Rotary compressor and refrigerating cycle device having bearings containing annular groove/elastic portion arrangement
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Solution Overview
Problem
In rotary compressors, the attrition between the rotary shaft and bearings leads to increased contact pressure and reduced reliability, which existing designs fail to adequately address, affecting the compressor's performance and longevity.
Innovation Solution
The design incorporates annular grooves and elastic portions in both the main and sub-bearings, with specific shapes and dimensions to distribute contact pressure evenly and reduce attrition, including a straight shape for the main bearing's groove and a tapered shape for the sub-bearing's elastic portion, enhancing lubricity and reducing wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bearing designs are used, then the structure is simple, but attrition between the rotary shaft and bearings increases and reliability decreases
Solution Approach 1:
The patent applies local quality by creating an annular groove with an elastic portion at a specific location within the bearing (at the end portion on the cylinder chamber side). This localized elastic structure selectively absorbs contact pressure in the high-stress region where the rotary shaft contacts the bearing, rather than uniformly modifying the entire bearing. This resolves the contradiction by improving reliability through targeted pressure distribution while maintaining overall structural simplicity.
Solution Approach 2:
The elastic portion acts as a pre-designed cushioning element that absorbs contact pressure between the rotary shaft and bearing before excessive wear occurs. By incorporating this elastic buffer in advance within the annular groove, the design prevents attrition and reliability degradation before they happen, rather than addressing wear after it occurs. This resolves the contradiction by enhancing reliability through preventive pressure absorption while keeping the structural addition minimal.
2Stress or pressure
If the annular groove depth is increased, then contact pressure distribution improves, but the bearing strength decreases
Solution Approach 1:
The patent applies parameter changes by specifying precise dimensional parameters for the annular groove (depth of 0.5-2.0mm, width of 1-3mm) and the elastic portion (thickness of 0.3-1.5mm). These controlled parameter variations optimize the pressure distribution function while maintaining bearing strength. The elastic portion's thickness parameter is specifically tuned to provide sufficient cushioning without compromising the bearing's structural integrity. This resolves the contradiction by using precise parameter control to achieve both improved contact pressure distribution and maintained bearing strength.
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 attrition and contact surface pressure, enhancing the reliability and performance of the rotary compressor by optimizing the contact between the rotary shaft and bearings, thereby improving the compressor's operational efficiency and lifespan.
Implementation Method 1
an annular groove and an elastic portion located inside the annular groove are formed in each bearing
Data Source
AI summary
In one embodiment, an annular groove and an elastic portion are formed at an end portion of a main bearing on a side facing a cylinder chamber. An annular groove and an elastic portion is formed at an end portion of the sub-bearing on a side facing the cylinder chamber. A depth of the annular groove of the main bearing is formed larger than that of the sub-bearing. An outer peripheral surface of the elastic portion of the main bearing is formed in a straight shape so that thicknesses of a base portion and a tip portion of the elastic portion are the same. An outer peripheral surface of the elastic portion of the sub-bearing is formed in a tapered shape so that a thicknesses of a base portion of the elastic portion is larger than that of a tip portion of the elastic portion.