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Патент USA US2407013

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`
Sept. 3, 1946.
V
`
uR, J, lFlELD
FUEL APUMP GOVERNOR
Filed Nov. _15, 1944
'.9710
»
2,AQ7,013
2,407,013
Patented Sept. 3, 1946
UNITED ` STAT-.Es PATENT OFFICE
Richard Joseph rItielda Ealing, London, England,
assigner .to Joseph Lucas Li‘?‘i‘îtéjd, Birmingham',
England
Application November, 15 ,
1944,` serial Np. r563.5287
In Grcatßritain October >15, 1,942
2 claims. (C1. 121-38)
1
.
,
par-t a the plungers- d are moved in one direc
`This invention relates to the governing means
tion by an angularl‘y movable swash plate e and
thèopposite direction by springs as f, the lat
ter being situated in the bores c, and serving to
hold an end falce of the body part in contact with
employed for automatically controlling the` out
put of a variable-delivery fuel pump used in con
junction with prime movers, the governing means
being responsive to variable fluid pressure condi
aflat seating g` in the casing b. The swash plate
tions.V In particular the invention relates to a
e is of annularform and is pivoted at diametrical
governing means consisting of a spring _loaded
1y opposite positions to the casing b. The seating
piston or diaphragm adapted to actuate the>` out
d is’iorme'dwith a port h communicating With a
put controlling means of the pump, the piston
or diaphragm being contained in a chamber. The 1.o. liquid inlet i inthe casing b and with another
y port y' communicating with a liquid outlet k: in
piston (which term will hereafter be used as in
cluding also a diaphragm) is subject on both
the @eine
.
The body part a is adapted to serve also as a
sides to the action of fluid pressure. Means _are
provided for effecting an unrestricted pressure
fluid supply to one side of the piston, and Lthis
fluid can also gain access to the other side
through a restricted passage s_o that‘pressure dif
ferences can occur temporarily for actuating the
piston, the pressures at the two sides being equal
during a steady pressure condition in the system.
At the side of the chamber opposite to that which
centriiugal'pump, and for this purpose is formed
with an axial bore m which at> one end communi
Cates with the inlet i through another port n
in the Seating y, and at the other end communi
cates with a 'plurality of ` radial passages as o in
the body part."`Liqi1id from the inlet i llows
through thebore mand is expelled by ‘centrifu
gal action through the radial passages o into the
interior of the pump casing b around the body
receives the unrestricted fluid supply there is
provided a release Valve which is responsive to
any predetermined condition associated with the
system, such as the speed of the pump. Govern-Y
part
a.
'
'
`
'
'
In one end of the _casing b is formed a cylin
25
drical chamber phaving closed ends. Within
the chamber p is arranged a piston q loaded by a
spring r, and extending from one side of this
ferred to as of the kind specified.
piston and through a bore in the casing b. at the
The above described governing means possesses
inner end of the chamber is a rod s connected to
the disadvantages that undesired pressure or vol
ume fluctuations may be set 11p in the liquid de 30 the swash plate e. Instead of the piston a dia
phragm may be employed, and as already stated
livered by the pump, and the object of the pres
I desire this alternative to> be included in the terni
ent invention is to enable this condition to be
piston. The inner portion ofy the chamber p, that
minimised in a simple and satisfactory manner.
ing means as above described are hereinafter re
The invention comprises the combination with
a governing means as above described, of a var
iableevolume chamber arranged in communica
tion with the valve-controlled side of the piston
chamber, the Variable-volume chamber being
such that it permits movement of the piston in
response to a pressure change independently of
the valve.
'
In the accompanying sheet of explanatory
drawings:
is the portion at the piston rod side of the piston
35 q, is 'n in'free communication with the outlet lc
through a passage l in the casing b, and this por
tion 0f the chamber also communicates with the
other or outer portion of the chamber (which
contains the spring 1°) through a restricted pas
sage t. The cluter end of the ‘chamber p is pro
vided With a ventru which at its outer end forms
a seating for a Valve u, this latter being respon
sive to any predetermined condition associated
with the system.
`
Figure 1 is a diagrammatic sectional elevation
45
`In the `example shown the valve 1f is formed
of a liquid fuel pump embodying the invention.
or secured on one end'of a lever w, the latterbe
Figure 2 is a fragmentary sectional side View
illustrating a modified form of the invention.
ing pivoted` at a positiontbetween its ends on the
outer end of the chamber p, and being loaded by
The liquid fuel pump shown in the drawing
a spring :v which tends to hold the valve on its
comprises a rotary body part a arranged in a
casing b and having formed around its axis a 50 seating. » The lever w is contained in a chamber y
formed on or securedïto the adjacent end of the
plurality of bores as c in each of which is ar
ranged a reciprocatory plungerv d. The body part
casing'b, fand'this chamber communicates with
a is adapted to be driven in any convenient man~
‘the pump inlet i. The outer side of the chamber
y is bounded by a controlling diaphragm z having
55 `~at its centre an abutment 2 which is adapted to
ner by the prime mover to be supplied with liquid
fuel from the pump. During rotation of the body
.
