Railway Car Center Bearing

Abstract

The bolster bowl of a railcar truck bolster is lined with a horizontal wear plate disposed across the bottom of the bowl and a wear ring positioned along the side of the bowl. The wear ring is engaged with retaining means carried by the bowl rim for holding the ring in position. The engagement between the retaining means and the wear ring is such that no rigid connection exists between the two, or in other words the highly stressed ring is not provided with rigid connections which are subject to failure. The retaining means may take the form of an annular plate welded to the bowl rim and overlapping the upper end of the wear ring, a groove in the bowl rim which receives a rib on the ring, a rib on the bowl rim which engages and projects into a groove on the ring; and a backing ring surrounding the wear ring and connected thereto through an intervening elastomeric layer. Also, the wear ring at its lower end may turn under the wear plate so that the weight of a railcar body on the wear plate will hold the wear ring in place.

Description

BACKGROUND OF THE INVENTION

This invention relates in general to railcar truck bolsters and, more particularly, to hardened liners for the bowls on the truck bolsters.

Broadly speaking, the conventional means for joining a railcar truck with the car body it supports is nothing more than a cylindrical socket cast into the truck bolster and a mating cylindrical boss attached to the body bolster which forms part of the car body underframe. This construction prevents the car's trucks from shifting laterally or longitudinally with respect to the car frame and body, but nevertheless allows them to rotate under the car frame. The cylindrical socket is termed a bolster bowl, while the mating cylindrical boss is often called a center plate.

Since the weight of the entire car body is normally transmitted to the supporting bolster through the center plates and mating bolster bowls and further in view of the fact that considerable friction develops at the engaged surfaces of the center plates and bowls, the cast bowls wear relatively rapidly. This wear in time renders both the center plates and truck bolsters unserviceable. While the former are easily replaced, the latter are not and indeed necessitate a complete disassembly of the car trucks for replacement.

To alleviate the foregoing wear problem and thereby extend the life of truck bolsters, manufacturers of bolsters have fitted hardened steel liners in the bolster bowls. These liners each normally comprise a circular horizontal plate which fits into the bottom of the bowl and an annular wear ring which extends around the side of the bowl. Each liner is held in place by a weld which bridges the upper end of the wear ring and the encircling cast rim defining the bolster bowl. When welds of this nature are employed on the truck bolsters of railcars which experience extremely rough handling, such as the cars used to transport bulk commodities, they have exhibited a tendency to crack. Failure of the weld, of course, frees the wear ring so that it no longer serves its purpose.

It is believed that failure of the welds is occasioned by the fact that the wear rings are not truly concentric with the cylindrical bowl surfaces against which they fit, the deviation being due to the fact that the rings are rolled and not machined into a circular configuration. While rolling operations are inexpensive in comparison to machining operations, they do not create precise circular shapes. Where deviations exist between the concentricity of a cylindrical bowl surface and wear ring fitted therein, extreme stresses develop in the welds at those points of deviation when the railcar is subjected to severe impacts. These stresses in turn create cracks which propagate through the entire weld and bring about the failure of the weld.

It is also reasoned that the welds are inherently weak since they are not made in a common steel. In particular, the wear ring is usually a manganese steel, whereas the truck bolster and its integral bowl are usually a cast mild steel. A weld joining these two different steels is usually not as strong a weld joining components formed from either one of the steels.

OBJECTS OF THE INVENTION

One of the principal objects of the present invention is to provide retaining means for securely retaining a hardened liner in the bolster bowl of a railcar truck bolster. Another object is to provide a liner which will remain in the bolster bowl even when subject to extremely severe shocks. An additional object is to provide retaining means of the type stated which are extremely simple in construction. A further object is to provide a liner wear ring which distributes the impact forces over a wide area. Still another object is to provide the side of a bolster bowl with a hardened wear ring which is not joined to the encircling bowl at highly stressed areas along the wear ring. These and other objects and advantages will become apparent hereinafter.

The present invention is embodied in a liner for a bolster bowl of a truck bolster. The liner includes a wear plate extending across the bottom of the bowl, a wear ring positioned at the side of the bowl, and means for retaining the wear ring in the bowl. The invention also resides in a method of installing a liner in a bolster bowl. The invention also consists in the parts and in the arrangements and combinations of parts hereinafter described and claimed.

