Device for protecting rotating electrical machine bearing faults.
A passive detection and decoupling device for rotating electrical machines addresses the unreliability and bulkiness of existing systems by using a torque amplifier and brake mechanism to stop the rotor upon eccentricity detection, ensuring safe operation and reducing damage risks.
Patent Information
- Application Number
- FR2023009330
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-09-05
- Publication Date
- 2025-07-18
- Estimated Expiration
- 2043-09-05
AI Technical Summary
Existing protection mechanisms for rotating electrical machines, such as mechanical fuses and dynamic decoupling devices, are either unreliable or bulky, and fail to effectively detect and respond to eccentricity in the rotor's rotation, leading to potential damage or fire risks due to bearing malfunctions.
A passive detection and decoupling device comprising a first element extending around the rotor and a second element integral with the stator, which switches from a rest to a braking configuration when rotor eccentricity is detected, using a torque amplifier and brake mechanism to stop the rotor before significant damage occurs.
The device provides reliable, compact protection against rotor eccentricity by passively detecting and stopping the rotor, minimizing damage and fire risks without adding bulk or reliance on external controls, thus enhancing the safety and reliability of rotating electrical machines.
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Abstract
Description
Title of the invention: Device for protecting against bearing faults in rotating electrical machines.
[0001] The invention relates to the field of aeronautics, and in particular that of rotating electrical machines, of the motor or generator type, allowing the transformation of electrical energy into mechanical energy and vice versa, to be fitted to means of transport, such as aircraft, for example airplanes or helicopters. Nevertheless, the invention is not restricted to the field of transport and is suitable for any rotating electrical system with stages. More specifically, the invention relates to a device for protection against a lack of concentricity in the rotation of the rotor of the rotating electrical machine.
[0002] The field of application of the invention concerns electricity generators and electrically powered motors associated with their converters which comprises: - an electrical machine of the synchronous or asynchronous type but not exclusively with: • On the stator, a main winding, which may be, by way of non-limiting example, polyphase; • On the rotor, a squirrel cage or magnets indifferently mounted, on the surface, or buried, and without presuming the type of magnetization or magnets; • A rotating bearing assembly or rotor rotation guide comprising, for example, a bearing to ensure rotation of the rotor. - A shaft allowing the electrical machine to be coupled to a relay box such as a gearbox or other, by means of splines.
[0003] Certain events can unfortunately lead to a malfunction of the generator and / or motor assembly, these include events of the type: - A loss of lubrication of one of the bearings or rotation guides. This type of fault can lead to heating of the bearing device and a risk of propagation of high temperature up to the point of self-ignition of the malfunctioning bearing, - Or a slow or sudden failure of a bearing, or even several bearings. This type of fault can cause a loss of rotor support relative to the stator with unwanted heat generation at the air gap and a risk of high temperature propagation.
[0004] These two events generally cause the rotor to be off-center relative to the stator as well as heating of the components leading to a breakage of one of the components or even the entire machine. It is then necessary, in this type of situation, to stop the rotation of the rotor in order to minimize damage and to protect against any unwanted bursting or breakage or any outbreak of fire in the rotating electrical machine.
[0005] It is known, to avoid these dreaded events, to use means of different natures: - A mechanical fuse type device or "breakable section" on the shaft line of the rotating machine. This type of device has the advantage of being relatively simple and not bulky. The major disadvantage of this device is that uncoupling can only be done if the rotor torque is sufficiently high. More precisely, this breakable section functions like a fuse whose mechanical strength is predetermined. Therefore, for this fuse to break, it is necessary that a sufficient force, or torque, be imposed on it. However, with a low resistance mechanical fuse can also cause the latter to break even when the shaft is healthy and no feared event has occurred. However, such a breakage is only possible in the case of a mechanical blockage sufficient to brake the rotor.And in the case of a loss of lubrication in a bearing, it is possible to observe a burst or extreme heating in the rotating electrical machine without this generating a significant braking torque sufficient to break the transmission shaft. - A dynamic decoupling device which consists of an actuator that ensures the coupling of the two shafts, that of the rotating electrical machine and that of the drive system for example. The device includes controlled decoupling means. Thus, in the event of detection of a malfunction, these means are activated to decouple the shafts when they are rotating. This dynamic device can be a viable solution, however, it suffers from some major drawbacks. The volume required to install this type of device as well as its mass is inadequate with the space usually available for the integration of the rotating electrical machine. In addition, decoupling can only be done on command, itself based on detection by means of an algorithm or when a threshold is exceeded.As a result, the reliability of the dynamic device is strongly linked to the reliability of the detection system, the algorithm and the control electronics. Therefore, the addition of such a dynamic device significantly degrades the reliability of the rotating electrical machine.
