Temperature-controlled segregation of hot and cold oil in a sump of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9534520-B2
Application number	US-201213479373-A
Country	US
Kind code	B2
Filing date	May 24, 2012
Priority date	May 24, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

The volume of lubricating oil stored in the sump of an internal combustion engine for a vehicle is in significant excess of the volume of oil circulating through the engine at any one time. The circulating oil, drawn from the sump, may be rapidly heated during its passage through the engine, but the excess volume remaining in the sump dilutes and cools the circulating oil as it returns to the sump. By separating the oil volume into a portion which is circulated through the engine and a second portion which has only limited opportunity to mix with and cool the circulating oil the circulating oil may attain its operating temperature more rapidly. Once the stored volume of oil in the engine has also reached its operating temperature the circulating oil and stored oil may be recombined.

First claim

The invention claimed is:

1. A method of heating a volume of oil contained in a sump of an internal combustion engine from a reduced initial temperature to its operating temperature, the sump having side-walls and a bottom, the engine having an oil circulation system suitable for conveying some portion of the oil volume through the engine and thereby heating the oil; the method comprising:
employing a metal porous separator located in the sump, the porous separator having generally vertical upstanding walls extending from the sump bottom and having outwardly extending upper walls extending from the upstanding walls to the sump sidewalls, the separator serving to partition the sump volume into a first sump volume at least partially contained within the upstanding walls of the separator and a second sump volume contained between the upstanding and upper walls of the separator and the side-walls of the sump;
the porous separator comprising a wire mesh or perforated sheet, the separator being less than about a millimeter in thickness, wherein the separator comprises a plurality of openings with a characteristic dimension of between about 100 and 300 micrometers and has a thickness of between 2 and 3 times the characteristic dimension, the separator partitioning the oil volume into two portions, a circulating portion contained within the first sump volume and selectively accessible by the engine oil circulation system and a contained portion, substantially retained in the sump and contained within the second sump volume, the porous separator having a permeability to oil which increases with increasing oil temperature, the porous separator being shaped to receive oil returning to the sump container from the oil circulation path and to further contain the oil pickup for delivery of oil to the oil circulation path, the contained portion being external to the circulating portion and enclosed between the separator and the sump side-walls and bottom;
repeatedly circulating the circulating oil portion through the engine and raising its temperature;
the pores and thickness of the separator cooperating to initially limit mixing of the circulating and contained oil portions to control the heat loss from the circulating oil portion to the contained oil portion until the contained oil portion attains a target temperature, less than the operating temperature; and then,
the separator gradually promoting mixing of the circulating and contained oil portions by progressively reversing the partitioning of the oil volume to enable the entire oil volume to be accessible to the oil circulation system and capable of circulation through the engine when the contained volume attains its operating temperature.

2. The method of heating a volume of oil contained in an internal combustion engine recited in claim 1 in which partitioning is reversed by selecting a separator which is substantially permeable to oil at the operating temperature of the oil.

3. The method of heating a volume of oil contained in an internal combustion engine recited in claim 1 in which the initial reduced temperature is substantially ambient temperature.

4. The method of heating a volume of oil contained in an internal combustion engine recited in claim 1 in which the oil operating temperature is about 90° C. or greater.

5. The method of heating a volume of oil contained in an internal combustion engine recited in claim 1 in which the target temperature is about 60° C.

6. A multi-cylinder, reciprocating piston, internal combustion engine, the engine comprising moving parts, in addition to the piston in each cylinder, and further comprising an oil circulation system, operative during engine operation, for delivering oil from a specified stored volume of oil in a lubrication oil sump container below the pistons and moving parts of the engine, in an oil circulation path for lubrication of the moving parts of the engine with the oil, the circulating oil returning to the lubrication oil sump container;
the lubrication oil sump container being shaped with side-walls and a bottom, to define space for the storage of a specified volume of lubrication oil, the volume of oil in the sump container being subject to ambient temperatures when the engine is not operating and progressively heated by engine operation to substantially stable temperatures of above about 90° C. during engine operation, the specified volume of lubrication oil being larger than the amount of oil continually drawn from the specified oil volume and delivered through the oil circulation path during engine operation, the sump container comprising an oil pick-up through which oil is delivered into the oil circulation path during engine operation and an upper opening for the return of oil from the oil circulation path;
the sump container further comprising a thin-walled perforated sheet porous separator comprising a plurality of openings with a characteristic dimension of between about 100 and 300 micrometers, the thin-walled perforated sheet porous separator having a thickness which is 2 to 3 times the characteristic dimension, the thin-walled perforated sheet porous separator having generally vertical upstanding walls extending from the sump bottom and having outwardly extending upper walls extending from the upstanding walls to the sump sidewalls, the separator serving to partition the sump volume into a first sump volume at least partially contained within the upstanding walls of the separator and an second sump volume contained between the upstanding and upper walls of the separator and the side-walls of the sump;
the walls of the porous separator having a plurality of openings, generally uniformly distributed, each of which openings is permeable to oil flow at temperatures of about 60° C. but resists the flow of cold oil through the separator during an engine cold start, so that, upon an engine cold start, the separator serves to initially separate the unheated oil within the sump container into two oil volumes, a circulating oil volume contained within the first sump volume and an enclosed oil volume contained within the second sump volume;
the circulating oil volume containing an at least like volume of oil to that oil being used in the oil circulation path, the circulating oil volume receiving engine-heated oil returning to the sump container from the oil circulation path, the oil pick-up being immersed in the circulating oil volume for delivery of oil to the oil circulation path;
the separator providing resistance to the infiltration of oil from the enclosed volume into the circulating volume until, by conduction and/or convection through the separator, the enclosed oil volume is heated sufficiently by the returning engine-heated oil that the enclosed oil permeates the separator and mixes with the circulating oil volume, enabling the entirety of the specified volume of sump lubricating oil to circulate through the oil circulation system of the engine.

7. The engine recited in claim 6 in which the separator provides minimal resistance to oil flow when the engine oil attains its operating temperature.

8. The engine recited in claim 6 in which the volume of circulating exterior oil is at least about one and one-half quarts.

9. The engine recited in claim 6 in which the ratio of circulating exterior oil to the total oil volume is about 25 to 30%.

10. A multi-cylinder, reciprocating piston, internal combustion engine, the engine comprising moving parts, in addition to the piston in each cylinder, and further comprising an oil circulation system, operative during engine operation, for delivering oil from a specified stored volume of oil in a lubrication oil sump container below the pistons and moving parts of the engine,

Assignees

• Mordukhovich Gregory
• Gm Global Tech Operations Llc

Inventors

• Mordukhovich Gregory

Classifications

• F01M2005/023

  Oil sump with partition for facilitating heating of oil during starting · CPC title

• F01M2011/0045

  for controlling the oil temperature · CPC title

• F01M11/0004 Primary

  Oilsumps · CPC title