Patent Grant
12264606
None.
Engines have a number of reciprocating and/or rotating components that reside within the crankcase. Examples of the reciprocating and/or rotating components include the crankshaft, connecting rods, and pistons (collectively referred to herein as the “cranktrain”). Many of these components such as pistons require oil for cooling and lubrication. The lube oil is pumped from a sump into a system of passages to the frictional interfaces or to cooling nozzles that spray components in need of cooling. Once lube oil exits the frictional interfaces or component cooling interfaces, its job is done. Maintaining an ample volume of oil in the sump is important to ensure that it is available to be pumped through the engine at all times, including when the engine is operating at adverse angles during uphill, downhill, or sidehill driving. As the level of oil available in the sump falls, the risk of terminal engine damage due to oil starvation rises.
However, and with reference to
The above mentioned problem has been addressed by various technologies to limited degree. For example, and with reference to
U.S. Pat. No. 10,934,904 to Banks III describes another lube oil aeration and thermal control system. With reference to
Accordingly, a new and improved system that overcomes the above mentioned shortcomings is desired.
Embodiments of the invention include systems that serve to keep as much oil as possible in the oil sump while minimizing the volume of oil in the cranktrain/crankcase, and to minimize the level of oil aeration.
In embodiments, a system for collecting lube oil in an oil sump in an internal combustion engine with a rotating cranktrain comprises: a first side wall and a second side wall opposite the first side wall; an oil accumulation ramp extending downwards from the second side wall to the first side wall, and separating the oil sump from the cranktrain; and an oil entrance aperture arranged in the ramp near the first side wall for directing oil accumulating on the ramp into the oil sump.
In embodiments, the system further comprises a plurality of air return ports or passages extending through the ramp from the oil sump to the crankcase. In other embodiments, the oil accumulation ramp includes solely one or at least one air return port extending through the ramp from the oil sump to the crankcase.
In embodiments, the air return ports commence at least 1 to 2 in., or more preferably, 1 to 1.5 in. from the second wall.
In embodiments, the air return ports have a passageway length ranging from 0.25 to 1 in.
In embodiments, a ratio (R1) of the cross sectional area of the air return ports (collectively) to the oil entrance aperture ranges from ⅓ to 1/1, and in some embodiments is about ½ to ⅝.
In embodiments, at least one flow delineator or barrier is incorporated into the ramp and arranged between adjacent air return ports to obstruct airflow and divert airflow into the adjacent air return ports. In embodiments, the flow delineators are arranged on the sides of the air return ports regardless of whether the flow delineator is between two adjacent air return ports.
In embodiments, the air return ports are arranged to create vectorized airflow jets.
In embodiments, a plurality of air return ports is arranged to aim the flow along the lateral plane towards the rear, middle or front of the engine. In embodiments, the air return ports aim the flow along the lateral plane towards the oil pump pickup in the oil sump. This serves to push the oil into the oil sump and towards the area of the oil pump pickup.
In embodiments, when the air return ports are inline, some of the air return ports are arranged at an angle (5-45 degrees) from the medial plane while other air return ports are arranged to direct the flow straight (0 degrees).
In embodiments, an air flowpath extends from the oil sump towards the second wall, upwards and through one port, through the crankcase air-oil interface region, through a downstream air-oil entrance aperture adjacent the first wall, and back to the sump. In this embodiment, along such a functional flowpath or streamline, there is only one slot or port for the airflow to travel from the sump to the air-oil interface region. There are no downstream air return ports along a functional flowpath. This configuration is advantageous because there are fewer obstructions to airflow, and drag is reduced along the functional flowpath.
The arrangement and shape of the air return ports (namely, the tuning) as described herein serves to optimally direct air out of the oil sump while maintaining the oil in the sump, as well as maintain higher pressure in the oil sump. Removing air from the oil in the sump will improve the lubricating and cooling capability of the oil, which will improve performance and longevity of the engine and lubricating oil.
In embodiments, the air return ports are tunable through the use of port throttles. For example, in some embodiments, the size of the outlet of each of the air return ports is adjustable. In a particular embodiment, a port throttle is operable to move from an open position in which the port outlet is uncovered, to a second position in which the port outlet is completely occluded, or partially occluded.
In embodiments, the air return ports are tuned based on sensor data or feedback arising from the engine such as, for example, engine speed, oil pressure, and/or oil temperature. In embodiments, the air return ports are adjusted based on the change in engine speed. In embodiments, when a change in engine speed is detected, a port throttle control module is operable to adjust the throttle to the port(s) and in particular embodiments, by rotating the throttle. The port throttle control module may operate the port throttles in proportional response to changes in one or multiple parameters as defined by calibration software.
In embodiments, the oil accumulation ramp comprises a plurality of regions, each having a different curvature.
