Rotary Compressor Blade Hole Deformation Prevention

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Solution Overview

Problem

Conventional compressors experience deformation of the blade hole due to press-fitting, leading to abnormal wear and seizure, which affects the refrigeration apparatus's reliability.

Innovation Solution

The compressor design includes a pipe connection member with a press-fitting portion positioned at a distance from the cylinder's center that is equal to or greater than the distance to the blade hole's outer end, along with a valve structure in the suction passage to regulate refrigerant flow, preventing backflow and improving refrigerating capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the press-fitting portion is positioned close to the center for compact design, then the device complexity is reduced, but the blade hole deforms causing abnormal wear and seizure

Engineering Contradiction:
Improvestructural simplicityVSAvoidblade hole deformation
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent transitions from considering only radial positioning to incorporating axial positioning (distance from center point along the axial direction) as an additional dimension. By specifying that the axial distance from the center point to the press-fitting portion is equal to or greater than the radial distance to the blade hole's outer end, the design protects the blade hole from deformation while maintaining structural compactness through precise spatial arrangement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the press-fitting portion is positioned far from the center to avoid blade hole deformation, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improveblade hole deformation suppressionVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the positioning parameters of the press-fitting portion by specifying precise distance relationships: the axial distance from the center point must be equal to or greater than the radial distance to the blade hole's outer end. This parameter-based approach ensures reliable blade hole protection while maintaining structural simplicity through optimized geometric relationships rather than complex additional components.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the suction passage is configured to allow intermediate-pressure refrigerant flow, then the refrigerating capacity is improved, but the device complexity increases due to valve structure

Engineering Contradiction:
Improverefrigerating capacityVSAvoidvalve structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The suction passage is designed with multi-functionality: it serves both as a structural connection element and as a flow control pathway. By configuring the suction passage to allow intermediate-pressure refrigerant flow directly, the patent achieves enhanced refrigerating capacity without adding separate complex valve structures, as the suction passage itself performs multiple functions including flow guidance and pressure regulation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4006346B1Rotary compressor and refrigeration apparatus
Publication Date: 2023.06.07 DAIKIN INDUSTRIES LTD
  • EP4006346B1 patent drawingFigure 1
  • EP4006346B1 patent drawingFigure 2
  • EP4006346B1 patent drawingFigure 3

AI summary

A compressor includes a cylinder (101); a cylinder chamber (103); a piston turning along an inner peripheral surface (101a) of the cylinder (101); a blade that partitions the cylinder chamber (103) into a high pressure side region and a low pressure side region together with the piston; a blade hole (104) allowing the blade to advance and retract; a suction passage (120) that extends from an outer peripheral surface of the cylinder (101) to the inner peripheral surface (101a) of the cylinder (101) and guides a refrigerant to the cylinder chamber (103); and a pipe connection member (200) having a press-fitting portion (201b) press-fitted into the suction passage (120) from a radially outer side of the cylinder (101). A distance (R2) from a center point (O1) of the cylinder chamber (103) to the press-fitting portion (201b) is equal to or longer than a distance (R1) to a radially outer end of the blade hole (104).