Electric disc brake actuator with vibration damping differential reduction gear, component, brake and

Abstract

The invention relates to a rotary drive reduction gear or reduction gear motor in an electric brake actuator. The invention relates to a planetary gear train comprising one or more planetary gear sets (2) parallel or coaxial to a linear actuation direction (500), said planetary gear sets having at least one rotationally fixed ring gear (21). The reduction gear comprises a damping device (204) at least partially made of an elastomeric material, said damping device being arranged around the fixed ring gear and being radially and / or axially compressed between the fixed ring gear and the brake housing (41). Generally, the reduction gear is a differential planetary gear set (2) driven by a sun gear having planetary gears (22) that mesh with both a fixed ring gear (21) and a movable ring gear (23). The latter drives a nut of a reversible screw-nut mechanism (3) generating a linear force. The overall irreversibility is generated by the differential gear set. The invention also relates to a component for determining a damper for implementing said reduction gear, to a motor unit comprising said damper, to a brake and to a method for assembling said damper.

Description

[0001] The invention relates to a rotary drive reduction gear or reduction gear motor in an electric brake actuator, which comprises one or more planetary gear sets parallel and / or coaxial to a linear actuation direction, the planetary gear set being provided with at least one rotationally fixed ring gear.

[0002] The reduction gear also includes a damping device at least partially made of an elastomeric material, which is arranged around the fixed ring gear and is radially and / or axially compressed between the fixed ring gear and the brake housing, thereby providing radial and / or axial vibration damping between the fixed ring gear and the brake housing.

[0003] Typically, the reduction gear is a differential planetary gear set driven by the sun gear, where the planetary gears mesh with both the fixed ring gear and the movable ring gear. The latter drives the nut in the reversible screw-nut mechanism, generating a linear force. The total irreversibility is generated by the differential gear set.

[0004] The invention also relates to components defining a damper for realizing the reduction gear, a motor unit including the damper, a brake and an assembly method thereof. Background Art

[0005] Various reduction gear and reduction gear motor configurations have been proposed for electric brake actuators, in particular for road vehicles, especially light vehicles and commercial vehicles.

[0006] In order to provide the linear force required to apply the brake pads, it is generally recommended to use a reduction gear comprising one or more planetary gear sets driven by a conventional rotary electric motor (e.g. a brushless DC motor or a brushed contactor). Such a planetary gear set comprises at least one central sun gear driving planetary gears which rotate around said central sun gear and mesh with the internal teeth of both the sun gear and the ring gear.

[0007] For example, they are driven on the input side by a sun gear, while the planetary gears are supported on a fixed ring gear to provide rotation on the output side via a planet carrier.

[0008] In some configurations, such as in document US4804073, the same set of planetary gears meshes simultaneously with a fixed annulus and a movable annulus, which have a different number of teeth from each other. Due to this difference, the rotation of the movable annulus obtained at the output has a very high reduction ratio. In this document, the motor is "end" mounted, coaxial with the differential reduction gear.

[0009] In other documents, such as document FR2999257A1, the motor shaft is parallel to the output of the reduction gear and is laterally offset from the output of the reduction gear.

[0010] However, these configurations have limitations and drawbacks in several aspects, such as their large axial or lateral dimensions, which make them difficult to integrate into vehicles. In addition, the vibrations generated in the reduction gear motor are a source of noise and wear, which can impair comfort and reliability.

[0011] In FR 3053422, it is proposed to add an external damper to the motor cover or the reduction gear motor housing. However, this type of solution has its disadvantages in terms of complexity and size, and even in terms of fragility in assembly and use.

[0012] One of the objects of the invention is to overcome all or part of the disadvantages of the prior art. In particular, the object is to minimize brake noise and wear due to vibrations while limiting size, fragility, integration and adaptation flexibility, manufacturing or assembly complexity, or optimizing the available compromises between these factors.

