the bearing base, and a hemispherical recess opened on one side as a spherical receiving recess and fitted and fixed A wedge in a cylindrical recess. A linear motion guiding device includes: a guiding member having an upper surface guiding surface and two side guiding surfaces; and a movable pedestal disposed on an outer side of the guiding member and having an upper surface facing surface and a facing surface One side of the side guiding surface; a ball screw that is erected toward the guiding member on at least one of the lower surface of the movable pedestal upper surface and the inner surfaces of the pair of side plates; a static pressure gas bearing according to any one of the preceding claims, wherein the spherical ball body is disposed between the ball body of the ball screw and the surface guiding surface facing the at least one surface and the guiding surfaces of the two sides; and any one of claims 1 to 12 a static pressure gas bearing, which is disposed in the at least one The inner surface of the upper surface of the movable pedestal other than the surface and the inner surface of the pair of side plates and the upper surface of the lower surface of the movable pedestal facing the at least one surface and the upper surface of the inner surface of the pair of side plates and two Between the side guide surfaces; the ball spheroidal ball is swayed by the ball base as a center of the ball bearing body of the hydrostatic gas bearing according to any one of claims 13 to 17, and is accommodated in the request item 13 The spherical receiving portion of the spherical body receiving mechanism of the hydrostatic gas bearing of any one of the above-mentioned items, wherein the bearing base system of at least one of the static pressure gas bearings of any one of claims 1 to 12 is fixed to The lower surface of the movable pedestal other than the at least one surface and the inner surfaces of the pair of side plates.