Spiral Spring Coupling for Wider Shaft Rotation and Strength
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Solution Overview
Problem
Conventional spiral spring devices restrict the rotational range of the rotary shaft and face challenges in securing sufficient strength and housing functional components due to the limited coupling methods, which become inadequate when the rotary shaft is downsized.
Innovation Solution
The spiral spring device features an inner end shaped to follow the outline of a noncircular shaft, coupled by tightening, allowing increased rotational range and strength, with the outer end wound around a sub shaft for secure locking, and enabling housing of functional components within a hollow shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the inner end of the spiral spring is coupled to the rotary shaft by inserting into a slit or by welding, then the coupling strength is sufficient, but the rotational range of the rotary shaft is restricted
Solution Approach 1:
The inner end of the spiral spring is divided into multiple segments (first inner end and second inner end) that can be coupled to different shafts independently. This segmentation allows the spring to accommodate larger rotational ranges while maintaining coupling strength through distributed attachment points rather than a single restricted connection.
2Volume of moving object
If the rotary shaft is downsized, then the apparatus size is reduced, but it becomes difficult to secure sufficient strength at the connection part and to house functional components inside the shaft
Solution Approach 1:
The spiral spring is configured to wrap around and nest within the shaft structure, with the inner end following the outline of the shaft. This nesting arrangement maximizes the use of available space in downsized shafts while maintaining coupling strength through conformal contact rather than requiring large attachment areas.
3Reliability
If the inner end of the spiral spring is coupled to the rotary shaft by traditional methods, then the coupling is secure, but the spring force always acts on the shaft which restricts rotation
Solution Approach 1:
The coupling mechanism transitions from a static fixed connection to a dynamic adjustable connection. The inner end of the spiral spring can dynamically adjust its position and orientation to follow the shaft's outline, allowing the coupling to maintain reliability while accommodating dynamic rotational movements without constant spring force restriction.
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 enhances the rotational range of the rotary shaft, secures strength at the connection point, and facilitates easier housing of functional components, providing a backstop function and increased freedom of rotation while maintaining torque accumulation.
Implementation Method 1
the inner end of the spiral spring is formed into a shape that follows the outline of the shaft to be coupled to the shaft by tightening
Implementation Method 2
If the rotary shaft 140 rotates in the forward direction (clockwise in the illustrated example), the spiral spring 100 is wound around, and torque is accumulated
Implementation Method 3
The outer end 120 is wound around the fixed shaft 150 of the apparatus so that the outer end 120 is locked to the fixed shaft 150 to be coupled to the fixed shaft 150
Data Source
AI summary
Provided is a spiral spring device that increases the rotational range of the rotary shaft of an apparatus, that secures the strength of the rotary shaft, and that makes the functional components to be more easily housed inside of the rotary shaft, in which an inner end of a spiral spring is coupled to a shaft, and an outer end of the spiral spring is coupled to a sub shaft that is different from the shaft of the apparatus. The inner end of the spiral spring is shaped to follow the outline of the shaft to be coupled to the shaft by tightening.