Compressor Piston Suction Port Layout for Miniaturized Compression

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Solution Overview

Problem

Conventional compressors face reduced compression efficiency due to miniaturization, which leads to decreased suction port cross-sectional area and increased stiffness of suction valves, resulting in poor response characteristics and leakage issues.

Innovation Solution

A piston design with a cylindrical slider and a head having an inner and outer body with bridges, where the suction port is formed between the inner and outer bodies, and a suction valve is coupled to the head to improve the effective cross-sectional area and durability, while reducing flow path resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the piston diameter is decreased for miniaturization, then the compressor size is reduced, but the suction port cross-sectional area decreases and suction valve stiffness increases

Engineering Contradiction:
Improvecompressor sizeVSAvoidsuction port cross-sectional area
Core Design Contradiction:
Volume of moving objectVSArea of moving object

Solution Approach 1:

The suction port is repositioned from the front surface of the piston to the rear surface, utilizing the axial dimension. This allows the suction port to be formed in the rear surface of the piston while the suction valve is positioned in front of it, creating a spatial arrangement that increases the effective cross-sectional area without increasing the piston diameter.

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

Solution Approach 2:

The piston structure is segmented into distinct functional zones: the suction port in the rear surface, the suction valve in front of the piston, and the compression chamber. This segmentation allows independent optimization of each component, enabling the suction port area to be increased through rear surface configuration while maintaining the miniaturized piston diameter.

Inventive Principle:
Principle #1Segmentation

2Length of moving object

If the opening part length of the suction valve is shortened for miniaturization, then the valve size is reduced, but the valve stiffness increases and response characteristics deteriorate

Engineering Contradiction:
Improvesuction valve sizeVSAvoidvalve response characteristics
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

A valve guide is introduced as an intermediary component to guide the suction valve. This guide structure provides lateral support to the shortened suction valve, reducing its stiffness in the opening/closing direction while maintaining its compact size. The valve guide acts as a mediator that allows the short valve to achieve proper response characteristics without increasing valve length.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of moving object

If multiple suction ports are formed spaced from the center for increased area, then the suction port area increases, but the valve coupling and sealing become more difficult

Engineering Contradiction:
Improvesuction port areaVSAvoidvalve coupling and sealing
Core Design Contradiction:
Area of moving objectVSEase of manufacture

Solution Approach 1:

Multiple suction ports formed in the rear surface of the piston are merged into a single suction valve structure. The suction valve is designed with a configuration that can seal against the combined area of multiple ports, simplifying the coupling mechanism. This merging approach maintains the total suction area while making the valve installation and sealing process more straightforward.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3985253B1Piston for compressor and compressor having same
Publication Date: 2023.11.22 LG ELECTRONICS INC
  • EP3985253B1 patent drawingFigure 1
  • EP3985253B1 patent drawingFigure 2
  • EP3985253B1 patent drawingFigure 3~4

AI summary

A piston (200) for a compressor and a compressor including the same are disclosed. The piston (200) is used in a compressor which compresses and discharges refrigerant suctioned into a cylinder (140), and the piston (200) includes a cylindrical slider (220) having an outer diameter corresponding to an inner diameter of the cylinder and forming a suction space (102) in which the refrigerant suctioned in the cylinder (140) is received, and a head (210) coupled to the slider (220), in which a compression space (103) is provided in the front and the suction space (102) is provided in the rear, and in which a suction port (214) communicating with the suction space (102) and the compression space (103) is formed, wherein the head (210) includes an inner body (211) and an outer body (212) surrounding the inner body (211), and the suction port (214) is formed between the inner body (211) and the outer body (212). The outer body (212) includes an insert part (212c) inserted into the slider (220), and a cover part (212b) positioned in front of the insert part (212c), extending outward from the insert part (212c) in the radial direction, and facing a front end part of the slider (220).