Unitized oil cooler and filter assembly

A cooler and filter assembly (2) is disclosed including a cooler housing (4) containing an elongated internal cavity (14) opening into generally planar end faces (16 and 18) of the cooler housing (4) and further including a support structure (6) for mounting the cooler housing (4) on an internal combustion engine and for providing internal supply and return passages (104, 106, 108 and 110) for both engine coolant and lubrication oil through only one of the planar end faces (16) of the cooler housing (4). A thermostatically controlled valve (118) and an oil pressure responsive valve means (80) control the flow of oil through the cooler and filter assembly (2) to insure efficient and safe operation of the assembly (2). A heat exchange means (24) includes a fixed plate-like member (30) for mounting one end of each of a plurality of elongated tubes (26) and also contains oil supply and return apertures (54 and 56) which allow for simplification of the arrangement of flow passages within the assembly (2).

DESCRIPTION 
1. Technical Field 
This invention relates to an oil cooler and filter assembly adapted to be 
mounted directly on the block of an internal combustion engine by means of 
a cooler support having internal fluid flow passages directly 
communicating with oil and coolant flow ports opening through the side of 
the engine block. 
2. Background Art 
Numerous attempts have been made to simplify the design of oil coolers for 
internal combustion engines. One particularly important objective in prior 
designs has been to minimize the number of external conduits leading to 
and from the cooler assembly. Each such conduit is not only a source of 
potential leaks but also is subject to accidental damage during 
installation or use of the engine which could lead to catastrophic failure 
should either the lubrication fluid or engine coolant be lost. External 
conduits can also impart an extremely cluttered appearance to an engine 
and, thus, tend to decrease its marketability. 
Attempts to reduce the number of external conduits has generally centered 
on the design of a mounting bracket for an oil cooler assembly wherein 
lubrication oil supply and return passages contained within the mounting 
bracket are designed for communication with supply and return ports formed 
directly on the side of an engine block. U.S. Pat. Nos. 3,561,417 to 
Downey and 3,353,590 to Holman disclose examples of oil cooler assemblies 
in which the mounting bracket for the oil cooler assembly contains 
internal supply and return passages for the engine lubricating oil. 
However, neither of these disclosures suggests a means of providing 
coolant supply and return passages within the same mounting bracket. 
Further complicating the difficulty of internalizing the fluid supply and 
return passages is the necessity of providing proper flow control 
functions in order to obtain optimum operation of the oil cooler and 
associated lubrication filter. For example, it is known to be desirable to 
avoid lubrication oil cooling under certain engine operating conditions. 
This is normally accomplished by a flow diverting valve which responds to 
lubrication oil temperature. The patent to Holman (U.S. Pat. No. 
3,353,590) discloses a valve of this type mounted within the cooler 
housing. It is also desirable to be able to bypass flow around an oil 
filter whenever the filter becomes clogged or plugged to assure, thereby, 
that oil will continue to circulate to the vital components of the engine. 
No single prior art cooler assembly design has shown how to internalize 
the supply and return passages while also providing internally mounted 
bypass and temperature sensing valves. 
Economy of manufacture is, of course, a primary objective of any practical 
oil cooler/filter assembly design. However, this requirement is often at 
odds with other objectives such as durability and reliability. In this 
later regard, differential thermal expansion of those components which 
form the heat exchanger portion of the cooler assembly can lead to 
premature failure if the cooler assembly is improperly designed. Attempts 
to accommodate thermally induced differential changes in component sizes 
within a heat exchanger have been disclosed in U.S. Pat. Nos. 2,240,537 to 
Young; 2,512,748 to Lucke and 4,207,944 to Holtz et al. In particular, 
the patent to Lucke discloses a shell within which is mounted a plurality 
of tubes each of which is connected at one end to an anchored sheet and at 
its other end to a floating type sheet sealingly engaged at its perimeter 
to the heat exchanger housing by means of a rubber ring to compensate for 
relative expansion of the tubes and shell. While useful for the purposes 
disclosed, the designs disclosed by these patents fail to suggest how the 
coolant inlet and outlet passages can be arranged to begin and end 
adjacent the same end portion of the assembly in a manner which would 
assist in simplifying the mounting and sealing structure of the oil cooler 
assembly. In this regard, U.S. Pat. No. 1,831,337 to Bennett discloses a 
heat exchanger including a casing or shell and a pair of tube nests placed 
longitudinally within a chamber formed in the shell wherein the tube nests 
are supported by a tube sheet or plate rigidly connected with the shell. A 
header containing a transfer chamber is connected to the ends of the tubes 
remote from the plate to effect transfer of fluid received through the 
tubes of one nest for return through the tubes of the second nest. The 
header is said to be "floating" but does not suggest specifically that the 
header may move longitudinally in response to thermally induced changes in 
the length of the tubes relative to the shell and does not suggest sealing 
the space between the floating head and shell to confine heat exchange 
fluid flow in a manner to maximize heat exchange fluid flow in a manner to 
maximize heat exchange efficiency. 
