Patent Application
20120067319
The present invention relates generally to windage trays for vehicle engines.
During operation of an engine the rotation of an engine crankshaft may cause windage. Windage refers to an oil and air mixture that occurs as a result of oil spray from the crankshaft mixing with air in the crankcase housing of the engine. The oil is eventually gravity fed from within the crankcase housing to a wet sump for the engine. The overall oil requirement for an engine is increased to compensate for the oil that is mixing with air and forming windage. Additionally, windage also increases aeration of the oil that has reached the wet sump area of the engine. Therefore, to reduce the amount of windage that occurs, a windage tray may be used to provide a barrier between the wet sump area of the engine and the crankshaft.
A windage tray for an engine having a crankshaft and a sump includes a tray that is located at least partially between the crankshaft and the sump. The windage tray has at least one first extension extending from the tray generally toward the sump to direct oil from the crankshaft toward the sump.
An engine comprises a crankshaft and a sump located proximate to the crankshaft for collecting oil from the crankshaft. The engine also includes a windage tray located at least partially between the crankshaft and the sump. The windage tray includes at least one tail extending from the windage tray generally toward the sump to direct oil from the crankshaft toward the sump.
The above features and advantages, and other features and advantages of the present invention will be readily apparent from the following detailed description of the preferred embodiments and best modes for carrying out the present invention when taken in connection with the accompanying drawings and appended claims.
Referring to the drawings, wherein like reference numbers refer to the same or similar components throughout the several views,
As the crankshaft 16 rotates, clockwise as indicated by arrow 18 in the embodiment illustrated in
Referring to
At least one window 30 may be defined within the tray 25 of the windage tray 24. The window 30 may be formed by using material of the windage tray 24 to form the tail 26, the scrapers 28, or both the tail 26 and the scrapers 28. In this manner, at least one of the tails 26 and the scrapers 28 may be formed without requiring additional material. The windage tray 24, tails 26 and scrapers 28 may be formed by casting, stamping, forging, injection molding, or the like. Further, the tail 26 and/or the scrapers 28 may be formed integrally with the windage tray 24 or may be formed separately and attached to the windage tray 24. One skilled in the art would be able to determine the suitable method of forming the windage tray 24, tails 26, and scrapers 28 for a particular engine 10.
As the crankshaft 16 rotates, the scrapers 28 may “catch” some of the oil that is flung from the crankshaft 16. The oil is gravity-fed from the scrapers 28 through the windows 30. The tail 26 then directs the oil toward the sump 20. In this manner oil 22 from the crankshaft 16 more quickly returns to the sump 20. By more quickly returning the oil to the sump 20 this increases the draw down level of the oil 22. The oil 22 draw down level is the amount of oil in the sump 20 during engine operation. Increasing the oil 22 drawn down level means a larger supply of oil is available in the sump 20 for cooling and lubrication. Increased oil 22 drawn down level overall reduces the total amount of oil 22 that must be provided in the engine 10 since a larger portion of the oil 22 is located in the sump 20 at a given time and is available to lubricate the engine 10, and less oil 22 is draining within chamber 14 toward the sump 20 or mixed with air to form windage. Due to the decrease in the required amount of oil 22 by the engine 10, the size of the sump 20 may also be decreased for cost, weight, and size savings of the engine 10. Additionally, there is less windage formed and the oil 22 in the sump 20 is less aerated and may more quickly be pumped through for cooling and lubrication of the engine 10.
In the embodiment shown, there is a plurality of scrapers 28 protruding from the windage tray 24 toward the crankshaft 16. The number, location, and angle of the scrapers 28 may vary depending on the shape of the windage tray 24 and the crankshaft 16. Additionally, in the embodiment shown, the scrapers 28 are integrally formed within the windage tray 24 and the tail 26 is secured to the windage tray 24 on an opposing side from the crankshaft 16.
The tail 26 deflects oil that is caught by the scrapers 28 and that drains through the windows 30 back to the sump 20. In the embodiment shown, the tail 26 has a slight curve and forms an angle 32 relative to the portion of the windage tray 24 that defines the windows 30. The number, location, curvature, and angle of the tail(s) 26 may vary depending on the geometry of the windage tray 24, and the relative location and distance from the sump 20. Additionally, in the embodiment shown, the scrapers 28 and tail 26 are located generally outward from a tangent at bottom dead center (BDC) of the crankshaft 16. That is, the point where the rotational position of the crankshaft 16 begins to move back toward top dead center (TDC) position of the engine 10 (i.e. just after BDC). TDC and BDC refer to the rotational position of the crankshaft 16 relative to the position of the pistons (not shown) for the engine 10, as is commonly referred to in the art. The scrapers 28 and tail(s) 26 may be located in other various locations relative to the crankshaft 16. For example, just prior to the rotational position where the crankshaft 16 reaches the BDC position of the engine 10. The terms prior and after refer to the rotational position of the crankshaft 16 relative to the windage tray 24. That is, the rotational position of the crankshaft 16 at the point closest to the ends of the protrusions that form the scrapers 28, the opening of the windows 30, or the beginning of the protrusion that forms the tail(s) 26 depending on the design of the windage tray 24. In the embodiment shown, the reference point may be any of the tail 26, the scrapers 28, or the windows 30 as the windage tray 24 includes all three.
Further, although both the scrapers 28 and the tails 26 are shown. The tails 26 and scrapers 28 may operate independently of one another and a windage tray 24 may include only one or the other, or may include both tails 26 and scrapers 28 located at different locations on the windage tray 24 relative to the crankshaft 16. One skilled in the art would be able to determine the appropriate location, position and number of the scrapers 28 and the tails 26 for a particular windage tray 24.
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.
