US2607329A - Two-cycle crankcase compression engine - Google Patents

Description

1952 L. A. SUHADOLNIK ET AL 2,607,329

I TWO-CYCLE CRANKCASE COMPRESSION ENGINE Filed Dec. 15, 1949 s Sheets-Sheet 1 5 IN VEN TORS AAWPWOF AszmooLu/k & HA??? 6. SANGEE g- 19, 1952 L. A. SUHADOLNI K ET AL 0 TWO-CYCLE CRANKCASE COMPRESSION ENGINE Filgd Dec. 15, 1949 :5 Sheets-Sheet 2 19, 1952 L. A. SUHADOLNlK ET AL 2,607,329

TWO-CYCLE CRANKCASE COMPRESSION ENGINE Filed Dec. 13, 1949 3 Sheets-Sheet 5 INVENTORS A Awemce A. Sub A06! IV/k & H wey a. JA NGEE fly A TOE/v06 Patented Aug. 19, 1952 TWO-CYCLE CRANKCASE COMPRESSION ENGINE Lawrence A. Suhadolnik. Shaker. Heights, and

I Harry G. Sanger, Euclid, hio

Application December 13, 1949, Serial No. 132,755

This invention relates broadly to internal combustions and more specifically to improvements in the organization and structure of the valves, the operating mechanism therefor, and the construction of the crankshaft.

One of the objects of the invention resides in the provision of a pair of fuel inlet valves arranged for operation by a single cam.

Another object of the invention is to provide a composite crank and cam shaft and'improved journal bearings therefor.

Another object of the invention is to provide a crankcase having a limited volumetric capacity and a carburetor inlet valve to meter the fuel charge.

Another object of the invention is to provide a crankshaft structure embodying, a pair of aligned subassemblies which are designed for removal from either side of the engine.

Further objects of the invention reside in the provision of a relativelysmall engine which-is light in weight, eflicient of operation, and constructed to facilitate simple machining operationsand ready assembly.

Other objects and advantages, more or less ancillary to the foregoing, and the manner in which all the various objects are realized,will appear in the following description, which, considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

In the drawings:

Fig. 1 is a vertical sectional view of the improved engine;

Fig. 2 is a vertical section of the engine taken on a plane indicated by the lines 22 in Fig. .1;

Fig. 3 is a vertical section of the engine taken on a plane indicated by the line 32-3 in Fig.1 with the piston shown in its elevated position;

and

Figs. 4 to 8 are diagrammatic views illustrating the operative cycle of the engine.

Referring first to Fig. 1, the engine comprises a combined cylinder block and crankcase I!) having a boss in-the base thereof constituting a carburetor companion flange for the reception of a valve cage H, a cylinder I2 having a'piston' l3 and inlet valve hi therein, and a cylinder head l5 embodying the combustion chamber l6 and spark plug H. The crankcase is bored for the reception of bearing blocks IB'and 19, which in turn are bored for the support of the crankshaft bearings 20, and crankcase packing glands -2| The bearing blocks areformedwith flanged end portions 22 drilled for the reception of cap 11 Claims. (01. 123-73) screws 23 mounted on faced areas 24 in. the op.- posed sides of the crankcase; 1

The crankshaft embodies two separable sections 25 and 26 disposed in coaxial ali nment with each other and interconnected through the telescopic engagement of a pintle 21 on the crank arm 28-with a borein theend of a boss 29 in the crank armgw. The boss forms the journal bear.-

ing for the connecting rod 3| and the bore therein'is slightly larger than the pintle and provided with a snap ring F constituting a fulcrum to permit oscillation of the crank section 26in the event of misalignment of the crankshaft journal bearings. Thevcrank arms areof annular form,. disposed in close: proximity with the end Walls of the bearing blocks l8 and I9 and'the central body of the connecting rod 3i. The'opposed faces of :the crank arms are formed with recesses-therein to accommodate the hub of the journal bearing ,theconnecting rod; Theqcrank section '25 isiprovidedwitha cam 32 formed integral therewith and disposed betweena crankcase fuelvalve 33 and the cylinder valve M in a plane common to the axes thereof. 5

The cam, as will be seen in Fig. 2; is engaged with shoes 35 guided in: radial openings machined in the bearing block I8 intermediate. the bearings 20. The block i8 is furthermachined with an annular groove 36 in the circumferential wall thereof, the flange 31 defined by the groove being provided with a plurality of openings forming transverse passageways .38 for the admissionof the fuel mixture from the valve 33 to the crankcase.

