Actuating device for disc brake

Abstract

An actuating device (1) for a brake disc (2), comprising: a circulating ball screw-nut screw assembly (3), where the circulating ball screw-nut screw assembly (3) comprises a threaded shaft (4) and a nut screw (5) externally screwed onto the threaded shaft (4), where the thrust bearing (8) is mounted on the threaded shaft (4), where the thrust bearing (8) is mounted on the threaded shaft (4). The threaded shaft (4) and the nut screwing portion (5) extend in a direction of an actuation axis (6) coaxial with the threaded shaft (4), and wherein the threaded shaft (4) extends between a front end and a rear end of the threaded shaft (4), and wherein the nut screwing portion (5) is configured to receive a torque generated by a gear motor (7), and rotation of the nut screw (5) relative to the threaded shaft (4) causes the threaded shaft (4) to translate relative to the nut screw (5) in the direction of the actuation axis (6), the thrust bearing (8) providing a reaction stop for the nut screw (5) in the direction of the actuation axis (6), and the thrust bearing (8) being positioned within an extension of the threaded shaft (4) and between the front and rear ends of the threaded shaft (4).

Description

Technical Field

[0001] The invention relates to an actuating device for a disc brake, in particular an electromechanical disc brake, and also to a disc brake provided with such an actuating device. Background Art

[0002] A known actuating device for a disc brake comprises a gear motor associated with a recirculating ball screw-nut threading assembly, which is formed by a threaded shaft and a nut threading, and the recirculating ball screw-nut threading assembly converts the torque generated by the gear motor into a braking force against the pads of the disc brake.

[0003] It is known to apply a torque generated by a gear motor to a threaded shaft in order to translate a nut threaded portion in the direction of the pads of a disc brake, thereby generating a braking force.

[0004] These known actuating devices are mounted directly on an axial joint of the vehicle and thus become part of the unsprung weight of the vehicle.

[0005] Such a configuration implies several technical problems, including a large axial dimension at the axial joints of the vehicle and an undesirably large increase in the unsprung weight of the vehicle.

[0006] The larger axial dimension, ie the larger axial dimension in the direction in which the braking force is applied, results from the need to provide a thrust bearing at the rear end of the threaded shaft and a system for transmitting the torque generated by the gear motor.

[0007] A larger axial dimension would hamper the design of the wheel engagement, thus limiting the maximum steering capability of the vehicle.

[0008] Furthermore, greater weight has a negative impact on vehicle dynamics and leads to higher energy consumption and CO2 emissions.

[0009] An actuating device of this known type is described, for example, in WO2021229375A1. Summary of the invention

[0010] It is an object of the present invention to provide an actuating device for a disc brake having features such as to avoid at least some of the disadvantages present in the prior art.

[0011] A particular object of the invention is to provide an actuating device for a disc brake which has reduced axial dimensions and weight but with unchanged or improved efficiency.

[0012] These and other objects are achieved by an actuating device for a disc brake according to claim 1 .

[0013] The dependent claims relate to preferred and advantageous embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to better understand the present invention and appreciate its advantages, some non-limiting exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which:

[0015] - Figure 1 is a side view of a caliper for a disc brake according to an embodiment of the present invention taken along an axial cross section;

[0016] - Figure 2 is a top view of a caliper for a disc brake according to an embodiment of the present invention taken along an axial cross section;

[0017] - Figure 3 is a front perspective view of an actuating device for a disc brake according to an embodiment of the present invention;

[0018] - Figure 4 yes Figure 3 A rear perspective view of an actuating device for a disc brake as depicted in;

[0019] - Figure 5 yes Figure 3 A side view of an actuating device for a disc brake as depicted in;

[0020] - Figure 6 yes Figure 5 An axial cross-sectional view of an actuating device for a disc brake as depicted in;

[0021] - Figure 7 yes Figure 3 An exploded view of an actuating device for a disc brake as depicted in;

[0022] - Figure 8 yes Figure 4 An exploded view of the actuating device depicted in ;

[0023] - Fig.9A is a front perspective view of an actuating device for a disc brake according to an embodiment of the present invention;

[0024] - Fig. 9B yes Fig.9A A rear perspective view of an actuating device for a disc brake as depicted in;

[0025] - Fig. 9C yes Fig.9A An axial cross-sectional view of the actuator device depicted in ;

[0026] - Fig. 10Ais a front perspective view of an actuating device for a disc brake according to an embodiment of the present invention;

[0027] - Fig. 10B yes Fig. 10A A rear perspective view of an actuating device for a disc brake as depicted in;

[0028] - Fig. 10C yes Fig. 10A An axial cross-sectional view of the actuator device depicted in ;

[0029] Fig.11 is an axial cross-sectional view of an actuating device for a disc brake according to an embodiment of the present invention;

[0030] - Fig.12 is an axial cross-sectional view of an actuating device for a disc brake according to another embodiment of the present invention;

[0031] - Fig.13 is a front exploded view of an actuating device for a disc brake according to an embodiment of the present invention;

[0032] - Fig.14 yes Fig.13 Exploded rear view of the actuator depicted in . DETAILED DESCRIPTION

[0033] In the following description, unless otherwise specified, the term "front" orientation refers to the orientation of the side, face, surface, etc. in the advancing (braking) direction of the threaded shaft, and the term "rear" orientation refers to the orientation of the side, face, surface, etc. in the retracting direction of the threaded shaft. The terms "radial", "circumferential", and "axial" shall mean relative to the actuating axis of the threaded shaft, unless otherwise specified. "Translation" and "rotation" relative to the actuating axis or relative to the axial direction refer to the translation or rotation that rotates integrally with the threaded shaft of the circulating ball screw-nut screwing assembly relative to the axis and translates integrally with the circulating ball screw-nut screwing assembly. "Axial direction" refers to a direction parallel to or consistent with the actuating axis.