[0013] Also known from EP2824354 is a rotary reduction gear or reduction gear motor device for producing a linear displacement of a brake piston in an electric brake actuator, the device being integrated into the brake housing and comprising one or more epicyclic gear trains parallel or coaxial to the linear actuation direction, the epicyclic gear train using at least one fixed ring gear rotating relative to the brake housing, including a damping device at least partially made of elastomeric material and arranged around the main transmission. Summary of the invention

[0014] The invention provides a rotary drive reduction gear or reduction gear motor device for generating a linear displacement of a brake piston in an electric brake actuator, the device being integrated into a brake housing or intended to be mounted on the brake housing, wherein:

[0015] The device comprises one or more planetary gear sets parallel or coaxial with the linear actuation direction,

[0016] The one or more planetary gear sets utilize at least one ring gear that is fixed against rotation relative to the brake housing.

[0017] According to the present invention, the device comprises:

[0018] Damping device,

[0019] It is made at least partially of elastomeric material,

[0020] The damping device is arranged around the ring gear or is designed to be arranged in this way,

[0021] so as to be radially and / or axially compressed between the fixed gear ring and the brake housing, and

[0022] Radial and / or axial vibration damping is thereby provided between the stationary ring gear and the brake housing.

[0023] According to particular characteristics, the inner and / or outer surface of the damping device carries one or more radially projecting peripheral ribs which are radially compressed once in place, and in particular each of the peripheral ribs is continuous over the entire periphery, thereby producing an axial seal.

[0024] According to another feature, the damping device comprises a generally circular cylindrical sleeve surrounding the fixed gear ring or its support, the cylindrical sleeve having an axial bearing flange A1 , A2 at one or both ends of the cylinder so as to be axially compressed between the fixed gear ring and the brake housing.

[0025] More particularly, at least one axial bearing flange A1 has on its outer surface one or more at least axially extending lips A11 , A12 , A31 and A32 , which lips extend at least axially, in particular continuously over the entire periphery, so as to produce a radial seal.

[0026] Optionally, the damping device comprises an internal reinforcement member embedded in the elastomer, the rigidity and / or elasticity of the internal reinforcement member being greater than the rigidity and / or elasticity of the elastomer, and the internal reinforcement member is especially a metal reinforcement member.

[0027] According to another feature, the fixed annulus is held against rotation by an electric motor housing which alone directly or indirectly carries the electric motor driving the reduction gear, the electric motor housing forming an insert connected to the brake housing to compress the damping device.

[0028] According to a preferred set of embodiments, the device according to the invention comprises a so-called differential planetary reduction gear coaxial with the motor and driven at the input end by a sun gear, said sun gear driving a set of planetary gears, each of which meshes with both the fixed and movable ring gears, the fixed and movable ring gears having a different number of teeth from each other. On the output side, the movable ring gear rotates a screw-nut mechanism, in particular a reversible screw-nut mechanism, which generates a linear drive of the brake piston between a retracted position and an extended position, thereby exerting a linear pressure in the so-called forward direction to generate a clamping force on the disc between the clamping pads.

[0029] According to an advantageous feature, the differential planetary reduction gear sets in rotation a reversible screw-nut mechanism which converts the rotation into a linear displacement applied to the brake piston.

[0030] According to another advantageous feature, the ring gear of the differential planetary reduction gear rotates the nut of the screw-nut mechanism, which is held against translation by a shoulder formed in a recess in the caliper housing, while its screw is held stationary and non-rotating by a brake piston, thereby driving the translation by the rotation of the nut.

[0031] According to other aspects, the present invention also proposes:

[0032] A damping device arranged to implement a reduction gear or reduction gear motor arrangement as described herein.

[0033] A reduction gear motor arrangement for a brake actuator, characterized in that it comprises a reduction gear or a reduction gear motor arrangement as described herein.

[0034] A disc brake for a road vehicle, in particular a sliding or floating disc brake for a road vehicle or a motor vehicle, characterised in that it comprises a reduction gear or reduction gear motor arrangement as described herein.

[0035] According to yet another aspect, the invention proposes a method for fitting a vehicle, in particular a road vehicle, with brakes, characterized in that the method comprises:

[0036] mounting an electric motor carrying a sun gear shaft on a motor housing to form a motor unit, or providing such a motor unit; and

[0037] Assembling the motor housing of the motor unit to the brake housing,

[0038] A reduction gear as described herein is formed by interconnecting one or more parallel or coaxial planetary gear sets, the fixed ring gear of which is held against rotation by the motor housing,

[0039] The damping device is compressed radially and / or axially between the brake housing and the fixed gear ring or its support.

