Patent Publication Number: US-11027755-B2

Title: Railroad car truck with warp restraints

Description:
PRIORITY CLAIM 
     This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62/594,283, filed Dec. 4, 2017, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     Conventional freight railroad cars in North America and other parts of the world typically include a car body and two spaced apart trucks. The car body or car body under frame typically includes two spaced apart center plates that respectively rest on and are rotatably or swivelly received by bolster bowls of the two trucks. The trucks rollingly support the car body along railroad tracks or rails. Each truck typically has a three piece truck configuration that includes two spaced apart parallel side frames and a bolster. The side frames extend in the same direction as the tracks or rails, and the bolster extends transversely or laterally to the tracks or rails. The bolster extends laterally through and between and is supported by the two spaced apart side frames. Each side frame typically defines a center opening and pedestal jaw openings on each side of the center opening. Each end of each bolster is typically supported by a spring group positioned in the center opening of the side frame and supported by the lower portion of the side frame that defines the center opening. 
     Each truck also typically includes two axles that support the side frames, four wheels, and four roller bearing assemblies respectively mounted on the ends of the axles. The truck further typically includes four bearing adapters respectively positioned on each roller bearing assembly in the respective pedestal jaw opening below the downwardly facing wall of the side frame that defines the top of the pedestal jaw opening. The wheel sets of the truck are thus received in bearing adapters placed in leading and trailing pedestal jaws in the side frames, so that axles of the wheel sets are generally parallel. The bearing adapters permit relatively slight angular displacement of the axles. The spring sets or groups permit the bolster to move somewhat with respect to the side frame, about longitudinal or horizontal, vertical, and transverse axes (and combinations thereof). 
     Directions and orientations herein refer to the normal orientation of a railroad car in use. Thus, unless the context clearly requires otherwise, the “longitudinal” axis or direction is substantially parallel to straight tracks or rails and in the direction of movement of the railroad car on the track or rails in either direction. The “transverse” or “lateral” axis or direction is in a horizontal direction substantially perpendicular to the longitudinal axis and the straight tracks or rails. “Vertical” is the up-and-down direction, and “horizontal” is a plane parallel to the tracks or rails including the transverse and longitudinal axes. A truck is considered “square” when its wheels are aligned on parallel rails and the axles are parallel to each other and perpendicular to the side frames. The “leading” side of the truck means the first side of a truck of a railroad car to encounter a turn; and the “trailing” side is opposite the leading side. 
     Existing trucks do not fully address the ever increasing and expected future demands for freight railroad car truck performance in the railroad industry. More specifically, while the various current known and commercially available three piece truck configurations meet current Association of American Railroads (“AAR”) specifications, enhanced specifications are being developed by the AAR and it is expected that the current three piece truck configurations may not meet these new AAR specifications. These AAR enhanced specifications set forth or codify these continuing and ongoing demands in the railroad industry for improved freight railroad car truck performance to: (a) reduce railroad car component wear and damage such as wheel wear and damage; (b) reduce rolling resistance; (c) reduce fuel consumption; (d) reduce the need for and thus cost of railroad track or rail repair (including reducing the cost of rail and tie maintenance); (e) reduce truck hunting and improve high speed stability (“HSS”) for both empty and loaded railroad cars; and (f) improve curving performance for both empty and loaded railroad cars. 
     Ideally, on straight tracks or straight rails, a three piece truck with parallel side frames and parallel wheel set axles perpendicular to the side frames (i.e., a perfectly “square” truck) rolls without inducing lateral or transverse forces between the wheel tread and the rail. However, at higher speeds, even minor imperfections or perturbations in the tracks or rails or in the equipment can lead to a condition known as “hunting” that refers to a yawing or oscillating lateral movement of the wheel sets along the tracks or rails that causes the railroad car to move side-to-side on the tracks or rails. More than minor imperfections or perturbations in the tracks or rails or in the railroad car equipment or components can lead to greater truck hunting even at lower speeds. Hunting tends to increase wheel wear and damage, increase fuel consumption, increase the need for railroad track or rail repair, and decrease HSS. In certain instances, hunting has also led to derailments, damage to the lading, and damage to the freight railroad cars. 
     Curved railroad tracks or rails pose a different set of challenges for the standard three-piece truck. When a railroad car truck encounters a curve or turn, the distance traversed by the wheels on the outside of the curve is greater than the distance traversed by wheels on the inside of the curve, resulting in lateral and longitudinal forces between the respective wheels and the tracks or rails. These wheel forces often cause the wheel set to turn in a direction opposing the curve or turn. On trucks with insufficient rigidity, this can result in a condition variously known as “warping,” “lozenging,” “parallelogramming,” and/or “unsquaring,” wherein the side frames remain parallel, but one side frame moves forward with respect to the other side frame. This condition is referred to herein as warping for brevity. 
     Another known issue relates to various known 3-piece railroad truck suspensions that have side frames with flat rectangular surfaces against which friction wedges are pressed to produce frictional (i.e., Coulomb) damping to control vertical bounces and other oscillatory modes. Normally, significant clearance exists between the side frame&#39;s column face and nearby surfaces of the bolster to enable assembly and proper relative motion during use. This clearance is undesirable in that it enables the truck assembly to become warped or change shape from the intended parallel and perpendicular arrangement (i.e., to undergo warping). 
     Such warping (alone or in combination with hunting) can cause increased wear on the tracks or rails and railroad car truck components or equipment. Such warping (alone or in combination with hunting) also tends to increase rolling resistance that increases railroad car fuel consumption, decreases railroad car efficiency, and increases railroad engine pollution. 
     Accordingly, there is a need to meet these ongoing demands in the railroad industry for improved freight railroad car truck performance that reduces or minimizes warping. 
     SUMMARY 
     Various embodiments of the present disclosure provide a new railroad car, and more particularly a new railroad car having a new railroad car truck with warp restraints that reduces, inhibits, and/or minimizes the above warping related problems. 
     In various embodiments, the railroad car truck with warp restraints of the present disclosure includes a first side frame, a second side frame, a bolster, and a plurality of warp restraints. In various embodiments, each warp restraint includes a first bearing connected to or integrally formed as part of the bolster and a second opposing bearing connected to or integrally formed as part of the side frame. In various embodiments, the warp restraints are each positioned to reduce, inhibit, or minimize warping of the railroad car truck of the present disclosure. 
     More specifically, in various embodiments, the railroad car truck of the present disclosure has four such warp restraints including: (1) a first plurality or set of warp restraints at a first end portion of the bolster and at the first side frame; and (2) a second plurality or set of warp restraints at a second end portion of the bolster and at the second side frame. For the first plurality of warp restraints, each first warp restraint includes a first bearing connected to or integrally formed with a first portion of the bolster and a second opposing bearing connected to or integrally formed with the first side frame. For the second plurality of warp restraints, each second warp restraint includes a first bearing connected to or integrally formed with a second portion of the bolster and a second opposing bearing connected to or integrally formed with the second side frame. 
     In other various embodiments, the railroad car truck of the present disclosure has eight such warp restraints including: (1) a first plurality or set of warp restraints at a first end portion of the bolster and at the first side frame; and (2) a second plurality or set of warp restraints at a second end portion of the bolster and at the second side frame. 
     The opposing bearings of each warp restraint apply opposing forces to the side frames and bolster to reduce, inhibit, and/or minimize warping. More specifically, when the bolster moves from a square or perpendicular position relative to the side frames (or relative to each respective side frame), the respective warp restraints independently and in various groups or combinations co-act to apply opposing biasing forces to the bolster and the side frames to cause the bolster and/or side frames to move in the respective opposing direction and return to their normal square, perpendicular, or substantially perpendicular positions relative to each other, and thus act or co-act to reduce, inhibit, and/or minimize warping as further described below. It should also be appreciated that although the warp restraints of the present disclosure are not primarily intended to produce resistance against other directional movements of the bolster relative to the side frames, in various circumstances and embodiments, the warp restraints of the present disclosure can act or co-act to permit certain directional movements and act or co-act to reduce, inhibit, and/or minimize certain other directional movements alone or in combination with other components of the railroad car truck (such as but not limited to friction wedges that provide vertical dampening or gibs that provide lateral restraint). 
     It should be appreciated that that warp restraints of the present disclosure are in addition to the various other conventional components of a conventional railroad car truck. 
     Other objects, features, and advantages of the present disclosure will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings, wherein like reference numerals refer to like parts. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a side view of a conventional freight railroad car positioned on conventional railroad tracks. 
         FIG. 2  is a top view of a bolster and two side frames of a conventional freight railroad car truck, and illustrating the bolster in a warped condition relative to the side frames. 
         FIG. 3A  is a top view of a bolster, two side frames, and four warp restraints of one example embodiment of the freight railroad car truck of the present disclosure, and illustrating the bolster in a square condition relative to the side frames. 
         FIG. 3B  is a top view of a bolster, two side frames, and four warp restraints of the example embodiment of the freight railroad car truck of  FIG. 3A , wherein the truck is in a warped position, and wherein certain of the warp restraints are applying biasing forces to urge the truck back to a square position. 
         FIG. 4  is an exploded perspective view of the bolster, two side frames, and four warp restraints of the freight railroad car truck of  FIG. 3A , and illustrating the bearings of the warp restraints integrally cast with the bolster, and the bearings of the warp restraints integrally cast with the respective side frames. 
         FIG. 5  is an enlarged fragmentary perspective view of the bolster, one of the side frames, and two warp restraints of the freight railroad car truck of  FIG. 3A , and illustrating the bearings of the warp restraints integrally cast with the bolster, and the bearings of the warp restraints integrally cast with the side frame. 
         FIG. 6  is an enlarged fragmentary top view of one end portion of the bolster, a first one of the side frames, and a first one of the two sets of warp restraints of the freight railroad car truck of  FIG. 3A . 
         FIG. 7  is an enlarged fragmentary top view of one end portion of the bolster, a first one of the side frames, and a first one of the two sets of warp restraints of freight railroad car truck of an alternative embodiment of the present disclosure. 
