Scroll Compressor Sound Isolation Member Design
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Solution Overview
Problem
Conventional scroll compressors experience undesirable vibrations and noise due to capacity modulation, leading to inefficiencies and inadequate sound reduction, as existing sound damping materials fail to provide long-term noise reduction and are prone to fatigue and swelling.
Innovation Solution
The implementation of a scroll compressor design featuring a sound isolation member with a composite material comprising a polymer and particles, which has a higher acoustic impedance than the compressor components, and a coefficient of thermal expansion (CTE) of less than or equal to 1.5×10−3 mm/(mm-°K), strategically positioned to reduce vibration and sound transmission by maximizing acoustic impedance mismatch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional sound damping materials are used in scroll compressors, then some noise reduction is achieved, but the materials are prone to fatigue and swelling, leading to inadequate long-term noise reduction
Solution Approach 1:
The patent applies composite materials consisting of a polymer matrix combined with particles (such as rubber particles, metal particles, or ceramic particles) to create a sound isolation member that maintains dimensional stability and fatigue resistance while providing effective sound damping. This composite structure prevents the swelling and fatigue issues associated with conventional single-material dampers.
Solution Approach 2:
The patent modifies the material parameters by controlling the coefficient of thermal expansion (CTE) to be less than or equal to 1.5×10−3 mm/(mm-°K.), ensuring the sound isolation member maintains its physical properties under thermal cycling conditions. This parameter control prevents degradation and maintains reliability over time.
2Object-affected harmful factors
If a sound isolation member with high acoustic impedance is introduced, then sound transmission is reduced, but the device complexity increases
Solution Approach 1:
The sound isolation member is nested within the existing fastener structure, where it is positioned between the fastener and the non-orbiting scroll member. This nesting approach integrates the sound isolation function into the existing structural components without adding separate external elements, thereby minimizing increases in device complexity.
Solution Approach 2:
The sound isolation member serves multiple functions: it provides sound damping, acts as a vibration isolator, and maintains the mechanical connection between components. By combining these functions into a single component, the patent reduces the need for additional separate parts, thereby limiting the increase in device complexity.
3Loss of energy
If capacity modulation is performed to reduce compressor capacity, then energy efficiency is improved, but undesirable vibrations and sounds are generated
Solution Approach 1:
The sound isolation member acts as an intermediary element between the fastener and the non-orbiting scroll member. During capacity modulation events, this intermediary component absorbs and dampens the vibrations and sounds generated by the varying relative orbital movement between scroll members, thereby reducing the harmful acoustic emissions while allowing capacity modulation to continue for energy efficiency.
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
This design significantly reduces noise levels and enhances sound attenuation, as demonstrated by a 7.3 dBA reduction in sound pressure range during transient unloading events, while maintaining fatigue resistance and minimizing volume swell, thus improving the operational efficiency and quietness of the compressor.
Implementation Method 1
The composite material has a second acoustic impedance value greater than the first acoustic impedance value of the non-orbiting scroll member. The sound isolation member is disposed between at least a portion of the fastener and at least a portion of the non-orbiting scroll member to reduce vibration and sound transmission.
Implementation Method 2
A sound isolation member comprises a biasing member operable to bias the non-orbiting scroll member in an axial direction, so as to reduce vibration and sound generated by movement of the non-orbiting scroll member during scroll compressor operation.
Data Source
AI summary
Scroll compressor designs are provided to minimize vibration, sound, and noise transmission. The scroll compressor has a bearing housing, and orbiting and non-orbiting scroll members. The non-orbiting scroll member has a radially extending flanged portion with at least one aperture substantially aligned with the axially extending bore. At least one fastener is disposed within the aperture and the bore. A sound isolation member contacts at least one of the non-orbiting scroll member, the fastener, or the bearing housing, to reduce or eliminate noise transmission. The sound isolation member may be formed of a polymeric composite having an acoustic impedance value greater than the surrounding materials. The sound isolation member may be an annular washer, an O-ring, or a biasing member, by way of non-limiting example. In other variations, fluid passages are provided within the fastener and/or bearing housing to facilitate entry of lubricant oil to further dampen sound and noise.