Electric balance ring, and rolling bearing comprising such a ring
Patent Information
- Application Number
- EP2022862407
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-10-20
- Publication Date
- 2025-08-27
AI Technical Summary
Existing electrical balancing rings experience wear issues that lead to a decrease in electrical conduction over time, requiring multiple membranes in parallel to compensate, which increases complexity.
An electrical balancing ring with a wear zone at the second end that is thicker than the membrane body, maintaining a constant contact surface and ensuring high electrical conductivity, along with optional features like a conductive coating and radial slots to enhance durability and flexibility.
The ring maintains constant electrical conductivity over a long operating time due to the thicker wear zone, reducing wear and increasing longevity while allowing for efficient electrical charge transfer.
Smart Images
Figure 1.1
Abstract
Description
[0001] Electrical balancing ring, and rolling bearing comprising such a ring
[0002] TECHNICAL FIELD
[0003] The present invention relates to an electrical balancing ring or grounding ring, used to transmit electrical charges or an electric current between a fixed element and a rotating element movable in rotation relative to the fixed element around an axis of rotation. Typically, the ring is used to conduct electrical charges between a casing and a shaft of a machine, or more particularly between a stator and a rotor of an electrical machine.
[0004] STATE OF PRIOR ART
[0005] The invention thus relates to an electrical balancing ring comprising: a first, annular, rigid armature, mounted integrally on one of the fixed element and the rotating element, an annular membrane, made of an elastic material, extending between a first end in contact with the first armature, and a second end in contact with the other of the fixed element and the rotating element, said membrane having a body between the first end and the second end, a second, annular, rigid armature, mounted integrally with the first armature and adapted to pinch and fix the membrane between the first armature and the second armature, and in which the first armature and the membrane are capable of conducting an electric current between the fixed element and the rotating element.
[0006] Document US 2020 / 0295634 shows such an electrical balancing ring. However, this ring has problems with wear of its membrane, which modifies the electrical conduction over time and therefore the performance of the product. According to variants, a plurality of membranes are installed in parallel to try to compensate for this drawback, but at the cost of a certain complexity.
[0007] STATEMENT OF THE INVENTION
[0008] A first object of the present invention is to provide an electrical balancing ring which is durable, that is to say having an electrical conduction which varies little over time.
[0009] For this purpose, the membrane of the electric ring comprises a wear zone at the second end, said wear zone being thicker than the body of the membrane, and the wear zone forming a contact surface configured to slide in contact on a sliding surface of the other element and ensure high electrical conductivity between the fixed element and the rotating element.
[0010] Thanks to these arrangements, the wear zone, which wears during operation, has a contact surface that maintains a substantially constant surface area. Thus, the electrical conductivity of the ring remains constant.
[0011] In various embodiments of this product, one and / or the other of the following provisions may optionally be used in addition.
[0012] In one aspect, the wear zone of the membrane extends in the direction of the axis of rotation over a length greater than or equal to the thickness of the body of the membrane, the ring being in the mounting position between the fixed element and the rotating element.
[0013] In one aspect, the wear zone has a thickness greater than the thickness of the membrane body.
[0014] In one aspect, the wear zone has a mass configured to provide contact between the contact surface and the sliding surface for a rotational speed range of the rotating element.
[0015] In one aspect, the membrane is attached to the second frame.
[0016] In one aspect, the membrane includes radial slots extending to the second frame and terminating in an open portion.
[0017] In one aspect, the membrane comprises an electrically conductive coating, said coating being at least on the contact surface of the wear zone.
[0018] In one aspect, the membrane is formed from a PTFE material containing a conductive filler, such as carbon.
[0019] According to one aspect, the second armature is capable of conducting an electric current between the fixed element and the rotating element.
[0020] In one aspect, the second frame has a radial height greater than a radial height of the first frame.
[0021] In one aspect, the radial height of the second armature is at least twice the radial height of the first armature, and the radial height of the first armature is less than half the distance between the fixed element and the rotating element.
[0022] According to one aspect, the first frame and / or the second frame comprise pins adapted to penetrate the membrane and secure the membrane to the first and / or second frame.
[0023] In one aspect, the second frame has an inner end that is curved toward a second end of the membrane, in the mounting position of the ring.
[0024] A second object of the present invention is to provide a rolling bearing comprising an electrical balancing ring according to the preceding characteristics, and rolling bodies arranged in a rolling space to allow relative rotation of the rotating element with respect to the fixed element around the axis of rotation.
