ROTATING MACHINE ASSEMBLY INCLUDING A BEARING WITH OIL FILM COMPRESSION DAMPING
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2021-12-02
- Publication Date
- 2026-06-26
Abstract
Description
Description Title of the invention: ASSEMBLY FOR ROTATING MACHINE COMPRISING A BEARING WITH SHOCK ABSORBER OIL FILM COMPRESSION WEAVING technical field
[0001] = The invention relates to an assembly for a rotating machine, a rotating machine including such an assembly and a turbomachine formed by such a machine rotating. PREVIOUS STATE OF THE ART
[0002] — Conventionally, aircraft turbomachine shafts are guided in rotation by roller bearings to which shock absorbers can be associated by com- Oil film pressure, also called "squeeze film damper" in English. The document EP 1 650 449 A1 describes an example of an oil film compression damper.
[0003] Such a damper is notably formed by an annular damping chamber, spaced between a part integral with the outer ring of the bearing and a housing surrounding said outer ring, delimited by two sealing devices such as segments, and supplied with a low-compressibility fluid and preferably with Oil under pressure through one or more ports provided for this purpose in the crankcase. Such a The damper dampens the radial vibrations of the shaft caused by its rotation. and by the imbalance of its mechanical load. This damping depends in particular the radial play of the damping chamber, that is to say its thickness, as well as the pressure of the fluid supplying the damping chamber.
[0004] — However, depending on the operating phases of the turbomachine, the damping The desired damping for the shaft can vary. A rigid shaft damping can, for example, for example, being favorable for certain operating phases of the turbomachine while other operating phases of the turbomachine require more flexibility in the shaft's damping.
[0005] … Furthermore, the control of the fluid pressure supplying the chamber damping, which can allow for more or less rigidity to be given Damping is limited if the required pressure is too low due to risks of cavitation or even air ingress into the damping chamber can degrade the operation of the shock absorber.
[0006] Finally, depending on the operating phases of the turbomachine, the radial clearance Optimal clearance can vary. A small, or conversely, a large radial clearance can be advantageous for certain operating phases of the turbomachine and unfavorable in other operating phases of the turbomachine. Therefore, there is a need to offer a fluid film compression damper that is more adaptable to the different operating phases of the turbomachine. Description of the invention To this end, the invention relates to an assembly for a rotating machine rotating about a central axis of axial orientation, comprising a bearing to guide a shaft of said rotating machine and a stator element having an inner annular surface delimiting an annular housing in which the bearing is housed, the bearing comprising an outer ring having an outer annular surface radially oriented towards the stator element and a movable ring radially interposed between the stator element and the outer ring and defining radially with the outer ring and / or with the stator element a first and / or a second cavity designed to receive a flow of a pressurized fluid so as to form a circumferential fluid film capable of damping a displacement of the outer ring relative to the stator element in a plane orthogonal to the central axis,the moving ring having an inner annular surface radially delimiting the first cavity with the outer annular surface of the outer ring and / or an outer annular surface radially delimiting the second cavity with the inner annular surface of the stator element. According to the invention, at least one of the inner and outer annular surfaces of the moving ring is conical and the moving ring is able to move axially relative to the stator element, so as to vary a volume of the first and / or the second cavity. According to various implementations which can be taken together or separately: - the inner annular surface and the outer annular surface of the moving ring are axially convergent-divergent; - the inner annular surface of the moving ring and the outer annular surface of the outer ring are cylindrical or conical and their generatrices form the same first angle with the central axis; - the outer annular surface of the moving ring and the inner annular surface of the stator element are cylindrical or conical and their generatrices form the same second angle with the central axis; - the bearing includes sealing elements axially delimiting the first and / or second cavity and forming annular segments with which the moving ring is mounted to slide axially via an internal or external annular surface in permanent contact with the external or internal annular surface of the moving ring; - the annular segments forming the sealing elements are self-adjusting diameter by overlap; - the assembly includes an actuator designed to move the movable ring in axial translation relative to the stator element between a minimum damping clearance position, in which a volume of the first and / or second cavity is minimal, and a maximum damping clearance position, in which the volume of the first and / or second cavity is