US2424795A

US2424795A - Reenforced elliptical oil cooler

Info

Publication number: US2424795A
Application number: US472462A
Authority: US
Inventors: Burns Bruce
Original assignee: Garrett Corp
Current assignee: Garrett Corp
Priority date: 1943-01-15
Filing date: 1943-01-15
Publication date: 1947-07-29
Anticipated expiration: 1964-07-29

Description

July 29,1947. UR S 2,424,795

. REENFORCED ELLIPT-ICAL OIL COOLER Filed Jan. 15, .1945 '2 Shets-Sheet 1 fiuly 29', 1947. B. BURNS REENFORCED ELLIPTICAL OIL COOLER Filed Jan. 15, 1945 2 Sheets-Sheet 2 Imvcmor: BRUCE BUR/Y5 Patented July 29, 1947 REENFORCED ELLIPTICAL OIL COOLER Bruce Burns, Los Angelcs, Calif., assignor to The Garrett Corporation, Airesearch Manufacturing Company division, Los Angeles, Callt, a corporation of California Application January 15, 1943, Serial No. 472,462

2 Claims. (Cl. 257-128) My present invention relates to radiators, and relates in particular to a radiator especially adapted for the cooling of oil from the crank case of an internal combustion engine, and which is especially suited for aircraft installation.

It is an object of the invention to provide an oil cooler having greater capacity for a given height than can be obtained by use of the commonly employed cylindric type of oil cooler construction. In air craftit is quite often found that the space to receive the oil cooler is limited in vertical dimension and that an oil cooler of cylindrical form which would flt into this space will not have an oil cooling capacity sufficient to cool the aircraft engine with which it is to be used, thus making it necessary to employ a pair of small cylindrical oil coolers in tandem relation.

It is an object of the present invention to provide a cooler of flattened, elliptical form which is amply strong to withstand the pressures developed in the oil cooling system to which it is connected, without excessive weight, and, due to its increased width as compared to its height, having much larger capacity than is obtainable from a cylindric cooler of the same height.

It is an object of the invention to provide an oil cooler having a shell which is tubular, that is to say, has the general characteristics of a tube in that it is open, from front to rear, this shell being flattened to substantially elliptical form, the shell having tension plates extending substantially parallel to the minor axis and from front to rear of the shell, these tension plates also acting as bafiles for directing the flow of oil to be cooled along a tortuous path through the cooler. It will be understood that the crossseotion of the shell need not be a true ellipse, but portions of the shell which lie in transverse relation to the minor axis of the shell may be substantially parallel to the major axis of the shell for a considerable distance. In the preferred practice of the invention, however, the shell is continuously curved in the direction corresponding .to its circumference.

It is an object of the invention to provide an oil cooler of flattened or elliptical form with rounded ends, and which is relatively strong for its weight, by reason of the employment in this cooler of the simple and effective manner in which it is reinforced by a jacket member which also provides ducts for the flow of oil to the inlet opening of the cooler shell and which provides warm -up channels effective in the transmis sion of heat through the wall of the shell into 2 the interior of the cooler to thaw out the oil in the marginal portions of the cooler during starting periods.

It is an objectof the invention to provide a cooler of the class described h'aving bafile so formed that zig-zag flow channels ar provided along the inner surface of the cooler shell from the inlet to the outlet of the shell, in which passages cold or sluggish oil may receive heat which been conveyed through the wall'of the shell from hot oil in the warm-up passages formed by the jacket which reinforces the cooler shell.

It is a further object of the invention to provide a means for effectively reinforcing theflattened shell of an oil cooler of the character described herein, such means comprising tension plates having flanges on their extremities, these flanges being secured to the shell so that forces acting within the shell and tending to deform the same from elliptical to cylindric form are carried by these tension plates.

I Further objects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawings which are for illustrative purposes only,

Fig. l is a perspective view of a preferred embodiment of my invention, having portions cut' away so as to show internal construction.

Fig. 2 is a sectional view taken substantially as indicated by the line 2-2 of Fig. 1.

Fig. 3 is a sectional view taken as indicated by the line Zi3 of Fig. 2-.

Fig. 4 is a perspective view of one of sion plates employed in the cooler.

Fig. 5 is a fragmentary section showing a manner in which the plate may be connected to the cooler shell by use of flange members.

Fig. 6 is a fragmentary sectional View similar to Fig. 5, but showing one of the flanges int tegrally formed on the edge of the tension plate.

Fig. 7 is a fragmentary perspective view showing the arrangement of tubes adjacent a tension plate.

Fig. 8 is an enlarged fragmentary section showing a wall of the cooler shell and the manner in which the jacket is secured thereon.