         FIG. 8  is an enlarged top view of a bolster, two side frames, and eight warp restraints of another example embodiment of the freight railroad car truck of the present disclosure. 
         FIG. 9  is an enlarged fragmentary top view of one end portion of the bolster, a first one of the side frames, and four warp restraints of the freight railroad car truck of  FIG. 8 . 
         FIG. 10A  is a top view of a bolster, two side frames, and four warp restraints of another example embodiment of the freight railroad car truck of the present disclosure, and illustrating the bolster in a square condition relative to the side frames. 
         FIG. 10B  is a top view of a bolster, two side frames, and four warp restraints of the example embodiment of the freight railroad car truck of  FIG. 10A , wherein the truck is in a warped position, and wherein certain of the warp restraints are applying biasing forces to urge the truck back to a square position. 
         FIG. 11  is an exploded perspective view of the bolster, two side frames, and four warp restraints of the freight railroad car truck of  FIG. 10A , and illustrating the bearings of the warp restraints integrally cast with the bolster and the bearings of the warp restraints integrally cast with the respective side frames. 
         FIG. 12  is an enlarged fragmentary perspective view of the bolster, one of the side frames, and two warp restraints of the freight railroad car truck of  FIG. 10A , and illustrating the bearings of the warp restraints integrally cast with the bolster and the bearings of the warp restraints integrally cast with the side frame. 
         FIG. 13  is an enlarged fragmentary top view one end portion of the bolster, a first one of the side frames, and a first one of the two sets of warp restraints of the freight railroad car truck of  FIG. 10A . 
         FIG. 14  is an enlarged top view of a bolster, two side frames, and eight warp restraints of another example embodiment of the freight railroad car truck of the present disclosure. 
         FIG. 15  is an enlarged fragmentary top view of one end portion of the bolster, a first one of the side frames, and four of the warp restraints of the freight railroad car truck of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings and particularly to  FIGS. 1 and 2 , a conventional railroad car truck that is generally indicated by numeral  20  is shown with respect to freight railroad car  10  configured to roll along railroad tracks or rails  5 . The conventional truck  20  includes a bolster  24 , a bolster bowl  26  on the bolster  24 , a first side frame  28 , and a second side frame  30 . Generally, the bolster  24  extends transversely to the direction of the railroad tracks or rails  5 , and the side frames  28  and  30  extend longitudinally in the same direction as the railroad tracks or rails  5 . As indicated by the arrows in  FIG. 2 , the side frames  28  and  30  are subject to warping where the side frames  28  and  30  remain parallel, but one side frame (such as side frame  28 ) moves forward with respect to the other side frame (such as side frame  30 ). When this occurs, the bolster  24  is not square with either of the side frames  28  or  30  and results in the above described problems. 
     1 st  Example Embodiment 
     Referring now to  FIGS. 3A, 3B, 4, 5, and 6 , one example embodiment of the railroad car truck with warp restraints of the present disclosure is shown and generally indicated by numeral  50 . In this illustrated example embodiment of the present disclosure, the railroad car truck  50  includes a bolster  40 , a bolster bowl  42  on the bolster  40 , a first side frame  60 , and a second side frame  80 . Generally, the bolster  40  is configured to extend transversely to the direction of the railroad tracks or rails (not shown in  FIG. 3A, 3B, 4, 5 , or  6 ), and the side frames  60  and  80  are configured to extend longitudinally in the same direction as the railroad tracks (not shown in  FIG. 3A ,  3 B,  4 ,  5 , or  6 ). The side frame  60  includes: (a) a longitudinally extending body  62 ; and (b) two downwardly extending pedestal jaws (including a first pedestal jaw  64  and a second pedestal jaw  66 ) on opposite sides of the center opening  68  in the body  62  of the side frame  60 . The body  62  includes a first side wall, a top wall, a second side wall, and a bottom wall that generally define the center opening  68 . The side frame  80  includes: (a) a longitudinally extending body  82 ; and (b) two downwardly extending pedestal jaws (including a first pedestal jaw  84  and a second pedestal jaw  86 ) on opposite sides of the center opening  88  in the body  82  of the side frame  80 . The body  82  includes a first side wall, a top wall, a second side wall, and a bottom wall that generally define the center opening  88 . 
     In this illustrated example embodiment of the present disclosure, as best shown in  FIGS. 3A, 3B, 4, 5, and 6 , the railroad car truck with warp restraints  50  includes: (1) a first plurality or set of warp restraints  100  and  200 ; and (2) a second plurality or set of warp restraints  500  and  600 . More specifically, in this illustrated embodiment, (a) warp restraint  100  includes a first bearing  110  integrally formed at and extending from a first portion of the bolster  40  and a second opposing bearing  140  integrally formed at and extending from the first side frame  60 ; (b) warp restraint  200  includes a first bearing  210  integrally formed at and extending from the first portion of the bolster  40  and a second opposing bearing  240  integrally formed at and extending from the first side frame  60 ; (c) warp restraint  500  includes a first bearing  510  integrally formed at and extending from a second portion of the bolster  40  and a second opposing bearing  540  integrally formed at and extending from the second side frame  80 ; and (d) warp restraint  600  includes a first bearing  610  integrally formed at and extending from the second end portion of the bolster  40  and a second opposing bearing  640  integrally formed at and extending from the second side frame  80 . Thus, (a) bearings  110 ,  210 ,  510 , and  610  are integrally formed at and extend from the respective portions of the bolster  40  (on the inward sides of the side frames  60  and  80 ); (b) bearings  140  and  240  are integrally formed at and extend from the inward side of the first side frame  60 ; and (c) bearings  540  and  640  are integrally formed at and extend from the inward side of the second side frame  80 . 
     It should be appreciated that each of the warp restraints  100 ,  200 ,  500 , and  600  in various embodiments are identical or substantially identical (except for their positioning and arrangement of their connectors to, connections with, or formations with the side frames and the bolster). Therefore, warp restraints  100  and  200  are primarily discussed in further detail below as examples of the warp restraints of this example embodiment. However, it should be appreciated that the warp restraints of the present disclosure do not need to be identical or substantially identical and can vary based on the respective positions and connections to or formations with the side frames and the bolster. For example, the two bearings of any set of warp restraints may be different. 
     Example warp restraint  100  includes a first bearing  110  integrally formed with a first portion of the bolster  40  and a second opposing bearing  140  integrally formed with the first side frame  60 . It should be appreciated that the first bearing  110  may be connected to the bolster  40  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  140  may be connected to the bolster  40  by one or more suitable second bearing connecters (not shown). 
     As best shown in  FIGS. 5 and 6 , the first bearing  110  includes: (a) a substantially horizontally extending mounting bracket  112  integrally connected to the bolster  40 ; (b) a movable engagement pad  114  pivotally connected to the mounting bracket  112 ; (c) a connection arm  113  extending transversely from the back of the engagement pad  114 ; and (d) a pivot pin (not shown). The movable engagement pad  114  is pivotally connected to the mounting bracket  112  by the connection arm  113  and by the pivot pin (not shown). The engagement pad  114  includes an inner substantially vertically extending engagement surface  114   a . In this illustrated embodiment, the engagement pad  114  includes a mounting base  115  and a wear member  116  removably connected to the mounting base  115  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  114  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  112 , the engagement pad  114 , the connection arm  113 , and the pivot pin can be configured such that the engagement pad  114  is pivotal about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  114  and/or the engagement surface  114   a  each extend in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement pad  114  and/or the engagement surface  114   a  is: (a) angled outwardly; (b) angled inwardly; (c) initially angled upwardly; (d) initially angled downwardly; (e) initially angled outwardly and upwardly; (f) initially angled outwardly and downwardly; (g) initially angled inwardly and upwardly; or (h) initially angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  114  and/or along the engagement surface  114   a  in its initial position; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 5 and 6 ), may be obtuse, or may be acute. An example of this is further illustrated in the alternative example embodiment of  FIG. 7  discussed below. 
     As also best shown in  FIGS. 5 and 6 , the second bearing  140  includes: (a) a substantially vertically extending side frame mounting wall  142  integrally connected to the inner surface of the side frame  60 ; (b) a substantially vertically extending engagement wall  144  integrally connected to the side frame mounting wall  142  and extending inwardly transversely from the side frame mounting wall  142 ; (c) a substantially vertically extending engagement pad  146  integrally connected to the engagement wall  144 ; and (d) a plurality of substantially horizontally extending braces (such as brace  148   a ) each integrally connected to the side frame mounting wall  142  and integrally connected to the engagement wall  142 . The engagement wall  144  includes an inner substantially vertically extending engagement side  144   a . The engagement pad  146  includes an inner substantially vertically extending engagement surface  146   a.    
     In this illustrated embodiment, the engagement wall  144 , the engagement side  144   a , the engagement pad  146 , and the engagement surface  146   a  also extend in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  144 , the engagement side  144   a , the engagement pad  146 , and/or the engagement surface  146   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40  as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  144 , along the engagement side  144   a , through the engagement pad  146 , or through the engagement surface  146   a ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 5 and 6 ), may be obtuse, or may be acute. An example of this is further illustrated in the alternative example embodiment of  FIG. 7  discussed below. 
     The first bearing  110  and the second opposing bearing  140  are thus configured to engage each other (as generally shown in  FIGS. 3A, 3B, 5, and 6 ). More specifically, the engagement surface  114   a  of the engagement pad  114  is configured to engage the engagement surface  146   a  of the engagement pad  146  (as shown in  FIGS. 5 and 6 ). The configuration of the warp restraint  100 , and specifically the configuration of the first bearing  110  and the second opposing bearing  140 , bias or co-act to provide biasing forces on the bolster  40  and the side frame  60  toward the normal square position to reduce, inhibit, or minimize warping as further described below. 
