GB2247871A - Railcar bogie and bolster - Google Patents

Abstract

A three piece freight rail car bogie with a bogie bolster 14 having distal ends (82, 84) that extend outward of the bogie side frames (10, 12) to beneath the sides of a rail car body and the bolster ends preferably have seats (90) for self leveling sliding bearings (110) which directly support the car body at the side sills. Pref. the bearings fit in concave seats in the bolster. Pref. the bolster has a central pin support (60) and spaced gibs for holding the side frames (10, 12). <IMAGE>

Description

RAILCAR BOGIE AND BOLSTER This invention relates to an improved freight railcar bogie and more particularly is directed to an improved bogie bolster having distal ends that extend outward of the bogie side frames to support the weight of a carbody at its side sills.

Although there are other designs for freight railcar bogies, (also known as "trucks" the preponderance of freight car bogies in domestic U.S. service are known as three piece outboard bearing bogies That is to say the Dogie: comprises three principal parts, namely a floating bogie bolster laterally connecting two side frames; and the side frames are mounted on two wheelsets each including two flanged wheels mounted on an axle. The bogiebolster is spring supported on what is commonly referred to as a "secondary suspension" system for vertical cushioning movement on the side frames. Bearings are mounted on the axles adjacent each wheel and the ends of each side frame are primarily suspended between corresponding bearings on the two axles.In freight car bogie construction there is no significant vertical spring movement of the primary suspension. Where the bearings and side frames are located outboard of the wheels, the bogie is referred to as outboard bearing.

In most rail car assemblies two bogies are required, one at each car end, and the car under frame includes longitudinal side sills and transverse body bolsters, the latter being located directly above the bogie bolsters and serving to transfer the car load to center bearing plates (or bowls) at the geometric center of the bogie bolsters. There is usually also a center sill at the ends of the rail car intersecting the body bolsters which center sills contain coupling gear and serve to transmit longitudinal draft and buff forces to the car body bolster and thence to the bogie bolster.

Examples of other rail car bogie designs may be found in the following United States patents: I. Rail car bogie connecting the car body directly to the bogie side frame: No. 516,935 springs extend directly above the side frames to support the car body without a bogie bolster; No. 900,760 springs extend directly upwardly from each side frame to the car body and a bogie crosspiece is rigidly fastened to both side frames: No. 2,011,918 springs support each side frame on axles outboard of the wheels with rigid cross beams between the side frames, and the car body sits on rollers carried by the side frames; and No. 3,961,584 springs supporting the car body extend upward from side frames that are bolted to a horizontal cross plate.

II. Rail car bogie supporting the car body upon bolster ends outboard of the side frames: No. 731,626 a passenger car body is supported on springs carried on a second transverse beam outboard of side frames that are otherwise connected by a bogie bolster (a second embodiment for freight cars supports the car body on springs seated on a bogie bolster inboard of the wheels); No. 1,211,789 levers pivotally mounted on side frames support the car body on structures inward of the side sills; No. 4,237,791 an inboard bearing bogie has a bolster that carries car supporting pneumatic springs outboard of the wheels.

III. Other: No. 2,046,391 an inboard bearing bogie supports the car body on a bolster centerplate and has auxiliary roller type side bearings on ends of the bolster outboard of the wheels.

From the foregoing prior art and other knowledge of the railroad industry it can be ascertained that freight car construction, as contrasted to passenger car construction, favors a minimum of bogie parts and simplified suspension systems so as to reliably carry heavy loads at minimum operating expense and low original eauipment cost. Simplicity of design with minimum weight and number of parts will usually contribute toward those goals. Additionally the industry seeks rail car dynamic stability for operating safety; and efforts to lower a car center of gravity and to reduce car roll will contribute toward that goal.

Viewed from one aspect the invention provides a rail car bogie having a transverse bogie bolster carried on springs in side frames, wherein distal ends of said bogie bolster extend outwardly of said side frames and are arranged constantly to carry the weight of a car body thereon.

There is thus provided, a rail car bogie that will resist the tendency of a rail car body to roll from side to side.

