CN116717541A - Aerostatic bearing and aerostatic turntable - Google Patents
Aerostatic bearing and aerostatic turntable Download PDFInfo
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- CN116717541A CN116717541A CN202310895871.3A CN202310895871A CN116717541A CN 116717541 A CN116717541 A CN 116717541A CN 202310895871 A CN202310895871 A CN 202310895871A CN 116717541 A CN116717541 A CN 116717541A
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- thrust plate
- bearing
- aerostatic
- motor
- hemispherical
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- 230000002706 hydrostatic effect Effects 0.000 claims description 37
- 238000007789 sealing Methods 0.000 claims description 12
- 238000012545 processing Methods 0.000 abstract description 5
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- 238000003825 pressing Methods 0.000 description 9
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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
- 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
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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
- F16C32/0692—Construction or mounting aspects of hydrostatic bearings, for exclusively rotary movement, related to the direction of load for axial load only
Abstract
The invention relates to the technical field of aerostatic rotary tables, and provides an aerostatic bearing and an aerostatic rotary table, wherein the aerostatic bearing comprises a rotating body and a throttle assembly, and the aerostatic bearing comprises the following components: the rotor includes first thrust plate, second thrust plate and hemisphere bearing, first thrust plate and second thrust plate set up relatively, hemisphere bearing locates between first thrust plate and the second thrust plate, the three is fixed continuous, and first thrust plate and second thrust plate are perpendicular with hemisphere bearing's central line, but throttle ware subassembly and rotor normal running fit have first air gap between throttle ware subassembly and the first thrust plate, have the second air gap between throttle ware subassembly and the hemisphere bearing, throttle ware subassembly has first venthole and second venthole, first venthole orientation first thrust plate, second venthole orientation hemisphere bearing. The invention can solve the problem that the air bearings such as radial air bearings, thrust air bearings and the like used by the aerostatic turntable have high requirements on processing precision in the related technology.
Description
Technical Field
The invention relates to the technical field of aerostatic rotary tables, in particular to an aerostatic bearing and an aerostatic rotary table.
Background
Aerostatic rotary tables are commonly used for precision and ultra-precision devices such as integrated circuit production equipment, flat panel display equipment, semiconductor production equipment, ultra-precision machine tools, and the like. In order to meet the high requirements of the aerostatic turntable on the rotation precision, the bearings of the aerostatic turntable usually adopt gas bearings, such as radial gas bearings and thrust gas bearings, and the rotary motion can be realized through the combination of the radial gas bearings and the thrust gas bearings, but the radial gas bearings and the thrust gas bearings have extremely high requirements on the dimensional precision and the shape precision of bearing parts, so that the radial gas bearings and the thrust gas bearings have extremely high requirements on the machining precision and high manufacturing cost.
Disclosure of Invention
The invention provides a gas hydrostatic bearing and a gas hydrostatic turntable, which are used for solving the problem that air bearings such as radial air bearings and thrust air bearings used for the gas hydrostatic turntable have high requirements on processing precision in the related art.
The present invention provides a gas hydrostatic bearing comprising: a rotor and restrictor assembly, wherein:
the rotating body comprises a first thrust plate, a second thrust plate and a hemispherical bearing, wherein the first thrust plate and the second thrust plate are oppositely arranged, the hemispherical bearing is arranged between the first thrust plate and the second thrust plate, the first thrust plate, the hemispherical bearing and the second thrust plate are fixedly connected, and the first thrust plate and the second thrust plate are perpendicular to the central line of the hemispherical bearing;
the throttle assembly and the rotating body can be in running fit, a first air gap is formed between the throttle assembly and the first thrust plate, a second air gap is formed between the throttle assembly and the hemispherical bearing, the throttle assembly is provided with a first air outlet hole and a second air outlet hole, the first air outlet hole faces the first thrust plate, and the second air outlet hole faces the hemispherical bearing.
According to the aerostatic bearing provided by the invention, the restrictor component is provided with the hemispherical groove, the hemispherical groove is rotatably sleeved on the periphery of the hemispherical bearing, and the second air gap is formed between the inner wall of the hemispherical groove and the hemispherical bearing;
the throttle assembly has a first end face and a second end face arranged opposite to each other, the first end face is arranged opposite to the first thrust plate, a first air gap is formed between the first end face and the first thrust plate, and the second end face is arranged opposite to the second thrust plate.