The valve cage l l includes a plate 39 boredlfor the reception of a spider 4B for guiding the stem of the valve 33 and chamfered toform a seat for the head thereof. The cage further includes an elbow M- flangedfor-engagementwith the plate39 and cored to receivethe-valvezhead and a spring 42 for urging thevalve against its seat and for maintaining the shoe 35 in contact with the cam. The'elbow is provided with a post 43 disposed in axial alignment with the stem of the valve and formed with a boss thereon for the support of the spring 42. The outer end of the elbow is provided in the customary mannerwith a flange for the support of the carburetor 44. The valve 33 is disposed approximately 45 from the medial axisof'the valve M, which, as illustrated in Fig. 1, is parallel to theaxis of the cylinder 13. and normal to the axis of the crankshaft section 25. The head of the valve 14 is seated in a sleeve 46 mounted in a counterbore in a chamber 41 communicating with the groove the cylinder head in super-tangential relation with the valve in a plane common to the axes of the valve and cylinder. 7

The connecting rod 3| is mounted on needle bearings 53 on the boss 29, the upperend there- 7 of being connected in a similarmarmefto-arwfist 5-and-the-depressionin the crankcase will effect the pin 54 in the piston 55. The cylinderis prferably provided with a lever:56,-;='which,';tggether with the cylinder block, is cross-drilled in the central portion thereof to provide exhaust-ports 51 tangential the upperface of the piston when -disposed-in"itsr lowersdeaidzcenten:position.

The outer end of theecrankshaft' 25 is=zprovided with ea fiywheel 2'58 :zkeyed izthereon and :locked agains ateral movementibyzarnut 59. iArpacking 'gland-E 2 l isdisposedzbetweemthe inner face:of.-;the

flywheelrand thelendzwall.oiithexcrankshaftirbear- 'ingLblock-am. iThesouter: endaaofiatheashaft' 2521s diametrically freducediforcthezsupportrofrasmag- -netoii60 .;of conventionalr-form- :which isr mounted on a qnlateiifi l' piloted ioniaiishouldervinithez bearing: block M 9 :and i-retaine'd :tthereon :byra :snap ring fiz.

'zfIhe: .crankshaftebearineszznzcompriser ningsztfit having annular zgroovesit B4: thereinzadjacent :Lthe outer: ends thereof. I-hecbore, in the'ring iSZIJXEO- wided-mith rollers fi5 tormed'iwith diametrically reduced eridportionstiifizwhichzaare engaged-smith 2a; split-ring 6 hot right:-angular:transversezsection. In assembly, the: inner i flanges of :the ':-'rings sa-re seatedi-in thergroovesxM-iand' the outeri'flanges 414 descent 0f the piston, the ffuel r charge :in :ithe

crankcase will be compressed and'-f'fiow:,through the'passageways' 38-':and into theichamber 47!. iBefore' the -piston reaches'bottomideadcenteniabout of the descent 'thereo'f) the cam will open" the walve I 4 fEigf 5) iarrdzthe" fuelccharge willaenter sthe :combustion chamber it. :When Etherpiston rreachessbottomrdead; center iFigzfG) 'the cam -will ibe int-'itsLposition-ofzmaxinmm lift; but continued movementi thereofrwi'll effect::the.:closure:ofzthe valve as ,the: crankshaftr pass esaa: point; 31b0l1t545 7 0 fbeyondcbottom; deadscenter during. theselevation oftzthe piston .(Eig: :7 r C'ontinuedymovement'of vthe :piston wi-ll.compresslthe'fuel. chargeentrapped :within:theccombustionxchamber:runtil: the :crank armrreachessawpointapproximately 15: forward 7 5 4 top dead center whereupon the ignition system will fire the compressed fuel charge and cause the expansion thereof. As the crank pin passes top dead center, the expanded gases will effect the descent of the piston until it reaches its lowermost position and liberates the burned products of combustion through the exhaust ports 51.

