Sensorized Suspension Assembly for a Vehicle, Associated Methods, and Wheel Hub Unit

Abstract

In a vehicle suspension assembly (1), a sensorized system (4) is applied to a wheel hub unit, wherein a radially outer cylindrical surface (13) of an outer ring (5) of the wheel hub unit, which is configured to be coupled to a suspension strut or a steering knuckle (3), has four circumferential flats (12) that are angularly spaced from one another on the radially outer cylindrical surface, each flat defining a flat surface (19) that extends axially on a pair of annular tracks (10) for rolling elements (9) of the outer ring; each flat integrally carries a sensor module (14) including a pair of extensometers (15), the pair of extensometers being positioned parallel to one another and each extensometer being oriented in a circumferential direction at the location of a respective annular track so as to extend along a circumferential extension of the annular track; a circuit (16) receives signals from each sensor module and sends them to a data socket carried by the suspension strut or the steering knuckle.

Description

Technical Field

[0001] The present invention relates to a suspension assembly for a vehicle, the suspension assembly comprising a wheel hub unit and a suspension strut or a steering knuckle, the assembly comprising a sensorized system for detecting in real time the forces and torques applied to the tyres of each wheel to provide this information to a control unit of the vehicle to improve stability control and make it more effective. Background Art

[0002] In currently used suspension assemblies, sensors capable of detecting the rotational speed of each wheel of the vehicle are used only, and a sensorized suspension assembly capable of detecting the stress received by the tyre during travel and then transmitted to the wheel hub unit on which the vehicle wheel is mounted is not used.

[0003] US6619102B2 describes a wheel hub unit including a rolling bearing, the outer ring of the rolling bearing having a flange for fixing to a suspension strut and provided with circumferential and radial elastic deformation regions, and a single strain sensor is fitted to each of the circumferential and radial elastic deformation regions. This solution is complex and costly to implement and has not been proven effective in correctly detecting the forces acting on the tyre.

[0004] US6658943B2 describes a rolling bearing having double-row tapered rollers, wherein the radially outer cylindrical surface of the outer ring of the bearing is provided with four sensor modules, the four sensor modules being circumferentially fixed to the cylindrical surface and angularly spaced from each other. Each module includes a pair of strain sensors positioned at 90° to each other. However, this solution has also not been proven effective in correctly detecting the forces acting on the tyre and requires the use of relatively complex sensor modules. Summary of the Invention

[0005] The object of the present invention is to provide a sensorized system, a wheel hub unit and a suspension assembly for a vehicle comprising such a sensorized system, the sensorized system for detecting in real time the forces and moments applied to the tyre of the wheel mounted on the wheel hub unit of the suspension assembly, the sensorized system being free from the drawbacks of the prior art and at the same time reliable, economical and easy to implement in existing wheel hub units.

[0006] Accordingly, according to the present invention, there is provided a suspension assembly for a vehicle including a suspension strut or a steering knuckle and a wheel hub unit, and a wheel hub unit and a sensorized system associated with each other, the vehicle suspension group including a hub bearing unit, a suspension strut or a steering knuckle for the hub bearing unit, and a sensorized system for detecting mechanical stress acting on the hub bearing unit; the hub bearing unit includes a radial outer ring, a flanged hub, and a plurality of rolling elements, wherein the flanged hub is inserted into the interior of the radial outer ring in a radially coaxial manner on the side where the first end of the outer ring facing the outside of the vehicle is located during use, the plurality of rolling elements are inserted into the outer ring to enable the flanged hub to rotate relative to the outer ring, and the outer ring is stationary during use; characterized in that the sensorized system includes, in a combined form:

[0007] - Four flat portions, which are angularly spaced apart from each other on the radially outer cylindrical surface of the outer ring, each flat portion extending axially on at least one annular rolling track for the rolling elements formed on the radially inner surface of the outer ring and oriented in a circumferential direction transverse to the axis of symmetry of the radially outer cylindrical surface of the outer ring;

[0008] - A deformation sensing module, integrally fixed to each flat portion, each sensing module including at least one deformation sensor, the at least one deformation sensor being arranged at the corresponding annular rolling track for the rolling elements and oriented in the circumferential direction so as to extend along the circumferential extension of the annular rolling track; and

[0009] - A circuit for acquiring signals emitted by or associated with each of the sensing modules,

[0010] to detect in real time the forces and torques applied to the tire of the wheel mounted on the hub bearing unit during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will now be described with reference to the drawings, which show non-limiting examples of embodiments of the present invention, wherein:

