Motor-Driven Compressor Mounting Lug Design

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Solution Overview

Problem

Existing motor-driven compressors face deformation and misalignment issues due to uneven clamping forces and poor dimensional accuracy when mounting lugs are fastened, leading to noise and reduced durability of the rotary shaft and its bearings.

Innovation Solution

A motor-driven compressor design featuring a first housing with radially opposite mounting lugs and a separate second housing with a third mounting lug, where the lugs are strategically positioned to distribute stress and prevent deformation, ensuring the electric motor and compression mechanism remain aligned.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If mounting lugs are formed integrally with the main housing at positions outside the compression mechanism and electric motor, then the motor-driven compressor can be mounted on the vehicle engine, but the main housing may be deformed due to differences of clamping forces and poor dimensional accuracy, causing misalignment of the compression mechanism and electric motor

Engineering Contradiction:
Improveintegral formation of mounting lugsVSAvoidalignment precision of compression mechanism and electric motor
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The housing is divided into a main housing and a separate mounting bracket. The mounting bracket is detachably connected to the main housing and contains the mounting lugs. This segmentation allows the mounting bracket to absorb deformation from fastening forces, preventing transmission of these forces to the main housing and thereby maintaining alignment precision of the compression mechanism and electric motor.

Inventive Principle:
Principle #1Segmentation

2Strength

If mounting lugs are fastened to bosses by bolts, then the motor-driven compressor can be securely mounted, but the main housing may be deformed due to uneven clamping forces, leading to displacement of the rotary shaft and reduced bearing durability

Engineering Contradiction:
Improvemounting strengthVSAvoidbearing durability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The mounting bracket serves as an intermediary component between the main housing and the mounting lugs. It absorbs and isolates the deformation caused by uneven clamping forces from the fastening process, preventing these deformations from affecting the main housing and the rotary shaft alignment, thereby protecting bearing durability while maintaining secure mounting strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If mounting lugs are positioned on the main housing, then fastening can be simplified, but vibration from the compression mechanism may be transmitted to the vehicle engine

Engineering Contradiction:
Improvefastening structure complexityVSAvoidvibration transmission to vehicle engine
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The mounting function is segmented into two parts: the main housing provides structural support, while the separate mounting bracket handles the fastening and vibration isolation. The mounting bracket with its flexible connection to the main housing acts as a vibration buffer, reducing vibration transmission to the vehicle engine while maintaining simple fastening structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2075470B1Motor-driven compressor
Publication Date: 2017.04.19 TOYOTA INDUSTRIES CORP
  • EP2075470B1 patent drawingFigure 1
  • EP2075470B1 patent drawingFigure 2

AI summary

A motor-driven compressor has a compression mechanism, a rotary shaft, an electric motor, a motor drive circuit and a housing assembly. The compression mechanism, the electric motor and the motor drive circuit are disposed along the axial direction of the rotary shaft in the housing assembly. The housing assembly has first and second housings. The first housing mounts the electric motor and the compression mechanism. The first housing has first and second mounting lugs formed integrally with the peripheral surface of the first housing. The second housing is joined to the first housing for accommodating the motor drive circuit. The second housing has a third mounting lug formed integrally with the second housing. The first through third mounting lugs are fastened to a mounting object to which the motor-driven compressor is to be mounted by means of fastening members.