L-Shaped Bushing Plain Bearing for Wind Turbine Gearbox Deformation
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Solution Overview
Problem
Existing planetary gear stages in wind turbines face challenges with deformation and wear due to high dynamic forces and speed variations, particularly when using plain bearings, which can lead to reduced effectiveness and potential failure.
Innovation Solution
A planetary gear stage design featuring L-shaped bushings fixedly connected to planet shafts, forming a U-shape with axial and radial sliding supports, allowing for adaptation to deformations and increased durability through adjustable sizing and locking mechanisms, suitable for various planet carriers and gear sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If planet gears are made thinner to reduce weight, then weight of the gearbox is reduced, but flexibility increases leading to higher deformation during operation
Solution Approach 1:
The planet bearing arrangement is designed to be adaptive and dynamic, automatically adjusting to deformation of the planet gear. The bearing elements can move relative to each other to accommodate changes in the gear geometry while maintaining proper support and alignment during operation.
Solution Approach 2:
The bearing arrangement allows for parameter changes in the support geometry to match the deformed state of the planet gear. This includes adjustable clearances and positions that adapt to the actual operating conditions and deformation levels of the thinner planet gears.
2Device complexity
If plain bearings are used instead of roller bearings, then device complexity is reduced, but wear resistance and reliability deteriorate under high dynamic forces
Solution Approach 1:
The plain bearing arrangement incorporates dynamic adaptation capabilities, allowing the bearing elements to adjust their positions and contact points in response to varying loads and deformations. This dynamic behavior enhances wear resistance and reliability without increasing structural complexity.
Solution Approach 2:
The planet bearing arrangement is divided into multiple independent bearing elements that can move and adjust individually. This segmentation allows each element to optimize its contact with the planet gear, distributing loads more effectively and reducing wear on any single point.
3Manufacturing precision
If fixed L-shaped bushings are used to support planet gears, then manufacturing precision is improved, but adaptability to deformation deteriorates
Solution Approach 1:
While the L-shaped bushings are manufactured with high precision, the overall bearing arrangement is designed to be dynamic and adaptive. The bushings maintain their precise geometry for manufacturing accuracy but allow controlled movement and adjustment to accommodate planet gear deformation during operation.
Solution Approach 2:
The bearing support system is segmented into multiple L-shaped bushings that can move independently relative to the planet shaft. This segmentation allows the system to maintain manufacturing precision in the bushing geometry while adapting to deformation through the relative movement of the segmented components.
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 design enhances the lifespan of plain bearing arrangements by accommodating deformations, reducing wear, and maintaining effectiveness under high operational loads, thus supporting the growing demands of multi-megawatt wind turbines.
Implementation Method 1
a radial sliding support in between the radial contact surface of the fixed L-shaped bushings and the radial contact surface of the planet gear
Implementation Method 2
an axial sliding support between the axial contact surface of the fixed L-shaped bushings and the axial contact surface of the planet gears
Data Source
Figure 1~2
Figure 3(a)~4(b)
Figure 5~6
AI summary
The present invention provides a planetary gear stage (2) for a gearbox (1 ). The planetary gear stage (2) comprises a ring gear (8), a sun gear (9) and a planet carrier (4) for driving at least three planet shafts (6) each onto which at least one planet gear (5) having a radial contact surface (18) and an axial contact surface (20) is rotatably mounted by means of a plain bearing arrangement (7). The plain bearing arrangement (7) comprises two bushings (12) fixedly connected to the planet shaft (6), each fixed bushing (12) being L-shaped in cross-section and having a radial contact surface (13) and an axial contact surface (14). The fixed L-shaped bushings (12) are mounted to form a cross-sectional U-shape and are locked in axial direction at both outer sides by an abutment (15, 16, 24). At least part of the planet gear (5) is located within the U-shape formed by the fixed L-shaped bushings (12). The plain bearing arrangement (7) furthermore comprises a radial sliding support (17) in between the radial contact surface (13) of the fixed L-shaped bushings (12) and the radial contact surface (18) of the planet gear (5) and an axial sliding support (19) in between the axial contact surface (14) of the fixed L-shaped bushings (12) and the axial contact surface (20) of the planet gears (5).