Patent US5382095A successfully refreshed from Google Patents.
US5382095A
Expired / Lapsed
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Static pressure bearing device
Assignee: Canon Inc
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Filing: 1994-02-14
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Granted: 1995-01-17
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Expires: 2014-02-14
Abstract
Abstract An apparatus for preventing the self-excited vibration of a static pressure bearing device includes a movable bed and a porous pad. The movable bed is noncontactly supported by the static pressure of pressurized fluid spouted from the porous pad toward the surface of a fixed bed. The porous pad is designed such that the natural frequency of a vibration system including the movable bed is regulated so that among the fluctuation components of the static pressure when the dimension of a bearing gap varies periodically, a periodic fluctuation component having a phase delay of 90° relative to a decrease in the dimension of the bearing gap may be positive and of a frequency equal to the aforementioned natural frequency.
Inventors
- 👤 Kotaro Akutsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:36
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70691; G03F7/70716; F; F16; F16C; F16C32/00; F16C32/06; F16C32/0603; F16C32/0614; F16C32/0618; G03F7/708; G03F7/70808; G03F7/70816; Y; Y10; Y10S; Y10S384/00; Y10S384/90; Y10S384/902
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
105 words
A static pressure bearing device comprising a porous restrictor type spouting device for spouting pressurized fluid into a gap between a pair of objects and noncontactly supporting the two objects by the static pressure thereof, static pressure in the gap having a periodic fluctuation component having a phase delay of 90° relative to the periodic fluctuation of the dimension of the gap when a periodic variation in the dimension of the gap occurs, the natural frequency of a vibration system of each of the objects being regulated such that the periodic fluctuation component is a positive value of a frequency equal to the natural frequency.
Claim 2
Dependent Claim
105 words
A static pressure bearing device comprising a porous restrictor type spouting device for spouting pressurized fluid into a gap between a pair of objects and noncontactly supporting the two objects by the static pressure thereof, static pressure in the gap having a periodic fluctuation component having a phase delay of 90° relative to the periodic fluctuation of the dimension of the gap when a periodic variation in the dimension of the gap occurs, the natural frequency of a vibration system of each of the objects being regulated such that the periodic fluctuation component is a positive value of a frequency equal to the natural frequency.
Claim 3
Dependent Claim
40 words
A static pressure bearing device according to claim 1, wherein said spouting device has a porous member having a permeability or transmittance of 5×10 -16 m 2 or less and having a porosity or porosity rate of 20% or less.
Claim 4
Dependent Claim
111 words
A static pressure bearing device for noncontactly supporting a movable bed relative to a fixed bed comprising: a porous pad for spouting fluid between the movable bed and the fixed bed; and a supply line for supplying pressurized fluid to said porous pad; the natural frequency of a system having the movable bed noncontactly supported relative to the fixed bed by the porous pad being regulated so as to be in a frequency area in which the pressure fluctuation characteristic of the fluid between the movable bed and the fixed bed delayed by 90° in phase relative to the spacing vibration between the movable bed and the fixed bed is positive.
Claim 5
Dependent Claim
111 words
A static pressure bearing device for noncontactly supporting a movable bed relative to a fixed bed comprising: a porous pad for spouting fluid between the movable bed and the fixed bed; and a supply line for supplying pressurized fluid to said porous pad; the natural frequency of a system having the movable bed noncontactly supported relative to the fixed bed by the porous pad being regulated so as to be in a frequency area in which the pressure fluctuation characteristic of the fluid between the movable bed and the fixed bed delayed by 90° in phase relative to the spacing vibration between the movable bed and the fixed bed is positive.
Claim 6
Dependent Claim
33 words
A device according to claim 3, wherein said porous pad has a permeability or transmittance of 5×10 -16 m 2 or less and has a porosity or porosity rate of 20% or less.
Claim 7
Independent Claim
134 words
A method of manufacturing a static pressure bearing device for noncontactly supporting a movable bed relative to a fixed bed comprising: measuring a variation in the static pressure of fluid between the movable bed and the fixed bed when the movable bed is vibrated at a predetermined frequency; detecting the pressure fluctuation characteristic of the fluid between the movable bed and the fixed bed delayed by 90° in phase relative to the spacing vibration between the movable bed and the fixed bed on the basis of the result of the measurement; and regulating the natural frequency of a system having the movable bed noncontactly supported relative to the fixed bed by a porous pad to thereby cause the natural frequency to exist in a frequency area in which the pressure fluctuation characteristic is positive.
Claim 8
Independent Claim
134 words
A method of manufacturing a static pressure bearing device for noncontactly supporting a movable bed relative to a fixed bed comprising: measuring a variation in the static pressure of fluid between the movable bed and the fixed bed when the movable bed is vibrated at a predetermined frequency; detecting the pressure fluctuation characteristic of the fluid between the movable bed and the fixed bed delayed by 90° in phase relative to the spacing vibration between the movable bed and the fixed bed on the basis of the result of the measurement; and regulating the natural frequency of a system having the movable bed noncontactly supported relative to the fixed bed by a porous pad to thereby cause the natural frequency to exist in a frequency area in which the pressure fluctuation characteristic is positive.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-01-16 | 1998-07-18 | 1999-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-16 | 2002-07-18 | 2003-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-16 | 2006-07-18 | 2007-01-17 | $7700.00 | Window Closed / Lapsed |