Friction-Optimized Vacuum Orbiter Pump

Abstract

The present invention relates to a dry-running, oil-free orbiter vacuum pump, on which a friction-optimized surface is provided on components. The dry-running orbiter vacuum pump comprises inter alia a pump housing with a cylindrical pump chamber and an orbiter eccentric piston with a guide slot and a cylindrical exterior surface, a cylindrical cross-section of the orbiter eccentric piston being smaller than a cylindrical cross-section of the pump chamber. At at least one of a radial air gap and an axial air gap formed in the cylindrical pump chamber between the orbiter eccentric piston and the pump housing at least one sliding surface is arranged in a manner exposed to the air gap; wherein the at least one sliding surface comprises a microstructure including cavities for decreasing an exposed surface of the at least one sliding surface.

1 . A dry-running orbiter vacuum pump comprising:
 a pump housing with a cylindrical pump chamber;   an orbiter eccentric piston with a guide slot and a cylindrical exterior surface, a cylindrical cross-section of the orbiter eccentric piston being smaller than a cylindrical cross-section of the pump chamber;   a shaft for driving the orbiter eccentric piston by means of an eccentric crankpin that meshes with the orbiter eccentric piston;   a blocking slide received in the guide slot of the orbiter eccentric piston, one end of the blocking slide being pivotably mounted at the pump housing between an inlet and an outlet;   characterized in that   at at least one of a radial air gap and an axial air gap formed in the cylindrical pump chamber between the orbiter eccentric piston and the pump housing at least one sliding surface is arranged in a manner exposed to the air gap; wherein   the at least one sliding surface comprises a microstructure including cavities for decreasing an exposed surface of the at least one sliding surface.   
     
     
         2 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the cavities of the microstructure have a closed contour towards the surface of the at least one sliding surface.   
     
     
         3 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the cavities of the microstructure have a dimension of 10 to 100 μm in a depth direction to the surrounding surface of the at least one sliding surface.   
     
     
         4 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the cavities of the microstructure have a dimension of 10 to 1000 μm in an extension direction of a contour to the surrounding surface of the at least one sliding surface.   
     
     
         5 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the cavities of the microstructure have the shape of a spherical cap, of an ellipsoid spherical cap, of an elongated hole or of a groove.   
     
     
         6 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the microstructure of the at least one sliding surface is produced at the corresponding surface of the pump housing or of the orbiter eccentric piston by means of laser-assisted melting of the material.   
     
     
         7 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 a material, on which the microstructure of the at least one sliding surface is produced, is provided as a surface insert that is inserted into a component body of the pump housing or of the orbiter eccentric piston.   
     
     
         8 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the microstructure of the at least one sliding surface is produced on a metal material provided by the pump housing or by the orbiter eccentric piston.   
     
     
         9 . The dry-running orbiter vacuum pump according to  claim 8 , wherein
 the metal material, on which the microstructure of the at least one sliding surface is produced, is surface hardened by means of hard anodizing.   
     
     
         10 . The dry-running orbiter vacuum pump according to  claim 8 , wherein
 the metal material, on which the microstructure of the at least one sliding surface is produced, is provided as a sintered layer sintered onto a material of the pump housing or of the orbiter eccentric piston.   
     
     
         11 . The dry-running orbiter vacuum pump according to  claim 1 , wherein
 the at least one sliding surface is additionally also arranged at at least one surface of the blocking slide, wherein   the at least one sliding surface at the blocking slide also comprises the microstructure including cavities for decreasing an exposed surface of the at least one sliding surface.