Hollow Strain-Wave Gear Plug Reinforcement for Torque Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hollow strain-wave gear devices face a challenge in increasing the diameter of the hollow section without increasing the outside diameter and reducing the weight by decreasing the wall thickness of the wave generator plug, which leads to a reduction in torque performance due to reduced rigidity.
Innovation Solution
A hollow strain-wave gear device with a rigid internally toothed gear, a flexible externally toothed gear, a wave generator that causes the cylindrical part to flex and mesh with internal teeth, and a hollow rotating shaft with a plug reinforcement part of greater radial wall thickness adjacent to the wave generator plug to enhance rigidity and prevent torque reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the wall thickness of the wave generator plug is reduced to decrease device weight, then the weight is reduced, but the rigidity of the wave generator decreases leading to reduced torque performance
Solution Approach 1:
The patent applies local quality by providing a plug reinforcement part with greater wall thickness at a specific location adjacent to the wave generator plug, while other portions of the hollow rotating shaft maintain reduced wall thickness. This localized reinforcement increases rigidity and torque performance where needed without increasing overall device weight.
2Volume of moving object
If the diameter of the hollow section is increased without increasing outside diameter, then the weight is reduced and hollow section capacity is improved, but the wall thickness must be reduced which decreases rigidity and torque performance
Solution Approach 1:
The plug reinforcement part provides localized thickening at the wave generator plug region, enabling the hollow section diameter to be increased elsewhere while maintaining sufficient wall thickness and rigidity where the wave generator operates.
3Volume of moving object
If the wall thickness of the hollow rotating shaft is reduced to increase hollow section diameter, then the hollow section capacity is improved, but the rigidity of the wave generator plug decreases
Solution Approach 1:
The plug reinforcement part is positioned adjacent to the wave generator plug to provide localized rigidity support, allowing the rest of the hollow rotating shaft to have reduced wall thickness for increased hollow section diameter.
Solution Approach 2:
The hollow rotating shaft is segmented into regions with different wall thicknesses: the plug reinforcement part has greater wall thickness for rigidity, while other portions have reduced wall thickness for weight reduction and increased hollow section 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 solution effectively prevents a reduction in torque performance while minimizing weight and inertia by reinforcing the wave generator plug with a high-rigidity plug reinforcement part, allowing for increased hollow section diameter without compromising rigidity or requiring design changes to other parts.
Implementation Method 1
a wave generator arranged coaxially inside the cylindrical part of the externally toothed gear, the wave generator causing the cylindrical part to flex in an ellipsoidal shape
Data Source
AI summary
A hollow strain-wave gear device (1) has a wave generator (5), a wave generator plug (5a) of which is integrally formed in a portion of a hollow rotating shaft (6). A plug reinforcement part (5d), which is adjacent to the wave generator plug (5a), has a thickness larger than that of the wave generator plug (5a), and is integrally formed in the hollow rotating shaft (6). The wave generator plug (5a) is reinforced by the highly rigid plug reinforcement part (5d) formed adjacently to the wave generator plug (5a). It is thus possible to prevent or suppress a decline in the rigidity of the wave generator plug (5a) when the hollow rotating shaft has a thin thickness in order to reduce the weight of the hollow rotating shaft (6) and increase the diameter of the hollow portion thereof. Consequently, it is possible to suppress a decline in ratcheting torque.