DE102019116203A1 - Fluid filter with axially flowable wound filter elements - Google Patents

Abstract

The invention relates to a fluid filter (10) for filtering a fluid, in particular fuel, oil or water, comprising: - a filter housing (12) with a longitudinal axis (24); - a first wound filter element (20) arranged in the filter housing (12) and through which the fluid can flow in an axial direction, with a wound filter medium (26) and with axial flow channels (68, 70), which are mutually closed with respect to the end faces (60) of the wound filter element (20) and by at least one layer (72) of the Filter medium (26) are separated from one another in the radial direction; and - a second wound filter element (22) which is arranged in the filter housing (12), the two wound filter elements (20, 22) being arranged one behind the other in an axial direction to the longitudinal axis (24) and being fluidly connected in series, and wherein the filter housing (12) has two separate fluid connections (46a, 46b; 48a, 48b) for each of the two wound filter elements (20, 22).

Description

Technical field

The invention relates to a fluid filter, in particular for fuel, oil, water or air, comprising a filter housing with a longitudinal axis and a first wound filter element which is arranged in the filter housing and through which the fluid can flow in an axial direction. The wound filter element has a wound filter medium and axial flow channels which are mutually closed with respect to the end faces of the wound filter element and are separated from one another in the radial direction by at least one layer of the filter medium.

State of the art

A fluid filter mentioned at the outset is, for example, from DE 10 2014 102 436 A1 known. The known fluid filter has only a limited filter performance and thus only a limited area of use. It is therefore the object of the invention to provide a fluid filter with an improved filter performance and at the same time as compact as possible.

Embodiment (s) of the invention

The object of the invention is achieved by a fluid filter with the features specified in claim 1. Preferred developments of the invention are specified in the description and in the subclaims.

The fluid filter according to the invention has a second wound filter element which is arranged in the filter housing, the two wound filter elements being arranged one behind the other in a direction axial to the longitudinal axis of the filter housing and being connected fluidically in series. From a fluidic point of view, the two wound filter elements are therefore connected in series. The wound filter element through which the fluid flows first serves as a prefilter, while the wound filter element through which the fluid flows last functions as a main filter. The fluid filter according to the invention has a greater filter performance than the known fluid filter. According to the invention, the two wound filter elements can be constructed identically or they can differ from one another, for example, in terms of their size, the pore size of their respective filter medium or also in their functional filter area. Because the fluid filter or the filter housing has separate fluid connections for an inflow and an outflow of the fluid for each of the two wound filter elements, a pump can be interposed between the two wound filter elements. By means of the pump, the fluid can be fed to the winding filter element, which functions as the main filter, at a desired operating pressure, thus ensuring a volume flow of the fluid per unit time corresponding to the demand. Preferably, the pump can also be used to generate a pressure difference across the winding filter element serving as a prefilter. At the same time, the pump can be reliably protected from damage by particles and the like by the fluidically arranged winding filter element. The pump can preferably be a gear pump or a suction-pressure pump (e.g. a piston pump). In particular, the pump can be designed as a low-pressure fuel delivery pump.

According to a preferred development of the invention, a sealing washer is arranged in the axial direction between the two wound filter elements, which sealingly abuts the inside of the filter housing. The sealing disk delimits a radially extending flow channel in the axial direction with the end faces of the wound filter elements facing each other. The sealing disk thus delimits two housing chambers from one another in a fluid-tight manner in the filter housing, in each of which one of the two wound filter elements is arranged. The fluid can, if the filter housing is provided with radial or lateral fluid connections, be supplied to or removed from the filter elements in the radial direction via the aforementioned radial flow channels. That is, the fluid flows in the flow channels in the radial direction towards or away from the filter elements. In other words, the fluid can flow from one of the lateral fluid connections in the radial direction through one of the radially extending flow channels to one of the filter elements or from one of the filter elements in the radial direction through one of the radially extending flow channels to one of the lateral fluid connections. In contrast, the filter elements themselves are flowed through by the fluid to be filtered in the axial direction.

According to the invention, the sealing disk can in particular be designed as a plastic injection molded part. This offers cost advantages for mass production of the fluid filter. The sealing disk can be provided on the circumferential side with a sealing element, via which the sealing disk bears against the filter housing in a fluid-tight manner. The sealing element can be arranged, for example, held in a radial groove of the sealing washer, or it can also be injection molded or glued directly to the sealing washer.