In summary, no oil cooler and filter assembly design has been known 
heretofore which provides a compact, simplified assembly which minimizes 
the number of external fluid flow conduits while at the same time provides 
full flow control capabilities and accommodates thermally induced 
differential expansion of components. 
DISCLOSURE OF THE INVENTION 
It is a primary object of this invention to overcome the deficiencies of 
the prior art as discussed above by providing an oil cooler and filter 
assembly including a support structure for mounting a cooler housing on 
the engine and for providing isolated fluid flow passages between the 
engine and the cooler housing. This primary object is obtained in part by 
the provision of a flat plate-like member sandwiched between the cooler 
housing and support structure for supporting the ends of a plurality of 
heat exchanger tubes wherein the plate-like member contains at least one 
oil inlet aperture through which oil flows from the support structure into 
the cooler housing and at least one oil return aperture through which oil 
flows from the cooler housing into the support structure. 
It is another object of the subject invention to provide a compact, 
relatively light weight, oil cooler and filter assembly in which the flow 
passages for supply and return of both lubricating oil and engine coolant 
are provided through a single end support structure for the cooler 
housing. Within the cooler housing are mounted a plurality of heat 
exchanger tubes each of which is fixed at one end by a plate-like member 
and is free to move axially at the other end relative to the cooler 
housing. 
Still another object of the subject invention is to provide a compact oil 
cooler and filter assembly containing a thermostatically operated oil flow 
control valve mounted within the support structure for diverting oil flow 
around the heat exchanger element whenever the oil temperature is below a 
predetermined level combined with a bypass valve mounted at the end of the 
oil cooler housing remote from the support structure to cause lubrication 
oil flow to be bypassed around an oil filter whenever the pressure 
differential across the filter reaches a predetermined level. The bypass 
valve is also designed to generate a warning signal whenever the 
predetermined pressure differential across the filter reaches a second 
predetermined level which is less than the first predetermined level. An 
end brace for the cooler housing includes an end cover which is designed 
to capture and retain the bypass valve in a recess formed at the end of 
the cooler housing remote from the support structure containing the supply 
and return flow passages. 
Still other and more specific objects of the subject invention may be 
appreciated from the following Brief Description of the Drawings and the 
Best Mode for Carrying Out the Invention.

BEST MODE FOR CARRYING OUT THE INVENTION 
For a complete understanding of the subject invention, reference is 
initially made to the overall oil cooler and filter assembly design 
illustrated in FIG. 1. As is shown in this figure, the subject oil cooler 
and filter assembly 2 basically includes three major components; namely, a 
cooler housing 4, a support structure or means 6 for mounting the cooler 
housing 4 on the side of an engine (not illustrated) for providing fluid 
flow passages between the cooler housing and the recirculating coolant and 
lubrication oil circuits of the engine and brace means 8 for providing 
additional mounting support between the cooler housing 4 and the engine on 
which the cooler assembly and filter are mounted. 
