Pump bearing arrangement

Abstract

A pump bearing arrangement, suitable particularly for rapidly rotating pumps such as turbomolecular pumps, comprises a pump rotor ( 10 ) con-nected to a rotor shaft. The rotor shaft ( 14 ) is supported in a shaft housing ( 20 ) by two bearing arrangements ( 12 ). Each bearing arrangement ( 12 ) has an inner bearing ring ( 16 ) connected to the rotor shaft ( 14 ) and an outer bearing ring ( 22 ) connected to the shaft housing ( 20 ). Bearing supports ( 24 ) are disposed between the two bearing rings. At least one vibration element ( 26 ) is provided between the outer bearing ring ( 22 ) and the shaft housing ( 20 ), serving for damping and further having a thermal conductivity of at least 0.3 W/mK for dissipating heat.

1 . A pump bearing arrangement, particularly for rapidly rotating pumps such e.g. as turbomolecular pumps, comprising
 a rotor shaft connected to a pump rotor, and   a shaft housing with the rotor shaft supported therein via two bearing arrangements,   each bearing arrangement comprising an inner bearing ring, an outer bearing ring and bearing supports arranged between said bearing rings, and   a vibration element for damping, arranged in abutment on the outer bearing ring and the shaft housing and respectively the rotor shaft, said vibration element further serving for heat dissipation, wherein said vibration element has a thermal conductivity of at least 0.3 W/mK.   
     
     
         2 . The pump bearing arrangement according to  claim 1 , wherein the thermal conductivity of the vibration elements is higher than 0.35 W/mK, preferably higher than 0.4 W/mK. 
     
     
         3 . The pump bearing arrangement according to  claim 1 , wherein the vibration element comprises an elastomeric material. 
     
     
         4 . The pump bearing arrangement according to  claim 1 , wherein the vibration element comprises silicone. 
     
     
         5 . The pump bearing arrangement according to  claim 1 , wherein the vibration element comprises Elastosil, preferably Elastosil R840. 
     
     
         6 . The pump bearing arrangement according to  claim 1 , wherein a gap is formed between the outer bearing ring and the shaft housing. 
     
     
         7 . The pump bearing arrangement according to  claim 1 , wherein the vibration element is free of metal particles. 
     
     
         8 . The pump bearing arrangement according to  claim 1 , wherein the vibration element has a Shore A hardness of 40-85 Shore A. 
     
     
         9 . The pump bearing arrangement according to  claim 1 , wherein the vibration element has an annular shape. 
     
     
         10 . The pump bearing arrangement according to  claim 1 , wherein the vibration element has a rectangular or circular cross section. 
     
     
         11 . The pump bearing arrangement according to  claim 1 , wherein, for damping radial movements, the vibration element surrounds the outer bearing ring. 
     
     
         12 . The pump bearing arrangement according to  claim 1 , wherein the vibration element is arranged in a groove provided in the shaft housing. 
     
     
         13 . The pump bearing arrangement according to  claim 1 , wherein a plurality of vibration elements are provided. 
     
     
         14 . Use of a vibration element in pump bearing arrangements, particularly for rapidly rotating pumps, said vibration element having a thermal conductivity of at least 0.3 W/mK. 
     
     
         15 . Use according to  claim 14 , wherein the vibration element is provided according to  claim 1 . 
     
     
         16 . The pump bearing arrangement according to  claim 1 , wherein the thermal conductivity of the vibration elements is higher than 0.4 W/mK, preferably higher than 0.4 W/mK. 
     
     
         17 . A turbomolecular pump comprising:
 a pump rotor;   a rotor shaft connected to the pump rotor;   a shaft housing;   at least one bearing arrangement which supports the rotor shaft in the shaft housing, the bearing arrangement including:
 an outer bearing ring, 
 an inner bearing ring connected with the rotor shaft, 
 rolling elements between the inner and outer bearing rings, 
 an elastomeric vibration damping element having a thermal conductivity of at least 0.3 W/mK disposed between the outer bearing ring and the shaft housing.