According to the aerostatic bearing provided by the invention, the first air outlet hole is positioned on the first end face, the second air outlet hole is positioned on the inner wall of the hemispherical groove, a third air gap is formed between the second end face and the second thrust plate, the second end face is provided with the third air outlet hole, and the third air outlet hole faces the second thrust plate.
According to the aerostatic bearing provided by the invention, the aerostatic bearing further comprises a sealing structural part, the sealing structural part is connected to the outer wall of the throttle assembly, the sealing structural part is provided with a first annular bulge, the first thrust plate is provided with a first annular groove, and the first annular bulge stretches into the first annular groove.
According to the aerostatic bearing provided by the invention, the flatness of the surface of the first thrust plate facing the second thrust plate is 1.5-2.5 mu m, the flatness of the surface of the second thrust plate facing the first thrust plate is 1.5-2.5 mu m, the parallelism of the first thrust plate and the second thrust plate is 2.5-3.5 mu m, and the roundness of any section of the hemispherical bearing is 0.4-0.6 mu m.
The invention also provides a gas static pressure rotary table, which comprises the gas static pressure bearing.
According to the aerostatic turntable provided by the invention, the end face of the first thrust plate, which is away from the hemispherical bearing, forms the table top of the aerostatic turntable.
According to the aerostatic rotary table provided by the invention, the aerostatic rotary table further comprises a motor mandrel, a motor rotor, a motor stator and a stator shell, wherein the motor mandrel is fixedly connected with the rotating body, the motor rotor is fixedly connected with the motor mandrel, the motor stator is rotatably connected with the motor rotor, the stator shell is fixedly connected with the motor stator, and the stator shell is fixedly connected with the throttle assembly.
According to the aerostatic rotary table provided by the invention, the aerostatic rotary table further comprises an encoder, the encoder comprises an encoder body and a reading head, the encoder body is fixedly arranged on the motor mandrel, the reading head is fixedly arranged on the stator shell, and the encoder is used for measuring the positioning precision of the motor mandrel.
According to the aerostatic turntable provided by the invention, the inner ring of the motor stator is sleeved on the motor rotor, and the outer ring of the motor stator is abutted against the stator shell;
the outer ring of the motor stator is convexly provided with a second annular bulge towards the direction close to the stator shell, the inner wall of the stator shell is provided with a second annular groove which is arranged around the axis of the motor mandrel, the aerostatic turntable further comprises a pressing ring, the pressing ring is arranged on the notch of the second annular groove, at least part of the pressing ring is opposite to the bottom of the second annular groove, and the motor stator is positioned between the bottom of the second annular groove and the pressing ring along the axial direction of the motor mandrel.
The radial gas bearing structure in the combination of the radial gas bearing and the thrust gas bearing in the related art is provided with an inner cylindrical surface, the resultant force acting on the radial gas bearing acts on a line, a rotation axis formed by the resultant force acting on the radial gas bearing is formed by fitting a plurality of action points, when the radial gas bearing and the thrust gas bearing are processed, the influence of fitting accuracy of the rotation axis on the installation verticality of an upper thrust plate and a lower thrust plate of the radial gas bearing and the thrust gas bearing is considered, and the influence of each action point of the radial gas bearing on the installation verticality of the upper thrust plate and the lower thrust plate of the radial gas bearing and the thrust gas bearing is considered.
Whereas in the embodiment of the invention the resultant force acting on the hemispherical bearing acts on a point. The rotation axis formed by the hemispherical bearing passes through a combined force action point, namely a theoretical spherical center point of the hemispherical bearing, so that the rotation axis of the hydrostatic bearing is a straight line passing through one point (namely the spherical center), and when the hydrostatic bearing is processed, only the flatness of the first thrust plate and the second thrust plate after processing is considered to be within an allowable range, so that the installation perpendicularity of the first thrust plate and the second thrust plate with the hemispherical bearing is ensured, and even if the first thrust plate and the second thrust plate are perpendicular to the center line of the hemispherical bearing, compared with the technical scheme of using the combination of the radial gas bearing and the thrust gas bearing in the related art, the requirements on the flatness of the first thrust plate and the second thrust plate after processing are correspondingly reduced. Therefore, the aerostatic bearing has lower requirements on machining precision.
