US2443875A

US2443875A - Lubricating system for engines

Info

Publication number: US2443875A
Application number: US479033A
Authority: US
Inventors: Carl C Spangenberger
Original assignee: Avco Manufacturing Corp
Current assignee: Avco Manufacturing Corp
Priority date: 1943-03-13
Filing date: 1943-03-13
Publication date: 1948-06-22
Anticipated expiration: 1965-06-22

Description

June 22, 1948. c. c. SPANGENBERGE'R 2443875 y LUBRICETING sYs'rEl Fon ENGINES 2 Sheets-Sheet 1 mercin aaron 1s, 194s,

Car/'Z @omge/ayer 2V 24' I A@ M Patented June 22,1948 4 UNITED STATES rii'rialv'r oFFlCE 2,443,875 Lunarca'rmo SYSTEM Foa ENGINES Carl C. Spangenber'ger, Williamsport, Pa., assignor to Aveo Manufacturing Corporation, a corporation of Delaware Application March 13, 1943, Serial No. 479,033

n 4 calms. (ctms-19s) v 2i and with a similar oil-sump 22 at the opposite end. A carburetor b is connected to deliver a combustible mixture to an uptake b1 which en, tendsl upwardly throughsthe crankcase and conducts the mixture to the intake manifold. An

air iilter c is connected to the air'intake of the uid and arresting surging in the iiuid before the liquid oil is returned from the crankcase to the supply tank for recirculation; with means for separating the liquid oil from the air and gas in the fluid drawn by the oil-scavengingpump from a plurality of sumps in the crankcase ofthe engine, either of which mayrun dry when the engine is used on aircraft or military tanks which in their maneuvering are tilted at severe angles so that the oil in the crankcase 4will flow by gravity to oneend thereof while the other becomes dry; with means for delivering the gas or vapor separated from liquid oil to an air filter provided with an oil bath; with separator means which is eiiicient in separating the oil from the air and gas and in arresting the surge caused by the drawing of fluid from the wet and dry sumps: and which is reliable in its operation.

Other objects will appear from the detailed description.

The invention consists in the several novel features which are hereinafter set forth and more particularly dened by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a diagrammatic view of lubricating apparatus embodying the invention, and an engine for which the apparatus is used.

Fig. 2 is a side elevation of the separator.

Fig. 3 is a vertical section taken on the line I-l of Fig. 2.

Fig. 4 is a plan of the separator.

Fig. 5 is a section taken on the line 5-5 of Fig. 2.

Fig. 6 is a view partly in elevation and partly in section of the air or vapor discharge tube `separator.

Fig. 7 is asection taken on the line l-'l of Fig. 6. y

The, invention is'exemplied with an internal combustion engine a of the opposed cylinder type which comprises a crankcase a1 provided with a depression at one of its ends forming an oil-sump carburetor and comprises an outer casing c1, the lower end of which contains a column of oil, a central tubular member cz which contains a filtering medium c4 such as steel wool, and has its lower end extended into the oil column and has its upper end communicatively connected to the air intake of the carburetor. An air inlet c3 is connected to the casing c1 above the oil column. Air is ldrawn by the suction in the carburetor,

'into the inlet c3, through the oil-column in casing c1, member c2 and filtering medium c4.

The lubricating system is of that type in which oil under 4pressure is drawn from a reservoir, forced under pressure through or around the bearings and parts to be lubricated, is' then collected in the crankcase, and returned. by a scavenging pump from the sump to the lreservoir for recirculation.

The lubricating apparatus comprises a tank or container I0 for a supply of oil for lubrication; an engine-driven oil pump I2.' usually of the gear-type, for drawing oil through a conduit Il,

from the tank I0, and which has a sufcient capacity to discharge oil in excess ofthat required for pressure lubrication at all engine speeds; a conduit l5 having the necessary number of branches for delivering oil to all bearings and parts to be lubricated, and connected to the discharge side of pump I2; a by-pass valve ll which is spring-loaded so it is responsive to a predetermined pressure in theconduit I5, and will by- Dass the oil in excess of that desired for lubrication, to a conduit I6, an oil cooler or radiator I9. to which the oil flows from conduit I6; and a conduit 20 for deliveringthe oil from the radiator I9 to the tank I-Il. The oil from the bearings and parts lubricated drainsinto and collects in the crankcase al of the engine. as well understood in the art.

