Braking system

Abstract

A braking system (1), in particular of the Brake-By-Wire type, comprising an electromechanical actuation device (3) extending along an actuation axis (4); a hydraulic chamber (5), extending substantially coaxial to the actuation axis (4), and configured to contain hydraulic fluid (10), wherein the electromechanical actuation device (3) comprises an electric motor (2); a motion converter (6) configured to transform a rotary motion into a translatory motion and comprising a rotation component (8) and a translation component (9) operatively connected to each other, wherein the translation component (9) comprises a pressure wall (11) and a sliding wall (12) at least partially slidingly housed inside the hydraulic chamber (5), so that a rotation of the rotation component (8) about the actuation axis (4) corresponds to a translation of the translation component (9) along the actuation axis (4), inside the hydraulic chamber (5), wherein the translation component (9) is translatable between a maximum retraction position and a maximum extension position, and wherein the pressure wall (11) is configured to act in pressure on the hydraulic fluid (10) in the hydraulic chamber (4), upon a translation of the translation component (9) towards the maximum extension position, so as to actuate the braking assembly.

Description

“Braking system”

[0001] Field of the invention

[0002] The present invention relates to a braking system of the Brake-By-Wire (“BBW’) type for two- or more-wheeled vehicles, operable by a driver by means of a brake pedal or lever.

[0003] Prior art

[0004] In BBW-type braking systems, there is a decoupling between the force and displacement applied to the brake pedal or lever by the driver and the resulting braking force that is applied by the calipers to the wheels of the vehicle. In particular, the force and displacement applied by the driver to the brake pedal or lever are transduced into an electric signal which is processed by a control unit to command the actuation of the calipers of the braking system.

[0005] A BBW braking system comprises at least one braking assembly acting on a wheel of the vehicle, generally operable by a volumetric pump connected to an electromechanical actuation device powered by an electric motor. The volumetric pump is formed by a piston sliding in a cylinder. In particular, in known systems, the piston of the volumetric pump is connected to the electromechanical actuation device, for example through a threaded or articulated connection, so that an actuation of the electromechanical actuation device corresponds to a translation of the piston connected thereto within the cylinder, thus generating a hydraulic fluid pressure adapted to activate the braking assembly. In addition, in systems of this type, the presence of pressurised fluid allows decoupling of the piston from the caliper. In particular, in such systems known to the inventors, such decoupling is intended to prevent, during braking and as a result of a consequent elastic deformation of the caliper, forces acting in a direction transverse to the actuation axis, that is, shear stresses which are poorly tolerated by the electromechanical actuation device, for example a screw-nut system, from being discharged onto the electromechanical actuation device. However, the provision of such elements suitable to decouple the piston from the electromechanical actuation device undesirably increases the bulk of such braking systems known to the inventors, particularly in the axial direction of the volumetric pump.

[0006] BBW braking systems are also known comprising dry screw-nut systems, in which the nut acts as a dry piston of an electromechanical caliper and transmits a braking force directly onto the pad of the electromechanical caliper. A system of this type is for example known from US20230151879A1. However, systems of this type do not have high reliability or durability since they are significantly stressed by forces acting in adirection transverse to the actuation axis of the screw-nut system, that is, by shear stresses which are poorly tolerated by the screw-nut system, generated during braking and as a result of the consequent elastic deformations to which the caliper is subjected.

[0007] Moreover, such known braking systems exhibit complexity and high costs, due to the presence of numerous interconnected components, subjected to high mechanical stresses, which require appropriate sizing and related tolerances that affect the overall precision and efficiency of the system.

[0008] Solution

[0009] The purpose of the present invention is to provide an improved braking system, capable of overcoming at least some of the drawbacks highlighted in the known art.

[0010] A particular object of the present invention is to provide a braking system having reduced bulk compared to the known art.

[0011] A further particular object of the present invention is to provide a braking system having a simplified configuration compared to the known art, and which at the same time exhibits greater operational precision and higher efficiency of operation.

[0012] These and other objects are achieved by means of a braking system according to claim 1.

[0013] The dependent claims refer to preferred and advantageous embodiments of the present invention.