Drawings
In order to more clearly illustrate the invention or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view of a structure of a hydrostatic bearing provided by the present invention;
fig. 2 is a schematic structural view of the aerostatic turntable provided by the invention.
Reference numerals:
110. a first thrust plate; 120. a second thrust plate; 130. a hemispherical bearing;
200. a restrictor assembly; 210. a spherical restrictor; 220. a planar restrictor; 230. a throttle housing;
310. a first air gap; 320. a second air gap; 330. a third air gap;
400. sealing the structural member; 410. a first annular projection;
510. a motor mandrel; 520. a motor rotor; 530. a motor stator; 531. a second annular projection; 540. a stator housing; 550. a compression ring;
610. an encoder body; 620. a reading head;
a. a center line.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
As shown in fig. 1-2, the present invention discloses a hydrostatic bearing for a hydrostatic turntable, the disclosed hydrostatic bearing comprising a rotor and a restrictor assembly 200, wherein:
the rotor includes a first thrust plate 110, a second thrust plate 120, and a hemispherical bearing 130, where the first thrust plate 110 and the second thrust plate 120 are disposed opposite to each other, the hemispherical bearing 130 is disposed between the first thrust plate 110 and the second thrust plate 120, and the first thrust plate 110, the hemispherical bearing 130, and the second thrust plate 120 are fixedly connected. Alternatively, the first thrust plate 110 and the hemispherical bearing 130 may be coupled by screw fixation, and the second thrust plate 120 and the hemispherical bearing 130 may be coupled by screw fixation.
The first thrust plate 110 and the second thrust plate 120 are each perpendicular to the center line a of the hemispherical bearing 130. The hemispherical bearing 130 may include a first plane and a second plane disposed opposite to each other, the first plane being opposite to and parallel to the first thrust plate 110, the second plane being opposite to and parallel to the second thrust plate 120, and an axis of the hemispherical bearing 130 perpendicular to the first plane and the second plane being a center line a of the hemispherical bearing 130.
The restrictor assembly 200 is rotatably matched with the rotating body, a first air gap 310 is formed between the restrictor assembly 200 and the first thrust plate 110, a second air gap 320 is formed between the restrictor assembly 200 and the hemispherical bearing 130, the restrictor assembly 200 is provided with a plurality of first air outlet holes and a plurality of second air outlet holes, the first air outlet holes face the first thrust plate 110, compressed air is discharged towards the direction of the first thrust plate 110 through the first air outlet holes so as to form an air mold in the first air gap 310, the second air outlet holes face the hemispherical bearing 130, and compressed air is discharged towards the direction of the hemispherical bearing 130 through the second air outlet holes so as to form an air mold in the second air gap 320.
The restrictor assembly 200 may be provided with a first air path, which may have a first air inlet hole and a first air outlet hole that are communicated, the first air inlet hole is used for communicating an external compressed air source, so that compressed air can be introduced into the first air gap 310 through the first air outlet hole, and the restrictor assembly 200 may also be provided with a second air path, which has a second air inlet hole and a second air outlet hole that are communicated, and the second air inlet hole is used for communicating an external compressed air source, so that compressed air is introduced into the second air gap 320 through the second air outlet hole.
Referring again to fig. 1, the air outlet direction of the first air outlet hole may be perpendicular to the first thrust plate 110, so that the compressed air discharged through the first air outlet hole can act on the first thrust plate 110, forming a restraining force F toward the first thrust plate 110 and perpendicular to the first thrust plate 110. The air outlet direction of the second air outlet hole may be toward the center of the hemisphere bearing 130 such that the compressed air discharged through the second air outlet hole acts on the hemisphere bearing 130 to form a restraining force fball toward the center of the hemisphere bearing 130.