     Likewise, example warp restraint  200  includes a first bearing  210  integrally formed with a first portion of the bolster  40  and a second opposing bearing  240  integrally formed with the first side frame  60 . It should be appreciated that the first bearing  210  may be connected to the bolster  40  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  240  may be connected to the bolster  40  by one or more suitable second bearing connecters (not shown). 
     More specifically, as best shown in  FIGS. 5 and 6 , the first bearing  210  includes: (a) a substantially horizontally extending mounting bracket  212  integrally connected to the bolster  40 ; (b) a movable engagement pad  214  pivotally connected to the mounting bracket  212 ; (c) a connection arm  213  extending transversely from the back of the engagement pad  214 ; and (d) a pivot pin (not shown). The movable engagement pad  214  is pivotally connected to the mounting bracket  212  by the connection arm  213  and by the pivot pin (not shown). The engagement pad  214  includes an inner substantially vertically extending engagement surface  214   a . In this illustrated embodiment, the engagement pad  214  includes a mounting base  215  and a wear member  216  removably connected to the mounting base  215  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  214  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  212 , the engagement pad  214 , the connection arm  213 , and the pivot pin can be configured such that the engagement pad  214  pivots about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  214  and/or the engagement surface  214   a  extends in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement pad  214  and/or the engagement surface  214   a  is: (a) angled outwardly; (b) angled inwardly; (c) initially angled upwardly; (d) initially angled downwardly; (e) initially angled outwardly and upwardly; (f) initially angled outwardly and downwardly; (g) initially angled inwardly and upwardly; or (h) initially angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  214  or along the engagement surface  214   a  in its initial position; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 5 and 6 ), may be obtuse, or may be acute. An example of this is further illustrated in the alternative example embodiment of  FIG. 7  discussed below. 
     As also best shown in  FIGS. 5 and 6 , the second bearing  240  includes: (a) a substantially vertically extending side frame mounting wall  242  integrally connected to the inner surface of the side frame  60 ; (b) a substantially vertically extending engagement wall  244  integrally connected to the side frame mounting wall  242  and extending inwardly transversely from the side frame mounting wall  242 ; (c) a substantially vertically extending engagement pad  246  integrally connected to the engagement wall  244 ; and (d) a plurality of substantially horizontally extending braces (such as brace  248   a , brace  248   b , brace  248   c , and brace  248   d ) each integrally connected to the side frame mounting wall  242  and integrally connected to the engagement wall  242 . 
     The engagement wall  244  includes an inner substantially vertically extending engagement side  244   a  (that extends substantially parallel with the center line, center plane, or center axis of the bolster). The engagement pad  246  includes an inner substantially vertically extending engagement surface  246   a  (that extends substantially parallel with the crosswise axis of the bolster). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  244 , the engagement side  244   a , the engagement pad  246 , and/or the engagement surface  246   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40  as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  244 , along the engagement side  244   a , through the engagement pad  246 , or through the engagement surface  246   a ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 5 and 6 ), may be obtuse, or may be acute. An example of this is further illustrated in the alternative example embodiment of  FIG. 7  discussed below. 
     The first bearing  210  and the second opposing bearing  240  are thus configured to engage each other (as generally shown in  FIGS. 3A, 3B, 5, and 6 ). More specifically, the engagement surface  214   a  of the engagement pad  214  is configured to engage the engagement surface  246   a  of the engagement pad  246  (as more specifically shown in  FIGS. 5 and 6 ). The configuration of the warp restraint  200 , and specifically the configuration of the first bearing  210  and the second opposing bearing  240 , bias or co-act to provide biasing forces on the bolster  40  and the side frame  60  toward the normal square position to reduce, inhibit, or minimize warping as further described below. 
     In this example embodiment, the removable wear members  116  and  216  of the respective engagement pads  114  and  214  of the bearings can be made from a relatively hard plastic material with self-lubricating characteristics such as from an acetal resin such as a DELRIN material. DELRIN is a registered trademark of E. I. du Pont de Nemours. 
     In this example embodiment, engagement pads  146  and  246  are made from a suitable steel for strength. 
     It should be appreciated that in various embodiments, the removable wear members  116  and  216  are respectively removeably attached to the mounting bases  115  and  215  to facilitate replacement of such wear member as they wear out. 
     In various such embodiments, before replacement but after the wear members are worn to a certain degree, suitable shims (not shown) may be employed to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more of the first and second bearings can include one or more biasing members (not shown) to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more adjustment devices (not shown) can be used with the bearing members to maintain engagement between the respective sets of first and second bearings. In various embodiments, the adjustment devices include opposing threaded members that are rotatably adjustable to maintain engagement between the respective sets of first and second bearings. 
     As mentioned above, warp restraints  500  and  600  of the present disclosure are identical to warp restraints  100  and  200  except that warp restraints  500  and  600  are attached to the second side frame  80  and the second portion of the bolster  40 . Thus, these warp restraints  500  and  600  are not described in further detail. 
     It should be appreciated that bearing  110  (and specifically the mounting bracket  112  thereof), bearing  210  (and specifically the mounting bracket  212  thereof), bearing  510  (and specifically the mounting bracket thereof), and bearing  610  (and specifically the mounting bracket thereof) can be integrally cast with the bolster  40  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  140  (and specifically the mounting wall  142  thereof) and bearing  240  (and specifically the mounting wall  242  thereof) can be integrally cast with the side frame  60  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  540  (and specifically the mounting wall thereof) and bearing  640  (and specifically the mounting wall thereof) can be integrally cast with the side frame  80  in various embodiments of the present disclosure. 
     When warping occurs as generally shown in  FIGS. 2 and 3A , the bolster  40  is not square with either of the side frames  60  or  80 . Warping is somewhat of a particular combination of forces wherein each end of the bolster wants to twist inside of the aperture of the respective side frame. The warp restraints  100 ,  200 ,  500 , and  600  of the present disclosure can: (1) independently apply counter biasing forces to the bolster  40 ; and (2) apply counter biasing forces to the bolster  40  in groups, wherein such forces act independently or in combination or co-act to cause the bolster  40  to return to its normal position and thus reduce, inhibit, and/or minimize warping. Specifically, in certain embodiments, depending upon the specific positioning, arrangements, and configurations of the respective engagement pads (such as engagement pads  114  and  146  and engagement pads  214  and  246 ), the engagement pads will exert opposing forces on the opposing bearings (such as opposing bearing  110  and  140  and opposing bearing  210  and  240 ) to move away from such positions and back toward their normal positions. 
     For example, if the warping shown on the right end portion of the bolster in  FIG. 2  or  FIG. 3A  begins to occur or occurs to the truck of the present disclosure, the warps restraints  100 ,  200 ,  500 , and  600  can act individually and in groups to apply biasing forces to the bolster  40  to cause the bolster  40  to return to its normal or square position and thus act or co-act to reduce, inhibit, and/or minimize warping. Likewise, if the warping is reversed, the warp restraints  100 ,  200 ,  500 , and  600  can act individually and in groups to apply biasing forces to the bolster  40  to cause the bolster  40  to return to its normal or square position and thus co-act to prevent, reduce, inhibit, and/or minimize warping. 
     The four warp restraints  100 ,  200 ,  500 , and  600  of the present disclosure thus act independently and/or co-act in groups to bias the bolster toward the square positions relative to the side frames  60  and  80  such that the centerline or center plane of the bolster (that extends transversely relative to straight tracks) is perpendicular or substantially perpendicular to the centerlines or center planes of the respective side frames  60  and  80  (that extend longitudinally relative to straight tracks). 
     2 nd  Example Embodiment 
     Referring now to  FIG. 7 , another embodiment of the railroad car truck with warp restraints of the present disclosure is shown and generally indicated by numeral  1050 . This illustrated example embodiment of the present disclosure is similar to the embodiment of  FIGS. 3A, 3B, 4, 5, and 6 , except that: (1) the first plurality or set of warp restraints (not shown)  1100  and  1200  are angled relative to the first side frame  1060 ; and (2) the second plurality or set of warp restraints (not shown) are angled relative to the second side frame (not shown in  FIG. 7 ). More specifically, in this illustrated embodiment, (a) warp restraint  1100  includes a first angled bearing  1110  integrally formed at and extending from a first portion of the bolster  1040  and a second angled opposing bearing  1140  integrally formed at and extending from the first side frame  1060 ; and (b) warp restraint  1200  includes a first angled bearing  1210  integrally formed at and extending from the first portion of the bolster  1040  and a second angle opposing bearing  1240  integrally formed at and extending from the first side frame  60 . 
     It should be appreciated that each of the warp restraints in this illustrated example embodiment are identical or substantially identical (except for positioning and arrangement of their connectors to, connections with, or formations with the side frames and the bolster). However, it should be appreciated that the warp restraints of the present disclosure do not need to be identical or substantially identical and can vary based on the respective positions and connections to or formations with the side frames and the bolster. For example, the two bearings of any set of warp restraints may be different. 
     More specifically, example warp restraint  1100  includes a first bearing  1110  integrally formed with a first portion of the bolster  1040  and a second opposing bearing  1140  integrally formed with the first side frame  1060 . It should be appreciated that the first bearing  1110  may be connected to the bolster  1040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  1140  may be connected to the side frame  1060  by one or more suitable second bearing connecters (not shown). 
     As shown in  FIG. 7 , the first bearing  1110  includes: (a) a substantially horizontally extending mounting bracket  1112  integrally connected to the bolster  1040 ; (b) a movable engagement pad  1114  pivotally connected to the mounting bracket  1112 ; (c) a connection arm  1113  extending transversely from the back of the engagement pad  1114 ; and (d) a pivot pin (not shown). The movable engagement pad  1114  is pivotally connected to the mounting bracket  1112  by the connection arm  1113  and by the pivot pin (not shown). The engagement pad  1114  includes an inner substantially vertically extending engagement surface  1114   a . In this illustrated embodiment, the engagement pad  1114  includes a mounting base  1115  and a wear member  1116  removably connected to the mounting base  1115  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  1114  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  1112 , the engagement pad  1114 , the connection arm  1113 , and the pivot pin can be configured such that the engagement pad  1114  is pivotal about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  1114  and/or the engagement surface  1114   a  extend at an angle to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). In other words, in this embodiment, the engagement pad  1114  and/or the engagement surface  1114   a  is angled outwardly to provide the desired forces on the bolster  1040  and the side frames  1060  and  1080  to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster. Thus, in this embodiment, the angle between: (a) a plane extending through the engagement pad  1114  or along the engagement surface  1114   a ; relative to: (b) a plane extending through the side frame  1060  is obtuse. 
