Lightweight vacuum pump with oxidized surfaces

Abstract

A light weight vacuum pump is made with either or all of the stator, rotors and vanes made of aluminum or aluminum alloy that has been subjected to high energy oxidation, such as plasma electrolytic oxidation (PEO), electrolytic plasma oxidation (EPO) or micro-arc oxidation (MAO), to treat and harden the surface.

We claim: 
     
         1 . A vacuum pump system comprising:
 a motor; and   a vacuum pump operably connected to the motor, the vacuum pump having one or more rotors and one or more stators formed from material selected from the group consisting of aluminum, aluminum alloy or sintered aluminum powder, wherein the one or more rotors and one or more stators are treated with a high energy oxidation process selected from the group consisting of plasma electrolytic oxidation, electrolytic plasma oxidation, micro-arc oxidation or spark discharge anodizing.   
     
     
         2 . The vacuum pump system of  claim 1  further comprising:
 a plurality of vanes operably connected to the one or more rotors wherein the plurality of vanes are formed of material selected from the group consisting of aluminum, aluminum alloy or sintered aluminum powder, and wherein the plurality of vanes are treated with a high energy oxidation process selected from the group consisting of plasma electrolytic oxidation, electrolytic plasma oxidation, micro-arc oxidation or spark discharge anodizing. 
 
     
     
         3 . The vacuum pump system of  claim 1  further comprising:
 a plurality of vanes operably connected to the one or more rotors wherein the plurality of vanes are formed of material selected from the group consisting of untreated polymer, carbon or graphite. 
 
     
     
         4 . The vacuum pump system of  claim 1  further comprising:
 an oil pump operatively connected to one of the one or more rotors. 
 
     
     
         5 . The vacuum pump system of  claim 1  further comprising:
 an oil tank configured to submerge the vacuum pump in oil during operation. 
 
     
     
         6 . A vacuum pump comprising:
 a stator having a cylindrical volute with a cylindrical inner wall, a first end wall and a second end wall;   a rotor rotatably disposed within the stator, said rotor having an outer cylindrical surface;   a vane coupled to the rotor and translatably disposed relative to the rotor, said vane having a sealing surface at a radial outer edge of said vane;   wherein one or more of the stator, rotor or vane comprises a wear surface comprising aluminum, and at least one wear surface has a Vickers hardness in the range of 1000 to 3000 HV.   
     
     
         7 . A vacuum pump system comprising:
 vacuum pump comprising:
 a stator having a cylindrical volute with a cylindrical inner wall, a first end wall and a second end wall; 
 a rotor rotatably disposed within the stator, said rotor having an outer cylindrical surface; 
 a vane coupled to the rotor and translatably disposed relative to the rotor, said vane having a sealing surface at a radial outer edge of said vane; 
 wherein one or more of the stator, rotor or vane comprises a wear surface comprising aluminum, and at least one wear surface has a Vickers hardness in the range of 1000 to 3000 HV; 
   a motor operably connected to the vacuum pump;   wherein the rotor, stator or vane are formed from material selected from the group consisting of aluminum, aluminum alloy or sintered aluminum powder;   wherein the rotor, stator and vane are treated with a high energy oxidation process selected from the group consisting of plasma electrolytic oxidation, electrolytic plasma oxidation, micro-arc oxidation or spark discharge anodizing.   
     
     
         8 . The vacuum pump of  claim 7  further comprising:
 an oil pump operatively connected to one of the one or more rotors. 
 
     
     
         9 . The vacuum pump of  claim 7  further comprising:
 an oil tank configured to submerge the vacuum pump in oil during operation.