US2189888A - Thermal control of internal combustion engines - Google Patents

Description

Feb; 13, 1940. L E, ENDSLEY 2,189,888

THERMAL CONTROL OF INTERNAL COMBUSTION ENGINES Filed Feb. '7, 1938 2 Sheets-Sheet 1 a g 8 N L oouooooqioooo 0- x 1 l I 1\ II I i 111111!!! I! II IIIIIIIIIIIIII FIG. 1.

. INVENTOR LOUIS E. ENDSLEY ATTORNEY COMBUSTION ENGINES Feb. 13, 1940. E. ENDSLEY' THERMAL CONTROL OF INTERNAL Filed Feb. '7, 1938 2 Sheets-Sheet 2 INVENTOR M LOUIS E. ENDSLEY 62M 4 new till Patented Feb. 13,- 1940, 1

UNITED STATES THERMAL CONTROL OF INTERNAL COMBUSTION enemas Louis E. Endsley, Pittsburgh, Pa., Fairbanks, Morse & 00., Chicago,

ration of Illinois assignor to 111., a com Application February '7, '1938, Serial No. 189,110

20 Claims. This invention relates to thermal control of internal combustion engines, and particularly to improved methods of and means for regulating the temperatures of lubricating oil and water utilizedin connection with internal combustion engines employed for locomotive propulsionr According to prevailing practice, particularly in connection with locomotives of so-called Diesel-electric type, the necessary compactness of power plants due to space restrictions necessarily imposed by permissible locomotive dimensions, operates to restrict the available area of cooling radiators for oil and water. Recent railroad experience with equipment of the type noted in- I dicates that failure in engine operation has resulted by reason of these conditions, due directly to excessive oil and/or water temperatures. It is accordingly among the major objectives of the present invention, not only to provide heat exchange equipment of suflicient capacity to care for maximum attainable oil and water conditions, but to provide for a positive automatic optimum regulation of .the rates of cooling of either or both the lubricating oil and water utilized with an internal combustion engine as a locomotive prime mover.

Specifically in connection with locomotive engine cooling, an entirely different set of conditions prevails when the locomotive is in operation at speed, due to the greatly enhanced air-speed as compared with cooling conditions when the locomtive is at rest, and air circulation must be entirely mechanically provided for. For these reasons it will at once appear to those skilled in the art that the problem is presently one which exists principally in locomotives propelled by internal combustion engines as distinguished from the problem prevailing in connection with engines of non-mobile type, although many of the improvements to be described are applicable to stationary engines. It is accordingly an object of the present invention to provide suitable agencies for directing air into cooling relation with a portion of a heat interchanger assembly such as a radiator, in response to movement of the locomotive, and also to provide improved means for assuring a definite necessary minimum rate of air movement irrespective of motion of thelocomotive.

Yet another object of the invention is attained in an improved arrangement of air-directing and propelling agencies, which will function equally, or substantially so, in either direction of operation of the locomotive, i. e., forward or backward. The advantage of these provisions as an important objective of the invention is at once appreciated, when it is considered that heretofore prevailing cooling equipment will function normally, only in one di ection of operation of the engine, being the usual normal forward movement.

More specifically, as reflected in the present design embodying the invention, is the objective of providingan improved movable louvre assembly which operates preferably under full automatic thermostatic control in response to oil temperatures and water temperatures in a locomotive of a type characterized by internal combustion engine propulsion, such as Diesel-electric locomotives.

A further important and general object of the invention is attained in an automatic compensation of cooling effects on either or both oil and water systems in a locomotive type internal combustion engine, to care for differences otherwise resulting from the eifects of head winds, tail winds, as well as lateral windage efiects on the locomotive, at the same time caring for differences in cooling rate which would occur, but for present improvements, due to the reversal in direction of movement of the locomotive.

Somewhat ancillary to-the foregoing object, are certain objective improvements in design of cooling system for an internal combustion engine of the type noted, whereby the system will operate effectively, in either direction of movement of the locomotive, and desirably under full automatic regulation of either or both water and oil temperatures.

Still further objects of the invention may be stated as the improvement of provisions for limiting the temperature rise of either jacket water or lubricating oil, or both thereof, including provisions, operative upon attainment of predetermined limits, so as to vary, as through engine governor loading, theengine power and hence the rate of dissipation of waste heat by the engine.

Yet another important object of the invention is attained in improved facilities for proportioning a given supply of cooling air, between those parts of the supply devoted respectively to the cooling of jacket water and to the cooling of the lubricating oil, this object being desirably attained by an interrelated system of controls which more or less independently serve respectively to control jacket water temperature and the temperature of the lubricating oil, the arrangement being further such that a variable supply of cooling air may yet be most advantageously proportioned between the noted cooling agenies.

Another object of the invention, akin to those heretofore stated, may be noted as the maintenance of water temperatures or'oil temperatures, or both, within optimum ranges, practically irrespective of ambient temperatures and windage conditions.

The foregoing and numerous other objects will appear as the description proceeds, when considered in connection with the accompanying drawings, illustrating a presently preferred exemplary embodiment of the invention. -In the drawings:

Fig..l is aplan view of an end portion of a locomotive unit with the top or roof structure broken away, and showing the preferred disposition of the locomotive engine with respect to the radiators and certain other temperature regulat- Lng instrumentalities; Fig. 2 is a sectional elevation taken at line 2--2 of Fig. 1; Fig. 3 is a transverse sectional elevation taken at line 3-3 of Fig. 1; Fig. 4 is a plan view of that portion of the locomotive unit illustrated in Fig. Land-showing, schematically, various temperature controlling elements and their connections such as may be utilized in practicing the invention, and Fig. 5 shows a portion of a modified control system.

