Fluid bearing, device, stage, spindle, method of manufacturing fluid bearing, and method of manufacturing article

Abstract

To easily manufacture a fluid bearing.SOLUTION: A fluid bearing (101) includes a portion (10A) which has a bearing surface (10S) disposed to face a guide surface (20S) of a shaft (20) with a gap (AG) therebetween, and a hole (131) communicating with a fluid supply source (50) and opened to the bearing surface (10S). The portion (10A) includes a structure which is connected to a side surface (13S) constituting the hole (131) and fills at least a part of the hole (131).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fluid bearing, an apparatus, a stage, a spindle, a method for manufacturing a fluid bearing, and a method for manufacturing an article. [Background technology]

[0002] Conventionally, fluid bearings have been proposed in which a fluid is ejected between a guide surface and a bearing surface, and the ejected fluid applies pressure to lift the bearing body from the guide surface. Some such fluid bearings have a porous material disposed in the portion where the fluid is ejected toward the guide surface, which functions as a porous restrictor and increases the rigidity of the bearing (see, for example, Patent Documents 1 and 2). Patent Document 1 discloses manufacturing a ceramic having a porous portion by incorporating a porous foam in a ceramic molded body and firing the resulting body. Patent Document 2 also discloses using a metal powder sintering 3D printer to manufacture a porous layer integrally formed on the side that becomes the bearing surface, with the porous layer support portion having a plurality of flow holes formed therein. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 06-297421 [Patent Document 2] Japanese Patent Application Publication No. 2019-190591 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the process for producing the porous material in the above-mentioned Patent Document 1 is complicated, and it is desirable to produce a fluid bearing more simply. On the other hand, the above-mentioned Patent Document 2 attempts to easily produce a fluid bearing using a 3D printer. However, it is necessary to form a porous layer over the entire portion that will become the bearing surface, which again poses the problem of not being easy to produce.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a fluid bearing, a device, a stage, a spindle, a method for manufacturing a fluid bearing, and a method for manufacturing an article that can be easily manufactured. [Means for solving the problem]

[0006] One aspect of the present invention is a fluid bearing comprising a portion having a bearing surface arranged opposite a guide surface of a shaft via a gap, and a hole that is connected to a fluid supply source and opens into the bearing surface, the portion having a structure that is connected to a side that constitutes the hole and fills at least a portion of the hole.

[0007] One aspect of the present invention is a fluid bearing comprising a portion having a bearing surface arranged opposite a guide surface of a shaft via a gap, a hole opening into the bearing surface, and a communication passage connecting a fluid supply source with the hole, the hole being arranged between a communication port communicating with the communication passage and the opening, and having a bending portion that bends the direction of fluid flow.

[0008] One aspect of the present invention is a fluid bearing comprising a portion having a bearing surface arranged opposite a guide surface of a shaft via a gap, a hole opening into the bearing surface, and a communication passage connecting a fluid supply source with the hole, wherein the hole is arranged between a communication port communicating with the communication passage and the opening, and has a spiral portion that causes the fluid to flow in a spiral direction.

[0009] One aspect of the present invention is a fluid bearing comprising a portion having a bearing surface arranged opposite a guide surface of a shaft via a gap, and a hole communicating with a fluid supply source and opening into the bearing surface, the portion being formed by a three-dimensional printing device so that the hole has a resistance imparting portion that imparts resistance to the flow of fluid.

[0010] One aspect of the present invention is a method for manufacturing a fluid bearing having a portion having a bearing surface arranged opposite a guide surface of a shaft via a gap, and a hole that is connected to a fluid supply source and opens into the bearing surface, characterized in that the method includes a step of molding the portion using a three-dimensional printing device so as to have a structure that is connected to a side that constitutes the hole and is formed so as to fill at least a portion of the hole. [Effects of the Invention]

[0011] According to the present invention, the fluid bearing can be easily manufactured. [Brief explanation of the drawings]

[0012] [Figure 1] 1A is a cross-sectional view showing a hydrostatic bearing according to the first embodiment, FIG. 1B is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the first embodiment, and FIG. 1C is a plan view showing a bearing surface of the hydrostatic bearing according to the first embodiment. [Figure 2] (a) is a front view showing a single unit cell formed in a branch shape, (b) is a perspective view showing a single unit cell formed in a branch shape, (c) is a front view showing a lattice structure in which multiple unit cells are periodically arranged, and (d) is a perspective view showing a lattice structure in which multiple unit cells are periodically arranged. [Figure 3] 10(a) is a cross-sectional view showing a hydrostatic bearing according to a second embodiment, and (b) is a plan view showing a bearing surface of the hydrostatic bearing according to the second embodiment. [Figure 4] 10A is a cross-sectional view showing a hydrostatic bearing according to a third embodiment, FIG. 10B is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the third embodiment, and FIG. 10C is a plan view showing a bearing surface of the hydrostatic bearing according to the third embodiment. [Figure 5] 10(a) is a cross-sectional view showing a hydrostatic bearing according to a fourth embodiment, and (b) is a plan view showing a bearing surface of the hydrostatic bearing according to the fourth embodiment. [Figure 6]10A is a cross-sectional view showing a hydrostatic bearing according to a fifth embodiment, FIG. 10B is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the fifth embodiment, and FIG. 10C is a plan view showing a bearing surface of the hydrostatic bearing according to the fifth embodiment. [Figure 7] (a) is a cross-sectional view showing a hydrostatic bearing having a porous material according to a first comparative example; (b) is a plan view showing a bearing surface of the hydrostatic bearing having a porous material according to the first comparative example; (c) is a cross-sectional view showing a hydrostatic bearing having a slot according to a second comparative example; and (d) is a plan view showing a bearing surface of the hydrostatic bearing having a slot according to the second comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below exemplify preferred configurations and manufacturing methods of the present invention, and the scope of the present invention is not limited to these configurations and manufacturing methods. Furthermore, unless otherwise specified, the configuration of the hydrostatic bearing, the manufacturing method of the hydrostatic bearing, and the like in the following description do not limit the scope of the present invention to these embodiments.

