Element which Generates a Magnetic Field

Abstract

An element which generates a magnetic field for fastening a compressor wheel to a turboshaft of an exhaust-gas turbocharger, has a basic body and a thread. In order to specify an element which generates a magnetic field for fastening a compressor wheel to a turboshaft, which element generates as high a magnetic field strength as possible and nevertheless can absorb without damage the forces and the tightening torques which occur during fastening of the compressor wheel to the turboshaft, the entire basic body includes a magnetic material and a sleeve is arranged in the basic body, which sleeve includes a non-magnetic material and has the thread which can be screwed to a mating thread of the turboshaft.

1 .- 7 . (canceled) 
   
   
       8 . A fastening element that generates a magnetic field configured to fasten a compressor wheel to a turboshaft of an exhaust-gas turbocharger, the fastening element comprising:
 a body composed of a magnetic material, the body having a bore therethrough in a fastening direction; and   a sleeve composed of non-magnetic material and having an internal thread, the sleeve being arranged in the bore of the body,   wherein the internal thread of the sleeve is configured to mate with a corresponding thread on the turboshaft.   
   
   
       9 . The fastening element according to  claim 8 , wherein the sleeve is a press-in sleeve. 
   
   
       10 . The fastening element according to  claim 8 , wherein the bore further comprises an internal toothing system and the sleeve is connected in a positively locking connection in the bore of the body by the internal toothing system. 
   
   
       11 . The fastening element according to  claim 8 , wherein the sleeve is a nonmagnetic metal. 
   
   
       12 . The fastening element according to  claim 8 , wherein the sleeve is plastic. 
   
   
       13 . The fastening element according to  claim 10 , wherein the sleeve is connected to the body by at least one crimped connection. 
   
   
       14 . The fastening element according to  claims 11 , wherein the sleeve is austenitic steel. 
   
   
       15 . The fastening element according to  claims 14 , wherein the austenitic steel is a high-strength austenitic steel. 
   
   
       16 . The fastening element according to  claim 10 , wherein the sleeve is connected to the body by at a crimped connection at each end of the bore. 
   
   
       17 . The fastening element according to  claim 10 , wherein the magnetic material of the body is a permanent magnet. 
   
   
       18 . The fastening element according to  claim 13 , wherein the crimped connection forms a planar surface between the body and the sleeve. 
   
   
       19 . The fastening element according to  claim 10 , wherein the sleeve is anchored in the bore of the body by at least one of a mechanical connection or a bonding connection. 
   
   
       20 . The fastening element according to  claim 8 , wherein the body has a perimeter in a shape of a regular equilateral 
   
   
       21 . An exhaust-gas turbocharger comprising:
 a compressor comprising a compressor housing and a compressor wheel;   a threaded turboshaft;   a fastening element configured to attach the compressor wheel to the threaded turboshaft,   the fastening element comprising:
 a body composed of a magnetic material, the body having a bore therethrough in a fastening direction; and 
 a sleeve having an internal thread configured to mate with the thread on the turboshaft, the sleeve being arranged in the bore of the body; and 
   a sensor responsive to a magnetic field generated by the fastening element.   
   
   
       22 . The exhaust-gas turbocharger according to  claim 21 , wherein the sensor is mounted to the compressor housing. 
   
   
       23 . The exhaust-gas turbocharger according to  claim 21 , wherein the sensor is responsive to the magnetic field generated by the fastening element through the compressor housing. 
   
   
       24 . The exhaust-gas turbocharger according to  claim 21 , wherein the sleeve is a non-magnetic material.