Compressor Bearing Member Design for Friction Reduction

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Solution Overview

Problem

In reciprocating compressors, increased frictional loss and interference between rotor and stator occur due to extended bearing portions and reduced press-fit lengths, leading to inefficient oil supply and reliability issues.

Innovation Solution

A compressor design featuring a bearing member with a specific tilt angle configuration and a double-row angular contact ball bearing to minimize contact area and ensure proper press-fit, along with a boss portion to prevent interference, while maintaining efficient oil supply without increasing frictional loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the bearing portion is extended to support the crankshaft, then the crankshaft support stability is improved, but the frictional loss between the bearing portion and crankshaft increases

Engineering Contradiction:

Improvecrankshaft support stabilityVSAvoidfrictional loss

Core Design Contradiction:

Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent extracts the bearing function from the extended bearing portion by introducing a separate bearing member (angular contact ball bearing). This removes the harmful frictional contact between the extended bearing portion and crankshaft while preserving the support stability function. The bearing member is positioned at the lower end of the crankshaft, separating the support function from the harmful friction-generating structure.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary bearing member (angular contact ball bearing) between the crankshaft and the bearing portion. This intermediary element provides the necessary support stability while minimizing direct frictional contact. The bearing member acts as a mediator that transfers loads efficiently without the excessive friction that would occur with direct contact between the extended bearing portion and crankshaft.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If the press-fit length between rotor and crankshaft is reduced, then the device complexity is decreased, but interference between rotor and stator occurs

Engineering Contradiction:

Improvepress-fit structure complexityVSAvoidinterference prevention

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent replaces the mechanical press-fit connection between rotor and crankshaft with a magnetic coupling system. The rotor and crankshaft are magnetically coupled without direct mechanical contact, eliminating the need for long press-fit lengths while preventing interference. The magnetic coupling provides sufficient torque transmission without the mechanical constraints that would cause interference between rotor and stator.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If the crankshaft diameter is increased to ensure larger oil passage area, then the oil supply efficiency is improved, but the frictional loss increases

Engineering Contradiction:

Improveoil supply efficiencyVSAvoidfrictional loss

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent extracts the oil supply function from the crankshaft structure by introducing a separate oil feeder at the lower end of the crankshaft. This allows the crankshaft to maintain a smaller diameter (reducing frictional loss) while the dedicated oil feeder ensures adequate oil supply to the bearing member and compression device through its own oil passage system.

Inventive Principle:

Principle #2Taking out (Extraction)

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

The design reduces frictional loss and prevents interference between rotor and stator, ensuring stable operation and efficient oil supply even at increased crankshaft diameters.

Implementation Method 1

a bearing member provided between the frame and the crankshaft and supporting the crankshaft with respect to the frame

Methodology Applied

Scientific EffectBall bearing: Ball Bearing

Implementation Method 2

double-row angular contact ball bearing

Methodology Applied

Scientific EffectAngular contact:

Implementation Method 3

Some of the oil is sucked up through an oil passage 55 of the crankshaft 5 to be supplied to each bearing surface

Methodology Applied

Scientific EffectLubrication: Lubrication

Data Source

PatentUS10859076B2Compressor

Publication Date: 2020.12.08 LG ELECTRONICS INC

AI summary

A compressor according to the present disclosure may include a bearing member located out of a range in an axial direction of a rotor. Accordingly, the bearing member and the rotor cannot overlap each other so as to reduce a bearing area. This may result in reducing a frictional loss of the compressor and ensuring a press-fit length of the rotor, so as to prevent interference between the rotor and a stator. Also, an area of an oil passage can be increased without an increase in the frictional loss, resulting in an increase in an amount of oil supplied.