[0014] <Comparative Example> First, the hydrostatic bearing according to the comparative example will be described with reference to Fig. 7. Fig. 7(a) is a cross-sectional view showing a hydrostatic bearing having a porous material according to the first comparative example. Fig. 7(b) is a plan view showing the bearing surface of the hydrostatic bearing having a porous material according to the first comparative example. Fig. 7(c) is a cross-sectional view showing a hydrostatic bearing having a slot according to the second comparative example. Fig. 7(d) is a plan view showing the bearing surface of the hydrostatic bearing having a slot according to the second comparative example.

[0015] (First Comparative Example) As shown in FIGS. 7(a) and 7(b), the stage 100 according to the first comparative example includes a shaft 20 having a guide surface 20S and a hydrostatic bearing 110 having a main body 110A with a bearing surface 110S disposed opposite the guide surface 20S via an air gap AG. The main body 110A may also be referred to as a "part." The main body 110A is formed with a connection hole 11 connected via a pipe 51 to a fluid supply source 50, which may be a factory facility such as a compressor, that supplies air. The connection hole 11 is connected to a supply chamber 12 formed inside the main body 110A. A porous material 120 is fixed to the main body 110A so as to close the supply chamber 12. A clogging layer 121 is formed on the porous material 120 on the side of the bearing surface 110S. A sealant 130 is bonded to the main body 110A so as to surround the porous material 120 and the clogging layer 121. The sealant 130 is intended to prevent the supplied air from leaking outside the bearing surface 110S and leaking to places other than the bearing surface 110S, and is made of a material such as an epoxy adhesive.

[0016] In the stage 100 configured in this manner, air supplied from the fluid supply source 50 is supplied to the air gap AG between the guide surface 20S and the bearing surface 110S through the porous material 120 and the clogging layer 121. This generates static pressure between the guide surface 20S and the bearing surface 110S, causing the bearing surface 110S (i.e., the hydrostatic bearing 110) to levitate in a non-contact manner relative to the guide surface 20S. This type of hydrostatic bearing 110 is called a porous hydrostatic bearing because the porous material 120 and the clogging layer 121 provided in the porous material 120 act as a throttle.

[0017] It is known that such porous hydrostatic bearings are prone to self-excited vibration known as pneumatic hammer vibration if they do not have a clogging layer 121. The clogging layer 121 can be formed, for example, by impregnating the surface of the porous material 120 with resin, or, if the porous material 120 is made of metal, by burrs formed when processing the surface of the porous material 120. In either configuration, a uniform clogging layer 121 must be formed over the entire surface of the bearing surface 110S, making the hydrostatic bearing 110 highly difficult to manufacture. For example, if a uniform clogging layer 121 cannot be formed, the hydrostatic bearing 110 will float at an angle. If the angle is large, one end of the opposing guide surface 20S and the bearing surface 110S will come into contact, preventing non-contact floating.

[0018] (Second Comparative Example) 7(c) and 7(d), the stage 200 according to the second comparative example, like the first comparative example, includes a shaft 20 having a guide surface 20S and a hydrostatic bearing 210 having a main body 210A on which a bearing surface 210S arranged opposite the guide surface 20S is formed. The main body 210A is formed with a connection hole 11 connected to a fluid supply source 50 via a pipe 51, and the connection hole 11 is connected to a supply chamber 12 formed inside the main body 210A. The main body 210A is also formed with a slot 213 connected to the supply chamber 12. The slot 213 is a wide flow path with a narrow gap.

[0019] In the hydrostatic bearing 210 using the restriction provided by the slot 213 configured in this manner, air supplied from the fluid supply source 50 is supplied through the slot 213 to the air gap AG between the guide surface 20S and the bearing surface 210S. This generates hydrostatic pressure between the guide surface 20S and the bearing surface 210S, causing the bearing surface 210S (i.e., the hydrostatic bearing 210) to levitate in a non-contact manner relative to the guide surface 20S. This type of hydrostatic bearing 210 is called a slot hydrostatic bearing, as the slot 213 acts as a restriction.

[0020] In order to improve the rigidity of such a slot hydrostatic bearing, the narrow gap in the slot needs to be approximately the same as the air gap AG, which is the gap between the guide surface 20S and the bearing surface 210S. Therefore, the slot gap needs to be formed uniformly over the entire surface of the bearing surface 210S, which makes it difficult to manufacture the hydrostatic bearing 210. For example, if the gap in the slot 213 is not uniform, the hydrostatic bearing 210 will float at an angle, and if the angle is large, one end of the opposing guide surface 20S and bearing surface 210S will come into contact, preventing non-contact floating.

