US20170284464A1 - Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block - Google Patents
Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block Download PDFInfo
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- US20170284464A1 US20170284464A1 US15/478,445 US201715478445A US2017284464A1 US 20170284464 A1 US20170284464 A1 US 20170284464A1 US 201715478445 A US201715478445 A US 201715478445A US 2017284464 A1 US2017284464 A1 US 2017284464A1
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- Prior art keywords
- throttle
- groove
- minute
- block
- opposite
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
- F16L55/02—Energy absorbers; Noise absorbers
- F16L55/027—Throttle passages
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
- F16C32/0622—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings via nozzles, restrictors
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
- B23Q1/25—Movable or adjustable work or tool supports
- B23Q1/26—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members
- B23Q1/38—Movable or adjustable work or tool supports characterised by constructional features relating to the co-operation of relatively movable members; Means for preventing relative movement of such members using fluid bearings or fluid cushion supports
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C29/00—Bearings for parts moving only linearly
- F16C29/02—Sliding-contact bearings
- F16C29/025—Hydrostatic or aerostatic
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
- F16C32/0625—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings via supply slits
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0629—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion
- F16C32/064—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion the liquid being supplied under pressure
- F16C32/0651—Details of the bearing area per se
- F16C32/0655—Details of the bearing area per se of supply openings
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0629—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion
- F16C32/064—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion the liquid being supplied under pressure
- F16C32/0651—Details of the bearing area per se
- F16C32/0659—Details of the bearing area per se of pockets or grooves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0681—Construction or mounting aspects of hydrostatic bearings, for exclusively rotary movement, related to the direction of load
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2220/00—Shaping
- F16C2220/60—Shaping by removing material, e.g. machining
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2240/00—Specified values or numerical ranges of parameters; Relations between them
- F16C2240/40—Linear dimensions, e.g. length, radius, thickness, gap
- F16C2240/42—Groove sizes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2322/00—Apparatus used in shaping articles
- F16C2322/39—General build up of machine tools, e.g. spindles, slides, actuators
Definitions
- the present invention relates to a throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block.
- static pressure bearings In machine tools, as a guide device for a table having a linear motion axis or a rotational axis, static pressure bearings are used.
- a static pressure bearing in a case of a structure with a linear motion axis, for example, a static pressure pocket is formed on a bearing surface of a slide or a guide, and a working fluid such as oil or air is supplied to the static pressure pocket.
- the slide floats above the guide as a fixed portion by the static pressure of the working fluid, whereby the slide can be moved along the guide in a non-contact manner.
- a throttle unit (pipe resistance device) needs to be disposed in the middle of piping for supplying the working fluid from a pump to the static pressure pocket, for restricting the flow rate of the working fluid supplied from the pump.
- the pipe resistance i.e., restriction strength (degree of restriction) increases as the cross sectional area of minute fluid path (restriction path) becomes smaller or as the length thereof becomes longer.
- restriction strength degree of restriction
- the optimal restriction strength is obtained when the pressure of the working fluid in the static pressure pocket is 0.5 times as large as the pressure from the pump, and at the same time the largest rigidity of the bearing can be achieved.
- General throttle units include a unit using a thin tube like an injection needle (hereinafter referred to as a “needle throttle unit”), and a unit using a minute fluid path for restriction between a male thread and a female thread (hereinafter referred to as a “screw throttle unit”).
- the screw throttle unit is disclosed, for example, in Japanese Laid-Open Patent Publication No. 11-210905.
- the man hours for assembling the unit are large since the structure for incorporating the needle is complicated; the individual differences in the restriction strength are large since the variety of inner diameter errors of the respective needles is likely to affect the restriction strength; the unit has low reliability since the needle tends to fall off, and thus the restriction strength may change over time; due to a limit to the needle thinness, a thin needle is required to be long and have a special shape, for securing a certain degree or more of the restriction strength, so that the cost is high for preparing such a needle; and it is difficult to clean the unit when the needle is clogged with foreign material or the like.
- a throttle unit (hereinafter referred to as a “groove throttle unit”) in which a block with a plane surface having a groove thereon and another block with a plane surface are overlapped with each other to form a minute fluid path for realizing restriction.
- a minute fluid path has a simple cross sectional shape of a substantial square, and the minute fluid path is constituted by a simple component.
- the throttle unit described in Japanese Laid-Open Patent Publication No. 2006-266358 is capable of changing the restriction strength stepwise by lengthening the fluid path (path for restriction) which is achieved by stacking the blocks having grooves machined on plane surfaces to form the minute fluid paths.
- the individual differences in the restriction strength can be suppressed within a certain range.
- the restriction strength is increased, as the sectional area of a minute fluid path (a path for restriction) becomes smaller or the minute fluid path becomes longer.
- the resistance of a fluid path is proportional to a fluid path length, and inversely proportional to the fourth power of a fluid path diameter (the second power of a sectional area) of the fluid path. That is, a groove width and a groove depth which define a sectional area, particularly the formation of the groove depth which corresponds to the aforementioned fluid path diameter, require further accuracy.
- the groove depth is an important factor that influences the restriction strength.
- the groove disclosed in Japanese Laid-Open Patent Publication No. 2006-266358 has a cross section of a substantial square.
- the groove depth depends on a machine accuracy of the machine tool.
- the groove depth generally includes an error of about 50 ⁇ m with respect to a target value. Therefore, even when a substantially square cross section having a 100 ⁇ m groove depth is to be obtained, the groove depth after machining has an error of ⁇ 25%, from 75 ⁇ m to 125 ⁇ m. Thus, a single groove itself has a significantly large individual difference of ⁇ 56% in the restriction strength.
- the target value of the groove depth for a substantially square cross section is 1000 ⁇ m (1 mm), which is ten times as large as the aforementioned value, the error included in the machined groove depth is reduced to one tenth thereof, i.e., ⁇ 2.5%. Then, the single groove's individual difference in the restriction strength can be suppressed to ⁇ 5%.
- the fluid path length needs to be 100 times as long as that of the conventional one.
- Japanese Laid-Open Patent Publication No. 2006-266358 as a means for lengthening the groove, a plurality of lines (grooves) are formed on one plane surface of the block, or an additional block with a groove is provided.
- the groove shape to be machined is complicated, the cost becomes high due to increased man hours, and the restriction strength may be changed over time due to the clogging with foreign material. Further, it is expected that cleaning such a groove is difficult. Also, the number of components becomes large, undesirably resulting in high cost and a large size of the unit.
- Factors which affect the machine accuracy of a machine tool include thermal displacement by the influence of atmospheric temperature around the machine tool. If a groove depth is measured after machining, it is possible to machine the groove more accurately by adding some correction (thermal displacement correction) to the machine tool. Thus, it is extremely important to measure the groove depth after machining.
- a throttle unit used in a static pressure bearing it is preferable for a throttle unit used in a static pressure bearing to have a simple structure, minimize the individual differences in the restriction strength, have constant restriction strength without change over time, realize a low cost and a small size, and achieve easy cleaning.
- no such a throttle unit that satisfies all the aforementioned demands has been proposed so far.
- the cross section of the groove has a substantially square shape, the shape observed from above is the same even when the groove depth of the cross sectional shape varies due to the machine accuracy of the machine tool. Therefore, the groove depth, which is defined in the depth direction in the view field of the microscope, cannot be measured, and also it is difficult to machine the groove accurately.
- the present invention has been devised taking into consideration the aforementioned problems, and has the object of providing a throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block, which make it possible to ensure accurate groove machining and obtain an accurate groove shape, by enabling the groove depth as well as the groove width to be measured according to a general method in which the groove is observed from above with a microscope.
- the present invention is characterized by a throttle unit in which a working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole, the unit comprising a grooved block including at least one minute groove on a plane surface, an opposite block including a plane surface that is opposite to the minute groove, wherein the grooved block and the opposite block are opposite to each other and detachably joined to each other, the throttle fluid path is formed by the minute groove and the plane surface of the opposite block, at least one surface of the minute groove is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the grooved block.
- the cross section of the minute groove has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof.
- the groove depth as well as the groove width of the minute groove can be measured by a general method in which the groove is observed with a microscope from the direction perpendicular to the plane. Since the groove depth of the minute groove can be measured, more accurate machining can be achieved by correcting the machining device (machine tool) based on the machining result, and am accurate groove shape can be obtained.
- the minute groove may extend linearly from the supply hole to the discharge hole.
- the minute groove can be manufactured (by cutting) easily, in contrast to a conventional polygonal-chain minute groove constituted by a plurality of linear portions.
