(19)
(11)EP 3 442 898 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
01.04.2020 Bulletin 2020/14

(21)Application number: 17728941.0

(22)Date of filing:  17.04.2017
(51)Int. Cl.: 
B66C 23/84  (2006.01)
F16C 39/02  (2006.01)
F16C 19/30  (2006.01)
F16C 35/06  (2006.01)
F16C 21/00  (2006.01)
B66C 23/52  (2006.01)
(86)International application number:
PCT/NL2017/050239
(87)International publication number:
WO 2017/179986 (19.10.2017 Gazette  2017/42)

(54)

SLEW BEARING, METHOD FOR USING A SLEW BEARING, HOISTING CRANE AND VESSEL

DREHKRANZLAGER, VERFAHREN ZUR VERWENDUNG EINES DREHKRANZLAGERS, HEBEKRAN UND SCHIFF

PALIER DE PIVOTEMENT, PROCÉDÉ D'UTILISATION D'UN PALIER DE PIVOTEMENT, GRUE DE LEVAGE ET NAVIRE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 15.04.2016 NL 2016617

(43)Date of publication of application:
20.02.2019 Bulletin 2019/08

(73)Proprietor: Itrec B.V.
3115 HH Schiedam (NL)

(72)Inventors:
  • SLOB, Wouter Johannes
    3115HH Schiedam (NL)
  • TIELEMAN, Hubertus Lourens Leendert
    3115HH Schiedam (NL)
  • ROODENBURG, Joop
    3115HH Schiedam (NL)
  • VAN DER HOEK, Teunis
    3115HH Schiedam (NL)

(74)Representative: EP&C 
P.O. Box 3241
2280 GE Rijswijk
2280 GE Rijswijk (NL)


(56)References cited: : 
WO-A1-2015/060720
WO-A1-2015/088332
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The invention relates to a slew bearing, a method for using a slew bearing, a hoisting crane and a vessel.

    [0002] Slew bearings are known to allow large structures to rotate relative to a base about a substantially vertical rotation axis while transmitting weight loads, tilting loads and/or radial loads between the large structure and the base.

    [0003] An example of such a large structure is a hoisting crane which is a large type crane that is for example used in the off shore industry, e.g. see WO2015/088332A1 of the same applicant. Hoisting cranes have a crane structure comprising a crane housing and a jib, which jib is often configured to be pivoted about a substantially horizontal axis. The slew bearing is then provided between the crane housing and a base supporting the crane structure allowing the crane structure and thus the jib to be rotated about a vertical rotation axis.

    [0004] Another example of such a large structure is a turret as for instance used in floating production, storage and offloading vessels, wherein a slew bearing is arranged between the turret and the hull of the vessel to allow weathervaning in which the vessel will normally lay head to the prevailing environment.

    [0005] A drawback of slew bearings, especially large slew bearings that have to transmit relatively large loads, is that inspection and/or maintenance of the bearing may be regularly required to determine whether the slew bearing is still functioning properly and/or to keep the slew bearing in good condition. However, to allow inspection and/or maintenance, a part of or even the entire slew bearing needs to be dismantled to allow personnel access to the interior components of the slew bearing requiring inspection and/or maintenance. During this period, the slew bearing cannot perform its function and the large structure supported thereby are non-operational.

    [0006] It is therefore an object of the invention to provide a slew bearing which requires less downtime as a result of inspection and/or maintenance.

    [0007] This object is achieved by a slew bearing according to claim 1, comprising:
    • a stationary bearing ring to be fixed to a base;
    • a moveable bearing ring to be fixed to a moveable object and which moveable bearing ring is concentric with the stationary bearing ring,
    wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis,
    wherein the slew bearing further comprises an upper main axial bearing having a row of axial load rollers, which rollers are arranged between a top roller raceway and a bottom roller raceway, said top roller raceway being connected to the moveable bearing ring and said bottom roller raceway being connected to the stationary bearing ring, and said rollers configured to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring,
    wherein the slew bearing further comprises an upper auxiliary axial bearing having upper low-friction pads arranged on the moveable bearing ring and corresponding lower low-friction pads arranged on the stationary bearing ring to engage with the upper low-friction pads, wherein the upper low-friction pads are arranged parallel to the top roller raceway, and the lower low-friction pads are arranged parallel to the bottom roller raceway in order to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring when the upper and lower low-friction pads engage with each other, wherein the moveable bearing ring comprises one or more main portions with at least a part of the top roller raceway of the upper main axial bearing and one or more corresponding auxiliary portions, each auxiliary portion comprising at least a part of the upper low-friction pads,
    wherein the one or more main portions are moveable relative to the corresponding one or more auxiliary portions between an operational position, in which the at least part of the top roller raceway engages with axial load rollers to transfer axial loads between the moveable bearing ring and the stationary ring, and a maintenance position, in which the at least part of the top roller raceway is disengaged from the axial load rollers,
    and wherein the one or more auxiliary portions are configured such that the at least part of the upper low-friction pads are engageable with lower low-friction pads when the corresponding one or more main portions are in the maintenance position to transfer axial loads between the moveable bearing ring and the stationary ring.

    [0008] The advantage of the slew bearing according to the invention is that at least a part of the top roller raceway can be disengaged from the rollers for inspection of and/or maintenance to the upper main axial bearing while the corresponding loss of transferability of axial loads is compensated for by the upper auxiliary axial bearing so that during the inspection and/or maintenance the slew bearing is still operational although in some applications or embodiments it may be preferred to perform inspection and/or maintenance during favourable conditions as the full capacity of the slew bearing may not be available.

    [0009] In an embodiment, an actuator device is provided to move the one or more main portions between the operational position and the maintenance position.

    [0010] In an embodiment, the moveable bearing ring comprises a single main portion and a single auxiliary portion, but it is also envisaged that a plurality of auxiliary portions are provided that are evenly distributed over the circumference of the moveable bearing ring, e.g. ten auxiliary portions of about one meter long every 36 °.

    [0011] In an embodiment, the one or more main portions comprise the entire top roller raceway so that the entire upper main axial bearing can be inspected and/or maintained at once. In case the one or more main portions comprise only a part of the entire roller raceway, all the rollers can be inspected and/or maintained by either pushing the rollers around or by rotating the large structure until the rollers of interest are located at a main portion in the maintenance position to allow access to these rollers of interest. In this way all the rollers can be inspected and/or maintained.

    [0012] In an embodiment, the rollers are provided in a plurality of roller boxes, wherein preferably at least one of the roller boxes or the rollers contained therein is provided with a sensor for measuring a parameter or the condition of the slew bearing and a memory for storing measurement data. Providing a main portion in the maintenance position then allows to read out the memory to get offline access, e.g. by making a physical connection, to the measurement data omitting the need of (real-time) wireless communication. This also applies to applications that do not make use of roller boxes, but in which sensor and memory are provided in a single roller.