DESCRIPTION OF THE DRAWINGS

In the accompanying drawings which form part of the specification and wherein like numerals refer to like parts wherever they occur:

FIG. 1 is an end view of a rail car underframe supported by a truck bolster having a bolster bowl provided with a liner constructed in accordance with and embodying the present invention;

FIG. 2 is an enlarged fragmentary sectional view of the truck bolster at the bolster bowl;

FIG. 3 is a fragmentary plan view of the truck bolster at its bolster bowl;

FIG. 4 is a fragmentary sectional view of a truck bolster at the bolster bowl and showing a modified liner construction and retaining means therefor;

FIG. 5 is a fragmentary sectional view of a truck bolster and showing another modified liner construction retaining means therefor;

FIG. 6 is a fragmentary sectional view of a truck bolster and showing a further modified liner construction and retaining means therefor;

FIG. 7 is a fragmentary sectional view of a truck bolster and showing still another modified liner and retaining means therefor;

FIG. 8 is a fragmentary sectional view of a truck bolster showing a liner very similar to the liner in FIG. 7, but retained by retaining means of a slightly different nature;

FIG. 9 is a sectional view of a truck bolster showing yet another modified liner and retaining means therefor, and

FIG. 10 is a fragmentary plan view of a truck bolster of FIG. 9.

DETAILED DESCRIPTION

Referring now in detail to the drawings (FIG. 1), 2 designates railcar truck bolster which extends transversely of the railcar of which it forms a part. The truck bolster 2, of course, comprises part of a railcar truck and is the portion of the car truck on which the car body rests. In particular, the truck bolster 2 underlies and is engaged with a body bolster 4 forming part of the underframe for the car body.

The truck bolster 2, which is a unitary casting, includes an enlarged center section 10, a pair of tapered arms 12 merged with the centered section 10 and extending therefrom, and end portions 14 projecting from the reduced ends of the tapered arms 12. The underside of each end portion 14 constitutes a spring seat 16 which engages the coil compression springs (not shown) of the truck. Cast integral with the enlarged center section 10 at the upper surface thereof is an upwardly projecting rim 20 which forms the periphery of an upwardly opening bolster bowl 22 of cylindrical shape and shallow depth.

The body bolster 4, which overlies the truck bolster 2, may be a one piece casting or it may be a welded fabrication. Irrespective of the nature of its construction, the body bolster 4 possesses its greatest thickness at its center where it intersects a centersill 24 which also forms part of the car underframe. At the intersection of the centersill 24 and body bolster 4, a center plate 26 is fastened to the bolster 4. This center plate 26 includes a cylindrical boss 28 which fits into the bolster bowl 22 and an integrally formed rectangular flange 30 which projects from the boss 28 and is secured firmly to the underside of the body bolster 4. The axial dimension of the cylindrical boss 28 exceeds the depth of the bolster bowl 22 so that the body bolster 4 is elevated above the truck bolster 2. Both the center plate 26 at its cylindrical boss 28 and the bolster 2 at the center of its bolster bowl 22 are provided with registered bores through which a center pin 32 extends.

Beyond the centersill 24 and the center plate 26, the body bolster 4 also tapers to a narrower configuration and interposed between these tapered portions of the body bolster 4 and the underlying tapered arms 12 of the truck bolster 2 are side bearings 34 for preventing the underframe and car body from rocking excessively. Actually the side bearings 34 are bolted to the tapered arms 12 of the truck bolster 2 and roll or otherwise bear against hardened bearing plates 36 fastened to the body bolster 4.

The integrally cast bowl rim 20 forming the bolster bowl 22 is on its inwardly presented face machined to form a cylindrical abutment face 40 (FIG. 2). Likewise, the upper end of the rim 20 is machined about the same center to form a shallow annular relief 42 which opens upwardly toward the body bolster 4 and inwardly into socket formed by the rim 20. Also within the confines of the socket defined by the rim 20 the upper surface of the truck bolster 2 is machined to create a flat seat 44, the plane of which is perpendicular to the axial centerline of the cylindrical abutment face 40.

