阅读说明：本技术 用于回转环轴承的球塞保持 (Ball plunger retention for a slew ring bearing ) 是由 D.C.帕图沃思 A.D.米纳德奥 W.M.戈贝利 于 2019-08-22 设计创作，主要内容包括：一种用于风力涡轮的轴承组件包括轴承,该轴承包括：外圈；内圈,其相对于外圈是可旋转的；以及多个滚子元件,其定位于限定在外圈与内圈之间的至少一个滚道内。此外,外圈或内圈中的至少一个限定径向开口。轴承组件还包括至少一个球塞,其定位在外圈或内圈中的至少一个的径向开口内。(一个或多个)球塞可移除,使得多个滚子元件可插入外圈与内圈之间。而且,(一个或多个)球塞的至少一部分具有锥形截面。(A bearing assembly for a wind turbine includes a bearing, the bearing comprising: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer and inner rings. Further, at least one of the outer race or the inner race defines a radial opening. The bearing assembly also includes at least one ball plunger positioned within the radial opening of at least one of the outer race or the inner race. The ball plunger(s) are removable such that the plurality of roller elements are insertable between the outer race and the inner race. Also, at least a portion of the ball plunger(s) has a tapered cross-section.)

1. A bearing assembly for a wind turbine, comprising:

a bearing, the bearing comprising: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer ring and the inner ring, at least one of the outer ring or the inner ring defining a radial opening; and

at least one ball plunger positioned within the radial opening of at least one of the outer race or the inner race, the at least one ball plunger being removable such that the plurality of roller elements are insertable between the outer race and the inner race, at least a portion of the at least one ball plunger comprising a tapered cross-section.

2. The bearing assembly of claim 1, wherein the tapered cross-section is positioned between an outer portion and an inner portion of the at least one ball plunger so as to define a transition region thereof.

3. The bearing assembly of claim 2, wherein the outer portion defines a first diameter and the inner portion defines a second diameter, the first diameter tapering to the second diameter in the transition region.

4. The bearing assembly of claim 2, further comprising an external retaining means disposed at or adjacent to a distal-most end of the outer portion of the at least one ball plunger.

5. The bearing assembly of claim 4, wherein the external retaining means comprises at least one of a circlip, a snap ring, a clamp, or a bonding means.

6. The bearing assembly of claim 5, wherein the bonding means comprises at least one of a weld, an adhesive, or a chemical-based solvent.

7. The bearing assembly of claim 4, further comprising at least one spacer or shim positioned between a distal-most end of the outer portion of the at least one ball plunger and the outer retaining means.

8. The bearing assembly of claim 2, further comprising an anti-rotation device extending perpendicular to the longitudinal axis of the at least one ball plunger and engaging an outer surface of the transition region of the at least one ball plunger so as to prevent rotation thereof.

9. The bearing assembly of claim 2, further comprising one or more O-rings disposed circumferentially around an inner portion of the at least one ball plunger.

10. The bearing assembly of claim 9, wherein the inner portion of the at least one ball plunger further comprises at least one annular recess, the one or more O-rings being disposed within the at least one annular recess.

Technical Field

The present subject matter relates generally to wind turbines, and more particularly to ball plug retention for a slew ring bearing (such as a pitch bearing or a yaw bearing of a wind turbine).

Background

Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and in this regard, wind turbines have gained increased attention. Modern wind turbines typically include a tower, generator, gearbox, nacelle, and one or more rotor blades. The rotor blades derive kinetic energy from the wind using known foil principles, and transmit the kinetic energy through rotational energy to turn a shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy, which may be deployed to a utility grid.

In order to properly orient the nacelle and the rotor blades with respect to the direction of the wind, wind turbines typically include one or more yaw bearings and/or pitch bearings. The yaw bearing and/or pitch bearing are typically slew bearings, which are rotating roller element bearings that typically support a load, but slowly rotating or slowly oscillating loads. Thus, the yaw bearing allows the nacelle to rotate and is mounted between the tower and the nacelle, while the pitch bearing allows the rotor blades to rotate and is mounted between one of the rotor blades and the rotatable hub. A typical yaw bearing and/or pitch bearing comprises an outer ring and an inner ring, wherein a plurality of roller elements (e.g. ball bearings) are configured between the rings.