- a conventional polygonal-chain minute groove constituted by a plurality of linear portions.
- a plurality of the minute grooves may be arranged on a same line through the supply hole.
- the minute grooves With this structure, at the time of machining the minute grooves, a groove is machined only once across the supply hole. Then, the groove divided by the supply hole can be used as independent minute grooves. Since the plurality of minute grooves are formed in a single machining path, it is possible to reduce man hours for the machining.
- a plurality of the throttle fluid paths may be connected to the single supply hole.
- the discharge holes which are independent from each other, may communicate with the plurality of throttle fluid paths, and the working fluid that is supplied to the single supply hole may branches into the plurality of throttle fluid paths, and be discharged from the plurality of discharge holes.
- the number of throttle units provided in the static pressure bearing device can be reduced.
- additional parts for changing restriction strength are unnecessary, it is possible to minimize the number of parts, the portions to be sealed, and piping.
- the structure is simple, and the man hours for machining and assembling are small. Also, individual differences in the restriction strength are small, the cost is lowered, and it is easy to clean the unit.
- either the grooved block or the opposite block may function as a slide component, a guide component, or another throttle unit component.
- the structure can be simplified, the number of parts can be reduced, the installation space can be saved, and some piping can be omitted, and the like, since the throttle unit can be constituted substantially by one component.
- a width and a depth of the minute groove may be continuously changed, at least along part of a fluid path extending from the supply hole to the discharge hole.
- a minimum depth of a fluid path in the minute groove from the supply hole to the discharge hole may be 1000 ⁇ m or less.
- the present invention is characterized by a static pressure bearing device in a structure with a linear motion axis or a structure with a rotation axis, in which a static pressure bearing is constituted between a movable portion and a fixed portion of the structure with the linear motion axis or the structure with the rotation axis, the device comprising, a fluid supply line configured to supply a working fluid to a static pressure pocket formed in the movable portion or the fixed portion; and a throttle unit provided in the fluid supply line, wherein the throttle unit comprises any one of the above-described throttle units.
- the present invention is characterized by a method of manufacturing a grooved block that includes at least one minute groove on a plane surface, wherein the grooved block is a component of a throttle unit, a working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole, wherein the throttle unit comprises the grooved block, and an opposite block including a plane surface that is opposite to the minute groove, the grooved block and the opposite block are opposite to each other and detachably joined to each other, and the throttle fluid path is formed by the minute groove and the plane surface of the opposite block, the method comprising a cutting step of cutting a plane surface of a workpiece block to form the minute groove, at least one surface of the minute groove being constituted by a curved surface or a inclined surface that is inclined with respect to the plane surface of the workpiece block, a depth calculating step of calculating a groove depth of the minute groove that has been formed in the
- the throttle unit With the throttle unit according to the present invention, it is possible to ensure accurate groove machining and obtain an accurate groove shape, by enabling the groove depth as well as the groove width to be measured in a general method in which the minute groove is observed from above with a microscope. Therefore, by installing the throttle unit, it is possible to reduce the weight of parts, realize compact structure, reduce the cost by decreasing the number of parts and manufacturing steps, achieve high reliability, and improve maintainability due to easy disassembly and cleaning.
- FIG. 1 is a schematic cross sectional view of a static pressure bearing device according to an embodiment of the present invention
- FIG. 2 is an exploded perspective view of a throttle unit of the static pressure bearing device shown in FIG. 1 ;
- FIG. 3A is a plan view of a grooved block on which a minute groove is formed according to a first example
- FIG. 3B is a cross sectional view taken along a line IIIB-IIIB in FIG. 3A ;
- FIG. 4A is a plan view of a grooved block on which a minute groove is formed according to the first example, while the groove depth is deeper than that in FIG. 3A ;
- FIG. 4B is a cross sectional view taken along a line IVB-IVB in FIG. 4A ;
- FIG. 5A is a plan view of a grooved block on which a minute groove is formed according to a second example
- FIG. 5B is a cross sectional view taken along a line VB-VB in FIG. 5A ;
- FIG. 6A is a plan view of a grooved block on which a minute groove is formed according to the second example, while the groove depth is deeper than that in FIG. 5A ;
- FIG. 6B is a cross sectional view taken along a line VIB-VIB in FIG. 6A ;
- FIG. 7A is a plan view of a grooved block on which a minute groove is formed according to a third example
- FIG. 7B is a cross sectional view taken along a line VIIB-VIIB in FIG. 7A ;
- FIG. 8A is a plan view of a grooved block on which a minute groove is formed according to the third example, while the groove depth is deeper than that in FIG. 7A ;
- FIG. 8B is a cross sectional view taken along a line VIIIB-VIIIB in FIG. 8A ;
- FIG. 9A is a plan view of a grooved block on which a minute groove is formed according to a fourth example.
- FIG. 9B is a cross sectional view taken along a line IXB-IXB in FIG. 9A ;
- FIG. 9C is a cross sectional view taken along a line IXC-IXC in FIG. 9A ;
- FIG. 10A is a schematic cross sectional view of a static pressure bearing device according to another embodiment of the present invention.
- FIG. 10B is an exploded perspective view of a throttle unit of the static pressure bearing device shown in FIG. 10A ;
- FIG. 11 is an exploded perspective view of a static pressure bearing device according to still another embodiment of the present invention.
- FIG. 12 is a front view of a grooved block of the static pressure bearing device shown in FIG. 11 .
- a static pressure bearing device 10 A shown in FIG. 1 is equipped with a bearing unit 12 , and a throttle unit 14 A attached to the bearing unit 12 .
- the bearing unit 12 is equipped with a structure with a linear motion axis, in which a guide as a fixed portion and a slide as a movable portion are provided.
- a plurality of static pressure pockets are formed on a bearing surface of the slide or the guide.
- a working fluid such as air is supplied to the static pressure pockets, the slide floats above the guide by the static pressure of the working fluid and can move along the guide in a non-contact manner.
- the bearing unit 12 may have a structure with a rotary axis.
- the throttle unit 14 A is attached to the slide or guide of the bearing unit 12 . As shown in FIGS. 1 and 2 , the throttle unit 14 A is equipped with a supply hole 16 through which the working fluid is introduced, throttle fluid paths 18 for restricting the flow rate of the introduced working fluid, and discharge holes 20 for discharging the working fluid which has passed through the throttle fluid paths 18 . To the supply hole 16 , a pump 22 as a supply source of the working fluid is connected through a fluid path supply line. The discharge holes 20 communicate with the static pressure pockets of the bearing unit 12 .
- the throttle unit 14 A is equipped with a grooved block 24 including a plane surface 15 and minute grooves 25 formed on the plane surface 15 , and an opposite block 26 detachably attached to the grooved block 24 and having a plane surface 27 which is opposite to or face toward the minute grooves 25 .
- the grooved block 24 and the opposite block 26 are joined so as to be opposite to each other in an assembled state.
- the throttle fluid paths 18 are formed by the minute grooves 25 and the plane surface 27 of the opposite block 26 .
- the supply hole 16 is formed in the opposite block 26 .
- the supply hole 16 penetrates through the opposite block 26 in the thickness direction. More specifically, the supply hole 16 has an introduction portion 30 , and a diffusion portion 32 that is formed on the downstream side (grooved block 24 side) of the introduction portion 30 .
- the diffusion portion 32 diffuses the working fluid in the directions that are perpendicular to the thickness direction of the opposite block 26 , i.e., the directions in which the plurality of minute grooves 25 are separated from each other.
- the diffusion portion 32 supplies the working fluid to the plurality of throttle fluid paths 18 which will be described later.
- the throttle fluid paths 18 are minute fluid paths for reducing pressure of the working fluid by restricting the flow rate of the working fluid.
- the throttle fluid paths 18 (minute grooves 25 ) linearly extend between the supply hole 16 and the discharge holes 20 . It is preferable that the minute grooves 25 have a minimum depth of 1000 ⁇ m or less, in the fluid path from the supply hole 16 to the discharge holes 20 .
- the plurality of (three, in the illustrated embodiment) minute grooves 25 are formed on the grooved block 24 .
- the throttle unit 14 A has the plurality of (three, in the illustrated embodiment) throttle fluid paths 18 which are independent of each other.
- the plurality of throttle fluid paths 18 communicate with the single supply hole 16 . That is, the throttle unit 14 A has the single supply hole 16 which is commonly used for the plurality of throttle fluid paths 18 .
- the discharge holes 20 are formed in the grooved block 24 .
- the discharge holes 20 penetrate through the opposite block 26 in the thickness direction.
