Abstract:
A railway truck to railway car body interface is provided. The railway truck is comprised of a bolster supported between two sideframes. The truck bolster includes a center bowl, and the car body includes a body bolster opening. A center plate is placed between the truck bolster center bowl and the car body bolster opening. A wear liner, usually comprised of an elastomeric material, is provided between the sides of the center bowl and the center plate.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    A railway freight car is comprised of a car body and two three piece freight trucks. Two center plates are also provided, which are centrally attached and located near the ends of the car body. The center plate is a casting that extends from the car body into a center bowl of the bolster of the three piece freight truck. The three piece freight truck consists of a bolster and two side frames. The vertical weight of the car body is transferred from the bottom of the centerplate to the mating surface of the truck bolster center bowl. Two sidebearings also transfer the loaded weight of the car body to the bolster. The car body weight is then transferred from the bolster through the suspension, into the side frames, and finally through the axles and wheelset, continuing onto the track. The bolster center bowl has a circular vertical wall that captures the center plate lower section circular vertical wall. The circular interface restricts the movement of the center plate to only rotation of the three piece freight truck relative to the car body. The vertical walls between the center bowl and the center plate have a radial space to allow for assembly clearance. 
         [0002]    The stability of the railway freight car is a function of track irregularities and mass acceleration, created by the speed of travel. The track irregularities and the speed of travel tend to laterally displace and accelerate the mass of the three piece freight trucks. The laterally displaced and accelerated mass at the bolster center bowl circular vertical wall travels through the radial clearance space impacting the car body center plate lower section vertical circular wall. The impact transfers the lateral displacement and accelerated mass energy into the car body where it is momentarily stored. When the car body restores to equilibrium it returns the displaced mass and energy back through the vertical wall of the center plate, traveling through the radial clearance space and impacting the center bowl of the three piece freight truck. The cycling of displacement of energy causes the railway freight car to become unstable. 
         [0003]    The present invention relates to absorbing the displacement energy from the bolster center bowl circular vertical wall to the car body center plate circular vertical wall. Radially preloaded spring elements, placed between the circular walls of the bolster center bowl and car body center plate lower section circular vertical wall, eliminate the impact and absorb the displacement energy being transferred between the three piece truck and car body. Absorbing the displacement energy between the car body and three piece truck, allows increased speed of travel while maintaining the stability of the railway freight car. 
       SUMMARY OF THE INVENTION 
       [0004]    Track irregularities coupled with the speed of travel of the freight car laterally displace and accelerate the mass of three piece freight trucks. The laterally displaced and accelerated mass at the bolster center bowl circular vertical wall travels through the radial clearance space impacting the car body center plate lower section vertical circular wall. This impact transfers the displaced and accelerated mass energy into the car body where it is momentarily stored. When the car body restores to equilibrium, the displaced mass and energy return and the impact between the center plate and center bowl walls is reversed. The returned displacement of energy causes the railway freight car to become unstable. 
         [0005]    The present invention relates to absorbing the displacement energy between the bolster center bowl circular vertical wall to the car body center plate lower section circular vertical wall. Radially preloaded spring elements, placed between the circular walls of the bolster center bowl and car body center plate lower section vertical wall, eliminate the impact and absorb the displacement energy being transferred between the three piece truck and car body. Absorbing the displacement energy between the car body and three piece truck, allows increased speed of travel while maintaining the stability of the railway freight car. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    In the drawings, 
           [0007]      FIG. 1  is a sectional view of a railway freight car of a railway truck to car body interface assembly in accordance with a first embodiment of the present invention; 
           [0008]      FIG. 2  is a partial exploded view of the center bowl relationship to the center plate with an elastomeric vertical wear liner of a railway truck to car body interface assembly in accordance with a first embodiment of the present invention; 
           [0009]      FIG. 3  is an isometric view of the elastomeric vertical wear liner of a railway truck to car body interface assembly in accordance with a first embodiment of the present invention; 
           [0010]      FIG. 4  is a detailed partial exploded section view of the center bowl relationship to the center plate of a railway truck to car body interface assembly in accordance with a first embodiment of the present invention; 
           [0011]      FIG. 5  is a detailed partial section view of the center bowl engaged in the center plate of a railway truck to car body interface assembly in accordance with a first embodiment of the present invention; 
           [0012]      FIG. 6  is an isometric view of the linear spring vertical wear liner of a railway truck to car body interface assembly in accordance with a second embodiment of the present invention; 
           [0013]      FIG. 7  is a partial exploded view of the center bowl relationship to the center plate with a linear spring vertical wear liner of a railway truck to car body interface assembly in accordance with a second embodiment of the present invention; 
           [0014]      FIG. 8  is a partial top view of the bolster and the relationship of the center bowl and sectioned center plate with the linear spring vertical liner of a railway truck to car body interface assembly in accordance with a second embodiment of the present invention; 
           [0015]      FIG. 9  is an isometric view of the bonded vertical wear liner of a railway truck to car body interface assembly in accordance with a third embodiment of the present invention; 
           [0016]      FIG. 10  is a partial exploded view of the center bowl relationship to the center plate with a bonded vertical wear liner of a railway truck to car body interface assembly in accordance with a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring now to  FIG. 1 , a railway freight car  1  is seen to be comprised of a car body  2 , and a three piece freight car truck  3 . The car body  2  includes center plate  5 , centrally attached near the end of car body  2 . Center plate  5  extends down from car body  2 , into the center bowl  4  of bolster  6  of the three piece freight car truck  3 . There is also a king pin  7 , centered between the center bowl  4  and center plate  5  and extending into central openings in each. King pin  7  is used to locate the car body  2  above three piece truck  3  during assembly, as well as a guide to keep the three piece truck  3  under the car body  2 , if they were to become vertically disengaged in service. Side bearings  28  are present between bolster  6  and car body  2  to assist in supporting the loaded weight of car body  2 . 
