US2762317A - Rocking railway journal box - Google Patents

Description

Sept- 11, 1956 P. G. PALMGREN RocxING RAILWAY JOURNAL Box- 7 Sheets-Sheet 1 Filed June 2l, 1950 Sept. l1, 1956 P. G. PALMGREN ROCKING RAILWAY JOURNAL BOX 7 Sheets-Sheet 2 Filed June 2l, 1950 Sept. 11, 1956 P. G. PALMGREN ROCKING RAILWAY JOURNAL Box 7 Sheets-Sheet 3 Filed June 21, 1950 Jaffe/57" Sept. 11, 1956 P. G. |=-ALMGREN RocKING RAILWAY JOURNAL Box Filed June 2l, 1950 7 Sheets-Sheet 4 sept. 11, 1956 P. G. PALMGREN 2,762,317

RocxING RAILWAY JOURNAL Box Filed June 21, 1950 7 Sheets-Sheet 5 Sepfgll, 1956 P. G. PALMGREN 2,762,317

ROCKING RAILWAY JOURNAL BOX Filed June 2l 1950 '7 Sheets-Shogi, 6

Sept 11, 1956 P. G. PALMGREN 2,762,317

ROCKING RAILWAY JOURNAL BOX Filed June 2l, 1950 7 Sheets-Sheet 7 United States Patent RoCKrNG RAILWAY JOURNAL Box Per Gunnar Palmgren, Philadelphia, Pa., assign'or to SKF Industries, Inc., Philadelphia, Pa., a corporation oi Delaware Application June 21, 1950, Serial No. 169,357

6 Claims'. (Cl. 10S-223) This invention relates to a journal box for railway axles arranged to permit limited axial motionof the axle within a self-aligning bearing assembly.

A principal object is to provide a journal'box capable of swinging laterally to accommodate the unavoidabl weaving motion of the axle on the track.

Another object is to construct 'the journal box so that it may follow the weaving motion of the axle by rocking laterally on an outer curved supportingsurface. -Y

Another object is to limit the lateral rocking of the box substantially to the extent'of the relative lateral motion between frame and axle.

Another object is to construct the rocking surface so that it creates a force tending to reverse its direction of swing, said force starting from zero and increasing in value as the box tilts farther from upright position.

Still another object is to construct the rocking surface so that the rocking movement is controlled either by steps or smooth rolling motion against increasingl resistance.

A further object is to contour the interseating surfaces of the box and frame so that the carV load will `produce couples tending to slow down swinging of the axle relatively to the frame. i

In a preferred embodiment, the invention contemplates a railway axle journal box and side frame assembly wherein the axle is afforded the required limited axial oat through freedom of the box to rock inthe frame, the resulting angular displacement of .the box with respect to the axle journal being accommodated through medium of a single self-aligning roller bearing for said journal suitably mounted in the box.

Fig. l shows in sectional elevation the railway journal box of this invention;

Fig. la is a sectional elevational view showing thebox and bearing outer race tilted by movement ofthe axle totheleft;

Fig. 2 is a view similar to Fig. 1 showing another and preferred embodiment of the invention;

Fig. 2a is a view similar to Fig.. la illustrating the mode of operation of the embodiment shown in Fig. 2;

Fig. 3 shows a front elevational view ofthe boxassembled in the side frame of a railway car;Y

Fig. 4 is an end view of theframe and. boxfassembly as viewed from the line 4-4,.Fig..3; y

Figs. 5, 6, 7 and 8 are fragmentary sectional elevational views illustrating modifications within the sc'ope of :the invention, and f' y Figs. 9 and 10 are diagrammatic views illustrating `two different applications of the principles of the invention.