A preferred embodiment provides a rail car bogie that will enable weight reduction in the car body structure.

The preferred rail car bogie supports a car body at the side sills on the secondary suspension system of a floating bolster.

The present invention also provides a bogie bolster for a three piece freight rail car bogie wherein the ends of a floating bolster extend outwardly beyond the side frames to beneath the car sides to directly carry a car body at the body side sills and thereby permit elimination of the heavy center bearing and redesign of the car body bolster with consequent weight savings.

Certain embodiments of the invention will now be described, by way of example only, with reference to the drawings, wherein: Figure 1 is a perspective view from beneath a car body (partially shown) and car bogie incorporating an embodiment of the present invention; Figure 2 is a perspective view from above the car bogie of Figure 1 with car body removed; Figure 3 is a partial (half) detail view of a bogie bolster in accordance with the present invention; Figure 4 is a plan view of the bolster (half) of Figure 3; Figure 5 is a sectional elevation view of the bolster (half) of Figure 4; Figure 6 is a perspective view of one bolster bearing embodiment of the preferred embodiment; Figure 7 is a side elevation of the bolster bearing of Figure 6; Figure 8 is an end elevation of the bolster bearing of Figure 6; and Figure 9 is a perspective view of another embodiment of a bolster bearing suitable for use in the present invention.

As shown in Figures 1 and 2 a preferred embodiment of the present invention is directed to a three piece outboard bearing rail car bogie comprising two side frames generally 10, 12 and a uniaue transverse bolster generally 14 that extends substantially the full width of a railcar and is supported on a secondary suspension system comprising coil springs 16, 18 mounted on the side frames 10, 12 respectively.

Each of the side frames, usually of cast steel, includes an upper compression member 20, a lower tension member 22 having a spring seat 24 and two pedestal jaws 26, 28. The latter are supported upon journal bearings 34, 36 fitted upon a pair of axles 40, 42 outboard of wheel sets 44, 46 and 48, 50, respectively.

According to the illustrated embodiment the bolster 14, preferably also of cast steel, has a box-like body 52 with top wall 56, bottom wall 54 and interconnecting side walls 58. A pin receptor 60 is centrally located in top wall 56 and two distal ends 62, 64 extend outwardly of the body 52 at a distance from receptor 60 beyond the side frames 10, 12. Each distal end 62, 64 includes flat, horizontal, surfaces 68 adapted to directly carry a rail car body generally 80 at or adjacent the side sills 82, 84 thereof. Preferably the bolster also includes an interior web 66 parallel to and central of the side walls 58.

As shown in FIGURES 3-5, the surfaces 68 of distal ends 62, 64 are provided with seats 70 to receive friction side bearings generally 110 (more fully described hereinafter) to permit controlled sliding movement between the bolster ends 62, 64 and the railcar body 80. Preferably the seats 70 have concave spherical segment surfaces 74, so as to receive convex concentric undersurfaces on bearings 110, which permit the bearings to tilt in all directions and thereby enable the bearings 110 to be self-adjusting to the railcar body 80.It will also be seen in FIGURES 3-5 that the ends of bolster 14 incline inwardly from top to bottom (so as to keep within the American Association of Railroads standard clearance line at track side) and accordingly it is advantageous to locate the low point of seat spherical surface 74 slightly offset inwardly (toward the receptacle 60) from the center of the concave seat 70. Additionally, it will be noted that the spherical surface 74 extends smoothly to the horizontal surface 68 in a direction transverse of the bolster 14 but in the direction of the bolster axis is truncated by shallow transverse arcuate walls, namely an inner cylindrical wall 76 and an outer conical wall 78 both such arcuate walls having radii from the center of pin receptor 60.

As illustrated in FIGURE 1, it is convenient to locate an outrigger member 86 between each car side sill 82, 84 and the corresponding bolster distal ends 62, 64. In the preferred embodiment, the outriggers 86 are permanently secured to the car body 80 at the side sills 82, 84 and the underside of each outrigger 86 may have a wear pad 88 that slidingly rests on the respective side bearing 110 at each bolster end.