[0006] The invention aims to overcome all or part of the problems mentioned above by proposing a passive and compact detection and decoupling device. The detection device makes it possible to detect any eccentricity in the rotation of the shaft and to act as soon as a fault in the rotation of the shaft is detected.
[0007] For this purpose, the subject of the invention is a rotating machine comprising a coaxial rotor and stator, the rotor being configured to be movable in rotation about an axis of rotation x, the rotating machine comprising at least one bearing configured to guide the rotation of the rotor, the at least one bearing being in contact with a surface of the rotor, the bearing comprising a rolling device extending concentrically around the rotor and a device for detecting a rotation defect, the rotation defect detection device comprising a first element and a second element, the first element extending concentrically around the rotor, the second element being integral with the stator, the detection device being configured to switch from a rest configuration, in which the first element is distant from the rotor and the second element, to a braking configuration, in which the first element is driven in rotation by the rotor and in which the second element exerts a reaction opposite to the rotation of the rotor on the first element, the detection device being configured to switch from the rest configuration to the braking configuration when the rotation of the rotor is eccentric relative to the axis of rotation x.
[0008] According to one aspect of the invention, the first element is juxtaposed with the rolling device along the axis of rotation x.
[0009] According to one aspect of the invention, the rolling device is distant from the surface of the rotor by a first predefined distance, the first element being distant from the surface of the rotor by a second distance, the second distance being defined according to the following formula: D2 = x*D}
[0010] Where D2 represents the second distance separating the rotor surface from the first element, represents the first distance separating the rotor surface from the rolling device andx represents the predefined eccentricity detection ratio.
[0011] According to one aspect of the invention, the first element comprises a protrusion and wherein the second element comprises a stop, the stop being in contact with the protrusion in the braking configuration and distant from the protrusion in the rest configuration.
[0012] According to one aspect of the invention, the protrusion is defined along an axis radial to the rotor.
[0013] The invention will be better understood and other advantages will appear on reading the detailed description of an embodiment given as an example, description illustrated by the attached drawing in which:
[0014] [Fig-1] [Fig. 1] represents a front view of an assembly model of a bearing of rotating machine according to the invention;
[0015] [Fig.2] [Fig.2] represents a side view of an assembly model of a bearing of rotating machine according to the invention of [Fig.l];
[0016] [Fig.3] [Fig.3] represents a schematic view of a first element of a rotation fault detection device of [Fig.l];
[0017] [Fig.4] [Fig.4] represents a schematic view of a second element of the rotation fault detection device of [Fig.l].
[0018] For the sake of clarity, the same elements will bear the same references in the different figures.
[0019] Figure 1 shows a front view of a bearing 10 of a rotating machine comprising a coaxial rotor 20 and stator 30. The rotor 20 is thus configured to be movable in rotation about an axis of rotation X- The rotor 20 is movable in rotation in the stator 30 which is fixed relative to the rotor 20. The rotating machine also comprises at least one bearing 10 configured to guide the rotation of the rotor 20 in an aligned manner relative to the axis of rotation x. The rotor 20 of the rotating machine passes through the at least one bearing 10 according to a passage section 101, as shown in [Fig.l].
[0020] In other words, the at least one bearing 10 maintains the rotation of the rotor 20 relative to the axis of rotation X- The at least one bearing 10 is in contact with a surface 200 of the rotor 20.
[0021] The at least one bearing 10 may be in point contact with the surface 200 of the rotor 20. Preferably, the at least one bearing 10 is in permanent contact with the surface 200. In other words, the at least one bearing 10 is connected to the concentric surface 200.
[0022] To do this, the at least one bearing 10 comprises a rolling device 100 extending concentrically around the rotor 20. The rolling device 100 is in direct contact with the surface 200 of the rotor 20. The rolling device 100 thus allows the rotor 20 to be movable in rotation relative to the at least one bearing 10. As an indicative example, the rolling device 100 may be any type of bearing ensuring the rotational movement of the rotor 20 relative to the at least one fixed bearing 10. Preferably, the rolling device 100 is a ball bearing.
