US1616941A

US1616941A - Internal-combustion engine

Info

Publication number: US1616941A
Application number: US2276A
Authority: US
Inventors: Lionel M Woolson
Original assignee: Packard Motor Car Co
Current assignee: Packard Motor Car Co
Priority date: 1925-01-14
Filing date: 1925-01-14
Publication date: 1927-02-08
Anticipated expiration: 1944-02-08

Description

1,616,941 1927' L. M. WOOLSON INTERNAL COMBUSTION. ENG INE Filed Jan. 14, 1925 E E gone! m. MOOISOR Patented. Feb. i927.

earner LIONEL M. WOOLSON, F DETROIT, MICHIGAN, ASSIGNOR T0 PACKARD MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

INTERNAL-COMBUSTION ENGINE.

Application filed January This invention relates to internal combustion engines, more particularly to the cooling systems thereof and it has for one of its objects to provide a cooling system in which the weight of fluid necessary to cool the engine shall be much reduced and the ratio of engine weight to power developed shall be thereby decreased.

Another object of the invention is to provide an engine cooling'system for use on motorvehicles in which the head resistance caused by the radiator shall be materially reduced.

, A further object of the invention is to provide an engine cooling system having cooling jackets or spaces surrounding the engine cylinders in which the surfaces of the jacket and the cylinder barrel shall be protected from rust and other corrosion.

- Other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig; 1 is a view in side elevation, partially broken away and partially in section, of a portion of an internal combustion engine illustrating the invention, and

Fig. 2 is an enlarged sectional view of a %ortion of the engine shown in Fig. 1.

3o efinement in the design of water-cooled internal combustion engines has progressed to a. point where the weight of the cooling system carried is a material factor in the ratio of engine weight to power output.

Particularly is this true in engines such as are used in the propulsion of aircraft; such engines having "been built in which the weight is'as low as 1.5 to 1.7 pounds per brake horsepower developed, but-in which 40 the weight of the radiator and cooling water carried is 35 percent to 40 percent of the total engine weight. Ordinarily, the temperature at which the cylinder walls of an engine may be operated is limited by the boiling temperature of water at the atmos pheric pressures encountered, and-"sufficient water must be carried with a given'rate of circulation to maintain the cylinder wall temperature below this point under all power "outputs, since it is essential that. no appreciable loss of water by evaporation shall occur. The weight of cooling water which'must be carried by an engine of given size is thus approximately fixed.

14, 1 92l5. Serial No. 2,276.

preventing loss from evaporation. This result is accomplished by retarding the transfer of heat from the cylinder walls to the cooling water which is circulated around them, so that less heat is absorbed by the water. Preferably the cylinder walls are given a thin film or coating of any suitable heat retarding material, byrwhich the flow of heat through the cylinder walls to the cooling space is checked. In this way not only is the weight of cooling water reduced,

butthe size of radiator required may be also reduced in proportion, thus decreasing both the weight and the wind resistance of the vehicle which is being driven. This last named feature is particularly valuable in aeronautics in which the parasitic resistance overcome represents the expenditure of a large proportion of the total power.

Referring to the drawings, at 10 is shown a portion of an internal combustion engine having a crankcase 11 on which is mounted a bank 12 of cylinders 13. As shown, the bank of cylinders 12 is formed as an integral cylinder block, but it is to be understood that the bank may-consist, if desired, of individual cylinders, separately secured to the crankcase, or in groups of cylinders of any desired number, as is well understood in the art to which this invention relates. The crankcase 11 is provided with suitable bear ings 14, in which is journaled a crankshaft 15, and this crankshaft is connected by connecting rods 16 to pistons 17, adapted to reciprocate in the cylinders 13 in the usual manner.

The cylinders 13 are provided with a suitable head, which in the embodiment illustrated comprises an integral head casting 18, provided with a combustion chamber 19 for each of the cylinders 13, and provided with suitable passages 21 for the circulation of cooling water; the passages 21 forming a water jacket for the cylinder head.- Each of the cylinders 13 is also provided with a cooling space 22 formed in the cylinder block 12 to surround the cylinder, and constituting a water jacket therefor, these jackets being connected in any suitable manner, not shown. If separate cylinders are employed, each of these cylinders will have an independent water jacket, as will be readily understood. Suitably mounted in a housing engine 10, preferably at the forward end of the cylinder block 12, is a water pump 23, adapted to maintain a forced circulation -of cooling water through the

jackets

21 and 22 as is readily understood. The pump 23 may be of any suitable type but is preferably of the rotary type, having a shaft 24, driven by a pulley 25 and a belt 26 from any convenient rotating. part of the engine, such as the engine camshaft (not shown).

Mounted forwardly of the engine 10 is the usual radiator 27, having at itsazpper end an inlet 28 for heated water from the water jacket 21, and at its lower end. an outlet 29, connected by suitable means, such as the conduit 31, with the intake of the pump 23. The radiator 27 has a core portion comprising air passages or tubes 32 extending from front to rear, around which the water in the radiator flows as it moves from the upper to the lower portionof the radiator, being cooled in the process, as is well understood. The forward end of the pump shaft 24 is preferably provided with a fan 33 by which the natural draught of air through the tubes 32 is augmented. The radiator inlet 28 is connected by any suitable conduit 34 with a jacket outlet 35, formed on the cylinder head block 18 and communicating with the water jacket 21.