Making reference to the embodiment of the invention selected for present disclosure, it is contemplated that each locomotive, as utilized in service, shall be comprised of a pair of functionallyindependent locomotive units connected back to back; each such unit consisting, as to major items of equipment, of one or more internal combustion engines of water-cooled type, say direct-connected to'an electric generator, provided with the usual 'exciter and control equipment. Propulsion is directly effected by driving motors carried by the driving trucks, the installationembodying electric control equipment which may be of one of the types .now known in the art and hence is not herein described in detail. The two units normally constituting the complete locomotive are preferably articulately connected, depending on length of the coupled units, roadbed conditions and other factors. It is to be understood however, that the control features of the present invention are equallyapplicable to a single unit locomotive.

The cooling system is advantageously located, by reason of facility of cooling air supply, near the end ofthe unit, although this location is not absolutely necessary nor indispensable tothe operation of the apparatus to be described. As both of the units areor may be identical, the description will, for brevity, be confined to one thereof which may be presently considered as the cooling assembly for the forward locomotive unit of the operatively related pair. 7

Referring now by numerals of reference toth drawings, the front end portion of thebody or housing of the locomotive proper, is indicated generally at 20, and the end closure of the body shown at 2|, provided with a louvred or grilled opening 22 for the entrance of cooling air. The louvres of the grille 22 maybe and bypreference are, manually movable-into positions of difierent angularity so as relatively to obstruct or close the front louvre opening, or to permit any selected volume of air up to the practical maximum, to enter the air space to be described, within the locomotive. The right side wall 25 of the locomotive body, is interrupted to provide an opening- 26, mounted just within which is a water radiator 21. This radiator is preferably disposed vertically, or in any event, in a plane approximating that of the side wall 25 of the body. In corresponding position and for example of corresponding extent, is an oil radiator 28 carried by the side wall 30 in similar relation to the mounting of the water radiator 21. It may be noted that the water radiator is connected by supply and return. piping 3| (Fig. 4) to the usual cooling water Jacket of the engine designated generally at 32, and thus serves in known manner to receivethe cooling water, sub- .iect same to the cooling effect of the stream of cooling air, and thence through the return piping, restore the water to the jacket. The oil radiator 28 is by preference connected, not directly to the oil circulating system of the engine, but to a heat interchanger 33, so that the radiator 28 serves indirectly to cool the oil through the agency of water circulation. The interechanger 33, not shown in detail, may consist for example of one of the well known types of tube and header exchanger. The advantages of water cooling of the oil will be appreciated by those skilled in the art, and although the unit 28 is referred to as an oil radiator, it is nevertheless preferred to be utilized as a water radiator for ,the indirect cooling of theoil.

In Fig. 4, numeral 34 denotes piping connecting the so-called oil radiator 28 and interchanger 33, andjnumeral 35 denotes the oil lines interconnecting the engine and interchanger 33.

. Extending within the nose or head end portion of the locomotive, is a substantially air-tight cooling-air conduit, so formed as to constitute a chamber of substantial size, the opposite walls of this conduit being indicated at 36, which walls may be continued to form top and bottom closure portions 31. The chamberedconduit for the cooling air has its closure completed on the inner end by a partition structure which is shown as substantially V-shaped in horizontal'section, the V-shaped partition structure being indicated at 38, and 39 representing the two 1at-- eral arms or branches of the conduit resulting from the shape and location of the partition structure.

- Disposed alongside the water radiator, preferably but not necessarily externally. thereof, is an assembly of adjustable louvres, the individual louvre forming elements 40 of which are each pivotedat its inner edge or end, and the louvres of the group being connected for corresponding opening and closing movement as through link elements I, each pivotally connected between adjacent pairs of louvres. For reasons which will hereinaftrmore clearly appear, it is preferred that the louvres 40' be of a. quasistreamline horizontal section so as to minimize turbulence, eddies and cavitation effects of the air in passing. through both the louvres and the radiator.- It will be obvious from the arrangement of the set of louvres 40 adjacent the water radiator 21, that by closing the louvres, air circulation will be substantially precluded through or adiacent the radiator. This adjustment is, according to the present -invention,

preferably fully automatic in nature, and is attained through the agency of a bell crank control lever 42 and servo-motor 43, the actuating element 44 of which is pivotally connected to the bell crank lever 42. The details of structure and function of the servo-motor 43 arehereinafter described in more detail in connection with the description of control features.

' e The streamline section of the movable louvre- 5 but to a lesser extent.

25 inafter more clearly appear.

the openings provided between the louvres 22 in advantage is realized in minimizing the resistance of these elements to the air. Some improvement is also noted on the front end of the locomotive by reason of the streamline louvres, It has been determined that with identical units connected back to back, some 25% more power is required for cooling air displacement in the rear unit, than in the forward unit, but that this difference can 10 be somewhat reduced by the streamline section of the louvre-forming elements.

Similarly to the automatic water radiator louvres, is provided a set of adjustable louvres for the oil radiator 28, the latter louvres being 15 indicated at 45, and articulately connected through link elements 46 in a manner preferably similar to the linkage for the louvres 40. The adjustment of the louvres between fullopen and full-closed positions is effected 20 through a bell crank lever for example, 41, connected to the actuated element 48 forming a part of or associated with a servo-motor 49. The device 49 is or may be identical with the servo-motor 43, and hence its structure will here- The oil radiator louvre elements 45 are preferably, after the manner of the water radiator louvres, of streamline form, and are so formed for the same purpose.

