Note: Descriptions are shown in the official language in which they were submitted.
ENGINE CAMSHAFT AND PISTON LUBRICATION
Technical Field
This invention relates to internal combustion
engines and more particularly to the lubrication of
components such as camshaft valve actuating cams and
piston skirts in such engines. In its more specific
aspects the invention provides gutter forming ribs in
the valley walls of a V-type internal combustion engine
to direct excess lubricant to the cams and piston skirts
for adequate lubrication thereof.
Background of the Invention
It is conventional in V-type internal com-
bustion engines to provide a cylinder block having walls
defining two V arranged banks of cylinders with a valley
between the banks and a crank chamber below. Pistons
are provided in the cylinders which have skirts engaging
the cylinder walls, the pistons being connected with a
crankshaft for reciprocation in the cylinders. The
cylinders are commonly provided with valves controlling
access to the combustion chambers and with means for
actuating the valves that are engageable with the cams
of a camshaft longitudinally arranged in the valley
between the ban]cs and driven by the crankshaft. Further,
it is usual to provide a pressure lubrication system
through which lubricating oil is delivered from an oil
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sump below the engine crank chamber to the moving parts
of various components of the valve actuating means, the
excess oil being directed back to the sump, at least in
part, through an open passageway through the valley
between the cylinder banks, running along the walls
thereof before dropping through the crank chamber to
the oil sump.
In engines of the type described above, some
means either specially provided or inherently existing
are relied upon for lubrication of the camshaft cams
which actuate the valve mechanism and for lubrication
of the cylinder walls and piston skirts which recipro-
cate within the cylinders in engagement with the walls.
In some cases, lubrication of these components is
ade~uately taken care of by the throw off or splash of
oil from rotation of the engine crankshaft and the
mechanism attached thereto. In other cases, separate
pressure lubricating devices have been provided for
spraying oil onto the camshaft cams and the cylinder
walls or the piston skirts in order to provide adequate
lubrication to these parts. The provision of such
additional lubricating means generally adds to the cost
of manufacture of an engine and is therefore resorted to
only in cases where ade~uate lubrication i5 not provided
by the crankshaft throw off and splash oil distributed
within the engine crank chamber and commonly penetrating
upwardly into the cylinder bank valley.
Summary of the Invention
The present invention provides novel means for
the lubrication of moving parts of an engine within and
below the valley portion of the cylinder block between
the cylinder banks. In particular, the invention pro-
vides means for lubricating the cams of a camshaft
located within the valley and the skirts of pistons
which extend below their respective cylinders at the
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lower portions of their strokes into a portion of the
crank chamber below the valley. The improved arrange-
ment utilizes a system of gutter forming ribs cast
integral with the walls of the valley at suitable loca-
tions such as around the valve lifter carrying liftergallery immediately above the camshaft as well as on
the valley walls near their lower ends immediately
above the bottoms of the respective cylinders. The
provision of gutters through cast-in ribs in the manner
described is accomplished with little or no additional
cost since it is accomplished during the initial casting
of the cylinder block.
These and other features and advantages of the
invention will be more fully understood from the follow-
ing description of a preferred embodiment taken togetherwith the accompanying drawings.
Brief Descri tion of the Drawings
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In the drawings:
Figure 1 is a transverse cross-sectional view
of a V-type internal combustion engine having lubrica-
tion means in accordance with the invention;
Figure 2 is a longitudinal view of the engine
of Figure 1 showing certain features of the lubrication
means;
Figure 3 is a fragmentary top view of a
portion of the engine block as viewed from the plane
indicated by the line 3-3 of Figure 1 and illustrating
features of the camshaft lubrication means;
Figure 4 is a fragmentary cross-sectional view
from the plane of line 4-4 of Figure 3 and illustrating
the shape of the upper gutter forming ribs;
Figure 5 is a fragmentary cross-sectional view
from the plane of line 5-5 of Figure 3 further illus-
trating the upper rib configuration;
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Fi~ure 6 is a fragmentary cross-sectional view
of the engine block looking downwardly from the plane of
line 6-6 of Figure 1 and illustrating features of the
piston skirt lubricating means;
Figure 7 is a fragmentary cross-sectional view
from the plane of line 7-7 of Figure 6 showing the con-
figuration of the lower gutter forming ribs; and
Figure 8 is a fragmentary cross-sectional view
from the plane of line 8-8 of Figure 6 further illus-
trating the lower rib configuration.
Best Mode for Carryin~ Out the Invention
Referring now to the drawings in detail,
numeral 10 generally indicates a six cylinder V-type
internal combustion piston engine intended primarily for
automotive vehicle application. Engine 10 includes a
cast and machined cylinder block 11 including a lower
crankcase section 12 defining a crank chamber 14 and
supporting thereabove left and right hand banks 15 and
16, respectively, of cylinders (as viewed from the rear
of the engine opposite the direction of the view of
Figure 11. The cylinder banks 15, 16 are arranged in
V fashion with a 6Q bank angle. The inner walls 19, 20
of the left and right hand cylinder banks, respectively,
define a generally V shaped open section intermediate
the cylinders that is commonly referred to as the valley
21.
An oil pan 23, mounted on the bottom of the
crankcase section 12 of the cylinder block, provides a
sump 24 for containing a supply of lubricating oil for
the engine and encloses the lower part of the crank
chamber 14. A crankshaft 25 is rotatably supported in
conventional fashion by the cylinder block within the
crank chamber and includes a plurality of crank throws
27 connected by connecting rods 28 to pistons 29
reciprocably movable within each of the six cylinders 17
of the engine.
