Eccentric Oscillating Speed Reducer Rigidity and Bearing Life
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Solution Overview
Problem
Eccentric oscillating speed reducers face issues with radial and axial rigidity and bearing lifetime due to high-torque and complex forces applied during high-speed reduction, leading to potential distortion and fatigue damage.
Innovation Solution
The design incorporates supporting members that penetrate through axial penetration holes of external gears, reducing radial forces and using a combination of roller and ball bearings to support both radial and axial loads, along with an annular gear with cosine curve depressions to minimize stress concentration and friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-torque rotational motion is delivered through eccentric shafts during high-speed reduction, then power transmission capability is improved, but the eccentric shafts tend to bend and get distorted, leading to fatigue damage
Solution Approach 1:
The patent divides the shaft system into multiple segments: eccentric shafts for power transmission and support pillars for structural support. This segmentation allows the eccentric shafts to focus on torque transmission while the support pillars provide structural stability and prevent bending, thereby maintaining power transmission capability while improving shaft durability.
Solution Approach 2:
The patent introduces support pillars as intermediary elements that connect the housing to the external gears. These pillars act as mediators that bear radial loads and provide structural support, preventing the eccentric shafts from bending under high-torque conditions while allowing the power transmission function to continue uninterrupted.
2Ease of manufacture
If support pillars pass through external gears without contact with support penetration holes, then assembly ease is improved, but radial forces are not adequately supported, reducing bearing lifetime
Solution Approach 1:
The patent provides both embodiments: one where support pillars contact the support penetration holes (copying the prior art structure) and another where they don't contact (improving assembly ease). The design allows manufacturers to choose the appropriate embodiment based on their specific needs, maintaining bearing lifetime through proper radial force support while offering assembly ease as an alternative.
3Object-generated harmful factors
If the output portion is not in contact with external gears, then friction is reduced, but radial and axial rigidity decreases, affecting operational precision
Solution Approach 1:
The patent introduces roller bearings as intermediary elements between the output portion and the external gears. These roller bearings reduce friction through rolling contact while providing the necessary radial and axial rigidity to maintain operational precision. This mediator approach allows the output portion to remain non-contacting with external gears while still achieving the required rigidity.
4Force
If tapered roller bearings are used to support radial and axial loads, then load bearing capacity is improved, but radial and axial rigidity and bearing lifetime are reduced due to complex forces
Solution Approach 1:
The patent segments the bearing support function into multiple components: roller bearings for radial load support and ball bearings for axial load support. This segmentation allows each bearing type to operate in its optimal performance range, reducing the complex forces that would otherwise reduce the lifetime of a single tapered roller bearing system while maintaining overall load bearing capacity.
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 enhances radial and axial rigidity, extends the life of the eccentric shafts, and reduces friction and vibrations, resulting in improved operational precision and durability.
Implementation Method 1
at least a supporting member penetrating through a first support penetration hole of the first external gear and a second support penetration hole of the second external gear, and contacting eccentrically with inner peripheries of the penetration holes
Implementation Method 2
reduces friction and vibrations
Implementation Method 3
using a combination of roller and ball bearings to support both radial and axial loads
Implementation Method 4
reduces friction and vibrations
Implementation Method 5
an annular gear with cosine curve depressions to minimize stress concentration and friction
Implementation Method 6
minimize stress concentration and friction
Data Source
AI summary
An eccentric oscillating speed reducer includes: first and second external gears, each having shaft penetration holes in respective circumferences thereof; eccentric shafts, having first and second crank portions passing through the shaft penetration holes, with the first and second external gears furnished on the first and second crank portions, respectively; a supporting member inserted through a first shaft penetration hole of the first external gear and a second shaft penetration hole of the second external gear, and being in eccentric contact with inner peripheries of the shaft penetration holes; first and second output portions, each having shaft penetration holes on respective circumferences thereof, with both ends of an axis of each of the eccentric shafts furnished in the shaft penetration holes, and the first and second output portion being connected by the supporting member; and an annular gear engaged with the first and second external gears.