There is desirably provided for the forced cir- 30 culation of air through the chamber of cooling air duct, in order to assure at all times a dependable air circulation even though the locomotive be at rest, a variable displacement device for the cooling air. This consists, according to present pref- 35 erence but without any understood restriction as to type, of a propeller type fan or blower (see Fig. 4), the blower being actuated by a reversible motor 50, and the blower assembly indicated generally at 5!. The fan itself is provided with blades 52, each mounted for a limited rotative movement about its own longitudinal axis, and associated with variable pitch mechanism 53. Mechanism for varying the pitch of propeller blades is well known in the art and a full de- 15 scription of a type thereof suitable for use in connection with the present invention may be found in the monthly periodical Aero Digest, issue of July, 1938.

For the purpose of effecting automatically, the

so desired change in pitch of the blower or fan there is provided a servo-motor 54, which may be of a-type similar to the devices 43 and 49 above described, and the detail of which will hereinafter more fully appear.

A further agency for control of the stream of cooling air directed'into the cooling air conduit,

consists of a swingably mounted air control fin or splitter 55, pivoted as at 56. The splitter fin is utilized for the purpose, as will later more clearly m appear, of relatively obstructing the fiow of air to one of the radiators, thus favoring the flow to the other, andv hence proportioning the supply of air between the pair thereof in the unit. This control is, by great preference, fully automatic in nature, and is effected through an articulate link-.

age generally referred to at 51 and actuated by the control-actuating member 58 of a fin servomotor 59. The latter may be and is by preference of the same general type as the devices 43,

49 and 54 heretofore referred to.

From the preferred arrangement of the two 10- comotive units articulately assembled to form the complete locomotive, it will appear obvious that as one of the units is moving in, a relatively forward direction, air will be received through the head end of the locomotive, and thence be displaced rearwardly into the chamber or conduit branches 39, under the influence of the forward movement of the locomotive'as well as under any displacement effect of the variable blower assembly 5|. Assuming the air control fin 55 to be in a central or midposition, substantially half of the air will be diverted laterally toward and into the' water radiator, the remaining half in an opposite direction and into the oil radiator. After passing through the radiators, assuming the louvres to be open, the air stream will find its exit laterally of and along the locomotive body. It will be obvious that with both sets of louvres in their fully closed position, substantially no cooling effect will be exhibited on the two radiators. Such a condition will desirably obtain during the starting period of the engine and during a preliminary warming period. Following a preliminary temperature rise in the cooling water and oil radiators, the effect of the control system hereinafter described is such that the louvres will open to an extent usually suflicient to permit the passage of air through the radiators in such volume as to maintain temperatures therein, at the predetermined optimum according to thermostat setting, as will later appear. During this first stage of the control cycle, it will be assumed for convenience of description, that the variable pitch propeller is operating at zero pitch, or, since it may be of fixed pitch type and operated by a variable speed motor for example, it will be assumed that there has resulted no substantial displacement of air thereby. Assuming, however,

. tioning of temperatures of the two radiators, the

system will serve, through the fin servo-motor 59, to move the control fin 55 from an initial position of rest, toward one of the radiators, for example, the water radiator 21, thus relatively restricting the air flow thereto, and relatively enhancing the air flow toward the oil radiator 28. However, should there still occur an undesirable further risein temperature in one or either radiator, in spite of the wide open louvres associated therewith, the pitch of the variable pitch propeller fan 5| is automatically augmented through the effect of servo-motor 54 to increase the volume of cooling air to the radiators which will obviously have the effect of still further tending to offset the rising fluid temperature. Should this last change of control still not be sufficient to restore the temperatures in both of the radiators to a value within the predetermined limit, there is provided,.

as hereinafter more fully described, an automatic loading control of the engine, which in effect, serves as an automatic load-limiting arrangement operating to reduce the power of the engine, for example, as through the loading of its governor spring, to a safe figure such that the cooling system can care for the waste heat as fast as dissipated into oil, water or both, by the engine.

It is a preference that the capacities of the two radiators 21 and 28 be such as to care for the full load 01% the engine at any reasonably expected maximum ambient air temperature, say '110 degrees F.

provision there would occur some interference with the air stream by the adjacent car of the train just rearwardly of the locomotive.

To the end of maintaining the propeller type fan in correct angular relation to the air stream 1 moving inwardly or outwardly of the end porof the radiator, and because of the .agencies and their function,

tion of the cooling air conduit, it is a distinct preference to locate the fan shaft at a substantial pitch or angle to the horizontal. The genera1 course of the air into and through the cooling conduit, variable displacement device, radiators, etc., has been heretofore referred to in reference to the forward direction of the locomotive. It will be understood however that in case the assembly of Fig. 1 is moved inthe relatively reverse direction, as on the rear unit of the articulated pair of units, the direction of air movement will be relatively the reverse of that described. Consequently, while in the front end of the coupled units the louvres form air exit passages, in the rear such unit they will serve as air pickup members, deflecting the air inwardly relative reversal of rotation of the displacement device ii, the displacement assembly will serve in the rear unit to discharge the air upwardly and outwardly through what was formerly discussed as the intake portion of the cooling air conduit. It will nevertheless appear that the displacement of the blades of the variable pitch propeller, and the lateral control displacement of the fin or air splitter 55, will have the same functions as heretofore described.

Proceeding now to a'description of control through which are attained the results above discussed, there has been selectedas an illustrative embodiment, a

v temperature control system of combined electric and pneumatic type, and wherein somewhat separate, yet functionally interrelated control organizations, one for the jacket cooling water and another for the lubricating oil, are provided. The two control organizations may be substantially identical with respect to the character and relationship of their component parts, and accordingly an explanation of water jacket temperature control, will serve in substantial part, to cover both control organizations. The manner in which the water jacket and oil temperature regulating means differ, will be pointed out as the description proceeds.

