Electric Compressor Motor Clamping to Prevent Stator Distortion

Solution Overview

Problem

Existing electric compressors used in battery-powered vehicles face inefficiencies and noise issues due to high radial clamping forces that distort the stator geometry, reducing performance and generating unwanted noise.

Innovation Solution

The electric compressor employs a plurality of clamping mechanisms spaced about the motor's outer diameter to constrain the motor within the housing, using tabs and channels to secure the motor without an interference fit, maintaining geometric integrity and reducing noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a radial clamping force is applied by an interference fit between the stator outer diameter and housing inner diameter, then the motor is held in place relative to the housing, but the stator geometry becomes distorted which increases noise and reduces efficiency

Engineering Contradiction:

Improvemotor positioning stabilityVSAvoidnoise

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The clamping mechanism is segmented into multiple discrete clamps distributed around the stator perimeter, rather than a continuous radial interference fit. Each clamp independently secures the stator at specific locations, maintaining positioning stability while avoiding continuous radial pressure that causes distortion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The clamping force is applied locally at discrete clamp positions rather than uniformly across the entire stator circumference. This localized approach secures the motor adequately while minimizing overall distortion of the stator geometry, thereby reducing noise generation.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If a radial clamping force is applied by an interference fit, then the motor is held in place relative to the housing, but the stator geometry becomes distorted which reduces compressor efficiency

Engineering Contradiction:

Improvemotor positioning stabilityVSAvoidcompressor efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The clamping mechanism is segmented into multiple discrete clamps distributed around the stator perimeter, rather than a continuous radial interference fit. Each clamp independently secures the stator at specific locations, maintaining positioning stability while avoiding continuous radial pressure that causes distortion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The clamping force is applied locally at discrete clamp positions rather than uniformly across the entire stator circumference. This localized approach secures the motor adequately while minimizing overall distortion of the stator geometry, thereby reducing noise generation.

Inventive Principle:

Principle #3Local quality

3Stability of the object's composition

If an interference fit of 300 microns or more is used to clamp the stator, then the motor is securely held in place, but the stator radius changes within a range of ~(-91) microns to ~(+49) microns causing distortion

Engineering Contradiction:

Improvemotor positioning stabilityVSAvoidstator geometry precision

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The clamping mechanism is segmented into multiple discrete clamps distributed around the stator perimeter, rather than a continuous radial interference fit. Each clamp independently secures the stator at specific locations, maintaining positioning stability while avoiding continuous radial pressure that causes distortion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The clamping force is applied locally at discrete clamp positions rather than uniformly across the entire stator circumference. This localized approach secures the motor adequately while minimizing overall distortion of the stator geometry, thereby reducing noise generation.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP4394183B1Electric compressor with motor fixed by clamping mechanisms

Publication Date: 2026.02.18 MAHLE INT GMBH

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AI summary

An electric compressor includes a housing, a refrigerant inlet port, a refrigerant outlet port, an inverter module, a motor, a drive shaft, clamping mechanisms, and a compression device. The refrigerant inlet port is coupled to the housing and configured to introduce the refrigerant to an intake volume. The refrigerant outlet port is coupled to the housing and is configured to allow compressed refrigerant to exit a discharge volume. The inverter module is adapted to convert direct current electrical power to alternating current electrical power. The motor is mounted inside the housing. The plurality of clamping mechanisms are spaced about the outer diameter of the motor and configured to constrain the motor within housing. The compression device, coupled to the drive shaft, receives the refrigerant from the intake volume and compresses the refrigerant as the drive shaft is rotated by the motor.