[0040] In particular, it is noted that the invention makes it possible to reduce the noise and wear caused in the rigid structure of the brake caliper due to the operation of the electric planetary gear set. This is particularly relevant in the case of such a differential reduction gear, which allows compactness and high force and stroke capacity while facilitating assembly and / or maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Other features and advantages will become apparent from the detailed description of a purely non-limiting embodiment and from the accompanying drawings, in which:

[0042] Figure 1 To illustrate the use of Figure 3A longitudinal cross-sectional zoom view of a sliding disc brake caliper of an electric actuator of a damping device, without showing the motor cover and the electronics, according to an example of an embodiment, with an input pinion mounted on the motor shaft in the stator;

[0043] Figure 2 is a longitudinal cross-sectional zoom diagram, according to Figure 1 A variation of the example showing the use of Figure 3 A sliding disc brake caliper having an electric actuator for a damping device, the motor housing being mounted around a recessed portion of a caliper housing;

[0044] Figure 3 is a longitudinal cross-sectional zoom view of a damping device used in an embodiment of the present invention;

[0045] Figure 4 To show Figure 2 A longitudinal cross-sectional view of the dynamics and distribution of the main components of the actuator shown in;

[0046] Figure 5 To show the motor cover and electronics without Figure 2 Isometric view of the motor with the reduction gear removed;

[0047] Figure 6 To show the basis Figure 4 A longitudinal cross-sectional view of the dynamics of the actuator and the distribution of the main components, a variant of the example shown, in which the rotor is mounted on an external bearing;

[0048] Figure 7 To show the basis Figure 6 A longitudinal cross-sectional view of the dynamics of the actuator and the distribution of the main components, in which the rotor bearing and the stationary ring gear are mounted on the same tube, which forms a common centering element assembled, for example, with the motor housing;

[0049] Figure 8 To show the basis Figure 2 , Figure 4 and Figure 5 or Figure 7 or Figure 8 an isometric view of a disc brake of the example shown;

[0050] Fig. 9 is a perspective exploded view to scale, showing Figure 2 and Figures 4 to 8 Assembly example of the actuator shown. DETAILED DESCRIPTION

[0051] The example of the embodiment proposed in this article is applicable to an electric actuator of a sliding disc brake caliper, wherein the reduction gear is a differential epicyclic type, wherein the planetary gears are meshed on a fixed ring gear and a movable ring gear, and the movable ring gear drives a nut in a reversible screw-nut mechanism made of a ball screw 313.

[0052] However, the invention is also applicable to irreversible screw-nut assemblies, or to non-differential planetary gear sets comprising at least one fixed ring gear. The fixed ring gear damping device is then mounted in a similar manner and / or with adaptations available to a person skilled in the art.

[0053] First embodiment

[0054] Figures 2 to 9 An example of a floating caliper disc brake with an electric actuator is shown, in which the input sun gear is fixedly mounted to a shaft 13 in the stator of a motor 11 .

[0055] Figure 4 The diagram shows Figure 2 Kinematics and structure of the example in . Figure 2 The kinematics of the example in also conforms to Figure 4 Figure in .

[0056] exist Figure 2 and Figure 4 In the example of the embodiment, the motor 1 is of the type with an inner stator 111 and an outer rotor (or "exo-rotor") 112, here taking a DC motor with permanent magnets in the stator and magnetic windings in the stator as an example. However, other known motor types may also be used, such as conventional outer rotor types.

[0057] The rotor 112 is fixed to the input sun gear 12 , which comprises a shaft 13 guided in rotation by rolling bearings 14 mounted in the tubular portion of the stator 111 .

[0058] Here, the fixed gear ring 21 is connected to the motor housing 10 by fitting within a skirt 102 that protrudes axially from the front of the motor housing. In this example, the fit is tight and anti-rotation is achieved by a mating shape (in this case, an axial protrusion 211) that protrudes from the fixed gear ring and fits into a void in the skirt 102. Once assembled, the fixed gear ring 21 is fitted into the hole at the entrance of the brake housing recess 410.

