Improvements in Rotary Blowers.
Year: 1893

page_text: Date of Application, 8th Dec., 1893-Accepted, 13th Jan., 1894
[Communicated from abroad by EDWARD P. REICHHELM, of Jersey City, New
Jersey, United States of America.]
Improvements in Rotary Blowers.
I, CHARLES CHURCHILL, Managing Director of Charles Churchill & Co.,
Limited, Engineers of 21, Cross Street, Finsbury, in the City of London, 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 relates to improvements in rotary blowers.
Numerous blowers have been made in which the rotating shaft is eccentric to the
case of the blower and the fans or blades are projected from a cylinder or drum
concentric with the rotating shaft so that the outer edges of such fans or blades
travel in contact with the interior of the eccentric case at one side thereof, there
being an abutment at the opposite side in contact with the surface of the said
cylinder or drum.
In my improved rotary blower, I make use of a ring at each end of the series of
fans or blades, such rings being grooved and receiving within them ring-segments
to which the fans or blades are pivoted, so that, whilst the fans or blades are
projected and retracted as required, in their revolution, the blower can be driven
at a great speed and is almost noiseless, the grooved rings and ring-segments
revolving together. Moreover the construction is such that the said rings and ring-
segments can be kept thoroughly lubricated and there is a large extent of wearing
surface; these parts are, therefore, not liable to become loose, and the weight of
the said parts is so balanced that the centrifugal action does not tend to produce
friction.
In the accompanying drawing
Figure 1 is a longitudinal section, and
Figure 2 a transverse section of one form of my improved rotary blower, and
Figure 3 is a detached view showing one of the fans or blades and part of the
case and of one of the grooved rings.
The case is composed of the beads A, B with the intermediate arch or cylindrical
segment C, the inlet casing D into which air is permitted to flow freely, and the
outlet casing E from which the air is driven through any suitable pipe or
connection F. The driving shaft G is not central to this case, but is below the
centre from which the segment C is struck, and such shaft G is supported in suitable
bearings a in the heads A, B of the case; oil-cups b may be applied to the said
bearings for lubricating the same.
Upon the driving shaft G is fixed a cylindrical drum H which is slotted radially
for the reception of the fans or blades I; this drum H may be hollow to a greater
or less extent to diminish the weight, its cylindrical surface should, however, be
unbroken except at the slots that receive the fans or blades, and this surface is in
contact with the abutment K, which is preferably secured in the bottom of the case
immediately below the driving shaft G, so that the drum H and the abutment K
form a separating partition between the inlet D and the outlet E.
In the heads A, B there are annular recesses for the reception of the rings L, M,
respectively, which rings fit into the said recesses but are free to rotate therein.
It is advantageous to make these rings L, M, hollow or with annular recesses c
for containing oil or other lubricating material supplied from the oil-cups N and O,
[Price 8d.]