According to the invention, the sealing washer can be loosely inserted in the filter housing and, for example, be held clamped between the two wound filter elements. However, the sealing disk is preferably arranged, in particular molded, on an end disk of one of the two wound filter elements. As a result, the production costs and assembly times of the fluid filter can be reduced further. In the latter case, the end plate and the sealing plate can thus be made together in one piece as an injection molded part.

According to the invention, at least one of the two radial flow channels (= radial channels) can be fluidly connected via a fluid tube to a fluid connection of the filter housing arranged on the end face of the filter housing. This allows axial flow through the wound filter element in a structurally simple manner even with an end-side fluid connection. This is advantageous for the possible range of use, particularly with regard to difficult installation conditions, of the fluid filter. The first fluid tube can at least partially extend through the sealing washer. In this case, the fluid pipe is preferably sealed off from the sealing disk via a (radial) sealing element. In the latter case, the fluid tube thus opens into the radial flow channel of the wound filter element which is arranged at a further distance from the front fluid connection of the filter housing. The aforementioned fluid tube can also be used to mount the wound filter element penetrated by the fluid tube in the axial direction in the filter housing and, if necessary, also to achieve a vibration-proof mounting of this wound filter element in the filter housing.

According to the invention, the fluid tube can be arranged fixed to the housing on the filter housing. When the filter elements are replaced at intervals, the overall operating costs of the fluid filter can be reduced. On the other hand, this also helps to avoid waste.

According to a preferred development of the invention, both radially extending flow channels can also be fluidly connected via a fluid tube to a fluid connection arranged on the end face of the filter housing. The two fluid tubes are preferably arranged coaxially to the longitudinal axis of the fluid filter. As a result, a particularly compact structure of the fluid filter can be achieved and an unnecessary space requirement at the expense of the available filter area of one of the wound filter elements can be avoided. An additional installation space outside the fluid filter required for the connection of fluid lines can also be further minimized. This is particularly advantageous in the case of cramped installation spaces, such as in motor vehicles, in particular trucks.

With regard to a particularly compact construction of the fluid filter, it has proven to be advantageous if at least some of the fluid connections of the filter housing are on the side, ie. H. radial, are arranged.

With a view to a further simplified assembly, the two wound filter elements can be mechanically coupled to one another via the sealing washer. As a result, the two wound filter elements can be used as one structural unit, i. H. a filter unit to be handled together, inserted into or removed from the filter housing.

The two wound filter elements can each have an annular end disk at both ends. The filter medium can be supported or stiffened by such end plates. In addition, in particular with the interposition of a ring or radial sealing element, a sealing contact of the wound filter elements on the filter housing can be achieved in order to thereby define flow spaces for the fluid or to fluidically seal a clean side and a raw side of the filter element against one another.

The mutually facing end sheaths of the two wound filter elements can, if the sealing washer is not made in one piece with one of these end washers, be locked or glued to the sealing washer.

It goes without saying that the filter housing can consist entirely or partially of plastic or metal. The two wound filter elements are moreover preferably arranged interchangeably in the filter housing.

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

• 1 einen Fluidfilter mit einem Filtergehäuse, in dem zwei Wickelfilterelemente axial hintereinanderliegend angeordnet und durch eine Dichtscheibe voneinander getrennt sind, wobei die Wickelfilterelemente fluidisch hintereinandergeschaltet und von dem zu filternden Fluid jeweils in axialer Richtung durchströmbar sind und wobei das Filtergehäuse für jedes der Wickelfilterelemente jeweils zwei Fluidanschlüsse aufweist, in einem Längsschnitt;
• 2 zwei Wickelfilterelemente, die den Wickelfilterelementen des Fluidfilters gemäß 1 ähnlich sind und die an der Dichtscheibe befestigt sind und so eine gemeinsam handzuhabende Filtereinheit bilden;
• 3 ein schematisiertes Schnittmodell eines Filtermediums der Wickelfilterelemente gemäß 1;
• 4 einen Fluidfilter, bei dem das Filtergehäuse zwei stirnseitige und zwei radiale Fluidanschlüsse aufweist, in einem Längsschnitt; und
• 5 einen Fluidfilter mit drei stirnseitigen Fluidanschlüssen und einem radialen Fluidanschluss, wobei zwei der stirnseitigen Fluidanschlüsse mit jeweils einem Fluidrohr verbunden sind, die zueinander koaxial verlaufend angeordnet sind, in einem Längsschnitt.

