Mechanical translator with ultra low friction ferrofluid bearings

Abstract

A mechanical translator includes at least one magnet that is disposed on a substrate to carry a load and has a magnetic axis generally transverse to the substrate, establishing a magnetic field with maximum external density adjacent the substrate. An ultra low friction interface is obtained with ferrofluid bearings, such as a light mineral oil medium mixed with isoparaffinic acid, which establish a critical angle of displacement from a horizontal static position of less than 1 degree, and preferably less than 10 minutes. A controller of magnetic material can be placed on the opposite side of the substrate to control the movement of the magnets.

I claim:  
     
         1 . A mechanical translator, comprising: 
 a substrate, and    a magnet disposed for movement on said substrate, said magnet arranged to carry a load and having a magnetic axis generally transverse to said substrate.    
     
     
         2 . The mechanical translator of  claim 1 , wherein said translator has a critical angle of displacement from a horizontal static position of less than 1 degree.  
     
     
         3 . The mechanical translator of  claim 2 , wherein said critical angle is less than 10 minutes.  
     
     
         4 . The mechanical translator of  claim 1 , further comprising a lubricant between said magnet and substrate.  
     
     
         5 . The mechanical translator of  claim 4 , wherein said lubricant comprises a ferrofluid.  
     
     
         6 . The mechanical translator of  claim 5 , wherein said ferrofluid includes a light mineral oil medium.  
     
     
         7 . The mechanical translator of  claim 6 , said ferrofluid further comprising isoparaffinic acid mixed with said light mineral oil.  
     
     
         8 . The mechanical translator of  claim 5 , said ferrofluid having a viscosity less than 5 cp.  
     
     
         9 . The mechanical translator of  claim 5 , further comprising a controller of magnetic material on the opposite side of said substrate from said magnet, said controller controlling the movement of said magnet.  
     
     
         10 . The mechanical translator of  claim 9 , said substrate comprising a portion of an enclosure, with said magnet inside and said controller outside said enclosure.  
     
     
         11 . A mechanical translator, comprising: 
 a substrate, and    a magnet disposed for movement on said substrate, said magnet arranged to carry a load and establishing a magnetic field which has its maximum external density adjacent said substrate.    
     
     
         12 . The mechanical translator of  claim 11 , wherein said translator has a critical angle of displacement from a horizontal static position of less than 1 degree.  
     
     
         13 . The mechanical translator of  claim 12 , wherein said critical angle is less than 10 minutes.  
     
     
         14 . The mechanical translator of  claim 11 , further comprising a lubricant between said magnet and substrate.  
     
     
         15 . The mechanical translator of  claim 14 , wherein said lubricant comprises a ferrofluid.  
     
     
         16 . The mechanical translator of  claim 15 , wherein said ferrofluid includes a light mineral oil medium.  
     
     
         17 . The mechanical translator of  claim 16 , said ferrofluid further comprising isoparaffinic acid mixed with said light mineral oil.  
     
     
         18 . The mechanical translator of  claim 15 , said ferrofluid having a viscosity less than 5 cp.  
     
     
         19 . The mechanical translator of  claim 15 , further comprising a controller of magnetic material on the opposite side of said substrate from said magnet, said controller controlling the movement of said magnet.  
     
     
         20 . The mechanical translator of  claim 19 , said substrate comprising a portion of an enclosure, with said magnet inside and said controller outside said enclosure.  
     
     
         21 . A mechanical translator, comprising: 
 a substrate, and    a plurality of magnets disposed for movement on said substrate and carrying a platform, said magnets having respective magnetic axes generally transverse to said substrate.    
     
     
         22 . The mechanical translator of  claim 21 , wherein said magnets are connected to respective fixed locations on said platform.  
     
     
         23 . The mechanical translator of  claim 21 , said platform comprising a magnetic material.  
     
     
         24 . The mechanical translator of  claim 21 , said platform comprising a nonmagnetic material.  
     
     
         25 . The mechanical translator of  claim 24 , said platform comprising a magnetic field shielding alloy.  
     
     
         26 . The mechanical translator of  claim 21 , wherein said translator has a critical angle of displacement from a horizontal static position of less than 1 degree.  
     
     
         27 . The mechanical translator of  claim 26 , wherein said critical angle is less than 10 minutes.  
     
     
         28 . The mechanical translator of  claim 21 , further comprising a lubricant between said magnets and said substrate.  
     
