CN113803196A

CN113803196A - Fluid filter assembly

Info

Publication number: CN113803196A
Application number: CN202010556347.XA
Authority: CN
Inventors: 乔基奥·基隆迪
Original assignee: UFI Filters SpA
Current assignee: UFI Filters SpA
Priority date: 2020-06-17
Filing date: 2020-06-17
Publication date: 2021-12-17

Abstract

A filter assembly for a fluid of a vehicle fuel system, the filter assembly extending along a main axis and comprising a head group fluidly connectable with a conduit of the fuel system. Additionally, the filter assembly includes a filter cartridge integrally and fluidly coupleable to the head set, the filter cartridge including: a filter element; a cup engageable to the head stack by a rotational operation, the cup including at least a portion of a housing in which the filter element is housed, wherein the housing is open at an axial end including the head rim; a cap integrally connected to the filter element, wherein the cap comprises an axial annular gasket adapted to sealingly engage the head set and comprises a radial annular gasket adapted to perform a radial sealing engagement, the cap being free to rotate relative to the cup. The head group comprises an axially projecting pin element and the cover comprises a slot specially shaped to receive the pin element, enabling the head group and the cover to be mutually positioned in a specific angular position.

Description

Fluid filter assembly

Technical Field

The present invention relates to a filter assembly for a fluid, preferably a fuel, preferably diesel fuel. In addition, the invention relates to a vehicle fuel system comprising said filter assembly. Finally, the invention relates to a method for assembling such a filter assembly.

Background

The invention finds its preferred application in the automotive field. Indeed, the background of the invention is in particular a fluid filter assembly, in particular of vehicle fuel (preferably diesel).

The filtering assemblies known in the prior art generally comprise a cup (or tank) and a head group coupled to each other in an integral manner. Thus, the filter assembly is adapted to be fluidly connected to the fuel system of the vehicle, i.e. the cup and head set is correspondingly fluidly connected to the fuel system of the vehicle. In other words, the fluid, preferably fuel, enters the known filter assembly for filtration (dirt) and the fluid, preferably (clean) filtered fuel, exits the filter assembly. In particular, the cup and head set are particularly designed to house therein a filtering element adapted to perform a specific filtering operation when the fluid passes, for example on solid particulate matter and/or liquid particulate matter (for example water).

The main problem of the known filter assemblies consists of the complicated coupling method between the various components described above.

The assembly (and similar disassembly) operations of the fluid filter assembly itself are particularly complex in the presence of complex coupling methods of the various components. This problem is therefore particularly felt to have an adverse effect on the maintenance operations of the filter assembly, in particular on the replacement of the filter cartridge.

Disclosure of Invention

Accordingly, it is desirable to provide a filter assembly that overcomes the above-described typical problems of the prior art. In other words, it is desirable to provide a filter assembly that is simple to assemble and disassemble. That is, it is desirable to provide a filter assembly in which maintenance operations are greatly simplified.

This object is achieved by a filter assembly according to claim 1. In addition, the object is also achieved by a fuel system comprising the filter assembly according to claim 17. In addition, the object is achieved by a method of assembling a filter assembly according to claim 18. The claims dependent on these claims show preferred embodiments with further advantageous aspects.

Drawings

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

FIG. 1 illustrates a filter assembly in perspective, cut-away, parts separated, according to a preferred embodiment of the present invention;

figures 2 and 2' show, in section, a perspective view and a longitudinal view, respectively, of the filter assembly shown in figure 1 in an assembled configuration;

FIGS. 3a and 3b show a bottom perspective view and a top perspective view, respectively, of the head stack and filter cartridge included in the filter assembly of FIG. 1;

FIG. 4 illustrates a filter assembly in perspective, cut-away, parts separated, according to another preferred embodiment of the present invention;

FIG. 5 illustrates, in cross-section, a perspective view of the filter assembly shown in FIG. 4 in an assembled configuration;

fig. 6a and 6b show a bottom perspective view and a top perspective view, respectively, of the head stack and cartridge included in the filter assembly of fig. 4.

