Improvements in Dynamo Electric Driving Apparatus especially suitable for Propelling Vehicles.
Year: 1897

page_text: Date of Application, 18th Aug., 1897-Accepted, 25th Sept., 1897
Improvements in Dynamo Electric Driving Apparatus especially
suitable for Propelling Vehicles.
I, PAUL LEOPOLD GOLDSCHMIDT, of 17 Rue des deux Eglises, Brussels, Belgium,
Engineer 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 relates to improvements in dynamo electric apparatus designed
for use in transmitting power, more particularly in propelling vehicles, especially
traction engines.
Heretofore, the most general and frequently met with electric motors have been
constructed with movable field magnets although sometimes, the field-magnets
have been fixed whilst the armatures have rotated. Now, according to the present
invention, both the field-magnet and the armature are arranged to move in opposite
directions. This has the result, first of considerably reducing the number of
revolutions, and secondly, of dispensing with the use of differential gears, which
has heretofore been necessary for the purpose of rendering the motion of the two
driving wheels independently of one another when using electric motors for pro-
pelling vehicles (such as traction engines) over roads where curves or bends occur.
The accompanying drawings illustrate apparatus according to this invention.
Fig. 1 is an elevation partly in section, and Fig. 2 is a plan of Fig. 1.
As will be seen the apparatus comprises an armature a and field-magnet b. The
current is supplied by means of the ring or commutator c.
The armature and the field-magnet are keyed on separate shafts m and n which
run in suitable fixed bearings d which are in turn mounted on the main driving
shaft in such a manner that the said shaft is capable of rotary movement.
One of the shafts, for example, the shaft m of the field magnet 6 terminates in a
toothed wheelf which gears with a toothed wheel h fixed to the wheel k. The
other axle, that is to say the axle n of the armature a, also terminates in a toothed
wheel f', which gears with an internally toothed wheel g fixed to the other
wheel k¹.
The power can, of course, be taken off from the ends of the shafts m and n in any
other manner than by means of toothed wheels.
The operation of the above described arrangement will be clearly understood.
As is obvious, the otherwise indispensable arrangement of gearing for reducing
the number of revolutions of the motor and which causes loss of power due to
frictional resistance, is rendered unnecessary because the speed is reduced to one
half by reason of the motion of the armature as well as the field-magnets. A
further result of this arrangement consists in that a motor of half the weight of
that which would otherwise be necessary under equal conditions, is sufficient
which is of considerable importance in the case of traction engines and vehicles.
Furthermore the use of differential gear-the disadvantage of which, namely con-
siderable wear and tear, and consequently faulty working, loss of power, and
increase of weight, are well known--is rendered superfluous by the use of this
arrangement.

page_text: Assuming the case that the wheel k runs on the inside of a curve, then it will
be readily understood that the wheel k¹, which runs outside, will be moved more
quickly, the special arrangement of the dynamo described rendering the use of
differential gear unnecessary. In fact, by reason of the simplicity of the con-
struction, the improved arrangement has a much more favourable useful effect
than obtains in the case when differential gearing is used.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. Dynamo electric driving apparatus in which the motion of the armature a
and of the field-magnet b is respectively transmitted directly to shafts 'm and n
in such a manner that the number of revolutions is reduced in consequence of the
relatively independent motion of the field-magnet 6 and of the armature a, whereby
intermediate and differential gearing can be dispensed with and the said shafts
rendered independent of each other, substantially as described.
+
2. The lynamo electric driving apparatus for vehicles shewn in and described
with reference to the annexed drawings.
1
101 1
100%
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.