Improvements in Electric Motor Cars.
Year: 1892

page_text: e of Application, 22nd Jan., 1892-Accepted, 12th Mar., 1892
COMPLETE SPECIFICATION.
Improvements in Electric Motor Cars.
1 SIDNEY HOWE SHORT, Electrician of Cleveland State of Ohio in the United
States of America do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :--
This invention has reference to improvements in electric motor cars, and it
relates more particularly to the propelling mechanism of such cars and has for its
object the simplification of such mechanism and its efficient operation, without the
intervention of gearing for coupling the propelling motor with the driving axle or
axles of the car.
I have found that when a current of sufficiently low potential is used for actuating
the motor of an electric locomotive, it is practicable to couple the rotary element
of the motor, whether it be the armature or the field magnet, directly with the
driving axle or axles, provided that the motor is so constructed that it will generate
a comparatively high counter-electric-motive force at a moderate speed. In my
gearless motor car, therefore, the magnetic field of force must be intense, and for
this purpose the field magnets must be powerful and must be so related to the
armature that the magnetic lines of force are as little diffused as possible. With
this provision I have found it not only practicable, but of great advantage to couple
the armature directly to the driving axle, and to dispense with all gearing for
The
reducing the speed of the axles with reference to the speed of the armature.
advantages are manifold, and among them may be named a considerable reduction
of friction and consequent wear of the mechanism; the case of access to the
mechanism for inspection and repair; the avoidance of noise which is necessarily
caused by every kind of gearing, and greater efficiency of the motor and consequent
reduction of the running expenses.
In the following detailed description in which reference is made to the accom-
panying drawing, my invention is described in detail, but I desire it to be understood
that I do not mean to be limited to the identical details of construction hereinafter
shown and described, since these may be very easily changed without departing
from the fundamental idea which underlies my invention.
Figure 1, represents a plan view, partly in section, of an electric motor car truck,
with a motor for each driving axle;
Figure 2, a sectional view on line - of Figure 1 ;
Figure 3, a perspective view of one driving axle with the wheels and the pro-
pelling motors, with slight modifications.
Figure 1, is a detail view, partly in elevation and partly in section, of the
coupling between the armature and the driving wheel or axle, and
A
Figure 5, represents an end view of the motor armature partly broken away.
Like numerals of reference indicate like parts all throughout the drawing.
Referring now more particularly to Figures and 2, it will be seen that the car
axle boxes 1, are mounted upon a suitable truck frame and that the car axles 2,
carrying the wheels 3, are mounted in the axle boxes in the ordinary manner.
sleeve 4, the inner diameter of which is considerably greater than that of the car
axle, surrounds the latter, and this sleeve passes at one end loosely through the
yoke 5, of the field magnets 6, and is journaled in a bracket 7, which extends from
said yoke; while to the other end of the sleeve is secured an expanded thimble 8,
which in effect is a continuation of the sleeve, and which is journaled in the yoke 9,
of the field magnets, as will hereinafter be more fully described. From this
thimble 8, project at right angles to the same, at diametrical opposite sides, the

page_text: :
forks 10, the legs of which are provided with metal cups 11, in each of which is
fitted a block 12, of soft rubber, which projects from the cup and has fitted upon
its free end another metal cup 13, so that the outer faces of the metal cups 13 face
each other. Between these two metal cups 13, extends an arm 14, from the
driving wheel on this end of the car-axle; and it will now be seen that if the
sleeve 4, rotates, rotation will also be imparted to the driving wheel. and axle, by
means of the forks 10, and the arms 14, extending between the same and in sliding
contact with the metal cups 13. The rotation of the sleeve 4, is produced by the
armature 15, mounted upon the sleeve, as will be readily understood.
In this construction the armature is axially mounted with reference to the car
axle; is loose upon the car axle, and may have an up and down and lateral move-
ment with reference to the same.
The armature carrying sleeve, as has been seen, is journaled at one end in the
bracket 7, which extends from one of the field magnet yokes, and is journaled at
the other end in the field magnet yokes 9, proper. I have found it to be of
peculiar advantage to reduce the friction in these bearings as much as possible,
and with a view to this I provide roller bearings between the yoke 9, and the
thimble S. As will hereinafter more fully appear, the field magnets are made in
two parts, the.division line passing through the center of the yoke, and this enables
me to provide the roller bearing for the thimble 8, by inserting in the wide opening
in the center of the yoke 9, a flanged sleeve 16, and in the annular recess thus
formed between the sleeve 16, and the thimble 8, are placed the anti-friction
rollers 17. A similar construction is used, or may be used in the bearing for the
other end of the sleeve 4, in the bracket 7. From the field magnet yoke there
extend arms 51, 91, which are elastically connected with the side or end bars of the
truck frame by couplings 18, the details of construction of which are illustrated in
Figure 2. In this manner the field magnets are held against rotation with the car
axle, but are allowed a slight up and down movement, while the axle is allowed an
up and down movement and also lateral vibrations by the springs upon which the
journal boxes are mounted, as usual, and by the self-accommodating coupling
between the sleeve, upon which the armature is mounted, and the driving wheel.
These displacements of the car axle with reference to the sleeve 4, or its extension,
the thimble 8, should never exceed a certain limit, since this displacement corre-
ponds to a displacement of the armature with reference to the field magnets. For
this reason interpose an elastic cushion between the sleeve and the car axle.
This elastic cushion may consist of a sleeve 19, of soft rubber interposed between
the car axle and the sleeve 4, as indicated on the right hand side of Figure 1; but
by preference, I avoid the use of such soft rubber sleeve and use in place thereof
metallic springs placed within the thimble 8, between the inner wall of the latter
and the car axle. For this purpose a short metallic sleeve 20, is secured upon the
car axle where the same passes through the thimble 8, and a number of helical or
leaf springs 20¹, are interposed between that sleeve 20 and the thimble, thus
affording an elastic cushion between the car axle and the armature, and limiting
the relative displacement of the two by reason of the shocks and jars incidental to
the travelling of the car.
The connection of the field magnets with the truck frame is shown in detail in
two modifications in Figures 1 and 2. In one of these forms the arms 5', 9¹, which
extend from the yokes of the field magnet, are straight, and pass over the cross
bars 21, of the truck frame. To these cross bars are bolted heads 22, by bolts
passing through ears 23, and through the cross bars; these heads have each a
central perforation which corresponds to a like perforation in the armis 51, 91, and
through which, and through a soft rubber cushion 24, interposed between each head
and the corresponding arm 51 or 91, passes a bolt 25. By preference the bolt
where it passes through arms 5' or 9', is insulated from the latter, as indicated by
appropriate shading in Figure 2.
In the other form the arms 51, 91, are curved outwardly and upwardly, and are
connected with the side bars of the truck frame, in the same manner in which the