Description of reference numerals:

1 a fluid filter assembly; X-X major axis; 2 head group; 20 a head wall; 21 sets of inlet nozzles; 22 sets of outlet nozzles; 25 head engaging means; 250 engaging the ferrule; 255 a first axial insertion portion; 27 a discharge nozzle; 29 a pin element; 29' tip; 290 a sidewall; 291 sliding walls or edges; 295 a radial wall; 3, a filter element; 4 a filter element; 40 a filter media; 5 cups of the milk; 50 an accommodation chamber; 51 a head edge; a 55-cup engaging means; 550 cup rings; 551 against the step; 555 a first axial insertion portion; 6, covering; 60 axial annular gaskets; 61 filtering the inlet mouth; 62 a filter outlet nozzle; 65 a radial annular gasket; 67 a water discharge part; 69 grooves; 690 side portions; 695 a radial portion; 7 a discharge conduit; 8, an auxiliary cup; 81 auxiliary head edge; rs pin radial distance; ra axial gasket radial distance; rr radial gasket radial distance; rd displaces the radial distance.

Detailed Description

In the accompanying drawings, reference numeral 1 indicates a filter assembly for a fluid, preferably fuel, preferably diesel fuel, according to the invention.

In practice, the filter assembly 1 of the present invention is suitable for use as part of a vehicle fuel system in which fluid flows. Preferably, the fuel system is specifically designed to supply fuel to the engine group of the vehicle, and therefore the filter assembly 1 is adapted to filter the fuel.

In particular, the filter assembly 1 is adapted to filter unwanted suspended particles from a fluid.

According to a variant of an embodiment, the filter assembly 1 is adapted to separate other undesired liquids (for example water) suspended in the fluid to be filtered from the fluid, preferably from the fuel.

According to the invention, the filtering assembly 1 of the fluid extends along a main axis X-X.

In this context, when referring to the axial dimension, reference is made to the dimension corresponding to or parallel to the main axis X-X; in addition, when circumferential or annular dimensions are concerned, reference is made to the dimensions extending on a circumference concentric with the main axis X-X; in addition, when referring to the radial dimension, reference is made to the dimension extending in the radial direction with respect to the main axis X-X; furthermore, when referring to the tangential dimension, reference is made to the dimension tangential to a circle concentric to the main axis X-X; finally, when referring to the transverse dimension, the dimension orthogonal to the main axis X-X is taken as a reference.

According to the invention, the filter assembly 1 comprises a head group 2, the head group 2 being fluidly connectable to a pipe of the fuel system. In particular, the head group 2 is fluidly connected to an inlet duct of the system, in which the fluid to be filtered flows, and to an outlet duct of the system, in which the filtered fluid flows.

According to a preferred embodiment, the head group 2 comprises a group inlet mouth 21 and a group outlet mouth 22, through which the fluid flows in and out, respectively, of the group inlet port 21 and the group outlet port 22.

According to a preferred embodiment, the head group 2 comprises a group inlet mouth 21 in the form of a nozzle and a group outlet mouth 22 in the form of a nozzle.

According to the invention, the filter assembly 1 comprises a filter cartridge 3, the filter cartridge 3 being integrally and fluidly couplable to the head group 2. In other words, by assembling the filter assembly 1 by joining the head group 2 to the filter cartridge 3, the fluid flowing in the filter cartridge 3 will undergo a filtering operation.

According to the invention, the filter insert 3 comprises a filter element 4, the filter element 4 comprising a filter medium 40 that can be traversed by a fluid.

According to a preferred embodiment, the filter media 40 is axially traversable.

According to a further preferred embodiment, the filter media 40 is tubular and is capable of being radially traversed by a fluid. Preferably, the filter media 40 is capable of being traversed by fluid from the inside to the outside.

According to a preferred embodiment, the filter media 40 is made of a synthetic material (e.g., PA6, PA66, PBT, PET, etc.), a cellulosic material, or a combination of both. Preferably, in a preferred embodiment, the filter media 40 includes the presence of glass fibers.

