US2493617A - Oil separator for crankcase vapors - Google Patents

Description

Jan. 3, 19'50 H. A. cHUBBucK OIL SEPARATOR FOR CRNKCASE VAPORS 3 Sheets-Sheet 1 HORACE A CHUBBUGK.

Filed llarch 7, 1946 INVENTOA 67' d ATTO R NEYS.

Jan.l 3, 1950 OIL Filed March 7, 1946 H. A. CHUBBUCK SEPARATOR FOR RANKCASE VAPORS 3 Sheets-Sheet 2 Fig. 4

HORACE A. CHUBBUCK.

Jan. 3, 1950 H. A. cHuBBucK 2,493617 OIL SEPARATOR FOR CRANKCASE VAPORS Filed March '7, 1946 3 Sheets-Sheet 3 HORACE A. CHUBBUCK.

NVENTOR. 67C- Y:

f# VM ATTORNEYS.

l Patented Jan. 3, 1950 UNITED STATES PATENT OFFICE OIL SEPARATDR corporation of Delaware Application March 7, 1946, Serial No. 652,776

This application relates to internal combustion engine construction and more particularly to an oil separator designed to prevent loss of lubricating oil in the gasses discharged from the crankcase by a crankcasey Ventilating system, although it is adaptable to' any situation requiring the separation of a finely dispersed liquid suspended in an aerosol.

The crankcases of internal combustion engines have for many years been ventilated, a wide variety of expediente having been tried to attain the proper degree of ventilation. Such ventilation is desirable to remove cylinder blowby gasses, to prevent thel accumulation in the crankcase of water and acids, and to minimize the adverse effects of dilution of the `lubricating oil with unburned fuel.

The rapidly moving parts and high oil pressures used in modern engines result in a substantial degree of atomization of the oil and the formation of a comparatively stable aerosol. The ventilation of crankcases in the usual manner causes large losses of lubricating oil in the disperse phase in this aerosol. The prime object of this invention is to provide an apparatus for breaking the aerosol so that crankcase ventilation can proceed without loss of lubricating oil in the discharged gasses.

With this and,4 other objects in view, the invention comprises the arrangement, construction and combination of the Various elements making up the structure described in the specification, claimed in the claims and illustrated in the accompanying drawings, in which:

Figure 1 is an elevation partially in section of an automobile engine showing in general the relationship of the oil separator and the engine.

Figure 2 is a central longitudinal enlarged section of the working parts of applicantsl novel oil separator.

Figure 3 is' a central section further enlargedy of a check valve. This check valve is encircled in Figures 1 and 2.

Figure 4 is a plan view of the check valve disc.

Figure 5 is a central section of the separating head taken along the line 4 4 in Figure 6.

Figure 6 is a plan view of the separating head. Y

In applicants invention, advantage is taken l of the engine suction to create the subatmospheric pressure in crankcase upon which the ventilation depends. ,Referring tov Figure 1, the Ventilating system comprises a breather pipe cap FOR CBANKCASE VAPORS Horace A. Chubbuck, Dearborn,

to Ford Motor Company,

Mich., assignor Dearborn, Mich., a

8 Claims. (Cl. 123-119) I0 packed with a filtering material II such as steel wool, and mounted upon breather pipe I2. The breather pipe I2 opens into valve chamber I3 which is connected by holes I4 to crankcase I5. In the crankcase the Ventilating air becomes mixed with crankcase vapors and minute droplets of lubricating oil, becoming in effect a d1lute aerosol in which lubricating oil is the disperse phase. This aerosol leaves the crankcase via conduit I6.

Conduit I6 terminates in separator head generally indicated at I1 and best seen in Figures 5 and 6. Separator head I1 comprises a base plate I8 to which is secured conduit I6 and two curved tubes I9. These curved tubes are given such a conguration that curved tube ends 2| are parallel and closely spaced. Base plate I8 is further provided with an oil drain aperture 20 for the removal of separated oil.

