Lubricant retention system

Abstract

In a first aspect, a lubricant retention system for a pitch bearing of a wind turbine is provided. The lubricant retention system includes a base and a plurality of annular seal segments for connection to the base and for connection to each other to form an annular seal assembly. The base is for connection to a wind turbine. The plurality of annular sealing segments includes a distal end portion. When the lubricant retention system is mounted on the wind turbine blade, the distal end portion extends toward the second bearing member to define a chamber for retaining lubricant from the pitch bearing. Further, the plurality of annular sealing segments includes a releasable annular sealing segment to be releasably connected to another annular sealing segment. In another aspect, a wind turbine blade is provided that includes a lubricant retention system according to any of the examples disclosed herein. In another aspect, a method for installing a lubricant retention system for a pitch bearing in a wind turbine blade is provided.

Description

Technical Field

[0001] The present disclosure relates to a lubricant retention system for a pitch bearing of a wind turbine, a blade root portion having such lubricant retention systems, and a method for installing a lubricant retention system in a wind turbine blade. Background Art

[0002] Modern wind turbines are generally used to supply power to the grid. This type of wind turbine generally includes a rotor having a rotor hub and a plurality of blades. The rotor rotates under the action of the wind on the blades. The rotation of the rotor shaft directly ("directly drives") or drives the generator rotor by using a gearbox. The gearbox (if present), the generator, and other systems are generally installed in a nacelle on top of a wind turbine tower.

[0003] An auxiliary system generally provided on a wind turbine is a pitch system. The pitch system is used to adapt the position of the wind turbine blades to changing wind conditions. The pitch system generally includes a pitch bearing, which includes an outer ring, an inner ring, and one or more rows of rolling elements between the two rings. The rolling elements allow the two rings to rotate relative to each other. A lubricant, such as oil or grease, is provided between the rings to prevent excessive wear of the rings and the rolling elements. The rolling elements (such as balls or rollers) can be arranged between an inner raceway of the inner ring and an outer raceway of the outer ring to reduce the friction between these rings.

[0004] Depending on the type of rolling elements, the pitch bearing can be, for example, a ball bearing or a roller bearing. The rolling elements of a ball bearing are balls that rotate between an inner raceway and an outer raceway. In a roller bearing, the rolling elements arranged between the raceways are generally cylindrical or conical in shape and are generally referred to as rollers.

[0005] Alternatively, a plain bearing or a sliding bearing can also be used. In these bearings, a lubricating film can be provided between the flat surfaces of the inner ring and the outer ring to reduce friction.

[0006] The wind turbine blade can be attached to the inner ring or the outer ring, while the hub is connected to the other of the (inner or outer) rings. When the pitch system is actuated, the blade can perform a relative rotational movement with respect to the hub. Therefore, the inner bearing ring can perform a rotational movement with respect to the outer bearing ring.

[0007] The pitch bearing can include a bearing seal element to reduce the leakage of lubricant from the pitch bearing. For example, a bearing seal element can be provided to seal a bearing gap formed between the inner ring and the outer ring. The lubricant can generally overflow through the bearing gap between the rings.

[0008] In addition, grooves can be machined in one or both rings to accumulate lubricant. The grooves widen the bearing clearance between the inner and outer rings to increase the stored lubricant. A bearing seal element can also cover the grooves to reduce lubricant spillage. The bearing seal element is generally referred to as the main seal.

[0009] However, the bearing seal element does not completely prevent lubricant leakage from the pitch bearing. Therefore, lubricant leakage can eventually appear on the ground, which can create a potential environmental pollution risk.

[0010] In addition, the groove volume for accumulating lubricant is relatively small and fills up quickly. Therefore, maintenance operations to empty the lubricant from the cavity must be performed frequently.

[0011] Brush seals with brush bundles can be used to absorb the grease leaking from the pitch bearing. These brush seals are generally arranged relatively close to the bearing clearance between the outer and inner rings of the pitch bearing. However, the bristles can become saturated quite quickly. The ability of the brush seals to retain grease may decrease over time. Therefore, maintenance operations to clean these brush seals must be performed regularly. In some cases, it may not be feasible to clean and reuse the brush seals, and thus it may be necessary to completely replace the brush seals. Cleaning the brush seals usually involves replacing the entire brush seal. Therefore, these maintenance operations can be labor-intensive. Additionally, the brush seals can be difficult to install in existing wind turbine blades.

[0012] The present disclosure provides examples of systems and methods that at least partially address some of the disadvantages mentioned above. Summary of the Invention

[0013] In a first aspect, a lubricant retention system for a pitch bearing of a wind turbine is provided. Examples of such pitch bearings include: a first bearing member for coupling to a wind turbine blade; and a second bearing member for coupling to a rotor hub of the wind turbine. The first bearing member rotates relative to the second bearing member.

[0014] The lubricant retention system includes a base and a plurality of annular seal segments. The base is for connection to the wind turbine blade. The base includes a base outer surface to mate with the surface of the wind turbine blade. The plurality of annular seal segments are for connection to the base. The annular seal segments of the plurality of annular seal segments are connected to each other to form an annular seal assembly. Additionally, the plurality of annular seal segments include distal portions. When the lubricant retention is installed on the wind turbine blade, the distal portions extend towards the second bearing member to define a chamber for retaining lubricant from the pitch bearing. The plurality of annular seal segments further include releasable annular seal segments for releasably connecting to another annular seal segment of the plurality of annular seal segments.

[0015] According to this aspect, the retention of lubricant (such as oil and / or grease) leaking from the pitch bearing is improved. Thus, the risk of the lubricant leaking from the pitch bearing reaching the ground is reduced. Consequently, the risk of environmental pollution can be minimized. When the distal portions of the plurality of annular seal segments extend towards the second bearing member of the pitch bearing, the bearing clearance between the first bearing member and the second bearing member is surrounded by the lubricant retention system. Thus, a seal arrangement is formed between the distal portions of the plurality of annular seal segments and the second bearing member. As a result, a cavity for accumulating the lubricant leakage from the pitch bearing is formed. This cavity allows for storing a larger volume of lubricant than that absorbed by the machined grooves in the bearing members or the bristles of the sealing brush arranged to directly cover the bearing clearance between the first bearing member and the second bearing member. Therefore, the frequency of maintenance operations for clearing the cavity can be reduced. Connecting the base of the lubricant retention system to the wind turbine blade allows the lubricant retention system to be installed in an existing wind turbine in an easy manner. Attaching the lubricant retention system to the pitch bearing may be more complex because the available space on the pitch bearing for attaching the lubricant retention is more limited. Thus, the base of the lubricant retention system can be attached to the blade at the production factory, on the ground before lifting the blade, or even in the blade already connected to the rotor hub. Thus, when the base is attached to the wind turbine blade, the plurality of annular seal segments can be coupled to the blade.

[0016] Additionally, if the lubricant retention system is connected to the pitch bearing, structural problems may occur or design changes may be required for the pitch bearing. For example, holes may need to be machined in one of the bearing members in order to screw the lubricant retention system into that bearing member. This can adversely affect the structural performance of the pitch bearing. Thus, the risk of crack generation and propagation on the pitch bearing can increase.

[0017] As explained previously, the plurality of annular seal segments are connected to each other to form an annular seal assembly. Thus, the annular seal segments are connected edge to edge to form a complete annular seal assembly. The plurality of annular seal segments can first be positioned around the blade and then joined together. This simplifies the installation of the lubricant retention system. The size of these annular seal segments is smaller than if the annular seal were made as a single piece. The existing lifting or hoisting equipment of the wind turbine can be utilized to lift the plurality of annular seal segments instead of a single-piece annular seal. Logistics is thus improved.

[0018] At least one of the annular seal segments is releasable. A releasable annular seal segment is an annular seal segment among the plurality of annular seal segments that can be attached to or detached from the remaining one or more annular seal segments of the annular seal assembly in an easy manner. Thus, the releasable annular seal segment can be easily removed from the annular seal assembly. Therefore, it is possible to easily perform an inspection of the lubricant level accommodated in the cavity formed by the annular seal assembly. In addition, the lubricant accommodated in the cavity can be extracted through the orifice caused when the releasable annular seal segment is removed. Thus, the maintenance and inspection operations can be simplified and optimized.

[0019] In another aspect, a blade root portion of a wind turbine blade is provided. The blade root portion includes a blade shell and a blade root attachment portion. The blade shell includes an inner blade shell surface and an outer blade shell surface. The blade root attachment portion is configured to attach the blade root portion to a first bearing member of a pitch bearing. The blade root portion further includes a lubricant retention system according to any of the examples disclosed herein. The base of the lubricant retention system is coupled to the blade shell and / or coupled to the blade root attachment portion.

