Insulated motor core and method for producing same

Abstract

A motor core coated with a multi-layer insulating film. The insulating film preferably includes in order: an electrodeposited coating film applied upon an outer surface of the motor core; a first spray coated insulating film applied upon an outer surface of the electrodeposited coating film the first film having a pencil hardness of between about 2H and 4H; and a second spray-coated insulating film applied upon an outer surface of the first spray-coated insulating film, the second film having a pencil hardness of between about 3H and 6H. The invention is additionally directed to a variety of methods for forming such insulation-coated cores.

1 . A method for preparing a motor core coated with a multi-layer insulating film, the method comprising: 
 (a) coating a motor core, having first and second opposed surfaces, with an electrodeposited coating film;    (b) applying, to an outer surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H; and    (c) applying, upon an outer surface of the first spray-coated insulating film, a second spray-coated insulating film having a pencil hardness of between 3H and 6H.    
   
   
       2 . The method of  claim 1 , wherein the core is formed of a plurality of laminated metal plates.  
   
   
       3 . The method of  claim 1 , wherein the electrodeposited coating film has a mean thickness of between about 10 and 25 μm.  
   
   
       4 . The method of  claim 1 , wherein the first spray-coated insulating film has a mean thickness of between about 20 and 35 μm.  
   
   
       5 . The method of  claim 1 , wherein the second spray-coated insulating film has a mean thickness of between about 5 and 15 μm.  
   
   
       6 . The method of  claim 1 , wherein the second spray-coated insulating film is formed from a paint having a denatured silicate resin obtained by reacting a silicate resin with silicic acid.  
   
   
       7 . The method of  claim 1 , wherein the electrodeposited coating film is formed from a cationic electrodeposition paint or an anionic electrodeposition paint.  
   
   
       8 . The method of  claim 1 , wherein the electrodeposited coating film is formed from a paint comprising a resin selected from the group consisting of epoxy resins, urethane resins, polyester resins and polyamide resins.  
   
   
       9 . The method of  claim 8 , wherein the first spray-coated insulating film is formed from an epoxy paint.  
   
   
       10 . The method of  claim 1 , wherein the first and the second spray-coated insulating films are substantially free of at least one of lead, tin and silicon.  
   
   
       11 . A method for preparing a motor core coated with a multi-layer insulating film, the method comprising: 
 (a) coating a motor core, having first and second opposed surfaces, with an electrodeposited coating film;    (b) placing the electrodeposition-coated core upon a coating tool;    (c) applying, to an outer portion of a first surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H;    (d) applying, upon an outer portion of the first spray-coated insulating film on the first core surface, a second spray-coating insulating film having a pencil hardness of between 3H and 6H;    (e) turning the motor core over upon the coating tool so as to expose the second opposed surface thereof for further coating;    (f) applying, to an outer portion of a second surface of the electrodeposition film, a first spray-coated insulating film having a pencil hardness between 2H and 4H; and    (g) applying, upon an outer portion of the first spray-coated insulating film on the second opposed core surface, a second spray-coated insulating film having a pencil hardness of between 3H and 6H.    
   
   
       12 . The method of  claim 11 , wherein the first spray-coated insulating film is produced by heating a first spray-coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees centigrade.  
   
   
       13 . The method of  claim 11 , wherein the second spray-coated insulating film is produced by heating a second spray-coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees centigrade.  
   
   
       14 . The method of  claim 11 , wherein the electrodeposited coating film is formed from a cationic electrodeposition paint or an anionic electrodeposition paint.  
   
   
       15 . The method of  claim 11 , wherein the electrodeposited coating film has a mean thickness of between about 10 and 25 μm.  
   
   
       16 . The method of  claim 11 , wherein the first spray-coated insulating film has a mean thickness of between about 20 and 35 μm.  
   
   
       17 . The method of  claim 11 , wherein the second spray-coated insulating film has a mean thickness of between about 5 and 15 μm.  
   
   
       18 . The method of  claim 11 , wherein the core includes a plurality of laminated metal plates.  
   
   
       19 . The method of  claim 13 , wherein the second spray-coating insulating paint is a paint having a denatured silicate resin obtained by reacting a silicate resin with a silicic acid.  
   
