Railway car truck and side bearing assembly

In a railway car truck car body assembly including spaced side frames, each supported by the journal bearings of a pair of spaced, transversely extending wheel axles;

• a bolster extending transversely between said side frames;
• a spring assembly supported on said spaced side frames and engaging a spring receiving assembly integral with the lower surface of said bolster;
• said spring assembly effective to cushion said truck;
• said bolster having a center bearing;
• and a pair of side bearings mounted upon said bolster on either side of said center bearing adapted to receive the weight of the car body;
• a railway car body having a depending center portion engaging said center bearing;
• and transversely spaced depending side portions engaging said side bearings on either side of said depending center portion;
• the improvement comprising:
• each of said side bearings having an upper surface made of a first low friction material;
• said depending side portions each having a lower surface engaging said upper surface made of a second low friction material;
• one of said first and second low friction materials being at least one of nylon, polyesters, polycarbonates, polyacetals and polysulfones;
• and the other of said first and second low friction materials comprising polytetrafluoroethylene;
• whereby the weight of the car body is taken by said side bearings, and whereby the coefficient of friction between said upper and lower surfaces is sufficiently low that said truck easily rotates with respect to said car body.