PASSIVE STEERING FOR A THREE PIECE RAILWAY TRUCK

DIRECTION PASSIVE DESTINEE A UN WAGON DE CHEMIN DE FER A TROIS PIECES

English Abstract

The traditional three piece railway freight truck prevents the wheel sets from achieving radial alignment to curves by the rigid side frames restraining the wheelsets. The side frames also constrain the wheelset from radial aligning to curves by the limited gap between the wheelset bearing and the side frame pedestal jaws. The present invention opens the side frame pedestal jaws to allow the wheel sets to yaw and align radially to curves. The side frame is supported on wheel sets by elastomeric pads and bearing adapters. The present invention utilizes the elastomeric pad stiffness to compress in pitch motion that allow the wheel set to move in an arc forward or backward in the open jaws of the side frame. The elastomeric pad stiffness also allows the wheelset to twist the pads allowing the wheelset to radially align to the curve. The pads elastic stiffness is sufficient to return when the wheelset is align to straight track.

French Abstract

Linvention concerne le traditionnel camion de fret ferroviaire qui empêche les essieux montés darriver à un alignement radial par rapport aux courbes grâce aux châssis latéraux contenant les essieux montés. Les châssis latéraux limitent également les essieux montés dadopter un alignement radial par rapport aux courbes en limitant lécart entre le roulement des essieux montés et la plaque de garde des châssis latéraux. La présente invention ouvre la plaque de garde des châssis latéraux pour permettre aux essieux montés de virer et de saligner radialement aux courbes. Les châssis latéraux sont appuyés aux essieux montés par des tampons élastomères et des adaptateurs de roulement. La présente invention utilise la rigidité du tampon élastomère qui se comprime en mouvement de tangage qui permet aux essieux montés de bouger en arc vers lavant ou vers larrière dans les plaques de garde ouvertes des châssis latéraux. La rigidité du tampon élastomère permet également aux essieux montés de tordre les tampons, permettant aux essieux montés de saligner radialement à la courbe. La rigidité du tampon élastomère est suffisante pour reprendre sa forme initiale lorsque les essieux montés est aligné à une voie droite.

Claims

What is claimed is:
1. A railway car truck comprising
a bolster and two parallel sideframes,
the bolster having two ends each received in an opening in one of the
sideframes,
a spring group supporting the bolster end in each sideframe,
each sideframe having two pedestal ends,
two axles each having two ends,
two wheels each fitted to a journal portion of each axle,
a plurality of axle bearings each fitted on one of the axle ends,
a plurality of adapters each with an adapter pad, with each adapter and
adapter pad received
in one of the sideframe pedestal ends,
wherein each adapter pad has a resistance to pitch and twist such that a
longitudinal steering
force created between the wheels to rails of a wheelset of from 5,000 to 7,000
pounds is
sufficient to radially align the wheelset with a curve in a railway track,
wherein
the sideframe pedestal end is comprised of longitudinally spaced jaws that
allow the adapter
pad to deform to allow the wheel set to yaw to align with the curve in the
railway track and,
wherein
the adapter pad will deform enough to allow the wheel set to yaw to align with
a curve of up
to 10 degrees in the railway track curve.
~6~

2. A railway car truck comprising
a bolster and two parallel sideframes,
the bolster having two ends each received in an opening in one of the
sideframes,
a spring group supporting the bolster end in each sideframe,
each sideframe having two pedestal ends,
two axles each having two ends and two journal portions,
a wheel fitted to a journal portion of each axle,
a plurality of axle bearings each fitted on one of the axle ends,
a plurality of adapters each with an elastomeric adapter pad, with each
adapter and
elastomeric adapter pad received in one of the sideframe pedestal ends,
wherein each adapter pad has a resistance to pitch and twist such that a
longitudinal steering
force created between the wheels to rails of a wheelset of from 5,000 to 7,000
pounds is
sufficient to radially align the wheelset with a curve in a railway track,
wherein
the sideframe pedestal end is compriscd of longitudinally spaced jaws that
allow the adapter
pad to deform to allow the wheel set to yaw to align with the curve in the
railway track and,
wherein
the adapter pad will deforin enough to allow the wheel set to yaw to align
with a curve of up
to 10 degrees in the railway track.
~ 7 ~