According to the principle of force decomposition, the fball can be decomposed into a radial constraint force F and a constraint force F oriented toward the second thrust plate 120 and perpendicular to the second thrust plate 120 1 On F being equal to F under 1 In this case, the axial direction of the hydrostatic bearing (i.e., the direction perpendicular to the first thrust plate 110, in the case where the hydrostatic bearing is fitted to the hydrostatic turntable to be fitted to the motor spindle 510, the axial direction of the hydrostatic bearing coincides with the axial direction of the motor spindle 510) is restrained, and the runout of the hydrostatic bearing can be controlled. Since the outer surface of the hemispherical bearing 130 is spherical, the diameters F acting on the hemispherical bearing 130 in opposite directions are mutually oppositeThe radial constraint of the aerostatic bearing (namely, the radial constraint of the aerostatic bearing in the direction parallel to the first thrust plate 110 is realized, and the axial direction of the aerostatic bearing is consistent with the radial direction of the motor mandrel 510 under the condition that the aerostatic bearing is assembled on the aerostatic turntable to be matched with the motor mandrel 510), so that the radial runout of the aerostatic bearing is controlled, and the rotation precision of the aerostatic bearing is ensured.
The radial gas bearing structure in the combination of the radial gas bearing and the thrust gas bearing in the related art is provided with an inner cylindrical surface, the resultant force acting on the radial gas bearing acts on a line, a rotation axis formed by the resultant force acting on the radial gas bearing is formed by fitting a plurality of action points, when the radial gas bearing and the thrust gas bearing are processed, the influence of fitting accuracy of the rotation axis on the installation verticality of an upper thrust plate and a lower thrust plate of the radial gas bearing and the thrust gas bearing is considered, and the influence of each action point of the radial gas bearing on the installation verticality of the upper thrust plate and the lower thrust plate of the radial gas bearing and the thrust gas bearing is considered.
Whereas in the embodiment of the invention the resultant force acting on the hemispherical bearing 130 acts on a single point. The rotation axis formed by the hemispherical bearing 130 passes through the action point of the combined force, that is, the theoretical spherical center point of the hemispherical bearing 130, when the rotation axis of the hydrostatic bearing in the invention is a straight line passing through one point (that is, the spherical center), and when the hydrostatic bearing is processed, only the flatness of the processed first thrust plate 110 and the second thrust plate 120 is considered to be within the allowable range, so that the installation perpendicularity of the first thrust plate 110 and the second thrust plate 120 with the hemispherical bearing 130 is ensured, even if the first thrust plate 110 and the second thrust plate 120 are perpendicular to the central line of the hemispherical bearing 130, compared with the technical scheme of using the combination of the radial gas bearing and the thrust gas bearing in the related art, the flatness requirements of the first thrust plate 110 and the second thrust plate 120 after the processing are correspondingly reduced. Therefore, the aerostatic bearing has low requirements on machining precision, can be used for an aerostatic turntable, has low requirements on machining precision, and solves the problem that air bearings such as radial air bearings and thrust air bearings used for the aerostatic turntable have high requirements on machining precision in the related technology.
In addition, the radial gas bearing and the thrust gas bearing in the related art have higher requirements on the installation accuracy, but the gas hydrostatic bearing has lower requirements on the installation position accuracy due to the structural characteristics of the self-centering ball in the motion state of the hemispherical bearing 130, and the installation position accuracy of the gas hydrostatic bearing in the invention is 50% of the installation accuracy requirements of the radial gas bearing and the thrust gas bearing.
Of course, the aerostatic turntable in the related art may use a double hemispherical spherical gas bearing, but the axial height (the axial height refers to the height of the bearing along the axial direction of the motor mandrel 510 after the bearing is assembled with the motor mandrel 510) is larger, so that it is difficult to meet the space requirements of the working occasions such as integrated circuit production equipment, checksum measurement equipment, medical equipment, ultra-precise machine tools and the like, regardless of the combination of the double hemispherical spherical gas bearing and the radial gas bearing.
The hydrostatic bearing in the invention achieves the full constraint condition (namely axial constraint and radial constraint, see above) of the hydrostatic bearing through one hemispherical bearing 130, reduces the axial height of the hydrostatic bearing, and can meet the space requirement of working occasions with lower requirements on axial height such as radio equipment, inspection and measurement equipment and medical equipment under the dimensional requirement of the same table surface specification when the hydrostatic bearing is applied to the hydrostatic turntable, wherein the axial height of the hydrostatic turntable in the invention is 65% of the axial height of the hydrostatic turntable by using the combination of the radial bearing and the thrust bearing, and is 40% of the axial height of the hydrostatic turntable by using the double hemispherical spherical bearing.
In order to realize rotatable connection of the throttle assembly 200 and the rotator, the throttle assembly 200 may be provided with a hemispherical groove, and the hemispherical groove may be rotatably sleeved on the outer circumference of the hemispherical bearing 130, so as to realize rotatable fit of the throttle assembly 200 and the rotator, and simultaneously realize limiting of the throttle assembly 200 in a plane parallel to the first thrust plate 110, and a second air gap 320 is formed between the inner wall of the hemispherical groove and the hemispherical bearing 130.
The restrictor assembly 200 may have a first end surface and a second end surface disposed opposite each other, the first end surface may be disposed opposite the first thrust plate 110, and a first air gap 310 is formed between the first end surface and the first thrust plate 110, and the second end surface may be disposed opposite the second thrust plate 120, so as to achieve a limit of the restrictor assembly 200 in a direction perpendicular to the first thrust plate 110.
Under this kind of structure, can realize the rotatable coupling of throttle subassembly 200 and rotor, can realize the spacing of throttle subassembly 200 in the plane parallel with first thrust plate 110 again, can also realize the spacing of throttle subassembly 200 in the direction of perpendicular to first thrust plate 110 to realize the rotatable coupling of throttle subassembly 200 and rotor, and need not extra connecting piece and connect throttle subassembly 200 and rotor, simple structure.
In a further technical solution, the first air outlet hole may be located at the first end surface, the second air outlet hole may be located at an inner wall of the hemispherical groove, a third air gap 330 may be located between the second end surface and the second thrust plate 120, the second end surface may be provided with third air outlet holes, the number of the third air outlet holes may be multiple, and the third air outlet holes may face the second thrust plate 120. The air outlet direction of the third air outlet hole may be perpendicular to the second thrust plate 120.
In this case, the compressed air discharged through the third air outlet toward the second thrust plate 120 can form F-down toward the second thrust plate 120 2 In the embodiment of the present invention, fupper=flower 1 Under +F 2 The restriction of the aerostatic bearing in the axial direction can be realized, and the second end surface is provided with a third air outlet hole facing the second thrust plate 120, so that the contact area of the spherical surface of the throttle assembly 200 and the hemispherical bearing 130 and the contact area of the second end surface and the second thrust plate 120 can be conveniently adjusted to adjust the contact area of the rotating bodyUnder F 1 Under +F 2 So that under F 1 Under +F 2 Equal to F Upper part 。
In an alternative embodiment, the restrictor assembly 200 may include a spherical restrictor 210, a planar restrictor 220, and a restrictor housing 230, the spherical restrictor 210 and the planar restrictor 220 may be both fixedly disposed on the restrictor housing 230, the first air outlet and the first air inlet may be disposed on the planar restrictor 220, the end surface of the planar restrictor 220 provided with the first air outlet and the end surface of the restrictor housing 230 facing the first thrust plate 110 together form a first end surface, the spherical restrictor 210 may include a hemispherical groove and a second end surface, the second air outlet may be disposed in the hemispherical groove, the third air outlet may be disposed on the second end surface, the second air inlet may be disposed on the spherical restrictor 210, and the second air inlet may be in communication with both the second air outlet and the third air outlet.
The throttle housing 230 may be provided with a gas passage communicating with the first gas inlet and the second gas inlet, where the gas passage is used to communicate with an external clean and dry compressed gas source, so that the external compressed gas can be sequentially discharged toward the first thrust plate 110 through the gas passage, the first gas inlet and the first gas outlet, so that the external compressed gas can be sequentially discharged toward the hemispherical bearing 130 through the gas passage, the second gas inlet and the second gas outlet, and the external compressed gas can be sequentially discharged toward the second thrust plate 120 through the gas passage, the second gas inlet and the third gas outlet.
The spherical restrictor 210 and the planar restrictor 220 may be fixedly provided to the restrictor housing 230 by means of screw connection, adhesion, or the like.