More particularly, the four-point slew ring bearing has ball plungers that are removable so that the roller elements can be easily inserted between the rings. Currently, one or more tapered (taper) pins are used in conventional ball plungers to help retain the radial seat of the plunger. For example, the one or more tapered pins may be inserted through the ball plunger(s), i.e., in a direction substantially perpendicular to the longitudinal axis of the ball plunger(s). At times, the tapered pin(s) may result in areas of increased stress concentration.

Accordingly, the art is continually seeking new and improved systems and methods for ball plug retention for slewing ring bearings (such as pitch or yaw bearings of wind turbines).

Disclosure of Invention

Aspects and advantages of the disclosure will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the disclosure.

In one aspect, the present subject matter is directed to a bearing assembly for a wind turbine. The bearing assembly includes a bearing, the bearing including: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer and inner rings. Further, at least one of the outer race or the inner race defines a radial opening. The bearing assembly also includes at least one ball plunger positioned within the radial opening of at least one of the outer race or the inner race. The ball plunger(s) are removable such that the plurality of roller elements are insertable between the outer race and the inner race. Also, at least a portion of the ball plunger(s) has a tapered cross-section.

In one embodiment, the tapered cross-section may be positioned between the outer and inner portions of the ball plunger(s) so as to define a transition region thereof. In another embodiment, the outer portion may define a first diameter and the inner portion may define a second diameter, wherein the first diameter tapers to the second diameter in the transition region.

In further embodiments, the bearing assembly may further comprise an external retaining means arranged at or adjacent to the most distal end of the outer portion of the ball plunger(s). In such embodiments, the external retaining means may comprise, for example, a circlip, a snap ring, a clamp, a coupling means, or the like. More particularly, in one embodiment, the bonding means may comprise a weld, an adhesive, or a chemical-based solvent.

In additional embodiments, the bearing assembly may further comprise a spacer or shim positioned between a distal-most end of the outer portion of the at least one ball plunger and the outer retaining means.

In several embodiments, the bearing assembly may include an anti-rotation device that extends perpendicular to the longitudinal axis of the ball plunger(s) and engages the outer surface of the transition region of the ball plunger(s) so as to prevent rotation thereof.

In particular embodiments, the bearing assembly may include one or more O-rings disposed circumferentially around an inner portion of the ball plunger(s). For example, in one embodiment, the inner portion of the ball plunger(s) may include at least one annular recess, with one or more O-rings disposed within the at least one annular recess. In another embodiment, the bearing assembly may include a plurality of O-rings disposed circumferentially around an inner portion of the ball plunger(s) within the at least one annular recess. In such embodiments, the plurality of O-rings may be aligned along the longitudinal direction of the ball plunger(s).

In yet another embodiment, the inner portion of the ball plug(s) may include a partial raceway defining a portion of at least one raceway of the outer or inner ring, the partial raceway being disposed on the inner portion of the ball plug(s).

In further embodiments, the bearing may comprise a pitch bearing or a yaw bearing of the wind turbine. In additional embodiments, the plurality of roller elements may include, for example, balls, spheres, rollers, tapered rollers, barrel rollers, or cylindrical elements.

In another aspect, the present subject matter is directed to a bearing assembly for a wind turbine. The bearing assembly includes a bearing, the bearing including: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer and inner rings. Further, at least one of the outer race or the inner race defines a radial opening having a tapered diameter. Moreover, the bearing assembly includes at least one ball plunger having an outer portion and an inner portion. The outer portion defines a first diameter and the inner portion defines a second diameter, wherein the first diameter is greater than the second diameter. The ball plunger(s) is positioned within a radial opening of the outer race or the inner race and is removable such that the plurality of roller elements are insertable between the outer race and the inner race.

In one embodiment, the ball plunger(s) may have a varying cross-section that substantially corresponds to the tapered diameter of the radial opening. Further, the varying cross-section of the ball plug(s) may be located between the outer portion and the inner portion of the ball plug(s).