     As also shown in  FIG. 7 , the second bearing  1140  includes: (a) a substantially vertically extending side frame mounting wall  1142  integrally connected to the inner surface of the side frame  1060 ; (b) a substantially vertically extending engagement wall  1144  integrally connected to the side frame mounting wall  1142  and extending inwardly transversely from the side frame mounting wall  1142 ; (c) a substantially vertically extending engagement pad  1146  integrally connected to the engagement wall  1144 ; and (d) a plurality of substantially horizontally extending braces (such as brace  1148   a ) each integrally connected to the side frame mounting wall  1142  and integrally connected to the engagement wall  1142 . The engagement wall  1144  includes an inner substantially vertically extending engagement side  1144   a . The engagement pad  1146  includes an inner substantially vertically extending engagement surface  1146   a  (that extends transversely to the crosswise axis of the bolster  1040 ). 
     In this illustrated embodiment, the engagement wall  1144 , the engagement side  1144   a , the engagement pad  1146 , and the engagement surface  1146   a  extend at an angle to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). In other words, in this example embodiment, the engagement wall  1144 , the engagement side  1144   a , the engagement pad  1146 , and/or the engagement surface  1146   a  are angled to assist in providing the desired forces on the bolster  1040  and the side frames (such as side frame  1060 ) to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster  1040  as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  1144 , along the engagement side  1144   a , through the engagement pad  1146 , or through the engagement surface  1146   a ; relative to: (b) a plane extending through the side frame  1060  is acute. 
     The first bearing  1110  and the second opposing bearing  1140  are thus configured to engage each other (as generally shown in  FIG. 7 ). More specifically, the engagement surface  1114   a  of the engagement pad  1114  is configured to engage the engagement surface  1146   a  of the engagement pad  1146 . The configuration of the warp restraint  100 , and specifically the configuration of the first bearing  1110  and the second opposing bearing  1140 , bias or co-act to provide biasing forces on the bolster  1040  and the side frame  1060  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     Likewise, example warp restraint  1200  includes a first angled bearing  1210  integrally formed with a first portion of the bolster  1040  and a second opposing angled bearing  1240  integrally formed with the first side frame  1060 . It should be appreciated that the first bearing  1210  may be connected to the bolster  1040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  1240  may be connected to the bolster  1040  by one or more suitable second bearing connecters (not shown). 
     More specifically, as shown in  FIG. 7 , the first bearing  1210  includes: (a) a substantially horizontally extending mounting bracket  1212  integrally connected to the bolster  1040 ; (b) a movable engagement pad  1214  pivotally connected to the mounting bracket  1212 ; (c) a connection arm  1213  extending transversely from the back of the engagement pad  1214 ; and (d) a pivot pin (not shown). The movable engagement pad  1214  is pivotally connected to the mounting bracket  1212  by the connection arm  1213  and by the pivot pin (not shown). The engagement pad  1214  includes an inner substantially vertically extending engagement surface  1214   a . In this illustrated embodiment, the engagement pad  1214  includes a mounting base  1215  and a wear member  1216  removably connected to the mounting base  1215  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  1214  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  1212 , the engagement pad  1214 , the connection arm  1213 , and the pivot pin can be configured such that the engagement pad  1214  pivots about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  1214  and/or the engagement surface  1214   a  extend at an outward angle to provide the desired forces on the bolster  1040  and the side frames (such as side frame  1060 ) to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster  1040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  1214  or along the engagement surface  1214   a ; relative to: (b) a plane extending through the side frame  1060  is obtuse. 
     As also shown in  FIG. 7 , the second bearing  1240  includes: (a) a substantially vertically extending side frame mounting wall  1242  integrally connected to the inner surface of the side frame  1060 ; (b) a substantially vertically extending engagement wall  1244  integrally connected to the side frame mounting wall  1242  and extending inwardly transversely from the side frame mounting wall  1242 ; (c) a substantially vertically extending engagement pad  1246  integrally connected to the engagement wall  1244 ; and (d) a plurality of substantially horizontally extending braces (such as brace  1248   a ) each integrally connected to the side frame mounting wall  1242  and integrally connected to the engagement wall  1242 . The engagement wall  1244  includes an inner substantially vertically extending engagement side  1244   a  (that extends substantially parallel with the crosswise axis of the bolster). The engagement pad  1246  includes an inner substantially vertically extending engagement surface  1246   a  (that extends transversely to the crosswise axis of the bolster  1040 ). 
     In this embodiment, the engagement wall  1244 , the engagement side  1244   a , the engagement pad  1246 , and/or the engagement surface  1246   a  is angled to assist in providing the desired forces on the bolster and the side frames to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster. Thus, in this embodiment, the angle between: (a) a plane extending through the engagement wall  1244 , along the engagement side  1244   a , through the engagement pad  1246 , or through the engagement surface  1246   a ; relative to: (b) a plane extending through the side frame  60  is acute. 
     The first bearing  1210  and the second opposing bearing  1240  are thus configured to engage each other (as generally shown in  FIG. 7 ). More specifically, the engagement surface  1214   a  of the engagement pad  1214  is configured to engage the engagement surface  1246   a  of the engagement pad  1246 . The configuration of the warp restraint  1200 , and specifically the configuration of the first bearing  1210  and the second opposing bearing  1240 , bias or co-act to provide biasing forces on the bolster  40  and the side frame  60  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     In these embodiments, the wear members of the engagement pads of the bearings can be made from a relatively hard plastic material with self-lubricating characteristics such as from an acetal resin such as a DELRIN material. 
     In this example embodiment, engagement pads  1146  and  1246  are made from a suitable steel for strength. 
     It should be appreciated that in various embodiments, the wear member are respectively removably attached to the mounting bases to facilitate replacement of such wear members as they wear out. 
     In various such embodiments, before replacement but after the wear members are worn to a certain degree, suitable shims (not shown) may be employed to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more of the first and second bearings can include one or more biasing members (not shown) to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more adjustment devices (not shown) can be used with the bearing members to maintain engagement between the respective sets of first and second bearings. In various embodiments, the adjustment devices include opposing threaded members that are rotatably adjustable to maintain engagement between the respective sets of first and second bearings. 
     It should be appreciated that bearing  1110  (and specifically the mounting bracket  1112  thereof), bearing  1210  (and specifically the mounting bracket  1212  thereof), and the other respective bearings (and specifically the mounting brackets thereof), can be integrally cast with the bolster  40  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  1140  (and specifically the mounting wall  1142  thereof) and bearing  1240  (and specifically the mounting wall  1242  thereof) can be integrally cast with the side frame  1060  in various embodiments of the present disclosure. Likewise, it should be appreciated that the other bearings (and specifically the mounting walls thereof) can be integrally cast with the other side frame in various embodiments of the present disclosure. 
     3 rd  Example Embodiment 
     Referring now to  FIGS. 8 and 9 , another example embodiment of the railroad car truck with warp restraints of the present disclosure is shown and generally indicated by numeral  1050 A. 
     In this illustrated example embodiment of the present disclosure, the railroad car truck with warp restraints  1050 A includes: (1) a first plurality or set of warp restraints  100  and  200 ; (2) a second plurality or set of warp restraints  500  and  600  (on the outer side of the bolster and first side frame); (3) a third plurality or set of warp restraints  300  and  400 ; and (4) a fourth plurality or set of warp restraints  700  and  800  (on the outer side of the bolster and second side frame). In this illustrated example embodiment of the present disclosure: (1) the first plurality or set of warp restraints  100  and  200  are the same as the warp restraints  100  and  200  of  FIGS. 3A to 6 ; and (2) the second plurality or set of warp restraints  500  and  600  are the same as the warp restraints  500  and  600  of  FIGS. 3A to 6 . Thus, these warp restraints are indicated by the same numerals as in  FIGS. 3A to 6 , are not described again in this section, and the above descriptions apply to such warp restraints. 
     Warp restraints  300 ,  400 ,  700 , and  800  are similar to warp restraints  100 ,  200 ,  500 , and  600 , and are thus similarly described below. 
     Warp restraint  300  has a first bearing  310  including: (a) a substantially horizontally extending mounting bracket  312  integrally connected to the bolster  40 ; (b) a movable engagement pad  314  pivotally connected to the mounting bracket  312 ; (c) a connection arm  313  extending transversely from the back of the engagement pad  314 ; and (d) a pivot pin (not shown). The movable engagement pad  314  is pivotally connected to the mounting bracket  312  by the connection arm  313  and by the pivot pin (not shown). The engagement pad  314  includes an inner substantially vertically extending engagement surface  314   a . In this illustrated embodiment, the engagement pad  314  includes a mounting base  315  and a wear member  316  removably connected to the mounting base  315  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  314  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  312 , the engagement pad  314 , the connection arm  313 , and the pivot pin can be configured such that the engagement pad  314  is pivotal about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  314  and/or the engagement surface  314   a  each extend in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement pad  314  and/or the engagement surface  314   a  is: (a) angled outwardly; (b) angled inwardly; (c) initially angled upwardly; (d) initially angled downwardly; (e) initially angled outwardly and upwardly; (f) initially angled outwardly and downwardly; (g) initially angled inwardly and upwardly; or (h) initially angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, or minimize warping of the side frames  60  and  80  relative to the bolster  40 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  314  and/or along the engagement surface  314   a  in its initial position; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 8 and 9 ), may be obtuse, or may be acute. 