[0020] Similar to the first aspect, a system that is easy to install can be utilized to prevent leakage of lubricant from the pitch bearing. In addition, the inspection and maintenance operations of the lubricant retention system can be improved.

[0021] In other aspects, a wind turbine blade is provided that has a blade root portion with a lubricant retention system according to any of the examples disclosed herein. A rotor is also provided that has a rotor hub and one or more blades that have a lubricant retention system according to any of the examples disclosed herein. In addition, a wind turbine having such a rotor is provided.

[0022] In another aspect, a method for installing a lubricant retention system for a pitch bearing of a wind turbine blade is provided. The pitch bearing includes a first bearing member and a second bearing member, and the first bearing member is configured to rotate relative to the second bearing member.

[0023] The method includes connecting the base of the lubricant retention system to a blade root portion of a wind turbine blade, the blade root portion being configured to be coupled to the first bearing member. Additionally, the method includes connecting a plurality of annular seal segments to the base in a manner such that the distal portions of the plurality of annular seal segments extend toward the second bearing member to define a chamber for retaining lubricant from the pitch system. The method further includes connecting the plurality of annular seal segments to each other to form an annular seal assembly, wherein connecting the plurality of annular seal segments includes releasably connecting a releasable annular seal segment among the plurality of annular seal segments to another annular seal segment among the plurality of annular seal segments.

[0024] In yet another aspect, a method for performing maintenance operations in a wind turbine is provided. The method includes removing a releasable annular seal segment from an annular seal assembly formed by a plurality of annular seal segments of a lubricant retention system for a pitch bearing. Additionally, the method includes inspecting a level of lubricant leaking from the pitch bearing and retained in a chamber defined by the annular seal assembly.

[0025] Advantages obtained from these aspects may be similar to the advantages mentioned with respect to the previous aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Non-limiting examples of the present disclosure will be described below with reference to the drawings, in which:

[0027] Figure 1 A perspective view of a wind turbine according to one example is shown;

[0028] Figure 2 A simplified internal view of a nacelle of a wind turbine according to one example is shown;

[0029] Figure 3 A perspective view of a wind turbine blade according to one example is shown;

[0030] Figure 4 A cross-sectional view of a lubricant retention system according to an example of the present disclosure mounted on a wind turbine blade is shown;

[0031] Figure 5 is Figure 4 An enlarged view of the lubricant retention system;

[0032] Figure 6 A lubricant retention system according to an example of the present disclosure is shown;

[0033] Figure 7A A cross-sectional view of a lubricant retention system according to an example of the present disclosure mounted on a wind turbine blade is shown;

[0034] Figure 7B A distal portion of a plurality of annular seal segments according to an example of the present disclosure is shown;

[0035] Figure 7C A distal portion of a plurality of annular seal segments according to an example of the present disclosure is shown;

[0036] Figure 8 is Figure 7A An enlarged view of the connection of the base to the blade shell;

[0037] Figure 9A An annular seal assembly of a lubricant retention system according to an example of the present disclosure is schematically presented;

[0038] Figure 9B Schematically presents an annular seal assembly of a lubricant retention system according to an example of the present disclosure;

[0039] Figure 10 Schematically presents a bottom view of a portion of an annular seal assembly according to an example of the present disclosure;

[0040] Figure 11 is a block diagram of a method for installing a lubricant retention system for a pitch bearing in a wind turbine blade according to an example of the present disclosure; and

[0041] Figure 12 is a block diagram of a method for performing maintenance operations in a wind turbine. DETAILED DESCRIPTION

[0042] In these figures, the same reference numerals are used to denote matching elements.

[0043] Figure 1 Shows a perspective view of an example of a wind turbine 1. As shown, the wind turbine 1 includes a tower 2 extending from a support surface 3, a nacelle 4 mounted on the tower 2, and a rotor 5 coupled to the nacelle 4. The rotor 5 includes a rotatable hub 6 and at least one wind turbine blade 7 coupled to and extending outwardly from the rotor hub 6. For example, in the illustrated example, the rotor 5 includes three wind turbine blades 7. However, in alternative embodiments, the rotor 5 may include more or fewer than three blades 7. Each wind turbine blade 7 may be spaced from the rotor hub 6 to facilitate rotation of the rotor 5 such that the kinetic energy of the wind can be converted into useful mechanical energy and subsequently into electrical energy. For example, the rotor hub 6 may be rotatably coupled to a generator 10 ( Figure 2 ) positioned within or forming part of the nacelle 4 to permit the generation of electrical energy.

[0044] Figure 2 Shows Figure 1 a simplified internal view of an example of the nacelle 4 of the wind turbine 1. As shown, the generator 10 may be disposed within the nacelle 4. Generally, the generator 10 may be coupled to the rotor 5 of the wind turbine 1 to utilize the rotational energy generated by the rotor 5 to generate electrical power. For example, the rotor 5 may include a main rotor shaft 8 coupled to the rotor hub 6 to rotate therewith. The generator 10 may then be coupled to the rotor shaft 8 such that rotation of the rotor shaft 8 drives the generator 10. For example, in this figure, the generator 10 includes a generator shaft 11 rotatably coupled to the rotor shaft 8 via a gearbox 9. In other examples, the generator may be directly coupled to the rotor hub or rotor shaft.

[0045] It should be recognized that the rotor shaft 8, the gearbox 9, and the generator 10 can be generally supported within the nacelle 4 by a platen or a support frame 12 positioned at the top of the tower 2.

[0046] The nacelle 4 is rotatably coupled to the tower 2 by a yaw system 20. The yaw system includes a yaw bearing (not visible in Figure 2 ), which has two bearing members configured to rotate relative to each other. The tower 2 is coupled to one of the bearing members, and the platen or the support frame 12 of the nacelle 4 is coupled to the other bearing member.

[0047] The blade 7 is coupled to the rotor hub 6 by a pitch bearing 31 located between the blade 7 and the rotor hub 6. The pitch bearing 31 includes an inner ring and an outer ring ( Figure 4 shown in). The wind turbine blade can be attached to the inner bearing ring or the outer bearing ring, while the hub is connected to the other. When the pitch system 30 is actuated, the blade 7 can perform relative rotational movement with respect to the rotor hub 6. Thus, the inner bearing ring can perform rotational movement with respect to the outer bearing ring. Figure 2 The pitch system 30 in includes a pinion 32 that meshes with a pitch ring gear 33 provided on the inner bearing ring to rotate the wind turbine blade.

[0048] Figure 3 An example of a wind turbine blade 7 is shown. The wind turbine blade 7 extends from a blade root end 71 to a blade tip end 72 in a longitudinal direction or a span direction 70. The blade 7 includes a blade root region or portion 50 closest to the rotor hub, an airfoil portion or profile portion 52 farthest from the rotor hub, and a transition portion 51 between the blade root portion 50 and the airfoil portion 52. The blade 7 includes a leading edge 53 that faces the rotational direction of the blade 7 when mounted on the rotor hub, and a trailing edge 54 that faces the opposite direction of the leading edge 53.

[0049] The airfoil portion 52 has a shape designed to generate lift, while the blade root portion 50 has a circular or elliptical cross-section for structural considerations and to facilitate the attachment of the blade to the rotor hub. The diameter or chord of the blade root portion 50 can be constant along the entire blade root portion 50. At the transition portion 51, the profile gradually changes from the circular or elliptical cross-section of the blade root portion 50 to the airfoil profile of the airfoil portion 52.

[0050] The wind turbine blade 7 includes a blade shell 73. The blade shell may include two blade shell parts, such as a pressure side blade shell and a suction side blade shell. The pressure side blade shell may be connected (e.g., glued or bonded) to the suction side blade shell along the leading edge 53 and the trailing edge 54, along a joining line. The blade shell 73 includes an outer or external surface that defines the outer shape of the blade (e.g., the profile at the blade root portion and the profile at the airfoil portion). The blade shell 73 also includes an inner or internal surface (not shown) that defines the internal volume of the blade and faces the load-bearing structure. The blade shell 73 may be made of a fiber-reinforced polymer, such as glass fiber and / or carbon fiber.

[0051] The blade root portion 50 includes a blade root attachment portion 55 that is configured to attach the blade root portion to a first bearing member of a pitch bearing, such as a bearing ring. The blade root attachment portion may include a plurality of fastening components distributed along the root end. In some examples, the blade root end includes a blade flange to face the first bearing member. The blade root end may include a structural reinforcement, such as a reinforcement plate or a reinforcement ring, at the attachment portion of the blade root portion to increase the structural resistance of the blade root portion.