The cooler housing 4 specifically includes an oil filter connection means 
10 for supporting a conventional type oil filter 12 in a manner to cause 
oil entering the cooler housing to pass through the filter prior to 
exiting the cooler housing 4 unless the oil filter 12 has become clogged 
or plugged in some manner. The cooler housing 4 is further characterized 
by an elongated internal cavity 14 extending the full length of the 
housing and opening at opposite ends into a planar end face 16 adjacent 
the support structure 6 and a planar end face 18 adjacent the brace means 
8. As is apparent in FIG. 1, end face 16 is formed on a radially directed 
end flange 20 of the cooler housing 4 while end face 18 is formed on a 
somewhat smaller radially directed end flange 22 located on the opposite 
end of the cooler housing 4. 
Positioned substantially within cooler housing 4 is a heat exchange means 
24 for causing the lubrication oil and engine coolant to flow through the 
coolant housing 4 in fluidically isolated, heat exchange relationship. The 
heat exchange means 24 includes a plurality of elongated tubes 26 the end 
portions of which are illustrated in FIG. 1 adjacent the end flange 22. 
Heat exchange means 24 also includes tube mounting means 28 for mounting 
the elongated tubes 26 in spaced apart, parallel nested relationship 
within the elongated internal cavity 14. The tube mounting means 28 
includes a flat plate-like member 30 sandwiched between end face 16 of the 
cooler housing 4 and an adjacent planar side 32 of the support structure 
6. The heat exchange means 24 further includes a header 34 connected to 
the end of each elongated tube 26 remote from the flat plate-like member 
30. Header 34 contains a transfer cavity (not illustrated) which 
communicates in sealed relationship with the interior of each of the 
elongated tubes 26. Header 34 is otherwise sealed from the exterior and is 
shaped to permit limited sliding movement within elongated internal cavity 
14 of the cooler housing 4. 
Brace means 8 includes a cover 36 for partially closing one end of internal 
cavity 14 and for retaining a fluid seal 38 in sliding engagement with the 
exterior surface of header 34. Seal 38 serves the purpose of accommodating 
differential thermal expansion between the length of cooler housing 4 and 
tubes 26 while maintaining internal cavity 14 in a sealed condition. 
Cover 36 contains an aperture or opening 40 having a radial extent which is 
less than the radial extent of internal cavity 14. This arrangement tends 
to discourage dirt and other environmental contaminants from reaching 
fluid seal 38 and at the same time provides access to a cleaning plug 42 
adjacent the lower portion of header 34 to thereby allow header 34 and the 
connected elongated tubes 26 to be flushed out during cleaning operation. 
For a more complete understanding of the internal design of the subject 
cooler and filtering assembly, your attention is directed to FIG. 2 which 
discloses in greater detail the configuration of the flat plate-like 
member 30 referred to above. FIG. 2 clearly shows that the end of each 
elongated tube 26 is received in a corresponding aperture 46 in plate-like 
member 30. A first group of tube ends are identified by the numberal 44 
while the ends of the remaining group are identified by the numeral 48. As 
will be described in greater detail hereinabelow, support structure 6 
includes a coolant inlet passage arranged to supply engine coolant to the 
elongated tubes 26 forming group 48. After traveling through the group 48 
tubes, the coolant is transferred in header 34 to the first group 44 of 
tubes for return to the support structure 6. A coolant return passage 
within support structure 6 receives the returning coolant ad discharges 
the same into the engine coolant system. A plurality of bores 52 are 
positioned and shaped to receive mounting bolts, not illustrated, used to 
mount the cooler housing 4 on the support structure 6. Plate-like member 
30 also contains an oil supply aperture 54 through which oil flows from 
the support structure 6 into the cooler housing 4. Plate-like member 30 
further includes an oil return aperture 56 through which oil flow from the 
cooler housing 4 is returned to the support structure 6. As will be 
described in greater detail below, support structure 6 contains an 
alternate flow passage through which engine lubrication oil flows into the 
cooler housing whenever the incoming lubrication oil is below a 
predetermined temperature. Flow of such cold lubrication oil is 
accommodated by a cold oil supply opening 58. 
Reference is now made to FIG. 3 which discloses a cross sectional view of 
the end flange 20 of cooler housing 4 take along lines 3--3 of FIG. 1. 