3. The railway cart truck of claim 2 wherein
the sideframe pedestal jaws that are opened .331 inches on either side of the
bearing to allow
the adapter pad to deform to allow the wheel set to yaw to align with the
curve in the railway
track.
4. A railway car truck comprising
a bolster and two parallel sideframes.
the bolster having two ends each received in an opening in one of the
sideframes,
a spring group supporting the bolster end in each sideframe,
each sideframe having two pedestal ends,
two axles each having two ends and two journal portions,
a wheel fitted to a journal portion of each axle,
a plurality of axle bearings each fitted on one of the axle ends,
a plurality of adapters each with an elastomeric adapter pad, with each
adapter and
elastomeric adapter pad received in one of the sideframe pedestal ends,
wherein each adapter pad has a resistance to pitch and twist such that a
longitudinal steering
force created between the wheels to rails of a wheelset of from 5,000 to 7,000
pounds is
sufficient to radially align the wheelset with a curve in a railway track,
wherein
the sideframe pedestal end is comprised of longitudinally spaced jaws that
allow the adapter
pad to deform to allow the wheel set to yaw to align with the curve in the
railway track and,
wherein
~8~

the sideframe pedestal jaws that are opened .331 inches on either side of the
bearing to allow
the adapter pad to deform to allow the wheel set to yaw to align with the
curve in the railway
track.
~9~

