Roll-Ring Torque Multiplier for Low-Friction High-Ratio Gearing
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Solution Overview
Problem
Existing torque multipliers face inefficiencies in power transmission, particularly in high ratio categories, leading to energy wastage and design trade-offs, with issues such as expensive manufacturing, limited hollow bore clearance, noise, vibration, and low energy efficiency due to sliding interfaces.
Innovation Solution
The design incorporates a unique combination of high torque density, high efficiency, and high linearity using a plurality of roll rings with a modified hypotrochoidal lobe interface, reducing inertia and friction, and distributing load evenly between lobes for improved torque linearity and capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional cycloid or planetary gearing is used, then torque multiplication is achieved, but energy efficiency deteriorates due to sliding interfaces
Solution Approach 1:
The patent replaces traditional sliding mechanical interfaces (cycloid disc sliding against lobes, planetary gear tooth sliding) with rolling element interfaces. Roll rings with rolling elements engage between the lobes and the cycloid disc, converting sliding friction into rolling friction. This substitution dramatically reduces energy loss while maintaining torque transmission reliability through the rolling contact mechanism.
2Volume of moving object
If hollow bore clearance is increased, then cable routing and packaging are improved, but torque density deteriorates
Solution Approach 1:
The patent segments the torque transmission function across multiple roll rings arranged in series or parallel configurations. Each roll ring handles a portion of the total torque, allowing the individual rings to be compact while the overall assembly provides a large hollow bore. This segmentation enables both high torque density in each ring and large bore clearance in the overall device.
Solution Approach 2:
The patent utilizes the radial dimension by arranging roll rings at different radii from the central bore. Multiple roll rings can be positioned at different distances from the center, allowing torque to be transmitted through multiple radial zones. This dimensional arrangement maximizes the use of available space, achieving both high torque density and large hollow bore clearance simultaneously.
3Manufacturing precision
If manufacturing precision is improved to reduce lash, then torque transmission accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The roll rings act as intermediary elements between the lobes and the cycloid disc, providing a buffering mechanism that tolerates manufacturing variations. The rolling elements within the roll rings accommodate minor dimensional deviations and misalignments, reducing the sensitivity to manufacturing precision requirements while maintaining low lash and smooth torque transmission.
4Loss of energy
If friction is reduced through rolling interfaces, then energy efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The roll rings serve multiple functions simultaneously: they provide rolling contact to reduce friction, they act as structural support elements, they distribute loads across multiple rolling elements, and they maintain the geometric relationship between lobes and cycloid disc. This multi-functionality reduces the need for separate friction-reduction components, thereby limiting the increase in overall manufacturing complexity.
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 approach enhances energy efficiency, reduces friction, and achieves high torque density with a compact form factor, enabling smooth and quiet operation while maintaining a large hollow bore, thus addressing the inefficiencies and limitations of prior art torque multipliers.
Implementation Method 1
the outside diameter of each roll ring is in contact with, and rolls against, both lobes and an eccentric bearing
Data Source
AI summary
Numerous examples of a torque multiplier and associated methods are disclosed. In one example, a torque multiplier comprises a first shaft for providing a first torque; a second shaft for providing a second torque; and a gear structure coupled to the first shaft and the second shaft to multiply the first torque to generate the second torque, the gear structure comprising a lobe ring, a plurality of roll rings in contact with the lobe ring, a pin structure comprising a plurality of pins, each of the pins located inside one of the roll rings; and a bearing in contact with the plurality of roll rings.