CN112237770A

CN112237770A - Filter cartridge with compensation device

Info

Publication number: CN112237770A
Application number: CN201910642168.5A
Authority: CN
Inventors: 乔基奥·基隆迪
Original assignee: Shanghai Sofima Automobile Filter Co ltd
Current assignee: Shanghai Sofima Automobile Filter Co ltd
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2021-01-19
Anticipated expiration: 2039-07-16
Also published as: CN112237770B

Abstract

A filter cartridge (1) of a filter assembly for a fluid (10), extending along a filter axis (X-X), comprising: a tubular filter medium (2) comprising a central cavity (20), through which filter medium (2) a fluid can pass in a radial direction; a first plate (3) and a second plate (4) respectively comprising a first through hole (30) and a second through hole (40) respectively defined by a first edge (31) and a second edge (41); a compensating device (5) of variable shape and/or position to vary the volume of the flow portion through which the aqueous fluid flows, the variation of shape and/or position being due to crystallization of the fluid. The compensation device (5) comprises: a filling element (6) housed at least partially in the central cavity (20) and comprising a first end (61) and a second end (62); an annular gasket element (7) elastically yieldable, comprising an outer gasket edge (71) sealingly engaging the first plate (3) and an inner gasket edge (72) sealingly engaging the first end (61).

Description

Filter cartridge with compensation device

Technical Field

The present invention relates to a filter cartridge for a fluid filtration assembly. Furthermore, the invention relates to a filter body of a fluid filter assembly, which is adapted to receive a filter cartridge. In addition, the invention also relates to the filter assembly as a whole.

Background

The invention is preferably used in the automotive field. In particular, the subject of the invention is in fact a filtering assembly for fluids, in particular for fluids that may cause a risk of crystallization (with vehicles used in low temperature environments), such as water or urea. In particular, water is understood to be a broad fluid that is wholly or partially water-containing.

In particular, the main problems that plague this type of device concern the following possibilities: when subjected to low temperatures, the fluid freezes or crystallizes (hereinafter, freezing and crystallization are collectively referred to as crystallization), resulting in an increase in volume in the fluid flow region and resulting in plugging of the fluid flow region. Obviously, depending on the type of fluid, the (crystalline) threshold temperature varies: for example, for pure water the threshold temperature is 0 ℃ and for urea the threshold temperature is-11 ℃.

In particular, the increase in volume can result in tension and deformation on the filter cartridge and/or corresponding components of the filter assembly.

In addition, in particular, it is undesirable to have a large amount of water on the clean side of the filter. Under given environmental conditions, this water may crystallize, blocking the flow at the output.

In addition, it is undesirable to have a large amount of freely accessible "free" volume that is suitable for containing the filtered fluid and thus results in an increased amount of stress being transferred to the filter element and filter body after the aqueous fluid has been frozen.

For the above reasons, solutions of filter assemblies comprising respective filling and compensation members and/or portions are known, i.e. firstly, these members and/or portions are adapted to occupy the space of the filter assembly to limit the amount of water inside the filter assembly; secondly, since they are deformable, they are adapted to allow the available volume of space to be used by the fluid flowing into the filter assembly, if desired. Note that "deformable" means that the shape and/or position of the component undergoes a change depending on the state of the fluid (i.e., liquid or solid).

The known solutions have particularly complex shapes and geometries which complicate the production and assembly phases of the filter cartridge and/or of the filtering assembly.

Furthermore, it has been demonstrated that the periodic nature of the deformation of the parts and/or the filling and compensation portions affects their lifetime. Over time, the parts and/or the filling and compensating parts lose their deformability and in some cases even break.

Disclosure of Invention

Accordingly, there is a need to provide a filter cartridge for a filter assembly and a filter assembly for a fluid including the filter cartridge that fully respond to the needs of the art while overcoming these problems.

The object of the present invention is to provide a filter cartridge, a filter body adapted to house the filter cartridge and a filter assembly which present a simple, effective and long lasting compensation device which solves the apparent problems of the prior art solutions.