[0025] BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Other characteristics and advantages of the product will appear during the following description of at least one of its embodiments, given as a non-limiting example, with reference to the attached drawings.
[0027] On the drawings:
[0028] - Figure 1 is a sectional view of an electrical balancing ring according to the present disclosure;
[0029] - figure 2 is a view identical to figure 1 showing dimensions of the elements of the ring;
[0030] - Figure 3 is a partial front view showing a variant of the ring of Figure 1 having radial slots;
[0031] - Figure 4A, Figure 4B, Figure 4C and Figure 4D show variant shapes of the wear zone of the ring of the type of Figure 1;
[0032] - Figure 5 is a sectional view of an electrical balancing ring of the type of Figure 1 further comprising a sealing member; and
[0033] - Figure 6 is a sectional view of a rolling bearing incorporating an electrical balancing ring of the type of Figure 1.
[0034] In the various figures, the same numerical references designate identical or similar elements.
[0035] DETAILED DESCRIPTION
[0036] Figure 1 shows an embodiment of an electrical balancing ring 10 which is intended to be mounted between a fixed element 11 and a rotating element 12 movable in rotation relative to the fixed element around an axis of rotation AX. The ring 10 comprises: - a first armature 20, of annular type around the axis of rotation, which is rigid and which is mounted integral with one of the fixed element 11 and the rotating element 12,
[0037] - a membrane 30, also of the annular type around the axis of rotation, made of an elastic material, and
[0038] - a second frame 40, also of the annular type around the axis of rotation, which is rigid and which is mounted integrally with the first frame 30.
[0039] The first armature 20 and the membrane 30 are capable of conducting an electric current, in particular so that an electric current can circulate between the fixed element 11 and the rotating element 12, or vice versa.
[0040] The membrane 30 extends between a first end 31 in contact with the first frame 20, and a second end 32 in contact with the other of the fixed element and the rotating element. The membrane 30 comprises a body 33 between the first end 31 and the second end 32.
[0041] In particular, the fixed element 11 may be an external element, i.e. the furthest from the axis of rotation AX, i.e. located around the rotating element 12 which is then an internal element. This is the case of using a rotating element 12 which is a rotating shaft (figure 1).
[0042] Conversely, the fixed element 11 can be an internal element, i.e. closest to the axis of rotation AX, i.e. located inside the rotating element which is then an external element.
[0043] For the sake of simplification of the present description, it will now be considered that the first frame 20 is connected to the external fixed element 11, and that the second end 32 is in contact with the other element, i.e. the internal rotating element 12, but of course the other use is also suitable for the present disclosure. The second frame 40 is adapted to pinch and fix the membrane 30 between the first frame 20 and the second frame 40. In other words, the membrane 30 is fixed by pinching between the first frame and the second frame, for example at the time of fixing the second frame 40 on the first frame 20.
[0044] According to the present disclosure, the membrane 30 comprises a wear zone ZU at the second end 32 of said membrane 30. This wear zone ZU is thicker than the body 33 of the membrane 30. In FIG. 2, the thickness of the body 33 of the membrane is noted (e), this thickness being taken in a direction substantially perpendicular to the core of the body of the membrane 30. The thickness of the wear zone ZU of the membrane 30 is noted (b), this thickness is taken in a direction perpendicular to the axis of rotation AX, in the mounting position of the ring on the rotating element 12.
[0045] Furthermore, the membrane 30 may have a non-constant thickness. Thus, the thickness of the membrane at the first end 31, denoted (el) may be greater than the thickness (e) of the body 33 of the membrane 30.
[0046] The wear zone ZU thus forms a contact surface 34 configured to slide in contact on a sliding surface 14 of the other element, i.e. the rotary element 12 of FIG. 1.
[0047] The electrical balancing ring 10 can therefore conduct an electric current from the rotating element 12 to the membrane 30 by the contact of the contact surface 34 of the wear zone ZU with the second end 32 of the membrane 30, then by the body 33 of the membrane 30 to the first armature 20 in contact with the first end 31 of the membrane 30, then by the first armature 20 to the fixed element 11 thanks to the contact between this first armature 20 and the fixed element 11. The electrical conduction can also take the reverse path. The electrical conductivity of the electrical balancing ring 10 is thus high, and makes it possible to efficiently evacuate electrical charges.
