FILTER DEVICE

Abstract

The invention relates to a filter device with a removable termination part (81; 82) and a housing (3) that receives a replaceable filter element (5) having two end caps (25,47), between which a filter material (12) extends. The invention is characterized in that a positioning device (65) is arranged between the termination part (81; 82) and one end cap (47), said positioning device positioning the filter element (5) within the housing (3), at least when viewed in the circumferential direction of the filter element, in interaction with at least one corresponding positioning element (71) of said end cap (47).

Description

The invention relates to a filter device having a removable end piece and having an enclosure, which holds a replaceable filter element having two end caps between which a filter material extends. Furthermore, the invention relates to a filter element, which is provided in particular for a filter device of this type.

Filter devices of this type are, as shown by way of example in DE 10 2007014813 A1, state of the art and are used in a variety of designs and embodiments for the filtration of process fluids, hydraulic fluids such as hydraulic oils, liquid fuels and lubricants, for the treatment of liquid media and the like. The reliability of such filter devices depends to a very large extent on the fact that, after replacement due to certain operating phases having elapsed, the installed or newly installed filter elements exactly fulfill the specifications, such as filter fineness, filter surface and other parameters. If the relevant filter device is equipped with an inappropriate filter element resulting in reduced or even no performance, which can result in malfunction or even damage, in particular in expensive technical equipment, it can cause significant economic losses.

In view of this, the invention addresses the problem of providing a filter device characterized by an improved functional reliability in a simple design.

According to the present invention, this problem is solved by a filter device having the features of claim 1 in its entirety.

According to the characterizing part of claim 1, a significant feature of the invention is that a positioning device is arranged between the end part and one of the end caps, which, in conjunction with at least one corresponding positioning element of this end cap, positions the filter element, at least viewed in its circumferential direction, within the enclosure. Because the positioning, and thus the establishing of the functional position of the filter element, depends on the presence of the positioning element matching the positioning at one of the end caps, the positioning device forms a so-called safeguard, which ensures that the filter device can only be operated in conjunction with a filter element that is specifically suited and intended for the particular application.

In advantageous exemplary embodiments, the filter housing has at least one housing head, to which the enclosure is attached, wherein the positioning device is arranged between one of the end caps and a housing cover of the housing head forming the end piece.

In exemplary embodiments in which the enclosure is attached to an annular body, which is mounted to a wall part of a tank storing fluid via a support ring, the positioning device can be arranged between one of the end caps and the tank cap forming the end piece.

In advantageous exemplary embodiments, the positioning device has a guide web, which engages with a guide channel arranged as a positioning element in one of the end caps and which is open towards the interior of the filter element. The tongue and groove engagement thus formed between the positioning device and the end cap forms a type of key-lock system, which ensures that the filter element can only reach the functional position if the positioning device and the end cap geometrically match.

Advantageously, the arrangement may be such that one of the end caps has a guide ring on its inside, projecting on both sides beyond an abutment ring, to which one free, frontal end of the filter material is attached, wherein the guide channel, the outer circumference of which is attached to the guide ring, preferably extends along the former's entire height.

In particularly advantageous exemplary embodiments, the guide ring has a boundary surface projecting inwardly, in the direction of the interior of the filter element, which boundary surface interacts with at least one stepped boundary shoulder at an insert ring of the positioning device, which ring engages, preferably flush, in the operating state with the guide ring from the side of the filter head, wherein there is a predeterminable axial distance between the boundary surface and the boundary shoulder. While a rotational position of the filter element is predetermined by the tongue and groove engagement of the guide web of the positioning device with the guide channel of the end cap, the axial alignment of the filter element is performed with limited play. This means that for a filter element, the other end cap of which is attached to the enclosure, there are no special requirements for length tolerance.

Advantageously, the arrangement can be made such that the guide web at the insert ring protrudes outwardly in the direction of the guide channel from the insert ring and has an installation length which is shorter than the guide length provided for the guide web within the guide channel recessed in one of the end caps.

