U.S. patent number 3,809,046 [Application Number 05/285,607] was granted by the patent office on 1974-05-07 for valve guide stabilizing and sealing insert.
This patent grant is currently assigned to K-Line Industries, Inc.. Invention is credited to James A. Kammeraad.
United States Patent |
3,809,046 |
Kammeraad |
May 7, 1974 |
VALVE GUIDE STABILIZING AND SEALING INSERT
Abstract
An insert for sealing and stabilizing the valve stem of a poppet
valve in the upper portion of a valve guide of an internal
combustion engine. The insert comprises a cylindrical steel jacket
having an inner layer of Teflon bonded thereto. The inner diameter
of the insert corresponds to the diameter of the valve stem and
extends coaxially and forms a substantial continuation of the valve
guide wall. The insert extends beyond the upper end of the valve
guide a distance of about 25 to 50 per cent of its length for
stabilizing the reciprocation of the valve stem in cooperation with
the remainder of the valve guide while preventing excessive amounts
of lubricating oil from entering the valve guide.
Inventors: |
Kammeraad; James A. (Holland,
MI) |
Assignee: |
K-Line Industries, Inc.
(Holland, MI)
|
Family
ID: |
23094985 |
Appl.
No.: |
05/285,607 |
Filed: |
September 1, 1972 |
Current U.S.
Class: |
123/188.9;
123/188.6 |
Current CPC
Class: |
F01L
3/08 (20130101) |
Current International
Class: |
F01L
3/08 (20060101); F01L 3/00 (20060101); F01l
003/08 () |
Field of
Search: |
;123/188P,188GC ;277/199
;308/238,DIG.7,5V |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
571,554 |
|
Aug 1945 |
|
GB |
|
198,944 |
|
Jun 1923 |
|
GB |
|
388,333 |
|
Aug 1908 |
|
FR |
|
334,854 |
|
Jan 1904 |
|
FR |
|
1,148,812 |
|
Jul 1961 |
|
DT |
|
604,551 |
|
Nov 1945 |
|
GB |
|
869,384 |
|
Jan 1960 |
|
GB |
|
Primary Examiner: Myhre; Charles J.
Assistant Examiner: Rutledge, Jr.; W.
Attorney, Agent or Firm: Price, Heneveld, Huizenga &
Cooper
Claims
The embodiments of the invention in which an exclusive property
or
1. A valve guide stabilizing seal for internal combustion engines
comprising an insert mounted within the upper portion of a valve
guide, said insert comprising: a cylinder having an outer layer of
metal and a bonded inner layer of a lubricious, plastic bearing
material; said cylinder including an axial slot extending
substantially along the entire length thereof allowing said
cylinder to be compressed; said cylinder, when compressed, having
an inside diameter corresponding to the outside diameter of a valve
stem reciprocally mounted within said valve guide thereby sealing
said valve stem, and an outside diameter greater than said inside
diameter of said valve guide and corresponding to the diameter of a
relieved area in said upper portion of said valve guide; said
insert extending upwardly beyond the upper boundary of said valve
guide, the relative dimensions of said relieved area and said
insert being such that said slot will close tightly when said
insert is force-fitted into and
2. The stabilizing seal of claim 1 wherein said cylinder has two
ends at
3. The stabilizing seal of claim 2 wherein both end of said
cylinder
4. The stabilizing seal of claim 1 wherein said plastic bearing
layer has a
5. The stabilizing seal of claim 4 wherein said plastic bearing
layer is
6. The stabilizing seal of claim 1 wherein said plastic bearing
layer is
7. The stabilizing seal of claim 1 wherein said insert extends
upwardly beyond the upper boundary of said valve guide a distance
between about 25
8. The stabilizing seal of claim 1 wherein said plastic bearing
layer has a
9. The stabilizing seal of claim 1 wherein said axial slot includes
two parallel portions spaced circumferentially apart and joined by
a circumferential portion, said slot adapted to allow said insert
to compress to the size of said enlarged area upon the insertion of
said
10. In an internal combustion engine including a cylinder head, at
least one valve guide having an extending shoulder portion
including a portion of said valve guide, and at least one valve,
including a valve stem, reciprocally mounted within said valve
guide; the combination of said valve guide and means for sealing
and stabilizing said valve stem in said valve guide; said means
including a cylindrical insert having an outer layer of metal and
an inner layer of a lubricious, synthetic, resinous bearing
material; said insert mounted in the upper portion of said valve
guide within said shoulder and extending beyond the end of said