     The second bearing  340  includes: (a) a substantially vertically extending side frame mounting wall  342  integrally connected to the outer surface of the side frame  60 ; (b) a substantially vertically extending engagement wall  344  integrally connected to the side frame mounting wall  342  and extending inwardly transversely from the side frame mounting wall  342 ; (c) a substantially vertically extending engagement pad  346  integrally connected to the engagement wall  344 ; and (d) a plurality of substantially horizontally extending braces (such as brace  348   a ) each integrally connected to the side frame mounting wall  342  and integrally connected to the engagement wall  342 . The engagement wall  344  includes an inner substantially vertically extending engagement side  344   a . The engagement pad  346  includes an inner substantially vertically extending engagement surface  346   a.    
     In this illustrated embodiment, the engagement wall  344 , the engagement side  344   a , the engagement pad  346 , and the engagement surface  346   a  also extend in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  344 , the engagement side  344   a , the engagement pad  346 , and/or the engagement surface  346   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40  as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  344 , along the engagement side  344   a , through the engagement pad  346 , or through the engagement surface  346   a ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 8 and 9 ), may be obtuse, or may be acute. 
     The first bearing  310  and the second opposing bearing  340  are thus configured to engage each other (as generally shown in  FIGS. 8 and 9 ). More specifically, the engagement surface  314   a  of the engagement pad  314  is configured to engage the engagement surface  346   a  of the engagement pad  346  (as shown in  FIGS. 8 and 9 ). The configuration of the warp restraint  300 , and specifically the configuration of the first bearing  310  and the second opposing bearing  340 , bias or co-act to provide biasing forces on the bolster  40  and the side frame  60  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     Likewise, example warp restraint  400  includes a first bearing  410  integrally formed with a first portion of the bolster  40  and a second opposing bearing  440  integrally formed with the first side frame  60 . It should be appreciated that the first bearing  410  may be connected to the bolster  40  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  440  may be connected to the bolster  40  by one or more suitable second bearing connecters (not shown). 
     More specifically, as shown in  FIGS. 8 and 9 , the first bearing  410  includes: (a) a substantially horizontally extending mounting bracket  412  integrally connected to the bolster  40 ; (b) a movable engagement pad  414  pivotally connected to the mounting bracket  412 ; (c) a connection arm  413  extending transversely from the back of the engagement pad  414 ; and (d) a pivot pin (not shown). The movable engagement pad  414  is pivotally connected to the mounting bracket  412  by the connection arm  413  and by the pivot pin (not shown). The engagement pad  414  includes an inner substantially vertically extending engagement surface  414   a . In this illustrated embodiment, the engagement pad  414  includes a mounting base  415  and a wear member  416  removably connected to the mounting base  415  by one or more suitable fasteners (not shown). 
     In this illustrated embodiment, the engagement pad  414  is pivotal about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin (not shown). It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  412 , the engagement pad  414 , the connection arm  413 , and the pivot pin can be configured such that the engagement pad  414  pivots about a differently extending axis. 
     In this illustrated embodiment, the engagement pad  414  and/or the engagement surface  414   a  extends in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement pad  414  and/or the engagement surface  414   a  is: (a) angled outwardly; (b) angled inwardly; (c) initially angled upwardly; (d) initially angled downwardly; (e) initially angled outwardly and upwardly; (f) initially angled outwardly and downwardly; (g) initially angled inwardly and upwardly; or (h) initially angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, and/or minimize warping of the side frames  60  and  80  relative to the bolster  40 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  414  or along the engagement surface  414   a  in its initial position; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 8 and 9 ), may be obtuse, or may be acute. 
     As also shown in  FIGS. 8 and 9 , the second bearing  440  includes: (a) a substantially vertically extending side frame mounting wall  442  integrally connected to the outer surface of the side frame  60 ; (b) a substantially vertically extending engagement wall  444  integrally connected to the side frame mounting wall  442  and extending inwardly transversely from the side frame mounting wall  442 ; (c) a substantially vertically extending engagement pad  446  integrally connected to the engagement wall  444 ; and (d) a plurality of substantially horizontally extending braces (such as brace  448   a , brace  448   b , brace  448   c , and brace  448   d ) each integrally connected to the side frame mounting wall  442  and integrally connected to the engagement wall  442 . 
     The engagement wall  444  includes an inner substantially vertically extending engagement side  444   a  (that extends substantially parallel with the center line, center plane, or center axis of the bolster). The engagement pad  446  includes an inner substantially vertically extending engagement surface  446   a  (that extends substantially parallel with the crosswise axis of the bolster). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  444 , the engagement side  444   a , the engagement pad  446 , and/or the engagement surface  446   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  40  and the side frames  60  and  80  to reduce, inhibit, or minimize warping of the side frames  60  and  80  relative to the bolster  40  as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  444 , along the engagement side  444   a , through the engagement pad  446 , or through the engagement surface  446   a ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 8 and 9 ), may be obtuse, or may be acute. 
     The first bearing  410  and the second opposing bearing  440  are thus configured to engage each other (as generally shown in  FIGS. 8 and 9 ). More specifically, the engagement surface  414   a  of the engagement pad  414  is configured to engage the engagement surface  446   a  of the engagement pad  446 . The configuration of the warp restraint  400 , and specifically the configuration of the first bearing  410  and the second opposing bearing  440 , bias or co-act to provide biasing forces on the bolster  40  and the side frame  60  toward the normal square position to reduce, inhibit, or minimize warping as further described below. 
     In this embodiment, the removable wear members  316  and  416  of the respective engagement pads  314  and  414  of the bearings can be made from a relatively hard plastic material with self-lubricating characteristics such as from an acetal resin such as a DELRIN material. 
     In this example embodiment, engagement pads  346  and  446  are made from suitable steel for strength. 
     It should be appreciated that in various embodiments, the removable wear members  316  and  416  are respectively removably attached to the mounting bases  315  and  415  to facilitate replacement of such wear members as they wear out. 
     In various such embodiments, before replacement but after the wear members are worn to a certain degree, suitable shims (not shown) may be employed to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more of the first and second bearings can include one or more biasing members (not shown) to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more adjustment devices (not shown) can be used with the bearing members to maintain engagement between the respective sets of first and second bearings. In various embodiments, the adjustment devices include opposing threaded members that are rotatably adjustable to maintain engagement between the respective sets of first and second bearings. 
     It should be appreciated that bearing  110  (and specifically the mounting bracket  112  thereof), bearing  210  (and specifically the mounting bracket  212  thereof), bearing  510  (and specifically the mounting bracket thereof), and bearing  610  (and specifically the mounting bracket thereof) can be integrally cast with the bolster  40  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  140  (and specifically the mounting wall  142  thereof) and bearing  240  (and specifically the mounting wall  242  thereof) can be integrally cast with the side frame  60  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  540  (and specifically the mounting wall thereof) and bearing  640  (and specifically the mounting wall thereof) can be integrally cast with the side frame  80  in various embodiments of the present disclosure. 
     Warp restraints  700  and  800  of the present disclosure are identical to warp restraints  300  and  400  except that warp restraints  700  and  800  are attached to the second side frame  80  and the second portion of the bolster  40 . 
     When warping begins to occur or occurs as generally shown in  FIG. 2 , the bolster  40  is not square with either of the side frames  60  or  80 . Warping is somewhat of a particular combination of forces wherein each end of the bolster wants to twist inside of the aperture of the respective side frame. The warp restraints  100 ,  200 ,  300 ,  400 ,  500 ,  600 ,  700 , and  800  of the present disclosure can: (1) independently apply counter biasing forces to the bolster  40 ; and (2) apply counter biasing forces to the bolster  40  in groups, wherein such forces act independently or in combination or co-act to cause the bolster  40  to return to its normal position and thus reduce, inhibit, and/or minimize warping. Specifically, in certain embodiments, depending upon the specific positioning, arrangements, and configurations of the respective engagement pads, the engagement pads will exert opposing forces on the opposing bearings to move away from such positions and back toward their normal positions. 
     The eight warp restraints  100 ,  200 , 300 ,  400 ,  500 ,  600 ,  700 , and  800  of this example embodiment of the present disclosure thus act independently and co-act in groups to bias the bolster toward the square positions relative to the side frames  60  and  80  such that the centerline or center plane of the bolster (that extends transversely relative to straight tracks) is perpendicular or substantially perpendicular to the centerlines or center planes of the respective side frames  60  and  80  (that extend longitudinally relative to straight tracks). 
     In further alternative example embodiments of the railroad car truck with warp restraints of the present disclosure that are not shown, the railroad car truck with warp restraints includes: (a) the third plurality or set of warp restraints  300  and  400 ; and (b) the fourth plurality or set of warp restraints  700  and  800 , but do not include: (1) the first plurality or set of warp restraints  100  and  200 ; and (2) the second plurality or set of warp restraints  500  and  600 . 
     4 th  Example Embodiment 
     Referring now to  FIGS. 10A, 10B, 11, 12, and 13 , another example embodiment of the railroad car truck with warp restraints of the present disclosure is shown and generally indicated by numeral  2050 . In this illustrated example embodiment of the present disclosure, the truck  2050  includes a bolster  2040 , a bolster bowl  2042  on the bolster  2040 , a first side frame  2060 , and a second side frame  2080 . Generally, the bolster  2040  is configured to extend transversely to the direction of the railroad tracks or rails (not shown in  FIGS. 10A, 10B, 11, 12, and 13 ) and the side frames  2060  and  2080  are configured to extend longitudinally in the same direction as the railroad tracks (not shown in  FIGS. 10A, 10B, 11, 12, and 13 ). The side frame  2060  includes: (a) a longitudinally extending body  2062 ; and (b) two downwardly extending pedestal jaws (including a first pedestal jaw  2064  and a second pedestal jaw  2066 ) on opposite sides of the center opening  2068  in the body  2062  of the side frame  2060 . The body  2062  includes a first side wall, a top wall, a second side wall, and a bottom wall that generally define the opening  2068 . The side frame  2080  includes: (a) a longitudinally extending body  2082 ; and (b) two downwardly extending pedestal jaws (including a first pedestal jaw  2084  and a second pedestal jaw  2086 ) on opposite sides of the center opening  2088  in the body  2082  of the side frame  2080 . The body  2082  includes a first side wall, a top wall, a second side wall, and a bottom wall that generally define the opening  2088 . 
