US1678644A - Cooling system for internal-combustion engines - Google Patents

Description

July 3l, 1928. 1,678,644

H. c. MALLQRY COOLING sYsTEN FOR INTERNAL coNBusTroN ENGINES Filed April 15, 1919 2 sheets-sheet 1 July 31, 1928.

H. C. MALLORY COOLING SIYSTEM FOR INTERNAL COMBUSTION ENGINES 2 sheets-Sheet 2 Filed April 15 1919 Patented' July 31, 192s.

-JUN1TED STATES PATENT or-'rlcr.. i

HARRY C. IALLOBY, F LONG ISLA-.ND CITY, NEW YORK; SUE B, i yISLBA/'LRIX 0F SAID BARRY C. MALLOBL DECEAS mma: Anm'- cooLING Systran non 'm'rnnnan-connus'rion ENGINEs. A

i. Application mcd 41114115, 1819. Serial No. 290,957.

`vThe general object of the present invention is to provide animproved cooling system for an internal combustion engine.4 More specifically my invention relates to\a. circulato cooling system in which the cooling fluid 1s' vaporized in the engine cooling space and is condensed elsewhere inthe s stem, the resultant liquid of condensation ing returned to the cooling engine space,

and has for its objects the provision of effective means for maintaining a proper liquid level in the engine cooling system and for preventing an improper reverse flow of the cooling liquid, and for holding in the system a variable amount of cooling liquid in excess; of that required for circulation to take care of leakage and vaporization losses. My invention is especially adapted for use in, and in some vof its aspects is to be regarded as comprising improvements on the type of circulatory cooling system disclosed and claimed vin m prior application* Serial No. 163.332, filed pril 20, 1917 in which air -is supplied to and withdrawn from the system as required' to maintain a constant pressure less than atmospheric in the system under varying. conditions of service. All these objects and otherswill become apparent on consideration of several specific embodiments4 of the invention shown in thel accompanying drawings and described in this specification. It will be understood that modifications may be made within the scope of the invention. v

Fig. 1 is an elevation partly in section illustrating one embodiment of my invention.

Fig. 2 is a similar view of a different embodiment.

Referring particularly to the form of the invention shown in Fig. 1, the engine frame 1 has its cylinders 2 surrounded by a casing enclosing the liquid jacket space 3 with the free liquid level surface 4 and the vapor space 5 above the same. The shell o1'- tube 14 and the enclosed space with which it connects at its-upper end thus forms a chamber which is in communication through the conduit 15 with the' engine cooling space 3 at a level substantially below the vapor space 5, and Which is provided with an overflow outlet connected by the annular space 16 and conduit. 18 to the inlet side of the-pump and serving to ix the height of Water level in the coolin l space 3. From this vapor space 5 a conduit 6 leads to the upper header 7 of a radlator, or. condenser 8, whose lower vheader is 9. Thence a return conduit .leads to the rotary pump 11 which has the delivery pipe 12.

The vertical cylindrical shell v17 encloses the annular space 16 from which an overdow conduit 18 leads to ,the intake side of the pump 11.'` The coaxial inner tube or shell 14 is open at the top and encloses an annular space' connected at its bottom end by the `pipe 15 with the liquid jacket space 3. An-

other co-axial inner pipe 13 is open at the top a little below the up er end of the pi e 14 and is connected at t e bottom with t e pump delivery pipe 12.

Standing on top of the tank shell 17 is a casing 20 having a transverse lower wall 37 on which stands a thermostatic element 22. This element 22 consists of a circumferentially corrugated thin walled expansible and collapsible member containing a small quantity of a liquid having a boiling point such that the vapor tension within the shell 22 will expand the shell for temperatures above a certain critical temperature, but leave it in -collapsedcondition forlower temperatures.