This view clearly illustrates the circular cross sectional configuration 
of internal cavity 14. Oil entering the cooler housing 4 through oil 
supply aperture 54 will enter an oil supply transfer groove 60 formed in 
planar end face 16. Groove 60 is positioned to communicate with oil supply 
aperture 54 in plate-like member 30 and to communicate at the other end 
with the elongated internal cavity 14. Baffles 62 are intersected by tubes 
26 and are spaced axially along the internal cavity 14 (best illustrated 
in FIG. 1) to form a serpentine oil flow path within the internal cavity 
14. Obviously, oil moving through this pattern will come into heat 
exchange contact with the external surfaces of elongated tubes 26 through 
which the engine coolant is internally flowing. 
As will be described in greater detail hereinbelow, cooler housing 4 also 
contains an oil return transfer flow path 64 communicating at one end with 
the elongated internal cavity 14 adjacent flange 22 and at the other end 
with the oil return aperture 56 of plate-like member 30. The portion of 
the oil return transfer path 64 shown in FIG. 3 includes an oil return 
channel 66 extending in parallel relationship with the elongated internal 
cavity 14 along substantially the entire length of the cooler housing 4. 
Flow path 64 further includes a transfer groove 68 formed in end face 16 
to communicate at one end with oil return channel 66 and at the other end 
with oil return aperture 56 in plate-like member 30. Transfer groove 68 is 
required because return channel 66 is ot aligned with return aperture 56 
as is clearly evidenced by comparison of FIGS. 2 and 3. The same figures 
show that bolt receiving apertures 52 are designed to be aligned with 
corresponding bolt receiving apertures 70 in flange 20 of the cooler 
housing 4. 
FIG. 3 also shows that the cooler housing 4 contains a cold oil supply 
channel 69 which extends along substantially the entire length of the oil 
cooler housing in parallel relationship with return channel 66. The cold 
oil supply channel 69 communicates at one end with the cold oil supply 
opening 58 contained in plate-like member 30 and at the other end with the 
oil filter connection means 10 in a manner to cause oil flowing through 
the cold oil supply channel to pass through the oil filter before 
returning to the support structure 6 through the oil return channel 66. 
Reference is now made to FIG. 4 in which flange 20 of the cooler housing 4 
is illustrated as being bolted to the support structure 6 (not 
illustrated) by threaded bolts 73. FIG. 4 also discloses brace means 8 
including cover 36 in greater detail. In particular, cover 36 contains 
aperture 40 through which access to cleaning plug 42 may be had. Cover 36 
is also adapted to close off oil return channel 66 (illustrated in dashed 
lines). In addition to threaded mounting bolts 72 which pass through 
corresponding apertures in cover 36 for threaded engagement with 
corresponding bores in cooler housing 4, two additional mounting bolts 74 
are arranged to pass through corresponding holes in one leg of an L-shaped 
bracket 76. A second leg of bracket 76 is arranged to be mounted on the 
engine by means of threaded bolts 78. The configuration of brace means 8 
(including cover 36 and L-shaped bracket 76) is further illustrated in 
FIG. 5 which is a top elevational view of these elements. 
Referring now to FIG. 6, a cross sectional view of the cover 36 and cooler 
housing 4 taken along lines 6--6 of FIG. 4 is illustrated. This portion of 
the cooler housing contains an oil pressure responsive valve means 80 
received in a valve recess 82 opening into end face 18 of cooler housing 
4. Cover 36 provides the useful function of capturing and retaining the 
oil pressure responsive valve means 80 when placed within recess 82. One 
end of recess 82 communicates with the circular inlet channel 84 formed by 
the oil filter connection means 10 through a return opening 86. A cross 
bore 88 intersects with recess 82 and also with oil return channel 66 as 
best illustrated in FIG. 4. Oil return channel 66 also communicates with 
the central channel 90 of the oil filter connection means 10. Central 
channel 90 receives the filtered oil from the oil filter. By this 
arrangement, valve means 80 is positioned to respond to the differential 
input pressure existant between inlet channel 84 and central channel 90. 