Referring to Figs. 1 to 3 inclusive, the cooler the tenhas a shell it which consists of a metal sheet ii of elongated form, curved to form a continuous loop, with the ends :2 thereof joined so that the sheet then forms a short tube flattened, as shown in Figs. 1 and 3, so that in cross-section it will have the general form of an ellipse, the major axis of which is nearly twice the length -3 of its minor axis. For convenient reference, the shell is described as having a front end F, a rear end R, and sides S. At its leftside, toward the rear end, the shell has an inlet port l3, and at ,its opposite, or right side, near its front end has an outlet port 14. The interior of the shell is divided into consecutive sections 15 by tension and baflle plates I8 lying in planes which are transverse with relation to the major axis of the shell and extend from front to rear of the shell. These plates It, as shown in Fig. 2, are preferably parallel to each other and to the longitudinal axis of the shell, and, as shown in Fig. 3, are parallel to the minor axis of the shell and accordingly at right angles to the major axis of the shell.

- The plates (3, as shown in Fig. 4, have therein openings l I to provide intercommunication be tween adjacent chambers or sections 15 which the plates [6 segregate within the shell Ill. The extreme upper and lower openings l1 comprise notches in the upper and lower edges of the plates so that when the plates are in operative position within the shell, the wall of the shell will form one boundary of each of the openings l1. Therefore, the openings ll are brought into closest possible proximity to the wall or sheet I I from which the shell i is formed. The openings I1 and ii are disposed alternately at the front and rear ends of the plates l6 within the shell [0, as shown in Fig. 2, so thatoil flowing through the interior of the cooler from the inlet l3 to the outlet M will flow through the zigzag path indicated by the arrows I8 of Fig. 2 from rear to front and front to rear of the cooler.

The upper and lower edges of the plates l are tied to the upper and lower portions of the shell so that these plates It not only serve as baflle plates for directing the flow of oil in a desired manner through the interior of the cooler, but effectively restrain the upper and lower wall portions of the shell in from moving or deflecting upwardly anddownwardly respectively, when oil pressure is built up in the sections I5 of the cooler and tends to deform the shell from an elliptical tube to a cylinder. For attachment of the plates lBto the shell HI flanges l9 are secured to the upper and lower edges of the plates l6, as shown in Fi 5. by use ofwelds 20, and these flanges l8 are in turn firmly secured to the wall ll of the shell in by welds 2|. In Fig. 6 I show a plate attaching means consisting of an angle 22 welded at 23 adjacent an oppositely extending flange 24 which is bent on the edge of the plate IS. The angle 22 and the flange 24 are connected by. welds 25, to the wall or sheet I I of the shell I0.

Although not shown in Fig, 2, it will be understood that each of the sections i'5 contains a bundle of tubes 25 through which a heat absorbing fluid, ordinarily air, may flow from front to rear of the cooler in the known manner of cooler construction.

As shown in Fig. 7, these tubes 25 have at their ends

tubular walls

26 and 21 of two separate cross-sectional configurations. These tubular walls or enlargements 26 are joined together by solder and cooperate in forming closures for the front and rear ends of the sections I5. The tubular wall 26 are hexagonal and the tubular walls 21 are pentagonal so as to be placeable one upon the other along a side of a plate 16 in the manner shown in Figs. 1, 3, and 6. The

tubular walls 21 have side sections 28 for engagement with 'a plate I6, upper and low r S tions 29, perpendicular to the sections 28, for

engagement with similar sections on the ends of- Being flat, or substantially flat, the baflle plates l6 are non-distensible and consequently are adapted to function as tie elements for securely tying together the opposite sides of the shell across the minor axis thereof so as to prevent any appreciable distortion of the shell under the expansive pressure of .the oil being forced therethrough. It is to be noted that even a slight amount of expansion of the shell across its minor axis would result in pulling of the shell away from the adjacent tubes or pulling of the tubes apart so as to cause a leak in the cooler.

The shell III is surrounded by a jacket 32 which has'a dual function, namely, that of strengthening the shell and of providing channels for a warm-up flow of oil. As clearly shownfin Fig. 3, the jacket 32 comprises upper and

lower halves

33 and 34 although it is preferably formed from a single elongated sheet of metal 35 so as to be in fact a substantially single piece member which extends around the exterior face of the shell l0 and. has parts thereof joined to the shell. The edge portions 36 of the sheet 35 engage edge portions of the shell l0 and are connected thereto by seam welds 31, although spot welding may be employed for this purpose and the joint between the edge portions 36 and the edges of the shell l0 sealed by use of solder. mean a progressively formed continuous spot weld or resistance weld.

Between the edge portions 33 thereof, the sheet 35 is formed with channels or

depressions

38 and 39, the channel 36 occupying a central position with respect to the front and rear ends of the cooler and the channels 39 being placed on opposite sides of the channel 38. These

channels

38 and 39, as shown in Fig. 8, each consists of a pair of spaced side walls 40 extending inward from the outer wall 4! of the jacket 32, and the bottom wall 42 connecting the inner edges of the side walls 40, this bottom wall 42 engaging the surface of the shell l0 and being secured thereto by a seam weld 43.

