Electrohydraulic actuator for brake

Abstract

The invention relates to an electro-hydraulic actuator (100) for actuating a brake caliper, in particular for actuating a brake caliper of a disc brake of a vehicle having two or more wheels, comprising:-an electric motor (1) having a drive shaft (2); -a conversion mechanism (3) connected to the drive shaft (2) to convert a rotational movement of the drive shaft (2) into a linear translational movement of a float (4) of a hydraulic pump or brake master cylinder of the brake in an axial direction (X-X) to pressurize the brake fluid; -a first housing (5) configured to house the conversion mechanism (3) and to support a second housing (6) of the electric motor (1), the conversion mechanism (3) comprising:-a deceleration unit (7) having at least one output engagement (8), -a reduction unit (10) for reducing the rotational movement of the drive shaft (2) and transmitting the reduced rotational movement of the drive shaft (2) to at least one output engagement portion (8),-a conversion unit (10) for converting the rotational movement of the at least one output engagement portion (8) into a translational movement of the float (4), the conversion unit (10) comprises a rotating member (11) connected to the at least one output engagement portion (8) and a pushing member (12) capable of linear translation, where the rotating member (11) is mechanically coupled to the pushing member (12) to convert rotation of the rotating member (11) into linear translation of the pushing member (12), and where the pushing member (12) is mechanically coupled to the rotating member (11). The invention relates to a device (1) for rotating a float (4) in an axial direction (X-X), comprising:-a rotating member (11) connected to the float (4) in such a way as to allow displacement of the float (4) in the axial direction (X-X),-a bearing (9) connected to the rotating member (11) and to the first housing (5) in such a way as to allow rotation of the rotating member (11) relative to the first housing (5), the rotating member (11) being connected to the bearing (9) by means of mechanical interference coupling in such a way as to allow displacement of the float (4) in the axial direction (X-X), the bearing (9) being connected to the rotating member (11) in such a way as to allow rotation of the rotating member (11) relative to the first housing (5). And comprising a plastically deformed portion (33) in contact with the bearing (9) so as to avoid shape coupling such that the bearing (9) transmits torque to the rotating member (11) by means of mechanical interference coupling and such that the rotating member (11) is supported by the bearing (9), therefore, the restraining reaction of the conversion unit (10) caused by the action of the floating piece (4) on the brake fluid is directly released to the bearing (9).

Description

Technical Field

[0001] The invention relates to an electrohydraulic actuator for a brake, and to a braking system for a vehicle, preferably of the brake-by-wire type. Background Art

[0002] Braking systems of the "brake-by-wire" (BBW) type for automobiles are well known and widely used. A linear transducer connected to a brake pedal is configured to detect brake pedal travel and transmit an electrical signal indicative of a user's request for braking torque to a control unit. This control unit processes the transducer's signal and controls the electric motor of a hydraulic pump based on the required braking torque. The hydraulic pump, operated by the electric motor, pressurizes hydraulic fluid and delivers it to the hydraulic pressure unit of the vehicle's brakes.

[0003] Compared to conventional braking systems, in which the brake pedal acts directly on a hydraulic circuit, a "brake-by-wire" system offers the advantage of being able to generate and control the braking system's hydraulic pressure without relying on the force applied by the brake pedal. Furthermore, at least partially replacing the hydraulic circuit with an electric circuit allows for savings in hydraulic fluid, reduces weight, and reduces the environmental impact of the entire braking system.

[0004] Solutions are known for electrohydraulic actuators for hydraulic brakes, comprising an electric motor with a drive shaft and a conversion mechanism connected to the drive shaft for converting the rotational movement of the drive shaft into a translational movement configured to act on a translatable part of a hydraulic pump.

[0005] The conversion mechanism comprises a mechanically coupled rotating member and a pusher member adapted to linearly translate as the rotating member rotates. In known solutions, the rotating member is connected to a bearing so as to rotate relative to a housing of a linear actuator, thereby receiving the rotational motion of the drive shaft. The bearing is typically connected to a reduction gear, which allows the rotational motion of the drive shaft to be reduced and transmitted to the rotating member.

[0006] The conversion mechanism is subjected to a constraining reaction acting on the hydraulic pump transmitted by the translation portion, and the constraining reaction is discharged to the receiving portion of the linear actuator.

[0007] In known solutions, the rotating member is typically connected to the bearing by form coupling, wherein the bearing and the rotating member respectively comprise a polygonal coupling seat and a polygonal coupling pivot adapted for form coupling with each other, or vice versa. In such known solutions, an axial abutment surface is also provided between the bearing and the rotating member, so that the restraining reaction transmitted from the translatory part acting on the hydraulic pump is released to the bearing.

[0008] While these solutions are satisfactory for torque transmission from the motor to the rotating member, they do not prevent relative axial movement of the rotating member with respect to the bearing, which may cause the surfaces of the polygonal coupling seat and the polygonal coupling pivot to wear over time, thereby reducing the performance and reliability of the electro-hydraulic actuator.

[0009] Furthermore, it was found that providing an axial abutment surface between the rotating member and the bearing may result in misalignment between the rotating member and the bearing, thereby causing radial loads that impair the reliability of the electro-hydraulic actuator.

[0010] Therefore, the need is felt within the industry to produce electrohydraulic actuators for brakes provided with switching mechanisms that are in time safer and more reliable than known solutions.

[0011] There is a felt need within the industry to produce an electro-hydraulic actuator for brakes that allows for simplified assembly, reduced components, and reduced weight and size, while having the same performance as electro-hydraulic actuators for brakes.

[0012] There is therefore a strong need felt within the industry to provide solutions for electrohydraulic actuators that are more compact, lighter and have a small number of components compared to known solutions, at least with the same performance, while allowing simplified assembly. Summary of the Invention

[0013] The object of the present invention is to provide an electro-hydraulic actuator, preferably a linear actuator, for a braking system of a vehicle, for example of the brake-by-wire type.

[0014] This object and other objects and advantages are achieved by an electrohydraulic actuator according to claim 1 and a brake system according to claim 10 .

[0015] Advantageous embodiments are the subject matter of the dependent claims.

[0016] By means of the proposed solution, the machining of the components of the linear actuator can be simplified and the assembly thereof can be facilitated.

[0017] By means of the proposed solution, torque and force transmission can be allowed between the bearing and the rotating member via surfaces parallel to the thrust direction, thereby avoiding misalignment between the bearing and the rotating member.

[0018] By means of the proposed solution, a higher compactness of the electrohydraulic actuator can be ensured, thereby reducing the number of components compared to known solutions.