In another embodiment, the bearing assembly may include an external retaining device disposed adjacent a distal-most end of the outer portion of the ball plunger(s). For example, in one embodiment, the external retaining device may include a locknut or retaining plate and one or more mechanical fasteners engaged with the locknut or retaining plate and extending parallel to the longitudinal axis of the ball plunger(s).

In yet another aspect, the present subject matter is directed to a bearing assembly for a wind turbine. The bearing assembly includes: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer and inner rings. At least one of the outer race or the inner race defines a set of radial openings. The bearing assembly also includes sets of ball plungers each having an outer portion and an inner portion. The outer portion defines a first diameter and the inner portion defines a second diameter, wherein the first diameter is greater than the second diameter. Each of the ball plungers is positioned within one of the radial openings such that outer portions thereof contact each other. Further, the set of ball plungers may be removed such that a plurality of roller elements may be inserted between the outer race and the inner race.

It should be understood that the bearing assembly may also include any of the embodiments and/or combinations of features as described herein.

Technical solution 1. a bearing assembly for a wind turbine, comprising:

a bearing, the bearing comprising: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer ring and the inner ring, at least one of the outer ring or the inner ring defining a radial opening; and

at least one ball plunger positioned within the radial opening of at least one of the outer race or the inner race, the at least one ball plunger being removable such that the plurality of roller elements are insertable between the outer race and the inner race, at least a portion of the at least one ball plunger comprising a tapered cross-section.

Claim 2. the bearing assembly of claim 1, wherein the tapered section is positioned between the outer and inner portions of the at least one ball plunger so as to define a transition region thereof.

The bearing assembly of claim 3, wherein the outer portion defines a first diameter and the inner portion defines a second diameter, the first diameter tapering to the second diameter in the transition region.

Claim 4. the bearing assembly of claim 2, wherein the bearing assembly further comprises an external retaining means disposed at or adjacent to a distal-most end of the outer portion of the at least one ball plunger.

Claim 5. the bearing assembly of claim 4, wherein the external retaining means comprises at least one of a circlip, a snap ring, a clamp, or a coupling means.

Claim 6. the bearing assembly of claim 5, wherein the bonding means comprises at least one of a weld, an adhesive, or a chemical-based solvent.

Claim 7. the bearing assembly of claim 4, wherein the bearing assembly further comprises at least one spacer or shim positioned between a distal-most end of the outer portion of the at least one ball plunger and the outer retaining means.

Claim 8. the bearing assembly of claim 2, wherein the bearing assembly further comprises an anti-rotation device extending perpendicular to the longitudinal axis of the at least one ball plunger and engaging an outer surface of the transition region of the at least one ball plunger so as to prevent rotation thereof.

Claim 9. the bearing assembly of claim 2, wherein the bearing assembly further comprises one or more O-rings disposed circumferentially around an inner portion of the at least one ball plunger.

The bearing assembly of claim 9, wherein the inner portion of the at least one ball plunger further comprises at least one annular recess, the one or more O-rings being disposed within the at least one annular recess.

The bearing assembly of claim 10, wherein the bearing assembly further comprises a plurality of O-rings disposed circumferentially about an inner portion of the at least one ball plunger within the at least one annular recess, the plurality of O-rings aligned along a longitudinal direction of the at least one ball plunger.

Claim 12 the bearing assembly of claim 2, wherein the inner portion of the at least one ball plunger includes a partial raceway defining a portion of at least one raceway of at least one of the outer race or the inner race.

Solution 13. the bearing assembly of any of the preceding claims, wherein the bearing comprises at least one of a pitch bearing or a yaw bearing of a wind turbine.

The bearing assembly of any of the preceding claims, wherein the plurality of roller elements comprises at least one of: balls, spheres, rollers, tapered rollers, barrel rollers, or cylindrical elements.