The positioning device can form an annular body, which bears the insert ring at the foot end and a head ring at the head end, which is at least partially in abutment with abutment parts of the housing head or the tank cap. For a housing cover detachably mounted to the housing head, the abutment parts can advantageously be formed at the latter.

In particularly advantageous exemplary embodiments, the arrangement is such that latching parts at the head ring of the annular body engage with the abutment parts of the housing head in a latching manner for the purpose of axially mounting the positioning device at the housing head. The assembly process can be performed easily and conveniently by closing the housing while the positioning devices are latched to the abutment parts.

Advantageously, the arrangement may be such that at least one fastening bolt is provided between the head ring and abutment parts at the housing cover or at the tank cap. When the positioning device is securely attached by means of the bolt, the assembly process is particularly safe and comfortable.

Preferably, a plurality of, preferably three, spacing webs extend between the insert ring and the head ring, of which at least one bears the guide web projecting on the former's outside.

In particularly advantageous exemplary embodiments, one of the end caps, arranged concentrically to its guide ring, bears an outer ring for receiving a sealing ring, wherein a further sealing ring is arranged between the head ring of the positioning device and the abutment parts of the housing cover.

Advantageously, the outer circumference of the filter element can be circular-cylindrical with the assigned one end cap, and the inner circumference of the interior components, such as the filter material, can form a Reuleaux triangle. A filter material designed in that way can have a larger filter surface when installed in a given installation space than would be possible for a filter element having filter material with a circular cylindrical cross-sectional shape.

In a filter material forming a hollow body, the arrangement is advantageously such that a connecting longitudinal seam of the preferably pleated filter material ends in a position aligned with the guide channel in one of the end caps.

The filter device can, as usual, have a bypass device, which is provided at the other end cap of the filter element which opens onto the unfiltered side in the interior of the filter element.

By forming a filtrate chamber, the filter element can be accommodated in the enclosure at a predeterminable radial distance, which can be perforated at least in an axial longitudinal area adjacent to the bypass device. As a result, the filter device is suitable for installation in an appropriate fluid reservoir tank.

The other end cap, provided with the bypass device, may be firmly connected to the enclosure forming an attachment point, wherein one of the end caps is attached to the housing head to form a floating bearing acting axially.

With particular advantage, a tag can be arranged in the peripheral area of one of the end caps, which tag can be read by means of an RFID sensor, which is located at a wall part encompassing the relevant end cap. As is known, tags are data storage devices containing passive transponders, the data of which can be read by a state-of-the-art RFID sensor using radio waves. In the arrangement provided for by the invention, where the tag is located at the peripheral area of an end cap and the scanner is located at an encompassing wall part, the distance between the data storage device and the reader can be minimized, permitting secure data transmission even at low electrical power. Data specifying the filter element can be stored in the data storage device. For instance, these may be data that permit the identification of only the chip of the filter element, for instance, in terms of its filter material, the media to be filtered, the dimensions, the manufacturing date and the like. In addition, data may be stored to allow identification of the individual filter element, such as a unique and preferably continuous serial number. If and to the extent to which this involves data which are already defined during the production of the filter element, these data can be stored in a non-rewritable and read-only memory area of the data storage device such that they cannot be modified and in particular cannot be manipulated. Alternately or additionally, data that are generated only after the production of the filter element can also be stored.

In exemplary embodiments, in which one of the end caps is located within the housing head of the device, the sensor is advantageously arranged at the end cap encompassed by the housing head and the RFID sensor is arranged at the housing head. If the RFID sensor is connected to a higher-level machine control of a hydraulic system, it can only be put into operation once the assigned filter element has been identified. In this way, the hydraulic system cannot be started or operated if a plagiarized product of poor quality is used, which could damage the hydraulic system.

According to claim 21, the subject matter of the invention is also a filter element, in particular provided for a filter device according to any one of claims 1 to 20, having a filter material, which extends between two end caps, one of which has a guide channel, which opens towards the interior of the filter element.

Advantageous embodiments and further developments of the filter element are given in the subsequent dependent claims 22 to 25.

The invention is explained in detail below with reference to exemplary embodiments shown in the drawing.

