Braking device comprising a braking disc radially decoupled from its external support

Abstract

This braking device comprises an annular braking disc and an external support ring (2) coaxial with the braking disc and fixedly attached to a lateral support. The support ring (2) comprises a set of connecting elements (6) arranged on a circumference of the support ring (2) and extending in a radial direction, each connecting element (6) being fixedly attached to the support ring (2) and being housed in an associated cavity (7) of complementary shape formed radially inside the braking disc, each connecting element (6) being able to slide in the associated cavity (7). Figure for abstract: Figure 3

Description

Title of the invention: Braking device comprising a braking disc radially decoupled from its external support Technical field

[0001] The invention relates to a disc braking device.

[0002] The invention also relates to a wheel motor equipped with such a braking device as well as a motor vehicle equipped with such a wheel motor or such a braking device. Previous techniques

[0003] Conventional disc brake devices are subject to deformation due to thermal stresses, which can lead to operational problems, such as uneven wear of the brake pads and warping of the brake disc.

[0004] Furthermore, when a conventional braking device is associated with a wheel motor, deformations due to thermal stresses can alter the operation of the wheel motor, which is very sensitive to differential deformations, in particular due to the presence of permanent magnets. Statement of the invention

[0005] To overcome the problems posed by the state of the art, the invention aims to propose a disc braking device which allows free radial thermal deformations of the disc.

[0006] The subject of the invention is a braking device comprising an annular braking disc and an external support ring coaxial with the braking disc and fixed securely to a lateral support.

[0007] The support ring comprises a set of connecting elements arranged on a circumference of the support ring and extending in a radial direction. Each connecting element is fixedly attached to the support ring and is housed in an associated cavity of complementary shape formed radially inside the brake disc. Each connecting element can slide in the associated cavity.

[0008] Such a configuration allows free radial thermal deformation of the braking disc, while guaranteeing circumferential and axial connection between the braking disc and the support ring.

[0009] Preferably, the brake disc is of the ventilated type and comprises first and second opposite and coaxial annular plates each comprising on an inner surface a plurality of ribs spaced from each other in the circumferential direction and extending radially from an outer surface of each plate, the ribs of the first plate being arranged opposite the ribs of the second plate and together forming the cavities housing the connecting elements.

[0010] Such a brake disc benefits from improved cooling thanks to the increase in the heat exchange surface. In addition, such a configuration promotes uniform behavior of the brake disc in the face of thermomechanical stresses.

[0011] Advantageously, the support crown is axially offset on the side of said lateral support relative to the braking disc. Such a configuration facilitates the manufacture of the braking device.

[0012] According to an advantageous characteristic, the support ring is provided on a first front face with a first group of notches spaced from each other in the circumferential direction and arranged axially on the side of the brake disc. Such a support ring benefits from reduced weight while improving ventilation of the disc.

[0013] According to another advantageous characteristic, the support ring is provided on a second front face with a second group of notches spaced from each other in the circumferential direction and arranged axially on the side of said lateral support. Such a support ring further improves the weight of the ring and the ventilation of the disc.

[0014] For example, the connecting elements each comprise an anchoring part overmolded with the support ring. This feature facilitates manufacturing and guarantees a secure fixing between the connecting elements and the support ring.

[0015] Preferably, the connecting elements each comprise a radial protrusion such as a rod or a tube intended to be housed in the cavities. Such connecting elements facilitate manufacturing.

[0016] According to another characteristic, the braking device further comprises a braking caliper engaging the braking disc from an inner side of the disc, and brake pads interposed between the caliper and the braking disc.

[0017] According to another aspect, the invention relates to a wheel motor for a motor vehicle provided with a braking device as described above, in which the lateral support is a rotor of the wheel motor.

[0018] According to another aspect, the invention relates to a motor vehicle comprising at least one braking device as described above or comprising at least one wheel motor as described above. Brief description of the drawings

[0019] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made in reference to the attached drawings in which:

[0020] [Fig-1] is a perspective view of a wheel motor equipped with a device for braking according to an exemplary embodiment of the invention;

[0021] [Fig.2] is a sectional view along axis II-II of [Fig.l]; and

[0022] [Fig.3] is a sectional view along axis III-III of [Fig.2]. Detailed description of at least one embodiment

[0023] Figures 1 to 3 show a wheel motor for an electrically powered motor vehicle. A wheel motor is an assembly that incorporates an electric traction motor capable of propelling a vehicle.

[0024] The wheel motor comprises a braking device comprising an annular braking disc 1 and a support ring 2 external and coaxial with the braking disc 1.

[0025] The outer support ring 2 is fixedly attached to a lateral support 3 and is connected to the brake disc 1. The lateral support 3 is here a rotor 4 of the wheel motor 5. In an embodiment not illustrated, the lateral support 3 can be a wheel rim.

[0026] The lateral support 3 is coaxial with the braking disc 1 and has an annular outer surface 3b arranged radially at the same level as an outer surface 2c of the support ring 2. In other words, the outer surface 3b of the lateral support 3 is radially external to the braking disc 1 and the braking disc 1 is supported from the outside, by means of the support ring 2.

