Strain Wave Gear Unit Structure With Integrated Sliding Support
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Solution Overview
Problem
Conventional strain wave gearing with rolling bearings is bulky and heavy, limiting weight reduction and compactness.
Innovation Solution
Employing a sliding bearing instead of a rolling bearing to support a rigid internally toothed gear and a flexible externally toothed gear, with a wave generator that flexes the externally toothed gear to mesh with the internally toothed gear, allowing for a compact unit structure with reduced component count and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rolling bearing is used to support the internally toothed gear and externally toothed gear, then the bearing can support radial and thrust loads with low friction, but the device becomes bulky and heavy
Solution Approach 1:
The invention extracts and removes the rolling bearing from the strain wave gearing system, replacing it with a sliding bearing structure formed by bearing surfaces on the housing and gear components. This elimination of the separate rolling bearing component achieves weight reduction and compactness while maintaining the essential support function through direct sliding contact between bearing surfaces.
2Reliability
If a rolling bearing is used to support the internally toothed gear and externally toothed gear, then the bearing can support radial and thrust loads with low friction, but the device complexity increases
Solution Approach 1:
The invention merges the bearing support function directly into the housing and gear components by forming bearing surfaces on these parts. The sliding bearing structure integrates the support function with the existing components, eliminating the need for a separate rolling bearing assembly and reducing overall device complexity.
3Device complexity
If the outer ring of the rolling bearing is integrally formed with the unit housing, then the unit structure becomes compact and the number of component parts is reduced, but weight reduction is limited
Solution Approach 1:
The invention replaces the rolling contact mechanical system with a sliding contact system. By using sliding bearing surfaces instead of rolling bearings, the design achieves both structural integration and weight reduction, as the sliding bearing can be formed as part of the housing and gear components without requiring separate heavy rolling element assemblies.
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 sliding bearing enables a more compact and lightweight strain wave gearing design while maintaining required surface characteristics through plating treatments, enhancing wear resistance and lubricity.
Implementation Method 1
a sliding bearing for supporting a first part and a second part in a radial direction and in a thrust direction so that the first and second parts can relatively rotate
Implementation Method 2
The surface portions, which define the outer-ring portion and the inner-ring portion of the annular convex part and the annular concave part, are made to be a plating treatment surface subjected to a hard plating treatment, a solid lubricant plating treatment or other plating treatment
Data Source
AI summary
A cup-type strain wave gearing having a unit structure and having: a stationary-side part including a unit housing and an internally toothed gear; a driving-side part including an output member and an externally toothed gear; and a sliding bearing supporting the stationary-side part and the driving-side part in the radial direction and the thrust direction in a state in which relative rotation is possible. The sliding bearing has a cylindrical bushing accommodated in a radial gap, and annular bushings accommodated respectively in thrust gaps. Thus, it is possible to provide an advantageous strain wave gearing having a unit structure that is more lightweight and compact than when a rolling bearing is used.