Nested Planetary Gear Mechanism for High Deceleration Ratio
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Solution Overview
Problem
Conventional deceleration mechanisms using planetary gears face challenges in achieving high deceleration ratios without increasing the number of stages, leading to larger radial widths and difficulties in downsizing, especially in precision equipment requiring high precision control.
Innovation Solution
A rotation-transmitting mechanism with a first and second stage, featuring a driving rotating body and planetary rotating bodies that revolve around a first rotating body, allowing for a high deceleration ratio in a small number of stages by generating a slight difference in absolute rotation speeds between the inner and outer circumferential portions, facilitating downsizing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of planetary gear stages is increased to achieve high deceleration ratio, then the deceleration ratio is improved, but the axial length becomes large
Solution Approach 1:
The invention places the first planetary gear set inside the second planetary gear set, with the sun gear of the first stage located within the carrier of the second stage. This nested configuration allows both gear stages to occupy the same axial space, achieving high deceleration ratio without increasing axial length.
Solution Approach 2:
Instead of arranging gear stages sequentially along the axial direction (one-dimensional arrangement), the invention transitions to a radial nesting arrangement where gear stages are positioned at different radial levels. This dimensional change allows compact packaging of multiple stages within a limited axial envelope.
2Measurement precision
If the radial width is increased to achieve high deceleration ratio without increasing stages, then the deceleration ratio is improved, but the downsizing becomes difficult
Solution Approach 1:
By nesting the first planetary gear set within the second stage structure, the invention achieves high deceleration ratio within a compact radial envelope. The inner sun gear and outer ring gear are positioned concentrically, minimizing radial width while maximizing gear ratio through the nested configuration.
Solution Approach 2:
The invention merges the structural elements of two planetary gear stages into a unified nested configuration, where components of the first stage (sun gear, planet gears) are integrated within the structure of the second stage. This merging achieves high deceleration ratio without requiring separate radial spaces for each stage.
3Measurement precision
If multiple planetary gear stages are superposed in axial direction, then the deceleration ratio is improved, but the device complexity increases
Solution Approach 1:
The nested configuration consolidates two planetary gear stages into a single integrated unit rather than separate axial stages. This reduces the number of discrete stage components and simplifies the overall device structure while maintaining the compound deceleration effect.
Solution Approach 2:
The nested planetary gear mechanism performs multiple functions simultaneously: it provides compound deceleration, supports multiple planet gears for load distribution, and maintains compact dimensions. This multi-functionality reduces the need for additional separate components, simplifying the overall device 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
The mechanism achieves a high deceleration ratio in two stages, enabling precise control and easy downsizing of the rotation-transmitting mechanism, as well as precise extension and retraction of conveying apparatuses and precise rotation control of driving apparatuses.
Implementation Method 1
a first planetary rotating body 3 and a second planetary rotating body 4 which are brought into contact with a second outer circumferential surface 1b of the inner rotating body 1 and a second inner circumferential surface 2b of the outer rotating body 2, respectively, and revolve around the inner rotating body 1
Data Source
AI summary
A rotation-transmitting mechanism capable of obtaining a high deceleration ratio in a small number of stages, and a conveying apparatus and driving apparatus using the rotation-transmitting mechanism are provided. In one form, a rotation-transmitting mechanism includes an inner rotating body and an outer rotating body arranged coaxially with the inner rotating body. Further, the rotation-transmitting mechanism includes a driving rotating body and rotating body arranged on an input side (lower stage), and two planetary rotating bodies arranged on an output side (upper stage). When the driving rotating body is rotated by a motor on the input side, the two planetary rotating bodies revolve around the inner rotating body while rotating on the output side. At this time, the planetary rotating bodies revolve very slowly around the inner rotating body.