CA2351933A1 - Sump arrangement having a filter with standoffs provided to maintain flow channels - Google Patents

Abstract

A sump for use with a transmission or lubricating system of an internal combustion engine includes a sump pan which has a partition wall supported therein, the partition wall having an opening therethrough in which is positioned a filter element. The partition wall divides the pan into an upper chamber and a lower chamber with a suction tube that passes through the partition wall and projects, into the lower chamber. Dirty oil pools in the upper chamber and then passes through the filter element into the lower chamber by gravity and by suction created by a recirculation pump attached to the suction tube. In order to keep the partition from flexing so that the filter element restricts flow of oil in the lower chamber to the suction tube, a plurality of spacers are mounted between a frame of the filter element and the floor of the lower chamber. The spacers maintain a gap, which gap provides a channel allowing filtered oil to flow without undue restriction or blockage to the suction tube.

Description

,~ i , SUMP ARRANGEMENT HAVING A FILTIER WITH STANDOFFS
PROVIDED TO MAINTAIN FLO~rV CHANNELS
The present invention relates to a sump arrangement with a filter having standoffs provided to maintain a liquid flow channel. More particularly, the present invention relates to such a sump arrangement for use with transmissions and engine lubricating systems.
Background of the Invention Generally, transmissions used with automotive vehicles and lubricating systems for engines used to power automotive vehicles include oil sumps. The oil sumps have some type of filtering device to remove particulates from transmission and lubricating oil as the oil circulates. There has been considerab'.~e interest in providing oil sump arrangements wherein a filter element is located in an oil pan on a partition which extends across the oil pan in spaced relation to thc~ floor of the oil pan.
With this arrangement, transmission oil in the transmission case: pools on the partition and passes through the filter element by gravity and due to suction created from an oil pump which recirculates clean oil from a chamber between the floor of the oil pan and the partition.
This suction creates a low pressure area beneath the filter element. It has proven difficult to maintain the gap between the bottom of the filter element and the flaor of the pan.
Consequently, flow to the suction tube of recirculated fluid pump becomes restricted, blocking or partially blocking, the flow channels to the suction pump tube.
Since this can result in oil starvation in both transmissions and engines, it is desirable to prevent this phenomenon. The phenomenon is especially insidious because it may occur only during engine acceleration when there is a sudden demand for oil. During acceleration surges if oil is not available then the engine or transmission is subject to far more wear than occurs during normal cruising operation. Discovering 'that flexing of the partition can be the cause of oil starvation was also a problem because the phenomenon is hidden within the transmission or lubricating oil pan.
In order to save weight and expense, there is continuing incentive to reduce the thickness of components in situations where components are shielded from external impacts and abrasions. When weight reduction occurs with partitions within sump pans, the partitions tend to become more flexible which results in the partitions flexing under pressure which tends to close flow channels and restrict the amount of fluid available during recirculation. Accordingly, there is a need to permit weight and material reduction while avoiding flow channel restriction. With respect to filter components, which have materials which it is desirable to recycle, reducing the amount of material to be recycled is very desirable. Moreover, even if these materials .are disposed of dump sites, it is desirable to reduce their volume by reducing the amount of material utilized.
In view of the aforementioned considerations, the present invention is directed to a sump with an integral filter wherein the sump is used as a device that employs recirculating oil. The sump comprises a sump pan having a floor and a side wall adapted to be mounted beneath the housing of the device. The sump pan defines a space of a selected height to accommodate a volume of fluid a:nd has an inlet of a suction tube adapted to cormect with a suction pump. A partition wall is suspended within the space defined by the sump pan and divides the space into an upper chamber and a lower chamber, the partition wall having an area which overlies the floor of the sump pan and having a major opening therethrough. The filter element is disposed in the major opening. The filter element has a dirty side and a clean side and includes a filter media disposed in a frame that extends downwardly toward the floor of the sump pan.
A
plurality of spacers are disposed between the filter frame and the floor of the sump pan, the spacers being distributed so as to allow liquid flow in all directions around the spacers toward the suction tube for recirculation through the device utilizing the oil. The spacers are engaged by both the frame and the floor when suction is applied to the suction pump inlet, to maintain adequate clearance between the frame and the floor so as to provide sufficient flow of filtered fluid in a direction toward the inlet of the suction tube.
In a further aspect of the invention, the filter media is a pleated filter media and in still a further aspect of the invention, the pleated filter media has pleats which extend transverse to the direction in which the fluid flows toward the inlet of the suction tube.
In still a further aspect of the invention the frame is molded unitary with the partition and has flanges which extend substantially paxallel to the direction in which the liquid flows toward the inlet of the suction pump.
In still a further aspect of the invention, the partition wall in the sump pan includes a minor opening therethrough wherein the suction tube extends through the minor opening and is integral with the partition:
In another aspect of the invention, the partition within the sump has a side wall and a peripheral flange which overlies a peripheral flange on the sump pan to suspend the partition wall within the space defined by the sump pan.
In accordance with still additional aspects of the invention, the spacers are either an the frame of the filter element or the spacers project from the floor of the sump pan, the spacers being either separate elements fixed to the floor of the sump pan or elements unitary with the floor of the sump pan.
In most aspects of the invention; both the sump pan and the partition are made of plastic material.

Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in 'which like reference characters designate the same or similar parts through the several views, and wherein:
Figure 1 is a side elevation of a prior art oil sump arrangement shown attached to a transmission case;
Figure 2 is a perspective view, in elevation, of a portion of the sump arrangement of Figure 1, but modified in accordance with the principles of the present invention;
Figure 3 is a side view of the sump arrangement of Figure 2;
Figure 4 is an end elevation of a second embodiment of the invention;
Figure 5 is a side elevation of the second embodiment of the invention; and Figure 6 is a side view elevation of a third embodiment of the invention.
Referring now to Figure 1, there is shown a sump 10 with an integral filter element 12 wherein the sump is attached to a transmission case 14. While a transmission case 14 is illustrated, it is within the scope of this invention to. utilize the sump arrangement of Figure 1 as a lubricating oil sump for m internal combustion engine (not shown). The sump comprises a pan 16 and a partition v~all 18 wherein the partition wall has a major opening 20 in which the filter element 12 is positioned and a minor opening 22 which receives therethiough a suction tube 24 fon a transmission oil recirculating pump 26.
The partition wall 18 divides the sump pan 1fi into an upper chamber 28 and a lower chamber 29. Dirty transmission oil 30 or lubricating oil depending on the application of the sump 10, pools on top of the partition wall 18 in the upper chamber 28.
Gravity and suction created by the recirculating pump 26 through the suction tube 24 pulls the dirty oil 30 through the filter element 12 and into the lower chamber 29 to provide a supply of clean oil 32 that has had the p~articulates removed by the filter element.
Operation of the suction pump 26 creates a lower pressure within the lower chamber 29 than the upper chamber 28: As the suction tube 24 pulls the clean oil 32 from the lower chamber 29, the partition 18 flexes enough so that the bottom 34 of the filter element 12 approaches or contacts the floor 36 of the aump pan 16. Normally, there is a gap 38 between the bottom of the filter element 12 and the floor 36 of the sump pan 16 which provides a channel for the clean oil 32 to flow to the suction tube 24.
When the partition 18 flexes downwardly, the gap 38 is restricted and may bcome closed altogether, thereby starving the transmission served by the sump l0 of oil. The same phenomenon may also occur with an engine if the oil being recirculated is lubricating oil.