[0052] Figure 4 A cross-sectional view of a lubricant retention system according to an example of the present disclosure is shown, and Figure 5 is Figure 4 an enlarged view of the lubricant retention system. The lubricant retention system 100 of this example is coupled to the blade root portion 50. The blade root portion 50 includes a blade shell 73 that includes an inner blade shell surface 74 and an outer blade shell surface 75. The outer blade shell surface 75 defines the profile of the blade.

[0053] The blade root portion 50 further includes a blade root attachment portion 55 that is configured to attach the blade root portion 50 to a first bearing member 36 of a pitch bearing 31. A second bearing member 37 is coupled to the rotor hub 6. Thus, the first bearing member 36 is configured to be coupled to the wind turbine blade 7, and the second bearing member 37 is configured to be coupled to the rotor hub 6 of the wind turbine. The blade root portion 50 of this example includes a circular cross-section.

[0054] In this example, the first bearing member 36 is an outer ring, and the second bearing member 37 is an inner ring. However, in other examples, the first bearing member is an inner ring, and the second bearing member is an outer ring.

[0055] The blade root attachment portion 55 includes a receiving portion for securing a blade fastener 57. The receiving portion can be, for example, an insert with internal threads or a T-bolt connector. The first bearing member 36 of this figure includes a through-hole. The fastener 57 can pass through the hole of the first bearing member 36 and can be secured to the receiving portion of the blade root attachment portion 55 to connect the blade 7 to the first bearing member 36. A plurality of fasteners or bolts can be distributed along the circumference of the first bearing member 36 to connect the pitch bearing 31 to the blade.

[0056] In this figure, the blade root attachment portion 55 includes a mounting flange 56 to face the upper surface 41 of the first bearing member 36. In some instances, the blade root attachment portion 55 includes a reinforcement element to increase the radial stiffness of the blade. The reinforcement element can be a reinforcement ring. The reinforcement ring can be arranged between the mounting flange and the laminate.

[0057] In Figure 4 this case, the rotor hub 6 includes threaded holes. Fasteners (such as bolts) can pass through the holes of the second bearing member 37 and can be secured (such as threadedly connected) in the threaded holes of the rotor hub 6. Thus, the fastener can connect the rotor hub 6 to the second bearing member 37. A plurality of fasteners can be threadedly connected in the plurality of threaded holes formed at the rotor hub 6 to connect the second bearing member 37 to the rotor hub 6. In other instances, the rotor hub and the second bearing member can include a plurality of through-holes. Bolts can be inserted into these through-holes and secured with nuts to connect the second bearing member to the hub.

[0058] The pitch bearing 31 of this example is a ball bearing, and a bearing clearance 38 is formed between the first bearing member 36 and the second bearing member 37. A lubricant (such as grease and / or oil) can be provided between the bearing members to reduce friction. The lubricant can flow through the bearing clearance 38 between the first bearing member 36 and the second bearing member 37. In this example, grooves 39 are machined on the upper sides of the first bearing member and the second bearing member. The lubricant can accumulate in the grooves 39. The pitch bearing 31 of this figure further includes a bearing seal element 35 covering the grooves 39. The bearing seal element 35 can help reduce the leakage of the lubricant from the bearing clearance 38. However, the bearing seal element 35 does not completely prevent the leakage of the lubricant from the pitch bearing 31. The bearing seal element 35 of this example is an example of a main seal element.

[0059] The lubricant retention system 100 includes a base 110 connected to the blade root portion 50. Thus, the base 110 is configured to be connected to the wind turbine blade 7. The base 110 includes a base outer surface 112. In this figure, the base outer surface 112 mates with the inner blade shell surface 74. In other examples, the base outer surface 112 mates with the outer blade shell surface 75. Thus, the base outer surface 112 is configured to mate with a surface of the wind turbine blade 7, such as the blade shell 73 and / or the blade root attachment portion 55. The base 110 of this example further includes a base inner surface 113 opposite the base outer surface 112.

[0060] The base 110 of this example extends along a base longitudinal direction 129 from a base root end 114 to a base tip end 115. When the base 110 is coupled to the wind turbine blade, the base longitudinal direction 129 is parallel to the longitudinal direction of the wind turbine blade. In this example, the base root end 114 of the base 110 is spaced from the upper surface 41 of the first bearing member 36. However, in other examples, the base root end 114 may rest on the upper surface 41 of the first bearing member 36. In these examples, the base outer surface 112 may be coupled to the blade shell 73, such as to the inner blade shell surface 74, and / or to the blade root attachment portion 55, such as to the inner surface of the mounting flange 56.

[0061] The base 110 of this example can be connected to the blade according to any of the examples disclosed herein. For example, the base outer surface 112 can be fixed to the blade shell 73 using glue or an adhesive. However, other suitable connection methods may alternatively be used. For example, a pressure element can be used to apply an outward pressure to the base inner surface 113 to fix the base 110 to the blade shell 73. The pressure element can be a disk with a variable diameter, which can be arranged inside the wind turbine blade to apply an outward radial pressure on the base.

[0062] In other examples, a portion of the base (such as the base outer surface) can be integrally incorporated within the blade shell. During blade manufacture, the base can be arranged between the fibers of the blade shell.

[0063] The base 110 of this example extends 360°. In some examples, the base 110 can include a plurality of annular base segments that form the base 110 extending 360°. In some examples, the base can be formed by a single annular element extending 360°. The segments can be connected to each other, for example, by glue, an adhesive, or by a bolt connection.

[0064] The base 110 can include a plastic material. For example, the base 110 can be made of a glass-reinforced plastic. The base can be made of a flexible material to adapt the base 110 to the diameter of the blade root portion 50.

[0065] The lubricant retention system 100 further includes an annular seal assembly 200. Although Figure 4 not shown in Figure 4 , the annular seal assembly 200 is formed by a plurality of annular seal segments 120 connected to each other. The annular seal segments 120 extend from a proximal portion 122 to a distal portion 121. The proximal portion 122 is connected to the base 110 and the distal portion faces the second bearing member 37.

[0066] The annular seal assembly 200 extends 360°. The angular extension of each of the annular seal segments 120 depends on the number of segments. For example, the annular seal assembly 200 can be formed by two annular seal segments 120. These two annular seal segments 120 can thus extend substantially about 180°. The annular seal assembly can be formed by any suitable number of annular seal segments between two and twenty, for example between two and six annular seal segments. For example, when the annular seal assembly is formed by connecting six annular seal segments, each of the annular seal segments extends substantially 60°.

[0067] The annular seal segments 120 are connected edge-to-edge to form a complete annular seal assembly 200. One edge of one annular seal segment 120 is connected to one edge of an adjacent annular seal segment 120, and so on. At least one of the plurality of annular seal segments can be removably connected to an adjacent or neighboring annular seal segment. For example, a releasable annular seal segment is configured to be removably connected to a first adjacent annular segment and a second annular seal segment of the plurality of annular seal segments. For example, one or more removable annular seal segments can be connected to an adjacent annular seal segment by a bolt connection. In other instances, snap-fit connectors can be used to removably connect one edge of one annular seal segment to one edge of an adjacent annular seal segment.

[0068] The annular seal segments 120 can be made of a flexible material to adjust the length of the distal portion 121 to accommodate the shape of the second bearing member 37. An example of a flexible material is rubber. In some instances, the annular seal segment can include an internal reinforcement to provide stiffness to the rubber in order to maintain a particular shape of the annular seal segment 120.

[0069] In other instances, the annular seal segments 120 can include a plastic material, such as glass-reinforced plastic.

[0070] In some instances, each of the plurality of annular seal segments is a releasable annular segment. Thus, the annular seal segments can be removably connected to adjacent annular seal segments. Thus, the annular seal assembly can be easily removed to perform maintenance or inspection operations.

[0071] In some instances, one or more of the annular seal segments 120 are removably coupled to the base 110. In some instances, a releasable annular seal segment may be removably coupled to the base 110. In some instances, a plurality of annular seal segments 120 are removably coupled to the base 110.

[0072] In some instances, the base may include a base engagement portion, and one or more of the annular seal segments may include a seal segment engagement portion for removably coupling the base to the annular seal segment. One of these engagement portions may include a receiving portion and the other may include a protrusion that mates with the receiving portion. The annular seal segment 120 may be pressed against the base 110 to lock the protrusion onto the receiving portion. Thus, a non-permanent connection may be formed. A snap-fit connector may be employed to removably connect one or more of the annular seal segments 120 to the base 110. In other instances, one or more of the annular seal segments 120 may be bolted to the base 110.

[0073] The distal portion 121 of the annular seal segment 120 forming the annular seal assembly 200 extends toward the second bearing member 37. In this instance, the distal portion 121 contacts the second bearing member 37. In other instances, the distal portion 121 does not contact the second bearing member 37. Thus, a gap may be defined between the distal portion 121 and the second bearing member 37.