Considering Figure 2, curved tubes I3 open into separator chamber 22 which communicates with annular discharge -chamber 23 through a plurality of openings 24 formed in the periphery of member dividing the separating chamber 22 and annular discharge chamber 23. Concentric baile 25 is so placed that gas flowing through openings 24 will impinge upon the underside of this baille and deposit thereon any oil droplets which may have escaped separation in separator chamber l2. Separator chamber 22 is connected to the crankcase by oil return 28 which extends to a point just above the bottom of the crankcase as shown in Figure 1. It will be noted that in normal operation the lower end of oil return 26 will always be below the level of the surface of the lubricating oil.

Annular discharge chamber 23 is connected to the intake manifold by two separate discharges. The most direct discharge is through passageway 21 drilled through the wall of the I intake manifold 28. For reasons which will become apparent as the description proceeds, this passageway 2l is partially closed by plug 29 having an axial metering orifice 30. The second discharge from annular discharge chamber 23 into intake manifold 28 is by way of conduit 3|, check valve 32 and conduit 33 into shell 34 of air cleaner 35 and thence into the intake manifold 28 via carburetor 38. Check valve 32 comprises an upper tting 31 threaded into alower tting 38 which in turn is threaded into boss 39 in intake manifold 28. This check valve permits vapors to pass only in an upward direction. This action is caused by disc 40 which rests upon upper face Il of lower fitting 38. The action of disc I is immediately apparent fromv a consideration of Figure 4. This figure is a plan view of the disc 40, showing its configuration.

The operation of the device described above is detailed herewith. The ventilating air is drawn into breather pipe I2 through a breather pipe cap IIIV which is provided with a. fibrous iltering material II. This breather pipe I2 opens into valve chamber I3. From valve chamber I3 the ventilating air enters the crankcase I5 through holes I4. The ventilating air becomes mixed in the crankcase with crankcase vapors and finely atomized oil droplets and is discharged through conduit I6 into the oil separator I1. In oil separator I1 the mixture of air, crankcase vapors and oildropletsis received into curved tubes I9. The restricted diameter of these tubes imparts to this mixture a high velocity. These tubes divide the oil bearing mixture into two streams which are then impinged upon each other at high velocity. The resulting impacts of the oil droplets upon each other and upon the metal parts results in a coalescense of the minute suspended droplets into larger droplets capable of settling out under the inuence of gravity in the relatively quiescent conditions prevailing in separator chamber 22 which receives the discharge from curved tubes I9. The oil so removed collects in the bottom of separator chamber 22 and is discharged into the crankcase by oil return 26. The discharge from tubes I9 and any oil which escaped separation in separator chamber 22 flows through holes 24 and is impinged upon bafIle 25 before flowing into discharge chamber 23. Batlle 25 serves to remove residual oil droplets from the discharge.

Annular discharge chamber 23 discharges the oil free gases and ventilating air into the intake manifold 28 via one of two distinct paths, the choice of paths being dependent upon the operating conditions at the moment.

During normal engine operation when there is a substantial vacuum in intake manifold 28, annular discharge chamber 23 is discharged into the intake manifold 28 through passageway 21 which is partially closed by plug .29 having an axial metering orifice I0. During this normal operation check valve 32 will remain closed and prevent an excess of air from entering annular discharge chamber 23 and destroying the vacuum therein.-

During operation under heavy load, the pressure at the opening of passageway 21 so closely approaches atmospheric pressure that the differential is insumcient to cause a proper ilow of air through the crankcase for adequate ventilation. Under these circumstances check valve 32 opens and metering orice 30 is by-passed through theair cleaner 35 and carburetor 36 and in this way an adequate flow of ventilating air is insured when under heavy load. i

Care is taken to correlate the size of metering orifice 30 with the size and character of the other openings into the crankcase so that a practically complete vacuum in the intake manifold is incapable of producing sumcient vacuum in oil separator I1 to draw lubricating oil directly into the separator through oil return 26 which is, of course, submerged partially in oil. While the precise size of the metering orice should be experimentally determined for each design, a diameter of .090 inch has been found satisfactory on the current Lincoln engine.

