Segmented Flexible Gear Structure for Compact High-Reduction Transmissions
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Solution Overview
Problem
Existing transmissions with flexible gear wheels face challenges in achieving sufficient elastic deformation, especially with smaller diameters, while maintaining high torsional rigidity and minimizing gear play between input and output.
Innovation Solution
The design incorporates a pin element in the recess of toothed segments, arcuate spring segments that act on the toothed segments at the waist, and a configuration where half of the toothed segments have a recess, allowing for increased flexibility and strength, with spring segments connecting adjacent segments to ensure radial elasticity and tangential stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the flexible gear wheel is made more flexible to achieve sufficient elastic deformation, then the adaptability improves, but the torsional rigidity deteriorates
Solution Approach 1:
The flexible gear wheel is divided into multiple toothed segments connected by spring segments. This segmentation allows the gear to deform elastically through the spring segments while maintaining overall structural integrity and torsional rigidity through the rigid toothed segments.
Solution Approach 2:
Different parts of the gear have different properties: the spring segments provide flexibility and elastic deformation capability, while the toothed segments provide rigidity for force transmission. This local differentiation resolves the contradiction between overall flexibility and local rigidity requirements.
2Length of moving object
If the diameter of the transmission is reduced to make it more compact, then the length decreases, but the capability to achieve sufficient elastic deformation deteriorates
Solution Approach 1:
By segmenting the gear into toothed segments and spring segments, the design achieves sufficient elastic deformation capability in a compact form. The spring segments provide the necessary flexibility without requiring a large diameter, as the deformation is concentrated in these specific segments rather than requiring overall gear size increase.
Solution Approach 2:
The spring segments are designed with specific geometric parameters (arcuate shape, connection points at waists) that maximize elastic deformation capability within a compact diameter. The parameter optimization allows small-diameter transmissions to achieve the required flexibility.
3Adaptability or versatility
If the spring segments are made larger to increase flexibility, then the adaptability improves, but the device complexity increases
Solution Approach 1:
The spring segments and toothed segments are merged into a single integrated flexible gear wheel structure. This combining approach increases flexibility while avoiding the complexity of separate assemblies, as the spring segments are directly connected to the toothed segments in a unified 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
This configuration enables a short transmission with high torsional rigidity and sufficient elastic deformations, maintaining minimal gear play and ensuring flexibility even with small diameters, while allowing for a good compromise between flexibility and strength.
Implementation Method 1
The spring segments are designed as arcuate webs that extend on a circular line in the circumferential direction of the flexible gear, so that they have elasticity in the radial direction and are stiff in the tangential direction. Thus, a deformation of the flexible gear is allowed only in the radial direction.
Data Source
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AI summary
The present invention relates to a transmission with a ring gear in which a flexible gear is arranged, wherein the flexible gear is connected to a wave generator and the wave generator deforms the flexible gear so that it engages with the ring gear in certain areas, and wherein the flexible gear comprises at least two tooth segments which are connected to each other by means of spring segments, and at least one of the tooth segments has a recess in which a journal element is arranged. The object of the present invention is to provide a transmission that, particularly even with smaller transmission diameters, allows sufficient elastic deformation of the flexible gear and has a very short overall length while still exhibiting high torsional stiffness.According to the invention, each of the spring segments has a central plane that includes a central axis of the transmission and divides the respective spring segment into two areas of equal length, and each recess has a central plane that includes the central axis of the transmission and divides the recess into two equal areas, and the central plane of each spring segment has a different distance to the central plane of the recess located next to it on each side of the central plane of the spring segment.