In Fig. 4, 60 designates a bi-metallic bar or thermostat element, shown as mounted in the conduit 3i which connects the water jacket outlet of the engine to the radiator 21, the element 60 being desirably located directly in the path of the water as it leaves the engine, so that its temperature will follow closely that of the water in the Jacket. Warping movement of element 60 in accordance with changes in water temperature, is transmitted by suitable means to the control unit indicated generally at iii, of a reversible electric motor 62, such means being illustrated diagrammatically as comprising a plunger 63 which extends from the thermostat element 60 outwardly through apacking gland inthe wail of pipe 3| for connection with a switch lever 64, representing the actuating member of the motor control unit 6|. Such control unit may consist of what may be termed a double-pole, double throw reversing switch, having a pair of contacts 65, insulated from each other and mounted on the extended arm of the switch lever 64, the contacts 65 being connected to a supply of direct current provided by the mains 66. Suitably spaced at opposite sides of contacts 65, are the paired contactsli'l and 68 connected by leads 69 and 10, respectively, to motor 62, in such manner that the motor will rotate in one direction when supplied with current through contacts 61, and in the opposite direction when supplied with current through contacts 68. The motor field winding H is connected by suitable leads'to the mains 66.

Motor 62 is operatively connected, through a suitable reduction gear mechanism indicated generally at I2, to the control arm 13 of a pneumatic, so-called self-lapping valve 14 which provides a means for regulating accurately the air pressure applied to the pneumatic servo-motors 43 and 54, previously referred to. Self-lapping valves are well known, particularly in connection with their application to brake systems for railway cars, such valves serving automatically to lap ofithe flow of air when the pressure in the brake cylinder, or other pneumatic actuating device controlled thereby, builds up to a pressure corresponding to the particular position of the valve lever arm. If lower pressure is desired the valve arm is moved, for example, to the left (Fig. 4); if greater, to the right-the cylinder pressure immediately falling or rising an amount corresponding to lever movement. A detailed description of a self-lapping valve assembly suitable for use in the control system of the present invention, may be found in bulletin No. 2455 of April 1932, published by Westinghouse Traction Brake Co. of Pittsburgh, Pa.

The gear reduction mechanism 12 may include a driven rack bar 15 mechanically coupled to lever arm 13 of the self-lapping valve, a pair of limit switches 16 and 11 being arranged with respect to the lever arm 13 and disposed in the motor circuits 69 and I0 so that movement of lever 13 to either of its extreme positions opens one of the limit switches. It will appear that when one of the limit switches is'opened, as aforesaid, motor 62 will stop and can be reenergized to rotate only in a relatively reversed direction. It is desirable to provide for a slow movement of the valve lever 13 and the reduction gear assembly 12 should be ned so that the lever arm travels from its zero pressure point to its maximum pressure position in not less than one minute.

The self-lapping valve is connected, as by conduit -18, to a suitable reservoir. 19 providing a supply of air under pressure, and controls the pressure of the air in the pipe 80 leading to the cylinders of servo-motors l3 and 54 through self-lapping valve 14 and the louvre control servo-motor 43, is such that the water radiator louvres are fully closed when lever 13 is in one extreme position, and fully open when lever 13 is, for example, mid-way between its extreme positions, each increment or decrement of lever movement producing achange of corresponding degree in the positions of the louvre fins 40.

The self-lapping valve 14 serves, additionally, to regulate the displacement capacity of the fan 5| which is adapted to augment the flow of air through the water and oil radiators when such becomes necessary in order to reduce abnormal engine temperatures, the fan becoming effective for this purpose only when the water radiator louvres are in full-open position. Thus valve 14 may be adapted, for example, to eifect a gradual pressure variation in line 80 through a range of from to 60 pounds per square inch gauge pressure. Now, the spring associated with servo-m0- tor 43 may be so designed and loaded to permit of full displacement of the servo-motorpiston when 30 pounds of air pressure is applied thereto, such full displacement position corresponding to full open position of the louvres 40, and to a midway position of the valve lever 13. When air pressure in line 80 is increased beyond 30 pounds per square inch, as by movement of valve lever 13 beyond its midway position, servo-motor 54 becomes effective to increase the displacement capacity of fan assembly The impeller or fan assembly 5! is driven by the electric motor 50 which may be of variable speed type, the motor speed being controlled by a suitable variable resistance unit actuable by the servo-motor 54. However, I prefer to employ an impeller of constant speed type wherein changes in displacement capacity are effected by altering the pitch of the impeller blades. Devices of this character are well known and a detailed description of the same is believed unnecessary. In Fig. 4, an operative connection between servo-motor 54 and the pitch changing mechanism (not shown) of impeller 5| is indicated as provided by a direct connection to the piston, the servo-motor 54 being adapted by virtue of its spring loading, to

vary the propeller blades from zero to maximum pitch when subjected to control pressures within a range of from 30 to, say; 60 pounds per square inch.

The foregoing description sets forth means, which function in a manner to be hereinafter explained, for controlling and maintaining the temperature of the engine jacket water within predetermined limits when the engine is running. A series of instrumentalities similar to those previously described is provided for controlling the temperature of the engine lubricating oil. Thus, a second thermostat 83, which may correspond to thermostat 60, is located in the oil line or piping 35, preferably at a point where the oil leaves the engine, the thermostat 83 having a reversing switch 84 associated therewith which controls the energization and direction of rotation of a reversible motor 85 which, in turn, actuates the control lever of a self-lapping valve 86. Such' valve is connected as by branch pipe 81 to a servo-motor 49, serving to regulate the air pressure thereto for adjusting the positions of louvre vanes 45 associated with the oil-cooling radiator 28. The servo-motor 59, heretofore described, is

operable in a somewhathigher pressure range than the unit '49, and is in communication with the self-lapping valve 85 through branch pipe 88,

and is connected to the lever mechanism 5'! which actuates the deflecting fin 55. It will thus appear that the water radiator louvres 40 and the air impeller 5| are under the control of thermostat 60 which is thermally responsive to the jacket cooling water, and the oil radiator louvres 45 and the deflecting fin 55 are under the control of thermostat 83 responsive to temperatures of the lubricating oil.

