An Improved Flexible and Electrically Insulating Shaft Coupling.
Year: 1894

page_text: Date of Application, 17th Feb., 1894-Accepted, 24th Mar., 1894
An Improved Flexible and Electrically Insulating Shaft Coupling.
I WILLIAM RICHARD WYNNE of 130 Walmersley Road Bury in the County of
Lancaster 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 :—
My invention consists in providing an improved flexible and insulating coupling
for transmitting power between two rotatable shafts whose axes are in a straight
line or nearly so.
My invention is particularly applicable to connect together the shafts of engines
and dynamos that are to revolve at the same speed and still remain electrically
disconnected or insulated from each other.
"
It is also particularly applicable to form the power transmitting connection for
use with those appliances known as "rotary transformers" or "dynamotors
wherein it is desirable that the electrical energy delivered at high pressure to one
part of the appliance shall be effectually cut off from the electrical energy
regenerated at a lower pressure in the other part of the appliance and still permit
the synchronous rotation of the two parts.
A coupling known as "Brotherhood's flexible shaft coupling" had for its object
the transmission of power between two shafts in a somewhat similar manner but
was not suitable for transmitting large amounts of power while the coupling about
to be described is designed for that purpose and in addition to provide for the
electrical isolation of the driving shaft from the driven shaft.
In carrying out my invention of an improved flexible insulatiug coupling I
provide projecting lugs upon the opposing faces of two discs keyed or fastened
upon the two shafts to be connected one of those discs being preferably larger than
the other. Over or between the lugs of the discs I wind leather belting or other
suitable material until a ring is formed of sufficient thickness to transmit the power
required and bolt or clamp the ring so formed to the lugs on both discs in such
manner that neither the lugs nor the bolts passing through the lugs formed upon
the one disc are in metallic connection with the lugs or the bolts passing through
the lugs formed upon the other disc.
In the place of leather belting I employ other flexible insulating substances such
as india rubber belting or a complete ring of india rubber with canvas or other
fabric worked up inside the rubber covering to limit its elasticity and give sufficient
strength to resist the torsional stress.
Metallic ribbons or wires so perforated or disposed as not to form a metallic
connection between the opposing discs, strips of vulcanised fibre cloth or other
tough insulating substances may be inserted between successive layers or rings of
binding material to increase the torsional strength of the connection.
The annexed drawing shows the two discs provided with lugs and the mode of
arranging and securing by bolts the flexible coupling material..
I prefer when practicable rather than using thick bands of the coupling material
o increase the diameter of the power transmitting band or ring and by thus
ncreasing its peripheral velocity to reduce the intensity of the torsional stresses
per unit of cross section in the material of which it is composed,

page_text: 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 :-
The improved flexible and electrically insulating shaft coupling above described.
Choh1904