[0012] Figure 1 and Figure 2 Schematically show two orthogonal views of a sensorized suspension assembly of a vehicle according to the present invention, which are a side view and a rear view or an "inner" view respectively;

[0013] Figure 3 Schematically show, at an enlarged scale, a cross-sectional view taken along plane III-III Figure 1 of the sensorized suspension assembly;

[0014] Figure 4 Schematically shows a rear three-quarter perspective view, enlarged, of a radially outer ring of a wheel hub unit forming part of a suspension assembly for Figure 1 and Figure 2 ;

[0015] Figure 5 Schematically shows a perspective view of a part of an outer ring of a sensorized Figure 4 in accordance with the present invention; and Figure 6 Schematically shows, at a further enlarged scale, details of an outer ring of a sensorized Figure 4 in accordance with the present invention. DETAILED DESCRIPTION

[0016] Referring to Figure 1 and Figure 4 , in these figures the numeral 1 denotes the overall vehicle suspension assembly, which includes a wheel hub unit 2, a suspension upright or knuckle 3 for the wheel hub unit 2, and a sensorized system 4 generally configured to detect mechanical stresses acting on the wheel hub unit 2.

[0017] The wheel hub unit 2 includes a rolling bearing 34, which in turn includes: a radially outer ring 5 and a radially inner ring 35; an annular flanged hub 6, which is coaxially and radially inserted inside the radially outer ring 5 and is angularly and integrally joined to the inner ring 35; and a plurality of rolling elements 9 ( Figure 3 ), inserted between the outer ring 5 and the flanged hub 6 (in the present case between the outer ring 5 and the inner ring 35), to enable the flanged hub 6 to rotate relative to the outer ring 5 (since the outer ring 5 is attached / fixed to the suspension upright or knuckle 3, it is stationary in use).

[0018] The flanged hub 6 is inserted into the radially outer ring 5 of the rolling bearing 34 from the side of the first end 7 of the outer ring 5 that faces the exterior of the vehicle in use (in the example shown, the side facing the flange 8 that extends radially and prominently on the outside of the hub 6). Figure 3 )

[0019] In the non-limiting example shown, the rolling elements 9 include two rows of balls.

[0020] In all cases, the rolling elements 9 are configured to engage with a radially inner surface 11 formed on the outer ring 5 ( Figure 3)Two corresponding annular rolling tracks (or raceways) 10 on it, in the illustrated example, the radially inner surface 11 is substantially cylindrical.

[0021] The rolling elements 9 also engage in a known manner with corresponding annular rolling tracks (known but not described for simplicity) formed radially on the outer side of the inner ring 35 (or directly on the hub 6 in the absence of the inner ring 35).

[0022] According to one aspect of the invention, the sensorized system 4 includes ( Figure 4 ) four flat portions 12 (only two of the four flat portions 12 can be seen in the figure), the four flat portions 12 being formed ( Figure 5 and Figure 6 ) to be angularly spaced from each other on the radially outer cylindrical surface (or radially outerward cylindrical surface) 13 of the outer ring 5 of the wheel hub unit 2.

[0023] Each flat portion 12 extends axially over at least one of the annular rolling tracks 10 for the rolling elements 9 (or axially extends across the rolling track 10 / axially extends beyond the rolling track 10 / axially extends above the rolling track 10), and in a preferred example of the illustrated embodiment, extends axially over two tracks 10.

[0024] Each flat portion 12 is also oriented circumferentially transverse to the axis of symmetry A of the radially outer cylindrical surface 13 of the outer ring 5.

[0025] The sensorized system 4 also includes a strain sensor module 14 integrally fixed to each flat portion 12 ( Figure 5 and Figure 6 ).

[0026] According to another aspect of the invention, each sensor module 14 further includes a strain sensor 15 of a known type (e.g., a strain gauge or an extensometer), the strain sensor 15 being located at the position of each corresponding annular rolling track 10 for the rolling elements 9, and according to another aspect of the invention, being oriented in the circumferential direction such that it extends along the circumferential development of the annular track 10 at the position where it is located.

[0027] Finally, the sensorized system 4 includes an electrical circuit 16 ( Figure 3 and Figure 5) The circuit 16 is for picking up the electrical signals sent by or only related to each sensor module 14.

[0028] In a preferred example of the illustrated embodiment, as described above, the radially outer ring 5 of the wheel hub unit 2 has a pair of rolling tracks 10 for the rolling elements 9 (positioned one in front of the other ( / successively) axially).

[0029] In addition, each sensor module 14 includes a pair of known strain sensors 15, and the pair of known strain sensors 15 are positioned parallel to each other and fixed to the corresponding portions 180 of each flat portion 12 ( Figure 4 ) which are located at substantially the same axial positions as the axial positions of the tracks 10 of the aforementioned pair of rolling tracks for the rolling elements 9.

