Strain Wave Gear Brake Nested Between Input and Output Shafts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional strain wave gearing systems in surgical robotic manipulators require large braking mechanisms to restrict motion, which increases the overall size and complexity of the gearbox, whereas the proposed solution involves a compact braking assembly that mechanically brakes the wave generator to the flex cup within the gearing system, reducing the footprint and number of components.
Innovation Solution
A braking assembly with a first braking member attached to the input shaft of the wave generator and a second braking member attached to the output shaft of the flex cup, which engage to prevent relative motion between the input and output portions, allowing for a smaller and more compact design by integrating the braking mechanism within the strain wave gearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional braking mechanism is used to restrict motion of the output shaft or input shaft relative to the housing, then the braking function is achieved, but the braking mechanism must be relatively large and increases the overall size of the gearbox
Solution Approach 1:
The braking mechanism is nested within the strain wave gearing structure. The first braking member is attached to the input shaft and the second braking member is attached to the output shaft, with both members positioned within the existing shafts and housing. This nesting approach allows the brake to be packaged inside the already existing output/input shaft, reducing the overall footprint and eliminating the need for a separate external braking mechanism.
Solution Approach 2:
The braking function is merged with the strain wave gearing system. Instead of having a separate braking mechanism coupled to the housing, the brake is integrated into the gearing structure by attaching braking members to the input and output shafts. This merging allows the brake to utilize the existing structural space and reduces the number of separate components, thereby reducing the overall size while maintaining the braking function.
2Reliability
If a brake is coupled to the housing to restrict motion, then the braking function is achieved, but the number of components and complexity of the gearbox increases
Solution Approach 1:
The braking function is merged with the strain wave gearing system. Instead of having a separate braking mechanism coupled to the housing, the brake is integrated into the gearing structure by attaching braking members to the input and output shafts. This merging allows the brake to utilize the existing structural space and reduces the number of separate components, thereby reducing the overall size while maintaining the braking function.
Solution Approach 2:
The strain wave gearing structure serves multiple functions: it provides the gear reduction mechanism and also houses the braking mechanism. The input shaft and output shaft serve both as transmission elements and as mounting structures for the braking members. This multi-functionality reduces the need for additional dedicated braking components and simplifies the overall gearbox design.
3Reliability
If a large braking mechanism is used to brake the entire gearing system to the housing, then the braking function is achieved, but the envelope size and overall footprint of the gearbox increases
Solution Approach 1:
The braking mechanism is nested within the strain wave gearing structure. The first braking member is attached to the input shaft and the second braking member is attached to the output shaft, with both members positioned within the existing shafts and housing. This nesting approach allows the brake to be packaged inside the already existing output/input shaft, reducing the overall footprint and eliminating the need for a separate external braking mechanism.
Solution Approach 2:
Instead of braking the entire gearing system to the housing, the braking action is applied locally at the interface between the input shaft and output shaft. The first braking member on the input shaft engages with the second braking member on the output shaft, creating a localized braking point that is more efficient and requires less space than a distributed braking system coupled to the housing.
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 solution reduces the holding torque requirements due to high gear reduction and friction, enables a compact design by packaging the brake inside the existing shafts, and minimizes the number of components between the output and brake, resulting in a smaller and more efficient gearbox.
Implementation Method 1
the first braking member contacts the second braking member to mechanically brake the input portion to the output portion
Data Source
AI summary
A braking assembly for a strain wave gearing of a surgical robotic manipulator, the braking assembly including a first braking member fixedly coupled to an input portion of a strain wave gearing of a surgical robotic manipulator; and a second braking member fixedly coupled to an output portion of the strain wave gearing, and wherein during a braking operation the first braking member contacts the second braking member to mechanically brake the input portion to the output portion.