[0019] By means of the proposed solution, it is possible to ensure a simplified assembly of the mechanism for converting the rotational movement of the drive shaft into a translation of a translational portion acting on the brake fluid, while reducing the assembly time of an electrohydraulic actuator having the same performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Further features and advantages of the electro-hydraulic actuator and brake system will become apparent from the following description of a preferred embodiment given by way of non-limiting indication with reference to the accompanying drawings, in which:

[0021] - Figure 1 shows an axonometric view of an electro-hydraulic actuator for a brake system according to the present invention;

[0022] - Figure 2 Shown Figure 1 Exploded isometric view of the actuator, the exploded isometric view being cut along a cutting plane passing through the axial direction XX, in which the floating member adapted to act on the brake fluid is movable;

[0023] - Figure 3 A cross-sectional side view of an electro-hydraulic actuator is shown, the cross-sectional side view being taken along a plane passing through Figure 1 Sectioned by a cutting plane in the axial direction XX;

[0024] - Figure 4 Shown Figure 3 Details of the cross section in

[0025] - Figure 5 and Figure 6 An axially opposite isometric view of a gear of a reduction unit is shown, which is adapted to be constrained to a first housing portion of an electro-hydraulic actuator by being fitted with a bearing adapted to rotatably support a conversion unit, so as to axially lock the conversion unit and receive a restraining reaction transmitted from the conversion unit to the bearing;

[0026] - Figure 7 and Figure 8Axially opposite isometric views of a conversion unit are shown, such as a screw-nut assembly with recirculating balls, comprising: a rotating member, such as a screw, mechanically coupleable to a translating push member, such as a nut, for example by means of a plurality of balls, to allow the push member to translate when the rotating member rotates, the rotating member being adapted to receive the rotation of an electric motor; a push cap adapted to be integral with the push member and to be in contact with a floating member and to pressurize a brake fluid, for example in a pressure chamber connected to a brake device, and adapted to reduce friction between the rotating member and the push member; and an anti-rotation sleeve shaped to be inserted into a housing locked in a rotatable manner relative to a first housing and to guide the push member in a low-friction and rotationally anti-translational manner, for example by means of at least one or more corresponding flat surfaces thereof, in a form-coupling with the push member, for example by means of a form-coupling with the push member, for example by means of a form-coupling with at least one flat surface, preferably two flat surfaces;

[0027] - Figure 9 yes Figure 3 Detail of a section in which a bearing is shown, which is maintained in its axial position at least when subjected to a constraint reaction transmitted from the conversion unit to the bearing and from the constrained reduction unit to the first housing portion, and is configured to receive the constraint reaction transmitted from the conversion unit from the bearing. DETAILED DESCRIPTION

[0028] According to a general embodiment, an electrohydraulic actuator for actuating a brake caliper, in particular a brake caliper of a disc brake of a vehicle having two or more wheels, is generally indicated by the reference numeral 100 .

[0029] The electro-hydraulic actuator 100 includes an electric motor 1 having a drive shaft 2 .

[0030] The electrohydraulic actuator comprises a conversion mechanism 3 connected to the drive shaft 2 to convert the rotational movement of the drive shaft 2 into a linear translational movement of a float 4 of the hydraulic pump or master cylinder of said brake in the axial direction XX to pressurize the brake fluid.

[0031] The electro-hydraulic actuator includes a first housing portion 5 configured to accommodate the conversion mechanism 3 and support a second housing portion 6 of the electric motor 1. In an embodiment, the electro-hydraulic actuator 100 includes the second housing portion 6, wherein the second housing portion 6 is coupled to the first housing portion 5. According to an embodiment, the electro-hydraulic actuator 100 includes a sealing gasket 80 interposed between the second housing portion 6 and at least one shoulder of the first housing portion 5.

[0032] The conversion mechanism 3 includes a reduction unit 7 having at least one output engagement portion 8 and configured to decelerate the rotational motion of the drive shaft 2 and transmit the decelerated rotational motion of the drive shaft 2 to the at least one output engagement portion 8 .

[0033] The conversion mechanism 3 comprises a conversion unit 10 for converting the rotational movement of the at least one output coupling 8 into a translational movement of the floating element 4 .

[0034] The conversion unit 10 comprises a rotating member 11 connected to at least one output joint 8 and a pushing member 12 that can be linearly translated, wherein the rotating member 11 is mechanically coupled to the pushing member 12 to convert the rotation of the rotating member 11 into a linear translation of the pushing member 12, thereby allowing the floating part 4 to be displaced in the axial direction XX.

[0035] The conversion mechanism 3 includes a bearing 9 connected to the output coupling portion 8 , the rotating member 11 , and the first accommodation portion 5 to allow the rotating member 11 to rotate relative to the first accommodation portion 5 .

[0036] In an embodiment, by constraining the bearing 9 in the first housing 5, the bearing 9 is assembled (packed) between the first housing shoulder 15 and the reduction unit 7, so that the constrained reaction of the conversion unit 10 caused by the action of the floating member 4 on the brake fluid is directly released to the reduction unit 7.

[0037] By arranging the reduction unit 7 to be constrained to the first accommodation portion, the bearing can be constrained within the first accommodation portion without using additional mechanical stop components to lock the bearing 9 in the bearing seat portion defined by the first accommodation portion with a clearance equal to the assembly clearance or with no clearance.

[0038] In an embodiment, the reduction unit 7 is constrained to the first housing 5, thereby locking the bearing 9 with clearance in the bearing seat defined by the first housing, thereby leaving an assembly clearance between the reduction unit and the bearing 9. For example, the assembly clearance is defined by the axial distance between the bearing 9 when it directly or indirectly abuts the shoulder 15 of the first housing and the reduction unit when constrained in a fully assembled position with the first housing. For example, the assembly clearance is less than one millimeter, preferably less than half a millimeter. Thus, preload conditions, such as axial preload, on the bearing 9 and / or the reduction unit 7 can be avoided. The bearing 9 receives the restraint reaction of the conversion unit 10 caused by the action of the floating element 4 on the brake fluid, thereby restoring the assembly clearance and releasing directly onto the reduction unit 7, thereby abutting the reduction unit 7.

[0039] In an embodiment, the reduction unit 7 is constrained to the first housing 5 , abutting against the bearing 9 and locking the bearing 9 in a play-free manner in the bearing seat defined by the first housing.

[0040] In an embodiment, the reduction unit 7 includes at least one rotationally locked reduction gear 16. In an embodiment, the reduction gear 16 includes a reduction gear coupling portion 17 for forming an integral connection with the first housing portion 5 of the conversion mechanism 3, the reduction gear coupling portion being configured to constrain the at least one reduction gear 16 within the first housing portion 5, e.g., axially constrain the at least one reduction gear 16 to prevent axial movement.

[0041] By setting the reduction gear coupling portion 17, the reduction gear can be constrained to the first accommodating portion 5, thereby locking the rotational movement and axial movement of the reduction gear 16, so that the bearing 9 is locked in its seat with or without clearance, thereby directly releasing the constraint reaction caused by the action of the floating member 4 to the reduction gear 16.

[0042] According to an embodiment, the reduction gear coupling portion 17 comprises a thread. Thus, the reduction gear 16 and / or the crown gear 23 can be screwed into the first housing 5 until abutment is achieved, or until an assembly gap is left, with the reduction gear abutment portion abutting against the bearing 9, thereby ensuring axial fixation of both the reduction gear 16 and / or the crown gear 23 and the bearing.

[0043] In an embodiment, the reduction gear 16 comprises an abutment portion 18 adapted to abut against the bearing 9 , thereby forming an axial constraint on the bearing 9 .

[0044] In an embodiment, the bearing 9 is fastened between the abutment portion 18 and the first housing shoulder 15 with or without clearance, so that the restraining reaction of the conversion unit 10 due to the action of the floating member 4 on the brake fluid is released directly onto the abutment portion 18 and indirectly onto the first housing 5.

[0045] In an embodiment, the bearing 9 is a ball bearing.