[0023] The at least one bearing 10 also comprises a device 110 for detecting a rotation defect of the rotor 20. The detection device 110 is configured to switch from a rest configuration to a braking configuration of the rotor 20 if the at least one bearing is no longer guided and produces an orbit, that is to say its rotation is no longer perfectly concentric, and a rubbing contact with surrounding elements The detection device 110 acts as a freewheel type mechanism which is not directly driven in rotation and mounted with a clearance relative to the rotor 20.
[0024] The rotation fault detection device 110 comprises a first torque amplifier element 110' and a second element 110' detecting a rotation eccentricity of the rotor 20. The first element 110' or torque amplifier of the rotor 20 is an element extending concentrically around the rotor 20, in a similar manner to the bearing device 100.
[0025] In the rest configuration of the rotation fault detector 110, the first element or torque amplifier of the rotor 110' is a free element, i.e. mobile in rotation, in an identical manner relative to the rotor 20, but not necessarily driven in rotation by the rotor 20. In other words, the first element 110' or torque increaser of the rotor 20 is in freewheeling mode relative to the rotor 20 and relative to the stator 30 and there is a clearance or a distance between the rotor 20 and the first element 110'.
[0026] The second element 110'' or detector of an eccentricity of the rotation of the rotor 20 is an element integral with the stator 30 and fixed relative to the rotor 20.
[0027] Furthermore, in the rest configuration of the rotor 20 rotation fault detector 110, the first element 110' or torque increaser of the rotor 20 is distant from the rotor 20 and from the second element 110”. Thus, the rotor is only connected to the at least one bearing 10 via the rolling device 100 and the second element 110' is not connected to the first torque increaser element 110' of the rotor 20. In other words, the first element 110' or torque increaser of the rotor 20 is disconnected from the rotor 20 and from the second element 110”.
[0028] This rest configuration of the rotation fault detector 110 thus reflects a nominal operation of the rotating machine and of the rotor 20. More precisely, the rest configuration makes it possible to conclude that the rotation of the rotor 20 is substantially concentric and that the axis of rotation x of the rotor 20 is not mobile during the rotation of the rotor 20.
[0029] In the braking configuration of the detection device 110, the first element 110' or torque increaser of the rotor 20 is driven in rotation by the rotor 20. Any type of drive can be envisaged, such as for example a magnetic drive using magnets between the rotor 20 and the first element 110'. Preferably, the first element 110', when it is driven in rotation by the rotor 20, is then mechanically connected to the rotor 20.
[0030] More precisely, when the rotation of the rotor 20 is no longer concentric, that is to say when the axis of rotation x of the rotor 20 is mobile in any way, then this eccentricity is detectable at the level of the first element 110'. Indeed, the rotation imperfect rotation of the rotor 20 and the eccentricity of the rotation of the rotor 20 allows the rotor 20 to be in contact with the first torque increasing element 110'. The first torque increasing element 110' is then driven by the rotor 20, due to the mechanical contact between the rotor which is rotating and the first element 110', rotating, in a similar manner to the rotor 20.
[0031] Thus, unlike the rest configuration, in the braking configuration of the detection device 110, the rotor 20 and the first element 110' perform rotations.
[0032] The first element 110', once driven by the rotor 20, thus makes it possible to increase the rotational torque of the rotor 20. Indeed, the torque of the rotor 20 is thus a combination of the torque of the rotor 20 and of the first element 110'. Furthermore, it may be envisaged that the first element 110 comprises a larger dimension than the rotor 20. More precisely, if the first element 110' is circular in shape, as shown in [Fig.l], it may be envisaged that the section, or the diameter of the first element 110' is greater than the diameter or the section of the rotor 20, so that the rotation of the first element 110' significantly increases the rotational torque of the rotor 20, when the rotor 20 drives the first element 110' in rotation.
[0033] Alternatively, it may also be envisaged that the first element is denser or has a density greater than the density or density of the rotor 20 in order to increase the rotational torque of the rotor 20, when the rotor 20 drives the first element 110' in rotation.