In the Figures:

FIG. 1 shows a simplified sectional view of an exemplary embodiment of the filter device according to the invention, not drawn to scale;

FIG. 2 shows an oblique perspective view of the filter element and the positioning device of the exemplary embodiment of the filter device;

FIG. 3 shows a perspective oblique view of the filter element and the positioning device in engagement with the former, in a cut-away drawing having a central sectional plane;

FIG. 4 shows an enlarged perspective oblique view of the head part of the exemplary embodiment, wherein the functional position is shown, in a cut-away drawing having a centrally extending, vertical sectional plane;

FIG. 5 shows a perspective oblique view of the filter element and the positioning device interacting therewith, viewed from below, as a cut-away drawing having a horizontal sectional plane;

FIG. 6 shows a cross section of the filter element of the device according to the invention;

FIG. 7 shows an enlarged perspective oblique view of the head part of a second exemplary embodiment, wherein the functional position is shown, in a cut-away drawing having a centrally extending, vertical sectional plane;

FIG. 8 shows a perspective oblique view of a third exemplary embodiment of the filter device according to the invention, as a cut-away drawing having a vertical sectional plane.

With reference to the attached drawings, the invention is described by way of example of so-called tank-installation filter devices. In a first exemplary embodiment, a housing head 1, which in conjunction with an enclosure 3 forms the filter housing for receiving a filter element 5, is attached to an upper opening 7 in a tank 9, which is shown only schematically. The rest of the tank, holding a fluid supply, is not shown. As usual in the case of tank installation filter devices, the enclosure 3 is provided, at least in a lower length area 11, which is below the normal liquid level in the tank, with a perforation through which filtrate emerges from the chamber 13 in the filtering process, which chamber is located between the outside of the filter material 12 of the filter element 5 and the enclosure 3 and forms the clean side during the filtration process. The inflow of the unfiltered matter is routed from a fluid inlet 15 in the housing head 1 to the inner filter cavity 17, which is encompassed by the filter material 12. As can be seen more clearly in FIGS. 2 to 4, a fluid-permeable support tube 19 is arranged as a sheath of the filter material 12 on the outside of the filter material 12, when [the filtrate] flows through the filter material 12 from the inside to the outside during the filtering process. The enclosure 3, as shown in FIG. 1, has a bottom part 21 at the lower end of the perforated part 11, which bottom part has the shape of a shell that is open towards the bottom, and in the bottom of the shell there is a centrally located opening 23. The contact area for an end cap 25 located at the lower end of the filter material 12 of the filter element 5 forms the top of the bottom part 21. At the outer circumference, the bottom part 21 is firmly connected to the lower end of the enclosure 3 via a flange 27. As best shown in FIG. 3, the lower end cap 25 has a centrally located inner passageway 29 leading to the inner chamber 17, which is normally closed by a bypass valve 31. The bypass valve 31 has a two-piece valve housing, having an upper housing part 33, which extends in the form of a bell into the interior 17 and has a central opening 35 at the upper end. While this bell forms a valve body 33, which is clipped to the end cap 25, a second valve body 37 is formed integrally with the end cap 25 and has a ring of spaces disposed between retaining webs 39 arranged at intervals, which retaining webs form the holder of a closing spring 41 of the bypass valve 31. The closing spring pre-stresses a closing body 43 for sealing engagement with a seat surface 45 at the edge of the opening 35 of the valve body 33, from which it can be lifted in a pressure-actuated manner.

The end cap 47 forming the apron for the upper end of the filter material 12 has an upwardly projecting outer ring 51 above its peripheral edge 49, which forms the apron for the filter material 12 and the support tube 19 resting thereon. The latter has a circumferential, recessed annular groove 53 as a receptacle for a sealing ring 55 (FIG. 4). When the filter element 5 is inserted into the filter housing, cf. FIGS. 1 and 4, the sealing ring 55 forms the seal against the housing head 1. The end cap 47 has a central passage encompassed by a guide ring 57. An upper part 59 and a lower part 61 of the guide ring protrude on both sides of an abutment ring 63, at the underside 15 of which the facing frontal end of the filter material 12 is attached. The guide ring 57 including its upper part 59 and its lower part 61 interacts with a positioning device 65 shown separately in FIG. 2. The guide ring 57, at the upper part 59 of which, as shown in FIG. 2, a handle bar 67 is pivotally mounted, has a radially outwardly facing bulge 69 (FIGS. 2, 5 and 6), which encompasses an inner, axially extending guide channel 71, for the interaction with the positioning device 65.