The flat seat 44 supports a horizontal wear plate 46 (FIGS. 2 and 3) of circular shape which extends across and occupies substantially the entire bottom side of the bolster bowl 22. The wear plate 46 is formed from a hard steel such as 11% to 14% manganese steel. The abutment face 40, on the other hand, is lined by a vertical wear ring 48 (FIGS. 2 and 3) which fits tightly against that face 40 and extends inwardly beyond the outer margin of the wear plate 46 so as to retain the wear plate 46 within the bolster bowl 22. The wear ring 48 is likewise formed from a hard steel such as 11 to 14 percent manganese steel. The horizontal wear plate 46 and the vertical wear ring 48 in combination constitute a wear resistant liner 49 for the bolster bowl 22.

Actually, the wear ring 48 is formed from flat bar stock which is beveled at its ends and then rolled into a circular configuration. When the ends are brought together, the bevels thereon form a groove which opens into the interior of the bowl 22. Thus, the wear ring 48 is initially split and this facilitates installation of the ring 48 within the bowl 22. Once the split wear ring 48 is inserted into the bowl 22, it is expanded into tight abutment with the abutment face 40 of the bowl rim 20, and while being held in the expanded condition, its ends are welded together at the inwardly opening groove created by the bevels on those ends, thus forming a butt weld 50 within the ring 48. This weld 50 maintains the ring 48 in its expanded condition. The exposed inwardly presented surface of the weld 50 is ground flush with the inwardly presented surface of the ring 48 so that surface forms a continuous cylindrical surface. Along its upper end the ring 48 is provided with a relief 52 which opens both upwardly and outwardly toward the annular relief 42 on the bowl rim 20. Indeed, the base of the relief 52 aligns with the base of the relief 42 so that the two reliefs 42 and 52 in combination form an upwardly opening recess.

The recess created by the two reliefs 42 and 52 receives an annular retainer plate or ring 54 (FIGS. 2 and 3), and the outer edge of the ring 54 is beveled, as is the opposite edge on the bowl rim 20, so that a V-shaped groove is created between the two beveled edges. At this groove the retainer plate 54 and bowl rim 20 are welded together, thus forming a butt weld 56 along the periphery of the retainer plate 54, and the weld 56 may be continuous or intermittent. The plate 54, as its name implies, serves to retain both the wear ring 48 and the wear plate 46 within the bolster bowl 22. No mechanical or rigid connection, however, exists between the retainer plate 54 and the wear ring 48, the retention being effected solely by the overlapping inner portion of the plate 54. While the retainer plate 54 need not be formed from an exceptionally hard steel, it should be formed from a steel which, from a welding standpoint, is compatible with the steel from which the truck bolster 2 is formed.

As the railcar body having the body bolster 4 extending across its underside is lowered onto the truck provided with the truck bolster 2, the cylindrical boss 28 of the center plate 26 is guided into the bolster bowl 22 on the truck bolster 2. When so fitted the bottom face of the cylindrical boss 28 rests on the wear plate 46, and indeed the weight of the car body is transferred to the truck through the wear plate 46. The cylindrical side wall of the boss 28, on the other hand, is positioned against the inwardly presented face of the wear ring 48. This positioning enables the truck bolster 2 and the truck, of which it forms a part, to rotate relative to body bolster 4 and the car body, but prevents longitudinally or transverse shifting movement between the truck and body bolsters 2 and 4.

Since the wear plate 46 and wear ring 48 are formed from extremely hard steel, they experience little wear as the center plate 26 rotates relative to them. This prolongs the life of the truck bolster considerably. Likewise the wear ring 48, due to its extreme hardness, does not deform under the severe impacts experienced by heavily laden cars in switching, bumping and coupling operations. The wear ring 48 does, however, distribute these impacts over a relatively large area of the softer bowl rim 20 so that extreme stress concentrations do not occur in the truck bolster casting at the bowl 22 therein.

