Patent Application
20110011367
Exemplary embodiments of the present invention are directed to an internal combustion engine lubrication system and, more particularly an oil pan for an internal combustion engine having an insert including an oil sump that facilitates rapid warm-up of oil therein.
Customer demand driven by high fuel prices as well as governmental regulations relating to the fuel efficiency of internal combustion engines, especially those used in vehicular applications, are driving fuel economy considerations into the design and operation of engines. In addition, environmental and customer concerns are dictating longer intervals between vehicle servicing, such as oil changes, often resulting in an increase in engine oil volume.
Increases in engine oil volume may run contrary to the desire for higher fuel efficiency and improved emissions performance in that larger volumes of oil require a longer warming period following an initial cold start of the engine. Internal combustion engines operate at peak efficiencies when the oil used for lubrication of its moving parts has reached a steady state operating temperature.
The need exists for an internal combustion engine lubrication system that facilitates higher oil volumes for longer service intervals but rapidly heats the oil to normal, steady state operating temperatures.
In an exemplary embodiment of the present invention, a baffle assembly for disposition in the oil pan sump region of an internal combustion engine comprises an upper flange partially closing the oil sump region, an oil pick-up well, opening through the upper flange and defined by a wall portion, for receipt of heated oil returning from the internal combustion engine, an oil reservoir defined in the oil sump region by the wall portion wherein oil in the oil reservoir is separated from oil in the oil pickup well, a viscosity sensitive oil flow restrictive passage extending between the oil pick-up well and the oil reservoir defining fluid communication therebetween and an oil pick-up for fluid communication with an oil pump of the internal combustion engine and having a pick-up inlet disposed in the oil pick-up well that is configured to withdraw oil therefrom.
In another exemplary embodiment of the present invention an internal combustion engine lubrication system comprises an internal combustion engine, an oil pan assembled to the internal combustion engine and having a bottom, a plurality of sides extending from the bottom to define an open top end, for sealing engagement with a mating surface of the internal combustion engine, and an oil sump region therein. A baffle assembly is disposed in the oil sump region and is configured to divide the oil sump region into an oil pick-up well, configured for receipt of oil returning from the internal combustion engine, and an oil reservoir for storage of bulk oil therein. An oil pick-up configured for fluid communication with an oil pump of the internal combustion engine has a pick-up inlet disposed in the oil pick-up well configured to withdraw oil therefrom. A viscosity sensitive oil flow restrictive passage is disposed between the oil pick-up well and the oil reservoir for fluid communication therebetween.
In yet another exemplary embodiment of the present invention a method for rapidly warming the engine oil in the oil pan of an internal combustion engine comprises defining an oil pick-up well in the oil pan, disposing an oil pick-up, in fluid communication with an oil pump of the internal combustion engine, in the oil pick-up well to withdraw oil therefrom, directing oil returning from the internal combustion engine to the oil pick-up well and defining a viscosity sensitive oil flow restrictive passage in the oil pick-up well to define fluid communication with oil in the oil reservoir in the oil pan.
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.
Other objects, features, advantages and details appear, by way of example only, in the following detailed description of embodiments, the detailed description referring the drawings in which:
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
In accordance with an exemplary embodiment of the present invention,
Referring to
The baffle assembly 34 partitions the sump region 26 into an oil reservoir 52, and an oil pick-up well 53,
In an exemplary embodiment, upon engine start-up, especially following a cold engine start-up, supply oil 60 is drawn from the oil pick-up well 53 by the engine oil pump (not shown) through the pick-up inlet 32 of the oil pick-up 30. The supply oil 60 is circulated through the lubrication system of the internal combustion engine 5, where is it warmed, and subsequently returned to the oil pan 14 as indicated by return oil flow 58. Due to the at least partial closure of the oil sump region 26 by the baffle perimeter 46 of the upper flange 36, return oil flow 58 is directed back to the oil pick-up well 53 rather than to the oil reservoir 52. The result is that heated engine oil 24 returning to the oil pick-up well 53 as return oil flow 58 will be preferentially available to the pick-up inlet 32 of the oil pick-up 30 and thus, the oil pump and engine lubrication system. As such, a reduction in the time required for the internal combustion engine 5 to reach steady state operating temperature is achieved, thereby improving the efficiency and emissions performance of the engine. In an exemplary embodiment the baffle assembly 34, or at least the portion of the assembly defining the oil pick-up well 53 such as interconnecting wall portion 40, may be constructed of an insulative material defining an additional thermal barrier between the warm oil in the oil pick-up well 53 and the cooler oil in the oil reservoir 52. The material may comprise a high density, temperature tolerant plastic or composite material or may comprise a double walled sheet assembly constructed of metal or a plastic or composite material.
In an exemplary embodiment illustrated in
In an exemplary embodiment, the flow characteristics of the replacement oil 64 is determined by the viscosity of the oil, the nature of the fluid flow (e.g. laminar or turbulent flow) the shape and the dimensions of the viscosity sensitive oil flow restrictive passage 44 which is defined by the distance “d1” between the lower flange 38 and the bottom 42 of the oil sump region 26 or by the distance “d2” between the perimeter 66 of the lower flange 38 and the outer wall 68 of the oil sump region 26, or both (
In an exemplary embodiment shown in
In another exemplary embodiment illustrated in
Upon engine start-up, especially following a cold engine start-up, supply oil 60 is drawn from the oil pick-up well 53 by the engine oil pump (not shown) through the pick-up inlet 32 of the oil pick-up 30. The supply oil 60 is circulated through the lubrication system of the internal combustion engine 5, where is it warmed, and subsequently returned to the oil pan 14 as indicated by return oil flow 58. Due to the at least partial closure of the oil sump region 26 by the baffle perimeter 46 of the upper flange 36, return oil flow 58 is directed back to the oil pick-up well 53 rather than to the oil reservoir 52. The result is that heated engine oil 24 returning to the oil pick-up well 53 as return oil flow 58 will be preferentially available to the pick-up inlet 32 of the oil pick-up 30 and thus, the oil pump and engine lubrication system. As such, a reduction in the time required for the internal combustion engine 5 to reach steady state operating temperature is achieved, thereby improving the efficiency and emissions performance of the engine. During engine startup and steady state operation thereof, return oil flow 58 and supply oil flow 60 are relatively equal and, as such, the oil level in the sump region 26 will remain at relatively equal levels in the oil reservoir 52 and the oil pick-up well 53. As illustrated in
The flow characteristics of the replacement oil 64 is determined by the viscosity of the oil, the nature of the fluid flow (e.g. laminar or turbulent flow) the shape and the dimensions of the oil flow restrictive passages 80 which are defined by the length of the passages as a function of the thickness of the wall portion 40 and the diameter thereof. As a result, the flow characteristics, or rate of flow, of the replacement oil 64 may be customized for a particular engine application by varying the length and the diameters of the oil flow restrictive passages 80.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the present invention.
