Elastomer Series Coupling for Supercharger Noise and Misalignment
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Solution Overview
Problem
Roots-type superchargers generate unwanted noise due to gear rattle and bounce, particularly at low speed operations, and misalignment between the input shaft and rotor shaft, which can be exacerbated by decoupling from the belt system.
Innovation Solution
A coupling assembly is introduced between the input shaft and rotor shaft, comprising a first and second hub, side coupling assemblies with elastomeric inserts, and a central hub with coupler pins, providing torsional damping and accounting for misalignment through oval-shaped openings and arcuate passages, allowing for parallel and series damping to reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a rigid coupling is used between input shaft and rotor shaft, then power transmission efficiency is improved, but noise and vibration increase due to gear rattle and bounce
Solution Approach 1:
The patent introduces a coupling assembly as an intermediary component between the input shaft and rotor shaft. This coupling includes elastomeric elements that act as mediators to transmit power while simultaneously dampening vibrations and reducing noise from gear rattle and bounce, thus resolving the contradiction between efficient power transmission and noise reduction
Solution Approach 2:
The patent changes the physical parameters of the coupling system by using elastomeric materials with specific durometer ratings and designing flexible coupling elements that can deform elastically. This allows the coupling to maintain power transmission while absorbing vibrational energy, thereby reducing noise without sacrificing too much power transmission efficiency
2Object-generated harmful factors
If decoupling is implemented to reduce noise, then noise and vibration are reduced, but misalignment between shafts cannot be accommodated
Solution Approach 1:
The patent employs dynamic coupling elements that can flex and adapt to misalignment conditions. The elastomeric inserts and flexible coupling components are designed to deform under load, allowing the coupling to dynamically adjust to angular and parallel misalignment between shafts while maintaining vibration damping capabilities
Solution Approach 2:
The coupling assembly uses composite construction combining rigid metallic components (hubs, shells) with flexible elastomeric elements. This composite structure provides both the strength needed for power transmission and the flexibility required to accommodate misalignment, while the elastomeric portion continues to provide noise and vibration reduction
3Object-generated harmful factors
If a flexible coupling with elastomeric elements is used, then noise and vibration are reduced, but power transmission efficiency decreases
Solution Approach 1:
The patent applies local quality by using rigid materials in areas requiring strength and power transmission (hub centers, mounting flanges) while using flexible elastomeric materials only in specific locations where vibration damping is needed (coupling inserts, flexible elements). This localized application of different material properties minimizes power loss while maximizing noise reduction
Solution Approach 2:
The coupling design uses partial flexibility - the elastomeric elements are designed with specific durometer ratings and geometries that provide just enough flexibility for vibration damping without excessive deformation that would cause significant power loss. The coupling provides sufficient stiffness to maintain efficient power transmission while incorporating just enough flexibility to reduce noise
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 coupling assembly effectively minimizes noise by absorbing rotational energy and accommodating misalignment, reducing the transmission of unwanted vibrations and enhancing the operational stability of the supercharger.
Implementation Method 1
The first and second side elastomeric inserts provide dampening between (i) the first side coupling body and the central hub and (ii) the second side coupling body and the central hub
Implementation Method 2
A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger can include a first hub, a second hub, a first side coupling assembly, a second side coupling assembly, a central hub and a plurality of coupler pins
Data Source
AI summary
A coupling assembly arranged between an input shaft and a rotor shaft of a supercharger includes a first hub, a second hub, a central hub, and a plurality of coupler pins. The first hub can be mounted with the input shaft. The second hub can be mounted with the rotor shaft. The central hub can be disposed in between the first and second hubs. The central hub can have an elastomeric body that defines a series of passages therein. The passages can taper inwardly throughout and provide incremental dampening against the first and second plurality of pins. The plurality of coupler pins can be received in the central hub bores. The first and second plurality of pins can be received by the passages in the elastomeric body.