Rack-Pinion Tooth Chamfering for Jam-Free Moving Engagement
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Solution Overview
Problem
In existing rack and pinion transmission systems, interference and jamming often occur during the moving meshing process due to arbitrary rotation angles of the pinion gear, damaging the end surfaces and affecting transmission smoothness.
Innovation Solution
The design incorporates a pinion gear with pinion teeth and a rack with alternating sloped and flat rack teeth, where the sloped teeth are longer and angled to allow smooth sliding, and chamfer surfaces on the pinion teeth intersect to prevent interference and jamming by ensuring proper meshing alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a pinion gear moves from one rack to another with arbitrary rotation angle, then the device can be compact and meet miniaturization design requirements, but interference and jamming occur between the pinion gear and rack during the moving engagement process
Solution Approach 1:
The pinion gear is pre-positioned on the extension line of the intersection line of the two chamfer surfaces before engagement, ensuring that the chamfer surfaces make contact first during the moving engagement process. This preliminary positioning prevents interference and jamming by guiding the engagement sequence, allowing the pinion gear to transition between racks without arbitrary rotation angle issues while maintaining compact device design
2Device complexity
If the pinion gear and rack engage with arbitrary rotation angle, then the device structure can be simplified, but the accuracies of the end surfaces of the pinion gear and rack are damaged
Solution Approach 1:
The chamfer surfaces are designed to intersect at an intersection line that passes through the pinion gear center, and the pinion gear is pre-positioned on this extension line. This ensures that during engagement, the chamfer surfaces contact first, guiding the pinion gear into proper alignment before the main tooth surfaces engage. This preliminary alignment action prevents arbitrary rotation angle issues while maintaining simple device structure and protecting end surface accuracy
3Adaptability or versatility
If the pinion gear moves between racks with arbitrary rotation angle, then the device can operate flexibly, but interference occurs between the pinion gear and rack during the moving engagement process
Solution Approach 1:
The pinion gear is pre-positioned on the extension line of the intersection line of the two chamfer surfaces, and the chamfer surfaces are designed with specific acute angles relative to reference planes. This preliminary configuration ensures that during mobility operations, the chamfer surfaces make contact first, guiding the pinion gear into proper engagement position and preventing interference. This allows flexible pinion gear movement between racks while eliminating harmful interference effects
Data Source
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AI summary
A rack and pinion transmission assembly, and a transmission device comprising the transmission assembly. The rack (10) comprises sloped rack teeth (111) and flat rack teeth (112) disposed alternately in the transmission direction of the rack (10); both a front end surface (1111) and a rear end surface (1112) of the sloped rack teeth (111) are planes; the length of the sloped rack teeth (111) is greater than the length of the flat rack teeth (112) in the width direction of the rack (10); tooth flanks (212) on two sides of the pinion teeth (21) are respectively connected with the end surfaces of the adjacent pinion teeth (21) by chamfer surfaces (213), and the two adjacent chamfer surfaces (213) intersect at an intersection line. The rack and pinion transmission assembly of this structure meshes smoothly, which can avoid the problem of interference or jamming during the engagement of the pinion gear (20) and the rack (10).