In an embodiment of the present invention, the aerostatic bearing may further include a sealing structure 400, the sealing structure 400 may be connected to the outer wall of the restrictor assembly 200, alternatively, the sealing structure 400 may be connected to the outer wall of the restrictor housing 230 by a screw, the sealing structure 400 may be provided with a first annular protrusion 410, the first thrust plate 110 may be provided with a first annular groove, and the first annular protrusion 410 may extend into the first annular groove, thereby preventing external dust from entering the first air gap 310 between the first end surface and the first thrust plate 110.
Alternatively, the sealing structure 400 may be a labyrinth ring.
The flatness of the surface of the first thrust plate 110 facing the second thrust plate 120 may be 1.5-2.5 μm, for example 2 μm, and the flatness of the surface of the second thrust plate 120 facing the first thrust plate 110 may be 1.5-2.5 μm, for example 2 μm, and the first thrust plate 110, the second thrust plate 120 and the restrictor assembly 200 may be polished by a polishing method to ensure the flatness of the first thrust plate 110, the second thrust plate 120 and the restrictor assembly 200.
The parallelism of the first thrust plate 110 and the second thrust plate 120 may be 2.5-3.5 μm, for example, 3 μm.
The dimensional accuracy and shape accuracy of the hemispherical bearing 130 and the portion of the restrictor assembly 200 that cooperates with the hemispherical bearing 130 (i.e., the spherical restrictor 210) may be regulated by an investigation method, and the roundness of any section of the hemispherical bearing 130 may be 0.4-0.6 μm, for example, 0.5 μm, and the hemispherical bearing 130 and the portion of the restrictor assembly 200 that cooperates with the hemispherical bearing 130 may be investigated with each other, thereby ensuring the dimensional accuracy and shape accuracy of the spherical restrictor 210.
The gas hydrostatic bearing has lower precision requirement, which is 50% of the precision requirement of the radial gas bearing and the thrust gas bearing, and the precision of the gas hydrostatic bearing is ensured by the grinding process, so that the manufacturing cost of the gas hydrostatic bearing is reduced.
Based on the aerostatic bearing of the embodiment of the invention, the invention also discloses an aerostatic turntable, which comprises the aerostatic bearing, and the aerostatic bearing ensures the stability of the rotation precision of the rotating motion of the aerostatic turntable and the certain bearing rigidity of the aerostatic turntable.
In the related art, a gas static pressure turntable combined by a radial gas bearing and a thrust gas bearing is used, and the actual position accuracy between the relevant surfaces of the radial gas bearing and the thrust gas bearing part is extremely high. In the embodiment of the invention, due to the structural characteristic of self-centering in the movement state of the hemispherical bearing 130, the requirement of the hydrostatic bearing on the installation precision is lower, so that the installation position precision of the part with the connection relation with the hydrostatic bearing of the hydrostatic turntable is correspondingly reduced, and the installation efficiency of the part with the connection relation with the hydrostatic bearing of the hydrostatic turntable is improved.
In an embodiment of the present invention, the end surface of the first thrust plate 110 facing away from the hemispherical bearing 130 may form a table surface of the aerostatic turntable. In this case, the first thrust plate 110 can be used as a table surface of the aerostatic turntable while forming a part of the aerostatic bearing, and has a dual-purpose effect, thereby simplifying the structure of the aerostatic turntable.
The aerostatic turntable may further include a motor spindle 510, a motor rotor 520, a motor stator 530, and a stator housing 540, the motor spindle 510 may be fixedly connected to the second thrust plate 120 of the rotor through a screw, the motor rotor 520 may be fixedly connected to the motor spindle 510 through a screw, the motor stator 530 may be rotatably connected to the motor rotor 520, the stator housing 540 may be fixedly connected to the motor stator 530, and the stator housing 540 may be fixedly connected to the throttle assembly 200 through a screw, so as to implement assembly of the aerostatic turntable.
