Refrigerant Compressor Stator Mounting for Minimal Rotor Gap

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing refrigerant compressors face challenges in maintaining a minimal gap between the stator and rotor due to shape changes in the motor housing section, affecting the efficiency of the electric motor.

Innovation Solution

The use of resilient support elements that are elastically deformed to maintain the stator centered within the motor housing section, compensating for thermal and pressure-related diameter changes, and allowing for a consistent small gap between the stator and rotor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the stator is rigidly mounted to the motor housing section, then the manufacturing and assembly process is simple, but the gap between the stator and rotor increases due to thermal and pressure-induced diameter changes, reducing motor efficiency

Engineering Contradiction:
Improvegap between stator and rotorVSAvoidstator mounting structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The stator mounting structure transitions from a rigid fixed connection to a dynamic spring-elastic support system. The support elements are designed to be elastically deformable, allowing the stator to move radially and maintain optimal positioning relative to the rotor despite thermal expansion or pressure-induced diameter changes in the motor housing section. This dynamic adaptation ensures the gap between stator and rotor remains minimal across varying operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mounting structure utilizes changes in the elastic deformation parameter of the support elements to compensate for dimensional changes in the motor housing section. As temperature or pressure varies, the support elements elastically deform to adjust the stator's radial position, maintaining the optimal gap. The support elements are dimensioned to remain within the elastic range throughout all operating conditions, enabling continuous adaptation without permanent deformation.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the motor housing section undergoes thermal or pressure-induced diameter changes, then the operating range and adaptability improve, but the stator positioning becomes unstable, affecting motor efficiency

Engineering Contradiction:
Improveoperation under varying thermal and pressure conditionsVSAvoidstator positioning stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The mounting structure is designed to be dynamically adaptive rather than statically rigid. The spring-elastic support elements enable the stator to shift position in response to thermal expansion or pressure-induced diameter changes of the motor housing section, maintaining stable relative positioning between stator and rotor. This dynamic capability allows the system to operate efficiently across a wide range of thermal and pressure conditions while preserving positioning stability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The support elements automatically adjust the stator position in response to dimensional changes in the motor housing section without external intervention. The elastic deformation of the support elements self-compensates for diameter variations, keeping the stator centered and maintaining the optimal gap. This self-adjusting mechanism ensures stable stator positioning across varying operating conditions without requiring external control systems.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If support elements are designed to compensate for diameter variations, then the stator remains centered and gap is minimized, but the support elements must withstand elastic deformation in all operating conditions without entering plastic deformation range

Engineering Contradiction:
Improvestator centering and gap consistencyVSAvoidelastic property stability of support elements
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The support elements are dimensioned and material-selected to ensure that the maximum elastic deformation required to compensate for diameter variations remains within the elastic limit of the material throughout all operating conditions. By carefully controlling the geometric parameters and material properties, the design ensures that the support elements continuously operate in the elastic range, preventing permanent deformation and maintaining stable elastic properties over time and across temperature/pressure cycles.

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

This solution ensures a high efficiency of the electric motor by maintaining a minimal gap between the stator and rotor, while allowing for diameter variations and thermal expansion without plastic deformation of the support elements.

Implementation Method 1

the spring-elastic bodies are dimensioned such that they are in an elastically deformed state in all operating conditions of the motor housing section occurring during the operation of the refrigerant compressor

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the electric motor is cooled by a refrigerant flowing between the stator mounting surface and the outside of the stator and through the support elements parallel to the rotor axis

Methodology Applied
Scientific EffectConvection cooling: Convection

Data Source

PatentEP3929436B1Refrigerant compressor
Publication Date: 2024.02.21 BITZER KUEHLMASCHINENBAU GMBH
  • EP3929436B1 patent drawingFigure 1
  • EP3929436B1 patent drawingFigure 2
  • EP3929436B1 patent drawingFigure 3

AI summary

In order to make it as easy as possible to mount the stator (172) in a refrigerant compressor (10) comprising a total housing (12) with a motor housing section (22) in which a motor compartment (98) with an electric motor (102) comprising a stator (172) and a rotor (174) is arranged therein, and a compressor housing section (24) which has a compressor unit (26), it is proposed that the stator (172) be mounted in the motor housing section (22) by means of support elements (192, 194) inserted into the motor housing section (22), which on the one hand bear against a stator receiving surface (184) of the motor housing section (22) and on the other hand surround the stator (172) inserted into the support elements (192, 194) on its outside and support it springily relative to the stator receiving surface (184).