Wind Turbine Planetary Bearing Lubrication With Axial Pockets
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Solution Overview
Problem
Existing planetary gear systems in wind turbines face challenges with lubricant distribution in plain bearings, leading to inefficiencies and structural weaknesses due to high pump pressures and the need for larger, heavier designs to accommodate lubricant channels, which increase installation space and weight requirements.
Innovation Solution
The implementation of lubricant pockets with a circumferential groove and radial channels allows for efficient lubricant distribution at low pump pressure, creating a lubricant reservoir within the plain bearing, ensuring adequate lubrication and reducing the need for extensive lubricant channels, thereby minimizing structural weakening and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pump pressure is used to deliver lubricant into the lubricant supply system, then sufficient lubricant reaches the load zone, but excessive lubricant escapes from the sliding bearing
Solution Approach 1:
The patent changes the pressure parameter from high to low (less than 5 bar) and compensates by optimizing the geometric parameters of the lubricant supply system - specifically the axial length of lubricant pockets (at least 60% of planet gear width) and the positioning of radial channels to open into circumferential grooves. This parameter transformation resolves the contradiction by achieving sufficient lubrication through geometric optimization rather than pressure increase.
2Loss of substance
If large volumes of lubricant are injected at low pump pressure, then lubricant losses are prevented, but a lubricant distribution device with large cross-section is required
Solution Approach 1:
The patent segments the lubricant distribution function into three distinct geometric features: radial channels for lubricant delivery, circumferential grooves for distribution, and lubricant pockets for localized storage. This segmentation allows the system to achieve effective lubrication with a compact design, avoiding the need for a large cross-section distribution device while preventing lubricant losses.
Solution Approach 2:
The patent utilizes the axial dimension extensively by designing lubricant pockets with axial length L ≥ 0.6B (where B is the width of the planet gear). This dimensional approach allows the system to store and distribute sufficient lubricant volume without increasing the radial or circumferential footprint, thus maintaining compact device complexity while preventing lubricant loss.
3Reliability
If channels are made to pass through sliding partners to supply lubricant, then lubricant reaches the bearing, but the sliding partner is weakened
Solution Approach 1:
The patent applies local quality by concentrating the lubricant supply function in specific localized features (radial channels opening into circumferential grooves that feed lubricant pockets) rather than requiring channels to pass completely through the sliding partner. This localized approach delivers necessary lubrication while preserving the overall structural integrity and strength of the sliding partner.
4Strength
If the sliding partner is made larger to compensate for channel weakening, then load transmission capability is maintained, but weight and installation space increase
Solution Approach 1:
The patent incorporates lubricant pockets with axial length L ≥ 0.6B that are pre-formed in the sliding partner surface. These pockets serve as preliminary lubricant reservoirs that ensure adequate lubrication is available before the planetary gear begins rotation, eliminating the need to oversize the sliding partner for lubrication purposes and thereby reducing weight while maintaining load transmission capability.
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 sliding ability and wear resistance of planetary gear bearings, maintaining effective lubrication and load transmission while reducing the weight and size of the components, thus optimizing the performance and efficiency of wind turbine planetary gears.
Implementation Method 1
Under the hydrodynamic pressure conditions prevailing there, this lubricant film forms a lubricating film separating the two sliding partners
Implementation Method 2
a lubricant film is created between the involved surfaces. This film is provided with a lubricant immersion bath
Data Source
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AI summary
The invention relates to a planetary transmission (4) of a wind turbine (1), comprising a ring gear (10), a sun gear (9), multiple planetary gear wheels (11) and a planetary carrier (15), wherein the planetary gear wheels (11) are slidingly mounted on the planetary shafts (12) thereof, wherein the planetary gear wheels (11) are arranged thereon coaxially relative to the planetary shafts (12), as well as comprising at least one cavity (23) on a surface (13.1; 13.2) of one of the two sliding partners (11, 12) that are in sliding contact with one another, wherein each cavity (23) extends axially and in the circumferential direction on the surface (13.1; 13.2) of the respective sliding partner (11; 12) and is formed with a radial depression in relation to the rest of the casing contour of said sliding partner (11; 12), and comprising a lubricant distribution unit (18; 20, 21) which is fed by a pump (19) and has first openings (22.1), wherein said first openings (22.1) terminate in the cavity/cavities (23). In order to improve the formation of a lubricant film, it is proposed that: each cavity provided on a surface (13.1; 13.2) of one of the two sliding partners (11; 12) that are in sliding contact with one another is a lubricant pocket (23), with an axial length L of at least 60% of the axial width (B1) of the planetary gear wheel (11); a circumferential groove (24; 30.1, 30.2) is provided, running entirely in the sliding partner (11; 12) that is arranged coaxially relative to the other sliding partner (11; 12) provided with at least one lubricant pocket (23) of this type, and/or which extends in the sliding partner (11; 12) provided with the at least one lubricant pocket (23), on the circumference thereof and exclusively between the lubricant pockets (23); and the lubricant distribution unit (18) comprises second openings (22.2) which terminate either in or opposite the circumferential grooves (24; 30.1, 30.2).