Scroll Compressor Holding Plate Radial Positioning

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Solution Overview

Problem

Existing scroll compressors face challenges in effectively controlling and limiting relative axial, radial, and rotational movements between scroll members, which can lead to inefficiencies and potential damage due to thermal expansion and design tolerances.

Innovation Solution

A holding plate is introduced to secure the pilot ring and non-orbiting scroll body, preventing rotation and limiting radial movement, while maintaining a small gap for piloting, and is designed to form surface-to-surface contact with the non-orbiting scroll body, allowing for limited axial movement and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the non-orbiting scroll body is rigidly fixed to prevent all movement, then rotational stability is improved, but thermal expansion compliance deteriorates

Engineering Contradiction:
Improverotational stabilityVSAvoidthermal expansion compliance
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The fixing mechanism is segmented into multiple functional elements: the pilot ring provides radial positioning, the holding plate prevents rotation, and the limited axial movement capability allows thermal expansion. This segmentation enables each element to perform its specific function without interfering with others, resolving the contradiction between stability and compliance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a completely rigid fixation to a dynamic fixation that allows controlled movements. The non-orbiting scroll body is permitted to move axially within limits while maintaining rotational stability, adapting its position in response to thermal expansion during operation.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If the pilot ring is positioned close to the piloted surface for precise radial control, then radial positioning precision is improved, but manufacturing tolerance sensitivity increases

Engineering Contradiction:
Improveradial positioning precisionVSAvoidtolerance sensitivity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The pilot ring is positioned at a distance from the piloted surface that is close enough to provide effective radial control but not so close as to create excessive sensitivity to manufacturing tolerances. This partial action approach achieves sufficient radial positioning precision without the drawbacks of excessive closeness.

Inventive Principle:
Principle #16Partial or excessive action

3Stability of the object's composition

If the holding plate forms surface-to-surface contact with the non-orbiting scroll body, then rotational prevention is improved, but axial movement flexibility may be reduced

Engineering Contradiction:
Improverotational preventionVSAvoidaxial movement flexibility
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The holding plate makes surface-to-surface contact with the non-orbiting scroll body at specific localized areas rather than across the entire surface. This localized contact is sufficient to prevent rotation while leaving other areas free to accommodate axial movement, thus resolving the contradiction between rotational stability and axial flexibility.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3198147B1Holding plate for piloted scroll compressor
Publication Date: 2020.07.29 BITZER KUEHLMASCHINENBAU GMBH
  • EP3198147B1 patent drawingFigure 1
  • EP3198147B1 patent drawingFigure 2
  • EP3198147B1 patent drawingFigure 3

AI summary

A scroll compressor that includes a housing and scroll compressor bodies disposed in the housing. The scroll bodies include a non-orbiting scroll body (also referred to as "fixed") and a moveable body, where scroll bodies have respective bases and respective scroll ribs that project from the respective bases. The scroll ribs are configured to mutually engage, and the movable scroll body orbits relative to the fixed scroll body for compressing fluid. A pilot ring engages a perimeter surface of the fixed scroll body to limit movement of the fixed scroll body in the radial direction. A simplified holding plate prevents rotation between the pilot ring and the fixed scroll body.