Laminate Gear Structure for Engine Noise Vibration Harshness
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Solution Overview
Problem
Conventional metal gears in engine and counterbalance shaft systems generate significant noise vibrations and harshness due to limited damping and high contact forces, which are exacerbated by torque fluctuations, making them unsuitable for high-torque applications.
Innovation Solution
The use of laminate gear structures composed of alternating layers of metal and plastic sheets, which form a composite gear that reduces metal-to-metal contact and enhances damping, thereby mitigating noise vibrations and harshness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional metal gears are used in engine and counterbalance shaft systems, then strength and durability are maintained, but noise vibrations and harshness increase due to limited damping and high contact forces
Solution Approach 1:
The patent applies composite materials by combining metal and plastic layers to form a laminate gear structure. The metal layers provide the necessary strength and durability for high-torque applications, while the plastic layers provide damping to reduce noise vibrations and harshness. This composite approach resolves the contradiction by integrating the advantages of both materials.
Solution Approach 2:
The patent applies local quality by assigning different materials to different regions of the gear structure. Metal layers are positioned to provide strength where needed, while plastic layers are positioned to provide damping where noise reduction is prioritized. This localized material assignment allows the gear to simultaneously achieve strength and noise reduction.
2Object-generated harmful factors
If alternative materials such as plastic are used for gears, then noise vibrations and harshness are reduced, but durability becomes insufficient for high-torque applications
Solution Approach 1:
The patent uses composite materials to combine plastic layers (for noise reduction) with metal layers (for durability). The metal layers are strategically positioned within the laminate structure to provide the necessary strength for high-torque applications while the plastic layers provide damping. This composite construction resolves the contradiction by making both durability and noise reduction properties available in the same component.
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 laminate gear structure effectively reduces noise vibrations and harshness by introducing plastic-to-plastic interfaces, providing necessary strength and durability while minimizing metal-to-metal contact, thus addressing the limitations of conventional metal gears in high-torque environments.
Implementation Method 1
these gears may provide limited damping, and the material stiffness properties may result in or be the source of tonal noise (whine), rattle, or other noise vibration and harshness (NVH)
Data Source
AI summary
A gear train for an engine is provided with a driving gear and a driven gear. The driving gear is formed by a laminate structure of a plurality of plastic sheets and a plurality of metal sheets, with the plastic and metal sheets alternating with one another. The driven gear is formed by another laminate structure of another plurality of plastic sheets and another plurality of metal sheets, with the plastic and metal sheets alternating with one another. The gear train may be provided for use with an engine crankshaft and an associated balance shaft. A method of forming the gear is also provided.