Technical solution 15. a bearing assembly for a wind turbine, comprising:

a bearing, the bearing comprising: an outer ring; an inner ring rotatable relative to the outer ring; and a plurality of roller elements positioned within at least one raceway defined between the outer ring and the inner ring, at least one of the outer ring or the inner ring defining a radial opening, the radial opening comprising a tapered diameter; and

at least one ball plunger including an outer portion and an inner portion, the outer portion defining a first diameter and the inner portion defining a second diameter, the first diameter being greater than the second diameter, the at least one ball plunger being positioned within a radial opening of at least one of the outer race or the inner race, the at least one ball plunger being removable such that the plurality of roller elements are insertable between the outer race and the inner race.

These and other features, aspects, and advantages of the present disclosure will be further supported and described with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

Drawings

A full and enabling disclosure of the present disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 illustrates a perspective view of one embodiment of a wind turbine according to the present disclosure;

FIG. 2 illustrates a perspective, interior view of an embodiment of a nacelle of the wind turbine shown in FIG. 1;

FIG. 3 illustrates a perspective view of an embodiment of one of the rotor blades of the wind turbine shown in FIG. 1;

FIG. 4 illustrates a perspective view of an embodiment of a pitch bearing of a wind turbine according to the present disclosure;

FIG. 5 illustrates a top view of an embodiment of a pitch bearing of a wind turbine according to the present disclosure;

FIG. 6 illustrates a partial, cross-sectional view of an embodiment of a pitch bearing of a wind turbine according to the present disclosure;

FIG. 7 shows a cross-sectional view of the pitch bearing of FIG. 5 along section line 7-7, particularly illustrating details of one embodiment of a ball plunger according to the present disclosure; and

FIG. 8 shows a cross-sectional view of another embodiment of a ball plug of a pitch bearing according to the present disclosure;

FIG. 9 illustrates a partial, perspective view of yet another embodiment of a ball plunger set for a pitch bearing according to the present disclosure, particularly illustrating the ball plunger set stacked together such that an anti-rotation feature is not required; and

fig. 10 shows a cross-sectional view of the embodiment of fig. 9.

Detailed Description

Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. It is therefore intended that the present disclosure cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

In general, the present subject matter is directed to a bearing assembly for a wind turbine that eliminates the conventional tapered pins described herein. More particularly, a taper may be introduced in the bearing to retain the ball plunger in the radial seat of the plunger. In addition, to prevent the ball plunger from rotating and being forced out of its radial seat, the ball plunger may also be clamped with a circlip/snap ring on the outer ring of the bearing.

Accordingly, the bearing assembly of the present disclosure provides many advantages not found in the noted field. For example, by eliminating the tapered pin, stress concentrations in the outer race due to the intersection of the tapered pin bore and the tap hole are eliminated. Thus, stresses and cracks may be reduced throughout the bearing assembly.

The present disclosure is described herein as it may relate to a wind turbine bearing, which comprises at least a yaw bearing, a pitch bearing and/or the like. However, it should be appreciated that systems and methods according to principles of the present disclosure are not limited to use with wind turbines, but may be applicable to any suitable bearing application. For example, it should be understood that the systems and methods as described herein are configured to fit (fit) within conventional slew bearings and/or improved slew bearings known in the art and later developed, and are not limited to a particular slew bearing configuration.

Referring now to the drawings, FIG. 1 illustrates a side view of an embodiment of a wind turbine 10. As shown, the wind turbine 10 generally includes a tower 12 extending from a support surface 14 (e.g., the ground, a concrete pad, or any other suitable support surface). In addition, wind turbine 10 may also include a nacelle 16 mounted on tower 12 and a rotor 18 coupled to nacelle 16. Rotor 18 includes a rotatable hub 20 and at least one rotor blade 22 coupled to hub 20 and extending outwardly from hub 20. For example, in the illustrated embodiment, the rotor 18 includes three rotor blades 22. However, in alternative embodiments, rotor 19 may include more or less than three rotor blades 22. Each rotor blade 22 may be spaced about hub 20 to facilitate rotating rotor 19 to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy. For example, hub 20 may be rotatably coupled to a generator 24 (FIG. 2) positioned within nacelle 16 to allow electrical energy to be generated.