According to the invention, the filter cartridge 3 comprises a cup 5 and a cover 6 which can be combined to define a housing in which the filter element 4 is placed.

Preferably, the cup 5 is shaped in such a way that: the cup 5 is laterally delimited by a rear wall and laterally by side walls in a housing area.

The cup 5 includes a housing 50, and the filter element 4 is housed in the housing 50. Wherein the housing 50 is open at an axial end comprising a head edge 51. Preferably, the cup 5 comprises the housing 50 as a whole. Preferably, the cup 5 comprises an integral part of the housing 50.

According to the invention, the cup 5 can be coupled to the head group 2 by a rotating operation.

In practice, the cup 5 comprises cup engagement means 55 and the head set 2 comprises head engagement means 25. The cup engagement means 55 and the head engagement means 25 can be engaged with each other by a rotating operation. Preferably, these rotational operations also involve simultaneous mutual axial movements.

According to a preferred embodiment, the head engaging means 25 comprises an engaging collar (collar)250 and the cup engaging means 55 comprises a cup collar 550. Preferably, the two ferrules are particularly shaped to engage each other in a rotation involving an axial translation of the part that is part of the cup 5 and of the head group 2.

In other words, the cup 5 and the head set 2 are joined together in a rototranslation (rototranslation) manner.

According to a preferred embodiment, the engaging collar 250 comprises a fastening portion and the cup collar 550 comprises a fastening portion, the mutual engagement of which in the rotational direction involves a mutual movement in a rotational translation.

According to a preferred embodiment, the engagement collar 250 comprises a threaded portion and the cup collar 550 correspondingly comprises a threaded portion. Preferably, the pitch of the aforesaid threaded portion is such that it gradually moves axially.

According to a preferred embodiment, the engagement collar 250 is adapted to receive a cup collar 550.

According to a preferred embodiment, the engaging collar 250 and the cup collar 550 are specially shaped in such a way that: at least one of the

first portions

255, 555 with axial insertion and the second fastening portion as described above is provided.

According to a preferred embodiment, the engagement collar 250 and/or the cup collar 550 comprise an abutment step 551, the abutment step 551 being adapted to act as an axial stop to prevent further axial translation of the mutual axial movement between the head group 2 and the cup 5.

According to a preferred embodiment, the cartridge 3 comprises a cover 6, the cover 6 being able to be joined to the cup 5 at the head edge 51. In other words, the cover 6 defines the top of the receiving chamber 50.

Preferably, the cover 6 comprises a filtering inlet mouth 61 and a filtering outlet mouth 62, the filtering outlet mouth 62 being positioned in a radial position between the main axis X-X and the axial annular gasket 60, flowing into and out of the filter cartridge through the filtering inlet mouth 61 and the filtering outlet mouth 62. Preferably, one of the filtering inlet mouth 61 and the filtering outlet mouth 62 is positioned on the main axis X-X.

In particular, the lid 6 is able to engage with the head rim 51 in the axial direction and to rotate freely with respect to the cup 5. In other words, the head edge 51 is adapted to transmit the axial action to the cover 6. Preferably, the head edge 51 is directly engaged with the lid 6. According to a variant of one embodiment, the cover 6 engages indirectly (i.e. by other components in the cartridge 3) with the head edge 51, as described below.

In other words, the lid 6 can be axially fixed to the cup 5, but at the same time the lid 6 is free to rotate with respect to the main axis X-X. In other words, in the assembled condition of the filter cartridge 3, the cover 6 is axially fixed to the cup 5, preferably to the head rim 51, while remaining free to rotate with respect to the axis X-X. That is, during the swivelling coupling operation of the cup 5 and the head group 2, the cover 6 is only allowed to move along the axis X-X.

According to the invention, in addition, the cover 6 is integrally connected to the filter element 4. That is, the movement undergone by the cover 6 with respect to the cup 5 and/or with respect to the head group 2 is the same as the operation undergone by the filtering element 4. In other words, a specific axial or angular position of the cover 6 corresponds to a specific axial or angular position of the filter element 4.