The fluid which collects in the crankcase a1 is drawn from sumps 2|,122through conduits 23, 25 by a duplex, engine-driven scavenging pump 24 of the gear type. This uid may include liquid. air` or gas. or a mixture of liquid and air or gas. Engines used on vehicles, such as air` craft or military tanks, are often tilted longitudi nally at severe angles during maneuvering. The sumps 2l, 22 are provided at opposite ends of the crankcase so that the pump 24 .will draw oil from one or the other of the sumps. The pump 24 will, at times, draw air, gas or vapor either alone or mixed with oil, from one of the sumps. Since the scavenged fluid consists of oil and air or gas, which may vary in proportions. it is necessary to separate the liquid from the air or gas, for recirculation, and furthermore, surge-pressures orV pulsations and foaming result in the scavenged iluid discharged by the pump, and vmay .cause slugs to, be produced in the discharge from said pump. Such surge-pressures, unless arrested, and such slugs,- unless prevented,.produce danger# ous transitory pressures or impulses, which are likely to cause breaks in the conduits. The presence ofsubstantial amounts of air and gas in the recirculated oil may also result in ineillcient lubrication of the bearings. The pumps l2 and 24 are constantly driven from the engine, as well understood in the art, s'o they will always operate proportionately to engine-speed.

The apparatus of the invention includes a combined centrifugal separator and surge arrestor, generally designated 34 to which the mixed fluid scavenged from the sumps is delivered under pressure by the duplex pump 24.

The body of separator 34 comprises a convex bottom 42, a cylindrical side 44, and a convex top 43. The tubular inlet 33, which receives fluid drawn from both sumps in the crankcase by the scavenging pump 24, is connected to the side wall 44 below the tcp 43, and to deliver iluld tangentially into the upper portion of' the chamber 34e in the separator body. The tubular outlet 35 is communicatively connected to the wall 44 of the separator body adjacent the bottom 42 .to discharge liquid tangentially from said wall. The

or gas separated from the liquid to the top of tank l0.

Due to the restriction of the ilow of oil by the lter I8 and the cooler or radiator I9, the pres- Vsure in the separator-chamber 84a must be greater than that in the tank l0 to cause the oil to ilow to said tank. To maintain this diitangential discharge of uid under pressure into ferential of pressure, the restriction of the air or gas ow from the separator 34 .to the tank I0 must be sumcient so that when the normal amount of air or gas from the scavenging pump 24 is flowing through conduit 40 to tank I0, the pressure drop necessary to force the amount of oil being delivered by pump 24 is at least equivalent to that necessary to force the liquid oil discharged from separator 34 through the oil-lter I8 and radiator I8 with the oil'by-passed by the valve I4, to conduit I6. The pressure maintained in the separator 34 may be between 20 and 40 lbs. per square inch gauge pressure, varying with the engine speed, the .pumps I2 and 24 being constantly driven in proportion to the engine speed. The ratio of the 'air or gas and the oil in the mixed fluid delivered by the scavenging pump 24 may also vary as the result of one of the sumps in the crankcase being temporarily dry. The tube` 48 has a relatively large diameter, in practice substantially from 1%" to 11/2", with an inside volume of approximately 32 cubic inches, so that it williorm a chamber of substantial area which will be illled with liquid before the latter can reach the discharge orifice 55. Since the ow restriction ratio of airto oil through the oriilce 55, for example 2?," in diameter, is approximately 1 to 1000, the pressure in tube 48 o will be greatly reduced due to the ilow of oil inwhat as indicated by dotted lines in Fig. 3, and

causes the air and gas to be separated from the liquid in the space above the liquid column and in the vortex. -'I'he liquid-oil is discharged tangentially from the lower portion of chamber 34a in the separator and ilows under pressure through the oil illter I8, conduit Il, radiator or cooler I9. and conduit 20 to the tank I0 for recirculation by the pump I2.

A tube 48 in the top 45 of theseparator body functions as an outlet for the air and gas sepa'.-

rated from the liquid oil in the central and upper portions of chamber 34.- This tube 48 is xed in a nipple 53 which is screw-threaded into a ring 43l which is welded to the top 43. 'A cap 55 is screw-threaded to the upper end of tube 48. A coupling-nipple 54 is screwf-threaded into the cap 55 and is :provided with a restricted oriilce 55 for limiting the outow of air and gas from the separator body. The lower end 48n of tube 48 is conoidal and has a small opening 50 in theV apex of the conoidal portion. Two helical rows of apertures 49 are provided in the tube 48 above the conoidal portion "Fand below a transverse wall which is xed, for example by welding, to the cylindrical wall 44 of the separator body. Wall 45 forms the top o! chamber I4'L around the tube 48 and forms. below the top 45, a cushioning chamber 34b in the upper portion of the separator body `and above the chamber 54. A pair of diametrically opposite apertures 41 extend through wall 45 to permit air to pass betweenchambers 34l andfl4. Thetube 48 extends through the stead of air through the perforations 49 in the tube 48. This lowering of the pressure in the tube 48 decreases the airiiow and increases the time required before the liquid will rise or ilow through orice 55. If the liquid level in the separator continues to rise, it will compress the air or gas in the upper portion of tube 48, together with any other air from pump 24. to increase the pressure of the liquid in chamber 34a. This causes an increased iiow of liquid through outlet 35. Normally, this high-percentage oil-condition is transitory and the percentage of gas in the uid'delivered by pump 24 is suihcient to prevent the level of liquid oil in the tube 48 from rising to the oriilce 55. The gas or air released from the oil tends to push the oil downwardly and according to its percentage, will progressively open the perforations 49 from uppermost downward, and the gas will bubble upwardly through the upper portion of the tube and the restricted that no roaming is present in tank I0. It has been found that with an orice 55 fr" in diameter only a slight amount oi liquid oil will ilow :through said orifice in a system dowing approximately 44 gallons per minute. Anyv liquid` oil which `flows through oriiice 58 ,will be collected .and recovered in tank I8. l

Any surging which occurs in the fluid which is pumped into the separator will be arrested by -the cushioning e'ect o! the confined air or gas tank I8 is connected by a conduit 4I to the air intake c3 of an air lter c. This air illter com` prises a closed casing c1 containing an oil bath on tts bottom, a tubular member c2 containing l suitable filter material such as steel wool c4. "The,

lower endoi' member c2 terminatesin the oil bath and'its upper end is communicatively connected to the air intake of, and subject to suc- 'tion from, the carburetor b. The gas or vapor in the upper end of the supply tank I8 is drawn by the suction of the carburetor through the conduit 4I, mixed with the air entering the air inlet c3, passes through the oil bath where the oil in the vapor or gas is separated from the air and retained to replenish the oil in the-bath. The cleaned air passes through the material c4 to the intake of the carburetor. This draws the fumes or vapor from the supply tank I8 to the oil bath of the air filter so that thervapor and fumes will not contact with or condense upon the outside of` the surrounding parts. This also prevents the collection of dust by the condensate on the parts of the vehicle around the engine.

The operation-of the apparatus will be as follows: The pump I2 draws oil from the tank I0 through the .conduit II and delivers It via the conduit I3, valve-casing I4, and conduit I5 and its branches I5*` to the bearings' and parts of the engine which require lubrication. The oil from the parts lubricated flows to the crankcase a1 and into the sumps 2|, 22. The 'pump I2 has a suillcient capacity to discharge oil in excess of the volume required for lubrication of the parts. The spring-loaded valve I4 maintains the desired pressure' in conduits to the lubricated parts at varying engine speeds. and4 by-passesA 3.3 of the separator 34. On account of the tilting of the engine when used on aV vehicle or aircraft, one branch of the pump 24 may draw mostly oil from one of the sumps and mostly air` Maarn the chamber 34. The oil is forced under sufvalve I4, to the `tank I0.

Normall'yVat least Vthe upper apertures 48 are open so that no liquid will iiow therethrough to the upper portion ofthe tube 43. The liquid level inthe separator and tube 48 may fluctuate. As

the percentage of air and gas increases, the lic;

uid level will drop and expose additional apertures l49, which are preferably helically arranged, for the iiow of air or. gas from the chamber 84a into the tube 48. As" the liquid level rises. the compression of the air or 'gas will tend to increase the pressure upon the liquid and its discharge from the separator. This results in separation of the liquid from the gas and maintaining a sumcient drop in pressure between the tube 48 and the upper portlonof the tank I0 for the delivery of the liquid-oil through the filter and cooler' to the supply tank for'recirculation.

The scavenging pump, particularly while discharging a high percentage of air or gas from one sump and a high percentage of oil from the other sump, mayproduce slugs or surging in the uid entering and in the separator body. The chamber 3l!b into which the air and gas can ow i through perforations '41, acts as a cushioning or or vapor from the other sump. rThe fluid discharged by the duplex scavenging pump 24` may consist of intermingled oil, foam, air and vapor or slugs which will be delivered'throughthe tangential inlet 33 into the chamber 34 of the separator. This tangential delivery under pressure to the cylindrical side wall 44, will cause the -liquld to swirl around, and be subjected to centrifugal force in the chamber 34. and form a vortex in chamber 34e. The oil constituent of expansion chamber for the 'air or gas which arrests the surging and breaks up the slugs of the liquid before it is discharged from the separator. This eliminates dangerous transitory pressures and impulses in the conduits. oil illter andcooler between the separator and the supply tank I0.

The vapor or gas. or fumes therefrom. which are delivered to the supply tank ID, are drawn by the.

suction of the carburetor b through the conduitV 4I and the air filter c so that no condensate will form on the conduits and on the parts of the vehicle surrounding the engine. The oil in the vapor drawn into the iilter c will be trapped by the oil bath in said filter and replenish the oil drawn from the bath by the carburetor.