page_text: for the purpose of lubricating the said rings. In each ring L or M there is also an
annular channel d for receiving the ring-segments P, Q, which segments are
provided with holes for the reception of the pivots e, of the fans or blades I. These
fans or blades I are preferably formed with projections or lugs fextending toward
the driving shaft G so as to pass at each end of the central or hub portion of the
drum H, and they may extend directly to the surface of the driving shaft G; I
prefer, however, to make the driving shaft G at the portions that are adjacent to
the lugs flattened or polygonal, so that the said lugs may be longer than would
otherwise be practicable without increasing the diameter of the case.
These lugs f
serve as guides to steady the fans or blades and prevent any risk of the same
binding in the slots within the drum H. These fans or blades 1 fit the slots in the
said drum, but can be freely moved outwardly or inwardly in such slots.
As will be noticed in Figure 2, the curved portion C of the blower-case is made
of slightly larger diameter near the inlet D in order that the outer ends of the
fans or blades I may not come in contact with the interior surface of the cylinder
segment C until after they have passed the inlet D. The length of the curved
portion C of the case must be greater than the distance between the outer edges
of two adjacent fans or blades, so that one fan will rise and come in contact
with the interior cylindrical surface of such case before the edge of the preceding
fan leaves such cylindrical surface of the case.
As the driving shaft G is rotated in the direction of the arrow 1, Figure 2,
the fans or blades I cause a constant movement of the air through the case,
driving such air from the inlet D and discharging the same through the outlet E,
and in consequence of the rings L, M being concentric with the interior of the
cylindrical segment C of the case, the ring-segments P, Q within the annular
grooves of such rings L, M, move the fans or blades in and out of the drum H
so that their outer ends travel in contact with the interior surface of the portion C
of the case, and the said fans or blades swing at their opposite edges on the
pivots e in the ring-segments P, Q. As the shaft G and drum H are revolved
and the fans or blades are carried around therewith, these in turn give motion to
the ring-segments P, Q within the annular grooves in the rings L, M. These
rings L, M are free to rotate by the contact of the ring-segments with such
rings, and the centrifugal force acting upon the fans or blades is taken by the
ring-segments P, Q at opposite sides of and within the rings L, M, so that these
rings L, M rotate freely within the heads A, B of the case, and the motion given
to the ring-segments within the annular recesses of the rings L, M only results
from the difference in the positions of the pivots e in relation to the centre around
which the rings L, M revolve; hence there is but little friction resulting from
the movements of the ring-segments within the annular recesses of the rings L, M,
and such rings L, M are nearly balanced by the centrifugal action upon the fans.
This blower, therefore, runs almost noiselessly and with but little power or friction,
and is easily lubricated, because the oil passing from the cups N, O into the
annular recesses containing the rings L, M, lubricates the said rings, and there are
holes through which the lubricating material passes from the outside recesses c of
the said rings L, M to the annular recesses in their inner faces, thus lubricating
not only the ring-segments P, Q and the pivots e, but also the edges of the fans or
blades I where they slide in and out in the slotted drum H; hence the wear and
friction are very slight.
In consequence of the case having the inlet and outlet casings D and E, the
edges of the fans or blades are not in contact with any portion of the case before
and after passing the abutment K until they come in contact with the inner
surface of the segmental portion C of the case, and, during that portion, of the
revolution, the air is displaced from the inlet side and forced into the exit side of
the case.
It is advantageous to lubricate the upper surface of the abutment K with which
the surface of the drum H is in contact so as to diminish friction, and the pad or
surface of this abutment may supply or transfer lubricating material to the outer

page_text: edges of the fans which have to travel in contact with the inner surface of the
cylindrical segment C of the case.
I prefer to employ the ring-segments P, Q, because the wear and friction are
more evenly distributed. If, however, the projecting pins e are enlarged to the
width of the recesses in the rings L, M, the ring-segments P, Q may be dispensed
with, and it is sometimes advantageous to lengthen the pins e on one of the fans
so that they will enter holes in the rings L, M, and the said rings L, M, will be
rotated at the same speed as the said fan. Under all circumstances, the rings I, M
revolve around the circular bearings in the heads A, B of the case, and it is
desirable that these circular bearings shall be as small as is practically consistent
with the eccentricity of the main shaft G, so as to lessen the friction of the rings
as they travel around the bearings. It will also be apparent that the ring-segments
upon one of the fans might be fastened within the curved rings L, M so as to
cause the said rings to rotate with the said fan, and rollers might be provided upon
the pins e instead of the segments P, Q.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed as communicated to me by
my foreign correspondent, I declare that what I claim is :-
First. The rings arranged within the annular recesses of the case so that they
are free to revolve therein, and suitably connected with the fans or blades working
in the slots of the drum, substantially as set forth.
Second. The combination, with the driving-shaft and the slotted drum arranged
eccentrically within the case, of rings with annular grooves working in annular
recesses in the heads of the case, fans or blades movable within the slots of the
drum and provided with projecting pivots, and ring-segments receiving such
pivots and working within the annular grooves of the rings, substantially as set
forth.
Third. The combination, with the driving-shaft and the slotted drum arranged
eccentrically within the case, of the fans or blades working in the slots in the drum
and having lugs projecting toward the said driving-shaft, and rings concentric with
the case, to which the fans are connected, substantially as, and for the purposes,
Bet forth.
Fourth. The improved apparatus constructed substantially as described with
reference to the accompanying drawing and operating as above specified.
Dated this 8th day of December 1893.
CHARLES CHURCHILL.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.