[0021] (Summary of Comparative Examples) As explained above, the hydrostatic bearing 110 of the first comparative example and the hydrostatic bearing 210 of the second comparative example are difficult to manufacture, and there has been a demand for the development of a hydrostatic bearing that can be manufactured more easily. Note that in the explanation of the first and second comparative examples, the fluid is a gas, namely, air, but this is not limiting, and a liquid, such as oil or water, may also be used.

[0022] First Embodiment Next, a hydrostatic bearing as a fluid bearing according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1(a) is a cross-sectional view showing the hydrostatic bearing according to the first embodiment. FIG. 1(b) is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the first embodiment. FIG. 1(c) is a plan view showing the bearing surface of the hydrostatic bearing according to the first embodiment. FIG. 2(a) is a front view showing a single unit cell formed in a branch shape. FIG. 2(b) is a perspective view showing a single unit cell formed in a branch shape. FIG. 2(c) is a front view showing a lattice structure in which a plurality of unit cells are periodically arranged. FIG. 2(d) is a perspective view showing a lattice structure in which a plurality of unit cells are periodically arranged.

[0023] As shown in FIGS. 1A and 1C, the stage 1 according to the first embodiment includes a shaft 20 serving as a first component having a planar guide surface 20S, and a hydrostatic bearing 101 having a main body 10A. The main body 10A of the hydrostatic bearing 101 is provided with a bearing surface 10S, which is also planar and faces the guide surface 20S via an air gap AG. A component (not shown) serving as a second component (e.g., a processing tool, measuring instrument, workpiece, etc. in the case of a processing device, instrumentation device, or manufacturing device) is fixed and mounted on the hydrostatic bearing 101. Meanwhile, the shaft 20 constitutes a guide rail of the stage, which is formed, for example, in a rectangular column shape. In other words, the guide surface 20S is one surface of the rectangular column and is formed as a flat surface extending in the direction of movement of the stage 1. Therefore, in the stage 1, a component (not shown) mounted on the hydrostatic bearing 101 and guided by the shaft 20 can move smoothly along the guide surface 20S.

[0024] The main body 10A of the hydrostatic bearing 101 according to the first embodiment is formed by a three-dimensional modeling device, a so-called 3D printer. The main body 10A may be made of any material, such as metal, ceramic, carbon, or resin, depending on the rigidity (load resistance) of the hydrostatic bearing 101.

[0025] The main body 10A is generally configured to include a cup-shaped outer portion 10B having a rectangular outer shape when viewed from the Z direction, which is perpendicular to the bearing surface 10S, and an inner portion 10C disposed within the outer portion 10B. A connection hole 11 having an outer opening 11a and an inner opening 11b is formed in the outer portion 10B of the main body 10A. A pipe 51 is connected to the outer opening 11a of the connection hole 11, and the pipe 51 is connected to a fluid supply source 50 (hereinafter referred to as the "fluid supply source") that supplies air, such as a compressor. A supply chamber 12 is formed between the outer portion 10B and the inner portion 10C of the main body 10A. The supply chamber 12 is formed inside the main body 10A and is arranged to expand in the X and Y directions, which are parallel to the bearing surface 10S, and is connected to the inner opening 11b. Between outer portion 10B and inner portion 10C of main body 10A, hole 131 is formed at the outer edge of supply chamber 12 and arranged to extend in the Z direction perpendicular to bearing surface 10S. That is, in main body 10A, connecting hole 11 and supply chamber 12 form a communication passage that connects fluid supply source 50 and hole 131.

[0026] In the first embodiment, structure 15, which will be described in detail later, connects outer portion 10B and inner portion 10C, so there is no need to connect outer portion 10B and inner portion 10C in supply chamber 12. However, in order to increase the rigidity of hydrostatic bearing 101, a pillar may be formed in supply chamber 12, for example, to connect outer portion 10B and inner portion 10C.

[0027] The hole 131 of the hydrostatic bearing 101 according to the first embodiment has a side surface 13S that is the inner surface of the outer portion 10B and the outer surface of the inner portion 10C. That is, as shown in FIG. 1(c), the hole 131 extends in the X and Y directions and is formed as a rectangular, continuous, elongated hole when viewed from the Z direction (a direction intersecting the bearing surface 10S). In other words, when viewed from the Z direction, the hole 131 is formed in a rectangular shape with a certain distance between the rectangular inner surface that defines the inner shape of the outer portion 10B and the rectangular outer surface that defines the outer shape of the inner portion 10C. One opening 13a of the hole 131 is configured as a communication port that communicates with the supply chamber 12 (communication passage), and the other opening 13b opens to the bearing surface 10S. The side surface 13S can also be considered a boundary surface that separates an air-impermeable region from an air-permeable region. In addition, in this embodiment, the side surface 13S is described as the inner surface of the outer portion 10B or the outer surface of the inner portion 10C, but this is not limiting, and a side wall may be provided as a wall for forming the hole 131. Furthermore, a portion having a predetermined thickness that forms the inner surface of the outer portion 10B, or a portion having a predetermined thickness that forms the outer surface of the inner portion 10C may be considered to be a side wall.

