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Патент USA US2112045

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l March 22, 1938.
Filed April 3„ 1955
ï `l7
`Sammel RPuffeF,
, b5
His Attow?eg.
Patented Mar. 22, 1938
Samuel VIt. Puiïer, Saugus, Mass., assignor to
General Electric Company, a corporation of
New York
Application April 3, 1935, Serial No. 14,433
1 Claim. (Cl. 286-27)
The present invention relates to combustion
engines, more specifically to the arrangement of
The arrangement shown by 'way of example in
valve means for controlling the flow of exhaustA the drawing comprises al combustion engine hav
or combustion gases from a combustion chamber
5 or cylinder to an exhaust conduit or manifold.
The usual arrangement includes a valve casing, a
valve with a stem slidably disposed in a channel of
the valve casing and a disk secured to the stem
and in cooperative relation with an opening of the.
10 cylinder.
The valve is operated by means includ
ing a rocker arm disposed in a rocker arm box.
In general practice
mosphere or into a conduit or exhaust manifold,
15 the pressure in which>
is substantially equal to
that of the surrounding atmosphere. At times,
however, itbecomes desirable to utilize available
mosphere. Under such conditions’of increased
back pressure it has been observed that the ex
with an inlet or suction conduit I3 and an outlet
or a discharge conduit I4. The latter fprms‘an
air duct to an inlet I5 of a second stage. Inter
posed in the air duct is a carbureter I6 in which
the exhaust gases, after
leaving this valve, are discharged directly to at
energy in these exhaust gases in a turbine wheel,
a waste heat boiler, or by other means.
20 mostveiîìcient utilization of this energy requires
that the pressure in the exhaust manifold be ap
preciably higher than that of the surrounding at
ing a casing I0 to which is ñanged a casing II
of a supercharger. The supercharger in this par
ticular instance has two stages, a ñrst stage I2
fuel is mixed with the air discharged from the 10
ñrst stage and forced into the inlet I5 of the
second stage. 'I'he second stage has an outlet Il
which forms an intake for an engine cylinder I8.
The engine cylinder I8 is connected to an exhaust
conduit or manifold I9 in which the pressure is 15
maintained higher than that of the surrounding
atmosphere. 'I'he ñow of combustion gases from
the engine cylinder I8 to the exhaust conduit I9
`is. controlled
by means including a valve mecha- `
nism 20. The mechanism, as shown in Fig. 2,
comprises a valve stem 2I slidably disposed in a 20
sleeve 22 formed in a valve casing 23. The valve
casing 23 in the present instance is integrally
united with a portion of the cylinder I8. The
25 haust valves become overheated, the valve stems
become pitted and scored and the life of the en ' lower end of the valve stem is secured to a valve
tire valve structure and other parts cooperating
disk 24, which latter is in cooperative relation 25
therewith is materially shortened. The principal
with a seat 25 on the cylinder I8. 'I'he upper
end of the valve stem 2I is engaged by a rocker
arm 26 held on a fulcrum 21 and connected to
cause of this difficulty is that with the constant
30 back pressure in the exhaust manifold higher
than the surrounding atmospheric pressure, hot
exhaust gases flow through the clearance space
between the valve stem and the surrounding
channel into the rocker arm box.
This ñow -of
35 gases overheats the
valve stem, prevents lubri
cant from entering the space between the valve
stem and the channel, and further tends to build
up a pressure inside
_the rocker arm box which
causes expelling of lubricant from this box
40 through any opening,
however minute.
The object of- my invention is to provide an
improved construction and arrangement of the
type of combustion engi
nes above specified to re
duce the injurious elîects of exhausting into -a
45 manifold or other chamber
wherein a relatively
high pressure exists.
For a consideration of what I believe to be novel
and my_invention, attention is directed to the fol
lowing description and the claim appended there
50 to in connection with
In the drawing, Fig.the accompanying‘drawing.
1 is a somewhat diagram
matic view of an internal combustion engine em
bodying my invention; Fig. 2 is an enlarged detailA
view of a part of Fig. 1, and Figs. 3 and 4 are
modifications according
to my invention.
a push rod 28. The valve is normally biased
towards closing position and held in contact with 30
the right-hand end of the rocker arm 26 by means
of a coiled spring 29 surrounding the upper end
of the valve stem 2l. The .latter and the rocker
arm 26 are enclosed by a rocker arm box or cas
ing 30. 'I'he push rod is enclosed by a tube 38°. 35
The fulcrum 21 and other movable parts of the
valve mechanism are lubricated to reduce friction
and wear thereof.
During operation the push rod 28 is periodically
reciprocated to cause opening and closing of the 40
valve. When the valve is opened or unseated,
gases are discharged from the cylinder I8 into the
exhaust conduit I9, in which as 'described above
there may be a pressure higher than the sur
rounding atmospheric pressure. Due to this dif 45
ference in pressure, the hot exhaust gases nor
mally have a tendency to flow upward into thc
small clearance existing between the valve stem
2| and the wall of the surrounding channel 22.
This flow of hot gases forces out and burns away 50A
all lubricant in the clearance space, causes over- '
heating of the valve stem, and ‘by creating a pres
sure above atmosphere in the rocker arm box,
expels the lubricant therefrom. This upward
The modiñcation of my invention shown in Fig.
