Water-cooling oil cooler

Abstract

 A number of fin plates (26) were mounted on at least one cooling tube (25) through which water flows and which is provided within a sealed shell filled with oil to be cooled. Each of the fin plates have a plurality of oil flow holes (28) and a plurality of oil flow retarding members (29). These holes and members are made by pressing the fin plate. The fin plate and each oil flow retarding member define at least one opening (30) between them. The oil flows through each oil flow holes in the direction perpendicular to the fin plate, then hits against each oil flow retarding member and finally flows through said opening along the fin plate.

Description

[0001] This invention relates to a water-cooling oil cooler, and more particularly to an oil cooler comprising at least one tube which is extended lengthwise of a sealed shell filled with oil and through which water flows to cool the oil.

[0002] To increase the heat conducting area of a cooler of this type it has been proposed to form so-called low fins integral with a straight tube by, for example, rolling, and on the outer periphery of the tube. A tube with low fins serves to cool oil more effectively than does a so-called bare tube which has no fins since the low fins increase cooling efficiency. To increase the heat conducting area still more, it has been proposed to use a straight tube with so-called middle fins or so-called high fins mounted on the outer periphery of the tube.

[0003] The conventional water-cooling oil cooler comprising one or more straight tubes with fins indeed possesses a high cooling efficiency. But the oil cooler is rather costly because it is time-consuming to mount and fix fins on each straight tube. It is thus very expensive particularly if it has many cooling tubes with fins.

[0004] It is accordingly an object of this invention to provide a water-cooling oil cooler which can be easily manufactured and thus at a low cost and which cools oil more effectively than the conventional water-cooling oil collers.

[0005] To achieve the above object a water-cooling oil cooler according to this invention comprises a plurality of so-called fin plates and at least one cooling tube. The fin plates are arranged parallel to one another at regular intervals and have each at least one hole. The cooling tube extends through the holes of the fin plates in the direction perpendicular to the fin plates. Each of the fin plates has a number of oil flowing holes and a number of oil flow retarding members. The oil flow holes are made and the oil flow retarding members are formed by pressing the fin plate. The oil flow retarding members protrude from one side of the fin plate. Each oil flow retarding member and the fin plate define at least one opening between them. The opening member causes oil flowing through the oil flow hole to flow through the opening in at least one direction parallel to the fin plate.

[0006] With the above-mentioned structure, both surfaces of each fin plate provide a large heat conducting area common to the cooling tubes and the fin plates can be made identical by pressing, i.e. an easy process. Thus, the oil cooler of the above-mentioned structure has a high cooling efficiency and can be manufactured at a low cost.

[0007] In particular, the oil flow retarding members help enhance the cooling efficiency of the oil cooler. These members are so positioned as to face the respective oil flow holes. Thus, oil flows first through the respective oil flow holes in the direction perpendicular to each fin plate, hits against the respective oil flow retarding members, flows in at least one direction parallel to the fin plate through the opening and further flows to the next fin plate.

[0008] As a result, the oil is made to flow slowly and remains for a long time within a sealed shell which houses the cooling tubes and the fin plates. Since the oil flows slowly, the cooling water draws the heat from the oil more effectively than in the conventional water-cooling oil coolers.

[0009] This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a vetical sectional view of a water-cooling oil cooler of this invention;

Fig. 2 is an enlarged view of part A of Fig. 1;

Fig. 3 is an enlarged plan view of the fin plate of the oil cooler shown in Fig. 1;

Fig. 4 shows the fin plate of Fig. 3 as viewed from above;

Fig. 5 is an enlarged perspective view of a fin plate and cooling tubes;

Fig. 6 is an enlarged sectional view taken along line 6-6 of Fig. 5;

Fig. 7 is an enlarged partial view of a modified fin plate;

fig. 8 is a sectional view taken along line 8-8 of Fig. 7;

, Fig. 9 is an enlarged partial view of another modified fin plate; and

Fig. 10 is a sectional view taken along line 10-10 of Fig. 9.

[0010] The embodiment and modifications of this invention will now be described with reference to the drawings attached hereto.

[0011] As shown in Fig. 1, a water-cooling oil cooler embodying this invention comprises a sealed shell 11. The shell 11 comprises a hollow cylinder 12, a cover 15 secured to the right end of the cylinder 12 and a cover 16 secured to the left end of the cylinder 12. A partition 13 is sandwiched between the cylinder 12 and the cover 15, and another partition 14 is sandwiched between the cylinder 12 and the cover 16. A tube 17 is connected to the outer periphery of the cylinder 12 and communicates with the interior of the cylinder, thus defining an inlet port. Similarly, a tube 18 is connected to the outer periphery of the cylinder 12 and communicates with the interior of the cylinder 12, thus defining an outlet port. Through the tube 17 oil to be cooled flows into the cylinder 12, and through the tube 18 the oil flows out of the cylinder 12. A drain pipe 19 is connected to the outer periphery of the cylinder 12 and communicates with the interior of the cylinder 12 so as to allow the oil to be discharged from the cylinder 12. The tubes 17 and 18 are connected to the oil circuit of, for example, a machine which uses oil.

