Scroll Compressor Lubricant Groove Positioning

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Solution Overview

Problem

In scroll compressors, lubricant supply to the thrust bearing is inadequate during startup or long-time stop conditions, leading to potential compressor failure due to seizure and lubricant shortage.

Innovation Solution

A scroll compressor design featuring a crankshaft with a lubricant channel, an orbiting scroll with a discoidal base plate, and a frame with an annular thrust surface, where the lubricant channel groove on the orbiting scroll's base plate faces the thrust surface, ensuring continuous lubricant supply to the thrust bearing during orbiting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lubricant is stored in the frame and supplied by overflow, then lubricant supply is simple, but lubricant cannot be supplied during startup or long-time stop conditions

Engineering Contradiction:
Improvelubricant supply reliabilityVSAvoidlubricant supply structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The lubricant channel groove is pre-formed in the orbiting scroll's base plate at a position that faces the thrust surface during operation. This preliminary positioning ensures that when the orbiting scroll rotates into its operating position, the groove automatically aligns with the thrust surface to supply lubricant, eliminating the need for complex active lubrication systems while ensuring reliable lubrication during startup and long-time stop conditions.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If annular groove is formed in central region of orbiting scroll, then manufacturing is simple, but lubricant supply to thrust bearing fails during orbiting

Engineering Contradiction:
Improvelubricant supply continuityVSAvoidgroove positioning precision
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of forming the lubricant channel groove in the central region of the orbiting scroll, the invention positions the groove in the outer circumferential region of the base plate. This dimensional repositioning ensures that the groove remains within the thrust surface region during orbiting while maintaining ease of manufacture. The groove's location in the outer region allows it to face the thrust surface continuously as the orbiting scroll rotates, ensuring uninterrupted lubricant supply.

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

3Quantity of substance

If lubricant channel groove is positioned to face thrust surface, then lubricant supply is effective, but groove must stay within thrust surface region during orbiting

Engineering Contradiction:
Improvelubricant distribution amountVSAvoidgroove position control
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The lubricant channel groove is positioned in the outer circumferential region of the base plate, specifically in the region that faces the thrust surface during operation. This local positioning ensures that the groove is optimally located to supply lubricant to the thrust surface while remaining within the thrust surface region during orbiting. The groove's width and position are designed to maintain this relationship throughout the orbiting cycle, ensuring both effective lubricant distribution and precision compliance.

Inventive Principle:
Principle #3Local quality

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 ensures sufficient lubrication to the thrust bearing, preventing seizure and ensuring reliable operation during startup and long-time stop conditions, while maintaining an appropriate balance of lubricant distribution for efficient compressor performance.

Implementation Method 1

The orbiting scroll has an inner channel and a lubricant channel groove. The inner channel allows the lubricant supplied through the crank shaft to flow outward. The lubricant channel groove has an annular shape in the outer circumferential region of the one surface of the base plate facing the thrust surface and allows the lubricant supplied through the inner channel to be supplied to the thrust surface.

Methodology Applied
Scientific EffectFluid flow through channel:

Implementation Method 2

During the orbiting of the orbiting scroll, the orbiting scroll slides against the thrust bearing of the frame. Thus, it is required that lubricant be supplied to the thrust bearing to prevent seizure or other defect.

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

EP 0 469 700 A1 discloses a lubrication system for a scroll machine which, to any extent desired, can utilize the centrifugal forces generated by the orbiting of the orbiting scroll member to influence, either positively or negatively, the flow of fluid in a portion of the lubricant system.

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP3438457B1Scroll compressor and refrigeration cycle device
Publication Date: 2019.10.09 MITSUBISHI ELECTRIC CORP
  • EP3438457B1 patent drawingFigure 1
  • EP3438457B1 patent drawingFigure 2
  • EP3438457B1 patent drawingFigure 3~4

AI summary

A scroll compressor includes a crank shaft, an orbiting scroll, and a frame. The crank shaft has a lubricant channel allowing lubricant to flow through the lubricant channel. The orbiting scroll is attached to the crank shaft and includes a base plate that is discoidal. The frame has a thrust surface against which the orbiting scroll slides. The thrust surface has an annular shape and faces an outer circumferential region of one surface of the base plate of the orbiting scroll. The orbiting scroll has an inner channel and a lubricant channel groove. The inner channel allows the lubricant supplied through the crank shaft to flow outward. The lubricant channel groove has an annular shape in the outer circumferential region of the one surface of the base plate facing the thrust surface and allows the lubricant supplied through the inner channel to be supplied to the thrust surface. The lubricant channel groove is formed such that the lubricant channel groove stays within a region of the thrust surface while the orbiting scroll is orbiting.