[0030] In particular, as is well known to those skilled in the art, in a rolling bearing, especially in a rolling bearing with two rows of balls shown in a non - limiting manner, there are / are defined theoretical contact lines which, for each row of rolling elements, intersect the outer surface of the bearing (in this case the radially outer cylindrical surface 13 of the outer ring 5) (intercept the outer surface of the bearing).

[0031] According to one aspect of the present invention, the flat portions 12 are formed on the surface 13 in such a way that these theoretical contact lines intersect the surface 13 exactly at the positions of each of the flat portions 12 (especially at the corresponding points defined in the design stage), and the corresponding points must, according to another aspect of the present invention, correspond to the angular and axial positions where the sensors or extensometers 15 are located (corresponding to the portions 180 in the current case).

[0032] Therefore, the strain sensors or extensometers 15 only measure the load components in the tangential direction, and the advantage of this positioning is that the load components are read along the line of action of the load exchanged between the rolling elements and the rolling tracks.

[0033] Therefore, the positions of the strain sensors 15 on the flat portions 12 are not randomly selected, but according to the present invention, are defined on both the side located inside the vehicle or on the vehicle - inner side and the side located outside the vehicle or on the vehicle - outer side by the intersection of the lines / bands of the contact (working) angles of the respective tracks 10 of the rolling bearing 34 with the surface 19 defining the flat portions 12 themselves.

[0034] Due to this specific relative configuration of the flat portions 12, the tracks 10, and the sensors 15, when the wheel hub unit 2 is used on a vehicle, it has surprisingly been proven that the sensorized system 4 can detect in real - time the forces and torques applied to the tire 160 of the wheel 17 mounted on the wheel hub unit 2 ( Figure 1 )).

[0035] According to the non - limiting examples shown, the sensor 15( Figure 5 ) includes a strain gauge formed by a plurality of arms 18 made of a known piezoresistive material that can change its resistance in response to even small length changes of the arms 18. Clearly, other types of strain sensors are suitable for the present invention: for example, the material of the arms 18 can be a piezoelectric material capable of emitting an electrical signal automatically generated by the piezoelectric effect due to deformation, or the sensor 15 can be of the capacitive type or any other type capable of precisely detecting each (elastic) deformation of the flat portion 12 due to the forces exchanged with the rolling elements 9 (forces obtained from the stresses received by the tire 160 during use).

[0036] According to a preferred aspect of the present invention, the module 14 is fixed to the flat portion 12 by gluing. In particular, the sensor module 14 includes a sheet of flexible plastic material (such as ) that carries the arms 18 applied to one of its surfaces, and these arms can be, for example, screen - printed on the sheet, and the sheet is glued to the corresponding flat portion 12 in close contact therewith. On the other hand, the sensor 15 can be directly formed on the flat portion 12, for example, by in - situ laser deposition, welding, screen - printing, or other techniques.

[0037] In all cases, in order to ensure that the sensorized system 4 operates correctly, according to one aspect of the present invention, the flat portion 12( Figure 4 ) is preferably constructed such that each flat portion defines a corresponding surface 19 that is flat or planar and is positioned perpendicular to the axis of symmetry A of the radially outer cylindrical surface 13 of the outer ring 5.

[0038] Basically, the flat portions 12 are positioned along chords of a circumference corresponding to the cross - section of the radially outer cylindrical surface 13, and these chords are oriented perpendicular to the radii of the circumference that intercept these chords.

[0039] The flat portions 12 are spaced apart from each other circumferentially, preferably at a constant interval, for example, positioned at 90° to each other.

[0040] The radially outer ring 5 of the wheel hub unit 2 is preferably integrally coupled to the suspension strut or the steering knuckle 3; in particular, the radially outer ring 5 is assembled in the first transverse hole 20 of the suspension strut or the steering knuckle 3 in an interference fit Figure 3)In [the situation], the first transverse hole 20 is formed perpendicular to the first surface 21 and the second surface 22 of the suspension strut or the steering knuckle 3 that face each other, where the first surface 21 and the second surface 22 face the outside and the inside of the vehicle respectively during use, such that the second surface 22 faces away from the opposite side of the first end 7 of the outer ring 5.

[0041] According to this preferred configuration, the sensorized system 4 includes at least one pin 23 ([ Figure 3 ) in a manner combined with what has been described. The at least one pin 23 is prominently fitted into the second hole 24 of the suspension strut or the steering knuckle 3 on the side where the second surface 22 is located, and is radially located outside the first hole 20 and beside the first hole 20.