The circulation of water through the cooling system described is well known. Water from the delivery side of the pump 23 en- .ters a suitable distributing conduit (not shown) by means of which it is introduced into the various cylinder cooling jackets 22,

through which it flows in parallel, absorbing heat from the cylinder wall. The heated water rises and enters the cylinder head jacket 21, absorbingheat from the cylinder wallsand particularly from the combustion chambers 19, and flows forwardly into the outlet 35, through conduit 34and radiator inlet 28 into the upper end of the radiator 27. Here it is subjected to the cooling ac tion of the air passing through the tubes 32. The cooled water is drawn from the bottom of the radiator through the outlet 29 and passes through the conduit 31 into the intake of the pump 23, thus completing the cycle.

As previously explained, the volume and hence the weight of cooling water which is necessarily carried by the engine is practically established for any given maximum power output of the engine. This volume must be suflicient to absorb the heat gener ated at such power output without exceeding the boiling temperature of water. In the present invention the quantity of water carried is decreased, and the temperature of the walls of the cylinders 13 is correspondingly increased by retarding the transfer of heat from the cylinders 13 to the cooling water in the

jackets

21 and 22. To accomplish this the walls of the cooling spaces are coated with a thin film of heat resisting or insulating material so that the transfer of heat therethrough takes place at a much less rapid rate. Any suitable material may be used for this purpose but it has been found that certain of the phenol condensation products, such as the well known bakelite, provide a very satisfactory coating. This material is heat resistant, is waterproof, and may be repeatedly wetted and dried without cracking or other deterioration.

This material may be applied to the cylinder jackets in any suitable Way. In engines having independent cylinders, in which the cooling jackets are affixed to the cylinder walls after manufacture thereof, the bakelite insulation may be applied to the inner walls of the cylinders in the form of thin sheets before attachment of the cooling jackets to the cylinder forgings, or it may be mouldedin place. In engines cast en bloc, as in the embodiment disclosed herein, the insulating film may be conveniently applied in the form of a varnish. In this method of application the cooling spaces of the engine are filled with such a varnish which is allowed to stand a short time, and are then drained. Drying of the varnish fihn thus applied to the walls of the cooling jackets may be hastened by a draught of air from any suitable source, introduced through the pump intake and exhausting through the jacket outlet .35. After a coating of such varnish has been suitably dried, another coat may be applied in a similar manner until an insulating film 36 of sufficient thickness has been built up on the inner surfaces of the

cooling spaces

21 and 22. This varnish may be prevented from entering the pump chamber by blocking ofi the distributing conduit during the filling and draining operations.

The varnish film 36 forms a shield between the walls of the cylinders 13 and the combustion chambers 19, and the water in the

cooling spaces

21 and 22, which retards or checks the flow of heat into the cooling water. It is obvious that this will cause the cylinder Walls to rise to a higher temperature, and that a smaller volume of "cooling water will maintain the walls at this may therefore be materially reduced, and this not only greatly decreases the ratio of weight to horsepower of the engine but permits the use of a smaller radiator and thereby lowers the head resistance of the vehicle on which the engine is mounted.

It, is also apparent that the varnish film 36 forms a protective coating for the interior of the cooling space, preventing rust and other corrosion of the'metal of the cylinder walls. a

It will be understood that various forms of the invention other than those described above may be used without departing from the spirit .or scope of the invention.

What is claimed is: 1. The combination in an internal combustion engine, of a cylinder, having walls and a head, a jacket for said wallsand head defining therewith a cooling space adapted to contain cooling fluid, and a thin covering for said walls and head within said space and impervious to the cooling fluid to retard the transfer of heat from the cylinder to said fluid.

2. The combination with an engine having cylinders and a head, and a jacket surrounding the cylinders and head adapted to contain cooling fluid, of heat retarding varnish onthe inner walls of said jacket adapted to delay the transfer of heat from the cylinders and head to the cooling fluid.

3. The combination with an engine cylinder having a jacket defining a cooling space,

cylinder and said cooling space, said means of heat retarding means between the comprising a varnish containing a condensation product of phenol.

4. The combination with an engine cylinder having walls and a jacket defining a cooling space, of a thin coating of heat retarding Varnish on the cylinder and jacket walls within the cooling space adapted to afiect the flow of heat through said cylinder walls tosaid cooling space.

5. The combination in an int rnal combustion engine, of a cylinder having walls and a head surrounded by a cooling fluid,-

and a thin heat-retarding covering for said walls and head adapted to prevent corrosion by the cooling fluid.

6. The combination in an internal com.- bustion engine, of a cylinder having walls and a head, a jacket for said walls and head defining therewith to contain cooling fluid, and a thin coating for said Walls and head in contact with the cooling fluid and ada ted to resist corrosion thereby, to retard t e flow of heat from said walls and head to said fluid.

7. The combination with an engine cyla cooling space adapted.

inder having a jacket defining a cooling v space, of cooling fluid in said space to absorb heat from the walls of the cylinder, and a thin coating of heat retarding material on said walls in contact with said fluid adapt- Ed is) prevent corrosion of said walls by said In testimony whereof I aflix my signae ture.

" LIONEL M. WOOLSON.