[0034] 1. Referring to the drawings, an actuating device 1 for a disc brake 2 includes a recirculating ball screw-nut threaded portion assembly 3 and a thrust bearing 8.

[0035] The recirculating ball screw-nut threaded part assembly 3 comprises a threaded shaft 4 which is screwed externally onto a threaded shaft 4 .

[0036] The threaded shaft 4 and the nut threaded portion 5 extend in the direction of an actuation axis 6 which is coaxial with the threaded shaft 4 .

[0037] The threaded shaft 4 extends between a front end portion of the threaded shaft 4 and a rear end portion of the threaded shaft 4 .

[0038] According to an aspect of the invention, the nut screw part 5 is configured to receive the torque generated by the gear motor 7 , and rotation of the nut screw part 5 relative to the threaded shaft 4 causes the threaded shaft 4 to translate relative to the nut screw part 5 in the direction of the actuation axis 6 .

[0039] Furthermore, the thrust bearing 8 is formed as a reaction rest for the nut screwing 5 in the direction of the actuation axis 6 .

[0040] Furthermore, a thrust bearing 8 is located in an extension of the threaded shaft 4 and between the front end portion and the rear end portion of the threaded shaft 4 .

[0041] Advantageously, the actuator 1 thus constructed has a small axial dimension. In fact, applying the torque of the gear motor 7 to the nut screwing 5 avoids placing the system for transmitting this torque at the rear end of the threaded shaft 4, thus reducing the axial dimension.

[0042] An additional advantage is that since the thrust bearing 8 is located within the axial extension of the threaded shaft 4 and between the front end and the rear end of the threaded shaft 4, the axial dimensions of the threaded shaft 4 and the thrust bearing 8 at least partially overlap, thereby reducing the axial dimension of the entire actuator 1.

[0043] According to an embodiment of the present invention, the threaded shaft 4 is positioned through the thrust bearing 8 .

[0044] Advantageously, this configuration eliminates the axial dimension of the thrust bearing 8 , since the thrust bearing 8 is completely contained within the axial dimension of the threaded shaft 4 .

[0045] According to an embodiment, the thrust bearing 8 comprises a first ring 9 and an opposite second ring 10 .

[0046] In the operating configuration, the first collar 9 rotates relative to the threaded shaft 4 , whereas the second collar 10 does not rotate relative to the threaded shaft 4 .

[0047] According to an embodiment, the first ring-shaped piece 9 of the thrust bearing 8 is formed as a single piece with the nut threading part 5 .

[0048] Advantageously, this configuration further reduces the axial dimensions of the actuator device 1 , since the dimensions caused by positioning a special rotating ring between the nut screw 5 and the second ring 10 , opposite thereto, are avoided.

[0049] Specifically, the thrust bearing 8 comprises a rolling member enclosed between two rolling tracks, of which a first rolling track 11 is defined by a first ring-shaped member 9 and a second rolling track 12 is defined by a second ring-shaped member 10 .

[0050] According to this embodiment, the nut threaded portion 5 defines a first rolling track 11 .

[0051] Alternatively, the thrust bearing 8 is distinct from the nut threaded part 5. Therefore, the first ring 9 of the thrust bearing 8 is distinct from the nut threaded part 5 and is positioned against the nut threaded part 5.

[0052] According to an embodiment, the thrust bearing 8 is a ball bearing. Alternatively, the thrust bearing 8 is a roller bearing.

[0053] According to an embodiment, the nut screwing part 5 is formed with external teeth 36 configured to receive torque from the gear motor.

[0054] According to an embodiment, the actuation device 1 comprises a force sensor 13 .

[0055] The force sensor 13 is configured to detect the braking force applied by the actuator device 1 .

[0056] Specifically, the force sensor 13 is configured to detect a force applied by the actuator device 1 in the axial direction.

[0057] According to an embodiment, the force sensor 13 is at least partially superposed on the threaded shaft 4 in the axial direction.

[0058] Advantageously, such a configuration further reduces the axial dimensions of the actuating device 1 , since the respective axial dimensions of the threaded shaft 4 and the force sensor 13 at least partially overlap.

[0059] According to a preferred embodiment, the force sensor 13 is substantially annular in shape. According to an embodiment, the threaded shaft 4 is positioned through the force sensor 13 .

[0060] Advantageously, this configuration eliminates the axial dimension of the force sensor 13 , since the force sensor 13 is completely superimposed on the axial dimension of the threaded shaft 4 .

[0061] According to an embodiment, the force sensor 13 is positioned adjacent to the thrust bearing 8 in a direction opposite to the nut threading 5 .

[0062] In particular, the force sensor 13 is adjacent to the second ring 10 of the thrust bearing 8 .

[0063] According to the present embodiment, the force sensor 13 is configured to detect the reaction force acting on the thrust bearing 8 .

[0064] Advantageously, by detecting the forces acting on the thrust bearing 8 , the force sensor 13 is able to determine the braking force applied by the actuating device 1 .

[0065] According to an alternative embodiment, the force sensor 13 is positioned behind the threaded shaft 4 and at the rear end thereof.

[0066] According to an embodiment, the force sensor 13 is substantially cylindrical, disc-shaped or axisymmetric in shape.

[0067] According to an embodiment, the actuating device 1 comprises a spacer 51 .

[0068] The spacer 51 is positioned coaxially with the threaded shaft 4 , and is interposed between the force sensor 13 and the thrust bearing 8 .

[0069] According to the present embodiment, the spacer 51 is configured to release the reaction force acting on the thrust bearing 8 to the force sensor 13 .

[0070] Advantageously, the force sensor 13 is able to determine the braking force applied by the actuating device 1 by detecting the force coming from the thrust bearing 8 and acting on the spacer 51 .

[0071] According to an embodiment, the spacer 51 is substantially cylindrical in shape.

