US1991758A - Air cleaner - Google Patents

Description

Feb. 19, 1935. 'w .w ow ER 1,991,758

AIR CLEANER Filed 1360.15, 1953 I Patented Feb. 19, 1935 UNITED STATES PATENT OFFICE AIR CLEANER Application December 15, 1933, Serial No. 702,483

7 Claims. (01. 183-15) My present invention provides a simple and reliable air cleaner of high emciency adapted for use "in connection with internal combustion engines and capable of meeting all of the requirements of internal combustion engines 01' high power capacity having a small number of cylinders wherein the air is drawn to the carburetor with pulsating actions that vary, to a considerable extent, the velocity of the air flow through the air cleaner. The present invention is shown as embodied in an air cleaner, some of the features of which are common to that illustrated in the drawings of my companion application, 8. N.

702,482, filed of date December 15, 1933.

My present invention is illustrated in the single view or drawing which is an axial section taken through the complete air cleaner. The air cleaner, as shown, involves an outer casing or shell 5, preferably in the form of an upright cylinder, the lower end or which is primarily open. An axial air intake tube 6 extends downward through the casing 5. A large or main ,oil we11 7, or cup-shaped form and closed at its bottom, is telescoped onto the lower end or the easing 5 and closes the lower end of said casing. This oil well 7 is made readily detachable and is secured to the casing by suitable means such as upwardly spring-pressed hook-b0lts'8 that work through lugs 9 on the exterior of the casing and engage out-turned lugs 10 on the exterior of the upper edge of said oil well.

At the upper end of the casing is an air chamber 11 that surrounds the upper portion oi. the air intake tube 6 and is provided with an air outlet 12 adapted to be coupled to the carburetor of an internal combustion engine. An oil distributing dust-intercepting screen A is placed in the annular space between the casing and the intake tube and extends from the bottom or 40 1 chamber 11 down to a point near to but considerably above the lower end of the air intake tube.

This screen is preferably made from quite finely woven wire and may take various forms. For example, it may be such as that disclosed in the application of William H. Schulz, S. N. 616,885, filed June 14, 1932, and entitled "Air cleaner".

For the purpose of this case,.attention is simply called to the fact that the screen, as shown, is made up of annular woven wire members, the 50 surfaces of which are inclined in such a way that the oil intercepted by the screen will run down over and form films of oil over the openings of the screens and through which oil films, the air will be caused to pass and, by the oilfilms, the 5 dust will be intercepted and returned tov the oil well. At its extreme lower end, the air intake tube 6 isprovided with an outstanding annular flange 13. The elements so far specifically described are common to the structure illustrated in the companion application above identified. 5

As a highly important feature of the present invention, the oil well is provided just below and immediately surrounding the lower end of the air tube with a secondary or minor oil receptacle in the nature of a closed bottom oil cup 41 shown 10 as formed by an annular collar 15, the lower edge of which is secured to the bottom of the oil well .7. The normal or static oil level 01' the oil well is at 11-1! and which level, it will be noted, is well above the lower end of the air tube 6. The. 15 cup-forming collar 15, it is important to note, extends somewhat above the plane or the flange 13, but well below the normal oil level.

Spaced concentrically from the cup-forming collar 15 and from the walls of the oil well and 20 of the casing is an annular baiiie 16 which may be supported in various diirerent ways, for example, by means of spacing studs or lugs 1'! that connect the same to the cup-forming collar 15, so that both of the said members 15 and 16 will 25 be removable with the oil well. This baille, it is important to note, terminates at its lower edge high above the bottom or the oil well 7 and extends above the upper edge of the collar 15 and terminates at its upper edge'approximately at 30 the oil level yy. It will now be noted that the flange 13, on the lower end of the air tube 6, forms a restricted annular air passage 18 between the same and the collar 15. r

Operation Normally, as stated, the oil level will be approximately at the line 1/1I. Under the action of suction produced by the engine, a more or less rapid current of air will be drawn to the car- 40 buretor, through the air intake tube 6 into the chamber formed within the oil cup 14. thence upward through the screensinto the air chamber 11 and out through the air discharge tube 12. Air discharged from the lower end of the air tube 6 willbe dashed against the oil in the oil cup 14 and the oil in said cup will be depressed to an extent depending on the velocity or the air and will be dashed into a spray or foam and carried upward by the air through the openings in the 5 screen, to a greater or less height, depending on the force of the air. The oil displaced from the cup 14 and passed upward into the screen chamber will, under any normal degree of air velocity. ultimately be intercepted by the screen elements and will accumulate thereon and run downward over the declined surfaces thereof. That portion of the oil displaced from the cup 14, which runs over the outward declines of the screens, will accumulate and form a head of oil in the lowerouter portion of the oil well, that are radially outward of the annual baffle 16. Oil accumulating on'the inward declines of the screen elements, will eventually reach an eddy space closely adjacent the intake tube, which eddy space forms as a result of the flange 13, and will be free to run downward along the intake tube. Under continued operation with substantially constant air velocity the oil level in the cup 14 will remain substantially constant, there being under these conditions substantially no flow of oil either into or out of the cup 14, and oil supply to air stream will be afforded from the following noted sources, to wit: (a), from between the cup 14 and baffle 16, as a result of suction produced by the rapid movement of air passed over the edge of-the cup 14, and the head of oil maintained outward of this point, (b), from the upper edge of the baffle 16 by oil from the annular head of oil overflowing the baflle 16, and (c), from downwardly flowing oil in the eddy space adjacent the intake tube which overflows the edge of the flange 13. Substantially all of the oil supplied to the air stream from the sources (a), (b) and (c), noted, is whipped up by the air at the point of highest air velocity and is returned to the screen chamber, substantially the only return of oil from the screen chamber to the oil well being outward of the bafile 16. It will be obvious that under the conditions above noted, there will be a continual circulation of oil downward between the bafile 16 and the wall of the oil well and upward between bafile 16 and cup 14.