The problem being solved is a vexing one, because it is necessary to keep the pan 16 as shallow as possible in order to conserve space and road clearance, while keeping the pan 16 and associated structure, such as the partition wall 18 and filter element 12 as light as possible in order to minimize weight without sacrificing strength.
As is seen from the top in Figure 2, the filter element 12 is comprised of a frame 42 having two side plates 44 and 46 as well as at least one intermediate plate 48. While one intermediate plate 48 is shown there may be two or more intermediate plates. In any event, between the illustrated plate 48 and the adjacent plates which happen to be plates 44 and 46, there are disposed filter media 52 and 54. Filter media 52 and 54 are pleated filter media which have peaks 56 and valleys 58 which extend perpendicular to the extent of the plates 44,46 and 48 which comprise the frame 4.?. Consequently, the valleys 58 of the filter media present a substantial barner to fluid flow through the gap 38 to suction tube 24. This can seriously restrict flow because the filter media 52 and 54 then become dams forcing fluid flow around the filter element 12 instead of beneath the filter element i.e., through the gap 38.
Referring now to Figures 3 and 4, applicant has solved this vexing problem by disposing spacers 70 along bottom edges 72 of the plates 44, 46 and 48. When pressure increases enough to cause the partition 18 to flex, the spacers 70 prevent flexing by engaging the upper surface 74 of the floor 36 of pan 16. Consequently, the gap remains open providing clearance and a substantially obstruction free channel to the suction tube 24. The spacers 70 are spaced from one another in all directions so that fluid may flow with lateral components as well as mainly longitudinal components toward the suction tube 24, thereby substantially reducing restriction to flow which may have otherwise occurred. As is apparent from Figures 3 and 4, the spacers 70 are unitary with the plates 44, 46 and 48, the plates being preferably unitary with the partition wall 18.
The partition wall 18 is preferably a molded unit which can be molded in a single molding operation because it is comprised of a horizontally extending surface 76 and a generally vertically extending wall 78. The vertically f;xtending wall 78 has a flange 79 with a plurality of bolt holes 80 therethrough which receive bolts 82 for fastening to the housing 14 of the transmission or to an engine block i;not shown), if the pan 16 is used to collect and recirculate lubricating oil.
Referring now to Figures 5 and 6 there is shown a second embodiment of the invention wherein spacers 90 are employed to engage plates 44', 46' and 48', the spacers 90 being formed on. the floor 36' of the sump pan 16. As is clear from Figures 5 and 6, the spacers 90 are not ribs but are rather singular projections which are aligned with the bottom surfaces 72' of the plates 44, 46 and 48 that comprise of the frame 42 of filter element 12. While the arrangement of Figures 5 and ti is preferred, it is also within the purview of this invention to simply provide ribs which extend parallel with the longitudinal extent of plates 44, 46 and 48, however, by having parallel ribs flow is generally restricted to a direction toward the suction tube 24, and therefore does not accommodate with lateral flow components situations where one filter media or one portion of a filter media may become excessively clogged and thus obstruct flow toward the suction tube 24. Consequently, the arrangement o:E'Figures 3-6 is preferred.
Referring now to Figure 7, there is shown another embodiment in which spacers 96 are simply discreet elements which are fixed to the ;Floor 74 of the pan 16 by welding, adhesive or magnetic attraction. With the arrangement of Figure 7, the spacers 96 are not permanently affixed and may be deleted or moved depending on considerations such as the vertical height of the plates 44, 46 and 48 or the vertical height of the specific filter media 52 or 54 being employed.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, witlhout departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

Claims (6)

1. A sump with an integral filter used with a device that employs recirculating oil, the sump comprising:
sump pan having a floor and a side wall adapted to be mounted beneath a housing of the device; the sump pan defining a space of a selected height to accommodate a volume of liquid and having an inlet of a suction tube for a suction pump in communication therewith;
a partition wall suspended within space defined by the sump pan and dividing the space into an upper chamber and a lower chamber, the partition wall having an area which overlies the floor of the sump pan and having a major opening therethrough;
a filter element disposed in the major opening, the filter element having a dirty side and a clean side, the filter element including a filter media disposed in a frame that extends downwardly toward the floor of the sump pa;n, and a plurality of spacers disposed between the filter frame and the floor of the sump pan, the spacers being distributed to allow liquid flow in all directions around the spacers toward the suction tube for recirculation through the device, the spacers being engaged by both the frame and floor while suction is applied to the suction pump inlet, whereby adequate clearance is maintained between the frame and the floor to provide sufficient flow of filtered liquid in a direction toward the inlet of a suction tube.

2. The sump of claim 1 wherein the filter media is a pleated filter media.

3. The sump of claim 2 wherein the pleated filter media has pleats which extend transverse to the direction in which the liquid flows toward the inlet of the suction tube.

4. The sump of claim 3 wherein the frame is molded unitary with the partition wall and has flanges which extend substantially parallel to the direction the liquid flows toward the inlet of the suction pump.

5. The sump of claim 4 wherein the partition wall includes a minor opening therethrough and wherein the suction tube extends through the minor opening and is integral with the partition wall.

6. The sump of claim 5 wherein the major opening covers more than half of the area of the partition wall.
8. The sump of claim 1 wherein the major opening covers more than half of the area of the partition wall.

9. The sump of claim 1 wherein the partition wall includes a minor opening therethrough and wherein the suction tube extends through the minor opening and is integral with the partition wall.
10. The sump of claim 1 wherein the partition wall has a side wall extending upwardly therefrom and a peripheral flange which overlies a peripheral flange on the sump pan to suspend the partition wall within the space defined by the sump pan.
11. The sump of claim 1 wherein the major opening covers more than half of the area of the partition wall.
12. The sump of claim 1 wherein the partition wall includes a minor opening therethrough and wherein the suction tube extends through the minor opening and is integral with the partition wall.
13. The sump of claim 1 herein the spacers are on the frame of the filter element.
14. The sump of claim 1 wherein the spacers are projections extending upwardly from the floor of the sump pan and disposed in alignment with the frame, whereby when the partition wall flexes downwardly the frame engages the projections and maintains the clearance between the floor and the filter element.
15. The sump of claim 1 wherein the spacers are separate elements fixed to the floor of the sump pan in alignment with the frame.
16. The sump of claim 1 wherein the sump pan and partition are molded of plastic material.