As shown in Fig. 2, the channel 38 extends entirely around the right side of the shell so as to divide the jacket 32 into front and rear halves. As shown in Figs. 1 and 3, the channels 39 are discontinued at points 44 at the right hand side of the cooler so that they will not passacross the

jacket spaces

45 and 46. At the left side of the shell all three of the upper and

lower channels

38 and 39 are discontinued at the points 41 so as to leave at the left side of the jacket a continuous channel or space 48 which communicates with the

jacket passages

49 and 50 which exist between the

channel

38 and 39 and also with the inlet port 13 of the shell. It will be noted that the passages 49 communicate with the chamber 45, Fig. 2, and that the passages 50 of the jacket communicate with the chamber 46. In spaced relation to the right side of the cooler there is an attachment plate 5| to which a control valve 52 may be secured, whereby inlet duct 53, outlet duct 54, and bypass duct 55 may be connected to the interior of the control valve 52 and to the spaces of the cooler, as shown in s Fig. 2. i

The inlet duct 53 connects with the inlet chamber 45 of the jacket. The outlet duct 54 connects By seam weld wedelivered by the valve 63 with the outlet port i4 of the shell and extends through a portion of the chamber 46. The bypass duct 55 connects with the chamber 46. During normal operation of the cooler, oil to be cooled is conducted into the valve 52 through oil inlet pipe 56 and is transmitted through the inlet traverses the path indicated by the arrows l8.

Should there be an increased resistance to flow of oil through the cooler resulting, for example, from congealing of oil in the spaces between the tubes 25, the bypass valve mechanism of the valve 52 will open and permit oil to flow from the chamber 48 rightward through the jacket passages 50 as indicated by the arrows 60 of Fig. 3, to the chamber 46 from whence the oil will flow, as indicated by arrows 6|, through the bypass duct 55 to the control valve 52. In this event hot oil will flow from the-chamber 45, Fig. 2, leftward through the jacket ,passages 49 to the leftward ends of the jacket passages 50, and then right ward through the jacket passages 50 so as to be 52 into the oil return pipe This bypass flow of oil through the

jacket passages

49 and 50 will heat the shell "I, and the shell ID will conduct heat to the oil within the cooler contacting the inner face of the shell, thereby increasing the fluidity of the oil in contact with the inner face of the shell, so that due to the pressure differential existing between the inlet port l3 and the outlet port ll of the shell,

transverse relation to the major axis of said shell, said plates having in alternate order openings near the front and rear ends thereof connecting said spaces so as to form a continuous zigzag passage within the interior of said shell, there being tension bearing connections adequate to withstand the full loads imposed on said shell by fluid'underpressure therewithin, tying the upper and lower portions of said plates to said shell so that said plates will act in tension to prevent deformation of said shell toward cylindrical form under said pressure; tubes for a heat absorbing medium extending through said spaces from front to rear of said shell, there being means at the ends of said tubes cooperating therewith to close the front and rear ends of said spaces; means supported on the cooler to form let port and a bypass port; and a jacket on the exterior of said shell, said jacket comprising a metal wall corrugated so that edge portions and intermediate portions thereof will engage the shell, said edge portions and said intermediate portions being seam-welded to the outer face of said shell so thatsaid jacket will reenforce said shell and form passage meansfor said inlet port to said inlet opening, and from said first named passage to said bypass port. 4

2. In a cooler of the class described, the combination of: an elliptical shell having an inlet and outlet for passing oil into and out of the interior of said shell; plates dividing the interior of said shell into a plurality of spaces and connected v to thefltop and bottom of said shell to reenforce a flow of such oil may be started along the top and bottom portions of the sections l5 and through the openings II' in the upper and lower edges of the plates l6 which connect the upper and lower portions of the sections IS in series so as to define a zigzag path of flow for oil, such path of "flow lying in contact with the inner face of the shell and therefore in the zone heated by conduction of heat through the shell from the hot oil which flows through the

jacket passages

49 and 50. This relationship between the jacket passages, the shell, and the openings ii in the plates l6 results in a condition in the cooler which 'contributes to rapid warming up of the same from a cold or congealed state whereby maximum effectlveness of the cooler is obtained.

I claim as my invention:

1. In a cooler of the class described, the combination of: a tubular shell flattened so as to have approximate elliptical form with its major axis horizontally disposed and its minor axis vertically disposed, said shell having an inlet opening at one side thereof and an outlet opening at the other side thereof; spaced substantially fiat plates extending from the top to the bottom of said shell and from front to rear of said shell, said plates dividing the interior of said shell into a plurality of side by side spaces disposed in the same against deformation, said plates having in alternate order openings near the front and rear ends thereof connecting said spaces thereby to provide a continuous zigzag passage within the interior of said shell; tubes for a heat absorbing medium extending through said spaces from front to rear of said shell; and a reenforcing member surrounding said shell and forming a series of side by side warm up passages along the exterior of the shell, having portions spaced from the shell to form theouter walls of said passages and having other portions extended inwardly to the shell and welded thereto to form the side walls of said passages and provide reenforcing support to the shell.

BRUCE BURNS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS an inlet port, an outconducting hot oil from