Because of the necessity for axial clearance between wheel ange and rail, and because of Vthe conical Vshape of the wheel rim, there is always a tendency in rail cars for the axle to move back and forth axially whenthe car is in motion. In addition, the rail is never quite straight which also results in axial motion of theaxl. In order to reduce communication of axle motion tov the truck, andvv thence to the car body, journal `bearings of the-plain type are allowed clearance-for axiall oatfbetweenthrust surfaces of journal and of the brass of the bearings. This permits the journals to slide axially across the brass pil-L lows to the limit of the total clearance before'striking the thrust shoulders. 'f

The present invention provides a journal box organization, including a self-aligning anti-friction bearing as'- sembly, wherein the box is aiforded freedom for angulardisplacement of suicient magnitude to accommodate the axial weaving of the axles without communication of undue amounts of that axial motion to the trucks of the' car body. In this organization the self-aligning bearing assembly functions to permit the relative angular move-` ments between the box and the axle which must neces-z sarily accompany the aforesaid angular displacements of the box. "Q

In one embodiment, the invention consists of a journal box 1 provided with a truck frame lsupporting surfacelil` at the top in the form of a segment of a cylinder struck from a horizontal axis through the center 3 of the bea'ry ing, normal to the axis of the journal, ther said surfacel being curved therefore in the direction longitudinally "of the axle. The box is also provided with 'lugs 5d and 5b integral with the box and arranged to limit its angular moi` tion, and to support lateral loads, as its cylindrical vsu face rocks on a at surface 6 in the side frame 7. The boil contains a single self-aligning roller bearing 8 for theaxle journal having an outer raceway surfacem9 of spheric-lf form also centering at 3. The box has a widthconsidf ably greater than that of the side frame 7, -and the sid lugs at the sides have a horizontal spread greater than tli pedestal opening, as in Fig. 4 wherein the box is shown" in the pedestal opening. v Lugs 5a and 5b are spacedfroinl the walls of the side frame by'clearances `10er and 10b which correspond with the amount of rocking resulting Y when the axle moves axially from central to extremele'ft'fi or right, position with respect to the Aside frame. Y When tHe"4 axle moves to the left, the inner face of lug 5a strikes thej adjacent wall 11a of the side frame, while lug 5b strikjes" wall 11b when the axle moves right. Fig. `1 showsuthe box in central vertical positon. It will be noted thatin Fig. 1a the center 3 of the inner racel ofV the bearingjhas moved with axle 12 horizontally to the left, asindicated by arrow A. The box and outer race have rocked through small angle d. r

Fig. 1 shows the self-aligning roller bearing, fat the left] end of the axle, in its upright central'position. The lugs 19a and 1911 at the top of the box, spaced Ifrom the side walls of the frame by small clearances 20a and v20Mb serve!l to position the box close to the center while allowing'the necessary swing. Since the axle would seldom lie perfectly perpendicular to the direction Aof the track, it will-y axle to point 3a. It also carries,y the inner race 13 andy rollers 14 the same distance.y lressure of the load oriv tlie cylindrical top of the box. prevents the latterffromiovl" ing horizontally left but forces it to rock as' illustrated.`

Freedom for this rocking v mc` ve`ment,with its resultant angular displacement of the box with respect tothe axle,-v`v is afforded by the self-aligning bearing which provid's the necessary horizontal axis of oscillation for 'the axle@ journal in the box, said axis intersecting the bearingmcer'v ter 3 normal to the journal axis and paralleling'or ap?" proximately paralleling the aforesaid axis of thel rocking surface 2. Since axial motionof theaxle occurs only; when the train travels, the rollers will -fllow a helical path over the 'outer raceway up' 'tdthe amount of tari-"5'" gential pressure across-.the `contact surfacef9 at which*v ,lttllmbodmeat @which ,theaxs ofthe Cylindrical rocking surface coincides with the center 3 of the spherical outer raceway of the bearing, the outer ring of the bearing and the box will `rock shownlin Fig.v la,'movingthc location of load s upport'to the left fromyerticalplane 16, which contains' ltl'1e centers ofbearingUand of box when in their upright positions, to plane 17 which contains thecenter ofthe bearing -in its shifted position. In this case the box lrocks without raising the frame .relatively to the horizontal centerlineof the axle, encountering only the extremely low resistance of rolling friction, and limited by the striking of thelug 5a against wall 1in of the frame.` Since the line of loading always Ipasses verticallyvthroughthe center 3 of the supporting bea-ring, the, box remains stable .in every rocked position. Forces created by the continual weaving motion among car bodies, frames, trucks and axles, due to conicity of wheel rims, unevenness of tracks, and play between members of truck frames, ac-t to keep the box in oscillation within limits permitted by the lugs.