[0072] According to the embodiment, the spacer 51 defines an accommodation groove, and the thrust bearing 8 is accommodated in the accommodation groove of the spacer 51 .

[0073] According to an embodiment, the actuating device 1 comprises a thrust plate 14 .

[0074] The thrust plate 14 is operatively connected to the front end of the threaded shaft 4 .

[0075] The thrust plate 14 is configured to receive a braking force from the threaded shaft 4 .

[0076] The braking force is generated by the translation of the threaded shaft 4 caused by the rotation of the nut screwing part 5 .

[0077] Furthermore, the thrust plate 14 is configured to release such braking force to the pad of the disc brake 2, thereby applying the braking force.

[0078] Preferably, the thrust plate 14 is made of steel. According to an alternative embodiment, the thrust plate 14 is made of aluminum or an aluminum alloy or other light alloys.

[0079] According to an embodiment, the actuating means comprise an engagement member 18 interposed between the threaded shaft 4 and the thrust plate 14 .

[0080] The engagement member 18 is configured to transmit force between the threaded shaft 4 and the thrust plate 14 .

[0081] Furthermore, the engagement member 18 is configured to allow and accommodate rotational and / or translational displacement of the thrust plate 14 relative to the threaded shaft 4 .

[0082] Advantageously, when the actuating device 1 is actuated to apply a braking force, the engagement member 18 allows the thrust plate 14 to be in full contact with the pad of the disc brake 2 , even if the caliper of the disc brake 2 is deflected by the force applied by the actuating device 1 .

[0083] An additional advantage is that the coupling element 18 avoids the generation of an unbalanced load on the recirculating ball screw-nut threading unit 3, which would otherwise cause the caliper of the disc brake 2 to deform under the action of the braking force.

[0084] According to the embodiment, the thrust plate 14 is formed with a front plate wall 15 and a rear plate wall 16 .

[0085] The front plate wall 15 faces the pad of the disc brake 2 , and the rear plate wall 16 faces the threaded shaft 4 .

[0086] The threaded shaft 14 is formed with a front shaft wall 17 that faces the rear plate wall 16 of the thrust plate 14 .

[0087] According to the present embodiment, the engaging member 18 is interposed between the rear plate wall 16 and the front axle wall 17 .

[0088] According to an embodiment, the engagement piece 18 is formed with a conical or frustoconical wall 19 which abuts against the thrust plate 14 and an opposite plane wall 20 which abuts against the threaded shaft 4 .

[0089] According to an embodiment, the rear panel wall 16 defines an engagement piece receiving portion 21 in which the engagement piece 18 is positioned.

[0090] According to an embodiment, the engagement member receiving portion 21 defines a concave surface associated with the engagement member 18 .

[0091] According to a preferred embodiment, the engagement member receiving portion 21 defines a spherical portion surface.

[0092] Advantageously, the geometric connection between the conical or truncated conical wall 19 of the coupling 18 and the spherical surface of the coupling accommodating portion 21 reduces radial loads acting on the circulating ball screw-nut screw assembly 3 and allows relative rotation and movement between the threaded shaft 4 and the thrust plate 14 and / or between the thrust plate 14 and the coupling 18.

[0093] According to an embodiment, the front shaft wall 17 and the plane wall 20 of the coupling member 18 are made so that: when the actuating device 1 is actuated to apply a braking force, the static friction generated between the front shaft wall 17 and the plane wall 20 is smaller than the static friction generated between the thrust plate 14 and the pad of the disc brake 2, or smaller than the static friction generated between the thrust plate 14 and the conical or frustoconical wall 19 of the coupling member 18.

[0094] Advantageously, the low friction between the front shaft wall 17 and the planar wall 20 reduces radial stresses acting on the recirculating ball screw-nut threading part assembly 3 .

[0095] In fact, the friction is so low that the engagement element 18 acts as a separation element between the threaded shaft 4 and the thrust plate 14 in the event of radial load peaks due to the thrust plate 14 coming into contact with the pads of the disc brake 2 .

[0096] According to such a configuration, during application of braking force, the pad of the disc brake 2 is not supported by the threaded shaft 4 but is always supported by the caliper of the disc brake 2. Therefore, the tangential force applied to the pad by the brake disc is released to the caliper of the disc brake 2, thereby allowing the radial load acting on the front shaft wall 17 to be reduced.

[0097] According to an embodiment, the actuating device 1 comprises a radial bearing 46 .

[0098] The radial bearing 46 is configured to withstand radial stresses acting on the actuating device 1 and arising from the transmission of torque from the gear motor to the actuating device 1 .

[0099] According to a preferred embodiment, the radial support 46 is connected externally to the nut screw part 5 .

[0100] Even more preferably, the radial support 46 is positioned adjacent to the thrust bearing 8 on the side facing the thrust plate 14 .

[0101] Advantageously, this configuration reduces the axial dimensions of the actuating device 1 .

[0102] Preferably, the radial support 46 is a "roller" type support. Alternatively, the radial support 46 is a ball bearing.

[0103] According to an embodiment, the threaded shaft 4 is at least partially hollow in the axial direction and is formed with an inner wall 23. The inner wall 23 defines a through cavity 24. Alternatively, the inner wall 23 defines an open blind cavity 41 at the front shaft wall 17.

[0104] According to an embodiment, the through cavity 24 extends between a front opening 25 defined at the front axial wall 17 and a rear opening 26 defined at the rear axial wall.

[0105] According to the embodiment, the inner wall 23 of the threaded shaft 4 is formed with a backing step portion 29 .

[0106] According to an embodiment, the backing step 29 defines a front cavity portion 30 extending between the backing step 29 and the front opening 25 and a rear cavity portion 31 extending between the backing step 29 and the rear opening 26 .

[0107] The radial cross section of the front cavity portion 30 is smaller than the radial cross section of the rear cavity portion 31 .

