The present invention relates to a windage tray for an internal combustion engine.
An oil pan is typically disposed beneath an engine block and crankshaft of an internal combustion engine, and is configured to receive oil that drains or is otherwise exhausted from the engine block, valvetrain, crankshaft, and/or main bearings that support the crankshaft. The oil collects in a sump of the oil pan and is then pumped from a sump pick-up location into a lubrication system associated with the internal combustion engine.
The rotation of the crankshaft and the reciprocal motion of pistons will cause gases to move within the crankcase, the volume within which the crankshaft is housed, causing turbulence. These turbulent gases may be referred to as “windage.” During operation of the internal combustion engine, some oil that would otherwise drain into the oil pan may instead become entrained in the gases. Accordingly, some vehicle engines include an oil deflector, also referred to as a “windage tray” to separate the crankshaft from the oil pan in order to reduce or eliminate the effects of crankshaft rotation on oil stored or collected in the oil pan. The oil deflector operates to remove oil from the gasses and prevent the entrainment of oil by the gases, which allows the oil to drain back to the sump and be recirculated through the engine's lubrication system. Additionally, the operating efficiency of the internal combustion engine may be reduced due to the inefficient transfer of gases within the crankcase as a result of the pumping action associated with the reciprocal motion of pistons within the internal combustion engine. This gas transfer characteristic is referred to as “bay-to-bay breathing”. The transfer of gases between volumes or bays of the crankcase is often impeded by structural obstructions such as bulkheads, main bearing caps, etc.
A windage tray apparatus is provided and is configured to be mountable within a crankcase at least partially defined by an engine block of an internal combustion engine. The crankcase has a first bay and a non-adjacent second bay, i.e. at least a third bay disposed between the first and the second bay. The internal combustion engine has a crankshaft rotatably supported within the crankcase. The windage tray includes a tray member and a passage at least partially defined by said tray member and in communication with the first bay and the non-adjacent second bay. The passage is operable to substantially allow gas transfer between the first bay and the non-adjacent second bay to reduce the motoring friction of the internal combustion engine. An internal combustion engine incorporating the claimed windage tray is also disclosed.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
Referring to the drawings wherein like reference numbers correspond to like or similar components throughout the several views, there is shown in
The engine block 12 at least partially defines a crankcase 18. The crankcase 18 includes a first bay 20, corresponding to a first and second cylinder (both not shown), a second bay 22, corresponding to a third and fourth cylinder (both not shown), a third bay 24, corresponding to a fifth and sixth cylinder (both not shown), and a fourth bay 26, corresponding to a seventh and eighth cylinder (both not shown). The engine block 12 is characterized as having a “deep skirt” design such that skirt portions 28 and 30 depend or extend from the engine block 12 and cooperate with the main bearing caps 16 to partially define the first, second, third, and fourth bay 20, 22, 24, and 26. The first, second, third, and fourth bay 20, 22, 24, and 26 each vary in volume with the operation of the internal combustion engine 10 and contain an amount of gas therein.
A windage tray 32 is configured to mount within the crankcase 18 of the internal combustion engine 10. The windage tray 32 is preferably positioned between the crankshaft 14 and the oil pan of the internal combustion engine 10 and is operable to reduce oil entrainment of the windage or turbulent gases within the crankcase 18 during operation of the internal combustion engine 10. The windage tray 32 is preferably formed from a stamped metal, such as steel or aluminum. A plurality of nuts 34, one of which is shown in
An exemplary firing order, i.e. the order in which a fuel and air mixture contained within the cylinders is ignited to effect or initiate the expansion stroke of the respective piston, for the internal combustion engine 10 is 1-8-4-3-6-5-7-2 (following the cylinder numbering convention wherein one bank of the eight cylinder engine includes the odd numbered cylinders in ascending order, while the opposite bank includes the even numbered cylinders in ascending order). As such, the relative displaced volume within the first, second, third, and fourth bays 20, 22, 24, and 26 as a result of the reciprocal motion of the pistons may be mapped with respect to the rotational angle of the crankshaft 14 as shown in graph 36 of
Referring to
Referring now to
Shields 50 and 52, shown in
Referring to
A plurality of recesses 62 are defined by the tray member 44 and are operable to substantially enclose at least a portion of the fasteners 17 thereby allowing the windage tray 32 to fit closer to the crankshaft 14 when mounted to the internal combustion engine 10. The method of mounting the windage tray 32 with respect to the internal combustion engine 10 will be discussed in greater detail hereinbelow with reference to
Referring now to
By reducing the flow restriction between the first bay 20 and the fourth bay 26 of the crankcase 18 via the passage 46, the crankcase fluid pumping losses of the internal combustion engine 10 may be reduced, thereby improving the high speed power output of the internal combustion engine 10. Additionally, the windage tray 32 is operable to reduce the oil entrainment within the gases thereby further reducing frictional losses within the internal combustion engine 10. As a result of reduced frictional losses, the windage tray 32 may lower bulk oil temperatures at high engine speed and full load operating conditions. Furthermore, the windage tray 32 is effective in reducing the oil aeration thereby improving the effectiveness of the lubrication system of the internal combustion engine 10 at high engine speeds under part and full load operating conditions.
The discussion hereinabove have focused mainly on the bay-to-bay breathing characteristics of an eight cylinder v-type internal combustion engine: however, those skilled in the art will recognize that the claimed windage tray may be incorporating within alternate engine architectures, such as six cylinder v-type and inline engines, while remaining within the scope of that which is claimed. While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.
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