Rotor assembly

Abstract

A rotor assembly that includes a shaft and an impeller and/or a rotor core. The shaft is secured within a bore in the impeller and/or the rotor core by an adhesive such that the concentricity of the shaft is smaller than that of the bore. A method of manufacturing the rotor assembly is also described.

1 . (canceled) 
     
     
         2 . A rotor assembly comprising a shaft and an impeller, the shaft being secured within a bore of the impeller by an adhesive, wherein a centreline of the bore is offset from a centreline of the impeller by a first amount, a centreline of the shaft is offset from the centreline of the impeller by a second amount, and the second amount is less than the first amount. 
     
     
         3 . The rotor assembly of  claim 2 , wherein the impeller is formed of plastic. 
     
     
         4 . The rotor assembly of  claim 2 , wherein the rotor assembly comprises a rotor core, and the shaft is secured within a bore of the rotor core by an adhesive, and wherein a centreline of the bore in the rotor core is offset from a centreline of the rotor core by a third amount, a centreline of the shaft is offset from the centreline of the rotor core by a fourth amount, and the fourth amount is less than the third amount. 
     
     
         5 . The rotor assembly of  claim 4 , wherein the rotor assembly comprises a bearing cartridge located between the impeller and the rotor core. 
     
     
         6 . The rotor assembly of  claim 4 , wherein the rotor core is formed of a rare-earth magnetic material. 
     
     
         7 . A method of manufacturing a rotor assembly comprising:
 providing a shaft;   providing an impeller; and   adhering the shaft within a bore in the impeller such that a centreline of the bore is offset from a centreline of the impeller by a first amount, a centreline of the shaft is offset from the centreline of the impeller by a second amount, and the second amount is less than the first amount,   wherein adhering the shaft within the bore comprises applying an adhesive to the shaft and inserting the shaft into the bore whilst rotating the shaft relative to the impeller.   
     
     
         8 . The method of  claim 7 , wherein the method comprises:
 providing a rotor core; and   adhering the shaft within a bore in the rotor core such that a centreline of the bore in the rotor core is offset from a centreline of the rotor core by a third amount, a centreline of the shaft is offset from the centreline of the rotor core by a fourth amount, and the fourth amount is less than the third amount,   wherein adhering the shaft within the bore comprises applying an adhesive to the shaft and inserting the shaft into the bore whilst rotating the shaft relative to the impeller.   
     
     
         9 . A rotor assembly comprising a shaft and an impeller, the shaft being secured within a bore of the impeller by adhesive, wherein an angle of inclination of the shaft relative to a centreline of the impeller is less than an angle of inclination of the bore relative to the centreline of the impeller. 
     
     
         10 . The rotor assembly of  claim 9 , wherein the impeller is formed of plastic. 
     
     
         11 . The rotor assembly of  claim 9 , wherein the rotor assembly comprises a rotor core, and the shaft is secured within a bore the rotor core by an adhesive, and wherein an angle of inclination of the shaft relative to a centreline of the rotor core is less than an angle of inclination of the bore relative to the centreline of the rotor core. 
     
     
         12 . The rotor assembly of  claim 11 , wherein the rotor assembly comprises a bearing cartridge located between the impeller and the rotor core. 
     
     
         13 . The rotor assembly of  claim 11 , wherein the rotor core is formed of a rare-earth magnetic material.