Filter element

Abstract

A filter element has a filter body having a longitudinal axis and a concentric shape relative to the longitudinal axis. The filter body has a first end face and a second opposite end face. A first end disk is arranged at the first end face. A second end disk is arranged at the second end face. A support tube concentric to the longitudinal axis extends between the first and second end disks. At least one of the first and second end disks has support knobs arranged in a circular arrangement about the longitudinal axis and extending in axial direction outwardly. The support knobs, when the filter element is mounted in a housing that receives the filter element, rest against an inner cover contour of the housing and fold over in radial direction outwardly so as to be supported axially and radially on the housing.

Claims

1. A filter element comprising: a filter body having a longitudinal axis and a concentric shape relative to the longitudinal axis, the longitudinal axis defining an axial direction, the filter body having a filter medium, the filter body having a first axial end face and an opposing second axial end face; a first open or closed end disk arranged at the first end face; a second end disk arranged at the second end face; a support tube arranged concentric to the longitudinal axis, the support tube is a cylinder having a first radius, the cylinder at the first radius extending from between the first end disk to the second end disk; wherein at least one of the first and second end disks comprises a plurality of circumferentially spaced apart support knobs having a base arranged on an axially outer surface of the end disk, the plurality of circumferentially spaced apart support knobs arranged in a circular arrangement on a circle having the radius of the of the cylinder and concentric to the longitudinal axis, the plurality of circumferentially spaced apart support knobs extending in axial direction outwardly away to a support knob tip; wherein the plurality of circumferentially spaced apart support knobs are configured and adapted for directly engaging against and elastically folding over in a radially outward direction against a radial flank of a projecting truncated cone formed on the interior of a housing into which the filter element is installable, the folded plurality of circumferentially spaced apart support knobs operable to support the filter element axially and radially in the housing; wherein a radially inner face of the plurality of circumferentially spaced apart support knobs, starting from the base to the support knob tip, slopes radially outwardly at a first angle relative to a direction perpendicular to the axially outer surface of the end disk, such that the plurality of circumferentially spaced apart support knobs have a cross section that narrows starting from the base to the support knob tip; wherein a radially outer face of the of the plurality of circumferentially spaced apart support knobs extends axially outwardly at a second angle relative to the direction perpendicular to the axially outer surface of the end disk, the second angle<the first angle, such that the plurality of circumferentially spaced apart support knobs are configured to elastically fold over on their radially outer face in a radially outward direction; wherein the support tube is aligned radially directly underneath and supported axially on the plurality of circumferentially spaced apart support knobs, such that the support tube distributes forces in an axial direction from the filter element onto an underside of the plurality of circumferentially spaced apart support knobs.

2. The filter element according to claim 1, wherein the first or second end disk end disk which has the one or several support knobs, additionally includes a relief groove formed in the respective end disk, the relief groove arranged in radial direction outwardly from a radially outer face of the one or several support knobs.

3. The filter element according to claim 2, wherein the relief groove is arranged at the radially outer face of the one or several support knobs.

4. The filter element according to claim 1, wherein the support tube at the plurality of circumferentially spaced apart support knobs has an L-shaped cross section, a first leg of the L-shaped cross section formed by a tubular body of the support tube; a second leg of the L-shaped cross-section formed by a radially outwardly extending annular leg of the support tube, the annular leg arranged on an axial end of the tubular body.

5. The filter element according to claim 1, wherein the second end disk and the support tube together are formed as a monolithic component.

6. The filter element according to claim 1, wherein the second end disk is comprised of a polyurethane foam or an elastomer.

7. The filter element according to claim 1, wherein the first end disk has a radial seal that seals relative to the housing.

8. The filter element according to claim 1, wherein the filter medium is selected from the group consisting of paper, paper reinforced with plastic fibers, and plastic-coated paper, and combinations thereof; wherein the filter body has a folded zigzag shape and is annularly closed.

9. The filter element according to claim 1, wherein the one or several support knobs are several support knobs arranged in a circular arrangement with gaps between adjacent support knobs; wherein the gaps between the adjacent support knobs in the circular arrangement are uniform.

10. The filter element according to claim 1, wherein the one or several support knobs are several support knobs arranged in a circular arrangement with gaps between adjacent support knobs, wherein the gaps between the adjacent support knobs in the circular arrangement are non-uniform.

11. The filter element according to claim 1, wherein the one or several support knobs are arranged on the second end disk and the second end disk is of a closed configuration, closing over an interior of the filter body and the support tube.

