Rotary Compressor Sealing Stopper for Oil Equalizing Pipe

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Solution Overview

Problem

Existing rotary compressors require separate models with and without oil equalizing pipes, leading to complex manufacturing and management due to difficulties in sealing the opening end of the oil equalizing pipe against refrigerant pressure.

Innovation Solution

A rotary compressor design featuring a sealing stopper that tightly seals the opening end of the oil equalizing pipe, allowing for brazing with cycle piping while maintaining airtightness, even under high-pressure conditions, using a copper-based metallic material with a cylindrical peripheral wall and end wall configuration to secure the seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a rubber stopper is used to seal the opening end part of the oil equalizing pipe, then the sealing is simple and easy to install, but the stopper cannot withstand the pressure of the refrigerant

Engineering Contradiction:
Improvesealing installation easeVSAvoidpressure withstanding capability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sealing stopper is divided into multiple functional parts: a peripheral wall portion for brazing connection, an end wall portion for sealing the opening, and a recessed portion for receiving the pipe end. This segmentation allows each part to specialize in its function - the peripheral wall provides structural strength for pressure resistance, while the end wall provides the sealing surface, resolving the contradiction between ease of installation and pressure withstanding capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sealing stopper serves multiple functions simultaneously: it seals the opening end part of the oil equalizing pipe, provides a brazing surface for permanent sealing, and structurally reinforces the pipe opening to withstand refrigerant pressure. This multi-functionality eliminates the need for separate components and resolves the contradiction by integrating sealing, strengthening, and installation functions into a single component.

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

2Reliability

If a dedicated rotary compressor without an oil equalizing pipe is prepared for single use, then the sealing problem is avoided, but the manufacture and management become complicated

Engineering Contradiction:
Improvesealing reliabilityVSAvoidcompressor model variety
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sealing stopper enables the oil equalizing pipe to serve dual purposes: it can be sealed during shipping and storage, and later permanently sealed by brazing when the compressor is installed. This universality allows a single compressor design to be used in both parallel configurations (where oil equalization is needed) and single configurations (where the opening is permanently sealed), eliminating the need for separate compressor models and reducing manufacturing complexity.

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

Solution Approach 2:

The sealing stopper provides preliminary sealing of the oil equalizing pipe opening during shipping and storage, allowing the compressor to be safely transported and stored with the pipe opening sealed. This preliminary action enables a single standardized compressor design to be used universally, with the option to permanently seal the opening later via brazing, thereby avoiding the need to manufacture separate models for different application scenarios.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the opening end part of the oil equalizing pipe is sealed for shipping, then the compressor can be transported safely, but the subsequent brazing operation becomes difficult

Engineering Contradiction:
Improvetransport safetyVSAvoidbrazing workability
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing stopper is segmented into a peripheral wall portion that protrudes from the end wall, creating a dedicated brazing surface that extends beyond the pipe opening. This segmentation allows the brazing operation to be performed on the peripheral wall surface, which is more accessible and provides a larger working area, thereby improving brazing workability while maintaining transport safety through the end wall sealing function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The peripheral wall portion of the sealing stopper extends the brazing surface from the two-dimensional pipe opening to a three-dimensional protruding structure. This dimensional change provides additional space and accessibility for the brazing operation, making it easier to perform while the end wall portion maintains the sealing function for safe transport. The multi-dimensional structure resolves the contradiction between transport safety and brazing accessibility.

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

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 design simplifies manufacturing and management by allowing a single rotary compressor model to be used in both parallel and single configurations, ensuring secure joint strength and sealability, and improving workability during brazing operations.

Implementation Method 1

the rubber stopper cannot withstand the pressure of the refrigerant

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

the peripheral wall part and the opening end part are brazed to each other

Methodology Applied
Scientific EffectBrazing: Brazing

Data Source

PatentEP3683399B1Rotary compressor and refrigeration cycle device
Publication Date: 2021.05.12 TOSHIBA CARRIER CORP
  • EP3683399B1 patent drawingFigure 1
  • EP3683399B1 patent drawingFigure 2
  • EP3683399B1 patent drawingFigure 3A~3C

AI summary

Rotary compressor including an airtight container (35) accommodating therein a compression mechanism section (37) compressing a working fluid, and filled with refrigerating machine oil lubricate the compression mechanism section (37), a connecting pipe (26a, 26b) connected to the airtight container (35) and including an opening end part (71) opened to the outside of the airtight container (35), and a sealing stopper (72) detachably fitted on the opening end part (71) of the connecting pipe (26a, 26b) and tightly sealing up the opening end part (71). The sealing stopper (72) includes a cylindrical peripheral wall part (73) to be brazed to the connecting pipe (26a, 26b) in a state where the peripheral wall part (73) surrounds an outer circumferential surface of the opening end part (71) of the connecting pipe (26a, 26b), and an end wall part (74) provided in such a manner as to be continuous with the peripheral wall part (73) and opposed to an apical surface (71a) of the opening end part (71).