[0014] Figures

[0015] In order to better understand the invention and appreciate its advantages, some exemplary and non-limiting embodiments thereof will be described below, with reference to the accompanying figures, in which:

[0016] - figure 1 is a front perspective view of an electromechanical actuation device of a braking system, according to one embodiment of the invention;

[0017] - figure 2A is an exploded front perspective view of a braking system, according to one embodiment of the invention;

[0018] - figure 2B is an exploded rear perspective view of the braking system shown in figure 2A;

[0019] - figure 3 is an exploded front perspective view of a braking system, according to a further embodiment of the invention;

[0020] - figure 4 is an exploded front perspective view of a braking system, according to a further embodiment of the invention;

[0021] - figure 5 is an exploded front perspective view of a braking system, according to a further embodiment of the invention;

[0022] - figure 6 is an exploded front perspective view of a braking system, according to a further embodiment of the invention;

[0023] - figure 7 is an axial sectional view of the braking system shown in figures 2A-2B;

[0024] - figure 8 is an axial sectional view of the braking system shown in figure 3;

[0025] - figure 9 is an axial sectional view of the braking system shown in figure 4;

[0026] - figure 10 is an axial sectional view of the braking system shown in figure 5;

[0027] - figure 11 is an axial sectional view of the braking system shown in figure 6.

[0028] Description of some preferred embodiments

[0029] With reference to the figures, a braking system, in particular of the Brake-By- Wire type, is generally denoted by the reference number 1.

[0030] The braking system 1 comprises an electromechanical actuation device 3. The electromechanical actuation device 3 extends along an actuation axis 4. Preferably, the electromechanical actuation device 3 extends substantially coaxial to the actuation axis 4.

[0031] The braking system 1 further comprises a hydraulic chamber 5 configured to contain hydraulic fluid 10. The hydraulic chamber 5 extends substantially coaxial to the actuation axis 4. Preferably, the hydraulic chamber 5 has a substantially cylindrical shape.

[0032] The electromechanical actuation device 3 is configured to actuate a braking assembly. The braking system is adapted to apply a braking force to a wheel or axle of a vehicle and may be, by way of example, a disc brake comprising a brake caliper associated with a brake disc connected to a wheel of the vehicle.

[0033] Moreover, the electromechanical actuation device 3 is fluidly connectable to the braking assembly by means of at least the hydraulic chamber 5, preferably by means of exclusively the hydraulic chamber 5.

[0034] In particular, the hydraulic chamber 5 comprises an outlet hole 30 which opens into the hydraulic chamber 5 and fluidly connects the hydraulic chamber 5 to the braking assembly.

[0035] The electromechanical actuation device 3 comprises an electric motor 2, a motion converter 6 and, optionally, a transmission 7.

[0036] The electric motor 2 is configured to generate and transfer mechanical powerto the motion converter 6.

[0037] The motion converter 6 is configured to transform a rotary motion into a translatory motion.

[0038] Where provided, the transmission 7, in particular a speed reducer, is interposed between the electric motor 2 and the motion converter 6.

[0039] The motion converter 6 comprises a rotation component 8 and a translation component 9 operatively connected to each other.

[0040] The rotation component 8 is configured to receive a rotary motion from the electric motor 2 or, when provided, from the transmission 7.

[0041] The translation component 9 comprises a pressure wall 11 , substantially transverse to the actuation axis 4. Moreover, the translation component 9 comprises a sliding wall 12, substantially parallel to the actuation axis 4, preferably substantially coaxial to the actuation axis 4.

[0042] The sliding wall 12 is at least partially slidingly housed inside the hydraulic chamber 5. Specifically, the sliding wall 12 is translatable relative to the hydraulic chamber 5 in a direction parallel to the actuation axis 4, but is constrained to the hydraulic chamber 5 in a direction transverse to the actuation axis 4.

[0043] In this way, a rotation of the rotation component 8 about the actuation axis 4, in particular induced by the electric motor 2, corresponds to a translation of the translation component 9 along the actuation axis 4, within the hydraulic chamber 5.

[0044] The translation component 9 is translatable between a maximum retraction position and a maximum extension position.

[0045] In particular, the translation component 9 is positioned at a minimum distance from the electric motor 2 and / or the transmission 7 at the maximum retraction position, whereas it is positioned at a maximum distance from the electric motor 2 and / or the transmission 7 at the maximum extension position.

[0046] The pressure wall 11 is configured to act in pressure on the hydraulic fluid 10 that can be contained in the hydraulic chamber 5, at a translation of the translation component 9 towards the maximum extension position, so as to actuate the braking assembly.