[0028] As shown in FIG. 1(b), a structure 15 is disposed in the region of the hole 131 surrounded by the side surface 13S, as a resistance applying portion that applies resistance to the air flowing through the hole 131. The structure 15 has a lattice structure in which unit cells US, each consisting of a branched lattice as shown in FIGS. 2(a) and 2(b), are periodically arranged as shown in FIGS. 2(c) and 2(d). In other words, the structure 15 is configured as a lattice structure in which branched lattices are periodically arranged. In this structure 15, the branches of the unit cells US located at the ends are joined to the side surface 13S of the hole 131. In other words, the structure 15 is formed so that a portion of the structure 15 is joined to the hole 131, or in other words, is formed so as to be integrated with the main body 10A. Although the structure 15 has been described as being integrally formed, it is sufficient that a portion of the structure 15 is connected to the side surface 13S of the main body 10A. Therefore, the structure 15 may be formed as a separate part from the main body 10A and connected to the side surface 13S. In this way, the structure 15 is arranged so as to fill at least a part of the hole 131. The unit cell US shown in Fig. 2 is an example, and other shapes may be used. Furthermore, the structure 15 may be formed by combining a plurality of unit cells of different shapes.

[0029] The white portions shown in Fig. 1(b) are gaps in the structure 15, and indicate spaces through which a fluid can pass. Note that although the white portions are shown as being independent of one another in Fig. 1(b), in reality they are connected to one another in the direction from the front to the back of the page, and air supplied from the fluid supply source 50 can pass through the hole 131 and be ejected from the opening 13b of the bearing surface 10S.

[0030] In the hydrostatic bearing 101 according to this embodiment configured as described above, air is supplied from the fluid supply source 50 to the air gap AG between the guide surface 20S and the bearing surface 10S through the structure 15 of the hole 131. This generates hydrostatic pressure between the guide surface 20S and the bearing surface 10S, causing the bearing surface 10S (i.e., the hydrostatic bearing 101) to levitate in a non-contact manner relative to the guide surface 20S.

[0031] Furthermore, as described above, when the bearing surface 10S is viewed from the vertical direction, the structure 15 (opening 13b) is disposed outside the inner portion 10C so as to surround the inner portion 10C in a rectangular shape (see FIG. 1(c)). This makes it difficult for the static pressure generated on the bearing surface 10S of the inner portion 10C to leak outward due to the air blown out from the opening 13b, and the static pressure is increased over the entire surface of the bearing surface 10S of the inner portion 10C.

[0032] Then, by three-dimensionally forming the main body 10A of the hydrostatic bearing 101 using a 3D printer (a manufacturing method including a process for forming the main body 10A), the hydrostatic bearing 101 having the lattice structure 15 in the hole 131 can be easily manufactured. Furthermore, by changing the density of the lattice structure in the structure 15, the resistance to the air flow can be changed, which means that the flow rate of air ejected onto the bearing surface 10S can be easily changed. For example, in the case of a unit cell US as shown in FIG. 2 , by thickening each branch of the branched lattice, the density can be increased and the flow rate of air ejected onto the bearing surface 10S can be reduced. Conversely, by thinning each branch of the branched lattice, the density can be reduced and the flow rate of air ejected onto the bearing surface 10S can be increased. In this way, the flow rate of air ejected onto the bearing surface 10S can be intentionally changed through the structure 15, which makes it easy to uniform the flow rate of air ejected onto the entire bearing surface 10S.

[0033] Here, we will explain the advantages of the hydrostatic bearing 101 according to the first embodiment over the hydrostatic bearing 210 using the slot restrictor according to the second comparative example described above. Assume that the outer edge shape of the bearing surface 10S shown in FIG. 1(c) and the outer edge shape of the bearing surface 210S shown in FIG. 7(b) are substantially the same, and the positions at which air is ejected onto these bearing surfaces are also substantially the same, and the flow rates of the ejected air are also substantially the same. This results in the same air gap AG, and the bearing stiffness of both is substantially the same. Note that the flow rates of the ejected air being substantially the same means that the fluid resistance of the air passing through the structure 15 shown in FIG. 1 is substantially the same as the fluid resistance of the air passing through the slot 213 shown in FIG. 7(b).

[0034] In order to increase the rigidity of the hydrostatic bearing 210 using the slot restrictor in the second comparative example, the gap of the slot 213 needs to be approximately the same as the gap of the air gap AG. More specifically, the gap of the slot 213 needs to be approximately 10 μm. It is extremely difficult to manufacture the gap of the slot 213 uniformly at approximately 10 μm over the entire surface of the bearing surface 210S, and if the gap becomes uneven, the hydrostatic bearing 210 will tilt and will not float, which is a problem.

[0035] On the other hand, in the hydrostatic bearing 101 according to the first embodiment as shown in FIG. 1, even if the area surrounded by the side surface 13S (the width of the hole 131) is wider than the slot 213, by increasing the density of the structure 15, it is possible to achieve fluid resistance equivalent to that of a slot restriction. The density of the structure 15 can be easily adjusted by manufacturing using a 3D printer, making it easy to make the flow rate of air ejected from the bearing surface 10S uniform. In this way, even a hydrostatic bearing 101 that has higher rigidity and suppresses tilt during levitation compared to a slot restriction can be easily manufactured.