shoulder for stabilizing said valve stem and sealing the same to
prevent undesired oil passage through said guide; said insert
having an inner diameter corresponding to the diameter of said
valve stem; said inner diameter forming a substantial continuation
of said valve guide; said insert being retained within said valve
guide independently of any mechanism for operating the valve which
includes said valve stem and further including an axial slot
through both of said metallic and plastic layers extending
11. The combination of claim 10 wherein said lubricious, synthetic
bearing
12. The combination of claim 11 wherein said metallic layer is
thicker than
13. The combination of claim 10 wherein said cylindrical insert
includes two ends at least one of which includes a chamfer on the
outside diameter
14. The combination of claim 13 wherein said end of said valve
guide at said extending shoulder includes a chamfer to facilitate
installation of
15. The combination of claim 10 wherein said insert extends beyond
the end of said shoulder about 25 to 50 per cent of the length of
said insert.
16. The combination of claim 10 wherein said lubricious, synthetic
bearing layer includes spiral grooving therealong for additional
lubrication of
17. The combination of claim 10 wherein said axial slot includes
two circumferentially spaced portions each extending approximately
one-half the axial length of said insert such that the ends thereof
are adjacent one another; said adjacent ends of said portions being
joined by a
18. The combination of claim 10 wherein said axial slot includes
two parallel portions spaced circumferentially apart and joined by
a circumferential portion at the middle of said insert; said slot
adapted to allow said insert to compress to the size of said valve
stem when inserted
19. A combination stabilizing and sealing insert for use in the
valve guide of an internal combustion engine, said valve guide
having a valve stem reciprocally mounted therein, the extremity of
said guide having a relieved area therein to accept and retain a
section of said insert, said insert comprising a cylindrical metal
jacket having a layer of lubricious plastic bearing material bonded
to the interior thereof, said jacket and plastic layer having a
longitudinal slot therethrough along the entire length of said
insert, said slot forming a gap along the entire length of said
insert when said insert is in a relaxed condition prior to
insertion into said relieved area, said gap being closable by
radial compression upon insertion of said insert into said relieved
area, the relative dimensions of said relieved area, the insert and
the valve stem being such that (a) the insert will be tightly
received and retained by said relieved area independently of any
mechanism for operating the valve which includes said valve stem
upon insertion of the insert thereinto; (b) said gap will close
tightly upon such insertion; and (c) the inner diameter of the
installed insert equals as closely as possible the outer diameter
of the valve stem; the axial length of said relieved area being
substantially less than the axial length of said insert whereby a
substantial portion of said insert will extend in exposed fashion
beyond said guide.
Description
This invention relates to valve guide inserts for internal
combustion engines and, more particularly, to a combination
stabilizer and seal inserted within a portion of a valve guide of
an internal combustion engine.
BACKGROUND OF THE INVENTION
Valve guides of internal combustion engines through which the valve
stem of a poppet valve reciprocates are susceptible to great
amounts of wear over the lifetime of the engine. The wear in the
guides is generally the greatest at either end thereof. Such wear
is caused by the wobbling of the valve stem as it reciprocates
through the valve guide with the center of the valve guide acting
as a type of fulcrum around which the stem pivots.
The latest internal combustion engines are designed, from an
anti-pollution standpoint, such that the valves reciprocate through
a greater distance than previously deemed necessary. Since the
valves are typically actuated by a rocker-arm mechanism, which
mechanisms have a longer arcuate path of travel and exert at least
some lateral thrust on the valve stem, the increased travel
distance has accentuated the wear problem. Further, the use of
non-leaded fuels has tended to reduce the lubrication of the valve
guide thereby also increasing the overall wear thereof.
