Compressor Scroll Chamber Kinetic Energy Absorption

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Solution Overview

Problem

The increasing tip speed of impeller wheels in turbochargers poses a risk of fragments scattering and causing excessive kinetic energy upon breakage, potentially compromising containment properties and increasing production costs due to complex structures.

Innovation Solution

A compressor design featuring a cylindrical support part connecting the guide casing and scroll-chamber inner forming part, reinforced with ribs to absorb kinetic energy in multiple stages, and a silencer with additional ribs to prevent axial force propagation, maintaining containment properties while simplifying the structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the tip speed of the impeller wheel is increased to achieve higher pressure ratio and capacity, then the productivity and power of the compressor is improved, but the kinetic energy of fragments increases upon breakage, worsening the containment property

Engineering Contradiction:
Improvecompressor capacityVSAvoidcontainment property
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by providing a deformable scroll chamber that can absorb kinetic energy from impeller fragments before they reach critical components. The scroll chamber is designed to deform in the axial direction upon impact, creating a cushioning effect that prevents fragments from flying out of the housing, thus maintaining containment property even at high tip speeds

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses the scroll chamber as an intermediary element between the impeller wheel and the housing. The scroll chamber acts as a mediator that absorbs and dissipates fragment kinetic energy through controlled deformation, preventing direct transmission of harmful forces to the housing and maintaining system reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a gap is provided in the inner housing to allow kinetic energy absorption through deformation, then the containment property is improved, but the structural strength and rigidity of the housing deteriorates

Engineering Contradiction:
Improvecontainment propertyVSAvoidhousing strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by providing the gap only at specific locations where kinetic energy needs to be absorbed, rather than throughout the entire housing structure. The scroll chamber is designed with selective deformability at the gap location while maintaining structural integrity in other critical areas, thus balancing containment property with overall housing strength

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the housing structure by dividing it into rigid portions and the deformable scroll chamber portion. This segmentation allows different parts of the housing to serve different functions: rigid parts maintain structural strength while the segmented scroll chamber provides controlled deformation for kinetic energy absorption

Inventive Principle:
Principle #1Segmentation

3Strength

If the scroll chamber structure is reinforced to prevent breakage during impeller breakage, then the housing strength is improved, but the kinetic energy absorption capability deteriorates

Engineering Contradiction:
Improvescroll chamber strengthVSAvoidkinetic energy absorption
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by carefully controlling the geometric parameters of the scroll chamber, including the gap size, chamber thickness, and material properties. These parameter adjustments allow the scroll chamber to achieve optimal balance between strength and deformability, enabling it to withstand normal operating loads while still deforming sufficiently to absorb fragment kinetic energy

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 effectively reduces kinetic energy absorption and maintains containment properties with a simpler structure, preventing fragment damage and ensuring reliability without increasing production costs.

Implementation Method 1

a large force may be applied to a part forming the scroll chamber to break a scroll part in response to a shock greater than a shock strength applied to the inner housing by a fragment or the like of the impeller wheel

Methodology Applied
Scientific EffectKinetic energy absorption: Deformation

Data Source

PatentEP3073091B1compressor
Publication Date: 2019.09.18 MITSUBISHI HEAVY IND LTD
  • EP3073091B1 patent drawingFigure 1
  • EP3073091B1 patent drawingFigure 2
  • EP3073091B1 patent drawingFigure 3

AI summary

An object is to provide a compressor with an improved containment property and a simple structure. A compressor (10) includes: a guide casing (16) housing an impeller wheel (14) for compressing an intake fluid, and being configured to guide the intake fluid; a scroll-chamber frame (20) forming a scroll chamber (18) configured to guide the intake fluid having passed through the guide casing (16) to outside; and a cylindrical support part (32) of a cylindrical shape having the same central axis as a rotational axis (S), disposed outside the guide casing (16) in the radial direction and inside a scroll-chamber inner forming part (22) in the radial direction. The scroll-chamber inner forming part (22) and the guide casing (16) are connected to each other via the cylindrical support part (32).