In particular, valve means 80 includes a spring biased piston assembly 92 
which normally maintains inlet opening 86 in a closed condition but which 
yields to a predetermined pressure differential to first create an 
electrical warning signal through electrical terminal 94 and subsequently 
opens to create a flow path which bypasses the oil filter and allows oil 
entering circular inlet channel 84 to pass through recess 82 and cross 
bore 88 and into return channel 66. The operation of valve means 80 is 
described in much greater detail in commonly assigned co-pending 
applications, Ser. No. 214,673, filed Dec. 9, 1980, entitled: Early 
Warning Bypass Valve Assembly and continuation-in-part application, Ser. 
No. 318,101, filed Nov. 5, 1981, entitled: Bypass Valve and Alarm 
Assembly. 
FIG. 7 illustrates a bottom elevational view of the cooler housing 4 
clearly illustrating the configuration of end flanges 20 and 22 as well as 
the position of oil return channel 66 and cold oil supply channel 69. In 
particular, cold oil supply channel 69 intersects circular inlet channel 
84 of the oil filter connection means 10. Thus when cold oil is directed 
through supply channel 69, such oil entirely bypasses the heat exchanger 
structure within the internal cavity 14 of the cooler housing 4 and enters 
the oil filter directly through circular inlet channel 84. All oil 
returning from the filter passes through return opening 86 which 
communicates directly with oil return channel 66 for return to the support 
structure 6. The position of valve recess 82 is also illustrated in FIG. 
7. 
Referring now to FIG. 8, which is a cross sectional view of the oil cooler 
housing 4 taken along lines 8--8 of FIG. 7, the remaining portions of the 
oil return transfer flow path 64 are illustrated. In particular, the oil 
return transfer flow path 64 includes a connecting passage 96 
communicating at one end with the elongated internal cavity 14 at a point 
adjacent flange 22 of the cooler housing and communicating at the other 
end with circular inlet channel 84 of the oil filter connecting means 10. 
Thus, in all cases, except upon operation of the oil pressure responsive 
valve means 80, all oil flowing through internal cavity 14 will pass 
through the oil filter connected to connection means 10 and return to the 
cooler housing through return opening 86. 
FIG. 9, a cross sectional view taken along lines 9--9 of FIG. 7, further 
illustrates the relationship of valve recess 82, cross bore 88 and oil 
return channel 66 as were discussed above. 
Reference is now made to FIGS. 10-20 which disclose various views of the 
support structure 6 designed in accordance with the subject invention. In 
particular, FIG. 10 discloses a top elevational view of the support 
structure 6 wherein it is shown that the support structure 6 includes a 
generally planar first side 98 adapted to engage the side of an internal 
combustion engine having an oil support port, an oil return port and a 
coolant supply port formed in closely adjacent relationship. These engine 
block ports are not illustrated in FIG. 10. Support structure 6 further 
includes a generally planar structure 6 further includes a generally 
planar second side 32 arranged perpendicular to first side 98. Second side 
32 is adapted to cooperate with flange 20 of the cooler housing 4 in a 
manner to rigidly fix plate-like member 30 of the heat exchange means 24. 
Aperture 102, formed on the top side of support structure 6, is a 
discharge opening for engine coolant and is adapted to be connected to an 
external conduit for directing the engine coolant to another portion of 
the engine. 
A small section of the side elevational view of support structure 6 
illustrated in FIG. 11 has been broken away to shown, in cross section, a 
portion of the coolant return passage 104 extending from second side 32 to 
coolant discharge port 102. The portion of coolant return passage 104 
opening into second side 32 is aligned generally with the first group 44 
of elongated tubes 26 illustrated in FIG. 2. This portion of coolant 
return passage 104 is best illustrated in FIG. 12 which is an elevational 
view of second side 32. Coolant is supplied to the remaining group 48 of 
elongated tubes 26 (as illustrated in FIG. 2) by means of a coolant supply 
passage 106 which opens into second side 32 as illustrated in FIG. 12. 
Similarly, an oil supply passage 108 and an oil return passage 110 also 
open into second side 32 as illustrated in in FIG. 12. In certain 
circumstances, oil entering the oil supply passage 108 will be diverted 
through a cold oil supply branch 112 which opens into second side 32 as 
also illustrated in FIG. 12. A plurality of threaded bores 114 are 
arranged to receive threaded bolts 73 as illustrated in FIG. 4. 
