Segmented Planet Wheel Transmission for Compact Gear Ratio Control

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Solution Overview

Problem

Traditional planet gear systems require complex configurations to shift between different gear ratios, making them costly, unreliable, and inefficient, especially for large gear ratios.

Innovation Solution

A transmission system with planet wheels comprising multiple segments that interact differently with the sun wheel and annulus ring, allowing for simple, reliable, and cost-effective gear ratio changes through selective locking and unlocking mechanisms, enabling various interaction principles and materials for torque transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional planet gear systems use complex wheel configurations to shift between different gear ratios, then gear ratio changing capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvegear ratio changing capabilityVSAvoidwheel configuration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The planet wheel is divided into multiple independent wheel segments that can selectively interact with different gear elements (sun wheel or annulus ring). This segmentation allows the same planet wheel structure to provide multiple gear ratios by changing which segments engage with which elements, eliminating the need for complex multi-wheel configurations in traditional systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A single planet wheel with multiple segments serves multiple functions by being able to interact with both the sun wheel and the annulus ring through different segments. This multi-functionality allows one planet wheel assembly to replace what would traditionally require multiple different wheel configurations to achieve the same gear ratio changing capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If traditional planet gears use more gear components to achieve large gear ratios, then gear ratio range is improved, but manufacturing cost and assembly complexity increase

Engineering Contradiction:
Improvegear ratio rangeVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The planet wheel is divided into multiple independent wheel segments that can selectively interact with different gear elements (sun wheel or annulus ring). This segmentation allows the same planet wheel structure to provide multiple gear ratios by changing which segments engage with which elements, eliminating the need for complex multi-wheel configurations in traditional systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple functional elements (multiple wheel segments capable of interacting with both sun wheel and annulus ring) are merged into a single integrated planet wheel assembly. This consolidation reduces the total number of separate components needed to achieve large gear ratios, simplifying manufacturing and assembly while expanding gear ratio range.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2021653B1A transmission
Publication Date: 2009.08.26 TOMATECH AS
  • EP2021653B1 patent drawingFigure 1
  • EP2021653B1 patent drawingFigure 2
  • EP2021653B1 patent drawingFigure 3

AI summary

The invention provides a transmission providing a gear ratio between an input shaft and an output shaft. The transmission comprises an annulus ring, a sun wheel being rotatable around a central axis of the transmission, a planet carrier being rotatable around the central axis of the transmission, and a set of planet wheels, each wheel comprising a plurality of wheel segments with different diameters, the planet wheels being fixed in rotational bearings of the planet carrier and being arranged to rotate epicyclically around the central axis. The annulus ring and the sun wheel each interacts with one of the wheel segments e.g. via meshing toothed gear wheels. The gear facilitates various interaction means at different locations in the gear, and thus facilitates a potentially less noisy, lighter, smaller or stronger gear by use of a low amount of components.