HEAT EXCHANGER

Description

[0001] The invention relates to a heat exchanger, in particular an oil-air cooler, for heat exchange between a first fluid, in particular hydraulic oil, and a second fluid, in particular air, comprising: a number of first flow channels for the passage of the first fluid, a number of second flow channels for the passage of the second fluid, a distribution tank for dividing the first fluid into first ends of the first flow channels, a collection tank for collecting the first fluid exiting from the second ends of the first flow channels, an outlet, in particular for a suction port, for diverting, in particular suctioning, the first fluid from the collection tank, a filter with a filter element for filtering the first fluid before entering the outlet, wherein the filter is arranged inside the collection tank such that the first fluid is guided from the outside through the filter element into an interior of the filter.

[0002] US Patent 2015 / 041414 discloses a heat exchanger according to the preamble of claim 1 and shows an assembly for cooling and filtering hydraulic fluid, consisting of an inlet tank, an outlet tank, and a heat exchanger. The outlet tank has a removable tank cover at its upper end, through which a vertically arranged cylindrical filter element located inside the outlet tank can be accessed. The filter element is attached to the outlet tank at its two end openings. The fluid in the outlet tank can only flow radially into an inner cavity of the filter element. The lower end of the filter is connected to an outlet manifold with multiple outlets. The outlet manifold has a pipe projection that extends into the inner cavity of the filter at its lower end. The inlet tank and the outlet tank have connections for a fluid monitoring device.However, this design could impair the filter performance.

[0003] WO 2005 / 093357 A1 discloses a generic cooling device in which a filter unit is arranged downstream of a cooling unit in the direction of fluid flow, in this case, a hydraulic fluid. The cooling unit is designed as a finned cooler. The fluid guide channels open on both sides into fluid collection chambers that extend along the longitudinal sides of the cooling unit. In this prior art, the filter unit is arranged outside the fluid collection chamber. The filter element is housed in its own filter casing. The contaminated fluid flows through the filter element from the outside to the inside, so that fluid discharge occurs via the interior of the filter element. This filtration ensures that the cleaned fluid cannot form deposits in the connected hydraulic components. Fluid cleaned by the filter element is discharged via a drain into a separate collection pipe within the collection chamber.Furthermore, connection points are provided for the discharge of the purified fluid from the collection pipe. However, this design is very complex. Another disadvantage is the large installation space required by the lateral positioning of the filter housing.

[0004] IT 2020 0003 2120 A1 discloses a device with a heat exchanger consisting of an upper heat exchanger plate, a lower heat exchanger plate, and a plurality of intermediate heat exchanger plates. Oil to be cooled enters and exits via oil connections and flows between them in inlet and outlet channels and oil flow zones. Fluid flow zones that can be supplied with coolant are arranged between the oil flow zones. The device has a filter with a filter element through which fluid can flow from the outside to the inside and which projects into the outlet channel. The filter element also has a connecting section that leads into an oil circulation channel. This design does not include a distribution tank or a collection tank.

[0005] Further general prior art is shown in DE 10009864 A1 and DE 102005054755 B3.

[0006] CN 203926234U shows a cooler in which a filter is arranged horizontally in a collection chamber above the cooling channels. However, a separate filter housing is required, which is a disadvantage. Furthermore, the filter is relatively short, thus limiting its filtration efficiency. The filter protrudes into the collection chamber on one side through a mounting opening. Another disadvantage is that the cooled fluid must be discharged on the side of the mounting opening.

[0007] The CN 103994130A shows a similar cooler with the disadvantages described above.

[0008] In contrast, the object of the present invention is to alleviate or eliminate at least some disadvantages of the prior art. This object is achieved with a heat exchanger according to claim 1. Preferred embodiments are specified in the dependent claims.

[0009] According to the invention, it is provided that the outlet has an outlet part which projects into the interior of the filter, the filter is arranged to fit precisely on the outlet part, a maintenance cover is provided for closing an access opening leading into the interior of the collection container for replacing the filter, and the maintenance cover has at least one through-opening leading into the interior of the filter.