[0108] According to an embodiment, the actuating device 1 comprises a retaining screw 22 configured to connect the threaded shaft 4 in the axial direction to the thrust plate 14. Thus, by means of the retaining screw 22, a retraction of the threaded shaft 4 corresponds to a retraction of the thrust plate 14. Thus, the retaining screw 22 ensures that the thrust plate 14 is separated from the pads of the disc brake 2, thereby reducing any residual braking torque acting on the brake disc during non-operation of the actuating device 1.

[0109] Furthermore, the retaining screw 22 is formed with a screw head 27 and a threaded shank 28 .

[0110] According to an embodiment, the screw head 27 is connected to the threaded shaft 4 and is located inside the through cavity 24, and the screw head 27 has an axial clearance relative to the backing step 29, while the threaded shank 28 extends through the front cavity portion 30 and is connected to the thrust plate 14. Advantageously, the axial clearance of the screw head 27 relative to the backing step 29 allows the degree of freedom granted by the joint 18 to be preserved. The retaining screw 22 is configured to ensure that the retraction of the threaded shaft 4 also causes the retraction of the thrust plate 14.

[0111] According to an embodiment, the retaining screw 22 has an axial clearance and a radial clearance relative to the inner wall 23 of the threaded shaft 4 .

[0112] Advantageously, such a gap is configured to allow a rotational and / or translational displacement of the retaining screw 22 and therefore of the thrust plate 14 screwed to the retaining screw 22 relative to the threaded shaft 4 .

[0113] This effect is particularly advantageous in the case where the thrust plate 14 is completely adhered to the pad of the disc brake 2 during deformation of the caliper of the disc brake 2 under the action of braking forces.

[0114] According to an alternative embodiment, the actuating device 1 comprises a snap-on retaining connection 40 configured to connect the threaded shaft 4 to the thrust plate 14 in the axial direction.

[0115] The snap-retaining connector 40 includes a threaded shank 28 and a snap-connecting head 52 .

[0116] The threaded shank portion 28 is connected to the thrust plate 14 , and the snap-connection head 52 is snap-connected to the threaded shaft 4 .

[0117] According to an embodiment, the snap-retaining connector 40 is configured to be insertable into the blind cavity 41 by a snap-retaining connection, such that the snap-retaining connector 40 resists a pull-out force out of the blind cavity 41 .

[0118] According to an embodiment, the snap-fit ​​connection head 52 is located inside the blind cavity 41. The threaded shank 28 extends through the blind cavity 41, exits from the front axle wall 17, and is connected to the thrust plate 14.

[0119] The snap-retaining connection 40 is configured to ensure that retraction of the threaded shaft 4 results in retraction of the thrust plate 14. Thus, by means of the snap-retaining connection 40, retraction of the threaded shaft 4 corresponds to retraction of the thrust plate 14. Thus, the snap-retaining connection 40 ensures that the thrust plate 14 is separated from the pad of the disc brake 2, thereby reducing any residual braking torque acting on the brake disc during non-operation of the actuating device 1.

[0120] According to a preferred embodiment, the snap-connection head 52 comprises a plurality of petals 53 extending at least partially in a radial direction relative to the stem 28 .

[0121] The petal-shaped portion 53 is configured to be elastically biased when the petal-shaped portion 53 approaches the axis of the threaded rod portion 28. The snap-fit ​​connection head 52 and the petal-shaped portion 53 can thus be inserted into the blind cavity 41. Specifically, the petal-shaped portion 53 can be inserted beyond the backing step portion 29.

[0122] After the petal-shaped portion 53 is successfully inserted into the blind cavity 41, the petal-shaped portion 53 is configured to extend away from the axis of the threaded shank 28 to form a snap connection with the threaded shaft 4. Specifically, when the petal-shaped portion 53 passes through the backing step 29, the petal-shaped portion 53 releases its elastic potential energy, thereby extending again at least partially in the radial direction relative to the threaded shank 28.

[0123] Advantageously, this configuration of the snap-retaining connection 40 accommodates any rotational and / or translational displacement of the snap-retaining connection 40 and therefore of the thrust plate 14 screwed thereto, relative to the threaded shaft 4 .

[0124] According to another alternative embodiment, the actuating device 1 comprises a retaining pin 54 configured to connect the threaded shaft 4 to the thrust plate 14 in the axial direction.

[0125] The retaining pin 54 includes a threaded shank 28 and a pin head 55 .

[0126] According to an embodiment, the pin head 55 is coated with a polymer material. Preferably, the pin head 55 is coated with a rubber overmoulding.

[0127] According to an embodiment, the pin head 55 defines at least one ventilation hole 56 that passes through the pin head 55 in a direction parallel to the threaded shank 28 .

[0128] Preferably, the pin head 55 defines a plurality of ventilation holes 56 .

[0129] Advantageously, the pin head 55 coated with polymer material acts as a suction cup through the ventilation holes 56. Thus, the retaining pin 54 can be connected to the threaded shaft 4 by means of a "suction cup" effect, ie vacuum suction, through the pin head 55 thus configured.

[0130] Advantageously, this configuration of the retaining pin 54 adapts to any rotational and / or translational displacement of the retaining pin 54 and therefore of the thrust plate 14 screwed thereto, relative to the threaded shaft 4 .

[0131] According to an embodiment, the pin head 55 is located inside the blind cavity 41. The threaded shank 28 extends through the blind cavity 41, exits from the front axle wall 17, and connects to the thrust plate 14. According to this configuration, the pin head 55 adheres to the inner wall 23 defining the blind cavity 41 by a suction cup effect.

[0132] The retaining pin 54 is configured to ensure that retraction of the threaded shaft 4 results in retraction of the thrust plate 14. Thus, by means of the retaining pin 54, retraction of the threaded shaft 4 corresponds to retraction of the thrust plate 14. Thus, the connection of the retaining pin 54 ensures that the thrust plate 14 is decoupled from the pads of the disc brake 2, thereby reducing any residual braking torque acting on the brake disc during non-operation of the actuating device 1.