[0042] The sensorized system 4 further includes a mounting part (seat) 25, and the mounting part 25 is formed by axially penetrating the flanged edge 26 of the second end 27 of the outer ring 5 ([ Figure 4 ). The flanged edge 26 is opposite to the first end 7 and interacts by bearing against the second surface 22 of the suspension strut or the steering knuckle 3.

[0043] The axially penetrating mounting part 25 of the flanged rim 26 includes a radial recess or notch in the edge 26 and defines a circular mounting part that is radially open towards the outside of the flanged edge 26.

[0044] According to an aspect of the present invention, the pin 23 engages with the mounting part 25 to angularly integrate the outer ring 5 of the wheel hub unit 2 with the suspension strut or the steering knuckle 3, thereby ensuring that the sensor 15 correctly measures the deformation of the flat surface 19 of each flat part 12 caused by the operating stress borne by the tire 160 and the corresponding wheel 17.

[0045] In particular, the mounting part 25 including the radial notch or recess in the edge 26 only partially engages with the pin 23, and the pin 23 is a cylindrical pin.

[0046] To ensure the correct operation of the pin 23, the mounting part 25 engages it on the circumferential part of the pin 23, and this circumferential part is larger than half of the circumference of the pin 23.

[0047] According to another aspect of the present invention, the radially outer cylindrical surface 13 of the outer ring 5 is also provided with an annular groove 28 ([ Figures 4 - 6 ). The annular groove 28 intersects all four flat parts 12 and is defined by a bottom wall 29, and the bottom wall 29 is formed to be substantially flush with the flat parts 12, especially flush with the flat surface 19 defined by the flat parts.

[0048] According to an aspect of the present invention, the circuit 16 includes an electrically insulating conductive strip 30 accommodated in the annular groove 28Figure 6 ) The conductive strip 30 is substantially flush with the annular groove 28 and in contact with the bottom wall 29, thereby passing over each sensing module 14 in a contacting manner, and the conductive strip 30 is configured to electrically connect the sensor module 14 in parallel to a data socket 31 ( Figure 1 - to Figure 3 ), which is integrally fixed to the surface 22 of the suspension upright or steering knuckle 3 that faces away from the opposite side of the first end 7 of the outer ring 5.

[0049] The conductive strip 30 is wound into a loop on the outer ring 5 inside the groove 28 and is bent at an angle (in particular a right angle) at the point where the conductive strip 30 closes on itself to form a loop, preferably at a circumferential position (according to an initially defined pitch or angular interval) between two closely adjacent flat portions 12, or in fact at the position of any one of the flat portions 12.

[0050] More specifically, the conductive strip 30 is bent at an angle towards the flanged edge 26 of the second end 27 of the outer ring 5 to extend out of the groove 28, and the flanged edge 26 interacts by bearing against the second surface 22 of the suspension upright or steering knuckle 3.

[0051] The conductive strip 30 passes axially through the flanged edge 26 via an axial groove 32 formed radially through the flanged edge 26 and is electrically connected to the data socket 31. The data socket is integrally carried by the surface 22 by means of a bracket 33 ( Figure 2 and 3 ), and the bracket 33 is fixed to the suspension upright or steering knuckle 3 by screws or other equivalent connecting members.

[0052] As described above, it is important that the flat portions 12 are formed such that each flat portion defines a flat surface 19 that is perpendicularly positioned perpendicular to the axis of symmetry A of the cylindrical surface 13 of the radially outer side of the outer ring 5.

[0053] Additionally, according to another aspect of the present invention, the pins 23 and the mounting portions 25 are not only configured to angularly integrate the outer ring 5 with the suspension upright or steering knuckle 3, but are particularly configured to serve as an angular reference for the angular positioning of the outer ring 5 such that the flat portions 12 are positioned in opposite and alternating pairs (the pairs being horizontal and vertical respectively).

[0054] Finally, it is apparent from the above description that the invention per se also relates to a sensorized system 4 configured to detect in real time forces and torques applied to a tire 160 of a vehicle wheel 17 mounted on a wheel hub unit 2, the wheel hub unit 2 comprising: a radially outer ring 5 integrally carried in a fixed position by a vehicle suspension upright or knuckle 3; a flanged hub 6 configured to angularly support the vehicle wheel 17 in an integrated manner and received within the outer ring 5 of the wheel hub unit 2; and a plurality of rolling elements 9 interposed between the flanged hub 6 and the outer ring 5 and engaging a pair of annular raceways 10 formed on a radially inner surface 11 of the outer ring 5.