According to a preferred embodiment, the cover 6 is integral with the filter element 4. In other words, the cover 6 corresponds to the upper plate of the filter element 4; preferably, the cover 6 is, for example, directly connected to the filter media 40.

According to a variant of an embodiment, the cover 6 may be integrally mounted to the filter element 4. That is, the filter element 4 comprises at least one end plate adapted to be integrally mounted to the cover 6 at an axial end thereof.

According to the invention, the cap 6 comprises an axial annular gasket 60, the axial annular gasket 60 being adapted to sealingly engage the head group 2 in the axial direction in an engagement operation between the cup engagement means 55 and the head engagement means 25. That is, with the filter assembly 3 assembled, the axial annular gasket 60 is screwed in the axial direction on the head group 2.

Preferably, therefore, the axial annular gasket 60 is intended to engage with the head group 2 in the axial direction, so as to provide a barrier to the filtering area inside the cartridge 3 from the outside environment.

In particular, the head group 2 comprises a head wall 20, the head wall 20 being preferably flat, an axial annular gasket 60 being able to engage on the head wall 20.

Preferably, the material of axial annular gasket 60 is selected from the family of elastomeric materials (e.g., FPM, FKM, FFKM, VMQ, FVMQ, HNBR, NBR, AEM, ACM, EDPM, etc.) having such chemical composition: suitable to ensure a suitable chemical and physical resistance in contact with the working fluid.

According to a preferred embodiment, the axial annular gasket 60 is positioned at an axial gasket radial distance Ra from the main axis X-X.

Further, according to the invention, the cover 6 also comprises a radial annular gasket 65, the radial annular gasket 65 being adapted to achieve a radial sealing engagement.

According to the invention, the axial annular gasket 60 and the radial annular gasket 65 are adapted to hermetically separate the filtering area of the cartridge 3 engaged with the head group 2 from the external environment.

In particular, the radial annular gasket 65 is suitable to seal in a radial direction, allowing the rotational movement of the cover 6 with respect to the main axis X-X. Preferably, the radial annular gasket 65 is adapted to perform a radial sealing action allowing a rotational movement of the lid 6 with respect to the cup 5 about the axis X-X.

Preferably, the material of radial annular gasket 65 is selected from the family of elastomeric materials (e.g., FPM, FKM, FFKM, VMQ, FVMQ, HNBR, NBR, AEM, ACM, EDPM, etc.) having such chemical composition: suitable to ensure a suitable chemical and physical resistance in contact with the working fluid.

According to a preferred embodiment, the radial annular gasket 65 is positioned at a radial gasket radial distance Rr from the main axis X-X.

Preferably, the axial gasket radial distance Ra is smaller than the radial gasket radial distance Rr.

Furthermore, according to the invention, the head group 2 comprises a pin element 29, the pin element 29 projecting axially substantially parallel to the main axis X-X, the cover 6 comprising a slot 69, the slot 69 being particularly shaped to accommodate the pin element 29.

According to the invention, the head group 2 and the cover 6 can be mutually positioned in a specific angular position by inserting the pin element 29 into the slot 69. According to the invention, during the assembly operation of the filter cartridge 3 to the head group 2, thanks to the engagement between the pin element 29 and the groove 69, the cover 6 and the filter element 4 remain fixed in a predetermined angular position while the cup 5 undergoes a rotation-locking operation involving axial juxtaposition of the filter cartridge 3 with the head group 2 and consequent tightening of the axial annular gasket 60 (and of the cup 5 and therefore of the filter cartridge 3 to the head group 2).

According to a preferred embodiment, the pin element 29 protrudes from the head wall 20.

According to a preferred embodiment, the pin element 29 comprises a tip 29' remote from the head wall 20.

Preferably, the pin element 29 has a conical shape close to the tip 29'.

According to a preferred embodiment, the pin element 29 comprises at least one sliding wall or edge 291 (preferably two sliding walls or edges 291), the sliding wall or edge 291 being inclined in a manner suitable for easy insertion of the pin element 29 into the slot 69.