[0047] Advantageously, a braking system 1 thus configured has reduced bulk, in particular along the actuation axis 4, since the pressure wall 11 adapted to pressurise the hydraulic fluid 10 for the actuation of the braking assembly is comprised in the motion converter 6. Consequently, the connection of a volumetric pump or of an additional“piston” element to the motion converter 6 is avoided, since in the braking system 1 thus configured, it is the motion converter 6 itself that acts directly on the hydraulic fluid 10 to actuate the braking assembly.

[0048] With a further advantage, a braking system 1 thus configured is therefore simplified compared to the known art, since it does not require an additional “cylinderpiston” component to be connected to the motion converter 6, and also exhibits greater operational precision and consequently higher efficiency of operation. With a further advantage, a braking system 1 thus configured also exhibits greater reliability and durability since the motion converter 6 actuates the braking assembly by acting on the hydraulic fluid 10 inside the hydraulic chamber 5, thus not acting in direct contact with a pad of the braking assembly, and therefore avoiding being subjected to shear stresses acting in a direction transverse to the actuation axis 4.

[0049] The hydraulic chamber 5 comprises a guide surface 17 facing the actuation axis 4. In the operating configuration, the guide surface 17 faces the portion of the sliding wall 12 slidingly inserted into the hydraulic chamber 5.

[0050] According to one embodiment, the braking system 1 comprises a primary gasket 13 and a secondary gasket 14.

[0051] The primary gasket 13 and the secondary gasket 14 are distinct from each other.

[0052] The primary gasket 13 and the secondary gasket 14 are integrally connected to the hydraulic chamber 5. Preferably, the primary and secondary gaskets 13, 14 are housed inside respective gasket seats formed in the hydraulic chamber 5.

[0053] Moreover, the primary gasket 13 and the secondary gasket 14 are positioned interposed between the hydraulic chamber 5, in particular between the guide surface 17 and the sliding wall 12.

[0054] The primary gasket 13 and the secondary gasket 14 are positioned coaxial to the actuation axis 4.

[0055] The primary gasket 13 is positioned opposite the electric motor 2 and / or the transmission 7, with respect to the secondary gasket 14. Consequently, the secondary gasket 14 is positioned interposed between the primary gasket 13 and the electric motor 2 and / or the transmission 7.

[0056] The primary gasket 13 is configured to allow the pressurisation of the hydraulic fluid 10. In particular, under normal or “by-wire” operating conditions, the primary gasket 13 is configured to sealingly separate a portion of the hydraulic chamber 5, within which pressurised hydraulic fluid 10 is present from an adjacent portion of the hydraulicchamber 5 within which unpressurised hydraulic fluid 10 is present. Therefore, the primary gasket 13 is configured to prevent leakages of pressurised hydraulic fluid 10.

[0057] The secondary gasket 14 is configured to sealingly separate a portion of the hydraulic chamber 5 within which unpressurised hydraulic fluid 10 is present from an adjacent portion of the hydraulic chamber 5 within which hydraulic fluid 10 is absent. Therefore, under normal or “by-wire” operating conditions, the secondary gasket 14 is configured to prevent leakages of unpressurised hydraulic fluid 10. Under “back-up” conditions, the secondary gasket 14 is configured to allow the pressurisation of the hydraulic fluid 10, preventing leakages of pressurised hydraulic fluid 10.

[0058] The primary gasket 13 and the secondary gasket 14 define, inside the hydraulic chamber 5, a feeding chamber 16.

[0059] The feeding chamber 16 therefore corresponds to a portion of the hydraulic chamber 5 extending, along the actuation axis 4, between the primary gasket 13 and the secondary gasket 14.

[0060] Moreover, the primary gasket 13 defines, inside the hydraulic chamber 5, a pressure chamber 18.

[0061] The pressure chamber 18 is opposite the feeding chamber 16 with respect to the primary gasket 13.

[0062] The pressure chamber 18 therefore corresponds to a portion of the hydraulic chamber 5 extending, along the actuation axis 4, from the primary gasket 13 in the direction opposite to the secondary gasket 14.

[0063] The braking system 1 further comprises a feeding pipe 15, configured to convey hydraulic fluid 10 into the hydraulic chamber 5.

[0064] For example, the feeding pipe 15 fluidly connects the hydraulic chamber 5 to a hydraulic fluid reservoir 10.

[0065] According to one embodiment, the feeding pipe 15 leads into the feeding chamber 16.

[0066] Advantageously, a braking system 1 thus configured does not require additional gaskets besides the primary and secondary gaskets 13, 14, so positioned. As no additional gaskets are required for generating the pressure of the hydraulic fluid 10 and for the sealing of the dry zone, devoid of hydraulic fluid 10, the translation component 9 is subjected to lower sliding friction, so that a smaller amount of power, received from the electric motor 2, is dissipated to overcome the resistance of the gaskets to the translatory motion of the translation component 9, and a greater amount of power is usable to actuate the braking assembly.

[0067] According to one embodiment, the primary gasket 13 and / or the secondary gasket 14 is a lip seal.

[0068] According to one embodiment, the braking system 1 does not comprise gaskets interposed between the sliding wall 12 and the hydraulic chamber 5, other than the primary gasket 13 and the secondary gasket 14.

[0069] According to one embodiment, the sliding wall 12 defines at least one through- hole 19, preferably a plurality of through-holes 19.

[0070] The at least one through-hole 19 extends through the sliding wall 12, at least in a direction transverse to the actuation axis 4.

[0071] The at least one through-hole 19 is configured to make a fluid connection between the feeding chamber 16 and the pressure chamber 18.

[0072] Advantageously, by means of the combined action of the at least one through- hole 19 and of the primary gasket 13, it is possible to fluidly connect the pressure chamber 18 to the feeding chamber 16, so as to feed the pressure chamber 18 with the hydraulic fluid 10 and, upon a determined translation of the translation component 9, to seal the pressure chamber 18 from the feeding chamber 16, so as to pressurise the hydraulic fluid 10 and actuate the braking assembly. With a further advantage, this configuration reduces the overall bulk of the braking system 1.

[0073] Specifically, the translation component 9 is translatable from a position in which the at least one through-hole 19 fluidly connects the pressure chamber 18 to the feeding chamber 16 to a position in which the primary gasket 13 closes the at least one through-hole 19, isolating or sealing the pressure chamber 18 from the feeding chamber 16. In particular, the isolation of the pressure chamber 18 from the feeding chamber 16 is achieved when the at least one through-hole 19 is positioned, with reference to the actuation axis 4, at the primary gasket 13 or at least partially beyond the primary gasket 13, that is, when the primary gasket 13 closes the at least one through-hole 19 and thus closes the fluid connection. Upon a further translation of the translation component 9, such as to position the at least one through-hole 19 beyond the primary gasket 13, the fluid connection remains prevented by the seal made by the primary gasket 13 and it is possible to pressurise the hydraulic fluid 10 in the pressure chamber 18.

[0074] According to one embodiment, when the translation component 9 is positioned in the maximum retraction position, the at least one through-hole 19 fluidly connects the pressure chamber 18 to the feeding chamber 16.

[0075] Advantageously, this configuration makes it possible to actuate the braking assembly also under “back-up” conditions, and in particular in the event of a failure ormalfunction of the electric motor 2 or of a control unit of the electric motor 2. In fact, in the absence of mechanical power induced by the electric motor 2, the braking assembly can still be actuated by means of, for example, a hydraulic back-up pump fluidly connected to the feeding pipe 15 or to the feeding chamber 16.

[0076] According to one embodiment, the braking system 1 comprises a hydraulic back-up pump fluidly connected to the feeding chamber 16.

[0077] According to one embodiment, the maximum retraction position corresponds to a resting position of the translation component 9. That is, in the absence of external forces induced by the electric motor 2, the translation component 9 is positioned in the resting position.

[0078] According to one embodiment, in the maximum retraction position, the at least one through-hole 19 is positioned interposed between the primary gasket 13 and the secondary gasket 14.

[0079] According to one embodiment, in the maximum retraction position, the at least one through-hole 19 is positioned interposed between the feeding pipe 15 and the primary gasket 13, with reference to the actuation axis 4. Advantageously, this configuration reduces the idle stroke of the translation component 9 required to perform braking.

[0080] According to one embodiment, in the maximum retraction position, a circumference coaxial to the actuation axis 4 and substantially interpolating the centre of the one or more through-holes 19 is interposed between a circumference coaxial to the actuation axis 4 and substantially interpolating the primary gasket 13 and a radial or transverse axis to the actuation axis 4 interpolating the extension of the feeding pipe 15 at its opening into the feeding chamber 16.