The positioning device 65 has the form of a one-piece plastic body having a foot part formed by an insert ring 73 and an upper head ring 75 extending in a parallel plane to the former. These rings are interconnected by three spacer webs 77 evenly distributed along the perimeter, the length of which corresponds approximately to the diameter of the insert ring 73. As an engagement part that is in engagement with the guide channel 71 at the end cap 47 in the operative position (see FIGS. 3 and 4), the insert ring 73 of the positioning device 65, has, similar to the top part 59 of the guide ring 57 of the end cap 47, a bulge 79, which projects radially and forms an axially extending guide web, which in the operating position is fittingly guided in the guide channel 71. The axial length of the bulge 79 is smaller than the guide length available in the guide channel 71. The filter element 5 is rotatably positioned due to the engagement of the bulge 79 with the guide channel 71 of the end cap 47.

As can be seen most clearly from FIG. 4, the positioning device 65 is inserted between the housing head 1 and the end cap 47 of the filter element 5. To that end, the head ring 75 abuts abutment parts, which are located at a housing cover 81 forming the end part of the housing head 1, and which cover is detachably bolted to the remaining part of the housing head 1. Engagement parts 83 projecting at the top of the head ring 75, spaced apart from one another, engage with recesses in the housing cover 81 not shown, which leave a free radial play for the engagement parts 83. Further abutment parts are located at a cone body 85, which passes through the central opening 87 of the head ring 75. To this end, tongue-shaped latching parts 88, which originate from the edge of the opening 57 of the head ring 75, come into latching engagement with a circumferential notch 89 at the cone body 85. The head ring 75 is sealed against the cone body 85 using a sealing ring 90 seated at the inner circumference of the opening 87. The frictional connection between the sealing ring 90 and the cone body 85 forms a further immobilization of the head ring 75.

The bottom part of the lower end cap 25 forming an attachment point 21 at the enclosure 3, supports, as mentioned above and shown in FIG. 1, the filter element 5 against axial downwards movements. At the upper end of the filter element 5, a floating bearing permitting upward motion is formed at the end cap 47 via the sealing ring 55. To limit this motion to a desired axial play, a radially projecting rib 91 is formed at the inside of the lower part 61 of the guide ring 57 of the end cap 47, the upper side of which forms a boundary surface 92. This acts as an abutment surface in conjunction with a stepped boundary shoulder 93, which is formed in lobe-shaped extension 94 extending over the rib 91, which extension extends away from the lower edge of the insert ring 73 downwards into the interior 17. The clearance between the rib 91 and the shoulder 93 limits the possible axial play of the floating bearing at the end cap 47, which can be used to compensate any length tolerances of the filter element 5.

As is most clearly shown in FIG. 6, the outer periphery of the filter element 5 formed by the support tube 19 is circular, while the inner circumference of the inner components of the end cap 47, i.e., the guide ring 57 at the underside 61 of which the rib 91 with the boundary surface 92 is located, has the non-circular shape of a Reuleaux triangle.

As shown in FIGS. 5 and 6, in this kind of shaping, the bulge 69 encompassing the guide channel 71 is oriented towards the assigned end of the connecting longitudinal seam 95, which is used to interconnect the ends of the web of the pleated filter material 12, for example a mesh pack. As shown in FIG. 6, the pleat height of the filter material web is reduced in the area of the longitudinal seam 95 formed by welding or gluing. Unlike the upper end cap 47, all components of the lower end cap 25 have a circular cylindrical outer and inner circumference.

