U.S. patent number 3,795,203 [Application Number 05/169,254] was granted by the patent office on 1974-03-05 for roll dampening railway trucks.
This patent grant is currently assigned to Rockwell International Corporation. Invention is credited to Gustav B. Sundby.
United States Patent |
3,795,203 |
Sundby |
March 5, 1974 |
ROLL DAMPENING RAILWAY TRUCKS
Abstract
Railway trucks including frame sections consisting of a side
frame and a transom extending transversely therefrom; spherical
bearings connecting the frame sections for relative movement about
an axis extending diagonally of the truck; wheel and axle
assemblies connected to the side frames by pivoted journal arms;
air bellows between the journal arms and side frames for adjusting
the height of the side frames relative to the rails on which the
truck is riding; a bolster supported from the side frames by
bolster spring assemblies; lateral and vertical shock absorbers
connected between the bolster and the truck frame sections; and
snubbers for limiting longitudinal and lateral movement of the
bolster relative to the truck frame sections.
Inventors: |
Sundby; Gustav B. (Atchison,
KS) |
Assignee: |
Rockwell International
Corporation (Pittsburgh, PA)
|
Family
ID: |
22614849 |
Appl.
No.: |
05/169,254 |
Filed: |
August 5, 1971 |
Current U.S.
Class: |
105/182.1;
105/164; 105/218.2; 105/199.1 |
Current CPC
Class: |
B61F
5/24 (20130101) |
Current International
Class: |
B61F
5/24 (20060101); B61F 5/02 (20060101); B61f
003/08 (); B61f 005/24 (); B61f 005/36 () |
Field of
Search: |
;105/176,182R,193,199R,194,218A,224R,164 ;280/124F |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Forlenza; Gerald M.
Assistant Examiner: Beltram; Howard
Claims
What is claimed and desired to be secured by Letters Patent is:
1. In a railway car, the combination of a carbody; a truck
comprising side frames; means for supporting said carbody on said
truck; fore and aft wheel and axle assemblies; means supporting
said side frames from said wheel and axle assemblies at locations
corresponding generally to the four corners of the truck; and
selectively operable means for independently altering the position
of either of said side frames relative to the wheel and axle
assemblies from which they are supported during curve negotiation
to control the roll of the carbody supported from the truck and
also adjust the longitudinal spacing between the fore and aft
wheels on opposite sides of the truck.
2. A railway truck or the like, comprising fore and aft wheel and
axle assemblies; side frames; means supporting said side frames
from said wheel and axle assemblies at locations corresponding
generally to the four corners of the truck; and selectively
operable means for independently altering the position of either of
said side frames relative to the wheel and axle assemblies from
which they are supported during curve negotiation to control the
relative vertical position of the side frames to thereby adjust the
longitudinal spacing between the fore and aft wheels on opposite
sides of the truck.
3. The railway truck of claim 2 in which said means supporting said
side frames from said wheel and axle assemblies includes journal
arms, one end of each journal arm being pivotally attached to one
of said side frames and the other end thereof having journalled
thereon the associated one of said wheel and axle assemblies.
4. The railway truck of claim 3 in which said journal arms are
pivotally attached to said side frames for movement about an axis
parallel to and below the axis of rotation of the associated wheel
and axle assembly.
5. The railway truck of claim 3 in which said journal arms are the
sole means between the side frames and the wheel and axle
assemblies for guiding the vertical movement of said side frames
with respect to said wheel and axle assemblies.