   
       20 . The method of  claim 12 , wherein the first spray-coating insulating paint is an epoxy paint.  
   
   
       21 . The method of  claim 1 , wherein the first and second spray-coated insulating films are substantially free of at least one of lead, tin and silicon.  
   
   
       22 . A method for preparing a motor core coated with a multi-layer insulating film, the method comprising: 
 (a) coating a motor core, having first and second opposed surfaces, with an electrodeposited coating film;    (b) placing the electrodeposition-coated core upon a coating tool;    (c) applying, to an outer portion of a first surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H;    (d) turning the core over upon the coating tool to expose the second opposed surface of the core;    (e) applying, to an outer portion of a second surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H;    (f) applying, upon an outer portion of the first spray-coated insulating film on the second opposed core surface, a second spray-coated insulating film having a pencil hardness of between 3H and 6H;    (g) turning the core over on the coating tool to expose the coated first surface of the core; and    (h) applying, upon an outer portion of the first spray-coated insulating film on the coated first core surface a second spray-coated insulating film having a pencil hardness of between 3H and 6H.    
   
   
       23 . The method of  claim 22 , wherein the first spray-coated insulating film is produced by heating a first spray-coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees centigrade.  
   
   
       24 . The method of  claim 22 , wherein the second spray-coated insulating film is produced by heating a second spray-coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees centigrade.  
   
   
       25 . The method of  claim 22 , wherein the electrodeposited coating film is formed from a cationic electrodeposition paint or an anionic electrodeposition paint.  
   
   
       26 . The method of  claim 22 , wherein the electrodeposited coating film has a mean thickness of between about 10 and 25 μm.  
   
   
       27 . The method of  claim 22 , wherein the first spray-coated insulating film has a mean thickness of between about 20 and 35 μm.  
   
   
       28 . The method of  claim 22 , wherein the second spray-coated insulating film has a mean thickness of between about 5 and 15 μm.  
   
   
       29 . The method of  claim 22 , wherein the core includes a plurality of laminated metal plates.  
   
   
       30 . The method of  claim 22 , wherein the second spray-coated insulating films are substantially free of at least one of lead, tin and silicon.  
   
   
       31 . A method for preparing a motor core coated with a multi-layer insulating film, the method comprising: 
 (a) coating a motor core, having first and second opposed surfaces, with an electrodeposited coating film;    (b) placing the electrodeposition-coated core upon a coating tool;    (c) applying, to an outer portion of a first surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H;    (d) turning the core over upon the coating tool to expose the second, opposed surface of the core;    (e) applying, to an outer portion of a second surface of the electrodeposited film, a first spray-coated insulating film having a pencil hardness of between 2H and 4H;    (f) turning the core over upon the coating tool to expose the first surface of the core;    (g) applying, upon an outer portion of the first spray-coated insulating film on the first core surface, a second spray-coated insulating film having a pencil hardness of between 3H and 6H;    (h) turning the core over upon the coating tool to expose the second surface of the core; and    (i) applying, upon an outer portion of the first spray-coated insulating film upon the second opposed core surface, a second spray coated insulating film having a pencil hardness of between 3H and 6H.    
   
   
       32 . The method of  claim 31 , wherein the first spray-coated insulating film is produced by heating a first spray coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees, centigrade.  
   
   
       33 . The method of  claim 31 , wherein the second spray-coated insulating film is produced by heating a second spray-coating insulating paint applied upon the motor core at a temperature in the range between about 180 and 200 degrees centigrade.  
   
   
       34 . The method of  claim 31 , wherein the electrodeposited coating film is formed from a cationic electrodeposition paint or an anionic electrodeposition paint.  
   
   
       35 . The method of  claim 31 , wherein the electrodeposition film has a mean thickness of between about 10 and 25 μm.  
   
   
       36 . The method of  claim 31 , wherein the first spray-coated insulating film has a mean thickness of between about 20 and 35 μm.  
   
   
       37 . The method of  claim 31 , wherein the second spray-coated insulating film has a mean thickness of between about 5 and 15 μm.  
   
   
       38 . The method of  claim 31 , wherein the core includes a plurality of laminated metal plates.  
   
   
       39 . The method of  claim 31 , wherein the second spray-coated insulating films are substantially free of at least one of lead, tin and silicon.