The space 21 within the casing 20 around the thermostatic element 22 is connected to space 16 within the tank 17 by the annular series of holes' 34 through the floor 37. Avapor conduit 19 connects the space 21 with the lower header 9. At the top of the casing 20 is a port 23 from-which a suction pipe 25 extends to the suction manifold 26. The port 23 may be closed on its upper side by the ball check valve 24 and on its lower side by .the valve member 38 carried by the thermostatic element 22.

27 and 30 are filling caps. 28 is a safety valve set to permit the escape of vapor for pressures' slightly above normal atmospheric pressure. 29 is a vacuum relief valve to permit the inflow of air for pressures within the system slightly below normal atmospheric pressure. I l

The fan 31 for cooling the condenserl 8 is driven by the belt 32 and gearing within the casing 33, and said gearing also drives the pump 11.

The flexible tubular joints 35 and 36 of circumferentially corrugated thin metal in the respective conduits 6 and 10 serve to absorb vibrations and yield to differential stresses between the engine and the condenser.

Assuming that-the system is in normal operating condition, its further continued operation will now be described. When the engine is running, the water (or other liquid) 3 will be at its boiling, temperature and the vapor will fill the space 5, pass along the conduit 6 to the radiator 8 and there be condensed accumulating in liquid form 1n the lower header 9. The pump 11 will draw the liquid from the tank 9 and deliver 1t over the upper end of the pipe 13, thence part of the liquid will descend and pass through the conduit 15 to the engine jacket space 3 to make up the loss therefrom by vaporization. The excess of the water delivered over the top of the pipe 13 will pass over the top of the pipe 14 and return to the intake side of the pump through the pi e 18.

gl'hus it will be seen that an approxlmately constant liquid level 4 will be maintained 1n the engine jacket space 3. If this level 4 gets lower than normal', ractically all of the water delivered by t e pump will be returned through the conduit 15; if it gets higher than normal practically all the water delivered by the pump will be by-passed through the condmt 18. Thus the normal level 4 -will be maintained. This operation as just described will not be variedteven if the quantity of liquid in the reservoir space formed by the lower condenser header or tank 9 is varied. Therefore it will be seen that a convenient excess of liquid may be maintained in the tank 9 and that the water level in the engine jacket s ace will be automatically self-adjusting w etherthe excessl of water in the system is great or small.

The overflow device is placed forward of the center of the engine in order that when goingup grade the water line in the engine jacket will be automatically adjusted during this period enough to prevent uncovering the forward cylinders. The dotted line 39 represents the new Water level when going up a hill of certain grade. The proper position for the overflow device will be determined to suit the various types of engines.

The pipe 25 connected to the suction intake manifold 26 of the engine is under a suction tendin to draw vapor throughthe port 23 from t e s ace'21. If the space 21 is filled with liqui vapor, its heat will be sufiicient to expand the thermostatic element 22 and cause the valve 38 to close the port 23. The heat of the vapor in the space 21 will be radiated from the casing 20 and such vapor will condense andthe condensate will ow down through thel openings 34 into the tank 17 permitting additional vapor to enter the Space 21 along the conduit 19. Thus the temperature in the space 21 will not drop below the vapor temperature in the system andthethermostat 22 will kee the port 23 closed by the valve 38./shoul there be any air in the system it will eventually iind its way along the conduit 19 to the space- 21 and cool by radiation from the casing 2O to the point Where its temperature will cause the collapse of the thermostatic element 22,

lthus opening the valve 38 from the port 23.

reason the pressure inside of the system should become excesslve, as for example, if

the fan belt should break, the safety valve 28 will affordv relief. The check valve 24 prevents drawing air and fuel mixture into the s stem in case the pressure therein shoul fall to 'a point below the suction in the engine intake manifold. y

The ports 34 give assurance that the vapor pressure at the top of the tank 17 shall be substantially the same as at 5 in the engine jacket space, there being a free connection traced as follows: 34--21- 19--8-6. Thus there will be no possible Siphon action by which the overiow 18 could drain the liquid from the s ace 3 to a substantially lower level than t at indicated at 4. j

The pump 11 may be a rotary pump or a centrifugal pump without-valves so that when it stops, the liquid in the pipes 13 and 12 will drain back therethrough to the header-tank 9. But it will be seen that stoppage of the pump 11 can not drain the llquid jacket space 3, because of the vapor pressure balance at the Ytop of the pipe 13 as already pointed out.

