Heat exchanger assembly

Abstract: In order to eliminate components and fixtures, facilitate assembly, avoid leaks, and reduce cost in a heat exchanger for exchanging heat between two fluids such as a coolant and oil, the heat exchanger includes a header plate (24) having a central opening defined by a column integrally formed with the header plate (24) together with a radial opening (30). A plurality of heat exchange units (32) are stacked on the header plate. The heat exchange units (32) each comprise a pair of plates (34, 36) joined together at inner and outer peripheral edges to thereby sealingly define a plurality of first chambers (42) for the flow of one of the fluids wherein a column-receiving opening (44) is provided radially inwardly of the first chambers (42) thereof. The heat exchange units (42) further include aligned first openings (46) and aligned second openings (48) on opposite sides of the column-receiving openings for joining the first chambers in a first fluid flow path, and the radial opening in the header plate comprises a first fluid inlet for directing the first fluid through one of the first openings into the first fluid flow path where it flows until it reaches a first fluid outlet therefor. The heat exchange units are stacked on the header plate about the column where they are arranged in a spaced series by spacers which serve to define a plurality of second chambers (54) for the flow of the second fluid between each pair of the spaced series of heat exchange units. A tank (56) covers the heat exchange units stacked on the header plate. With this arrangement, the tank (56) is integrally secured to the header plate and to the column to sealingly confine the second chambers (54), and it has an inlet (62) for directing the second fluid into the second chambers (54) and an outlet (64) for receiving the second fluid from the second chambers after it has flowed through a second fluid flow path.

Description: This invention generally relates to a heat exchanger assembly and, more particularly, a heat exchanger assembly having an extruded header plate and central column. US-A-4561494 discloses a heat exchanger including a header plate having a central opening and a radial opening; a plurality of heat exchange units stacked on the header plate and each made of a pair of plates joined together at inner and outer peripheral edges to define a plurality of sealed first chambers for the flow of a first heat exchange fluid and to define a plurality of openings aligned with said central opening; spacer means for maintaining said heat exchange units in spaced relation; aligned first openings and aligned second openings in said heat exchange units on opposite sides of said plurality of openings for joining said chambers in a first heat exchange fluid flow path with said radial opening comprising an inlet for said first heat exchange fluid flow path; said spacer means arranging said heat exchange units in a spaced series to define a plurality of areas for the flow of a second heat exchange fluid between each pair of said spaced series of heat exchange units; a tank enclosing said stack of heat exchange units therewith; an inlet for directing said second heat exchange fluid into said plurality of areas; and an outlet for receiving said second heat exchange fluid from said plurality of areas; said inlet, said outlet and said plurality of areas defining a second heat exchange fluid flow path. Heat exchangers made according to US-A-4561494 have proved to be extremely successful in commercial applications. This is particularly true of applications such as cooling the lubricating oil in an internal combustion engine. In this connection, the disclosed structures are relatively simple in design, inexpensive to fabricate, and readily serviceable when required. Nonetheless, it is desirable to provide additional advantages in a heat exchanger assembly including, for example, a reduction in the number of components, an elimination of the need for fixtures, a reduction in the number of joints, an enhancement in ease of fabrication, and a reduction in expense. As will be appreciated, the present invention differs from those set forth in the above identified patents in providing these and other advantages which are disclosed and claimed herein. The present invention is characterised in that said central opening is defined by a column integrally formed with said header plate and extending through said plurality of openings, and said tank is sealed to said header plate and to said column. In a highly preferred embodiment, the header plate and central column are integrally formed of impact extruded aluminum. In one form of the invention, a stand-off is also integrally formed with the header plate on the side thereof opposite the column in order to space the heat exchange unit, for instance, from an engine block or the like. In either case, an O-ring receiving recess may be integrally formed during extrusion to form a seal on the engine block. Advantageously, the heat exchange units and the column have cooperative alignment means for ensuring alignment of respective ones of the first and second openings. The alignment means preferably comprises a tab and recess arrangement wherein a pair of integrally extruded axially extending tabs or ears is formed on the column and a pair of corresponding tab-receiving recesses is formed on each of the plates. With this arrangement, the heat exchange units may be rapidly stacked on the header plate about the central column in proper alignment to thereby facilitate assembly. In a most highly preferred embodiment, the spacer means comprises a plurality of buttons on the plates. The buttons are