If the cylindrical truck frame supporting surface is struck from an axis which lies below the bearing center 3, say through the point '4 in Figs. 2 and 2a, so that the surface has a radius longer than the distance from bearing center to the said surface, rocking of thebox as illustrated in Fig. 2a, will move the said axis of the cylindrical surface to 4a, whichis a greater distance than it moves the bearing center. The plane of load application lby the frame to the top of the box will thus have moved from location 16 to location 1S wherein the said plane passes through the shifted point 4a. The plane of load application, therefor, stands a distance g to the left of the support plane 17, so that a couple is created 'tending to reversethe direction of swing of the box, the couple having l a value Ain pounds inches equal to the product of load ture increases as the surface progresses on either side of the plane of symmetry, as illustrated at 2l in Fig. 5, will throw the loading plane further and further beyond the supporting plane, as the box rocks further and further from the vertical position. In other words, the restoring force will increase at a higher rate thanwith a cylindrical surface. When the radius of curvature reaches infinity the surface becomes flat and the loading plane shifts instantly from the center of the at to its edge. A flat surface, therefor, maintains the box in a definite position until the rocking couple overcomes the restoring couple, i. e., until force along the center line of the axletimes its distance from the flat, overbalances the load times onehalf the width of the dat.

Obviously also the tilting characteristic of the box may come in part from an antifriction bearing of the type having its inner instead of its outer race of spherical form, as shown in Fig. 6, wherein the inner race ring is indicated by the reference numeral 22 and the spherical race surface ofthis ring, the center of which correspondsto the center 23 of the bearing, by the reference numeral 24. The rollers 25, in this instance, have concave rolling surfaces conforming to the convex surfaces 24 of the inner race and 26, 26 of the outerrace. The required tilting characteristics may be obtained also by the use of a bearingassembly which includes an adapter for the bearing', see Fig. 7, having a sphericalsnrface 27 for contact with a matching spherical surface 28 within the box, the bearing 29 in this case beingof conventional double row tape-red type. Any such spherical surface combined with a rocking surface in accordance with the principles set forth above will permit lateral motions of the axle and provide the same restoring forces at every location of the loading plane as lin the above described embodiment, the value of those forces depending upon the ratio in that loading plane, of the radius of curvature of the rocking surface to the distance from the bearing center to the rocking surface.

The supporting surface may possess different forms at diterent symmetrical locations on either side of the central plane of the box, which give it an action characteristic. of each location. A supporting surface composed of a series of ats each successively diverging toward the axle at a small angle from the preceding one, would regulate the tilting in steps, as distinguished from the smoother action provided by curves. A polygonal surface of this character is illustrated in Fig. 8 wherein as in the otheriigures theside frame is indicated by the reference numeral 7, and the individual flats of the rocking surface of the journal box by the reference numeral 30. yThe angle between the adjoining flats should not exceed that which would result in the box moving into an unstable position when shifting from one flat to another, i. e the center of the bearing should never advance l frame, and Figures 2, 5 and 7 illustrate organizations in which 'restoring couples rcome into play as soon as the box `starts tilting from vertical position, and increase with continued tilting. The principle of the inventori, however, as indicated above, may tind other embodiments.-

In one lmodification, Fig. 9, the frame surface 41, or if desired a supplementary surface attached thereto, is

` concave in form so as to embrace the convex seating surface 42 on the box. With this arrangement, and for any given angular displacement of the box, the axial displacement of the interseating lor contact area between the surfaces will be not only greater than the axial displacement of the bearing center, but the ratio will be relatively high. Thus, a displacement of the bearing center 3, Fig. 9, from the vertical .plane 43 tothe point 3a,'will be accompanied by an axial movement of the contact area from the plane 43 to the vertical plane 44. This affords a relatively quick and large restoring couple which may be indicated by the arrows 45 and 46.