[0133] According to an embodiment, the rear plate wall 16 is formed with a nut-like screw-on portion 32 extending axially in the direction of the threaded shaft 4 .

[0134] According to this embodiment, the threaded shank 28 is screwed to the nut-like screw-on portion 32 of the thrust plate 14 .

[0135] Specifically, the threaded shank 28 of the retaining screw 22 , or the threaded shank 28 of the snap-retaining connection 40 , or the threaded shank 28 of the retaining pin 28 is screwed to the nut-type screwing portion 32 of the thrust plate 14 .

[0136] According to a preferred embodiment, the nut-type screw portion 32 extends through the front opening 25 of the threaded shaft 4 into the front cavity portion 30 .

[0137] According to an embodiment, the engagement piece 18 defines a through hole extending between the conical or frustoconical wall 19 and the planar wall 20 , and the nut-type screw-on portion 32 of the thrust plate 14 extends through the through hole.

[0138] According to an embodiment, the actuating device 1 comprises a plug 33 located inside the inner wall 23 of the threaded shaft 4 .

[0139] The plug 33 is configured to seal the through cavity 24 defined by the inner wall 23 .

[0140] Advantageously, the plug 33 prevents dust, moisture, liquid or external contaminants from entering through the gap between the retaining screw 22 and the inner wall 23 of the threaded shaft 4, or the gap between the snap-on retaining connector 40 and the inner wall 23, or the gap between the retaining pin 54 and the inner wall 23, which would otherwise damage the components of the actuator 1 located at the rear shaft wall.

[0141] According to a preferred embodiment, the plug-shaped member 33 is located inside the rear cavity portion 31 of the through hole 24 .

[0142] According to an embodiment, the plug 33 is located behind the threaded shaft 4 , at the rear wall of the threaded shaft 4 , inside the bushing 44 , and is configured to seal the rear wall of the threaded shaft 4 .

[0143] Advantageously, the plug 33 prevents dust, moisture, liquid or external contaminants from entering through the gap between the retaining screw 22 and the inner wall 23 of the threaded shaft 4, or the gap between the snap-on retaining connector 40 and the inner wall 23, or the gap between the retaining pin 54 and the inner wall 23, which would otherwise damage the components of the actuator 1 located at the rear shaft wall.

[0144] According to an embodiment, the actuating device 1 comprises a dynamic seal, which is located outside the nut threading 5 at the thrust plate 14 .

[0145] The dynamic seal is configured to achieve fluid sealing between the nut threading portion 5 and the thrust plate 14 .

[0146] According to another preferred embodiment, the dynamic seal is a "lip" type seal.

[0147] According to an embodiment, the actuating device 1 comprises a static seal 35 connected to the thrust plate 14 and extending radially outwards from the thrust plate 14 .

[0148] The static seal 35 is configured to achieve a fluid seal between the actuating device 1 and the pads of the disc brake 2 .

[0149] Advantageously, the static seal 35 protects the mechanical components of the actuating device 1 from contact with dust, moisture or other contaminants.

[0150] According to the embodiment, the nut screwing part 5 defines a circumferential accommodation part 37 . The circumferential accommodation part 37 is interposed between the outer tooth part 36 and the thrust plate 14 .

[0151] The static seal 35 is located in a circumferential receptacle 37 .

[0152] According to an embodiment, the thrust plate 14 defines a circumferential groove 38 extending inwardly from the thrust plate 14 in a radial direction.

[0153] According to the present embodiment, the static seal 35 is located in the circumferential accommodation portion 37 , and one end portion of the static seal 35 is inserted into the circumferential groove 38 .

[0154] According to another preferred embodiment, the static seal 35 is a “bellows” type seal.

[0155] According to an embodiment, the actuating device 1 comprises a locking ring 34 .

[0156] The locking ring 34 is located outside the nut screwing part 5. The locking ring 34 is interposed between the static seal 35 and the outer tooth portion 36 of the nut screwing part 5 and contacts with the static seal 35 and the outer tooth portion 36 of the nut screwing part 5.

[0157] The locking ring 34 is configured to hold the actuating device 1 at a predetermined position inside the caliper of the disc brake 2 .

[0158] According to an embodiment, one end of the locking ring 34 is positioned against the external toothing 36. Advantageously, this end against the external toothing 36 prevents any disassembly of the actuating device 1 due to vibrations that can be generated during its operation.

[0159] According to a preferred embodiment, the locking ring 34 has an "S-shaped" or "Z-shaped" profile in an axial section parallel to the actuation axis 6. According to this embodiment, one end of the locking ring 34 abuts against the static seal 35 and the other end of the locking ring abuts against the external toothing 36.

[0160] According to an embodiment, the actuating device 1 comprises anti-rotation means 39 .

[0161] The anti-rotation device 39 is configured to allow translation of the threaded shaft 4 in the axial direction and prevent rotation of the threaded shaft 4 around the axial direction.

[0162] Therefore, the anti-rotation device 39 is configured to prevent rotation of the nut screw portion 5 from rotating the threaded shaft 4 .

[0163] According to an embodiment, the anti-rotation means 39 comprises an anti-rotation pin 43 engaged on the threaded shaft 4 .

[0164] According to an embodiment, the anti-rotation means 39 further comprises a bushing 44. The bushing 44 is connected to the caliper of the disc brake 2 by an interference coupling.

[0165] The bushing 44 is connected to the threaded shaft 4. Specifically, the bushing 44 is connected to the threaded shaft 4 at the rear wall of the threaded shaft 4.

[0166] The bushing 44 defines a bushing insertion slot 45 which passes therethrough in a radial direction and extends in an axial direction.