In embodiments, the oil accumulation ramp comprises a warped upper surface, directing the oil accumulated thereon both downwards and in the direction of the oil pickup, and optionally, the curvature varies with distance from the second wall. In embodiments, the curvature of the warped surface varies with distance from the oil pump pickup.
In embodiments, the oil accumulation ramp and side walls are incorporated into one-piece midpan assembly adapted to be fastened to the crankcase on the top, and to the oil pan on the bottom.
In embodiments, an internal combustion engine having reduced lube oil aeration comprises: an engine block including a rotating cranktrain and a plurality of oil passages; a crankcase; an oil sump for collecting and storing oil arranged below the crankcase; an oil accumulation ramp extending from a first side wall to a second side wall and separating the crankcase from the oil sump; and an entrance aperture in the ramp in the vicinity of the first wall to direct oil accumulated on the ramp into the oil sump.
In embodiments, the engine further comprises a plurality of air return ports extending through the oil accumulation ramp for directing air from the oil sump towards the cranktrain.
In embodiments, the engine further comprises an oil filter arranged along a flowpath of the oil, downstream of the oil pump, and prior to the oil distribution galleries.
In embodiments, the engine further comprises an oil cooler arranged along the flowpath of the oil, downstream of the oil pump, and prior to the oil distribution galleries.
An objective and advantage of embodiments of the invention is to keep as much oil as possible in the oil sump while minimizing the volume of oil in the cranktrain/crankcase.
An objective and advantage of embodiments of the invention is to minimize the level of oil aeration, reduce oil temperature, and increase oil pressure.
An objective and advantage of the invention is to increase air pressure in the sump to reduce the risk of oil pump inlet cavitation, and to reduce the work required by the oil pump to circulate oil through the engine.
The above-mentioned aspects, as well as other features, aspects and advantages of the present technology will now be described in connection with various embodiments, with reference to the accompanying drawings. The illustrated embodiments, however, are merely examples and are not intended to be limiting. Throughout the drawings, similar symbols typically identify similar components, unless context dictates otherwise where:
It is to be understood that the embodiments of the invention described herein are not limited to particular variations set forth herein as various changes or modifications may be made to the embodiments of the invention described and equivalents may be substituted without departing from the spirit and scope of the embodiments of the invention. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features that may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the embodiments of the present invention. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the embodiments of the present invention. All such modifications are intended to be within the scope of the invention.
Additionally, the separation of various system components in the implementations described herein should not be understood as requiring such separation in all implementations, and it should be understood that the described components and systems can generally be integrated together in a single product or packaged into multiple products. Additionally, other implementations are within the scope of this disclosure.
Conditional language, such as “can,” “could,” “might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include or do not include, certain features, elements, and/or steps. Thus, such conditional language is not generally intended to imply that features, elements, and/or steps are in any way required for one or more embodiments.
Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “an,” “said” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.
It will also be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the present invention.
Some embodiments have been described in connection with the accompanying drawings. Distances, angles, etc. are merely illustrative and do not necessarily bear an exact relationship to actual dimensions and layout of the devices illustrated. Components can be added, removed, and/or rearranged. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with various embodiments can be used in all other embodiments set forth herein.
While a number of embodiments and variations thereof have been described in detail, other modifications and methods of using the same will be apparent to those of skill in the art. Accordingly, it should be understood that various applications, modifications, materials, and substitutions can be made of equivalents without departing from the unique and inventive disclosure herein or the scope of the claims.
All existing subject matter mentioned herein (e.g., publications, patents, patent applications and hardware) is incorporated by reference herein in its entirety except insofar as the subject matter may conflict with that of the present invention (in which case what is present herein shall prevail). U.S. Pat. No. 10,934,904 to Banks III, filed Jul. 3, 2020, is incorporated by reference in its entirety for all purposes.
Now, with reference to
The ramp 330 is shown generally sloping downward, dropping in elevation from the second wall 304 to the first wall 302. In the embodiment shown in
The system 300 shown in
The ramp 430 serves as a barrier separating the crankcase region 432 from the lower oil region in the sump 434, thus minimizing the disturbance and aeration generated by the crankcase region to the oil in the sump.
The system 400 shown in
The system 400 shown in
The shape and number of air return ports 410 through the ramp 430 may vary. In embodiments, 2-10 air return ports are provided, and more preferably, 3-6 air return ports are provided. In embodiments, each port has an identical cross section. For example, and without limitation, each port can have a smooth elongate slot or rectangular cross section with a height ranging from 0.5 to 1 in, and a width (W) ranging from 3 to 5 in., and a passageway length ranging from 0.25 to 1 in. In other embodiments, the air return ports differ from one another.
