Stepped Compressor Cover Assembly for Reduced Height and Clearance

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Solution Overview

Problem

Conventional rolling rotor compressors face limitations in reducing height due to bottlenecks in upper and lower housing cover structures, which restrict further height reduction while ensuring electrical clearance and preventing deformation and heat transfer issues.

Innovation Solution

An assembly structure featuring a plate-shaped housing cover with an annular axial end surface and recessed platform, allowing for increased electrical clearance and reduced heat transfer, combined with laser welding for secure bonding, thereby reducing overall compressor height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the upper housing cover is designed with a rounded corner to distribute stress and avoid concentration, then the strength and reliability are improved, but the electrical clearance between the motor winding and the housing cover cannot be reduced further

Engineering Contradiction:
Improvestrength and reliabilityVSAvoidelectrical clearance
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The housing cover is divided into two separate components: a rounded corner portion that maintains stress distribution and strength, and a flat portion that provides electrical clearance. This segmentation allows each portion to optimize its function independently, resolving the contradiction between strength and electrical clearance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The housing cover transitions from a two-dimensional flat surface to a three-dimensional structure with a rounded corner portion and a flat portion. This dimensional change enables the rounded corner to provide stress distribution while the flat portion maintains electrical clearance, solving the contradiction between these two requirements.

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

2Stability of the object's composition

If the lower housing cover is designed to prevent deformation of the housing bottom surface, then the structural stability is improved, but the overall height of the compressor cannot be reduced further

Engineering Contradiction:
Improvestructural stabilityVSAvoidoverall height
Core Design Contradiction:
Stability of the object's compositionVSLength of moving object

Solution Approach 1:

The lower housing cover is segmented into a first portion and a second portion, where the first portion prevents deformation of the housing bottom surface to ensure structural stability, while the second portion reduces the overall height of the compressor. This segmentation allows each portion to optimize its function independently.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the lower housing cover are designed with different local qualities: the first portion has properties suited for preventing deformation and ensuring structural stability, while the second portion has properties optimized for reducing overall height. This local quality differentiation resolves the contradiction between these two requirements.

Inventive Principle:
Principle #3Local quality

3Reliability

If laser welding parameters are increased to ensure sufficient weld strength, then the sealing reliability is improved, but the risk of burn-through and porosity formation increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidburn-through and porosity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The laser welding parameters are optimized by changing multiple parameters simultaneously: focal spot size, intensity, trajectory, angle, and dwell time. This parameter optimization ensures sufficient weld strength for sealing reliability while avoiding burn-through and porosity formation, resolving the contradiction between these requirements.

Inventive Principle:
Principle #35Parameter changes

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 assembly structure effectively reduces compressor height by increasing electrical clearance and preventing deformation, while enhancing rigidity and sealing capabilities, thus improving performance and reliability.

Implementation Method 1

laser welding is employed for sealing and fastening

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP4707602A1Compressor cover and housing assembly structure and compressor
Publication Date: 2026.03.11 SHANGHAI HITACHI ELECTRICAL APPLIANCES CO LTD
  • EP4707602A1 patent drawingFigure 1a~1b
  • EP4707602A1 patent drawingFigure 1c~2a
  • EP4707602A1 patent drawingFigure 2b~3a

AI summary

A compressor cover and housing assembly structure, and a compressor using the assembly structure. The assembly structure comprises a cover (1) and a housing (2), wherein the housing (2) has an annular axial end face, the radial outer portion of the axial end face being a radial flat surface (21), and the radial inner portion of the axial end face being a stepped surface (22) which sinks from the radial flat surface (21) towards the middle of the housing (2) to form a recessed boss (20); and the cover (1) is plate-shaped, the cover (1) has an inner face facing the axial end face, the outer periphery of the inner face being a mating flat surface (11) which matches and fits against the radial flat surface (21), and the inner face being provided with a protrusion (10) on the radial inner side of the mating flat surface (11) which matches and meshes with the recessed boss (20). A flattened plate-shaped design is used for the cover, and the mating flat surface located at the outer periphery and the protrusion are formed on the inner face of the cover, thereby forming a flange-free stepped cover, eliminating the need for the stretch flanging structure and process of the cover, and effectively reducing the overall height of the compressor.