Resin Speed Reducer Output Member for Stable Screw Fastening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing speed reducers using resin materials face challenges with creep phenomena and loosening of screw fastening structures due to self-lubricating properties of resin, leading to potential shear or creep failures.
Innovation Solution
The speed reducer incorporates output members formed of resin with multiple first screw holes for fine-thread screws, featuring weight reduction portions between screw holes in the circumferential direction to enhance structural integrity and prevent loosening.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If resin material is used for output member to reduce weight, then weight is reduced, but screw fastening structure loosens over time due to self-lubricating property and creep
Solution Approach 1:
The patent applies preliminary action by providing reinforcement portions at the screw fastening locations before assembly. These reinforcement portions prevent the resin material from deforming or loosening under load, proactively addressing the creep and self-lubrication issues before they can cause fastening failure.
Solution Approach 2:
The patent applies local quality by adding reinforcement portions only at specific locations where screws are fastened, rather than making the entire output member metal. This localized reinforcement maintains the overall weight reduction benefit while providing targeted structural support where needed to prevent loosening.
2Ease of manufacture
If resin material is used for output member, then manufacturing cost is reduced, but structural stiffness decreases leading to potential shear failure
Solution Approach 1:
The patent applies local quality by providing reinforcement portions at specific screw fastening locations. This allows the majority of the output member to remain as cost-effective resin material while adding localized metal or composite reinforcement only where structural stiffness is critical to prevent shear failure.
Solution Approach 2:
The patent applies composite materials by combining resin material with reinforcement portions made of different materials (such as metal inserts or fiber-reinforced sections). This composite approach maintains the cost and weight advantages of resin while providing the structural stiffness and strength of stronger materials at critical locations.
Data Source
AI summary
A speed reducer includes an output member to which a driven member is connected, in which the output member is formed of resin and includes a plurality of first screw holes into which fine-thread screws for connection of the driven member are screwed and each of which includes a bottom, and the output member is provided with a weight reduction portion between the plurality of first screw holes in a circumferential direction.