[0036] Next, the advantages of the hydrostatic bearing 101 according to the first embodiment over the hydrostatic bearing 110 using the porous material 120 according to the first comparative example will be described. As described above, the hydrostatic bearing 110 using the porous material according to the first comparative example requires the formation of a uniform clogging layer 121. However, even if the clogging layer 121 is created by resin impregnation or burr removal, it is not easy to create a uniform clogging layer 121. Furthermore, even if the clogging layer 121 is created using a 3D printer (a metal fusion 3D modeling device that sinters metal powder with laser light), it is not easy to create a uniform clogging layer 121. In particular, if a uniform clogging layer 121 cannot be created, self-excited vibrations known as pneumatic hammering will occur, which necessitates, for example, the need to finely adjust the output settings (laser density) of the laser light, thereby making it difficult to easily manufacture the hydrostatic bearing.

[0037] On the other hand, in the hydrostatic bearing 101 according to the first embodiment as shown in Fig. 1, the structure 15, which is a lattice structure, is simply created in the area surrounded by the side surface 13S, and uniform air ejection is possible simply by adjusting the density of the structure 15. Therefore, compared to hydrostatic bearings using porous materials, the hydrostatic bearing 101 that suppresses the occurrence of pneumatic hammer can be manufactured more easily. Furthermore, by creating the structure 15 using a 3D printer, the hydrostatic bearing 101 can be manufactured even more easily.

[0038] Second Embodiment Next, a second embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 3. Fig. 3(a) is a cross-sectional view showing a hydrostatic bearing according to the second embodiment. Fig. 3(b) is a plan view showing a bearing surface of the hydrostatic bearing according to the second embodiment. In the description of this second embodiment, the same reference numerals are used for parts similar to those in the first embodiment, and their description will be omitted.

[0039] 3(a) and 3(b), the hydrostatic bearing 102 according to the second embodiment is different from the hydrostatic bearing 101 according to the first embodiment in that the hole 132 is provided with four bent portions 13C1, 13C2, 13C3, and 13C4 and does not have the structure 15. Since the hydrostatic bearing 102 does not have the structure 15, the supply chamber 12 has a plurality of pillars (not shown) that connect the outer portion 10B and the inner portion 10C.

[0040] Specifically, the hole 132 of the hydrostatic bearing 102 is a slot, which is a narrow gap and a wide flow path. The hole 132 is formed with bent portions 13C1, 13C2, 13C3, and 13C4 as resistance-applying portions along the air flow direction, from the opening 13a to the opening 13b. These bent portions 13C1, 13C2, 13C3, and 13C4 are each bent at 90 degrees (right angles). That is, the hole 132 is folded back in the Z direction by these bent portions 13C1, 13C2, 13C3, and 13C4, forming a so-called labyrinth structure. This allows the hole 132 to extend the air flow path from the opening 13a to the opening 13b without narrowing the gap, thereby increasing the resistance of the air passing through, compared to a simple linear slot (see, for example, the second comparative example). In short, when forming a slot, it is generally easier to make the length uniform than to make the gap uniform. Therefore, in a hydrostatic bearing 102 in which holes 132 serving as slots are formed, it is easier to make the flow rate of air ejected onto the bearing surface 10S uniform than in the case of forming slots with narrow gaps. Also, although it is difficult to form such folded holes 132 by cutting or the like, they can be easily manufactured by molding the main body 10A of the hydrostatic bearing 102 with a 3D printer.

[0041] In addition, the hole 132 of the hydrostatic bearing 102 shown in Figure 3 has been described as having four 90-degree bends, but this is not limited to this, and the number of bends and the bend angle can be any number.

[0042] The other configurations, actions, and effects of the second embodiment described above are the same as those of the first embodiment, and therefore will not be described again.

[0043] <Third embodiment> Next, a third embodiment, which is a partial modification of the second embodiment, will be described with reference to Fig. 4. Fig. 4(a) is a cross-sectional view showing a hydrostatic bearing according to the third embodiment. Fig. 4(b) is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the third embodiment. Fig. 4(c) is a plan view showing the bearing surface of the hydrostatic bearing according to the third embodiment. In the description of this third embodiment, the same reference numerals are used for parts similar to those of the first and second embodiments, and their description will be omitted.

[0044] 4(a) and 4(c), hydrostatic bearing 103 according to the third embodiment differs from hydrostatic bearing 102 according to the second embodiment in that structure 15 is formed in hole 133 as a resistance applying portion. Note that, in hydrostatic bearing 103, because structure 15 is present, it is not necessary to provide multiple pillars (not shown) in supply chamber 12 that connect outer portion 10B and inner portion 10C.

[0045] Specifically, similar to the second embodiment, the hole 133 of the hydrostatic bearing 103 has bent portions 13C1, 13C2, 13C3, and 13C4 bent at 90 degrees in the air flow direction from the opening 13a to the opening 13b. Furthermore, as shown in FIG. 4(b), a structure 15 is formed in the area surrounded by the side surface 13S of the hole 133. The structure 15 is formed as a lattice structure (see FIG. 2) similar to the first embodiment, with some branches of the structure 15 joined to the side surface 13S. The hydrostatic bearing 103 configured in this manner can also be formed using a 3D printer. Furthermore, similar to the second embodiment, such a hole 133 can lengthen the air flow path, thereby increasing the resistance of the air passing through it. Furthermore, similar to the first embodiment, the resistance of the air passing through it can be increased by increasing the density of the structure 15. In other words, it is possible to set the desired fluid resistance and apply static pressure uniformly across the entire surface of the bearing surface 10S by changing the density of the structure 15 and the length of the air flow path of the holes 133. This makes it possible to easily manufacture a hydrostatic bearing 103 that is highly rigid and suppresses tilt during levitation.

