Hermetic compressor and refrigeration device comprising same

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Solution Overview

Problem

The existing bearing devices in sealed compressors face issues with insufficient lubricating oil supply to the balls, leading to increased noise and decreased efficiency due to oil flowing to the outer peripheral sides of the races, and potential instability in the contact state between the raceway grooves and balls, which can impede smooth rolling.

Innovation Solution

The implementation of a sealed compressor design with raceway grooves on the upper and lower races, along with limiting means to prevent displacement, ensures stable lubricating oil supply to the balls and maintains smooth rolling by preventing deviation between the raceway grooves, thereby reducing noise and enhancing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If flat plate shaped upper and lower annular races are used, then the structure is simple, but lubricating oil flows to outer peripheral sides causing insufficient oil supply to balls

Engineering Contradiction:
Improvestructural simplicityVSAvoidlubricating oil supply stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The flat plate shaped races are segmented by introducing annular grooves that divide the surface into functional zones. The grooves create distinct oil supply channels and contact regions, preventing oil from flowing to outer peripheral sides while maintaining adequate oil supply to the balls.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the race surfaces are given different functional qualities through the annular grooves. The grooved regions channel lubricating oil toward the ball contact points, while other regions maintain structural integrity. This local differentiation ensures reliable oil supply without compromising overall structural simplicity.

Inventive Principle:
Principle #3Local quality

2Reliability

If raceway grooves are provided on upper and lower races, then lubricating oil supply to balls is improved, but deviation between raceway grooves may occur impeding smooth rolling

Engineering Contradiction:
Improvelubricating oil supply stabilityVSAvoidcontact state stability between raceway grooves and balls
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The upper and lower annular grooves are positioned asymmetrically relative to each other, with intentional offset designed to compensate for manufacturing deviations and operational deformations. This asymmetric arrangement ensures that even when deviation occurs, the grooves maintain adequate alignment for smooth ball rolling while continuing to channel oil effectively.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The design anticipates potential deviation between raceway grooves and incorporates tolerance compensation features in advance. The grooves are designed with sufficient width and depth margins that accommodate expected manufacturing variations, cushioning against the harmful effects of misalignment before they can impede smooth rolling.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Stability of the object's composition

If limiting means are added to prevent displacement of upper race, then smooth rolling is maintained, but device complexity increases

Engineering Contradiction:
Improveupper race position stabilityVSAvoidbearing device structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The limiting means is merged with the existing bearing structure by integrating it into the housing or mounting components. Rather than adding separate independent limiting devices, the design combines the limiting function with structural elements already present in the compressor, thereby maintaining position stability while minimizing increases in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration ensures smooth rotation of the balls, reduces sliding losses, and increases the efficiency of the sealed compressor by stabilizing the lubricating oil supply and maintaining proper contact between the races and balls, resulting in a quieter and more efficient operation.

Implementation Method 1

raceway grooves formed by annular grooves are provided on the main surface of the upper race and on the main surface of the lower race, respectively... ensures stable lubricating oil supply to the balls

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 2

at least one limiting means for limiting a displacement of the upper race with respect to the shaft... maintains smooth rolling by preventing deviation between the raceway grooves

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Fastener

Implementation Method 3

The balls are placed on the raceway groove of the upper race and on the raceway groove of the lower race... reduces sliding losses, and increases the efficiency

Methodology Applied
Scientific EffectRolling contact: Ball Bearing

Data Source

PatentEP2851563B1Hermetic compressor and refrigeration device comprising same
Publication Date: 2021.03.10 PANASONIC HOLDINGS CORP
  • EP2851563B1 patent drawingFigure 1
  • EP2851563B1 patent drawingFigure 2
  • EP2851563B1 patent drawingFigure 3

AI summary

A sealed compressor comprises a sealed container (101) which accommodates an electric component (105) and a compression component (106); wherein the compression component (106) includes a shaft (110) including a main shaft section (111) and an eccentric shaft section (112), a cylinder block (114), a piston (126), and a main bearing unit (120) mounted to the cylinder block (114) and supporting the main shaft section (112) such that the main shaft section (112) is rotatable, a thrust ball bearing (132) mounted to a thrust surface (130) of the main bearing unit (120); and the thrust ball bearing (132) includes a plurality of balls(134) held in a cage (133), an upper race (135) having main surfaces one of which is in contact with upper portions of the balls (134); and a lower race (136) having main surfaces one of which is in contact with lower portions of the balls (134) and; a restricting means for restricting a displacement of the upper race (135) with respect to the shaft (110).