[0046] In an embodiment, said reduction gear coupling portion 17 comprises at least one threaded portion 19 obtained on a radially outer reduction gear wall 21 of the reduction gear 16, which is adapted to be connected to a threaded counterpart 20 obtained on a first radial wall 22 of said first accommodation portion 5, thereby constraining the reduction gear 16 in the first accommodation portion 5, e.g. axially constraining the reduction gear 16 to prevent movement in the axial direction XX, e.g. until the reduction gear abutment portion 18 abuts against the bearing 9 or reaches a fully assembled position, e.g. against the first accommodation portion shoulder, thereby leaving an assembly gap between the reduction gear abutment portion 18 and the bearing 9.

[0047] In an embodiment, the reduction gear coupling portion 17 comprises a bayonet connection portion which is connected to a bayonet connection counterpart obtained in the first radial wall 22 of the first housing 5, thereby constraining the reduction gear 16 in the first housing 5, for example axially constraining the reduction gear 16 against movement in the axial direction XX until the reduction gear abutment portion 18 abuts against the bearing 9.

[0048] In the embodiment, the reduction gear abutment portion 18 is an annular surface that delimits the reduction gear 16 in the axial direction.

[0049] In an embodiment, said reduction unit 7 comprises a reduction gear 16 comprising a crown wheel 23 with integrated internal teeth and rotationally locked to the first housing 5 .

[0050] In the embodiment, the electric motor 1 and the conversion mechanism 3 are arranged in cascade along the axial direction XX.

[0051] In an embodiment, the bearing 9 comprises a fixed bearing part 13 that is rotationally locked to the first housing 5 and a rotating bearing part 14 that is rotatable relative to the fixed bearing part 13. In an embodiment, the fixed bearing part 13 is a ring. In an embodiment, the rotating bearing part 14 is a disk.

[0052] In an embodiment, the rotary bearing portion 14 is connected to the at least one output joint 8 so as to rotate integrally with the at least one output joint 8. In an embodiment, the rotary bearing portion 14 includes the output joint 8.

[0053] In the embodiment, the rotating member 11 is connected to the rotating bearing portion 14 to rotate integrally with the rotating bearing portion 14 .

[0054] In the embodiment, the bearing 9 is axially constrained within the first housing 5 , wherein the fixed bearing portion 13 abuts against the first housing shoulder 15 on one side and against the reduction gear abutment portion 18 of the reduction unit 7 on the other side.

[0055] In an embodiment, the crown gear 23 with internal teeth comprises a reduction gear coupling portion 17 for forming an integral connection with the first housing 5 , thereby axially locking the crown gear 23 in the first housing 5 .

[0056] In an embodiment, the crown gear 23 with internal teeth includes a reduction gear abutment portion 18, which is suitable for abutting the fixed bearing portion 13 and / or receiving the fixed bearing portion 13 in an abutting manner, thereby axially locking the bearing 9 in the first accommodation portion 5, so that the axial reaction of the conversion unit 10 caused by the action of the floating member 4 on the brake fluid is released onto the reduction gear abutment portion 18 of the crown gear 23.

[0057] In an embodiment, the crown gear 23 with internal teeth comprises an interlocking portion 25 adapted to interfere with a radially outer bearing wall 26 of the fixed bearing part 13 in order to radially secure the fixed bearing part 13. In an embodiment, the crown gear 23 with internal teeth comprises an interlocking portion 25 adapted to receive the radially outer bearing wall 26 of the fixed bearing part 13 with clearance in order to centre the axis distance of the pins of the bearing relative to the axis of the crown gear 23.

[0058] In an embodiment, the reduction gear abutment portion 18 forms a shoulder for the interlocking portion 25 , wherein the interlocking portion 25 protrudes axially from the reduction gear abutment portion 18 in a cantilevered manner.

[0059] In an embodiment, the interlocking portion 25 comprises a flared portion 27 adapted to receive and formed as a guiding cone for centrally inserting the fixed bearing part 13 into the interlocking portion 25 .

[0060] In an embodiment, said interlocking portion 25 comprises a contact portion 28 adapted to interfere with and / or face the radially outer bearing wall 26 of the fixed bearing part 13 to radially secure the fixed bearing part 13 and / or to center the bearing 9 relative to the crown wheel 23 .

[0061] In an embodiment, the crown wheel 23 comprises a central crown tooth portion 24 having internal teeth.

[0062] In an embodiment, the reduction gear coupling portion 17 extends axially over an axial coupling length L1 that is greater than the axial center length L2 along which the central crown gear portion 24 extends axially. In an embodiment, the crown gear 23 includes at least one connecting seat 29, for example, a blind hole formed on a surface axially opposite to the reduction gear abutment portion 18, which is adapted to receive a tool for connecting (e.g., screwing) the crown gear 23 to the first receiving portion 5. In an embodiment, the reduction gear coupling portion 17 extends axially over an axial coupling length L1 that is less than the axial center length L2 along which the central crown gear portion 24 extends axially.

[0063] In an embodiment, the reduction unit 7 includes a planetary reduction gear or a harmonic reduction gear.

[0064] In an embodiment, said reduction unit 7 comprises at least a first reduction portion comprising at least a first reduction stage operatively associated with a crown gear 23 having internal teeth.

[0065] In an embodiment, the reduction unit 7 comprises at least one planetary gear train 30, and a central pinion 31 having external teeth that is integral with and / or formed by the end of the drive shaft 2, wherein the planetary gears 9 of at least one planetary gear train 9 mesh with both the central pinion 31 and the crown gear 23.

[0066] In an embodiment, each planet gear 9 rotates about a planet gear pin or pivot 32. In an embodiment, each planet gear pin 32 is constrained to a rotating bearing portion 14. In an embodiment, the rotating bearing portion 14 comprises a satellite retaining plate. In an embodiment, each of the at least one output joint 8 comprises a planet gear pin 32. In an embodiment, each planet gear pin 32 rotates in the same circumferential direction about the axial direction XX.

[0067] In an embodiment, the rotating member 11 includes a shank portion 34. In an embodiment, the shank portion 34 has a side surface 35 that laterally delimits the shank portion. In an embodiment, the bearing 9 includes a connection hole defined by a connection hole surface 36. In an embodiment, the shank portion 34 is adapted to be connected to the connection hole.

[0068] In an embodiment, rotating member 11 is connected to bearing 9 via form-fitting coupling. In an embodiment, connection hole surface 36 and side surface 35 of handle portion 34 are polygonal surfaces suitable for form-fitting coupling. For example, connection hole surface 36 and side surface 35 of handle portion 34 are prismatic surfaces with a star-shaped base. According to an embodiment, handle portion 34 is a star-shaped prism. In an embodiment, the connection hole defines a star-shaped prism.

[0069] According to one aspect of the present invention, the rotating member 11 is connected to the bearing 9 by means of a mechanical interference coupling and includes a plastically deformed portion 33 in contact with the bearing 9, thereby avoiding form coupling, so that the bearing 9 transmits torque to the rotating member 11 by means of a mechanical interference coupling, and the rotating member 11 is supported by the bearing 9, thereby releasing the restraining reaction of the conversion unit 10 caused by the action of the floating member 4 on the brake fluid directly onto the bearing 9.

[0070] By providing a mechanical interference coupling, i.e., a force coupling, between the rotating components 11, such as a screw in a screw-nut assembly, the processing of the connection system between the rotating component 11 and the bearing 9 can be simplified, avoiding the need to make a polygonal geometric shape to couple a portion of the rotating component 11 to a portion of the bearing 9.

