Compressor and refrigerating device

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Solution Overview

Problem

The existing compressor designs face challenges with fluctuating oil levels and low recovery efficiency of lubricating oil, leading to increased oil circulation ratios and reduced performance, especially under varying working conditions.

Innovation Solution

The compressor design incorporates a shell with a compression assembly that divides the cavity into two sections, featuring an oil return channel with a specific oil inlet configuration. This configuration includes a dividing line that splits the oil inlet into two areas, ensuring that the lubricating oil flows effectively from the first cavity to the second cavity, improving oil recovery and reducing oil circulation ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the oil return channel is disposed in the compression assembly to enable lubricating oil circulation, then the oil circulation is achieved, but the oil level fluctuates greatly and recovery efficiency is low

Engineering Contradiction:
Improveoil circulationVSAvoidoil level stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The oil inlet is divided into two distinct areas by a dividing line: a first area facing the motor cavity and a second area facing the compression assembly. This segmentation allows differential oil flow control, enabling oil to be drawn from the motor cavity while preventing excessive refrigerant-mixed oil from the compression assembly from entering, thus stabilizing oil levels while maintaining circulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the oil inlet are assigned different functions: the first area (facing motor cavity) allows oil suction for circulation, while the second area (facing compression assembly) is restricted to prevent refrigerant contamination. This local quality differentiation resolves the contradiction by enabling circulation where needed while blocking harmful flow paths.

Inventive Principle:
Principle #3Local quality

2Productivity

If lubricating oil is pressurized from motor cavity to oil cavity under pressure difference, then oil circulation is enabled, but refrigerant enters the oil cavity through the oil return channel

Engineering Contradiction:
Improveoil circulationVSAvoidrefrigerant contamination
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The oil inlet is segmented into a first area and a second area separated by a dividing line. The second area specifically faces away from the compression assembly, creating a restricted zone that prevents refrigerant-laden oil from the compression assembly from entering the oil return channel, while the first area maintains normal oil circulation function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design uses the pressure difference that originally caused harmful refrigerant intrusion and converts it into a beneficial selective flow mechanism. The pressure-driven oil circulation through the first area is maintained, while the geometric configuration of the second area exploits the pressure gradient to block refrigerant contamination, turning the harmful pressure effect into a protective feature.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If the oil inlet area is increased to improve oil recovery, then more oil can return to the sump, but the oil level fluctuation increases

Engineering Contradiction:
Improveoil recovery efficiencyVSAvoidoil level stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The oil inlet is divided into two functional areas with the dividing line positioned at a specific height. This segmentation allows the system to maintain a large total inlet area for high recovery efficiency while the vertical positioning of the dividing line prevents excessive oil level fluctuations by blocking the upper portion from drawing in refrigerant-mixed oil during high-flow conditions.

Inventive Principle:
Principle #1Segmentation

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 enhances the recovery efficiency of lubricating oil, stabilizes the oil level in the sump, and reduces the oil circulation ratio, thereby improving the reliability and energy efficiency of the compressor across different operating conditions.

Implementation Method 1

the lowering of the oil level in the motor cavity may cause the entrance of a part of a refrigerant into the oil cavity through the oil return channel along with the lubricating oil, and this renders a low recovery efficiency of the lubricating oil

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP3964712B1Compressor and refrigerating device
Publication Date: 2025.03.05 GUANGDONG MEIZHI PRECISION MFG
  • EP3964712B1 patent drawingFigure 1~2
  • EP3964712B1 patent drawingFigure 3
  • EP3964712B1 patent drawingFigure 4

AI summary

The present invention provides a compressor and a refrigeration device. The compressor comprises a shell, a compression assembly, a motor, an oil sump and an oil return channel. The shell constructs a cavity, one part of the compression assembly is connected with the shell and located in the cavity, and the cavity is divided into a first cavity and a second cavity by the compression assembly. One part of the motor is arranged in the first cavity, and the part of the shell located below the central axis of the motor is a first shell. The oil sump is arranged in the second cavity. The oil return channel is arranged in the compression assembly, and is provided with an oil inlet facing the first cavity. According to the present invention, the distance between a dividing line in the oil inlet and the inner-side wall of the first shell, and the inner diameter of the shell meet a preset relationship, and the area of the part of the oil through area located below the dividing line and the area of the oil inlet meet a certain relationship, so that it is difficult to expose the oil inlet in refrigerants, the recovery efficiency of lubricating oil is improved, and the oil level fluctuation is relatively stable, and the oil circulation ratio of the compressor is reduced, and the reliability and energy efficiency grade of the compressor are improved.