Archery Bow Axle Assembly Gap Elimination
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Solution Overview
Problem
Conventional archery bow axle systems, including floating and threaded systems, fail to eliminate gaps between components, leading to inconsistent and imprecise cam rotation due to lateral movement and wear, affecting the accuracy and smoothness of the bow's operation.
Innovation Solution
An axle assembly that compresses bearing and other components between limb portions to clamp them tightly, eliminating gaps and allowing the cam to freely rotate, utilizing a compression mode with an axial clamping force to ensure precise alignment and rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a floating axle system with spacers is used to position cam components, then the components can be located in a general lateral position, but gaps remain between components allowing lateral movement and inconsistent rotation
Solution Approach 1:
The patent changes the dimensional parameter of the axle system by introducing a compression mechanism that reduces the axial distance between components from a floating configuration to a compressed configuration. This parameter change eliminates gaps while maintaining bearing function, resolving the contradiction between ease of positioning and rotation consistency.
Solution Approach 2:
The patent introduces a compression spacer as an intermediary element between the cam components and the axle. This mediator transmits the compression force from the set screw to the cam components, eliminating gaps without requiring direct contact that would bind the bearings, thus resolving the contradiction.
2Manufacturing precision
If a threaded axle system with fastener is used to eliminate gaps between components, then zero space is achieved, but the fastener bottoms out before compressing components, failing to eliminate slack
Solution Approach 1:
The compression spacer acts as an intermediary that ensures compression force is transmitted to the cam components. The spacer's compressible nature allows it to bridge the gap between the fastener and components, ensuring that tightening the set screw actually compresses the components to eliminate slack, rather than the fastener simply bottoming out.
Solution Approach 2:
The patent changes the mechanical state of the components from uncompressed to compressed by introducing a controlled compression mechanism. This parameter change in the axial dimension allows the system to achieve true zero-gap contact between components, resolving the manufacturing precision and reliability contradiction.
3Reliability
If compression force is applied to components on the axle, then gaps are eliminated, but the compression can crush the bearings and prevent cam rotation
Solution Approach 1:
The patent applies local quality by differentiating the functional requirements of different components. The compression force is applied locally to the cam components to eliminate gaps, while the bearings are protected from compression through the intermediary spacer. This localized application of compression resolves the contradiction between gap elimination and cam rotation.
Solution Approach 2:
The compression spacer serves as a mediator that selectively transmits compression force. It allows compression to be applied to the cam components for gap elimination while preventing compression from reaching the bearings, thus preserving their rotational capability. This intermediary element resolves the contradiction between reliability and ease of operation.
4Measurement precision
If zero gap compression is applied to eliminate lateral movement, then rotation precision improves, but the system becomes overly constrained and increases noise
Solution Approach 1:
The patent changes the axial parameter (gap distance) to zero through controlled compression, while maintaining the radial parameter (rotation freedom) through the intermediary spacer. This selective parameter change achieves rotation precision without excessive system constraint, as the compression is limited to the axial dimension only.
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 enhances the consistency of cam rotation, reduces noise, and increases torsional rigidity, providing a smooth draw and improved rotational efficiency, comparable to solid limb bows, while maintaining precise component alignment.
Implementation Method 1
The axle assembly and/or fastener is operable in a compression mode to apply a compression force, such as an axial clamping force, to the bearing inner portion so the bearing inner portion is nonrotatable relative to the axle
Data Source
AI summary
An archery bow is provided including an axle assembly that compresses bearing and other components between limb portions to clamp those components against one another, with zero gaps therebetween, yet enable a cam to freely rotate relative to the axle. The bow can include bearings having an inner portion, and an outer portion non-rotatably joined with a cam. A fastener is operable in a compression mode to exert a compression force, such as an axial clamping force, against the bearing inner portion so it is non-rotatable relative to the axle, while the outer portion remains uncompressed and rotatable relative to the axle. The assembly can include a compression spacer clamped under the compression force between inner portions of bearings. These constructions can enhance the consistency of cam rotation and promote a smooth draw of the bow. Related methods are also provided.