According to a preferred embodiment, the pin element 29 comprises a lateral wall 290, preferably having a circumferential or tangential extension with respect to the main axis X-X, and a radial wall 295, preferably having a radial extension with respect to the main axis X-X.

According to a preferred embodiment, the slot 69 is substantially complementary to the cross-section of the pin member 29, the slot 69 including a side portion 690 and a radial portion 695

In other words, the pin element 29 is substantially T-shaped in cross-section. Similarly, the slot 69 correspondingly defines a generally T-shaped receiving area.

According to a preferred embodiment, the pin element 29 is received in the slot 69, maintaining a "clearance" (i.e., the slot 69 is slightly larger than the pin element 29). Preferably, for an effective coupling between the cup 5 and the head set 2, there is no play in the circumferential/tangential direction, whereby a locked rotation is performed between the two parts.

According to a preferred embodiment, the slot 69 is a through hole.

According to a preferred embodiment, the slot 69 is a recess (recess) formed in the cover 6, which is adapted to receive the pin element 29.

According to a preferred embodiment, the pin element 29 extends axially by an axial length with respect to the main axis X-X, so that, in an assembly operation, the pin element 29 is first inserted in the slot 69 and then a rotation operation is performed to lock the cartridge 3 to the head group 2.

According to a preferred embodiment, the pin element 29 extends axially with respect to the main axis X-X, so that the tip 291 is in a position: which faces at least the fastening portion of the engagement collar 250 in a radial direction (i.e., in a transverse plane). For example, according to a preferred embodiment, the pin element 29 extends axially until its tip 291 faces radially the threaded portion.

According to another preferred embodiment, the pin element 29 brings the tip 291 in a position in which: which is higher than the engaging portion in the radial direction (i.e., in the transverse plane). For example, according to a preferred embodiment, the pin element 29 extends axially until the pin element 29 has the tip 291 at a higher position than the start of the threaded portion.

According to a preferred embodiment, the pin element 29 (and similarly the slot 69) is positioned at a radial pin distance (Rs) from the main axis (X-X).

Preferably, the radial pin distance Rs is less than the axial washer radial distance Ra.

Preferably, the radial pin distance Rs is less than the radial washer radial distance Rr and the axial washer radial distance Ra.

According to a preferred embodiment, the filtering element 4 comprises water separation means suitable for separating any water particles in the fluid to be filtered, so as to collect the water in a region close to the bottom of the cup 5 (in other words close to the bottom wall).

According to this embodiment, the head group 2 comprises a water outlet nozzle 27, the cap 6 comprising a water discharge 67 suitable for being fluidly connected to the water outlet nozzle 27, the water discharge 67 extending parallel to the main axis X-X to be mounted axially inside the water outlet nozzle 27.

According to a preferred embodiment, the filter cartridge 3 further comprises a drain conduit 7, the drain conduit 7 being adapted to extend in an axial direction from the cap 6 towards the bottom of the cup 5.

According to a preferred embodiment, the discharge 67 is located in a region where the slot 69 is located opposite with respect to the main axis X-X. Preferably, the slot 69 and the drain 67 are each located in a respective half.

According to a preferred embodiment, the drain 67 is positioned at a radial drain distance Rd from the main axis X-X.

Preferably, the radial drain distance Rd is smaller than the axial gasket radial distance Ra.

Preferably, the radial drainage distance Rd is less than the radial gasket radial distance Rr and the axial gasket radial distance Ra.

According to a first preferred embodiment, the lid 6 engages radially sealingly the side wall of the cup 5 by means of a radial annular gasket 65. Preferably, the radial annular gasket 65 radially sealingly engages the side wall of the cup 5 in a region close to the head rim 51.

Preferably, the radial annular gasket 65 radially sealingly engages the side wall of the cup 5, leaving the lid 6 free to rotate with respect to the axis X-X.