[0012] The space defined by the partition 13 and the cover 15 is divided by a partition 15a into a water inlet chamber 22 and a water outlet chamber 23. The cover 15 has an inlet port 20 which opens to the water inlet chamber 22 and an outlet port 21 which opens to the water outlet chamber 23. Thus, water to cool oil flows into the chamber 22 through the inlet port 20 and flows out of the chamber 23 through the outlet port 21. On the other hand, the space or a chamber 24 is defined by the partition 14 and the cover 16. In the chamber 24 the cooling water circulates.

[0013] In the cylinder 12 a number of cooling tubes 26 extend parallel to one another in the axial direction of the cylinder 12. Each of these tubes 25 is supported by the partition 13 at one end and by the partition 14 at the other end and communicates with the chamber or 23 at one end and with the chamber 24 at the other end.

[0014] As schematically shown in Fig. 1, a number of metal fin plates 26 are arranged between the partitions 13 and 14 at short regular intervals in the axial direction of the cylinder 12. The fin plates 26 are thin discs which are parallel to one another and whose diameter is substantially equal to the inner diameter of the cylinder 12. In other words, each of the fin plates 26 has an outer profile which is substantially identical with the cross section of the interior of the sealed shell 11. Thus, the fin plates 26 fit to the inner periphery of the cylinder 12. Each of the fin plates 26 has holes 27 as shown in Fig. 3, which have been made by pressing. Through these holes 27 of each fin plate 26 the cooling tubes 25 extend in the axial direction of the cylinder 12.

[0015] As shown in Figs. 2 and 3, each of the fin plates 26 has a number of oil flow holes 28 and a number of oil flow retarding members 29. The holes 28 are made and the member 29 are formed by pressing the fin plate 26. As shown in Fig. 4, the oil flow retarding members 29 has a U-shaped sectional profile and protrude from one side of the plate 26.

[0016] Oil to be cooled enters the sealed shell 11 through the tube 17 and flows through the oil flow holes 27 of the fin plates 26 toward the tube 18. In the meantime., water to cool the oil flows through the cooling tubes 25 and draws the heat from the oil. More specifically, the cooling water enters the inlet chamber 22 through the inlet port 20, flows to the chamber 24 through the cooling chambers which communicate with the inlet chamber 22, further flows from the chamber 24 to the outlet chamber 23 through the cooling tubes 25 which communicate with the outlet chamber 23, and finally is discharged from the outlet chamber 23 through the outlet port 21.

[0017] It will now be described more in detail how the oil flows through the elongated oil flow holes 28 of each fin plate 26, with reference to Fig. 6 which is a sectional view taken along line 6-6 of Fig. 5. As mentioned above, the members 29 of each fin plate 26 protrude from one side of the fin plate 26 and have a _U-shaped sectional profile. That portion of each member 29 which corresponds to the bottom of letter U extends along the respective elongated oil flow hole 28 as illustrated in Fig. 6, wherein numerals 30 designate a pair of openings defined by the members 29 and the fin plate 26. The oil flows through both openings 30 in the opposite directions. The oil passes through the oil flow hole 28 in the direction perpendicular to the fin plate 26, hits against the member 29, flows upward though one opening 30 and downward through the other opening 30 and further flows to the next fin plate 26, as indicated by arrows in Fig. 6.

[0018] The members 29 function as buffer plates. They change the direction of oil flow and retards the flow of oil. The oil therefore flows slowly through the spaces defined by the cooling tubes 25 and the fin plates 26. The flow of oil is retarded effectively no matter whether or not the oil flow holes 28 of one fin plate 26 have the same shape and size as those of the next fin plates 26. Thus, the fin plates 26 can be made completely identical. This helps reduce the cost of the oil cooler particularly when, as shown in Fig. 1, a large number of fin lates 26 are used. Since the flow of oil is successfully retarded, more heat is drawn from the oil to the cooling water than otherwise. This helps enhance the cooling efficiency of the oil cooler.

