Improvements in or connected with Turbine Wheels.
Year: 1899

page_text: Date of Application, 20th Sept., 1899
Complete Specification Left, 14th May, 1900-Accepted, 14th July, 1500
PROVISIONAL SPECIFICATION.
Improvements in or connected with Turbine Wheels.
I, HEINRICH ZOELLY, of V Rämistrasse 58, Zurich, Switzerland, Engineer, do
hereby declare the nature of this invention to be as follows:-
In a wheel for steam or gas turbines according to this invention the parts
acted upon by the driving force consist of radial bars of comparatively great
length, the cross section of which increases towards the axis of the wheel so
that the radial bars, in so far as centrifugal action is concerned, are of uniform or
approximately uniform strength. The outer ends of the bars are shaped like
reaction-turbine buckets.
An example of a turbine-wheel according to this invention is shown in the
accompanying drawings.
Fig. 1 shows the wheel and a casing surrounding it in axial vertical section
and Fig. 2 is an end elevation of one half of the wheel, part being cut away;
Fig. 3 shows, to a larger scale, three vanes or radial bars of the turbine-wheel,
the first in elevation, the second in section according to the line A A of Fig. 5,
and the third in section according to the line B B of Fig. 5;
Figs. 4 and 5 are side elevations corresponding to Fig. 3, and
Fig. 6 shows a section according to the line CC of Fig. 5, whilst
Figs. 7, 8, 9, and 10 show, to a still larger scale, cross sections according to the
lines D D, E E, F F, and G G of Fig. 4.
The wheel shown is of the following construction:-
On a shaft b, mounted in bearings c of a casing d, there are fixed between
the bearings c two juxtaposed hub dises e e, the rims of which grasp the radial
bars a, which are placed close together. The hub discs are each provided near
their periphery with an annular groove, and these grooves form a space which
serves for the reception of the splayed feet of the radial bars and corresponds
in cross section to these feet, so as to prevent the radial bars from coming out.
In addition a thin disc is arranged on the radial bars on each side of the
wheel. These thin discs cover the openings between successive radial bars and
leave only the outer ends of the said bars free. They have the object of
preventing the suction which would be caused by these openings between the
radial bars. These discs h are thickened towards the axis so as to be of uniform
or approximately uniform strength throughout.
The parts hereinbefore described are held together by screw bolts f, which pass
through the hub-discs e e.
The bearings c of the shaft b are placed as close together as possible in order
lo prevent any flexure of the shaft between them.
In the example shown, the radial bars are (sec Figs. 4-10) made of the same
width and height along their entire length or at least nearly along their entire'
ength, inasmuch as they are only somewhat reduced at the outer ends. On one
ide each of the radial bars has two grooves k, which are separated by a ridge l
and which commence at the foot g, and, in order to form the radial bars into
ranes or buckets, become gradually wider and deeper, so that at the outer ends