maximal; - the actuator is servo-controlled according to the axial position of the movable ring; - the assembly includes a first stop designed to block the movable ring in axial translation, in a direction from the maximum damping clearance position to the minimum damping clearance position, when the movable ring moves from the maximum damping clearance position to the minimum damping clearance position and reaches the minimum damping clearance position; - the assembly includes a second stop designed to block the moving ring in axial translation, in a direction from the position of minimum damping clearance to the position of maximum damping clearance, when the moving ring moves from the position of minimum damping clearance to the position of maximum damping clearance and reaches the position of maximum damping clearance. The invention also relates to a rotating machine comprising a shaft and an assembly as previously described to guide the shaft in rotation around the central axis. The invention also relates to a turbomachine formed by a rotating machine as previously described. Brief description of the drawings Other aspects, objectives, advantages, and features of the invention will become clearer upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which: [Fig.1] is a schematic axial half-section view of a turbojet engine according to an embodiment of the invention: [Fig.2] is a schematic axial cross-sectional view of an assembly consisting of a bearing and a stator element, according to an embodiment of the invention, a movable ring of the bearing occupying a position of minimum damping clearance; [Fig.3] is a schematic axial cross-sectional view of the assembly illustrated in [Fig.2], with the moving ring of the bearing occupying the position of minimum damping clearance; [Fig.4] is a schematic axial cross-sectional view of the assembly illustrated in figures 2 and 3, with the moving ring of the bearing occupying a position of maximum damping clearance; [Fig.5] is a schematic axial cross-sectional view of the assembly according to another embodiment of the invention, the movable ring of the bearing occupying a position of maximum damping clearance; [Fig.6] is a schematic axial cross-sectional view of the assembly illustrated in [Fig.5], with the moving ring of the bearing occupying the position of minimum damping clearance; [Fig.7] is a schematic axial cross-sectional view of the assembly illustrated in figures 5 and 6, with the moving ring of the bearing occupying a position of maximum damping clearance; [Fig.8] is a schematic view of examples of sealing elements for the assembly illustrated in figures 2 to 7. DETAILED DESCRIPTION As a preliminary matter, an axial direction is defined, a radial direction which is orthogonal to the axial direction and a circumferential direction which is orthogonal to the axial and radial directions. Figure [Fig. 1] shows an example of a 10-engine turbojet for an aircraft. The turbojet 10 comprises a gas generator 11 forming, from upstream to downstream in the direction of gas flow along the axial direction, a low pressure compressor 12, a high pressure compressor 13, a combustion chamber 14, a high pressure turbine 15, a low pressure turbine 16 and an exhaust nozzle 17. The low-pressure compressor 12 and the low-pressure turbine 16 form a low-pressure unit and are connected to each other by a low-pressure shaft 18 centered on a central axis 19 with axial orientation. Similarly, the high-pressure compressor 13 and the high-pressure turbine 15 form a high-pressure unit and are connected to each other by a high-pressure shaft 20 centered on the central axis 19 and arranged around the low-pressure shaft 18. The turbojet 10 also includes, upstream of the gas generator 11, a fan 21 surrounded by a fan housing. The fan is driven in rotation around the central axis 19 by the low-pressure shaft 18, either directly or via a speed reducer. The turbojet 10 can further define a primary channel 22 intended for the flow of a primary flow through the gas generator 11, as well as a secondary channel 23 intended for the flow of a secondary flow located radially outside with respect to the primary flow. The low-pressure shaft 18, the high-pressure shaft 20, and a hub 24 of the fan 21 are guided in rotation about the central axis 19 by means of bearings 101 supported by housings of the turbojet 10. At least one of these bearings 101 is part of the... integral of an assembly 100 according to the invention, of which Figures 2 to 7 show various non-limiting examples of embodiment. The assembly 100 described below is also applicable to other turbomachine architectures such as shaft bearings connecting a compressor and an intermediate pressure turbine. More specifically, the assembly 100 comprises a bearing 101 and a stator element 102, such as a part of the housing or a component mechanically attached to it. The stator element 102 has an inner annular surface 103 defining an annular housing 104 in which the bearing 101 is housed. The bearing 101 comprises an inner ring 105 fixed to either the low-pressure shaft 18 or the high-pressure shaft 20, an outer ring 106, and rolling elements 107 extending radially between the inner ring 105 and the outer ring 106. Each of the inner ring 105 and outer ring 106 