[0010] Advantageously, the first fluid can flow directly from the second ends of the first flow channels inside the collection vessel to the outside of the filter element, i.e., without passing through a filter housing. There, the first fluid is filtered, meaning it is freed from particles, especially deposits. After filtration, the first fluid can be discharged from the inside of the filter via the outlet. Thus, a filter line can be integrated into the collection vessel. Advantageously, the outlet is connected to the inside of the filter, which can always be kept free of dirt. For example, no dirt can enter the outlet if the filter was placed on a dirty surface before being installed inside the collection vessel. This ensures that the first fluid is available at the outlet with a high degree of purity.This is particularly advantageous when the heat exchanger is used as a cooler for hydraulic oil, which is supplied from the outlet of a hydraulic system of a machine, such as a construction machine. By arranging the filter inside the collection tank, a compact, space-saving design is achieved. Since the filter element is subjected to radial flow from the outside to the inside, the collection tank, which is typically a collection box, can serve as the filter housing for the filter element. Advantageously, a separate filter housing around the filter element is unnecessary. The collection tank has several walls, specifically two narrow sides, two long sides, and a top, which enclose a collection chamber into which the second ends of the first flow channels for the first fluid directly open.Preferably, the filter extends over the arrangement of first flow channels such that imaginary vertical extensions of the first flow channels pass through the filter element. Preferably, the filter has a hollow cylindrical shape, which defines the interior space for receiving the filtered first fluid.

[0011] To discharge the first fluid, preferably hydraulic oil, and supply it, for example, to a construction machine, the outlet has a discharge section that projects into the interior of the filter. Advantageously, the connection section can be designed to be slim due to its connection with the interior of the filter. The interior is preferably completely surrounded circumferentially by the filter element. Thus, the first fluid can flow radially from outside the filter element through filter pores of the filter element into the interior of the filter and from there out of the collection container via the discharge section. The discharge section has an outlet channel through which the first fluid is discharged from the collection container to the outside. The outlet channel can be connected to a suction line to draw the first fluid from the interior of the filter, via the discharge section, into the suction line outside the collection container.

[0012] For stable mounting and secure installation of the filter via the outlet part, the filter is positioned precisely on the outlet part. With this design, the outlet part serves both to discharge the first fluid and to hold the filter element, preferably at a distance from the second ends of the first flow channels.

[0013] Furthermore, a maintenance cover is provided to close an access opening leading into the interior of the collection container for filter replacement. Removing the maintenance cover reveals an access opening dimensioned to allow the filter to be inserted into or removed from the collection container. The maintenance cover is preferably connected to the collection container via a detachable connection, such as a screw connection.

[0014] The maintenance cover has at least one opening leading into the interior of the filter, in which, for example, a sensor unit, in particular a contamination indicator, may be arranged, with which an operating parameter, in particular a degree of contamination of the filter, can be measured.

[0015] The arrangement of the filter prevents contamination of the fluid lines, especially oil lines, and thus of the entire system during filter changes.

[0016] For the purposes of this disclosure, location and direction references such as "top", "bottom", "horizontal", "vertical" refer to the intended operating condition of the heat exchanger.

[0017] In a preferred embodiment, the filter element is arranged exposed inside the collection container, particularly along its entire length (i.e., its extension in the direction of the longitudinal axis). Thus, the first fluid entering the distribution container via the second ends of the first flow channels can flow directly to the outside of the filter element, be filtered on the outside of the filter element, and then pass through the filter element into the interior of the filter element. Advantageously, the distribution container forms the filter housing in which the filter element is arranged exposed. This eliminates the need for a separate filter housing.

[0018] In a preferred embodiment, the outlet part is essentially cylindrical and, in particular, is an outlet nozzle. In another preferred embodiment, the filter element is tubular, particularly hollow cylindrical, with the outlet part being cylindrical to match the filter element.

[0019] In a preferred embodiment, a suction port can be connected to the connection part, preferably in different orientations to the flow direction within the connection part.

[0020] For stable mounting and secure installation of the filter using the outlet part, it is particularly advantageous if the filter is pushed onto the outlet part.