The above object is achieved by a filter cartridge as claimed in claim 1, by a filter body as claimed in claim 13. The above object is also achieved by a filter assembly according to claim 17. The claims dependent on these claims show preferred embodiments with further advantageous aspects.

Drawings

Further characteristics and advantages of the invention in any case will become apparent from the description given below of a preferred embodiment, formed by way of non-limiting example in connection with the accompanying drawings. Wherein:

FIG. 1 illustrates a longitudinal cross-sectional view of a filter assembly of the present invention according to a preferred embodiment;

FIG. 1a shows an enlarged portion of the filter assembly shown in FIG. 1;

FIG. 2 shows a longitudinal cross-sectional view of the filter assembly shown in FIG. 1 with parts separated;

fig. 3 shows a longitudinal sectional view with parts separated of a filter cartridge according to the invention.

Description of reference numerals:

1a filter cartridge; 2 a filter medium; 20 a central lumen; 3 a first plate; 30 a first via hole; 31 a first edge; 35 an annular retainer ring; 350 receiving the area; 351 a compensation zone; 36 outer annular grooves; 38 axial locking teeth; 39 a first radial gasket; 4 a second plate; 40 a second via; 41 a second edge; 45 auxiliary annular retainer rings; 450 an auxiliary reception area; 49 a second radial washer; 5 a compensating device; 6 a filler element; 61 a first end; 610 is open at the bottom; 616 an inner annular groove; 62 a second end; 7 an annular gasket member; 71 an outer gasket edge; 710 a recess; 711 annular ridge; 72 inner gasket edge; a 720 projection; 721 annular groove; 500 a filter body; 501, an inlet; 502 outlet port; 510 a cover; 510' an ambient pressure chamber; 517 a protruding part; 518 locking groove; a cup 520; 550 a filtration chamber; 551 a body wall; 900 a filter assembly; an X-X filter axis; a Y-Y body axis; the S dirty side.

Detailed Description

In the drawings, reference numeral 1 designates a filter cartridge according to a preferred embodiment of the invention. In addition, reference numeral 900 designates a filtering assembly for fluids which in turn comprises a filter cartridge 1 according to a preferred embodiment of the present invention. Furthermore, reference numeral 500 designates a filter body adapted to receive the filter cartridge 1.

Now entering the advantages of the present invention, the filter assembly 900 is suitable for filtering fluids that may be at risk of crystallization, such as water or urea, which, as already described, may be at risk of crystallization when operated at ambient conditions below 0 ℃ and-11 ℃, respectively.

According to the present invention, filter assembly 900 is adapted to be connected to a conduit of an aqueous fluid supply system (e.g., a urea injection system).

According to the present invention, as will be described broadly below, the filter assembly 900 includes a filter cartridge 1 and a filter body 500.

Preferably, the filter assembly 900 is fluidly connectable to a tank and a suction pump (not shown) adapted to draw aqueous fluid from the tank through the filter assembly 900. In other words, the filter assembly 900 operates in a suction mode.

The filter body 500 may be connected to a circuit conduit to receive "dirty fluid" (i.e., fluid to be filtered) and produce "clean fluid" (i.e., filtered fluid).

According to the present invention, the filter body 500 defines a filtering chamber 550 inside, and the filter cartridge 1 is accommodated in the filtering chamber 550. The filter body 500 includes an inlet 501 and an outlet 502 fluidly connected to a filtration chamber 550.

According to a preferred embodiment, the filter body 500 includes a cup 520 and a lid 510, the lid 510 closing the cup 520 to define a filter chamber 550 bounded by body walls 551.

According to a preferred embodiment, the cup 520 and the lid 510 are screwed to each other. Preferably, lid 510 is threaded into cup 520 (inside cup 520) as shown.

Preferably, the filter body extends in length along a body axis Y-Y. Preferably, the inlet 501 and outlet 502 are made on the cup 520.

According to a preferred embodiment, the body wall 551 extends in length parallel to (preferably around) the body axis Y-Y.

