United States Patent 3695739

The invention relates to a railroad car truck in which the side frames are carried inboard of the wheels on supports that are stationary relative to the side frames. The side frames are provided with spring seats that are substantially aligned with the planes of the wheels on either side of the truck and support through spring groups a bolster of special design that supports the weight of the car body at two points on either side of the bolster, which points are aligned with the respective spring groups. The truck bolster is pivoted to the car body bolster by the usual kingpin, but the coupling arrangement involved is such that none of the body weight is supported at the customary center plate area of the bolster, which area is eliminated in the present truck. The truck bolster at its midportion includes a socket structure into which a projection of the body bolster fits for applying longitudinally and laterally acting forces to the bolster from which they are transferred to the side frames through suitable engaging surfaces. In one form of the invention, the side frames are mounted on tubular housings for the axles, which housings are journalled relative to the wheels through special roller bearing or friction bearing arrangements that are herein disclosed. In another form of the invention, the side frames are mounted directly on the axles, which are stationary relative thereto, and which have the truck wheels journalled on the respective ends through a special friction type bearing arrangement, with the result that the truck wheels rotate independently of each other.

Oelkers Deceased., Alfred H. (San Antonio, TX)
Gerber, Independent Executor Thomas C. (Houston, TX)
Application Number:
Publication Date:
Filing Date:
Primary Class:
International Classes:
B61F15/12; (IPC1-7): F16C19/14
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US Patent References:

Primary Examiner:
Schwadron, Martin P.
Assistant Examiner:
Susko, Frank
Parent Case Data:

This application is a division of my copending application Ser. No. 688,037, filed Dec. 5, 1967 now U.S. Pat. No. 3,570,409.
What is claimed is

1. In a tapered roller bearing unit of the type including a stationary inner bearing cone, a rotatable outer bearing race, and a plurality of tapered rollers interposed between said cone and said race and mounted in a retaining cage to space said rollers about said cone, the improvement wherein:

2. The improvement set forth in claim 1 wherein:

3. The improvement set forth in claim 2 wherein:

My invention relates to a railroad car truck, and more particularly, to a car truck of the inboard type in which the vertical load supported by the truck is in substantial alignment with the track rails.

Conventional railway car trucks customarily have the truck side frames resting on the truck axles outboard of the wheels, and carry the weight of the car body on the truck bolster at its center plate area, where the truck is pivoted to the car body and the truck and body bolster so-called center plates engage.

My studies and analysis of railroad car truck operation have revealed that such an arrangement unnecessarily introduces excessive bending moments and resulting stresses on the truck bolster, axles, and wheels, due to the fact that the vertical loads carried by the truck are applied at the center of the bolster and then must be transferred outboard of the truck wheel onto the side frames that then transmit the loads to the customary axle journals from which the loads are transmitted to the wheels.

Furthermore, it has been customary to design a truck bolster so that it can support the entire portion of the car weight the truck is to carry at either side bearing, as well as at the center plate.

The result is that the truck bolsters and axles are made longer and stronger than they need be if the vertical loads were transmitted more directly to the rails.

This problem has become particularly acute in view of the current trend toward higher capacity cars in the 100-ton and above range, where the loads involved make strength requirements insofar as the truck is concerned especially critical. Furthermore, freight car trucks encounter a wide range of loadings, speeds, and track conditions in interchange service, and thus must be designed to handle these variations while providing years of trouble-free service.

The principal object of this invention is to provide a railway car truck arrangement in which the vertical loads imposed on a truck are transmitted substantially directly through the truck to the rails whereby undesirable moments and resulting stresses are eliminated or minimized.

A further principal object of the invention is to provide a four-wheel truck in which the weight of the car body is supported as close as is practical to vertical alignment with the rails.

Further objects of the invention are to provide an inboard type railroad car truck in which the wide frames are carried inboard of the wheels on supports that are stationary relative to the side frames, to provide friction and roller type journalling arrangements for journalling the wheels relative to the side frames, and to provide a railway car truck arrangement that is of relatively light weight construction and is economical of manufacture, that is convenient to install and service, and that is adaptable for use under a wide variety of service conditions on a long term trouble-free basis.