[0034] In the braking configuration, the second element 110” also exerts a reaction opposite to the rotation of the rotor 20 on the first element 110'. Thus, the second element 110” acts as a brake with respect to the first element 110' and with respect to the rotor 20. As an indicative example, the second braking element 110' may act as a magnetic brake with respect to the first torque-increasing element 110' and with respect to the rotor 20. Indeed, the first element 110' and the second element 110” may comprise magnets with opposite poles so that when the first element 110' is rotated by the rotor 20, the magnets of the first element 110' are brought closer to the magnets of the second element 110”. The magnets of the second element 110” then apply a magnetic repulsion force opposite to the torque of the rotor 20 and the first element 110' increasing the torque of the rotor 20.
[0035] Preferably, in the braking configuration, the second element 110” or brake is in mechanical contact with the first element 110' increasing the torque of the rotor 20. Thus, the second element 110” acts as a mechanical stop with respect to the rotation of the first element 110' and of the rotor 20. The second element 110'' thus blocks any rotation of the first element 110' and of the rotor 20 along the axis of x-rotation.
[0036] Preferably, the second element 110” is of a complementary shape to the first element 110'.
[0037] Thus, when the rotation of the rotor 20 is no longer concentric, that is to say when the axis of rotation x of the rotor 20 is mobile in any way, then the rotor 20, by virtue of its inhomogeneous movement and its eccentricity, drives the first element 110' in rotation which thus acts as a means of increasing the torque of the rotor 20 by being in rotation with the rotor 20. From then on, this increased torque is detected by the detection device 110 by means of the second element 110' which comes into contact with the first element in order to stop any rotation of the rotor 20 and of the first element 110'. The rotor 20 is then immobilized before its rotation degenerates too strongly.
[0038] In other words, the detection device 110 is configured to switch from the rest configuration to the braking configuration when the rotation of the rotor is eccentric relative to the axis of rotation x. Eccentric is understood to mean that the behavior and rotation of the rotor 20 deviates from the nominal or expected rotation of the rotor 20 or that the rotation of the rotor 20 no longer defines a concentric circle but rather that the rotation of the rotor 20 defines an elliptical or ovoidal movement. In addition, the rotation of the rotor 20 defines a radius R which is the distance between the axis of rotation X and the surface 200 of the rotor 20 along a plane perpendicular to the axis of rotation x, as shown in FIG. 1. Therefore, an eccentricity is also a distance between the axis of rotation x and the surface 200 of the rotor 20 along a plane perpendicular to the axis of rotation x when the rotational movement of the rotor 20 is no longer concentric.Thus, the eccentricity, when the rotational movement of the rotor 20 is no longer concentric, is greater than the radius R.
[0039] The rolling device 100 also comprises a tolerance with respect to the rotation of the rotor 20. The tolerance of the rolling device 100 is a radial distance from the rotor 20, i.e. along a radial axis R, defined in which the rolling function of the rolling device 100 is performed. If the rotational movement of the rotor 20, in other words if an eccentricity in the rotation of the rotor, exceeds this operating tolerance, then the rolling device 100 performs its rolling function of the rotor 20 in a degraded manner. This tolerance can thus be interpreted as a clearance between the rotor 20 and the rolling device 100.
[0040] The first element 110' is also positioned in the immediate vicinity of the rotor 20. The first element 110' then also comprises a second tolerance with respect to the rotation of the rotor 20. And, as for the rolling device 100, this second tolerance is a radial distance from the rotor 20, that is to say along the radial axis. However, unlike the rolling device 100, the second tolerance is translated as the threshold distance translating adequate or inadequate operation of the rotor. 20. In other words, if the rotational movement of the rotor 20, or if the potential eccentricities in the rotation of the rotor 20, remain less than the distance defined by the second tolerance, then the rotor 20 operates nominally. Therefore, the first element 110' is not driven by the rotor and the detection device 110 is in the rest configuration. Conversely, if the potential eccentricities in the rotation of the rotor 20 are greater than the distance defined by the second tolerance, then the rotor 20 operates in a degraded manner. The first element 110' is then driven in rotation by the rotor 20, which, preferentially, comes into contact with the first element 110' and the detection device 110 then switches into the braking configuration. Therefore, the first tolerance of the rolling device 100 is less than the second tolerance of the detection device 110.In this way, in the rest configuration of the detection device 110, the rotor 20 is in contact only with the rolling device 100. And, in the braking configuration, the measurable eccentricity at the rotation of the rotor 20 allows the rotor 20 to drive the first element 110' in rotation and to detect this eccentricity by means of the second element 110”.
