3D Meshing Tooth Profile for Strain Wave Gearing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cup-type or silk-hat-type strain wave gearing faces challenges in achieving 3-dimensional meshing along the tooth trace direction, with varying meshing loci causing interference and uneven contact between external and internal teeth, limiting load capacity and reliability.
Innovation Solution
The external teeth's tooth surface is designed to vary in inclination from the outer end to the inner end along the tooth trace direction, ensuring consistent meshing across multiple axis-perpendicular cross-sections, preventing interference and enhancing load capacity and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tooth profile is designed to achieve continuous meshing in one axis-perpendicular cross-section, then meshing continuity is improved in that section, but meshing quality deteriorates in other cross-sectional positions along the tooth trace direction
Solution Approach 1:
The tooth surface is designed with different inclination characteristics at different locations along the tooth trace direction. Specifically, the tooth surface inclination angle varies continuously from the diaphragm side to the open end side, creating local variations in meshing geometry that adapt to the changing flexion states at different positions, thereby achieving appropriate meshing in all cross-sections simultaneously
Solution Approach 2:
The invention transitions from traditional 2-dimensional tooth profiles (in the normal section) to 3-dimensional tooth surfaces by introducing variation in the tooth surface inclination along the tooth trace direction. This third dimension (tooth trace direction) allows the tooth surface to adapt to the varying flexion states at different axial positions, achieving continuous meshing across all cross-sections
2Object-affected harmful factors
If tooth thickness is decreased toward the diaphragm side to prevent interference, then interference is reduced, but meshing area is limited to one cross-section
Solution Approach 1:
Instead of uniformly decreasing tooth thickness, the invention applies local quality by varying the tooth surface inclination angle continuously along the tooth trace direction. This creates different effective tooth thicknesses at different locations, preventing interference at the diaphragm side while maintaining adequate meshing area across all sections through the gradual inclination change
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 design achieves wide-range 3-dimensional meshing, preventing interference and ensuring consistent contact between teeth, thereby increasing the load capacity and reliability of the strain wave gearing during high-load operations.
Implementation Method 1
The externally toothed gear is made to flex by the wave generator into an elliptical shape... Each portion of the external teeth of the externally toothed gear is repeatedly flexed in the radial direction while the wave generator rotates
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(c)
Figure 3
AI summary
A strain wave gearing (1) wherein the tooth profile of an external teeth (34) of a cup-shaped or silk-hat-shaped external gear (3) is set as follows. The tooth-tip tooth thickness (D2a, D2e) decreases gradually from an external-teeth outer end (34a) toward an external-teeth inner end (34e) along an external tooth trace direction. In addition, a pressure angle (αa, αe) at a pitch point (P) increases gradually from the external-teeth outer end (34a) toward the external-teeth inner end (34e) along the external tooth trace direction. Thus, it is possible to realize a cup-type or silk-hat-type strain wave gearing in which external teeth mesh with internal teeth in a wide range along the tooth trace direction, rather than only in one cross-section perpendicular to the axis in the tooth trace direction.