[0167] According to the present embodiment, the anti-rotation pin 43 is engaged on the threaded shaft 4 and passes through the bushing slot 45 .

[0168] According to an embodiment, the bushing 44 is made of aluminum.

[0169] According to an embodiment, the thrust bearing 8 and / or the force sensor 13 are connected to the bushing 44 .

[0170] Preferably, the bushing 44 externally surrounds the threaded shaft 4 at its rear end.

[0171] According to an embodiment, the recirculating ball screw-nut threaded part assembly 3, the retaining screw 22 and the anti-rotation pin 43 are made of steel.

[0172] According to another aspect of the invention, the disc brake 2 comprises: a caliper 47 comprising two side walls spaced apart from each other, the side walls defining a disc space for accommodating a brake disc portion 49; a device for fixing the caliper to the vehicle; a connecting structure extending across the disc space and connecting the side walls to each other; at least one pad accommodating portion formed in each of the side walls and suitable for accommodating at least one pad 48; a thrust device constrained to one or both side walls and suitable for biasing the pad 48 against the brake disc 49 to clamp the brake disc 49, wherein the thrust device comprises the actuating device 1 as described above.

[0173] Furthermore, the disc brake 2 includes a gear motor 7 and a transmission system 50 configured to transmit mechanical power generated by the gear motor 7 to the nut screwing portion 5 of the actuating device 1 .

[0174] According to an embodiment, the transmission system 50 comprises a gear that meshes with the external toothing 36 of the nut screwing part 5 .

[0175] It is obvious that those skilled in the art will be able to make changes or modifications to the present invention without departing from the scope of the appended claims.

[0176] Reference numerals list

[0177] 1. Actuating device

[0178] 2. Disc brakes

[0179] 3. Circulating ball screw-nut screwing assembly

[0180] 4. Threaded shaft

[0181] 5. Nut screwing part

[0182] 6. Actuation axis

[0183] 7. Gear motor

[0184] 8.Thrust bearing

[0185] 9. First ring-shaped member

[0186] 10. Second ring-shaped member

[0187] 11. The first rolling track

[0188] 12. Second rolling track

[0189] 13. Force Sensor

[0190] 14.Thrust plate

[0191] 15.Front wall

[0192] 16. Rear wall

[0193] 17.Front axle wall

[0194] 18.Joints

[0195] 19. Conical or frustoconical wall

[0196] 20. Plane wall

[0197] 21.Joint member accommodating portion

[0198] 22.Retaining screw

[0199] 23. Inner wall

[0200] 24.Through cavity

[0201] 25. Front opening

[0202] 26. Rear opening

[0203] 27. Screw head

[0204] 28.Threaded rod

[0205] 29. Backing step

[0206] 30. Front cavity part

[0207] 31. Back cavity

[0208] 32. Nut type screwing part

[0209] 33. Plug

[0210] 34. Locking ring

[0211] 35.Static seals

[0212] 36. External teeth

[0213] 37. Circumferential accommodation portion

[0214] 38. Circumferential groove

[0215] 39. Anti-rotation device

[0216] 40. Snap-on retaining connector

[0217] 41. Blind cavity

[0218] 43. Anti-rotation pin

[0219] 44. Bushing

[0220] 45.Bushing slot

[0221] 46. ​​Radial support

[0222] 47. Calipers

[0223] 48. Pad

[0224] 49. Brake disc

[0225] 50. Transmission system

[0226] 51. Spacers

[0227] 52. Clip-on head connection

[0228] 53. Petal

[0229] 54. Keep Pin

[0230] 55. Pin Head

[0231] 56. Ventilation holes.

Claims

1. An actuating device (1) for a brake disc (2), the actuating device (1) comprising: - Circulating ball screw-nut screw assembly (3), - thrust bearing (8), The circulating ball screw-nut screwing part assembly (3) comprises a threaded shaft (4) and a nut screwing part (5) screwed externally onto the threaded shaft (4). wherein the threaded shaft (4) and the nut screwing portion (5) extend in the direction of an actuating axis (6) coaxial with the threaded shaft (4), and wherein the threaded shaft (4) extends between a front end portion of the threaded shaft (4) and a rear end portion of the threaded shaft (4), Features: - the nut screw part (5) is configured to receive a torque generated by a gear motor (7), and a rotation of the nut screw part (5) relative to the threaded shaft (4) causes a translation of the threaded shaft (4) relative to the nut screw part (5) in the direction of the actuation axis (6), - the thrust bearing (8) provides a reaction stop for the nut screwing part (5) in the direction of the actuation axis (6), The thrust bearing (8) is positioned in the extension of the threaded shaft (4) and between the front end and the rear end of the threaded shaft (4).

2. The actuating device (1) according to claim 1, wherein: The threaded shaft (4) is positioned to pass through the thrust bearing (8).

3. The actuating device (1) according to claim 1 or 2, wherein: The thrust bearing (8) comprises a first ring-shaped member (9) and an opposite second ring-shaped member (10), wherein, in the operating configuration, the first ring-shaped member (9) rotates relative to the threaded shaft (4), while the second ring-shaped member (10) does not rotate relative to the threaded shaft (4), And wherein, the first ring-shaped member (9) of the thrust bearing (8) and the nut screwing portion (5) are formed as an integral piece.

4. Actuating device (1) according to any one of the preceding claims, comprising a force sensor (13) configured to detect a force actuated by the actuating device (1) in an axial direction, in, The force sensor (13) is at least partially superposed on the threaded shaft (4) in the axial direction.

5. The actuating device (1) according to claim 4, wherein: The force sensor (13) has a generally annular shape, and wherein the threaded shaft (4) is positioned to pass through the force sensor (13).

6. Actuating device (1) according to claim 4 or 5, wherein: The force sensor (13) is positioned adjacent to the thrust bearing (8) in a direction opposite to the nut screwing portion (5), and wherein the force sensor (13) is configured to detect a reaction force acting on the thrust bearing (8).