[0055] According to one aspect of the invention, the sensorized system 4 comprises:

[0056] a radially outer cylindrical surface 13 of the outer ring 5 of the wheel hub unit 2 configured to be coupled to a first transverse hole 20 in the suspension upright or knuckle 3;

[0057] – at least four circumferentially flat portions 12 formed on the radially outer cylindrical surface 13 of the outer ring 5 and angularly spaced from each other, each flat portion defining a flat surface 19 that axially extends on two of the pair of annular raceways 10 for the rolling elements 9 and extends transversely to a symmetry axis A of the radially outer cylindrical surface 13 of the outer ring 5;

[0058] four strain sensor modules 14, each strain sensor module integrally fixed to a respective flat portion 12, each sensor module comprising a pair of strain sensors 15 positioned parallel to each other, and each strain sensor 15 located at a position of a respective annular raceway 10 oriented in the circumferential direction to extend along a circumferential extension of the annular raceway 10; and

[0059] a circuit 16 for acquiring signals emitted by or associated with each sensor module 14.

[0060] According to the invention, the above-described sensorized system 4 further comprises: a second hole 24 formed in the suspension upright or knuckle 3 radially outside and next to (to the side of) the first hole 20 that receives the outer ring 5 of the wheel hub unit; a pin 23 protruding and fitted into the second hole 24; and a radially mounting portion 25 of the flanged edge 26 of the outer ring 5 that engages the pin 23, the flanged edge 26 interacting by bearing against the suspension upright or knuckle 3.

[0061] It is evident from the above description that the present invention also relates to the described wheel hub unit 2 and a method for detecting wheel stress, which method uses the present wheel hub unit 2, the wheel hub unit 2 including a standard rolling bearing 34, the standard rolling bearing 34 in turn including an outer ring 5 and a radial inner ring 35( Figure 3 ), the bearing 34 being integrated with a commercially available suspension strut or steering knuckle 3 (with minimal modification to the suspension strut or steering knuckle 3), and four pairs of strain sensors or extensometers 15 (two for each flat portion 12) can be integrally formed at 90° to each other in a specific area (at the position of the raceway 10) in a plan view and with specific dimensions on the outer ring 5, the specific area being formed on the outer diameter of the outer ring 5 with a specific radial depth, and this specific radial depth need not be the same for all flat portions 12 (since the choice of this depth at the design stage is based on the temper hardening profile of the raceway 10 and the optimization of the signals of the extensometers 15), and the specific dimensions are based on the dimensions of the extensometers 15 used and the performance of the suspension strut or steering knuckle 3.

[0062] Each extensometer 15 is preferably glued with glue (or an alternative bonding material) that can ensure the contact, positioning, and operation of the sensor 15 throughout the service life of the wheel hub unit 2. Each extensometer 15 will have a fixed standard size and will be positioned on the outer ring 5 at a specific location, each specific location being on a flat surface 19 directly above one of the two raceways 10, and this location has been proven to be the optimal location for maximizing load measurement because it has been found that this location corresponds to the projected area of the bearing contact angle relative to the extensometer 15 or the glued surface 19.

[0063] Each extensometer 15 is connected by welding to a flexible printed circuit formed by a conductive strip 30, the conductive strip 30 being placed on the annular groove 28 at 360° on the outer diameter of the outer ring 5.

[0064] Then, the flexible printed circuit 30 emerges from the outer ring 5 on the inside through the axial groove 32, and in order to provide an anti-rotation function (which has been found to be extremely important for correct operation), after the bearing 34 is installed on the suspension strut or steering knuckle 3, a specific hole 24 is made through the suspension strut or steering knuckle 3 at the position of a specific mounting portion 25 for the outer ring 5. Then, a pin 23 is inserted through the hole 24 and the corresponding radial outer mounting portion 25 to prevent any relative rotation. The anti-rotation function is necessary to avoid any risk of movement of the extensometer 15 relative to the direction of the load.

[0065] Initially, each pair of extensometers 15 is mounted on a specific mounting portion formed by the flat surface 19 of the flat part 12 and is correctly wired. After wiring, the entire cable is protected and fixed on the contact surface of the outer ring 5 by any known insulating coating (not shown for simplicity), which is necessary to avoid any movement within the receiving mounting portion defined by the hole 20 during the installation of the wheel hub unit 2.

[0066] The assembly of the wheel hub unit 2 with the suspension strut or steering knuckle 3 is carried out as follows.

[0067] First, with the extensometers 15 already assembled, the rolling bearing 34 is oriented at a specific angular position to provide a pair of extensometers 15 aligned with the vertical direction in the mounting portion 20 to detect optimal output data; the installation should be carried out carefully to avoid damaging and / or cutting the conductive strip 30 or cable that emerges from the flanged edge 26.