12. The filter element according to claim 1, wherein the one or several support knobs are arranged at and secured directly onto the support tube of the filter element.

13. The filter element according to claim 1 is an air filter.

14. A filter system comprising: a housing having a longitudinal axis and a substantially concentric shape relative to the longitudinal axis; a filter element disposed exchangeably in the housing, the filter element comprising: a filter body having a longitudinal axis and a concentric shape relative to the longitudinal axis, the longitudinal axis defining an axial direction, the filter body having a filter medium, the filter body having a first axial end face and an opposing second axial end face; a first open or closed end disk arranged at the first end face; a second end disk arranged at the second end face; a support tube arranged concentric to the longitudinal axis, the support tube is a cylinder having a first radius, the cylinder at the first radius extending from the first end disk to the second end disk; wherein at least one of the first and second end disks comprises a plurality of circumferentially spaced apart support knobs arranged in a circular arrangement on a circle having the radius of the of the cylinder and concentric to the longitudinal axis, the plurality of circumferentially spaced apart support knobs extending in axial direction outwardly away; wherein the plurality of circumferentially spaced apart support knobs are configured and adapted for directly engaging against and elastically folding over in a radially outward direction against a radial flank of a projecting truncated cone formed on the interior of a housing into which the filter element is installable, the folded plurality of circumferentially spaced apart support knobs operable to support the filter element axially and radially in the housing; wherein the support tube is aligned radially directly underneath and supported axially on the plurality of circumferentially spaced apart support knobs, such that the support tube distributes forces in an axial direction from the filter element onto an underside of the plurality of circumferentially spaced apart support knobs; a cover closing off the housing and concentrically configured relative to the longitudinal axis, the cover having a truncated cone structure that projects into the interior of the housing; wherein the truncated cone structure has a radially outer flank engaging directly against and folding the plurality of circumferentially spaced apart support knobs of the filter element so that the plurality of circumferentially spaced apart support knobs are folded over in radial direction outwardly; an inlet arranged on the housing and/or the cover, wherein the inlet supplies a medium to be filtered to the filter element; an outlet that discharges the medium that has been filtered, wherein the outlet is arranged on the housing concentric to the longitudinal axis; wherein the housing in the area of the outlet is provided with a sealing contour that corresponds with a radial seal of the first end disk of the filter element.

15. The filter system according to claim 14, further comprising: a cyclone separator that is disposed in the area of the inlet and further comprising a dirt outlet disposed on the housing or on the cover.

16. The filter system according to claim 14, further comprising a secondary element disposed in an interior of the filter element, wherein the secondary element is connected to the housing such that the secondary element remains in the housing when the filter element is exchanged.

17. The filter system according to claim 14, wherein the support tube at the plurality of circumferentially spaced apart support knobs has an L-shaped cross section, a first leg of the L-shaped cross section formed by a tubular body of the support tube; a second leg of the L-shaped cross-section formed by a radially outwardly extending annular leg of the support tube, the annular leg arranged on an axial end of the tubular body.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Further advantages result from the following description. In the drawings, embodiments of the invention are illustrated. The drawings, the description, and the claims contain numerous features in combination. A person of skill in the art will consider the features expediently also individually and combine them to other meaningful combinations.

(2) FIG. 1 shows in a perspective view a filter system according to an embodiment of the invention with tangential inlet, central outlet, and dirt outlet at the bottom.

(3) FIG. 2 shows in a perspective view a filter system according to an embodiment of the invention with radial inlet and central outlet.

(4) FIG. 3 is a longitudinal section view of the filter system according to an embodiment of the invention with tangential inlet, central outlet, and dirt outlet at the bottom.

(5) FIG. 4 is a perspective partial view of the filter element according to an embodiment of the invention with second end disk and support knobs.

(6) FIG. 5 is a partial cross-section view of the filter element according to an embodiment of the invention, illustrated in the mounted state, with radially outwardly folded support knobs.

(7) FIG. 6 is a partial section view of a filter element according to an embodiment of the invention, illustrated in the mounted state, with radial seal of a first end disk.

(8) FIG. 7 is an inside view of a cover of a housing of a filter system with rib-shaped projections on the inner cover contour according to an embodiment of the invention.

(9) FIG. 8 shows a section view of a second end disk of a filter element according to an embodiment of the invention.

