Method for producing the rotor of a drag vacuum pump and a rotor produced according to this method

Abstract

A one-piece rotor ( 1 ) for a drag vacuum pump ( 21 ) is designed, at least in sections, as a turbomolecular vacuum pump with rotor blades ( 5 ) and stator blades ( 9 ), The rotor ( 1 ) has a hub ( 2 ) whose peripheral surface supports the pump structures. The rotor-side pump structures include, at least in sections, blades ( 5 ), which are arranged in rows ( 4 ) and which are formed from the surface of a blank by means of metal cutting operations. The metal cutting operations include producing radial peripheral grooves ( 3 ) into which stator blade rows ( 9 ) engage when the pump is assembled. In order to simplify the machining of the rotor ( 1 ), another metal cutting operation provides the outer surface of the blank with one or more thread grooves ( 13 ).

1 . A method for producing a one-piece rotor for a drag vacuum pump which is designed, at least in sections, as a turbomolecular vacuum pump with rotor blades and stator blades, the rotor having a hub whose peripheral surface supports rotor-side pump structures, which rotor-side pump structures include, at least in sections, blades which are arranged in rows and which are formed from the surface of a blank by means of metal cutting operations, the metal cutting operations comprising: 
 producing radial peripheral grooves into which stator blade rows engage when the pump is assembled; and    in another metal cutting operation, providing the outer surface of the blank with one or more thread grooves.    
   
   
       2 . The method according to  claim 1 , wherein the thread grooves are produced first by milling and thereafter the peripheral grooves are produced by turning.  
   
   
       3 . The method according to  claim 1 , wherein the thread grooves and the peripheral grooves are both produced by turning.  
   
   
       4 . The method according to  claim 1 , wherein the peripheral grooves are produced first and thereafter the thread grooves are produced.  
   
   
       5 . A rotor manufactured according to the method of  claim 1 , wherein the thread grooves and the peripheral grooves form rotor blades.  
   
   
       6 . The rotor according to  claim 5 , wherein the thread grooves extend over the entire height and the peripheral grooves are section-wise.  
   
   
       7 . The rotor according to  claim 5 , wherein a depth of the peripheral and thread grooves decreases at least in sections from an intake side towards a delivery side of the rotor.  
   
   
       8 . The rotor according to  claim 5 , further including: 
 a coaxially arranged cylinder on a delivery side.    
   
   
       9 . A vacuum pump with the rotor produced according to the method of  claim 1 .  
   
   
       10 . A method of producing a rotor for a vacuum pump comprising, in a cylinder blank in any order: 
 cutting a series of spiral grooves; and    cutting a series of peripheral grooves;    such that a plurality of peripheral rows of blades are defined with the blades in each row angularly displaced form an adjacent row.    
   
   
       11 . The method according to  claim 10  wherein a depth of at least one of the peripheral and spiral grooves varies axially along the blank.  
   
   
       12 . A rotor produced in accordance with the method of  claim 10.