The car load is thus supported on the distal ends 62, 64 of bolster 14 and transmitted to the side frames 10, 12 through springs 16, 18. In accordance with prior three piece bogies the bolster 14 is movable vertically within each side frame between vertical columns 90, 92 and is provided with inner and outer column positioning gibs 94, 96 and friction shoe pockets 98. Since the present bolster 14 supports the car load at its ends 62, 64, the vertical dimension of the bolster at the pockets 98 is slightly greater than prior bolsters to withstand higher bending moments and the side frames 10, 12 and vertical columns 90, 92 are slightly higher to accommodate the greater vertical dimension of the bolster ends.

It will be understood that the present invention provides for supporting the weight of a car body 80 at the side sills 82, 84 rather than upon a center sill 100 which heretofore has been the standard practice for freight car construction. In this way the car under frame structure may be simplified and lightened and the need for a traditional transverse body bolster above each bogie bolster may be eliminated. The bogie bolster 14 thus does not require a center bearing bowl to support the car body, however, a central vertical connection such as a column or pin (not shown) is located between the receptor 60 on bolster 14 and the car center sill 100 so as to establish a center of rotation between bogie and car body and to transmit horizontal forces between bogie and car body.

Since the bolster 14 will turn beneath the car body 80, it is preferred to relieve the bolster distal end corners 102 so that no part of the bolster 14 will extend beyond the car side sills 82, 84 or the American Association of Railroads (AAR) standard clearance line at track side during curving.

In one embodiment for light weight car bodies each friction side bearing 110 received in seats 70 at the ends 62, 64 of bolster 14 is provided with a multi-friction means that functions to provide sufficient frictional engagement with pads 88 to control bogie hunting (transverse oscillations) even under no load (empty rail car) or low load conditions, yet also allow for relative turning (bogie curving) movement under a fully loaded condition. This is accomplished with a bearing member generally 110, shown in FIGURES 6-8, having a major friction body 112 comprised of a relatively low friction material such as teflon coated machined steel that has a first relatively low friction coefficient F1 of about .05-.07, which surrounds one or more secondary friction bodies 114 of relatively higher friction material such as cast steel that has a second friction coefficient F2 of about .35.Each secondary friction body 114 is received in a cavity 116 in the major friction body 112 and is biased outwardly by a spring 118. Both major and secondary friction bodies 112, 114 have flat upper friction surfaces or faces 120, 122 that bear against the pads 88 on car body outrigger 86. It will be understood that the frictional resistance to sliding motion between each bearing member 110 and corresponding pad 88 of a loaded car will have two components. One component R-l will be the product of the car weight (including load), the area of friction face 120 of the major friction body 112 and the first coefficient of friction F1. The second component R-2 will be an essentially constant product of the force of spring 118, the total area of secondary friction faces 122 of the secondary friction bodies 114 and the second coefficient of friction F2.The second component is, by selected design parameters, made sufficient to control the tendency of a given bogie configuration to hunt at expected empty car operating speeds.

In another embodiment for heavy weight car bodies and general application, a bearing member generally 110', shown in FIGURE 9, having a single friction means is received in each seat 70. The bearing member 110' comprises a solid body 112' having uniform friction face 120' either coated with a low friction material or supporting a pad 120a' of a low friction material such as an ultra high molecular weight polymer or the like.

Both bearing member embodiments generally 110 and 110' are preferably in the form of a slightly arcuate body 112, 112' or shoe that is substantially congruent with the concave seat 70 and have a convex and preferably spherical undersurface 124 that is slightly smaller and received in the concave seat 70 on the surface 68 of each distal end 66, 64 of bolster 14. In this way each bearing member 110 will be free to tilt transversely and longitudinally of the car so as to be self leveling against its respective Pad 88 under the weight of the car body 80.

