Piloted Scroll Compressor Radial Axial Restraint

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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

The implementation of a pilot ring that engages the perimeter surface of the first scroll body to limit movement in the radial direction, with radially-outward-projecting limit tabs configured to abut and fit within notches or slots in the pilot ring, thereby restricting axial and rotational movements, ensuring precise control and alignment of the scroll compressor components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If axial restraint is provided to control thermal expansion, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecontrol of thermal expansionVSAvoidaxial restraint mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pilot ring combines multiple restraint functions (radial, axial, and rotational) into a single integrated component. The radial limit tabs and axial limit tabs are formed as part of the same pilot ring structure, eliminating the need for separate restraint mechanisms and reducing overall device complexity while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pilot ring serves multiple functions simultaneously: it provides radial restraint through limit tabs engaging with the fixed scroll, axial restraint through notches engaging with limit tabs on the orbiting scroll, and rotational restraint through slot engagements. This multi-functionality improves reliability without adding separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple limit tabs are added to control radial, axial, and rotational movements, then reliability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvemovement controlVSAvoidpilot ring fabrication
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The pilot ring is designed with distinct functional segments: radial limit tabs for radial control, axial limit tabs with notches for axial control, and slots for rotational control. This segmentation allows each feature to be optimized independently while maintaining overall manufacturability through standard machining operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The limit tabs project radially outward from the pilot ring in a direction perpendicular to the plane of the pilot ring body. This three-dimensional configuration allows multiple restraint functions to be achieved within a compact structure without interfering with each other during manufacturing.

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

3Stability of the object's composition

If the pilot ring engages the perimeter surface to limit radial movement, then stability is improved, but the precision of axial and rotational control may be compromised

Engineering Contradiction:
Improveradial position stabilityVSAvoidaxial and rotational alignment
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The limit tabs act as intermediary elements between the pilot ring and the scroll members. These tabs provide precise geometric interfaces that translate the general radial restraint into specific axial and rotational position controls, ensuring high precision without compromising stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The design replaces complex mechanical alignment systems with simple geometric constraints: notches that fit over limit tabs for axial positioning, and slots that engage limit tabs for rotational positioning. This substitution maintains manufacturing precision while simplifying the overall system.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2836718B1Piloted scroll compressor
Publication Date: 2019.02.27 BITZER KUEHLMASCHINENBAU GMBH
  • EP2836718B1 patent drawingFigure 1
  • EP2836718B1 patent drawingFigure 2
  • EP2836718B1 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 first scroll body and a second scroll body, where the first and second 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 second scroll body is movable relative to the first scroll body for compressing fluid. A pilot ring engages a perimeter surface of the first scroll body to limit movement of the first scroll body in the radial direction. Further, the first scroll body has a radially-outward-projecting limit tab which abuts a portion of the pilot ring to limit movement of the first scroll body in one of the axial and rotational directions.