    [0013] In an embodiment, the slew bearing comprises an inner main radial bearing provided between the stationary bearing ring and the moveable bearing ring on an inner side of the stationary bearing ring and/or an outer main radial bearing provided between the stationary bearing ring and the moveable bearing ring on an outer side of the stationary bearing ring.

    [0014] In an embodiment, the inner main radial bearing and/or the outer main radial bearing are embodied as roller bearings comprising rollers arranged between a raceway on the moveable bearing ring and a raceway on the stationary bearing ring.

    [0015] In an embodiment, the rollers of the inner main radial bearing and/or the outer main radial bearing are substantially held in position using an upper groove and a lower groove, wherein preferably the upper groove is provided in a cover element that is removable allowing for easy assembly. The upper and lower grooves are preferably arranged in the stationary bearing ring, but may alternatively be arranged on the moveable bearing ring.

    [0016] The invention also relates to a hoisting crane comprising a crane structure, a slew platform supporting the crane structure, a base, and a slew bearing according to the invention, wherein the slew bearing is arranged between the base and the slew platform, wherein the stationary bearing ring is fixed to the base and the moveable bearing ring is fixed to the slew platform, thereby allowing the crane structure to rotate relative to the base about the rotation axis.

    [0017] In an embodiment, the one or more main portions and the one or more auxiliary portions are fixed to the slew platform, wherein the one or more auxiliary portions can be disconnected from the slew platform, wherein an actuator device is provided between auxiliary portions and the slew platform to lift the slew platform including the one or more main portions when the one or more auxiliary portions are disconnected from the slew platform thereby allowing to move the one or more main portions between the operational position and the maintenance position.

    [0018] The invention also relates to a vessel comprising a hull provided with an opening extending vertically through the hull, a turret extending in the opening of the hull, and a slew bearing according to the invention, wherein the slew bearing is arranged between the hull and the turret, wherein the stationary bearing ring is fixed to the hull and the moveable bearing ring is fixed to the turret, thereby allowing the turret to rotate relative to the hull about the rotation axis.

    [0019] In an embodiment, the one or more main portions and the one or more auxiliary portions are fixed to the turret, wherein the one or more auxiliary portions can be disconnected from the turret, wherein an actuator device is provided between auxiliary portions and the slew platform to lift the slew platform including the one or more main portions when the one or more auxiliary portions are disconnected from the slew platform thereby allowing to move the one or more main portions between the operational position and the maintenance position.

    [0020] The invention also relates to a method comprising the following steps:
    1. a) providing a slew bearing according to the invention with the one or more main portions being directly or indirectly connected to the one or more auxiliary portions with the one or more main portions in the operational position;
    2. b) disconnecting the one or more main portions from the one or more auxiliary portions;
    3. c) moving the one or more main portions to the maintenance position.


    [0021] In an embodiment, the method further comprises the step of performing inspection and/or maintenance on the upper main axial bearing, and subsequently moving the one or more main portions to the operational position followed by connecting the one or more main portions to the one or more auxiliary portions.

    [0022] In an embodiment, the one or more main portions and the one or more auxiliary portions are connected to a moveable object, wherein disconnecting the one or more main portions from the one or more auxiliary portions comprises disconnecting the one or more auxiliary portions from the moveable object, and wherein moving the one or more main portions to the maintenance position is carried out by providing an actuator device between the disconnected one or more auxiliary portions and moving the moveable object with the actuator device.

    [0023] Also disclosed is a slew bearing comprising:
    • a stationary bearing ring to be fixed to a base;
    • a moveable bearing ring to be fixed to a moveable object and which moveable bearing ring is concentric with the stationary bearing ring;
    • an upper main axial bearing arranged between the stationary bearing ring and the moveable bearing ring to transfer axial loads between the moveable bearing ring and the stationary bearing ring;
    • an upper auxiliary axial bearing arranged between the stationary bearing ring and the moveable bearing ring to transfer axial loads between the moveable bearing ring and the stationary bearing ring,
    wherein the stationary bearing and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis,
    wherein the upper auxiliary axial bearing is arranged parallel to the upper main auxiliary bearing,
    wherein the slew bearing has an operational configuration in which the main part of the axial loads are transferred between the stationary bearing ring and the moveable bearing ring by the upper main axial bearing,
    and wherein the slew bearing has a maintenance configuration in which at least a part of the upper main axial bearing is accessible for maintenance and/or inspection and in which the loss of bearing capacity of the upper main axial bearing is at least partially compensated for by the upper auxiliary axial bearing.

    [0024] Further, a slew bearing is disclosed comprising:
    • a stationary bearing ring to be fixed to a base;
    • a moveable bearing ring to be fixed to an object and which moveable bearing ring is concentric with the stationary bearing ring,
    wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis,
    wherein the slew bearing further comprises a row of axial load rollers, which rollers are arranged between a top roller raceway and a bottom roller raceway, said top roller raceway being connected to the moveable bearing ring and said bottom roller raceway being connected to the stationary bearing ring, and said rollers configured to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring,
    wherein the slew bearing further comprises low friction pads arranged on the moveable bearing ring and corresponding low friction pads arranged on the stationary bearing ring to engage with the low friction pads on the moveable bearing ring, wherein the low friction pads of the moveable bearing ring are arranged parallel to the top roller raceway, and the low friction pads of the stationary bearing ring are arranged parallel to the bottom roller raceway in order to be able to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring,
    characterized in that
    at least a first portion of the moveable bearing ring comprising the top roller raceway, after being disconnected from a second portion of the moveable bearing ring comprising the low friction pads, is moveable relative to the second portion in a direction parallel to the rotation axis between an operational position in which the top roller raceway engages with the rollers and a maintenance position in which the top roller raceway is at a distance from the rollers to allow inspection and/or maintenance, wherein in case the first portion is in the maintenance position, the axial loads at the location of the first portion are transferred between the moveable bearing ring and the stationary bearing ring via the low friction pads on the second portion of the moveable bearing ring and the corresponding low friction pads on the stationary bearing ring.

    [0025] The invention will now be described in a non-limiting way by reference to the accompanying drawings in which like parts are indicated by like reference symbols, and in which:
    Fig. 1
    depicts a cross section of a part of a vessel including a slew bearing according to an embodiment of the invention;
    Fig. 2
    depicts a cross section of the slew bearing of Fig. 1 during normal operation;
    Fig. 3
    depicts a schematic top view of a part of the slew bearing of Fig. 1;
    Fig. 4
    depicts the cross section of Fig. 2 during maintenance or inspection;
    Fig. 5
    depicts a hoisting crane according to an embodiment of the invention;
    Fig. 6
    depicts a cross section of a part of a vessel including a slew bearing according to another embodiment of the invention;
    Fig.7
    depicts a cross section of the slew bearing of Fig. 6 during normal operation; and
    Fig. 8
    depicts the cross section of Fig. 7 during maintenance or inspection.