- the throttle unit 14 A has the same number of the discharge holes 20 as the throttle fluid paths 18 . That is, the discharge holes 20 , which are independent from each other, communicate with the respective throttle fluid paths 18 .
- the working fluid supplied to the single supply hole 16 branches into the plurality of throttle fluid paths 18 , and is discharged from the plurality of discharge holes 20 . Then, the working fluid is supplied to the plurality of static pressure pockets formed in the bearing unit 12 .
- each of the minute grooves 25 is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface 15 of the grooved block 24 .
- the cross section of the minute groove 25 has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof. Due to this feature, the groove depth as well as the groove width of the minute groove 25 can be measured by a general method in which the groove is observed from above with a microscope.
- the minute grooves 25 can be formed by machining or cutting a plane surface of a workpiece block made of metal.
- FIGS. 3A through 8B respectively, figures indicated by references with a suffix “A” (e.g., 3 A) show observational cases in which the minute groove 25 is observed from above (plan view), and figures indicated by references with a suffix “B” (e.g., 3 B) are cross sectional views in which a cross sectional shape of the minute groove 25 is shown.
- an area surrounded by a broken line V indicates a field of view when observed with a microscope.
- a minute groove 25 A shown as one example (first example) of the minute groove 25 , has a trapezoidal cross section.
- the width of a bottom surface which corresponds to a lower base of the trapezoid, is smaller than the width of an opening (groove width), which corresponds to an upper base of the trapezoid.
- both side surfaces 34 which correspond to the two legs of the trapezoid, are inclined with respect to the thickness direction of the grooved block 24 .
- either one of the side surfaces 34 of the minute groove 25 A may be formed in parallel with the thickness direction of the grooved block 24 .
- FIGS. 3A and 3B show a case in which the minute groove 25 A having a trapezoidal cross sectional shape has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of the minute groove 25 A shown in FIGS. 3A and 3B , depending on the machine accuracy of the machine tool.
- a minute groove 25 B shown as another example (second example) of the minute groove 25 , has an arcuate or circular cross section.
- FIGS. 6A and 6B show a case in which the minute groove 25 B having an arcuate cross section has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of the minute groove 25 B shown in FIGS. 5A and 5B , depending on the machine accuracy of the machine tool.
- a minute groove 25 C shown as still another example (third example) of the minute groove 25 , has a polygonal cross section except for a substantial rectangular cross section.
- FIGS. 8A and 8B show a case in which the minute groove 25 C having a polygonal cross section (except for a substantial rectangular cross section) has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of the minute groove 25 C shown in FIGS. 7A and 7B , depending on the machine accuracy of the machine tool.
- the groove depth can be calculated from the groove width.
- the groove depth D can be calculated based on the groove width W 1 .
- the groove depth D can be calculated based on the width W 2 of the inclined surface (the width of inclined side surface 34 as observed from above).
- the groove depth can be calculated based on the groove width or the width of a portion that is part of the surface of the minute groove 25 and varies based on the groove depth.
- the minute groove 25 is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface 15 of the grooved block 24 .
- the cross section of the minute groove 25 has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof.
- the groove depth as well as the groove width of the minute groove 25 can be measured by a general method in which the minute groove 25 is observed from above (in the direction that is perpendicular to the plane surface 15 ) with a microscope. Since the groove depth of the minute groove 25 can be measured, more precise machining can be achieved by correcting the machining device (thermal displacement correction or the like) based on the machining result, and a precise groove shape can be obtained.
- the manufacturing method of the grooved block 24 includes a cutting step, a calculating step, and a correcting step.
- the cutting step the plane surface of a workpiece block is cut to form the minute groove 25 , and at least one surface of the minute groove 25 is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the workpiece block.
- the calculating step the minute groove 25 that has been formed in the cutting step is observed with a microscope in the direction perpendicular to the surface of the workpiece block (grooved block 24 ), and the groove depth of the observed minute groove 25 is calculated.
- the correcting step a machining device that performs the cutting is corrected, based on the groove depth calculated in the calculating step.
- the plurality of throttle fluid paths 18 communicate with the single supply hole 16 , and the discharge holes 20 , which are independent from each other, communicate with the respective throttle fluid paths 18 .
- the working fluid that is supplied to the single supply hole 16 branches into the plurality of throttle fluid paths 18 , and is discharged from the plurality of discharge holes 20 .
- the throttle unit 14 A it is possible to reduce the weight of parts, realize compact structure, reduce the cost by decreasing the number of parts and manufacturing steps, achieve high reliability, and improve maintainability by easy disassembly and cleaning.
- the minute groove 25 can adopt a simple linear shape, and thus it is possible to suppress clogging with the foreign material.
- a minute groove 25 D shown as still another example (fourth example) of the minute groove 25 , has continuously-changed groove width and groove depth at least partially in its overall length (from the supply hole 16 to the discharge hole 20 ).
- the groove width and the groove depth of the minute groove 25 D may be continuously changed over its overall length.
- the minute groove 25 D having a trapezoidal cross section is illustrated. More specifically, as shown in FIG. 9A , the groove width of the minute groove 25 D is continuously changed in the longitudinal direction of the minute groove 25 D.
- sizes of a cross sectional shape are different at different positions.
- the cross sectional shape of the minute groove 25 D, the groove width and the groove depth of which are continuously changed, may have an arcuate cross section in a similar manner to the minute groove 25 B shown in FIGS. 5A through 6B .
- it may have a polygonal cross section except for a substantial rectangular cross section in a similar manner to the minute groove 25 C shown in FIGS. 7A through 8B .
- a throttle unit 14 B shown in FIGS. 10A and 10B is equipped with a grooved block 24 a and an opposite block 26 a .
- the grooved block 24 a includes a plane surface, a supply hole 16 , minute grooves 25 , and discharge holes 20 .
- the opposite block 26 a includes a plane surface 27 that is opposite to the minute grooves 25 . That is, the throttle unit 14 B corresponds to the aforementioned throttle unit 14 A, though the supply hole 16 is formed in the grooved block 24 instead of the opposite block 26 .
- the respective minute grooves 25 can be any of the aforementioned minute grooves 25 A through 25 D.
- the static pressure bearing device 10 B shown in FIG. 10B is equipped with a bearing unit 12 , and the throttle unit 14 B that is detachably attached to the bearing unit 12 . With the throttle unit 14 B constituted as above, the same advantageous effects as those according to the aforementioned throttle unit 14 A can be obtained.
- a static pressure bearing device 10 C shown in FIG. 11 is equipped with a bearing unit 12 , and a grooved block 24 b detachably attached to the bearing unit 12 .
- FIG. 11 shows a state in which the grooved block 24 b is detached from the bearing unit 12 .
- the bearing unit 12 has a guide 38 as a fixed portion and a slide (not shown) as a movable portion.
- the guide 38 is provided with a plurality of static pressure pockets 40 .
- the guide 38 has the plane surface 27 that is opposite to the plurality of minute grooves 25 formed in the grooved block 24 b , in a state in which the grooved block 24 b is attached (fixed) to the bearing unit 12 .
- a plurality of throttle fluid paths 18 are formed by the plurality of minute grooves 25 and the plane surface 27 .
- a component of the guide 38 of the bearing unit 12 also functions as an opposite block 26 b that has the plane surface 27 opposite to the plurality of minute grooves 25 .
- the plurality of static pressure pockets 40 may be formed on the slide which is a movable portion.
- the minute grooves 25 can be any of the aforementioned minute grooves 25 A through 25 D.
- each of the minute grooves 25 linearly extend from the supply hole 16 to the discharge holes 20 .
- the two minute grooves 25 are arranged on the same line through the supply hole 16 .
- a plurality of (three, in the illustrated embodiment) pairs of the two minute grooves 25 arranged on the same line are provided.
- the plurality of minute grooves 25 (throttle fluid paths 18 ) communicate with the single supply hole 16 .
- the working fluid supplied to the single supply hole 16 branches into the plurality of throttle fluid paths 18 , and is discharged from the plurality of discharge holes 20 .
- a throttle unit 14 C is constituted by the grooved block 24 b as configured above, and the opposite block 26 b which also functions as a component of the guide 38 .
- the throttle unit 14 C can be constituted only by attaching the grooved block 24 b to the guide 38 that has the plane surface 27 and is a static pressure bearing component.
- the grooved block 24 b may function as a component of the guide. Otherwise, the grooved block 24 b or the opposite block 26 b may function as a component of the slide of the bearing unit 12 or a component of another throttle unit.
- the same advantageous effects as those according to the aforementioned throttle unit 14 A can be obtained.