6. A railway truck or the like, comprising fore and aft wheel and
axle assemblies; side frames; means supporting said side frames
from said wheel and axle assemblies comprising journal arms at
locations corresponding generally to the four corners of the truck
and means attaching each said journal arm at one end thereon to one
of said side frames for pivotal movement about an axis extending
transversely of the truck and located below the longitudinal
centerlines of the wheel and axle assemblies, said axles being
journalled on said journal arms at locations toward the free ends
of said arms; and selectively operable means for altering the
position of either of said side frames relative to said wheel and
axle assemblies during curve negotiation to control the relative
vertical position of the side frames to thereby adjust the
longitudinal spacing between the fore and aft wheels on opposite
sides of the truck, said means comprising an extensible bellows
associated with each journal arm, one end of each bellows being
mounted on the free end of the respective journal arm and the other
end of each bellows supporting the associated side frame; a
compressed air source; and means for connecting each said bellows
to said compressed air source to extend said bellows and raise the
associated side frame and for exhausting air from said bellows to
thereby collapse said bellows and lower the associated side
frame.
7. The railway truck or the like of claim 6, together with
resilient support means between each of said journal arms and the
associated side frame, the resilient support means being positioned
at a location between the bellows on the same journal arm and the
location at which the journal arm is pivotally fixed to the
associated side frame.
8. A railway truck comprising a first frame section comprising a
first side frame and a first transom rigidly fixed to said first
side frame and extending laterally therefrom; a second frame
section comprising a second side frame and a second transom rigidly
fixed to said second side frame and extending laterally therefrom,
the transoms of said first and second frame sections being spaced
from each other longitudinally of said truck; wheel and axle
assemblies journalled in said frame sections at opposite ends of
the truck and providing wheels at locations corresponding generally
to the four corners of said truck; first and second means for so
connecting said first frame section to said second frame section as
to permit vertical displacement of any one of said wheels relative
to the remaining wheels while maintaining said side frames
substantially in rectangular and vertical tram, said first and
second connecting means confining the relative movement between
said first and second frame sections to an axis extending
diagonally across said truck through said connecting means; means
supporting said frame sections from said wheel and axle assemblies
comprising journal arms at locations corresponding generally to the
four corners of the truck and means attaching each said journal arm
at one end thereof to one of said side frames for pivotal movement
about an axis extending transversely of the truck and located below
the longitudinal centerlines of the wheel and axle assemblies, said
axles being journalled in said journal arms at locations toward the
free ends of said arms; and selectively operable means for altering
the position of either of said side frames relative to said wheel
and axle assemblies during curve negotiation to control the
relative vertical position of the side frames to thereby adjust the
longitudinal spacing between the fore and aft wheels on opposite
sides of the truck, said means comprising an extensible bellows
associated with each journal arm, one end of each bellows being
mounted on the free end of the respective journal arm and the other
end of each bellows supporting the associated side frame; a
compressed air source; and means for connecting each said bellows
to said compressed air source to extend said bellows and raise the
associated side frame and for exhausting air from said bellows to
thereby collapse said bellows and lower the associated side
frame.
9. The railway truck of claim 8, wherein said carbody supporting
means includes a transversely extending bolster means and including
bolster spring assemblies supporting said bolster means from said
side frames, the vertical axes of said bolster spring assemblies
being disposed transversely of the truck with respect to the
longitudinal centerlines of the journal arms supporting the frame
sections of the truck from the wheel and axle assemblies.
Description
This invention relates to railway trucks and, more specifically, to
railway trucks capable of producing increased passenger comfort,
improved adhesion to the rails, and decreased wheel flange and
tread wear during curve negotiation.
In conventional railway trucks, the front and rear axles are
parallel during curve negotiation. Therefore, as a conventional
truck rounds a curve, the wheels negotiate the curve by a
combination of rolling and sliding motion. More specifically, the
inner and outer wheels are fixed to the same axle and therefore
rotate at the same speed; and the outer wheels follow a longer path
than the inner wheels. Therefore, during curve negotiation, the
inner wheels slide in the direction the truck is moving while the
outer wheels slide in the opposite direction. In addition, the
wheels are not tangent to the truck; and they therefore slide
laterally as the truck rounds a curve.
The sliding motions just described produce truck wheel tread and
flange wear. Also, sliding motions decrease the frictional forces
between the truck wheels and the rails during curve negotiation.
