Compliant Pin for Planetary Gear Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current planetary gear systems in wind turbines face misalignment issues due to manufacturing and design tolerances, as well as operational twisting and bending, leading to increased load on gears and potential failure.

Innovation Solution

The use of compliant pins that couple planet gears to carriers in planetary gear systems, which modify the compliance of the pins to maintain proper alignment and distribute loads effectively, reducing the impact of misalignment and operational loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If rigid pins are used to couple planet gears to carriers, then the structural strength and stability are improved, but misalignment between meshing teeth occurs due to manufacturing tolerances and operational twisting/bending

Engineering Contradiction:
Improvestructural strengthVSAvoidalignment precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The pin's compliance parameter is modified by introducing features such as reduced cross-sectional profile portions, channels, or bores that reduce the pin's stiffness in specific directions. This allows the pin to deform elastically under load, compensating for misalignments between gears while maintaining sufficient structural strength to transmit torques.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The pin transitions from a completely rigid static component to a dynamic component that can adapt its shape during operation. The compliant pin deforms elastically in response to varying loads and misalignments, allowing the system to self-adjust and maintain proper gear meshing conditions throughout the operational cycle.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If manufacturing and design tolerances are reduced to improve gear alignment, then alignment precision is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvealignment precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The compliant pin acts as an intermediary element between the carrier and planet gears, absorbing the effects of manufacturing tolerances and misalignments. Rather than requiring extremely precise manufacturing of all components, the compliant pin mediates the interactions, allowing standard tolerance ranges while maintaining proper gear meshing.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the pin compliance is increased to improve alignment compensation, then load distribution is improved, but the pin strength may be reduced

Engineering Contradiction:
Improveload distributionVSAvoidpin strength
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The pin is designed with non-uniform properties, featuring reduced cross-sectional profile portions, channels, or bores at specific locations to create localized compliance zones. These features reduce stiffness only where needed for alignment compensation while maintaining sufficient strength in other critical areas to handle the transmitted loads.

Inventive Principle:
Principle #3Local quality

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 compliant pins ensure proper alignment and reduced load distribution among gears, increasing the lifespan of the gear system and wind turbines by mitigating the effects of misalignment and operational loads.

Implementation Method 1

a compliant pin, which may include features that modify the compliance of the pin, such as a reduced cross-sectional profile, channels, or bores

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2559915B1Planetary gear system
Publication Date: 2016.06.01 GENERAL ELECTRIC CO
  • EP2559915B1 patent drawingFigure 1
  • EP2559915B1 patent drawingFigure 2
  • EP2559915B1 patent drawingFigure 3~4

AI summary

A pin (50) for coupling a planet gear (28) to a carrier (24) in a planetary gear system (20) is disclosed. The pin (50) includes a first end (52), a second end (54), and an outer surface (56) extending between the first end (52) and the second end (54). In some embodiments, the pin (50) further includes means for modifying the compliance of the pin (50) at an interface between the pin (50) and the carrier (24). In other embodiments, the pin (50) further include a compliance feature defined in the outer surface (56), the compliance feature allowing greater compliance of the pin (50) in the tangential direction (82) than in the radial direction (84).