IMPROVEMENTS IN CENTRIFUGAL MACHINES OTHERWISE KNOWN AS HYDRO-EXTRACTORS
Year: 1885

page_text: I, JOHN LAIDLAW of the firm of Watson, Laidlaw and Company of No. 98 Dundas
Street, Kingston, Glasgow, in the Counties of Lanark and Renfrew, North Britain,
Engineer do hereby declare the nature of my invention for IMPROVEMENTS IN
CENTRIFUGAL MACHINES OTHERWISE KNOWN AS HYDRO-EXTRACTORS and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My Invention, which relates to improvements in centrifugal machines otherwise
known as Hydro-extractors, is applicable to that class of machines known as
under-driven" centrifugal machines.
"
By my present Invention the vertical rotating shaft of an under-driven centri-
fugal machine is so supported as to be above the level of the lowermost portion of
the machine.
In order that my said Invention may be properly understood and readily carried
into effect, I will now proceed to describe the Drawings hereunto annexed.
Figure 1 (sheet 1) is a plan of a centrifugal machine constructed according to my
present Invention.
Figure 2 (sheet 2) is a view of the same partly in elevation and partly in
vertical section.
Figures 3 and 4 (sheet 1) are respectively a front elevation and a transverse
section on an enlarged scale of a detached portion of the same.
In constructing a centrifugal machine in accordance with my present Invention,
and as represented upon the annexed drawings, I support the vertical rotating
shaft a, within the tubular bearing b.-Between the case- or equivalently hardened
plug c, which is recessed into the lower end of the vertical shaft a, .and the
supporting surface of the bearing b, I provide the hardened disc d, the underside of
which is grooved for the ready circulation of oil besides having a vertical hole
therethrough to allow of the passage of the oil to the bearing surfaces. The upper
surface of this disc d, as also the under or contiguous surface of the plug c, are
formed convex so as to reduce the area of the surfaces in contact. A hole or oil
canal e, is bored lengthwise through the vertical shaft a, and into the upper end of
this oil canale, the plug f, is screwed, the said plug f, being provided with a
leather or equivalent washer to prevent the escape of oil at this part. Horizontal
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page_text: and radial holes g, are drilled through the shaft a, and connect with the vertical or
main oil canale, so that the oil passes outwards and lubricates the shaft a, at the
required intervals.
Upon the external periphery of the tubular bearing b, the annular projection h,
is formed. This projection h, forms the support of the bearing b, and constitutes
the neutral axis of the machine, that is to say, the axis upon which, when loaded
and in revolution, the rotating basket and its directly connected parts, oscillate or
vibrate. The annular projection h, is supported upon the ring i, of India rubber,
while a second ring j, of similarly elastic material is supported at the upper side of
the projection h. In place of the elastic ring i, the tubular bearing b, may be
provided at its centre of oscillation with a spherical bearing on the underside, with
an elastic ring above or below it. These two rings i, and j, are situated within the
casting, which is bolted or otherwise secured to the base plate or frame 1. This
base plate or frame 1, is supported upon the elastic ring m, for the reception of the
upper side of which, a groove is formed in the underside of the said base plate or
frame, whilst the underside of the said elastic ring m, rests in a corresponding
groove formed in the ring n, which constitutes the lower part of the casing. It is
to be understood that although I have shewn upon the annexed drawings a circular
ring m, of India rubber for supporting the centrifugal machine, yet any suitable
elastic medium may be substituted for the said ring m, such for example as spiral
springs, either continuous or at intervals, or blocks of India rubber may be placed
at intervals, in place of, as the continuous ring m. In the upper edge of the
casting k, the annular groove o, is formed, and from this groove, holes p, are diilled,
so that any oil flowing into the said groove o, will pass down through the holes p,
and pipe q, which is connected therewith.
At the upper part of the tubular bearing b, and to the outside thereof, the oil
reservoir r, is screwed tightly down upon the shoulder 8, and the ring or washer t,
fills up the space intervening between the said reservoir r, and the India rubber
ring.j. The tubular bearing b, is provided at its upper part with the holes u, which
form connections with the interior of the reservoir 7. The reservoir 7, is provided
with the overflow pipe v, the lower extremity of which is immediately over the
annular groove o.
