Robot Joint Fixing Structure to Limit Radial Load on Gear Meshing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robot joint structures face issues with adverse effects on gear meshing due to radial loads when a speed reducer is fixed to a robot member via pressure contact, leading to potential deformation and interference in the meshing between internal and external gears.
Innovation Solution
A robot joint structure incorporating a speed reducer with a fixing member that is non-rotatable relative to the internal gear, where the fixing member is made of a material with a higher Young's modulus than the internal gear, and the fastening members are positioned to avoid overlapping with the gear teeth, reducing the radial load's impact on the gear meshing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the fixing member is fastened to the first robot member by bringing the inner peripheral surface of the first robot member and the outer peripheral surface of the fixing member into pressure contact, then the fixing strength is improved, but the radial load adversely affects the meshing between the internal gear and the external gear
Solution Approach 1:
The patent positions the fastening members in a different axial location relative to the gear meshing zone. By arranging the fastening members axially adjacent to but not overlapping with the internal gear teeth, the radial clamping force is applied in a different axial dimension, avoiding direct interference with the gear meshing area while maintaining effective fixation.
Solution Approach 2:
The patent applies different functional requirements to different axial regions of the fixing member. The region where fastening members are positioned is optimized for mechanical fastening without gear interference, while other regions accommodate the gear meshing functionality. This local differentiation allows simultaneous optimization of both fixing strength and gear meshing quality.
2Volume of moving object
If the outer diameter of the robot members is reduced, then the compactness is improved, but the structural integrity and gear meshing stability may be compromised
Solution Approach 1:
By relocating the fastening members to an axial position that does not overlap with the gear teeth, the patent enables reduced outer diameter design without compromising gear meshing stability. The radial clamping force is applied in a different axial dimension, allowing compact cross-sectional dimensions while maintaining reliable gear engagement in the non-interfering axial zone.
3Object-affected harmful factors
If the fastening members are positioned to avoid overlapping with gear teeth, then the gear meshing is protected, but the fixing effectiveness may be reduced
Solution Approach 1:
The patent resolves this contradiction by utilizing the axial dimension for fastening member placement. The fastening members are positioned axially adjacent to the gear assembly without radial or axial overlap with the gear teeth, allowing full clamping force application while maintaining clear gear meshing paths. This dimensional separation enables both effective fixing and gear protection simultaneously.
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 effectively suppresses adverse effects on gear meshing by minimizing the deformation caused by radial loads, allowing for reduced outer diameters of the robot members while maintaining the inner diameter of the actuator, thus enhancing the structural integrity and reducing the risk of gear interference.
Implementation Method 1
The fixing member is fixed to the first robot member by bringing an inner peripheral surface of the first robot member and an outer peripheral surface of the fixing member into pressure contact with each other by fastening using the first fastening member
Implementation Method 2
The speed reducer includes an external gear, an internal gear that meshes with the external gear
Data Source
AI summary
A robot joint structure includes a first robot member, a second robot member, and a speed reducer incorporated in a joint portion that connects the first robot member and the second robot member to each other. The speed reducer includes an external gear, an internal gear that meshes with the external gear, and a fixing member that is provided so as to be non-rotatable relative to the internal gear and is fixed to the first robot member. The fixing member is fixed to the first robot member by bringing an inner peripheral surface of the first robot member and an outer peripheral surface of the fixing member into pressure contact with each other by fastening using a first fastening member. At least a part of an axial range of the first fastening member does not overlap internal teeth of the internal gear when viewed in a radial direction.