This is important as the consequence is a loss of adhesion and
traction as the truck rounds a curve.
Furthermore, curves in railway tracks are designed for negotiation
at a specific speed. At a lower speed a railway car will lean
excessively toward the inside of the curve, causing discomfort to
passengers in the car. Conversely, at speeds in excess of the
design speed, the bank or lean of the car will be insufficient; and
the passengers will, again, experience discomfort.
It is one important and primary object of the present invention to
provide railway trucks which do not have the just-enumerated
disadvantages of heretofore available railway trucks.
In the novel railway trucks of the present invention, by which the
foregoing and other important objects are achieved, the side frames
are supported from wheel and axle assemblies by pivoted journal
arms at the four corners of the trucks; and extensible bellows are
mounted between the free ends of the journal arms and the side
frames of the trucks. These bellows are connectable to a compressed
air source and to atmosphere through appropriate piping and valving
so that the bellows can be pumped up to extend them and bled to
collapsed them.
In a typical curve negotiation, air is admitted to the bellows on
both the inside and outside of the curve to extend them with more
air being supplied to those on the outside of the curve so that
their extension is greater. This increases the elevation of the
side frame on the outside of the curve relative to the elevation of
the side frame on the inside of the curve..sup.1 (1. Depending upon
the curve being negotiated, air may be bled from the bellows on the
inside of the curve rather than being supplied to them to produce
the height differential relative to the track of the truck side
frames.) As a result, the bank or lean of the car supported from
the truck is increased, making the negotiation of the curve more
comfortable for the passengers.
A further advantage of adjusting the elevation of the truck side
frames in the manner just described is that the speed with which
the curve can be safely negotiated is increased by twenty percent
or more. This is advantageous for obvious reasons.
Also, in railway trucks in accord with the present invention, the
pivot axes of the journal arms are below the axes of rotation of
the truck wheels. Accordingly, as the side frames on the outside
and inside of the curve are raised, the spacing between the outer
wheels is increased to a greater extent than that between the inner
wheels and the axles of the truck are displaced from their normal
positions in which they are at right angles to the side frames of
the trucks so that the axles are aligned at least closely along
radii of the curve. This eliminates or at worst greatly reduces
sliding motions of the wheels relative to the rails. Consequently,
tread and flange wear is reduced; and traction between the wheels
and the rails is improved.
To illustrate another circumstance in which the present invention
provides a decided advantage, it was pointed out above that railway
curves are designed for negotiation at one specific speed and that,
at considerably lower speeds, cars lean excessively toward the
inside of the curve. In this case the sequence described above can
be reversed. That is, the elevation of the side frame on the
outside of the curve can be reduced relative to that of the side
frame on the inside of the curve to decrease the lean of the car
and increase passenger comfort during the negotiation of the
curve.
One primary object of the invention has been identified above.
Another primary and related object of the invention is the
provision of novel, improved railway trucks capable of providing
increased passenger comfort and traction and of reducing wheel
tread and flange wear during curve negotiation.
Other important but more specific objects of the invention are to
provide novel, improved railway trucks:
1. which can be adjusted to regulate the degree of lean or bank of
a car supported from the truck during curve negotiation
independently of the superelevation of the track.
2. which can be adjusted during curve negotiation so that the axles
of the truck lie at least approximately along radii of the
curve.
3. in which the adjustments specified in objects 1 and 2 above can
be made independently of the load in a carbody supported from the
truck.
4. which include side frames supported from fore and aft wheel and
axle assemblies by pivoted journal arms, bellows between the free
ends of the journal arms and the side frames, and a system for
selectively admitting air to and bleeding it from various ones of
the bellows to alter the height of the side frames above the rails
on which the truck is riding.