    [0026] Fig. 1 depicts a part of a vessel 1 comprising a hull 3 with an opening 5 extending vertically through the hull 3. For clarity reasons, the drawing has been rotated 90 degrees such that the vertical extends parallel to the indicated Z-direction and the horizontal extends parallel to the indicated X-direction.

    [0027] A turret 7 is provided in the opening 5 of the hull 3. Turrets are usually cylindrical elements generally used in floating production storage and offloading vessels. The vessel 1 is then equipped with hydrocarbon processing equipment for separation and treatment of crude oil, water and gasses, arriving on board from sub-sea oil wells via flexible pipelines connected to the turret.

    [0028] The turret 7 can be moored to the seabed with chains, wires and anchors. A slew bearing 10 is provided between the hull 3 and the turret 7 to allow free and unrestricted 360° rotation of the vessel 1 around the turret 7. This allows weathervaning in which the vessel will normally lay head to the prevailing environment.

    [0029] Fig. 2 depicts a cross section of the slew bearing 10 and part of the turret 7 and hull 3 during normal operation. The slew bearing 10 comprises a stationary bearing ring 11 fixed to the hull 3 which acts as base for the slew bearing 10. The slew bearing 10 further comprises a moveable bearing ring 12 fixed to the turret 7, which moveable bearing ring is concentric with the stationary bearing ring. The stationary bearing ring 11 and moveable bearing ring 12 are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis 9 (see Fig. 1).

    [0030] The slew bearing 10 comprises a number of bearings to transfer loads that act in different directions between the moveable bearing ring and the stationary bearing. One of the provided bearings is an upper main axial bearing 20 allowing to transfer axial loads from the moveable bearing ring to the stationary bearing ring caused by the weight of the moveable bearing ring and turret 7 connected thereto.

    [0031] The slew bearing further comprises a lower main axial bearing 30 allowing to transfer axial loads between the stationary bearing ring and moveable bearing ring preventing the moveable bearing ring to disengage from the stationary ring.

    [0032] In order to transfer radial loads between the moveable bearing ring 12 and stationary bearing ring 11, the slew bearing 10 is provided with an inner main radial bearing 40 and an outer main radial bearing 50.

    [0033] The upper main axial bearing 20 comprises a row of axial load rollers 21, which rollers 21 are arranged between a top roller raceway 22 and a bottom roller raceway 23, the top roller raceway 22 being connected to the moveable bearing ring 12 and the bottom roller raceway 23 being connected to the stationary bearing ring 11. The use of the rollers 21 allows to transfer relatively high loads without too much wear and heat generation.

    [0034] The lower main axial bearing 30 and the inner and outer radial bearings 40, 50 can be embodied as roller bearings or plain bearings in which low-friction pads are engaged with each other and able to slide relative to each other. Plain bearings are much simpler in construction and therefore preferred when the loads are relatively low.

    [0035] In the particular embodiment shown, the moveable bearing ring 12 has a C-shaped cross section, comprising a top ring member 13, which can be best seen in Fig. 3 depicting a part of the slew bearing 10 from above, and a bottom ring member 14. The stationary bearing ring comprises a flange section 11a which extends in the radial direction, here, in the embodiment shown, the radially inward direction.

    [0036] In this embodiment, the moveable bearing ring 12 comprises a main portion 13a as part of the top ring member 13 which includes the entire top roller raceway 22 of the upper main axial bearing 20.

    [0037] The moveable bearing ring 12, in this case the top ring member 13 further comprises a plurality of auxiliary portions 13b distributed along the moveable bearing ring 12. The auxiliary portions 13b are provided with upper low-friction pads 61 as part of an upper auxiliary axial bearing 60. Corresponding lower low-friction pads 62 are arranged on the stationary bearing ring.

    [0038] The upper auxiliary axial bearing 60 is provided in parallel to the upper main axial bearing 20 and also able to transfer axial loads between the moveable bearing ring and stationary bearing ring when the upper low-friction pads and lower low-friction pads engage with each other.

    [0039] In this embodiment, during normal operation as shown in Fig. 2, the auxiliary portions 13b and the main portion 13a are connected to the turret 7 such that the main part of the axial loads is transferred between the moveable bearing ring and stationary bearing ring via the upper main axial bearing 20.

    [0040] The advantage of the auxiliary portions 13b and the upper auxiliary axial bearing will be apparent by reference to Fig. 4. In this Fig. 4, the auxiliary portions 13b have been disconnected from the turret 7 and an actuator device 70, e.g. a hydraulic jack system, is provided between the auxiliary portions 13b and the turret 7. By actuating the actuator device 70 it is possible to lift the turret 7 relative to the auxiliary portions 13b. Due to the fact that the main portion 13a is still connected to the turret, lifting the turret 7 will also lift the main portion 13a including top roller raceway 22 and allow access to the rollers 21.

    [0041] In other words, the main portion 13a is moveable relative to the auxiliary portions 13b between an operational position as shown in Fig. 2, in which the top roller raceway of the main portion engages with axial load rollers to transfer axial loads between the moveable bearing ring and the stationary ring, and a maintenance position as shown in Fig. 4, in which the top roller raceway is disengaged from the axial load rollers.

    [0042] In the maintenance position of the main portion 13a, the upper auxiliary axial bearing 60 will then take over the transfer of the axial loads between the moveable bearing ring and the stationary ring, so that the turret is still able to rotate relative to the hull. In other words, inspection and maintenance can be performed while the slew bearing is still fully functional albeit that it may be preferred to carry out inspection and/or maintenance during relatively mild and quiet weather conditions.

    [0043] Depending on the available space and the dimensions of the actuator device 70 additional support elements may be used. In the embodiment of Figs. 1-4, a support element 80 is provided on the auxiliary portions 13b for the actuator device 70 to reduce the available space between auxiliary portions and frame elements of the turret 7, thereby allowing to use a smaller actuator device.

    [0044] As indicated by the Figs. 2 and 4, the actuator device does not necessarily have to be provided permanently. It is well possible that during normal operation the actuator devices are not present and only installed when inspection and/or maintenance is required.

    [0045] Although the invention has been described by reference to Figs. 1-4 in which the slew bearing according to the invention is arranged between a turret and a hull of a vessel, it will be apparent that the invention can be used in many applications where a structure needs to be rotatable about a substantially vertical rotation axis. An example of such another application is a hoisting crane as shown in Fig. 5.

    [0046] Fig. 5 shows a side view of a hoisting crane. The hoisting crane comprises a crane structure 102, which crane structure comprises a jib 103. In the embodiment shown, the jib 103 can be pivoted about a substantially horizontal pivot axis 104.