Referring now to FIG. 2, a simplified, interior view of an embodiment of nacelle 16 of wind turbine 10 shown in FIG. 1 is shown. As shown, the generator 24 may be disposed within the nacelle 16 and supported atop a bedplate 36. Generally, generator 24 may be coupled to rotor 18 for generating electrical power from the rotational energy generated by rotor 18. For example, as shown in the illustrated embodiment, rotor 18 may include a rotor shaft 26 coupled to hub 20 for rotation therewith. The rotor shaft 26, in turn, may be rotatably coupled to a generator shaft 28 of the generator 24 through a gearbox 30. As is generally understood, rotor shaft 26 may provide a low speed, high torque input to gearbox 30 in response to rotation of rotor blades 22 and hub 20. The gearbox 30 may then be configured to convert the low-speed, high-torque input to a high-speed, low-torque output to drive the generator shaft 28, and thus the generator 24.

The wind turbine 10 may also include a turbine controller 32 centralized within the nacelle 16. Further, as shown, the turbine controller 32 is housed within a control cabinet 34. Moreover, turbine controller 32 may be communicatively coupled to any number of components of wind turbine 10 in order to control the operation of such components and/or to implement various corrective actions as described herein.

Referring back to FIG. 2, each rotor blade 22 may also include a pitch drive mechanism 38 configured to rotate each rotor blade 22 about its pitch axis 40 via a pitch bearing 42, thereby allowing the orientation of each blade 22 to be adjusted relative to the direction of the wind. Similarly, wind turbine 10 may include one or more yaw drive mechanisms 44 communicatively coupled to turbine controller 32, wherein each yaw drive mechanism(s) 44 is configured to change an angle of nacelle 16 with respect to the wind (e.g., by engaging a yaw bearing 46 of wind turbine 10).

Referring now to FIG. 3, a perspective view of one of the rotor blades 22 illustrated in FIGS. 1 and 2 is illustrated in accordance with aspects of the present subject matter. As shown, the rotor blade 22 includes: a blade root 23 configured for mounting rotor blade 22 to hub 20; and a blade tip 23, which is arranged opposite to the blade root 23. The body 27 of the rotor blade 22 may extend lengthwise between the blade root 23 and the blade tip 24, and may generally serve as a shell for the rotor blade 22. As generally understood, the body 27 may define an aerodynamic profile (e.g., by defining an airfoil-shaped cross-section, such as a symmetrical or cambered airfoil-shaped cross-section) to enable the rotor blade 22 to derive kinetic energy from wind using known aerodynamic principles. Accordingly, the body 27 may generally include a pressure side 29 and a suction side 31 extending between a leading edge 33 and a trailing edge 35. In addition, the rotor blade 22 may have: a span 37 defining the overall length of the body 27 between the blade root 23 and the blade tip 24; and a chord 39 defining the overall length of body 27 between leading edge 33 and trailing edge 35. As generally understood, the chord 39 may vary in length relative to the span 37 as the body 27 extends from the blade root 23 to the blade tip 24.

Moreover, as shown, the rotor blade 22 may also include a plurality of T-bolts or root attachment assemblies 41 for coupling the blade root 23 to the hub 20 of the wind turbine 10. In general, each root attachment assembly 41 may include: a barrel nut 43 mounted in a part of the blade root 23; and a root bolt 45 coupled to the barrel nut 43 and extending from the barrel nut 43 so as to project outward from a root end 47 of the blade root 23. As will be described in more detail below, root bolts 45 may generally be used to couple blade root 23 to hub 20 (e.g., via one of pitch bearings 42) by projecting outwardly from root end 47.

Referring now to fig. 4-8, various views of an embodiment of a bearing assembly 50 according to the present disclosure are shown. More particularly, as shown, bearing assembly 50 includes pitch bearing 42. It should be understood that the present disclosure is described with respect to pitch bearings, but other bearings are used within the spirit and scope of the present disclosure, such as yaw bearings, for example. As shown, pitch bearing 42 has an outer ring 52, an inner bearing ring 54, and a plurality of roller elements 56 disposed between rings 52, 54. As generally understood, outer race 52 may generally be configured to be mounted to a hub flange of hub 20 using a plurality of hub bolts and/or other suitable fastening mechanisms. Similarly, inner ring 54 may be configured to be mounted to blade root 23 using root bolts 45 of root attachment assembly 41.

