Wind Turbine Rotor Bearing Preload With Screwed Bearing Ring
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Solution Overview
Problem
Existing rotor bearing units in wind turbines face challenges with complex assembly, ring creep, inaccurate axial preload adjustment, and reduced service life due to press-fitted rings and settling phenomena, leading to potential bearing damage and inefficiencies.
Innovation Solution
A rotor bearing unit design featuring sleeve-like connecting structures with tapered roller bearings, where one bearing ring is screwed into a fastening flange, allowing precise axial preload adjustment and preventing ring creep, with modular components for easy assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If bearing rings are press-fitted into connecting structures, then assembly is simplified, but ring creep and settling phenomena occur leading to inaccurate axial preload and reduced service life
Solution Approach 1:
The bearing ring is divided into two functional parts: a press-fit portion that interfaces with the connecting structure for simplified assembly, and a screwed portion that interfaces with the fastening flange for precise axial preload adjustment. This segmentation allows each part to perform its specific function optimally without interference from the other.
Solution Approach 2:
The screwed portion of the bearing ring acts as an intermediary mechanism between the press-fit connection and the axial preload requirement. By providing a threaded interface, it enables precise adjustment of axial preload independent of the press-fit connection, eliminating the settling phenomena that occur with pure press-fit designs.
2Ease of manufacture
If bearing rings are press-fitted into connecting structures, then assembly is simplified, but disassembly becomes extremely difficult and damaging
Solution Approach 1:
The bearing ring is segmented into press-fit and screwed portions, allowing the screwed portion to be detached independently. This enables disassembly of the bearing ring from the fastening flange without requiring damage to the press-fit connection in the connecting structure, facilitating maintenance and repair.
Solution Approach 2:
The connection method is made dynamic and adjustable through the screwed portion. This allows the bearing ring to be easily assembled and disassembled by rotating the screwed portion, transforming a static press-fit connection into a dynamically adjustable and reversible connection.
3Ease of manufacture
If axial preload is adjusted using press-fitted rings, then assembly is simpler, but adjustment precision is insufficient due to settling phenomena
Solution Approach 1:
The screwed portion serves as an intermediary adjustment mechanism that decouples axial preload adjustment from the press-fit connection. This allows precise control of axial preload through thread engagement, eliminating the imprecision caused by settling in pure press-fit designs.
Solution Approach 2:
The axial preload parameter is adjusted by changing the engagement depth of the screwed portion through rotation. This provides continuous and precise control over the axial preload parameter, unlike the fixed and imprecise preload from press-fit alone.
4Reliability
If bearing rings are designed with large radial cross-section to prevent ring creep, then fitting joint contact force increases, but available installation space is exceeded
Solution Approach 1:
The bearing ring is segmented into press-fit and screwed portions, allowing the screwed portion to carry the axial preload function. This eliminates the need to increase the radial cross-section of the entire bearing ring for creep prevention, as the screwed connection provides sufficient contact force without additional radial dimension.
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
The solution provides a ready-to-install unit with improved precision in axial preload adjustment, reduced maintenance, and extended service life by preventing ring creep and simplifying assembly, while maintaining high load capacity and flexibility for different turbine types.
Implementation Method 1
two tapered roller bearings (4, 5) arranged at a distance from one another
Implementation Method 2
one of the bearing rings (6), which has a first bolt circle (16), is assigned to the fastening flange (10). The bearing ring (6) assigned to the fastening flange (10) is screwed through the bolt circle (16) into the rotor bearing unit (1) at the axial mounting surface (14) of the mounting flange (10), introducing an axial preload
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a rotor bearing unit (1) for a wind turbine, comprising: a sleeve-like inner connection structure (2) which extends along a central axis (A); a sleeve-like outer connection structure (3) which is coaxial with the inner connection structure (2); and two mutually axially spaced tapered roller bearings (4, 5) which each have at least one inner bearing ring (6, 7') fastened to the inner connection structure (2) and at least one outer bearing ring (8', 9') fastened to the outer connection structure (3); wherein at least one radially extending fastening flange (10, 11, 12, 13) having an axial fastening surface (14) is formed on the inner connection structure (2) and/or the outer connection structure (3), and wherein the fastening flange (10, 11, 12, 13) is assigned one of the bearing rings (6, 7', 8', 9'), which has a first hole circle (16) by means of which the bearing ring (6, 7', 8', 9') assigned to the fastening flange (10, 11, 12, 13) is screwed to the axial fastening surface (14) of the fastening flange (10, 11, 12, 13) in such a way that an axial preload is applied to the rotor bearing unit (1). The invention also relates to a method for setting the axial preload in a rotor bearing unit of this type.