Improvements in Dynamo-electric Machines.
Year: 1898

page_text: Date of Application, 14th Sept., 1898-Accepted, 3rd Dec., 1898
COMPLETE SPECIFICATION.
Improvements in Dynamo-electric Machines.
I, JAMES BURKE, of 23/24, Oudenarderstrasse, Berlin N., Germany, Electrical
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 the construction of magnet frames for
dynamo-electric machines-both generators and motors-and is applicable to
bipolar and multipolar machines with a two part field frame.
It is essential for the perfect working of a dynamo that the armature should be
concentrically placed in the magnetic field and that there should be a perfect
and permanent alignment between the two bearings carrying the armature.
With ordinary constructions of magnet frames it is not without difficulty that a
correct alignment and concentric position of the armature can be obtained after
having once removed the bearings and armature.
In order to obtain perfect alignment and concentric position of the armature
there is provided in accordance with this invention a frame or cradle made of a
single metal casting, provided at each end with bearings for the armature shaft.
This cradle is placed between the upper and lower half of the magnet frame,
forming part of the magnetic circuit, the whole being bolted together. Thus the
armature may be readily taken out of the dynamo or motor by removing the upper
part of the field and then lifting out the cradle without in the least disturbing the
alignment of the armature. The bearing boxes for the armature are preferably cast
in one piece with the cradle, but they may also be made separately and secured
thereto in some substantial manner. The cradle may also be provided with side
bearings for the purpose of supporting a counter shaft, parallel to the armature
shaft and in connection with the latter through some suitable transmitting
device.
In the accompanying drawings, Fig. 1 shows a front view of a dynamo constructed
in accordance with this invention, Fig. 2 an end view thereof and Fig. 3 a plan
view of the cradle which carries the armature.
Fig. 4 is a side view of a modified form of dynamo in accordance with this
invention.
Fig. 5 is a side elevation of a form of the machine adapted to be attached
to a ceiling and provided with a counter shaft driven by the armature shaft
by means of gear wheels and Fig. 6 is a plan view of the machine shown in
Fig. 5.
M and M¹ are the two halves of the magnetic field each of which is fitted with
one half of the number of pole pieces and magnet coils. R is a cradle supporting
the bearings and armature. This cradle is inserted between the two halves of the
magnet frame and connected firmly therewith by means of bolts B. C indicates
Land L' are the
the collector and S the driving pulley on the armature shaft.
bearing boxes for the armature shaft. The said bearings boxes form one
piece with the cradle R, and are fitted in the usual way with renewable
bearings.
Electromotors and the like constructed as herein described may be mounted on
a ceiling without material change in their construction, it being sufficient to reverse

page_text: the positions of the upper and lower parts of the magnet frame, leaving the cradle
in its original position, as shown in Fig. 5.
Fig. 4 shows a machine in which the cradle does not form part of the magnetic
circuit, but rests on lugs T cast with the lower half of the magnet frame to which
the cradle is fastened by means of screw-bolts.
In the modification shown in Figs. 5 and 6 the armature shaft is provided with a
gearwheel Z and the countershaft with a gearwheel Z'. A countershaft V is placed
in bearings D and D¹. It is evident that by this arrangement the shaft of the
armature and the countershaft V will at all times remain in a parallel position.
Such motors are particularly well adapted for use as street car motors, or, attached
to a ceiling, for the propulsion of line shafting.
Electromotors of such construction offer great advantages for use with electric
street cars or other electric vehicles, one of the axles taking the place of the
countershaft V, passing through the bearings D and D¹, the frame of the motor
being suspended by springs in the usual manner. It will be obvious that a second
countershaft may be provided on the opposite side of the cradle, bearings similar
to D and D¹ being provided, so that the inotor may act directly on two axles of the
vehicle.
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. A dynamo-electric machine, in which the armature is carried in a yoke or
cradle (R), which is supported by one of, or interposed between, the two parts or
members of the magnet frame, for the purpose of securing and maintaining perfect
aligument for the armature.
2. A dynamo-electric machine of the kind described in Claim 1, in which the yoke
or cradle is provided with side bearings (D, D¹) for supporting a countershaft or
countershafts, or vehicle axle or axles, V, that is or are connected with the armature
shaft by some suitable transmitting device substantially as described and for tho
purpose set forth.
3. Dynamo-electric machines constructed arranged and operating substantially
as hereinbefore described with reference to and shown in Figs. 1 to 3 iuclusive; or
inodified according to Fig. 4; or according to Figs. 5 and 6 of the accompanying
drawings.
Dated this 14+1 of Contouli 1909
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.