[0074] In this instance, the annular seal segment 120 extends from a radial direction 201 (perpendicular to the base longitudinal direction 129) to a direction that is substantially parallel to the base longitudinal direction 129. The annular seal segment 120 extends from the proximal portion 122 rearward toward the distal portion 121. The plurality of annular seal segments 120 define a sealing inner surface 125 that faces the bearing gap 38 between the first bearing member 36 and the second bearing member 37. In this instance, the sealing inner surface 125 includes a concave shape. The annular seal assembly may further include a sealing outer surface 126 that is opposite the sealing inner surface 125.

[0075] In use, the distal portion 121 of each of the annular seal segments extends beyond the base root end 114. Thus, the distal portion 121 is closer to the rotor hub 6 than the base root end 114.

[0076] In this instance, the distal portions 121 of the plurality of annular seal segments 120 contact the upper surface 42 of the second bearing member 37. Thus, the plurality of annular seal segments 120 extend from the blade 7 connected to the first bearing member 36 toward the second bearing member 37. The lubricant retention system 100 rotates with the first bearing member 36. The distal portions 121 of the plurality of annular seal segments 120 may apply pressure to the upper surface 42 of the second bearing member 37 but allow the first bearing member 36 to rotate relative to the second bearing member 37.

[0077] In some examples, a retaining member may be connectable to the distal portion 121. The retaining member may be employed to reduce the gap between the distal portion 121 and the second bearing member. For example, the gap may be formed between the upper surface 42 of the second bearing member 37 so as to extend in a direction substantially parallel to the longitudinal direction 129 of the base. This gap may be formed when the distal portion 121 is not in contact with the surface of the second bearing member 37. The retaining member may comprise a flexible material such as rubber or a brush having multiple bristles. The retaining member may alternatively or additionally comprise materials such as absorbent materials, textile materials, felt-like materials, hydrophobic materials, hydrophilic materials, combinations of hydrophobic and hydrophilic materials, sponge materials, porous materials, and / or filter materials or any combination thereof.

[0078] The retaining member 150 may have material properties such that it retains certain types of fluids while repelling others, for example, based on the viscosity or other physical or chemical properties of the fluid to be contained or repelled. For example, the material may absorb a lubricant such as a pitch bearing lubricant (e.g., grease), while allowing water to pass through and exit the chamber 101.

[0079] The retaining member 150 may have structural (e.g., geometric shape, porosity) properties such that it retains certain types of fluids while repelling others. For example, the material may absorb grease such as pitch bearing grease, while allowing water to pass through and exit the chamber 101.

[0080] The retaining member may extend substantially perpendicular to the upper surface 42 of the second bearing member 37. Alternatively, the retaining member may have a curved or arcuate profile, for example, forming a concave surface facing the inside of the formed chamber 101. The retaining member may be a separate element from the distal portion 121 or may be formed integrally with the distal portion 121.

[0081] As in this example, the distal portion 121 contacts the upper surface 42 of the second bearing member 37, forming a chamber 101 that encloses the bearing gap 38 of the pitch bearing 31. Lubricant overflowing from the groove 39 covered by the bearing seal element 35 may be retained within the chamber 101. Thus, the leakage points of the pitch bearing 31 are surrounded or substantially surrounded. Therefore, the sealing effect is improved. Lubricant leakage from the pitch bearing 31 may be stored within the chamber 101. Thus, the volume of lubricant leakage retained by the chamber may be increased. In this example, the chamber 101 is arranged inside the wind turbine blade 7. Therefore, Figure 4 and Figure 5 the chamber 101 in

[0082] Figure 6 A lubricant retaining system is shown according to some examples of the present disclosure. Compared with Figure 4 and Figure 5In contrast to the lubricant retention system 100, Figure 6 the lubricant retention system 100 is connected to the outer vane shell surface 75.

[0083] In this example, the first bearing member 36 includes an inner ring, and the second bearing member 37 includes an outer ring. The diameter of the second bearing member 37 in this figure is greater than the diameter of the first bearing member 36. As previously explained, the first bearing member and / or the second bearing member may include reinforcement elements to increase the radial stiffness of the blade hub connection.

[0084] The lubricant retention system 100 in this figure is similar to the example described with reference to Figure 4 and Figure 5 However, in this figure, the base outer surface 112 of the base 110 mates with the outer vane shell surface 75. In addition, the base root end 114 of the base 110 in this figure rests on the upper surface 41 of the first bearing member 36. The base outer surface 112 in this example also mates with the outer surface of the mounting flange 56. In other examples, there may be a gap between the base root end 114 and the upper surface 41 of the first bearing member 36.

[0085] In Figure 6 the base 110 surrounds the outer vane shell surface 75. Glue or an adhesive may be used to connect the base outer surface 112 to the vane housing surface 75. In some examples, a pressure element may be used to apply an inward pressure to the base 110. For example, a ring arranged around the base may press the base against the vane shell 73. A wire may be arranged around the base to fix the base to the outer vane shell surface 75, for example by winding the base and the vane.

[0086] As previously mentioned, in some examples, the plurality of annular seal segments 120 forming the annular seal assembly 200 extend to contact (or substantially contact) the upper surface 42 of the second bearing member 37 to form a chamber 101 for collecting lubricant leakage from the pitch bearing 31.

[0087] In other examples, the distal portion 121 may contact (or substantially contact) the lateral surface 43 of the pitch bearing. Thus, the fasteners connecting the second bearing member 37 to the rotor hub 6 may be covered by the annular seal assembly 200. Thus, these fasteners can be protected from environmental conditions (such as rain). Thus, corrosion of the fasteners can be reduced.

[0088] Figure 7A A cross-sectional view of a lubricant retention system mounted on a wind turbine blade according to an example of the present disclosure is shown, and Figure 8 is an enlarged view of the connection of the base to the Figure 7A vane shell.

[0089] The blade root portion 50 includes a blade root attachment portion 55 having a mounting flange 56 facing the upper surface 41 of the first bearing member 36. In this example, the first bearing member 36 is an inner ring, and the second bearing member 37 is an outer ring. In other examples, the first bearing member 36 may be an outer ring, and the second bearing member 37 may be an inner ring. According to any of the examples disclosed herein, the first bearing member 36 and the second bearing member 37 may be connected to the blade 7 and the rotor hub 6, respectively.

[0090] The pitch bearing 31 of this example includes a bearing seal element 35 disposed in a groove defined between the first bearing member 36 and the second bearing member 37. The bearing seal element 35 is the main seal of the pitch bearing 31.

[0091] The base 110 of this example includes a substantially cylindrical shape. The base 110 extends along a base longitudinal direction 129 from a base root end 114 to a base tip end 115. The base 110 of this example includes a base outer surface 112 that conforms to the outer shape of the blade shell 73. The base 110 further includes a base inner surface 113 facing the annular seal assembly 200. The base 110 encloses the outer shape of the blade 7.

[0092] In this example, the base 110 is bonded to the outer blade shell surface 75. For example, glue and / or an adhesive may be used to bond the base 110 to the outer blade shell surface 75. In these figures, a pair of double-sided tapes 130 are disposed between the base outer surface 112 and the outer blade shell surface 75. In this example, one double-sided tape is disposed at the base root end 114, and the other double-sided tape is disposed at the base tip end 115. In these figures, glue 131 is provided between a pair of double-sided tapes 130. The glue 131 may be injected into an annular recess defined between a pair of double-sided tapes 130. The combination of the glue 131 and the double-sided tapes 130 provides a bonding force to keep the base 110 connected to the outer blade shell surface 75. The double-sided tapes 130 may be used to position the base 110, and then glue may be applied to permanently bond the base outer surface 112 to the outer blade shell surface 75.

[0093] In other examples, the base 110 may be connected to the blade according to any other suitable method. For example, the base may also be integrally incorporated with the blade shell during blade manufacture.

[0094] The base 110 may be formed from a plurality of base segments. These base segments may be joined edge-to-edge. This may simplify the connection of the base 110 to the blade 7, particularly in existing wind turbine blades. In other examples, the base 110 may be formed from a single piece. Opposing edges of the single piece may be arranged to enclose the blade shell and then connected to each other.

[0095] The lubricant retention system 100 includes a plurality of annular seal segments 120. In these figures, each of the plurality of annular seal segments 120 is removably coupled to the base 110. In other instances, some of the annular seal segments 120 may be fixedly coupled to the base 110 and some of the annular seal segments 120 may be removably coupled to the base 110. The seal inner surface 125 faces the base inner surface 113. The seal inner surface 125 defines the inner surface of the annular seal assembly 200, that is, the surface configured to define a chamber 101 for retaining lubricant leakage.