- one groove-forming operation from one side of the supply hole 16 to the other side gives grooves divided by the supply hole 16 such that the grooves can be used as the independent minute grooves 25 . Since the plurality of minute grooves 25 are formed in a single machining path, it is possible to reduce man hours for the machining.
- the throttle unit 14 C can substantially be configured by a single component. In accordance with this feature, it is expected that the structure is simplified, the number of parts is reduced, the installation space is saved, and some piping is omitted.
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Abstract
Description
- This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2016-076039 filed on Apr. 5, 2016, the contents of which are incorporated herein by reference.
- Field of the Invention:
- The present invention relates to a throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block.
- Description of the Related Art:
- In machine tools, as a guide device for a table having a linear motion axis or a rotational axis, static pressure bearings are used. In a static pressure bearing, in a case of a structure with a linear motion axis, for example, a static pressure pocket is formed on a bearing surface of a slide or a guide, and a working fluid such as oil or air is supplied to the static pressure pocket. The slide floats above the guide as a fixed portion by the static pressure of the working fluid, whereby the slide can be moved along the guide in a non-contact manner.
- Generally, to obtain rigidity of the static pressure bearing, a throttle unit (pipe resistance device) needs to be disposed in the middle of piping for supplying the working fluid from a pump to the static pressure pocket, for restricting the flow rate of the working fluid supplied from the pump. The pipe resistance, i.e., restriction strength (degree of restriction) increases as the cross sectional area of minute fluid path (restriction path) becomes smaller or as the length thereof becomes longer. The optimal restriction strength is obtained when the pressure of the working fluid in the static pressure pocket is 0.5 times as large as the pressure from the pump, and at the same time the largest rigidity of the bearing can be achieved.
- General throttle units include a unit using a thin tube like an injection needle (hereinafter referred to as a “needle throttle unit”), and a unit using a minute fluid path for restriction between a male thread and a female thread (hereinafter referred to as a “screw throttle unit”). The screw throttle unit is disclosed, for example, in Japanese Laid-Open Patent Publication No. 11-210905.
- Problems of the needle throttle unit include the following points: the man hours for assembling the unit are large since the structure for incorporating the needle is complicated; the individual differences in the restriction strength are large since the variety of inner diameter errors of the respective needles is likely to affect the restriction strength; the unit has low reliability since the needle tends to fall off, and thus the restriction strength may change over time; due to a limit to the needle thinness, a thin needle is required to be long and have a special shape, for securing a certain degree or more of the restriction strength, so that the cost is high for preparing such a needle; and it is difficult to clean the unit when the needle is clogged with foreign material or the like.
- Problems of the screw throttle unit include the following points: The number of parts or components is large and the structure of the unit is complicated, so that man hours for assembling are large; Precise adjustment is indispensable and the individual differences in the restriction strength become large depending on the adjustment state; The restriction strength may change in time due to looseness of the screw; The cost is high because of the large number of components; And it is difficult to clean the unit when the unit is clogged with foreign material or the like.
- For overcoming part of the above problems, there is a throttle unit (hereinafter referred to as a “groove throttle unit”) in which a block with a plane surface having a groove thereon and another block with a plane surface are overlapped with each other to form a minute fluid path for realizing restriction. In a groove throttle unit disclosed in Japanese Laid-Open Patent Publication No. 2006-266358, a minute fluid path has a simple cross sectional shape of a substantial square, and the minute fluid path is constituted by a simple component. Thus, there is an advantageous effect that the restriction strength is not changed over time after assembly, the change of the restriction strength being caused by the falling-off or displacement of the components in the case of a needle throttle unit or a screw throttle unit.
- Further, the throttle unit described in Japanese Laid-Open Patent Publication No. 2006-266358 is capable of changing the restriction strength stepwise by lengthening the fluid path (path for restriction) which is achieved by stacking the blocks having grooves machined on plane surfaces to form the minute fluid paths. Thus, the individual differences in the restriction strength can be suppressed within a certain range.
- As described above, the restriction strength is increased, as the sectional area of a minute fluid path (a path for restriction) becomes smaller or the minute fluid path becomes longer. Generally, the resistance of a fluid path is proportional to a fluid path length, and inversely proportional to the fourth power of a fluid path diameter (the second power of a sectional area) of the fluid path. That is, a groove width and a groove depth which define a sectional area, particularly the formation of the groove depth which corresponds to the aforementioned fluid path diameter, require further accuracy.
- As described, the groove depth is an important factor that influences the restriction strength. The groove disclosed in Japanese Laid-Open Patent Publication No. 2006-266358 has a cross section of a substantial square. Thus, by a general method as a means for inspecting the groove depth, in which the groove is observed from above with a microscope, even though the groove width may be measured, the groove depth, which is defined in the depth direction in the view field of the microscope, cannot be measured.
- When a shape of the groove is formed by machining, the groove depth depends on a machine accuracy of the machine tool. In a case of using a machine tool, the groove depth generally includes an error of about 50 μm with respect to a target value. Therefore, even when a substantially square cross section having a 100 μm groove depth is to be obtained, the groove depth after machining has an error of ±25%, from 75 μm to 125 μm. Thus, a single groove itself has a significantly large individual difference of ±56% in the restriction strength.
- In order to decrease the aforementioned individual difference, it is necessary to reduce the influence of the error of about 50 μm included in the groove depth. Thus, it is necessary to lengthen the groove width and the groove depth to enlarge a cross sectional area, and further it is necessary to lengthen the groove length. For example, if the target value of the groove depth for a substantially square cross section is 1000 μm (1 mm), which is ten times as large as the aforementioned value, the error included in the machined groove depth is reduced to one tenth thereof, i.e., ±2.5%. Then, the single groove's individual difference in the restriction strength can be suppressed to ±5%. However, in order to secure restriction strength similar to the conventional one, the fluid path length needs to be 100 times as long as that of the conventional one.
- According to Japanese Laid-Open Patent Publication No. 2006-266358, as a means for lengthening the groove, a plurality of lines (grooves) are formed on one plane surface of the block, or an additional block with a groove is provided. However, since the groove shape to be machined is complicated, the cost becomes high due to increased man hours, and the restriction strength may be changed over time due to the clogging with foreign material. Further, it is expected that cleaning such a groove is difficult. Also, the number of components becomes large, undesirably resulting in high cost and a large size of the unit.
- Factors which affect the machine accuracy of a machine tool include thermal displacement by the influence of atmospheric temperature around the machine tool. If a groove depth is measured after machining, it is possible to machine the groove more accurately by adding some correction (thermal displacement correction) to the machine tool. Thus, it is extremely important to measure the groove depth after machining.
- It is preferable for a throttle unit used in a static pressure bearing to have a simple structure, minimize the individual differences in the restriction strength, have constant restriction strength without change over time, realize a low cost and a small size, and achieve easy cleaning. However, no such a throttle unit that satisfies all the aforementioned demands has been proposed so far. Further, like the minute groove disclosed in Japanese Laid-Open Patent Publication No. 2006-266358, if the cross section of the groove has a substantially square shape, the shape observed from above is the same even when the groove depth of the cross sectional shape varies due to the machine accuracy of the machine tool. Therefore, the groove depth, which is defined in the depth direction in the view field of the microscope, cannot be measured, and also it is difficult to machine the groove accurately.
- The present invention has been devised taking into consideration the aforementioned problems, and has the object of providing a throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block, which make it possible to ensure accurate groove machining and obtain an accurate groove shape, by enabling the groove depth as well as the groove width to be measured according to a general method in which the groove is observed from above with a microscope.
- In order to achieve the above object, the present invention is characterized by a throttle unit in which a working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole, the unit comprising a grooved block including at least one minute groove on a plane surface, an opposite block including a plane surface that is opposite to the minute groove, wherein the grooved block and the opposite block are opposite to each other and detachably joined to each other, the throttle fluid path is formed by the minute groove and the plane surface of the opposite block, at least one surface of the minute groove is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the grooved block.
- With the throttle unit according to the present invention, in which above configuration is adopted, the cross section of the minute groove has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof. Thus, the groove depth as well as the groove width of the minute groove can be measured by a general method in which the groove is observed with a microscope from the direction perpendicular to the plane. Since the groove depth of the minute groove can be measured, more accurate machining can be achieved by correcting the machining device (machine tool) based on the machining result, and am accurate groove shape can be obtained.
- In the throttle unit, the minute groove may extend linearly from the supply hole to the discharge hole.
- With this structure, the minute groove can be manufactured (by cutting) easily, in contrast to a conventional polygonal-chain minute groove constituted by a plurality of linear portions. Thus, it is possible to prevent the corners (bent portions) of the minute groove from being clogged with the foreign material.