Further, the roller elements 56 as described herein may include any one or combination of the following: one or more balls, spheres, rollers, tapered rollers, cylindrical elements, or any other suitable roller element. Additionally, any suitable number of roller elements 56 may be employed. Further, the roller elements 56 may be arranged in any suitable configuration. For example, as shown in fig. 6, two rows of roller elements 56 are employed, with each of the roller elements 56 being circumferentially spaced between the outer and inner races 52, 54. In still further embodiments, a single row or multiple axially spaced rows of roller elements 56 may be used in the bearing assembly 50 to provide additional strength. For example, in various embodiments, three or more rows of roller elements 56 may be employed.

Referring specifically to fig. 6, the roller elements 56 are configured to be received within individual raceways defined between the inner and outer rings 54, 52. In particular, a first raceway 66 may be defined between the inner and outer rings 54, 52 for receiving a first row of roller elements 56, and a second raceway 68 may be defined between the inner and outer rings 54, 52 for receiving a second row of roller elements 56. Thus, as shown in fig. 4, 5, 7 and 8, the outer ring 52 of the pitch bearing 42 may also include at least one ball plunger 48 for allowing the roller elements 56 to be placed between the outer ring 52 and the inner ring 54 and into the raceways 66, 68. For example, as shown in fig. 4, the outer race 52 includes two ball plungers 48 (i.e., one for each row of roller elements 56). Thus, the ball plunger(s) 48 may be removed and the roller elements 56 may be inserted through the outer race 52 into one of the raceways 66, 68. Furthermore, as shown in the illustrated embodiment, the ball plungers 48 may be arranged side by side. In alternative embodiments, the ball plungers 48 may be offset from one another. Additionally, as particularly shown in fig. 6, each raceway 66, 68 may be defined by separate walls of the outer and inner races 52, 54. For example, as shown, the first raceway 66 is defined by a first outer raceway wall of the outer race 52 and a first inner raceway wall of the inner race 54. Similarly, the second raceway 68 is defined by a second outer raceway wall of the outer race 54 and a second inner raceway wall of the inner race 54.

Thus, the inner ring 54 may be configured to rotate (via the roller elements 56) relative to the outer ring 52 to allow adjustment of the pitch angle of each rotor blade 22. As mentioned, relative rotation of outer race 52 and inner race 54 may be achieved using pitch adjustment mechanism 38 mounted within a portion of hub 20. In general, pitch adjustment mechanism 38 may include any suitable components and may have any suitable configuration that allows mechanism 38 to function as described herein. For example, as shown in fig. 2, the pitch adjustment mechanism 38 may include a pitch drive motor 58 (e.g., an electric motor), a pitch drive gearbox 60, and a pitch drive pinion 62. In such embodiments, the pitch drive motor 58 may be coupled to the pitch drive gearbox 60 such that the motor 58 imparts mechanical force to the gearbox 60. Similarly, the gearbox 60 may be coupled to the pitch drive pinion 62 for rotation therewith. Pinion gear 62 may then be in rotational engagement with inner race 54. For example, as shown in fig. 4, a plurality of gear teeth 64 may be formed along an inner circumference of inner race 54, wherein gear teeth 64 are configured to mesh with corresponding gear teeth formed on pinion gear 62. Thus, due to the meshing of gear teeth 64, rotation of pitch drive pinion 62 results in rotation of inner race 54 relative to outer race 52 and, therefore, rotation of rotor blades 22 relative to hub 20.

Referring now to fig. 7 and 8, various cross-sectional views of a ball plunger 48 according to the present disclosure are shown. As shown, the ball plunger 48 is received within a radial opening 53 defined in the outer race 52. It should be understood that the ball plunger 48/radial opening 53 may also be positioned in the inner race 54 (or both). Further, as shown in fig. 7, the radial opening 53 may have a tapered diameter (i.e., a diameter that gradually changes over a length). Alternatively, as shown in fig. 8, the radial opening 53 may have a varying diameter (i.e., the diameter changes abruptly via a stepped change).