FIG. 7 shows the area of the housing head 1 of a second exemplary embodiment of the filter device according to the invention. FIG. 7 shows housing cover 81 forming the end part in a position separate from the housing head 1. Deviating from the first exemplary embodiment, the head ring 75 of the positioning device 65 is not only attached by the frictional connection at the sealing ring 90 and the engagement of the latching parts 88 with the notch 89 of the cone body 85, but by at least one fastening bolt 74, which passes through the head ring 75 from below and attaches the cone body 85 to the top of the head ring 75, at which no protruding engaging parts 83 are provided, and thus determines the rotational position of the positioning device 65.

Another difference from the first exemplary embodiment is that a holder 78 for a tag 96 forming a passive transponder is integrally formed at the top end of the upper end cap 47 of the filter element 5. The tag 96 in the form of a flat chip is arranged in the holder 78 at a small distance from the wall of the housing head 1 encompassing the end cap 57, preferably exchangeably. In the wall, a sensor opening 80 is formed in such a position that an RFID sensor 97 bolted therein is aligned with the tag 96 when the filter element 5 is in the functional position predetermined by the positioning device 65, in which position the sensor 67 can scan the data stored in the tag 96.

FIG. 8 illustrates a third exemplary embodiment, in which, in the functional position of the filter element 5, the upper end cap 47 is not sealed against a housing head 1 by the sealing ring 55 located at its outer ring 51, but against the inside of an annular body 60, which is part of the assigned tank 9. In conjunction with a support ring 62, the annular body 60 also forms the mount of the enclosure 3. The support ring 62 in turn is held by a wall part 8, which forms an intermediate wall at the upper area of the tank 9, which separates an upper tank casing 64 from the main chamber of the tank 9 below, into which the enclosure 3 extends. The tank attachment 64 forms the inflow chamber 66 for the supply of the unfiltered material via the fluid inlet 15 located at the tank attachment 64. In the absence of the housing head 1 having the housing cover 81, in this exemplary embodiment, the end part, which constitutes the abutment parts for the positioning device 65, is formed by a tank cap 82, which can be detachably mounted to the top of the tank casing 64 as a closure part of the inflow chamber 66.

Claims

1. A filter device having detachable end pieces (81; 82) and having an enclosure (3), which holds a replaceable filter element (5) having two end caps (25, 47) between which a filter material (12) extends, characterized in that a positioning device (65) is arranged between the end parts (81; 82) and one of the end caps (47), which, in conjunction with at least one corresponding positioning element (71) of this end cap (47), positions the filter element (5), at least viewed in its circumferential direction, within the enclosure (3).

2. The filter device according to claim 1, characterized in that it has a filter housing having at least one housing head (1), to which the enclosure (3) is attached, and that the positioning device (65) is arranged between one of the end caps (47) and a housing cover (81) of the housing head (1) forming the end piece.

3. The filter device according to claim 1, characterized in that the enclosure (3) is fixed to an annular body (60), which is mounted to a wall part (8) of a tank (9) storing fluid via a support ring (62) and that the positioning device (65) can be arranged between one of the end caps (47) and the tank cap (82) forming the end piece.

4. The filter device according to claim 1, characterized in that the positioning device (65) has a guide web (79), which engages with a guide channel (71) arranged as a positioning element in one of the end caps (47) and which is open towards the interior (17) of the filter element (5).

5. The filter device according to claim 1, characterized in that one of the end caps (47) has a guide ring (57) on its inside, projecting on both sides beyond an abutment ring (63), to which one free, frontal end of the filter material (12) is attached, and that the guide channel (71), the outer circumference of which is attached to the guide ring (57), preferably extends along the former's entire height.

6. The filter device according to claim 1, characterized in that the guide ring (57) has a boundary surface (92) projecting inwardly, in the direction of the interior of the filter element (5), which boundary surface interacts with at least one stepped boundary shoulder (93) at an insert ring (73) of the positioning device (65), which ring engages, preferably flush, in the operating state with the guide ring (57) from the side of the filter head (1), wherein there is a predeterminable axial distance between the boundary surface (92) and the boundary shoulder (93).

7. The filter device according to claim 1, characterized in that the guide web (79) at the insert ring (73) protrudes outwardly projecting in the direction of the guide channel (71) from the insert ring (73) and has an installation length which is shorter than the guide length provided for the guide web (79) within the guide channel (71) recessed in one of the end caps (47).