- In the throttle unit, a plurality of the minute grooves may be arranged on a same line through the supply hole.
- With this structure, at the time of machining the minute grooves, a groove is machined only once across the supply hole. Then, the groove divided by the supply hole can be used as independent minute grooves. Since the plurality of minute grooves are formed in a single machining path, it is possible to reduce man hours for the machining.
- In the throttle unit, a plurality of the throttle fluid paths may be connected to the single supply hole. Also, the discharge holes, which are independent from each other, may communicate with the plurality of throttle fluid paths, and the working fluid that is supplied to the single supply hole may branches into the plurality of throttle fluid paths, and be discharged from the plurality of discharge holes.
- With this structure, the number of throttle units provided in the static pressure bearing device can be reduced. Thus, it is possible to lower the cost, simplify the structure, and omit some piping. Accordingly, since additional parts for changing restriction strength are unnecessary, it is possible to minimize the number of parts, the portions to be sealed, and piping. Further, the structure is simple, and the man hours for machining and assembling are small. Also, individual differences in the restriction strength are small, the cost is lowered, and it is easy to clean the unit.
- In the throttle unit, either the grooved block or the opposite block may function as a slide component, a guide component, or another throttle unit component.
- In accordance with this feature, it is expected that the structure can be simplified, the number of parts can be reduced, the installation space can be saved, and some piping can be omitted, and the like, since the throttle unit can be constituted substantially by one component.
- In the throttle unit, a width and a depth of the minute groove may be continuously changed, at least along part of a fluid path extending from the supply hole to the discharge hole.
- With this structure, even if foreign material somewhat clogs the minute groove, it is possible to easily gather the foreign material at a small cross sectional portion of the minute groove. Thus, the portion clogged with foreign material is easily confirmed at the time of cleaning operation for the disassembled device, and the foreign material can be removed efficiently.
- In the throttle unit, a minimum depth of a fluid path in the minute groove from the supply hole to the discharge hole may be 1000 μm or less.
- Further, the present invention is characterized by a static pressure bearing device in a structure with a linear motion axis or a structure with a rotation axis, in which a static pressure bearing is constituted between a movable portion and a fixed portion of the structure with the linear motion axis or the structure with the rotation axis, the device comprising, a fluid supply line configured to supply a working fluid to a static pressure pocket formed in the movable portion or the fixed portion; and a throttle unit provided in the fluid supply line, wherein the throttle unit comprises any one of the above-described throttle units.
- Still further, the present invention is characterized by a method of manufacturing a grooved block that includes at least one minute groove on a plane surface, wherein the grooved block is a component of a throttle unit, a working fluid is introduced from at least one supply hole, the introduced working fluid flows in a minute throttle fluid path, and the working fluid which has passed through the throttle fluid path is discharged from at least one discharge hole, wherein the throttle unit comprises the grooved block, and an opposite block including a plane surface that is opposite to the minute groove, the grooved block and the opposite block are opposite to each other and detachably joined to each other, and the throttle fluid path is formed by the minute groove and the plane surface of the opposite block, the method comprising a cutting step of cutting a plane surface of a workpiece block to form the minute groove, at least one surface of the minute groove being constituted by a curved surface or a inclined surface that is inclined with respect to the plane surface of the workpiece block, a depth calculating step of calculating a groove depth of the minute groove that has been formed in the machining step, observing the minute groove (25, 25A through 25D) with a microscope from a direction perpendicular to the surface of the workpiece block, and a correcting step of making a correction of a machining device that performs the cutting, based on the calculated groove depth.
- With the throttle unit according to the present invention, it is possible to ensure accurate groove machining and obtain an accurate groove shape, by enabling the groove depth as well as the groove width to be measured in a general method in which the minute groove is observed from above with a microscope. Therefore, by installing the throttle unit, it is possible to reduce the weight of parts, realize compact structure, reduce the cost by decreasing the number of parts and manufacturing steps, achieve high reliability, and improve maintainability due to easy disassembly and cleaning.
- The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which a preferred embodiment of the present invention is shown by way of illustrative example.
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FIG. 1 is a schematic cross sectional view of a static pressure bearing device according to an embodiment of the present invention; -
FIG. 2 is an exploded perspective view of a throttle unit of the static pressure bearing device shown inFIG. 1 ; -
FIG. 3A is a plan view of a grooved block on which a minute groove is formed according to a first example; -
FIG. 3B is a cross sectional view taken along a line IIIB-IIIB inFIG. 3A ; -
FIG. 4A is a plan view of a grooved block on which a minute groove is formed according to the first example, while the groove depth is deeper than that inFIG. 3A ; -
FIG. 4B is a cross sectional view taken along a line IVB-IVB inFIG. 4A ; -
FIG. 5A is a plan view of a grooved block on which a minute groove is formed according to a second example; -
FIG. 5B is a cross sectional view taken along a line VB-VB inFIG. 5A ; -
FIG. 6A is a plan view of a grooved block on which a minute groove is formed according to the second example, while the groove depth is deeper than that inFIG. 5A ;FIG. 6B is a cross sectional view taken along a line VIB-VIB inFIG. 6A ; -
FIG. 7A is a plan view of a grooved block on which a minute groove is formed according to a third example; -
FIG. 7B is a cross sectional view taken along a line VIIB-VIIB inFIG. 7A ; -
FIG. 8A is a plan view of a grooved block on which a minute groove is formed according to the third example, while the groove depth is deeper than that inFIG. 7A ; -
FIG. 8B is a cross sectional view taken along a line VIIIB-VIIIB inFIG. 8A ; -
FIG. 9A is a plan view of a grooved block on which a minute groove is formed according to a fourth example; -
FIG. 9B is a cross sectional view taken along a line IXB-IXB inFIG. 9A ; -
FIG. 9C is a cross sectional view taken along a line IXC-IXC inFIG. 9A ; -
FIG. 10A is a schematic cross sectional view of a static pressure bearing device according to another embodiment of the present invention; -
FIG. 10B is an exploded perspective view of a throttle unit of the static pressure bearing device shown inFIG. 10A ; -
FIG. 11 is an exploded perspective view of a static pressure bearing device according to still another embodiment of the present invention; and -
FIG. 12 is a front view of a grooved block of the static pressure bearing device shown inFIG. 11 . - A preferred embodiment of a throttle unit and a static pressure bearing device having the throttle unit, and a method of manufacturing a grooved block according to the present invention will be described below with reference to the accompanying drawings.