[0068] Therefore, at least a part of the circuit defined by the conductive strip or flexible printed circuit 30 and the extensometers 15 are also accommodated in the mounting portion 20 during use and are thus in a protected position where they can receive optimal stress.

[0069] When the rolling bearing 34 is installed on the vehicle inner side of the suspension strut or steering knuckle 3 by being press-fitted into the mounting portion 20, the outer ring 5 is axially locked against the suspension strut or steering knuckle 3 on the vehicle outer side by a first orbital forming operation, generating a shoulder rim 33 ( Figure 3 ). Finally, the flanged hub 6 is inserted through the vehicle outer side (from the side where the face 21 is located) into the interior of the outer ring 5 and the inner ring 35 and is integrally assembled with the inner ring 35 by a second orbital forming operation to generate a shoulder rim 36 ( Figure 3 ), taking care not to damage the flexible strip or cable 30 that emerges from the outer ring 5.

[0070] From the above description, the advantages of the proposed solution will be easily understood, namely:

[0071] Improve the performance of the vehicle;

[0072] Provide information about the load to the vehicle, which cannot currently be obtained by direct measurement;

[0073] Improve the reliability of the ESP software and the performance of the vehicle;

[0074] Autonomous driving;

[0075] Monitor the performance of the bearing.

[0076] Therefore, all the objectives of the present invention are achieved.

Claims

1. A vehicle suspension assembly (1) comprising a wheel hub bearing unit (2), a suspension strut or knuckle (3) for said wheel hub bearing unit, and a sensorized system (4) for detecting mechanical stresses acting on said wheel hub bearing unit; said wheel hub bearing unit comprising a radial outer ring (5), a flanged wheel (6), and a plurality of rolling elements (9), wherein, said flanged wheel (6) is inserted inside said radial outer ring in a radially coaxial manner on the side of a first end (7) of said outer ring that faces the exterior of the vehicle in use, said plurality of rolling elements (9) being inserted inside said outer ring to enable said flanged wheel to rotate relative to said outer ring, said outer ring being stationary in use; characterized in that said sensorized system comprises, in combination: - four flat portions (12) angularly spaced from one another on a radially outer cylindrical surface (13) of said outer ring (5), each flat portion extending axially on at least one annular rolling track (10) for said rolling elements (9) formed on a radially inner surface (11) of said outer ring and being oriented in a circumferential direction transverse to a symmetry axis (A) of said radially outer cylindrical surface of said outer ring; - a deformation sensing module (14) integrally fixed to each flat portion, each sensing module comprising at least one deformation sensor (15), said at least one deformation sensor (15) being arranged at a respective one of said annular rolling tracks (10) for said rolling elements and being oriented in the circumferential direction so as to extend along a circumferential extension of said annular rolling track (10); and - a circuit (16) for acquiring signals emitted by or associated with each said sensing module (14), to detect in real time, in use, forces and torques applied to a tyre of a wheel mounted on said wheel hub bearing unit; the radial outer ring (5) of said wheel hub bearing unit having a pair of annular rolling tracks (10) for said rolling elements arranged axially one behind the other, each said flat portion (12) extending axially corresponding to said pair of annular rolling tracks (10).

2. The suspension assembly according to claim 1, characterized in that, each sensing module (14) is formed by a pair of deformation sensors (15) arranged in parallel with one another, said pair of deformation sensors (15) being fixed to respective portions (180) of each flat portion arranged at an axial position substantially the same as the axial position of said pair of annular rolling tracks (10).

3. The suspension assembly according to claim 1 or 2, characterized in that, The radial outer ring (5) of the hub bearing unit is assembled in the first hole (20) of the suspension column or steering knuckle (3) by interference. The first hole (20) is formed perpendicular to the first surface (21) and the second surface (22) of the suspension column or steering knuckle that face each other. Wherein the first surface (21) and the second surface (22) face the outside and the inside of the vehicle respectively during use, such that the second surface (22) faces away from the opposite side of the first end (7) of the outer ring; The sensorized system further includes at least one pin (23). The at least one pin (23) is inserted into the second hole (24) of the suspension column or steering knuckle in a cantilever manner on the side where the second surface is located, and is located radially outside and beside the first hole (20); And a mounting portion (25), obtained by axially passing through the flange-shaped edge (26) of the second end (27) of the outer ring opposite to the first end (7), and the flange-shaped edge (26) is in abutting engagement with the second surface (22) of the suspension column or steering knuckle; The pin (23) engages with the mounting portion (25) to integrally form the outer ring of the hub bearing unit with the suspension column or steering knuckle in terms of angle.