(10) In the Figures, same or functionally the same components are identified with same reference characters. The Figures show only exemplary embodiments and are not to be understood as limiting the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(11) FIG. 1 shows in a perspective view a filter system 100 according to an embodiment of the invention with tangential inlet 102, central outlet 104 at an end face of the housing, and a dirt outlet 106 at the bottom. Illustrated is a round filter configuration comprised of a housing 108 that is closed off by a cover 110, for example, a screw-on closure or a bayonet coupling closure.

(12) When using the invention as an air filter system, dust-laden air flows in through inlet 102 that is tangentially arranged relative to the filter element mounted in the housing interior so that the air in the interior of the housing 108 is caused to rotate due to an incoming flow protector at the filter element. Filter element and incoming flow protector are not illustrated in the drawing. Due to the cyclone effect that is caused by the rotational movement of the air, centrifugal forces act on the dust particles of the incoming air so that the dust particles are separated partially at the housing wall and can be discharged from the filter system 100 via the dirt outlet 106. In this way, the filter element itself is loaded less and the service life of the filter element is increased. The purified air can then be discharged through the central outlet 104 from the housing 108.

(13) FIG. 2 shows a perspective view of a filter system 100 according to an embodiment of the invention with inlet 102 at the cover and central outlet 104. Illustrated is also a round filter configuration that is comprised of a housing 108 closed off by cover 110. The inlet through which the dust-laden air flows into the housing is arranged in this case centrally above the filter element arranged in the interior. The outlet 104 through which the purified air can flow out is also centrally arranged, as also shown in FIG. 1.

(14) Such filter systems as illustrated in FIGS. 1 and 2 are usually employed in the field of construction machinery and agricultural machinery. They are characterized by great robustness and have, due to the high dust load, a short service life. A filter system 100 with loaded filter element must be able to tolerate a weight increase of 10 kg or more.

(15) In FIG. 3, a longitudinal section of the filter system 100 according to an embodiment with tangential inlet 102, central outlet 104, and dirt outlet 106 at the bottom is illustrated. The housing 108 of the filter system 100 is closed off with a cover 110. A filter element 10 that is comprised of a support tube 14 arranged concentrically relative to longitudinal axis L and a filter body 12 is closed off at the two opposed end faces 15, 17 with a first end disk and a second end disk 16, 18 that may be embodied, for example, of polyurethane foam or an elastomer. Second end disk 18 and support tube 14 of the filter element 10 may be configured monolithically with each other.

(16) The filter body 12 can be folded, for example, in a zigzag shape, can be embodied to be of a closed annular shape, and can be comprised of a filter medium such as paper, paper reinforced with plastic fibers, and/or paper coated with plastic material.

(17) The second end disk 18 whose stability is increased by a reinforcement plate 30 has segment-shaped interrupted support knobs 20 which radially outwardly extending are arranged circularly about the longitudinal axis L and, upon mounting of the filter element in the housing 108 that is provided for housing the filter element, come to rest against an inner cover contour 114 of the cover 110 and fold or bend in radial direction 38 outwardly and, in this way, are supported axially as well as radially on the housing 108. On the opposite end face 15 of the filter element 10, a radial seal 26 is provided on the first end disk 16 whose stability is increased by a reinforcement ring 31. By means of the seal 26, the filter element 10 is supported by a sealing contour 116 on the housing 108 in radial direction and seals the unfiltered air chamber relative to the filtered air chamber. The filter element 10 is thus axially as well as twice radially clamped relative to the housing 108.

(18) Dust-laden air can flow in through the inlet 102 in the direction of arrow 40; in this case, the inlet 102 is a tangential inlet and enables a cyclone operation by means of the rotational movement of the air caused by the cyclone separator 36. Dust particles can be deposited at the inner housing wall, due to the partial preseparation caused by the rotational movement, and can be discharged from the filter system 100 downwardly by the force of gravity through the dirt outlet 106, when the filter housing 108 is installed in horizontal position. In operation, after partial separation of the dirt particles, the air flows through the filter body 12 in the direction of arrows 42, 44 into the interior 50 of the filter element. Dust particles are retained in the filter medium beginning at a certain particle size that depends on the filter medium. Depending on the dust introduction, the filter element 10 must therefore be exchanged after a certain operating time.

(19) Through the outlet 104, the filtered air flows out in the direction of arrow 46. In the interior 50 of the filter element 10, a secondary element 28 is mounted which is substantially comprised of a supporting structure with a relatively permeable filter medium, for example, a nonwoven. When exchanging the filter element 10, the secondary element 28 remains in the housing 108 for protection of the downstream air guiding manifold, for example, of an internal combustion engine, against penetration of dust particles and other objects. The secondary element 28 is screwed in fixedly with a screw-on part 32 on the outlet-side part of the housing 108.

