Strain Wave Gear Filter Prevents Bearing Contamination
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Solution Overview
Problem
Existing strain wave gearing designs fail to prevent foreign matters from intruding into the wave-generator bearing, leading to excessive sliding wear and defects due to the open sliding friction portion between the outer-ring outer peripheral surface and the external-gear inner peripheral surface.
Innovation Solution
A strain wave gearing with a foreign-matter intrusion preventing mechanism, featuring an annular filter and a lubricant-impermeable filter attachment plate that captures foreign matters from the lubricant and maintains separation between lubricants for the meshing and sliding portions, ensuring that foreign matters are not introduced into the wave-generator bearing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing member is disposed to prevent lubricant mixing between wave generator bearing and meshing portion, then lubricant separation is improved, but the sliding friction portion remains laterally open allowing foreign matter intrusion
Solution Approach 1:
A filter member is introduced as an intermediary component between the meshing portion and the wave generator bearing. This filter member captures foreign matters from the lubricant while allowing lubricant flow, thereby preventing foreign matter intrusion into the sliding friction portion without compromising lubricant separation between different lubricated areas.
Solution Approach 2:
The filter member utilizes porous material structure that allows lubricant to pass through while trapping foreign matters. The porous structure enables selective permeability where the lubricant flows through the pores but larger foreign particles are captured and retained on the surface or within the porous matrix.
2Use of energy by moving object
If the sliding friction portion is left open for lubrication access, then lubricant flow is improved, but foreign matters can intrude causing excessive sliding wear
Solution Approach 1:
The filter member serves as a mediator that maintains open access for lubricant flow while simultaneously providing protection against foreign matter intrusion. The lubricant can freely pass through the filter's porous structure, ensuring adequate lubrication, while the filter captures contaminants that would otherwise cause sliding wear.
Solution Approach 2:
The porous structure of the filter member allows efficient lubricant flow through the material while the pore size is controlled to trap foreign matters. This enables the system to maintain open lubrication pathways without sacrificing wear resistance, as the porous filter selectively permits lubricant passage while blocking harmful particles.
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
Effectively prevents foreign matters from entering the wave-generator bearing, reducing sliding wear and defects by ensuring reliable contact between the filter and the external gear's inner peripheral surface, while maintaining separation of lubricants for the meshing and sliding portions.
Implementation Method 1
a foreign-matter intrusion preventing mechanism having an annular filter capable of capturing foreign matters mixed in a lubricant passing therethrough
Implementation Method 2
the filter is in contact with the inner peripheral surface of the external-tooth forming portion in a slidable state
Implementation Method 3
preventing foreign matters from intruding into the sliding portion between the outer-ring outer peripheral surface and the inner peripheral surface of the external-tooth forming portion
Data Source
Figure 1(a)~1(b)
Figure 2
AI summary
A foreign-matter intrusion preventing mechanism (10) of a strain wave gearing (1) is provided with a filter attachment plate (12) attached to a wave generator plug (52) and a filter (11) attached to the ellipsoidal outer peripheral surface (12c) of the filter mounting plate. Lubricant flows, via the filter (11), between a wave generator bearing (54) and a meshing portion between an external gear (4) and an internal gear (3). Foreign matters included in the lubricant are captured by the filter (11). Because the filter (11) is in contact with the inner peripheral surface (47) of an external-tooth forming portion (46) of the external gear (4), foreign matters can be assuredly prevented from intruding into a sliding friction portion between an outer-ring outer peripheral surface (56) of the wave generator bearing (54) and the inner peripheral surface (47) of the external-tooth forming portion of the external gear.