The invention also relates to a filter cartridge 1. Preferably, the filter cartridge 1 is accommodated in the filter body 500. Preferably, the filter cartridge 1 extends in length along a filter axis X-X; with the filter cartridge 1 received in the filter body 500, the filter axis X-X corresponds to the body axis Y-Y.

According to the present invention, filter cartridge 1 includes a tubular filter medium 2, filter medium 2 including a central cavity 20. The filter media 2 extends axially about a filter axis X-X.

According to the invention, the fluid can pass through the filter medium 2 in a radial direction.

According to a preferred embodiment, fluid may pass through filter medium 2 from the outside to the inside. In other words, central cavity 20 is the "clean side" of the filter, and exterior space S at filter media 2 is the "dirty side".

According to a preferred embodiment, the filter medium 2 is for example a non-woven fabric made of polymer fibres (for example polypropylene, polyethylene or polyamide).

According to a preferred embodiment, the filter medium 2 is a pleated surface membrane (pleated surface septum) having a star-shaped geometry.

According to a preferred embodiment, the filter medium 2 is a tubular depth membrane (tubular-shaped depth septum).

According to the invention, the filter cartridge 1 further comprises a first plate 3, the first plate 3 being at a first end of the filter medium 2, the first plate 3 comprising a first through hole 30 at the filter axis X-X, defined by a first edge 31.

Further in accordance with the present invention, filter cartridge 1 further includes a second plate 4, second plate 4 at a second end of filter media 2, second plate 4 including a second throughbore 40 at filter axis X-X defined by a second edge 41.

According to the present invention, the first plate 3 and the second plate 4 are adapted to sealingly engage the body wall 551.

According to a preferred embodiment, the first plate 3 and the second plate 4 comprise a first radial gasket 39 and a second radial gasket 49, respectively. The first radial gasket 39 and the second radial gasket 49 are each radially outward to radially sealingly engage the body wall 551. Preferably, the first plate 3 and the second plate 4 have special outer housing grooves for gaskets.

According to a preferred embodiment, the "dirty side" is outside the filter medium 2 and is defined at both axial ends by a first radial gasket 39 and a second radial gasket 49.

According to a preferred embodiment, as shown in the figures, the first radial gasket 39 and the second radial gasket 49 have different radial distances from the filter axis X-X to facilitate insertion into the filter body 500.

Furthermore, according to a preferred embodiment, the first plate 3 comprises an annular collar (collar)35 extending around the X-X axis. According to a preferred embodiment, the first plate 3 comprises an annular collar 35, the annular collar 35 extending in an axial direction around the X-X axis on the opposite side of the first plate 3 with respect to the filter medium 2, thereby defining a receiving area 350, the purpose of which will be described in detail below.

According to a preferred embodiment, the second plate 4 also comprises an auxiliary annular collar 45, which auxiliary annular collar 45 extends axially on the opposite side of the second plate 4 with respect to the filter medium 2, so as to define an auxiliary receiving area 450, the purpose of which will be described in detail below.

According to the invention, the filter cartridge 1 further comprises compensation means 5 of variable form and/or position, so as to vary the volume of the flow portion through which the aqueous fluid flows. In particular, the change in shape and/or position of the compensation means 5 is caused by crystallization of the fluid. The change in shape and/or position of the compensating device 5 is also caused by crystallization of the filter medium 2 at the point of application.

In other words, the compensation means 5 are adapted to occupy a region of fluid flow and to change their shape and position based on the state of the fluid (i.e. whether there are crystalline crystals in the fluid).

According to the invention, the compensating device 5 comprises a filler element 6 and an annular gasket element 7.

The filler element 6 is at least partially accommodated in the central cavity 20.

Preferably, the filling element 6 occupies part of the space of the central cavity, leaving space for the fluid to flow within the central cavity 20 towards the first through hole 30 and/or the second through hole 40. In other words, the presence of the filling element 6 does not completely block the fluid path. In other words, the filling element 6 occupies a part of the volumetric region of the "clean side", thereby avoiding that the "clean side" is completely filled with fluid that may crystallize.