The pistons each include skirts 31 which
engage the walls of their respectively cylinders 17 and
form bearing surfaces through which the thrust loads
acting between the pistons and the cylinder walls are
carried. Upon rota~ion of the crankshaft, the pistons
reciprocate in their respective cylinders moving between
upper and lower dead center positions, the latter being
such that the lower portions of the piston skirts 31
extend below the lower edges of their respective cylin-
ders into the upper portion of the crank chamber. Thisis illustrated by phantom lines with respect to the
piston shown in the right hand cylinder bank 16 of
Figure 1 as well as by solid lines for that of the
center cylinder shown in Figure 2.
The upper ends of the cylinders 17 are closed
by left and right bank cylinder heads 32, 33 mounted
respectively on the upper ends of the cylinder banks
15, 16. The cylinder banks conventionally carry out-
board mounted exhaust manifolds 35, 36 which may be
supplied with secondary air through air supply valves
37, only one of which is shown. An intake manifold 39
mounted between the cylinder heads 32, 33 covers the
open top of the valley 21 and in turn supports a car-
buretor 40 on which an air cleaner 41 is mounted.
The cylinder heads are provided with inlet
and exhaust ports 43, 44, respectively, for communi-
cating their respective cylinders with the intake and
exhaust manifolds and other portions of the engine
intake and exhaust systems. The respective ports are
controlled by inlet and exhaust valves 45, 47, respec-
tively, which are actuated by suitable valve gear
including valve springs 48, rocker arms 49, pushrods 51
and hydraulic valve lifters 52, the latter being carried
in the bores 53 of bosses 55 formed as extensions of the
valley walls 19, 20 and defining a valve lifter gallery.
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The valve lifters 52 are actuated by the cams 56 of a
camshaft 57 which is rotatably supported in the cylinder
block, extending longitudinally through the valley 21
below the lifter gallery bosses 55. A driven gear 59
connects through a chain 60 with a drive gear 61 on the
crankshaft, thus providing a driving connection for the
engine camshaft.
Engine Lubrication
The engine 10 is provided with a pressure
lubrication system including an oil pump 63 driven from
the distributor drive gear 64 located near the rear end
of the camshaft and connected with an intake strainer 65
through which oil is drawn by the pump from the engine
oil sump. The pump directs oil through various passages
in the engine block and moving components to lubrication
points including the various bearing journals of the
crankshaft and camshaft. Oil is also supplied directly
to the valve lifters 52 and from them through the push-
rods to the rocker arms 49 which are enclosed by rocker
covers 67 mounted on the tops of the cylinder heads and
the adjacent intake manifold. The oil used in lubri-
cating the valve gear components, as well as the excess
oil supplied thereto, is returned to the engine sump by
gravity impelled flow downwardly along upper and inner
surfaces of the cylinder heads, through the open pushrod
spaces defined between the cylinder heads and the intake
manifold and into the valley 21, running along the walls
19, 20 thereof to the lower inner edge of the cylinders
at which point openings 72 are provided through which
the oil passes into the crank chamber and thence is
returned to the oil sump below.
Along the walls 19, 20 there are provided upper
and ~ower groups of gutter forming ribs arranged espe-
cially to intercept the excess lubricating oil being
3S returnea from lubrication of the upper portions of the
valve gear and passing downwardly along the valley
walls and to direct this oil onto the cams 56 of the
camshaft and subsequently, at least in part, onto the
inner skirts 31 of the various pistons in order to
provide for adequate lubrication of the cams, piston
skirts and the associated cylinder walls. The upper
gutter forming ribs 7~, as best shown in Figures 2-5,
are seen to extend from points 75 near the upper edges
of the cylinder block downwardly around the lifter
gallery bosses 55, with one set of ribs being provided
at each cylinder location. Each set of the upper ribs
is arranged to intercept a major portion of the return-
ing oil utilized for lubricating the components of its
respective cylinder location. This oil is directed
downwardly through gutters 76 extending around the
sides of the lifter gallery bosses 55, the gutters
terminating at points along openings 78 immediately
above the respective cams 56 of the camshaft, so that
the collected oil is directed onto the surfaces of the
cams for lubrication thereof.
Moving further downwardly along the sides of
the valley walls l9, 20, some of the oil passing the
upper ribs, in addition to that used for lubricating
the camshaft bearings, is intercepted near the lower
edges of the engine cylinders by a lower set of gutter
forming ribs 79 best shown in Figures 2 and 6-8. Ribs
79 extend longitudinally in both directions from the
planes of their adjacent cylinders defining gutters 80
which collect oil fxom the valley wall surfaces imme-
diately outside of their respective cylinders anddirect it to V-like openings 82 formed at the lower
edges of the respective valley walls which correspond
to the bottom edges of the respective cylinders. From
here the oil collected by the gutters is directed onto
the outer surfaces of the lower portions of the piston
skirts 31 when they reach the lower portions of their
strokes, thus providing lubrication for both the piston
skirts and their respective cylinders upon subsequent
upward movement of the pistons. It should be noted
that the lower group of gutter forming ribs 79 are
likewise arranged to collect oil flowing down the walls
at each of the various cylinder locations, which has
primarily been utilized in the lubrication of operative
elements of the valve gear and other moving parts
associated with the respective cylinders, and to use
this oil for providing adequate lubrication of the
inner piston skirts 31.
By the manner of providing upper and lower
groups of gutter forming ribs associated with each
respective cylinder location, the present invention
provides added lubrication to moving components of the
engine such as the camshaft cams and piston skirts
through means provided entirely as part of the engine
block casting and thus obtained with a mininum manu-
facturing cost.
While the~invention has been disclosed byreference to a specific embodiment chosen for purposes
of illustration, it should be understood that numerous
changes could be made without departing from the spirit
and scope of the inventive concepts disclosed. Accord-
ingly, it is intended that the invention not be limited
to the specific forms shown in the disclosed embodiment
but that it have the full scope provided by the language
of the following claims.
