Note: Descriptions are shown in the official language in which they were submitted.
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SPECIFICATION
The invention relates to a drive for electric rail
traction vehicles which includes a traction motor driving a
drive shaft, which through a pinion drives a large toothed
bull gear connected to the driving rail wheel.
Drives heretofore have used various mechanisms
including such as that shown in German LO 25 14 265 in which '
a traction drive motor is included positioned between two
driving axles driven by an angular gear. A coupling
allowing longitudinal displacements is disposed between at
least one of the angular gears, and the rotor of the
traction motor with the coupling requiring a bearing and the
angular gear requiring two bearings.
It is an object of the present invention to provide
a drive for electric rail traction vehicles which overcomes
disadvantages in structures heretofore used such as that
referred Jo above, and which makes it possible to drive the
axles of an electric rail traction vehicle by means of
single motors or the halves of a double motor through
reduction of the number of pinion shaft bearings and
obtaining a short overall structural length of the motor and
gearing lit
A further object of the invention is to provide a
drive for electric rail vehicles wherein a coupling is
included between the drive motor and the Pinion shaft which
allows longitudinal or axial displacements without damage to
the pinion due to axial displacements of shafts during
operation.
A feature of the invention which obtains the
foregoing objectives to attained by providing a drive motor
which is constructed to have a hollow shaft which supports
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the rotor of the drive motor and providing a pinion shaft
which is located within and coaxial with the hollow motor
shaft Because of this construction, a long pinion shaft
can be provided which can guide and support the motor shaft
at the side of the pinion so that only two radial bearings
are provided for the drive motor and the axle gearing
unit Thus, the number of bearings required is as low as
possible, and even with double motors a short structural
length is achieved, and this also makes it possible to
reduce the axle base of the bogies.
As a feature of the invention, the motor shaft which
is hollow includes a guide bushing for the pinion shaft.
With this arrangement, the guidance of the motor shaft and
the pinion shaft together behave like a statically unitary
supported overall system. By the selection of a suitable
material, for example, My, the formation of rust is avoided
despite the fact that little relative movement will occur
between the guide bushing and the pinion shaft.
It is a further feature of the invention that the
motor shaft is hollow and the pinion shaft which extends
therein are interconnected to each other in driving
relationship with a friction type lock, such as by a
releasable clamping ring to thus form a motor shaft pinion
shaft which are essentially a unitary structure in
operation. By means of employing a releasable connection,
an easy and simple disassembly of the motor and gearing
arrangement is obtained, and disassembly is accomplished by
releasing the clamping ring with subsequent extraction of
the pinion shaft from the hollow shaft. Thus, despite the
compact design of the motor shaft and pinion shut unit an
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easy and simple replacement of both and of the motor as jell
as the axle gearing is possible.
A further feature is the construction where the
friction type lock is disposed at the side of the traction
motor opposite the pinion. In this construction, a pinion
shaft of the longest possible length without requiring
further length of the structure is obtained.
It is a further feature of the invention that the
pinion shaft and motor shalt, which is hollow, are connected
to one another through a coupling. This solution is
utilized in a form of the invention when the pinion shaft
does not extend fully through the hollow shaft over its
entire length, but extends only through a portion of a
recessed or hollowed-out suction of the motor shaft. This
variation in structure is somewhat longer than the
arrangement with a pinion shaft which extends through the
full length of the hollow motor shaft, but has the advantage
that torsional elasticity can be achieved through the
coupling.
It is a further feature of the invention that the
motor shaft and pinion shaft unitary arrangement is
constructed so that the pinion is locate in the axle gear
housing Thus, the arrangement of the short structure is
attained having a pinion shaft that provides a substantial
spacing for the bearings.
A further feature of the invention is the
possibility of providing a traction motor which is designed
as a double motor. With a double motor, it is possible to
simu7.ataneously drive two driving axles emanating from one
motor housing. This makes possible the elimination of a
coupling for allowing longitudinal displacements, and the
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overall structural length can be shortened.
A further feature of the invention is that the drive
provides a thrust bearing such as a two row shoulder bearing
for the axial adjustment of the motor pinion shaft unit.
This results from the disposition of the thrust bearing at
the pinion so that an expansion of the motor shaft and
pinion shaft unit due to heating during operation does not
change the adjustment of the pinion. The expansion that
results extends from the pinion bearing in the direction of
the other radial bearing which allows expansion and
contraction of the pinion shaft. As a result of the
foregoing construction, a coupling between the motor and the
axle gearing can be eliminated thereby eliminating the
negative consequences which occur with the addition of such
coupling. The correct position of the pinion relative to
drive gear as wow as the provision of a bearing which is
free from the tension or stresses which are induced by
expansion and contraction, is guaranteed.