    [0047] The crane structure 102 further comprises a crane housing 105 with a slew platform 109 at a lower side thereof. To support the crane structure 102 including crane housing 105, a base 106 is provided, which base can be secured to a vessel. To enable rotation of the crane structure 102 about a vertical axis, the hoisting crane is provided with a slew bearing 107 between the base 106 and the slew platform 109. The slew bearing 107 has a rotational axis 108 that extends in a substantially vertical direction and allows the slew platform 109, and thus the crane structure 102 comprising the jib 103, to be rotated relative to the base 106 about that rotational axis 108.

    [0048] The slew bearing 107 can be similarly embodied as the slew bearing of Figs 1-4, with the difference that the moveable bearing ring is fixed to the slew platform 109 instead of the turret.

    [0049] Fig. 6 depicts a cross section of a vessel with a slew bearing 10 according to another embodiment of the invention. The slew bearing 10 comprises a stationary bearing ring 11 fixed to a hull 3 of the vessel, which hull 3 acts as base for the slew bearing 10. The slew bearing 10 further comprises a moveable bearing ring 12 fixed to a turret 7 or slew platform 105 of a crane, which moveable bearing ring 12 is concentric with the stationary bearing ring 11. The stationary bearing ring 11 and the moveable bearing ring 12 are configured to enable rotation of the moveable bearing ring 12 relative to the stationary bearing ring 11 about a rotation axis.

    [0050] The slew bearing 10 comprises a number of bearings to transfer loads that act in different directions between the moveable bearing ring 12 and the stationary bearing ring 11. One of the provided bearings is an upper main axial bearing 20 allowing to transfer axial loads from the moveable bearing ring 12 to the stationary bearing ring 11 caused by the weight of the moveable bearing ring 12 and structure 7 or 105 connected thereto.

    [0051] The slew bearing further comprises a lower main axial bearing 30 allowing to transfer axial loads between the stationary bearing ring 11 and the moveable bearing ring 12 preventing the moveable bearing ring 12 to disengage from the stationary bearing ring 11.

    [0052] In order to transfer radial loads between the moveable bearing ring 12 and the stationary bearing 11, the slew bearing 10 is provided with an inner main radial bearing 40 and an outer main radial bearing 50.

    [0053] The upper main axial bearing 20 comprises a row of axial load rollers 21, which rollers 21 are arranged between a top roller raceway 22 and a bottom roller raceway 23, the top roller raceway 22 being connected to the moveable bearing ring 12 and the bottom roller raceway 23 being connected to the stationary bearing ring 11. The use of the rollers 21 allows to transfer relatively high loads without too much wear and heat generation.

    [0054] The lower main axial bearing 30 can be embodied as roller bearings as well, but are in this embodiment embodied as plain bearings in which low-friction pads are engaged with each other and able to slide relative to each other. Plain bearings are much simpler in construction and therefore preferred when the expected loads are relatively low.

    [0055] In the particular embodiment shown, the moveable bearing ring 12 has a C-shaped cross section, comprising a top ring member 13 and a bottom ring member 14. The stationary bearing ring 11 comprises a flange section 11a which extends in the radial direction, here, in the embodiment shown, the radially inward direction.

    [0056] In this embodiment, the inner radial bearing 40 is embodied as a roller bearing comprising a row of radial load rollers 41, which rollers 41 are arranged between a first raceway 42 and a second raceway 43, wherein the first raceway 42 is connected to the stationary bearing ring 11 and the second raceway 43 is connected to the moveable bearing ring 12, in this case the top ring member 13 thereof.

    [0057] In this embodiment, the out radial bearing 50 is embodied as a roller bearing comprising a row of radial load rollers 51, which rollers 51 are arranged between a first raceway 52 and a second raceway 53, wherein the first raceway 52 is connected to the stationary bearing ring 11 and the second raceway 53 is connected to the moveable bearing ring 12, in this case the top ring member 13 thereof.

    [0058] As both the inner and outer radial bearings 40, 50 are embodied as roller bearing including rollers of which the respective rotation axes are oriented substantially vertical, there is the risk of rollers falling out of their intended position during assembly and maintenance. This has been solved in this embodiment by providing a respective removable cover element 11b, 11c. The rollers are then retained by the respective cover element 11b, 11c and a corresponding other portion of the stationary bearing ring 11, e.g. opposite the cover element 11b, 11c, to prevent them from inadvertently falling out of the stationary bearing ring 11. The cover portions 11b, 11c being removable allows for easy assembly and removal of the rollers in case of maintenance. As is preferred, the rollers may be provided with axial protrusions being received in corresponding recesses or grooves of said cover element 11b, 11c and said other portion of the stationary bearing ring 11. The recesses or grooves in the cover elements 11b, 11c may be referred to as upper grooves and the recesses or grooves in the other portion of the stationary bearing ring 11 may be referred to as lower grooves.

    [0059] Fig. 6 depicts a cross section of the slew bearing 10 at a location where the entire top ring member 13 is made of one piece and connected to the bottom ring member 14 via bolts 200. This connection may not be intended to be released during regular maintenance. For regular maintenance there are maintenance sections provided, e.g. distributed along the entire circumference of the slew bearing, allowing to get access to the upper main axial bearing 20. A cross section of the slew bearing at such a maintenance section is depicted in Fig. 7 for an operational situation and in Fig. 8 for a maintenance situation.

    [0060] At the maintenance sections, the moveable bearing ring 12 comprises a main portion 13a as part of the top ring member 13 which includes the top roller raceway 22 of the upper main axial bearing 20. The moveable bearing ring 12, in this case the top ring member 13 further comprises an auxiliary portion 13b. The auxiliary portion 13b is provided with upper low-friction pads 61 as part of an upper auxiliary axial bearing 60. Corresponding lower low-friction pads 62 are arranged on the stationary bearing ring 11. In this example, the cover element 11b also comprises the lower low-friction pads 62.

    [0061] The upper auxiliary axial bearing 60 is provided in parallel to the upper main axial bearing 20 and also able to transfer axial loads between the moveable bearing ring 12 and the stationary bearing ring 11 when the upper low-friction pads 61 and lower low-friction pads 62 engage with each other.

    [0062] In the operational situation shown in Fig. 7, the main portion of the axial loads is transferred between the moveable bearing ring 12 and the stationary bearing ring 11 via the upper main axial bearing 20 shown in Figs. 6 and 7.

    [0063] In the maintenance situation shown in Fig. 8, the turret 7 or the slew platform 105 of a crane is lifted with respect to the auxiliary portion 13b using an actuator device 70, e.g. a hydraulic system, between the auxiliary portion 13b and the turret 7 or the slew platform 105. Due to the fact that the main portion 13a is still connected to the turret 7 or the slew platform 105, lifting the turret 7 or the slew platform 105 will also lift the main portion 13a including the top roller raceway 22 and allow to access the rollers 21.