forms, in particular, a raceway for the rolling elements 107, said rolling elements 107 being circumferentially spaced around the central axis 19 by means of a separating cage (not shown). Each of the inner ring 105 and outer ring 106 can be made in one piece, as is the case in Figures 2 to 7. Alternatively (not shown), each of the inner ring 105 and outer ring 106 is formed by two half-rings. The rolling elements 107 are, for example, cylindrical rollers. In the first variant (not illustrated), the rolling elements 107 are conical or barrel rollers.In a second variant (not illustrated), the rolling elements 107 are balls arranged to form a ball bearing with two, three or four contact points. The outer ring 106 comprises, for example, a bearing portion 106a in which the raceway of the rolling elements 107 is formed, and a squirrel cage 106b, also called a flexible cage, extending axially, for example towards Laval, the bearing portion 106a. The squirrel cage 106b can be made as a single piece with the bearing portion 106a. Alternatively (not shown), the bearing portion 106a and the squirrel cage 106b form two separate parts assembled together. The squirrel cage 106b has radial openings 108 circumferentially distributed around the central axis 19, so as to impart flexibility. The squirrel cage 106b may further include an end 109, here a downstream end, which is axially arranged opposite the bearing portion 106a with respect to the radial openings 108 and which is fixed to the stator element 102. For this purpose, said end 109 is, for example, formed by a radial flange fixed to a corresponding radial flange 110 of the stator element 102. The squirrel cage 106b is elastically deformable so as to allow a small translational displacement of the outer ring 106, in a plane orthogonal to the central axis 19. The squirrel cage 106b thus ensures a suspension function. The outer ring 106, in particular the bearing portion 106a, further has an outer annular surface 111 radially oriented towards the stator element 102. The bearing 101 further includes a movable ring 112 radially interposed between the stator element 102 and the outer ring 106, in particular the bearing portion 106a, and defining radially with the outer ring 106 and / or with the stator element 102 a first and / or a second cavity 113, 114 designed to receive a flow of a fluid under pressure, such as oil, so as to form a circumferential film of fluid capable of damping a displacement of the outer ring 106 relative to the stator element 102 in a plane orthogonal to the central axis 19. The cavity or cavities 113, 114 thus provide damping by compression of the oil film, also called "squeeze film damper". The movable ring 112 has an inner annular surface 115 radially delimiting the first cavity 113 with the outer annular surface 111 of the outer ring 106 and / or an outer annular surface 116 radially delimiting the second cavity 114 with the inner annular surface 103 of the stator element 102. In order to introduce oil into the first and / or second cavity 113, 114, one or more supply channels 135 formed in the stator element 102 open, for example, onto the outer annular surface 116 of the moving ring 112, where appropriate, into the second cavity 114, and communicate with the first cavity 113 via one or more orifices 136 formed in the moving ring 112. According to the invention, at least one of the inner annular surfaces 115 and outer annular surfaces 116 is conical, and the movable ring 112 is able to move axially relative to the stator element 102, so as to vary a volume of the first and / or the second cavity 113, 114. In other words, the axial displacement of the movable ring 112 makes it possible to vary the thickness of the oil film in the first and / or the second cavity 113, 114. The "thickness" of the oil film is understood to be the radial distance between the outer annular surface 111 of the outer ring 106 and the inner annular surface 115 of the movable ring 112 and / or between the outer annular surface 116 of the movable ring 112 and the inner annular surface 103 of the stator element 102.The axial displacement of the movable ring 112 thus allows both a radial deflection of the movable ring 112 and a rigidity of the damping by compression and circulation of oil film operated by the first and / or the second cavity 113, 114 to be varied, and therefore makes this damping more adaptable according to the operating phases of the turbojet 10. The inner annular surface 115 of the movable ring 112 and the outer annular surface 111 of the outer ring 106 are, for example, cylindrical (figures 2 to 4). In alternative (figures 5 to 7), the inner annular surface 115 of the movable ring 112 and the outer annular surface 111 of the outer ring 106 are conical and their generatrices form the same first angle with the central axis 19. In each axial position of the movable ring 112, the thickness of the oil film of the first cavity 113 is thus constant. The outer annular surface 116 of the moving ring 112 and the inner annular surface 103 of the stator element 102 are, for example, conical, and their generatrices form the same second angle with the central axis 19 (Figures 2 to 7). Alternatively (not shown), the outer annular surface 116 of the moving ring 112 and the inner annular