Large Diameter Bearing With Radially Adjustable Support Pads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Standard bearing technology is impractical for large rotating structures, such as vertical axis wind turbines, due to excessive lateral forces and the difficulty in manufacturing geometrically accurate large steel bearing rings, particularly those with diameters over 15 meters.
Innovation Solution
A bearing arrangement featuring inner and outer coaxial cylindrical members with radially movable arcuately curved support plates and a fluid cushion or needle rollers to manage radial thrust, allowing for rotation about a vertical axis, with control mechanisms to maintain alignment and compensate for irregularities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard bearing technology is used for large rotating structures, then the structure can rotate, but the lateral forces become excessive and manufacturing geometrically accurate large steel bearing rings becomes impractical
Solution Approach 1:
The bearing ring is divided into multiple segmented blocks that can be manufactured separately and assembled together. Each block has a smaller, more manageable size that is feasible to manufacture with current capabilities, while collectively forming the complete large-diameter bearing ring structure needed to support the turbine.
Solution Approach 2:
The bearing system incorporates movable support plates that can radially move to accommodate varying lateral loads from wind forces. This dynamic adjustment capability allows the bearing to adapt to changing force conditions, distributing loads more effectively across the segmented structure.
2Length of stationary object
If the bearing arrangement has a substantial intrinsic diameter (15-20 metres or more), then it can support large wind turbines, but manufacturing geometrically accurate bearing rings becomes essentially infeasible
Solution Approach 1:
The large-diameter bearing ring is segmented into multiple smaller blocks that are manufactured separately with achievable precision, then assembled to form the complete large-diameter structure. This approach makes the overall system feasible while maintaining sufficient geometric accuracy through controlled assembly of manageable segments.
Solution Approach 2:
Instead of requiring the entire large-diameter ring to be manufactured with perfect geometric accuracy, the design accepts that segmented blocks will have minor variations, and uses the assembly process and operational adjustments to compensate, achieving sufficient functional precision without demanding impossible manufacturing tolerances.
3Force
If arcuately curved support plates are used to match the curvature of the facing surface, then radial thrust can be controlled, but the device complexity increases
Solution Approach 1:
The support plates are given an arcuate curvature that matches the facing surface of the bearing ring, enabling them to conform to the cylindrical geometry. This curved design allows the plates to effectively distribute and control radial thrust forces while maintaining compatibility with the overall bearing 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
Enables efficient and stable rotation of large structures by distributing and controlling lateral forces, making it feasible to use in wind turbines and other large diameter applications, while simplifying maintenance and operation.
Implementation Method 1
The axial thrust between that surface and the facing circular or annular surface of the other component may be transmitted by a cushion of fluid between them, constituting a hydrostatic bearing
Implementation Method 2
the cylindrical wall of one member carries a plurality of radially movable arcuately curved support plates, the curvature of the support plates matching the curvature of the facing surface of the other member, and being in contact therewith, and means to control the radial thrust exerted by the movable support plates
Data Source
AI summary
Bearing arrangements are described which enable rotation about a vertical axis with a very extended diameter bearing, for example 20 metres diameter. A usually stationary base supports a rotating member (12), e.g. on a fluid cushion. Separately, a ring of radially adjustable arcuate surface support pads on outer member (16) acts against a cylindrical surface of the inner member. The adjustability of the radially movable support pads (16) enables them to increase their thrust at parts of the circumferences of the bearing relative to others. This enables considerably smoother running to be achieved, both to compensate for the difficulties of producing complete circularity with a bearing diameter of substantial size, and for varying direction lateral loadings, e.g. as experienced by a vertical axis wind-driven turbine (1 , 5, 6).