Still other objects, uses, and advantages will be obvious or become apparent from a consideration of the following detailed description and the application drawings.

In the drawings:

FIG. 1 is a plan view of a railway car truck showing one embodiment of the invention;

FIG. 2 is a side elevational view of the truck shown in FIG. 1, with one of the wheels omitted to facilitate illustration;

FIG. 3 is an end view of the truck shown in FIGS. 1 and 2, taken from the right hand side of FIG. 1, and illustrating in the broken line position, at the right hand side of FIG. 3, the location of a standard railroad car truck axle journal, for comparative purposes, and which is omitted in accordance with this invention;

FIG. 4 is a top plan view of the bolster employed in the truck of FIGS. 1-3;

FIGS. 5 and 6 are fragmental cross-sectional views substantially along lines 5--5 and 6--6 of FIG. 4, illustrating the side bearing arrangement employed in connection with the truck of FIGS. 1-3;

FIG. 7 is a side elevational view of the bolster shown in FIG. 4, parts being shown in section;

FIG. 8 is an end view of the bolster shown in FIG. 7, parts being shown in section;

FIG. 8A is a fragmental cross-sectional view along line 8A--8A of FIG. 4;

FIG. 9 is a cross-sectional view substantially along line 9--9 of FIG. 1;

FIG. 10 is a large fragmental elevational view of one of the truck wheels associated side frame and bearing arrangement, shown partially in section substantially along line 10--10 of FIG. 1;

FIG. 10A is an enlarged sectional view of the roller bearing arrangement shown in FIG. 10;

FIG. 11 is a plan view of one of the side frames shown in the truck of FIGS. 1-3 together with a portion of the cross member that connects same to the other side frame of the truck;

FIG. 12 is a side elevational view of the side frame shown in FIG. 11;

FIG. 13 is an end view of the side frame shown in FIG. 12, taken from the right hand side of that figure;

FIG. 14 is a cross-sectional view through the side frame taken substantially along line 14--14 of FIG. 11;

FIG. 15 is a fragmental view similar to the view of FIG. 10 but illustrating a modified embodiment of the invention;

FIG. 16 is a view similar to that of FIGS. 10 and 15 but illustrating a further modified form of the invention; and

FIG. 17 is a diagrammatic cross-sectional view substantially along line 17--17 of FIG. 16.

However, it is to be understood that the specific drawing illustrations provided are supplied primarily to comply with requirements of the patent code, and that the invention may have other embodiments that are intended to be covered by the accompanying claims.


Reference numeral 10 of FIGS. 1-3 generally indicates one embodiment of my invention in which the truck 10 comprises spaced side frames 12 supported on tubular housings 14 of the respective axles 16 (see FIG. 9) on which are mounted wheels 18.

The individual housings 14 of the respective axles 16 are stationary with respect to the side frames 12 and wheels 18 are journalled with respect to the respective housing ends 20 by bearing units 22, which in the embodiment of FIGS. 1-14 takes the form of a special tapered roller bearing unit.

The side frames 12 are each formed with a spring seat structure or platform 24 on which a spring group indicated at 26 is mounted to support a bolster 28 that at either end thereof is formed with a similar spring seat structure or platform 30 against which the respective spring groupings 26 engage.

The truck 10 is pivotally connected to the car body by a suitable kingpin 32 (see FIGS. 3 and 9), with the kingpin being applied, broadly speaking, between the truck side frames and bolster and the car body bolster generally indicated at 34 in FIG. 9.

In accordance with the present invention, the usual center plate construction of the truck bolster is omitted and the truck bolster 28 is formed with a centrally located annular guide structure 36 that loosely receives a cylindrical extension 38 that, for existing cars, is affixed to the car body bolster center plate structure 40, as at 41 (as by welding), and for new cars will be an integral part of the body bolster or car body where the body bolster is eliminated.

Instead of the weight of the car body being supported at the truck bolster center plate as in present standard AAR structure, the weight of the car body in accordance with my invention rests on the truck bolster through a pair of spaced constant contact side bearings 42 that are positioned in alignment with the respective spring groupings 26 (see FIG. 9).