The drawing shows:

• 1 a fluid filter with a filter housing, in which two wound filter elements are arranged axially one behind the other and separated from one another by a sealing washer, the wound filter elements being fluidly connected in series and through which the fluid to be filtered can flow in the axial direction, and wherein the filter housing has two fluid connections for each of the wound filter elements , in a longitudinal section;
• 2 two wound filter elements which correspond to the wound filter elements of the fluid filter 1 are similar and are attached to the sealing washer and thus form a filter unit to be handled together;
• 3 a schematic sectional model of a filter medium of the wound filter elements according to 1 ;
• 4 a fluid filter, in which the filter housing has two front and two radial fluid connections, in a longitudinal section; and
• 5 a fluid filter with three front fluid connections and a radial fluid connection, wherein two of the front fluid connections are each connected to a fluid tube, which are arranged coaxially to each other, in a longitudinal section.

1 shows a fluid filter according to the invention 10 for a fluid to be filtered, for example fuel, oil or water, in a longitudinal section. The fluid filter 10 includes a filter housing 12 with a filter bowl 14 and with a housing cover 16 that has an insertion opening 18 of the filter bowl 14 sealed fluid-tight. The housing cover 16 can be in any known way on the filter bowl 14 attached, in particular screwed into or screwed onto it.

Inside the filter housing 12 are a lower first winding filter element 20 and an upper second winding filter element 22 arranged, through which the fluid to be filtered can flow, ie one after the other. The filter elements 20 . 22 are in one to the longitudinal axis 24 of the fluid filter 10 or filter housing 12 arranged axially one above the other or one behind the other and spaced apart. The two filter elements 20 . 22 each have a filter medium 26 on, around a longitudinal axis designated 28 of the respective filter element 20 . 22 is wrapped around. The filter media 26 thus each form a kind of filter media roll, which the respective filter element longitudinal axis 28 encircles in a ring. The filter media 26 can be covered on the outside with a fluid-tight (protective) cover 30 , for example a plastic film. The filter media 26 of the two wound filter elements 20 . 22 can differ from each other in their material, their pore size or in their active filter surface. This allows a differentiated filter behavior to be set. The two wound filter elements can also 20 . 22 (in the axial direction) a different height 32 and / or a different outside diameter 34 exhibit. The longitudinal axes 28 of the two wound filter elements 20 . 22 each fall with the longitudinal axis 24 of the filter housing 12 together. The two filter media 26 of the filter elements 20 . 22 are of the fluid to be filtered in each case in an axial main flow direction 36 , here as an example, flow from bottom to top.

Between the two filter elements 20 . 22 is a sealing washer 38 arranged. The sealing washer 38 has a first sealing element on the circumference 40 on. The sealing element 40 is designed here as an elastomeric O-ring. Through the sealing washer 38 is inside the filter housing 12 a first and a second housing chamber 42 . 44 formed, in each of which one of the wound filter elements 20 . 22 is arranged. The two housing chambers 42 . 44 are by means of the sealing washer 38 sealed against each other in a fluid-tight manner. According to 1 has the filter housing 12 for each of the two housing chambers 42 . 44 each have a first fluid connection 46a . 46b and a second fluid port 48a . 48b to the fluid to be filtered on the respective winding filter element 20 . 22 to supply or the fluid filtered through the respective wound filter element again from the filter housing 12 lead out.

In the present case, the first two fluid connections serve as examples 46a . 46b each as a fluid inlet and the second fluid ports 48a . 48b each as a fluid outlet. A respective raw side of the wound filter elements 20 . 22 is with 50 and a clean side is with 52 designated. The second fluid connection 48a the first housing chamber 42 and the first fluid connection 46b the second housing chamber 44 can be a pump 54 be interposed, by means of which the fluid to the second wound filter element 22 can be pumped. The wound filter element through which the fluid flows first 20 thus serves as a pre-filter element, while the fluidically connected second wound filter element 22 acts as a main filter element. It is understood that the two wound filter elements 20 . 22 can also be flowed through serially in a different order. In addition, the two filter elements 20 . 22 are also flowed through in the opposite direction.

