Slider Block Tilt for Scroll Compressor Shaft Deflection
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Solution Overview
Problem
Conventional scroll compressors experience misalignment and edge loading due to shaft deflections under load, leading to inefficiencies and potential bearing failure, as the cantilevered drive bearing transfers deflections to the slider block, causing misalignment and increased stress.
Innovation Solution
The design incorporates a slider block with a shorter drive surface that tilts about the edges of the drive pin when the shaft is deflected, providing radial compliance and maintaining alignment, and includes features like chamfered surfaces and notched openings to prevent gas trapping and reduce stress concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a cantilevered drive bearing is used to provide radial compliance, then the slider block can accommodate shaft deflections, but the shaft deflections cause misalignment and edge loading of the bearing
Solution Approach 1:
The slider block is designed to dynamically tilt and adjust its orientation in response to shaft deflections. The block can pivot about the drive pin axis, transforming from a rigid fixed-position bearing into a dynamic component that adapts its angle to maintain proper alignment with the drive shaft under varying load conditions
Solution Approach 2:
The drive bearing function is segmented into two independent components: the slider block that provides radial compliance and can tilt, and the drive pin that remains fixed on the shaft. This separation allows the slider block to independently accommodate both radial movements and angular misalignments without compromising bearing alignment
2Strength
If the drive surface extends the full length of the drive pin, then the bearing has maximum support, but shaft deflection causes edge loading and increased stress on the bearing surfaces
Solution Approach 1:
The drive surface length parameter is deliberately reduced to less than the full length of the drive pin. This parameter change allows the slider block to tilt and distribute contact stress more evenly across the reduced surface area, preventing edge loading while maintaining adequate bearing support through the optimized contact length
3Device complexity
If the slider block is rigidly fixed to the drive pin, then the structure is simpler, but shaft deflection causes misalignment and bearing failure
Solution Approach 1:
Instead of a rigid fixed connection, the slider block is designed with rotational freedom about the drive pin axis. This dynamic capability allows the block to automatically adjust its orientation to maintain alignment with the drive shaft during operation, accommodating angular misalignments caused by shaft deflections without requiring complex adjustment mechanisms
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 configuration reduces wear and stress on the bearing surfaces, maintaining proper alignment and reducing contact stress, thereby enhancing the durability and efficiency of the scroll compressor by allowing the slider block to tilt and distribute load effectively.
Implementation Method 1
The slider block is tiltable about one or more edges of the second drive surface when the drive shaft is deflected under load to provide improved radial compliance for the movable scroll body
Data Source
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AI summary
A scroll compressor that includes a housing and scroll compressor bodies disposed in the housing. The scroll bodies include a first scroll body and a second scroll body. The first and second scroll bodies have respective bases and respective scroll ribs that project from the respective bases. Further, the scroll ribs mutually engage such that the second scroll body is movable relative to the first scroll body to compress fluid. A drive shaft has an eccentric drive pin configured to engage a drive hub on the second scroll body. The scroll compress also includes a slider block that fits over the drive pin. The slider block has a first drive surface configured to engage a second drive surface of the drive pin. In particular embodiments, the slider block can tilt about one or more edges of the second drive surface when the drive shaft is deflected under load.