[0027] The support ring 2 is connected to the brake disc 1 by means of several connecting elements 6 arranged on a circumference of the support ring 2 and extending in a radial direction. Each connecting element 6 is fixed integrally to the support ring 2 and is housed in an associated cavity 7, particularly visible in [Fig. 3], so as to be able to slide therein. Each connecting element 6 comprises an anchoring part 6a embedded in the support ring 2 and a protrusion 6b integral with the anchoring part 6a and extending radially towards the brake disc 1. Each cavity 7 has a shape complementary to that of the radial protrusion 6b of the associated connecting element 6 and is formed radially inside the brake disc 1.

[0028] Preferably, the anchoring parts 6a of the connecting elements 6 are overmolded with the support ring 1, so as to guarantee their immobile fixing. The radial protrusions 6b of the connecting elements 6 comprise rods or tubes intended to be housed in the cavities 7.

[0029] The braking device further comprises a braking caliper 8 engaging the braking disc 1 via an inner side of the disc 1, and brake pads 9 interposed between the braking caliper 8 and the braking disc 1.

[0030] The brake disc is here of the ventilated type. Alternatively, it remains possible that the brake disc either solid and / or in one piece.

[0031] As particularly visible in Figures 1 and 2, the brake disc 1 comprises a first and a second annular plate 1a, 1b opposed and coaxial. The first annular plate 1a comprises an inner surface 10a arranged opposite an inner surface 10b of the second annular plate 1b. Each annular plate 1a, 1b comprises on its inner surface 10a, 10b a plurality of ribs 11a, 11b spaced from each other in the circumferential direction and extending radially from an outer surface of each plate.

[0032] The ribs 11a of the first plate 1a are arranged opposite the ribs 11b of the second plate 1b. The ribs 11a and 11b together form the cavities 7 housing the connecting elements 6.

[0033] In order to facilitate fixing, the support ring 2 is axially offset on the side of the lateral support 3, relative to the brake disc 1. The support ring 2 comprises a second front face 2a which is in axial contact with a front face 3a of the lateral support 3. The support ring 2 is fixed integrally to the lateral support 3 by means of fixing means 12 such as screws or bolts.

[0034] The support ring 2 also comprises a first front face 2b opposite the second front face 2a. The two front faces 2a and 2b delimit the axial thickness of the support ring 2.

[0035] The support ring 2 is here provided on the first front face 2b with a first group of notches 13 spaced from each other in the circumferential direction. The notches 13 are arranged axially on the side of the brake disc, so as to promote its ventilation. Preferably, the notches 13 release the passage of air from and to the inside of the brake disc 1.

[0036] The support ring 2 is here provided on the second front face 2a with a second group of notches 14 spaced from each other in the circumferential direction. The notches 14 are arranged axially on the side of the lateral support.

[0037] Alternatively, it remains possible not to provide notches 13 and / or notches 14.

Claims

Claims

1. Braking device comprising an annular braking disc (1) and an external support ring (2) coaxial with the braking disc (1) and fixedly attached to a lateral support (3), said braking device being characterized in that the support ring (2) comprises a set of connecting elements (6) arranged on a circumference of the support ring (2) and extending in a radial direction, each connecting element (6) being fixedly attached to the support ring (2) and being housed in an associated cavity (7) of complementary shape formed radially inside the braking disc (1), each connecting element (6) being able to slide in the associated cavity (7).

2. Braking device according to claim 1, wherein the braking disc (1) is of the ventilated type and comprises first and second annular plates (1a, 1b) opposite and coaxial each comprising on an inner surface (10a, 10b) a plurality of ribs (11a, 11b) spaced from each other in the circumferential direction and extending radially from an outer surface of each plate (1a, 1b), the ribs (11a) of the first plate (1a) being arranged opposite the ribs (11b) of the second plate (1b) and together forming the cavities (7) housing the connecting elements (6).

3. Braking device according to claim 1 or 2, wherein the support ring (2) is axially offset on the side of said lateral support (3) relative to the brake disc (1).

4. Braking device according to any one of claims 1 to 3, wherein the support ring (2) is provided on a first end face (2b) with a first group of notches (13) spaced from each other in the circumferential direction and arranged axially on the side of the brake disc (1).

5. Braking device according to any one of claims 1 to 4, wherein the support ring is provided on a second front face (2a) with a second group of notches (14) spaced from each other in the circumferential direction and arranged axially on the side of said lateral support (3).

6. Braking device according to any one of claims 1 to 5, in which the connecting elements (6) each comprise an anchoring part (6a) overmolded with the support crown (2).

7. Braking device according to any one of claims 1 to 6, in which the connecting elements (6) each comprise a radial protuberance (6b), such as a rod or a tube, intended to be housed in the cavities (7).

8. A braking device according to any one of claims 1 to 7, further comprising a braking caliper (8) engaging the braking disc (1) from an inner side of the disc (1), and brake pads (9) interposed between said caliper (8) and the braking disc (1).

9. Wheel motor for a motor vehicle provided with a braking device according to any one of claims 1 to 8, in which the lateral support (3) is a rotor of the wheel motor.

10. Motor vehicle comprising at least one braking device according to one of claims 1 to 8 or comprising at least one wheel motor according to claim 9.

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