According to another embodiment, the filter cartridge 3 comprises an auxiliary cup 8, the auxiliary cup 8 defining a filter chamber 80. Preferably, the filter element 4 is housed in the auxiliary cup 8. Preferably, the auxiliary cup 8 is housed in the cup 5 accordingly. According to a variant of an embodiment, the auxiliary cup 8 has a shape substantially complementary to the cup 5.

According to such an embodiment, the lid 6 engages radially sealingly the auxiliary cup 8 by means of a radial annular gasket 65. Preferably, a radial annular gasket 65 radially sealingly engages the side wall of the auxiliary cup 8. Preferably, the radial annular gasket 65 radially sealingly engages the side wall of the auxiliary cup 8 in a region close to the auxiliary head edge 81.

Preferably, the radial annular gasket 65 radially sealingly engages the side wall of the auxiliary cup 8, leaving the lid 6 free to rotate with respect to the axis X-X.

According to a preferred embodiment, the auxiliary cup 8 has a shape, for example comprising an abutment, preferably annular, engaging with the head edge 51. Preferably, the axial thrust action of the head edge 51 is released onto this abutment and therefore onto the cover 6.

According to a preferred embodiment, the auxiliary cup 8 is shaped so that it is locked in rotation with respect to the cup 5. In other words, when the auxiliary cup 8 is present, the lid 6 is free to rotate with respect to the auxiliary cup 8, while the auxiliary cup 8 remains fixed with respect to the cup 5, respectively.

According to a preferred embodiment, the cover 6 is made of a material selected from the plastic family.

Preferably, the cover 6 is made by a moulding process. Preferably, at the annular gasket, the cover comprises a specific annular housing groove.

According to a preferred embodiment, the axial annular gasket 60 and the radial annular gasket 65 are positioned on axially opposite sides of the cover 6.

As mentioned, the present embodiment also relates to a vehicle fuel system comprising a filter assembly 1 of a fluid, preferably fuel, preferably diesel, having the above-mentioned features.

The invention also relates to a method for assembling a filter assembly having the above-mentioned features. In particular, in a first step of the assembly method, the cartridge 3 is assembled by inserting the assembly comprising the filter element 4 and the cover 6, joined together, into the cup 5 until the cover 6 axially engages the head edge of the cup 5.

In addition, the assembly method provides a second step of assembling the cartridge 3 with the head group 2, in which the following steps are carried out:

axially juxtaposing the cartridge 3 and the head group 2 to insert the pin element 29 in the groove 69;

the operation of rotational coupling between the cartridge 3 and the head group 2 is carried out to allow mutual rotation between the cup 5 and the head group 2.

The filtering assembly for fluids described above, innovative, fully satisfies the objects of the present invention, overcoming the drawbacks common to the prior art. The object of the present invention is fully met, innovatively, by a fuel system of a vehicle comprising a filter assembly, which overcomes the usual drawbacks of the prior art. The object of the present invention is also fully met, innovatively, by a method of assembly of a filter assembly, overcoming the usual drawbacks of the prior art.

Advantageously, the filter assembly has features that make assembly and disassembly operations safe and simple.

Advantageously, the problem of possible sticking of the seal to its mating wall, which would normally hinder the removal of the cartridge, is overcome. Advantageously, the pin element makes it easier and more convenient to remove the axial annular washer from the head group during the rotary disassembly operation.

Advantageously, the filter assembly has an effective sealing area, in particular in the mutual engagement of the filter cartridge and the head group.

Advantageously, the filtering assembly comprises an axial annular gasket adapted to operatively engage the head group.

Advantageously, the axial gasket is mounted on a cover rotatable with respect to the tank and is objectified by suitable objectification elements, ensuring that the clamping action on the axial gasket acts in a direction parallel to the axis.

Advantageously, the axial annular gasket is screwed only in the axial direction using only the axial movement of the cap, so as to minimize particularly harmful, unwanted friction in the case where the annular gasket is designed to form a hydraulic seal against the environment.

Advantageously, the axial annular gasket operates only in the axial direction. Advantageously, the axial annular gasket is not subjected to circumferential friction. Advantageously, the dimensions of the axial annular gasket are related to the fact that it operates only in the axial direction.

