Patent ID: 11898932
Assignee: ZHUZHOU CRRC TIMES ELECTRIC CO. LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. The device for diagnosing a fault in a bearing of a motor according to claim 1, wherein the fault state of the bearing comprises a fault in a holder of the bearing, a fault in an outer ring of the bearing, a fault in an inner ring of the bearing and a fault in a rolling element of the bearing, and the fault feature extraction unit is configured to:
acquire a fault feature frequency of the holder of the bearing from following equation:, 1
    2
   
   ⁢
   
    
     f
     r
    
    (
    
     1
     -
     
      
       
        D
        B
       
       ⁢
       cos
       ⁢
       θ
      
      
       D
       P
      
     
    
    )
   
  
  ;
 

acquire a fault feature frequency of the outer ring of the bearing from following equation:, N
     B
    
    2
   
   ⁢
   
    
     f
     r
    
    (
    
     1
     -
     
      
       
        D
        B
       
       ⁢
       cos
       ⁢
       θ
      
      
       D
       P
      
     
    
    )
   
  
  ;
 

acquire a of a fault feature frequency of the inner ring of the bearing from following equation:, N
     B
    
    2
   
   ⁢
   
    
     f
     r
    
    (
    
     1
     +
     
      
       
        D
        B
       
       ⁢
       cos
       ⁢
       θ
      
      
       D
       P
      
     
    
    )
   
  
  ;
  and
 

acquire a fault feature frequency of the rolling element of the bearing from following equation:, D
     P
    
    
     D
     B
    
   
   ⁢
   
    
     f
     r
    
    (
    
     1
     -
     
      
       (
       
        
         
          D
          B
         
         ⁢
         cos
         ⁢
         θ
        
        
         D
         P
        
       
       )
      
      2
     
    
    )
   
  
  ,
 

wherein  represents a rotation frequency of the motor, DB represents a diameter of the rolling element of the bearing, DP represents a diameter of a bearing section, NB the number of rolling elements in the bearing, and θ represents a contact angle.