- A static
pressure bearing device 10A shown inFIG. 1 is equipped with a bearingunit 12, and athrottle unit 14A attached to the bearingunit 12. Though the detailed structure is not shown, the bearingunit 12 is equipped with a structure with a linear motion axis, in which a guide as a fixed portion and a slide as a movable portion are provided. A plurality of static pressure pockets are formed on a bearing surface of the slide or the guide. When a working fluid such as air is supplied to the static pressure pockets, the slide floats above the guide by the static pressure of the working fluid and can move along the guide in a non-contact manner. The bearingunit 12 may have a structure with a rotary axis. - The
throttle unit 14A is attached to the slide or guide of the bearingunit 12. As shown in FIGS.1 and 2, thethrottle unit 14A is equipped with asupply hole 16 through which the working fluid is introduced,throttle fluid paths 18 for restricting the flow rate of the introduced working fluid, and discharge holes 20 for discharging the working fluid which has passed through thethrottle fluid paths 18. To thesupply hole 16, apump 22 as a supply source of the working fluid is connected through a fluid path supply line. The discharge holes 20 communicate with the static pressure pockets of the bearingunit 12. - More specifically, the
throttle unit 14A is equipped with agrooved block 24 including aplane surface 15 andminute grooves 25 formed on theplane surface 15, and anopposite block 26 detachably attached to thegrooved block 24 and having aplane surface 27 which is opposite to or face toward theminute grooves 25. Thegrooved block 24 and theopposite block 26 are joined so as to be opposite to each other in an assembled state. Thethrottle fluid paths 18 are formed by theminute grooves 25 and theplane surface 27 of theopposite block 26. - The
supply hole 16 is formed in theopposite block 26. Thesupply hole 16 penetrates through theopposite block 26 in the thickness direction. More specifically, thesupply hole 16 has anintroduction portion 30, and adiffusion portion 32 that is formed on the downstream side (groovedblock 24 side) of theintroduction portion 30. Thediffusion portion 32 diffuses the working fluid in the directions that are perpendicular to the thickness direction of theopposite block 26, i.e., the directions in which the plurality ofminute grooves 25 are separated from each other. Thediffusion portion 32 supplies the working fluid to the plurality ofthrottle fluid paths 18 which will be described later. - The
throttle fluid paths 18 are minute fluid paths for reducing pressure of the working fluid by restricting the flow rate of the working fluid. The throttle fluid paths 18 (minute grooves 25) linearly extend between thesupply hole 16 and the discharge holes 20. It is preferable that theminute grooves 25 have a minimum depth of 1000 μm or less, in the fluid path from thesupply hole 16 to the discharge holes 20. - The plurality of (three, in the illustrated embodiment)
minute grooves 25 are formed on thegrooved block 24. Thus, thethrottle unit 14A has the plurality of (three, in the illustrated embodiment)throttle fluid paths 18 which are independent of each other. The plurality ofthrottle fluid paths 18 communicate with thesingle supply hole 16. That is, thethrottle unit 14A has thesingle supply hole 16 which is commonly used for the plurality ofthrottle fluid paths 18. - The discharge holes 20 are formed in the
grooved block 24. The discharge holes 20 penetrate through theopposite block 26 in the thickness direction. Thethrottle unit 14A has the same number of the discharge holes 20 as thethrottle fluid paths 18. That is, the discharge holes 20, which are independent from each other, communicate with the respectivethrottle fluid paths 18. In thethrottle unit 14A, accordingly, the working fluid supplied to thesingle supply hole 16 branches into the plurality ofthrottle fluid paths 18, and is discharged from the plurality of discharge holes 20. Then, the working fluid is supplied to the plurality of static pressure pockets formed in the bearingunit 12. - Next, the structure of the
minute grooves 25, which are formed on thegrooved block 24, is more specifically described. At least one surface of each of theminute grooves 25 is constituted by a curved surface or an inclined surface that is inclined with respect to theplane surface 15 of thegrooved block 24. The cross section of theminute groove 25 has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof. Due to this feature, the groove depth as well as the groove width of theminute groove 25 can be measured by a general method in which the groove is observed from above with a microscope. Theminute grooves 25 can be formed by machining or cutting a plane surface of a workpiece block made of metal. - Hereinafter, some patterns of a cross sectional shape of the
minute groove 25 will be illustrated. InFIGS. 3A through 8B , respectively, figures indicated by references with a suffix “A” (e.g., 3A) show observational cases in which theminute groove 25 is observed from above (plan view), and figures indicated by references with a suffix “B” (e.g., 3B) are cross sectional views in which a cross sectional shape of theminute groove 25 is shown. In each of these figures, e.g., an area surrounded by a broken line V indicates a field of view when observed with a microscope. - In
FIGS. 3A and 3B , aminute groove 25A, shown as one example (first example) of theminute groove 25, has a trapezoidal cross section. In theminute groove 25A, the width of a bottom surface, which corresponds to a lower base of the trapezoid, is smaller than the width of an opening (groove width), which corresponds to an upper base of the trapezoid. In theillustrated minute groove 25A, both side surfaces 34, which correspond to the two legs of the trapezoid, are inclined with respect to the thickness direction of thegrooved block 24. In this case, either one of the side surfaces 34 of theminute groove 25A may be formed in parallel with the thickness direction of thegrooved block 24.FIGS. 4A and 4B show a case in which theminute groove 25A having a trapezoidal cross sectional shape has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of theminute groove 25A shown inFIGS. 3A and 3B , depending on the machine accuracy of the machine tool. - In
FIGS. 5A and 5B , aminute groove 25B, shown as another example (second example) of theminute groove 25, has an arcuate or circular cross section.FIGS. 6A and 6B show a case in which theminute groove 25B having an arcuate cross section has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of theminute groove 25B shown inFIGS. 5A and 5B , depending on the machine accuracy of the machine tool. - In
FIGS. 7A and 7B , a minute groove 25C, shown as still another example (third example) of theminute groove 25, has a polygonal cross section except for a substantial rectangular cross section.FIGS. 8A and 8B show a case in which the minute groove 25C having a polygonal cross section (except for a substantial rectangular cross section) has been machined with a machine tool having the same shape, but the groove depth of the cross sectional shape becomes deeper than that of the minute groove 25C shown inFIGS. 7A and 7B , depending on the machine accuracy of the machine tool. - In comparison between
FIGS. 3A and 4A , betweenFIGS. 5A and 6A , and betweenFIGS. 7A and 8A , in which theminute groove 25 is observed from above, it is understood that the observed groove width is changed depending on the change in the groove depth, even if the groove is machined with the cutting tool having the same shape. That is, when the machine tool having the same shape is used, the deeper the groove depth is, the wider the groove width is. - With regard to the
minute grooves 25A through 25C having these cross sectional shapes, since the shapes of the machine tools are known, the groove depth can be calculated from the groove width. For example, as to theminute groove 25A having a trapezoidal cross section (seeFIG. 3B ), the groove depth D can be calculated based on the groove width W1. Otherwise, as to theminute groove 25A, the groove depth D can be calculated based on the width W2 of the inclined surface (the width ofinclined side surface 34 as observed from above). Regardingother minute grooves 25 having respective cross sectional shapes as well, the groove depth can be calculated based on the groove width or the width of a portion that is part of the surface of theminute groove 25 and varies based on the groove depth. - As described above, in the
throttle unit 14A, at least one surface of theminute groove 25 is constituted by a curved surface or an inclined surface that is inclined with respect to theplane surface 15 of thegrooved block 24. The cross section of theminute groove 25 has a shape such as a triangle, a trapezoid, a polygon (except for a substantial rectangle), an arc, or a combination thereof. Thus, due to this feature, the groove depth as well as the groove width of theminute groove 25 can be measured by a general method in which theminute groove 25 is observed from above (in the direction that is perpendicular to the plane surface 15) with a microscope. Since the groove depth of theminute groove 25 can be measured, more precise machining can be achieved by correcting the machining device (thermal displacement correction or the like) based on the machining result, and a precise groove shape can be obtained. - In this manner, the manufacturing method of the