    [0064] In other words, the main portion 13a is moveable relative to the auxiliary portion 13b between an operational position as shown in Fig. 7, in which the top roller raceway of the main portion engages with axial load rollers to transfer axial loads between the moveable bearing ring and the stationary ring, and a maintenance position as shown in Fig. 8, in which the top roller raceway is disengaged from the axial load rollers.

    [0065] In the maintenance position of the main portion 13a, the upper auxiliary bearing 60 will then take over the transfer of the axial loads between the moveable bearing ring and the stationary ring, so that the turret 7 or the slew platform 105 is still able to rotate relative to the hull of the vessel. In other words, inspection and maintenance can be performed while the slew bearing is still fully functional albeit that it may be preferred to carry out inspection and/or maintenance during relatively mild and quiet weather conditions.

    [0066] Depending on the available space and the dimensions of the actuator device 70 additional support elements may be used. An example of such a support element 80 is depicted in the figs. 7 and 8 to reduce the available space between the auxiliary portion 13b and the frame elements of the turret7 or the slew platform 105, thereby allowing to use a smaller actuator device 70.

    [0067] In this embodiment it is assumed that at the sections depicted in Fig. 6, the top ring member 13 stays connected to the lower ring member 14, so that lifting the turret 7 or the slew platform 105 requires the turret 7 or the slew platform 105 to be temporarily be disconnected from the top ring member 13. In that case the top ring member 13 portion of Fig. 6 may be connected to the auxiliary portion 13b. However, in an alternative embodiment, the top ring member 13 stays connected to the turret 7 or the slew platform 105, so that the connection between the top ring member 13 and the lower ring member 14 needs to be disconnected to allow the turret 7 or the slew platform 105 to be lifted. In that case, the top ring member 13 portion of Fig. 6 may be connected to the main portion 13a. An advantage of the latter embodiment is that access is obtained to all rollers at once.

    [0068] As shown in Fig. 8, lifting the main portion 13a also disengages the raceway 53 from the rollers 51. In absence of the raceway 53, the rollers 51 are kept in position by cover element 11c.


    Claims

    1. A slew bearing (10; 107) comprising:

    - a stationary bearing ring (11) to be fixed to a base (3; 106);

    - a moveable bearing ring (12) to be fixed to a moveable object (7; 102) and which moveable bearing ring is concentric with the stationary bearing ring,

    wherein the stationary bearing ring and the moveable bearing ring are configured to enable rotation of the moveable bearing ring relative to the stationary bearing ring about a rotation axis (9),
    wherein the slew bearing further comprises an upper main axial bearing (20) having a row of axial load rollers (21), which rollers are arranged between a top roller raceway (22) and a bottom roller raceway (23), said top roller raceway being connected to the moveable bearing ring and said bottom roller raceway being connected to the stationary bearing ring, and said rollers configured to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring, characterized in that
    the slew bearing further comprises an upper auxiliary axial bearing (60) having upper low-friction pads (61) arranged on the moveable bearing ring and corresponding lower low-friction pads (62) arranged on the stationary bearing ring to engage with the upper low-friction pads, wherein the upper low-friction pads are arranged parallel to the top roller raceway, and the lower low-friction pads are arranged parallel to the bottom roller raceway in order to transfer axial loads parallel to the rotation axis between the moveable bearing ring and the stationary bearing ring when the upper and lower low-friction pads engage with each other,
    in that the moveable bearing ring comprises one or more main portions (13a) with at least a part of the top roller raceway of the upper main axial bearing and one or more corresponding auxiliary portions (13b), each auxiliary portion comprising at least a part of the upper low-friction pads,
    in that the one or more main portions are moveable relative to the corresponding one or more auxiliary portions between an operational position, in which the at least part of the top roller raceway engages with axial load rollers to transfer axial loads between the moveable bearing ring and the stationary ring, and a maintenance position, in which the at least part of the top roller raceway is disengaged from the axial load rollers,
    and in that the one or more auxiliary portions are configured such that the at least part of the upper low-friction pads are engageable with lower low-friction pads when the corresponding one or more main portions are in the maintenance position to transfer axial loads between the moveable bearing ring and the stationary ring.
     
    2. A slew bearing according to claim 1, wherein an actuator device (70) is provided to move the one or more main portions between the operational position and the maintenance position.
     
    3. A slew bearing according to claim 1 or 2, wherein the moveable bearing ring comprises a single main portion and a plurality of auxiliary portions distributed evenly on the moveable bearing ring.
     
    4. A slew bearing according to any of claims 1-3, wherein the one or more main portions comprise the entire top roller raceway.
     
    5. A slew bearing according to any of claims 1-4, wherein the rollers are provided in a plurality of roller boxes.
     
    6. A slew bearing according to any of claims 1-5, wherein at least one of the rollers or a roller box holding a plurality of rollers is provided with a sensor for measuring a parameter or the condition of the slew bearing and a memory for storing measurement data that can be read-out by making a physical connection.
     
    7. A slew bearing according to any of claims 1-6, comprising an inner main radial bearing (40) arranged between the stationary bearing ring and the moveable bearing ring on an inner side of the stationary bearing ring.
     
    8. A slew bearing according to any of claims 1-7, comprising an outer main radial bearing (50) arranged between the stationary bearing ring and the moveable bearing ring on an outer side of the stationary bearing ring.
     
    9. A hoisting crane comprising:

    - a crane structure (102);

    - a slew platform (109) supporting the crane structure;

    - a base (106); and

    - a slew bearing (10; 107) according to any of the claims 1-8, wherein the slew bearing is arranged between the base and the slew platform, the stationary bearing ring being fixed to the base and the moveable bearing ring being fixed to the slew platform, thereby allowing the crane structure to rotate relative to the base about the rotation axis.


     
    10. A hoisting crane according to claim 9, wherein the one or more main portions and the one or more auxiliary portions are fixed to the slew platform, wherein the one or more auxiliary portions can be disconnected from the slew platform, wherein an actuator device is provided between auxiliary portions and the slew platform to lift the slew platform including the one or more main portions when the one or more auxiliary portions are disconnected from the slew platform thereby allowing to move the one or more main portions between the operational position and the maintenance position.
     
    11. A vessel (1) comprising:

    - a hull (3) provided with an opening (5) extending vertically through the hull;

    - a turret (7) extending in the opening of the hull;

    - a slew bearing (10) according to any of the claims 1-8, wherein the slew bearing is arranged between the hull and the turret, the stationary bearing ring being fixed to the hull and the moveable bearing ring being fixed to the turret, thereby allowing the turret to rotate relative to the hull about the rotation axis.