The retainer plate 54 prevents the wear ring 48 from working out of the bolster bowl 22 as the truck rotates relative to the car body, or in other words, it maintains the wear ring 48 in the proper position. Inasmuch as the wear ring 48 is not welded or otherwise rigidly attached directly to the bowl rim 20 or to the retainer ring 54 no welds or other rigid connections are located where they will be subjected to extremely high stress concentrations when the rail car experiences severe impacts. In other words, no weld extends along highly stressed areas of the wear ring 48. In this connection, it should be noted that the weld 56 is not in the wear ring 48, but is instead in the retainer ring 54, and its sole purpose is to prevent the wear ring 48 from working out of the bolster bowl 22. The impacts to which the wear ring 54 is subjected are absorbed in the cast bowl rim 20 and not in the butt weld 56. Consequently, the weld 56 remains intact, even through severe operating conditions.

When the wear plate 46 and the wear ring 48 wear out, they are merely replaced. This is achieved by breaking the butt welds 56 and 50 and then removing the retainer plate 54, the wear ring 48, and the wear plate 46 in that order. The foregoing parts are then replaced according to the procedures previously discussed. The replacement thus saves the cost of a new bolster casting in addition to the cost of disassembling the truck. The center plate 26 is replaced at relatively little expense when it is no longer serviceable.

It is possible to provide the bolster bowl 22 on the truck bolster 2 with a modified liner 60 (FIG. 4) which is very similar to the liner 49 previously discussed. The liner 60 includes the wear plate 46 at the bottom of the bowl 22 and further includes a wear ring 62 which is initially split so that it can be contracted and inserted with ease into the bowl 22. Once inserted the wear ring 62 is mechanically expanded against the cylindrical abutment face 40, and while held in its expanded condition, its end edges are welded together to form a butt weld 64. That butt weld 64 is ground off flush with the inwardly presented face of the ring 62. At its upper end, the wear ring 62 is provided with an outwardly and upwardly opening relief 66 which aligns with a similar relief 68 in the rim 20 of the bolster bowl. Indeed, the reliefs 66 and 68 face one another so as to form an upwardly opening recess, and set into this recess is a retainer ring 70. Along its outer periphery, the retainer ring 70 is attached to the bowl rim 20 by a lap weld 72.

The modified liner 60 is installed in the same manner as the liner 49 and likewise functions in the same manner as the liner 49.

It is possible to provide the bolster bowl 22 with still another modified liner 80 (FIG. 5), and that liner 80 also includes the same wear plate 46 at the bottom of the bolster bowl 22. The liner 80 additionally includes a wear ring 82 which is initially split so that it can be inserted into the bolster bowl, and is further provided with an outwardly opening circumferential groove 84 midway between its ends. The rim 20 of the bolster bowl 22, on the other hand, includes an integrally formed retaining rib 86 which aligns with and projects into the circumferential groove 84 when the wear ring 82 is inserted fully into the bolster bowl. The rib 86 interlocks with the wear ring 82 and prevents it from working out of the bolster bowl 22. The wear ring 82 is maintained in its expanded condition by means of a butt weld 88 which is ground flush with the inwardly presented surface of the ring.

To install the wear ring 82 in the bolster bowl 22, the ring 82 is first contracted to a size small enough to pass beyond the retaining rib 86. Once the ring 82 is fully inserted into the bolster bowl 22, it is mechanically expanded so that its outwardly presented faces abut snugly against the abutment face 40 on the bowl rim 20. While the ring 82 is mechanically held in its expanded condition, its ends are welded together, thus forming the butt weld 88. The wear ring 82 may initially be a unitary member having detached ends which are subsequently welded together or it may initially be in two or more segments which are welded together at their ends once they are installed in the bolster bowl 22.

It is possible to provide still another modified liner 90 (FIG. 6) which is very similar to the liner 80. The liner 90 includes the flat wear plate 46 at the bottom of the bolster bowl 22 and in addition includes a wear ring 92 which is encircled by the bowl rim 20. The wear ring 92 is in effect the reversal of the wear ring 82, that is, instead of having a circumferentially extending groove, it is provided with an outwardly projecting and circumferentially extending retaining rib 94. The bowl rim 20, on the other hand, is provided with an inwardly opening circumferentially extending groove 96 which aligns with and receives the retaining rib 94. The outwardly presented surface of the wear ring 92 is maintained in snug abutment against the abutment face 40 of the bowl rim 20, and when so disposed the rib 94, of course, interlocks with the circumferential groove 96. The wear ring 92 is initially split so that it can be contracted and installed in the bolster bowl 22, and once it is installed it is maintained in its expanded condition by means of a butt weld 98 across the formerly detached ends thereof.