In the embodiment shown in
By setting (or tuning) the number, arrangement, and shape of the slots, oil and air flow are optimized. Additionally, the inventors have found that the ratio (R1) of the cross sectional area of the air return ports (collectively) to the oil entrance aperture 420 is a useful parameter to tune. In the embodiment shown in
The system 400 shown in
The length of the divisor may vary. In embodiments, the divisor extends along the first side wall for the length of the oil pan, or at least for a length sufficient to match the size of the sump entrance aperture. In embodiments, the height of the divisor 450 ranges from 0.5 to 1.5 in. from the side wall.
Optionally, and with reference to
Additionally, the convex region 475 enhances air oil separation and reduced aerodynamic drag by taking advantage of the Coanda effect, by which high velocity air from the air return ports and crankcase will tend to adhere closely to the ramp surface and follow the surface curvature into the sump 434. As the lower mass air remains attached to the surface, higher mass oil will tend to separate from the air and fall out into the oil sump 434.
In embodiments, a radius of curvature of the convex region 475 ranges from 1 to 4 in. In embodiments, the distance between the oil level and the bottom of the lower ramp/flap portion 473 ranges from 0.5 to 2 in. In embodiments, the spacing between the end of the lower ramp/flap portion 473 and the second wall 404 ranges from 1.5 to 4 in.
The slat is shown having a convex curvature to match the curvature of the region 475 of the ramp. The thickness of the slat may be similar to the thickness of the ramp. Optionally, the slat includes a slight taper in the downward direction. The length of the slat may vary. In embodiments, the length of the slat ranges from 1 to 3 in.
The slat 478 cooperates with the ramp to both encourage flow attachment nearest the ramp (e.g., region 475), as well as to assist with turning flow entering from the divisor 450 in the same direction.
In some embodiments, and with reference to
The air return ports 610a, 610b, 610c, 610d, however, are arranged at different angles (σ) than the air return ports shown in
The air return ports 710a, 710b, 710c, 710d, however, are arranged at different angles (σ) than the air return ports shown in
The magnitude (or degree) of the angle (σ) for vectoring the air flow for each port may vary. In embodiments, the magnitude of the angles varies based on the longitudinal distance from the oil pump pickup 737. Air return ports further from the oil pump pickup have a greater (σ) than air return ports closer to the oil pump pickup 737. For example, in another embodiment not shown, port 710c may have an angle ranging 5-10 degrees, whereas port 710d may have an angle ranging from 15-20 degrees.
The arrangement and shape of the air return ports (namely, the tuning) as described herein serves to optimally direct air out of the oil sump while maintaining the oil in the sump, as well as maintain higher pressure in the oil sump. Moving air from the crankcase to the sump and returning air in this manner improves the performance of the engine and lubricating oil without incurring the parasitic losses and increased aeration associated with the use of impact devices. Additionally, providing a higher pressure in the sump reduces the work required by the oil pump, further reducing parasitic engine losses.
The ramp 830 serves as a divider or barrier separating the crankcase region 832 from the lower oil region in the sump 834, thus minimizing the disturbance and aeration generated by the crankcase region to the oil in the sump.
The system 800 shown in
The system 800 shown in
The number of air return ports through the ramp can vary. In embodiments, the number of air return ports ranges from 1-8, frequently 3-6, or optionally equals the number of crankshaft bays of the engine.
Islands or bridges (e.g., 872) separate adjacent ports (e.g., 810c, 810d). The islands or bridges aid in defining airflow vectoring, whether the airflow is aimed at an angle (or straight) as a discrete airflow jet(s) into the entrance aperture 820 along the first side wall 802, described herein. In embodiments, the islands or bridges 872 have a minimum distance ranging from the 0.2 to 1.5 in.
The shape of the air return ports may also vary. In embodiments, the cross section of the air return ports is rectangular or slot-like. However, the cross sectional shape may also be round or obround.
The oil pan assembly 801 shown in
An advantage of the design shown in
Optionally, the adjustment is in real time and based on feedback arising from the engine such as, for example, engine speed (e.g., RPM) or other parameters. In embodiments, when a change in engine speed is detected, a port throttle control electronic module 870 (operable with a motor 858) is programmed and operable to automatically adjust the throttle to the port(s) by rotating the cover about an axle or shaft 856. The port throttle control module may operate the port throttles in proportional response to changes in one or multiple parameters as defined by calibration software.
The arrangement and shape of the air return ports (namely, the tuning) as described herein serves to optimally direct air out of the oil sump while maintaining the oil in the sump, as well as maintain higher pressure in the oil sump. Moving air from the crankcase to the sump and returning air in this manner improves the performance of the engine and lubricating oil without incurring the parasitic losses and increased aeration associated with the use of impact devices. Additionally, providing a higher pressure in the sump reduces pump inlet cavitation and reduces the work required by the oil pump, further reducing parasitic engine losses.