7. The actuating device (1) according to any one of claims 1 to 3, comprising a force sensor (13) configured to detect a force actuated by the actuating device (1) in an axial direction, in, The force sensor (13) is positioned behind the threaded shaft (4) and at the rear end of the threaded shaft (4), And wherein, optionally, the force sensor (13) has a substantially cylindrical, disc-shaped or axisymmetric shape.

8. The actuating device (1) according to claim 7, comprising a spacer (51) positioned coaxially with the threaded shaft (4) and placed between the force sensor (13) and the thrust bearing (8), wherein: The spacer (51) is configured to release the reaction force acting on the thrust bearing (8) to the force sensor (13), And wherein, optionally, the spacer (51) defines a receiving groove, and the thrust bearing (8) is received in the receiving groove of the spacer (51).

9. Actuating device (1) according to any one of the preceding claims, comprising a thrust plate (14) operatively connected to the front end of the threaded shaft (4), The thrust plate (14) is configured to receive a braking force from the threaded shaft (4), wherein the braking force is generated by the translation of the threaded shaft (4) caused by the rotation of the nut screwing portion (5). The thrust plate (14) is configured to release the braking force to the pad of the disc brake (2) to generate a braking force, And among them, Optionally, the thrust plate (14) is made of steel.

10. The actuating device (1) according to claim 9, comprising a coupling member (18) disposed between the threaded shaft (4) and the thrust plate (14), wherein the coupling member (18) is configured as follows: - transmitting force between the threaded shaft (4) and the thrust plate (14); - Allowing and adapting to rotational and / or translational displacement of the thrust plate (14) relative to the threaded shaft (4).

11. Actuating device (1) according to claim 10, wherein: The thrust plate (14) is formed with a front plate wall (15) and a rear plate wall (16), wherein the front plate wall (15) faces the pad of the disc actuator (2), and the rear plate wall (16) faces the threaded shaft (4), The threaded shaft (4) is formed with a front shaft wall (17), and the front shaft wall (17) faces the rear plate wall (16) of the thrust plate (14). Wherein, the joint member (18) is placed between the rear plate wall (16) and the front shaft wall (17). And wherein the engagement member (18) is formed with: a conical or frustoconical wall (19) abutting against the thrust plate (14), and an opposite planar wall (20) abutting against the threaded shaft (4).

12. Actuating device (1) according to claim 11, wherein: The rear panel wall (16) defines a joint member receiving portion (21), in which the joint member (18) is positioned. and wherein the engagement member receiving portion (21) defines a concave surface associated with the engagement member (18), And, optionally, the engagement member receiving portion (21) defines a spherical surface.

13. Actuating device (1) according to claim 11 or 12, wherein: The front shaft wall (17) and the plane wall (20) of the engaging member (18) are made so that: when the actuating device (1) is actuated to generate a braking force, the static friction force generated between the front shaft wall (17) and the plane wall (20) is smaller than the static friction force generated between the thrust plate (14) and the pad of the disc brake (2), or the static friction force generated between the front shaft wall (17) and the plane wall (20) is smaller than the static friction force generated between the thrust plate (14) and the conical or frustoconical wall (19) of the engaging member (18).

14. Actuating device (1) according to any one of the preceding claims, comprising a radial bearing (46) configured to withstand radial stresses acting on the actuating device (1) and arising from the transmission of torque from the gear motor to the actuating device (1), in, Optionally, the radial support (46) is externally connected to the nut screwing part (5), And / or, the radial support (46) is positioned adjacent to the thrust bearing (8).

15. An actuating device (1) according to any one of claims 9 to 13, comprising a retaining screw (22), which is configured to connect the threaded shaft (4) to the thrust plate (14) in an axial direction so that retraction of the threaded shaft (4) corresponds to retraction of the thrust plate (14).

16. Actuating device (1) according to claim 15, wherein: The threaded shaft (4) is at least partially hollow in the axial direction and is formed with an inner wall (23), wherein the inner wall (23) defines a through cavity (24), the through cavity (24) extending between a front opening (25) defined at the front shaft wall (17) and a rear opening (26) defined at the rear shaft wall, The inner wall (23) is formed with a backing step portion (29), and the backing step portion (29) defines a front cavity portion (30) and a rear cavity portion (31), wherein the front cavity portion (30) extends between the backing step portion (29) and the front opening (25), and the rear cavity portion (31) extends between the backing step portion (29) and the rear opening (26), wherein a radial cross section of the front cavity portion (30) is smaller than a radial cross section of the rear cavity portion (31), The retaining screw (22) is formed with a screw head (27) and a threaded shaft (28). And wherein the screw head (27) is connected to the threaded shaft 4, and the screw head (27) is located in the through cavity (24), and the screw head (27) has an axial gap relative to the backing step portion (29), and the threaded rod portion (28) extends through the front cavity portion (30) and is connected to the thrust plate (14).

17. An actuating device (1) according to any one of claims 9 to 13, comprising a snap-on retaining connection (40) configured to connect the threaded shaft (4) to the thrust plate (14) in an axial direction, wherein: The snap-fit ​​retaining connector (40) comprises a threaded rod (28) and a snap-fit ​​connection head (52). And wherein the threaded rod portion (28) is connected to the thrust plate (14), and the snap-connection head (52) is snap-connected to the threaded shaft (4).