arranged in a common pattern on surfaces of the plates facing away from the first chambers of the heat exchange units such that the buttons automatically arrange the heat exchange units in a spaced series to define the second chambers. As a result, the buttons allow the flow of fluid between each pair of the spaced series of heat exchange units. For some applications, the heat exchange units have turbulator means within the first chambers which may comprise a separate component disposed between the plates of each of the heat exchange units. However, and most advantageously, the turbulator means may be formed by a plurality of parallel indentations in a ripple pattern on the surface of each plate facing toward the first chambers thereof. Other objects, advantages and features of the present invention will become apparent from a consideration of the following specification taken in conjunction with the accompanying drawings. Brief Description of the Drawings Fig. 1 is a view of a heat exchanger made according to the present invention and employed as an oil cooler mounted on the block of an engine in connection with an oil filter; Fig. 2 is an enlarged, horizontal sectional view illustrating various details of a heat exchanger made according to the present invention; Fig. 3 is an exploded perspective view illustrating the components of one of a plurality of heat exchange units to be stacked on a header plate; Fig. 4 is an enlarged, horizontal, sectional view of one plate embodiment for a heat exchange unit of a heat exchanger made according to the present invention; Fig. 5 is a plan view illustrating another plate embodiment for a heat exchange unit of a heat exchanger made according to the present invention; Fig. 6 is an enlarged, horizontal, sectional view of the plate embodiment illustrated in Fig. 5 illustrating details of the ripple pattern thereof; and Fig. 7 is a vertical, sectional view of another header plate embodiment having a stand-off for a heat exchanger made according to the present invention. Detailed Description of the Preferred Embodiments An exemplary embodiment of a heat exchanger made according to the invention is illustrated in Fig. 1 in the environment of an internal combustion engine having an engine block 10. A heat exchanger 12 connected to an oil filter 14 serves as an oil cooler for a first fluid such as a lubricating oil for the engine. The heat exchanger 12 includes inlet and outlet lines 16 and 18, respectively, for a second fluid which may be, e.g., an engine coolant or the like. As will be appreciated, lubricating oil is directed to the heat exchanger 12 via a passage 20 in the engine block 10 while return lubricating oil is received by the engine via a passage 22. As shown in Figs. 2 and 3, the heat exchanger 12 includes a header plate 24 which is provided with a central opening 26 defined by a column 28 integrally formed with the header plate 24, and the header plate 24 also has a radial opening 30. A plurality of heat exchange units 32 are stacked on the header plate 24. The heat exchange units 32 each comprise a pair of plates 34 and 36 joined together at inner and outer peripheral edges 38 and 40 to thereby sealingly define a plurality of first chambers 42 for the flow of the lubricating oil wherein a column-receiving opening 44 is formed radially inwardly of the first chambers 42 thereof. The heat exchange units 32 further include aligned first openings 46 and aligned second openings 48 on opposite sides of the column-receiving openings 44 for joining the first chambers 42 in a first fluid flow path, and the radial opening 30 in the header plate 24 comprises a first fluid inlet for directing the lubricating oil through one of the first openings 46 into the first fluid flow path where it flows until it reaches a first fluid outlet 50 therefor. The heat exchange units 32 are stacked on the header plate 24 about the column 28 where they are arranged in a spaced series by spacer means in the form of buttons 52 which serve to define a plurality of second chambers 54 for the flow of the coolant between each pair of the spaced series of heat exchange units 32. With this arrangement, a tank 56 containing the first fluid outlet 50 covers the heat exchange units 32 stacked on the header plate 24 and, as best shown in Fig. 2, the tank 56 is integrally secured to the header plate 24 as at 58 and to the column 28 as at 60. More specifically, the tank 56 is advantageously secured in a manner such as brazing so as to sealingly confine the coolant or cooling liquid within the tank 56 as it flows through the second chambers 54. It will be seen that the tank 56 has an inlet 62 for directing the coolant into the second chambers 54 and an outlet 64 for receiving the coolant from the second chambers 54. As best shown in Fig. 3, the coolant flows through the second chambers 54 in a second fluid flow path which is generally represented by the arrows 66, i.e., substantially entirely about the plates such as 34 and 36. As will be appreciated, the heat exchange units may be sealingly formed at the time of brazing the tank 56 to the header plate 24 and the column 28. This may all be done at one time by appropriately assembling all of the components before placing the heat exchanger in a brazing oven. As a result, the manufacture of the heat exchanger is greatly simplified which leads to still further cost savings. In the illustrated embodiment, the header plate 24 and column 28 may be advantageously integrally formed by impact extruding aluminum. It will also be seen that the heat exchange units 32 and the column 28 have cooperative alignment means, preferably in the form of a tab and recess arrangement wherein the