[0041] As an indicative example, for a rolling device 100 having a tolerance of 7 micrometers, i.e. there is a distance separating the surface 200 of the rotor 20 from the rolling device 100 equal to 7 micrometers, it may be envisaged that the second tolerance or distance between the surface 200 of the rotor 20 and the first element 110' is equal to 10 micrometers. Advantageously, it may be envisaged to define the distance separating the surface 200 of the rotor 20 from the first element 110', i.e. the second tolerance, relative to the distance separating the surface 200 of the rotor 20 from the rolling device 100. More precisely, the distance separating the surface 200 of the rotor 20 from the first element 110', i.e. the second tolerance, may be defined according to the following formula: D2 = x*Dl
[0042] Where D2 represents the distance separating the surface 200 of the rotor 20 from the first element 110, namely the second tolerance, D\ represents the distance separating the surface 200 of the rotor 20 from the rolling device 100, namely the first tolerance, andx represents the eccentricity detection ratio.
[0043] Preferably, the eccentricity detection ratio x is greater than 1 and less than 1.5. In an ideal configuration, the eccentricity detection ratio x is equal to 1.2.
[0044] Preferably, the first element 110' is juxtaposed with the rolling device 100 relative to the axis of rotation x. Therefore, from the point of view of the plane perpendicular to the axis of rotation x, the first element 110' and the rolling device 100 are superimposed. The first element 110' and the rolling device 100 are therefore positioned side by side, and preferably close to each other along the axis of rotation X- H it is not necessary for the first element 110' and the rolling device 100 to be linked.
[0045] Ideally, the first element 110' is fixed against the rolling device 100 so as to allow the detection device 110 to detect any eccentricity as close as possible to the rolling device 100.
[0046] The first torque increasing element 110' also comprises at least one protrusion 410. The at least one protrusion 410 takes the form of a protuberance. The second brake element 110" comprises a mechanical stop 420 of a shape complementary to the protrusion 410 allowing the at least one protrusion 410 to be in abutment or to bear against the stop 420. Preferably, the first element 110' comprises at least two protrusions 410 and the second brake element 110'' comprises the same number of mechanical stops 420.
[0047] Thus, in the braking configuration, the at least one protrusion 410, which undergoes the rotation of the first element 110', comes into contact with the mechanical stop 420 which exerts a force opposite to the rotation torque. Conversely, in the rest configuration of the detection device 110, the at least one protrusion 410 is distant from the stop 420.
[0048] Furthermore, the at least one protrusion 420 may preferably extend along the radial axis R.
[0049] Alternatively, the at least one protrusion 410 may extend parallel to the rotation axis X. This architecture then makes it possible to offset the first element 110' and the second element 110' along the rotation axis x so as to guarantee a distance between the first element 110' and the second element 110' in the rest configuration of the detection device 110.
[0050] Figure 2 shows a sectional view of the bearing of Figure 1 along a plane parallel to the axis of rotation X-
[0051] Furthermore, it may also be envisaged to add, in addition to the detection device 110, a mechanical fuse at the rotor. The mechanical fuse then makes it possible to generate a mechanical decoupling in the rotor 20 when the detection device 110 switches into the braking configuration. Indeed, as stated previously, the braking configuration makes it possible to generate, by means of the second element 110”, a braking force opposed to the rotational torque of the rotor 20 that is significant and sufficient for the mechanical fuse to activate and break. Thus, when the rotation of the rotor 20 is no longer concentric, that is to say when the axis of rotation x of the rotor 20 is mobile in any way, then the rotor 20, by virtue of its inhomogeneous movement and its eccentricity, drives the first element 110' in rotation, which thus acts as a means of increasing the torque of the rotor 20 by being in rotation with the rotor 20. From then on, this increased torque is detected by the detection device 110 by means of the second element 110” which comes into contact with the first element 110' so as to generate a friction torque sufficient to break the section to be broken, i.e. the mechanical fuse, in order to stop any rotation of the rotor 20 and the first element 110'. The rotor 20 is then immobilized before its rotation degenerates too strongly.
[0052] [Fig. 3] represents a schematic view of a preferred architecture of the first element 110' making it possible to increase the torque of the rotor 20 during its rotation, when the rotation of the rotor 20 is eccentric. Preferably, the first element 110' partially takes the form of an annular ring and as such comprises at least one concentric section 405 adapted to the shape of the rotor 20. As stated previously, the first element 110' also comprises, as stated previously, at least one protrusion 410.