Other important objects and features and further advantages of the
invention will become apparent from the appended claims and as the
ensuing detailed description and discussion proceeds in conjunction
with the accompanying drawing, in which:
FIG. 1 is a side view of a prior art railway truck;
FIG. 2 is a top view of the railway truck of FIG. 1;
FIG. 3 is a partial side view of the truck of FIGS. 1 and 2
modified for improved curve negotiation in accord with the
principles of the present invention;
FIG. 4 is a generally diagrammatic rear view of a railway car
supported by trucks constructed in accord with the principles of
the present invention as the car negotiates a curve;
FIG. 5 is a schematic illustration of a compressed air system for
trucks in accord with the present invention; and
FIG. 6 is a schematic representation of the manner in which the
truck axles are oriented during curve negotiation.
Referring now to the drawing, FIGS. 1 and 2 depict a railway truck
20 of a type which may be readily modified in accord with the
principles of the present invention to provide improved curve
negotiation and the other advantages of the invention discussed
above.
Truck 20 has a rectangular frame 22 consisting of two generally
L-shaped, rigid subassemblies or frame sections 24 and 26. These
subassemblies are formed by longitudinally extending side frames 28
and 30. Laterally extending transoms 32 and 24 are secured to or
made integral with the side frames. Subassemblies 24 and 26 are
interconnected at diagonally opposed points by spherical bearing
assemblies 36 and 38 to permit relative pivoting between the
L-shaped subassemblies about a diagonal axis 40 through the centers
of the spherical bearings and the center of the truck.
Truck frame 22 is supported on axles 42 and 44 by roller bearing
assemblies 46 which are resiliently mounted in side frames 26 and
28. Axles 42 and 44 each having two railway wheels 48 secured
thereto.
Because of the manner in which the frame subassemblies 24 and 26
are interconnected by bearing assemblies 36 and 38, there is only
one type of motion therebetween. This is a pure pivotal movement of
one subassembly with respect to the other about axis 40.
Accordingly, as truck 20 rolls onto an uneven stretch of track on
which one of the wheels 48 furthest from axis 40 is at a low point
in the track, the associated frame subassembly tends to pivot
downwardly about axis 40 to re-establish even wheel loading.
Conversely, when a wheel furthest from the pivot axis is on a high
point on a rail, its frame subassembly pivots upwardly about axis
40 to re-establish even wheel loading.
Thus, the construction of frame 22 provides independent side frame
action. However, as the spherical bearings do not permit
longitudinal play between the frame subassemblies, the side frames
of the truck 20 are rigidly maintained in rectangular tram.
Further, as the spherical bearings do not permit vertical play
between the ends of the transoms and the opposite side frames, the
side frames are maintained in vertical tram. Finally, as the
spherical bearings permit no lateral play between the transoms and
the opposite side frames, they effectively rigidly transmit lateral
forces from one side to the other..sup.2 (2. The axle bearing
assemblies 46 provide the axial play and pivotal flexibility
between the side frames and the axles needed to permit the side
frames to independently follow track irregularities without binding
the journal bearings.)
A transversely extending bolster 50 is supported from truck frame
22 by bolster spring assemblies 52, which extend from platforms or
seats 54 on side frames 28 and 30 upwardly into spring caps 56 at
the ends of the bolster. As shown in FIG. 2, the bolster spring
assemblies may be located slightly outboard of truck side frames 28
and 30 with each spring assembly being on the same side of the
transverse centerline 58 of the truck as the spherical bearing
assembly 36 or 38 on the same side of the truck. This location of
the spring assemblies in a diagonally hinged truck of the type
depicted in FIGS. 1 and 2 keeps wheels 48 from unloading as they
pass over high and/or low spots in a track..sup.3 (3. Much the same
result can be achieved by locating the spring assemblies inboard of
the truck frames and on the opposite side of centerline 58 from the
spherical bearing assembly on the same side of the truck.)
