Compact Automatic Winding System Using Planetary Gear Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing automatic winding systems for watches are bulky and energy inefficient due to significant reduction ratios achieved through multiple meshing gears, which complicates the reduction gear train and increases friction.
Innovation Solution
A compact automatic winding system utilizing a unidirectional drive system with a reducer that includes eccentrically mounted wheels and guide pins, allowing for a strong reduction in rotation speed through a differential tooth mechanism, ensuring unidirectional operation and modularity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple meshing gears are used to achieve significant reduction ratio, then the reduction ratio is improved, but the device complexity and bulk increase
Solution Approach 1:
The patent combines multiple gear functions into a single planetary gear mechanism. The planetary gear system integrates the sun gear, planet gears, and ring gear into one compact unit that achieves the required reduction ratio of approximately 100:1, eliminating the need for multiple separate meshing gear stages and reducing overall device complexity.
Solution Approach 2:
The planetary gear mechanism employs a nested configuration where planet gears are positioned between the sun gear and ring gear, with the carrier holding the planet gears. This nested arrangement allows multiple gear elements to occupy the same spatial envelope, achieving high reduction ratios in a compact form factor without increasing device bulk.
2Productivity
If multiple meshing gears are used to achieve significant reduction ratio, then the reduction ratio is improved, but the energy consumption increases due to friction
Solution Approach 1:
By merging multiple gear stages into a single planetary gear mechanism, the patent reduces the total number of meshing interfaces from multiple separate gear pairs to just two primary meshing zones (sun-planet and planet-ring). This consolidation significantly reduces cumulative friction losses while maintaining the required reduction ratio.
Solution Approach 2:
The nested planetary gear configuration minimizes the radial space required for each gear stage, reducing the overall moment arm and consequently the frictional torque at each meshing point. The compact nested arrangement also reduces the number of bearing supports required, further decreasing energy losses.
3Reliability
If large-diameter ball bearing is used to ensure unidirectional rotation, then the unidirectional operation is improved, but the device bulk increases
Solution Approach 1:
The patent integrates the unidirectional constraint function directly into the planetary gear mechanism itself. The inherent geometry of the planetary gear system, combined with a simple ratchet mechanism on the output shaft, provides reliable unidirectional operation without requiring a separate large-diameter ball bearing, thus maintaining compact dimensions.
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 system achieves a high reduction ratio while maintaining compactness and reducing energy consumption, making it less sensitive to shocks and easier to implement, with adaptable gear teeth for flexible reduction ratios.
Implementation Method 1
a unidirectional drive system comprising an input, on which is mounted integrally the oscillating mass 10, and an output ring 12b arranged not to be driven by the input 12a only in one direction
Implementation Method 2
The outer face of the second output ring 12b is arranged eccentrically with respect to the axis AA. We define the eccentricity e as the distance between the axis AA and the axis of the center of the second output ring 12b
Implementation Method 3
The first wheel 18 comprises a toothing of N1 teeth on its outer portion and is therefore driven eccentrically around the axis AA... The second wheel 26 has an internal toothing of N2 teeth, with N2 greater than N1 by at least one tooth
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to an automatic winding system comprising: - an oscillating mass (10) pivoting on an axis (AA), a one-way drive system (12) comprising an input to which is securely attached the oscillating mass (10), and an output designed to be driven by the input in only one direction, - a reducer (16) kinematically connecting the output of the one-way drive system to the ratchet (30) of a barrel.