According to the invention, in the case of a filter medium 2 which is passed through from the outside inwards, the change in shape and/or position of the compensating device 5 due to the formation of crystals changes the through-section of the "clean side" of the filter medium.

The filling element 6, which extends in the length direction along the filter axis X-X, comprises a first end 61 and a second end 62.

Preferably, the first end 61 extends from the central cavity 20. Preferably, the first end 61 is received in the receiving area 350.

Preferably, the second end 62 protrudes from the second through hole 40. Preferably, the second end 62 protrudes from the second through hole 40 in any axial configuration of the annular gasket element 7. In other words, the second end 62 is received in the auxiliary receiving area 450.

According to a preferred embodiment, the filling element 6 has a tubular shape and is made of a rigid material (preferably a plastic material) that does not change under the action of the fluid. According to a preferred embodiment, the filling element 6 is hollow, comprising a bottom opening 610 at the first end 61.

Instead, the annular gasket element 7 yields elastically to allow axial movement of the filling element 6 when the crystal is formed.

According to a preferred embodiment, the annular gasket element 7 is housed in a receiving zone 350 present in the first plate 3.

In fact, the annular gasket element 7 is operatively connected to the first plate 3 and to the filler element 6 in such a way that: the annular gasket member 7 includes an outer gasket edge 71 and an inner gasket edge 72, the outer gasket edge 71 sealingly engaging the first plate 3 and the inner gasket edge 72 sealingly engaging the first end 61.

According to a preferred embodiment, the outer gasket edge 71 is operatively connected to the first plate 3 by means of co-moulding (co-moulding).

According to a preferred embodiment, the inner gasket edge 72 is operatively connected to the first end 61 by co-molding (co-molding).

According to a preferred embodiment, the first plate 3 comprises an outer annular groove 36, the outer gasket edge 71 being sealingly received in this outer annular groove 36.

Further, the first end 61 preferably includes an inner annular groove 616, the inner gasket edge 61 being sealingly received in the inner annular groove 616.

Preferably, the outer gasket edge 71 sealingly engages the first edge 31. In other words, an outer annular groove is made in the first edge 31.

Preferably, the outer gasket edge 71 sealingly engages the annular retainer 35. In other words, the outer annular groove 36 is made in the annular retainer 35. This embodiment is shown by way of example in the drawings.

Preferably, the outer gasket edge 71 sealingly engages an abutment ring comprised in the first plate 3, radially between the first edge 31 and the annular collar 35. Preferably, an outer annular groove 36 is made on this abutting ring.

Preferably, the annular collar 35 comprises an outer annular groove 36 and a seat for a gasket housing 39.

According to a preferred embodiment, the outer annular groove 36 and the inner annular groove 616 are radially aligned with each other (in a "normal" gasket configuration, i.e. not altered by the radial thrust of the fluid).

According to a preferred embodiment, the annular gasket element 7 extends radially in a moulded shape.

According to a preferred embodiment, the annular gasket element 7 is shaped so as to perform an axial thrust action on the filling element 6. In particular, in the figures, as an example of a preferred embodiment, the annular gasket element 7 is shown in its "normal" configuration, i.e. without elastic alteration due to the presence of crystals in the fluid. When subjected to a thrust force, the shape of the annular gasket element 7 is elastically deformed.

In particular, the annular gasket element 7 is shaped so as to comprise a recess 710, the recess 70 defining a compartment facing the filter medium 2.

Furthermore, according to a preferred embodiment, the annular gasket element 7 extends radially, comprising a projection 720 radially juxtaposed with the recess 710. Preferably, the recess 710 is adjacent the outer gasket edge 71 and the boss 720 is adjacent the inner gasket edge 72. Preferably, in some embodiments, and vice versa, the recess 710 is proximate the inner gasket edge 72 and the boss 720 is proximate the outer gasket edge 71.