[0071] By providing a mechanical interference coupling, rotational torque and axial force can be transmitted between the rotating member 11 and the bearing 9 through the interference coupling portion of the rotating member 11 and the bearing 9 .

[0072] In an embodiment, the handle portion 34 is cylindrical. In an embodiment, the handle portion 34 has a shape that is not suitable for transmitting torque by form coupling.

[0073] In an embodiment, the connection hole surface 36 is a cylindrical surface.

[0074] In an embodiment, the handle portion 34 includes the plastic deformation portion 33 in contact with the connection hole surface 36 .

[0075] In an embodiment, the cylindrical surface of the connecting hole 36 and the cylindrical surface of the shank portion 34 are parallel to the pushing direction AA.

[0076] In an embodiment, the rotating member 11 includes a rotating body 37. In an embodiment, the handle portion 34 is connected to the rotating body 37 and extends from the rotating body 37 in a cantilever manner along the pushing direction AA.

[0077] In an embodiment, the rotating body 37 comprises a mechanical coupling device to the pushing member 12 .

[0078] In an embodiment, the rotating member 11 includes an annular valley 38 on the rotating body 37 , which surrounds the handle portion 34 .

[0079] In an embodiment, the rotating member includes an annular ridge 39 on the rotating body 37 , wherein the annular ridge 39 abuts against a bearing abutment surface 40 opposite to the reduction unit 7 along the pushing direction AA.

[0080] In an embodiment, the conversion unit 10 is a screw-nut assembly, preferably, the screw-nut assembly has circulating balls.

[0081] In an embodiment, the conversion unit 10 is a ball-in-ramp device.

[0082] In an embodiment, the rotating member 11 is a screw having a helical external thread. In an embodiment, the pushing member 12 is a nut having a helical internal thread. In an embodiment, the conversion unit 10 includes a plurality of balls 41 arranged to make contact between the helical internal thread and the helical external thread, wherein the pushing member 12 defines a recirculation channel for moving the balls 41.

[0083] In an embodiment, the conversion unit 10 has a central axis A which is parallel to or coincident with the axial direction XX.

[0084] In an embodiment, the conversion unit 10 comprises a push-type cap 42 integrally connected to the push-type member 12 such that it translates linearly and integrally with the push-type member 12 between the rest configuration and the push configuration.

[0085] In an embodiment, the push-type hat 42 is configured to be in contact with the float 4 and to transmit a pushing action to the float 4 .

[0086] In an embodiment, the pushing hat 42 extends from the pushing member 12 in a cantilever manner and forms a hat cavity 43 suitable for accommodating the rotating member 11 .

[0087] In an embodiment, the push-type cap 42 includes a cap side wall 44 and a cap bottom wall 45. The cap side wall 44 includes a cap inner surface 48 that radially delimits the cap cavity 43 and faces the rotating member 11 without mechanical coupling thereto. The cap bottom wall 45 includes a cap inner bottom surface 49 that axially delimits the cap cavity 43 and faces the free end 46 of the rotating member 11.

[0088] Hat bottom wall 45 includes a hat outer bottom surface 50 axially opposite to hat inner bottom surface 49 and configured to contact float 4 and transmit a pushing action to float 4 .

[0089] In an embodiment, the cap inner bottom surface 49 is tapered along the central axis A toward the free end 46 of the rotating member 11 to only partially and around the central axis A contact the free end 46 of the rotating member 11 .

[0090] In the rest configuration, the cap inner bottom surface 49 is in contact with the free end 46 , defining a mechanical stop for the electro-hydraulic actuator 100 .

[0091] In the pushing configuration, the hat outer bottom surface 50 and the float surface 4 are in contact, thereby transferring axial forces from the pushing member 12 to the float 4 .

[0092] By means of the contact along the central axis A between the inner bottom surface 49 of the tapered cap and the free end surface 46 facing the push cap 42, it is ensured that the mechanical stop for the electrohydraulic actuator is in its rest position, wherein the push member 12 is in its home position or zero position, from which it cannot be retracted further.

[0093] By contacting along the central axis A between the inner bottom surface 49 of the tapered cap and the free end surface 46 facing the push-type cap 42, the contact between the push-type cap 42 and the rotating member 11 can be limited to a surface portion about the central axis A that is smaller than a cross-section of the rotating member perpendicular to the axial direction XX and / or the exposed surface of the free end 46 of the rotating member 11 facing the axial direction XX. At most, the contact between the push-type cap 42 and the rotating member 11 can be limited to a surface portion coinciding with a contact point passing through the central axis A. Thus, by reducing the contact surface between the push-type cap 42 and the rotating member 11, translation of the push-type cap 42 under the action of the rotating member 11 can be facilitated after a mechanical stop is reached between the two components. In other words, the static friction torque between the free end 46 of the rotating member 11 and the push-type cap 46 that needs to be overcome to allow the rotating member 11 to rotate and the push-type cap 42 to translate accordingly can be reduced, thereby reducing or preventing jamming between the two contacting surfaces.

[0094] In an embodiment, the hat outer bottom surface 50 is tapered along said central axis A toward the float 4 so as to contact the float 4 only partially and around the central axis A.

[0095] In an embodiment, the hat-shaped member inner bottom surface 49 and the hat-shaped member outer bottom surface 50 taper in opposite directions along the central axis A toward the free end 46 of the rotating member 11 and toward the floating member 4, respectively, so as to only partially and around the central axis A contact the free end 46 of the rotating member 11 and the floating member 4, respectively.

[0096] By setting the outer bottom surface 50 of the cap-shaped member to taper in the direction of the floating member 4 along the axial direction XX relative to the central axis A, the translational force of the pushing cap-shaped member 42 generated by the coupling of the rotating member 11 and the pushing member 12 can be transmitted around the central axis A and at most on the central axis A.

[0097] In an embodiment, the hat inner bottom surface 49 is a curved surface that is centrally located on the central axis A. In an embodiment, the hat inner bottom surface 49 is a curved surface that is centrally located on the central axis A with its greatest extension. In an embodiment, the hat inner bottom surface 49 is a curved surface that has a radius R1 and is centrally located on the central axis A.

[0098] In an embodiment, the hat outer bottom surface 50 is a curved surface that is centrally located on the central axis A. In an embodiment, the hat outer bottom surface 50 is a curved surface that is centrally located on the central axis A at its greatest extension. In an embodiment, the hat outer bottom surface 50 is a curved surface that has a radius R2 and is centrally located on the central axis A.

[0099] In an embodiment, the radius R1 of the inner bottom surface 49 is smaller than the center radius R2 of the hat outer bottom surface 50 .

[0100] In an embodiment, the hat inner bottom surface 49 and the hat outer bottom surface 50 are curved surfaces having opposing concavities.

[0101] In an embodiment, the inner bottom surface 49 of the cap is at least partially a cover surface of a sphere and / or a spheroid and / or an ellipsoid whose maximum extension is centered on the central axis A and whose concave side faces the outer bottom surface 50 of the cap, so that the maximum extension of the inner bottom surface 49 of the cap is configured to contact the rotating member.

[0102] In an embodiment, the hat outer bottom surface 50 is at least partially a cover surface of a sphere and / or ellipsoid and / or ellipsoid with maximum extension centrally located on said central axis A and concavely facing the hat inner bottom surface 49 .

[0103] In an embodiment, the inner hat bottom surface 49 and the outer hat bottom surface 50 are at least partially axially opposite spheres and / or cap surfaces of a sphere and / or an ellipsoid with its apex located at said central axis A.