surface 103 of the stator element 102 are cylindrical. In each axial position of the moving ring 112, the thickness of the oil film in the second cavity 114 is thus constant. The inner annular surface 115 and the outer annular surface 116 of the moving ring 112 are axially convergent-divergent. For example, they converge upstream and diverge downstream. The same is true of the outer annular surface 111 of the outer ring 106 and the inner annular surface 103 of the stator element 102. The moving ring 112 thus has a thickness that varies along the axial direction. The "thickness" of the moving ring 112 is understood to be the radial distance between the inner annular surface 115 and the outer annular surface 116 of the moving ring 112. One or more of the outer annular surface 111 of the outer ring 106, the inner annular surfaces 115 and outer annular surfaces 116 of the moving ring 112 and the inner annular surface 103 of the stator element 102 may have projections or recesses, in particular non-axissymmetric, so as to create local pressure and velocity variations of the oil in the first and / or second cavity 113, 114. The bearing 101 may also include sealing elements 117, 118 axially delimiting the first and / or second cavity 113, 114 ([Fig. 2]). The sealing elements 117, 118 ensure the sealing of the first and / or second cavity 113, 114. For this purpose, the sealing elements 117, 118 form, for example, annular segments with which the movable ring 112 is axially slidably mounted, notably via an inner annular surface 119 or outer annular surface 120 in permanent contact with the outer annular surface 116 or inner annular surface 115 of the movable ring 112. The annular segments forming the sealing elements 117, 118 are, in particular, diameter-compensating by overlap, their free ends being designed to remain in contact with each other when a diameter of said annular segments varies. The sealing elements 117, 118 thus ensure The sealing of the first and / or second cavity 113, 114 regardless of the axial position of the movable ring 112. For this purpose, said free ends may each have a flat surface or be beveled. Figure 8 shows examples of such annular segments. The inner annular surface 119 of the sealing elements 117 axially delimiting the first cavity 113 is, in particular, cylindrical when the outer annular surface 116 of the movable ring 112 with which it is in contact is cylindrical (Figures 2 to 4). Conversely, it is conical and of the same generating direction as the outer annular surface 116 of the movable ring 112 with which it is in contact, when said outer annular surface 116 is conical (Figures 5 to 7). Similarly, the outer annular surface 120 of the sealing elements 118 axially delimiting the second cavity 114 is, in particular, cylindrical when the inner annular surface 115 of the movable ring 112 with which it is in contact is cylindrical. It is conical, however, and of the same generatory type as the inner annular surface 115 of the movable ring 112 with which it is in contact, when said inner annular surface 115 is conical (figures 2 to 7). The sealing elements 117, 118 can each be housed in grooves 121, 122 cut into the outer annular surface 111 of the outer ring 106 and / or in the inner annular surface 103 of the stator element 102. The sealing elements 117, 118 are in particular in axial contact with the groove 121, 122 in which they are housed. According to an unillustrated embodiment of the invention, the first and / or second cavity 113, 114 are axially segmented by sealing elements 117, 118 as previously described. Each segment of the first and / or second cavity 113, 114 can be supplied by a separate supply channel 135, so as to allow them to be supplied with fluid at different pressures. Forced oil circulation between the first and second cavities 113, 114 can also be created when only one of said first and second cavities 113, 114 is segmented, thus allowing for better distribution of the oil in said first and second cavities 113, 114. The assembly 100 also includes, for example, an actuator 123 designed to move the movable ring 112 in axial translation relative to the stator element 102 between a minimum damping clearance position (Figures 2, 3, and 6), in which the volume of the first and / or second cavity 113, 114 is minimal, and a maximum damping clearance position (Figures 4, 5, and 7), in which the volume of the first and / or second cavity 113, 114 is maximal. In the minimum damping clearance position, the volume of the first or second cavity 113, 114 may be zero. "Zero volume" is understood to mean that a radial distance between the The volume of the inner annular surfaces 115, 103 and the outer annular surfaces 111, 116 of the moving ring 112 and the outer ring 106, or of the stator element 102 and the moving ring 112, is zero, and therefore these surfaces are in contact with each other. For example, in Figures 2, 3, and 6, the volume of the second cavity 114 is zero. The moving ring 112 can, of course, occupy any intermediate position between the minimum damping clearance position and the maximum damping clearance position. The actuator 123 can also be servo-controlled based on the axial position of the moving ring 112. For this purpose, the actuator 123 includes, for example, at