grooved block 24 includes a cutting step, a calculating step, and a correcting step. In the cutting step, the plane surface of a workpiece block is cut to form theminute groove 25, and at least one surface of theminute groove 25 is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the workpiece block. In the calculating step, theminute groove 25 that has been formed in the cutting step is observed with a microscope in the direction perpendicular to the surface of the workpiece block (grooved block 24), and the groove depth of the observedminute groove 25 is calculated. In the correcting step, a machining device that performs the cutting is corrected, based on the groove depth calculated in the calculating step. - In the aforementioned Japanese Laid-Open Patent Publication No. 2006-266358, since a total length of a fluid path is increased by connecting a plurality of linear minute grooves that extend in different directions from each other, corners (bent portions) of the minute grooves tend to be clogged with foreign material. In contrast, the
throttle unit 14A according to the present embodiment, preferable restriction strength can be obtained even if the cross sectional shape of thethrottle fluid path 18 is small and a fluid path length of thethrottle fluid path 18 is short. Thus, thethrottle fluid path 18 can be made linear, i.e., simply extend from thesupply hole 16 to thedischarge hole 20 linearly. Accordingly, theminute groove 25 can be manufactured (by cutting) easily, and it is possible to suppress clogging with the foreign material in theminute groove 25. - Further, in the
throttle unit 14A, the plurality ofthrottle fluid paths 18 communicate with thesingle supply hole 16, and the discharge holes 20, which are independent from each other, communicate with the respectivethrottle fluid paths 18. The working fluid that is supplied to thesingle supply hole 16 branches into the plurality ofthrottle fluid paths 18, and is discharged from the plurality of discharge holes 20. With this feature, the number ofthrottle units 14A that are provided in the staticpressure bearing device 10A can be reduced. Thus, it is possible to lower the cost, simplify the structure, and omit some piping. Accordingly, since additional parts for changing restriction strength are unnecessary, it is possible to minimize the number of parts, the portions to be sealed, and piping. Further, the structure is simple, and the man hours for machining and assembling are small. Also, individual differences in the restriction strength are small, the cost is lowered, and it is easy to clean the unit. - Therefore, by installing the
throttle unit 14A, it is possible to reduce the weight of parts, realize compact structure, reduce the cost by decreasing the number of parts and manufacturing steps, achieve high reliability, and improve maintainability by easy disassembly and cleaning. - In the meantime, the
minute groove 25 can adopt a simple linear shape, and thus it is possible to suppress clogging with the foreign material. However, on the other hand it is impossible to completely avoid the clogging with foreign material depending on the cleanliness of supplied working fluid, also in view of the smallness of the cross sectional shape of the throttle fluid path 18 (minute groove 25). Thus, it is necessary to confirm the location of foreign material and remove it at the time of disassembling and cleaning operations for the device. - In
FIGS. 9A through 9C , aminute groove 25D, shown as still another example (fourth example) of theminute groove 25, has continuously-changed groove width and groove depth at least partially in its overall length (from thesupply hole 16 to the discharge hole 20). The groove width and the groove depth of theminute groove 25D may be continuously changed over its overall length. InFIGS. 9A through 9C , theminute groove 25D having a trapezoidal cross section is illustrated. More specifically, as shown inFIG. 9A , the groove width of theminute groove 25D is continuously changed in the longitudinal direction of theminute groove 25D. InFIGS. 9B and 9C , sizes of a cross sectional shape (groove width and groove depth) are different at different positions. - The cross sectional shape of the
minute groove 25D, the groove width and the groove depth of which are continuously changed, may have an arcuate cross section in a similar manner to theminute groove 25B shown inFIGS. 5A through 6B . Alternatively, it may have a polygonal cross section except for a substantial rectangular cross section in a similar manner to the minute groove 25C shown inFIGS. 7A through 8B . - When the above-described
minute groove 25D having continuously-changed groove width and groove depth is adopted, even if the foreign material somewhat clogs theminute groove 25D, it is possible to easily gather foreign material at a portion having a small cross sectional shape of theminute groove 25D. Thus, the portion clogged with foreign material is easily confirmed at the time of cleaning operation for the disassembled device, and the foreign material can be removed efficiently. - A
throttle unit 14B shown inFIGS. 10A and 10B is equipped with agrooved block 24 a and anopposite block 26 a. Thegrooved block 24 a includes a plane surface, asupply hole 16,minute grooves 25, and discharge holes 20. Theopposite block 26 a includes aplane surface 27 that is opposite to theminute grooves 25. That is, thethrottle unit 14B corresponds to theaforementioned throttle unit 14A, though thesupply hole 16 is formed in thegrooved block 24 instead of theopposite block 26. Therespective minute grooves 25 can be any of theaforementioned minute grooves 25A through 25D. The static pressure bearing device 10B shown inFIG. 10B is equipped with a bearingunit 12, and thethrottle unit 14B that is detachably attached to the bearingunit 12. With thethrottle unit 14B constituted as above, the same advantageous effects as those according to theaforementioned throttle unit 14A can be obtained. - A static pressure bearing device 10C shown in
FIG. 11 is equipped with a bearingunit 12, and agrooved block 24 b detachably attached to the bearingunit 12.FIG. 11 shows a state in which thegrooved block 24 b is detached from the bearingunit 12. The bearingunit 12 has aguide 38 as a fixed portion and a slide (not shown) as a movable portion. Theguide 38 is provided with a plurality of static pressure pockets 40. - The
guide 38 has theplane surface 27 that is opposite to the plurality ofminute grooves 25 formed in thegrooved block 24 b, in a state in which thegrooved block 24 b is attached (fixed) to the bearingunit 12. In the state in which the grooved block 2 b is attached (fixed) to the bearingunit 12, a plurality ofthrottle fluid paths 18 are formed by the plurality ofminute grooves 25 and theplane surface 27. Thus, a component of theguide 38 of the bearingunit 12 also functions as anopposite block 26 b that has theplane surface 27 opposite to the plurality ofminute grooves 25. The plurality of static pressure pockets 40 may be formed on the slide which is a movable portion. - A
single supply hole 16, the plurality of (six, in the illustrated embodiment)minute grooves 25 which communicate with thesingle supply hole 16, and the plurality of discharge holes 20 which communicate with therespective minute grooves 25, are formed in thegrooved block 24 b. Theminute grooves 25 can be any of theaforementioned minute grooves 25A through 25D. - As shown in
FIG. 12 , each of theminute grooves 25 linearly extend from thesupply hole 16 to the discharge holes 20. The twominute grooves 25 are arranged on the same line through thesupply hole 16. A plurality of (three, in the illustrated embodiment) pairs of the twominute grooves 25 arranged on the same line are provided. The plurality of minute grooves 25 (throttle fluid paths 18) communicate with thesingle supply hole 16. The working fluid supplied to thesingle supply hole 16 branches into the plurality ofthrottle fluid paths 18, and is discharged from the plurality of discharge holes 20. - As shown in
FIG. 11 , a throttle unit 14C is constituted by thegrooved block 24 b as configured above, and theopposite block 26 b which also functions as a component of theguide 38. Thus, the throttle unit 14C can be constituted only by attaching thegrooved block 24 b to theguide 38 that has theplane surface 27 and is a static pressure bearing component. - In this case, the
grooved block 24 b may function as a component of the guide. Otherwise, thegrooved block 24 b or theopposite block 26 b may function as a component of the slide of the bearingunit 12 or a component of another throttle unit. - With the throttle unit 14C, the same advantageous effects as those according to the
aforementioned throttle unit 14A can be obtained. Further, according to the throttle unit 14C, at the time of machining theminute grooves 25, one groove-forming operation from one side of thesupply hole 16 to the other side gives grooves divided by thesupply hole 16 such that the grooves can be used as theindependent minute grooves 25. Since the plurality ofminute grooves 25 are formed in a single machining path, it is possible to reduce man hours for the machining. - Further, since the
grooved block 24 b or theopposite block 26 b functions as a component of the slide (slide component), or a component of the guide (guide component), or a component of another throttle unit (another throttle unit component), the throttle unit 14C can substantially be configured by a single component. In accordance with this feature, it is expected that the structure is simplified, the number of parts is reduced, the installation space is saved, and some piping is omitted. - The present invention is not limited to the embodiment described above, and various modifications can be made to the invention without deviating from the essential scope of the present invention as set forth in the appended claims.
Claims (9)
