Tapered Ball Plug Retention for Crack-Resistant Slewing Bearings
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Solution Overview
Problem
Conventional ball plug retention systems for slewing ring bearings in wind turbines, such as pitch or yaw bearings, experience stress concentration and potential cracking due to the use of taper pins, which are not effectively addressed by existing solutions.
Innovation Solution
A bearing assembly with a tapered cross-section ball plug and exterior retention means like circlips or snap rings, along with an anti-rotation device and O-rings, to securely position the ball plug within the radial opening, eliminating the need for taper pins and reducing stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If taper pins are used to retain the ball plug in conventional designs, then the ball plug can be secured in position, but stress concentration and cracking occur in the bearing structure
Solution Approach 1:
The invention removes the taper pin from the ball plug retention system entirely. The ball plug is retained through its tapered cross-section fitting within a corresponding tapered bore in the bearing, eliminating the need for separate taper pins and their associated stress concentration points.
Solution Approach 2:
The ball plug transitions from a cylindrical shape to a tapered cross-section. This geometric parameter change allows the plug to wedge securely within the tapered bore through friction and mechanical interference, providing retention without requiring additional fastening elements like taper pins.
2Ease of operation
If taper pins are inserted through the ball plug to maintain radial seating, then the plug can be positioned correctly, but areas of increased stress concentration are created
Solution Approach 1:
The taper pin is completely extracted from the system. The ball plug's tapered geometry itself provides the positioning and retention function that previously required a separate taper pin, eliminating the source of stress concentration.
Solution Approach 2:
The retention function previously performed by a separate taper pin is merged into the ball plug's own geometry. The tapered cross-section of the plug and corresponding tapered bore work together as an integrated retention mechanism, eliminating the need for additional components.
3Reliability
If conventional ball plug designs are used with taper pins, then the plug can be retained, but the structural integrity of the bearing assembly is compromised
Solution Approach 1:
The harmful taper pin is removed from the bearing assembly. The retention function is achieved through the tapered interface between the ball plug and bearing bore, which maintains structural integrity by avoiding the stress concentrations introduced by taper pins.
Solution Approach 2:
The retention mechanism utilizes a composite approach combining the tapered geometry of the ball plug with the corresponding tapered bore, creating a unified retention system that distributes stresses more evenly throughout the bearing assembly structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enhances the structural integrity of the bearing assembly by eliminating stress concentrations and preventing ball plug rotation, thereby reducing the risk of cracking and improving overall bearing performance.
Implementation Method 1
at least a portion of the ball plug(s) has a tapered cross-section. The tapered cross-section is positioned between an outer portion and an inner portion of the ball plug(s) so as to define a transitional region
Implementation Method 2
exterior retention means arranged at or adjacent to a distal-most end of the outer portion of the ball plug(s). In such embodiments, the exterior retention means may include, for example, a circlip, a snap ring, a clamp, bonding means
Implementation Method 3
an anti-rotation device in contact with an inner surface of the radial opening, the anti-rotation device extending perpendicular to a longitudinal axis of the at least one ball plug and engaging the outer portion of the at least one ball plug so as to prevent rotation thereof
Implementation Method 4
The inner portion of the ball plug(s) includes at least one annular recess. According to the claimed invention, the bearing assembly includes a plurality of O-rings arranged circumferentially around the inner portion of the ball plug(s) within the at least one annular recess
Data Source
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AI summary
A bearing assembly for a wind turbine includes a bearing comprising an outer race, an inner race rotatable relative to the outer race, and a plurality of roller elements positioned within at least one raceway defined between the outer and inner races. 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 plug positioned within the radial opening of at least one of the outer race or the inner race. The ball plug(s) is removable such that the plurality of roller elements can be inserted between the outer and inner races. Moreover, at least a portion of the ball plug(s) has a tapered cross-section.