Compressor Bearing Housing Fixation Without Welding Pins

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The use of a welding pin for fixing a bearing housing to a casing results in reduced press-fit holding force due to plastic deformation of the tooth shape during welding, leading to inadequate fixation in some cases, especially when carbon dioxide is used as a refrigerant.

Innovation Solution

The bearing housing is fixed to the casing through interference fitting and supported by a support that is welded to the casing, with the support being easily assembled using bolts and having better weldability than the bearing housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a welding pin is used to fix the bearing housing to the casing, then the bearing housing can be fixed to the casing, but the tooth shape on the welding pin is plastically deformed by heat during welding, reducing press-fit holding force and leading to inadequate fixation

Engineering Contradiction:
Improvefixation reliabilityVSAvoidpress-fit holding force
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A support member is introduced as an intermediary component between the bearing housing and the casing. The support member is welded to the casing and supports the bearing housing, thereby avoiding direct welding of the welding pin to the bearing housing and preventing plastic deformation of the tooth shape. This intermediary structure resolves the contradiction by decoupling the welding process from the press-fit interface.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If the bearing housing is fixed to the casing by interference fitting alone, then the tooth shape can be preserved, but the fixation may be insufficient under operational loads

Engineering Contradiction:
Improvepress-fit holding forceVSAvoidfixation reliability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention merges two fixation methods: interference fitting (for preserving the tooth shape and providing initial positioning) and welding (for providing strong mechanical attachment). The support member is welded to the casing and also contacts the bearing housing, combining the advantages of both interference fitting and welding to achieve reliable fixation under operational loads.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If carbon dioxide is used as refrigerant, then refrigeration performance is improved, but the welding pin expands more due to heat, causing greater plastic deformation and reduced holding force

Engineering Contradiction:
Improverefrigeration efficiencyVSAvoidpress-fit holding force
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The support member serves as a mediator that absorbs the thermal expansion effects during welding of carbon dioxide refrigerant systems. By welding the support member to the casing rather than directly attaching a welding pin to the bearing housing, the design accommodates the greater heat input required for carbon dioxide refrigeration while preserving the press-fit holding force of the bearing housing.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method ensures stable fixation of the bearing housing to the casing without a welding pin, even when carbon dioxide is used as a refrigerant, reducing moments acting on the fixation point during operation and preventing lubricating oil scattering.

Implementation Method 1

The bearing housing is fixed to the casing by interference fitting

Methodology Applied
Scientific EffectInterference fitting: Elasticity

Implementation Method 2

a press-fit holding force is reduced

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

The support is fixed to the casing by welding

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 4

The support is fixed to the bearing housing with a bolt

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Implementation Method 5

The fluid guide is configured to guide a fluid flowing into the first space to an outer periphery of the electric motor

Methodology Applied
Scientific EffectFluid flow: Fluid Spray

Data Source

PatentEP4647580A1Compressor and refrigeration cycle apparatus
Publication Date: 2025.11.12 DAIKIN INDUSTRIES LTD
  • EP4647580A1 patent drawingFigure 1
  • EP4647580A1 patent drawingFigure 2
  • EP4647580A1 patent drawingFigure 3

AI summary

Provided are a compressor in which a bearing housing can be suitably fixed to a casing without using a welding pin and a refrigeration cycle apparatus using the compressor. A compressor (100) includes a casing (110), a bearing housing (130), an electric motor (140), and a support (161). The casing (110) has a tubular shape. The bearing housing (130) and the electric motor (140) are fixed in the casing (110) so as to be separated from each other in an axial direction of the casing (110). The support is disposed in a first space (S1) located between the bearing housing (130) and the electric motor (140). The bearing housing is fixed to the casing by interference fitting. The support is fixed to the casing (110) by welding and supports the bearing housing (130).