Counter-Rotating Planetary Gear Drive for Compact High Gear Ratios
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Solution Overview
Problem
Conventional gear drives face challenges in achieving large gear ratios in compact designs, making them difficult to install in smaller applications, and existing systems struggle to efficiently transfer motion with counter-rotating outputs.
Innovation Solution
The design incorporates a gear box with two planetary gears and their respective carriers and ring/sun gears, allowing for counter-rotating outputs through specific couplings and drive interfaces, enabling larger gear ratios in smaller packages and efficient motion transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional gear drives use multiple gears of different sizes to achieve large gear ratios, then the mechanical advantage is improved, but the device size and complexity increase making them difficult to install in smaller applications
Solution Approach 1:
The patent employs planetary gear sets where planet gears are nested around a sun gear, with ring gears enclosing the entire planetary assembly. This nested configuration allows multiple gear interactions to occur within a compact cylindrical volume, achieving large gear ratios without proportionally increasing device size. The first and second planetary gear sets are arranged concentrically, with components of one set integrated with components of the other set, maximizing space utilization.
Solution Approach 2:
The invention transitions from conventional linear gear arrangements to a three-dimensional planetary configuration. By utilizing radial and axial dimensions simultaneously, the gear drive achieves complex motion transformation (including counter-rotating outputs) within a compact footprint. The planetary gears rotate on multiple axes, enabling sophisticated gear ratio multiplication without increasing the primary dimensional footprint.
2Adaptability or versatility
If conventional gear drives use multiple gears and shafts to achieve counter-rotating outputs, then the motion transfer capability is improved, but the device complexity and number of components increase
Solution Approach 1:
The patent merges two planetary gear sets into a single integrated assembly where components serve dual functions. The first carrier is coupled to the second ring gear, and the first ring gear is coupled to the second carrier, creating interconnected motion paths. This integration allows counter-rotating outputs to be achieved without requiring completely separate gear trains, reducing overall component count and simplifying the assembly.
Solution Approach 2:
Each planetary gear set is designed to perform multiple functions: the sun gears serve as both input and output elements, the planet gears simultaneously engage with both sun gears and ring gears, and the carriers and ring gears are interconnected to provide multiple motion transfer paths. This multi-functionality enables the compact transmission of complex motion relationships including counter-rotation.
3Ease of operation
If conventional gear drives are designed for compact size, then the ease of installation is improved, but the ability to achieve large gear ratios is reduced
Solution Approach 1:
The nested planetary configuration allows the gear drive to achieve large gear ratios within a compact cylindrical housing that can be easily installed in space-constrained applications. The concentric arrangement of sun gears, planet gears, and ring gears maximizes the gear ratio capability relative to the outer diameter, enabling compact installation without sacrificing mechanical advantage.
Data Source
AI summary
A gear box includes a first planetary gear and a second planetary gear. The gear box further includes a first carrier of the first planetary gear coupled to a second ring gear of the second planetary gear. The gear box also includes a first ring gear of the first planetary gear coupled to a second carrier of the second planetary gear. The gear box further includes a first sun gear of the first planetary gear coupled to a first output shaft. The gear box also includes a second sun gear of the second planetary gear coupled to a second output shaft.