Planetary Gear Housing Isolation With Raised Linear Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Planetary gear devices experience noise and vibration issues due to the transmission of vibrations from the inner gear to the housing, despite previous attempts to mitigate these through separate structural units, as the contact area between the inner gear and housing remains significant, leading to continued noise production.
Innovation Solution
The implementation of separate structural units for the inner gear and housing, featuring raised portions on both components that create a gap and limit movement through linear contact, reducing the contact area and thereby minimizing vibration transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the inner gear and housing are formed with fitting shapes that enable contact, then the inner gear is supported within the housing, but the contact area becomes significant, causing vibration transmission and noise
Solution Approach 1:
The patent divides the contact interface into multiple discrete contact points through raised portions on both the inner gear and housing. Instead of continuous surface contact, the segmentation creates isolated contact regions that reduce overall vibration transmission while maintaining positional stability.
Solution Approach 2:
The patent applies local quality by creating specific raised portions at predetermined locations on the inner gear and housing. These localized structures provide targeted support and movement limitation while minimizing the overall contact area, allowing the majority of the gear surface to remain non-contacting for vibration isolation.
2Object-generated harmful factors
If the inner gear and housing are separated with a gap, then vibration transmission is reduced, but the inner gear movement becomes uncontrolled
Solution Approach 1:
The patent segments the gap space into controlled regions defined by raised portions. The gap provides overall vibration isolation while the segmented contact points at specific locations maintain necessary movement control, achieving both isolation and stability simultaneously.
Solution Approach 2:
The raised portions act as intermediary elements between the inner gear and housing. These intermediaries transmit only specific controlled movements while isolating general vibrations, serving as mediators that reconcile the conflicting requirements of gap-based isolation and contact-based control.
3Object-generated harmful factors
If linear contact is implemented through raised portions, then the contact area is reduced to limit movement, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the contact system into discrete raised portions that can be manufactured independently. This segmentation allows each raised portion to be formed with standard tolerances rather than requiring precise alignment across large surface areas, reducing overall manufacturing difficulty.
Solution Approach 2:
The patent changes the contact parameter from surface-area-based contact to point/line-based contact through raised portions. This parameter change reduces the cumulative tolerance requirements, as point contacts require less precise alignment than extended surface contacts, thereby lowering manufacturing precision demands.
Data Source
AI summary
Separate structural units for an inner gear and a housing of a planetary gear device include an inner gear with a first raised portion formed on the outer peripheral surface of the inner gear, where the first raised portion extends towards in a direction that is inclined with respect to the axial direction of the inner gear. A housing includes a second raised portion formed on an inner peripheral surface, where the second raised portion extends in a direction that is inclined in respect to the axial direction. The housing contains the inner gear such that there is a gap formed between the inner peripheral surface of the housing and the outer peripheral surface of the inner gear. Movement of the inner gear within the interior of the housing is limited through linear contact of the first raised portion and the second raised portion.