Advantageously, the filter cartridge 3 is suitable for "clean" maintenance operations, collecting the dirt inside it. Advantageously, thanks to the axial position of the axial annular gasket, the leakage of fluid and of dirt collected in the cup is minimized.

Advantageously, since the filter element is housed in the filter cartridge, direct interaction on the filter medium is minimized, thereby limiting possible damage and contamination.

Advantageously, the cap can be produced by a simple moulding operation.

It is clear that a person skilled in the art can modify the invention to meet contingent requirements, all of which are included within the scope of protection defined by the following claims.

Claims

1. A filter assembly (1) for a fluid, preferably fuel, preferably diesel fuel, of a vehicle fuel system, wherein the filter assembly (1) extends along a main axis (X-X) and comprises:

i) a head group (2), the head group (2) being fluidly connectable with a conduit of the fuel system;

ii) a filter cartridge (3), said filter cartridge (3) being rigidly and fluidly engageable to said head group (2), said filter cartridge (3) comprising:

a filter element (4), the filter element (4) comprising a filter medium (40) that is penetrable by a fluid;

a cup (5), said cup (5) being rotatably operatively engageable to said head group (2), said cup (5) comprising cup engagement means (55), said cup engagement means (55) being rotatably engageable with corresponding head engagement means (25) comprised in said head group (2), wherein said cup (5) comprises at least a portion of a housing (50), said filter element (4) being housed in said housing (50), wherein said housing (50) is open at an axial end comprising a head edge (51);

a cover (6), said cover (6) being firmly connected with said filtering element (4), wherein said cover (6) comprises an axial annular gasket (60) and comprises a radial annular gasket (65), said axial annular gasket (60) being suitable for sealing said head group (2) in the axial direction in the engagement operation between the cup engagement means (55) and the head engagement means (25), said radial annular gasket (65) being suitable for performing a radial sealing engagement that makes said cover (6) free to rotate with respect to said cup (5), wherein said axial annular seal (60) and said radial annular seal (65) separate the filtering area from the outside;

wherein the head group (2) comprises a pin element (29), the pin element (29) projecting axially substantially parallel to a main axis X-X, the cover (6) comprising a slot (69), the slot (69) being particularly shaped to house the pin element (29) so as to enable the head group (2) and the cover (6) to be mutually positioned in a single angular position.

2. Filter assembly (1) according to claim 1, wherein the pin element (29) and similarly the groove (69) are positioned at a pin radial distance (Rs) from the main axis (X-X), the axial annular gasket (60) being positioned at an axial gasket radial distance (Ra) from the main axis (X-X), wherein the pin radial distance (Rs) is smaller than the axial gasket radial distance (Ra).

3. Filter assembly (1) according to any of the previous claims, wherein said axial annular gasket (60) is positioned at an axial gasket radial distance (Ra) from said main axis (X-X), said radial annular gasket (65) is positioned at a radial gasket radial distance (Rr) from said main axis (X-X), wherein said axial gasket radial distance (Ra) is smaller than said radial gasket radial distance (Rr).

4. Filter assembly (1) according to any one of the preceding claims, wherein the head engagement means (25) comprise an engagement collar (250), the engagement collar (250) being rotatably engageable with the cartridge (3), wherein the pin element (29) extends axially with respect to the main axis (X-X) so that, in an assembly operation between the cup (5) and the head group (2), the pin element (29) is housed in the groove (69) during or before a rotation operation of blocking the cartridge (3) by the head group (2).

5. Filter assembly (1) according to claim 6, wherein the engagement collar (250) comprises a threaded portion, wherein the engagement means (55) of the cup (5) respectively comprise an engagement collar (450), the engagement collar (450) being in the form of a threaded portion.

6. Filter assembly (1) according to any one of the preceding claims, wherein the head group (2) comprises a head wall (20) engageable by the axial annular gasket (60), wherein the pin element (29) protrudes from the head wall (20).