     
         29 . The mechanical translator of  claim 28 , said lubricant comprising a ferrofluid.  
     
     
         30 . The mechanical translator of  claim 29 , further comprising a controller of magnetic material on the opposite side of said substrate from said magnets and platform, said controller controlling the movement of said magnets and platform.  
     
     
         31 . The mechanical translator of  claim 30 , said substrate comprising a portion of an enclosure, with said magnets and platform inside said enclosure and said controller outside.  
     
     
         32 . A mechanical translator, comprising: 
 a substrate, and    a plurality of magnets disposed for movement on said substrate and carrying a platform, said magnets establishing respective magnetic fields which have their maximum external densities adjacent said substrate.    
     
     
         33 . The mechanical translator of  claim 32 , wherein said magnets are connected to respective fixed locations on said platform.  
     
     
         34 . The mechanical translator of  claim 32 , said platform comprising a magnetic material.  
     
     
         35 . The mechanical translator of  claim 32 , said platform comprising a nonmagnetic material.  
     
     
         36 . The mechanical translator of  claim 35 , said platform comprising a magnetic field shielding alloy.  
     
     
         37 . The mechanical translator of  claim 32 , wherein said translator has a critical angle of displacement from a horizontal static position of less than 1 degree.  
     
     
         38 . The mechanical translator of  claim 37 , wherein said critical angle is less than 10 minutes.  
     
     
         39 . The mechanical translator of  claim 32 , further comprising a lubricant between said magnets and said substrate.  
     
     
         40 . The mechanical translator of  claim 39 , said lubricant comprising a ferrofluid.  
     
     
         41 . The mechanical translator of  claim 40 , further comprising a controller of magnetic material on the opposite side of said substrate from said magnets and platform, said controller controlling the movement of said magnets and platform.  
     
     
         42 . The mechanical translator of  claim 41 , said substrate comprising a portion of an enclosure, with said magnets and platform inside said enclosure and said controller outside.  
     
     
         43 . Vapor deposition apparatus, comprising: 
 a vacuum chamber having a floor,    at least one magnet disposed for movement on said floor and carrying a platform for a substrate, each magnet having a magnetic axis generally transverse to said floor,    a vapor source for depositing a thin film on a substrate carried by said platform, and    a controller of magnetic material outside said chamber on the opposite side of said floor from said magnets, said controller arranged to translate to impart a corresponding translation to said magnets and platform.    
     
     
         44 . The vapor deposition apparatus of  claim 43 , wherein said translator has a critical angle of displacement from a horizontal static position of less than 1 degree.  
     
     
         45 . The vapor deposition apparatus of  claim 44 , wherein said critical angle is less than 10 minutes.  
     
     
         46 . The vapor deposition apparatus of  claim 43 , further comprising a ferrofluid providing a lubricant between said magnets and said floor.  
     
     
         47 . A mechanical translator, comprising: 
 a substrate, and    at least one magnet disposed for movement on said substrate and arranged to carry a load, each magnet having a magnetic axis at an angle of at least 45° to said substrate and a critical angle of displacement from a horizontal static position of less than 1 degree.    
     
     
         48 . The mechanical translator of  claim 47 , wherein said critical angle is less than 10 minutes.  
     
     
         49 . The mechanical translator of claims  47 , further comprising a respective ferrofluidic bearing supporting each magnet.  
     
     
         50 . The mechanical translator of  claim 47 , comprising a plurality of said magnets carrying a common load platform.  
     
     
         51 . The mechanical translator of  claim 47 , further comprising a controller of magnetic material on the opposite side of said substrate from said at least one magnet, said controller controlling the movement of said at least one magnet.  
     
     
         52 . The mechanical translator of  claim 51 , said substrate comprising a portion of an enclosure, with said at least one magnet inside and said controller outside said enclosure.  
     
     
         53 . An ultra low friction ferrofluid mixture, comprising: 
 a light mineral oil medium,    isoparaffinic acid mixed with said light mineral oil, and magnetizable nanoparticles suspended in said mixture.    
     
     
         54 . The ferrofluid mixture of  claim 53 , said mixture having a coefficient of static friction not greater than about 0.0012.  
     
     
         55 . The ferrofluid mixture of  claim 54 , wherein the ratio of isoparaffinic acid to light mineral oil in said mixture is in the range of about 2:1 to about 4:1.