(20) The filter element 10 can be designed as an air filter, in particular an air filter of an internal combustion engine. However, its use as a diesel particulate filter is conceivable also in a similar configuration.

(21) FIG. 4 shows a perspective partial view of a filter element 10 according to an embodiment of the invention with second end disk 18 and support knobs 20. It can be seen that the second end disk 18 seals off the filter medium 12 as a closure of the filter medium 12. On the second end disk 18, interrupted segments as support knobs 20 are provided on a circular area; upon installation in a housing and support on an inner cover contour, the support knobs 20 can bend or fold in radial direction 38 outwardly. A radially inner face 20A of the support knobs 20, starting from the base 20C to the support knob tip 20D, slope radially outwardly at a first angle relative to a direction perpendicular to the axially outer surface of the second end disk 18, such that the support knobs 20 have a cross section that narrows starting from the base 20C to the support knob tip 20D. A radially outer face 20B of the support knobs 20 extends axially outwardly at a second angle relative to a direction perpendicular to the axially outer surface of the second end disk 18, the second angle<the first angle, such that the support knobs 20 are configured to elastically fold over on their radially outer face 20B in a radially outward direction.

(22) In FIG. 5, a partial section view of a filter element 10 according to an embodiment of the invention in the mounted state with folded-over support knobs 20 is illustrated. In the section view, the folded-over support knobs 20 of the second end disk 18 can be seen which are pressed in radial direction 38 outwardly upon assembly by being pressed against the cover 110 and deflected by the inner cover contour 114. The folding action of the support knobs 20 is favored by the relief groove 22 which in radial direction is arranged external to the support knobs 20. The folded-over support knobs 20 can be supported on the projection 24 of the second end disk 18 so that a fixed clamping action in axial and radial directions of the end face 17 of the filter element 10 is enabled.

(23) Also illustrated in FIG. 5 is the support tube 14 that provides a stiff structure to the filter element 10 as well as the filter body 12 which engages the second end disk 18. Also illustrated is a reinforcement disk 30 which is embedded in the second end disk. The projection 24 can be designed as a circumferentially extending ring which surrounds the circular area of the support knobs 20 or is segmented so as to match the segmented arrangement of the support knobs 20.

(24) FIG. 6 shows a partial section view of a filter element 10 according to an embodiment of the invention illustrated in the mounted state with radial seal 26 of the first end disk 16. The filter element 10, a section of which is illustrated with support tube 14 and filter body 12, is closed off at the end face 15 by the first end disk 16 to which is applied a radial seal 26. With this radial seal 26 the filter element 10 is pressed into a sealing contour 116 of the housing 108 so that in this way a reliable radial sealing action is provided. Also illustrated is a secondary element 28 that is mounted in the interior 50 of the filter element 10 and, by means of a screw-on part 32, is screwed and fastened to the outlet-side end 104 of the housing 108. In case of exchange of the filter element 10, the secondary element 28 protects the downstream air guiding path, for example, into an internal combustion engine, from becoming soiled. The screw-on part 32 is sealed with an O-ring 34 relative to the housing 108.

(25) FIG. 7 shows the inner view of a cover 110 of a housing of a filter system with rib-shaped projections 112 on the inner cover contour 114 according to an embodiment of the invention. By meshing with the support knobs of a second end disk of a filter element, the rib-shaped projections can secure the filter element against rotation in operation even in case of a possible vibration excitation.

(26) FIG. 8 shows a section of a second end disk 18 of a filter element 10 according to an embodiment of the invention in the not yet clamped state. The second end disk 18 closes off the filter element, comprised of filter body 12 and support tube 14, at an end face. A support knob 20 of the second end disk 18 is illustrated in the not yet clamped state. Clearly shown are also a relief groove 22 as well as a projection 24. The relief groove 22 facilitates folding over of the support knobs 20 in radial direction outwardly wherein however the support knob 20 can be supported in turn on the projection 24. In this way, a fixed axial clamping action of the filter element 10 is enabled. The support tube 14 has an annular attachment or projection 48 with L-shaped cross-section in order to spatially distribute an axial force introduction into the second end disk 18. The same principle of force distribution is also conceivable at the other end of the support tube 14 with the first end disk 16.

(27) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.