Compact bearing system and machine stage system equipping the same

Patent metadata

Field	Value
Publication number	US-10077806-B2
Application number	US-201615210902-A
Country	US
Kind code	B2
Filing date	Jul 15, 2016
Priority date	Jul 15, 2015
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A compact bearing system capable of variable load carrying capability and precision motion on a guideway includes a bearing body, a fluid medium, a sealing bearing member and a pressurizing actuation means installed as an integral part of the bearing body. The bearing body includes an internal pocket with an open side facing a surface of said guideway. The fluid medium is contained inside said internal pocket and is in contact with said surface of said guideway on said open side. The sealing bearing member is in contact with said surface of said guideway and seals a clearance between said bearing body and said surface of said guideway to limit leakage of said fluid medium. The pressurizing actuation means pressurizes the confined fluid medium through a small passage, and the pressurized fluid medium carrying a main portion of a load carried on said compact bearing system.

First claim

What is claimed is:

1. A hydraulic bearing system capable of variable load carrying capability and precision motion on a guideway and requiring no external fluid circulation or external pressurizing mechanism, the hydraulic bearing system comprising:
a bearing body comprising a central internal pocket with an open side facing a surface of said guideway;
a fluid medium contained inside said central internal pocket and being in contact with said surface of said guideway on said open side;
a central sealing bearing member being in contact with said surface of said guideway and sealing clearance between said bearing body and said surface of said guideway to confine said fluid medium and limit leakage out of said internal pocket at a predetermined minimal level, thereby making said central internal pocket a sealed pocket; and
a pressurizing actuation means capable of exerting an actuation force to pressurize said fluid medium in said central internal pocket, said pressurizing actuation means being installed as an integral part of said bearing body and pressurizing the confined fluid medium through a passage to generate a load-carrying force against the surface of said guideway, wherein said passage has a cross-sectional area smaller than a contact area between said fluid medium and said guideway such that said load-carrying force is larger than said actuation force based on the principle of connected vessels, and the pressurized fluid medium carrying a main portion of a load carried on said hydraulic bearing system.

2. The hydraulic bearing system of claim 1 , further comprising a pressure regulation means capable of exerting a regulating force to pressurize said fluid medium in said central internal pocket, said pressure regulation means being installed on said bearing body and maintaining pressure of said confined fluid medium within a predetermined range thereby maintaining the range of a load carrying force during operation.

3. The hydraulic bearing system of claim 2 , said pressure regulation means comprising a spring loaded piston to apply said regulating force to said fluid medium through a passage leading to said internal pocket, said passage having a cross-sectional area smaller than the contact area between said fluid medium and said guideway such that said regulating force can be reduced by applying the principle of connected vessels.

4. The hydraulic bearing system of claim 1 , wherein said pressurizing actuation means comprises a mechanism of a piston in said passage, said piston being actuated by an electric actuator installed on said bearing body.

5. The hydraulic bearing system of claim 1 , wherein said pressurizing actuation means comprises a membrane spring and a pushing pin mechanism actuated by an electric actuator installed on said bearing body.

6. The hydraulic bearing system of claim 1 , wherein said central sealing bearing member comprises a coupling means that allows relative displacement with respect to said bearing body.

7. The hydraulic bearing system of claim 6 , further comprising:
at least one additional pocket in said bearing body with an open side facing said surface of said guideway, said additional pocket surrounding said central internal pocket and forming a separate pocket;
additional fluid medium contained inside said additional pocket and being in contact with said surface of said guideway;
at least one additional sealing bearing member corresponding to said additional pocket, said additional sealing bearing member being in contact with said surface of said guideway and sealing clearance between said bearing body and said surface of said guideway to confine said additional fluid medium inside said additional pocket and limit fluid medium leakage rate; and
at least one additional pressurizing actuation means pressurizing the confined fluid medium inside said additional pocket through an additional passage by applying the principle of connected vessels;
thereby said additional pocket with the corresponding additional sealing bearing member and said central internal pocket with said central sealing bearing member forming a multi-layer structure of cascaded pockets.

8. The hydraulic bearing system of claim 7 , wherein:
said pressurizing actuation means and said additional pressurizing actuation means setting said fluid medium in said cascaded pockets at different pressures with the highest pressure in the central internal pocket;
said system further comprising a pumping system for recycling said fluid medium from pockets of lower pressure back to said central internal pocket.

9. A machine stage system capable of variable load carrying capability and precision motion and requiring no external fluid circulation or external pressurizing mechanism, said system comprising a guideway and a carriage having a set of hydraulic bearing systems riding on said guideway, each of the hydraulic bearing systems comprising:
a bearing body comprising an internal pocket with an open side facing a surface of said guideway;
a fluid medium contained inside said internal pocket and being in contact with said surface of said guideway on said open side;
a sealing bearing member being in contact with said surface of said guideway and sealing clearance between said bearing body and said surface of said guideway to confine said fluid medium and limit leakage out of said pocket at a predetermined minimal level, said sealing bearing member comprising a coupling means that allows relative displacement with respect to said bearing body, thereby making said internal pocket a sealed pocket; and
a pressurizing actuation means capable of exerting an actuation force to pressurize said fluid medium in said internal pocket, said pressurizing actuation means being installed as an integral part of said bearing body and pressurizing the confined fluid medium through a passage to generate a load-carrying force against the surface of said guideway, said passage having a cross-sectional area smaller than a contact area between said fluid medium and said guideway such that said load-carrying force is larger than said actuation force based on the principle of connected vessels, the pressurized fluid medium carrying a main portion of a load carried on each of said hydraulic bearing systems.

10. The machine stage system of claim 9 , wherein said surface of said guideway comprises at least one porcelain tile, wherein said porcelain tile is a polished tile or a glazed tile.

11. The machine stage system of claim 9 , further comprising a bearing actuation control system for individually controlling said pressurizing actuation means of each of said hydraulic bearing systems in order to adjust displacements and orientations of said carriage in microscale in multiple degrees of freedom.

Assignees

• Univ Nat Tsing Hua

Inventors

• Tsao Che-Chih
• Li Zong-Lin

Classifications

• F16C32/0644

  Details of devices to control the supply of liquids to the bearings · CPC title

• F16C2322/39

  General buildup of machine tools, e.g. spindles, slides, actuators · CPC title

• F16C32/0648 Primary

  by sensors or pressure-responsive control devices in or near the bearings · CPC title