[0021] To hold the filter in the desired position within the collection container, it is advantageous for the maintenance cover to have a retaining element, in particular a retaining pin, projecting into the interior of the filter. It is especially preferred if the filter is held in position by both the outlet and the retaining element. For a cylindrical filter element, it is advantageous for the retaining element to be a cylindrical retaining pin projecting into the interior of the filter. Furthermore, it is advantageous if the filter can be mounted in the collection container not only in a single, predetermined orientation, but in two orientations rotated by 180°.

[0022] If the maintenance cover and the outlet are located on opposite sides, especially on two opposite narrow sides, of the collection container, the outlet part can be particularly effectively protected from contamination during the installation and removal of the filter.

[0023] By spatially separating the maintenance cover from the (oil) outlet, and especially from any associated suction connection, the routing of lines on the vehicle can be optimized. The supply and return lines can be located on the side facing the vehicle's axle, reducing line lengths and enabling a more compact and protected design. At the same time, ease of servicing remains unchanged, as the maintenance cover is located on the outside of the vehicle and is therefore easily accessible for maintenance work. The prevention of contamination during filter changes has already been mentioned above.

[0024] In a preferred embodiment, a first longitudinal end of the filter is held by the outlet part and a second longitudinal end of the filter by the retaining part of the maintenance cover. This design achieves a stable mounting of the filter at opposite longitudinal ends. A further advantage is that incorrect positioning of the filter in the collection container is reliably prevented, since the maintenance cover can only be attached to the collection container if the filter is supported by the retaining part on the maintenance cover and thus correctly positioned.

[0025] In a preferred embodiment, the maintenance cover, particularly on the retaining part, has at least one through-opening to form a filter bypass, through which unfiltered first fluid can be introduced into the interior of the filter. Preferably, a valve is provided, particularly inside the retaining part of the maintenance cover. In an open position, the unfiltered first fluid can be introduced through the through-opening of the maintenance cover into the interior of the filter and discharged via the outlet. In a closed position, the unfiltered first fluid cannot enter the interior of the filter. Preferably, the valve is moved from the closed to the open position when a pressure at the outlet reaches a predetermined value. This can occur, for example, when the first fluid can no longer pass through the filter element.By enabling the filter bypass, it can be ensured that even unfiltered fluid is provided at the outlet.

[0026] In a preferred embodiment, the longitudinal axis of the filter element is arranged essentially horizontally. In this embodiment, the first flow channels can be traversed from bottom to top. The collection vessel extends transversely to the first flow channels above them. The filter is arranged horizontally above and at a distance from the second ends of the flow channels.

[0027] Preferably, the collection container is cuboid in shape with two vertical short sides, two vertical long sides, and a horizontal top. The length of the collection container is its horizontal extent parallel to the long sides. The width of the collection container is its horizontal extent parallel to the short sides. The height of the collection container is its vertical extent.

[0028] Preferably, the filter element extends over essentially the entire length of the collection container. This allows for particularly effective filtration of the first fluid.

[0029] In one embodiment, the collection container and / or the maintenance cover are made of metal, in particular aluminum. The filter may have a metal filter holder structure. The filter element with the filter pores may be made of paper and / or metal and / or microfiber.

[0030] The invention is further explained below with reference to an embodiment illustrated in the drawings.

[0031] Figs. 1 to 4 show different views of a heat exchanger according to the invention, which is designed as an oil-air cooler for providing cooled hydraulic oil for a suction line.

[0032] Fig. 5 shows a split-view view of parts of the cooler.

[0033] Fig. 6 shows a cross-sectional view of the cooler in the area of ​​the collection tank.

