Transmission of Power thereto.
Year: 1886

page_text: Transmission of Power thereto.
We, ARTHUR LE NEVE FOSTER, Engineer, and FREDERICK VILHELM ANDERSEN,
Electrician, both of 23 Regency Street, Westminster, in the County of Middlesex,
do hereby declare the nature of our invention for IMPROVEMENTS IN DYNAMO
ELECTRIC MACHINES AND IN THE TRANSMISSION OF POWER THERETO and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
The objects of our invention for improvements in dynamo electric machines and
in the transmission of power thereto are as follows:-
1. To provide more efficient means for securing or mounting an annular armature
on its shaft.
2. To arrange or construct the bearings for the armature shaft in such a manner
that the said bearings together with the armature, commutator and brushes can be
withdrawn from the bed plate without affecting the other parts of the machine.
3. To provide efficient means for varying the positions of the brushes employed
to collect the current from the commutator of a dynamo electric generator so that
the lead can readily be adjusted.
4. To provide means whereby the position of the whole machine may be adjusted
without interfering with its foundation so as to allow the belting by which the
machine is driven to be readily tightened as may be required.
5. To provide means whereby the direction of rotation of the armature will be
constant even if the direction of rotation of the prime mover is reversed and thus
dispense with the ordinary mechanism and double set of brushes by which the
lead is adjusted and the current maintained in a constant direction on the reversal
of the armature shaft.
In carrying our invention into practical effect, each end of the armature core is
mounted on an annular series of bars concentric with the armature shaft and
projecting from arms extending radially from a hub keyed on the shaft and forced
to rotate with it. The two hubs when the core is in place are forced together by
means of a fixed collar on one end of the shaft and a nut working on a screw
thread cut on the other end of the shaft. The core is insulated from its supports
which are made of non-magnetic material. The armature is thus maintained
concentric with the shaft by the annular series of bars and is firmly secured by
being compressed between the projecting ends of the radial arms of the two hubs.
The standards supporting the bearings of the armature shaft are cast or otherwise
formed in one piece and are secured to the bed plate of the machine by bolts. When
the bolts are withdrawn, the bearings can be slid along the said bed plate parallel
to the armature shaft to withdraw the armature and attendant parts. The brush
holders are mounted on a metallic ring free to revolve in a grooved sheave secured

page_text: to the frame supporting the armaturé. The ring is provided with a segment of
worm teeth gearing with a worm by means of which the positions of the brushes
are adjusted. The bed plate of the machine is arranged so as to be capable of
sliding on a cast iron foundation frame secured to the foundation and is adjusted
and secured in the required position by means of screws. Mounted on the armature
shaft are two pulleys driven from the driving pulley in opposite directions by
means of a straight and a crossed belt respectively. The adjacent ends of the
hubs of the pulleys have ratchet teeth formed in them corresponding to similar
teeth on the ends of a sleeve sliding on the shaft between the pulleys and caused
to rotate with the shaft by means of a feather; the two sets of teeth being cut so
as to be capable of driving the shaft in one direction only. The pulleys are forced
towards the sleeve by springs and it will readily be seen that the teeth of the hub
of that pulley rotating in the required direction will gear with the teeth of the
corresponding end of the sleeve and the teeth of the other pulley hub will pass by
the teeth of the corresponding end of the sleeve. The teeth of the pulley in gear
with the sleeve also draws the sleeve to that side so that the other teeth pass one
another without touching.
Fig. 1 in the accompanying drawings is a longitudinal section of an armature
constructed according to this invention, the winding being omitted.
Fig. 2 is an end elevation of the same, a portion of the winding being shown in
Bection.
'
Fig. 3 is an elevation of a dynamo electric machine showing our improvements
in the construction of the framework.
Fig. 4 is an end view of the same.
Figs. 5 & 6 are detail views showing the method of supporting the brushes for
collecting the current from the commutator of a dynamo electric machine, the
brushes being shown raised from the commutator in fig. 5; and
Figs. 7, 8 & 9 shew our improvements in the driving gear.
-
The annular iron core a, figs. 1 & 2, which is preferably built up of thin flat
rings of iron and paper cemented together, is supported on two annular series of
bars b arranged concentric with and parallel to the armature shaft o and extending
respectively from either end of the armature to the centre. The annular series of
bars b are supported from the hubs & by means of the radial series of arms e. The
hubs & are keyed on the shaft c but can be forced along it. In order to prevent
the core from slipping round on its frame and to firmly secure the rings in position,
the two end rings a¹ are made considerably thicker than the intermediate rings
and are formed with slots or notches f engaging with projections on the arms e.
The core is compressed end wise by means of a collar g on one end of the shaft and
nuts h working on screw threads formed on the other end of the shaft, the
projecting ends of the radial arms e being forced against the end rings and so
compressing the whole core.
When
The armature shaft c, figs. 3 & 4, is supported in bearings i on standards 1, m
cast in one piece and secured to the bed plate n of the machine by bolts o.
the bolts o are withdrawn the standards 1, m can be slid along the bed plate n
parallel to the shaft c so as to withdraw the armature and attendant parts which
all remain in their relative positions.
The brush holders p, figs. 5 & 6, are mounted on a metallic ring q free to revolve
is a grooved sheave bolted to the standard l. The ring q is formed_with a
segment of worm teeth r gearing with a worm 8 supported in bearings t bolted to
the standard . The worms is rotated by means of a small hand wheel w and
serves to accurately adjust the positions of the brushes simultaneously to vary the
lead and at the same time secures them in their positions.
The bed plate n, figs. 3 & 4, of the machine is fitted to slide on a foundation
frame secured to the fixed foundation. When the position of the machine is to
be adjusted to take up the slack of the belt or other purpose, the screws y are
loosened and the adjustment made by aid of the screws z, when the screws y are
again tightened.

