Recoil Spring Dustproofing via Overlapping Wall Labyrinth Seal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine starting devices face challenges in preventing foreign substances from entering and causing damage to the recoil spring, especially in dusty environments, leading to potential malfunction and increased device thickness due to existing dustproof solutions.
Innovation Solution
A space-saving design featuring a labyrinth seal formed by overlapping circumferential wall portions on the rope reel and starter case, combined with a plate to partition the recoil spring, preventing foreign substances from reaching the spring while allowing easy discharge of intruded substances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dustproof cover with ring-like convex-concave portions is used to prevent foreign substance intrusion, then the reliability of the recoil spring is improved, but the thickness of the starting device increases
Solution Approach 1:
The patent applies nesting by integrating the dustproof function directly into the existing structural components. The first circumferential wall portion of the rope reel and the second circumferential wall portion of the starter case are designed to overlap and form a labyrinth seal together, eliminating the need for a separate dustproof cover. This nested approach prevents foreign substances from reaching the recoil spring while maintaining a compact thickness.
Solution Approach 2:
The patent merges the dustproof function with the structural housing components. Instead of adding a separate dustproof cover, the circumferential wall portions of the rope reel and starter case are combined to form an integrated seal structure. This merging of functions achieves both structural support and dustproof protection without increasing device thickness.
2Reliability
If ring-like convex-concave portions are used to prevent foreign substance intrusion, then the reliability is improved, but the foreign substances become difficult to discharge once intruded
Solution Approach 1:
The patent segments the internal space by introducing a plate that divides the housing space into separate regions. This plate creates a barrier that prevents foreign substances from reaching the recoil spring while also providing a designated area where accumulated dust can be easily removed. The segmentation allows for easy discharge of foreign substances from the partitioned space.
3Volume of moving object
If the starting device is downsized to improve maneuverability, then the portability is improved, but the protection against foreign substances becomes more difficult to maintain
Solution Approach 1:
The patent achieves compact sizing by nesting the dustproof function within the existing structural components. The overlapping circumferential wall portions form a labyrinth seal that provides effective dustproof protection without requiring additional external coverings. This nested design maintains small device volume while ensuring reliable protection against foreign substances.
Solution Approach 2:
The patent uses thin film-like circumferential wall portions that provide effective sealing with minimal thickness. The first and second circumferential wall portions are designed as thin structural elements that overlap to form a seal, achieving dustproof protection without adding significant bulk to the device, thus maintaining compact size.
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
Effectively prevents foreign substance intrusion and deformation of the recoil spring in a compact design, ensuring reliable operation without increasing device thickness.
Implementation Method 1
a recoil spring (31) that is housed between the starter case (11) and the rope reel (20) to exert urging force in a direction to rewind the rope (30)
Implementation Method 2
the first circumferential wall portion (21c) and the second circumferential wall portion (12f) are disposed so that end edges of the first circumferential wall portion (21c) and the second circumferential wall portion (12f) overlap each other when viewed in a radial direction
Data Source
AI summary
A rope reel includes first circumferential wall portion that is erectly provided so as to surround outer circumference of recoil spring. A starter case includes second circumferential wall portion that is erectly provided so as to adjoin inner circumferential face or outer circumferential face of first circumferential wall portion. The first circumferential wall portion and the second circumferential wall portion are disposed so that end edges of the first circumferential wall portion and the second circumferential wall portion overlap each other when viewed in radial direction. A plate is disposed between starter case and recoil spring inside first circumferential wall portion. Thus, it is possible to provide structure which is realized in space-saving manner to make foreign substances difficult to intrude into starting device in order to prevent deformation or damage of recoil spring, and from which the foreign substances are easily discharged even if foreign substances have intruded.