For the embodiment shown in
Without intending to be bound to theory, the flow delineators have advantages based on the engine crankshaft anatomy. Crankshaft main bearing bulkheads form vertical walls within the crankcase. These walls are parallel to the medial plane, beginning below the crankshaft axis and extending upwards to meet the interior walls of the engine block. These discrete regions formed are referred to as crank bays and contain one to two piston and rod assemblies within them. Because the majority of the oil-air mixture circulating within the crankcase results from the motion of the crankshaft, rods, and pistons within these discrete crank bays, they are also the regions where the majority of oil is deposited onto the oil accumulation ramp. In embodiments, we aim the airflow jet(s) via the position of the ports (e.g., ports 910c, 910d) and flow delineators (e.g., flow delineator 944) to the areas corresponding to the crank bays and main bearing bulkheads, respectively, to create the most effective use of return airflow—the configuration focuses airflow where it will have maximum effect, namely, to drive oil from the ramp and into the sump. Additionally, by reducing the total air outlet area the velocity is maximized and thus more effective in driving oil from the ramp.
Additionally, for embodiments, flow delineators may be arranged on the sides of an air return port regardless of whether the flow delineator is between two adjacent air return ports.
In embodiments, and with reference to
In embodiments, the shape is a depression and can be characterized by a width (Wd), height (Hd), valley portion 948, and a rear sloping portion 949. In embodiments, the width corresponds generally to the spacing or gap between the crank bays and can range from 0.2 to 1.5, and in some embodiments 0.8 to 1.2 inches. In embodiments, the height can range from 0.5 to 1 inches. In embodiments, the sloping rear wall has a curvature or slope that matches the slope or angle of the ramp 930.
The concave curvature of the depressed delineators provides for convex curvature on the opposite side at which the air enters. Convex curvature of the flow delineators at the air entrance provides for favorable flow dynamics. In embodiments this curvature may be extended along the passageway length by continuously curving the port sidewalls to achieve a converging nozzle geometry or to otherwise improve air discharge characteristics. Port sidewalls may also be curved along their vertical orientation to create an obround port sidewall form.
Testing was performed to compare the prior art oil pan assembly as shown in
Oil pan testing was conducted under carefully controlled conditions on an engine dynamometer. The engine, oil system, and facilities (e.g. process water, fuel supply, ambient room conditions) were all fully instrumented with all sensor data being collected both during engine warming as well as during all tests. For all tests the engine was carefully brought to identical running conditions following a prescribed warm-up procedure. Once these conditions were met a test cycle was conducted comprising steady-state running at each of the three engine speeds noted in the test summary. This test was repeated at least three times for all configurations to ensure repeatability of the data collected.
Other than that, specified below, all parameters (namely, engine and test rig, oil cooling system, fuel rate and timing, oil and coolant flows, oil filter, boost pressure, air/fuel ratio) were the same as between Design 1 and Design 2. Testing for each design was performed at 2400 RPM, 2800 RPM, and 3150 RPM. The oil in the sump, oil pressure, and oil temperature were measured for each RPM. The oil in the rotating group is considered to be the balance of the total volume of oil in the engine, less the measured volume of oil in the sump.
The data also evidences that Design 2 has reduced oil temperature and, in connection with the 2800 and 3150 RPM testing, increased oil pressure.
Additionally, aeration was measured at 3150 RPM. Aeration decreased by about 32%. This data shows Design 2 is a clear improvement over Design 1. As described herein the consequences of maintaining more oil in the pan where it is supposed to be and less resident oil in the rotating group, and less aeration increases the durability of the engine and the longevity of the engine oil. Decreased aeration also substantially increases the effectiveness of the oil to lubricate and to remove heat from moving parts. The inventor notes that even a single-digit performance percent change can amount to the difference between winning and losing an automotive race, improving fuel economy, and preventing oil starvation while operating a vehicle on an incline. The example described above shows double-digit percent improvements using the multiple discrete port configuration of
Many modifications and variations of the present invention are possible in light of the above teachings. For example, in embodiments, the oil accumulation ramp includes solely one or at least one air return port extending through the ramp from the oil sump to the crankcase.
Additionally, for embodiments, a flow delineator may be arranged on the side of an air return port regardless of whether the flow delineator is between two adjacent air return ports.
Additionally, although the system has been described with general reference to a “V” engine, the system is applicable to inline engines, “V” engines of any angle, and horizontally opposed engines (commonly referred to as flat or boxer engines). The invention is not intended to be so limited except where recited in any claims.
It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. Features and components may be made from multiple pieces or formed as single piece units. For example, although the oil pan assembly shown in
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