It is possible to provide a further liner 100 (FIG. 7) which has the capability of absorbing extremely severe impacts and further distributes those impacts over a relatively broad portion of the bowl rim 20. The modified liner 100 utilizes the same wear plate 46 at the bottom of the bowl 20 and in addition includes a wear ring 102. This wear ring may be formed from flat bar stock rolled into a cylindrical configuration and thereafter welded together along a butt weld 104, or it may be cut from tube stock, in which case it is continuous throughout. Irrespective of the manner in which the wear ring 102 is constructed, it is disposed inwardly from a rigid backing ring 106 which is press fitted into the bowl rim 20. In this connection, the backing ring may be a split ring having spaced apart ends to enable it to contract. Moreover, in that case it would have an initial diameter slightly larger than the diameter of the abutment face 40 and should further be provided with a beveled lower end 108. The wear ring 102 and the backing ring 106 are separated by an intervening layer 110 which is bonded to both of the rings 102 and 106. Finally, the backing ring 106 is joined to the bowl rim 20 along a lap weld 112.

The wear ring 102 is installed in the bolster bowl 22 by aligning the beveled lower end 108 on its backing ring 106 with the abutment face 44 of the bowl rim 22. Thereafter, the backing ring 106 is pressed into the bolster bowl 22, in which case it will contract and pass across the abutment face 44. Once the backing ring 106 and wear ring 102 are fully inserted into the bowl 22, the backing ring 106 is welded to the bowl rim 20 at the lap weld 112.

The liner 100 may be held in place by a retaining ring 114 (FIG. 8) which is very similar to the retaining ring 54 for the liner 49. The ring 114 at its periphery is joined to the bowl rim 20 along a butt weld 116. The ring 114 projects radially inwardly across the backing ring 106 and the intervening elastomeric layer 110 and its inner edge is recessed in a relief 118 formed in the wear ring 102.

It is possible to provide yet another modified liner 120 (FIGS. 9 and 10) for the bolster bowl 22, and that liner includes a horizontal wear plate 122 which rests upon the flat seat 44 at the bottom of the bowl 22. The periphery of the wear plate 122 is set inwardly from the cylindrical abutment face 40, and that abutment face 40 continues downwardly below the flat seat 44 and into an annular relief 124 which in part underlies the wear plate 122. The liner 120 further includes a wear ring 126 which abuts tightly against the abutment face 40 and at its lower end is provided with inwardly turned tabs 128. The wear ring 126 extends downwardly below the peripheral edge of the wear plate 122 and the tabs 128 at its lower end are disposed within the annular relief 124. The tabs 128 are furthermore joined to the underside of the wear plate 122 along an intermittent lap weld 130. Finally, the wear ring 126 at its upper end may be joined to the bowl rim 20 by a lap weld 132.

The wear plate 122 and the wear ring 126 are joined together to form a unitary liner construction before installation into the bolster bowl 22. The liner 120 is installed in the bolster bowl 22 by press fitting the wear ring 126 across the abutment face 40. Thereafter, the lap weld 132 is made, if desired. Since the wear plate 122 along its outer periphery overlies the tabs 128 at the lower end of the wear ring 126, the wear ring will not work out of the bolster bowl even if both of the welds 130 and 132 break.

Moreover, the intermittent lap weld 130 along the tabs 128 prevents the lower end of the wear ring 126 from deforming inwardly under impacts experienced in use. Hence, the wear ring 126 does not become tapered after extended periods of use.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

Claims

What is claimed is:

1. In a truck bolster having an upwardly opening bolster bowl defined by a generally cylindrical sidewall and a bottom wall, the improvement comprising: a wear plate extending across the bottom wall; a liner positioned in the bolster bowl against the generally cylindrical sidewall thereof, the liner being continuous in the circumferential direction and having a continuous inwardly presented wear surface; and a retaining ring fastened firmly to the bolster and projecting over at least a portion of the liner to retain the liner in the bolster bowl, the retaining ring being initially detached from the bolster to permit installation of the liner in the bowl and further being separate from the liner so that stresses imposed on the liner are generally not transferred to the retaining ring.