     
    12. A vessel according to claim 11, wherein the one or more main portions and the one or more auxiliary portions are fixed to the turret, wherein the one or more auxiliary portions can be disconnected from the turret, wherein an actuator device is provided between auxiliary portions and the slew platform to lift the slew platform including the one or more main portions when the one or more auxiliary portions are disconnected from the slew platform thereby allowing to move the one or more main portions between the operational position and the maintenance position.
     
    13. A method comprising the following steps:

    a. providing a slew bearing (10; 107) according to any of the claims 1-8, with the one or more main portions (13a) being directly or indirectly connected to the one or more auxiliary portions (13b) with the one or more main portions in the operational position;

    b. disconnecting the one or more main portions from the one or more auxiliary portions; and

    c. moving the one or more main portions to the maintenance position.


     
    14. The method according to claim 13, further comprising the step of performing inspection and/or maintenance on the upper main axial bearing, and subsequently moving the one or more main portions to the operational position followed by connecting the one or more main portions to the one or more auxiliary portions.
     
    15. The method according to claim 13, wherein the one or more main portions and the one or more auxiliary portions are connected to a moveable object (7; 102), wherein disconnecting the one or more main portions from the one or more auxiliary portions comprises disconnecting the one or more auxiliary portions from the moveable object, and wherein moving the one or more main portions to the maintenance position is carried out by providing an actuator device between the disconnected one or more auxiliary portions and moving the moveable object with the actuator device.
     


    Ansprüche

    1. Drehkranzlager (10; 107) umfassend:

    - einen stationären Lagerring (11), welcher an einer Basis (3; 106) zu befestigen ist;

    - einen beweglichen Lagerring (12), welcher an einem beweglichen Objekt (7; 102) zu befestigen ist, und wobei der bewegliche Lagerring konzentrisch bezüglich des stationären Lagerrings ist,

    wobei der stationäre Lagerring und der bewegliche Lagerring ausgestaltet sind, um eine Drehung des beweglichen Lagerrings relativ zu dem stationären Lagerring um eine Drehachse (9) zu ermöglichen,
    wobei das Drehkranzlager darüber hinaus ein oberes axiales Hauptlager (20) mit einer Reihe von axialen Lastrollen (21) umfasst, wobei die Rollen zwischen einer oberen Rollenlaufbahn (22) und einer unteren Rollenlaufbahn (23) angeordnet sind, wobei die obere Rollenlaufbahnmit dem beweglichen Lagerring verbunden ist und die untere Rollenlaufbahn dann mit dem stationären Lagerring verbunden ist, und wobei die Rollen ausgestaltet sind, um axiale Lasten parallel zu der Drehachse zwischen dem beweglichen Lagerring und dem stationären Lagerring zu übertragen,
    dadurch gekennzeichnet,
    dass das Drehkranzlager darüber hinaus ein oberes axiales Hilfslager (60) umfasst, welches obere reibungsarme Pads (61), welche auf dem beweglichen Lagerring angeordnet sind, und entsprechende untere reibungsarme Pads (62), welche auf dem stationären Lagerring angeordnet sind, um mit den oberen reibungsarmen Pads in Eingriff zu kommen, aufweist, wobei die oberen reibungsarmen Pads parallel zu der oberen Rollenlaufbahn angeordnet sind, und wobei die unteren reibungsarmen Pads parallel zu der unteren Rollenlaufbahn angeordnet sind, um axiale Lasten parallel zu der Drehachse zwischen dem beweglichen Lagerring und dem stationären Lagerring zu übertragen, wenn sich die oberen und die unteren reibungsarmen Pads miteinander in Eingriff befinden,
    dass der bewegliche Lagerring ein oder mehrere Hauptabschnitte (13a) mit zumindest einem Teil der oberen Rollenlaufbahn des oberen axialen Hauptlagers und ein oder mehrere entsprechende Hilfsabschnitte (13b) umfasst, wobei jeder Hilfsabschnitt zumindest einen Teil der oberen reibungsarmen Pads umfasst,
    dass der eine oder die mehreren Hauptabschnitte beweglich relativ zu dem entsprechenden einen oder den entsprechenden mehreren Hilfsabschnitten zwischen einer Betriebsposition, in welcher sich der mindestens eine Teil der oberen Rollenlaufbahn in Eingriff mit den axialen Lastrollen befindet, um axiale Lasten zwischen dem beweglichen Lagerring und dem stationären Ring zu übertragen, und einer Wartungsposition, in welcher sich der mindestens eine Teil der oberen Rollenlaufbahn nicht in Eingriff mit den axialen Lastrollen befindet, sind,
    und dass der eine oder die mehreren Hilfsabschnitte ausgestaltet sind, so dass der mindestens eine Teil der oberen reibungsarmen Pads in Eingriff mit den unteren reibungsarmen Pads bringbar ist, wenn sich der entsprechende eine oder die entsprechenden mehreren Hauptabschnitte in der Wartungsposition befinden, um axiale Lasten zwischen dem beweglichen Lagerring und dem stationären Ring zu übertragen.
     
    2. Drehkranzlager nach Anspruch 1, wobei eine Betätigungsvorrichtung (70) bereitgestellt ist, um den einen oder die mehreren Hauptabschnitte zwischen der Betriebsposition und der Wartungsposition zu bewegen.
     
    3. Drehkranzlager nach Anspruch 1 oder 2, wobei der bewegliche Lagerring einen einzigen Hauptabschnitt und eine Mehrzahl von Hilfsabschnitten, welche gleichmäßig auf dem beweglichen Lagerring verteilt sind, umfasst.
     
    4. Drehkranzlager nach einem der Ansprüche 1-3, wobei der eine oder die mehreren Hauptabschnitte die gesamte obere Rollenlaufbahn umfassen.
     
    5. Drehkranzlager nach einem der Ansprüche 1-4, wobei die Rollen in einer Mehrzahl von Rollenkästen vorhanden sind.
     
    6. Drehkranzlager nach einem der Ansprüche 1-5, wobei zumindest eine der Rollen oder ein Rollenkasten, welcher eine Mehrzahl von Rollen hält, mit einem Sensor, um einen Parameter oder den Zustand des Drehkranzlagers zu messen, und mit einem Speicher, um Messdaten zu speichern, welche ausgelesen werden können, indem eine physikalische Verbindung hergestellt wird, versehen ist.
     
    7. Drehkranzlager nach einem der Ansprüche 1-6, welches ein inneres Hauptradiallager (40) umfasst, welches zwischen dem stationären Lagerring und dem beweglichen Lagerring auf einer Innenseite des stationären Lagerrings angeordnet ist.
     
    8. Drehkranzlager nach einem der Ansprüche 1-7, welches ein äußeres Hauptradiallager (50) umfasst, welches zwischen dem stationären Lagerring und dem beweglichen Lagerring auf einer Außenseite des stationären Lagerrings angeordnet ist.
     