[0048] During operation of the ring 10, the sliding and possibly the friction of the contact surface 34 of the membrane 3 on the sliding surface 14 causes wear of this contact surface and wear of the wear zone ZU which reduces in thickness. However, the thickness of this wear zone ZU thicker than the body 33 of the membrane 30 makes it possible to maintain an area of the contact surface 34 substantially constant, as long as the wear zone ZU is not completely worn: as long as its thickness does not tend towards zero. Thus, thanks to this contact surface 34 of the wear zone ZU, the electrical conductivity of the ring can remain constant over a very long operating period.
[0049] In the mounting position of Figure 1 and Figure 2, the wear zone ZU of the membrane 30 extends in the direction of the axis of rotation AX over a length (a). For example, the length (a) is greater than or equal to the thickness (e) of the body 33 of the membrane 30: a >= e.
[0050] Advantageously, this length (a) is greater than 1 mm, and it may be greater than 2 mm. Thus, the contact surface 34 has an area S34 of:
[0051] A34 = 7t. D. a
[0052] With D the diameter of the rotating element 12, a is the length of the wear zone ZU. Optionally, the length (a) is greater than or equal to the thickness (el) of the first end 31 of the membrane 30: a >= el.
[0053] Thanks to this length (a) of the wear zone ZU, the ring 10 has a high electrical conductivity. By increasing the length (a), this electrical conductivity can be increased. The wear zone ZU also has a thickness (b), this thickness (b) being taken in a direction perpendicular to the direction of the axis of rotation (AX), in the mounting position. Advantageously, this thickness (b) is greater than the thickness (e) of the body 33 of the membrane 30, and preferably greater than twice the thickness (e) of the body 33 of the membrane 30. Thus, the wear zone is sufficiently thick to ensure a long service life for the ring 10, while maintaining a constant and high electrical conductivity.
[0054] For example, the thickness (e) of the membrane 30 is between 0.4 mm and 1 mm. Thus, the thickness (b) of the wear zone ZU is then between 0.5 mm and 3 mm.
[0055] Furthermore, the second end 32 of the membrane 30 comprises the wear zone ZU, and according to the notations in FIG. 2, the thickness (c) of the second end 32 is substantially equal to the sum of the thickness (e) of the membrane and the thickness (b) of the wear zone ZU: c = b + e.
[0056] The second frame 40 is for example mounted securely inside the first frame 30, possibly by fitting or by crimping.
[0057] According to the embodiment presented in Figure 1, the first frame 20 and the second frame 40 have an L shape nested inside each other. Each of these frames 20, 40 is formed of a cylindrical sleeve 21, 41 which extends in the direction of the axis of rotation AX, extended by a lateral annular flange 22, 42 perpendicular to the axis of rotation AX and inwards in the direction of this axis of rotation.
[0058] The cylindrical sleeve 21 of the first frame 20 is then adapted to be mounted by fitting into a hollow cylindrical housing 13 of the fixed element 11. The annular membrane 30 has an external diameter adapted to be housed in the cylindrical sleeve 21 of the first frame 20, a first face 35 of the first end 31 of this membrane 30 against the lateral annular flange 22 of the first frame 20.
[0059] The cylindrical sleeve 41 of the second frame 40 is then adapted to be mounted by fitting into the internal surface of the cylindrical sleeve 21 of the first frame 20, until it presses the lateral annular flange 42 of the second frame 40 against a second face 36 of the membrane 30 (at its first end 31, and therefore until it clamps the first end 31 of the membrane 30.
[0060] According to one embodiment, the second armature 40 has a radial height (h) of the lateral flange 42 greater than a radial height (g) of the lateral flange 22 of the first armature 20, so that the lateral flange 42 extends towards the axis of rotation AX more than the lateral flange 22 of the first armature 20. The membrane 30 has a second face 36 then in contact on the radial height (h) of the lateral flange 42 of the second armature 40, up to an internal end 43 of the second armature 40. Then the body 33 of the membrane 30 is free and extends in a curved manner in the direction X of the axis of rotation AX up to the second end 32 and the wear zone ZU.