[0104] By providing a curved inner bottom surface 49 of the cap, the curvature can be increased and / or the radius of such a surface can be reduced, thereby promoting the push-type cap 42 to translate under the action of the rotating member 11 after reaching the mechanical stop between the two components, that is, the static friction torque between the free end 46 of the rotating member 11 and the push-type cap 46 that needs to be overcome can be reduced to allow the rotating member 11 to rotate and the push-type cap 42 to translate accordingly, thereby reducing or preventing jamming between the two contact surfaces.

[0105] In an embodiment, the free end 46 of the rotating member 11 includes a central free end surface 47. In an embodiment, the central free end surface 47 is flat and perpendicular to the central axis A. In an embodiment, the central free end surface 47 tapers along the central axis A toward the inner bottom surface 49 of the cap so as to only partially contact the inner bottom surface 49 of the cap around the central axis A. In an embodiment, the central free end surface 47 is a curved surface centered on the central axis A. In an embodiment, the central free end surface 47 is a curved surface centered on the central axis A. In an embodiment, the central free end surface 47 is a curved surface centered on the central axis A with its maximum extension. In an embodiment, the central free end surface 47 is a curved surface having a radius R3 and centered on the central axis A. In an embodiment, the central free end surface 47 is at least partially a cover surface of a sphere and / or ellipsoid and / or ellipsoid centered on the central axis A with its maximum extension.

[0106] In an embodiment, in the rest configuration, the hat inner bottom surface 49 is in contact with the central free end surface 47 .

[0107] In an embodiment, the float 4 defines a float coupling seat 79 adapted to partially house, with clearance, the push-on cap 42. The float 4 comprises a central float surface 51 defining the float coupling seat 79 in the axial direction.

[0108] In an embodiment, the central float surface 51 is flat and perpendicular to the central axis A.

[0109] In an embodiment, the central float surface 51 tapers along the central axis A toward the hat outer bottom surface 50 so as to only partially contact the hat outer bottom surface 50 about the central axis A. In an embodiment, the central float surface 51 is a curved surface centered on the central axis A. In an embodiment, the central float surface 51 is a curved surface centered on the central axis A. In an embodiment, the central float surface 51 is a curved surface centered on the central axis A with a maximum extension. In an embodiment, the central float surface 51 is a curved surface having a radius R3 and centered on the central axis A. In an embodiment, the central float surface 51 is at least partially a cap surface of a sphere and / or a spheroid and / or an ellipsoid centered on the central axis A with a maximum extension.

[0110] In the pushing configuration, the hat outer bottom surface 50 and the central float surface 51 are partially in contact, thereby transmitting axial forces from the pushing member 12 to the float 4 .

[0111] In an embodiment, the push-on cap 42 is made in one piece with the push-on member 12 .

[0112] In an embodiment, the push-type hat 42 is made as a single piece separately from the push-type member 12. In an embodiment, the push-type hat 42 and the push-type member 12 are made of different materials. In an embodiment, the push-type hat 42 is made of steel or aluminum, and the push-type member 12 is made of alloy steel.

[0113] In an embodiment, the push-type cap-shaped member 42 includes a cap-shaped member coupling portion 61, which is suitable for shape coupling to the push-type member coupling corresponding portion 62 of the push-type member 12. For example, the cap-shaped member coupling portion is suitable for shape coupling to the push-type member coupling corresponding portion 62 of the push-type member 12 by threaded coupling or by bayonet coupling or interference coupling.

[0114] In an embodiment, the hat coupling portion 61 is a radially outer thread formed on an end portion of the hat sidewall 44 on an outer side surface of the hat.

[0115] In the embodiment, the pushing member coupling counterpart 62 is formed on the radial inner surface of the pushing member 12 .

[0116] In an embodiment, each segment of the push-type cap 42 has a smaller radial dimension than each segment of the push-type member 12, so as to avoid direct or indirect interference of the cap side wall 44 with the first housing 5 or with the anti-rotation device 63, on which the push-type member 12 translates with low friction.

[0117] In an embodiment, each axial projection or orthogonal projection of the push-type cap 42 along the axial direction XX is completely housed in each section of the push-type member 12, thereby avoiding direct or indirect interference of the cap side wall 44 with the first housing 5 or with the anti-rotation device 63, on which the push-type member 12 translates with low friction.

[0118] By providing the push-type cap-shaped member 42, the axial extension of the push-type member 12 (such as a nut) can be limited, the weight of the conversion unit 10 can be limited, and the surface involving contact friction during the translation of the push-type member 42 can be limited to only the surface of the push-type member 42 that contacts the first accommodating portion 5 or the surface that contacts the anti-rotation device 63.

[0119] In an embodiment, the conversion unit 10 comprises an anti-rotation sleeve 63 which is housed in said first housing 5 and is constrained to the first housing 5 and is rotationally locked.

[0120] In an embodiment, the anti-rotation sleeve 63 delimits, via its anti-rotation side wall 71 , an open cavity suitable for accommodating the conversion unit 10 , so as to avoid direct contact between the push-type member 12 and the first housing 5 .

[0121] In an embodiment, the anti-rotation side wall 71 includes at least one flat linear anti-rotation surface 72 parallel to the axial direction XX, which is suitable for facing a corresponding flat linear push-type member surface 73 parallel to the axial direction XX and sliding on the corresponding flat linear push-type member surface 73 facing parallel to the axial direction XX.

[0122] In an embodiment, the anti-rotation side wall 71 comprises at least two flat rectilinear anti-rotation surfaces 72 parallel to the axial direction XX, which are adapted to face each other and slide with low friction on corresponding rectilinear flat pushing member surfaces 73 parallel to the axial direction XX.

[0123] In an embodiment, the anti-rotation sidewall 71 comprises at least one curvilinear anti-rotation surface 74 parallel to the axial direction XX, which connects the flat rectilinear anti-rotation surface 72 on the opposite side.

[0124] In an embodiment, the anti-rotation sidewall 71 includes at least two curved anti-rotation surfaces 74 parallel to the axial direction XX, the at least two curved anti-rotation surfaces connecting the linear anti-rotation surface 72 .

[0125] In an embodiment, the pushing member 12 includes a pushing member surface 75 adapted to face the curved anti-rotation surface 74 but not contact the curved anti-rotation surface 74 , such that the pushing member is in sliding contact with the linear anti-rotation surface 72 .

[0126] In an embodiment, two linear anti-rotation surfaces 72 face each other.

[0127] In an embodiment, the anti-rotation sidewall 71 includes a plurality of axial ribs 78 on the outside or radially outer side or on the opposite side of the defined open cavity. In an embodiment, the axial ribs 78 are configured to center the anti-rotation sleeve 63 housed in the first housing portion 5. In an embodiment, the axial ribs 78 are configured to contact the third radial wall 68 of the first housing portion defining the conversion unit seat 64 with clearance or interference, thereby connecting the anti-rotation sleeve 63 to the first housing portion 5 in a manner that rotationally locks the anti-rotation sleeve 63.

[0128] In an embodiment, the anti-rotation sleeve 63 comprises at least one fixing flange 76 projecting in a cantilevered manner from the anti-rotation side wall 71, wherein the fixing flange 76 is adapted to be integrally constrained to the first housing 5. In an embodiment, the fixing flange 76 is adapted to be inserted into corresponding seats obtained in the third radial wall 68 of the first housing and in the second shoulder 69 of the first housing.