The wound filter elements 20 . 22 each have an annular end plate at both ends 56 each with a - centrally arranged - recess 58 on. The end disks 56 can on the filter medium 26 of the respective winding filter element 20 . 22 each glued, welded to it or to the filter medium 26 be injected. The end disks pointing away from each other 56 of the two wound filter elements 20 . 22 are each with a second sealing element 40 , here an elastomeric O-ring, and are located on the filter housing 12 sealing on the inside around the respective clean side 52 and the respective raw side 50 to seal against each other.

The sealing washer 38 has in addition to the subdivision of the filter housing 12 in two housing chambers 42 . 44 another function. The sealing washer 38 bounded by the mutually facing first end faces 60 of the two wound filter elements 20 . 22 each have a radially extending flow channel 62 . 64 for the fluid. The two flow channels 62 . 64 are each with a lateral, ie radial, fluid connection 48a . 46b of the filter housing 12 fluidly connected.

The sealing washer 38 can be loose in the filter housing 12 inserted and between the two wound filter elements 20 . 22 be held clamped, for example. In the embodiment shown here, the sealing washer 38 however at the end plate 56 of the second winding filter element 22 formed. The sealing washer 38 can be used together with this end plate 56 be designed as a plastic injection molded part. It is understood that the sealing washer 38 alternatively also on the end plate 56 can be glued or welded to it. The sealing washer 38 can alternatively also on the end plate 56 of the first winding filter element 20 or on the facing end plates 56 both wound filter elements 20 . 22 molded, glued, locked or otherwise attached.

2 shows two wound filter elements 20 . 22 that the in 1 shown winding filter elements 20 . 22 are similar. The spirally wound filter medium 26 of the upper second winding filter element 22 is easy to recognize. The sealing washer 38 is here on both winding filter elements 20 . 22 attached. The two wound filter elements 20 . 22 thereby form with the sealing washer 38 a common filter unit 66 ,

3 shows a highly schematic sectional model of the filter medium 26 of the two wound filter elements 20 . 22 from the 1 and 2 , The filter medium 26 has first and second axial channels 68 . 70 on, which are arranged parallel to each other. The first and second axial channels 68 . 70 are each by at least one layer 72 of the filter medium 26 separated from each other. The first axial channels 68 have only on the raw side arranged end face 60 of the wound filter element 20 . 22 first flow openings 74 on. The second axial channels 70 have only on the front side arranged on the clean side 60 second flow openings 76 on. The first and second axial channels 68 . 70 are each designed as a so-called blind channel. The first axial channels 68 are on the clean side and the second axial channels 70 are on the raw side, for example with an adhesive 78 , locked. The fluid flows in the main flow direction 36 in the first axial channels 68 one and can only be in the radial direction through the at least one layer 72 of the filter medium 26 to the adjacent second axial channels 70 reach. The fluid is passed through the filter medium 26 filtered and flows through the second axial channels 70 in the main axial flow direction 36 from.

4 shows a further embodiment of a fluid filter 10 in a longitudinal section. The fluid filter 10 differs from that in 1 fluid filter shown 10 essentially in that the radial flow channel 64 the second housing chamber 44 or the second winding filter element 22 via a first fluid pipe 80 with a fluid connection of the filter housing arranged at the end 12 is fluidly connected. The fluid pipe 80 extends through the first wound filter element 20 as well as the sealing washer 38 therethrough. An inside opening 82 of the first fluid tube 80 flows into the second flow channel 64 or is fluidly connected to it. The fluid pipe 80 and the sealing washer 38 are by means of another sealing element 83 , here an O-ring, sealed against each other in a fluid-tight manner. In the 4 shown lower end plate 56 of the first winding filter element 20 lies on the inside via a further sealing element, designated 85, on the fluid pipe 80 sealing in the radial direction.

The fluid flows through the first fluid connection 46a in the first housing chamber 42 and flows through the wound filter element 20 in the axial direction along the specific main flow direction 36 , The fluid is through the second fluid port 48a out of the filter housing 12 led out and passes through the fluid connection 46b in the second housing chamber 44 , The fluid flows through the second wound filter element 22 in the axial direction here along the main flow direction 36 from top to bottom and is going over the fluid tube 80 and the second fluid connection 48b out of the filter housing 12 dissipated. Of course, there is also a flow in opposite directions with regard to the two wound filter elements 20 . 22 possible.

