US2244641A - Heating and cooling system for engine lubricating oil - Google Patents

Description

June 3, 1941. L. F. FEDDERs HEATING AND COOLING SYSTEM FOR ENGINE LUBRICATING OIL 27, 1959 2 Sheets-Sheet 1 Filed OCTI INVENTOR Lou/ls E'Fe ens W ATTORNEY June 3, 1941;v L F, FEDDERSl 2,244,641

HEATING AND COOLING 'SYSTEM FOR ENGINE LUBRICATING OIL Filed O'ct. 27, 1939 2 Sheets-Sheet 2 J5 Z vim* (/4 44 ATTORNEY Patented June i3, 19.41 Y

HEATING` AND COOLING SYSTEM 4FOR ENGINE LUBRICATNG OIL Louis F. Fedders, Buffalo, N. Y., assignor to Fcdders Manufacturing Company, Inc., Buialo,

Application October 7, 1939, Serial No. 301,631

'z claims. (ci. 12s-196) This invention relates to radiators for cooling Fig. 4 is a perspective view of the sheet metal the oil supply of internal combustion engines. portion of the preheating jacket;

'I'he invention is especially pertinent to the oil Figs. 5 and 6 are side elevations oi further emcooling problem of airplane engines; where heat bodiments of the invention;

dissipation requirements are extremely critical. 5 Fig. 7 is a section on the line 1-1 of Fig. 5;

It has heretofore been recognized that oil radi- Fig. 8 ls an end view of the cooler of Fig. 6. ators are subject to blocking by cold oil, and that In Fig. 1 there is diagrammatically shown a even after the lengine has been properly warmed jacketed glycol-cooled engine I, having inlet and up the blockade continues and renders the oil outlet conduits Il and l2 leading to the glycol radiator, or portions thereof, ineffective. Flying 10 radiator I3, the latter conduit having a liquid` at high altitudes and at extremely low temperacirculating pump I4 interposed therein. The oil tures further aggravatesv this condition, and it circuit for the engine includes an auxiliary pump will be apparent that when critical demands for 15 which receives oil from the engine sump oil cooling subsequently arise, the oil cooler must through a conduit I6, and delivers it to the oil respond nstantiy. 0r the engine may be seriously l5 radiator or cooler 20 through a conduit I1. After y overheated. -passing through the cooler 20, the oil is directed radiator during critical acceleration periods.

` plane under all flying conditions. l, 40

It has been Proposed to utilize the heated oil back to the engine crankcase through a conduit in the crankcase to preheat or thaw the oil ra- |3 The e0e1er 15 jaeketed, as win presently be diator under control of a by-pass circuit which described,- to receive hot glycol from the engine responds to a pressure valve or like instrumen- 2o block through a conduit 2i for. preheating the tallty. This expedient has proved itself to be oil, and the glycol is directed thence to the sucineincient when used in the most modern hightion side of the pump i4 through a conduit 22. powered aircraft, chiefly because of the inability It will be understood that, according to modern 0f the preheater t0 COIlVey eIlOugh heat t9 the 25 practice, the glycol is retained atarelatlvely high temperature, say about 300 F., by suitable con- 111 the 'present HVGDOII, both Oilhealing and y trol devices cooperating with the glycol radiator oil coolingV are automatically available in response i3.

to temperature conditions in the oil cooler. In The 011 circuit also includes e, by..pass, herein .the formel instance a true heating effect 1S 0b- 30 shown diagrammatically as a conduit 24 contained by utilizing the glycol fluid which is taken meeting the Outlet of the 011 pump |5 to the directly fronle the engine block at temperatures crankcase of the engine. 'I'his arrangement prerangl'ng above 300'F- This hea-t Supply plus a' vents rupture of the oil radiator elements when orlllcal control fol' the nppllca'tlon thereof'lssuff' excessive head pressures are encountered, in flolent lo 'bring the oll 1 n the ,ranlatol' tf? tno 35 which event oil is returned directly to the crankf proper degree of fluidity m a mlmmum of time case through the conduit 24 under control of a during warming-up periods of Ithe engine, and We11 kn9wn type of pressure responsiv valve 25 further it continues to maintain such condition included in such cmg/uit If desired the on. cook automatically during active operation of the air mg circuit may be dissiated non; the bearing In the structure of the present invention, it is ou supply means' mwhch event a' separate'bear' further proposed to simplify the oil cooler and the associated connections and controls to protion vide addedy effectiveness, 'as more fully'set-l forth As Shown ln Fig- 2 the ooollng ull-lf' of the oll m the accompanying speccation and drawings, 45 Vradiator 20 is preferably in the form of a cylindriwherem; cal .tube bundle or core 30, which, as is well known Fig. 1 is a diagrammatic view oi an airplane enln the nrt faolloofted of elongated tubes 3l. gine and its accessories including a glycol radihaving nested hexagonal ends or heads 32 which ator and the oil cooler and circuit of the present are soldered together t0 form a rigid Structure' invention; 50 The core is circumferentially sealed by an en- .Fig. 2 is .afront elevation of the oil cooler with Closing Sheet metal tube 33, whose ends are solportions broken away to show ,the passage struc-Y .deledio the peripheral heads 32 of the core. AS

tures; n thus far described, it will be apparent that cool- Fig. 3 is a section' on the une a-s of Fig. 2, ing air may pass through the tubes 3l, while oil with portions Shown in e1evatien Nintroduced through the tube 33 may pass about ing pump 21 may be used to perform this func- A the tubes in heat exchange relation with the air streams through the walls i the tubes.