Let it be assumed that the described means are applied to a locomotive powered by an internal combustion engine which operates with maximum efficiency when its jacket temperature is maintained between the limits of 170 degrees and 180 degrees F. Under such condition the water thermostat and its attendant switch would be designed so as to start motor 62 in one direction when the water temperature reached 177 degrees, and to start the motor in the reverse direction when the water temperature drops to. 173 degrees, the motor being idle for intermediate temperatures. The switch contacts 61 and 68 are thus arranged in contemplation of a possible over-run of approximately 3 degrees, before the means which control the flow of air through the water radiator become effective.

When the jacket temperature falls to or below.

173 degrees F. the self-lapping valve 14 reduces the air pressure to servomotors 43 and 54 toward zero effective value, approaching the fully closed condition of louvres 40 associated with the water radiator and tending to reduce the pitch setting of the fan blades 52, so that relatively less cooling air is displaced thereby. When the jacket temperature rises to 177 degrees the contacts 65 of the thermostat switch engage the contacts 68,

which it may be mentioned, are preferably spring-mounted for the principal urposes of providing for their yieldable engagement, and also for purposes of adjustment. The engagement of contacts 65 energizes motor 62 which causes lever I3 slowly to increase the air pressure in the servomotors 43 and 54. As the air pressure increases, the water radiator louvres open correspondingly so as to permit more cooling air to pass through the radiator to reduce the jacket temperature. If the jacket temperature is not thus lowered after the louvres attain wide-open condition, corresponding to 30 pounds or more pressure in the servomotor 43, the self-lapping valve continues to increase the pressure in lines 80, 8| and 82. Servomotor 54 becomes eiiective when the line pressure exceeds 30 pounds, to increase the fan output, the fan attaining its maximum displacement capacity when a pressure of 60 pounds per square inch in line 82 is reached.

Under all except very extreme conditions, the increased flow of cooling air throughthe water radiator resulting from the open louvres, the augmented air flow due to the fan, or both, will reduce the jacket temperature and cause the thermostat to interrupt the motor circuit before the jacket temperature exceeds 180 degrees F. Now, if the jacket temperature drops to or below 173 degrees F., the motor will be reenergized in the reverse direction, resulting, first, in a gradual reduction of air displacement by fan assembly 5 I, and thereafter, if necessary, gradual closing of the water radiator 40.

The maintenance of the oil temperature between predetermined llmits is accomplished in a similar manner, the oil radiator louvres being adjusted to pass more -or less air as dictated by the oil thermostat 83. However, with the controls con nected as shown by Fig. 4, no direct operative relathan the water radiator.

tion exists between the oil thermostat and the tan. If the oil temperature is not reduced after the oil radiator louvres have been moved to full open position, displacement of the fin 55 to direct a greater portion of the cooling air through the oil radiator is effected. Such fin adjustment obviously will tend to reduce the amount of cooling air passing through the water radiator which, if necessary, will result in increasing the fan output as previously explained; there is thus provided a distinct functional interrelation between oil temperature and volume of cooling air directed toward and through the oil radiator.

When the temperature of the atmosphere is degrees, which may be regarded as a, practical maximum, the several radiators require substantially equal amounts oi cooling air to maintain the oil and water at their desired temperature levels, which are approximately degrees F. for the oil and 1'75 degrees F. for the water. However, as the atmospheric temperature drops, the oil radiator requires decreasingly less cooling air Moreover, a side wind will tend to increase air flow through one of the radiators and decrease the flow of air through the radiator at the opposite side of the locomotive. Thefin 55 operates to compensate for these varying conditions, coacting with other described means for controlling the flow of cooling air, and hence serves to maintain in predetermined ranges, the oil and water temperatures.

If desired, the deflecting fin may be dispensed with and control of cooling air eifected solely through the agency of the radiator louvres and the fan. In a system thusly modified, the previously described method of louvre control may be employed. However, instead of providing two so-called secondary servo-motors (54 and 58) which begin to function after the oil and water louvres are moved to full open position, a single secondary servo-motor, common to both oil and water temperature controlling organizations, is operatively connected to the fan mechanism so that air displacement by the fan will be regulated in accordance with the demands of either of the radiators. In the modified arrangement the fan output should be determined by the particular cooling system, oil or water, having the greatest demand for augmented air flow.

This result may be accomplished in the manner illustrated schematically in Fig. 5, showing a constant speed motor 580 which drives a fan 52a of variable pitch propeller type, the mechanism (not shown) 'for varyingthe blade pitch being actuated by an axially movable shaft connected to the piston of a pneumatic servo-motor 88. The servo-motor 88 may be of the general type heretofore described, and wherein air pressure in excess of 30 pounds per square inch in its cylinder, initiates movement of the piston, such movement being opposed by a spring.

The air pipe 8!! leading to a servo-motor 88 is adapted to communicate selectively with either of the air pipes 82a and 88a through a valve structure 8|,hereinafter described. It will be understood that pipes 82a and 88a of the modified system constitute branches leading from selflapping valves 14 and 86, respectively, replacing pipes 82 and 88 of the system originally describedand illustrated in Fig. 4.