At the in 5 fluid filter shown 10 is compared to the fluid filter 10 according to 4 in addition the radial flow channel 62 . 64 the first housing chamber 42 or the first winding filter element 20 via a second fluid tube 84 with one on the filter housing 12 arranged second fluid connection 48a fluidly connected. The first and second fluid tubes 80 . 84 are to the longitudinal axis 24 of the filter housing 12 arranged coaxially, the first fluid tube 80 in sections within the second fluid tube 84 is arranged progressively. The two fluid pipes 80 . 84 can like this in 5 is shown, be made in one piece and for example via one or more radial webs 86 be connected. The filter housing 12 here only has a lateral fluid connection for the second wound filter element 22 on. The design is based on that of the sealing washer 38 assigning end plate 56 of the first winding filter element 20 here with an annular opening or recess 58 provided for the fluid. The fluid can be the first and / or the second wound filter element 20 . 22 via the respective fluid connections 46a . 46b . 48a . 48b if necessary, can also be fed in the opposite direction.

QUOTES INCLUDE IN THE DESCRIPTION

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Patent literature cited

• DE 102014102436 A1 [0002]

Claims (12)

A fluid filter (10) for filtering a fluid, in particular fuel, oil or water, comprising: - A filter housing (12) with a longitudinal axis (24); - A first wound filter element (20), which is arranged in the filter housing (12) and through which the fluid can flow in an axial direction, with a wound filter medium (26) and with axial flow channels (68, 70), which are relative to the end faces (60) of the Winding filter element (20) are mutually closed and separated from one another in the radial direction by at least one layer (72) of the filter medium (26); and - A second wound filter element (22) which is arranged in the filter housing (12), the two wound filter elements (20, 22) being arranged one behind the other in an axial direction to the longitudinal axis (24) and being fluidly connected in series, and the filter housing (12) for each of the two wound filter elements (20, 22) each having two separate fluid connections (46a, 46b; 48a, 48b). Fluid filter after Claim 1 , characterized in that in the axial direction between the two wound filter elements (20, 22) a sealing disc (38) is arranged, which abuts the inside of the filter housing (12) in a sealing manner, the sealing disc (38) with mutually facing end faces (60) each of the wound filter elements (20, 22) delimits a radially extending flow channel (62, 64) in the axial direction. Fluid filter after Claim 2 , characterized in that the sealing disc (38) is designed as a plastic injection molded part. Fluid filter after Claim 2 or 3 , characterized in that the sealing washer (38) is attached, in particular molded, to an end washer (56) of at least one of the two wound filter elements (20, 22). Fluid filter according to one of the preceding claims, characterized in that at least one of the two radial flow channels (62, 64) via a fluid tube (80, 84) with a fluid connection (46a, 46b; 48a, 48b) arranged on the end face of the filter housing (12) connected is. Fluid filter after Claim 5 , characterized in that the fluid pipe (80, 84) extends at least in sections through the sealing disk (38), the fluid pipe (80, 84) preferably sealingly abutting the sealing disk (38) via a sealing element (83). Fluid filter after Claim 6 , characterized in that the fluid tube (80, 84) is fixed to the housing on the filter housing (12), in particular molded onto the filter housing (12). Fluid filter according to one of the Claims 5 to 7 , characterized in that both radial flow channels (62, 64) are each connected via a fluid tube (80, 84) to a fluid connection (46a, 46b, 48a, 48b) of the filter housing (12) arranged on the end face. Fluid filter after Claim 8 , characterized in that the two fluid tubes (80, 84) are arranged coaxially. Fluid filter according to one of the preceding claims, characterized in that at least some of the fluid connections (46a, 46b; 48a, 48b) of the filter housing (12) are arranged on the side of the filter housing (12). Fluid filter according to one of the preceding claims, characterized in that the two wound filter elements (20, 22) are mechanically coupled to one another via the sealing disk (38). Fluid filter according to one of the preceding claims, characterized in that the wound filter elements (20, 22) are arranged interchangeably in the filter housing (12).

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