[0129] In an embodiment, the anti-rotation sleeve 63 comprises two diametrically opposed fixing flanges 76 adapted to be inserted into suitable seats obtained in the third radial wall 68 of the first housing and in the second shoulder 69 of the first housing. In an embodiment, the fixing flanges 76 are coupled to the suitable seats in a form factor or mechanically by using fixing screws 77.

[0130] In an embodiment, the anti-rotation sleeve 63 is made of a low friction polymer material.

[0131] In an embodiment, the anti-rotation sleeve 63 is made of a metal material, such as steel or aluminum.

[0132] In the embodiment, the first accommodation portion 5 includes a first radial wall 22 defining a speed reduction unit seat 65 of the first accommodation portion.

[0133] In an embodiment, the first housing portion 5 comprises a second radial wall 67 defining a bearing seat portion 66 of the first housing portion.

[0134] In an embodiment, the first housing portion 5 comprises a third radial wall 68 of the first housing portion defining a conversion unit seat 64 .

[0135] In an embodiment, the conversion unit seat 64 is in communication with the floating member seat 104 and is in communication with the speed reduction unit seat 65 and the bearing seat 66 .

[0136] In an embodiment, the first radial wall 22 of the first housing portion is connected to the second radial wall 67 of the first housing portion by a first shoulder 15 of the first housing portion.

[0137] In an embodiment, the second radial wall 67 of the first housing is connected to the third radial wall 68 of the first housing by a second shoulder 69 of the first housing.

[0138] In an embodiment, the third radial wall 68 of the first receptacle is connected to the cylinder wall 104 via the third shoulder 70 of the first receptacle.

[0139] In the embodiment, the first accommodation portion 5 accommodates the reduction unit 7 , the conversion unit 10 and the floating member 4 in cascade along the axial direction XX.

[0140] In the embodiment, the first housing portion 5 defines, at one end thereof located downstream of the floating element 4 , an axial first housing portion opening 53 located on the side axially opposite to the electric motor 1 .

[0141] In an embodiment, the electro-hydraulic actuator 100 comprises a hydraulic cover 52 which is fluid-tightly connected to the first housing 5 to close the axial first housing opening 53. In an embodiment, the first housing 5 is made in a single piece.

[0142] In the embodiment, the hydraulic cover 53 is manufactured as an independent piece separated from the first accommodation portion 5 .

[0143] In an embodiment, the sum of the axial extensions of the reduction unit seat, the bearing seat and the conversion unit seat along the axial direction XX is greater than the axial extension of the floating element seat.

[0144] In an embodiment, the axial extension of the floating element seat is less than half the axial extension of the first housing 5 .

[0145] By providing the hydraulic cover 52, an electro-hydraulic actuator 100 having a first accommodation portion 5 can be manufactured, wherein the first accommodation portion 5 is made as a single piece and has a large extension along the axial direction XX, and the first accommodation portion is suitable for defining the floating member seat, the conversion unit seat, the bearing seat and the reduction unit seat, while ensuring that the cylinder wall of the floating member seat can be internally machined with high precision without the need for using working devices to pass through the reduction unit seat, the bearing seat and the conversion unit seat.

[0146] In the embodiment, the reduction unit 7 , the conversion unit 10 and the floating member 4 are coaxial.

[0147] In an embodiment, the electro-hydraulic actuator 100 includes an elastic element 54 accommodated in the first accommodation portion 5 and inserted between the hydraulic cover 52 and the floating member 4 , which constantly biases the floating member 4 in a direction opposite to the floating member feeding direction.

[0148] In an embodiment, the electro-hydraulic actuator 100 includes a hydraulic cover gasket 59 disposed between the hydraulic cover sidewall 60 of the hydraulic cover 52 and the cylinder wall 103 to form a seal in the pressure chamber 110 .

[0149] In an embodiment, the hydraulic cover 53 has a T-shaped cross section.

[0150] In an embodiment, the first housing 5 comprises a cylinder wall 103 which internally delimits a float seat 104 .

[0151] In an embodiment, the cylinder wall 103 defines a pressure chamber 110 that is fluidly connectable to a braking device. In an embodiment, the cylinder wall 103 defines a first stage pad seat 105 and a second stage pad seat 106 .

[0152] In an embodiment, the first housing 5 defines a supply conduit 111 fluidly connectable to a tank and / or a fluid inlet valve. The supply conduit 111 leads to a supply opening 112 on the cylinder wall 103 between the first and second stage liner seats 105, 106.

[0153] In an embodiment, the first stage gasket seat 105 is delimited radially by an axial seat wall 107 and axially by a first radial seat wall 108 and a second radial wall 109 connected to the axial seat wall 107 as an undercut.

[0154] In an embodiment, the electro-hydraulic actuator 100 includes a float 4. In an embodiment, the float 4 is slidably received in a float seat 104 in a sealing manner to pressurize a fluid in a pressure chamber 110 that is fluidically connectable to a brake device.

[0155] In an embodiment, the electro-hydraulic actuator 100 includes a first-stage gasket 1 .

[0156] In an embodiment, the first-stage gasket 1 is received in the first-stage gasket seat 105 with an axial gap between the first radial seat wall 108 and the second radial wall 109. In an embodiment, when the first-stage gasket 1 abuts the first radial seat wall 108, the first-stage gasket 1 is configured to form a seal with the floating member 102 and the first-stage seat axial wall 107, thereby fluidically isolating the pressure chamber 110 from the supply line 111. In an embodiment, when the first-stage gasket 1 abuts the second radial wall 109, the first-stage gasket 1 is configured to form a seal with the floating member 102, thereby avoiding forming a seal with the first-stage seat axial wall 107, thereby fluidly connecting the supply line 111 and the pressure chamber 110 to increase the fluid pressure in the pressure chamber. In an embodiment, the first-stage gasket is a triple-lip gasket.

[0157] In an embodiment, the electro-hydraulic actuator 100 includes a second-stage gasket 113, wherein the second-stage gasket 113 is received in the second-stage gasket seat 106 to form a static seal and a dynamic seal with the float 102 and the cylinder wall 103. In an embodiment, for example, the second-stage gasket 113 is a double-lip gasket.

[0158] According to an embodiment, the float 4 is axially movable between a float rest configuration and at least one advanced float configuration to pressurize a fluid, such as brake fluid, in the pressure chamber 110 .

[0159] In an embodiment, the float 4 comprises a first hollow float portion 55 delimited by a radial float wall 56. In an embodiment, the first hollow float portion 55 is in fluid connection with the pressure chamber 110. In an embodiment, the radial float wall 56 has at least one radial opening 57 therethrough.

[0160] In an embodiment, the float 4 and said radial float wall 56 delimit a second hollow float portion comprising a float coupling seat 79 .

[0161] In an embodiment, the float 4 comprises an axial float wall 58 , wherein the axial float wall 58 axially delimits the first hollow float portion 55 on one side and axially delimits the float coupling seat 79 on the opposite side.

[0162] In an embodiment, an elastic element 54 is inserted between the hydraulic cover 52 and the axial float wall 58 to constantly bias the float 4 in a direction opposite to the float feed direction.

[0163] In an embodiment, until the float 4 is arranged so that the through radial opening 57 is arranged between the first-stage gasket 112 and the second-stage gasket 113 , the pressure chamber 110 is in fluid communication with the supply duct 111 through the through radial opening 57 .