page_text: straight arms are connected with the cross bars of the truck frame, so that in each:
case the field magnets are supported on opposite sides of the car axlé: .
Each of the field magnets, has four pole pieces, symetrically arranged with
reference to the car axle, and to the armature, so that there are altogether cight
poles, between which the armature revolves.
1
By reference to Figure 3, it will be seen that the field magnets and armature are
protected against the accession of dirt, and against external mechanical injury, by.
an enveloping casing 26, which may be made of sheet iron, but which by preference
is made of cast iron. It is made in two parts, each part provided with four lugs 27,
by which the two parts are bolted together, as illustrated. Each half of this.
enveloping casing may be cast in one piece with sections of the field magnet yokes,
that is to say, each half of the casing may have one half of a field magnet yoke at
each end formed with it, as indicated in Figure 3; but the casing may also be
formed independently of the field magnets, as will be readily understood.
On top of the casing there is formed an opening 28, by which access may be had
to the armature and field magnet; this opening need not be closed, since it is in a
position where dirt cannot easily reach the motor.
In Figure 3, there is shown a modified: structure of the coupling, between the
armature sleeve and the driving wheels. In this case instead of a fork 10 pro-
jecting from the thimble 8, as shown in Figures 1 and 4, there is only one arm 10',
which has formed at its free end a head 29, while on the arm 14, which projects
from the wheel, there is formed a socket 30, which receives the rubber cushion 12,
and a bolt passing rather loosely through the head 29, the rubber cushion and the
arm 14, establishes the coupling between the armnature and the driving wheel. By
preference, two such connections are made with each driving wheel.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. An electric motor car having the armature of an electric motor axially
mounted with reference to a driving axle and directly connected therewith,
without the intervention of gearing, and the field magnets journaled upon the
armature shaft and held against rotation by an elastic connection with the truck
frame.
2. An electric motor car having the armature of an electric motor mounted
upon a sleeve concentric with and cushioned against a car axle and directly
connected with the driving wheels, and the field magnets journaled upon the
sleeve and held against rotation by an elastic connection with the truck frame.
3. An electric motor car having the armature of an electric motor axially
mounted with reference to and directly connected with a driving axle or driving
wheel, and field magnets also axially mounted, with their pole pieces extending
parallel with the car axle, and symetrically disposed with reference thereto and to
the armature.
4. An electric motor car having an electric motor composed of an axially
mounted and directly connected armature; field magnets the yokes of which are
journaled in roller bearings concentric with the car axle, and an elastic connection
between the field magnets and the truck, whereby the magnets are held from
rotation but are allowed a rocking motion, substantially as described.
5. A gearless electric motor car, having the armature of the electric motor
mounted axially with reference to a car axle and elastically cushioned against the
same, and self accommodating coupling between the armature and driving wheels ;
in combination with field magnets journaled concentric with the car axle, and an
elastic connection with the truck frame for preventing rotation of the field magnets,
substantially as described.
6. A gearless electric motor car having the armature of an electric motor axially
and elastically mounted upon the car axle; an elastic self accommodating coupling
between the armature and driving wheels and field magnets journaled upon the

page_text: armature support and held against rotation by an elastic connection with the truck
frame, substantially as described.
7. A gearless electric motor car having the armature and field magnets supported
by a car axle, and an elastic connection between the field magnets and truck frame
for preventing the rotation of the former; in combination with an elastic self
accommodating coupling between the armature and driving wheels, substantially as
described.
8. An electric motor car having the armature of an electric motor axially
mounted with reference to a car axle and a magnetic bridge or shield over the coils
of the armature and in contact with the core of the armature; in combination with
field magnets the poles of which are in inductive proximity to the magnetic bridge,
substantially as described.
Dated this 22nd day of January 1892.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicant.