US2375718A

US2375718A - Crankcase air-pressure control means

Info

Publication number: US2375718A
Application number: US484194A
Authority: US
Inventors: Walter G Winkels; Thomas W Ashcroft
Original assignee: Fairbanks Morse and Co
Current assignee: Fairbanks Morse and Co
Priority date: 1943-04-23
Filing date: 1943-04-23
Publication date: 1945-05-08
Anticipated expiration: 1962-05-08

Description

May 8, 1945 w. G. WINKELS ETAL .2,375,718

CRANKCASE IR-PRESSURE. CONTROLMEANS v Filed April 23, 194s .72' 58 75 ATTORNEY Patented May 8, 1945 MEAN `Walter G;- vvirikn, United states Navy, and Thomas W. Ashcroft`Be`loit`, Wis., assignors to Fairbanks; Morse &"Oo., Chicago, "Illu,

a cor- Appncation April 23, 1943, serial No. 484,194

(c1. 1er- 194) 9^ Gl'aims; This'invention relates. to crankcase air-pressure control means, andn moreV particularly toian improved device for controlling air-pressure within a substantially closed `cranls'casev of an internal combustion eng-ine,l pump, compressor or the like.

A `principal object of thepresent invention resides in the provisionv of a novel and effectivecontrol device for substantiallyI closedV crankcases of engines and the like, which affords crankcase compression relief `and air-pressure` controlin aimanner generally'to prevent` above-atmospheric; air

pressures within thecrankcase during engine `operation, and moreparticularly, tofacilitate maintenance of sub-atmospheric pressures in the l crankcase, evento the extent of a slight negative pressure or partial vacuum therein, throughout at least a greater portion `of each cycle ofengine piston` operation, whereby there is thus prevented or` very materiallyureduced such loss oflubricat- -ing `uid from the crankcase interior, as otherwise would tend to occur by reason of above-atmospheric air pressure in thecrankcase tending to force lubricant outwardly, as throughV `cylinder ports, crankcase joints, andgpast such `operating parts of the engine which extend through wall portions of the crankcase.

` i Another object of theinvention resides in the provisions` of a relatively compact andI effective crankcase air control device of the character `inydicated', adapted for controlling the `pressure `Within; `the, crankcase by release from the crankcase during engine operaffording periodic air ation, wherein` therdeviceembodies a lubricant 'condensing chamberfand` lubricant absorbing means thereinf'orthe removal ofV lubricant from the crankcase air released through the device, and controlled means for effecting; return of the lubricant thus removed, to the crankcasa A further `object of theinventionis to provide an improved device for `the purpose indicated, p

which utilizes an operating partofr the engine as an active element of the. device; and which pro- Vides an` oil entrappingl and. condensingshield `ai'. theoutlet thereof-l for insuring against discharge ofA oil particles inte the-r` atmosphere about the engine.` i

f l `Other objectsand advantages of theinvention I will appear from4 the following' description of a preferred embodiment thereofl as exemplified `in the accompanying drawing, in which:

Fig. 1 is a longitudinali elevation partly section of an internal combustion engine embodying the presently improved crankcase air` controlldevice;

generally at I0.

upper portionor the crankcase, taken from the line 2--2 in` Fig. ,1, showing the crankcaseV device.

therein, the View alsoillustrating a magneto'device in driven connection with a drive gear in the crankcaseportion shown, and Fig. 3` is a-sectional elevation through 'theeleviceas viewed from 1ine3-3 inFig. 2. l

Referring to the drawing by suitable characters of reference, the improved control device in the embodiment presently preferred and` herein illustrated, is-shown by Way of an` example `of its application, in association with an internal combustion engine of closed `crankcase type, indicated Briefly, the enginel shown by Fig. 1 includes a frame assembly providing a cylinder II anda crankcaseIZ, acrankshaft I4 in the crankcase, a piston I5 operable-.in cylinder II, and a'connecting rod I6 between the pistonand crankshaft., All magneto generator I8 (Fig. 2)provided for supplying engine ignition current, is arranged externally to and preferably above the crankcase I-2 adjacent anupward extensionr I9 of the crankcase An opening: 20 in one Wall 22A of crankcase extension I9 `aiiords projection of` the magneto shaft coupling element123 int the chamber 2lil provided-by the extension I9, for driven connection `with a gear j i 26 therein forming an element of! a gear train Fig. 2 is an enlarged sectional-elevation or an 55 in the outer Vertical wall comprising enmeshing gears 26, 2l,` 28 and 30. Thel latter gear `3l) is located on and driven by the crankshaft I4, so that the magneto is operated from thel crankshaftl through `the described gear train. For a purpose hereinafter to appear,

` the gear-driveratio of the gear train is such that -1 the gear 26 and. hence the-magneto shaft,` will be rotated atiengine crankshaft speed, although not necessarily in the same direction as crankshaft rotation. p

Since the chamber ,2.4i of extension I9 is in full communication with ther main crankcasef chamber 3|, as appears `in Fig.` 2, the openingr receiving the magneto shaft coupling 23 therethrough, ist sealed about the mag-neto frameextension 32 at/the `opening in, any suitable manner,

- `as by a gasket indicatedI at-34.

The device of the present invention. isf located inI the crankcase extension i 9, as appears inFigs. Zta-nd 34,- and` employs the magneto drive gear `2li asian element thereon An aperture 35 is provided 36` of crankcase extension` I.9.,.. giving access to the extension chamber 24and'this opening is normally closed by a removable: closure plate or cover member 38 which is suitably sealed at the opening, by a gasket 39 or like means. Centrally of the closure plate and projecting horizontally and inwardly therefrom, is a gear support or spindle 40 which by preference, is formed integrally with the closure. The spindle is reduced as at 42 to provide a shoulder 43 and a gear journalling seat 44 over the inner longitudinal end portion of the spindle. Gear 26 rotatably receivedon spindle seat 44 and against shoulder 43, is formed to provide a cylindrical hub extension 46 having an end wall 41 transversely notched or recessed as at 48, for driving connection to the magneto shaft coupling 23 by means of coupling lugs 56 engaged in the gear hub recesses 48 (Fig. 2).

The spindle 4|) is interiorly recessed longitudii nally thereof, to provide a chamber 5| open at its outer end 52 and closed at its opposite or inner end 54 by a spindle end walll55, the chamber as shown by Figs. 2 and 3, preferably being of cylindrical form and tapered convergently toward the open end 52 thereof. Communication between 'the spindle chamber 5| and the chamber 24 in the crankcase extension i9, is eiected through an upper inlet port 56 through the spindle wall at the inner end 54 of the chamber 5|, and a diametrically opposite outlet port 58 of lesser capacity. The hub extension 46 of gear 26which overlies the spindle portion in which the ports 56 and 58 are located, is here utilized as a rotary v alve element for controlling port communication with the chamber 24 of the crankcase extension I9. To this end, the gear hub is provided with an aperture 59 preferably of a diameter equivalent to the diameter of the larger port 56 in the spindle, located for successive registry with theA ports 56 and 58 during rotation of the gear 26.

A discharge or outlet attachment generally indicated at 68, is suitably removably secured on the external face of the closure member 38 in registry with the open end 52 of the spindle chamber 5|, and includes a casing 62 and an upwardly directed discharge neck 63 open at its upper end 64. A protective cap or hood 66 overlying the open end of discharge neck 63 and projecting laterally on opposite sides thereof, as

'at 61 (Fig. 3), provides for downward air discharge through the openings 68. As indicated, the attachment casing 62 is sealed in its assembly connection to the closure 38 as by a suitable gasket element 10.

Opposed longitudinal channels 1| in the walls of the spindle chamber 5|, afford a support for a removable screen 12 preferably of coarse wire mesh which extends horizontally through the chamber 5| and the chamber 14 provided by the attachment casing 62. Bearing on the upper surface of the screen 12 within the chamber 5|, is an oil-absorbent member of felt pad which may have its longitudinal margins 16 compressed in the channels 1| as shown. The pad further may be attached directly to the screen by a suitable clasp or staple element 18, so that the screen and pad may b'e inserted or removed as a unit.

In the operation of the presently improved crankcase air control device, the gear 26 is set initially such that its hub valve aperture 59 is in full registry With the upper spindle port 56, when the engine piston is near the crank end of its stroke. Thereafter and during engine operation, the gear 26 rotated from the crankshaft at engine speed, will establish successively, a rela tively short-period opening of the crankcase chamber to the atmosphere through the chamber 24 of crankcase extension |9, gear valve aperture 59 in register with spindle` port 56, spindle chamber 5|, chamber 14 of attachment or shield toward the crank end of itsstroke, the control device then becomes effective to vent tc atmosphere some of the crankcase air, whereby to relieve the slight, above-atmospheric air pressure in the crankcase so as immediately to restore the crankcase air pressure to atmospheric or sub.

atmosphericv value. Since in the normal function of the engine, some oil will be entrapped in the air thus released, this oil must be removed in the compression-relieving process. To this end, the spindle chamber 5| through which the oil-laden crankcase air passes, serves in the presently preferred embodimentof the device, as an oil condensing chamber for removing some of the oil from the-air vented therethrough. The oil thus condensed in the chamber, collects on and is absorbed by the felt pad 15 on screen i12, and hence is prevented from passing to the exterior of the device. The felt pad 15 being centrally disposed in chamber 5| and hence directly in the pathof air flow therethrough, is of. itself an effectiveagency for direct absorption of oil particles entrapped in the air vented through the chamber. Thus by the condensing function of the chamber 5| and the oil absorbing actionof the Ypad 15 therein, a major portion of the oil in the Vented crankcase air, will be removed for ultimate return to the crankcase. vSuch small portion of oil as may remain in the air attaining the chamber 14 and'neck 63 of the attachment 6, will be condensed therein and will collect in the zones of chambers 14 and 5| below the screen 12.v Similarly, oil accumulated by the absorbent pad 15 ultimately will drip through the screen into the lower portion of chamber 5|. It is to be noted that the wire mesh screen 12 has an important function-in the present assembly, in that it effectively prevents the air vented to atmosphere through the chambers 5| and 14, from picking up any of the oil accumulating below the the cil accumulated in the chamber below the screen 12 and collecting in the Zone of the port 58 by reason of the tapered form of -chamber 5|, will be returned by suction through port 58 and gear aperture 59 into the chamber 24 of crankcase extension I9, and thence into the engine crankcase. In the normal and intended function of the device, atmospheric air will not be drawn into the crankcase `in this stage ofoperation, this by reason of the limited capacity of the port 58 and the relatively short period in which it is opened to the crankcase by valve portV 59, which thus enables the lubricant pool in chamber 5| and above the port 58, to act as an air seal even during the suction return of a portion thereof toy the crankcase. f l

`extend through wall The resulting suctionuetention of-l lubricating `iiuidfin the crankcase, together with the return j ltherein may phere, means including a cravatte mom. theforegumg description df operation, it

willi appear now that` the;control` deviceai'n: its i function to relieve crankcase compression in the compression cycleof engine piston operation, and to prevent suction return ofair' to the crankcase inA thecycle of pistonlsuctidn eit'ect in* the crank-e case, affords a fully effective means for controlling crankcase air pressures to the extent that itA prevents existence ci aboveatmospheric` prese sure therein, and facilitates maintenance `of subatmospheric or even? a 4slight negative pressure i or slightfvacuuminthe crankcase, during at least the greater portion of each gine piston operation. Asa consequence of the sub'atmospheric pressures or slight vacuum thus established in the-cranltcase, the crankcase lubrieating iiuidf is most effectively retained therein,

against `leakage or loss to the crankcase4 exterior, as through cylinder ports, crankcase joints, and past i such operating' partsfof the engine which portions of the crankcase.

thereto, of i'lui'd condensed and otherwise re1- moved `frornthe crankcase air vented toV atmos-` pher-e through the present novel control device, eiectivelyi conserves the crankcase' lubricating fluid to an important degree, as will be now fully appreciated. H

The present crankcase air-pressure control de vice fully attains the objects herein expressed and additionally, `presents a relatively compact mechanism having but few parts,` and wherein the operating valve elementthereof is embodied by preference, in the engine driven magneto drive gear of the engine assembly` illustrated.

- Although the device isshown herein as applied lined by the appended claims.`

We claim:

complete' c vcle of ene crankoase inl eachperiod of dei/clomid"suction` inthe crank;

M a; A'r control` dene-dorme character described for a substantially closed-Y crankcase, comprising a-memberextending within the engine cran'kcase andprovided'with a chamber therein open to the a-tmosphere;`said member having spaced ports `communicatingl with saidfchamlberj. `valve means in" control of said" ports and operable for successively opening the ports to the `crankcase `interior, `anclva-lveactuating means for operating' said valve meansv in timed relation to the cycleof developed pressure and suctionvin the crankcashe, the operation `of said valve means thereby serv` ing te openl oney of said ports in the periodsor` .piston developed pressure and the other portan the periods" of pistondeveloped suction in the 41 Awcrankcase air-pressure control device for internal Acombustion engines-,` comprising ameni-` lber extending within thev engine crankcase and i provided with a chamber therein open to the-atmosphere, said member havingspaced ports communicating Withjsaid`-ch`amber, an element rotata-ble on said mem-ber in a position: toj overlie said portsY and; having' an"openingjtherei1r lo'- cated-for registry with' said ports, said element l `during rotation serving throughsaid opening therein, to open said ports to the crankcase interior, and engine controlled means for operating said element in timed relation to the cyother port in the l. .A control device of the character `described forA a substantially closed erankcase, comprising means providing a` chamber openlto the atmosvalve. for establishing cle of developed 'pressure and suction in the crankcase. and means controlled by the valve,

for establishing in the suction period of said cycle, communication the crankcase. Y.

2. A control device of the character described between said chamber and for asubstantially` closed crankcase, comprising a member havinga chamber therein open to the atmosphere and provided with spacedports for communication with the crankcase interior, and;

valve means operatively supported bysaid member, adapted for opening said 7ports to theV crank# case interior in each cycle of` developed pressure and suction in the crankcase,` such that one of piston developed permit discharge lairthroughsaid chamber; and for opening the t of lubricant collected in said @lumber `by said f collector means in `cle of piston developed pressure and suction in the crankcase, the operation of saidfelement thereby, serving to open one of said ports in the periods of piston developed pressure and the i periods of piston developed suc tion inthe crankcase. l 5. A crankcase air-pressure contro-1 device for internal` combustion engines, comprising a member providing a lubricant condensing chamber for lubricant-laden air, said chamber fbeing open to atmosphere and having spaced `ports -for com- `munication with the crankcase interior, and engine controlled valverneans `in control or' said ports, adaptedfor opening one of said ports in the period of piston developed pressure in the` ,crankcasa to permit passage of lubricant-laden crankcase Lair through said condensing chamber, and for opening the other of said ports `period of crankcase suction, to effect suction return to the cra-nkcase of lubricant condensed in,"

said chamber. i

'6. A` crankcase air-pressure control device for internal combustion engines, comprising a memlber projecting within the engine crankcase and having a chamber phere, said member` being provided with spaced ports affording communication 'between the chamber and the said chamber, and anengine actuated rotary valve on said member, effective for opening one of said ports in the period of pressure in the crankcase, to o-f lubricant-laden crankcase other of said ports in the period of crankcase suction, to eiect suction return to thecrankcase collector means.

' said ports isthereby opened in each period of developed pressure` and the other port opened '7. A crankcase air-pressure control device for internal combustion engines, comprising a member extending into the engine crankcase and providing a chamber' therein open to the crankcase exterior, said chamber having spaced ports for communication with the crankcas'e interior, a

in the therein "open to the atmoscrankcase interior, lubricant ohambered outlet attachment in registry with the open end of said chamber, an engine controlled valve on said member, adapted for open-f ing one of said ports to the crankcase interior in the period of piston developed pressure in the crankcase, for `permitting discharge of lubricantladen crankcase air through said chamber and said chambered outlet attachment, and means including the ohambered outlet attachment, effective for condensing and collecting lubricant from the crankcase air discharged through said chamber and attachment, said valve being effective inthe period of crankcase suction, to open the other of said ports for the suction return to the crankcase of lubricant collected by said means. v Y

v8. The combination with an internal combustion engine providing an engine driven gear in the crankcase for operating a device adjunctive to the engine organization, of a crankcase airpressure control device comprising a member eX- tending within the crankcase and providing a bearing support l-for said gear, said memberhaving a chamber therein open to the atmosphere and spaced ports for communication with the r crankcase interior, said gear -being adapted as a control valve for said ports, operable for opening 1 one 'of saidports to the crankcase interior in each periodV of pistony developed pressure in the crankcase, and for opening another of the ports thereto in each period of piston developed suction in the crankcase.

9. The combination with an internal combustion engine providing an engine driven gear in the crankcase having a hub extension for driving `connection with a device adjunctive to the engine organization, of a crankcase air-pressure control device comprising a member extending Within the crankcase and providing a bearing support for said gear and hub extension, said member providing a chamber thereinopento the atmosphere