It is customary, in the internal combustion engine art, to provide
a seal at each of the valve stem locations to prevent the leakage
of undesirable quantities of oil into the combustion chamber
through the valve guide passageway. These seals typically are of
the "umbrella" type which reciprocates with the valve stem or of
the "positive" type which is affixed in stationary fashion to the
exposed shoulder portion of the valve guide. Satisfactory seals for
this purpose are available although the same do increase the cost
of engine manufacture and maintenance. One of the objects of this
invention, as will be apparent hereinafter, is to provide an insert
of the general type described which functions not only to stabilize
the wobbling tendency of the valve stem and, thus, reduce guide
wear, but also to perform the dual function of the seal, rendering
a separate seal element unnecessary.
SUMMARY OF THE INVENTION
Accordingly, this invention provides a combination stabilizer and
seal for valve guides having the dual primary purposes of
preventing the wear of the ends of valve guides and facilitating
the lubrication of the valve guide. An accompanying purpose of the
invention is to provide an oil seal which prevents excessive
lubricating oil from the upper valve assemblies from entering the
valve guide, and, thus, the combustion chamber of the cylinder
therebelow.
The valve guide stabilizing seal of the present invention generally
comprises a cylindrical insert inserted in a valve guide in an
internal combustion engine such that it extends approximately 25 to
50 per cent of its length beyond the end of the extending shoulder
portion of the valve guide at the upper end thereof. The insert
comprises an outer layer or jacket of metal such as steel and an
inner concentric layer of a lubricious plastic bearing material
which, in the preferred embodiment, is a layer of Teflon bonded
securely to the outer metal layer. The cylindrical insert includes
an axial slot therethrough and extending along one side thereof in
a stepped fashion for allowing the bushing to be compressed to the
size of an enlarged opening formed in the upper end of the valve
guide. The stepped configuration of the axial slot prevents the
opposing edges along the slot from moving axially relative to one
another during installation of the insert as well as retarding oil
leakage through the slot.
When force-fitted in the enlarged portion of the valve guide, the
inner diameter of the stabilizing seal will form a substantial
continuation of the valve guide. The ends of the stabilizing and
sealing insert may be chamferred to facilitate the insertion in the
enlarged area and to prevent a build-up of lubricating oil thereon.
Further, the Teflon inner lining may include knurling or spiral
groove to aid the controlled lubrication of the valve stem.
These and other objects, advantages and features of the invention
will become apparent from a study of the following description
taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary, cross-sectional, side elevation of a
typical poppet valve mounted in a valve guide of an internal
combustion engine cylindrical head, the valve guide including the
stabilizing seal of the present invention;
FIG. 2 is a side elevation of the stabilizing seal shown in FIG.
1;
FIG. 3 is a cross-sectional view of the stabilizing seal taken
along plane III--III of FIG. 2; and
FIG. 4 is a fragmentary, enlarged, cross-sectional view of the
stabilizing seal of FIGS. 1 through 3 shown during its insertion
within the valve guide of a typical cylinder head.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, the valve guide stabilizing seal 10 of the
present invention is shown inserted in the upper end 13 of a
typical valve guide 12 formed in a typical cylinder head 14 of an
internal combustion engine. A typical reciprocating poppet valve
16, including a valve head 18 and a valve stem 20, is reciprocally
mounted within the combined valve guide 12 and stabilizing seal 10.
One or more valve springs 22 and 24 are mounted concentrically over
an extending shoulder portion 26 of valve guide 12 and engage a
valve retainer (not shown) secured to the upper end of the valve
stem 20 (not shown) in conventional fashion. The inside diameter of
the shoulder portion 26 defines the upper portion 13 of the valve
guide. An enlarged or relieved area 27 is formed in upper portion
13 to receive the stabilizing seal bushing therein. The valve 16 is
reciprocated in the conventional manner by means of either a push
rod and rocker-arm assembly (not shown) or an overhead camshaft
(not shown), either of which engages the upper end of valve stem
20.
The stabilizing seal 10 is mounted as shown in FIG. 1 to provide an
extension of the normal length of the guide valve 12 as well as an
effective seal preventing excessive amounts of lubricating oil from
the rocker-arm housing from entering the valve guide while
simultaneously facilitating the lubrication of the valve stem 20 by
means of the Teflon inner layer, as will be more fully described
below.