The valve structure 8| includes a freely movable piston 82 which operates under a pressure differential in lines 82a and 88a to place the one having the greatest pressure in direct communication with servo-motor 88, and serving simulnor 86, and serves,

taneously to close of! communication between the other line and the said servo-motor. By means of valve structure 8| the control of fan output is under the domination of the particular air line 82a or 88a carrying the greatest pressure, and hence is influenced by the system, oil or water, having the greatest demand for augmented flow of cooling air. It will be obvious that the purpose of valve 8| is to enable servo-motor 88 to be effected by the pressures in either of the lines 820. or 88a, yet to prevent undesired equalization of the pressures in these lines.

In the modified system, the louvres associated with'the oil and water radiators will open to an extent depending upon the air pressure in their respective servo-motors, such air pressures bein regulated by the self-lapping valves which, in turn, are controlled by thermostats in the oil and water lines of the engine. If, for example, the

temperature of the jacket water is not reduced 20 after the water radiator louvres have attained full open condition, the control air pressure in line am will rise sufficiently to actuate the fan servo-motor 88, causing the fan to increase the flow of cooling air. The control arrangement prevails on the oil side of the combined system. Excessive temperatures in either the water jacket, lubricating oil, or both, will result in increasing the fan output. If the same louvre and fan 25 fan power or amount of cooling air passing 30 through one of the radiators is sufficient to. reduce the temperature of its associated system but the demand for augmented air flow continues in the other system, the fan will continue to displace air in accordance with the demands of the latter system. However, the amount of cooling air flowing 'through' the radiator of the first system,

whose temperature has been reduced, will be curtailed by the radiator louvres of that system.

In addition to the means heretofore described for maintaining the engine temperature within predetermined limits, it is deemed advisable to provide means which function to reduce the power of the'engine, and hence its heat output, should the radiators be inadequate, due to extremely high atmospheric temperatures or excessive engine loading or both, or failure of one or more of the described control elements. Thus the thermostat switches BI and 84 are preferably equipped with auxiliary contacts 82- and 83, respectively, as shown in Fig. 4, which; communicate through suitable means with the governor or other direct control mechanism of the locomotive engine and function to eifect' areduction in engine power should the jaclgetwater and/or oil temperatures reach dangerous values. Thus. the auxiliary contacts 82 are arranged to close an electric circuit which effects energization of an electromagnetic control device 94, when the water temperature rises to say 200 degrees F. The control unit 84 is shown operatively connected to a control arm 85 of the engine goverwhen energized, to move the governor control arm 85 to a position corresponding to reduced engine power. The oil thermostat is likewise through contacts 83 and associated conductors, arranged to reduce the engine power, through the governor 85, should the oil temperature rise to say degrees F., or higher.

The electromagnetic control device 84 may consist of any of several known types of electric motor and reduction gear assemblies, operatively connected to the governor control arm 85; however, as shown for simplicity, the electromagnetic control unit may consist of a solenoid operatively connected to a slotted end of the lever 95, the armature rod or shaft 91 being extended'for connection to a dash pot 98. The provision of a dash pot, or some equivalent motion-delaying expedient, is preferred, since it is desirable in the event maximum safe temperatures are reached in one or either of the OH and water radiators, to effect a gradual reduction of engine governor loading, or otherwise to attain a gradual reduction in engine power output. It may also be desirable in certain installations, to effect a gradual restoration of the engine control to its setting prevailing prior to the energization of the unit 94. A convenient expedient through which may be attained a delayed complete actuation of the lever 95 in one or both directions, is shown in connection with dash pot 98. If it be supposed for example, that the dash pot consists of a double end fluid-containing cylinder, the ends of the cylinder on opposite sides of the piston may be put in communication as through a small interconnecting conduit 99, the rate of passage of oil or other fiuid through which may be regulated as by valve I00. It will readily appear from the foregoing description that the arrangement is usually such that actuation of lever 95 in a direction to reduce engine power, is effected by energization of the unit 94, and the opposite or restoring movement effected through spring "II, which may consist either of the main governor spring,'or of a separate compression spring for actuation of the lever 95 toward an inoperative or ineffective position.

The foregoing description of the physical arrangement of cooling air control and reaction elements, as'well as the description of the control operating system, have included, for completeness, provisions for varying the effective cooling air fiow through both the oil and water radiators, the agencies for directing a greater or less proportion of the input cooling air, toward either of the paired'radiators, as well as thevariable displacement device such as the blower assembly 5| and its automatic regulating expedients, whereby is attained a complete control of air flow through the cooling conduit. It is nevertheless, in spite of the complete control facilities described,.within the scope and purview of the invention, to utilize separately, or in any subcombination or grouping, any of the individual control agencies herein described. For example, it is understood as constituting a distinct advance in the art, to employ of itself, the improved con trol arrangement, for either radiator alone, provided by the movable louvres 40 or 45. Even though such louvres be fixed and not susceptible of control, manual or automatic, it would nevertheless be within the scope of the invention to utilize for example, the cooling air proportioning arrangement exemplified currently by the air splitter fin 55 and associated parts; In the same manner, the variable air displacement device, exemplified by the assembly Si, is susceptible of advantageous use of itself, particularly when subject to thermostatic control by the electropneumatic arrangement disclosed, or some analogous regulating agency.

Apart from the advantages to be attained by utilizing the subcombinations or individual control provisions, the physical arrangement of airdirecting elements is believed to be the most advantageous yet presented to the art, of locomotive engine cooling, and to exhibit many advantages, irrespective of whether, for example, the eifective volume of air through the radiators r trolled.

For a better understanding of operation of the control system presently disclosed by way of example, reference has been made to specific pressure ranges in the fluid-pressure portion of the control system; similarly, by way of illustration, optimum orders of oil and water tempera tures have been referred to as illustrative of usual best operating conditions, and as illustrative of ordinarily considered safe maxima of temperatures. It is however to be understood that the values herein given are merely illustrative and not to be regarded in any manner as restrictive of temperature or pressure values or ranges.