Inasmuch as there is no body of liquid within the condenser 8, except for a comparatively small quantity `in the lower header 9, it will be seen that the total quantity of. liquid in the system is less than for an all liquid circulatory cooling system. Accordingly, the response on starting the englne usually will be more prompt, because there is a comparatively small body of water to be -heated.

When the engine is cool after standing for a time, the element 22 will be collapsed and the valve 38 open. The moment the en- .g1ne'starts,`a suction begins to be exerted through the pipe 25, so that the whole sys? llo '1.67am l as it takes to heat the small body of water 3, the whole system is brought up to normal operating kcondition with all the air rethe total amount of heat generated varies moved, andthere-is no delay in establishing this normal condition due to any diiiiculty in removing the air. j

In the operation of internal combustlon engines, as used in automobiles and airplanes, the heat generated in the combustion chambers is applied approximately as.

widely 'according to whether the engine is lightly loaded or` heavily loaded, and whether it 1s driven' slow or fast. Another feature that will aiect the temperature of theliquid materially is whether the weather 1s warm or` cold. 4

With an al1-liquid cooling system, it follows that under some conditions the cooling temperature will be much higher than under others, and that a practical conditions. evertheless, a constant temperature is desirable and -it should be a fairly -high temperature, aroundl the temperature of boiling water. It will be seen that my 'system gives this desired temperature and keeps it approximately constant, whether the Weather be hot or cold and whether the engine be running fast or slow, heavily loaded or lightly. In all cases the temperature in the engine jacket space 3 is approximately the boiling temperature of the liquid employed. The 25% of the heat of combustion that must be taken away by the cooling system is taken in the form of latent heat of vaporization and is dissipated through the condenser 8.

An important feature of the success of my system is the provision of simple and eiliclent means promptly to remove air and start the condenser to function ufpo'n starting the engine. Another -feature o my system that contributes in an important degree to its success is the pressure balanced water sealed over-flow by which the liquid level is maintained practically constant in the engine jacket space.

In so far as air enters the system and escapes through the port 23 and pipe 25, it will be saturated air and its introduction into the engine cylinders will have a beneficial-eiect to prevent the formation of carbon therein. A The system being almost entirely closed to the external air there will be very -little loss of liquid so that it will need replenishing only at long intervals. This feature of adantage is promoted by providing a tank g in which a reserve excess of supply may `Hood and radiator covers are y constant operating temperatureis impossible for all be carried. If a non-freezing fluid is used as` in. cold weather, it will not be quickl lost by liquid cooling systems.

One important advantage of the liquidvapor' system as contrasted with the allliquid system, is that the practically constant working temperature in the former case greatly improves lubrication, `ving a conlstant temperature for which t oil best suited may be chosen. The constant temperature also improves Carburation. 4Another advantage that may -be mentioned is that a much smaller pump may be employed than for an all-liquid' system, because the volume of water passed is far less on account of the latent heat of vaporization being hi h compared to the heat necessary to raise t e temperature of water in its liquid form.

cold Weather, because the liquid in the space 3 will be at boiling temperature in any weather and( the condenser 8 can only condense thevapor that is delivered to it. Vapor radiators may be placed in they automo ile for Vheating purposes and supplied with vapor by branch conduits from the main conduit 6.

The modification shown in Fig. 2 differs principally from that of Fig. 1 in the following respects. The pump delivery pipe 12 goes directly to the lower part of the enboiling out asis common in the a1 e quality of l unnecessary in,

gine jacket space 3 instead of through the pressure balanced liquid sealed over-flow. Accordingly, when the pumpl 11 is shut down the `jacket 3 drains back through the pump 11. An auxiliary tank 9a is provided` which augments the reservoir space formed by the header 9. The tank 9a has a capacity suiicient to receive all the water in the jacket space 3. One of the advantages of this arrangement is that in case of freezing weather, there can be no danger of freezing the water in the engine jacket space. The tank l9a can be easily protected and even if it should be burst by freezing, the damage would be comparatively slight.

