Gear Assembly Mesh Stiffness Tuning for Low Noise and Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gear assemblies in high-speed and high-power density systems face challenges in balancing noise, vibration, and scuffing resistance due to inherent design trade-offs, particularly in terms of mesh stiffness fluctuations.
Innovation Solution
A gear assembly with a three-dimensional distribution of physical size and elastic modulus optimization in zones, utilizing fiber-reinforced composites and energy dissipation zones with metallic coatings to modulate mesh stiffness and reduce noise and vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the mesh stiffness is increased to improve load carrying capacity, then the gear strength is improved, but the noise and vibration increase
Solution Approach 1:
The patent applies local quality by creating zones with different elastic moduli within the gear tooth structure. Specifically, it uses a gradient elastic modulus distribution where the elastic modulus varies continuously from the tooth root to the tooth tip, allowing different regions to have optimized stiffness characteristics. This enables the gear to have high load carrying capacity in contact zones while reducing noise and vibration in other regions.
Solution Approach 2:
The patent changes the elastic modulus parameter spatially within the gear tooth structure. By optimizing the three-dimensional distribution of elastic modulus in different zones (tooth root, tooth body, tooth tip), the patent achieves a balance between mesh stiffness and NVH performance. The elastic modulus is adjusted to control mesh stiffness fluctuations while maintaining adequate load carrying capacity.
2Object-generated harmful factors
If the mesh stiffness fluctuation is reduced to improve NVH performance, then the noise and vibration are reduced, but the scuffing resistance deteriorates
Solution Approach 1:
The patent applies local quality by creating energy dissipation zones with specific material properties at critical locations. These zones are positioned to dissipate energy and reduce mesh stiffness fluctuations, thereby reducing noise and vibration. Simultaneously, the zones are designed with appropriate friction characteristics to maintain scuffing resistance at the gear contact surfaces.
Solution Approach 2:
The patent uses composite materials with different elastic moduli and friction characteristics in different zones of the gear tooth. By combining materials with complementary properties, the patent achieves both reduced mesh stiffness fluctuation (for better NVH) and maintained scuffing resistance through zones with appropriate friction properties.
3Strength
If the elastic modulus is increased to improve stiffness, then the mesh stiffness is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent optimizes the elastic modulus parameter distribution to achieve adequate mesh stiffness with a relatively simple gradient profile. By using a continuous gradient rather than discrete steps, the patent reduces manufacturing complexity while still achieving the desired stiffness characteristics. The gradient distribution is designed to be manufacturable through conventional processes.
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
The solution effectively reduces noise and vibration while maintaining power density by ensuring mesh stiffness fluctuations are within predefined thresholds, enhancing the performance of gear assemblies in high-speed and high-power applications.
Implementation Method 1
The respective zones are each composed of respective fibers embedded in a polymeric matrix, with the respective fibers in the respective zones being oriented in a respective alignment. The respective elastic modulus of the respective zones may be modulated by varying the respective alignment across the respective zones.
Implementation Method 2
The respective elastic modulus of the respective zones may be modulated by varying the respective alignment across the respective zones. The second alignment is at an angle relative to the first alignment, the angle being between 45 and 90 degrees.
Implementation Method 3
The energy dissipation zones include metallic coatings applied over the respective first contact region. The energy dissipation zones are positioned to substantially flatten the base temperature profile.
Implementation Method 4
The energy dissipation zones are positioned to substantially flatten the base temperature profile.
Data Source
AI summary
A gear assembly includes a first gear having a first hub surrounded by a first plurality of teeth. The first plurality of teeth each define a respective first contact region. The gear assembly includes a second gear having a second hub surrounded by a second plurality of teeth. The second plurality of teeth are adapted to mesh with the first plurality of teeth at the respective first contact region in order to drive a respective load in a first direction. The first hub and the first plurality of teeth include respective zones defining a respective elastic modulus. A three-dimensional distribution of the respective physical size and the respective elastic modulus of the respective zones is optimized such that a fluctuation of mesh stiffness along the respective first contact region is at or below a first predefined threshold.