Reference is now made to FIG. 13 which discloses an elevational view of the 
generally planar first side 98 of support structure 6. In particular, 
coolant supply passage 106 opens into the first side 98 as illustrated in 
FIG. 13. Similarly, oil supply passage 108 and oil return passage 110 open 
into side 98 as shown in FIG. 13. First side 98 contains a recess portion 
114 which is closed and is formed merely to lighten the total weight of 
the support structure 6. The coolant supply port and the engine oil supply 
and return ports referred to above are formed on the engine in a pattern 
which causes these ports to align with passages 106, 108 and 110, 
respectively, in side 98. A gasket or other sealing material may be 
applied between the surface 98 and the engine block to assure the 
integrity of the seal between the engine and the support structure 6 and 
between the various flow paths into and out of the support structure 6. 
Similarly a pair of gaskets or other sealing material 122 and 124 (FIG. 1) 
may be interposed between the plate-like member 30 and side 32 of support 
structure 6 and also between the plate-like member 30 and end face 16 of 
the cooler housing 4 to seal around the oil supply aperture 54, the oil 
return aperture 56, the cold oil supply opening 58, the first group 44 of 
tube ends and the second group 48 of remaining tube ends, whereby oil and 
coolant may pass between the support structure 6 and cooler housing 4 
without leakage from one passage to another and without leakage to the 
exterior of the cooler and filter assembly. Reference is now made to FIGS. 
14 and 15 which disclose cross sectional views of the support structre 6 
taken along lines 14--14 and 15--15, respectively, of FIG. 10. Both FIGS. 
14 and 15 disclose an open top recess 116 adapted to receive a 
thermostatically controlled valve means 118 for causing the oil entering 
supply passage 108 to be diverted into cold oil supply branch 112 whenever 
the incoming oil temperature is below a predetermined level. The exact 
structure and configuration of thermostatically controlled valve means 118 
is not disclosed since any well known thermostatically operated valve 
structure may be used. 
FIG. 16 discloses a cross sectional view of the support structure 6 taken 
along lines 16--16 of FIG. 11 and particularly shows a bore 120 for 
receiving a mounting bolt for holding the support structure 6 in contact 
with the block of an internal combustion engine. Similar bores are 
illustrated in FIG. 11. 
FIG. 17 is a cross sectional view of the section of the oil return passage 
110 which opens into second side 32. The portion of oil return passage 110 
shown in FIG. 17 intersects with another portion illustrated in FIG. 19 
which is a cross sectional view of the oil return passage 110 as it 
intersects with the first side 98 of the support structure 6. An 
additional passage 122 is shown in FIG. 19 for communication with a 
conduit designed to receive oil from an engine turbocharger. Oil may be 
supplied to a turbocharger through passage 123 as illustrated in FIG. 8. 
FIG. 18 is a cross-sectional view of the portion of oil supply passage 108 
that intersects with second side 32 and FIG. 20 is a cross sectional view 
of the portion of oil supply passage 108 which intersects with first side 
98. Although not specifically illustrated, a portion of oil supply passage 
108 shown in FIG. 20 intersects with top opening recess 116 as illustrated 
in FIGS. 14 and 15 to supply the incoming oil which flows either into the 
portion of oil supply passage 108 illustrated in FIG. 15 or into cold oil 
supply branch 112 illustrated in FIG. 14. 
INDUSTRIAL APPLICABILITY 
The subject cooler and filter assembly is particularly suitable for use on 
internal combustion engines having recirculating oil and coolant circuits. 
The thermostatic valve can be designed to promote more efficient engine 
operation by causing the lubrication oil temperature to be more nearly 
optimal throughout a greater range of engine operating conditions than is 
possible without such thermostatic valve control. The compact size, yet 
highly rugged and reliable, design makes the subject cooler and filter 
assembly ideal for use on vehicle engines such as heavy duty ignition 
compression engines used on trucks and construction equipment. Another 
advantage is that only a pair of relatively simple gaskets are needed to 
form a substantial number of critical seals in the disclosed assembly 
design.