A further feature of the invention is that the
traction motor axle and drive axle are positioned parallel
to each other. In other form, the axle gearing it designed
as a herringbone gearing with the tenth arranged so that no
axial thrust or stress is transferred to the drive shaft or
driven shaft. As a result of the parallel relationship in
shafts, the possibility is created fox special use in cases
of providing a motor disposition parallel to the driving
axle with the aforementioned elimination of the couplings
and with the provision of only two bearings. With the
herringbone gearing, good assembly and dismantling
possibilities derive. In this arrangement, the motor pinion
shaft is supported and seated as determined by static
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limitations, and operational factors do not induce
unforeseen stresses and problems An advantage of the
arrangement is that the control and guidance of the axle for
the drive wheel occurs automatically a a result of the
herringbone gearing so that a thrust bearing can be
eliminated. In viewing the structure from the center of the
herringbone gearing, the motor shaft and pinion shaft can
freely expand when heated so that no axial forces occur to
adversely affect the inter meshing toothed driving
relationship.
Other objects, advantages and features will become
more apparent with the additional teachings of the
principles of the invention in the following description of
the preferred embodiments in the specification, drawings and
claims, in which:
Figure 1 is a sectional view taken through a drive
unit along the axis of the pinion shaft ox a structure
constructed and operating in accordance with the principles
of the present invention;
Figure 2 it a vertical sectional view of another
form of the invention taken along the axis of the pinion
drive shaft; and
Figure 3 is a sectional view taken along the axis ox
the drive shaft of another form of the invention
As illustrated in Figure 1, the structure shown can
be constructed as the housing of a moo or single drive, but
it can also be constructed as halt of a bimotor drive in a
monoblock structure as is, for example, well suited for
short haul tray f to .
In the case of a bimotor drive in a monoblock
structure support is not required since two sides of the
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monoblock are held by the axle gearings Otherwise, a
support of the motor housing occurs in the center of gravity
of the axle gearing and motor unit, that is, at the axle
gearing at the side of the traction motor.
In the structure shown the drywall motor is shown to
the right of the figure, and the driving rail wheel and its
driving gear are shown to the left, all enclosed in a rigid
housing of parts suitably interconnected. These housing
parts may be secured to each other in various suitable ways
which need not be described in detail, but will be apparent
to those versed in the art from the description of the
overall structure. The enclosure includes a housing 1 for
the driving electric motor which includes a stators winding 2
mounted within the housing, and a rotor winding 3 which is
rotatable carried in the housing. The rotor winding 3 is
coccal mounted on a hollow shaft 4. Extending coccal
within the hollow shaft 4 is a pinion shaft 5. The pinion
shaft 5 is drivingly and releasable connected to the motor
hollow shaft 4 by a friction type lock with a releasable
clamping ring such as including a bi-conical ring 12, which
is a preferred form, although other forms of releasable
driving connections between the shafts 4 and 5 may be
adopted.
The pinion shaft 5 is supported radially for
rotation in radial bearings it and 7 which are suitably
carried on the overall housing, which housing includes the
motor housing 1 and the gear housing 17. Also included
within the structure it a thrust bearing 8 which supports
the pinion shaft 5 and which is located between the motor
and a pinion gear 14 on the shaft so that essentially all of
the driving portion of the shaft 5 is between the thrust
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bearing 8 and the connection of the shaft 5 to the hollow
motor shaft 4. The connection 12 which drivingly
interconnects the motor shaft 4 and the gear shaft Jo it
constructed so that relative axial movement can be
countenanced between the hollow motor shaft 4 an the drive
shaft 5 and therefore no internally induced axial stresses
will be transmitted to the thrust bearing 8 so that this
contributes to retaining the alignment between the drive
pinion 14 and the driven bull gear 15.
The hollow shaft 4 of the motor 1, and the elements
carried thereon are not seated in ball bearings, but rather
are supported on the pinion shaft 5 held on a bushing 9
positioned between the pinion shaft 5 and the hollow shaft 4
on the left side of the motor, as shown in the drawing,
which is the opposite end of the motor from the location of
the drive connection 12. The bushing positively carries the
hollow shaft 4, but accommodates relative limited axial
movement such as might occur with changes in length due to
temperature variation. The other end of the hollow shaft 4,
opposite the bushing is axial supported by the drive
connection 12.
The bearings 6 an 7 which radially support the
pinion shaft 5 are sealed and protected by a labyrinth seal
13, protecting the bearing 6 and by flanged seal 11,
protecting the radial bearing 7 and the thrust bearing 8.
The hollow motor shaft 4 alto carries a fan 18 which
ventilates the interior of the housing 1 through end
openings aye and 18b in the housing for cooling the motor.
A driving axle 16 is secured to the driving rail
wheel and carries a bull gear 15 driven by the pinion 14.