4. A hub bearing unit (2) for a vehicle suspension assembly (1), the hub bearing unit (2) being configured to be coupled to a suspension column or steering knuckle (3) of the suspension assembly (1) and including a sensorized system (4) for detecting mechanical stresses acting on the hub bearing unit; The hub bearing unit includes a rolling bearing (34), and the rolling bearing (34) includes a radial outer ring (5), a flanged hub (6), and a plurality of rolling elements (9). Wherein, The flanged hub (6) is coaxially inserted radially inside the radial outer ring on the side where the first end (7) of the outer ring faces the outside of the vehicle during use. The plurality of rolling elements (9) are inserted inside the outer ring to enable the flanged hub to rotate relative to the outer ring, and the outer ring is stationary during use; It is characterized in that the sensorized system (4) includes in combination: Four flat portions (12), angularly spaced from each other on the radially outer cylindrical surface (13) of the outer ring (5). Each flat portion extends axially on at least one annular rolling track (10) for the rolling elements (9) formed on the radially inner surface (11) of the outer ring. Each flat portion (12) is oriented in the circumferential direction transverse to the axis of symmetry (A) of the radially outer cylindrical surface (13) of the outer ring. - A deformation sensing module (14), integrally fixed on each flat portion. Each sensing module includes at least one deformation sensor (15). The at least one deformation sensor (15) is arranged at the corresponding annular rolling track (10) for the rolling elements and is oriented according to the circumferential direction such that it extends along the circumferential extension of the annular rolling track (10); And - A circuit (16) for obtaining signals emitted by or associated with each of the sensing modules (14); - The position of the deformation sensor (15) on the flat portion (12) corresponds to the position of the corresponding portion (180) of the flat surface (19) defined by each flat portion in the flat portion (12). The deformation sensor (15) is integrally fixed on the corresponding portion (180). The portion (180) of the flat surface is arranged at the intersection of the line or band of the contact or working angle of each annular rolling track (10) of the rolling bearing (34) with the flat surface (19) defined by each flat portion (12). The radially outer ring (5) of the hub bearing unit has a pair of annular rolling tracks (10) for the rolling elements arranged one in front of the other in the axial direction. Each flat portion (12) extends in the axial direction corresponding to the pair of annular rolling tracks (10).

5. The hub bearing unit (2) according to claim 4, characterized in that the sensorized system (4) further comprises at least one mounting portion (25) obtained by axially passing through the flange-like edge (26) of the second end (27) of the outer ring opposite to the first end (7). The flange-like edge (26) is configured to abut and cooperate with the suspension strut or steering knuckle in use. The mounting portion (25) is configured to receive a cylindrical pin (23) in use. The pin (23) is inserted into the suspension strut or steering knuckle in a cantilever manner to integrally fix the outer ring (5) and the suspension strut or steering knuckle in terms of angle. The mounting portion (25) axially passes through the flange-like edge of the second end of the outer ring and is a circular mounting portion that is radially open to the outside. The mounting portion (25) is configured to only partially engage with the pin (23) through a circumferential portion of the pin (23) that is greater than half of the circumference of the pin (23) in use.

6. The hub bearing unit according to claim 4 or 5, characterized in that the radially outer cylindrical surface (13) of the outer ring is provided with an annular groove (28). The annular groove (28) intersects all four flat portions (12) and is defined by a bottom wall (29) obtained to be substantially flush with the flat portions. The circuit (16) includes an electrically insulated conductive strip (30). The conductive strip (30) is received in the annular groove (28) and is substantially flush with the annular groove (28), so as to pass over each sensing module (14) in a contacting manner and is configured to connect the sensing module in parallel with a data socket (31) configured to be integrally fixed with the suspension strut or steering knuckle in use.

7. The hub bearing unit according to claim 6, characterized in that The conductive band (30) is folded between two of the flat portions (12) or at one of the flat portions at an angle towards a flange-like edge (26) of a second end (27) of the outer ring opposite the first end, and the flange-like edge (26) is configured to abut and cooperate with a strut or a steering knuckle of the suspension during use; the conductive band (30) passes through the flange-like edge through an axial groove (32) formed radially through the flange-like edge to be electrically connected to the data socket (31).

8. The hub bearing unit according to claim 4 or 5, wherein, the flat surface (19) defined by the flat portion (12) is arranged perpendicular to the normal of the symmetry axis (A) of the radially outer cylindrical surface (13) of the outer ring; the flat portions (12) are spaced apart from each other at a constant pitch in the circumferential direction so as to be arranged at a 90° angle to each other.