4 comprises a valve casing 5|) having a channel
effects is reduced or eliminated in accordance 5| for accommodating a valve stem 52. Two
with my invention by the provision of auxiliaryT . spaced apart annular recesses 53 and 54 sur
means which cause an artiñcial draft or blast
rounding the valve stem 52 are formed in the
along the valve stem 2|. Preferably I provide channel 5|. The recess 53 in this arrangement is
means for causing a counter-flow of iluid such as connected by a conduit 55 to a space subject to
air with respect to the flow of combustion gases. pressure equal to or less than that of the atmos
In the present instance I have shown two spaced
phere, for instance the intake chamber of a com
apart recesses 3| and 32 formed in the channel 22
pressor. The recess 53 is disposed near the lower
end of the valve stem, that is, adjacent the valve
end. The recess 3| which is formed nearest the disk, whereas the recess 54 is disposed on the
valve disk 24 is connected to a conduit 33 for con
side of the recess 53 remote from the valve disk.
ducting air (or other fluid) under pressure to the i The recess 54 communicates by a conduit 56 with
recess. rI‘he other end of the conduit 33 is con
the atmosphere. The provision of the recess 56
iiow of hot combustion gases with its injurious
15 nected to a source of air or other fluid having an
vented to atmosphere is important whenever the
stance it is shown connected to the air duct or
20 outlet conduit I4 (Fig. 1) of the ñrst supercharger
other recess 53 is connected to a point of subat
mospheric pressure because in this case the ex
istence of low pressure in the recess 53 would
cause the lubricant in the upper end of the valve
stem and the rocker arm, not indicated, to flow
absolute pressure higher than the (maximum,
average) absolute pressure within the exhaust
manifold or chamber I9. In this particular in
stage, the connection being made ahead of the
carbureter I6 whereby air from the first stage of
the supercharger is forced through the conduit
33 into the recess 3| surrounding the valve stem
25 2|. The portion of the channel 22 in the valve
casing intermediate the recess 3| and the lower
end of the channel is made slightly wider to form
a clearance 34 of a width suflìcient to permit a
iicw of air at high velocity from the recess 3|
30 towards the disk or lower portion of the valve
stem. This counterflow of air prevents or re
downward along the valve stem. This downward
flow of the lubricant is reduced byy the provision
of means creating a pressure equal to the atmos 25
phere at a point above the recess 53, in the pres
ent instance within the recess 54. During oper
ation, exhaust gases are permitted to flow upward
along the lower end of the valve stem 52 until
they reach the recess 53, whence they are dis 30
charged through the conduit 55. Thus, whereas
in the arrangement of Figs. l and 2 means are
duces the flow of combustion gases in the opposite provided for creating an artificial flow in down
that is, towards the valve stem,
direction. Since the pressure established in the warddirection,
of Fig. 4 means are provided 35
recess 3| is higher than that within the rocker
flow upward along the
35 arm box, this higher pressure might cause a iiow valve stem, and other means are provided for
of air through the clearance space between the
valve stem and the channel into the rocker arm reducing the iiow of air and lubricant from the
box, thereby effecting ejecting of lubricant from upper part of the valve stem into the recess 53.
this box. To prevent this I provide intermediate Furthermore, whereas in the arrangement of Fig.
the >iirst recess 3| and the rocker armbox a second 2 the lower end portion 34 ofthe channel is some
recess 32 which is vented to atmosphere through what wider to deñne an annular space with the
valve stem, in the arrangement of Fig. 4 the lower
a conduit 36. The channel portion 35 intermedi
ate the two recess 3| and 32 has a good sliding or end of the channel 5| has a sliding fit with the
packing iit with the valve stem. The cross sec
tional area of the conduit 36 and the recess 32 ist.
appreciably larger than that of the clearance be
tween the valve stem and the channel so that any
iiuid or gases passíngthrough the channel portion
35 will escape to atmosphere without creating in
the recess 32 a pressure above atmosphere.
The modification> of Fig. 3 comprises a valve
casing 40 forming a channel 4| for a valve stem
42. A recess 43 corresponding to the recess 3|
~ci' Fig. 2 is formed in the channel 4| and con
nected to a source 44 of high air or ñuid pressure.
In accordance with my invention a lower por
tion 45 of the channel 4| intermediate the recess
valve stem, similar to the sliding ñt intermediate
the two recesses 53 and 54 and corresponding to
the sliding ñt intermediate the recesses 3| and
32 of Fig. 2.
- Having described the method of operation of
my invention, together with the apparatus which
I now consider to represent the best embodiment 5o,
thereof, I desire to have it understood that the
apparatus shown is only illustrative and that the
invention may be carried out by other means. l
What I claim as new and desire to secure by
Letters Patent in the United States is:
A stumng box for an exhaust valve having a
stem and a disk for controlling the ñow of exhaust
gases from a source to an exhaust, means having
and made wide enough to permit the iiow of ' spaced upper and lower annular recesses sur 60
compressed air from the recess 43 towards the rounding the end of said stem near the disk,
lower portion of the stem 42. The arrangement means for maintaining in the lower recess a pres
is such that the air is discharged from the recess sure greater than that existing in such exhaust,
43 at high velocity, the velocity being gradually and means for venting the upper recess to at
converted into pressure as the air leaves the mosphere, the channel between the lower recess
and the disk forming a clearance to permit air
lower end of the- flared or Venturi-shaped chan
43 and the end of the channel 4| is Venturi-shaped
nel portion 45, thereby preventing or reducing ' contained in the lower recess to iiow at high ve
the ñow of combustion gases along the stem in locity along the stem towards the disk.
the opposite direction.
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