Use of no-bake mold process to manufacture side frame and bolster for a railway truck

Abstract

A method for casting a railroad component such as a component of a railway car truck. The component of the railway car truck may be, e.g., a side frame or a bolster of the railway car truck. The method includes manufacturing the railroad component made of steel in a no-bake manufacturing process including use of a chemically-bonded sand system that results in a sand mold from which the railroad component is cast. The railroad component resulting from the no-bake manufacturing process has a surface finish less than 750 micro-inches RMS, resulting in increased fatigue life compared to a railroad component manufactured by a green sand process.

We claim: 
     
         1 . A method for casting a bolster of a railway car truck, the method comprising:
 manufacturing a bolster made of steel in a no-bake manufacturing process including use of a chemically-bonded sand system that results in a sand mold from which the bolster is cast, the bolster that results having a surface finish less than 750 micro-inches RMS, resulting in increased fatigue life compared to a bolster manufactured by a green sand process.   
     
     
         2 . The method of  claim 1 , wherein the bolster resulting from the no-bake manufacturing process includes draft angles comprising 1.0 (one) degree or less for a plurality of typical features of the bolster. 
     
     
         3 . The method of  claim 1 , wherein the bolster resulting from the no-bake manufacturing process includes a pair of shoe pockets at respective ends configured to be inserted into bolster openings of respective side frames, and wherein a surface finish of the pair of shoe pockets is less than 500 micro-inches RMS. 
     
     
         4 . The method of  claim 3 , wherein a shoe pocket side wall draft angle of the bolster is no more than about ¾ degrees. 
     
     
         5 . The method of  claim 3 , wherein a margin of error in shoe pocket angles is within about ±0.5 degrees. 
     
     
         6 . The method of  claim 1 , wherein the bolster resulting from the no-bake manufacturing process includes inner and outer gibs, and wherein a margin of error in a spacing between respective inner and outer gibs of the bolster is within about ±0.063 inches. 
     
     
         7 . The method of  claim 6 , wherein respective inner and outer gib draft angles are not more than about ¾ degrees. 
     
     
         8 . A method of manufacturing a side frame of a railway car truck, the method comprising:
 manufacturing a side frame made of steel in a no-bake manufacturing process including use of a chemically-bonded sand system that results in a sand mold from which the side frame is cast, the side frame that results having a surface finish less than 750 micro-inches RMS, resulting in increased fatigue life compared to a side frame manufactured by a green sand process.   
     
     
         9 . The method of  claim 8 , wherein the side frame resulting from the no-bake manufacturing process includes draft angles comprising 1.0 (one) degree or less for a plurality of typical features of the side frame. 
     
     
         10 . The method of  claim 8 , wherein the side frame resulting from the no-bake manufacturing process includes a pair of pedestals defining a pedestal jaw into which a wheel assembly of a wheel set of the railway car truck is mounted, and wherein a surface finish of the pair of pedestals is less than 500 micro-inches RMS. 
     
     
         11 . The method of  claim 10 , wherein a pedestal roof draft angle of the side frame is no more than about ¾ degrees. 
     
     
         12 . The method of  claim 10 , wherein tolerances between centers of the pair of pedestals is within about ±0.038 inches. 
     
     
         13 . A method for casting a railway car truck assembly including a side frame and a bolster, the side frame including a pair of pedestals defining a pedestal jaw into which a wheel assembly of a wheel set of the railway car truck is mounted, the bolster including inner and outer gibs and a pair of shoe pockets at respective ends configured to be inserted into bolster openings of the side frame, the method comprising:
 manufacturing a side frame and bolster made of steel in a no-bake manufacturing process including use of a chemically-bonded sand system that results in at least one sand mold from which the side frame and the bolster are cast, the side frame and the bolster that results having a surface finish less than 750 micro-inches RMS, resulting in increased fatigue life compared to a side frame and a bolster manufactured by a green sand process.   
     
     
         14 . The method of  claim 13 , wherein the side frame and bolster resulting from the no-bake manufacturing process includes draft angles comprising 1.0 (one) degree or less for a plurality of typical features of the side frame and bolster. 
     
     
         15 . The method of  claim 13 , wherein a surface finish of at least one of: the pair of shoe pockets of the bolster, and the pair of pedestals of the side frame, is less than 500 micro-inches RMS. 
     
     
         16 . The method of  claim 13 , wherein a shoe pocket side wall draft angle of the bolster is no more than about ¾ degrees. 
     
     
         17 . The method of  claim 13 , wherein a margin of error in shoe pocket angles is within about ±0.5 degrees. 
     
     
         18 . The method of  claim 13 , wherein a margin of error in a spacing between respective inner and outer gibs of the bolster is within about ±0.063 inches. 
     
     
         19 . The method of  claim 13 , wherein respective inner and outer gib draft angles are not more than about ¾ degrees. 
     
     
         20 . The method of  claim 13 , wherein a pedestal roof draft angle of the side frame is no more than about ¾ degrees. 
     
     
         21 . The method of  claim 13 , wherein tolerances between centers of the pair of pedestals of the side frame is within about ±0.038 inches.