[0081] Advantageously, this configuration reduces the idle stroke of the translation component 9, and therefore the actuation times of the braking assembly, as the at least one through-hole 19 is also positioned, in the maximum retraction position, in proximity to the primary gasket 13. In this way, the distance necessarily travelable by the translation component 9 to begin the pressurisation of the hydraulic fluid 10 and thus actuate the braking assembly is reduced, that is, upon the axial overlap between the at least one through-hole 19 and the primary gasket 13.

[0082] According to one embodiment, the sliding wall 12 defines a plurality of through- holes 19 arranged circumferentially around the actuation axis 4, preferably positioned along a single circumference coaxial to the actuation axis 4.

[0083] According to one embodiment, the motion converter 6 is configured so that theaxial size of the sliding wall 12, that is, with reference to the actuation axis 4, is always superimposed on the axial size of the feeding chamber 16 along the entire stroke travelable by the sliding wall 12.

[0084] Therefore, along the entire stroke travelable by the translation component 9, between the maximum retraction position and the maximum extension position, the primary gasket 13 and the secondary gasket 14 are always in contact with the sliding wall 12.

[0085] Advantageously, this configuration ensures correct hydraulic sealing and greater service life of the components of the braking system 1 .

[0086] According to one embodiment, the rotation component 8 and the translation component 9 comprise at least one threaded wall. According to one embodiment, the axial size of the threaded wall of the rotation component 8 and of the translation component 9 is not superimposed on the axial size of the secondary gasket 14. Preferably, it is never superimposed along the entire stroke travelable by the translation component 9 between the maximum retraction position and the maximum extension position.

[0087] According to one embodiment, the pressure wall 11 is positioned comprised within the axial size of the sliding wall 12.

[0088] Advantageously, this configuration reduces the actuation times of the braking assembly.

[0089] According to one embodiment, the pressure wall 11 and an end portion of the sliding wall 12 define a blind hole 20 open in the direction opposite to the electric motor 2 and / or the transmission 7, that is, open towards the pressure chamber 18.

[0090] According to one embodiment, the at least one through-hole 19 is defined on the end portion of the sliding wall 12 which forms, together with the pressure wall 11 , the blind hole 20.

[0091] The sliding wall 12 also defines, in combination with the pressure wall 11 , a housing for the rotation component, opposite the blind hole 20 with respect to the pressure wall 11 . The rotation component 8 is housed in the rotation component housing. Advantageously, the pressure wall 11 and the primary and secondary gaskets 13, 14 separate the rotation component 8 from the hydraulic fluid 10.

[0092] According to one embodiment (fig. 7), the pressure wall 11 is integrally formed with the sliding wall 12. That is, the pressure wall 11 and the sliding wall 12 are formed as a single piece or in any case have structural continuity.

[0093] According to one embodiment (fig. 8), the translation component 9 comprisesa plug 21 , press-fitted inside the sliding wall 12. The plug 21 defines the pressure wall 11.

[0094] According to one embodiment (fig. 9), the translation component 9 comprises a plug 21 , screwed into the sliding wall 12. The plug 21 defines the pressure wall 11.

[0095] According to one embodiment (fig. 10), the translation component 9 comprises a plug 21 , fixed inside the sliding wall 12 by means of a fluid-tight mechanical retainer. The plug 21 defines the pressure wall 11.

[0096] According to one embodiment (fig. 11), the translation component 9 comprises a pressure gasket 22, fixed inside the sliding wall 12. The pressure gasket 22 defines the pressure wall 11.

[0097] According to one embodiment, the braking system 1 comprises a housing 23.

[0098] The housing 23 is connected to the hydraulic chamber 5, preferably it is positioned abutting against the hydraulic chamber 5.

[0099] The motion converter 6 is at least partially housed inside the housing 23.

[0100] Preferably, the transmission 7 and / or the electric motor 2 are housed inside the housing 23.

[0101] According to one embodiment, in the operating configuration, there is no hydraulic fluid 10 in the interior of the housing 23.

[0102] Advantageously, consequently, in the interior of the housing 23 there are no gaskets that could dissipate the energy coming from the electric motor 2.

[0103] According to one embodiment, in the translation component 9, for example a nut screw 26 of a ball screw 24 as described below, comprises an outer wall formed by a first outer wall portion 27 and a second outer wall portion 28, adjacent to each other.

[0104] The first outer wall portion 27 is positioned interposed between the electric motor 2, and / or the transmission 7, and the second outer wall portion 28.

[0105] According to one embodiment, the second outer wall portion 28 coincides with the sliding wall 12.