[0061] The inner end 43 of the second armature 40 is possibly curved in the direction X of the axis of rotation AX. Thus, the membrane 30 is not affected by wear at this inner end 43 and the body 33 of the membrane 30 more easily takes the desired curved shape, and determined by calculation and / or tests. Indeed, this curved shape, the thickness, and the material of the membrane 30 determines a radial force that the membrane exerts concentrically towards the axis of rotation and on the rotating element 12. This radial force determines the good contact of the wear zone ZU on the rotating element 12, and therefore the electrical conductivity of the ring and its capacity to maintain this conductivity in operation, i.e. during the rotation of the rotating element 12 and during the operating period.
[0062] According to a variant, the second armature 40 is also capable of conducting an electric current. In this case, the path of the electric current can pass between the membrane 30 and the first armature 20 as previously, but also between the membrane 30 and the second armature 40. The second armature 40 being mounted integral with the first armature 20, the other branch of the electric current passing through the second armature 40 then joins the first armature 20. This arrangement makes it possible to increase the electrically conductive area of the membrane 30 towards the first armature 20, this electrically conductive area being substantially the sum of a first area A 22 of direct contact between the membrane 30 and the first frame 20 (or area of the flange 22 of the first frame 22) and of a second area A 42 of contact between the membrane 30 and the second frame 40 (or area of the flange 42 of the second frame).
[0063] The first area A22 is substantially equal to: A 22 = 7t. g. [D+2.h+h] .
[0064] The second area A 42 is substantially equal to:
[0065] HAS 42 = 7t. h. [ D+2. d+2. hg] . Since the contact between the second armature 40 and the first armature 20 is a metal-metal contact, it is considered that its influence on the conductivity is low, that is to say that there is only a very low resistance to electrical conduction. Thus, thanks to the electrical conduction of the second armature 40, the electrical conductivity of the ring 10 can be reduced.
[0066] Furthermore, in the case of a second armature 40 capable of conducting electricity, a large radial height (h) makes it possible to obtain a large second area A 42 of contact between the membrane 30 and the second armature 40 (area of the flange 42 of the second armature). The electrical conductivity of the ring 10 can thus be increased.
[0067] According to one embodiment, the radial height (h) of the second reinforcement 40 is at least twice the radial height (g) of the first reinforcement 30.
[0068] The radial height (g) of the first armature 20 may be less than half the distance (Di) between the internal surface of the fixed element 11 and the rotating element 12. The membrane 30 is then kept pinched in the direction of the axis of rotation AX over only this radial height (g).
[0069] The radial height (h) of the second armature 40 may be less than half the distance (Di) between the inner surface of the fixed element 11 and the rotating element 12. In other words, the radial height (h) of the second armature 40 is less than the distance (d) between the inner end 43 and the rotating element 12. The size of the second armature 40 is thus limited and its cost is also limited. The body 33 of the membrane 30 retains a large curved area up to the wear zone ZU, to reduce the radial force and therefore the friction and wear of the wear zone ZU.
[0070] According to one embodiment, the first frame 20 and / or the second frame 40 may comprise pins adapted to penetrate the membrane 30 and secure it to said first and / or second frame. Thus, the membrane 30 is mechanically secured to at least one or both frames, and it is therefore held fixedly in the ring 10.
[0071] According to one embodiment, the membrane 30 may optionally be fixed to the first and / or second frame 20, 40. For example, the membrane 30 is fixed to the first and / or second frame by adhesion. According to one embodiment, the membrane 30 may be fixed to the first and / or second frame using rivets distributed angularly on a circumference of said membrane 30. The rivets pass through the membrane 30 and at least one of the frames, the first and / or the second frame.
[0072] According to one embodiment, the membrane 30 may comprise a conductive coating on its external surface. Optionally, the entire external surface of the membrane 30 is covered with this conductive coating. Alternatively, predetermined portions of the external surface of the membrane 30 are covered with this conductive coating. For example, the conductive coating may be located only on the wear zone ZU, the contact surface 34, or the first face 35 or the second face 36, or a combination of these locations. Thus, the electrical conductivity of the ring 10 may be improved.
[0073] According to one embodiment, the membrane 30 may be formed from a PTFE material. Preferably, this conductive material contains a conductive filler, such as carbon or the like.
[0074] According to one embodiment, the body 33 of the membrane 30 may comprise undulations configured to adjust a desired value of the rigidity or flexibility of said body of the membrane. In particular, these undulations are located between the internal end 43 of the second reinforcement 40 and the wear zone ZU.