[0164] In an embodiment, when the float 4 is in the advanced float configuration, i.e., when the through radial opening 57 is arranged to be axially advanced relative to the first-stage gasket 112, the pressure chamber 110 is fluidly isolated from the supply conduit 111 by the first-stage gasket 112 in the fluid isolation configuration, and the float 4 pressurizes the fluid in the pressure chamber 110.

[0165] In an embodiment, when the fluid in the supply conduit 111 exceeds the pressure of the fluid in the pressure chamber 110 , the first stage gasket switches to the fluid communication configuration, thereby allowing the pressure in the pressure chamber 110 to increase.

[0166] In an embodiment, the first stage gasket 112 is axially movable in the first stage gasket seat 105 between a fluid isolation configuration in which the first stage gasket 112 forms a seal with the axial seat wall 107 and the first radial seat wall 108 and forms a seal with the float 4, and a fluid communication configuration in which the first stage gasket 112 is spaced apart from the axial wall 112, abuts against the second radial seat wall 112 to allow fluid to pass therethrough, and forms a seal with the float 4.

[0167] The present invention also relates to a braking system for a vehicle, comprising at least one electro-hydraulic actuator 100 according to any of the previously described embodiments, wherein the at least one hydraulic actuator 100 is hydraulically connected to at least one braking device, such as a brake caliper.

[0168] Reference numerals

[0169] 1 electric motor

[0170] 2 drive shaft

[0171] 3 Conversion mechanism

[0172] 4 floating parts

[0173] 5. First accommodating portion

[0174] 6. Second accommodating portion

[0175] 7 reduction unit

[0176] 8 Output shaft

[0177] 9 bearings

[0178] 10 conversion units

[0179] 11 Rotating components

[0180] 12 Translationally movable push-type components

[0181] 13 Fixed bearing part

[0182] 14 Rotating bearing part

[0183] 15 first shoulder of the first accommodating portion

[0184] 16 reduction gears

[0185] 17 reduction gear coupling part

[0186] 18 reduction gear abutment portion

[0187] 19 threaded part

[0188] 20 threaded counterpart

[0189] 21 radial outer reduction gear wall

[0190] 22 first radial wall of the first accommodating portion

[0191] 23 crown gears

[0192] 24 Central crown gear part

[0193] 25 interlocking parts

[0194] 26 radial outer bearing wall

[0195] 27 flared part

[0196] 28 contact part

[0197] 29 is used for the connection seat of a device

[0198] 30 planetary gears

[0199] 31 Central pinion

[0200] 32 planetary gear pins or pivots

[0201] 33 Plastic deformation part

[0202] 34 handle part

[0203] 35 handle side surface

[0204] 36 connection hole surface

[0205] 37 Rotating body

[0206] 38 Annular Valley

[0207] 39 annular ridge

[0208] 40 bearing abutment surface

[0209] 41 ball bearings

[0210] 42 push-type cap-shaped piece

[0211] 43 cap-shaped cavity

[0212] 44 hat-shaped part side wall

[0213] 45 cap-shaped bottom wall

[0214] 46 Free end

[0215] 47 Central free end surface

[0216] 48 inner surface of the cap

[0217] 49 inner bottom surface of the cap-shaped member

[0218] 50 outer bottom surface of the hat-shaped part

[0219] 51 Central floating part surface

[0220] 52 hydraulic cover

[0221] 53 Axial opening of the first accommodating portion

[0222] 54 elastic elements

[0223] 55 first hollow floating part

[0224] 56 radial floating wall

[0225] 57 through radial opening

[0226] 58 axial floating part wall

[0227] 59 hydraulic cover gasket

[0228] 60 hydraulic cover side wall

[0229] 61 cap-shaped coupling portion

[0230] 62 Push-type member coupled to corresponding part

[0231] 63 Anti-rotation sleeve or anti-rotation device

[0232] 64 conversion unit seat

[0233] 65 reduction unit seat

[0234] 66 bearing seat

[0235] 67 second radial wall of the first accommodating portion

[0236] 68 third radial wall of the first accommodating portion

[0237] 69 second shoulder of the first accommodating portion

[0238] 70 The third shoulder of the first accommodating portion

[0239] 71 anti-rotation sidewalls

[0240] 72 linear anti-rotation surface

[0241] 73 linear push-type component surface

[0242] 74 Curved anti-rotation surface

[0243] 75 Curved push-type component surface

[0244] 76 Fixing flange

[0245] 77 anti-rotation fixing screw

[0246] 78 axial ribs

[0247] 79 floating member coupling seat

[0248] 100 electro-hydraulic actuators

[0249] 103 cylinder wall

[0250] 104 floating member seat

[0251] 105 first-stage cushion seat

[0252] 106 second-stage cushion seat

[0253] 107 axial seat wall

[0254] 108 first radial seat wall

[0255] 109 second radial wall

[0256] 110 pressure chamber

[0257] 111 supply pipeline

[0258] 112 first level liner

[0259] 113 Second level liner

[0260] L1 axial coupling length

[0261] L2 axial center length

[0262] XX Axial direction

[0263] RR radial direction

[0264] A central axis.

Claims

1. An electro-hydraulic actuator (100) for actuating a brake caliper, in particular for actuating a brake caliper of a disc brake of a vehicle having two or more wheels, the electro-hydraulic actuator comprising: - an electric motor (1) having a drive shaft (2); - a conversion mechanism (3) connected to the drive shaft (2) for converting the rotational movement of the drive shaft (2) into a linear translational movement of a floating member (4) of a hydraulic pump or a master cylinder of the brake in an axial direction (XX) for pressurizing the brake fluid; a first housing (5) configured to house the conversion mechanism (3) and a second housing (6) supporting the electric motor (1), The conversion mechanism (3) comprises: a reduction unit (7) having at least one output coupling (8) and configured to decelerate the rotational motion of the drive shaft (2) and transmit the decelerated rotational motion of the drive shaft (2) to the at least one output coupling (8), a conversion unit (10) for converting the rotational movement of the at least one output engagement portion (8) into a translational movement of the floating member (4), the conversion unit (10) comprising a rotating member (11) connected to the at least one output engagement portion (8) and comprising a pushing member (12) capable of linear translation along the axial direction (XX), wherein the rotating member (11) is mechanically coupled to the pushing member (12) to convert the rotation of the rotating member (11) into a linear translation of the pushing member (12), thereby allowing the floating member (4) to be displaced in the axial direction (XX), a bearing (9) connected to the output coupling (8), the rotating member (11) and the first housing (5) to allow the rotating member (11) to rotate relative to the first housing (5), Its characteristics are: The rotating member (11) is connected to the bearing (9) by means of mechanical interference coupling and includes a plastically deformed portion (33) in contact with the bearing (9) to avoid form coupling, so that the bearing (9) transmits torque to the rotating member (11) by means of mechanical interference coupling, and the rotating member (11) is supported by the bearing (9), thereby directly releasing the restraining reaction of the conversion unit (10) caused by the action of the floating member (4) on the brake fluid to the bearing (9).

2. The electro-hydraulic actuator (100) according to the preceding claim, comprising at least one of the following features or a combination of the following features: in, The rotating member (11) includes a handle portion (34), wherein the handle portion (34) is cylindrical; wherein the bearing (9) comprises a connection hole defined by a connection hole surface (36), wherein the connection hole surface (36) is a cylindrical surface, and wherein the shank portion (34) comprises the plastic deformation portion (33) in contact with the connection hole surface (35).