[0059] The input sun gear 12 meshes with a set of planet gears 22 which are held in a carrier of a planet carrier ring 220 .

[0060] These planetary gears 22 are long enough to mesh with a fixed annulus 21 and a movable annulus 23, coaxial with said fixed annulus and axially offset. In the present example, the fixed annulus 21 and the movable annulus 23 have the same internal diameter and both have a module compatible with the teeth of the satellite wheels, which is the same over the entire length of the satellite wheels.

[0061] In the present example, the movable ring gear 23 is guided in rotation, for example by lubricating friction, in a skirt 213 which projects axially from the fixed ring gear 21 and is coaxial therewith.

[0062] The number of teeth of the movable ring gear 23 is very close to that of the fixed ring gear 21, for example 4-5. It meshes with the planetary gears 22 supported on the fixed ring gear 21, in which case they have the same teeth, so the movable ring gear 23 is driven to rotate by the planetary gears at a very low speed compared to the speed of the input sun gear 12.

[0063] In this example, the motor 11 is connected in a motor housing 10, which is different from the caliper housing 41. The motor housing 10 has an axial skirt extending to the front side and fits around a portion 401 of the brake housing 41 forming a sleeve extending from the rear side. The interlock between the skirt and the sleeve 401 fixes the motor housing 10 to the caliper housing 41, here by anti-rotational engagement and translational retention with an external circlip 105.

[0064] The stator 111 of the motor 11 is sandwiched between a shoulder of the motor housing 10 and a shoulder of an intermediate cover 117, which also carries an electronic board 118 that controls the motor and integrates power electronics to power the windings. This intermediate cover 117 is closed at its rear end by a cover 119 that forms a heat radiator with the outside air to discharge the heat dissipated by the electronic board 118 through fins. This heat sink cover 119, for example made of a die-cast aluminum alloy, is in contact with the thermal components of the electronic board 118, usually through a thermally conductive paste.

[0065] The fixed gear ring 21 is arranged in a hole in a sleeve 401, which surrounds the brake housing recess 410. The fixed gear ring is radially retained by a radially damped cylindrical damper 204. The damper is made of an elastomeric material, and its cylindrical portion has a plurality of circumferential ribs which are compressed between the hole of the recess 410 and the surface of the skirt 213 of the fixed gear ring 21, providing sealing and radial damping.

[0066] On the front side, the end of the damper 204 is extended radially inwards by an annular constriction situated between the front end of the fixed toothed ring 21 and the shoulder of the recess 410 of the caliper housing 41. Advantageously, this annular constriction has concentric lips, here towards the front, which are compressed to promote sealing and axial damping.

[0067] At the rear, the end of the damper 204 is extended radially outwards by an annular flange which is sandwiched between the rear end of the sleeve 401 of the caliper housing 41 and the annular recess of the motor housing 10. Advantageously, this annular flange has concentric lips, here towards the rear, which are compressed to promote sealing and axial damping.

[0068] In this example, the lips A31 and A32 of the front bearing flange A3 bear on a sliding washer 402 which is free to rotate and bears axially on a shoulder formed in the caliper recess 410. The front end of the damping device 204 may also bear directly on such a shoulder.

[0069] In this way, the fixed ring gear 21 is held within the motor unit 1 by the motor housing 10 , with the damper 204 providing damping to prevent vibrations from being transmitted directly from the ring gear and possibly the motor housing 10 to the caliper housing 41 .

[0070] The movable ring gear 23 has a hole at the front with a longitudinal recess 231. The longitudinal recess 231 rotates the nut 31 of the screw-nut mechanism 3 via the longitudinal recess 312 supported on the outer surface of the nut 31.

[0071] The nut 31 of the screw-nut mechanism is fixed against translation and is driven in rotation by the movable ring gear 23 and meshes with the rotationally fixed screw 32 to move the screw in translation.

[0072] Thus, the rotation of the nut 31 produces a linear drive of the screw 32 in a tightening direction F1 or in an opposite withdrawal direction, depending on the direction of rotation of the motor.