     In this illustrated example embodiment of the present disclosure, as shown in  FIGS. 10A, 10B, 11, 12, and 13 , the railroad car truck with warp restraints  2050  includes: (1) a first plurality or set of warp restraints  2100  and  2200 ; and (2) a second plurality or set of warp restraints  2500  and  2600 . More specifically, in this illustrated embodiment: (a) warp restraint  2100  includes a first bearing  2110  integrally formed at and extending from a first portion of the bolster  2040  and a second opposing bearing  2140  integrally formed at and extending from the first side frame  2060 ; (b) warp restraint  2200  includes a first bearing  2210  integrally formed at and extending from the first portion of the bolster  2040  and a second opposing bearing  2240  integrally formed at and extending from the first side frame  2060 ; (c) warp restraint  2500  includes a first bearing  2510  integrally formed at and extending from a second portion of the bolster  2040  and a second opposing bearing  2540  integrally formed at and extending from the second side frame  2080 ; and (d) warp restraint  2600  includes a first bearing  2610  integrally formed at and extending from the second end portion of the bolster  2040 , a second opposing bearing  2640  integrally formed at and extending from the second side frame  2080 . Thus, bearings  2110 ,  2210 ,  2510 , and  2610  are integrally formed at and extend from the respective inward portions of the bolster  2040 , bearings  2140  and  2240  are integrally formed at and extend from the inward side of the first side frame  2060 , and bearings  2540  and  2640  are integrally formed at and extend from the inward side of the second side frame  2080 . 
     It should be appreciated that each of the warp restraints  2100 ,  2200 ,  2500 , and  2600  in various embodiments are identical or substantially identical (except for positioning and arrangement of their connectors to, connections with, or formations with the side frames and the bolster). Therefore, warp restraints  2100  and  2200  are primarily discussed in further detail below. However, it should be appreciated that the warp restraints of the present disclosure do not need to be identical or substantially identical and can vary based on the respective positions and connections to or formations with the side frames and the bolster. For example, the two bearings of any set of warp restraints may be different. It should also be appreciated that the warp restraint of the various different embodiments of the present disclosure may be used on a truck (i.e., the various example warp restraints of the present disclosure may be mixed on single truck or railroad car). 
     More specifically, example warp restraint  2100  includes a first bearing  2110  integrally formed with a first portion of the bolster  2040  and a second opposing bearing  2140  integrally formed with the first side frame  2060 . It should be appreciated that the first bearing  2110  may be connected to the bolster  2040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  2140  may be connected to the bolster  2040  by one or more suitable second bearing connecters (not shown). 
     As best shown in  FIGS. 10 and 11 , the first bearing  2110  includes: (a) a substantially horizontally extending mounting bracket  2112  integrally connected to the bolster  2040 ; (b) a rotatable engagement roller  2114  rotatably connected to the mounting bracket  2112 ; and (c) a pivot pin  2115 . The rotatable engagement roller  2114  is rotatably connected to the mounting bracket  2112  by the pivot pin  2115 . The engagement roller  2114  includes a substantially cylindrical engagement surface  2114   a  which at any point in time in its rotation includes a portion or engagement edge that is configured to engage the second bearing  2140 . In this illustrated embodiment, the engagement roller  2114  is rotatable about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin  2115 . It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  2112 , the engagement roller  2114 , and the pivot pin  2115  can be configured such that the engagement roller  2114  is rotatable about a differently extending axis. 
     In this illustrated embodiment, the portion or engagement edge of the engagement roller  2114  and/or the engagement surface  2114   a  that engages bearing  2100  extends in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement roller  2114  and/or the engagement edge of the engagement surface  2114   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly to provide the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, or minimize warping of the side frames  2060  and  2080  relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement edge of the engagement roller  2114 ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 10 and 11 ), may be obtuse, or may be acute. 
     As best shown in  FIGS. 12 and 13 , the second bearing  2140  includes: (a) a substantially vertically extending side frame mounting wall  2142  integrally connected to the inner surface of the side frame  2060 ; (b) a substantially vertically extending engagement wall  2144  integrally connected to the side frame mounting wall  2142  and extending inwardly transversely from the side frame mounting wall  2142 ; (c) a substantially vertically extending engagement pad  2146  integrally connected to the engagement wall  2144 ; and (d) a plurality of substantially horizontally extending braces (such as brace  2148   a ) each integrally connected to the side frame mounting wall  2142  and integrally connected to the engagement wall  2142 . The engagement wall  2144  includes an inner substantially vertically extending engagement side  2144   a . The engagement pad  2146  includes an inner substantially vertically extending engagement surface  2146   a.    
     In this illustrated embodiment, the engagement wall  2144 , the engagement side  2144   a , the engagement pad  2146 , and the engagement surface  2146   a  also extend in the same direction (such as parallel) to the centerline, center plane, or central axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  2144 , the engagement side  2144   a , the engagement pad  2146 , and/or the engagement surface  2146   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  2144 , along the engagement side  2144   a , through the engagement pad  2146 , or through the engagement surface  2146   a ; relative to: (b) a plane extending through the side frame  2060  may be right (as shown in  FIGS. 12 and 13 ), may be obtuse, or may be acute. 
     The first bearing  2110  and the second opposing bearing  2140  are thus configured to engage each other (as generally shown in  FIGS. 10A, 10B, 11, 12, and 13 ). More specifically, the engagement edge of the engagement roller  2114  is configured to engage the engagement surface  2146   a  of the engagement pad  2146  (as shown in  FIGS. 11 and 12 ). The configuration of the warp restraint  2100 , and specifically the configuration of the first bearing  2110  and the second opposing bearing  2140 , bias or co-act to provide biasing forces on the bolster  2040  and the side frame  2060  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     Likewise, example warp restraint  2200  includes a first bearing  2210  integrally formed with a first portion of the bolster  2040  and a second opposing bearing  2240  integrally formed with the first side frame  2060 . It should be appreciated that the first bearing  2210  may be connected to the bolster  2040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  2240  may be connected to the bolster  2040  by one or more suitable second bearing connecters (not shown). 
     More specifically, as best shown in  FIGS. 12 and 13 , the first bearing  2210  includes: (a) a substantially horizontally extending mounting bracket  2212  integrally connected to the bolster  2040 ; (b) an engagement roller  2214  rotatably connected to the mounting bracket  2212 ; and (c) a pivot pin  2215 . The engagement roller  2214  is rotatably connected to the mounting bracket  2212  by the pivot pin  2115 . The engagement roller  2214  includes a cylindrical engagement surface  2214   a  which at any point in time in its rotation includes a portion or engagement edge that is configured to engage the second bearing  2240 . In this illustrated embodiment, the engagement roller  2214  is rotatable about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin  2115 . It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  2212 , the engagement roller  2214 , and the pivot pin  2215  can be configured such that the engagement roller  2214  rotates about a differently extending axis. 
     It should be appreciated that in various alternative embodiments of the present disclosure, the engagement roller  2214  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, or minimize warping of the side frames  2060  and  2080  relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  2214  or along the engagement edge of the engagement surface  2214   a ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 12 and 13 ), may be obtuse, or may be acute. 
     As best shown in  FIGS. 12 and 13 , the second bearing  2240  includes: (a) a substantially vertically extending side frame mounting wall  2242  integrally connected to the inner surface of the side frame  2040 ; (b) a substantially vertically extending engagement wall  2244  integrally connected to the side frame mounting wall  2242  and extending inwardly transversely from the side frame mounting wall  2242 ; (c) a substantially vertically extending engagement pad  2246  integrally connected to the engagement wall  2244 ; and (d) a plurality of substantially horizontally extending braces (such as braces  2248   a ,  2248   b ,  2248   c , and  2248   d ) each integrally connected to the side frame mounting wall  2242  and integrally connected to the engagement wall  2242 . The engagement wall  2244  includes an inner substantially vertically extending engagement side  2244   a  (that extends substantially parallel with the crosswise axis of the bolster). The engagement pad  2246  includes an inner substantially vertically extending engagement surface  2246   a  (that extends substantially parallel with the crosswise axis of the bolster). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  2244 , the engagement side  2244   a , the engagement pad  2246 , and/or the engagement surface  2246   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, or minimize warping of the side frames relative to the bolster. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  2244 , along the engagement side  2244   a , through the engagement pad  2246 , or through the engagement surface  2246   a ; relative to: (b) a plane extending through the side frame  2060  may be right (as shown in  FIGS. 12 and 13 ), may be obtuse, or may be acute. 
     The first bearing  2210  and the second opposing bearing  2240  are thus configured to engage each other (as generally shown in  FIGS. 10A, 10B, 11, 12, and 13 ). More specifically, the engagement edge of the engagement roller  2214  is configured to engage the engagement surface  2246   a  of the engagement pad  2246  (as shown in  FIGS. 12 and 13 ). The configuration of the warp restraint  2200 , and specifically the configuration of the first bearing  2210  and the second opposing bearing  2240 , bias or co-act to provide biasing forces on the bolster  2040  and the side frame  2060  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     In this illustrated example embodiment, the engagement pads  2146  and  2246  are steel and the rollers  2114  and  2214  are made from steel. It should be appreciated that these engaging components can be made from other suitable materials. 
     It should also be appreciated that the rollers of the warp restraints are identical in the illustrated embodiments of  FIGS. 10A, 10B, 11, 12 and 13 , but may be different, and in particular may have different roller sizes (such as different roller outer diameters or different roller elasticity or spring characteristics). 