         [0018]    Referring now to  FIG. 2 , a partial exploded view is provided of bolster  6 , with center bowl  4 , center bowl surface  11 , and circular vertical wall  12 . Center plate  5  has a generally square, four sided upper section and a lower section circular vertical wall  14 , with a bottom  13 . The car body weight is transferred through center plate bottom  13  to a horizontal wear liner  8 . 
         [0019]    Horizontal wear liner  8 , usually comprised of steel, further transfers the car body weight to surface  11  of center bowl  4 . The three piece truck pivots about the center bowl  4  and center plate  5 . The center bowl  4  circular vertical wall  12  restricts the movement of center plate  5  lower section circular vertical wall  14 , to rotation. There is an elastomeric vertical liner  9  between the center plate  5  lower section circular vertical wall  14  and the center bowl  4  circular vertical wall  12 . Elastomeric vertical liner  9  has an interference fit between the center plate  5  lower section circular vertical wall  14 , and the center bowl  4  circular vertical wall  12 . There is compression at the interference fit between center plate  5  lower section circular vertical wall  14 , to the center bowl  4  circular vertical wall  12 . Center plate  5  is usually a unitary cast steel structure. Elastomeric vertical wear liner  9  is usually comprised of an elastic material with stiffness sufficient to create a preload between the center plate  5  lower section circular vertical wall  14 , and the center bowl  4  circular vertical wall  12 , when compressed. Circular shaped retainer  10  protects the elastomeric vertical wear liner  9  from being displaced or crushed during assembly of the car body  2  to the three piece truck  3 . Retainer  10  also keeps the elastomeric vertical wear liner  9  in place during travel of truck  3 . 
         [0020]    Referring now to  FIG. 3 , an isometric view of the elastomeric vertical wear liner  9  is provided. The elastomeric vertical wear liner  9  has a gap  18 , to compensate for the tolerance in manufacture of center bowl  4 . The vertical wear liner has a curved surface  15 , on the inner diameter to aid in the assembly insertion of center plate  5  lower section circular vertical wall  14  into center bowl  4 . 
         [0021]    Referring now to  FIG. 4 , a detailed partial exploded view of the bolster  6 , with center bowl  4  and center plate  5 , is provided. The elastomeric vertical wear liner  9 , is an elastic material, and is shown non-compressed. The elastomeric vertical wear liner  9  outer diameter bears against the center bowl  4  circular vertical wall  12 . The elastomeric vertical wear liner  9 , has a curved surface  15 , on the inside diameter which will allows center plate  5  lower section circular vertical wall  14  entry into center bowl  4 . As the center plate  5  lower section circular vertical wall  14  engages the elastomeric vertical wear liner  9  curved surface  15 , wear liner  9  will become compressed, preloading the elastomeric vertical wear liner  9 . The elastomeric vertical wear liner  9  is protected from being crushed by circular retainer  10  which is positioned on top of wear liner  9  and between its interface with center plate  5 . 
         [0022]    Referring now to  FIG. 5 , a detailed partial section view of the center plate  5  lower section circular vertical wall  14  inserted into center bowl  4  is provided. The elastomeric vertical wear liner  9  is compressed between center bowl  4  circular vertical wall  12  and center plate  5  lower section circular vertical wall  14 . The elastomeric vertical wear liner  9 , curved surface  15 , is compressed preloading elastomeric vertical wear liner  9 . 