2. The structure according to claim 1 wherein the liner is a wear ring which is initially split in the axial direction for easy installation in the bolster bowl and is thereafter urged against the cylindrical sidewall of the bolster bowl and welded together at the ends formed by the axial split so that it remains against the cylindrical sidewall.

3. The structure according to claim 2 wherein the wear ring projects into the bowl beyond the periphery of the wear plate so that the wear plate is retained in the bowl by the wear ring.

4. The structure according to claim 3 wherein the retaining means and the wear ring interlock.

5. The structure according to claim 2 wherein the bowl sidewall is a rim cast integral to and projecting upwardly from the bolster; wherein the rim at its upper end has an annular relief which opens inwardly into the bowl; wherein the wear ring has an annular relief which opens outwardly and aligns with the annular relief in the rim; and wherein the retaining ring fits in and substantially fills both reliefs.

6. The structure according to claim 1 wherein the liner includes a backing ring positioned against the cylindrical sidewall of the bolster bowl, a wear ring positioned within the backing ring and having the wear surface thereon, and an elastomeric material interposed between the backing and wear rings.

7. On a truck bolster, the improvement comprising: a bolster bowl member having an inwardly presented sidewall which surrounds a generally flat bottom wall so as to form a bolster bowl in the bolster, the sidewall being of cylindrical configuration, and a wear ring member positioned in the bowl against the cylindrical sidewall, the wear ring member being continuous in the circumferential direction and having a wear surface thereon which is presented inwardly toward the center of the bolster bowl, one of the members having a circumferentially extending rib which projects into a circumferentially extending groove in the other member, the rib being located intermediate the upper and lower ends of the wear ring member and cylindrical sidewall so that the cylindrical sidewall is both above and below the rib, the wear ring member being initially split in the axial direction to enable it to be installed in the bolster bowl and thereafter being urged into facewise abutment with the cylindrical sidewall, the ends formed by the axial split being welded together while the wear ring member is urged against the sidewalls so that the wear ring member remains in abutment with the cylindrical sidewall both above and below the rib.

8. The structure according to claim 7 wherein the rib is on the bolster bowl member and the groove is in the wear ring member.

9. The structure according to claim 7 wherein the rib is on the wear ring member and the groove is in the bolster bowl member.

10. The structure according to claim 7 and further characterized by a flat wear plate positioned against the flat bottom wall and extended beneath the wear ring member.

11. In a truck bolster having an upwardly opening bolster bowl defined by a generally cylindrical sidewall and a bottom wall, the improvement comprising: a wear plate extended over the bottom wall, and a liner covering the sidewall, the liner including a backing ring positioned snugly against and abutting the sidewall, a wear ring positioned inwardly from and encircled by the backing ring, the inwardly presented surface of the wear ring being continuous and forming a wear surface, and an elastomeric material interposed between and bonded to both the wear ring and the backing ring.

12. The structure according to claim 11 and further comprising an annular plate welded to the bowl sidewall and projecting inwardly across the upper end of the backing ring.

13. The structure according to claim 11 wherein the backing ring is initially split in the axial direction and on its outside surface tapers inwardly at its lower end.

14. On a truck bolster, the improvement comprising: a bolster bowl having a generally cylindrical sidewall, a bottom wall at the lower end of the bowl and an annular relief surrounding the bottom wall and extending downwardly therefrom, a wear ring positioned against the cylindrical sidewall, the wear ring being continuous in the circumferential direction and being turned inwardly at its lower end, the inwardly turned portion of the wear ring being disposed within the annular relief, and a wear plate extending across the bottom wall of the bolster bowl and overlying the inwardly turned portions of the wear ring.

15. The structure according to claim 14 wherein the inwardly turned portions of the wear ring are tabs which turn radially inwardly and underlie the wear plate; and wherein the tabs are fastened securely to the wear plate.