[0046] The other configurations, actions, and effects of the second embodiment described above are the same as those of the first embodiment, and therefore will not be described again.

[0047] <Fourth embodiment> Next, a fourth embodiment, which is a partial modification of the first embodiment, will be described with reference to Fig. 5. Fig. 5(a) is a cross-sectional view showing a hydrostatic bearing according to the fourth embodiment. Fig. 5(b) is a plan view showing the bearing surface of the hydrostatic bearing according to the fourth embodiment. In the description of this fourth embodiment, the same reference numerals are used for parts similar to those in the first embodiment, and their description will be omitted.

[0048] 5(a) and 5(b), the hydrostatic bearing 104 according to the fourth embodiment is different from the hydrostatic bearing 101 according to the first embodiment in that a helical portion 13H having a helical shape is provided in the hole 134 as a resistance applying portion, and the structure 15 is eliminated. Note that the main body 10A of the hydrostatic bearing 104 according to the fourth embodiment has an outer portion 13B and an inner portion 10C that are not physically separated by the hole 134, but for convenience, they can be considered to be separated by the hole 134 (spiral portion 13H).

[0049] Specifically, the hole 134 of the hydrostatic bearing 104 has a groove 13V1, a spiral portion 13H, and a groove 13V2. One groove 13V1 is formed in a rectangular shape and extends around the circumference when viewed from the Z direction, and opens to the supply chamber 12 through an opening 13a. The other groove 13V2 is also formed in a rectangular shape and extends around the circumference when viewed from the Z direction, and opens to the bearing surface 10S through an opening 13b. The spiral portion 13H is arranged so as to communicate with the groove 13V1 and the groove 13V2, i.e., the spiral portion 13H is arranged between the openings 13a and 13b, and is arranged at four locations in the circumferential direction when viewed from the Z direction. Each spiral portion 13H is formed, for example, by forming a hole having a circular cross section in a spiral shape. That is, the spiral portion 13H of the hole 134 allows the air flow direction to be spiral, thereby lengthening the path of air flow from the opening 13a to the opening 13b compared to, for example, a linear slot (see, for example, the second comparative example). This increases the resistance of the air passing through without reducing the diameter of the hole. In other words, it is generally easier to make the length of a hole of a somewhat larger diameter uniform than to make the diameter of the hole uniform by reducing it. Therefore, in a hydrostatic bearing 104 having the hole 134 formed therein, it is easier to uniformize the flow rate of air ejected onto the bearing surface 10S than in the case of small-diameter holes arranged in a straight line. Furthermore, although it is difficult to form the hole 134 having the spiral portion 13H formed therein by cutting or the like, it can be easily manufactured by molding the main body 10A of the hydrostatic bearing 104 using a 3D printer.

[0050] 5, the hole 134 of the hydrostatic bearing 104 is described as having four spiral portions 13H, but the number of spiral portions 13H is not limited to this and may be any number. However, it is preferable that the spiral portions 13H are arranged so as to be point-symmetric or line-symmetric when viewed from the Z direction.

[0051] 5, the hole 134 of the hydrostatic bearing 104 is described as being formed so that the spiral portion 13H is in communication with the groove portion 13V1 and the groove portion 13V2. However, this is not limiting, and the groove portion 13V1 or the groove portion 13V2 may be eliminated, and the end of the hole of the spiral portion 13H may be configured to open directly to the supply chamber 12 or the bearing surface 10S.

[0052] The other configurations, actions, and effects of the fourth embodiment described above are the same as those of the first embodiment, and therefore description thereof will be omitted.

[0053] Fifth Embodiment Next, a fifth embodiment, which is a partial modification of the fourth embodiment, will be described with reference to Fig. 6. Fig. 6(a) is a cross-sectional view showing a hydrostatic bearing according to the fifth embodiment. Fig. 6(b) is an enlarged cross-sectional view showing a structure formed in a hole of the hydrostatic bearing according to the fifth embodiment. Fig. 6(c) is a plan view showing a bearing surface of the hydrostatic bearing according to the fifth embodiment. In the description of this sixth embodiment, the same reference numerals are used for parts similar to those of the first and fourth embodiments, and their description will be omitted.

[0054] As shown in Figures 6(a) and 6(c), the hydrostatic bearing 105 according to the fifth embodiment is different from the hydrostatic bearing 104 according to the fourth embodiment in that a structure 15 is formed in the hole 134 as a resistance imparting portion.

[0055] Specifically, the hole 135 of the hydrostatic bearing 105 has four spiral portions 13H formed between the groove portion 13V1 and the groove portion 13V2, as in the fourth embodiment. Furthermore, in the area surrounded by the side surfaces 13S of the hole 135 (the side surfaces of the hole of the spiral portion 13H, the side surfaces of the groove portion 13V1, and the side surfaces of the groove portion 13V2), the structure 15 is formed as shown in FIG. 6(b). The structure 15 is configured as a lattice structure (see FIG. 2), as in the first embodiment, and some branches of the structure 15 are joined to the side surfaces 13S. The hydrostatic bearing 105 configured in this manner can also be formed using a 3D printer. Furthermore, in such a hole 135, the path through which air flows can be lengthened, as in the fourth embodiment, and the resistance of the passing air can be increased. Furthermore, as in the first embodiment, the density of the structure 15 can be increased, thereby increasing the resistance of the passing air. In other words, it is possible to set the desired fluid resistance and apply static pressure uniformly across the entire surface of the bearing surface 10S by changing the density of the structure 15 and the length of the path through which the air flows in the holes 135. This makes it possible to easily manufacture a hydrostatic bearing 105 that is highly rigid and suppresses tilt during levitation.

