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Патент USA US2873097

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Feb. 10, I959 '
Filed July 1a, 1953
2 Sheets-Sheet 1
Feb. 10, 1959
Filed July 16, 1953
2 Sheets-Sheet 2
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' jJTennelL
United States Patent 0
Patented Feb. 10, 1959
bine disc or drum periphery to a second radial return pas—
sage into the shaft bore and so to a return collector
ring on the shaft. It is convenient to divide the annular
channel into four equal sections, so that the water may
5 ?ow outwards along two diametrically opposite radial
Basil Joseph Terrell and Frederick John Bayley, Monk
channels and return to the shaft in directions normal to its
seaton, England, assignors to The Parsons and Marine
outward path, but this arrangement may be varied as
Engineering Turbine Research and Development Asso
ciation, Wallsend, England
In order that the invention may be more fully under
it will now be described by way of example with
Application July 16, 1953, Serial No. 368,402
7 ‘Claims. (Cl. 253-—39.15)
reference to the accompanying drawings, wherein:
Figure 1 is a radial section of the outer part of a
turbine disc, with blades each having an inverted T-root,
This invention relates to means for cooling gas turbines, 15
and shows the cooling arrangements;
Figure 2 is a transverse section taken on the plane
particularly turbines operating with gasv temperatures in
II, II of Figure 1;
excess of 1200° F., and its object is to provide means
Figure 3 is a view looking in the direction of the
arrow III of Figure 1, showing the cap or collar removed
whereby liquid cooling mediums may be utilized to the
best advantage.
Water is well known as a particularly suitable medium, 20
but if‘circulated from an outside source through the nar- _
row and thin walled passages which are inevitable in
typical internally, cooled turbine blades, the corrosion‘
and fouling associated with its use is a serious di?iculty.
One of the advantages secured by the present inventionv
is that it enables water to be circulated through a bladed
taching the cap or collar;
cool the blades without traversing the latter internally.
. The invention consists in a gas turbine bladed rotor
having features ‘as set forth in the claims ‘appended
Figure 7 is a view in the direction of the arrow VII
of Figuire 5 showing an identation in the cap or collar.
Other advantages are that the invention does not rely on
the normal blade-to-disc attachment for sealing the water
in the rotor, and it provides a construction giving the
Figure'S is a broken view of two adjacent blades form
ing part of a blade row, and shows a method of at-
taching the cap or collar;
Figure 6 is a broken view of one blade corresponding
to Figure 5, and showing an alternative method of at
the blade root and more highly stressed parts of the
rotor from the effect of the hot gases, and to e?ectively
necessary ?exibility to the blading while also adding to
Figure 4 is a longitudinal section on one side of the
axis of a four-stage turbine, showing the drum with blad
ing having a serrated root, and cooling arrangments
turbine rotor disc or drum in such a way as to protect
its strength.
and the blades in section;
Like parts in the dilferent ?gures are designated where
practicable by like reference numerals.
Referring to Figure 1 a turbine disc 1 is channelled
inwards from the outper periphery so as to form an an
nular channel 1“. The disc 1 is bladed with blades such
as 2’having an inverted T-root 29' seated on the bottom
or inner periphery 1A of the channel 19' which surrounds
In the preferred construction, the rotor disc or drum
a part 2b of the blade 2 additional to its e?ective length
is circumferentially channelled in way of the blade row 40 or span. A cap or collar 3 is inserted over the blades
or each blade row, the blades being attached to the
and is welded thereto and to the outer periphery of the
disc or drum by a blade root at the bottom of the channel,
disc thereby sealing the channel 18-.
and a cap or collar is inserted over the blades and at
Referring to Figures 2 and 3, a path for liquid coolant
tached to said disc or drum and to said blades so as to 45 into the annular channel 1a is formed by a radial pas
form conjointly with the channel a closed annular space,
sage lb and two radial passages 2° in the disc 1, and in
the space being in communication with passages in the
two adjacent blade roots 2"‘ respectively. Arrowheads
rotor whereby coolant is circulated through the channel
are inserted in the Figures 1, 2 and 3 to show the direc
around the blades and roots. Grooves or indentations
tions of ?ow of the coolant. It will be seen that coolant
may be provided in the cap or collar, disposed between 50 from the passage 1*’ in the disc 1 divides into two streams
the blades, for the purpose of providing a degree of
which ?ow through the passages 2c in the two adjacent
tangential ?exibility in the blade row or rows to take
blade roots, into the channel 1.“, wherein the ?ow is
up uneven thermal expansions, and for providing addi
maintained in two separate streams which are constrained
tional strength to resist the pressure of the liquid coolant
to flow circumferentially in the opposite directions by
Within the channel. Preferably also, baffles are provided
means of battles 4, shown in Figure 3, ?tted on each side
in the channel to direct the ?ow of coolant around the
of a blade, as shown, so as to bridge the channel 1“.
blades in a controlled manner, for example the coolant
Other ba?es such as 5 in Figure 3 are arranged to bridge
may be made to traverse each blade twice, i. e. on op
posite sides, the passages between the blades having
the annular passage 1a on one ‘side only so that the
coolant is made to traverse the blade twice, i. e. on op
roughly the same shape as the gas passages outside the 60 posite sides, with the advantage previously referred to.
drum or disc periphery. An advantage of this construc
The blades in this example are hollow, having cavities
tion is that the turbulence stimulated by changes in ?ow
2d wherein a heat transfer medium, for example water,
direction increases the rate of the heat transfer to the
is enclosed.
