Gear Tooth Flank Machining for Hybrid Motion Error Control
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Solution Overview
Problem
Bevel and hypoid gears experience noise due to parabolic motion errors caused by crowning, which limits smooth rolling and increases the risk of tooth damage, while existing solutions like double wave forms only reduce noise but not eliminate it.
Innovation Solution
A method of machining gear tooth surfaces to create a hybrid motion graph combining sinusoidal and parabolic elements, using free-form gear manufacturing machines and Universal Motion Concept (UMC) flank surface modifications to achieve smooth transitions and minimize noise generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If crowning is applied to limit tooth contact area, then tooth damage is prevented, but motion error increases causing noise
Solution Approach 1:
The invention changes the motion error function from a conventional parabolic form to a hybrid sinusoidal-parabolic form. This parameter change in the motion graph allows the contact area to be controlled while reducing the severity of velocity changes at tooth engagement, thereby reducing noise without sacrificing the protective effect of crowning.
2Reliability
If crowning is increased to protect teeth from edge contact, then tooth boundaries are protected, but motion error increases preventing smooth rolling
Solution Approach 1:
By modifying the motion error function to a hybrid sinusoidal-parabolic form, the invention reduces the magnitude of velocity changes at tooth engagement points. This allows for sufficient crowning to protect tooth boundaries while maintaining smoother rolling operation through reduced motion error effects.
Data Source
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AI summary
A method of machining a tooth flank of a gear with a gear machining tool. The method comprises rotating the tool and bringing the tool and the tooth flank into contact. Relative movements are provided between the tool and the gear to traverse the tool across the tooth flank along a path whereby the path produces a tooth flank geometry of a form which, when brought into mesh with a mating tooth flank under no load or light load to form a tooth pair, provides a motion graph curve comprising a sinusoidal portion (62, 89, 91, 90, 63) and a parabolic portion (92).