    9. Hebekran umfassend:

    - eine Kranstruktur (102);

    - eine Schwenkplattform (109), welche die Kranstruktur hält;

    - eine Basis (106); und

    - ein Drehkranzlager (10; 107) nach einem der Ansprüche 1-8, wobei das Drehkranzlager zwischen der Basis und der Schwenkplattform angeordnet ist, wobei der stationäre Lagerring an der Basis befestigt ist und der bewegliche Lagerring an der Schwenkplattform befestigt ist, wodurch es der Kranstruktur ermöglicht wird, sich relativ zu der Basis um die Drehachse zu drehen.


     
    10. Hebekran nach Anspruch 9, wobei der eine oder die mehreren Hauptabschnitte und der eine oder die mehreren Hilfsabschnitte an der Schwenkplattform befestigt sind, wobei der eine oder die mehreren Hilfsabschnitte von der Schwenkplattform getrennt werden können, wobei eine Betätigungsvorrichtung zwischen Hilfsabschnitten und der Schwenkplattform vorhanden ist, um die Schwenkplattform mit dem einen oder den mehreren Hauptabschnitten anzuheben, wenn die eine oder die mehreren Hilfsabschnitte von der Schwenkplattform getrennt sind, wodurch es ermöglicht wird, den einen oder die mehreren Hauptabschnitte zwischen der Betriebsposition und der Wartungsposition zu bewegen.
     
    11. Schiff (1) umfassend:

    - einen Rumpf (3), welcher mit einer Öffnung (5) versehen ist, welche sich vertikal durch den Rumpf erstreckt;

    - einen Drehturm (7), welcher sich in die Öffnung des Rumpfes erstreckt;

    - ein Drehkranzlager (10) nach einem der Ansprüche 1-8, wobei das Drehkranzlager zwischen dem Rumpf und dem Drehturm angeordnet ist, wobei der stationäre Lagerring an dem Rumpf befestigt ist und der bewegliche Lagerring an dem Drehturm befestigt ist, wodurch es dem Drehturm ermöglicht wird, sich relativ zu dem Rumpf um die Drehachse zu drehen.


     
    12. Schiff nach Anspruch 11, wobei der eine oder die mehreren Hauptabschnitte und der eine und oder die mehreren Hilfsabschnitte an dem Drehturm befestigt sind, wobei der eine oder die mehreren Hilfsabschnitte von dem Drehturm getrennt werden können, wobei eine Betätigungsvorrichtung zwischen Hilfsabschnitten und der Schwenkplattform vorhanden ist, um die Schwenkplattform mit dem einen oder den mehreren Hauptabschnitten anzuheben, wenn die eine oder die mehreren Hilfsabschnitte von der Schwenkplattform getrennt sind, wodurch es ermöglicht wird, den einen oder die mehreren Hauptabschnitte zwischen der Betriebsposition und der Wartungsposition zu bewegen.
     
    13. Verfahren, welches die folgenden Schritte umfasst:

    a. Bereitstellen eines Drehkranzlagers (10; 107) nach einem der Ansprüche 1-8, wobei der eine oder die mehreren Hauptabschnitte (13a) direkt oder indirekt mit dem einen oder den mehreren Hilfsabschnitten (13b) verbunden sind, wobei sich der eine oder die mehreren Hauptabschnitte in der Betriebsposition befinden;

    b. Trennen des einen oder der mehreren Hauptabschnitte von dem einen oder den mehreren Hilfsabschnitten; und

    c. Bewegen des einen oder der mehreren Hauptabschnitte zu der Wartungsposition.


     
    14. Verfahren nach Anspruch 13, welches darüber hinaus umfasst den Schritt einer Durchführung einer Inspektion und/oder Wartung auf dem oberen axialen Hauptlager und ein anschließendes Bewegen des einen oder der mehreren Hauptabschnitte zu der Betriebsposition gefolgt von einem Verbinden des einen oder der mehreren Hauptabschnitte mit dem einen oder den mehreren Hilfsabschnitten.
     
    15. Verfahren nach Anspruch 13, wobei der eine oder die mehreren Hauptabschnitte und der eine oder die mehreren Hilfsabschnitte mit einem beweglichen Objekt (7; 102) verbunden werden, wobei das Trennen des einen oder der mehreren Hauptabschnitte von dem einen oder den mehreren Hilfsabschnitten ein Trennen des einen oder der mehreren Hilfsabschnitte von dem beweglichen Objekt umfasst, und wobei das Bewegen des einen oder der mehreren Hauptabschnitte zu der Wartungsposition ausgeführt wird, indem eine Betätigungsvorrichtung zwischen dem getrennten einen oder den getrennten mehreren Hilfsabschnitten bereitgestellt wird und das bewegliche Objekt mit der Betätigungsvorrichtung bewegt wird.
     


    Revendications

    1. Palier de pivotement (10 ; 107) comprenant :

    une bague de palier fixe (11) à fixer sur une base (3 ; 106) ;

    une bague de palier mobile (12) à fixer sur un objet mobile (7 ; 102) et laquelle bague de palier mobile est concentrique par rapport à la bague de palier fixe,

    dans lequel la bague de palier fixe et la bague de palier mobile sont configurées pour permettre la rotation de la bague de palier mobile par rapport à la bague de palier fixe autour d'un axe de rotation (9),

    dans lequel le palier de pivotement comprend en outre un palier axial principal supérieur (20) ayant une rangée de rouleaux de charge axiaux (21), lesquels rouleaux sont agencés entre un chemin de roulement à galet supérieur (22) et un chemin de roulement à galet inférieur (23), ledit chemin de roulement à galet supérieur étant raccordé à la bague de palier mobile et ledit chemin de roulement à galet inférieur étant raccordé à la bague de palier fixe, et lesdits galets étant configurés pour transférer les charges axiales parallèles à l'axe de rotation entre la bague de palier mobile et la bague de palier fixe, caractérisé en ce que :

    le palier de pivotement comprend en outre un palier axial auxiliaire supérieur (60) ayant des coussinets supérieurs à faible frottement (61) agencés sur la bague de palier mobile et des coussinets inférieurs à faible frottement (62) agencés sur la bague de palier fixe pour se mettre en prise avec les coussinets supérieurs à faible frottement, dans lequel les coussinets supérieurs à faible frottement sont agencés parallèlement au chemin de roulement à galet supérieur et les coussinets inférieurs à faible frottement sont agencés parallèlement au chemin de roulement à galet inférieur afin de transférer les charges axiales parallèles à l'axe de rotation entre la bague de palier mobile et la bague de palier fixe lorsque les coussinets supérieurs et inférieurs à faible frottement se mettent en prise entre eux,

