Multi-Rotatable Planetary Gear Train With Controllable Torque Resistance

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Solution Overview

Problem

Existing mechanical interconnections of multiple rotatable devices (MIMRDs) face limitations such as complexity, lack of compactness, efficiency, and restricted transmission ratios, particularly in applications requiring high torques and variable transmission ratios.

Innovation Solution

A MIMRD design featuring a gear train with quasi-duplicated planetary gearing systems, including first and second stages, where each second stage comprises an input and output side with nearly identical planetary gearing sets, linked by a linking mechanism, and a torque resisting or controlling means to achieve high transmission ratios and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional mechanical interconnections are used, then the structure is simple, but the transmission ratio range is restricted and compactness is poor

Engineering Contradiction:

Improvetransmission ratio rangeVSAvoidstructure complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The gear train is divided into multiple stages, with each stage comprising a planetary gear set and a torque resisting or controlling means. This segmentation allows independent control of transmission ratios at each stage, enabling a wide overall transmission ratio range while keeping each individual stage relatively simple and compact.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The torque resisting or controlling means in each stage can dynamically adjust the torque resistance, allowing continuous variation of transmission ratios. This dynamic control mechanism enables seamless adjustment of transmission ratios without requiring complex mechanical reconfiguration, resolving the contradiction between adaptability and structural simplicity.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If high transmission ratios are achieved through conventional means, then the transmission ratio is high, but the device size and complexity increase

Engineering Contradiction:

Improvetransmission ratioVSAvoiddevice size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

Planetary gear sets are nested within each stage, with the sun gear, planet gears, and ring gear arranged in a compact concentric configuration. This nesting allows high transmission ratios to be achieved within a small radial space, avoiding the need for large, multi-stage conventional gear trains that would increase device volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The torque resisting or controlling means acts as an intermediary element that enables high transmission ratios by providing controlled resistance to torque flow. This intermediary mechanism allows the planetary gear set to achieve high reduction ratios without requiring excessively large gear dimensions, thus maintaining compact device size while achieving high transmission ratios.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple rotatable devices are interconnected, then the versatility and adaptability improve, but the device complexity and lack of compactness increase

Engineering Contradiction:

ImproveversatilityVSAvoidinterconnection complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each stage of the gear train is designed with universal components that can handle multiple functions: the planetary gear set provides both speed reduction and torque multiplication, while the torque resisting or controlling means can operate in different modes (fixed, variable, or reversible). This multi-functionality allows the system to achieve high versatility without proportionally increasing structural complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Multiple functional elements are merged into integrated assemblies: the planetary gear set combines sun gear, planet gears, and ring gear into a single compact unit, and the torque resisting or controlling means is integrated directly into each stage. This merging reduces the number of separate components and interconnections needed, achieving compactness while maintaining the ability to interconnect multiple rotatable devices with high versatility.

Inventive Principle:

Principle #5Merging (Combining)

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 allows for seamless variation of transmission ratios, achieving high efficiency and compactness, suitable for diverse applications from large wind turbines to small robotic joints, while maintaining reliability and adaptability.

Implementation Method 1

each second stage comprises an input side and an output side with nearly identical planetary gearing sets

Methodology Applied

Scientific EffectPlanetary gearing: Epicyclic Gearing

Implementation Method 2

achieving high transmission ratios and flexibility

Methodology Applied

Scientific EffectMechanical advantage: Mechanical Advantage

Data Source

PatentUS12486890B2Mechanical interconnection of multiple rotatable devices (MIMRD)

Publication Date: 2025.12.02 VRIJE UNIV BRUSSEL

AI summary

Mechanical interconnection of multiple rotatable devices that includes: a gear train, at least three rotatable devices, one or more first stages, and one or more second stages, a first element, i.e. a geared element or a planet carrier, of one of the second stages forming a torque resisting means being blocked or impeded in a controllable way. The third rotatable device interacting with a second element, i.e. a gearwheel, or a planet carrier, of one of the second stages.