In the embodiment 10A of FIG. 15, the axle housings 14 are omitted and the side frames are applied directly to the axles which are stationary with respect to the side frames. In this embodiment, the railway truck wheels 18A are journalled on the respective ends 44 of the axles through a special friction bearing arrangement generally indicated at 22A, with the individual wheels being held in place by nuts 46 and 48 cooperating with lock washer 50.

In the embodiment 10B of FIGS. 16 and 17, the tubular axle housings 14 are retained and the axle wheels 18B are journalled with respect thereto by a special friction type bearing unit 22B.

It will therefore be seen that the railway car truck of this invention distinguishes from prior art arrangements in a number of important particulars.

For instance, the side frames of the truck are inboard of the truck wheels (see FIG. 3), and the loads transmitted by the car body through the truck to the rails are transmitted through the truck in near vertical alignment with the truck rails (see FIGS. 3, 9 and 10). There is no car body load support function performed by the truck at the pivotal connection provided by kingpin 32.

Furthermore, the side frames as such are supported by supports that are stationary relative thereto; in the forms of FIGS. 1-14 and 16 and 17, the side frames are supported by the housings 14 of axles 16, while in the form of FIG. 15, the side frames are supported directly by non-rotating axles.

It will thus be noted that in accordance with this invention, the bending moments and resulting stresses imposed on the truck components by supporting the car body weight at the truck center plate area, and supporting the side frames on axle journals that are disposed outboard of the truck wheels (such as is indicated at 60 in FIG. 3) are eliminated, thereby avoiding overstressing of the bolster, axles, and wheels when heavy loads are imposed on the truck. Heretofore, it has been general practice to design the trucks so that the entire weight of the car body can be supported at either side bearing or at the car center plate, and if AAR standard outboard side frame mounting arrangements are employed, difficulties will be encountered due to overstressing especially when the modern high capacity cars travel at freight train speeds along lines that are built for high speed passenger trains, when banked curves and the like impose high off center stresses on the truck.

It will also be noted that in all forms of the invention, the railway car wheel disc (as distinguished from its hub) employs a relatively large bore as compared to standard AAR practice. I prefer that the bore be on the order of 15 inches and this is the result of my analysis of the diaphragm action that commonly occurs to railway car wheels under heavy loads. I have determined that having a wheel plate area 62 (see FIG. 10) of less radial distance will materially reduce the diaphragm effect if not eliminate same due to the significantly reduced leverage involved that acts on the wheel as it resists lateral forces due to weights imposed on the truck as a result of the engagement of the wheel flange 64 with the inside of the rail. The large bore of the wheel also permits a practical application of the wheel to its hub by a shop practice of shrinking a heated wheel onto a cold hub, instead of using a large press to force the wheel onto the axle as is now common practice.

Other significant advantages will be referred to and explained in detail as the description proceeds.


The details of the side frames 12 are illustrated in FIGS. 11-14 in which it will be seen that each side frame comprises a casting 70 forming a side frame member defining spring seat 24 that is shaped as indicated at 72 to accommodate a number of compression springs 74. As indicated in FIGS. 1 3 and 11, the side frame member 70 preferably is enlarged as at 76 so that the outer row of springs 74 will be in substantial alignment with the truck wheels 18 when the side frames and bolster are in operative relation as part of the truck.

In the particular design here shown all of the eight springs 72 per side frame are each the AAR class D4 double coils selected for the trucks to carry a 100-ton capacity car. For cars of different capacity, springs of other capacities may be similarly placed.

The side frame member 70 is provided with reinforced end portions 78 formed with openings 80 to receive a brass bearing 81 that is shaped to complement the shape of the respective openings 80 and that rests on top of the housing 14 or axle as the case may be (see FIG. 2). The members 70 also include a reinforcing hollow rib portion 82 under the spring seat portion 24 and an upstanding sidewall structure 84 reinforced as at 85 that is intended to resist lateral forces imposed by the bolster. Sidewall 84 preferably has applied thereto as by welding a hardened wear-resistant surface plate 86 for cooperation with a similar plate carried by the bolster. The side frame member 70 rests on its bearing 81 that in turn rests on the respective axle housings 14 or axle as the case may be. As part of the assembly procedure, the side frames are secured in place by applying suitable filler members 89 within the respective openings 80 and securing them in place with bolts 87.

