Flexible Shaft Square Tips Felt Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flexible shafts used for torque transmission suffer from significant noise and vibration due to manufacturing tolerances, leading to suboptimal durability and useful life, despite prior attempts using materials like flocked yarn, grease, or heat shrink tubing, which are costly and difficult to fabricate.
Innovation Solution
A wire wound flexible shaft with noncircular end portions, such as square or helical square shapes, featuring chamfered ends and wrapped felt strips made of thermoplastic material, which are fused to reduce noise and vibration by compressing between mating recesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If flocked yarn or flock fibers are applied to the lateral surfaces of the shaft ends, then noise and vibration are reduced, but manufacturing expense increases and fabrication difficulty increases
Solution Approach 1:
The patent applies felt strips made from inexpensive materials that can be easily wrapped and adhered to the shaft ends. These felt strips are simple, cost-effective consumable components that provide noise and vibration reduction without requiring complex manufacturing processes or expensive materials like flocked yarn.
2Object-affected harmful factors
If grease is applied to the lateral surfaces of the shaft ends, then noise and vibration are reduced, but durability decreases and useful life is limited
Solution Approach 1:
The patent removes the grease component from the solution entirely and replaces it with felt strips that provide noise and vibration reduction through mechanical contact and friction. This extraction of the grease element eliminates the durability and useful life limitations associated with grease degradation while maintaining the noise and vibration reduction function.
3Object-affected harmful factors
If heat shrink tubing is applied to the lateral surfaces of the shaft ends, then noise and vibration are reduced, but manufacturing expense increases
Solution Approach 1:
The patent replaces expensive heat shrink tubing with inexpensive felt strips that can be easily obtained and applied. The felt strips provide the same noise and vibration reduction function at a fraction of the cost, making the manufacturing process more economically viable.
4Object-affected harmful factors
If felt or similar material is wrapped around the shaft, then noise and vibration due to contact with surrounding casing are reduced, but manufacturing complexity increases
Solution Approach 1:
The patent applies felt strips only to the specific locations where noise and vibration reduction is needed - the lateral surfaces of the shaft ends that contact the mating recesses. This localized application avoids the complexity of wrapping felt around the entire shaft while still providing effective noise and vibration reduction at the critical contact points.
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 solution effectively reduces noise and vibration while improving durability and manufacturing cost-effectiveness by compressing felt strips between shaft ends and recesses, enhancing the shaft's useful life and performance.
Implementation Method 1
felt strips made of thermoplastic material, which are fused to reduce noise and vibration by compressing between mating recesses
Implementation Method 2
reduce noise and vibration by compressing felt strips between shaft ends and recesses
Implementation Method 3
Overlapping parts of the felt strips are preferably fused together, in which case they are made of thermoplastic material
Data Source
AI summary
A flexible shaft having square or helical square tips with thermoplastic felt covering and adherent to the tips including the tip ends. The felt has fused bulges adjacent the ends. When the tips are inserted into mating recesses of driving and driven members, the felt is deformed to improve the fit between the tips and the recesses and reduce noise and vibration when the driving member is rotated.