Epicyclic Gear Stage Preload Structure for Backlash Reduction
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Solution Overview
Problem
Existing epicyclic gear systems face challenges in reducing backlash, which affects the positional accuracy of instruments, particularly in multi-stage gearboxes where backlash contributes significantly to sensor inaccuracy, and existing solutions are often bulky, heavy, or complex.
Innovation Solution
The implementation of a biasing mechanism that urges the carrier and output shaft away from each other, using compressive springs or elastic materials, to preload the carrier and output shaft, ensuring equilibrium and eliminating backlash by ensuring full engagement of gear teeth, with the carrier shaped semi-circularly to follow the ring gear and the output shaft positioned within the ring gear's unoccupied space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing backlash reduction mechanisms are used in epicyclic gear stages, then backlash is reduced, but the system becomes bulky, heavy, or complex
Solution Approach 1:
The patent changes the geometric parameters of the carrier by providing a recess that receives the output shaft, and positions the biasing mechanism to act on the carrier. This parameter change allows the biasing force to be applied effectively without requiring complex additional mechanisms, thereby reducing backlash while maintaining simplicity
Solution Approach 2:
The biasing mechanism acts as an intermediary element between the carrier and output shaft, applying a controlled force to eliminate backlash. This intermediary approach allows for simple and effective backlash reduction without requiring complex direct coupling mechanisms
2Measurement precision
If existing backlash reduction mechanisms are used in epicyclic gear stages, then backlash is reduced, but the system becomes bulky or heavy
Solution Approach 1:
The patent modifies the carrier structure by providing a recess for the output shaft and positioning the biasing mechanism to act on the carrier. This parameter change enables effective backlash reduction using a lightweight biasing mechanism rather than heavy mechanical constraints, thereby reducing overall system weight while improving positional accuracy
3Measurement precision
If the carrier is constrained to reduce backlash, then positional accuracy improves, but the carrier's ability to accommodate planet gears and transmit torque is compromised
Solution Approach 1:
The patent segments the carrier structure by providing a specific recess portion that accommodates the output shaft while maintaining the main body of the carrier intact for supporting planet gears. This segmentation allows the biasing mechanism to act on the carrier without interfering with planet gear accommodation or torque transmission functions
Solution Approach 2:
The biasing mechanism serves as an intermediary that applies force to the carrier through the recess, enabling backlash reduction without directly constraining the planet gears or compromising the carrier's ability to accommodate multiple planet gears and transmit torque effectively
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 achieves an approximately 80% reduction in overall backlash in a four-stage epicyclic reduction gearbox, enhancing the accuracy of positional sensors and precision in low-powered applications like 3D printing by accurately communicating rotational inputs and reducing directional changes.
Implementation Method 1
the biasing mechanism being configured to urge the carrier and the output shaft away from one another
Implementation Method 2
using compressive springs or elastic materials, to preload the carrier and output shaft
Data Source
Figure 1
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AI summary
An epicyclic gear system having an epicyclic gear stage, the epicyclic gear stage comprising: a sun gear; a carrier, wherein the carrier comprises a plurality of planet gear axles; a plurality of planet gears, each planet gear being located on one of the planet gear axles; a ring gear; and an output shaft, wherein the output shaft is connected to the carrier via a biasing mechanism positioned between the carrier and the output shaft, the biasing mechanism being configured to urge the carrier and the output shaft away from one another.