The basket w, is secured to the casting a, the interior of which is bored out to
fit upon the upper portion of the vertical shaft a, which said upper portion is
turned slightly conical, and the said shaft rotates with the casting . The
casting, also supports the cylinder y, around which the convex ring 2, which
constitutes the band pulley, is secured by rivets a¹, or otherwise. The casting x,
is further formed with the annular lip b', which extends down into the reservoir 7.
The basket w, is arranged with suitable perforations through its periphery to allow
of the discharge of the liquid from the substance being dried, as is usual in the case
of other centrifugal machines, and the said basket rotates within the enclosing
casing c¹, the discharge orifice d', of which may be arranged at any desired part.
A brake band e¹, is provided around the basket w, and is suspended from the
casing c¹, by short lengths of chain f¹, which are arranged at intervals around the
said casing c¹, the necessary braking power being applied by the chain g', secured
to the free end of the brake band and coiled, by means of the hand wheel h¹,
around the shaft i', which brings the brake blocks, upon the said band e', with the
requisite degree of pressure, upon the brake ring r¹, which is riveted to the
basket w, in the manner shewn at Figure 2, that is to say, with an annular space
between the said ring q', and the exterior of the basket, thus preventing the
perforations at that part of the basket from being covered over. The casing c',
is supported from the ring n, and has, in the sides of the lower part thereof, two
openings, one for the passage therethrough of the discharge pipe d', the other for
the passage therethrough of the driving belt m', such openings being of sufficient
size to allow the easy placing of the driving belt m¹, on the pulley .
At intervals around the base plate or frame 1, there are secured the bearing
blocks 1¹, shewn more particularly on an enlarged scale at Figures 3 and 4 of the

page_text: annexed drawings. These blocks 1, of which three are shewn in dotted lines in
plan at Figure 1, are co-axial with the shaft a, and corresponding blocks k', are
secured to the enclosing casing c¹. The opposing surfaces of these blocks j', and k¹,
are hollowed out in the direction of their length, as represented in dotted lines at
Figure 3, and between these hollowed surfaces, buffers l', of India rubber are
located, it being explained that the blocks k¹, are adjusted sufficiently near the
blocks, to compress the buffers l', to any required extent.
The basket w, is rotated by means of a band m³, passing around the pulleys, and
at one part below the pulley n¹. This pulley n', is supported in the bracket o¹,
(Figure 1) the said bracket being secured to the casing c. The band m³, from the
pulleys, and n¹, passes on the driving pulley p¹, the shaft of which is provided
with the fast and loose pulleys q¹, and, as represented upon the annexed drawings,
with Weston's well-known Patent centrifugal friction pulley. These last mentioned
parts constituting no part of my present Invention need not be herein further
described.
In the operation of the machine, the basket w, is free to vibrate or oscillate
about a point which is in the plane of the centre line of the driving belt m', as it
passes round the pulley z, and at the intersection of the vertical axis of the shaft a,
with the said plane. The residual vibration over and above what is absorbed by
the elastic central bearing contained within the casting k, is translated by means of
the base plate or frame 1, to the outer elastic bearing m, whereby great steadiness
of running of the centrifugal machine is secured.
For the proper lubrication of the several parts of mechanism herein before
described, the plug f, is removed from the upper end of the shaft a, and oil is
poured into the oil canal e, until such time as the oil is seen flowing out from the
pipe q, it being then known that the reservoir r, is charged to the required extent
and the oil is passing out therefrom through the overflow pipe Around the
periphery of the shaft a, any suitably arranged grooves are provided, so that the
oil may, in the rotation of the machine, be caused to circulate as may be found
necessary.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
First In "under-driven" centrifugal machines, which are carried in an elastic
central bearing, the application or combination of a second elastic bearing external
to the said central bearing and to which external bearing the residual oscillations
or tremors, not absorbed by such central bearing, are translated by a base plate
or frame substantially as hereinbefore described with reference to the annexed
drawings.
Second-The attachment of the driving pulley 2, to the lower part of the basket
of that class of "under-driven" centrifugal machines which are carried in flexible
bearings substantially as hereinbefore described with reference to the annexed
drawings.