8. The filter device according to claim 1, characterized in that the positioning device (65) can form an annular body, which bears the insert ring (73) at the foot end and a head ring (75) at the head end, which is at least partially in abutment with abutment parts (81, 85) of the housing head (1) or the tank cap (82).

9. The filter device according to claim 1, characterized in that the abutment parts are formed at a housing cover (81) detachably mounted to the housing head (1).

10. The filter device according to claim 1, characterized in that latching parts (88) at the head ring (75) of the annular body engage with the abutment parts (85) of the housing head (1) in a latching manner for the purpose of axially mounting the positioning device (65) at the housing head (1).

11. The filter device according to claim 1, characterized in that at least one fastening bolt (84) is provided between the head ring (75) and abutment parts (85) at the housing cover (81) or at the tank cap (82).

12. The filter device according to claim 1, characterized in that a plurality of, preferably three, spacing webs (77) extend between the insert ring (73) and the head ring (75), of which at least one bears the guide web (79) projecting on the former's outside.

13. The filter device according to claim 1, characterized in that one of the end caps (47), arranged concentrically to its guide ring (57), bears an outer ring (51) for receiving a sealing ring (55), wherein a further sealing ring (90) is arranged between the head ring (75) of the positioning device (65) and the abutment parts (85) of the housing cover (1).

14. The filter device according to claim 1, characterized in that the outer circumference of the filter element (5) and the assigned one end cap (47) are circular-cylindrical, and the inner circumference of the interior components forms a Reuleaux triangle.

15. The filter device according to claim 1, characterized in that a connecting longitudinal seam (95) of the preferably pleated filter material (12) ends in a position aligned with the guide channel (71) in one of the end caps (47).

16. The filter device according to claim 1, characterized in that the other end cap (25) of the filter element (5) has a bypass device (31) which opens onto the unfiltered side in the interior (71) of the filter element (5).

17. The filter device according to claim 1, characterized in that the filter element (5) is accommodated in the enclosure (3) at a predeterminable radial distance thereby forming a filtrate chamber (13), which is perforated at least in an axial longitudinal area (11) adjacent to the bypass device (31).

18. The filter device according to claim 1, characterized in that the other end cap (25) having the bypass device (31) is firmly connected to the enclosure (3) forming an attachment point (21) and that one of the end caps (47) is attached to the housing head (1) in the enclosure (3) to form a floating bearing (55) acting axially.

19. The filter device according to claim 1, characterized in that a tag can be arranged in the peripheral area of one (47) of the end caps (25, 47), which tag (96) can be read by means of an RFID sensor (97), which is located at a wall part encompassing the relevant end cap (47).

20. The filter device according to claim 1, characterized in that the tag (96) is arranged at the end cap (47) encompassed by the housing head (1) and the RFID sensor is arranged at the housing head (1).

21. A filter element, in particular provided for a filter device according to claim 1 having a filter material (12), which extends between two end caps (25, 47), one (47) of which has a guide channel (71), which opens towards the interior (17) of the filter element (5).

22. The filter element according to claim 17, characterized in that one of the end caps (47) has a guide ring (57) on its inside, projecting on both sides beyond an abutment ring (63), to which one free, frontal end of the filter material (12) is attached, and that the guide channel (71), the outer circumference of which is attached to the guide ring (57), preferably extends along the former's entire height.

23. The filter element according to claim 17, characterized in that the guide ring (57) has inwardly, in the direction of the interior (17) of the filter element (5), projecting boundary surfaces (91, 92).

24. The filter element according to claim 17, characterized in that one of the end caps (47), arranged concentrically to its guide ring (57), bears an outer ring (51) for receiving a sealing ring (55).

25. The filter element according to claim 17, characterized in that the outer circumference of the filter element (5) and the assigned one end cap (47) are circular-cylindrical, and the inner circumference of the interior components forms a Reuleaux triangle and that all components of the lower end cap (25) have a circular cylindrical outer and inner circumference.