The aerostatic turntable may further include an encoder, the encoder may include an encoder body 610 and a reading head 620, the encoder body 610 may be fixedly disposed on the motor spindle 510 through a screw, the reading head 620 may be fixedly disposed on the stator housing 540 through a screw, and the encoder may be used for measuring positioning accuracy of the motor spindle 510. Alternatively, the encoder may be a circular encoder. The first thrust plate 110, the hemispherical bearing 130, the second thrust plate 120, the motor spindle 510, the motor rotor 520 and the encoder body 610 are rotated in synchronization, and the encoder body 610 and the reading head 620 generate a position difference in the rotation process of the above members, thereby measuring the positioning accuracy of the motor spindle 510.
In this case, the positioning accuracy of the motor core shaft 510 can be measured by the encoder, and the rotation angle of the motor core shaft 510 can be adjusted, thereby improving the accuracy of the rotation angle of the motor core shaft 510.
The inner ring of the motor stator 530 may be rotatably sleeved on the motor rotor 520, and the outer ring of the motor stator 530 may be abutted against the stator housing 540, thereby realizing radial limitation of the motor stator 530 on the motor core shaft 510, and also realizing rotatable fit of the motor stator 530 and the motor rotor 520.
There are various ways to achieve a secure connection of the motor stator 530 and the stator housing 540, for example, in an alternative embodiment, the secure connection of the motor stator 530 and the stator housing 540 may be achieved by a screw connection or an adhesive connection, or the like.
In another alternative embodiment, the outer ring surface of the motor stator 530 may be convexly provided with a second annular protrusion 531 in a direction approaching the stator housing 540, the inner wall of the stator housing 540 may be provided with a second annular groove disposed around the axis of the motor spindle 510, the aerostatic turntable may further include a pressing ring 550, the pressing ring 550 may be connected to the stator housing 540 by a screw, the pressing ring 550 may be disposed at a notch of the second annular groove, and at least part of the pressing ring 550 may be opposite to a bottom of the annular groove, and the motor stator 530 may be positioned between the bottom of the annular groove and the pressing ring 550 along the axial direction of the motor spindle 510. This configuration facilitates disassembly and assembly of the motor stator 530 and stator housing 540.
The materials of the first thrust plate 110, the hemispherical bearing 130, the second thrust plate 120 and the motor mandrel 510 may be steel materials with low thermal expansion coefficients, so that when conditions of external environments (such as installation and operation environments of a gas static pressure turntable, for example, the gas static pressure turntable may be used in a constant temperature environment of 20+/-1 ℃, and the external conditions of the temperature change gradient of +/-0.5 +.c/h. the working relative humidity of less than or equal to 40%) fluctuate, the components generate only tiny stress deformation, the motion stability of the rotating components of the gas static pressure turntable is improved, and the stress deformation of the rotating components of the gas static pressure turntable is avoided, thereby realizing the rotational motion feeding of nanometer resolution, and the gas static pressure turntable can be applied to an ultra-precise machining machine tool.
Alternatively, the steel material with low thermal expansion coefficient can be invar, also called invar alloy (invar), and has low thermal conductivity coefficient, and the thermal conductivity coefficient is 0.026-0.032 cal/cm & sec & deg.C, which is only 1/3-1/4 of that of the common carbon steel. Most metals and alloys expand in volume when heated and contract in volume when cooled, invar alloys have abnormal thermal expansion due to the shingle effect in a certain temperature range due to its ferromagnetism, and the expansion coefficient is extremely low, sometimes even zero or negative.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A hydrostatic bearing, comprising: a rotor and restrictor assembly (200), wherein:
the rotating body comprises a first thrust plate (110), a second thrust plate (120) and a hemispherical bearing (130), wherein the first thrust plate (110) and the second thrust plate (120) are oppositely arranged, the hemispherical bearing (130) is arranged between the first thrust plate (110) and the second thrust plate (120), the first thrust plate (110), the hemispherical bearing (130) and the second thrust plate (120) are fixedly connected, and the first thrust plate (110) and the second thrust plate (120) are perpendicular to the central line (a) of the hemispherical bearing (130);
the throttle assembly (200) is in rotatable fit with the rotor, a first air gap (310) is formed between the throttle assembly (200) and the first thrust plate (110), a second air gap (320) is formed between the throttle assembly (200) and the hemispherical bearing (130), the throttle assembly (200) is provided with a first air outlet hole and a second air outlet hole, the first air outlet hole faces the first thrust plate (110), and the second air outlet hole faces the hemispherical bearing (130).