Pro the purpose of accepting the pinion bearing 7, the axle
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gearing housing 17 has an annular extension or neck portion
19 which is flanged so as to be secured to the motor housing
1 by suitable means. The drive unit thus is compact and
retains adjuster with the pinion 14 maintaining its proper
axial position relative to the bull gear 15 as determined by
the radial support bearing 7 and the thrust bearing 8, which
are locked in positive adjustment at the time the mechanism
is assembled. The pinion shaft 5 is of considerable length
to permit torsional and radial elasticity due to drive
stresses and due to changes in dimension with thermal
changes, and the drive power for the mechanism is positively
delivered from the electric motor rotor through the gearing
to the driving rail wheel with a compact construction.
In the arrangement of Figure 2, another torsionally
elastic arrangement is provided with further torsional
elasticity introduced, and this construction provides a
slightly longer structure than the arrangement of Figure 1,
but employs similar principles in utilizing a motor shalt
which can be fully hollow but need only be only be partially
hollow. The motor shaft I is supported in radial bearings
21 and 23 which are supported in a motor housing 1'. The
motor includes a stators 2' within the housing and a rotor 3'
which is carried directly on the shaft 20 as is a
ventilating fan 18l. The motor shalt 20 has a hollow or
bored portion into which an end Z3 of the pinion shaft 5' is
inserted. The end 23 is guided or centered with a bushing
22 between the interior of the motor shaft 20 anal the
extension 23.
The rotational drive between the motor and the
pinion shaft 5' is accomplished by a torsionally elastic
connection 24 providing a driving coupling. the torsionally
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elastic connection, or coupling 24, is suitably connected
such as by splints shown diagrammatically by the dotted
lines to the motor shaft 20 and Jo the pinion shaft 5'0
A bull gear 29 is ion driving mesh with the pinion 31
on the pinion shaft 5 , and the bull gear 29 it carried on a
rail wheel axle 16'. The bull gear I and the drive pinion
31 are carried in the axle gearing housing 35 which has a
flange-like neck extension 33 to connect to the motor
housing 1'. The neck 33 is of sufficient length to
accommodate the elastic coupling 24. A bearing flange 30
holds a thrust bearing 32 and a radial bearing 27 which are
assembled by being inserted into the housing neck 33, and
these bearings radially and axially position the pinion
shaft 5 maintaining the pinion 31 in proper mesh with the
bull gear 29. The coupling 24 is connected to the pinion
shaft by splints as above described or by means of a
screwed-on bushing 25. this arrangement can be designed as
both a jingle motor drive having a support in the center of
gravity or as a bimotor arrangement in monoblock structure.
In the arrangement of Figure 3, a herringbone gear
drive is utilized Driving rail wheels 60 and 61 are shown
mounted on an axle 16",
A pinion shaft 44 extends through a hollow shaft 43
which supports the rotor winding 42 of the motor with a
ventilating fan 480 The motor is enclosed by a housing 40
which surrounds the twitter winding 41. A right hand end
bearing 28" at the end opposite a pinion 52 is supported in
the housing. A labyrinth seal having part I and 46
protects the bearing from the motor. A labyrinth seal I at
the other end of the pinion shaft protects a bearing 50
which supports the pinion end of the pinion shaft 44. the
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bearing 28i' and 50 are radial bearings, and the need for an
axial thrust bearing is eliminated by the use of the
herringbone pinion and herringbone bull gears 53 which have
teeth cut in opposite directions to eliminate axial thrust.
A guide bushing 47 is provided at the pinion end of
the pinion shaft 44 supporting and centering the hollow
shaft 43 of the motor. The other end of the pinion shaft
supports the hollow motor shaft 43 at the location of a
releasable bi-conical ring drive 12". The drive acts as a
clutch and may take various forms, but is shown as a bit
conical arrangement with a center hub that has sloping
shoulders and outer rings which clamp to the shoulders when
pressed together. The outer rings are connected to an end
ring mounted on the shaft so that when the outer rings are
pressed together, the shaft 44 will be drivingly connected
to the hollow shaft 43. Spreading of the rings will release
the two shafts. The arrangement transmits rotary driving
torque from the motor hollow shaft 43 to the pinion shaft 44
at the right end providing a pinion shaft of substantial
length to accommodate operational factors such as drive
torsion, misalignment, vibration and temperature changes.
The pinion shaft 44 is seated coccal and statically in
the bearings 28" and 50" at its ends. The arrangement of
the coaxial parallel nested shafts is particularly well
suited for driving axles with three phase motors. Within
the framework of the concepts of the invention, other
traction motors can be employed. The advantages of low
structural size and a low number of bearings is accomplished
through both arrangements.
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Thus it will be seen that we have provided an
improved drive for an electrical rail traction vehicle which
achieves the advantages and objectives above set forth, and
applicants wish to cover all equivalent structures and
embodiments embraced within the concepts of the foregoing
described invention.
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