7. Filter assembly (1) according to claim 6, wherein the pin element (29) comprises a tip (29 '), the tip (29 ') being distal from the head wall (20), wherein the pin element (29) has a tapered shape proximal to the tip (29 '), the tapered shape comprising at least one sliding wall or edge (291), the at least one sliding wall or edge (291) being inclined in a manner suitable for easy insertion of the pin element (29) into the slot (69).

8. Filter assembly (1) according to any one of the preceding claims, wherein the pin element (29) comprises a lateral wall (290) and a radial wall (295), the lateral wall (290) preferably having a circumferential or tangential extension with respect to the main axis (X-X), the radial wall (295) preferably having a radial extension with respect to the main axis (X-X) such that the pin element (29) has a substantially T-shaped cross-section, wherein the groove (69) has a shape suitable to accommodate the pin element (29).

9. Filter assembly (1) according to any of the preceding claims, wherein the material of the cover (6) is selected from the family of plastic materials.

10. A filter assembly (1) according to any one of the preceding claims, wherein the filter element (4) comprises means for separating water adapted to separate any water particles present in the fluid to be filtered, so as to collect the water in a region close to the bottom of the cup (5), wherein the head group (2) comprises a water discharge mouth (27) and the cover (6) comprises a water discharge (67), said water discharge (67) being adapted to be fluidly connected to said water discharge mouth (27), wherein the cartridge (3) further comprises a discharge conduit (7), said discharge conduit (7) being adapted to extend in an axial direction from the cover (6) towards the bottom of the cup (5).

11. Filter assembly (1) according to any one of the preceding claims, wherein said axial annular gasket (60) and said radial annular gasket (65) are positioned on axially opposite sides of said cover (6).

12. Filter assembly (1) according to any of the preceding claims, wherein the cover (6) is radially sealingly engageable with an inner surface of the cup (5), preferably in the region of the head edge (51) of the cup (5), by means of the radial annular gasket (65).

13. A filter assembly (1) according to any one of claims 1 to 11, wherein the filter cartridge (3) comprises an auxiliary cup (8), the auxiliary cup (8) defining a filter chamber (80), the filter element (4) being housed in the filter chamber (80), wherein the cover (6) is radially sealably engaged with the auxiliary cup (8), preferably in an auxiliary head edge region (81), by means of the radial annular gasket (65), wherein the auxiliary cup (8) is housed in the cup (5) respectively.

14. A filter assembly (1) as claimed in any one of the foregoing claims, wherein said head group (2) comprises a group inlet mouth (21) and a group outlet mouth (22) through which the fluid flows in and out, respectively, of said group inlet mouth (21) and group outlet mouth (22), wherein said cover (6) comprises a filtering inlet mouth (61) and a filtering outlet mouth (62), said filtering outlet mouth (62) being positioned in a radial position between said main axis (X-X) and said axial annular gasket (60).

15. Filter assembly (1) according to claim 14, wherein said filtering medium (40) is preferably tubular so as to be transversally passable by said fluid, wherein one of said filtering inlet mouth (61) and said filtering outlet mouth (62) is positioned on said main axis (X-X).

16. Filter assembly (1) according to any of the preceding claims, wherein the cover (6) is integral with the filter element (4) or the cover (6) is mountable integrally with the filter element (4).

17. A fuel system of a vehicle comprising a filter assembly (1) of a fluid, preferably fuel, preferably diesel, according to any of the preceding claims.

18. Method of assembling a filter assembly (1) according to any one of claims 1 to 16, the method comprising the steps of:

-assembling the filter cartridge (3) by axially inserting a group comprising the filter element (4) and the cover (6) firmly joined into the cup (5) until the cover (6) axially engages the region of the head edge of the cup (5);

-performing the assembly of the cartridge (3) and the head group (2) by carrying out the following steps:

i) -axially approaching the filter cartridge (3) to the head group (2) in such a way as to insert the pin element (29) in the slot (69);

ii) performing a rotational coupling operation between the cartridge (3) and the head group (2), allowing a mutual rotation between the cup (4) and the head group (2) by tightening the axial annular gasket (60).