A study of the foregoing disclosure will reveal that the invention in its broader aspects embraces a substant-iallycomplete system for effecting full automatic thermal control of locomotive engine jacket water and lubricating oil temperatures, and that, allparts of the control system being in substantial measure functionally interrelated, this full automatic control is effective and fully compensatory for all variable cooling factors, e. g.,

varying direction and velocity of wind, of itself or as influenced by motion of the locomotive. It will further appear that this is true irrespective of whether the unit, for example as shown by Fig. 4, is moving in a relatively forward or reverse direction, and irrespective of whether, by reason of the influence of the automatic adjustable louvres, the splitter fin assembly 55 and variable displacement device the wind is of either high or negligible velocity, directly abeam on either side of the locomotive, or so to speak, directly ahead or directly astern. It will further appear thatthe control system and physical arrangement ofparts as described, fully attains each of the objectives hereinabove specifically set forth, as well as other advantages and contributions to the art appearing in the description of parts and their operation.

Although the invention has been described by making a specific reference to a presently preferred arrangement and combination of control features, many of such agencies may be varied, as may the location and arrangement of many of the parts described in detail; accordingly the description is to be understood solely in an illustrative and not in a limiting sense, and within the full intended scope and meaning of the claims hereunt appended.

I claim:

l. The described method of thermal control of an internal combustion engine of a type provided with water-cooling and oil-cooling equipment including radiators respectively arranged for the cooling of water and oil, which consists in circulating cooling air in a defined passage into cooling relation to said radiators, separately controlling the effective areas of portions of said passage directed to said radiators, in response to temperature variations of liquid in the said radiators, and further varying the displacement of air into said passage in response to a predetermined temperaor said radiators, upon attaining therein of a predetermined temperature with the associated air passage relatively unobstructed.

3. The method of efiecting thermal control or water and oil temperatures in an internal combustion engine, which consists in cooling the engine cylinders and cooling the lubricating oil through the circulation of cooling liquids in spaced radiators, supplying cooling air from a common source and directing such air through a common conduit, thence separately into cooling relation to the respective radiators, and in proportioning the air delivered from the common conduit, to the individual radiators, substantially in accordance with thermal requirements of the respective radiators.

4. The method of efiecting thermal control. of water and oil temperatures in an internal combustion engine, which consists in cooling the engine cylinders and cooling the lubricating oil through the circulation of cooling liquids in spaced radiators, supplying cooling air from a common source and directing such air through a common conduit, thence separately into cooling relation to the respective radiators, and in proportioning the air delivered from the common conduit, to the individual radiators, substantially in accordance with thermal requirements 01' the respective radiators, and in increasing the displacement of air in the common passage or conduit, in response to predetermined temperature conditions in the fluid in, or in thermal communication with either of said radiators.

5. The herein described method of effecting a thermal control of an internal combustion engine provided with a water-cooling system and an oilcooling system, each including a radiator, which consists in displacing air through a branched conduit, thence into cooling relation with the respective radiators; proportioning the efl'ective flow of air in cooling relation to the respective radiators by control of the efiective sectional area of the branches of the conduit; further proportioning the air by varying the-delivery of air into the respective branches of the conduit all in response to thermal variations in the respective liquids to be cooled by the radiators, and further varying the displacement of cooling air in response to predetermined temperature variations of a relatively higher order, in one of said cooling systems.

6. The herein described method 01 eflectin thermal control of an internal combustion engine of water-cooled type and provided with a water cooling radiator, which consists in supplying cooling air to the radiator, through a defined air channel controlling the cooling air eflectively delivered to the radiator by-variation of the outlet area of the channel, ;In response to water temperature; varying, the displacement of air in said channel in response to water temperature variations of a diflerent order, and varying the loading of the engine in response to predetermined temperature .variations of an order exceeding that aforesaid.

7. In a cooling system for internal combustion engines of locomotive type, a pair of radiators arranged opposite each other and laterally of the locomotive, adapted respectively to cool the engine jacket water and the lubricating oil, an enclosing structure forming an air chamber between the radiators and provided with an air opening at one end, the side walls of the chamber being completed by a plurality of adjustable louvres adapted to be regulated to vary the extent or area of air opening at each side oi the chamber and through the radiators, and thermostatic control means operable responsively to variations in temperature of the liquid circulating in the radiators to vary the extent of opening of the louvres. v

8. In a cooling system for internal combustion engines of locomotive type, a pair of radiators disposed at opposite sides of the.locomotive, adapted respectively to cool the engine jacket water and the engine lubricating oil, an enclosing structure forming an air chamber between the radiators and provided with an air opening at one-end of the locomotive, a partition member in said chamber for directing air from said opening laterally toward said radiators, a plurality of adjustable louvres adapted to be regulated, and so located as to provide a variable area of air opening adjacent each radiator, a blower and drive assembly located near the first said air opening, and being of variable displacement type, and thermostatic means operable responsively to variations in temperature of the liquid circulating in at least one of the radiators, to vary the displacement of air by said blower.

9. In a cooling system for an internal combustion engine of locomotive type, a conduit for direction of cooling air, arranged longitudinally of the locomotive and near one end thereof, radiators disposed at opposite sides of the locomotive and laterally of the conduit, said radiators being adapted respectively to cool the engine jacket water and the lubricating oil, the conduit being provided with an opening at one end of the locomotive, and an adjustable partition structure disposed within the conduit and serving to direct and proportion the air .therein toward and to the radiators.