[0096] In this example, fasteners 140 may be used to connect the base 110 to the proximal portion 122 of each of the plurality of annular seal segments 120. The fasteners may be bolts, such as T-bolts. The fasteners may pass through corresponding holes provided at the base 110 and at the proximal portion 122. Threads may be fixed to the fasteners. To ensure the fluid tightness of the chamber 101, a pair of gaskets 141 may be provided between the base outer surface 112 and the seal inner surface 125 at the proximal portion 122 of the annular seal segment 120.

[0097] Each of the plurality of annular seal segments 120 forming the annular seal assembly extends from the proximal portion 122 to the distal portion 121. The distal portion 121 faces towards the second bearing member 37. In this example, the distal portion 121 further extends along a portion of the lateral surface 43 of the second bearing member 37 (i.e., in the direction 129). Thus, the distal portion 121 extends beyond the upper surface 42 of the second bearing member 37. Thus, the lubricant retention system 100 may define a chamber 101 to surround the bearing clearance 38 of the pitch bearing so as to accumulate lubricant leakage. Additionally, since the annular seal assembly 200 covers the pitch bearing 31 and the fasteners connecting the second bearing member 37 to the rotor hub 6, the lubricant retention system 100 prevents water and / or dust from entering the pitch bearing. The seal outer surface 126 may act as a cover for the pitch bearing. Thus, the protection of the pitch bearing is increased. Corrosion of the pitch bearing and / or the fasteners connecting the second bearing member 37 to the rotor hub 6 is prevented.

[0098] The lateral surface 43 extends between the upper surface 42 and the lower surface 44 of the second bearing member 37. The lower surface 44 of the second bearing member 37 faces the rotor hub 6, and the upper surface 42 faces the blade 7.

[0099] The proximal portion 122 of these figures extends substantially parallel to the base 110. The proximal portion 122 thus extends substantially parallel to the longitudinal direction 129 of the base. When a plurality of annular seal segments 120 are connected to each other to define an annular seal assembly, the proximal portions 122 of the plurality of annular seal segments define a cylindrical shape. The proximal portions 122 of the plurality of annular seal segments 120 define a proximal portion diameter. In this example, the proximal portions 122 of the plurality of annular seal segments 120 surround the base 110.

[0100] In this example, when a plurality of annular seal segments 120 are connected to each other to form an annular seal assembly 200, the distal portions 121 of the plurality of annular seal segments 120 define a cylindrical shape having a distal portion diameter. When assembled and installed on the blade, the distal portions 121 of the plurality of annular seal segments 120 extend substantially parallel to the longitudinal direction 129 of the base. The distal portion 121 of this example substantially surrounds the second bearing member 37.

[0101] The distal portion diameter of this example is greater than the proximal portion diameter. Thus, the diameter of the annular seal assembly increases from the proximal portion diameter to the distal portion diameter. Such an increase in diameter allows a chamber 101 to be defined to store lubricant leaking from the pitch bearing.

[0102] Each of the plurality of annular seal segments 120 includes a central portion 123 that connects the proximal portion 122 to the distal portion 121. The central portion 123 of each of the annular seal segments includes an inclined surface. When the plurality of annular seal segments 120 form an annular seal assembly, the central portion 123 includes a substantially frustoconical shape.

[0103] In this example, each of the plurality of annular seal segments 120 includes a retaining member 150 to reduce the gap (defined in the direction 201) between the distal portion 121 and the lateral surface 43 of the second bearing member 37 when the lubricant retaining system (100) is installed on the wind turbine blade (7). The retaining member 150 in these figures is connected to the distal portion 121. The retaining member 150 of this example extends substantially perpendicular to the lateral surface 43 of the second bearing member 37. In other examples, the retaining member 150 may extend in a curved or arcuate manner, for example, forming a recessed area facing the interior of the chamber 101.

[0104] In use, the retention member tip 151 of the retention member 150 remains in contact with the second bearing member 37. In some instances, the retention member 150 may apply pressure to the second bearing member 37 to prevent lubricant from flowing between the second bearing member 37 and the distal portion 121. In the examples of these figures, the retention member tip 151 is configured to contact the lateral surface 43 of the second bearing member 37. The retention member 150 in these figures faces the lateral surface 43 of the second bearing member 37. The retention member 150 may extend radially inward in the radial direction 201 from the distal portion 121 of the plurality of annular seal segments 120 to the retention member tip 151. Thus, the retention member 150 may seal the gap defined between the distal portion 121 and the lateral surface 43 of the second bearing member 37.

[0105] The retention member extends between the edges of each of the annular seal segments. When the annular seal segments are joined together, the plurality of retention members define a ring. Thus, the retention member may extend along the inner diameter of the annular seal assembly. In some instances, the retention member 150 is removably connected to the distal portion 121 of the plurality of annular seal segments 120. Thus, the retention member can be easily removed. Since the retention member can contact the second bearing member 37, the retention member tip 151 may be subject to wear. In addition, the retention member 150 may be overly impregnated with lubricant leaking from the pitch bearing. To maintain the sealing effect, the retention member 150 can be replaced with a new retention member. Thus, maintenance operations can be simplified.

[0106] In some instances, snap-fit connectors can be used to removably or detachably connect the retention member 150 to the distal portion 121. In some instances, the retention member 150 may include a protrusion, and the distal portion 121 may include a groove for receiving the protrusion. In some instances, the retention member 150 may be fastened or bolted to the distal portion 121.

[0107] In the examples of these figures, the annular seal segment 120 includes a plastic material. Thus, an annular seal assembly can be obtained that has sufficient stiffness to retain lubricant and a relatively low weight. For example, the plastic material may include glass-reinforced plastic. In other instances, the annular seal segment 120 may include rubber. Reinforcements may be provided within the rubber material to prevent excessive deformation of the annular seal assembly.

[0108] The base 110 may also include a plastic material. For example, the base 110 may be made of glass-reinforced plastic.

[0109] The retention member 150 may include a flexible material. Thus, the pressure applied by the retention member 150 to the second bearing member 37 (e.g., to the lateral surface 43 of the second bearing member 37) can be adjusted. In some instances, the retention member 150 may include rubber.

[0110] In some examples, the retaining member 150 includes a brush having a plurality of bristles. The bristles are oriented towards the second bearing member 37, for example extending perpendicular to the lateral surface 43 of the second bearing member 37. When contacting the second bearing member 37, the bristles may bend. The brush can absorb and retain a lubricant, such as grease. The sealing effect can be enhanced by combining the chamber 101 for storing the lubricant formed by the annular seal assembly 200 with the brush disposed at the distal portion 121. Thus, a large amount of lubricant leaking from the pitch bearing can be retained by the lubricant retention system according to the present disclosure.

[0111] According to some examples, as Figure 7B shown, the retaining member 150 may include a brush having bristles, some of the bristles may contact the lateral surface 43, while other bristles of the brush may not contact the surface 43. In some examples, the brush is sized such that no bristles contact the lateral surface 43 of the second bearing 37.

[0112] According to some examples, as Figure 7C shown, the retaining member tip 151 does not contact the lateral surface 43 of the second bearing 37. Thus, a gap 152 is left between the retaining member 150 and the lateral surface 43 of the second bearing 37.

[0113] Figure 9A The annular seal assembly of the lubricant retention system according to an example of the present disclosure is schematically presented. The annular seal assembly 200 of this figure can be used for the Figures 4 to 6 lubricant retention system 100 depicted in the present disclosure.

[0114] Figure 9A The annular seal assembly 200 is formed by four annular seal segments 120a, 120b, 120c, and 120d extending from the proximal portion 122 to the distal portion 121. The connection of these annular seal segments defines a sealing inner surface 125 facing the pitch bearing and a sealing outer surface 126 opposite to the sealing inner surface 125.

[0115] Each of these annular seal segments extends a circumferential arc of a certain length between a first edge and a second edge. For example, the annular seal segment 120a extends between a first edge 127a and a second edge 128a. In this example, each of these annular seal segments extends substantially 90° between the corresponding first edge and second edge. In other examples, the annular seal segment may extend any suitable portion of the circumferential arc.

[0116] In this example, the annular seal segment 120a is a removable annular seal segment. The annular seal segment 120a is removably connected to the annular seal segments 120b and 120d. The first edge 127a of the annular seal segment 120a is removably connected to the second edge 128b of the annular seal segment 120b, and the second edge 128a of the annular seal segment 120a is removably connected to the first edge 127d of the annular seal segment 120d. Thus, the annular seal segment 120a can be easily removed to inspect the level of lubricant held by the annular seal assembly 200.

[0117] The removable connection can be according to any of the examples disclosed herein. For example, a bolted connection and / or a snap-fit connection can be employed to removably connect the annular seal segment 120a to the annular seal segments 120d and 120b.