column 28 includes a pair of integrally extruded axially extending tabs or ears 68 and 70 and the plates, such as 34, have a pair of corresponding tab-receiving recesses 72 and 74, respectively, which serve to ensure proper alignment when the heat exchange units are stacked on the header plates. More specifically, the tabs 68 and 70 and tab-receiving recesses 72 and 74 thereby serve to ensure alignment of the respective ones of the first and second openings 46 and 48. In addition, the plates such as 34 may have ears 73 and 75 formed on the outer peripheral edges thereof. The header plate 24 as well as the tank 56 may then be formed so as to have a non-circular cross-section so as to generally conform to the shape of the plates having the ears thereon. As a result, the alignment of all of these components for assembly is thereby facilitated to further reduce cost. As best shown in Figs. 2 and 4, the buttons 52 are arranged in a common pattern on surfaces of the plates 34 and 36 facing away from the first chambers 42 of the heat exchange units 32. With this arrangement, the buttons 52 arrange the heat exchange units 32 in a spaced series. As a result, the buttons 52 define a plurality of second chambers 54 for the flow of the coolant between each pair of the spaced series of heat exchange units 32. In the embodiment illustrated in Fig. 3, the heat exchange units 32 have a separate turbulator 76 which is disposed within the first chambers 42 of each of the heat exchange units. It will be appreciated by referring to Figs. 5 and 6, however, that the heat exchange units 32 may each include an integrally formed turbulator. More specifically, the turbulator may be formed by a plurality of parallel indentations 78 in a ripple pattern on surfaces of the plates 34 and 36 facing toward the first chambers 42 thereof. As should now be apparent, the plates 34 and 36 making up any one of the heat exchange units 32 are identical in every respect which also serves to reduce the cost of manufacture and assembly rather significantly. It will be appreciated, however, that the plates, such as 34 and 36, of each one of the heat exchange units 32 are inverted relative to one another to thereby be disposed with the respective buttons 52 facing outwardly of the first chamber 42 thereof. Also, by forming the parallel indentations 78 at an angle to the axis 79 as shown in Fig. 5, the respective indentations 78 of the plates 34 and 36 making up any one of the heat exchange units 32 are at twice that angle to form the turbulator. Referring once again to Fig. 2, the column 28 will be seen to be hollow to receive a suitable conduit or rigid tube 80 therewithin. It will be appreciated that the conduit or tube 80 has one end 82 adapted to be connected to the engine block 10 or a fitting therein, and it has an opposite end 87 to which the filter 14 (see Fig. 1) may be mounted. As will be appreciated, the conduit or tube 80 serves as a return path as indicated by the arrow 86 for lubricating oil which is leaving the filter 14. When the heat exchanger 12 is utilized with a coolant and lubricating oil, the radial opening 30 in the header plate 24 comprises a lubricating oil inlet and the radial opening 50 in the tank 56 comprises a lubricating oil outlet. A lubricating oil may thereby pass through the passage 20 in the engine block 10, and then through the heat exchanger 12 by means of the respective aligned first and second openings 46 and 48 in the heat exchange units 32. Finally, the lubricating oil will pass from the heat exchanger 12 through the lubricating oil outlet 50 into the space 88 between the tank 56 and the dome 90 which will have an outlet 92 through which the lubricating oil may be directed into the filter 14. As will also be appreciated, the first chambers 42 comprise lubricating oil chambers and the second chambers 54 comprise coolant, i.e., cooling liquid, chambers and the second inlet 16 and second outlet 18 comprise, respectively, a coolant or cooling liquid inlet and outlet. By comparing Figs. 2 and 7, another aspect of the present invention will be appreciated. It will be seen that the header plate 24 may either comprise a substantially flat surface 94 on the bottom thereof or, alternatively, (see Fig. 7) the header plate 24 may include a stand-off 96 which is advantageously integrally formed by impact extrusion with the header plate 24 on the side thereof opposite the column 28. In either case, the flat surface 94 or the stand-off 96 includes means for creating a seal against the engine block. More specifically, the flat surface 94 and the stand-off 96 each include an O-ring receiving recess 97 and 98, respectively. The O-ring receiving recesses 97 and 98 are advantageously integrally formed during the impact extrusion process on the side of the header plate 24 opposite the column 28. In this manner, the header plate 24 may be sealed against the engine block 10 about the lubricating oil passage 20 provided therein. As will be appreciated, the stand-off 96 may be utilized where it is desired to isolate the heat exchanger 12 from the heat present in the engine block 10. From the foregoing, it will be appreciated that the present invention accomplishes a number of important objectives among which are the fact that the total number of components has been significantly reduced to thereby facilitate assembly while reducing cost. This also serves to eliminate a number of potential leak joints. In addition, the present invention eliminates the need for assembly and brazing fixtures as well as the need for a separate turbulator while also making it possible to incorporate an integral stand-off for further enhancing heat transfer characteristics.