         [0023]    Referring now to  FIG. 6 , an isometric view of a linear spring vertical wear liner  16  is provided. The linear spring vertical wear liner  16  is a metallic spring which develops it stiffness by deflecting the curved surfaces  19 , which make up the walls of the linear spring vertical wear liner  16 . The top of the linear spring vertical wear liner  16  has a tapered surface  17 , to aid in the assembly. The liner spring vertical wear liner  16  has a gap  20 , to compensate for the tolerance in manufacture of center bowl  4 . 
         [0024]    Referring now to  FIG. 7 , a partial exploded view of the bolster  16 , with center bowl  14 , consisting of a center bowl bottom surface  111  and circular vertical wall  112 . Center plate  15  has a generally square, four sided upper section and a lower section circular vertical wall  114 , with a bottom  113 . The car body weight is transferred through center plate  15  bottom  113 , to the horizontal wear liner  117 . Horizontal wear liner  117 , usually comprised of steel, further transfers the car body weight to surface  111  of center bowl  14 . The three piece truck pivots about the center bowl  14 , and center plate  15 . Center bowl  14  circular vertical wall  112  restricts the relative movement of center plate  15  and center bowl circular vertical wall  114 , to rotation. There is a linear spring vertical wear liner  116  between the center plate  15  lower section circular vertical wall  114 , and center bowl  14  circular vertical wall  112 . The linear spring vertical wear liner  116 , has an interference fit between the center plate  15  lower section circular vertical wall  114 , and center bowl  14  circular vertical wall  112 . Linear spring vertical wear liner  116  is comprised of a metallic spring material with a stiffness to create a preload between the center plate  15  lower section circular vertical wall  114 , and center bowl  14  circular vertical wall  112 , when compressed. Circular retainer  110  protects the linear spring vertical wear liner  116  from being displaced or crushed during assembly of the car body to the three piece truck. Retainer  110  also keeps the linear spring vertical wear liner  116  in place during travel of the three piece truck. 
         [0025]    Referring now to  FIG. 8 , a partial top view of the bolster  161 , and the relationship of the center bowl  141 , sectioned center plate  15 , with the linear spring vertical liner  116 . The linear spring vertical liner  116  with a spring curved surface, is alternately pressing against the circular vertical wall  112 , of the center bowl  141 , and the lower section circular vertical wall  114 , of center plate  15 . The curved surface is a compressed spring with a stiffness that preloaded the center bowl  141  to centerplate  15 . 
         [0026]    Referring now to  FIG. 9 , an isometric view of the bonded vertical wear liner  119 . The bonded vertical wear liner  119 , consists of a thin layer of low friction material  120 , on the inside diameter, bonded to an elastomeric center layer  121 . The bonded wear liner  119 , also has an outer diameter metal layer that is bonded to the elastomeric center layer  121 . The bonded wear ring  119  has a sloped surface  123 , on the top of the inside diameter low friction surface  120 . The slope surface  123 , guides the center plate circular vertical wall into the low friction surface  120 . Outside diameter low friction surface  122  is also present. 
         [0027]    Referring now to  FIG. 10 , a partial exploded view of the bolster  26 , with center bowl  24 , consisting of a center bowl bottom surface  211 , and circular vertical wall  212 . The center plate  25  has a generally square, four sided upper section and a lower section circular vertical wall  214 , with a bottom  213 . The car body weight is transferred through center plate  25  bottom  213 , to the horizontal wear liner  28 . The horizontal wear liner  28 , usually comprised of steel, further transfers the car body weight to the surface  211  of center bowl  24 . The three piece truck pivots about the center bowl  24 , and center plate  25 . The center bowl  24 , circular vertical wall  212 , restricts the movement of center plate  25 , lower section circular vertical wall  214 , to rotation. There is a bonded vertical wear liner  119 , between the center plate  25 , lower section circular vertical wall  214 , and the center bowl  24 , circular vertical wall  212 . The bonded vertical wear liner  119 , has an interference fit between the center plate  25 , lower section circular vertical wall  214 , and the center bowl  24 , circular vertical wall  212 . The bonded vertical wear liner  119 , has an elastic center material  121 , with a stiffness sufficient to create a preload between the center plate  25 , lower section circular vertical wall  214 , and the center bowl  24 , circular vertical wall  212 , when compressed. The bonded vertical wear liner  119 , outer ring  122 , is press fit against the center bowl  24 , circular vertical wall  212  inside. The press fit is the means to retain the bonded vertical wear liner  119  to center plate  24 .