9. A sensorized system (4) for real-time detection of forces and torques applied to a tire (160) of a vehicle wheel (17) mounted on a hub bearing unit (2), the hub bearing unit (2) comprising a radially outer ring (5), a flange hub (6) and a plurality of rolling elements (9), wherein, the radially outer ring (5) is integrally carried in a fixed position by a vehicle suspension strut or a steering knuckle (3), the flange hub (6) is configured to angularly support the vehicle wheel in an integral manner and is received within the outer ring (5), the plurality of rolling elements (9) being interposed between the flange hub and the outer ring and engaging with a pair of annular rolling tracks (10) formed on a radially inner surface (11) of the outer ring; characterized in that the sensorized system (4) comprises: - the radially outer cylindrical surface (13) of the outer ring, configured to be coupled inside a first hole (20) of the suspension strut or the steering knuckle; - at least four circumferential flat portions (12), angularly spaced apart from each other on the radially outer cylindrical surface (13) of the outer ring, each flat portion defining a flat surface (19) which extends axially on two of the pair of annular rolling tracks (10) for the rolling elements and transversely to the symmetry axis A of the radially outer cylindrical surface of the outer ring; - four deformation sensing modules (14), each deformation sensing module being integrally fixed to a corresponding flat portion, each sensing module comprising a pair of deformation sensors (15) arranged in parallel with each other, and each deformation sensor being located at a corresponding annular rolling track (10) oriented in the circumferential direction such that it extends along the circumferential extension of the annular rolling track; and - a circuit (16) for acquiring signals emitted from or associated with each of the sensing modules; and - A second hole (24) is formed radially outside a first hole (20) that houses an outer ring of the hub bearing unit in the suspension strut or knuckle and is adjacent to a side portion of the first hole (20). A pin (23) is inserted into the second hole in a cantilever manner, and a radially-mounted portion (25) of a flange-shaped edge (26) of the outer ring engages with the pin, and the flange-shaped edge abuts and mates with the suspension strut or knuckle.

10. A method for detecting wheel stress, comprising the following steps: - Providing a hub bearing unit (2) including a flanged hub (6) inserted in a rolling bearing (34), the rolling bearing (34) further including a radially outer ring (5), a radially inner ring (35), and a plurality of rolling elements interposed between the inner ring and the outer ring and engaging with a pair of annular rolling tracks formed on a radially inner surface of the outer ring; - Providing a suspension strut or knuckle (3); - Providing at least one deformation sensor (15) integrally coupled to a radially outer cylindrical surface (13) of the outer ring (5); - Providing a circuit (16) for acquiring a signal emitted by or associated with the deformation sensor; - Coupling the hub bearing unit (2) to the suspension strut or knuckle (3); characterized in that the method further comprises the following steps: i) Configuring the radially outer cylindrical surface (13) of the outer ring to be coupled within a first hole (20) or a mounting portion (25) of the suspension strut or knuckle; ii) Disposing at least four circumferentially flat portions (12) angularly spaced apart from each other on the radially outer cylindrical surface (13) of the outer ring, each flat portion defining a flat surface (19) that axially extends over two of the pair of annular rolling tracks (10) for the rolling elements and is transverse to a symmetry axis (A) of the radially outer cylindrical surface of the outer ring; iii) Securing four deformation sensing modules (14), each deformation sensing module (14) being integrated on a respective flat portion, each sensing module including a pair of deformation sensors (15) or strain gauges arranged in parallel with each other, and each deformation sensor (15) or strain gauge being disposed at a respective annular rolling track (10), oriented in a circumferential direction such that it extends along a circumferential extension of the annular rolling track, and connecting all the deformation sensors (15) to the circuit (16); iv) Coupling the rolling bearing (34) to the suspension strut or knuckle (3) such that the outer ring (5) is press-fitted into the first hole (20) or the mounting portion (25); v) In the suspension strut or the steering knuckle, a second hole (24) or mounting portion (25) is formed radially outside the first hole (20) or mounting portion (25) that houses the outer ring of the hub bearing unit and beside the first hole (20) or mounting portion (25), and a pin (23) is inserted into the second hole in a cantilever manner, and the pin is coupled to a radially mounting portion (25) of a flange-shaped edge (26) of the outer ring, while making the flange-shaped edge abut and cooperate with the suspension strut or the steering knuckle; vi) Insert the flanged hub (6) into the outer ring (5) of the rolling bearing (34) such that the flanged hub (6) is coupled to the inner ring (35) of the rolling bearing (34).

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