least one actuation assembly consisting of a cylinder 124 and a rod 125 equipped with a piston 126 mounted to slide axially within the cylinder 124 ([Fig. 2]). Several actuation assemblies are, for example, distributed circumferentially, regularly or irregularly, around the central axis 19. The piston 126 defines two chambers 127, 128 inside the cylinder 124, which are supplied with fluid, in particular air or oil. A variation in the fluid pressure difference between the two chambers 127, 128 of the cylinder 124 causes axial sliding of the piston 126 and therefore of the rod 125. The two chambers 127, 128 are, for example, supplied with fluid by a fluid circuit (not shown) controlled by an electronic control unit (not shown). Alternatively, the pneumatic or hydraulic actuator 123 can be replaced by an electric actuator. The rod 125 further has a first end 129 arranged outside the cylinder 124 and mounted fixed in axial translation with the movable ring 112. In this way, when the rod 125 slides axially due to a variation in the fluid pressure difference between the two chambers 127, 128 of the cylinder 124, it drives the movable ring 112 in axial translation. The first end 129 of the rod 125 can also be mounted to slide relative to the movable ring 112 in the radial plane, so as to leave the movable ring 112 free in radial translation. The assembly 100 may also include a first stop 130 designed to block the movable ring 112 in axial translation, in a direction from the position of maximum damping clearance to the position of minimum damping clearance, here upstream, when the movable ring 112 moves from the position of maximum damping clearance to the position of minimum damping clearance and reaches the position of minimum damping clearance (Figures 2, 3 and 6). This prevents the movable ring 112 from jamming between the outer ring 106 and the stator element 102 due to the taper of at least one of the inner 115 and outer 116 annular surfaces of the movable ring 112. The first stop 130 is, for example, formed by an axial surface of the stator element 102 arranged opposite a radial flange 131 of the movable ring 112, the radial flange 131 being designed to come into contact with the axial surface of the element of stator 102, when the movable ring 112 moves axially from the position of maximum damping clearance to the position of minimum damping clearance and reaches the position of minimum damping clearance. The radial flange 131 of the movable ring 112 is arranged on the thicker side of the movable ring 112. The assembly 100 may also include a second stop 132 designed to block the movable ring 112 in axial translation, in a direction from the minimum damping clearance position to the maximum damping clearance position, here downstream, when the movable ring 112 moves from the minimum damping clearance position to the maximum damping clearance position and reaches the maximum damping clearance position (Figures 4, 5, and 7). This prevents, in particular, the movable ring 112 from releasing the sealing elements 117, 118, thus compromising the sealing of the first and / or second cavity 113, 114.The second stop 132 is, for example, formed by an external axial surface of the cylinder 124 arranged opposite a projection 133 of the rod 125 of the actuator 123. The projection 133 is designed to come into contact with the external axial surface of the cylinder 124 when the rod 125 moves the movable ring 112 in axial translation from the position of minimum damping clearance to the position of maximum damping clearance, and the movable ring 112 reaches the position of maximum damping clearance. The projection 133 is notably supported by a second end 134 of the rod 125 when the first end 129 of the rod 125 moves away from the cylinder 124 to drive the movable ring 112 in axial translation towards the position of maximum damping clearance (Figures 2 to 7).The projection 133, on the other hand, is located on the side of the first end 129, when the first end 129 of the rod 125 approaches the cylinder 124 to drive the movable ring 112 in axial translation towards the position of maximum damping clearance. The projection 133 can be annular (Figures 2 to 7) or be angularly located. The stator element 102 can be made from several assembled parts. For example, the stator element 102 comprises a first part 137 including an annular portion 138 in which the inner annular surface 103 of the stator element 102 is formed and a central radial flange 139 extending from the annular portion 138, and a second part 140 carrying the radial flange 110 of the stator element 102, which is fixed to the squirrel cage 106b, and further comprising another radial flange 141 offset axially with respect to the radial flange 110, here upstream, and fixed to the central radial flange 139 of the first part 137 (Figures 2 and 5). Alternatively (not shown), the stator element 102 is made from a single piece. The set 100 described above is particularly advantageous because it allows to adapt the rigidity of the compression damping of the oil film operated between the bearing 101 and the stator element 102 to the different operating phases of the turbojet 10, by axially moving the movable ring 112 relative to the stator element 102 to vary the thickness of the oil film(s).