Description

H8324368CA
PASSIVE STEERING FOR A THREE PIECE RAILWAY TRUCK
BACKGROUND OF THE INVENTION
The traditional three piece railway freight truck consists of one bolster and
two side
frames. The bolster which carries the car body extends centrally through the
side frames. The
bolster is supported by a suspension consisting of springs that support the
bolster and friction
shoes with springs that create damping on vertical bolster movement. The
suspension is
centrally located and supported by the side frame. The side frames ends have
pedestal jaws that
support on and capture the bearing adapters. The bearing adapters are
supported on the wheelset
axle bearings. The wheel set consists of a live axle with wheels and bearings
at the ends.
The truck steering mechanism consists of tapered cone wheel treads. When the
truck
enters a curve, the rail turns out from under the center of the wheel treads.
As the rail moves out
from under the center of the wheel tread, the tapered cone changes each
wheel's diameter and the
circumference of the wheel on the outside of the curve becomes larger and the
wheel to the
inside of the curve circumference become smaller. The distance the wheels roll
down the rail
becomes uneven which yaws the wheelset and attempts to radially align the
wheel sets to the
curve.
The traditional three piece railway freight truck may prevent the wheel sets
from
achieving radial alignment to curves due to the rigid side frames acting to
restrain the wheelsets
from aligning with a curve in the rails. The side frames also may constrain
the wheelset from
radial aligning to curves by the limited gap of .144 inches on either side of
wheelset axle bearing
and the side frame pedestal jaws.
The present invention opens the side frame pedestal jaws to .331 inches on
either side of
wheelset axle bearing and the side frame pedestal jaws to allow the wheel sets
to yaw and align
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radially to curves. The side frame is supported on wheel sets by elastomeric
pads and bearing
adapters. The present invention utilizes the stiffness of the elastomeric pad
to allow the adapters
to pitch and twist in the open jaws of the pedestal. The adapter pitch motion
is what allows the
wheel set to move in an arc forward or backward in the open pedestal jaws of
the side frame.
The elastomeric pad also allows the wheelset to twist the pads allowing the
wheelset to radially
align to the curve. The pads elastic stiffness is sufficient to return when
the wheelset is align to
straight track.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings,
Fig. 1 is a perspective view of a traditional three piece railway freight car
truck assembly
of a passive steering three piece railway car truck in accordance with a first
embodiment of the
present invention;
Fig. 2 is a detailed exploded partial view of the relationship the pad and
adapter to the
side frame and wheel set of the passive steering three piece railway car truck
in accordance with
a first embodiment of the present invention;
Fig. 3 is a top view of a railway car truck in a curve with the adapters also
shown as
pitched in separate side views, of the passive steering three piece railway
car truck in accordance
with a first embodiment of the present invention;
FIGS. 4A-4D are detailed sectional views of a yawed railway car truck wheel
set with the
relationship between pitch and yaw of the adapter on the elastomeric adapter
pad, of the passive
steering three piece railway truck in accordance with a first embodiment of
the present invention.
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FIGS. 5A and 5B are detailed sectional views of a Pitched and twisted adapter
compressing the elastomeric adapter pad, of the passive steering three piece
railway truck in
accordance with a first embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to Fig. 1, is a perspective view of a traditional three piece
railway freight
car truck assembly 1 is seen to be comprised of two laterally spaced side
frames 3 between
which bolster 4 laterally extends. Bolster 4 is seen to extend through a
central opening in each
side frame 3. Suspension 5, usually comprised of a coil spring group, is seen
to support the
bolster 4. The side frames 7 are supported at the pedestals 14 by adapter pad
6 and adapter 7
setting on axle bearing 8 of the wheelsets 2. The wheelset 2 consists of two
wheels 10 pressed
onto a journal portion near ends of an axle 9. The wheelset 2 has axle
bearings 8 mounted at both
ends of axle 9. Adapter pads 6 are typically comprised of a structural
elastomer such as
Urethane.
Referring now to Fig. 2, is a detailed exploded partial view of the
relationship the
elastomeric adapter pad 6 and adapter 7 to side frame 3 at the pedestal 14.
The adapter 7 is
seated on bearing 8. The end of wheel set 2 is shown with wheel 10 on axle 9.
The wheel 10 has
a tread 16 that is outwardly tapered in a cone shape. Sideframe pedestal
opening is formed by
depending jaws 12 and pedestal roof 15. The inside surface of jaws 12 may
include lugs 13 to
help position and hold adapter 7. Elastomeric adapter pad 6 vertically
captured between the
adapter 7 top surface 26 and the pedestal roof 15. The Legs 27of the
elastomeric adapter pad 6
are laterally captured between the lugs 13 and the adapter 7.
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Referring now to Fig. 3, is a top view, with a side views of each pedestal 14
and wheel,
of a railway car truck 1 in a curve 11 with the adapters 7 pitched 22 and 23.
When the railway
car truck 1 enters a curve 11, the rail turns out from under the center of the
wheel treads 16. As
the rail moves out from under the center of the wheel tread, 16 the tapered
cone essentially
changes the wheel's diameter with regard to the center axle ¨ rail distance
such that the
circumference 17 of the wheel on the outside of the curve becomes larger and
the wheel to the
inside of the curve circumference 18 becomes smaller. The distance the wheels
roll down the
rail becomes uneven which yaws 19 the wheelset 2 and aligns the wheel sets 2
to the curve 11.
The side frame 3 at the pedestals 14 have open jaws 12 to allow the wheel sets
2 yaw 19. The
elastomeric adapter pads 6 become unevenly vertically loaded as the wheel set
2 yaws 19 on
adapter 7. The uneven vertical loading compresses the elastomeric adapter pad
6 at one end
more than the other. This acts to pitch the adapter in 22 for the inside of
the curve 11 and pitch
the adapter out 23 for the outside of the curve 11.
FIGS. 4A-4D show detailed sections of a yawed wheel set 2 with the
relationship
between pitch 22 and 23 and twist 24 and 25 of the elastomeric adapter pad 6
on adapter 7. The
wheel set 2 supports the adapter 7 and the elastomeric adapter pad 6 on the
pedestal roof 15 of
the side frame 3. The vertical load on the elastomeric adapter pad 6 is evenly
distributed when
the wheel set 2 is rolling on straight track. When the wheel set 2 is yawed in
curves the vertical
load on the elastomeric adapter pad 6 becomes uneven and the adapter pitches
22 and 23. As the
adapter pitch as shown at 22 and 23 the adapters also twist on the elastomeric
adapter pad 6. The
twisted 23 and 24 adapter 7 is constrained by lugs 13 in the top of the open
jaws 12. Each
adapter 7 and adapter pad 6 is received in one of the sideframe pedestal ends
formed by jaws 12.
Each adapter pad 6 has a resistance to pitch and twist such that a
longitudinal steering force
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created between the wheels to rails of a wheelset of from 5,000 to 7,000
pounds is sufficient to
radially align the wheelset with a curve of up to 10 degrees in a railway
track. Further, jaws 12
are open enough to allow such deformation of the adapter pads 6 to allow the
wheel set to yaw to
align with the curve in the railway track. The pedestal jaws 12 are opened
.331 inches on either
side of the bearing to allow space for the adapter 7 to pitch and twist
against adapter pad 6. The
open jaws 12 is sufficient for wheelset 2 to radial align to a 10 degrees in
the railway track curve.
FIGS. 5A and 5B show detailed sectional views of a Pitched 23 and twisted 25
adapter 7
compressing the elastomeric adapter pad 6. The yawed wheelset bearing 8
creates longitudinal
force about the bearing 8. The longitudinal force creates a moment about the
top surface 26 of
adapter 7. The longitudinal force and displacement of bearing 8 cause the
adapter 7 to compress
the elastomeric adapter pad 6 unevenly in the direction of the displacement.
The uneven vertical
displacement of the elastomeric adapter pad 6 pitches the adapter 7 and
bearing 8. Bearing 8 is
also yawing as it is displaced. The adapter 7 sitting on bearing 8 is forced
to accommodate the
yawing motion. Adapter 7 twist 25 the elastomeric adapter pad 6 and compress
the elastomeric
adapter pad 6 legs 27 against lugs 13 to allow the yawing motion.
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Representative Drawing