page_text: cnly a small thickness of material remains and the radial bars become thicker and
thicker from their outer ends, which constitute reaction-turbine vanes or buckets,
towards the axis so as to be of uniform or approximately uniform strength.
By omitting the ridge the construction shown by way of example would be
rendered still simpler and could then be employed specially for lateral steam
admission.
Data: 00LL 1
1000
I, HEINRICH ZOELLY, of V Rämistrasse 58, Zurich, Switzerland, 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:
In a wheel for steam or gas turbines according to this invention the parts acted
upon by the driving force consist of radial bars of comparatively great length,
the cross-section of which preferably increases towards the axis of the wheel so
that the radial bars, in so far as centrifugal action is concerned, are of uniform
or approximately uniform strength. The outer ends of the bars are shaped like.
reaction-turbine buckets.
An example of a turbine wheel according to this invention is shown in the
drawings annexed to my Provisional Specification.
Fig. 1 shows the wheel and a casing surrounding it in axial vertical section,
and
Fig. 2 is an end elevation of one half of the wheel, part being cut away;
Fig. 3 shows, to a larger scale, three of the radial bars of the turbine wheel,
the first in elevation the second in section according to the line A A of Fig. 5,
and the third in section according to the line B B of Fig. 5;
Figs. 4 and 5 are side elevations corresponding to Fig. 3, and
Fig. 6 shows a section according to the line C C of Fig. 5; whilst
Figs. 7, 8, 9, and 10 show, to a still larger scale, cross sections according to the
lines D D, E E, F F, and G G of Fig. 4.
The wheel shown is of the following construction:-
On a shaft b mounted in bearings e of a casing d, there are fixed between the
bearings e two juxtaposed hub-dises e e, the rims of which grasp the radial
bars a, which are placed close together. The hub discs are each provided near
their peripheries with an annular groove and the two such grooves form a chamber
which serves for the reception of the splayed feet 9 of the radial bars and corre-
sponds in cross section to these feet so as to prevent the radial bars from coming
out.
In addition, a thin disc h is arranged on the radial bars on each side of the
wheel. The thin discs h cover the openings between successive radial bars and
leave only the outer ends of the said bars fice; they have the object of preventing
the suction which would otherwise be caused by the openings between the radial
bars. The discs are thickened towards the axis so as to be of uniform or approxi-
mately uniform strength throughout and are secured in place by overlapping
portions of the discs e as shown in Fig. 1.
The parts herein before described are held together by screw bolts f, which pass
through the hub discs e e.

page_text: The bearings c of the shaft b are placed as close together as possible in order
to prevent any flexure of the shaft between them.
In the example shown, the radial bars (see Figs. 4-10) are made of the same
width and height along almost their entire length, being only somewhat reduced
at their outer ends. On one side each of the radial bars has two grooves or
channels which are separated by a ridge 7, and which commence at the foot g,
and, in order to form the radial bar into vanes or buckets, become gradually
wider and deeper to within a short distance of its outer extremity, and then, as
shown in Figs. 1 and 5, decrease in size to the said extrémity, so that at the
outer ends only a small thickness of material remains and the radial bars become
thicker and thicker from their outer ends, which constitute reaction-turbine vanes
or buckets, towards the axis so as to be of uniform or approximately uniform
strength.
By omitting the ridges 7 the construction shown by way of example would be
rendered still simpler and could then be employed specially for lateral steam
admission.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
1. In a turbine wheel, the combination of radial bars forming buckets separated
from each other for a part of their length, each bar having its receiving face
channelled for the greater portion of its length, and a pair of thin discs enclosing
the said bars from their inner ends for a greater portion of the length of the
channelled parts of the bars, substantially as set forth.
2. A turbine wheel according to the preceding claim in which the channels
of the radial bars increase in size from their inner ends outwardly, substantially
as set forth.
3. A turbine wheel according to Claim 2, in which the channels are provided
with divided ridges, substantially as set forth.
4. A turbine wheel according to Claim 1, in which the channels of the radial
bars increase in size from their inner ends outwardly to within a short distance
of their outer extremities and then decrease in size to the said extremities sub-
stantially as set forth.
5. A turbine wheel comprising a pair of hub discs having the supporting shaft
mounted therein, radial bars forming buckets and having their inner ends engaged
between the said hub discs, a pair of thin discs enclosing the said radial bars for
a part of their length, and means for retaining the said pairs of discs in position,
substantially as set forth.
6. A turbine wheel according to Claim 5, in which the thin discs are enclosed
by the hub discs, and the hub discs are clamped together to hold the radial bars
and the thin discs securely in position, substantially as set forth.
7. A turbine wheel according to Claim 5 or Claim 6, in which the hub discs
have annular grooves in their inner faces and the radial bars have enlarged
extremities engaging in the chamber formed thereby, substantially as set forth.
8. The improved turbine wheel constructed and arranged as herein before
described with reference to and shown in the drawings annexed to my Provisional
Specification.
Dated this 14th day of Mor 1000
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C.
Agent for the Applicant.