10. In a cooling system for an internal combustion engine of locomotive type, a conduit for direction of cooling air, arranged longitudinally of the locomotive and near one end thereof, radiators disposed at opposite sides of the locomotive and laterally of the conduit, adapted respectively to cool the engine jacket water and the lubricating oil, the conduit being provided with an opening near one end of the locomotive, an adjustable partition structure associated with the conduit and serving to direct and proportion the air therein toward and to the radiators, and a set of movable vanes adjacent each of said radiators, arranged, when closed, to complete the closure of the sides of the chambered conduit.

11. In a cooling system for an internal combustion engine of locomotive type, a conduit for direction of cooling air, arranged longitudinally of the locomotive and near one end thereof. radiators disposed,at opposite sides of the locomotive and laterally of Hie conduit, in fluid cooling communication respectively with the engine jacket water and the engine lubricating oil, the conduit being provided with an opening near one end' of the locomotive, a partition structure associated with the conduit and serving to direct the air therein toward and into the radiators, a set of movable vanes adjacent each of said radiators, arranged, when closed, to complete the closure of the conduit about the radiators, and means for independently regulating each set of said vanes, associated with the respective radiators, each in accordance with and responsive to the temperature of liquid circulated within the associated radiator.

12. In a cooling system for an internal combustion engine of locomotive type, a conduit for direction of cooling air, arranged longitudinally of the locomotive and near. one end thereof, radiators disposed at opposite sides 01' the locomotive and in the path oi. cooling air circulated in the conduit, said radiators being adapted respectively to cool the engine Jacket water and the lubricating oil, the conduit being provided with an opening near one end of the locomotive, a partition structure associated with the conduit and serving under certain conditions to a direct the air therein toward and into the radiators, a set of movable vanes adjacent each oi said radiators, arranged, when closed, to com- Plete the closure of the conduit about the radiators, means for independently regulating each set of said vanes, associated with the respective radiators, each in accordance with and responsive to the temperature of liquid circulated within the associated radiator, a fan or blower assembly within the conduit, and means operable responsively to temperature oi the engine Jacket water, for varying the displacement of air in the conduit by said blower assembly.

13. In a cooling system for an internal combustion engine of locomotive type, a cooling air conduit forming a chamber near one end of the locomotive, radiators arranged in liquid-cooling relation to the engine and disposed at opposite sides of the chamber and laterally oi the locomotive, said conduit having an air opening at the end of the locomotive and extending in a general direction longitudinally oi the locomotive, a movable vane element disposed internally of the conduit, and means operable in response to the temperature of liquid to be cooled by one of the radiators, for varying the position of said vane element in a direction from either radiator and toward the other, whereby to proportion the volume of air delivered to the respective radiators.

14. In-a cooling assembly for an internal combustion engine of locomotive type, a pair of oppositely disposed radiators, a conduit for cooling air, having its intake atone end of the locomotive and adapted, in one direction of operation of the locomotive, to discharge through the radiators, and a vane element movably mounted in said conduit so as to be-swung from either radiator and toward the other, whereby to proportion the air tram the conduit, directed to the respective radia rs.

15. In a cooling system for an internal combustion engine and in combination with a locomotive adapted for propulsion by the engine, the engine being oi a type requiring liquid cooling, a pair of radiators mounted laterally or and near one end of the locomotive, a chambered conduit structure having an opening adapted for air intake, and extending therefrom near one end of .the locomotive an thence between the radiators,

and a substanti v-shaped structure at the opposite end of the chambered conduit, and serving to deflectthe air i'rom said end of the chambered conduigflaterally into the radiators.

16. In a cooling system ror an internal combustion engine and in combination with a locomotive adapted for propulsion by the engine, the engine being of a type requiring liquid cooling, a pair of radiators mounted laterally or and near one end of the engine, a conduit structure extending from an inlet portion near one end of the locomotive andthence between the radiatomandalub stantislly v-shapedstructureattheoppositeend of the conduit, and serving to deflect the air from the intake portion of the conduit, laterally into the radiators, independent means including movable vane elements controlling the passage of air through the respective radiators, and thermostatic control means independently operably associated with said vane elements, for efiecting control thereof responsively to changes in temperature of liquids to be circulated in the respective radiators.

1'1. In combination in a cooling system for an internal combustion engine arranged for locomotive propulsion, and a locomotive driven thereby, a radiator constituting an element of a liquidcooling system of the engine, a cooling air conduit directed toward said radiator, a tan or blower arranged to supply air to said conduit, the loco motive being provided with an air intake passage having an inlet opening in the upper portion of one of its end walls, said passage extending inwardly and downwardly of the locomotive body structure, for communication with said conduit .and for supply of air to said blower.

18. In combination in a locomotive including an internal combustion engine .for propulsion thereof, a cooling system for the engine including a radiator, arranged along a side wall of the locomotive, an air inlet opening in the upper portion of an end wall of the locomotive, an air conduit extending from said opening inwardly and downwardly oi the locomotive body and terminating at said radiator, and a fan disposed in said conduit adjacent said opening, said fan being inclined to conform with the inclination oi the inlet portion of said conduit and adapted for the induction of air inwardly and downwardly o! the end oi. the locomotive body.

19. In a thermal control assembly for the cooling system of an internal combustion engine of locomotive type, and in combination with a loco-. motive propelled by the engine, a radiator in cooling association with'a circulating liquid from the engine, an assembly of adjustable louvres associated with the radiator, and arranged to control the eilective e of air therethrough, thermostatic control means for said louvres, operable in response to a predetermined temperature of said liquid, and an engine-load control device operable in conjunction with said thermostatic control means, but responsively to liquid temperatures 01' a higher order than those normally influencing the louvre-controlling eflects oi said thermostatic means.

20. In a thermal control assembly for the cooling system of an internal combustion engine of locomotive type and in combination with a locomotive propelled by the engine, a radiator in cooling association with a circulating liquid from the engine, an assembly of adjustable louvres assonouns I. mostly.

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