In Fig. 2 there is a pressure balanced liquid seaied' by-pass overflow essentially thc same as in Fig. l formed by connecting thc tube or shell 140 at its upper end directly into the casing 20, and by connecting the interior` of the tube 140 to the cooling space 3 by a conduit 15 as in Fig. 1, and by an overflow conduit 130 having its upper p0rtion axially disposed in but not iilling the shell 140. The lower end of the conduit 130 is connected to the tank 9a. The upper end of the pipe 13() fixes the height of water level in the engine cooling space as does the upper end of the shell 14 in the construction shown in Fig. 1.

1. A circulating system for cooling an internal combustion engine, comprising a llo liquid containing cooling rece tacle having a free vapor space above the liquid therein, a condensing space receiving vapor from said vapor space, `a reservoir space into which liquid of condensation passes by gravity from said condensing space, a/pu/mp passing liquid from saidVreservoir/space to said receptacle and a by-pass overflow connection about said pump for returning vto the inlet side of the pump liquid passing' from said reservoir space to said receptacle and having its outlet connected to the receptacle by a conduit opening to the receptacle at a level appreciably below said vapor space and having an intermediate portion substantiall)Tv above said level and a vapor pressure equalizing 'connection between said intermediate portion of said/conduit and said vapor space.

3. A closed circulating system for cooling an internal combustion engine com-.

prising a liquid containing cooling receptacle having a free vapor space above the liquid therein, a condensing space receiving vapor from said vapor space, a reservoir space located below said vapor space and receiving liquid of condensation from said condensing space and a pump for passing liquid from said reservoir space to said receptacle, and means regulating the height of water level in said receptacle comprising a chamber connected to said receptacle at a level appreciably below the desired water level and having an overflow outlet at the desired level, and provisions for passing water from said outlet back into the circulating system at the inlet side of said pump and for equalizing the vapor -pressures in said chamber and vapor space.

4. A closed circulating system for cooling an internal combustion engine comp-rising a liquid containing cooling receptacle having a free vapor space above the liquid therein, a condensing space receiving vapor from said vapor space, a reservoir space located below said vapor space and receiving liquid of condensation from said condensing space, and a pump for passing liquid from said reservoir space to said receptacle, and means for maintaining a desired water level in said receptacle, comprising a chamber connected to said receptacle at a level appreciably below said desired level and having an overflow outlet at said desired level which is connected into said system at the inlet side of 'said pump, and a vapor pressure equalizing connect1on` between'said chamber and vapor space.

5. A closed .circulating system for cooling an internal combustion engine comprising a liquid containing cooling receptacle having a a chamber having an overow outlet connected to the inlet side of said pump and xing the liquid level in said receptacle and an outlet from said chamber opening to said receptacle at a lower level and means for equalizing the vapor pressures in said chamber and vapor space.

6. In combination, an internal combustion engine having a cooling receptacle for a contained liquid and a space for vapor thereabove, a condenser, means to circulate fluid in the form of vapor from the chamber to the condenser and in the form of liquid from the condenser back to the chamber, and a liquid sealed overflow from said chamber to another part of said system to keep a substantially constant liquid level in said cham-v ber for a varying quantity of liquid in the system. Y

7 In combination, an internal combustion engine having a cooling receptacle for a contained liquid and a space for vapor thereabove, a condenser, means to circulate fluid in the form of vapor `from the chamber to the condenser and in the form of liquid from the condenser back to the chamber, and a liquid sealed pressure balanced overflow from said chamber to another part of said system to keep a substantially constant liquid level in said chamber for a varying quantity of liquid in the system.