18. Actuating device (1) according to claim 17, wherein: The threaded shaft (4) is at least partially hollow in the axial direction and is formed with an inner wall (23), wherein the inner wall (23) defines a blind cavity (41) that is open at the front shaft wall (17), Wherein, the inner wall (23) is formed with a backing step portion (29), The snap-fit ​​retaining connector (40) is configured to be inserted into the blind cavity (41) by snap-fit ​​connection, so that the snap-fit ​​retaining connector (40) resists a pull-out force from the blind cavity (41). wherein the snap-fit ​​connection head (52) is located inside the blind cavity (41), and wherein the threaded rod (28) extends through the blind cavity (41), away from the front shaft wall (17), and is connected to the thrust plate (14), The snap-fit ​​connection head (52) comprises a plurality of petal-shaped portions (53), the petal-shaped portions (53) at least partially extending in a radial direction relative to the rod portion (28), and the petal-shaped portions (53) are configured to be elastically biased when the petal-shaped portions (53) approach the axis of the threaded rod portion (28), so that the snap-fit ​​connection head (52) and the petal-shaped portions (53) can be inserted into the blind cavity (41) and exceed the backing step portion (29), And wherein, after the petal-shaped portion (53) is successfully inserted into the blind cavity (41), the petal-shaped portion (53) is configured to extend away from the axis of the threaded rod portion (28) to form a snap-fit ​​connection with the threaded shaft (4).

19. The actuating device (1) according to any one of claims 9 to 13, comprising a retaining pin (54) configured to connect the threaded shaft (4) to the thrust plate (14) in an axial direction, wherein: The retaining pin (54) comprises a threaded shank (28) and a pin head (55). wherein the pin head (55) is coated with a polymer material and defines at least one ventilation hole (56) passing through the pin head (55) in a direction parallel to the threaded shank (28), And wherein the retaining pin (54) can be connected to the threaded shaft (4) by means of vacuum adhesion by means of the pin head (55).

20. Actuating device (1) according to claim 19, wherein: The threaded shaft (4) is at least partially hollow in the axial direction, and the threaded shaft (4) is formed with an inner wall (23), wherein the inner wall (23) defines a blind cavity (41) that is open at the front shaft wall (17), Wherein, the inner wall (23) is formed with a backing step portion (29), Wherein, the pin head (55) is located in the blind cavity (41), The threaded rod (28) extends through the blind cavity (41), leaves the front shaft wall (17), and is connected to the thrust plate (14). And wherein the pin head (55) adheres to the inner wall (23) defining the blind cavity (41) by suction.

21. Actuating device (1) according to any one of claims 15 to 20, wherein: The rear plate wall (16) is formed with a nut-type screwing portion (32) extending axially in the direction of the threaded shaft (4). And wherein the threaded rod (28) is screwed to the nut-type screwing portion (32) of the thrust plate (14).

22. Actuating device (1) according to any one of the preceding claims, comprising a plug-like member (33) located in the inner wall (23) of the threaded shaft (4), in, The plug-shaped member (33) is configured to seal the through cavity defined by the inner wall (23). Or wherein the plug-shaped member (33) is located behind the threaded shaft (4), at the rear wall of the threaded shaft (4), inside the bushing (44), and the plug-shaped member (33) is configured to seal the rear wall of the threaded shaft (4).

23. Actuating device (1) according to any one of claims 9 to 13, comprising a static seal (35) connected to the thrust plate (14) and extending radially outwards from the thrust plate (14), The static seal (35) is configured to form a fluid seal between the actuating device (1) and a pad of the disc brake (2), in, Optionally, the nut screwing portion (5) defines a circumferential accommodating portion (37), and the thrust plate (14) defines a circumferential groove (38) extending inwardly from the thrust plate (14) in a radial direction, and wherein the static seal (35) is located in the circumferential accommodating portion (37), and one end of the static seal (35) is inserted into the circumferential groove (38), And / or wherein the static gasket (35) is a "bellows" type seal.

24. The actuating device (1) according to claim 23, comprising a locking ring (34) located outside the nut screwing part (5), wherein: The locking ring (34) is disposed between and in contact with the static seal 35 and the outer teeth (36) of the nut threading portion (5), and wherein the locking ring (34) is configured to hold the actuating device (1) at a predetermined position within the caliper of the disc brake (2), And wherein, optionally, the locking ring (34) has an "S-shaped" or "Z-shaped" profile in an axial section parallel to the actuation axis (6), and one end of the locking ring (34) abuts against the static seal (35), and the opposite end of the locking ring abuts against the external toothed portion (36).

25. An actuating device (1) according to any one of the preceding claims, comprising an anti-rotation device (39), which is configured to allow translation of the threaded shaft (4) in the axial direction and prevent the threaded shaft (4) from rotating around the axial direction.

26. Actuating device (1) according to claim 25, wherein: The anti-rotation device (39) comprises an anti-rotation pin (43) and a bushing (44), wherein the anti-rotation pin (43) is engaged on the threaded shaft (4), and the bushing (44) is connected to the threaded shaft (4), preferably, the bushing (44) is connected to the threaded shaft (4) by means of an interference fit. The bushing (44) is defined with a bushing slot (45) passing through in the radial direction and extending along the axial direction. and wherein the anti-rotation pin (43) is coupled to the threaded shaft (4) and passes through the bushing slot (45), and wherein, optionally, the bushing (44) is made of aluminum, And / or wherein the thrust bearing (8) and / or the force sensor (13) are connected to the bushing (44).

27. A disc brake (2), comprising: A caliper (47) comprising two side walls spaced apart from each other, the side walls defining a disc space for accommodating a brake disc portion (49); means for securing the caliper to a vehicle; a connecting structure extending across the disc space and connecting the side walls to each other; at least one pad receiving portion formed in each of the side walls and adapted to receive at least one pad (48); thrust means constrained to one or both side walls and adapted to bias the pad (48) against the brake disc (49) to clamp the brake disc (49), wherein the thrust means comprises an actuating device (1) according to any one of the preceding claims, And optionally, the disc brake (2) includes a gear motor (7) and a transmission system (50), the transmission system (50) is configured to transmit the mechanical power generated by the gear motor (7) to the nut screwing part (5) of the actuating device (1), and the transmission system (50) includes a gear meshing with the external toothed part (36) of the nut screwing part (5).

Images