Shaft-Side Pulley Groove Width for Robotic Surgical Cable Guidance
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Solution Overview
Problem
In robotic surgical instruments, the rotating cable can come into contact with the inner wall of the shaft when passed through the pulley group, leading to increased load on the cable and difficulty in smooth guidance due to oblique suspension.
Innovation Solution
A configuration where the groove width of the shaft-side pulley is greater than the other pulleys, reducing the likelihood of contact with the pulley groove and minimizing load on the elongate element, allowing for smoother guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the rotating cable is passed through the pulley group arranged at the end in the direction of the rotation axis, then the cable can be guided through the shaft, but the cable may come into contact with the inner wall of the shaft causing increased load and difficulty in smooth guidance
Solution Approach 1:
The shaft-side pulley is designed with a groove width that is greater than the groove widths of the other pulleys in the pulley group. This local variation in geometry creates additional clearance specifically at the critical location where the elongate element passes through, preventing contact with the shaft inner wall and reducing friction and load on the element.
2Ease of operation
If the groove width of the shaft-side pulley is increased, then the likelihood of contact with the pulley groove is reduced, but the device complexity increases
Solution Approach 1:
Instead of increasing the groove width of all pulleys uniformly, only the shaft-side pulley has an increased groove width. This localized modification addresses the specific problem of elongate element guidance and contact prevention without unnecessarily complicating the overall pulley system design.
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 ensures that the elongate element is less likely to change direction and is smoothly guided, reducing the load applied to it.
Implementation Method 1
The groove width of a shaft-side pulley, which is arranged at a position closest to the shaft among a plurality of pulleys including at least the first pulley and the second pulley and to which the elongate element is suspended, is greater than groove widths of the other pulleys among the plurality of pulleys
Data Source
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AI summary
This surgical instrument (40) includes a first pulley (51, 52) and a second pulley (53, 54). A shaft-side pulley (55, 56), which is provided at a position closest to the shaft (42) among a plurality of pulleys (5) including the first pulley (51, 52) and the second pulley (53, 54), has a groove width (D3) greater than groove widths (D1, D2) of the other pulleys (51, 52, 53, 54).