In addition to compression springs 74, it is preferable that a snubber device be applied between the bolster and the respective side frames, where indicated at 90 in FIG. 2, and for this purpose, the side frame spring seat area 24 is appropriately formed as at 92 to receive a suitable snubber 90 which preferably is of the type disclosed in my U.S. Pat. Nos. 2,130,678 and 2,210,840 (the disclosures of which are hereby incorporated herein by this reference).

In the embodiments illustrated, the side frame 12 comprises two castings 70 joined together by cross-member plates 94 riveted in place as at 96. However, in an alternate arrangement, the side frames 12 are cast as a single casting with a portion shaped comparably to member 94 integrally connecting the two members 70.

In either case, the side frame cross-member 94 is formed with a centrally disposed opening where indicated at 96 (see FIG. 9) to receive the kingpin 32, which opening 96 is reinforced by a suitable flanged sleeve 98 affixed as by welding to the top of the member 94 and a suitable annular plate 100 affixed as by welding to the under surface of member 94.

The end portions 78 of the side frames define opposed upstanding longitudinal thrust receiving surfaces 102 and 104 to which are affixed as by welding hardened wear-resisting plates 106 and 108 respectively that cooperate with corresponding plates affixed to the bolster.

The bolster 28 is illustrated in FIGS. 4-8, and generally comprises a one-piece casting defining relatively long side portions 110 and 112 joined together with the centrally located annular guide structure 36 by reinforced arm structures 114.

The undersides of the respective bolster side portions 110 and 112 are shaped to define the bolster spring seats 30 that correspond in configuration to the side frame spring seats 24 and are adapted to receive the upper ends of compression springs 74. The bolster side portions 112 and 110 are each formed with extensions 116 that cooperate with the extension 76 of the respective side frames to seat the respective outwardly disposed row of springs 74.

The ends 118 and 120 on the respective bolster side portions are formed with flat longitudinal thrust receiving surfaces 122 and 124, respectively, to which are applied as by welding the respective hardened wear-resisting plates 126 and 124 that are intended to cooperate with the respective side frame wear plates 108 and 106, respectively (see FIGS. 1 and 2).

The bolster side portions 110 and 112 are each formed with flat lateral thrust resisting surfaces 130 and 132 to which are respectively applied hardened wear-resisting plates 134 and 136 that cooperate with the respective plates 86 of the side frames (see FIG. 9).

Referring to FIG. 9, the proportioning of parts insofar as the bolster guide structure 36 and the body bolster attachment 38 are concerned is such that on lateral thrusts when the cylindrical extension 38 engages, for instance, the right hand side of the guide structure 36 as shown in FIG. 9, the left hand wear plate 134 will be brought into engagement with its opposing wear plate 86 of the side frame involved, and vice versa; when longitudinally acting thrusts are occasioned (such as draft forces acting longitudinally of the car), engagement of the body bolster extension 38 with the bolster guide structure 36 will bring either the bolster wear plates 128 into engagement with the side frame wear plates 106, or the bolster wear plates 126 into engagement with the side frame wear plates 108, depending upon which end of the car is moving forward.

The side bearings 42 cooperate with the upper surfaces 140 of the respective bolster side portions 110 and 112 and each side bearing generally comprises an arcuate plate member 142 that is affixed to the bolster as by welding at 144 and is recessed as at 146 for application thereto of a strip or layer 148 of any suitable anti-friction material such as bronze on which rests a steel block 150 that is received in a recess 152 formed in the car body bolster side bearing attachment 154, which recess 152 substantially complements the shape of a block 159 (see FIGS. 5 and 6). Attachment 154 is affixed to the body bolster or its equivalent in any suitable manner.