[0034] Figs. 1 to 4Figure 1 shows a heat exchanger 1, which in the illustrated embodiment is designed as a cooler for cooling a first fluid, here hydraulic oil, by heat exchange with a second fluid, here air. The heat exchanger 1 has a plurality of first flow channels 2, which preferably extend parallel to each other, for example in a vertical direction. The first fluid flows upwards from the first (lower) ends to the second (upper) ends of the first flow channels 2. In the spaces between the first flow channels 2, a plurality of second flow channels 3 are formed, through which the second fluid, here cooling air, flows. The cooling air is guided through the second flow channels 3 by means of a fan 4. In the illustrated embodiment, the fan 5 has a fan wheel 5 which rotates about an axis 5A.At the lower end of the heat exchanger 1, the first fluid is fed into a distribution tank 7 via an inlet 6, which in this example is an oil inlet. The distribution tank 7 encloses a distribution chamber inside, into which the first fluid is supplied via the inlet 6. The first flow channels 2 open into the common distribution chamber of the distribution tank 7, so that the first fluid is guided upwards from the distribution chamber through the first flow channels 3. Above the first flow channels 2, a collection tank 8 is arranged, which encloses a uniform, i.e., undivided, collection chamber 9 into which the second ends of the first flow channels 2 open. The collection tank 8 has a first narrow side 8A, a second narrow side 8B, two long sides 8C, and a top 8D. For clarity, the collection tank 8 is shown in the... Figs. 5 and 6With a lower height and simplified representation, the collection container 8 is open on the underside towards the first flow channels 2.

[0035] The heat exchanger 1 also has one, preferably exactly one, outlet 10 for discharging the cooled first fluid from the collection tank 8. In the embodiment shown, the outlet 10 is connected to a suction port 10A, which can be connected via a suction line (not shown) to a hydraulic line of a construction machine (not shown).

[0036] The heat exchanger 1 also has feet 22, which allow the heat exchanger to be placed on a (horizontal) floor surface. The feet 22 may have mounting openings 23, which allow the heat exchanger 1 to be fixed to the floor surface.

[0037] Furthermore, a filter 11 is provided, which is designed to separate solid particles from the first fluid before the first fluid enters the suction port 10A. The filter 11 is located entirely inside the collection container 8, i.e., within the collection space 9 bounded by the walls of the collection container 8.

[0038] In the embodiment shown, the filter 11 has a filter element 12 with a hollow cylindrical shape. In this embodiment, the filter element 12 has filter pleats. The filter element 12 has a plurality of filter pores through which the first fluid can pass. The longitudinal axis 11A of the filter element 12 extends horizontally along the length of the collection container 8, i.e., from the first narrow side 8A to the second narrow side 8B of the collection container 8.

[0039] The filter 11 is arranged inside the collection container 8 in such a way that it is exposed, i.e., without a surrounding filter housing, that the first fluid first hits the outside of the filter element 12 (see arrows 13 in Fig. 6This causes the dirt particles, such as hose or pump abrasion and air pollution, to be released on the outside of the filter element 12. The first fluid flows through the filter pores of the filter element 12, radially from the outside to the inside with respect to the longitudinal axis 11A of the filter element 12. Thus, after filtration, the first fluid enters an interior space 14 enclosed by the filter element 12 on the outside of the filter element 12. The outlet 10 has an outlet part 15, which in the illustrated embodiment is designed as a cylindrical outlet nozzle extending from a first narrow side 8A of the collection container 8 in the direction of the longitudinal axis of the filter element 12 into the interior space 14 of the filter 11. The filter 11 is arranged essentially precisely on the outlet part 15, so that a first longitudinal end of the filter 11 is supported by the outlet part 15.In the embodiment shown, the filter 11 is slid onto the outlet part 15 without tools. The outlet part 15 has an outlet channel 15A, which connects to the interior 14 of the filter element 12. Thus, the first fluid can be discharged longitudinally along the filter 11 (see arrows 16) from the interior 14 of the filter 11 via the outlet channel 15A out of the collection container 8.

[0040] The collection container 8 has an access opening 17, which is closed with a maintenance cover 18 when assembled and in use. In the embodiment shown, the access opening 17, fitted with the maintenance cover 18, is located on a second narrow side 8B opposite the first narrow side 8A of the collection container 8. The maintenance cover 18 has a maintenance cover plate 18A, which is mounted externally on the second narrow side 8B of the collection container 8, in the embodiment shown, with screws 18B. The access opening 17 is larger than the cross-section of the filter 11, so that the filter 11 can be removed from or inserted into the collection container 8 when the maintenance cover 18 is removed, for example, to replace a used filter 11 with a new one.The maintenance cover 18 has a retaining element 19 on its inner side facing the collection chamber 9, in this case a cylindrical retaining pin, which extends essentially snugly into the interior 14 of the filter 11. Thus, the first longitudinal end of the filter 11 is held by the outlet part 15 and the second longitudinal end of the filter 11 by the retaining element 19 of the maintenance cover 18.