As shown in FIGS. 2 and 4, bolster 50 has the usual centrally
located recess 60 into which a kingpin 62 secured to the underside
of a carbody 64 depends to pivotally secure the carbody to the
truck. Also, bolster 50 is connected to the side frames 28 and 30
of truck frame 22 by conventional vertical and lateral shock
absorbers 66 and 68 to keep vertical and lateral shock loads from
being transmitted to carbody 64. Longitudinal forces are absorbed
by snubbers or bumpers 70 in mounts 72 on the truck frame on
opposite sides of the bolster at each end thereof. Similar snubbers
or bumpers 74 in mounts 76 on the under side of bolster 50 are
engageable with co-operating stops (not shown) on side frames 28
and 30 to limit lateral movement of the bolster relative to the
side frame.
The details of truck 20 are described in U.S. Pat. No. 3,313,245
issued Apr. 11, 1967, to G. B. Sundby for RAILWAY TRUCK, which is
hereby incorporated herein. As the forementioned components are
described in the Sundby Patent and as their details are not part of
the present invention, they will not be described further herein
except as they relate to the present invention.
In the present invention axles 42 and 44 are suspended from truck
frame 22 by pivoted journal arms 78 rather then directly from the
side frames of the truck as in the prior art truck described above.
More specifically, journal arms 78 are pivotally connected at one
end thereof to mounts 80 depending from side frames 28 and 30 by
transversely extending pivot pins 82 at levels below those at which
the centerlines (or axes of rotation) of axles 44 lie. Axles 42 and
44 extend through journal arms 78 adjacent the free ends thereof
and are rotatably supported in the journal arms as by bearings
84.
As shown in FIG. 3, addition of the journal arms just described to
the truck 20 illustrated in FIGS. 1 and 2 requires minor
modifications in the configuration of side frames 28 and 30. The
precise manner in which the configuration of the side frames is
altered is of no consequence, however, and will vary from
application to application of the invention.
Referring again to FIG. 3, a coil type cushioning spring 86 and an
air bellows 88 are disposed between each journal arm 78 and the
associated side frame 28 or 30. The spring 86 and bellows 88 are
confined at their lower ends in seats 90 and 92 and in caplike
portions 94 at the ends of the associated side frames 28 and 30 at
their upper ends.
Referring now to FIG. 5, the air bellows 88 on one side of the
truck are connected to a source of compressed air or tank 96
through a system of diagramatically illustrated conduits identified
by reference character 98. The air bellows on the opposite side of
the truck are similarly connected to air tank 96 through conduit
system 100. The flow of air to and from the bellows 88 on the
first-mentioned side of the truck is controlled by a three-position
valve 102, and the flow to and from the bellows on the other side
of the truck is controlled by a similar valve 104.
In one active position, the valves connect the associated bellows
88 to air tank 96. In the other active position, the valves connect
the associated bellows to atmosphere through lines 106 and 108. In
the third position the bellows are isolated both from the air tank
and from atmosphere.
The positions of valves 102 and 104 are regulated by a controller
110. This controller may be of conventional construction and can be
operated manually for example by means of manually operated
switches which control electric motors adapted to selectively
position the valves 102 and 104, or automatically for example by
inertial devices responsive to centrifugal forces developed during
curve negotiations, all of which are well known in the art.
As a carbody supported by trucks constructed in accord with the
present invention rounds a curve, controller 110 is manually or
automatically activated to position the valves 102 or 104 so that
compressed air will flow from tank 96 to the bellows 88 on the
outside of the curve, pumping up or extending these bellows. At the
same time, the controller positions the other valve so that air
also flows to the bellows 88 on the inside of the curve, extending
these bellows but not to the same extent as those on the outside of
the track. As a result, the side frame on the outside of the curve
will be elevated to a greater extent with respect to the track than
the side frame on the inside of the curve as shown in FIG. 4..sup.4
(4. As indicated above, air may instead be bled from rather than
supplied to the bellows on the inside of the curve to collapse or
shorten them if dictated by the nature of the curve being
negotiated.) The carbody will accordingly be tilted toward the
inside of the curve to a degree greater than that resulting simply
from the superelevation of the track. Thus the degree to which the
carbody is tiled during curve negotiation, commonly referred to in
the art as "roll," may be controlled.
