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Патент USA US2116385

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>May 3, 1938.
Filed Dec. 15, 1936
Robert H. Col | in ham ,
Hi Attorney.
PatentedMay 3, 1938
r '
Robert H. Collingham, RugbyQEngla-nd, assignor _
tcGeneral Electric Company, a corporation of
New York
Application December 15, 1936, Serial No. 116,026
lln Great Britain December 17, 1935
1 Claim. (Cl. 137—158)
The present invention relates to elastic ?uid Theright-hand end of the leverZ?' is pivoted‘ to
turbine governing mechanisms, more speci?cally a bellows 2'! and the left-hand end of the lever
to the kind of governing mechanisms which con26 is connected by follow-up means including a
trol the inlet valve of the turbine in response to
$1 changes in the vacuum of the turbine condenser.
Such arrangements are important in order to prevent excessive blowing-01f from the boilers in case
link 28 and a forked member 28% to the sleeve I'I.
The bellows 21 communicates with the condenser 5 '
I2 through a pipe 29. The pressure in the bel
lows is counteracted by means of an adjustable
spring 30.
it is necessary to disconnect the turbine from the
, boiler during failure of the vacuum.
The object of my invention is to provide an
During normal vacuum condition the bellows
2'! is in its maximum depressed condition and 10
improved construction and arrangement for auto-
the pilot valve head 25 of the auxiliary pilot valve
matically controlling the ?ow of elastic ?uid to
turbines in response to pressure changes in the
is in its bottom position so that no force is exerted
by oil pressure on the bottom of the sleeve I‘I.
exhaust, that is, in response to changes of the
The latter then is held in its bottom position by
15 vacuum in the condenser of such turbines.
the action of a spring 3I.
The pilot valve I6 may 15
This is accomplished in accordance with my
invention by the provision of an, improved pilot
be normally controlled by a speed governor 3Ia
connected to the valve I6 and the motor I3 by
valve arrangement for controlling the ?ow of
actuating ?uid to a servo-motor for moving the
admission valve. The pilot valve according to
20 my invention has an element which is controlled
a follow-up lever 3")» With this arrangement
an increase in speed causes downward movement
in response to changes in vacuum in the con-
member iii whereby communication is established
denser to effect closing of the turbine inlet valve
as the vacuum in the condenser drops, and vice25 versa.
For a better understanding of what I believe
to be novel and my invention, attention is directed
to the following description and the claim appended thereto in connection with the accompanying drawing which illustrates an embodiment of a preferred arrangement of my invention.
between the inlet port 20 and the conduit I5, per
mitting the supply of actuating ?uid to the hy
draulic motor i3 and resulting in closing move-
The arrangement shown in the drawing com-
prises an elastic ?uid turbine it which has an
inlet valve II for controlling the ?ow of elastic
35 fluid thereto.
The exhaust of the turbine is con-
densed in a condenser I2.
The valve II is moved
by means of a servo-motor I3 to which actuating
fluid such as oil is supplied by a pilot valve I4
connected to the servo-motor I3 by a conduit I5.
40 The pilot valve M has a movable valve member
I6 disposed within a sleeve or bushing I1, which
latter has a number of ports I8 and is movably
disposed within a cylinder or casing I9. Actuating ?uid for operating the servo-motor or motors
45 I3 is conducted to the pilot valve through port 20
and discharged therefrom through a port 2I.
The sleeve I1 and the lower portion of the casing
I9 form a chamber 22 to which oil or like actuating ?uid under pressure is conducted to effect
50 movement of the sleeve. The ?ow of actuating
?uid to the chamber 22 and the discharge of ?uid
therefrom is controlled by an auxiliary pilot valve
23 which has a casing 24 attached to the casing
I9 and a movable valve member‘ 25 with a stem
55 connected to an intermediate point of a lever 26.
of the left-hand end of the ?oating lever 3Ib and
consequently downward movement of the valve 20
ment of the turbine inlet valve II. Similarly, a
drop in speed causes opening movement of the
valve II. As long as the sleeve I1 is in its lower
position, the governor 3Ia for normally control
ling the flow of elastic
?uid to the
turbine can 30
effect complete opemng of the admission valve I I.
If now for some reason the vacuum falls below a
predetermined value ?xed by the tension of the.
spring 30, the bellows is expanded and thereby
causes upward or opening movement of the aux
iliary pilot Valve 25 until actuating ?uid under 35
pressure is admitted to the chamber 22. This
causes upward movement of the sleeve I‘I until
the follow-up mechanism between the sleeve I1
and valve member 25 restores the auxiliary pilot
valve to its normal neutral position. Upward
movement of the sleeve I'I establishes connection
between the port 20 and the conduit I5 and thus
permits the ?ow of actuating ?uid to the lower
part of the hydraulic cylinder I3. This e?ects
upward movement of the piston of the servo
motor I3, resulting in closing movement of the
inlet valve I I and consequently a decreased ?ow
of elastic ?uid to the turbine Iii. The closing
movement of the inlet valve II is automatically
effected without any change in the main gover
nor setting, not shown, and the portion of the
load thrown o? by the setting may be transferred
to other turbines operating in parallel.
If the vacuum drops further, the operation de-
scribed above is repeated until the turbine is
the combination of a turbine having an inlet valve
carrying such a load that any further reduction
might cause dangerous heating of the low pres
for controlling the ?ow of actuating ?uid thereto,
sure end of the turbine. Preferably, therefore,
the vacuum trip is set to operate automatically
to effect shutting off of the steam supply at this
load. Actuating ?uid leaking along the outer
surface of the sleeve is discharged through an
opening 33 into a channel 34.
With my above invention I have accomplished
an improved construction and arrangement of
governing mechanism for elastic ?uid turbines,
especially useful in connection with arrangements
where a'plurality of turbo-alternators are con
nected to the same electrical system. My im
proved arrangement permits the reduction of the
load of any particular turbo-alternator with in
?nite ?neness of graduation.
What I claim as new and desire to secure by
20 Letters Patent of the United States is:
An elastic ?uid turbine arrangement including
a condenser for condensing elastic ?uid exhausted
from the turbine, and means for positioning the
inlet valve in response to changes in vacuum in 5
the condenser, said means comprising a servo
motor for moving the valve, a pilot valve for the
servo-motor, the pilot valve including a valve
member, a sleeve forming ports and surrounding
the valve member and a stationary casing sur
rounding the sleeve, the sleeve and the stationary
casing forming a chamber, means for controlling
the ?ow of actuating ?uid to the chamber in
response to changes in vacuum in the condenser
to e?ect movement of the sleeve, said means com
prising an auxiliary pilot valve, a device respon
sive to changes in vacuum for moving the aux
iliary pilot valve and a follow-up mechanism con
nected between the auxiliary pilot valve and the
15 "
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