Applied over the plate 142 is a suitable cover 156 which is closely received about the block 150 and rides on top of the plate 142 to protect the wear surface 158 on which the block 150 rides under the swinging action that the trucks will have with respect to the car body as the car rounds curves and the like. It is preferable that lubricant filled sponge be applied about the block 150 under cover 156 where indicated at 160, and that the cover 156 include a suitable passage structure where indicated at 162 for adding lubricant as may be required (see FIG. 6).

The arm structures 114 of the bolster may be sectioned in the generally channel shaped configuration indicated in FIG. 8A, with the deeper sides 167 on either side of the truck facing each other so as to insure adequate resistance to lateral thrusts imposed on guiding structure 36.

The relative length of the bolster side sections 110 and 112 lengthwise of the car (which preferably has a dimension on the order of about 45 inches) is a special significance since the proportioning involved avoids any tendency of the bolster to rock or twist about its axis transversely of the truck, thus overcoming a serious problem experienced with conventional truck bolsters. The supporting action of the spring groups is also spread out adequately to insure minimum bending moments. In a specific embodiment of my invention, the dimension of sections 110 and 112 lengthwise of the car is 45-3/4 inches, as compared to a corresponding dimension of about 17 inches for standard bolster designs.

The axles 16 of the embodiment of FIGS. 1-14 are formed with hub portions 170 (see FIG. 10) at either end thereof on which is press fitted a wheel hub 172 which in turn has press fitted on it the respective individual wheel discs 173 that each comprise wheel plate 62, flange 64, and rail engaging rim surface 174 (which is preferably of the standard AAR cylindrical type). As already indicated, the parts involved should be proportioned so that the wheel has a bore 175 on the order of 15 inches to reduce the radial dimension of wheel flange 64.

The axle housings 14 each comprise a tubular member 176 formed adjacent either end thereof to define a seat 178 on which the respective side frame mounting members 81 rest. As indicated in FIG. 10, the axle housings 14 are formed so that the cylindrical surface 182 defining their respective bores is spaced from the axle 16.

Operatively interposed between each end portion 20 of each axle housing 14 and the adjacent wheel 18 is the bearing unit 22 which is best illustrated in FIGS. 10 and 10A.

Bearing unit 22 in the form of FIGS. 1-14 is of the tapered roller bearing type and comprises an inner race or bearing cone 190 press fitted onto a reduced portion 192 of the respective tubular housing member end portions 20, an outer race or bearing cup 194 press fitted into a recess 196 formed in the wheel hub 172, and a plurality of tapered roller bearings 198 interposed between the races 190 and 194 in circumambient relation about the inner race 190 and held in spaced relation by retainer device or cage 200.

The cage 200 is annular in configuration and preferably formed from a suitable antifriction metal such as bronze; it is broached or otherwise suitably formed to define equally spaced openings 202 thereabout in which the respective rollers 198 are received.

It is to be noted that the inner and outer races and their roller bearings of unit 22 are each of single row construction, and in accordance with this invention, the comparable bearing unit at the other end of the axle 16 is applied in opposed fashion so that the bearing units 22 of each axle are in effect, self-balancing. As indicated in FIGS. 10 and 10A, the raceway surfaces 204 and 206 of the respective inner and outer races are frusto-conical in configuration and diverge inwardly of the truck (that is, in the direction of the longitudinal center line of the car). The unit 22 that is applied to the other end of the axle 16 is similarly oriented, and thus has its parts disposed in a position that is the reverse of that shown in FIGS. 10 and 10A.

Associated with each unit 22 is a closure plate 208 that is received over the end portion 20 of the respective axle housings 14 and is secured in place by suitable bolts 210. Ring 212 encircling the end portion 20 of the respective housing 14 is employed to prevent the entrance of dirt into the bearing unit 22; it is of the conventional locking ring type that is made of spring steel or the like and is snapped into the position shown.