Priority Applications (1)
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US16/688,303 US11125272B2 (en) | 2016-04-05 | 2019-11-19 | Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block |
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JP2016076039A JP6577404B2 (en) | 2016-04-05 | 2016-04-05 | Throttle unit, hydrostatic bearing device including the same, and method for manufacturing grooved block |
JP2016-076039 | 2016-04-05 |
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US16/688,303 Division US11125272B2 (en) | 2016-04-05 | 2019-11-19 | Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block |
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US20170284464A1 true US20170284464A1 (en) | 2017-10-05 |
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US15/478,445 Abandoned US20170284464A1 (en) | 2016-04-05 | 2017-04-04 | Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block |
US16/688,303 Active 2037-08-11 US11125272B2 (en) | 2016-04-05 | 2019-11-19 | Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block |
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US16/688,303 Active 2037-08-11 US11125272B2 (en) | 2016-04-05 | 2019-11-19 | Throttle unit and a static pressure bearing device equipped with the throttle unit, and a method of manufacturing a grooved block |
Country Status (6)
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US (2) | US20170284464A1 (en) |
JP (1) | JP6577404B2 (en) |
KR (1) | KR102159933B1 (en) |
CN (1) | CN107269699B (en) |
DE (1) | DE102017003276A1 (en) |
TW (1) | TWI692591B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170307010A1 (en) * | 2016-04-26 | 2017-10-26 | Dmg Mori Co., Ltd. | Machine tool and method for producing structure for machine tool |
CN112922961A (en) * | 2021-03-23 | 2021-06-08 | 哈尔滨工业大学 | Static pressure air flotation unit based on porous throttling unit and processing method |
CN114746659A (en) * | 2019-12-07 | 2022-07-12 | 雅科贝思私人有限公司 | Ultralow-profile aerostatic bearing and manufacturing method thereof |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102339495B1 (en) | 2019-11-27 | 2021-12-15 | 전남대학교 산학협력단 | Composition for strengthening skin barrier containing extract of Saragassum Horneri |
Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3137530A (en) * | 1961-10-20 | 1964-06-16 | Escher Wyss Ag | Hydrostatic bearing |
US3726573A (en) * | 1970-04-21 | 1973-04-10 | Toyoda Machine Works Ltd | High rigidity fluid bearings |
US3781069A (en) * | 1970-05-26 | 1973-12-25 | Uva Ab | Hydrostatic bearing |
US4285551A (en) * | 1978-07-03 | 1981-08-25 | Toyoda Koki Kabushiki Kaisha | Fluid bearing |
US4537217A (en) * | 1982-12-09 | 1985-08-27 | Research Triangle Institute | Fluid distributor |
US4978233A (en) * | 1988-09-17 | 1990-12-18 | Ina Lineartechnik Ohg | Hydrostatic bearing assembly |
US5193915A (en) * | 1991-06-13 | 1993-03-16 | Reinhold Leidenfrost | Device for delivering pressurized fluid from a stationary part to a rotatable shaft |
US5407280A (en) * | 1992-07-06 | 1995-04-18 | Joachim Heinzl | Miniature air bearings |
US5980110A (en) * | 1998-07-10 | 1999-11-09 | Thomson Industries, Inc. | Manifold for self-compensating hydrostatic bearing with integral compensators |
US6012845A (en) * | 1998-08-28 | 2000-01-11 | Thomson Industries Inc. | Self-compensating hydrostatic bearing with tape |
US6164827A (en) * | 1998-04-29 | 2000-12-26 | Eitzenberger; Hans | Aerostatic airbearing |
US20020153046A1 (en) * | 2001-04-20 | 2002-10-24 | Nanostream, Inc. | Flow control in multi-stream microfluidic devices |
US20040013545A1 (en) * | 2002-07-18 | 2004-01-22 | The Regents Of The University Of Michigan | Laminated devices and methods of making same |
US20080081114A1 (en) * | 2006-10-03 | 2008-04-03 | Novellus Systems, Inc. | Apparatus and method for delivering uniform fluid flow in a chemical deposition system |
US20100177994A1 (en) * | 2005-08-13 | 2010-07-15 | Schaeffler Kg | Hydrostatic profile rail guide |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3782791A (en) * | 1971-03-17 | 1974-01-01 | Udylite Corp | Vortex diffuser fluid bearing device |
US3902647A (en) * | 1971-03-17 | 1975-09-02 | Oxy Metal Industries Corp | Vortex diffuser fluid bearing device |
BE779833A (en) * | 1971-03-29 | 1972-06-16 | Rech De La Centre D Etudes | FLUID FILM SUSTENTATION DEVICE |
DE2733446A1 (en) * | 1977-07-25 | 1979-02-08 | Schenck Ag Carl | THROTTLE DEVICE FOR STREAMING MEDIA |
JPH11210905A (en) | 1998-01-26 | 1999-08-06 | Toshiba Mach Co Ltd | Throttle valve |
JP4063159B2 (en) * | 2003-07-18 | 2008-03-19 | セイコーエプソン株式会社 | Manufacturing method of fine structure element |
KR100658406B1 (en) * | 2003-03-31 | 2006-12-15 | 닛본 세이고 가부시끼가이샤 | Main shaft device and machine tool with the same |
JP2006029412A (en) * | 2004-07-14 | 2006-02-02 | Nippon Thompson Co Ltd | Static pressure type linear motion guide unit |
JP2006153141A (en) * | 2004-11-29 | 2006-06-15 | Fujikin Inc | Minute flow rate controller with entrance channel |
JP2006266358A (en) * | 2005-03-23 | 2006-10-05 | Mitsubishi Heavy Ind Ltd | Fixed restriction unit and static pressure guiding device provided with fixed restriction unit |
TWI334968B (en) * | 2006-11-10 | 2010-12-21 | Univ Chung Yuan Christian | Measurement instrument for restriction parameter and flow resistance |
CN101568754B (en) | 2006-12-28 | 2011-05-25 | 株式会社富士金 | Method of designing minute flow rate controller with entrance throttle groove |
JP5424318B2 (en) | 2009-08-25 | 2014-02-26 | ダイハツ工業株式会社 | Balance device in internal combustion engine |
JP5394204B2 (en) * | 2009-11-12 | 2014-01-22 | 株式会社ディスコ | Cutting blade consumption control method |
JP4992986B2 (en) * | 2010-01-22 | 2012-08-08 | 新東工業株式会社 | Hydrostatic bearing device and stage with hydrostatic bearing device |
US9017528B2 (en) * | 2011-04-14 | 2015-04-28 | Tel Nexx, Inc. | Electro chemical deposition and replenishment apparatus |
BRPI1105471A2 (en) * | 2011-11-16 | 2015-11-10 | Whirlpool Sa | restrictor and production process of a flow restrictor for aerostatic bearings |
JP2013145021A (en) * | 2012-01-16 | 2013-07-25 | Samsung Electro-Mechanics Japan Advanced Technology Co Ltd | Rotating device |
US9506498B2 (en) * | 2014-03-25 | 2016-11-29 | Specialty Components, Inc. | Gap sensing method for fluid film bearings |
JP6979296B2 (en) * | 2017-07-28 | 2021-12-08 | 株式会社ディスコ | Cutting method |
-
2016
- 2016-04-05 JP JP2016076039A patent/JP6577404B2/en active Active
-
2017
- 2017-04-01 CN CN201710213472.9A patent/CN107269699B/en active Active
- 2017-04-03 KR KR1020170042901A patent/KR102159933B1/en active IP Right Grant
- 2017-04-04 US US15/478,445 patent/US20170284464A1/en not_active Abandoned
- 2017-04-04 DE DE102017003276.9A patent/DE102017003276A1/en active Pending
- 2017-04-05 TW TW106111315A patent/TWI692591B/en active
-
2019
- 2019-11-19 US US16/688,303 patent/US11125272B2/en active Active
Patent Citations (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3137530A (en) * | 1961-10-20 | 1964-06-16 | Escher Wyss Ag | Hydrostatic bearing |
US3726573A (en) * | 1970-04-21 | 1973-04-10 | Toyoda Machine Works Ltd | High rigidity fluid bearings |
US3781069A (en) * | 1970-05-26 | 1973-12-25 | Uva Ab | Hydrostatic bearing |
US4285551A (en) * | 1978-07-03 | 1981-08-25 | Toyoda Koki Kabushiki Kaisha | Fluid bearing |
US4537217A (en) * | 1982-12-09 | 1985-08-27 | Research Triangle Institute | Fluid distributor |
US4978233A (en) * | 1988-09-17 | 1990-12-18 | Ina Lineartechnik Ohg | Hydrostatic bearing assembly |
US5193915A (en) * | 1991-06-13 | 1993-03-16 | Reinhold Leidenfrost | Device for delivering pressurized fluid from a stationary part to a rotatable shaft |
US5407280A (en) * | 1992-07-06 | 1995-04-18 | Joachim Heinzl | Miniature air bearings |
US6164827A (en) * | 1998-04-29 | 2000-12-26 | Eitzenberger; Hans | Aerostatic airbearing |
US5980110A (en) * | 1998-07-10 | 1999-11-09 | Thomson Industries, Inc. | Manifold for self-compensating hydrostatic bearing with integral compensators |
US6012845A (en) * | 1998-08-28 | 2000-01-11 | Thomson Industries Inc. | Self-compensating hydrostatic bearing with tape |
US20020153046A1 (en) * | 2001-04-20 | 2002-10-24 | Nanostream, Inc. | Flow control in multi-stream microfluidic devices |
US20040013545A1 (en) * | 2002-07-18 | 2004-01-22 | The Regents Of The University Of Michigan | Laminated devices and methods of making same |
US20100177994A1 (en) * | 2005-08-13 | 2010-07-15 | Schaeffler Kg | Hydrostatic profile rail guide |
US20080081114A1 (en) * | 2006-10-03 | 2008-04-03 | Novellus Systems, Inc. | Apparatus and method for delivering uniform fluid flow in a chemical deposition system |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170307010A1 (en) * | 2016-04-26 | 2017-10-26 | Dmg Mori Co., Ltd. | Machine tool and method for producing structure for machine tool |
US10590988B2 (en) * | 2016-04-26 | 2020-03-17 | Dmg Mori Co., Ltd. | Machine tool and method for producing structure for machine tool |
CN114746659A (en) * | 2019-12-07 | 2022-07-12 | 雅科贝思私人有限公司 | Ultralow-profile aerostatic bearing and manufacturing method thereof |
CN112922961A (en) * | 2021-03-23 | 2021-06-08 | 哈尔滨工业大学 | Static pressure air flotation unit based on porous throttling unit and processing method |
Also Published As
Publication number | Publication date |
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CN107269699B (en) | 2020-09-04 |
CN107269699A (en) | 2017-10-20 |
KR102159933B1 (en) | 2020-09-25 |
TW201736746A (en) | 2017-10-16 |
TWI692591B (en) | 2020-05-01 |
US20200080592A1 (en) | 2020-03-12 |
JP2017187105A (en) | 2017-10-12 |
DE102017003276A1 (en) | 2017-10-05 |
KR20170114959A (en) | 2017-10-16 |
JP6577404B2 (en) | 2019-09-18 |
US11125272B2 (en) | 2021-09-21 |
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