Passive steering for a three piece railway truck

Abstract

The traditional three piece railway freight truck prevents the wheel sets from achieving radial alignment to curves by the rigid side frames restraining the wheelsets. The side frames also constrain the wheelset from radial aligning to curves by the limited gap between the wheelset bearing and the side frame pedestal jaws. The present invention opens the side frame pedestal jaws to allow the wheel sets to yaw and align radially to curves. The side frame is supported on wheel sets by elastomeric pads and bearing adapters. The present invention utilizes the elastomeric pad stiffness to compress in pitch motion that allow the wheel set to move in an arc forward or backward in the open jaws of the side frame. The elastomeric pad stiffness also allows the wheelset to twist the pads allowing the wheelset to radially align to the curve. The pads elastic stiffness is sufficient to return when the wheelset is align to straight track.

What is claimed is: 
     
         1 . A railway car truck comprising
 a bolster and two parallel sideframes,   the bolster having two ends each received in an opening in one of the sideframes,   a spring group supporting the bolster end in each sideframe,   each sideframe having two pedestal ends,   two axles each having two ends,   two wheels each fitted to a journal portion of each axle,   a plurality of axle bearings each fitted on one of the axle ends,   a plurality of adapters each with an adapter pad, with each adapter and adapter pad received in one of the sideframe pedestal ends,   wherein each adapter pad has a resistance to pitch and twist such that a longitudinal steering force created between the wheels to rails of a wheelset of from 5,000 to 7,000 pounds is sufficient to radially align the wheelset with a curve in a railway track.   
     
     
         2 . The railway cart truck of  claim 1  wherein
 the sideframe pedestal end is comprised of longitudinally spaced jaws that allow the adapter pad to deform to allow the wheel set to yaw to align with the curve in the railway track. 
 
     
     
         3 . The railway car truck of  claim 2  wherein
 the adapter pad will deform enough to allow the wheel set to yaw to align with a curve of up to 10 degrees in the railway track curve. 
 
     
     
         4 . A railway car truck comprising
 a bolster and two parallel sideframes,   the bolster having two ends each received in an opening in one of the sideframes,   a spring group supporting the bolster end in each sideframe,   each sideframe having two pedestal ends,   two axles each having two ends and two journal portions,   a wheel fitted to a journal portion of each axle,   a plurality of axle bearings each fitted on one of the axle ends,   a plurality of adapters each with an elastomeric adapter pad, with each adapter and   elastomeric adapter pad received in one of the sideframe pedestal ends,   wherein each adapter pad has a resistance to pitch and twist such that a longitudinal steering force created between the wheels to rails of a wheelset of from 5,000 to 7,000 pounds is sufficient to radially align the wheelset with a curve in a railway track.   
     
     
         5 . The railway cart truck of  claim 4  wherein
 the sideframe pedestal end is comprised of longitudinally spaced jaws that allow the adapter pad to deform to allow the wheel set to yaw to align with the curve in the railway track. 
 
     
     
         6 . The railway car truck of  claim 5  wherein
 the adapter pad will deform enough to allow the wheel set to yaw to align with a curve of up to 10 degrees in the railway track. 
 
     
     
         7 . The railway cart truck of  claim 4  wherein
 the sideframe pedestal jaws that are opened 0.331 inches on either side of the bearing to allow the adapter pad to deform to allow the wheel set to yaw to align with the curve in the railway track.