The mergingof the flow `of the by-passed excess oil from valve I4 retards the flow of oil from the separator and filter to the cooler. v

It will be understood that the apparatus functions to continuously recirculate the oil from the supply tank III under pressure be lubricated. v

The invention exemplifies a lubricating annato the parts to ratus for an internal combustion engine iii which the lubricatingoil is continuously recirculated from one or more sumps in the crankcase, the

arating and surge arresting apparatus for the iluid scavenged from the crankcase which effects eilicient separation of the constituents oi.' the tluid and prevents dangerous transitory impulse pressures in the system.

The invention is not to be understood as re` stricted to the details set forth, since these may be modiiied within the scope of the appended claims without departing from the spirit and. scope of the invention.

Having mus described the invention. what I j claim as new and desire to secure by Letters Patent is:

1. A system for circulating oil for lubricating van internal combustion engine which is provided with an oil sump to which oilxlows from the parts lubricated and includes a container for a supply of oil and a carburetor, comprising a scaveg pump for drawing fluid containing liquid and gas or air from the sump, a centrifugal separater for separating the air or gas from the for delivering the air or gas from the separator to the container, and means' for applying suction from the carburetor to the gas or vapor in the container for its removal therefrom.

-2. A system for circulating oil for lubricating an internal combustion'engine which is provided with an oil sump to which oil flows from the parts lubricated and includes a container for a supply of oil and a carburetor, comprising a scavenging pump for drawing fluid containing liquid and gas or air froml the sump, a centrifugal separator' for separating the air or gas from the liquid in said fluid, and provided with a body connected for'receiving the fluid under pressure from the scavenging pump, means for conducting the separated oil from the separator to the container for 1 recirculation, restricted ilow means for delivering the air or gas from the separator to the container, an air filter of the oil-bathtyp'e, connected to the carburetor, and means for' sucking the gas or vapor from the container to the air' 3. A system for circulating oil for lubricating an internal combustion engine which is provided with an oil sump to which the oil ilows from the parts lubricated and includes a container for a supply of oil 'and a pressureA pump having a calpacitygfor delivering oil in excess of that required for lubricating the parts, and with means for by-passing said excess oil, comprising: a scavenging pump for drawing iiuid containing liquid and air or gas from the sump, a centrifugal separator for separating air or gas from the liquid and provided with a chamber connected to receive fluid under pressure from the scavenging recirculation, and means for conducting air or gas from the separator to the container.

4. A system for circulating oil for lubricating an internal combustionl engine which is provided with an oil sump to which the oil i'iows from the pump, an outlet for the separated liquid and a restricted outlet oriice for the separated air or gas, a `filter connected to receive oil from the separator, an oli cooler connected to receive oil from the lter, means for conducting oil from the lter to the container, means for merging the by- Parts lubricated and includes a container for a supply of oil and a pressure pump having a ca enging pump for drawinguid containing liquid and air or gas fromthe sump, a centrifugal sepa \rator for separating air or gas from thelliquid and provided with a chamber connected to receive' fluid under pressure from the scavenging pump, an outlet for the separated liquid and a restrictedoutlet orice for the separated air or gas, a lter connected to receive oil from the sepgarator, an oil cooler, means for conducting oil from thelter to the cooler, means for conducting the by-passed excess cil to ,the means for conducting oil from the filter to the cooler and retarding the ow of oil from the lter to the cooler, means for delivering the oil from the cooler to thecontainer for recirculation, and means for conducting air or gas from the separator to the container.

CARL C. SPANGENBERGER.

REFERENCES CITED The following references are of record in the file of this patenti .UNITED STATES PATENTS Number Name Date 1,329,038 Curtiss Jan. 27, 1920 1,440,808 Y Wineman Jan. 2, 1923 1,790,372 Good Jan. 27, 1931 1,857,652 McKinley May 10, 1932 1,864,095 Rodman June 21, 1932 1,903,412 Woolson Apr. 4,` 1933 1,907,706 Atwell May 9, 1933 2,024,336 Cavanaugh Dec. 17, 1935 2,073,096 Church Mar. 9, 1937 2,140,735 Clark Dec. 20, 1938 2,316,729 Tryon Apr. 3, 1943 2,323,525 Ebel July 16, 1943 2,335,420 Jones Nov. 30, 1943 2,379,579 Hunter July 3, 1945 FOREIGN PATENTS Number Country Date 359,401 Great Britain Oct. 12, 193i 501,998. Great Britain Mar. 9, 1939 692,505 Germany June 21, 1940 709,671 France May 20, 1931