     In various such embodiments, before replacement but after the wear members are worn to a certain degree, suitable shims (not shown) may be employed to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more of the first and second bearings can include one or more biasing members (not shown) to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more adjustment devices (not shown) can be used with the bearing members to maintain engagement between the respective sets of first and second bearings. In various embodiments, the adjustment devices include opposing threaded members that are rotatably adjustable to maintain engagement between the respective sets of first and second bearings. 
     It should be appreciated that bearing  2110  (and specifically the mounting bracket  2112  thereof), bearing  2210  (and specifically the mounting bracket  2212  thereof), bearing  2510  (and specifically the mounting bracket thereof), and bearing  2610  (and specifically the mounting bracket thereof) can be integrally cast with the bolster  2040  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  2140  (and specifically the mounting wall  2142  thereof) and bearing  2240  (and specifically the mounting wall  2242  thereof) can be integrally cast with the side frame  2060  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  2540  (and specifically the mounting wall thereof) and bearing  2640  (and specifically the mounting wall thereof) can be integrally cast with the side frame  2080  in various embodiments of the present disclosure. 
     5 th  Example Embodiment 
     Referring now to  FIGS. 14 and 15 , another example embodiment of the railroad car truck with warp restraints of the present disclosure is shown and generally indicated by numeral  2050 A. 
     In this illustrated example embodiment of the present disclosure, the railroad car truck with warp restraints  2050 A includes: (1) a first plurality or set of warp restraints  2100  and  2200 ; (2) a second plurality or set of warp restraints  2500  and  2600 ; (3) a third plurality or set of warp restraints  2300  and  2400 ; and (4) a fourth plurality or set of warp restraints  2700  and  2800 . In this illustrated example embodiment of the present disclosure: (1) the first plurality or set of warp restraints  2100  and  2200  are the same as the warp restraints  2100  and  2200  of  FIG. 10A to 13 ; and (2) the second plurality or set of warp restraints  2500  and  2600  are the same as the warp restraints  2500  and  2600  of  FIGS. 10A to 13 . Thus, these warp restraints are indicated by the same numerals as in  FIGS. 10A to 13 , are not described again in this section, and the above descriptions apply to such warp restraints. 
     Warp restraints  2300 ,  2400 ,  2700 , and  2800  are similar to warp restraints  2100 ,  2200 ,  2500 , and  2600 , and are thus similarly described below. 
     In this illustrated embodiment: (a) warp restraint  2300  includes a first bearing  2310  integrally formed at and extending from a first portion of the bolster  2040  and a second opposing bearing  2340  integrally formed at and extending from the first side frame  2060 ; (b) warp restraint  2400  includes a first bearing  2410  integrally formed at and extending from the first portion of the bolster  2040  and a second opposing bearing  2440  integrally formed at and extending from the first side frame  2060 ; (c) warp restraint  2700  includes a first bearing  2710  integrally formed at and extending from a second portion of the bolster  2040  and a second opposing bearing  2740  integrally formed at and extending from the second side frame  2080 ; and (d) warp restraint  2800  includes a first bearing  2810  integrally formed at and extending from the second end portion of the bolster  2040 , a second opposing bearing  2840  integrally formed at and extending from the second side frame  2080 . Thus, bearings  2310 ,  2410 ,  2710 , and  2810  are integrally formed at and extend from the respective outer portions of the bolster  2040 , bearings  2340  and  2440  are integrally formed at and extend from the outer side of the first side frame  2060 , and bearings  2740  and  2840  are integrally formed at and extend from the outer side of the second side frame  2080 . 
     It should be appreciated that each of the warp restraints  2300 ,  2400 ,  2700 , and  2800  in various embodiments are identical or substantially identical (except for positioning and arrangement of their connectors to, connections with, or formations with the side frames and the bolster). Therefore, warp restraints  2300  and  2400  are primarily discussed in further detail below. However, it should be appreciated that the warp restraints of the present disclosure do not need to be identical or substantially identical and can vary based on the respective positions and connections to or formations with the side frames and the bolster. For example, the two bearings of any set of warp restraints may be different. It should also be appreciated that the warp restraint of the various different embodiments of the present disclosure may be used on a truck (i.e., the various example warp restraints of the present disclosure may be mixed on single truck or railroad car). 
     More specifically, example warp restraint  2300  includes a first bearing  2310  integrally formed with a first portion of the bolster  2040  and a second opposing bearing  2340  integrally formed with the first side frame  2060 . It should be appreciated that the first bearing  2310  may be connected to the bolster  2040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  2340  may be connected to the bolster  2040  by one or more suitable second bearing connecters (not shown). 
     As shown in  FIGS. 14 and 15 , the first bearing  2310  includes: (a) a substantially horizontally extending mounting bracket  2312  integrally connected to the bolster  2040 ; (b) a rotatable engagement roller  2314  rotatably connected to the mounting bracket  2312 ; and (c) a pivot pin  2315 . The rotatable engagement roller  2314  is rotatably connected to the mounting bracket  2312  by the pivot pin  2315 . The engagement roller  2314  includes a substantially cylindrical engagement surface  2314   a  which at any point in time in its rotation includes a portion or engagement edge that is configured to engage the second bearing  2340 . In this illustrated embodiment, the engagement roller  2314  is rotatable about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin  2315 . It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  2312 , the engagement roller  2314 , and the pivot pin  2315  can be configured such that the engagement roller  2314  is rotatable about a differently extending axis. 
     In this illustrated embodiment, the portion or engagement edge of the engagement roller  2314  and/or the engagement surface  2314   a  that engages bearing  2100  extends in the same direction (such as parallel) to the centerline, center plane, or center axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement roller  2314  and/or the engagement edge of the engagement surface  2314   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly to provide the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, or minimize warping of the side frames  2060  and  2080  relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement edge of the engagement roller  2314 ; relative to: (b) a plane extending through the side frame  60  may be right (as shown in  FIGS. 14 and 15 ), may be obtuse, or may be acute. 
     As also shown in  FIGS. 14 and 15 , the second bearing  2340  includes: (a) a substantially vertically extending side frame mounting wall  2342  integrally connected to the outer surface of the side frame  2060 ; (b) a substantially vertically extending engagement wall  2344  integrally connected to the side frame mounting wall  2342  and extending inwardly transversely from the side frame mounting wall  2342 ; (c) a substantially vertically extending engagement pad  2346  integrally connected to the engagement wall  2344 ; and (d) a plurality of substantially horizontally extending braces (such as brace  2348   a ) each integrally connected to the side frame mounting wall  2342  and integrally connected to the engagement wall  2342 . The engagement wall  2344  includes an inner substantially vertically extending engagement side  2344   a . The engagement pad  2146  includes an inner substantially vertically extending engagement surface  2346   a.    
     In this illustrated embodiment, the engagement wall  2344 , the engagement side  2344   a , the engagement pad  2346 , and the engagement surface  2346   a  also extend in the same direction (such as parallel) to the centerline, center plane, or central axis of the bolster (that in turn extends transversely relative to straight tracks). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  2344 , the engagement side  2344   a , the engagement pad  2346 , and/or the engagement surface  2346   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, and/or minimize warping of the side frames relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  2344 , along the engagement side  2344   a , through the engagement pad  2346 , or through the engagement surface  2346   a ; relative to: (b) a plane extending through the side frame  2060  may be right (as shown in  FIGS. 14 and 15 ), may be obtuse, or may be acute. 
     The first bearing  2310  and the second opposing bearing  2340  are thus configured to engage each other (as shown in  FIGS. 14 and 15 ). More specifically, the engagement edge of the engagement roller  2314  is configured to engage the engagement surface  2346   a  of the engagement pad  2346  (as shown in  FIGS. 14 and 15 ). The configuration of the warp restraint  2300 , and specifically the configuration of the first bearing  2310  and the second opposing bearing  2340 , bias or co-act to provide biasing forces on the bolster  2040  and the side frame  2060  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     Likewise, example warp restraint  2400  includes a first bearing  2410  integrally formed with a first portion of the bolster  2040  and a second opposing bearing  2440  integrally formed with the first side frame  2060 . It should be appreciated that the first bearing  2410  may be connected to the bolster  2040  by one or more suitable first bearing connecters (not shown). It should also be appreciated that the second bearing  2440  may be connected to the bolster  2040  by one or more suitable second bearing connecters (not shown). 
     More specifically, as shown in  FIGS. 14 and 15 , the first bearing  2410  includes: (a) a substantially horizontally extending mounting bracket  2412  integrally connected to the bolster  2040 ; (b) an engagement roller  2414  rotatably connected to the mounting bracket  2412 ; and (c) a pivot pin  2415 . The engagement roller  2414  is rotatably connected to the mounting bracket  2412  by the pivot pin  2415 . The engagement roller  2414  includes a cylindrical engagement surface  2414   a  which at any point in time in its rotation includes a portion or engagement edge that is configured to engage the second bearing  2440 . In this illustrated embodiment, the engagement roller  2414  is rotatable about a horizontally or substantially horizontally extending axis (not shown) extending through the pivot pin  2415 . It should be appreciated that in various alternative embodiments of the present disclosure, the mounting bracket  2412 , the engagement roller  2414 , and the pivot pin  2415  can be configured such that the engagement roller  2414  rotates about a differently extending axis. 
     It should be appreciated that in various alternative embodiments of the present disclosure, the engagement roller  2414  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, and/or minimize warping of the side frames  2060  and  2080  relative to the bolster  2040 . Thus, in various embodiments, the angle between: (a) a plane extending through the engagement pad  2414  or along the engagement edge of the engagement surface  2414   a ; relative to: (b) a plane extending through the side frame  2060  may be right (as shown in  FIGS. 14 and 15 ), may be obtuse, or may be acute. 