[0118] In some examples, the first edge 127a can engage the second edge 128b. For example, one of these edges 127a and 128b can include a flat edge portion and the other can include a stepped edge portion. These shapes can enhance the connection between the annular seal segments 120a and 120b. In other examples, the edges 127a and 128b can include interlocking edges. The second edge 128a of the annular seal segment 120a and the first edge 127d of the annular seal segment 120d can be connected in a similar manner.

[0119] In this example, the annular seal segment 120c is permanently connected to the annular seal segments 120b and 120d. In other examples, each of the plurality of annular seal segments can be removably connected to an adjacent annular seal segment. The first edge 127b of the annular seal segment 120b and the second edge 128c of the annular seal segment 120c are permanently connected. Similarly, the first edge 127c of the annular seal segment 120c is permanently connected to the second edge 128d of the annular seal segment 120d. A fixed connection can be established using glue or welding methods.

[0120] In this example, the annular seal segment 120a is configured to be detachably connected to the base. This can allow the annular seal segment to be completely removed from the base and from the remaining annular seal segments. In some examples, the group of fixedly connected annular seal segments (in this example 120b, 120c, and 120d) can be detachably connected to the base. Thus, the group of annular seal segments can be disconnected from the base together.

[0121] Figure 9B An annular seal assembly of a lubricant retention system according to an example of the present disclosure is schematically presented. The annular seal assembly 200 of this figure can be used in FIGS. 7 to Figure 8The lubricant retention system 100 depicted in

[0122] In Figure 9B the example, the annular seal segments extend substantially 60°. The annular seal segments of this example are removable annular seal segments. For example, the annular seal segment 120d can be removably connected to the annular seal segments 120c and 120e. According to any of the examples disclosed herein, these annular seal segments can be connected to corresponding edges. For example, each of the annular seal segments can include a stepped edge portion and a flat edge portion. The stepped edge portion of one annular seal segment can mate with the flat edge portion of an adjacent annular seal segment. Thus, the positioning and connection of the annular seal segments can be improved.

[0123] The plurality of annular seal segments in this example are also removably connected to the base. Thus, each of the annular seal segments can be connected and disconnected from the base and from adjacent annular seal segments in a simple manner. Thus, inspection or maintenance operations can be simplified and performed more effectively.

[0124] Figure 10 A bottom view of a portion of an annular seal assembly according to an example of the present disclosure is schematically presented. The annular seal segment 120a of this example is removably coupled to the annular seal segments 120b and 120c.

[0125] The annular seal segments 120a, 120b, and 120c of this figure define a sealed inner surface 125 facing the pitch bearing and a sealed outer surface 126 facing the opposite side (e.g., the outside of the wind turbine).

[0126] The first edge 127a and the second edge 128a of the annular seal segment 120a are removably connected to the second edge 128b of the annular seal segment 120b and the first edge 127c of the annular seal segment 120c, respectively.

[0127] The annular seal segments of this example include stepped edge portions 161a and 161c and flat edge portions 162a and 162b. The stepped edge portions of the annular seal segments are configured to overlap the flat edge portions of adjacent annular segments.

[0128] When the annular seal assembly is assembled, the stepped edge portion extends outwardly so as to overlap the flat edge portion. Thus, the sealed inner surface 125 can remain substantially constant. However, the stepped edge portion generates a protrusion on the sealed outer surface 126. Thus, the stepped edge portion can engage the corresponding flat edge portion.

[0129] In this example, the annular seal segment 120a includes a first edge 127a having a stepped edge portion 161a and a second edge 128b having a flat edge portion 162a. The stepped edge portion 161a of the annular seal segment 120a engages the flat edge portion 162b disposed at the second edge 128b of the annular seal segment 120b. Similarly, the annular seal segment 120c includes a first edge 127a having a stepped edge portion 161c. The stepped edge portion 161c of the annular seal segment 120c engages the flat edge portion 162a of the second edge 128a of the annular seal segment 120a.

[0130] The seal fastener 163 can be inserted through holes disposed at the flat edge portion and the stepped edge portion. The seal fastener (e.g., a bolt) can be inserted from the sealed inner surface 125 toward the sealed outer surface 126. A nut can be fixed on the thread of the seal fastener to connect the stepped edge portion to the flat edge portions of two consecutive annular seal segments. Thus, a bolt connection can be established to connect the annular seal segments to each other. A gasket can be disposed between the flat edge portions and the stepped edge portions of two consecutive annular seal segments.

[0131] In this example, the annular seal segments 120a, 120b, and 120c respectively include retaining members 150a, 150b, and 150c. The retaining members 150a, 150b, and 150c can include brushes having a plurality of flexible bristles. At least some of these flexible bristles can press against the lateral surface of the second bearing member to seal a cavity for accumulating lubricant that overflows from the pitch bearing.

[0132] The retaining member of this figure is removably attached to the annular seal segment. A plurality of retaining member fasteners 152 can be provided for connecting the retaining member to the corresponding annular seal segment. For example, the retaining member 150a is bolted to the annular seal segment 120a by a plurality of retaining member fasteners 152.

[0133] Before connecting the annular seal segments to form an annular seal assembly, the retaining member can be connected to the corresponding annular seal segment. Thus, the retaining member can be installed at the manufacturing facility. For example, the retaining member 150a can be connected to the annular seal segment 120a by a retaining member fastener. Then, the annular seal segment 120a can be connected to the annular seal segments 120b and 120c by a seal fastener 163. In this example, the seal fastener 163 can also connect the retaining member to the annular seal member.

[0134] Figure 11 is a block diagram of a method 300 for installing a lubricant retention system for a pitch bearing in a wind turbine blade according to an example of the present disclosure. The lubricant retention system 100 and the wind turbine can be according to any of the examples disclosed herein. In this example, the pitch bearing 31 includes a first bearing member 36 and a second bearing member 37, and the first bearing member 36 is configured to rotate relative to the second bearing member 37.

[0135] At block 310, connecting the base 110 of the lubricant retention system 100 to a blade root portion 50 of the wind turbine blade 7, the blade root portion 50 being configured to be coupled to the first bearing member 36. The base 110 can be connected to the blade shell 73 and / or the blade root attachment portion 55, such as a mounting flange 56.

[0136] In some examples, connecting the base 110 to the blade root portion 50 includes positioning an outer surface 112 of the base 110 to mate with a surface of the wind turbine blade 7. Thus, the outer surface 112 of the base can mate with the surface of the wind turbine blade 7.

[0137] When the wind turbine blade 7 is coupled to the outer ring of the pitch bearing 31, the method can include mating the outer surface 112 of the base with an inner blade shell surface 74 and / or an inner surface of the blade root attachment portion 55 (e.g., an inner surface of the mounting flange 56). Thus, the base 110 is positioned within the wind turbine blade 7. In these examples, connecting the base 110 to the blade root portion 50 can include adhering the outer surface 112 of the base to the inner blade shell surface 74 and / or the inner surface of the blade root attachment portion 55.

[0138] When the wind turbine blade 7 is coupled to the inner ring of the pitch bearing 31, the method can include mating the outer surface 112 of the base with an outer blade shell surface 75 and / or an outer surface of the blade root attachment portion 55 (e.g., an outer surface of the mounting flange 56). Thus, the base 110 is positioned around the wind turbine blade 7.

[0139] In some instances, connecting the base 110 to the blade root portion 50 may include adhering the outer surface 112 of the base to the blade housing 73 and / or the blade root attachment portion 55. Adhering or bonding the outer surface 112 of the base to the blade 7 may include disposing a pair of double-sided tapes 130 between the outer surface 112 of the base and the blade 7. Then, glue 131 may be inserted between the pair of double-sided tapes 130 to increase the adhesion at the joint.

[0140] In some instances, the fastener 140 may be inserted from the outer surface 112 of the base through a hole disposed in the base 110 into the inner surface 113 of the base. The fastener 140 may be used to removably connect the base 110 to the annular seal segment 120. The fastener 140 may be disposed between the double-sided tapes 130. After the insertion of the fastener 140, glue 131 may be applied. The head of the fastener 140 may thus be fixed to the outer surface 112 of the base.

[0141] In some instances, a pressing element may be positioned on the inner surface 113 of the base to press the base 110 against the blade 7. The pressing element may be a ring with a variable diameter to adjust the pressure on the base.

[0142] These connection methods allow the lubricant retention system 100 to be connected to an existing wind turbine. Thus, an existing wind turbine can be retrofitted.

[0143] In other instances, the base 110 may be connected to the blade root portion 50 during manufacturing. For example, the blade housing 73 of the blade root portion 50 may be potted together with the base 110. In these instances, the method may further include coupling the blade 7 of the base 110 having the lubricant retention system 100 to the first bearing member 36. This may involve lifting the blade 7 and the base 110 of the lubricant retention system from the ground to attach the blade 7 to the first bearing member 36.

