Rail road car truck with bearing adapter and method

Abstract

A swing motion rail road freight car truck is provided that has a truck bolster and a pair of side frames, the truck bolster being mounted transversely relative to the side frames. The side frames have spring seats for the groups of springs. The springs seats may be rigidly mounted in the side frames. Friction dampers are provided in inboard and outboard pairs. The biasing force on the dampers urges then to that act between the bolster ands and sideframes to resist parallelogram deflection of the truck. The bearing adapters and sideframe pedestal seats interact on a rolling linear contact interface that has a relatively small radius of curvature.

1 . A rail road car truck comprising: 
 a pair of first and second side frames and a truck bolster resiliently mounted transversely relative thereto;    wheelsets, each wheelset having an axle having two wheels mounted thereto, and each axle being mounted to said side frames;    each of said side frames having pedestal seats for receiving mating bearing adapters;    a bearing adapter mounted to each end of each axle, each bearing adapter being matingly engaged in one of said pedestal seats;    said pedestal seats having a bearing surface for mating with said bearing adapter;    said mating bearing surface being chosen from the set of bearing surfaces consisting of (a) a planar surface; and (b) an arcuate surface having a radius of curvature greater than 50 inches;    said bearing adapter having a curved bearing surface upon which said bearing surface of said pedestal seat is engaged, said bearing surface of said bearing adapter and said bearing surface of said pedestal seat being in rocking engagement;    said curved bearing surface of said bearing adapter having a local radius of curvature for lateral rocking of less than 30 inches.    
   
   
       2 . The rail road car truck of  claim 1  wherein said radius of curvature is constant over an arc extending at least 2 degrees to either side of a central resting position.  
   
   
       3 . The rail road car truck of  claim 1  wherein said truck bolster has lateral travel relative to said side frames of at least 1 inch to either side of a central resting position.  
   
   
       4 . The rail road car truck of  claim 3  wherein said lateral travel of said truck bolster relative to said side frames is limited by abutment means mounted thereto.  
   
   
       5 . The rail road car truck of  claim 4  wherein said abutment means includes at least one gib mounted to one of (a) said truck bolster and (b) said side frames, and a mating abutment mounted to the other of (a) said side frames, and (b) said truck bolster.  
   
   
       6 . The railroad car truck of  claim 1  wherein said local radius of curvature is less than 10 inches.  
   
   
       7 . The railroad car truck of  claim 1  wherein: 
 each sideframe has first and second spaced apart sideframe columns and a sideframe window defined therebetween, an end of said truck bolster being located in said sideframe window;    a group of dampers is mounted to work between each sideframe and one end of said truck bolster;    each group of dampers includes a first damper, a second damper, and another damper;    said first damper is mounted laterally inboard of said second damper, and both said first and second dampers work between said first sideframe column and said one end of said truck bolster; and    said other damper works between said one ends of said truck bolster and said second sideframe column.    
   
   
       8 . The railroad car truck of  claim 7  wherein each group of dampers includes four dampers mounted in a four cornered arrangement.  
   
   
       9 . A bearing adapter for use in a rail road car truck, the bearing adapter being mountable to a bearing of an end of an axle of a rail road car wheelset, wherein the bearing adapter has an arcuate upper surface for engaging a pedestal seat of a side frame of the rail road car truck, said arcuate upper surface permitting transverse rocking of the side frame mounted thereon, said arcuate upper surface having a first region rockingly engageable with a contact surface of the pedestal seat, said first region including a topmost portion having a local radius of curvature of less than 30 inches, and said arcuate upper surface having a second region adjoining said first region, said second region being configured to rockingly engage said contact surface of the pedestal seat, and said second region of said arcuate upper surface has a different radius of curvature than said topmost portion.  
   
   
       10 . The bearing adapter of  claim 9  wherein said second region has a local radius of curvature greater than said topmost portion.  
   
   
       11 . The bearing adapter of  claim 9  wherein said radius of curvature of said topmost portion varies from a first radius of curvature at said topmost portion to a greater radius of curvature away from said topmost portion.  
   
   
       12 . The bearing adapter of  claim 9  wherein said radius of curvature is constant over a range of motion of at least 2 degrees of arc to either side of a central position.  
   
   
       13 . The combination of a bearing adapter for a rail road freight car truck, and a mating pedestal seat for a sideframe of a rail road freight car truck, said bearing adapter having a first bearing surface, said pedestal seat having a second bearing surface, said first and second bearing surfaces being in rocking engagement, and permitting lateral rocking of the sideframe, one of said bearing surfaces being chosen from the set of bearing surfaces consisting of (a) a planar surface; and (b) an arcuate surface having a radius of curvature greater than 50 inches; and the other of said bearing surfaces having a radius of curvature of less than 30 inches.  
   
   
       14 . The combination of  claim 13  wherein said radius of curvature of said other bearing surface is constant over an arc extending at least 2 degrees to either side of a central resting position.  
   
   
       15 . The combination of  claim 13  wherein said radius of curvature of said other bearing surface is less than 10 inches.  
   
   
       16 . The combination of  claim 13  wherein said other bearing surface has a first region located centrally thereon, and a second region located adjacent thereto, said second region having a local radius of curvature greater than said first region.  
   
   
       17 . The combination of  claim 16  wherein said radius of curvature of said bearing other surface varies from a first radius of curvature at a central region thereof to a greater radius of curvature away from said central region.  
   
   
       18 . A process of retrofitting a rail road car truck having first and second side frames, a truck bolster resiliently mounted transversely to said side frames, said sideframes being mounted to axles, said axles having bearings mounted thereto and first bearing adapters mounted to said bearings, said side frames having pedestal mounts, said bearing adapters being rockingly engaged with said pedestal mounts to permit lateral swinging of said side frames, each said bearing adapter having a first surface rockingly engaged to a mating second surface of said bearing pedestal mount, said first surface having a radius of curvature of greater than 50 inches, said process comprising the steps of (a) extracting said bearing adapters from said truck; (b) replacing said first bearing adapters with second bearing adapters having a rocking engagement surface having a smaller radius of curvature than before, and (c) installing an arrangement of dampers between the bolster and each sideframe, each sideframe having a pair of first and second sideframe columns and a sideframe window defined therebetween, each said arrangement of dampers including a first damper, a second damper and another damper, said first damper being mounted laterally outboard of said second damper, said first and second dampers both being mounted to work between an end of said bolster and said first sideframe column and said other damper being mounted to work between said bolster and said second sideframe column, and said second bearing adapters having a radius of curvature of less than 30 inches.  
   
   
       19 . A rail road car truck, said truck comprising first and second spaced apart sideframes and a truck bolster extending therebetween, said truck bolster having ends resiliently supported by said sideframes, said side frames being mounted on wheelsets, each said wheelset having bearings and bearing adapters mounted thereto, said bearing adapters having first rocking engagement surfaces, said sideframes having pedestal seats having second rocking engagement surfaces, said first and second rocking engagement surfaces being in mating engagement and permitting lateral rocking of said sideframes, one of said rocking engagement surfaces having a radius of curvature of less than 30 inches, each of said ends of said truck bolster having an arrangement of dampers, each said arrangement of dampers including a first damper, a second damper, and another damper, said first damper being mounted laterally outboard of said second damper, said first and second dampers both being mounted to work between an end of said bolster and said first sideframe column and said other damper being mounted to work between said bolster and said second sideframe column, and said bearing adapters having a radius of curvature of less than 30 inches.