     As also shown in  FIGS. 14 and 15 , the second bearing  2440  includes: (a) a substantially vertically extending side frame mounting wall  2442  integrally connected to the outer surface of the side frame  2040 ; (b) a substantially vertically extending engagement wall  2444  integrally connected to the side frame mounting wall  2442  and extending inwardly transversely from the side frame mounting wall  2442 ; (c) a substantially vertically extending engagement pad  2446  integrally connected to the engagement wall  2444 ; and (d) a plurality of substantially horizontally extending braces (such as braces  2448   a ,  2448   b ,  2448   c , and  2448   d ) each integrally connected to the side frame mounting wall  2442  and integrally connected to the engagement wall  2444 . The engagement wall  2444  includes an inner substantially vertically extending engagement side  2444   a  (that extends substantially parallel with the crosswise axis of the bolster). The engagement pad  2446  includes an inner substantially vertically extending engagement surface  2446   a  (that extends substantially parallel with the crosswise axis of the bolster). It should be appreciated that in various alternative embodiments of the present disclosure, the engagement wall  2444 , the engagement side  2444   a , the engagement pad  2446 , and/or the engagement surface  2446   a  is: (a) angled outwardly; (b) angled inwardly; (c) angled upwardly; (d) angled downwardly; (e) angled outwardly and upwardly; (f) angled outwardly and downwardly; (g) angled inwardly and upwardly; or (h) angled inwardly and downwardly, to assist in providing the desired forces on the bolster  2040  and the side frames  2060  and  2080  to reduce, inhibit, or minimize warping of the side frames relative to the bolster as further described below. Thus, in various embodiments, the angle between: (a) a plane extending through the engagement wall  2444 , along the engagement side  2444   a , through the engagement pad  2446 , or through the engagement surface  2446   a ; relative to: (b) a plane extending through the side frame  2060  may be right (as shown in  FIGS. 14 and 15 ), may be obtuse, or may be acute. 
     The first bearing  2410  and the second opposing bearing  2440  are thus configured to engage each other (as shown in  FIGS. 14 and 15 ). More specifically, the engagement edge of the engagement roller  2414  is configured to engage the engagement surface  2446   a  of the engagement pad  2446  (as shown in  FIGS. 14 and 15 ). The configuration of the warp restraint  2400 , and specifically the configuration of the first bearing  2410  and the second opposing bearing  2440 , bias or co-act to provide biasing forces on the bolster  2040  and the side frame  2060  toward the normal square position to reduce, inhibit, and/or minimize warping. 
     It should also be appreciated that the rollers of the warp restraints are identical in the illustrated embodiments, but may be different, and in particular may have different roller sizes (such as different roller outer diameters or different roller elasticity or spring characteristics). 
     In this illustrated example embodiment, the engagement pads  2346  and  2446  are steel and the rollers  2314  and  2414  are made from steel. It should be appreciated that these engaging components can be made from other suitable materials. 
     In various such embodiments, before replacement but after the wear members are worn to a certain degree, suitable shims (not shown) may be employed to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more of the first and second bearings can include one or more biasing members (not shown) to maintain engagement between the respective sets of first and second bearings. 
     In various other such embodiments, one or more adjustment devices (not shown) can be used with the bearing members to maintain engagement between the respective sets of first and second bearings. In various embodiments, the adjustment devices include opposing threaded members that are rotatably adjustable to maintain engagement between the respective sets of first and second bearings. 
     Warp restraints  2700  and  2800  of the present disclosure are identical to warp restraints  2300  and  2400  except that warp restraints  2700  and  2800  are attached to the second side frame  2080  and the second portion of the bolster  2040 . 
     It should be appreciated that bearing  2110  (and specifically the mounting bracket  2112  thereof), bearing  2210  (and specifically the mounting bracket  2212  thereof), bearing  2510  (and specifically the mounting bracket thereof), and bearing  2610  (and specifically the mounting bracket thereof) can be integrally cast with the bolster  2040  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  2140  (and specifically the mounting wall  2142  thereof) and bearing  2240  (and specifically the mounting wall  2242  thereof) can be integrally cast with the side frame  2060  in various embodiments of the present disclosure. Likewise, it should be appreciated that bearing  2540  (and specifically the mounting wall thereof) and bearing  2640  (and specifically the mounting wall thereof) can be integrally cast with the side frame  2080  in various embodiments of the present disclosure. 
     In further alternative example embodiments of the railroad car truck with warp restraints of the present disclosure that are not shown, the railroad car truck with warp restraints includes: (a) the third plurality or set of warp restraints  2300  and  2400 ; and (b) the fourth plurality or set of warp restraints  2700  and  2800 , but does not include: (1) the first plurality or set of warp restraints  2100  and  2200 ; and (2) the second plurality or set of warp restraints  2500  and  2600 . 
     It should be appreciated that the warp restraints of the present disclosure do not need to be identical or substantially identical and can vary based on the respective positions and connections to or formations with the side frames and the bolster. For example, the two bearings of any set of warp restraints may be different. It should also be appreciated that the warp restraint of the various different embodiments of the present disclosure may be used on a truck (i.e., the various example warp restraints of the present disclosure may be mixed on single truck or railroad car). 
     Additional Embodiments and Disclosure 
     It should be appreciated that in various embodiments and in various circumstances, the warp restraints of the present disclosure may also act to provide other biasing forces to the bolster relative to the side frames and/or may co-act with one or more other components of the railroad car truck to provide other biasing forces to the bolster relative to the side frames. These other biasing effects of the warp restraints of the present disclosure can be considered as secondary potential biasing effects. 
     More specifically, known prior art railroad cars trucks typically have bolsters that have free lateral or transverse movement relative to the side frames of around +/−½ inches, where the end of that lateral or transverse travel is limited by or arrested by stopping members that are often called “Gibs”. Gibs are the physical blocks that prevent movement beyond this travel allowance. In certain embodiments of the present disclosure, the warp restraints replace or act with certain of the Gibs. 
     In the case where the warp restraints of the present disclosure replace certain of the Gibs, the bearings can perform certain of the functions of the Gibs. In the case where the warp restraints of the present disclosure do not replace the Gibs, the warp restraints will allow for limited lateral movement of the bolster relative to the side frames. In certain embodiments, depending upon the position, shape, and angles of the bearings, the warp restraints may assist or help to limit the lateral movement of the bolster relative to the side frames. 
     In another example of possible secondary biasing forces provided by the warp restraints of the present disclosure, the warp restraints may co-act with the springs or spring groups of the truck to provide biasing forces to the bolster relative to the side frames. The lateral or transverse movement of the bolster relative to the side frames is partially controlled by the equilibrium preference of the spring group on which the bolster rides. In other words, the spring groups provide lateral as well as vertical elasticity to the interaction between the bolster and the springs. More specifically, in certain embodiments of the warp restraints lateral biasing forces (beyond that provided by the spring group) are expected to be produced. 
     Thus, in certain circumstances and certain embodiments of the present disclosure, if the bolster moves laterally or transversely outwardly relative to the side frame, the warp restraints may be expected to exert certain biasing forces on those respective bearings, that will in turn transfer such forces to the bolster and the side frame to cause the bolster to move in an opposite direction laterally or transversely inwardly relative to the side frame and return to its normal position. Likewise, in certain circumstances and embodiments of the present disclosure, if the bolster moves laterally or transversely inwardly relative to the side frame, the warp restraints may be expected to exert certain biasing forces on those respective bearings, that will in turn transfer such forces to the bolster and the side frame to cause the bolster to move in an opposite direction laterally or transversely outwardly relative to the side frame and return to its normal position. 
     The warp restraints of certain embodiments of the present disclosure can also inhibit or reduce longitudinal movement of the bolsters relative to the side frames depending upon the shape and angles of the bearings. For example, if the bolster begins to move forward longitudinally relative to the side frame, the bearings can, in certain configurations, exert biasing forces on those respective bearing that will in turn transfer such forces to the bolster and the side frame to cause the bolster to move in an opposite direction rearwardly longitudinally relative to the side frame and return to its normal position. Likewise, if the bolster begins to move rearward longitudinally relative to the side frame, certain of the warp restraints can, in certain configurations, exert biasing forces on those respective warp restraints, that will in turn transfer such forces to the bolster and the side frame to cause the bolster to move in an opposite direction forwardly longitudinally relative to the side frame and return to its normal position. 
     It should also be appreciated that most movements of the bolster relative to the side frames will likely be in a direction that may be a combination of different directions, and that the warp restraints can act in combination or co-act with one or more other components of the truck to cause the bolster and side frames to move in opposing directions to return to their normal positions; thus, co-acting to prevent, reduce, or inhibit warping while also possibly applying other additional secondary forces as explained above. 
     Additionally, it should be appreciated that the warp restraints of the present disclosure can be employed to take up clearance between the side frame and bolster, thereby producing more resistance to truck warping. 
     As mentioned above, it should be appreciated that the bearings of the warp restraints may be differently formed, and in particular, the bearings may have different sizes such as diameters, thicknesses or widths, elasticity or spring characteristics and shapes. 
     It should be appreciated from the above that that over the expected life of certain of the bearings or engagement members thereof, it is expected that the size or width of the engagement member may decrease due to: (1) abrasion against the surfaces upon which the surfaces of that engagement member; (2) plastic deformation of the engagement member due to compression; (3) corrosion; and/or (4) other degenerative processes. In such case, the present disclosure contemplates replacement of such members, adjustment of the positions of such member (or other members), and/or other devices employed to facilitate necessary engagements. 
     It should further be appreciated that the warp restraints of the present disclosure require relatively little material or weight to the truck to provide additional stiffness. 
     It should be appreciated that in various embodiments, one or more of the surfaces of the bearings do not need any lubrication. 
     It should be appreciated that in various embodiments, one or more of the surfaces of the bearings are self-lubricating. 
     It should also be appreciated that one or more of the surfaces or engagement members will in certain embodiments have a high resistance to compressive forces such as compressive forces caused by warping. Such materials can for example include a composite polyester. 
     It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, and it is understood that this application is to be limited only by the scope of the claims.