[0106] According to one embodiment, the first outer wall portion 27 has a greater radial size, that is, transverse to the actuation axis 4, than the radial size of the second outer wall portion 28.

[0107] Specifically, both the first outer wall portion 27 and the second outer wall portion 28 have a substantially cylindrical shape, extending coaxially to the actuation axis 4, and the diameter of the first outer wall portion 27 is greater than the diameter of the second outer wall portion 28.

[0108] In accordance with this embodiment, the first outer wall portion 27 and the second outer wall portion 28 define therebetween an abutment step 29, facing the hydraulic chamber 5.

[0109] Advantageously, the abutment step 29 is configured to determine the maximum extension position of the translation component 9, which corresponds to the position in which the abutment step 29 abuts, forming a mechanical stop, against the hydraulic chamber 5.

[0110] According to one embodiment, the motion converter 6 is a ball screw 24.

[0111] The ball screw 24 comprises a threaded shaft 25 and a nut screw 26 connected to each other.

[0112] In particular, the threaded shaft 25 and the nut screw 26 are coaxial to the actuation axis 4.

[0113] According to one embodiment, the threaded shaft 25 constitutes the rotation component 8, and the nut screw 26 constitutes the translation component 9.

[0114] According to an alternative embodiment, the threaded shaft 25 constitutes the translation component 9, and the nut screw 26 constitutes the rotation component 8.

[0115] According to one embodiment, the ball screw 24 is of the external recirculation type. That is, the balls of the ball screw 24 are deflected from the races and returned by the return tube of the ball guide, internally on the external part of the nut screw 26.

[0116] Advantageously, this configuration makes it possible to reduce the radial size of the ball screw 24.

[0117] According to one embodiment, the motion converter 6 is a screw-nut screw mechanism, formed by a screw and a nut screw meshed together. One of the screw or the nut screw forms the translation component 9, while the other of the screw or the nut screw forms the rotation component 8.

[0118] According to one embodiment, the motion converter 6 is a satellite roller screw, formed by a threaded shaft and a threaded screw meshed together by means of a plurality of threaded rollers. One of the screw or the nut screw forms the translation component 9, while the other of the screw or the nut screw forms the rotation component 8.

[0119] According to one embodiment, the motion converter 6 is a ball-in-ramp motion converter.

[0120] According to one embodiment, the braking system 1 comprises at least one braking assembly, which is configured to apply a braking force to a wheel or axle of avehicle.

[0121] By way of example, the braking assembly may comprise a disc brake comprising a brake caliper associated with a brake disc connected to a wheel of the vehicle.

[0122] The electromechanical actuation device 3 is configured to actuate the braking assembly. Moreover, the electromechanical actuation device 3 is fluidly connected to the braking assembly by means of the hydraulic chamber 5. In particular, the hydraulic chamber 5 comprises an outlet hole 30 which opens into the hydraulic chamber 5 and fluidly connects the hydraulic chamber 5 to the braking assembly.

[0123] Naturally, the person skilled in the art will be able to make changes or adaptations to the present invention, without however departing from the scope of the claims set out below.List of references1. Braking system2. Electric motor3. Electromechanical actuation device4. Actuation axis5. Hydraulic chamber6. Motion converter7. Transmission8. Rotation component9. Translation component10. Hydraulic fluid11. Pressure wall12. Sliding wall13. Primary gasket14. Secondary gasket15. Feeding pipe16. Feeding chamber17. Guide surface18. Pressure chamber19. Through-hole20. Blind hole21. Plug22. Pressure gasket23. Housing24. Ball screw25. Threaded shaft26. Nut screw27. First outer wall portion (of the translation component)28. Second outer wall portion (of the translation component)29. Abutment step30. Outlet hole