[0144] As presented at block 320, the method 300 further includes connecting a plurality of annular seal segments 120 to the base 110 in such a way that the distal portions 121 of the plurality of annular seal segments 120 extend towards the second bearing member 37 to define a chamber 101 for retaining lubricant from the pitch bearing 31. The annular seal segments 120 may be positioned according to any of the examples disclosed herein. For example, the annular seal segments 120 may be positioned such that the distal portions 121 face the upper surface 42 or the lateral surface 43 of the second bearing member 37.

[0145] The annular seal segments 120 may be removably connected to the base 110. In some instances, a plurality of annular seal segments 120 may be removably connected to the base 110. A snap-fit connection or a bolt connection may be employed to removably connect the annular seal segments 120 to the base 110.

[0146] In some instances, a fastener 140 fixedly attached to the base 110 may be inserted through a hole disposed at the proximal portion 122 of the annular seal segment 120. A nut may be threadedly coupled to the fastener 140 to secure the proximal portion 122. A gasket 141 may be disposed between the base 110 and the proximal portion 122 to enhance the sealing effect of the lubricant retention system 100.

[0147] In other instances, the annular seal segment 120 may be fixedly attached to the base. Glue or an adhesive may be used to fixedly attach the annular seal segment 120 to the base 110. In some instances, some of the plurality of annular seal segments 120 may be fixedly attached to the base 110, and some of the plurality of annular seal segments 120 may be removably or detachably attached to the base 110.

[0148] At block 330, connecting a plurality of annular seal segments to each other to form an annular seal assembly is presented. Connecting the plurality of annular seal segments includes releasably connecting a releasable annular seal segment of the plurality of annular seal segments to one or more other annular seal segments of the plurality of annular seal segments. Thus, at least one of the annular seal segments is removably attached to an adjacent one or more annular seal segments.

[0149] One or more releasable annular seal segments may be connected to an adjacent annular seal segment according to any of the instances described herein. For example, the stepped edge portion 161 of the annular seal segment 120 may be positioned to overlap the flat edge portion 162 of an adjacent annular seal segment. Once the stepped edge portion 161 engages the flat edge portion 162, a seal fastener 163 may be inserted through holes formed at the flat edge portion 162 and the stepped edge portion 161 of two consecutive annular seal segments. In some instances, a gasket may be disposed between the flat edge portion 162 and the stepped edge portion 161.

[0150] In some instances, the annular seal segments 120 may be connected to each other to form the annular seal assembly 200 before each of the annular seal segments 120 is connected to the base 110. In other instances, the plurality of annular seal segments 120 may first be connected to the base 110 and then the annular seal segments 120 may be joined together. In other instances, some of the plurality of annular seal segments 120 may be joined together before connecting these annular seal segments 120 to the base 110.

[0151] In some instances, method 300 may include attaching retention member 150 to each of a plurality of annular seal segments 120 prior to attaching the plurality of annular seal segments 120 to each other and / or attaching the plurality of annular seal segments 120 to base 110. The retention member may be attached to the annular seal segment according to any of the examples disclosed herein. Retention member 150 may be removably attached to annular seal segment 120, such as by bolting.

[0152] Figure 12 is a block diagram of a method 400 for performing maintenance operations in a wind turbine. The wind turbine includes a lubricant retention system 100 for collecting lubricant that spills from the pitch bearing 31. The lubricant retention system 100 may be according to any of the examples disclosed herein.

[0153] At block 410, a releasable annular seal segment is removed from an annular seal assembly 200 formed by a plurality of annular seal segments 120 of a lubricant retention system 100 for a pitch bearing 31. The releasable annular seal segment may be disconnected from the annular seal assembly 200 according to any of the examples disclosed herein. For example, a fastener that attaches the releasable annular seal segment to an adjacent annular seal segment may be unscrewed.

[0154] In some instances, removing the releasable annular seal segment may include disconnecting the releasable annular seal segment from base 110. For example, a proximal portion 122 of the releasable annular seal segment may be unscrewed from base 110.

[0155] As presented at block 420, method 400 further includes checking the level of lubricant leaking from pitch bearing 31 retained in chamber 101 defined by annular seal assembly 200. Thus, the amount of lubricant contained within chamber 101 may be observed.

[0156] Depending on the amount of lubricant collected by the lubricant retention system, the method may include extracting the lubricant retained in chamber 101 of lubricant retention system 100. In some instances, extracting the lubricant retained in chamber 101 may include disconnecting retention member 150 from a distal portion 121 of the releasable annular seal segment. Retention member 150 may be cleaned (e.g., with a brush having multiple bristles) to extract the lubricant impregnating the bristles. In some instances, the disconnected retention member 150 may be replaced with a new retention member to ensure the sealing effectiveness of the lubricant retention system.

[0157] Then, the releasable annular seal segments can be reconnected to the base 110 and adjacent annular seal segments. In some instances, method 400 can include disconnecting a plurality of releasable annular seal segments from the plurality of annular seal segments forming the annular seal assembly. The retaining members 150 of these releasable annular seal segments can be cleaned and / or replaced with new retaining members.

[0158] For completeness, various aspects of the present disclosure are set forth in the numbered clauses below:

[0159] Clause 1: A lubricant retention system for a pitch bearing of a wind turbine, wherein the pitch bearing comprises: a first bearing member for coupling to a wind turbine blade; and a second bearing member for coupling to a rotor hub of the wind turbine, the first bearing member being rotatable relative to the second bearing member; the lubricant retention system comprises:

[0160] A base for connection to a wind turbine blade, the base comprising a base outer surface configured to mate with a surface of the wind turbine blade;

[0161] A plurality of annular seal segments for connection to the base, wherein the annular seal segments among the plurality of annular seal segments are for connection to each other to form an annular seal assembly;

[0162] Wherein the plurality of annular seal segments includes distal portions, which, when the lubricant retention system is installed on the wind turbine blade, extend towards the second bearing member to define a chamber for retaining lubricant from the pitch bearing; and

[0163] Wherein the plurality of annular seal segments includes releasable annular seal segments for releasably connecting to another annular seal segment among the plurality of annular seal segments.

[0164] Clause 2: The lubricant retention system according to Clause 1, wherein the releasable annular seal segment is releasably connected to the base.

[0165] Clause 3: The lubricant retention system according to any one of Clauses 1-2, wherein when the lubricant retention system is installed on the wind turbine blade, the distal portion of the annular seal segment further extends along a portion of the lateral surface of the second bearing member.

[0166] Clause 4: The lubricant retention system according to any one of Clauses 1-3, wherein the plurality of annular seal segments includes a retaining member connected to the distal portion to reduce the gap between the distal portion and the second bearing when the lubricant retention system is installed on the wind turbine blade.

[0167] Clause 5: The lubricant retention system according to Clause 4, wherein the retaining member is for reducing the gap between the distal portion and the lateral surface of the second bearing member.

[0168] Clause 6: A lubricant retention system according to any one of Clauses 4 - 5, wherein the retention member is detachably connected to the distal portion of a plurality of annular seal segments.

[0169] Clause 7: A lubricant retention system according to any one of Clauses 4 - 6, wherein the retention member includes a brush having a plurality of bristles.

[0170] Clause 8: A lubricant retention system according to any one of Clauses 4 - 7, wherein the retention member extends radially inward from the distal portion of the plurality of annular seal segments to the tip of the retention member.

[0171] Clause 9: A lubricant retention system according to any one of Clauses 1 - 8, wherein the releasable annular seal segment is for releasably connecting to a first adjacent annular seal segment and a second annular seal segment among the plurality of annular seal segments.

[0172] Clause 10: A lubricant retention system according to any one of Clauses 1 - 11, wherein the plurality of annular seal segments includes:

[0173] a proximal portion for connecting to a base and extending substantially parallel to the base; the proximal portion defining a proximal portion diameter; and

[0174] a central portion connecting the proximal portion to the distal portion.

[0175] Clause 11: A lubricant retention system according to Clause 10, wherein the distal portion defines a distal portion diameter, and wherein the distal portion diameter is greater than the proximal portion diameter.

[0176] Clause 12: A lubricant retention system according to any one of Clauses 1 - 11, wherein the plurality of annular seal segments includes a stepped edge portion and a flat edge portion, wherein the stepped edge portion of the annular seal segments of the plurality of annular seal segments is for overlapping with the flat edge portion of an adjacent annular seal segment of the plurality of annular seal segments.

[0177] Clause 13: A lubricant retention system according to any one of Clauses 1 - 12, wherein the plurality of annular seal segments are releasable annular seal segments.

