Multi-Stage Planetary Reduction Gear with Nested Counter Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reduction gears with high reduction rates using parallel-axis-gear mechanisms face challenges such as increased offset and width due to large gear sizes, while those using planetary gear sets are limited by lower reduction rates and wider configurations.
Innovation Solution
A reduction gear design incorporating multiple planetary gear sets with shared center axes and counter gear sets, where the first and second planetary gear sets are arranged coaxially and share loaded torque, reducing the axial width and offset between input and output shafts while increasing the reduction rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If parallel-axis-gear mechanisms are used to achieve high reduction rate, then reduction rate is improved, but offset between input shaft and output shaft becomes large and axial width increases
Solution Approach 1:
The patent applies nesting by placing the counter gear set inside the axial width space of the planetary gear sets. The counter gear set is positioned within the inner circumferential area of the planetary gear width, allowing it to utilize the same axial space rather than adding to it. This nested arrangement enables the counter gear set to provide additional reduction without increasing the overall axial width of the transmission.
Solution Approach 2:
The patent transitions from a single-stage parallel-axis reduction to a multi-stage reduction system that operates in different spatial dimensions. The first and second planetary gear sets are arranged with their input and output shafts in parallel, creating a stacked configuration where reduction occurs across multiple axial levels. This dimensional arrangement allows high reduction ratios while maintaining compact offset between input and output shafts.
2Power
If number of parallel-axis-gears increases to achieve high reduction rate, then reduction rate is improved, but axial width becomes large
Solution Approach 1:
The counter gear set is nested within the axial width space of the planetary gear sets, specifically positioned within the inner circumferential area of the gear width. This allows the counter gear set to contribute to reduction ratio without adding to the overall axial width, as it shares the same axial space rather than extending it.
Solution Approach 2:
The patent merges the function of multiple gear sets by having the counter gear set share the same axial space as the planetary gear sets. The input shaft of the counter gear set is coupled with the output shaft of the first planetary gear set, and the output shaft of the counter gear set is coupled with the input shaft of the second planetary gear set, creating a combined reduction system that achieves high reduction ratio within compact axial width.
3Length of stationary object
If planetary gear mechanism is used to decrease offset between shafts, then offset is reduced, but reduction rate becomes small
Solution Approach 1:
The patent segments the reduction function into multiple independent planetary gear sets (first and second planetary gear sets) connected through a counter gear set. Each planetary gear set provides a portion of the total reduction ratio, and their combined effect achieves high overall reduction while maintaining the coaxial arrangement that minimizes offset between input and output shafts.
Solution Approach 2:
The patent uses a multi-dimensional arrangement where the first and second planetary gear sets are stacked with parallel input-output shafts. This creates a vertical arrangement along the axial direction while maintaining coaxial alignment radially, thereby achieving high reduction ratio through multiple stages without increasing the offset between the main input and output shafts.
4Force
If parallel-axis-gears with bearings are used, then torque transmission is achieved, but axial width increases due to bearing widths
Solution Approach 1:
The counter gear set is positioned within the inner circumferential area of the planetary gear width, nesting it inside the existing axial space. This arrangement allows the counter gear set to provide additional torque transmission and reduction functionality without requiring additional axial width beyond what is already occupied by the planetary gear sets.
Data Source
AI summary
A reduction gear having a planetary gear set for reducing the output rotation speed of a motor, a counter gear set for reducing the output rotation speed of the planetary gear set, and a planetary gear set for reducing the output rotation speed of the counter gear set. The output shaft and input shaft that are on the same axis and belong to the planetary gear set are arranged in parallel with the output shaft and input shaft that are on the same axis and belong to the planetary gear set. The input shaft of the counter gear set is common to the output shaft of the planetary gear set. The output shaft of the counter gear set acts commonly as the input shaft of the planetary gear set.