[0073] The nut 31 is guided in rotation by a rolling bearing 412 (in this case a roller bearing) mounted in a hole 410 of the caliper housing 41. The nut 31 is secured in axial translation in the tightening direction by an axial bearing surface against a shoulder facing forward of the caliper housing 41, by means of the rolling bearing 411 arranged between this shoulder and a bearing flange 311 around the nut 32.

[0074] This screw 32 of the screw-nut mechanism 3 is fixed to a support plate 33 acting as a brake piston, which transmits a linear drive to at least one clamping pad 502 , thereby generating a clamping force F1 on a disk 509 between the clamping pads 502 , 503 .

[0075] The input sun gear 32 has an axial recess 120 which is open on the front side and is designed to receive the screw 32 when the screw-nut mechanism 3 is in the retracted position (as shown in the figure).

[0076] The support plate 33 here is basically disc-shaped, and covers the meshing area between the screw rod and the nut, and in a sense, the support plate 33 radially protrudes beyond the meshing area. Here, it is surrounded by a bellows seal 413.

[0077] In the tightening direction, the piston plate 32 receives direct axial bearing of the screw 32 from the screw-nut mechanism. It is connected to the end of the screw 32 by an axial fastener (in this case a central screw 333), which provides traction on the plate when the screw moves in the withdrawal direction. The anti-rotation form 323 carried by the end of the screw 32 cooperates with a complementary structure carried by the back of the piston plate 33 to ensure rotational attachment. This itself is held in rotation by anti-rotation recesses 335. These are held in a known manner against rotation by studs protruding from the back of the internal clamping pad 502, which itself is held in the bracket 501.

[0078] As we understand, the damping sleeve 204 prevents vibrations generated at the fixed ring gear 21 from being directly transmitted to the sleeve 401 of the caliper housing 41 and limits the transmission of vibrations generated upstream of the motor and the transmission system.

[0079] It also allows the stationary ring gear 21 to naturally assume the centering position imposed thereon by the motor housing 10 without being overly constrained by the surface finish or internal geometry of the caliper recess 410 .

[0080] The radial ribs A21 and the axial lips A11 , A12 , A31 , A32 improve damping due to their inherent elasticity and the surrounding deformation clearances. They also help seal the caliper housing 41 from dust and fluids inside the epicyclic differential gear set.

[0081] exist Figure 2 In the example shown, the motor housing 10 is flatly mounted and axially supported on the caliper housing 41, with its back side surrounding the rear recess 410 accommodating the reduction gear 2, and is fixed, for example, by known methods. According to a particular feature, the motor housing 10 is engaged with the caliper housing 41 by means of a centering device, for example of known type.

[0082] Second embodiment

[0083] Figure 6 A second exemplary embodiment is shown and only the differences are described.

[0084] In this case, the motor 11 is also of external type with an outer rotor 112 and an inner stator 111. Unlike the first disclosed example, this time the outer rotor is guided from the outside. It is mounted in roller or needle bearings 15, which are themselves mounted in holes (recesses 110) in the motor housing 10. This feature is intended to be combined with the various variants described herein for the rest of the actuator.

[0085] Such external guidance is rarely, if ever, used in this type of environment, for example because the location of the bearings is typically inside the motor, limiting the speed at which the bearing components can move linearly relative to each other.

[0086] However, in this example, despite the additional radial space created by the outer bearing, this layout offers new advantages, especially for this type of actuator. In fact, by extending the recess 120 created in the center of the sun gear 12, the space freed up in the center of the motor extends the stroke of the screw 32 when the screw is retracted.

[0087] Furthermore, the choice of guiding the rotor from the outside improves the accuracy of the centering of the rotor relative to the centering support 101 formed for it by the motor housing 10, and therefore also the centering accuracy relative to the fixed ring gear 21 fixed to the motor housing (see reference numeral 162, corresponding to the common centering support part). This improved centering reduces the manufacturing accuracy requirements and improves, for example, the acoustic and wear properties, in particular for such a differential reduction gear with two different ring gears mounted on a common planetary gear.

[0088] Third embodiment

[0089] Fig. 9 A third example is shown, and only the differences from the second example are described here.

