Ratchet Wrench Support Wall Structure for Higher Torque
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Solution Overview
Problem
Conventional ratcheting tools have a limited maximum output torque due to the restricted diameter of the shaft and the thin support wall in the accommodation cavity, leading to potential deformation and breakage under high torque loads.
Innovation Solution
A ratchet wrench design featuring a handle, a working part with a circumferential wall and transition portion, a drive member with first teeth, a pawl with second teeth, and a first resilient element. The transition portion provides a support wall with a thickness ratio of 0.2 to 1 to the drive member's inscribed circle diameter, enhancing torque capacity without compromising structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the shaft diameter is increased to provide greater torque capacity, then the maximum output torque is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The shaft is divided into multiple sections with different diameters. The first shaft section has a larger diameter for high torque capacity, while the second shaft section has a smaller diameter for ease of assembly and reduced complexity. This segmentation allows the shaft to provide high torque where needed without requiring the entire shaft to be large diameter.
Solution Approach 2:
Different portions of the shaft are given different diameters based on local requirements. The first shaft section (near the pawl) has larger diameter for torque transmission, while the second shaft section (extending beyond the main body) has smaller diameter for assembly convenience. This local differentiation optimizes both torque capacity and manufacturing ease.
2Ease of operation
If adequate marginal clearance is left to allow pawl movement, then the ease of operation is improved, but the maximum output torque is reduced due to idle stroke
Solution Approach 1:
The pawl is designed to be movable relative to the main body through the shaft, allowing dynamic adjustment during operation. The clearance between the pawl and main body enables the pawl to move freely during engagement, providing ease of operation while the shaft's torque transmission capability maintains force output.
3Strength
If the accommodation cavity support wall is made thicker to withstand high torque, then the strength is improved, but the manufacturing precision and complexity increase
Solution Approach 1:
The support structure is segmented into the main body with integrated support walls and a separate shaft component. The support walls are formed as integral parts of the main body, allowing for standardized manufacturing processes while providing sufficient thickness for torque resistance. The shaft can be assembled separately with standard tolerances.
Solution Approach 2:
The support walls are merged with the main body structure rather than being separate components. This integration allows the support walls to be manufactured as part of the main body using standard forming processes, achieving both sufficient strength for high torque and ease of manufacturing without requiring precision machining of thin-walled structures.
4Ease of manufacture
If the shaft is made longer to extend beyond the main body for assembly, then the ease of manufacture is improved, but the maximum output torque is reduced due to increased lever arm
Solution Approach 1:
The shaft is segmented into two functional sections: a first shaft section that provides torque transmission with appropriate length, and a second shaft section that extends beyond the main body for assembly convenience. The first shaft section's length is optimized for torque transmission, while the second section provides assembly advantage without significantly compromising the overall torque capacity.
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 ratchet wrench achieves an increased maximum torque capacity while maintaining structural integrity, allowing it to withstand higher torque loads without deformation or breakage, and the design accommodates various gauges with corresponding torque requirements.
Implementation Method 1
a first resilient element, the first resilient element disposed within the accommodation cavity and configured to be able to apply a biasing force to the pawl to push the pawl toward an end of the accommodation cavity to disengage the second teeth from meshing engagement with the first teeth
Data Source
AI summary
A ratchet wrench, comprising: a handle; a working part, the working part comprising a circumferential wall and a transition portion, the circumferential wall defining an accommodation space therein in the shape of an opening, the transition portion coupling the handle to the circumferential wall, the transition portion defining an accommodation cavity therein, the accommodation cavity in communication with the accommodation space; a drive member, the drive member disposed within the accommodation space and configured to be rotatable about a center axis of the accommodation space, the drive member defining first teeth on its outer circumferential surface; a pawl, the pawl disposed within the accommodation cavity, the pawl having a first surface and a second surface, which oppose each other, the first surface provided thereon with second teeth, the second teeth configured to be able to be brought into meshing engagement with the first teeth, the second surface oriented to face a side wall of the accommodation cavity; and a first resilient element, the first resilient element disposed within the accommodation cavity and configured to be able to apply a biasing force to the pawl to push the pawl toward an end of the accommodation cavity to disengage the second teeth from meshing engagement with the first teeth.