It is important to maintain a high air velocity close to the point where the air makes its initial upward turn against the oil and passes between the intake tube and the wall of cup 14 so that under normal operating conditions, all of the oil delivered to the air stream at this point will be whipped up by the air and carried back into the screen-containing chamber, which chamber might well be termed an expansion chamber, since the air stream expands rapidly upon entering the same. This rapid and relatively great expansion of the air as it leaves the cup 14 and baflle 15, and enters the screen-containing expansion chamber, causes oil delivered into the air stream at this point to be finely broken up or atomized so that it will pass upward into the screen elements in the nature of a fine mist. Flange 13 serves the dual function of increasing air velocity at the point of its delivery to the screen or expansion chamber, and produces the eddy space adjacent the intake tube so as to permit return of oil to the high velocity point of the air stream and said flange 13, is therefore, a very desirable and important element.

Most and all of the heavy particles of dust are thrown directly into and arrested by the oil in the cup when the air makes its upward turn against the surface of the oil in said cup, and the balance of said dust or foreign substance which will represent only the very light and hardest to arrest dust or foreign substance, will turn with the air and be delivered to the screen-containing expansion chamber, where it will be arrested either by oil suspended in the air or on the screens and eventually will be returned to and deposited in the oil well. Oil flowing downward over the screen element forms films over the openings therein through which air must pass, so that all the dust carried in the expansion chamber is arrested therein and usually before having traveled but a short distance through the expansion chamber. The vertical extent of the screen-containing chamber is such that oil will not be carried up through all of the screens or screen elements even by intense pulsations produced by large two-cylinder internal combustion engines. Of course, also the altitude to which the oil will be carried will depend on the engine speed regardless of the number of cylinders and the variation in the intensity of the pulsations.

When the speed of the engine and hence the velocity of the air decreases, there will be an overflow of at least part of the oil from the oil Well into the oil cup, and when the engine is inoperative, the oil will reach a static condition and will then overflow into and completely fill the oil cup and the interior of the baffle 16, as the oil reaches its normal or static level.

The arrangement has, in practice, been found highly eflicient for the purposes indicated. It also has the advantage of affording a comparatively short air cleaner, due to the fact that the oil cup and oil well have a common bottom which shortens up the vertical extent or dimension of the oil well and hence of the entire air cleaner.

What I claim is:

1. An air cleaner comprising a casing having an oil well at its bottom and an air outlet at its upper portion, a closed bottomed oil cup in said well ofless diameter and vertical extension than said well, an air tube extended 'axially downward through said casing with its lower end arranged to deliver air into said oil cup, and an annular baflie spaced around said oil cup with its upper edge extended above the upper edge of said cup, the annular space between said baflle and cup being open for free communication with the bottom of said well. I r

2. An air cleaner comprising a casing having an oil well at its bottom and an air outlet at its upper portion, a closed bottomed oil cup insaid well of less diameter and vertical extension than said well, an air tube extended axially downward through said casing with its lower end arranged to deliver air into said oil cup, and an annular bafile spaced around said oil cup with its upper edge extended above the upper edge of said cup, the annular space between said baffle and cup. being open for free communication with the bottom of said well, the upper edge of said oil cup being above the lower end of said air tube and the upper edge of said bafile being approximately at a normal or static oil level that is well above the upper edge of said cup and above the lower end of said air tube.

3. An air cleaner comprising a casing having an oil well at itsbottom and an air outlet at itsupper portion, an oil cup in said well of less diameter and vertical extension than said well, an air tube extended axially downward through said casing with its lower end arranged to deliver air into said oil cup, and an annular bafiie spaced around said oil cup with its upper edge between said baffle and cup being open for free communication with the bottom of said well, said air tube at its lower end having an outstanding annular flange that forms a restricted annular air passage between the same and the well of said oil cup.

4. An air cleaner comprising a casing having an oil well at its bottom and an air outlet at its upper portion. an oil cup in said well of less diameter and vertical extension than said well, an air tube extended axially downward through said casing with its lower end arranged to deliver air into said oil cup, and an annular baffle spaced around said oil cup with its upper edge extended above the upper edge of said cup, the annular space between said baffie and cup being open for free communication with the bottom of said well, the upper edge of said oil cup being above the lower end of said air tube and the-upper edge of said bafile being approximately at a normal or static oil level that is well above the upper edge of said cup and above the lower end of said air tube, said air tube at its lower end having an outstanding annular flange that forms a restricted annular air passage between th same and the well of said oil cup.

5. The structure defined in claim 2 in which said oil cup and oil well have a common bottom and are together detachable from said casing.

6. An air cleaner comprising a casing having a closed bottomed oil well in its bottom and an air inlet at its upper portion, an oil cup in said well of less diameter than said well, an air intake tube extending axially downwardly through the casing with its lower end extending below the top of and arranged to deliver air into said oilcup, the oil in said well having a normal static level above the oil cup and the delivery end of the intake tube, whereby under the action of air passed through the cleaner, oil will be. displaced from the cup and build up a head of oil outward of the oil cup which will,.under continued flow of air, overflow the edges of the cup and maintain the air stream supply with oil.

7. The structure defined in claim 1 in which the oil well is detachably applied to the lower 1 end of the casing and in which the oil cup and annular baffle are carried by and. detachable with said oil well.

WILF'RED W; LOWTHER.

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