Referring now to Figure 4, a four-stage turbine drum
The coolant may ?ow from a collector ring on the 65 6 is channelled inwards from its outer periphery so as
to form four annular channels 62L corresponding to the
rotor shaft, axially along a shaft bore to a point roughly
corresponding to the cooled blade row centre-line; then
along a radial passage to‘ the__blade roots, through suit
able channels in one or more of these as convenient into
blade rows. The drum is bladed with blades 7, 8, 9 and
10 in their respective rows, and having a serrated root
in grooves 6b at the bottom of the annular channels 6“.
the beforementioned annular channel surrounding the 70 Cap or collars 11, 12, 13 and 14 are inserted one over
blades. The coolant may then ?ow in the circumfer
each blade row and are welded to the blades and to the
ential direction around a suitable proportion of the tur
outer periphery of the drum thereby sealing the channels
the blade roots, corresponding radial passages 7a, 8a, 9a
and 10a being arranged in the blade roots to carry the
2. A ‘gas turbine rotor according to claim 1, in which
said wall portions constitute a cavitied blade.
3. A gas turbine rotor according to claim 1, in which
the blades comprise interior cavities enclosed by said wall
coolant to and from the channels 6a in a manner along
portions containing heat transfer medium which is liquid
6“. Radial passages 6c are drilled in the drum to carry
coolant between a longitudinal bore 6d of the drum and
at least at the operational temperature of the turbine.
the lines described in connection with Fig. l. The chan
nels 6*"- may be ?tted with ba?les arranged similarly to
4. A gas turbine rotor according to claim 1, in which
those described with reference to Figures 1, 2 and 3 in
the said enclosed channel extends circurnferentially in
order to direct the coolant around the blades to the best
the direction of the blade row, and comprising means for
advantage. The blades in this example also are hollow, 10 attachment of the blades at the bottom of said channel,
and their cavities 15‘1 each contain a quantity of heat
and a cap adapted to beinserted over the blades and being
transfer medium.
Figure 5 shows two adjacent blades 15 and 16_0f a
blade row with their corresponding caps or collars 17
attached to the latter and to the rotor to constitute the
top of the enclosed channel.
5. A gas turbine rotor according to claim 1, compris
and 18 for the purpose of sealing the annular channel
in the disc or drum (not shown) to which they are to
be ?tted. Between the two blades and formed in the
meansa cap
for adapted
be blades
the the
of and
attached to the latter and to the rotor to consLitute the
cap 17 is a groove or indentation 1'7“ which takes the
top of the said enclosed channel, and grooves in said cap
shape of a crescent when seen in the view of Figure 7;
disposed between the blades to a?ord tangential?ezibihty
similar indentations are arranged in the collars between 20 to the bladerow.
the remaining blades of the blade row with the object
of providing tangential ?exibility, and also to give addi
tional strength to resist the pressure of the liquid coolant
within the channel. Figure 6 shows the attachment of
an alternative form of collar 19, having an inwardly
turned flange we, to a blade 2%.
We claim:
1. A gas turbine rotor comprising bla es constituting
a blade row and said blades havingsolid inner end por
6. A gas turbine rotor according .10 claim 1 Qompris
ing baffles in the said enclosed channel to direct allow of
coolant around the blades ina controlled manner
7. A gas turbine rotor according to claim '1, compris
' ing “deans for subdividing the raid enclosed channel into
a number of arcnate portions, each portion having sepa
rate coolant inlet and outlet passages
respectively wits cooler-1t "early and-return
the cat91
,,__c .
tions and spaced wall portions of relatively thin cross
sectional area extending radially outwardly therefrom,
Reterenees Cited in the?le of this patent
and means constituting an enclosed channel in the rotor
periphery, the solid inner end portions being located
radially inward of the channel with the wall portions of
Junggren _____________ __ May 17, 1921
Holzworth ___________ __ Sept. 23, 1941
Constant _____________ ___Aug. 23, 1951
Sollinger ____________ __,_ July “15, 1952
heat from said wall portions to coolantcircul?l?dithrough 40
Germany _______ __,_.._.,._,, Feb. 8, 1933
the said channel,
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thin cross-sectional area extending through the channel
and terminating outwardly of the channel, the parts of
the wall portions of relatively thin cross-sectional area
lying within the channel being spaced from the sides of
the channel to afford surfaces for the transference of
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