[0090] In this third example, the motor is connected to the motor housing 10 by a common centering support 16, forming a separate part from said housing 10. In this case, the centering support is a cylindrical tube, for example supported and / or treated by a material that makes it have greater rigidity than the rest of the motor housing 10. In this example, the fixed ring gear 21 is assembled and attached to the centering support 16 (as shown by the oval in the figure), for example by press fitting. Alternatively, the ring gear can be cut directly from the centering support.

[0091] Of course, the invention is not limited to the examples that have just been described, and many modifications may be made to these examples without exceeding the scope of the invention.

[0092] the term:

[0093] A1, A2 axial bearing flange

[0094] A3 front bearing flange

[0095] A11, A12, A31, A32 lips

[0096] 1 motor unit

[0097] 10 Motor housing, the motor housing serves as a center support

[0098] 101 Motor housing centering support for rotor bearing

[0099] 102 Motor housing skirt for fixing the center support of the gear ring 105 Assembly clip for mounting the motor housing on the caliper housing 11 Motor

[0100] 110 Inner stator recess

[0101] 111 Stator

[0102] 112 Rotor

[0103] 117 Intermediate motor cover

[0104] 118 Electronic Board

[0105] 119 Radiator cap

[0106] 12 Hollow sun gear

[0107] 120 sun gear inner recess

[0108] 13 Sun gear shaft

[0109] 14 Sun gear shaft rolling bearing

[0110] 15 External guide roller bearing of rotor

[0111] 16 Common centering support for rotor and fixed gear ring

[0112] 162 Common to the center support member forming a portion of the fixed ring gear support member

[0113] 191 Motor electrical connector

[0114] 2-turn differential reduction gear

[0115] 204 Cylindrical Damper

[0116] 21 Fixed gear ring

[0117] 211 Anti-rotation recess for fixing the ring gear

[0118] 213 Skirt of fixed gear ring

[0119] 22 Planetary gear

[0120] 220 planetary support ring

[0121] 23 Movable ring gear

[0122] 231 Coupling spline of movable gear ring

[0123] 3 screw-nut mechanism

[0124] 302 movable gear ring with nut assembly of screw-nut assembly

[0125] 31 Rotating nut

[0126] 311 Bearing flange of nut

[0127] 312 Nut coupling groove

[0128] 313 Ball bearings for screw-nut mechanisms

[0129] 32 Screw that is fixed to prevent rotation

[0130] 323 Nut Rotary Coupling Form

[0131] 33 support plate-brake piston

[0132] 333 Screws to attach the support plate to the threaded rod

[0133] 335 Anti-rotation notch in piston support plate

[0134] 4 Calipers

[0135] 401 rear sleeve caliper housing

[0136] 402 Sliding Washer 402, Free Rotation

[0137] 41Brake housing, caliper housing

[0138] 410 rear recessed caliper housing

[0139] 411 Axial stop with rolling bearing

[0140] 412 Guide bearing with rolling bearing

[0141] 413 Piston dust seal

[0142] 42 caliper nose, outer caliper arm

[0143] 43 Screws that assemble the caliper nose to the caliper housing

[0144] 500 Linear actuation direction

[0145] 501 Bracket

[0146] 502 inner clamping pad

[0147] 503 External clamping pad

[0148] 509 Brake disc

[0149] 51 brake (M1)

[0150] F1 clamping force

Claims

1. A rotary drive reduction gear or reduction gear motor device for achieving a linear displacement of a brake piston (33) in an electric brake actuator, the device being integrated into a brake housing (41) or intended to be mounted on such a brake housing, The device comprises one or more planetary gear sets (2) parallel or coaxial with the linear actuation direction (500), The one or more planetary gear sets utilize at least one ring gear (21) that is fixed against rotation relative to the brake housing (41), It is characterized in that The device comprises a damping device (204) at least partially made of an elastomeric material, The damping device is arranged around the gear ring (21) or is designed to be arranged in this way. so as to be radially and / or axially compressed between the fixed gear ring (21) and the brake housing (41), and Radial and / or axial vibration damping is thereby provided between the stationary ring gear and the brake housing.