As shown in FIGS. 2 and 3, the valve guide stabilizing seal 10
includes inner and outer concentric layers 30 and 32, respectively,
which layers are securely bonded together to form the walls or
sides of the insert 10. The insert 10 includes an axially extending
slot or cut 34 along one side thereof. The cut 34 provides a gap
along the length of the insert when it is in its related condition
prior to insertion into the relieved area of the valve guide. This
gap allows the insert to radially compress when pressed or
force-fitted into the relieved area 27 during installation. The
relative dimensions of relieved area 27, the insert 10 and the
valve stem are such that (1) the insert is tightly received and
retained by area 27; (2) the slot 40 closes tightly during such
installation, the insert then assuming a circular cross-sectional
configuration; and (3) the inner diameter of the installed insert
equals as closely as possible the diameter of the valve stem.
As shown in FIG. 2, the axially extending slot 34 is formed by two
parallel axially extending slot portions 36 and 38 which are spaced
circumferentially of one another and joined by a circumferentially
extending cut 40 therebetween. The cut 40 forms a "step" in the
axially extending cut 34, which step prevents the opposing edges 42
and 44 along the length of the slot 34 from moving axially relative
to one another as the bushing 10 is inserted in the relieved area
27 in the upper portion 13 of valve guide 12 and is concentrically
compressed thereby. Step 40 also functions to retard undesirable
oil flow along the slot 34 during operation of the engine.
Insert 10 includes chamfers 46 and 47 on either end thereof. The
chamfer on the end inserted in relieved area 27 facilitates that
insertion while the chamfer on the remaining end provides a sloped
area which prevents the build-up of lubricating oil adjacent the
point at which valve stem 20 enters the insert 10 (FIGS. 2 and
4).
The outer layer 32 of the stabilizing and sealing insert 10 is
formed from a mild steel having a thickness of between
approximately 0.010 and 0.019 inches. The inner concentric layer 30
of bushing 10 is preferably formed from a lubricious, polymeric
resin compound such as polytetrafluoroethylene (Teflon). The Teflon
layer 30 is securely bonded to the outer steel layer 32 by
conventionally known methods. The Teflon layer is in the range of
approximately 0.006 to 0.020 inches. The overall thickness of the
insert sidewall is therefore between 0.016 and 0.039 inches.
Various thicknesses of the steel and Teflon layers may be used
although, generally, in the preferred embodiment, the thickness of
the inner Teflon layer 30 will be equal to or less than the outer
steel layer 32. It has been found that with somewhat increased
thicknesses of the layers 30 and 32 within the ranges defined
above, the support for valve stem 20 in valve guide 12 is
significantly increased, thereby further reducing the wobbling
tendency of the valve stem during its reciprocation as well as the
wear accompanying such wobbling.
Although Teflon is preferred for the inner layer 30, other
self-lubricating or lubricious plastic resins capable of
withstanding high temperatures and long periods of wear, as is
Teflon, may be used as a substitute for the Teflon therein.
As shown in FIG. 1, when the stabilizing seal 10 is installed in
the upper portion of the valve guide, it extends a predetermined
distance Y above the end of the extending shoulder portion 26 of
the valve guide. The amount Y of protrusion or projection of the
stabilizing seal 10 is designed to be, in the preferred embodiment,
within the range of 25 to 50 per cent of the overall length X of
the cylindrical bushing 10 forming the stabilizing seal. It has
been found that when the protrusion of the seal is maintained
within this range, the stability of the reciprocating valve stem 20
is greatly increased thereby reducing the wear on the upper and
lower ends of the valve guide and providing longer life for the
engine. Further, the need for mounting additional oil seals over
the valve springs 22 and 24 or on the upper portion of the valve
stem 20, to prevent excessive amounts of lubricating oils splashed
over the upper valve assemblies from entering and draining through
the valve guide 12 into the combustion chamber, is obviated by the
sealing function of the bushing 10.
In this connection, the seal 10 will have an inside diameter
corresponding to the outside diameter of the valve stem 20, i.e.,
the tolerance between the stabilizing and sealing bushing and valve
stem will be as close to zero as possible. The valve guide below
the seal 10 may have standard production tolerances normally
encountered in engine manufacturing.
