Harmonic Speed Reducer Gear Geometry for Interference-Free Meshing
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Solution Overview
Problem
Conventional harmonic speed reducers with two rigid gears suffer from low mesh efficiency and shortened lifespan due to interference issues between deformed outer gear structures and inner gear structures, leading to decreased performance and durability.
Innovation Solution
The design includes a wave generator, a flexible gear with first and second outer gear structures and a division groove, and two rigid gears with specific inner gear structures, where the first rigid gear has a first angle between 0.1 degrees to 5 degrees and the second rigid gear has a second angle, optimizing the mesh efficiency by maintaining axial positioning and reducing deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the flexible gear is mounted onto the outer periphery of the wave generator, then the harmonic speed reducer can transmit power, but the outer gear structure deforms and causes interference with the inner gear structures, decreasing mesh efficiency and lifespan
Solution Approach 1:
The flexible gear is segmented into two distinct groups of outer gear structures: first outer gear structures engaged with the first rigid gear, and second outer gear structures engaged with the second rigid gear. The division groove physically separates these two groups, allowing independent optimization of each group's engagement characteristics without mutual interference
Solution Approach 2:
Different engagement parameters are applied to different local regions: the first outer gear structures have a first engagement parameter optimized for engagement with the first rigid gear, while the second outer gear structures have a second engagement parameter optimized for engagement with the second rigid gear. This local differentiation resolves the interference issue by allowing each region to operate under optimal conditions
2Adaptability or versatility
If the outer gear structure deforms during operation, then the flexible gear can accommodate the wave generator's motion, but interference occurs with the inner gear structures, reducing mesh efficiency
Solution Approach 1:
The flexible gear's outer gear structures are segmented into two groups separated by a division groove. This segmentation allows the first outer gear structures to deform and engage with the first rigid gear while the second outer gear structures engage with the second rigid gear, preventing interference between the two engagement zones while maintaining overall flexibility
Solution Approach 2:
Different engagement parameters are assigned to different local regions of the flexible gear. The first outer gear structures have parameters optimized for their specific engagement with the first rigid gear, while the second outer gear structures have parameters optimized for engagement with the second rigid gear, allowing localized adaptation without global interference
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 configuration increases mesh efficiency between the flexible gear and the rigid gears, enhancing the carrying capacity and prolonging the lifespan of the harmonic speed reducer by preventing axial movement and shaking during operation.
Implementation Method 1
After a flexible gear F of a conventional harmonic speed reducer having two rigid gears is mounted onto an outer periphery of a wave generator WG, an outer gear structure F1 of the flexible gear F will deform
Data Source
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AI summary
A harmonic speed reducer (100) is provided. The harmonic speed reducer (100) includes a wave generator (1), a flexible gear (2), a first rigid gear (3), and a second rigid gear (4). The wave generator (1) can be driven to rotate relative to a central axis (CP). The flexible gear (2) has a plurality of first outer gear structures (21), a division groove (2B), and a plurality of second outer gear structures (22). The first rigid gear (3) has a plurality of first inner gear structures (31) configured to be engaged with the first outer gear structures (21). The second rigid gear (4) has a plurality of second inner gear structures (41) configured to be engaged with the second outer gear structures (22). A first intersection line (3111) is defined between each of the first inner gear structures (31) and a sectional surface (S). An angle between the first intersection line (3111) and a first horizontal line (HI) is within a range from 0.1 degrees to 5 degrees.