2. Device according to the preceding claim, characterized in that The inner and / or outer surface of the damping device (204) carries one or more peripheral ribs (A21), which are radially compressed once in place, and in particular each of the peripheral ribs (A21) is continuous over the entire periphery, thereby producing an axial seal.

3. The device according to any one of the preceding claims, characterized in that The damping device comprises a cylindrical sleeve (A2) surrounding the fixed gear ring (21) or a support (102, 162) of the fixed gear ring, and the cylindrical sleeve (A2) has an axial bearing flange (A1, A2) at one or both ends of the cylinder so as to be axially compressed between the fixed gear ring (21) and the brake housing (41).

4. Device according to the preceding claim, characterized in that At least one axial bearing flange (A1, A2) has on its outer surface one or more at least axially extending lips (A11, A12, A31, A32), which lips extend at least axially, in particular continuously over the entire periphery, thereby producing a radial seal.

5. A device according to any one of the preceding claims, characterised in that The damping device comprises an internal reinforcement member embedded in an elastomer, wherein the rigidity and / or elasticity of the internal reinforcement member is greater than the rigidity and / or elasticity of the elastomer, and the internal reinforcement member is in particular a metal reinforcement member.

6. A device according to any one of the preceding claims, characterised in that The fixed ring gear (21) is held against rotation by a motor housing (10) carrying an electric motor (11) driving the reduction gear, the electric motor housing (10) forming an insert fitted to the brake housing (41) to compress the damping device.

7. A device according to any one of the preceding claims, characterised in that The device comprises a so-called differential planetary reduction gear (2) coaxial with the motor and driven at the input end by a sun gear (12), the sun gear driving a set of planetary gears (22), each of which meshes with both the fixed ring gear (21) and the movable ring gear (23), the ring gears (21, 23) having a different number of teeth from each other, The movable ring gear (23) rotates a screw-nut mechanism (3) which produces a linear drive of the brake piston between a retracted position and an extended position. A linear pressure is thereby applied in a forward direction to produce a clamping force (F1) on the disc between the clamping pads (502, 503).

8. Device according to the preceding claim, characterized in that The differential planetary reduction gear (2) rotates a reversible screw-nut mechanism (3), which converts the rotation into a linear displacement applied to the brake piston.

9. The device according to any one of the preceding claims 7 to 8, characterized in that The movable ring gear (23) of the planetary reduction gear (2) rotates the nut of the screw-nut mechanism (31), and the nut is held against translation by a shoulder formed in a recess (410) of the caliper housing, while its screw (32) is held stationary against rotation by a brake piston (33), thereby driving translation through the rotation of the nut.

10. A damping device, arranged to implement a damping device (204) of a reduction gear device according to any one of claims 1 to 9, the damping device being at least partially made of an elastomeric material and being suitable for being arranged around a fixed ring gear (21) of the reducer device so that when the reduction gear device is integrated into the brake housing, it is radially and / or axially compressed between the fixed ring gear (21) and the brake housing (41), and the damping device thereby provides radial and / or axial vibration damping between the fixed ring gear and the brake housing.

11. A reduction gear motor device for a brake actuator, characterized in that: It comprises a device according to any one of claims 1 to 9.

12. A disc brake for a road vehicle, in particular a sliding or floating disc brake for a road vehicle or a motor vehicle, characterized in that It comprises a reduction gear or a reduction gear motor arrangement according to any one of claims 1 to 9 , or a reduction gear motor arrangement according to claim 11 .

13. A method for fitting a vehicle, in particular a road vehicle, with brakes, characterized in that The method comprises: An electric motor (11) carrying a sun gear shaft (12) is mounted on a motor housing (10) to form a motor unit (1), or to provide such a motor unit; and Assembling the motor housing (10) of the motor unit (1) onto the brake housing (41), A reduction gear according to any one of claims 1 to 9 is formed by interconnecting one or more parallel or coaxial planetary gear sets, wherein the fixed ring gear (21) of the reduction gear is held by the motor housing (10) to prevent rotation, The damping device (204) is compressed radially and / or axially between the brake housing (41) and the fixed gear ring (21) or its support (102, 162).

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