Strain Wave Gear Support Bearing Structure for Misalignment Absorption
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Solution Overview
Problem
Strain wave gearings without an Oldham coupling are prone to misalignment and radial force due to loads applied from the load side, compromising their reliability.
Innovation Solution
The strain wave gearing employs support bearings with loosely fitted configurations and elastic rings to absorb misalignment, preventing unnecessary radial force on the wave generator by using first and second elastic rings to press the support bearings inward, thereby maintaining stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an Oldham coupling is provided between the input shaft and wave generator, then misalignment can be absorbed, but device complexity increases
Solution Approach 1:
The invention extracts and removes the Oldham coupling from the system, replacing it with a simpler support bearing structure that directly supports the input shaft, thereby eliminating the need for the complex Oldham coupling mechanism while still achieving misalignment absorption
Solution Approach 2:
The invention introduces support bearings as intermediary elements between the input shaft and the fixed-side member/output-side member, which mediate the misalignment forces and allow the input shaft to accommodate positional deviations without requiring the Oldham coupling's three-element structure
2Manufacturing precision
If support bearings are rigidly mounted, then positioning precision is improved, but misalignment absorption capability deteriorates
Solution Approach 1:
The invention transitions from a static, rigid mounting of support bearings to a dynamic configuration where the support bearings are positioned to allow controlled movement and rotation of the input shaft, enabling the system to adapt to misalignment conditions while maintaining adequate positioning
3Device complexity
If the input shaft is directly connected to the wave generator, then device complexity is reduced, but radial force acts on the wave generator due to misalignment
Solution Approach 1:
The invention introduces support bearings as intermediary elements between the input shaft and the fixed-side member/output-side member, which mediate the misalignment forces and allow the input shaft to accommodate positional deviations without requiring the Oldham coupling's three-element structure
Solution Approach 2:
The invention extracts and removes the Oldham coupling from the system, replacing it with a simpler support bearing structure that directly supports the input shaft, thereby eliminating the need for the complex Oldham coupling mechanism while still achieving misalignment absorption
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 effectively absorbs misalignment and prevents radial force on the wave generator, enhancing the reliability and operation of the strain wave gearing without the need for an Oldham coupling.
Implementation Method 1
a first elastic ring is mounted between an outer ring of the first support bearing and the device housing, the first elastic ring pressing the first support bearing in a radial direction toward the first shaft part
Implementation Method 2
a second elastic ring is mounted between an outer ring of the second support bearing and the output-side member, the second elastic ring pressing the second support bearing in the radial direction toward the second shaft part
Data Source
Figure 1(A)~1(B)
AI summary
A strain wave gearing (1) comprises: an input shaft (6) connected directly to a cam plate (41) of a wave generator (4); and first and second support bearings (7, 9) for supporting the input shaft. The first and second support bearings (7, 9) are respectively mounted to first and second bearing mounting parts (11, 13) in a state of being fit with a clearance. In order to remove backlash of the first and second support bearings (7, 9), outer rings for the first and second support bearings (7, 9) are pushed radially inside by first and second elastic rings (12, 14), respectively. Center misalignment, between the wave generator (4) and the first and second support bearings (7, 9), caused by a load applied from a load side to a second end plate (10) which is an output-side member is absorbed by the elastic deformation of the first and second elastic rings (12, 14), and unnecessary radial force is prevented from being applied to the wave generator (4).