2. The aerostatic bearing according to claim 1, wherein the restrictor assembly (200) is provided with a hemispherical groove rotatably sleeved on the outer periphery of the hemispherical bearing (130), and the second air gap (320) is formed between the inner wall of the hemispherical groove and the hemispherical bearing (130);
the restrictor assembly (200) has a first end surface and a second end surface disposed opposite one another, the first end surface being disposed opposite the first thrust plate (110), and the first end surface and the first thrust plate (110) forming the first air gap (310) therebetween, the second end surface being disposed opposite the second thrust plate (120).
3. The aerostatic bearing of claim 2, wherein the first air outlet hole is located at the first end face, the second air outlet hole is located at an inner wall of the hemispherical groove, a third air gap (330) is provided between the second end face and the second thrust plate (120), and the second end face is provided with a third air outlet hole, and the third air outlet hole faces the second thrust plate (120).
4. The hydrostatic bearing of claim 2, further comprising a sealing structure (400), the sealing structure (400) being connected to an outer wall of the restrictor assembly (200), the sealing structure (400) being provided with a first annular protrusion (410), the first thrust plate (110) being provided with a first annular groove, the first annular protrusion (410) protruding into the first annular groove.
5. The aerostatic bearing according to claim 1, wherein a flatness of a surface of the first thrust plate (110) facing the second thrust plate (120) is 1.5-2.5 μm, a flatness of a surface of the second thrust plate (120) facing the first thrust plate (110) is 1.5-2.5 μm, a parallelism of the first thrust plate (110) and the second thrust plate (120) is 2.5-3.5 μm, and a roundness of an arbitrary section of the hemispherical bearing (130) is 0.4-0.6 μm.
6. A aerostatic turntable comprising a aerostatic bearing as claimed in any one of claims 1 to 5.
7. The aerostatic turntable according to claim 6, wherein an end face of the first thrust plate (110) facing away from the hemispherical bearing (130) forms a table top of the aerostatic turntable.
8. The aerostatic turntable of claim 6, further comprising a motor spindle (510), a motor rotor (520), a motor stator (530), and a stator housing (540), wherein the motor spindle (510) is fixedly connected to the rotor, the motor rotor (520) is fixedly connected to the motor spindle (510), the motor stator (530) is rotatably connected to the motor rotor (520), the stator housing (540) is fixedly connected to the motor stator (530), and the stator housing (540) is fixedly connected to the throttle assembly (200).
9. The aerostatic turntable of claim 8, further comprising an encoder body (610) and a reading head (620), the encoder body (610) being fixedly arranged on the motor spindle (510), the reading head (620) being fixedly arranged on the stator housing (540), the encoder being for measuring a positioning accuracy of the motor spindle (510).
10. The aerostatic turntable of claim 8, wherein an inner ring of the motor stator (530) is sleeved on the motor rotor (520), and an outer ring of the motor stator (530) is abutted against the stator housing (540);
the outer ring of motor stator (530) towards being close to the direction of stator casing (540) protruding be equipped with second annular bulge (531), the inner wall of stator casing (540) is equipped with around the axis of motor dabber (510) sets up the second annular recess, aerostatic revolving stage still includes clamping ring (550), clamping ring (550) are located the notch of second annular recess, just clamping ring (550) at least part with the tank bottom of second annular recess is relative, motor stator (530) are followed the axial of motor dabber (510) is located the tank bottom of second annular recess with between clamping ring (550).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310895871.3A CN116717541A (en) | 2023-07-20 | 2023-07-20 | Aerostatic bearing and aerostatic turntable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310895871.3A CN116717541A (en) | 2023-07-20 | 2023-07-20 | Aerostatic bearing and aerostatic turntable |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116717541A true CN116717541A (en) | 2023-09-08 |
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ID=87866273
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310895871.3A Pending CN116717541A (en) | 2023-07-20 | 2023-07-20 | Aerostatic bearing and aerostatic turntable |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116717541A (en) |
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2023
- 2023-07-20 CN CN202310895871.3A patent/CN116717541A/en active Pending
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