By adjusting the length of the bellows on the outside and on the
inside of the curve in the manner just described, axles 42 and 44
can also be positioned during curve negotiation so that they lie
along or approximately along radii of the curve..sup.5 (5. As the
negotiation of the curve is completed, valves 102 and 104 are
positioned to allow air to bleed from belows 88 through lines 106
and 108, collapsing them to their normal degree of extension in a
typical curve negotiation. In other cases air has to be supplied to
the bellows on the inside of the curve to extend them to their
normal length.) As the bellows on the outside of the curve are
extended relative to those on the inside of the curve, the distance
between the wheels on the outside of the curve becomes greater than
that between the wheels on the inside of the curve. And both the
inside and outside wheels are shifted (see FIG. 6) so that axles 42
and 44 lie along radii of the curve.
This minimizes or even eliminates skewing or sliding of the wheels
through the curve, reducing both wheel tread and flange wear. In
addition, due to the elimination or minimization of sliding,
frictional forces between the wheels and the rails are in the
direction of the rails. Accordingly, there is greater adhesion
between the wheels and the rails and, consequently, better traction
through the curve.
Further, by adjusting the tilt of the carbody in the manner just
described, curve negotiation may be made more comfortable for the
passengers.
Yet another advantage is that curves can be negotiated at a higher
speed then they can be with a truck of conventional design. The
following example illustrates the increase in curve speed
negotiation which may be realized by utilizing the present
invention:
Static deflection of 4.5 in springs 86 Distance between the 59 in
rolling circles of wheels 48 Wheel base of the truck 102 in
Distance between the pivot 77.5 in axes 82 of the fore and aft
journal arms 78 Superelevation of the track 8 in Vertical
displacement of the 1.0 in axles 42 and 44 on the inside of curve
Vertical displacement of the 2.5 in axles 42 and 44 on the outside
of curve Longitudinal displacement of the 0.2216 in axles 42 and 44
on the inside of the track (.DELTA.S2 in FIG. 6) Longitudinal
displacement of 0.2216 in the axles 42 and 44 on the outside of the
track (.DELTA.S1 in FIG. 6)
without banking the balancing speed for a 1940 foot curve is 62
miles per hour. By banking or tilting the trucks as just described,
this speed is increased to 76 miles per hour.
At speeds lower than that at which a curve is designed to be
negotiated, the carbody may lean excessively toward the inside of
the curve. In addition to truck wheel tread and flange wear, this
can cause considerable discomfort to the passengers. Excessive lean
can be eliminated when trucks in accord with the present invention
are employed by pumping up and extending the bellows on the inside
of the curve relative to those on the outside of the curve to
produce the correct lean of the carbody for slower speeds of curve
negotiation.
It is also important, in conjunction with the foregoing, that the
performance changes obtained by banking the trucks are independent
of the load in the car supported from the trucks. This greatly
simplifies the task of correctly banking the trucks for correct
curve negotiation.
It will be obvious to those skilled in the arts to which the
present invention pertains that the principles of the invention are
applicable to many different types of railway trucks and that other
techniques may be used to elevate the side frames of the trucks. To
the extent that such applications of the invention are not
expressly excluded from the appended claims, they are fully
intended to be covered therein.
The invention may be embodied in other specific forms without
departing from the spirit or essential characteristics thereof. The
present embodiment is therefore to be considered in all respects as
illustrative and not restrictive, the scope of the invention being
indicated by the appended claims rather than by the foregoing
description, and all changes which come within the meaning and
range of equivalency of the claims are therefore intended to be
embraced therein.
* * * * *