Claims

Claims1. A braking system (1) in particular of the Brake-By-Wire type, comprising:- an electromechanical actuation device (3), extending along an actuation axis (4);- a hydraulic chamber (5), extending substantially coaxial to the actuation axis (4), and configured to contain hydraulic fluid (10), wherein the electromechanical actuation device (3) is configured to actuate a braking assembly, and is fluidly connectable to the braking assembly by means of at least the hydraulic chamber (5), wherein the electromechanical actuation device (3) comprises:- an electric motor (2);- a motion converter (6), configured to transform a rotary motion into a translatory motion;- optionally, a transmission (7) interposed between the electric motor (2) and the motion converter (6), wherein the motion converter (6) comprises a rotation component (8) and a translation component (9) operatively connected to each other, wherein the rotation component (8) is configured to receive a rotary motion from either the electric motor (2) or the transmission (7), wherein the translation component (9) comprises a pressure wall (11) substantially transverse to the actuation axis (4), and a sliding wall (12) substantially parallel to the actuation axis (4), wherein the sliding wall (12) is at least partially slidingly housed inside the hydraulic chamber (5), so that a rotation of the rotation component (8) about the actuation axis (4) corresponds to a translation of the translation component (9) along the actuation axis (4), inside the hydraulic chamber (5), wherein the translation component (9) is translatable between a maximum retraction position and a maximum extension position, and wherein the pressure wall (11) is configured to act in pressure on the hydraulic fluid (10) containable in the hydraulic chamber (5), upon a translation of the translation component (9) toward the maximum extension position, so as to actuate the braking assembly.

2. A braking system (1) according to claim 1 , wherein the hydraulic chamber (5) comprises a guide surface (17) facing the actuation axis (4), wherein the braking system (1) comprises a primary gasket (13) and a secondary gasket (14) integrally connected to the hydraulic chamber (5),wherein the primary gasket (13) and the secondary gasket (14) are positioned to be interposed between the guide surface (17) and the sliding wall (12), wherein the primary gasket (13) is configured to prevent leakages of pressurized hydraulic fluid (10), and wherein the secondary gasket (14), under normal operating conditions, is configured to prevent leakages of unpressurized hydraulic fluid (10), and / or wherein, optionally, the primary gasket (13) and / or the secondary gasket (14) are a lip seal.

3. A braking system (1) according to claim 2, wherein the primary gasket (13) and the secondary gasket (14) define, inside the hydraulic chamber (5), a feeding chamber (16) extending along the actuation axis (4) between the primary gasket (13) and the secondary gasket (14), wherein the primary gasket (13) defines, inside the hydraulic chamber (5), a pressure chamber (18) extending along the actuation axis (4) from the primary gasket (13) in the direction opposite to the secondary gasket (14), wherein the braking system (1) further comprises a feeding pipe (15) configured to convey the hydraulic fluid (10) into the hydraulic body (5), and wherein the feeding pipe (15) leads into the feeding chamber (16).

4. A braking system (1) according to claim 2 or 3, not comprising gaskets interposed between the sliding wall (12) and the hydraulic chamber (5), in addition to the primary gasket (13) and the secondary gasket (14).

5. A braking system (1) according to claim 2, wherein the primary gasket (13) and the secondary gasket (14) define, inside the hydraulic chamber (5), a feeding chamber (16) extending along the actuation axis (4) between the primary gasket (13) and the secondary gasket (14), wherein the primary gasket (13) defines, inside the hydraulic chamber (5), a pressure chamber (18) extending along the actuation axis (4) from the primary gasket (13) in the direction opposite to the secondary gasket (14), wherein the sliding wall (12) defines at least one through-hole (19), preferably a plurality of through-holes (19), extending through the sliding wall (12) at least in the direction transverse to the actuation axis (4), wherein the at least one through-hole (19) is configured to make a fluid connection between the feeding chamber (16) and the pressure chamber (18),and wherein the translation component (9) is translatable from a position in which the at least one through-hole (19) fluidly connects the pressure chamber (18) to the feeding chamber (16) to a position in which the primary gasket (13) closes the at least one through-hole (19), isolating the pressure chamber (18) from the feeding chamber (16).

6. A braking system (1) according to claim 5, wherein when the translation component (9) is positioned in the maximum retraction position, the at least one through-hole (19) fluidly connects the pressure chamber (18) to the feeding chamber (16), and wherein, optionally, the braking system (1) comprises a hydraulic back-up pump fluidly connected to the feeding chamber (16), and wherein, optionally, the maximum retraction position corresponds to a resting position of the translation component (9).

7. A braking system (1) according to claim 5 or 6, wherein, in the maximum retraction position, the at least one through-hole (19) is positioned to be interposed between the primary gasket (13) and the secondary gasket (14).

8. A braking system (1) according to any one of claims 5 to 7, wherein, in the maximum retraction position, the at least one through-hole (19) is positioned to be interposed between the feeding pipe (15) and the primary gasket (13), with reference to the actuation axis (4).