In another modification, Fig. l0, the frame may present a convex seating surface 47 to a convex box surface 48. With this arrangement the contact area betweenv the surfaces will have a lesser axial displacement than theaccompanying displacement of the axle. Thus, a movement of the bearing center 3 from the vertical plane 49 to the vertical plane 52, will be accompanied by an axial movement of the contact area from the plane 49 to the plane 50. In this case, therefore, the restoring couple is absent, and a small upsetting couple, indicated by the arrows 53 and 54, is developed. v

In general, the balanced condition illustrated in Fig. 1, or the restoring couples described above, are considered desirable, since they either avoid unstabilizing forces or actually produce lforces tending to stabilize the axle in central position and the box in upright position. The embodiment of Fig. 10, which in effect tends to stabilize the axle in the positions of extreme axial displacement from the central position with the box tilted to one or other side of the upright, may be found useful under certain conditions of load and structure. It is evident, also, that the required rocking action may be obtained by provision of a tiat frame-supporting surface on the box and a coactin'g convex seating surface on the frame.

Such arrangement, however, while falling within the broad principle of the invention, tends to increase the magnitude of the hp-setting couple.

A11 the above discussion of supporting surfaces assumes their formation accurately to specification. Such accuracy may prove impractical in some cases especially when using cast iron parts. Wear or pounding may also alter original surfaces and thus change the rocking action originally designed. This invention extends to all such variations.

As described above, the invention contemplates a journal box having a frame-supporting surface offset from the center line of the axle and arranged for coaction with a suitably formed frame surface to permit limited rocking movements of the box in the frame, together with selfaligning means within the box affording freedom for the accompanying relative angular movements between the box and the axle. The forms of the interseating surfaces, their location, and the form and arrangement of the selfaligning means may vary widely without departure from the invention.

It will be understood that the term rolling as used in the appended claims is intended to embrace tilting and any other form of relative movement between the interseating surfaces of the frame and journal box which is substantially free from sliding friction.

I claim:

l. A journal box for the axles of rail cars, said box comprising a self-aligning bearing assembly for the axle journal affording freedom for relative oscillatory movement between the axle and the box about a horizontal axis intersecting the center of said bearing assembly and normal to the journal axis, said box having also a surface remote from and above said axis of oscillation convexly curved in the direction longitudinally of said axle and forming a seat for the side frame of a rail car truck on which the box may rock with respect to said frame in response to longitudinal displacement of the axle, said seating surface and bearing jointly affording freedom for said longitudinal displacements of the axle with respect to the frame, and the radius of the said curvature of the seating surface exceeding the distance of said surface radially from the said axis of oscillation.

2. A journal box according to claim 1 wherein the curved frame-seating surface defines an arc of a cylinder.

3. A journal box according to claim l wherein the radius of curvature of the frame-seating surface is Variable and increases progressively on each side of a median position. l

4. A journal box according to claim 1 wherein the curved frame-seating surface exhibits a polygonal profile in the vertical cross sections normal to said horizontal axis.

5. A journal box according to claim 1 wherein the convexly curved seat for the side frame supports'a concave surface on the underside of said frame, the radius of the said seat being shorter than the radius of said concave surface.

6. In a rail car side frame and axle journal assembly, a journal box containing a self-aligning bearing for the journal comprising an inner race ring secured against axial displacement to the journal, an outer race ring secured against axial displacement in the box, and rolling elements confined between and securing said rings against relative axial displacement, said bearing affording freedom for oscillation of the box relative to the axle about a horizontal axis through the bearing center and normal to the journal axis, a side frame-seating surface on the box above said bearing center on which said frame is supported in vertical alignment with said center, said seat being convexly curved in the direction longitudinally of the axle so as to allow the box to rock on the frame in response to axial displacements of the axle withv respect to the latter, and the radius of curvature of said seating surface exceeding the distance of the surface radially from said horizontal axis.

References Cited in the le of this patent UNITED STATES PATENTS 1,813,975 Von Zweigbergk July 14, 1931 1,943,055 Brittain Ian. 9, 1934 1,966,923 Couch `luly 17, 1934 2,031,777 Johnson Feb. 25, 1936 2,071,947 Oelkers et al. Feb. 23, 1937 2,405,132 Brittain Aug. 6, 1946 2,488,853 Cottrell Nov. 22, 1949 FOREIGN PATENTS 350,298 England June l1, 1931 377,395 England .Tuly 28, 1932

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