[0075] Alternatively, the body 33 of the membrane 30 may comprise one or more thickness restrictions, for example located on one or more positions between the internal end 43 of the second reinforcement 40 and the wear zone ZU. This or these restrictions are for example a reduction in thickness on a circumference or a portion of circumference. This or these thickness restrictions may also be used to adjust a desired value of the rigidity or flexibility of said body of the membrane.
[0076] According to an embodiment presented in FIG. 3, the membrane 30 may comprise slots 37 which extend radially and which separate the body 33 from the membrane 30 according to angular sectors distributed over the circumference of the membrane 30. These slots 37 are through-slots. Each slot 37 passes through the membrane 30 between the second end 32 and a radial point located near the internal end 43 of the second frame 40.
[0077] Thanks to these slots, the membrane 30 is more flexible. The radial force is reduced. In addition, a smaller variation in the radial force is obtained in cases of circularity defect of the rotating element 12 and / or coaxiality defect between the fixed element 11 and the rotating element 12. The membrane 30 more easily maintains the electrical contact of the contact surface 34 with the sliding surface 14 of the rotating element 12. The electrical conductivity is increased and more stable in operation.
[0078] Optionally, the slots 37 end at said radial point with an open portion 38, as shown in FIG. 3. The open portion is for example a circular opening of a predetermined diameter. This open portion prevents tears in the membrane 30 at the radial point.
[0079] According to various embodiments presented in FIG. 4A, FIG. 4B, FIG. 4C and FIG. 4D, the wear zone ZU at the second end 32 of the membrane 30 may have various shapes in radial section. FIG. 4A shows a rectangular section; FIG. 4B shows a circular section; FIG. 4C shows an elliptical section; and FIG. 4D shows a trapezoidal section. These various shapes influence the radial force, the area of the contact surface 34, and thus the conductivity and their changes over time. They may be chosen according to the application and tests. These shapes also influence the variation over time (in operation) of the conductivity of the electrical balancing ring 10.
[0080] Figure 5 illustrates an embodiment of the electrical balancing ring 10 further comprising a sealing member 60. This sealing member is for example an annular elastic seal extending between a first fixed element 11 and the rotating element 12. It can be connected directly or indirectly in a sealed manner to the first armature 20 or to the membrane 30 or to the second armature 40. The sealing member 60 is for example made of an elastomer or rubber type material. The sealing member can also comprise a lip 61 to ensure sealing on the rotating element 12 and to limit friction on the rotating element 12.
[0081] The electrical balancing ring 10 may comprise a single sealing member as shown in FIG. 5, located on one side or the other of the membrane 30 in the direction of the axis of rotation AX. The membrane 30 is thus protected against external pollution which may come from the side on which said sealing member is located. By pollution is meant solid particles or fluids such as oil; these pollutions being able to affect the electrical conductivity of the membrane 30 and therefore of the electrical balancing ring 10 due to their possible interaction with the contact surface 34.
[0082] Alternatively, the electrical balancing ring 10 may comprise a sealing member 60 on each side of the membrane 30 in the direction of the axis of rotation AX. Thus, the membrane 30 is protected against external pollution on each side.
[0083] Furthermore, the sealing member(s) 60 may be made of a material also capable of conducting an electric current, i.e. with good electrical conductivity. For example, the sealing member has a material comprising electrically conductive particles, or one with an electrically conductive coating.
[0084] Figure 6 shows a particular example of application of the electrical balancing ring 10 previously described. This figure shows a rolling bearing 1 comprising on at least one side an electrical balancing ring 10 as described above in order to ensure the transfer of electrical charges. The rolling bearing is for example a rolling bearing of a motor vehicle, and more particularly for example a rolling bearing of a motor vehicle wheel, as shown in Figure 5.
[0085] This rolling bearing 1 includes in particular:
[0086] - a fixed organ 2,
[0087] - a rotating member 3 driven in rotation by a shaft 5 and on which is fixed, for example, a vehicle wheel, and
[0088] - rolling bodies 4 arranged in the rolling space 4e formed between the fixed member 2 and the rotating member 3 to allow the relative rotation of the rotating member 3 with respect to the fixed member 2 around the axis of rotation X, while taking up significant forces between the fixed member and the rotating member.
[0089] The fixed element 11 of the ring 10 is either directly the fixed member 2, or fixed to said fixed member 2 of the rolling bearing 1.