Claims: A heat exchanger including a header plate (24) having a central opening (26) and a radial opening (30); a plurality of heat exchange units (3) stacked on the header plate (24) and each made of a pair of plates (34,36) joined together at inner and outer peripheral edges (38,40) to define a plurality of sealed first chambers for the flow of a first heat exchange fluid and to define a plurality of openings (44) aligned with said central opening (26); spacer means (52) for maintaining said heat exchange units (32) in spaced relation; aligned first openings (46) and aligned second openings (48) in said heat exchange units (32) on opposite sides of said plurality of openings (44) for joining said chambers in a first heat exchange fluid flow path with said radial opening (30) comprising an inlet for said first heat exchange fluid flow path; said spacer means arranging said heat exchange units (32) in a spaced series to define a plurality of areas (54) for the flow of a second heat exchange fluid between each pair of said spaced series of heat exchange units; a tank (56) enclosing said stack of heat exchange units (32) therewith; an inlet (62) for directing said second heat exchange fluid into said plurality of areas (54); and an outlet (64) for receiving said second heat exchange fluid from said plurality of areas (54); said inlet (62), said outlet (64) and said plurality of areas (54) defining a second heat exchange fluid flow path; characterised in that said central opening (26) is defined by a column (28) integrally formed with said header plate (24) and extending through said plurality of openings (44), and said tank is sealed to said header plate and to said column. A heat exchanger according to claim 1, wherein said header plate and column are integrally extruded from aluminum. A heat exchanger according to claim 1 or 2, wherein said header plate and column are impact extruded from aluminum. A heat exchanger according to claims 1, 2 or 3, wherein said spacer means comprise buttons arranged in a pattern on said plates. A heat exchanger according to any of claims 1 to 4 wherein said heat exchange units and said column have cooperative alignment means (68,70,72,74). A heat exchanger according to claim 5 wherein said alignment means comprises a tab and recess arrangement. A heat exchanger according to any preceding claim wherein said heat exchange units have turbulator means (76) within said first chambers. A heat exchanger according to any preceding claim, wherein said heat exchanger includes a stand-off (96) integrally formed with said header plate opposite said column. A heat exchanger according to any preceding claim wherein said header plate has an O-ring receiving recess (98) integrally formed on the side thereof opposite said column. A heat exchanger according to claim 9, as appended to claims 2 or 3, wherein said O-ring receiving recess is integrally formed during extrusion on the side opposite said column. A heat exchanger according to claim 1 or claim 2 wherein said column includes a pair of integrally extruded, axially extending tabs (68,70). A heat exchanger according to claim 11, wherein said plates each have a pair of corresponding tab receiving recesses (72,74). A heat exchanger according to any preceding claim wherein said header plate (24) is generally planar and said tank (56) has a peripheral skirt joined to said header plate (24) about its periphery.

Inventors: DEKEUSTER RICHARD MARK, GOODREMOTE CHARLES ELMER, KERKMAN WILLIAM JOSEPH, DEKEUSTER, RICHARD MARK, GOODREMOTE, CHARLES ELMER, KERKMAN, WILLIAM JOSEPH
Applicants: MODINE MFG CO, MODINE MANUFACTURING COMPANY
Application year: 1991
Main classification: F28D9
IPC codes: F28F3, F28D9