4
3
bear on the end of the lever w remote from the
Likewise, if a pressure fall occurs at a sufficient
valve o. At the outer side of and bounded in part
rate liquid flows from the chamber 9 to the cham
by the diaphragm z is another chamber 3, this
ber p under the action of the spring loaded pis
latter being in communication with the above
ton l0, and subsequently returns either in re
mentioned centrifugal pump through a passage Ul sponse to a pressure rise or to pressure liquid sup
‘l in the casing b. Also the diaphragm z is loaded
plied to the end of the chamber p communicating
by a spring 5 connected to an adjusting member
with the chamber 9.
6, the latter being operable in any convenient
In the example shown in Figure 2, the passage
manner by an attendant to vary the effect of the
‘l interconnecting the chambers p and 9 is con
Sprlng.
10 trolled by a spring loaded Valve I2 which permits
Assuming the swash plate e to be in a position
freeV flow of liquid from the chamber p to the
of maximum obliquity, that isto say the position
chamber 9 but restricts the return ñow. In other
in which the pump gives its maximum output,
respects this example is similar to that shown in
the swash plate will remain'in’ this position s0
IFigure 1 with the exception that the restriction
long as the pressure in the chamber 3 (and thus 15 in the passage t interconnecting the ends of the
acting on the controlling diaphragm a) is below
chamber p is effected by a plug I3, suihcient
some predetermined amount. In this condition v. clearance being provided between the plug and
the valve v is in its closed position and the liquid
passage to allow a restricted flow of liquid
pressures at the two sides of the piston q are ` through the passage.
equal. But when the pressure acting on the dia
By this invention the above mentioned disad
phragm e exceeds the predetermined amount the
vantage of the earlier form of governing means
diaphragm will move the valve v 01T its seating.
is effectively avoided.
The-liquid pressure in the outer portion of the
This _invention is not, however, limited to the
piston chamber p will now fall and the piston q
particular examples described as constructional
will be moved by the fluid pressure in the inner 25 details may be varied to suit different require
portion of the cylinder against the action of the
ments. Thus instead of the piston-controlled
spring r, so moving the swash plate e in the di
variable-volume chamber above described I may
rection for reducing the pump output until a
employ a chamber provided with a diaphragm
new condition of equilibrium is reached. If the
and this may be loaded either by a spring or by
valve o subsequently moves on to its seating as a 30 gas under pressure; or I may employ an exten
result of the pressure on the diaphragm z falling
sible closed chamber constructed from flexible
below the predetermined amount, the liquid pres
sures at the two sides of the piston q again be
material, for example, corrugated sheet metal.
come equal, and the spring ï then serves to move
claim as new and desire to secure by Letters Pat
the piston in the direction for increasing the 35
pump output.
ent is:
Having thus described my invention what I
Y
1. Governing means of the kind specified, hav
ing in combination a fluid pressure responsive
member, a main chamber containing said mem
From the foregoing it Will be seen that as the
position of the swash plate e is dependent on the
ber, a passage for admitting an unrestricted sup
pressure of the liquid in the chamber 3 and as
this pressure is dependent on the speed of the 40 ply of pressure fluid to said main chamber at one
pump, the latter is governed by the speed of the
side of said member, a restricted passage for ad
mitting pressure fluid to said main chamber at
prime mover which drives the pump.
theother side of said member, a pressure-duid
In carrying the invention into effect as shown
release valve situated at the side of said main
in Figure 1, I connect the valve-controlled outer
end of the chamber p by means of a passage 'l to 45 chamber to vwhich pressure iiuid is admitted
through said restricted passage, and a variable
One end of a small variable-volume chamber 9
containing a spring loaded piston I0 which con
volume chamber arranged in communication with
the release valve side of said main chamber to
trols the volume of the latter chamber, the other
permit movement of said member in response to
end of this chamber being in communication
with the outer atmosphere through a vent Il. 50 a pressure change independently of said valve.
2. Governing means of the kind specified, hav
Under a steady condition in the system the pis
ing in combination a fluid pressure responsive
ton q of the governing means remains at rest.
member, a main chamber containing said mem
But when a variation (rise or fall) of iiuid pres
ber, a passage for admitting an unrestricted sup
sure occurs at a suñìcient rate the piston q can
move in the appropriate direction in immediate 55 ply of pressure Huid to said main chamber at one
side of said member, a restricted passage for ad
response to the change and independently of con
mitting pressure fluid to said main chamber at
sequential movement of the valve v, as liquid can
the other side of said member, a pressure-fluid
now iiow between the chamber p of the govern
release valve situated at the side of said chamber
ing means and the additional chamber 9 of var
iable volume. This liquid flow permits movement 60 to which pressure fluid is admitted through said
restricted passage, a variable-volume chamber
of the piston q of the governing means in re
arranged in communication with the release
sponse to pressure ñuctuations which are too
valve side of said main chamber to permit move
brief to permit movement of this piston under the
ment of said member in response to a pressure
control of the valve o. It will be understood that
change independently of said valve, and a second
valve arranged between said main chamber and
said variable-volume chamber, said second valve
9, this being permitted by movement of the piston
serving to permit free iloW of liquid from said
l0 against the action of its spring loading, and
main chamber to said variable-volume chamber,
if this pressure rise persists the valve v will be 70 but to restrict iiow in the opposite direction.
moved away from its seating, allowing return flow
of liquid from the chamber 9 to the chamber p.
RICHARD JOSEPH IFIELD.
when a pressure rise occurs at a suñicient rate
liquid flows from the chamber p to the chamber
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