3. Electrohydraulic actuator (100) according to the preceding claim, wherein The rotating member (11) comprises a rotating body (37), wherein the handle portion (34) is connected to the rotating body (37) and extends from the rotating body (37) in a cantilevered manner along a pushing direction (AA), wherein the rotating body (37) comprises a mechanical coupling device for coupling to the pushing member (12), The rotating member (11) includes an annular valley (38) on the rotating body (37), and the annular valley surrounds the handle portion (34). The rotating member (11) includes an annular ridge (39) on the rotating body (37), wherein the annular ridge (39) abuts against a bearing abutment surface (40) opposite to the reduction unit (7) along the pushing direction (AA).

4. The electro-hydraulic actuator (100) according to any one of the preceding claims, comprising at least one of the following features or a combination of the following features: in, The conversion unit (10) is a screw-nut assembly or a ball ramp device, preferably, the screw-nut assembly has circulating balls, and / or wherein, The rotating member (11) is a screw having a helical external thread, and wherein the pushing member (12) is a nut including a helical internal thread, wherein the conversion unit (10) includes a plurality of balls (41) arranged to make contact between the helical internal thread and the helical external thread.

5. The electro-hydraulic actuator (100) according to any one of the preceding claims, wherein: The conversion unit (10) has a central axis (A) parallel to or coinciding with the axial direction (XX), the conversion unit (10) comprising a push-type cap (42) integrally connected to the push-type member (12) so that the push-type cap translates linearly and firmly together with the push-type member (12) between a rest configuration and a push configuration, wherein the push-type cap-shaped member (42) is configured to contact the floating member (4) and transmit the pushing action to the floating member (4), The push-type cap-shaped member (42) extends from the push-type member (12) in a cantilever manner and forms a cap-shaped member cavity (43) suitable for accommodating the rotating member (11). The push-type cap-shaped member (42) comprises a cap-shaped member side wall (44) and a cap-shaped member bottom wall (45). wherein the cap sidewall (44) comprises a cap inner surface (48) which radially delimits the cap cavity (43) and faces the rotating member (11) without being mechanically coupled to the rotating member, wherein the cap bottom wall (45) comprises a cap inner bottom surface (49) which delimits the cap cavity (43) in the axial direction and faces the free end (46) of the rotating member (11), wherein the cap bottom wall (45) includes a cap outer bottom surface (50) which is axially opposite to the cap inner bottom surface (49) and is configured to contact the float (4) and transmit a pushing action to the float (4), Each section of the push-type cap-shaped member (42) has a smaller radial dimension than each section of the push-type member (12), thereby avoiding direct or indirect interference between the cap-shaped member side wall (44) and the first receiving portion (5) or the anti-rotation device (63), and the push-type member (12) translates on the anti-rotation device (63) with low friction.

6. Electrohydraulic actuator (100) according to the preceding claim, in, The cap inner bottom surface (49) tapers along the central axis (A) toward the free end (46) of the rotating member (11) to contact the free end (46) of the rotating member (11) only partially and around the central axis (A), wherein, in the stationary configuration, the cap inner bottom surface (49) contacts the free end (46) to define a mechanical stop of the electro-hydraulic actuator (100), and wherein, in the pushing configuration, the cap outer bottom surface (50) contacts the floating member (4) to transmit axial forces from the pushing member (12) to the floating member (4).

7. The electro-hydraulic actuator (100) according to any one of the preceding claims 5 to 6, comprising at least one of the following features or a combination of the following features: in, The cap outer bottom surface (50) tapers along the central axis (A) toward the floating member (4) to contact the floating member (4) only partially and around the central axis (A), wherein, in the pushing configuration, the cap outer bottom surface (50) and the floating member (4) are in contact around the central axis (A) to transmit an axial force from the pushing member (12) to the floating member (4), and / or wherein, The cap inner bottom surface (49) and the cap outer bottom surface (50) taper in opposite directions along the central axis (A) toward the free end (46) of the rotating member (11) and toward the floating member (4), respectively, so as to only partially and around the central axis (A) contact the free end (46) of the rotating member (11) and the floating member (4), respectively, wherein, in the stationary configuration, the cap inner bottom surface (49) contacts the free end (46) to define a mechanical stop of the electro-hydraulic actuator (100), and wherein, in the pushing configuration, the cap outer bottom surface (50) and the floating member (4) contact around the central axis (A) to transmit axial forces from the pushing member (12) to the floating member (4), and / or Wherein, the push-type cap-shaped member (42) includes a cap-shaped member coupling portion (61), and the cap-shaped member coupling portion is suitable for coupling to the push-type member coupling corresponding portion (62) of the push-type member (12). For example, the cap-shaped member coupling portion is suitable for coupling to the push-type member coupling corresponding portion (62) of the push-type member (12) through threaded coupling or bayonet coupling.

8. The electro-hydraulic actuator (100) according to the preceding claim, comprising at least one of the following features or a combination of the following features: in, The inner hat bottom surface (49) and the outer hat bottom surface (50) are at least partially axially opposite curved surfaces having their respective maximum extensions at the central axis (A), and / or wherein the free end (46) of the rotating member (11) comprises a central free end surface (47) that is flat and perpendicular to the central axis (A), wherein, in the stationary configuration, the cap inner bottom surface (49) is in contact with the central free end surface (47), and / or wherein the float (4) defines a float coupling seat (50) adapted to partially accommodate the push-type cap (42) with clearance, wherein the float (4) comprises a central float surface (51) axially defining the float coupling seat (50), wherein the central float surface (51) is flat and perpendicular to the central axis (A), Wherein, in the pushing configuration, the outer bottom surface (50) of the cap and the surface (51) of the central floating member are partially in contact, thereby transmitting the axial force from the pushing member (12) to the floating member (4).

9. The electro-hydraulic actuator (100) according to the preceding claim, comprising at least one of the following features or a combination of the following features: in, The first accommodation portion (5) accommodates the reduction unit (7), the bearing (9), the conversion unit (10) and the floating member (4) in a cascade manner along the axial direction (XX), wherein the axial direction (XX) is linear. wherein the conversion unit (10) comprises an anti-rotation sleeve (63) which is received in the first receiving portion (5) and is constrained to the first receiving portion (5) and is rotationally locked, wherein the anti-rotation sleeve (63) defines an open cavity suitable for accommodating the conversion unit (10) through its anti-rotation side wall (71) to avoid direct contact between the push-type member (12) and the first receiving portion (5), wherein the anti-rotation side wall (71) comprises at least two straight anti-rotation surfaces (72) parallel to the axial direction (XX), the at least two straight anti-rotation surfaces being adapted to face each other and to slide with low friction on corresponding straight push-type member surfaces (73) of the push-type member (12) parallel to the axial direction (XX), And / or wherein the bearing (9) is fitted between a first housing shoulder (15) and the reduction unit (7) so as to constrain the bearing (9) in the first housing (5) so that the constrained reaction of the conversion unit (10) caused by the action of the floating member (4) on the brake fluid is directly released onto the reduction unit (7).

10. A braking system for a vehicle, comprising at least one electro-hydraulic actuator (100) according to any one of the preceding claims, wherein: At least one of the hydraulic actuators (100) is hydraulically connected to at least one braking device, such as a brake caliper.

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