Wobble Plate Gearing for High Ratio Compact Drive
Solution Overview
Problem
Wobble plate drive mechanisms face challenges in achieving high gear ratios within a small volume due to issues like disengagement, vibration, and inefficiency caused by friction, making it difficult to efficiently convert oscillations of electrical current into rotational mechanical energy.
Innovation Solution
A wobble plate drive system with a stator having a central axis and stator teeth on an inner cylindrical surface, a wobble plate with wobble teeth on an outer cylindrical surface and face teeth on an upper annular surface, and an output gear with output teeth on a lower annular surface, where the wobble plate nutates around the stator, engaging wobble teeth with stator teeth and face teeth with output teeth, utilizing a rolling contact mechanism to minimize friction and achieve efficient motion transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of stationary object
If a wobble plate mechanism uses two gears with different tooth counts to achieve high gear ratio, then the gear ratio increases and volume decreases, but the mechanism experiences disengagement, vibration, and friction inefficiency
Solution Approach 1:
The patent divides the single wobble plate mechanism into three separate components: a stator gear, a wobble plate, and an output gear. This segmentation allows each component to have optimized tooth profiles and engagement characteristics, reducing disengagement and vibration while maintaining the compact high gear ratio design.
Solution Approach 2:
The patent applies different tooth profile geometries to different locations: the stator and output gear use involute tooth profiles for reliable engagement, while the wobble plate uses a specialized nutational motion profile. This local differentiation of tooth characteristics optimizes each engagement zone for its specific functional requirements, reducing friction and improving reliability.
2Device complexity
If a wobble plate mechanism uses traditional gear tooth engagement, then the structure is simple, but friction is high and efficiency is low
Solution Approach 1:
The patent replaces traditional sliding gear tooth contact with a rolling contact mechanism. The wobble plate's nutational motion creates rolling engagement between its teeth and the stator/output gear teeth, significantly reducing friction losses while maintaining structural simplicity.
Solution Approach 2:
The patent employs curved, nutational motion paths for the wobble plate teeth rather than straight-line engagement. The elliptical or nutational trajectory of the wobble plate creates rolling contact conditions, reducing sliding friction and improving efficiency while keeping the mechanical structure relatively simple.
3Force
If a wobble plate mechanism operates with high forces, then the gear ratio is maintained, but vibration and disengagement occur
Solution Approach 1:
The patent changes the motion parameters of the wobble plate from simple rotation to nutational motion with a specific inclination angle. This parameter change allows the mechanism to maintain high gear ratios through geometric relationships while distributing forces more evenly, reducing vibration and preventing disengagement.
Solution Approach 2:
The patent introduces dynamic nutational motion of the wobble plate, where the plate oscillates between two positions during rotation. This dynamic motion pattern allows continuous tooth engagement while maintaining smooth force transmission, reducing vibration and preventing disengagement that occurs in static or purely rotational systems.
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 configuration allows for a remarkably large gear ratio, enabling efficient conversion of electrical energy into rotational motion with minimal friction, suitable for applications requiring fine motor control within a small volume.
Implementation Method 1
utilizing a rolling contact mechanism to minimize friction and achieve efficient motion transfer
Data Source
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AI summary
A wobble plate drive system may include a stator having a central axis and a plurality of stator teeth disposed on an inner cylindrical surface. The system may further include a wobble plate having a wobble axis disposed at a non-zero angle relative to the central axis, an outer cylindrical surface, and an upper annular surface. A plurality of wobble teeth may be disposed on the outer cylindrical surface and a plurality of face teeth may be disposed on the upper annular surface. The system may further include an output gear having an output axis substantially aligned with the central axis and a lower annular surface. A plurality of output teeth may be disposed on the lower annular surface. The wobble plate may be configured to rotate, the plurality of wobble teeth may be configured to engage with the plurality of stator teeth, and the plurality of face teeth may be configured to engage with the plurality of output teeth as the wobble plate nutates around the stator.