9. A braking system (1) according to claim 2, wherein the primary gasket (13) and the secondary gasket (14) define, inside the hydraulic chamber (5), a feeding chamber (16) extending along the actuation axis (4) between the primary gasket (13) and the secondary gasket (14), wherein the primary gasket (13) defines, inside the hydraulic chamber (5), a pressure chamber (18) extending along the actuation axis (4) from the primary gasket (13) in the direction opposite to the secondary gasket (14), wherein the motion converter (6) is configured so that the axial size of the sliding wall (12) is always superimposed on the axial size of the feeding chamber (16) along the entire stroke travelable by the sliding wall (12), and / or wherein the rotation component (8) and the translation component (9) comprise at least one threaded wall, and wherein the axial size of the threaded wall of the rotation component (8) and the translation component (9) is not superimposed on the axial size of the secondary gasket (14).

10. A braking system (1) according to any one of the preceding claims, wherein the pressure wall (11) is positioned to be comprised within the axial size of the sliding wall (12), and / or wherein the pressure wall (11) and an end portion of the sliding wall (12) define a blind hole (20) open in the direction opposite to the electric motor (2) and / or the transmission (7), and wherein at least one through-hole (19) is defined on the end portion of the sliding wall (12) which forms the blind hole (20) together with the pressure wall (11).

11. A braking system (1) according to any one of the preceding claims, wherein the pressure wall (11) is integrally formed with the sliding wall (12), or wherein the translation component (9) comprises a plug (21) driven into the sliding wall (12), wherein the plug (21) defines the pressure wall (11), or wherein the translation component (9) comprises a plug (21) screwed into the sliding wall (12), wherein the plug (21) defines the pressure wall (11), or wherein the translation component (9) comprises a plug (21) fixed inside the sliding wall (12) by means of a fluid-tight mechanical retainer, wherein the plug (21) defines the pressure wall (11), or wherein the translation component (9) comprises a pressure gasket (22) fixed inside the sliding wall (12), wherein the pressure gasket (22) defines the pressure wall (11).

12. A braking system (1) according to any one of the preceding claims, comprising a housing (23) connected to the hydraulic chamber (5), preferably positioned to abut against the hydraulic chamber (5), wherein the motion converter (6) is at least partially housed inside the housing (23), wherein, optionally, the transmission (7) and / or the electric motor (2) are housed inside the housing (23), and wherein, in the operating configuration, the interior of the housing (23) is free from hydraulic fluid (10).

13. A braking system (1) according to any one of the preceding claims, wherein thetranslation component (9) comprises an outer wall formed by a first outer wall portion (27) and a second outer wall portion (28), wherein the first outer wall portion (27) is positioned to be interposed between the electric motor (2) and / or the transmission (7) and the second outer wall portion (28), wherein, preferably, the second outer wall portion (28) coincides with the sliding wall (12), wherein the first outer wall portion (27) has a greater radial size than the radial size of the second outer wall portion (28), so that the first outer wall portion (27) and the second outer wall portion (28) define an abutment step (29) facing the hydraulic chamber (5) therebetween, and wherein the abutment step (29) is configured to determine the maximum extension position of the translation component (9).

14. A braking system (1) according to any one of the preceding claims, wherein the motion converter (6) is a ball screw (24) comprising a threaded shaft (25) and a nut screw (26) connected to each other, wherein the threaded shaft (25) is the rotation component (8), and the nut screw (26) is the translation component (9), or wherein the threaded shaft (25) is the translation component (9), and the nut screw (26) is the rotation component (9), and wherein, preferably, the ball screw (24) is of the external recirculation type.

15. A braking system (1) according to any one of claims 1 to 13, wherein the motion converter (6) is a screw-nut screw mechanism formed by a screw and a nut screw meshed together, wherein one of the screw or the nut screw forms the translation component (9) while the other of the screw or the nut screw forms the rotation component (8), or wherein the motion converter (6) is a satellite roller screw formed by a threaded shaft and a threaded screw meshed together by means of a plurality of threaded rollers, wherein one of the screw or the nut screw forms the translation component (9) while the other of the screw or the nut screw forms the rotation component (8), or wherein the motion converter (6) is a ball-in-ramp motion converter.

16. A braking system (1) according to any one of the preceding claims, comprising at least one braking assembly configured to apply a braking force to a wheel or axle of avehicle, wherein the electromechanical actuation device (3) is configured to actuate the braking assembly, and is fluidly connected to the braking assembly by means of the first hydraulic chamber (5).

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