Cover plate 208 in accordance with this invention is formed with a rib 214 defining annular guiding surface 216 which is positioned and proportioned to be engaged by the end surface 218 of the roller bearing cage 200. Thus, as distinguished from conventional roller bearing units, in which movement of the rollers outwardly of the bearing is precluded by a steel-on-steel contact with a shoulder of the inner bearing cone, the rollers 198 are guided by the engagement of cage surface 218 with cover plate surface 216, which thus provides a guiding body of anti-friction material between the inwardly disposed ends of the rollers 198 and the cover plate 208.

It is preferred that the running clearance of rollers 198 between the inner and outer races be on the order of 0.005ths of an inch to accommodate expansion during operation, and this clearance may be controlled by applying appropriate shims between the cover plate and outer race where indicated at 220. When adjusted for this preferred running clearance, the axle housing moves freely endwise about four hundredths of an inch.

The cage 200 at its outer end is flared as at 222 and is provided with cylindrical surface 224 adapted to engage the surface 226 of the outer race to provide some guiding action on the outwardly directed end of the cage during operation of the truck, so as to insure that the cage runs centered with respect to the outer race 194.

The wheel hub 172 and the cover plate 208 define a chamber 228 in which the bearing unit 22 is mounted, which chamber is preferably charged with oil and provided with a suitable oil inlet that is closed by a suitable removable plug, similar to that indicated at 310 and 312, respectively, in the form of FIGS. 16 and 17.

The roller bearing unit 22 has several important advantages. For instance, the desired looseness or running clearance of the rollers 198 may be obtained with only one-tenth of the misalignment occasioned in conventional roller bearing units employed for outboard mounted side frames, as roller units 22 are approximately 10 times as far apart as the two sets of rollers in a typical AAR roller bearing unit for axle journals.

Furthermore, the outer race 194 of the bearing unit 22 revolves with the wheel 18 and achieves much better oil distribution about the rollers 198.

Moreover, more rollers pass through the load supporting zone of the bearing (the lower 130° segment of the arc struck by the bearing unit 22), which will be based on the difference in diameters of the races 190 and 194.

And, as already indicated, the movement of the rollers 198 is guided through a guide member of anti-friction material, which materially decreases the rate of heat build-up in the rollers.

In the embodiment of FIG. 15, the axle housings 14 are omitted and the side frames 12 are applied directly to a reduced portion 240 of the axle 16A in the manner indicated in FIG. 15, which otherwise is similar to the side frame application shown in FIG. 10.

In the embodiment of FIG. 15, the end 44 of each axle 16A includes a tapered portion 242 which receives a bearing member 244 formed from bronze, or the like, that is press fitted into the bore 246 of a wheel hub 248 on which the wheel disc 249 is press fitted in any suitable manner.

The wheel hub 248 forms a housing for the bearing 244 and is formed to define a plurality of annular lubricant reservoirs 250 interconnected by passages 252, which may be supplied with oil through suitable passages 254 and 255 closed by suitable removable plugs 256 and 258, respectively.

The bearing member 244 is formed with a plurality of spaced orifices 260 that lead to its bearing surface 262, and that are staggered axially of the axle 16A to achieve uniform oil distribution along the surface 262. Preferably, the bearing 244 is formed with similar orifices 260 in alignment with each reservoir 256, although only one set of the orifices 260 are shown for clarity.

Preferably, a lateral bearing 262A formed from bronze or the like is interposed between the lock washer 50 and the wheel hub 248 and the end portion 264 of bearing 244 that is aligned therewith in the area of lock washer 50.

Under normal operation, the wheels 18A carry vertical loads on the oil film that builds up between the bearing 244 and the axle portion 242.

In the specific embodiment illustrated in FIG. 15, the axle end 44 defines a collar 266 between which and the inner end 268 of bearing 245 is received an annular bearing member 270 that is likewise formed from a suitable antifriction material such as bronze, and against which bearing member 244 is pressed by the application of nut 46 to the axial end 44. Nut 48 serves to lock nut 46 in place.

One of the important features of the embodiment of FIG. 15 is that is provides independently rotating wheels for the truck. This eliminates the tendency of standard AAR trucks having wheels with tapered treads to shift from side to side as the wheels (which are made fast to the respective axles) try to follow the track rails. In this embodiment, the truck wheels are free to freely follow the track rails in a manner similar to the wheels of a highway trailer following the highway.