Referring now to FIG. 4, the method for installing the stabilizing
seal 10 in the enlarged or relieved area 27 of upper portion 13 of
valve guide 12 is shown in greater detail. First, the upper end of
the valve guide is bored with appropriate boring tools (not shown)
to form the enlarged portion 27 having a diameter larger than that
of the valve guide and equivalent to the outside diameter of the
compressed insert 10. Then, as depicted in FIG. 4, a punch-like
tool 50 is positioned at the upper end of the stabilizing seal 10
and is struck to force the seal 10 through a mounting adapter 52
and into the relieved area 27 of valve guide 12. The adapter 52
includes a chamfer 53 on its inner diameter to facilitate the
starting of the seal 10 downwardly therethrough. Otherwise, the
inner diameter of the adapter 52 is equivalent to the outside
diameter of the compressed stabilizing and sealing insert.
The tool 50 includes a shoulder 24 formed by a reduced diameter
section 55 on the end of the tool to assist positive engagement of
the tool with the insert 10 during the installation process. The
seal 10 is forced downwardly in a press-fit engagement into the
relieved area 27 and into abutment with shoulder 29 at the lower
end thereof. Use of the adapter 52 automatically compresses the
seal 10 to the diameter of enlarged area 27 such that insertion is
greatly facilitated. Additionally, the inside diameter of the upper
end of extending shoulder portion 26 may include a chamfer 28 as
shown in FIG. 4 to facilitate the installation of the seal 10.
Similarly, the insert 10 may include a chamfer 46 to aid the
insertion thereof on one end as shown in FIGS. 2 and 4. As
mentioned above, chamfer 47 on the opposite end prevents a build-up
of oil on the upper end of insert 10 thereby further preventing oil
from entering the valve guide passageway. After insertion of the
stabilizing and sealing insert 10 in enlarged portion 27 of
shoulder 26, the inner layer 30 of Teflon may be knurled or have a
spiraling groove formed therein as at 31 with a knurling spiraling
tool. Alternatively, the knurling or spiraling groove may be formed
prior to the forming of the insert 10 into its cylindrical
shape.
As shown in FIGS. 1 and 4, the compressed insert 10 has an outer
diameter corresponding in size to the enlarged area 27 in shoulder
26 which diameter is larger than the inside diameter of valve guide
12. When installed in the relieved area 27, the inside diameter of
the insert 10 forms a substantial continuation of the valve guide
12 thereby forming a coaxial extension of the valve guide. As
mentioned above, the inside diameter of the bushing 10 exactly
corresponds to the outside diameter of the valve stem 20.
Therefore, the valve guide stabilizing seal of the present
invention provides a valve guide extension which both stabilizes
the reciprocation of the stem 20 of valve 16 within valve guide 12,
as well as sealing and preventing excess amounts of lubricating oil
from the upper valve assemblies from entering the valve guide 12
and thence into the combustion chamber. The sealing function is
performed at the interface of the upper extremity of Teflon layer
30 and the valve stem. The stabilizing seal 10 eliminates wobble
during reciprocation of the valve stem especially in recently
developed engines having longer valve reciprocation distances. The
stabilization of the valve stem thereby significantly reduces the
amount of wear in both the upper and lower portions of valve guide
12.
Additionally, the stabilizing seal of the present invention
provides a lubricious inner layer of Teflon which further reduces
the wear on the valve stem during the stabilizing support thereof.
The combined effect of both the stabilization and sealing, as well
as the self-lubricating properties of the inner Teflon layer,
produce significantly reduced wear of the valve guide and valve
stem while lengthening the life of the internal combustion engine
in which they are installed.
It will be understood that terms such as "upper" and "lower" as
used in this description are used for explanation purposes only and
are not intended to limit the scope of the invention.
While one form of the invention has been shown and described, other
forms will now be apparent to those skilled in the art. Therefore,
it will be understood that the embodiments shown in the drawings
and described above is merely for illustrative purposes and is not
intended to limit the scope of the invention which is defined by
the claims which follow.
* * * * *