[0053] As stated previously, the rotor 20 is distant from the at least one concentric section 405. As an indicative example, the clearance, i.e. the distance separating the surface 200 of the rotor 20 from the concentric section 405 of the first element 110' may be between 0.001% and 0.05% of the diameter of the rotor 20. As an indicative example, the clearance between the surface 200 of the rotor 20 and the concentric section 405 of the first element 110' may be between 0.02 millimeters and 5 millimeters.
[0054] Thus, when the rotation of the rotor 20 is no longer perfectly concentric and the surface 200 is in contact with the concentric section 405, the first element 110' is driven in rotation with the rotor 20 until the protrusion 410 is in contact with the stop 420 and immobilizes the rotor 20 and first element 110' assembly.
[0055] For information purposes, in order to drive the first element 110' in rotation by means of the contact between the surface 200 and the concentric section 405, the friction torque between the surface 200 and the concentric section 405 must be greater than 0.5 Nm.
[0056] Advantageously, the first element 110' may also comprise a damping section 415 arranged close to the protrusion 405. More precisely, along a plane perpendicular to the axis of rotation x of the rotor 20, the stop 420 of the second element 110" is between the damping section 415 and the protrusion 410 of the first element 110'. Indeed, the local stresses at the interface between the protrusion 410 and the stop 420 being high, and for information purposes, greater than 800 Mpa, the damping section 415 withstands these stresses by deforming in particular so as to avoid any breakage of the first element 110'. The damping section 415 acts like a compression spring in order to withstand the local stresses during braking of the first element 110' and the rotor 20.
[0057] The second element 110'' shown in [Fig.4], comprises at least one stop 420 configured to interact directly with the at least one protrusion 410 of the first element 110' when the first element 110' is rotated by the rotor 20.
[0058] The invention thus proposes a so-called passive uncoupling device. Indeed, during a loss of lubrication or a slow or sudden breakage of a bearing, this breakage leads to a loss of guidance of the bearing of the rolling or other type. The detection device 110 then makes it possible to detect the orbiting of the rotor 20 and produce a torque resisting the rotation of the rotor 20. The invention also makes it possible not to add any additional controlled element other than that provided for the operation of the rotating machine, therefore advantageously has no impact on the volume and a negligible weight impact.
Claims
Claims
1. A rotating machine comprising a coaxial rotor (20) and stator (30), the rotor (20) being configured to be rotatable about an axis of rotation x, the rotating machine comprising at least one bearing (10) configured to guide the rotation of the rotor (20), the at least one bearing (10) being in contact with a surface (200) of the rotor (20), the bearing (10) comprising a rolling device (100) extending concentrically around the rotor (20) and a detection device (110) for a rotation defect, the detection device (110) for a rotation defect comprising a first element (110') and a second element (110”), the first element (110') extending concentrically around the rotor (20), the second element (110”) being integral with the stator (30), the detection device (110) being configured to switch from a configuration rest, in which the first element (110') is distant from the rotor (20) and from the second element (110”),to a braking configuration, in which the first element (110') is rotated by the rotor (20) and in which the second element (110”) exerts a reaction opposite to the rotation of the rotor (20) on the first element (110'), the detection device (110) being configured to switch from the rest configuration to the braking configuration when the rotation of the rotor (20) is eccentric relative to the axis of rotation x.,
2. A rotating machine according to claim 1, wherein the first element (110') is juxtaposed with the rolling device (100) along the axis of rotation X-
3. A rotating machine according to claim 1, wherein the rolling device (100) is spaced from the surface (200) of the rotor (20) by a first predefined distance, the first element (110') being spaced from the surface (200) of the rotor (20) by a second distance, the second distance being defined according to the following formula: D2 = x*D} Where D2 represents the second distance separating the surface (200) of the rotor (20) from the first element (110), represents the first distance separating the surface (200) of the rotor (20) from the rolling device (100) and x represents the predefined eccentricity detection ratio.
4. A rotating machine according to claim 1, wherein the first
5. element (110') comprises a protrusion (410) and wherein the second element (110”) comprises a stop (420), the stop (420) being in contact with the protrusion (410) in the braking configuration and distant from the protrusion (410) in the rest configuration. Rotating machine according to claim 4, in which the protrusion (410) is defined along an axis radial to the rotor (20).