According to a preferred embodiment, the annular gasket member 7 comprises at least one annular ridge 711 and at least one annular groove 721, thus having an "S" shaped cross-section.

According to a preferred embodiment, the annular gasket member 7 is of an elastomeric material, so that it has an elastically yielding property with elastic recovery. In other words, the annular gasket element 7 is in the "normal" configuration, without the thrust action due to the presence of the crystal.

Preferably, the annular gasket member 7 is made of a closed-cell elastomeric material, either silicone rubber, fluorosilicone rubber, acryl rubber, or propylene and vinyl rubber.

According to a preferred embodiment, the filter cartridge 1 further comprises at least two axial locking teeth 38, the axial locking teeth 38 being adapted to snap engage a portion of the filter body 500. In particular, the axial locking tooth 38 is adapted to snap-engage the filter cartridge 1 to the cap 510.

According to a preferred embodiment, the filter cartridge 1 is adapted to be coupled to the cover 510 such that, in operation of closing the cup 520 with the cover 510, the filter cartridge 1 can be inserted into the filter chamber 550.

According to a preferred embodiment, the axial locking tooth 38 extends axially from the annular collar 35, in a direction parallel to the filter axis X-X.

Preferably, the cap 510 is provided with at least one locking groove 518 (preferably facing outwardly), the axial locking tooth 38 being received in the locking groove 518.

In addition, according to a preferred embodiment, the cover 510 comprises a protrusion 517 extending in height so as to engage the annular gasket element 7.

Preferably, the protrusion 517 is radially disposed close to the outer gasket edge 71 to improve the sealing action against the first plate 3. In other words, the protrusion 517 is adapted to fix the annular gasket member 7 and to ensure a reliable sealing of the outer gasket edge 71. In still other words, the tabs 517 are adapted to retain the outer gasket rim 71 within the outer annular groove 36 under all operating conditions of the filter cartridge 1 and filter assembly 900.

According to a preferred embodiment, the protrusion 517 is a single annular protrusion 517. According to a preferred embodiment, the outer gasket edge 71 is tightly fastened to the first plate 3 and the protrusion 517.

According to a preferred embodiment, the cap 510 axially sealingly engages the annular gasket element 7.

According to a preferred embodiment, the lid 510 is joined to the cup 520 so as to define a chamber 510' at ambient pressure: in particular, this chamber 510' at ambient pressure is delimited at its lower part by the cover 510, and at its upper part by the hermetic (hermitic) connection between the annular gasket element 7 and the first plate 3, and between the first plate 3 and the body wall 551. In this chamber 510' at ambient pressure, the aqueous fluid is not circulated, and the corresponding part of the compensating device 5 is free to move (on the "clean side" or "dirty side", or anyway in the filtering chamber 550) after the formation of crystals in the space where the aqueous fluid circulates.

In other words, the chamber 510 'at ambient pressure provides a compensation space through which the compensation means 5 pass after a change in position and/or shape caused by the crystallization of the fluid, the change in position and/or shape of the compensation means 5 being formed on the opposite side of the chamber 510' at ambient pressure, in particular in the filter chamber 550. During this movement, the compensating device 5 remains in a sealed connection with the filter cartridge 1, in particular in a hermetic (hermetic) connection with the first plate 3. In this way, a minimum compensation volume for the entire service life of the filter cartridge 1 is ensured.

According to a preferred embodiment, the cover 510 does not require any additional gasket; in other words, the annular gasket element 7 and the gasket present on the first plate 3 are sufficient.

Preferably, the cover 510 defines, together with the compensation means 5, a chamber 510' at ambient pressure.

According to a preferred embodiment, the cover 510 is partially received in the receiving area 350.

Innovatively, the filter cartridge, filter body and filter assembly described above fully achieve the objects of the present invention and overcome the common disadvantages of the prior art.

In fact, advantageously, the object of the present invention is a filter cartridge, a filter body suitable for housing such a filter cartridge and a filtering assembly, which present a simple, effective and long-lasting compensation device, solving the common problems of the prior art.