Claims
Demands
1. Assembly (100) for rotating machine (10) rotating about an axis central (19) axially oriented, comprising a bearing (101) to guide a shaft (18, 20) of said rotating machine (10) and an element of stator (102) having an inner annular surface (103) delimiting an annular housing (104) in which the landing (101) is housed, the bearing (101) comprising an outer ring (106) having a outer annular surface (111) radially oriented towards the element of stator (102) and a radially interposed movable ring (112) between the stator element (102) and the outer ring (106) and defining ra- dialement with the outer ring (106) and / or with the stator element (102) a first and / or a second cavity (113, 114) designed for receive a flow of pressurized fluid so as to form a circumferential film of fluid capable of damping a displacement of the outer ring (106) relative to the stator element (102) in a plane orthogonal to the central axis (19), the movable ring (112) presenting an inner annular surface (115) radially delimiting the first cavity (113) with the outer annular surface (111) of the ex- ring exterior (106) and / or an exterior annular surface (116) delimiting ra- diamentally the second cavity (114) with the inner annular surface (103) of the stator element (102), the assembly (100) being characterized in that at least one of the surfaces inner (115) and outer (116) annular rings of the movable ring (112) is conical and in that the movable ring (112) is able to move axially with respect to the stator element (102), so as to vary a volume of the first and / or second cavity (113, 114).
2. Assembly (100) according to claim 1, wherein the surface inner annular surface (115) and outer annular surface (116) of the movable ring (112) are axially convergent-divergent.
3. Assembly (100) according to claim 1 or claim 2, in which the inner annular surface (115) of the movable ring (112) and the outer annular surface (111) of the outer ring (106) are cylindrical or the inner annular surface (115) of the movable ring (112) and the outer annular surface (111) of the outer ring (106) are conical and their generatrices form the same first angle with the central axis (19).
4. Assembly according to any one of claims 1 to 3, wherein the surface outer annular (116) of the movable ring (112) and the surface The inner annular portion (103) of the stator element (102) is cylindrical. or the outer annular surface (116) of the movable ring (112) and the inner annular surface (103) of the stator element (102) are conics and their generatrices form the same second angle with the central axis (19).
5. Set (100) according to any one of claims 1 to 4, wherein the bearing (101) includes sealing elements (117, 118) delimiting axially the first and / or second cavity (113, 114) and forming annular segments with which the movable ring (112) is mounted sliding axially via an annular surface in- interior (119) or exterior (120) in permanent contact with the surface outer (116) or inner (115) annular segment of the movable ring (112).
6. Assembly (100) according to claim 5, wherein the annular segments Nulars forming the sealing elements (117, 118) are to be made up of diameter per overlap.
7. Assembly (100) according to any one of claims 1 to 6, comprising an ac- tionneur (123) designed to move the movable ring (112) in translation axial relative to the stator element (102) between a play position minimum depreciation, in which a volume of the first and / or of the second cavity (113, 114) is minimal, and a playing position maximum damping, in which the volume of the first and / or of the second cavity (113, 114) is maximal.
8. Assembly (100) according to claim 7, wherein the actuator (123) is servo-controlled according to the axial position of the movable ring (112).
9. Assembly (100) according to claim 7 or claim 8, including a first stop (130) designed to lock the ring mobile (112) in axial translation, in a direction from the position of maximum damping clearance towards the damping clearance position minimal, when the movable ring (112) moves from the playing position maximum damping towards the damping play position minimal and reaches the minimum damping play position.
10. Assembly (100) according to any one of claims 7 to 9, comprising a second stop (132) designed to block the movable ring (112) by axial translation, in a direction from the playing position minimum damping towards the damping play position maximum, when the movable ring (112) moves from the playing position minimum damping towards the damping play position maximum and reaches the position of maximum damping clearance.
11. Rotating machine (10) comprising a shaft (18, 20) and an assembly (100) according to any one of claims 1 to 10 to guide the shaft (18, 20) rotating around the central axis (19).
12. Turbomachine (10) formed by a rotating machine according to claim- indication 11.