Rotary Compressor End Plate Groove Design for Swaging Integrity
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Solution Overview
Problem
Conventional rotary compressors experience a decrease in adhesiveness and airtightness between end plates due to deflection of bottom portions during swaging, leading to reduced volumetric efficiency and flatness issues.
Innovation Solution
The design includes first and second rivet-side enlarged diameter portions with a semicircular step, allowing a rosette-like axial motion of the punch during swaging without deflecting the bottom portions, maintaining the integrity of the end plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the bottom portions of the groove portions are made thin to prevent refrigerant gas backflow, then volumetric efficiency is improved, but the bottom portions deflect during swaging leading to reduced adhesiveness and airtightness
Solution Approach 1:
The groove portion is designed with non-uniform thickness: the bottom portion has small thickness to prevent refrigerant gas backflow and maintain volumetric efficiency, while the inner wall portions have large thickness to prevent deflection during swaging and maintain adhesiveness and airtightness. This local differentiation of thickness resolves the contradiction between volumetric efficiency and structural integrity.
2Ease of manufacture
If the diameter of the groove portion is enlarged to allow rosette-like axial motion of the punch, then ease of manufacture is improved, but the bottom portion deflects during swaging
Solution Approach 1:
The groove portion has enlarged diameter at the inner wall portions to accommodate rosette-like axial motion of the punch during swaging, while the bottom portion maintains small diameter to prevent deflection. This local differentiation allows the swaging operation to proceed smoothly without compromising the flatness of the bottom portion.
3Reliability
If the thickness of the bottom portion is increased to prevent deflection during swaging, then adhesiveness and airtightness are improved, but refrigerant gas backflow occurs reducing volumetric efficiency
Solution Approach 1:
The groove portion is designed with small thickness at the bottom portion to prevent refrigerant gas backflow and maintain volumetric efficiency, while the inner wall portions have large thickness to prevent deflection during swaging and maintain adhesiveness and airtightness. This local differentiation of thickness resolves the contradiction between volumetric efficiency and structural integrity.
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 prevents bottom portion deflection during swaging, maintaining adhesiveness and airtightness, and enabling a rosette-like axial motion for effective swaging without compromising the compressor's efficiency.
Implementation Method 1
pressing or applying pressure by the punch P to cause plastic deformation, first and second swaging portions 203Sa and 203Ta of the first and second rivets 203S and 203T
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A rotary compressor (1), used e.g. in an air conditioner, includes a compressing unit (12) having an end plate (160S, 160T) that closes an end portion of an annular cylinder (121S, 121T). The end plate includes a groove portion (163S, 163T) accommodating a discharge valve portion (200S, 200T, 201S, 201T) having a reed valve type discharge valve (200S, 200T) and a discharge-valve limiter (201S, 201T). The discharge valve portion is attached to the groove portion with a rivet (203S, 203T). The groove portion has a rivet-side enlarged diameter portion (163Sa, 163Ta) formed into a semicircular step shape, and a diameter of the rivet-side enlarged diameter portion other than a bottom side thereof is larger than a diameter of the bottom side. This prevents a punch P that swages the rivet from interfering with the groove portion when attaching the discharge valve portion to the groove portion with the rivet.