The tube 33 is formed with adjacent oil inlet and outlet ports 34 and 35, respectively. A baiile plate 36 is interposed between the ports, and it extends 'in a horizontal direction through a portion of the core and terminates inv a semi-circular scoop portion 31. A second bale plate 38 extends substantially radially inward from the tube 33 to, in effect, divide the passage formed by the scoop portion 31. Thus, oil entering the core through the port 34 is directed by the scoop porrtion 31 in a reentrant path through a central section o! the tube bundle, and thence it is diverted by the baille plate 38 to peripheral portions of the core, through which it flows in a clockwise direction to the outlet port 35. Viewing the baffle arrangement from the side (Fig. 3), it will be noticed that the baille plate 36 contains a port 40 located adjacent the end of the unit which is remote -from the inlet and outlet ports. This insures that oil will also ilow endwise along the tube spaces so that circulation is fairly uniform throughout the core.

The tube 33 forms part of an'element or preheating jacket 4| in cooperation with an outer concentrically spaced shell 42' and end wallsv43 and 44 (Fig. 4). The shell 42 is provided with glycol inlet and outlet ports 45 and 46. A transverse baille wall 41 within the jacket 4| separates the adjacent ports and enhances circulation oi' the hot iiuid about the device.

The jacket structure is cut back at one extremity, as indicated by the numeral 48, to ex- Y Dose the oil ports 34 andx35 in the tube 33. A

valve tting 50 is soldered to this portion of the tube 33, and it contains inlet and outlet passages and 52 leading into the ports 34`and 35 respectively, .and connecting such ports to the previously described conduits I1 and I8. The outlet passage 52 additionally is formed with a pocket 53 for receiving a thermostatic bulb 54. A glycol tting 55 is similarly soldered ov r the oil ports 45 and 45 of the shell 42, and such tting is formed with oil inlet and outlet passages 56 and 51 respectively leading to the glycol circuit conduits 2| and 22.

The iitting 55 is also formed with a seat 58 for receiving an outwardly opening valve 60. A .cap 5| is secured over an angular extension 59 on the tting 55, and such cap carries a thermostatic bellows 53. A tube 62 leads from the bellows 63 to the described bulb 54 in the oil outlet passage 52. The free extremity of the Abellows 63 engages the projecting stem of the valve 50.

In the operation of the oil cooler, it will be apparent that on starting a cold engine the oil -will circulate about the by-pass 24 of the auxiliary Dump I5, since the'normal oil path through the core of the oil cooler will be substantially blocked because of the highly viscous state of the oil in the narrow passages thereof. As the engine operates, the glycol uid in the engine block will heat up more rapidly than the oil, and since it is continuously circulated through the jacket during this period, it will be apparent that the oil in the core will be rapidly brought to the desired degree of iiuidity. When this occurs, flow through the oil cooler is immediately instituted, and the check valve 25 in the o il pump by-pass circuit gradually closes, until the full delivery of the pump I5 passes through the cooler.

It will thus be seen thatduring starting, 4or relatively cold engine conditions, the present de- Y vice acts not only to thaw the oil radiator, hrt

-may be mentioned that this feature is especially adapted to airplane engines oi! high horsepower ratings, where the normal glycol temperatures are retained at around 300 F., and the oil temperatures at 180 F., since this diierential not only insures a faster heat transfer. but a steeper heat gradient during warming-up periods. Thus,

during a phase of this period, the oil and glycol temperatures might be and 150?1 respectively, with the latter fluid always available to warm the former.

When y the oil subsequently approaches its proper operating temperature, the thermostatic'- ally controlled valve 50 automatically responds thereto and closes oil the ow of glycol to the jacket. It will be understood that the device is also useful under actual flying conditions. For example, during a long gravity glide from a high altitude, the oil coolers in the prior art have been subject to partial or complete blockage, which could only be relieved after the glide by the introduction oi copious volumes of hot oil in the jackets thereof. In the present invention, during the `Asame maneuver, the valve-60 would immediately Figs. 5 and 7, for example, the heating element 10 is cup-shaped and centrally located in the tube bundle 1|. Otherwise, the fittings yand circuits for the oil and glycol are similar to those of Fig. 2. In Figs. 6 and 8 the heating element 80 is cylindrical, but located\ centrally in the tube bundle 8|, so' that heat transference to the core is available from the inner and outer surfaces of the heating element. It will also be understood ythat while the invention has been described with particular reference to a liquid cooled engine, it

is intended thatfthe principle may be applied to other types of engines, whenever it is convenient touse the higher temperatures in the engine heating the oil cooler.