While this embodiment of the invention is shown as embodying a friction bearing arrangement, the same concept may be embodied employing a suitable roller bearing unit for journalling the wheel on the end of the axle.

In the embodiment 10B of FIGS. 16 and 17, the tubular axle housings 14 are retained and are provided with end portions 20B which cooperate with the friction bearing unit 22B associated with wheel hub 280 on which wheel disc 281 is press fitted.

Wheel hub 280 defines a hub portion 282 that is press fitted on the axle end 170. Hub 280 is formed to define annular portion 284 in which is press fitted a cylindrical bearing member or sleeve 286 that is press fitted into place and is provided with bearing surface 288 on which rides a bearing shoe 290 that is keyed to a reduced portion 292 of tubular housing end portion 20B, as by employing pin 294. Bearing member 286 and shoe 290 may be formed from a suitable antifriction material such as bronze and shoe 290 should be proportioned to extend across about 130 degrees of arc at the lower sector of the housing end portion 20B. Annular cover plate 296 is secured in place by suitable bolts 298 applied to hub 280 which serves to retain bearing member or sleeve 286 in place, and the wheel hub 280 and axle housing 14 are proportioned to provide the annular spaces indicated at 300, 302, 304, 306 and 308 that are filled with lubricant through a suitable port 310 that is closed by suitable removable plug 312. It is to be noted that the space 308 extends across the axle to the other end thereof and connects with a similar space 308 at the other end of the axle.

Bearing sleeve 286 is preferably formed with a plurality of openings 310 thereabout in alignment with spaces 304 and 306 to provide ready access of lubricant to load bearing parts of the bearing.

In the embodiment 10B, the tubular axle housings 14 must be restrained against revolving which may be done by a lug welded to the side frame engaging a suitable notch in the axle housing or some other suitable means.

It will therefore be seen that I have provided a railroad car truck that is especially adapted for application to freight cars of the 100-ton and over capacity, yet which is smaller and lighter in weight than conventional truck arrangement. One principal reason for this is that the loads applied to the truck are transmitted almost directly to the track rails in substantial vertical alignment therewith.

This substantially eliminates bending moments on the bolster axles and wheels.

As has been pointed out, the weight of the body is applied to the bolster directly over the spring groups that support the bolster, and in the illustrated embodiment the side bearings provide for adequate permanent lubrication thereof.

It is important that the snubber 90 employed be of the type that acts only vertically when in its operating position on the truck as this avoids the application of restrictions on bolster movement that will result in bolster twisting on vertical movement, as sometimes happens in connection with conventional friction type snubbers that act in opposed relation on either side of the bolster.

In the embodiments of FIGS. 1-14, 16 and 17, the axle housings provide an added safety factor in addition to protecting the axles and providing a mounting arrangement for the side frames. For instance, if a car that includes trucks 10 or 10B is in a wreck, it is quite likely that either the axle 16 or the housing 14 will hold, thus keeping the truck wheels aligned with the trackway and the car on the right of way.

Furthermore, in these embodiments of the invention, the wheel axles do not carry the car body weight as the car body weight is applied to the wheels through the axle housings and the bearing units interposed between such housings and the wheels.

In all embodiments of the invention, the center pivot structure at the kingpin provides only guiding action on the truck and no weight support insofar as holding up the car body is concerned. As indicated, the load of a body is transferred through the truck in the area of the side bearings, spring groups and side frame mountings that are disposed as close as practical to vertical alignment with the rails. The significant difference between applicant's arrangement and those of the prior art will be better appreciated upon considering that a 79-inch spread exists between the springs supporting the load in the standard AAR truck as against 43 inches in a dimensioned embodiment of the invention between the midportions of the side frame end portion 78 as applied to each axle, which, as is indicated in FIGS. 3 and 13, are in substantial alignment with respective spring groups on either side of the truck.

The foregoing description and the drawings are given merely to explain and illustrate my invention and the invention is not to be limited thereto, except insofar as the appended claims are so limited, since those skilled in the art who have my disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.