Method for producing a dynamic fluid bearing with high rotation precision and high hardness

Abstract

A method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure comprises the steps of: (1) selecting at least one rotary component provided with a predetermined surface pattern for supporting a distribution of fluid dynamic-pressure; (2) forming an opaque and hard amorphous diamond (DLC, a-D) film (or nano-crystalline diamond film) on the pivotal surface of the component by physical vapor deposition (PVD). Thereby the pivotal surfaces of the rotary component and the pattern thereon can have excellent hardness, wearing resistance, rotational stailbity and durability under repeated urging of dynamic fluid pressure.

1 . A method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure, comprising the steps of: 
 selecting at least a first component of a plurality of pivotally connected bearing components supporting fluid dynamic-pressure, said first component having a predetermined surface pattern;    forming an opaque and hard amorphous diamond (DLC, a-D) film on the pivotal surface of said first component by physical vapor deposition (PVD) using ion plating, said amorphous diamond film covering said pattern of said first component and/or the corresponding pivotal surface of a second component; and    combining said first component coated with an amorphous diamond (DLC, a-D) film and said second component so that the space between said first and second components form a trough for filling a fluid, whereby said pivotal surfaces of said first and second components can be urged with a pressure distribution as a fluid is filled in said trough.    
   
   
       2 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein said first component is a spindle and said pivotal surface thereof consists of a rod surface portion and an inclined surface portion of a bulged round terminal.  
   
   
       3 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein said first component is a sleeve and said pivotal surface thereof consists of the inner wall portion of a spindle hole and an inclined inner surface portion of a round terminal indentation.  
   
   
       3 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein said surface pattern is selected from a bulged pattern and a notched pattern.  
   
   
       5 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein the kinetic energy of said ion plating is gradually increased in a ranged of 150-250 eV.  
   
   
       6 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein the sp 3  binding of said amorphous diamond (DLC, a-D) film exceeds 85%.  
   
   
       7 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein the hardness of said amorphous diamond (DLC, a-D) film is 80-100 GPa.  
   
   
       8 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein said ion plating is directly injecting cathode arc on said components.  
   
   
       9 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 8  wherein said cathode arc is graphite cathode arc.  
   
   
       10 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 8  wherein the temperature of said components are maintained under 150° C.  
   
   
       11 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 8  wherein a catalytic agent is added to react with said graphite in said process of ion plating.  
   
   
       12 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 11  wherein said catalytic agent is selected from the group of molten Cr, Mn, Fe, Co and Ni elements.  
   
   
       13 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 8  wherein said components are selected from metal, ceramic and plastic.  
   
   
       14 . The method for manufacturing bearing components of high precision and hardness supporting fluid dynamic-pressure of  claim 1  wherein said fluid is selected from air and lubricating oil.