[0041] The maintenance cover 18 has at least one passage opening 20 leading into the interior 14 of the filter 11, in which, for example, a sensor unit 21, in particular a contamination indicator, can be arranged, with which an operating parameter, in particular a degree of contamination of the filter 11, can be measured.

[0042] Furthermore, the maintenance cover 18, particularly at the retaining part 19, can have at least one through-opening to form a filter bypass, through which unfiltered first fluid can be guided into the interior of the filter 11. Preferably, a valve is provided, particularly inside the retaining part 19 of the maintenance cover 18. In an open position, the unfiltered first fluid can be guided through the through-opening of the maintenance cover 18 into the interior of the filter 11 and discharged via the outlet 10. In a closed position, the unfiltered first fluid cannot enter the interior of the filter 11. Preferably, the valve is switched to the open position when a pressure at the outlet 10 reaches a predetermined value. This prevents damage, for example, to a pump connected to the outlet 10. Reference number list:

[0043] 1 Heat exchanger 2 First flow channels for oil 3 Second flow channels for air 4 Fan 5 Fan wheel 5A Shaft 6 Inlet 7 Distribution tank 8 Collection tank 8A First narrow side of the collection tank 8B Second narrow side of the collection tank 8C Long sides of the collection tank 8D Top of the collection tank 9 Collection chamber 10 Outlet 10A Suction port 11 Filter 11A Longitudinal axis 12 Filter element 13 Arrows 14 Interior 15 Outlet part 15A Outlet duct 16 Arrows 17 Access opening 18 Maintenance cover 18A Maintenance cover plate 19 Retaining part 20 Through opening 21 Sensor unit 22 Feet 23 Mounting openings

Claims

1. Heat exchanger (1), in particular an oil-air cooler, for heat exchange between a first fluid, in particular hydraulic oil, and a second fluid, in particular air, comprising: a number of first flow channels (2) for the passage of the first fluid, a number of second flow channels (3) for the passage of the second fluid, a distribution tank (7) for distributing the first fluid to first ends of the first flow channels (2), a collecting tank (8) for collecting the first fluid emerging from second ends of the first flow channels (2), an outlet (10), in particular for a suction connection (10A), for discharging, in particular for suction removal of, the first fluid from the collecting tank (8), a filter (11) with a filter element (12) for filtering the first fluid before entry into the outlet (10), wherein the filter (11) is arranged inside the collecting tank (8) in such a manner that the first fluid is guided from the outside through the filter element (12) into an interior space (14) of the filter (11), characterized in that the outlet (10) comprises an outlet part (15) which projects into the interior space (14) of the filter (11), the filter (11) is fitted precisely onto the outlet part (15), a maintenance cover (18) is provided for closing an access opening (17) leading into the interior of the collecting tank (8) for replacing the filter (11), and the maintenance cover (18) comprises at least one passage opening (20) leading into the interior space (14) of the filter (11).

2. Heat exchanger (1) according to claim 1, characterized in that the filter element (12) is arranged freely within the interior of the collecting tank (8).

3. Heat exchanger (1) according to claim 1 or 2, characterized in that the outlet part (15) is designed substantially cylindrical and in particular is an outlet nozzle.

4. Heat exchanger (1) according to any one of claims 1 to 3, characterized in that the filter (11) is pushed onto the outlet part (15).

5. Heat exchanger (1) according to any one of claims 1 to 4, characterized in that the maintenance cover (18) comprises a retaining part (19), in particular a retaining pin, projecting into the interior space (14) of the filter (11), for holding the filter (11).

6. Heat exchanger (1) according to any one of claims 1 to 5, characterized in that the maintenance cover (18) and the outlet (10) are provided on opposite sides of the collecting tank (8).

7. Heat exchanger (1) according to claim 6, characterized in that a first longitudinal end of the filter (11) is held by the outlet part (15) and a second longitudinal end of the filter (11) is held by the retaining part (19) of the maintenance cover (18).

8. Heat exchanger (1) according to any one of claims 1 to 7, characterized in that a longitudinal axis (11A) of the filter element (12) is arranged substantially horizontally.