I claim as my invention: v

1'. An apparatus for insuring continuous subatmospheric pressure in an internal combustion engine comprising a connection from the crankcase to the air induction system through a branched conduit, one branch'of said conduit opening directly into the intake manifold on the engine side of the butterfly valve through a restricted orifice and another branch of said conduit of substantial cross section opening into the air induction system. on the atmospheric side `of the butterfly valve and containing a check valve biased to permit ilow only toward the atmospheric side of the air induction system.

2. An apparatus for the recovery in bulk of finely divided oil droplets suspended in the gasses discharged from an internal combustion engine crankcase comprising an oil separator chamber communicating with the air induction system of the engine through a restricted orifice opening into the intake manifold on the engine side of the butterily valve and also communicating with said air induction system through a conduit of substantial cross section openingv into said induction system on the atmospheric side of the 1 butterfly valve and containing a check valve biased to permit flow only away from the oil separator chamber, and said oil separator chamber communicating with the crankcase by means of a conduit the discharge end of which is below the normal level of the lubricating oil, the size of said orifice, the size of all openings from the crankcase to atmosphere andv the height of the oil separator chamber above the lever of the lubricating oil being so fixed that a substantially perfect vacuum in the intake manifold will not 'cause a ow of oil from the crankcase into the oil separator chamber via the oil discharge confinely divided oil droplets suspended in the gasses discharged from an internal combustion engine crankcase comprising an oil separator chamber communicating with the air inductionV system of the engine through a restricted orifice opening into the intake manifold on the engine side of the butterfly valve and also through a conduit of substantial cross section opening into said system on the atmosphericside of the buttery valve and containing a check valve biased to permit flow only away from the oil separator chamber, said chamber also communicating with the crankcase by means of a conduit opening into -the crankcase at a point above the oillevel and terminating within the oil separator chamber in a n plurality of narrow tubes bent so that their discharge ends are opposed, parallel and closely spaced, and said chamber also communicating with the crankcase by means of a'conduit the discharge end of which is below the normal level of the'lubricating oil, the size of the said orice, the size of all openings from the crankcase to atmosphere and the height of the oil separator chamber above the level of the lubricating oil being so iixed that a substantially perfect vacuum in the intake manifold will not cause a'ow of oil from the crankcase into the oil separator chamber via the oil discharge conduit.

4. In the process of ventilating a crankcase, the step of dividing the eilluent gas from the crankcase among a plurality of constricted tubes and impinging the gas streams from these tubes upon each other.

5. In a crankcase ventilating apparatus a conduit adapted to conduct the eilluent gasses. said conduit being divided at its downstream end into 5 a plurality oi restricted tubes the ends oi which oppose each other and a separate conduit connecting the crankcase with a chamber containing said restricted tubes.

6. The method of breaking an aerosol comprising impinging upon each other a plurality of rapidly moving streams of said aerosol and immediaiely reducing the velocity of the gaseous phase of the aerosol below a point at which the resulting coalesced particles of the disperse phase will be entrained.

7. An apparatus for breaking an aerosol comprising means for impinging upon each other a plurality of rapidly moving streams of said aerosol and means for immediately reducing the velocity of the gaseous phase below a point at which the resultingv coalesced particles of the disperse phase will be entrained. A

8. The method of recovering in bulk iineiy divided liquid from suspending gas comprising impinging upon each other high velocity streams of the suspending gas carrying the ilnely divided liquid so as to coalesce the particles oi liquid and separating the coalesced liquid from the suspending gas by reducing the velocity oi such gas 'below a point at which said coalesced particles will be entrained.

Homes: A. vcHUnnUc-x.

asm-:annees CITED The following references are oi' record in the ille oi this patent.:

UNITED STATES PATENTS

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