[0056] In the description of the hole 135 of the hydrostatic bearing 105 shown in FIG. 6, the structures 15 are also formed in the grooves 13V1 and 13V2. However, this is not limiting, and the structures 15 may not be formed in the grooves 13V1 or 13V2, and may be formed only inside the hole of the spiral portion 13H. Also, the structures 15 may be formed in the grooves 13V1 and 13V2, and no structures may be formed in the spiral portion 13H. Furthermore, the structures 15 may be formed only in one of the grooves 13V1 and 13V2. In other words, the structures 15 may be formed only in a portion of the inside of the hole 135.

[0057] The other configurations, actions, and effects of the fifth embodiment described above are the same as those of the first and fourth embodiments, and therefore description thereof will be omitted.

[0058] <Possibilities for other embodiments> In the above first to fifth embodiments, air is supplied to the hydrostatic bearing 10 from the fluid supply source 50, and the air is ejected onto the bearing surface 10S from the holes 13. However, the present invention is not limited to this, and for example, a liquid such as water or oil may be supplied from the fluid supply source as the fluid; in other words, any fluid may be used.

[0059] Furthermore, in the above first to fifth embodiments, the hydrostatic bearing 10 that generates static pressure by supplying fluid between the bearing surface 10S and the guide surface 20S has been described as an example. However, the present invention is not limited to this, and may be, for example, a hydrodynamic bearing that generates dynamic pressure by relative movement between the bearing surface and the guide surface, or a hybrid type bearing that uses both hydrostatic pressure and hydrodynamic pressure, or in other words, any type of fluid bearing.

[0060] In the first to fifth embodiments, the main body 10A has been described as being completed solely by shaping using a 3D printer. However, this is not limiting. For example, the bearing surface 10S may be subjected to additional processing such as grinding or lapping as necessary to improve shape precision. Furthermore, other components (e.g., handles, flanges, etc.) may be attached to the main body 10A later or fastened with screws. In other words, any accessory components may be attached to the bearing.

[0061] Furthermore, in the above first to fifth embodiments, the main body 10A is described as being formed using a 3D printer, but this is not limited to this, and any method may be used as long as it can easily manufacture a similar shape.

[0062] Furthermore, in the above first to fifth embodiments, the hydrostatic bearing 10 provided on the stage 1 has been described as an example, but this is not limiting, and a hydrostatic bearing provided on a spindle can also be configured in the same manner as this embodiment. That is, in the case of a spindle, the shaft is cylindrical, the guide surface is cylindrical, and the main body of the hydrostatic bearing is hollow, so the bearing surface is also cylindrical. Furthermore, the hole 13 is formed so as to be elongated in the circumferential direction, and is usually not formed in the axial direction.

[0063] Furthermore, the stage 1 described in the first to fifth embodiments and modified spindles thereof can be provided in devices such as processing devices, measurement devices, and semiconductor manufacturing devices. That is, a device can be configured that includes a shaft as a first component, a fluid bearing movable relative to the shaft, and a second component supported by the fluid bearing. In this case, the second component can be various components such as a processing tool, a measuring instrument (such as a probe), or a workpiece stage. These devices can then be used to manufacture articles (workpieces).