page_text: The armature is driven by means of two pulleys 1, 2, figs. 7, 8 & 9, mounted
loosely on the armature shaft c. The pulleys 1, 2 are driven from pulleys on a
first motion shaft 3 by means of a straight and a crossed belt respectively. The
adjacent ends of the hubs of the pulleys 1, 2 each have ratchet teeth 4 formed in
them. Between the pulleys 1, 2 is a sleeve 5 having teeth 6, 7 formed in its ends
corresponding to the teeth 4. These teeth are so arranged that whichever set is
in operation, the shaft c can only be driven in the one direction. The pulleys 1, 2
are forced towards the sleeve by springs 8, 9. Supposing the shaft 3 to be rotating
in the direction of the arrow, it will readily be seen that the teeth 6 on the sleeve 5
engage with the teeth 4 of the pulley 1 and drive the shaft c in the direction shown
by the arrow, the teeth 4 on the pulley 2 passing clear of the teeth 7 on the sleeve 5.
Should however the direction of rotation of the shaft 3 be reversed, the teeth 7
will engage with the teeth 4 on the pulley 2 and the shaft c will be driven in the
same direction as before, the teeth 6 now passing clear of the teeth 4 of the
pulley 1. In order that those teeth not in gear may pass one another without
touching, the sleeve is constructed so as to be capable of sliding on the shaft c
between collars 10 (shown in dotted lines) which collars also limit the approach of
the pulleys 1, 2. When the teeth of the sleeve and one of the pulleys come into
gear, the sleeve is pulled towards that pulley by the inclination of the ratchet
teeth and out of gear with the other pulley which is pressed by its spring against
its collar 10.
Having now particularly described and ascertained the nature of our said
invention and in what manner it is to be performed, we declare that what we
claim is
1. Mounting the annular core of an armature on annular series of bars rigidly
connected by radial arms with hubs keyed on the armature shaft and capable of
being forced together to secure the said core between the projecting ends of the
radial arms by means of a collar on the shaft and a nut working on a screw thread
cut on the shaft substantially as described.
2. Mounting the armature shaft in such manner that it together with its bearings
and all parts mounted on them can be withdrawn from the bed plate without
affecting the other parts of the machine or the relative positions of the parts
withdrawn with the said shaft substantially as described.
3. Adjusting simultaneously the positions of the brushes for collecting the
electric currents from the commutator of a dynamo electric machine by means of
the segment of worm teeth and the worm substantially as described with reference
to figs. 5 & 6.
'
4. Mounting the bed plate of a dynamo electric machine so as to be capable of
adjustment on a foundation frame substantially as described and for the purpose
set forth.
5. The mechanism substantially as described with reference to figs. 7, 8 & 9 by
which the shaft of a dynamo electric generator is driven in the required direction
irrespective of the direction of rotation of the driving shaft.
Dated this twenty first day of January 1886.
·
WHEATLEY & MACKENZIE,
Agents for the Applicants.