Before vrtheer'ii'ston reaches bottom idead center, the-"ca-mwill "open the valve ['4 Fig."-5)-*and permit a portion of the compressed fuel charge in *the crankcase and chamber 47 to flow into the zcyli-r-ider-v-andrthusscavage the contents thereof.

: During the last quadrant of the ascent of the piston (Fig. 8) the cam will actuate the valve 33 "admission-of the fuel mixture from the carburetor :inlzmthemrankcase. Continued rotation of the crank and cam will close the valve 33 coincident "the' passage of the crank arm beyond top dead center (Fig. 4).

Althoug-h :the foregoing :description is .:necessarily ofwa idetailedrcharacter yin-order .thatarthe invention:zmaycbezcompletely,set% forth,-.-it is to ,be understood 'zthatzithe, specific gtermi-no'logy is not intended to be restrictive:or-rconfining, and: that various :rearrangements :of gparts and modifications'of detail mayzberesortedtmwithoutdeparting from thesscope :orr. spirit- 0f? the invention as ':herein-'claimed.

'Weiclaim:

1. An internal combustion-aengine-:comprisingsa crankcase, a. cylinder block thereon hav-ingra iuel 'chambertthereingagcylinder head- -on .said .;block having-a 'cumbustion: chamber therein,-.;an intake poppet valve in said fuel chamber adjacentesazid combustion chambena carburetorron saidscrankcase,- a,;carburetorspoppetsualvein saidzcrankcase subjacent saidfuel: chambeniima: plane; common to that of saidfintakeiya'lvesazcrankshaftimsaid crankcasesa connectingzrodthereom a; piston in sai'd:cyl-irrderzblockwoupledwith saideconnecting rod aicam: on= said: crankshafta disposed between and-rotatable :.:abouti the epoint :of intersection-mi the axes of said intakezandzcarburetor'valves, springs urging saidx valves into. operative engage 'mentlwith said cam, .saidwcrankcase ,havinggpas- :sageways atherein communicating with the scarburetonvfivexoperiing:the:crankcase and thefuel :chamber.

- 2.. *An internal :combustion a-engine comprisi-ng a crankcase, a cylinder block thereon::having=;a fuel chamber therein, a cylinderI-hea'deon said 'blockshaving Fa: combustion :chamber thereingan intake poppet valve in said fuelcchamberradjacenirsaidnombustionchambena-careburetor'on saidecrankcasemarcarburetor poppet valve insaid crankcase sub-iacentgsaid; fuel ;chamber; a: crank- .shaftiimsaid crankcase; a connecting rod thereon, a :piston irrasaid; cylinder bIGCkTiCOllPlBd with: said connecting rod, a cam on said crankshaft Idis- :posed-zbetween;andcoperativelmengaged withasaid intake and carburetorwvalvesaiand 1a crankshaft .-bearingclrrlock: in:saidrzcrankcase*having' passageways :therein 3 connecting sthe tcarburetor :valve qopeningnwithathe crankcase: and fuel chamber.

. 3.;An-.-internal combustion "engine comprising a crankcase: a cylinder :block thereon having .a fuelchamber .therein, wa cylinder head: on said :block havi-nsa combustion chamber therein, an -intake poppet =va1ve ins-said tfuel cchamber rad- ;iacent. :said combustionchamber, a carburetor on saidrcrankcase-a carburetor; poppet valve. in said :crankcase subjacent -.said 7 fuel chamber, .a :c-ranksha-ftin. ;said crankcase, a connecting; rod .thereon, :a; piston insaid--.'cylinder-. block: coupled with said connecting rod, acam on 'said'crankshaft disposed with the peak thereof in axial alignment with the connecting rod bearing and remote therefrom, said cam being disposed between and operatively engaged with said intake fuel chamber therein, a cylinder head on said block having a combustion chamber therein, an

intake poppet valve in-said fuel chamber adjacent said combustion chamber, a carburetor on said crankcase, a carburetor poppet valve in said crankcase subjacent said fuel chamber, a crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder block coupled with said connecting rod, a crankshaft bearing block in said crankcase valve, lifter shoes mounted for sliding movement in said block and disposed in a common plane transverse the axes of the crankshaft, a cam on said crankshaft engaged with said shoes, said bearing block having recesses therein connecting the carburetor valve opening with said crankcase and said fuel chamber.