[0064] <Summary of this embodiment> [Configuration 1] a portion having a bearing surface disposed opposite to the guide surface of the shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening to the bearing surface; The portion has a structure connected to a side surface that constitutes the hole and filling at least a portion of the hole. A fluid bearing characterized by: [Configuration 2] a hydrostatic bearing configured to apply pressure between the guide surface and the bearing surface by the fluid ejected from the hole; 2. The fluid bearing according to claim 1, [Configuration 3] The structure is a lattice structure. 3. The fluid bearing according to configuration 1 or 2. [Configuration 4] The lattice structure is a structure in which branched lattices are periodically arranged. 4. The fluid dynamic bearing according to configuration 3. [Configuration 5] The hole is formed to have an elongated hole shape when viewed from a direction intersecting the bearing surface. 5. The fluid dynamic bearing according to any one of configurations 1 to 4, wherein: [Configuration 6] the portion has a communication passage that communicates a fluid supply source with the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a bending portion that bends the flow direction of the fluid. 6. The fluid dynamic bearing according to any one of configurations 1 to 5, wherein: [Configuration 7] the portion has a communication passage that communicates a fluid supply source with the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a spiral portion that causes the fluid to flow in a spiral direction. 6. The fluid dynamic bearing according to any one of configurations 1 to 5, wherein: [Configuration 8] The part is formed by a three-dimensional modeling device. 8. The fluid dynamic bearing according to any one of configurations 1 to 7, wherein: [Configuration 9] a portion having a bearing surface disposed opposite to a guide surface of the shaft with a gap therebetween, a hole opening in the bearing surface, and a communication passage connecting a fluid supply source and the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a bending portion that bends the flow direction of the fluid. A fluid bearing characterized by: [Configuration 10] a portion having a bearing surface disposed opposite to a guide surface of the shaft with a gap therebetween, a hole opening in the bearing surface, and a communication passage connecting a fluid supply source and the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a spiral portion that causes the fluid to flow in a spiral direction. A fluid bearing characterized by: [Configuration 11] a portion having a bearing surface disposed opposite to the guide surface of the shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening to the bearing surface; the portion is formed by a three-dimensional modeling apparatus so that the hole has a resistance imparting portion that imparts resistance to a flow of a fluid; A fluid bearing characterized by: [Configuration 12] A fluid dynamic bearing according to any one of configurations 1 to 11; a first part having the guide surface; and a second component supported by the fluid bearing. An apparatus characterized in that [Configuration 13] A fluid dynamic bearing according to any one of configurations 1 to 11; a first component having the guide surface formed in a flat shape; and a second component supported by the fluid bearing. A stage characterized by: [Configuration 14] A fluid dynamic bearing according to any one of configurations 1 to 11; a first part having the cylindrical guide surface; and a second component supported by the fluid bearing. A spindle characterized by: [Method 15] A method for manufacturing a fluid bearing having a portion having a bearing surface arranged opposite to a guide surface of a shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening into the bearing surface, comprising: forming the part using a three-dimensional modeling device to have a structure connected to a side surface of the hole and formed so as to fill at least a portion of the hole; A method for manufacturing a fluid bearing. [Method 16] 13. Manufacturing an article using the apparatus according to claim 12. A method for manufacturing an article. [Explanation of symbols]

[0065] 1...stage / 101, 102, 103, 104, 105...hydrostatic bearing (fluid bearing) / 10A...main body (part) / 10S...bearing surface / 11...connecting hole (communicating passage) / 12...supply chamber (communicating passage) / 131, 132, 133, 134, 135...hole / 13C1...bent portion (resistance applying portion) / 13C2...bent portion (resistance applying portion) / 13C3...bent portion (resistance applying portion) / 13C4...bent portion (resistance applying portion) / 13H...spiral portion (resistance applying portion) / 13S...side surface / 15...structure (resistance applying portion) / 20...axis (first part) / 20s...guide surface / 50...fluid supply source / AG...air gap (gap) / US...unit cell (lattice) / Z...direction (direction intersecting the bearing surface)

Claims

1. a portion having a bearing surface disposed opposite to the guide surface of the shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening to the bearing surface; The portion has a structure connected to a side surface that constitutes the hole and filling at least a portion of the hole. A fluid bearing characterized by:

2. a hydrostatic bearing configured to apply pressure between the guide surface and the bearing surface by the fluid ejected from the hole; 2. The fluid bearing according to claim 1.

3. The structure is a lattice structure.

2. The fluid bearing according to claim 1.

4. The lattice structure is a structure in which branched lattices are periodically arranged.

4. The fluid bearing according to claim 3.

5. The hole is formed to have an elongated hole shape when viewed from a direction intersecting the bearing surface.

2. The fluid bearing according to claim 1.

6. the portion has a communication passage that communicates a fluid supply source with the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a bending portion that bends the flow direction of the fluid.

2. The fluid bearing according to claim 1.

7. the portion has a communication passage that communicates a fluid supply source with the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a spiral portion that causes the fluid to flow in a spiral direction.

2. The fluid bearing according to claim 1.

8. The part is formed by a three-dimensional modeling device.

2. The fluid bearing according to claim 1.

9. a portion having a bearing surface disposed opposite to a guide surface of the shaft with a gap therebetween, a hole opening in the bearing surface, and a communication passage connecting a fluid supply source and the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a bending portion that bends the flow direction of the fluid. A fluid bearing characterized by:

10. a portion having a bearing surface disposed opposite to a guide surface of the shaft with a gap therebetween, a hole opening in the bearing surface, and a communication passage connecting a fluid supply source and the hole, the hole is disposed between the opening and a communication port communicating with the communication passage, and has a spiral portion that causes the fluid to flow in a spiral direction. A fluid bearing characterized by:

11. a portion having a bearing surface disposed opposite to the guide surface of the shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening to the bearing surface; the portion is formed by a three-dimensional modeling apparatus so that the hole has a resistance imparting portion that imparts resistance to a flow of a fluid; A fluid bearing characterized by:

12. The fluid bearing according to claim 1; a first part having the guide surface; a second component supported by the fluid bearing; An apparatus characterized in that

13. The fluid bearing according to claim 1; a first component having the guide surface formed in a flat shape; a second component supported by the fluid bearing; A stage characterized by:

14. The fluid bearing according to claim 1; a first part having the guide surface that is cylindrical; a second component supported by the fluid bearing; A spindle characterized by:

15. A method for manufacturing a fluid bearing having a portion having a bearing surface arranged opposite to a guide surface of a shaft with a gap therebetween, and a hole communicating with a fluid supply source and opening to the bearing surface, comprising: forming the part using a three-dimensional modeling device to have a structure connected to a side surface of the hole and formed so as to fill at least a portion of the hole; A method for manufacturing a fluid bearing.

16. 13. Manufacturing an article using the apparatus according to claim 12. A method for manufacturing an article.

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