More particularly, as shown in fig. 7 and 8, the ball plunger 48 includes an outer portion 55 and an inner portion 57. Also, as shown, the outer portion 55 defines a first diameter 59 and the second portion defines a second diameter 61. For example, as shown, the first diameter 59 is larger than the second diameter 61. Additionally, as shown in the embodiment of fig. 7, the ball plunger 48 also includes a transition region 63 between the outer portion 55 and the inner portion 57. Thus, as particularly shown in fig. 7, the transition region 63 of the ball plunger(s) 48 has a tapered cross-section that matches the tapered diameter of the radial opening 53. More particularly, as shown, the first diameter 59 of the outer portion 55 tapers to the second diameter 61 of the inner portion 57 in a transition region 63. Additionally, as shown, the inner portion 57 of the ball plunger 48 may include a partial raceway 76 that defines a portion of at least one raceway 66, 68 of the outer or inner race 50, 52. Alternatively, as shown in fig. 8, the first diameter 59 of the outer portion 55 abruptly jumps at a step 78 to the second diameter 61 of the inner portion 57.

Still referring to fig. 7 and 8, the bearing assembly 50 may further include an outer retaining device 65 disposed at or adjacent to the distal-most end of the outer portion 55 of the ball plunger 48. For example, the external retaining means 65 may comprise a circlip, a snap ring, a clamp, a coupling means or the like. More particularly, in the embodiment of fig. 7, the external retaining means 65 may be a snap ring. In certain embodiments, the bonding means may comprise, for example, a weld, an adhesive, or a chemical-based solvent. In such embodiments, the ball plunger 48 may be retained, for example, by engaging an outer portion 55 of the ball plunger 48 within the radial opening 53. Alternatively, as shown in fig. 8, the external retaining means 65 may comprise a mechanical device, such as a locknut or a retaining plate, in combination with one or more mechanical fasteners 80, the mechanical fasteners 80 being engaged with the locknut or retaining plate and extending parallel to the longitudinal axis 69 of the ball plunger 48.

In additional embodiments, as shown in fig. 7 and 8, the bearing assembly 50 may include an anti-rotation device 70 configured to prevent rotation of the ball plunger 48. More particularly, as shown in FIG. 7, the anti-rotation device 70 may extend substantially perpendicular to the longitudinal axis 69 of the ball plunger 48 and may also engage the outer surface of the transition region 63 of the ball plunger 48. Alternatively, as shown in fig. 8, may extend substantially parallel to the longitudinal axis 69 of the ball plunger 48. It should be understood that the anti-rotation device may include, for example, an anti-rotation pin (e.g., optionally tapered) or an anti-rotation fastener.

Still referring to fig. 7 and 8, the bearing assembly 50 may include one or more O-rings 72 disposed circumferentially about the inner portion 57 of the ball plunger 48. For example, as particularly shown in fig. 7, the inner portion 57 of the ball plunger 48 may include at least one annular recess 74, with one or more O-rings 72 disposed within the annular recess 74. Additionally, as shown, the bearing assembly 50 may include a plurality of O-rings 72 disposed circumferentially about the inner portion 57 of the ball plunger 48 within an annular recess 74. In such embodiments, as shown, the O-ring 72 may be aligned in a longitudinal direction of the ball plunger 48 (i.e., along the longitudinal axis 69). Alternatively, as shown in fig. 8, the bearing assembly 50 may include a single O-ring disposed on the outer surface of the inner portion 57 of the ball plunger 48.

Additionally, as shown in the embodiment of FIG. 7, the bearing assembly 50 may also include a spacer 67 or shim positioned between the distal-most end of the outer portion 55 of the ball plunger 48 and the outer retaining device 65.

Referring now to fig. 9 and 10, the bearing assembly 50 may also include a set of ball plungers 48 positioned within adjacent radial openings 53 such that outer portions 55 thereof contact each other. For example, as shown, adjacent ball plungers 48 are stacked such that the anti-rotation device 70 described in fig. 7 and 8 may be eliminated in such embodiments.

This written description uses examples to disclose the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.