Scroll Compressor Rotation Restriction Mechanism

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Solution Overview

Problem

Scroll compressors face noise issues due to contact between the fixed and movable spiral walls at high speeds and increased refrigerant leakage at low speeds, as existing technologies fail to effectively manage centrifugal forces and orbital radii.

Innovation Solution

A scroll compressor design featuring a rotation restriction mechanism with cylindrical pins and circular holes, allowing the orbital radius of the movable scroll to adjust based on rotation speed, preventing contact at high speeds and optimizing contact at low speeds to minimize noise and leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If the movable scroll is spaced apart from the fixed scroll to avoid contact at high speed, then noise is reduced, but refrigerant leakage increases at low speed

Engineering Contradiction:
ImprovenoiseVSAvoidsealing performance
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent introduces a rotation restriction mechanism that dynamically adjusts the orbital radius of the movable scroll based on operating conditions. The mechanism includes a rotation restriction member with a conical surface that contacts the movable scroll, allowing the orbital radius to vary between a first value (larger, preventing contact at high speed) and a second value (smaller, ensuring contact at low speed). This dynamic adjustment resolves the contradiction by adapting the clearance between scrolls to the current operating speed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the orbital radius parameter of the movable scroll to resolve the contradiction. By providing a rotation restriction mechanism that can set the orbital radius to different values, the system maintains optimal clearance at high speeds (reducing noise) while ensuring sufficient contact at low speeds (preventing leakage). The conical surface of the rotation restriction member enables continuous or stepped adjustment of this critical geometric parameter.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the movable scroll contacts the fixed scroll at low speed, then sealing performance is improved, but noise increases at high speed

Engineering Contradiction:
Improvesealing performanceVSAvoidnoise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The rotation restriction mechanism dynamically controls the orbital radius to ensure contact at low speeds for sealing while preventing contact at high speeds to reduce noise. The mechanism responds to centrifugal force variations with rotation speed, automatically adjusting the clearance between movable and fixed scrolls to match operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotation restriction mechanism utilizes the centrifugal force generated during operation to automatically adjust the orbital radius. At high speeds, centrifugal force pushes the rotation restriction member outward, increasing the orbital radius and preventing contact. At low speeds, the mechanism naturally allows smaller orbital radius, enabling contact for sealing. This self-regulating behavior eliminates the need for external control systems.

Inventive Principle:
Principle #25Self-service

3Object-generated harmful factors

If the orbital radius is decreased to prevent contact at high speed, then noise is reduced, but refrigerant leakage increases at low speed

Engineering Contradiction:
ImprovenoiseVSAvoidrefrigerant leakage
Core Design Contradiction:
Object-generated harmful factorsVSLoss of substance

Solution Approach 1:

The invention implements dynamic adjustment of the orbital radius through the rotation restriction mechanism. The orbital radius is not fixed but varies with operating conditions, being larger at high speeds to prevent contact and smaller at low speeds to maintain sealing. This dynamic parameter adjustment simultaneously addresses both noise reduction and leakage prevention.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the orbital radius parameter based on operating speed. The rotation restriction mechanism with its conical surface enables the orbital radius to take on different values, optimizing the balance between preventing spiral wall contact (noise reduction) and maintaining compression chamber sealing (leakage prevention).

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

The design reduces noise during high-speed operation by preventing contact between spiral walls and minimizes refrigerant leakage during low-speed operation by adjusting the orbital radius, enhancing the compressor's performance and efficiency.

Implementation Method 1

a large centrifugal force acts on the movable scroll especially when the rotation shaft rotates at a high speed

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2730742B1Scroll compressor with rotation restriction mechanism
Publication Date: 2019.12.25 TOYOTA INDUSTRIES CORP
  • EP2730742B1 patent drawingFigure 1
  • EP2730742B1 patent drawingFigure 2
  • EP2730742B1 patent drawingFigure 3

AI summary

A scroll compressor includes a rotation shaft, a fixed scroll, a movable scroll, a compression chamber, and a shaft support. A movable member is movable in an axial direction of the rotation shaft toward and away from the movable scroll. A rotation restriction mechanism includes a pin and a hole that is loosely fitted into the hole. An orbital radius switching mechanism moves the movable member in a first direction when a rotation speed of the rotation shaft is increased, which decreases an orbital radius of the pin relative to the hole so that an orbital radius of the movable scroll is decreased, and moves the movable member in a second direction when the rotation speed of the rotation shaft is decreased, which increases the orbital radius of the pin relative to the hole so that the orbital radius of the movable scroll is increased.