Advantageously, the filter cartridge has a simple and reliable hermetic seal in various working configurations (i.e. at any operating temperature, i.e. even in the presence of crystals).

Advantageously, by simplifying the structure of the filter body, the compensation element is connected/integrated to the filter cartridge.

Advantageously, the compensation element is mounted in the central cavity of the filter medium to form a compact device and optimize the exploitation of the available space.

Advantageously, the filter cartridge has a gasket element accommodated in a receiving region, which defines a large compensation region in which the fluid and/or the fluid containing the crystal can flow. Advantageously, the compensation zone is locked in the cover.

Advantageously, the filter cartridge has an extremely limited number of components.

Advantageously, the filter cartridge and filter assembly generally have a limited number of gaskets.

Advantageously, the assembly of the filter cartridge is simple and reliable.

Advantageously, the filter cartridge and the compensating device can be assembled/disassembled with the cover simultaneously with insertion and extraction.

Advantageously, the filler element is not subject to wear, wear and/or breakage.

Advantageously, the filler element is made of a rigid material, facilitating the pressure transmission from the inner cavity of the filter cartridge to the annular gasket.

Advantageously, the operative connection envisaged between the compensation device and the filter cartridge is of the removable type, so that the compensation device can be reused.

Advantageously, the operative connection between the compensation device and the filter cartridge is foreseen of the removable type, making the replacement and maintenance operations faster and easier.

Advantageously, the filter cartridge and the compensating device are made of plastic material, so that the components are recyclable.

Advantageously, the cover and the compensating means are operatively connected to each other in such a way as to improve the sealing action of the gasket element.

Advantageously, the cover and the compensation means are operatively connected to each other in such a way as to have an axial end stop for the movement of the filling element, even in the event of breakage of the gasket element.

Advantageously, the cover and the compensation means are operatively connected to each other in such a way that: any leakage of fluid that may be contained by the cap is avoided even in the event of breakage of the gasket element.

Advantageously, all of the above advantages can be achieved by flow through the filter medium radially from the inside to the outside, or by flow through the filter medium from the outside to the inside.

It is clear that a person skilled in the art can modify the filter cartridge and/or the filter body and/or the filter assembly described above to meet contingent requirements, all of which are included within the scope of protection defined by the following claims.

Claims

1. A filter cartridge (1) of a filter assembly (900) of a fluid, such as water or urea, at risk of crystallization, the filter assembly (900) comprising a filter body (500), the filter body (500) comprising a filter chamber (550) defined by a body wall (551), wherein the filter cartridge (1) is housed in the filter chamber (550) and extends along a filter axis (X-X), the filter cartridge (1) comprising:

a tubular filter medium (2) extending axially around said filter axis (X-X), the filter medium (2) comprising a central cavity (20), wherein a fluid can pass through the filter medium (2) in a radial direction, preferably a fluid passes through the filter medium (2) from the outside to the inside;

-a first plate (3) and a second plate (4) at the ends of the filter medium (2), adapted to sealingly engage the body wall (551), the first plate (3) and the second plate (4) comprising a first through hole (30) and a second through hole (40) at the filter axis (X-X) defined by a first edge (31) and a second edge (41), respectively;

a shape and/or position variable compensating device (5) for varying the volume of a flow section through which an aqueous fluid flows, wherein the change in shape and/or position is caused by crystallization of the fluid, wherein the compensating device (5) comprises:

a) a filler element (6) at least partially housed in said central cavity (20), extending lengthwise along said filter axis (X-X), the filler element (6) comprising a first end (61) and a second end (62);

b) an annular gasket element (7) elastically yieldable to allow axial movement of the filling element (6) upon formation of crystallized crystals, wherein the annular gasket element (7) comprises an outer gasket edge (71) sealingly engaging the first plate (3) and an inner gasket edge (72) sealingly engaging the first end (61).

2. A filter cartridge (1) according to claim 1, wherein the first plate (3) comprises an annular collar (35), the annular collar (35) extending in an axial direction around the filter axis (X-X) on the opposite side with respect to the filter medium (2), wherein the annular collar (35) defines a receiving area (350), the first end of the filler element (6) and preferably the annular gasket element (7) being received in the receiving area (350).