[0090] The rotating element 12 of the ring 10 is either directly the rotating member 3, or fixed to said rotating member 3 of the rolling bearing 1.
[0091] The rolling bodies 4 may be balls or rollers or any other known type.
[0092] Thanks to the electrical balancing ring 10 according to the present disclosure, the rolling bearing 1 is able to transfer electrical charges to the fixed member and the rotating member, without passing through the rolling bodies, which can damage them. A vehicle equipped with such devices will thus be more durable.
[0093] Nomenclature
[0094] 10 Electric balancing ring
[0095] 11 Fixed element
[0096] 12 Mobile element
[0097] 13 Housing
[0098] 14 Sliding surface
[0099] 20 First frame
[0100] 21 Cylindrical sleeve
[0101] 22 Side flange
[0102] 30 Membrane
[0103] 31 First end
[0104] 32 Second end
[0105] 33 bodies
[0106] 34 Contact surface
[0107] 35 First side
[0108] 36 Second side
[0109] 37 slots
[0110] 38 Open Portion
[0111] 40 Second frame
[0112] 41 Cylindrical sleeve
[0113] 42 Side flange
[0114] 43 Inner end
[0115] ZU Wear Zone
Claims
CLAIMS 1. Electrical balancing ring (10) intended to be mounted between a fixed element (11) and a rotating element (12) movable in rotation relative to the fixed element around an axis of rotation (AX), the ring comprising: a first, annular, rigid frame (20), mounted integrally on one of the fixed element and the rotating element, a membrane (30), annular, made of an elastic material, extending between a first end (31) in contact with the first frame, and a second end (32) in contact with the other of the fixed element and the rotating element, said membrane having a body (33) between the first end and the second end, a second, annular, rigid frame (40), mounted integrally with the first frame and adapted to pinch and fix the membrane between the first frame and the second frame,wherein the first armature and the membrane are capable of conducting an electric current between the fixed element and the rotating element, and said ring being characterized in that the membrane comprises a wear zone (ZU) at the second end, said wear zone being thicker than the body of the membrane, and the wear zone forming a contact surface (34) configured to slide in contact on a sliding surface (14) of the other element and ensure electrical conductivity between the fixed element and the rotating element., 2. Ring according to claim 1, in which the wear zone of the membrane extends in the direction of the axis of rotation (AX) over a length (a) greater than or equal to the thickness (e) of the body (33) of the membrane (30), the ring being in the mounting position between the fixed element and the rotating element.
3. Ring according to claim 1 or claim 2, in which the wear zone (ZU) has a thickness (b) greater than the thickness of the body of the membrane.
4. Ring according to one of claims 1 to 3, in which the wear zone (ZU) has a mass configured to ensure contact between the contact surface and the sliding surface for a rotational speed range of the rotating element.
5. Ring according to one of claims 1 to 4, in which the membrane (30) is fixed to the second frame.
6. Ring according to one of claims 1 to 5, in which the membrane (30) comprises radial slots (37) extending to the second frame (40) and ending in an open portion (38).
7. Ring according to one of claims 1 to 6, in which the membrane (30) comprises an electrically conductive coating, said coating being at least on the contact surface (34) of the wear zone (ZU).
8. Ring according to one of claims 1 to 7, in which the membrane (30) is formed from a PTFE material containing a conductive filler, such as carbon.
9. Ring according to one of claims 1 to 8, in which the second armature (40) is capable of conducting an electric current between the fixed element and the rotating element.
10. Ring according to one of claims 1 to 9, in which the second reinforcement (40) has a radial height (h) greater than a radial height (g) of the first reinforcement (20).
11. Ring according to claim 10, wherein the radial height of the second armature is at least twice the radial height of the first armature, and the radial height of the first armature is less than half the distance (Di) between the fixed element and the rotating element.
12. Ring according to one of claims 1 to 11, in which the first frame and / or the second frame comprise pins adapted to penetrate the membrane and secure the membrane to the first and / or second frame.
13. Ring according to one of claims 1 to 12, in which the second frame (40) has an internal end (43) which is curved towards a second end (32) of the membrane, in the mounting position of the ring.
14. Rolling bearing (1) comprising an electrical balancing ring (10) according to one of claims 1 to 13, and rolling bodies (4) arranged in a rolling space to allow relative rotation of the rotating element with respect to the fixed element around the axis of rotation.