I'claimf 1; A combined heating and cooling system Vi'or 1 the lubricating oil of internal combustion engines of the glycol cooled type, comprising an oil radiator having a thermally related core and heating element, said core having air passages therethrough and having a plurality of internal oil passages therein, said oil passages forming in eiect a plurality of narrow paths through which hot oil may pass freely'y and through which cold oil may pass with diiliculty, pump means i'or directing oil through the core, a return conduit' from the core to the engine, a 4by-pass circuit for the pump having pressure-responsive means operative when the oil passages of the core are substantially blocked by cold oil, a glycol circuit including a feed conduit from the engine for directing the hot glycol iluidinto the heating element and a return conduit from the element to the engine, a valve interposed in the glycol circuit, and thermostatic means responsive to temperature conditions in the core for controlling said valve in the glycol circuit.

2. An oil radiator having a cylindrically shaped core containing a plurality of axial openings for the passage of cooling air and having internal oil passages therein forming in eiect a plurality of narrow paths 'through which hot oil may pass freely and through which cold oil may pass with diiiculty, a jacket enclosing and sealing the periphery of the core, o inlet andoutlet passages leading through the jacket into the core, a chamber formed within the jacket for the reception of a heating iiuid for the core, inlet and outlet passages leading into the chamber of the jacket, a

valve in one of the jacket passages, thermostatically operable means for controlling the valve including a. thermostatic bulb located in one of the oil passages whereby the operation of the valve in the jacket passage is controlled by the [oil temperature.

3. An oil radiator having a core containing a plurality of parallel openings for the passage of cooling air and having internal passages .therein forming in. eiect a plurality of narrow paths through which hot oil mayl pass freely and through which cold oil may pass with difiiculty, al hollow heating element organized within the core, oil inlet and outlet passages leading into the core, inlet and o utlet passages leading into the heating element, a valve in one of the element passages, thermostatically operable means for controlling the valve including a thermostatic bulb located in one of the oil passages, whereby operation of the valvein the element passage is controlled by the oil temperature. y

4. A combined heating and cooling system for the lubricating oil of internal combustion engines of the glycol cooled type, comprising an oil radiator having cooling air passages extending thereplurality of narrow paths through which hot oil lubricating oil for said engine, an oil radiator having a core and a thermally related heating element. said core also including separate and thermally related passages for the oil and for an extraneous cooling medium, said element being interposed in said high temperature iluid circuit,

.means responsive to the temperature of the oil in the core for controlling the flow of hot engine cooling liquid in its circuit and through said element, pump means associated with the engine for directing oil through said core, and a return conduit for oil extending from the core to the engine.

6. A combined heating and cooling system for the lubricating oil of an internal combustion engine of the type whose cylinder walls are cooled by liquid having a high working temperature under normal operating conditions, comprising a cooling liquid circuit associated with the engine, engine activated means for maintaining the liquid in said circuit at a temperature higher than the normal working temperature ot the 'lubricating oil for said engine, an oil radiator may pass freely and through which more viscous I cold oil may pass with diiculty, pump means for directing oil through the oil passages, a return conduit from the oil radiator to the engine, a by-pass circuit for the pump Ahaving pressureresponsive means operative when the oil passages are blocked by cold oil, a glycol circuit from the engine including therein a heating element thermally'associated with said oil radiator, a valve interposed inthe glycol circuit. and thermostatic means responsive to temperature conditions in the oil radiator for controlling said valve.

'5. A combined heating and cooling system for thelubricating oil oi' an internal combustion engine of the type whose cylinder walls are cooled by liquid having a high working temperature under normal operating'conditions, comprising a lcooling uid circuit associated with the engine,

engine activated means for maintaining the liquid in said circuit at a temperature higher than the normal working temperature of the having a core and a thermally related heating element, said core also including separate and thermally related passages for the oil and for ah' for cooling the oil, said elementrbeing interposed in said high temperature liquid circuit, means responsive to the temperature of the cil in the core for controlling the iiow of hot engine cooling liquid in its circuit and through said element, pump means associated with the engine for directing oil through said core, a return conduit for oil extending from the core to the engine, and a by-pass circuit for the pump havingv pressure-responsive means operative'when said core is blockedv by viscous oil conditions in said radiator core.

' 7. A combined heating and cooling systemior the lubricating oil of an internal combustion engine oi the type whose cylinder walls are cooled by glycol whose normal working temperature is higher than the normal working tempera- A ture of water in a water-cooled engine, comprising an oil radiator having a. thermally related core and heating element, said core also including separate and thermally related passages for the oil and for an extraneous cooling medium,

glycol circuit, and thermostatic meansresponsive v to temperature conditions in the oil in the core for controlling said valve in the glycol circuit.

LOUIS F. FEDDERS.

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