3. A filter cartridge (1) according to any one of the preceding claims, wherein the first plate (3) comprises an outer annular groove (36), the outer gasket edge (71) being sealingly received in the outer annular groove (36), and the first end (61) comprises an inner annular groove (616), the inner gasket edge (61) being sealingly received in the inner annular groove (616).

4. A filter cartridge (1) according to any one of the preceding claims, wherein the outer gasket edge (71) sealingly engages the first edge (31) or the annular collar (35) or an abutment collar; the abutment ring is included in the first plate (3) radially between the first edge (31) and the annular collar (35).

5. Filter cartridge (1) according to any one of the preceding claims, wherein the annular gasket element (7) extends radially in a moulded shape, the annular gasket element (7) comprising a recess (710), the recess (710) defining a compartment facing the filter medium (2).

6. A filter cartridge (1) according to claim 5, wherein the annular gasket element (7) extends radially, comprising a projection (720) radially juxtaposed with the recess (710); the recess (710) is proximate to the outer gasket edge (71) and the protrusion (720) is proximate to the inner gasket edge (72), or vice versa.

7. A filter cartridge (1) according to claim 6, wherein the annular gasket element (7) comprises at least one annular ridge (711) and at least one annular groove (721), having an "S" -shaped cross-section.

8. Filter cartridge (1) according to any one of the preceding claims, wherein the annular gasket element (7) is made of a closed-cell elastomeric material, silicone rubber, fluorosilicone rubber, acryl rubber, or acryl and vinyl rubber, such that it has an elastic yield property with elastic recovery.

9. A filter cartridge (1) according to any one of the preceding claims, wherein the filler element (6) extends axially such that the second end (62) protrudes from the second through hole (40) in any axial configuration of the annular gasket element (7).

10. A filter cartridge (1) according to any one of the preceding claims, wherein the filler element (6) is hollow and comprises a bottom opening (610) at the first end (61).

11. A filter cartridge (1) according to any one of the preceding claims, wherein the first plate (3) and the second plate (4) comprise a first radial gasket (39) and a second radial gasket (49), respectively, the first radial gasket (39) and the second radial gasket (49) each facing radially outwards to seal radially the body wall (551).

12. Filter cartridge (1) according to any one of the preceding claims, wherein the first plate (3) comprises at least two axial locking teeth (38), the axial locking teeth (38) being adapted to be snap-engaged to a portion of the filter body (500), preferably to a cover (510).

13. Filter body (500) of a filter assembly (900) of a fluid at risk of crystallization, such as water or urea, comprising a filter cartridge (1) according to any one of the preceding claims, wherein the filter body (500) comprises a cup (520) and a cover (510) closing the cup (520), the cup (520) and the cover (510) being mutually tightenable to define a filtering chamber (550) delimited by a body wall (551), wherein the filtering chamber (550) is able to house the filter cartridge (1).

14. A filter body (500) as claimed in claim 13, wherein the cover (510) comprises a protrusion (517), the protrusion (517) preferably being a single annular protrusion (517) extending in height to engage the annular gasket element (7) proximate the outer gasket edge (71) to improve the sealing action against the first plate (3).

15. A filter body (500) as claimed in any one of the preceding claims, wherein the cover (510) engages with the first plate (3) to define a chamber (510') at ambient pressure in which a corresponding part of the compensating device (5) is free to move.

16. Filter body (500) according to claim 13 or 14, for use in combination with a filter cartridge (1) according to claim 12, wherein the cover (510) comprises at least one locking groove (518), the axial locking tooth (38) being received in the locking groove (518) with the filter cartridge (1) connected to the cover (510).

17. A filter assembly (900) of a fluid, such as water or urea, at risk of crystallization, comprising a filter cartridge (1) according to any one of claims 1 to 12 and a filter body (500) according to any one of claims 13 to 16.