    en ce que la bague de palier mobile comprend une ou plusieurs parties principales (13a) avec au moins une partie du chemin de roulement à galet supérieur du palier axial principal supérieure et une ou plusieurs parties auxiliaires (13b) correspondantes, chaque partie auxiliaire comprenant au moins une partie des coussinets supérieurs à faible frottement,

    en ce que les une ou plusieurs parties principales sont mobiles par rapport aux une ou plusieurs parties auxiliaires correspondantes entre une position opérationnelle, dans laquelle la au moins une partie du chemin de roulement à galet supérieur se met en prise avec des galets de charge axiale afin de transférer les charges axiales entre la bague de palier mobile et la bague fixe, et une position de maintenance dans laquelle la au moins une partie du chemin de roulement à galet supérieur est dégagée des galets de charge axiale,

    et en ce que les une ou plusieurs parties auxiliaires sont configurées de sorte que la au moins une partie des coussinets supérieurs à faible frottement peut être mise en prise avec les coussinets inférieurs à faible frottement lorsque les une ou plusieurs parties principales correspondantes sont dans la position de maintenance pour transférer les charges axiales entre la bague de palier mobile et la bague fixe.


     
    2. Palier de pivotement selon la revendication 1, dans lequel un dispositif d'actionneur (70) est prévu pour déplacer les une ou plusieurs parties principales entre la position opérationnelle et la position de maintenance.
     
    3. Palier de pivotement selon la revendication 1 ou 2, dans lequel la bague de palier mobile comprend une seule partie principale et une pluralité de parties auxiliaires réparties régulièrement sur la bague de palier mobile.
     
    4. Palier de pivotement selon l'une quelconque des revendications 1 à 3, dans lequel les une ou plusieurs parties principales comprennent tout le chemin de roulement à galet supérieur.
     
    5. Palier de pivotement selon l'une quelconque des revendications 1 à 4, dans lequel les galets sont prévus dans une pluralité de boîtes à galets.
     
    6. Palier de pivotement selon l'une quelconque des revendications 1 à 5, dans lequel au moins l'un parmi des galets ou une boîte de galets contenant une pluralité de galets, est prévu(e) avec un capteur pour mesurer un paramètre ou la condition du palier de pivotement et une mémoire pour stocker des données de mesure qui peuvent être lues en réalisant une connexion physique.
     
    7. Palier de pivotement selon l'une quelconque des revendications 1 à 6, comprenant un palier radial principal interne (40) agencé entre la bague de palier fixe et la bague de palier mobile sur un côté interne de la bague de palier fixe.
     
    8. Palier de pivotement selon l'une quelconque des revendications 1 à 7, comprenant un palier radial principal externe (50) agencé entre la bague de palier fixe et la bague de palier mobile sur un côté externe de la bague de palier fixe.
     
    9. Grue de levage comprenant :

    une structure de grue (102) ;

    une plateforme de pivotement (109) supportant la structure de grue ;

    une base (106) ; et

    un palier de pivotement (10 ; 107) selon l'une quelconque des revendications 1 à 8, dans lequel le palier de pivotement est agencé entre la base et la plateforme de pivotement, la bague de palier fixe étant fixée sur la base et la bague de palier mobile étant fixée sur la plateforme de pivotement, permettant ainsi à la structure de grue de tourner par rapport à la base autour de l'axe de rotation.


     
    10. Grue de levage selon la revendication 9, dans laquelle les une ou plusieurs parties principales et les une ou plusieurs parties auxiliaires sont fixées sur la plateforme de pivotement, dans laquelle les une ou plusieurs parties auxiliaires peuvent être déconnectées de la plateforme de pivotement, dans laquelle un dispositif d'actionneur est prévu entre des parties auxiliaires et la plateforme de pivotement pour lever la plateforme de pivotement comprenant les une ou plusieurs parties principales lorsque les une ou plusieurs parties auxiliaires sont déconnectées de la plateforme de pivotement permettant ainsi de déplacer les une ou plusieurs parties principales entre la position opérationnelle et la position de maintenance.
     
    11. Navire (1) comprenant :

    une coque (3) prévue avec une ouverture (5) s'étendant verticalement à travers la coque ;

    une tourelle (7) s'étendant dans l'ouverture de la coque ;

    un palier de pivotement (10) selon l'une quelconque des revendications 1 à 8, dans lequel le palier de pivotement est agencé entre la coque et la tourelle, la bague de palier fixe étant fixée sur la coque et la bague de palier mobile étant fixée sur la tourelle, permettant ainsi à la tourelle de tourner par rapport à la coque autour de l'axe de rotation.


     
    12. Navire selon la revendication 11, dans lequel les une ou plusieurs parties principales et les une ou plusieurs parties auxiliaires sont fixées à la tourelle, dans lequel les une ou plusieurs parties auxiliaires peuvent être déconnectées de la tourelle, dans lequel un dispositif d'actionneur est prévu entre les parties auxiliaires et la plateforme de pivotement pour lever la plateforme de pivotement comprenant les une ou plusieurs parties principales lorsque les une ou plusieurs parties auxiliaires sont déconnectées de la plateforme de pivotement, permettant ainsi de déplacer les une ou plusieurs parties principales entre la position opérationnelle et la position de maintenance.
     
    13. Procédé comprenant les étapes suivantes consistant à :

    a. prévoir un palier de pivotement (10 ; 107) selon l'une quelconque des revendications 1 à 8, avec les une ou plusieurs parties principales (13a) qui sont directement ou indirectement raccordées aux une ou plusieurs parties auxiliaires (13b) avec les une ou plusieurs parties principales dans la position opérationnelle ;

    b. déconnecter les une ou plusieurs parties principales des une ou plusieurs parties auxiliaires ; et

    c. déplacer les une ou plusieurs parties principales dans la position de maintenance.


     
    14. Procédé selon la revendication 13, comprenant en outre l'étape consistant à réaliser le contrôle et/ou la maintenance sur le palier axial principal supérieur, et ensuite l'étape consistant à déplacer les une ou plusieurs parties principales dans la position opérationnelle, suivie de l'étape consistant à raccorder les une ou plusieurs parties principales aux une ou plusieurs parties auxiliaires.
     
    15. Procédé selon la revendication 13, dans lequel les une ou plusieurs parties principales et les une ou plusieurs parties auxiliaires sont raccordées à un objet mobile (7 ; 102), dans lequel l'étape consistant à déconnecter les une ou plusieurs parties principales des une ou plusieurs parties auxiliaires comprend l'étape consistant à déconnecter les une ou plusieurs parties auxiliaires de l'objet mobile, et dans lequel l'étape consistant à déplacer les une ou plusieurs parties principales dans la position de maintenance est réalisée en prévoyant un dispositif d'actionneur entre les une ou plusieurs parties auxiliaires déconnectées et en déplaçant l'objet mobile avec le dispositif d'actionneur.
     




    Drawing



























    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description