5. An internal combustion engine comprising a crankcase, a cylinder block thereon having a.

fuel chamber therein, a cylinder head on said block having a combustion chamber therein, an intake poppet valve in said fuel chamber adjacent said combustion chamber, a carburetor on said crankcase, a carburetor poppet valve in said crankcase subjacent said fuel chamber, a crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder block coupled with said connecting rod, a crankshaft bearing block in said crankcase having a circumferential groove therein aligned with said fuel chamber, a transverse opening leading from the groove to the chamber defined by the crankcase, valve lifter shoes in said block below said groove engaged with said inlet and carburetor valves, a cam on said crankshaft engaged with said shoes, and springs urging said shoes into engagement with said cam.

6. An internal combustion engine comprising a crankcase, a cylinder block thereon having a fuel chamber therein, a cylinder head on said block having a combustion chamber therein, an intake poppet valve in said fuel chamber adjacent said combustion chamber, a carburetor on said crankcase, a carburetor'poppet valve in said crankcase subjacent said fuel chamber, a crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder block coupled with said connecting rod, a crankshaft bearing block in said crankcase having recesses therein connecting with the carburetor valve opening, the interior of the crankcase, and the fuel chamber, a crankshaft section in said bearing block, a cam on the crankshaft intermediate said intake and carburetor poppet valves and operatively engaged therein, a second crankshaft bearing block in said crankcase in axial alignment with the first-named bearing block, a second crankshaft section journaled thereon, shoulders on said crankshaft sections restraining axial movement thereof, a flange on the outer end of each of said bearing blocksdemountably connected to the outer walls of said crankcase, whereby said bear- 6 ing blocks and the crank sections thereon may be removed as units from the opposed sides of the crankcase. j

"7. An internal combustion engine comprising a c'r'ank case, a cylinder block thereon having a 'fuel'cha'mber therein,'a cylinder head on said block having a combustion chamber therein, an intake poppet valve in said fuelchamber adjacent said combustion chamber, a carburetor on said crankcase, a carburetor poppet valve in said crankcase subjacent said fuel chambena crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder blockjc'oupled with'said connecting "rod, a crankshaft bearing block in said crankcase having re'cessesftl'ierein connecting with the carburetor valve opening, the interior of'the crankcase, and the fuelchamber, a

crankshaft section in-said bearing block, a cam on the'crankshaft intermediate said intake and carburetor poppet valves and operatively engaged therein, a second crankshaft bearing block. in said crankcase in axial alignment with the firstnamed bearing block, a second crankshaft section the other crankshaft section slidably engaged.

with the opening in said boss, and detachable means on said bearing blocks for the retention thereof.

8. An internal combustion engine comprising a crankcase, a cylinder block theeron having a fuel chamber therein, a cylinder head on said block having a combustion chamber therein, an intake poppet valve in said fuel chamber adjacent said combustion chamber, a carburetor on said crankcase, a carburetor poppet valve in said crankcase subjacent said fuel chamber, a crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder block coupled with said connecting rod, a crankshaft bearing block in said crankcase having recesses therein connecting with the carburetor valve opening, the interior of the crankcase, and thefuel chamber, a crankshaft section in said bearing block, a cam on the crankshaft intermediate said intake and carburetor poppetvalves and operatively engaged therein, a second crankshaft bearing block in said crankcase in axial alignment with the first-named bearing block, a second crankshaft section journaled thereon, shoulders on said crankshaft sections restraining axial movement thereof, and antifriction bearings in said bearing blocks comprising cylindrical races having internal grooves adjacent the outer ends thereof, rollers in said races, pins protruding from the opposed ends of said rollers, and snap rings of right angle cross section engaged in said grooves and with said pins.

9. An internal combustion engine comprising a crankcase having a carburetor passageway therein, a cylinder block thereon having a fuel passageway therein communicating with the first-named passageway, a cylinder head on said block having a combustion chamber therein, a crankshaft in said crankcase, a connecting rod thereon, a piston in said cylinder block coupled with said connecting rod, a single lift cam on said crankshaft, a poppet valve in the cylinder block passageway disposed in radial alignment with the axesof said cam and operatively engaged with the face thereof, and a poppet valve in the crankcase disposed in radial alignment with the axes of

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