[0178] Clause 14: A lubricant retention system according to any one of Clauses 1 - 13, wherein the plurality of annular seal segments includes a plastic material.

[0179] Clause 15: A blade root portion of a wind turbine blade, comprising:

[0180] a blade shell including an inner blade shell surface and an outer blade shell surface;

[0181] A blade root attachment portion for attaching a blade root portion to a first bearing member of a pitch bearing;

[0182] A lubricant retention system according to any one of clauses 1-14; wherein the base is connected to the blade shell and / or the blade root attachment portion.

[0183] Clause 16: A blade root portion according to clause 14, wherein the outer surface of the base is bonded to the blade shell and / or the blade root attachment portion, wherein a plurality of annular seal segments are attached to each other to form an annular seal assembly, and wherein the annular seal assembly is connected to the base.

[0184] Clause 17: A wind turbine blade comprising a blade root portion according to any one of clauses 15-16.

[0185] Clause 18: A wind turbine rotor comprising:

[0186] A rotor hub;

[0187] A wind turbine blade;

[0188] A pitch bearing including a first bearing member coupled to the wind turbine blade and a second bearing member coupled to the rotor hub, the first bearing member configured to rotate relative to the second bearing member;

[0189] A lubricant retention system according to any one of clauses 1-14; wherein the base is connected to the wind turbine blade shell; and a plurality of annular segments are connected to the base.

[0190] Clause 19: A method for installing a lubricant retention system for a pitch bearing in a wind turbine blade, wherein the pitch bearing includes a first bearing member and a second bearing member, the first bearing member rotating relative to the second bearing member, the method comprising:

[0191] Connecting a base of the lubricant retention system to a blade root portion of the wind turbine blade, the blade root portion configured to be coupled to the first bearing member;

[0192] Connecting a plurality of annular seal segments to the base in a manner such that distal portions of the plurality of annular seal segments extend toward the second bearing member to define a chamber for retaining lubricant from the pitch bearing; and

[0193] Connecting the plurality of annular seal segments to each other to form an annular seal assembly; wherein

[0194] Connecting the plurality of annular seal segments includes releasably connecting a releasable annular seal segment of the plurality of annular seal segments to another annular seal segment of the plurality of annular seal segments.

[0195] Clause 20: The method according to Clause 19 includes attaching a retaining member to each of the plurality of annular seal segments before connecting the plurality of annular seal segments to each other and / or connecting the plurality of annular seal segments to the base.

[0196] Clause 21: A method of performing a maintenance operation in a wind turbine, including:

[0197] removing a releasable annular seal segment from an annular seal assembly formed from a plurality of annular seal segments of a lubricant retaining system for a pitch bearing; and

[0198] checking the level of lubricant leaking from the pitch bearing held in a chamber defined by the annular seal assembly.

[0199] Clause 22: The method according to Clause 21 includes extracting the lubricant held in the chamber of the lubricant retaining system.

[0200] Clause 23: A wind turbine blade including a lubricant retaining system according to any one of claims 1 to 14.

[0201] Clause 24: A blade root portion of a wind turbine blade according to Clause 23, including:

[0202] a blade shell including an inner blade shell surface and an outer blade shell surface;

[0203] a blade root attachment portion for attaching the blade root portion to a first bearing member of a pitch bearing; and

[0204] wherein the base of the lubricant retaining system is coupled to the blade shell and / or the blade root attachment portion.

[0205] This written description uses examples to disclose the invention, including preferred embodiments, and also enables those skilled in the art to practice the invention, including making and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other examples have structural elements that are not different from the written language of the claims, or if they include equivalent structural elements that are not substantially different from the written language of the claims, then such other examples are intended to be within the scope of the claims. Aspects from the various embodiments and other known equivalents of each such aspect may be mixed and matched by those skilled in the art to form additional embodiments and techniques in accordance with the principles of this application. If reference numerals associated with the drawings are placed in parentheses in the claims, they are only for the purpose of attempting to increase the understandability of the claims and should not be construed as limiting the scope of the claims.

Claims

1. A lubricant retention system (100) for a pitch bearing (31) of a wind turbine, wherein the pitch bearing (31) comprises: A first bearing member (36) for connection to a wind turbine blade (7); and a second bearing member (37) for connection to a rotor hub (6) of a wind turbine, the first bearing member (36) being rotatable relative to the second bearing member (37); the lubricant retention system (100) comprising: a base (110) for connection to a wind turbine blade (7), the base (110) including a base outer surface to mate with the surface of the wind turbine blade (7); a plurality of annular seal segments (120) for connection to the base (110), wherein the annular seal segments of the plurality of annular seal segments (120) are for connection to each other to form an annular seal assembly (200); wherein the plurality of annular seal segments (120) includes a distal portion (121), wherein when the lubricant retention system (100) is installed on the wind turbine blade (7), the distal portion (121) extends towards the second bearing member (37) to define a chamber (101) for retaining lubricant from the pitch bearing (31); and wherein the plurality of annular seal segments (120) includes a releasable annular seal segment for releasably connecting to another annular seal segment of the plurality of annular seal segments (120).

2. The lubricant retention system (100) according to claim 1, wherein the releasable annular seal segment is for releasably connecting to the base (110).

3. The lubricant retention system (100) according to any one of claims 1 to 2, wherein when the lubricant retention system (100) is installed on the wind turbine blade (7), the distal portion (121) of the annular seal segment (120) further extends along a portion of the lateral surface (43) of the second bearing member (37).

4. The lubricant retention system (100) according to any one of claims 1 to 3, wherein the plurality of annular seal segments (120) includes a retaining member (150) connected to the distal portion (121) to reduce the gap between the distal portion (121) and the second bearing (37) when the lubricant retention system (100) is installed on the wind turbine blade (7).

5. The lubricant retention system (100) according to claim 4, wherein the retaining member (150) is detachably connected to the distal portion (121) of the plurality of annular seal segments (120).

6. The lubricant retention system (100) according to any one of claims 4 to 5, wherein the retaining member (150) includes a brush having a plurality of bristles.

7. The lubricant retention system (100) according to any one of claims 4 to 6, wherein the retaining member (150) extends radially inwards from the distal portion (121) of the plurality of annular seal segments (120) to the tip of the retaining member (151).

8. The lubricant retention system (100) according to any one of claims 1 to 7, wherein the plurality of annular seal segments (120) comprise: a proximal portion (122) for connection to the base (110) and extending generally parallel to the base (110); the proximal portion (122) defining a proximal portion diameter; and a central portion (123) connecting the proximal portion (122) to the distal portion (121).

9. The lubricant retention system (100) according to claim 8, wherein the distal portion (121) defines a distal portion diameter, and wherein the distal portion diameter is greater than the proximal portion diameter.

10. The lubricant retention system (100) according to any one of claims 1 to 9, wherein the plurality of annular seal segments (120) comprise a stepped edge portion (161) and a flat edge portion (162), wherein the stepped edge portion (161) of an annular seal segment of the plurality of annular seal segments (120) overlaps the flat edge portion (162) of an adjacent annular seal segment of the plurality of annular seal segments (120).

11. The lubricant retention system (100) according to any one of claims 1 to 10, wherein the plurality of annular seal segments (120) are releasable annular seal segments.

12. The lubricant retention system (100) according to any one of claims 1 to 11, wherein the plurality of annular seal segments (120) comprise a plastic material.

13. A wind turbine blade (7) comprising the lubricant retention system (100) according to any one of claims 1 to 12.

14. The wind turbine blade (7) according to claim 13, comprising: a blade shell (73) including an inner blade shell surface (74) and an outer blade shell surface (75); a blade root attachment portion (55) of a first bearing member (36) for attaching the blade root portion (50) to a pitch bearing (31); wherein the base (110) of the lubricant retention system (100) is coupled to the blade shell (73) and / or the blade root attachment portion (55).

15. A method (300) for installing a lubricant retention system (100) for a pitch bearing (31) in a wind turbine blade (7), wherein the pitch bearing (31) comprises a first bearing member (36) and a second bearing member (37), the first bearing member (36) rotating relative to the second bearing member (37), the method (300) comprising: connecting (310) the base (110) of the lubricant retention system (100) to a blade root portion (50) of the wind turbine blade (7), the blade root portion being configured to be coupled to the first bearing member (36); Connect a plurality of annular seal segments (120) to the base (110) in a manner such that the distal portions (121) of the plurality of annular seal segments (120) extend towards the second bearing member (37) to define a chamber (101) for retaining lubricant from the pitch bearing (31); and Connect the plurality of annular seal segments (120) to each other to form an annular seal assembly (200); wherein connecting (300) the plurality of annular seal segments (120) includes releasably connecting a releasable annular seal segment among the plurality of annular seal segments (120) to another annular seal segment among the plurality of annular seal segments (120).

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