8. In combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of said chamber to the upper part of said condenser, a return conduit for liquid from the lower part of said condenser to said chamber, a pump in said return conduit, a conduit from said chamber to the inflow side of the pump with an intermediate portion at the height ofthe desired liquid level in the chamber, and a thoroughfare from said portion to the chamber above said desired liquid level therein.

9. In combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of iso said chamber to the upper part of said condenser, a return conduit for liquid from the lower part of said condenser to said chamber, a pump in said return conduit, a liquid sealed conduit from said chamber to the inllow side of the pump and a pressure balancing connection to said conduit toy prevent breaking the seal therein.

10. In combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of said chamber to the -upper part of said condenser, a pump and conduits connected therewith for returning liquid from the lower part of said condenser to said chamber, and an over-How by ass conduit from the said chamber aroun the pump, said bypassconduit comprising a portion at the desired liquid level in said chamber with a pressure balancing connection at said portion.

11. In combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of said chamber to the upper part of said condenser, a return conduit for liquid from the lower part of said. condenser to said chamber, a pump in saidjreturn conduit, a liquid sealed overflow b ass conduit from said chamber to the in ow side of the pump, a branch conduit for vapor from above the liquid seal to the lower part of the condenser, means to create a suction above said liquid seal and a thermostatic valve controllin said last mentioned means.

12. combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of said chamber to the u per part of said condenser, a return condhit for liquid from the lower part of said condenser to said chamber, a pump in said return conduit, and a liquid sealed overflow bypass from the chamber around the pump located forwardly of the engine center so as to maintain a proper liquid level in the chamber for hill climbing.

13. In combination, an internal combustion engine having a chamber for liquid and vapor associated therewith, a condenser, a conduit for vapor from the upper part of said chamber to the upper part of said condenser, a return conduit for liquid from i the lowerpart of said condenser to said chamber, a ump in said-return conduit, a liquid seal overow bypass conduit from said chamber around the pump, means to create suction, and a branch conduitfrom the lower partof said condenser to said last mentioned means, said liquid seal having a connection withsaid branch conduit.

14. The combination with an engine cooling jacket of a liquid containing space connected to said jacket in a liquid circulating system of relatively small heat radiating capacity comprising a pump for passing liquid from said space into said jacket and a conduit for returning liquid from the jacket to said space, and a condensing space connected to said system to receive vapor therefrom and to return liquid of condensation by gravity to said liquid containing space.

15. In a cooling system for internal combustion engines, a jacket, a radiator normally acting as a condenser connected to the jacket, a reservoir connected to the radiator and placed at a lower level than the radiator so the radiator will empty automatically into the reservoir when the engine sto s, and means for lifting the cooling iuid'from the reservoir when the engine is running.

. 16. In a cooling system for internal combustion engines, a circuit comprising a jacket, a radiator normally acting as a condenser, a reservoir for cooling liquid at a low point in the system, a pump having a suction drawing cooling iiuid from the radi-A ator and from the reservoir and delivering it in the direction of the jacket.

17. In a cooling system for internal combustion engines a circuit for cooling fluid comprising a jacket, a radiator normally acting as a condenser, means for maintaining an excess supply of cooling liquid which said means serves to drain the radiator, causing the condenser action of the latter when the engine is running, and serving to eilipty it of liquid when the engine is 1 e.

18. In an internal combustion engine cooling system of the boiling and condensing type, the combination with the cooling jacket, of a radiator normally acting as a condenser, an excess water holding reservoir into which said radiator drains, a connection for passing fluid from the jacket into the radiator, and means for passing liquid from the reservoir into the `acket.

19. The combination wit the cooling jacket and condensing space of an engine cooling system of the vapor generating and condensing type, of a water containing space of small heat dissipating capacity into which liquid of condensation passes by gravity from the condenser, means for passin said cooling jacket at a rate excee ing that at which vapor is generated in said system, and a conduit of small heat dissipating capacity for returning water from the jacket to said water containing space.

water from said containing s ace into

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