It will be seen in FIGURES 6-9 that for each embodiment of the bearing members the body includes concentric arcuate end walls 136, 138 and straight side walls 140, 142 extending between the spherical undersurface 124 and the friction face 120. The arcuate end walls 136, 138 are formed to be concentric with the respective inner cylindrical wall 76 and outer conical wall 78 of a bearing seat 70 and the bearing body 112 is sized to fit therein. Accordingly, for a bolster of 9 foot 11 7/8 inch maximum dimension, the bolster distal ends 62, 64 are 16.88 inches wide and terminate in outer arcs having radii of 59.94 inches. The outer end and side walls of each bearing seat are approximately 1/2 inch thick and the inner cylindrical wall is formed on a radius of 50.56 inch (all radii measured from the center of the bolster pin receptor 60). It is desirable that each bearing member 110, 110' be sized to leave a peripheral gap of about .44 inch between its peripheral walls 136, 138, 140 and 142 and the perimeter of the bearing seat 70. Accordingly, the bearing bodies 112, 112' are cast to be approximately 15 inches between side walls 140, 142 and 8 inches between arcuate walls 136, 138 with inner wall 136 formed on a radius of 51 inches and the outer conical wall 138 formed from a top radius of 59 inches. The convex spherical undersurface 124 of each bearing member and the concave spherical surface 74 of bearing seat 70 are typically formed on radii of 15 inches.

For the one embodiment bearings 110 of FIGURES 6-8 the second friction bodies 114a and 114b may typically comprise discs of 4 inch diameter.

Variations and modifications may be made without departing from the scope of the invention which is defined in the following claims.

Claims (21)

CLAIMS:

1. A rail car bogie having a transverse bogie bolster carried on springs in side frames, wherein distal ends of said bogie bolster extend outwardly of said side frames and are arranged constantly to carry the weight of a car body thereon.

2. The rail car bogie of claim 1 including bearing means on each of said distal ends.

3. The rail car bogie of claim 2 including a sliding bearing means on each of said distal ends.

4. The rail car bogie of claim 1, 2 or 3 including recessed concave seats on each of said distal ends at locations to position bearings means therein beneath the side sills of a car body.

5. The rail car bogie of claim 4 wherein said concave seats include concentric arcuate inner and outer end walls on radii measured from the vertical center of said bogie bolster.

6. The rail car bogie of claim 5 wherein said outer end wall is conical.

7. The rail car bogie of claim 4, 5 or 6 wherein said concave seats include generally spherical bearing surfaces.

8. The rail car bogie of claim 7 including bearing means having substantially planar surfaces for constantly carrying the rail car body below the side sills thereof and having a generally spherical undersurface opposite said planar surfaces, said undersurfaces being congruent with said seats.

9. The rail car bogie of any preceding claim, in combination with a rail car body and an outrigger positioned between each said distal end and a side sill of said car body.

10. A rail car bogie bolster for use in a bogie as claimed in any preceding claim comprising: a box like body having upper and lower walls and side walls therebetween; a pin receptor centrally located in said upper wall; gibs on said side surfaces spaced from said pin receptor, said gibs adapted to position said bolster with respect to sideframes of a bogie; distal ends on said bolster extending beyond said gibs distances sufficient to support a rail car at about the side sills thereof.

11. The bogie bolster of claim 10 including bearing seats adjacent the bolster ends.

12. The bogie bolster of claim 11 including recessed concave bearing seats on each of said distal ends at locations to position bearing means therein beneath said side sills.

13. The bogie bolster of claim 12 wherein said bearing seats are recessed into the top suface of the bolster and have arcuate surfaces to facilitate leveling of bearings placed therein.

14. The bogie bolster of claim 13 wherein said recessed bearing seats include concentric arcuate inner and outer end walls on radii measured from said pin receptor.

15. The bogie bolster of claim 14 wherein said outer end wall is conical.

16. The bogie bolster of claim 13, 14 or 15 wherein said arcuate surfaces are spherical segments.

17. The bogie bolster of any of claims 10 to 16 including bearing means on each of said distal ends.

18. The bogie bolster of claim 17 including a sliding bearing means on each of said distal ends.

19. The bogie bolster of claim 17 or 18 wherein said bearing means includes convex undersurfaces and substantially planar upper surfaces for constantly bearing against and fully supporting a rail car body.

20. A rail car bogie substantially as herein described with reference to the accompanying drawings.

21. A rail car bogie bolster substantially as herein described with reference to the accompanying drawings.