[0019] In addition to the members 29, each fin plate 26 has a number of tubular flanges 31 as shown in Fig. 5. The flange 31 is formed around the peripheral edge of the hole 27 by pressing the plate 26 to make the holes 27. In putting the parts together to assemble the oil cooler, the cooling tubes 25 are inserted into holes 27 and fitted to the flanges 31 of each fin plate 26. The heat transmitted from the oil to each fin plate 26 is more effectively transmitted to the cooling water flowing through the tubes 25 than in case the flanges 31 are not provided.

[0020] The distance between the adjacent fin plates 26 is 2.5 to 3.0 mm. The oil flow retarding members 29 extend from the plate 26 about 2.0 mm, and the flanges 31 are about 2.0 mm long.

[0021] Each of the fin plates 26 may have such oil flow holes and oil flow retarding members as shown in Figs. 7 to 10, which differ in shape from the oil flow holes 28 and members 29 illustrated in Figs. 2, 3, 4, 5 and 6.

[0022] The fin plate 26 shown in Figs. 7 and 8 has rectangular oil flow holes 28 and pocket-shaped members 29 with an opening 30. The holes 28 are made and the members 29 are formed by pressing the plate 26. When the fin plate 26 shown in Figs. 7 and 8 is used in numbers in the oil cooler shown in Fig. 1, oil flows through each oil flow hole 28 in the direction perpendicular to the fin plate 26, flows upward through the opening 30 and further flows to the next fin plate 26, as indicated by arrows in Fig. 8. In this case, too, the flow of oil is retarded and there result in the same effects as achieved by the embodiment of Figs. 1 to 6.

[0023] The fin plate 26 shown in Figs. 9 and 10 has semicircular oil flow holes 28 and oil flow retarding members 29 shaped like round pockets and having an opening 30. The holes 28 are made and the members 29 are formed by pressing the plate 26. When the fin plate 26 shown in Figs. 9 and 10 is used in numbers in the oil cooler shown in Fig. 1, oil flows through each oil flow hole 28 in the direction perpendicular to the fin plate 26, flows upward through the opening 30 and further flows to the next fin plate 26, as indicated by arrows in Fig. 10. Also in this case, the flow of oil is retarded and there result in the same effects as accomplished by the embodiment of Figs. 1 to 6.

[0024] In the above-described embodiment and modifications, the fin plates 26 can be provided by a simple and easy process, i.e. pressing. This also helps reduce the cost of the oil coolers according to this invention.

[0025] Many variants of oil flow holes 28 and many variants of members 29 are possible within the scope of this invention though not shown in the drawings. It is therefore to be understood that the present invention is not limited to the particular embodiments shown in Figs. 1 to 10.

[0026] The water-cooling oil cooler of this invention is advantageous. First, the fin plates provide an extremely large area of heat conduction. Secondly, the oil flow retarding members integrally formed of the fin plates function as buffer plates, thus retarding the flow of oil thereby to achieve an effective heat exchange between the oil and the cooling water. Since the oil flow retarding members of each fin plate are identical with those of any other fin plate, the oil cooler can be manufactured at a low cost.

Claims

1. In a water-cooling oil cooler comprising a sealed shell (11) filled with oil to be cooled and at least one cooling tube (25) provided within the shell and extending lengthwise of the shell for conducting water to cool the oil, characterized in that said oil cooler further comprises:

a number of fin plates (26) mounted on said cooling tube (25), arranged at small intervals and extending parallel to one another and perpendicular to the axis of said cooling tube, each of said fin plates having a plurality of oil flow holes (28) and a plurality of oil flow retarding members (29) which have been made and formed by pressing the fin plate, each oil flow retarding member protruding from one side of the fin plate and defining at least one opening (30) through which said oil flows along said one side of the fin plate, whereby said oil flows first through each oil flow hole along the axis of said cooling tube, hits against each oil flow retarding member and flows through said opening.

2. An oil cooler according to claim 1, characterized in that said fin plates (26) have the same shape.

3. An oil cooler according to claim 1 or 2, characterized in that said oil flow holes (28) of each fin plate (26) are rectangular, and each oil flow retarding member (29) defines two openings (30, 30) through which oil flows in the opposite directions.

4. An oil cooler according to claim 1 or 2, characterized in that said oil flow retarding members (29) protrude from each fin plate (26) for the same distance.

5. An oil cooler according to claim 1 or 2, characterized in that said cooling tube (25) extends through a hole (27) made in each of said fin plates (26) and is fitted to a flange (31), said hole and said flange being provided by pressing the fin plate.

6. An oil cooler according.to claim 1 or 2, characterized in that said fin plates (26) are arranged equidistantly on said cooling tubes (25).

7. An oil cooler according to claim 1 or 2, characterized in that each of said fin plates (26) has an outer profile which is substantially identical with the cross section of the interior of said sealed shell (11).

Drawing