Composite Bearing and Cylinder Structure in Rotary Compressors

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Solution Overview

Problem

In rotary compressors, the manufacturing of bearings and cylinder bodies made of metal materials is challenging due to potential damage, noise generation, refrigerant leakage, and reduced compression efficiency from improper gap control between the rotor and bearings.

Innovation Solution

The bearings and cylinder bodies are formed of a composite material reinforced with reinforced fibers, allowing for easier manufacturing and reduced contact and gap management through deformation in response to rotor loads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal materials are used for bearings and cylinder main body, then strength and durability are improved, but manufacturing precision requirements increase and contact damage occurs

Engineering Contradiction:
ImprovestrengthVSAvoidgap control precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies composite materials consisting of a resin matrix and reinforced fibers to replace traditional metal materials for the bearing and cylinder main body. This composite structure provides sufficient strength and durability while enabling easier manufacturing with reduced precision requirements. The reinforced fibers embedded in the resin matrix create a material that combines the advantages of both metal strength and ease of forming, eliminating the need for complex machining operations and strict gap control that characterize metal component manufacturing.

Inventive Principle:
Principle #40Composite materials

2Duration of action of stationary object

If metal materials are used for bearings and cylinder main body, then durability is improved, but noise generation and contact damage increase

Engineering Contradiction:
ImprovedurabilityVSAvoidnoise and contact damage
Core Design Contradiction:
Duration of action of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The composite material structure with reinforced fibers embedded in a resin matrix eliminates the harmful contact and noise generation issues associated with metal-on-metal interactions. The resin matrix provides a non-metallic, non-conductive surface that reduces friction and prevents direct contact damage between the rotor and bearing components, while the reinforced fibers maintain structural integrity and durability throughout the operational life of the compressor.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If larger gap is formed between rotor and bearing, then manufacturing difficulty is reduced, but refrigerant leakage increases and compression efficiency decreases

Engineering Contradiction:
Improvemanufacturing easeVSAvoidcompression efficiency
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The composite material provides an optimal balance between manufacturing ease and compression efficiency. The material's inherent properties allow for sufficient structural strength without requiring extremely tight gap tolerances, making manufacturing simpler while maintaining effective sealing. The reinforced fiber structure ensures that even with moderate gaps, the bearing and cylinder maintain their functional integrity, preventing excessive refrigerant leakage and preserving compression efficiency.

Inventive Principle:
Principle #40Composite materials

4Manufacturing precision

If high accuracy manufacturing is applied to bearings and cylinder main body, then gap control is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvegap control precisionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The composite material enables simplified manufacturing processes while achieving adequate gap control. The material can be formed through molding or forming processes that do not require complex machining operations, reducing manufacturing complexity. The inherent dimensional stability of the composite structure provides sufficient gap control without the need for post-processing or precision fitting procedures that would increase device complexity.

Inventive Principle:
Principle #40Composite materials

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

Facilitates manufacturing by eliminating the need for precise gap management and reducing wear, noise, and refrigerant leakage, while improving compression efficiency and reducing assembly complexity and costs.

Implementation Method 1

The bearing and the cylinder are formed of a composite material made by reinforcing a resin with reinforced fibers

Methodology Applied
Scientific EffectDeformation: Deformation

Data Source

PatentEP4242462B1Rotary compressor
Publication Date: 2025.11.12 MITSUBISHI HEAVY IND THERMAL SYST
  • EP4242462B1 patent drawingFigure 1
  • EP4242462B1 patent drawingFigure 2
  • EP4242462B1 patent drawingFigure 3

AI summary

A rotary compressor (1) includes a hermetic housing (2) that forms an outer shell, an electric motor (5), a compression mechanism (6) accommodated in the hermetic housing (2) and configured to compress a refrigerant by using a driving force from the electric motor (5), and a drive shaft (14) connecting the electric motor (5) and the compression mechanism (6) and configured to rotate about a center axis extending in a vertical direction. The compression mechanism (6) includes an upper rotor (33) connected to the drive shaft (14) and accommodated in an upper cylinder chamber (31), an upper cylinder main portion (34) defining an outer side of the upper cylinder chamber (31) in a radial direction, and an upper bearing portion (35) rotatably supporting the drive shaft (14) and defining the upper cylinder chamber (31) in the vertical direction. The compression mechanism compresses the refrigerant between the rotating upper rotor (33) and the upper cylinder main portion (34). The upper bearing portion (35) and the upper cylinder main portion (34) are formed of a composite material made by reinforcing a resin with reinforced fibers.