Rotary Compressor Radially Offset Suction Holes

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Solution Overview

Problem

The manufacturability and efficiency of rotary compressors are hindered by suction losses, particularly when using inclined holes for the suction passage, which can increase manufacturing costs and reduce quality due to burr generation and complexity.

Innovation Solution

A rotary compressor design featuring a rotating shaft with eccentric parts, a partition plate, and suction holes that are radially offset, forming a second suction passage that branches from the first suction passage, with chamfered edges to enhance fluid flow and reduce suction channel losses, while maintaining manufacturability and quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If an inclined hole is used for the second suction passage to reduce flow loss, then suction efficiency is improved, but manufacturability deteriorates due to burr generation and processing complexity

Engineering Contradiction:
Improveflow lossVSAvoidmanufacturability
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The second suction passage is segmented into two separate axial holes (first suction hole in the first cylinder, second suction hole in the partition plate) rather than using a single inclined hole. This segmentation allows each hole to be drilled axially, which is easier to manufacture while collectively achieving the function of an inclined passage for reducing flow loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from a single inclined hole (one-dimensional approach) to two separate axial holes arranged in different radial positions (multi-dimensional approach). The radial offset between the first and second suction holes creates the equivalent effect of an inclined passage without requiring actual inclined drilling.

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

2Loss of energy

If an inclined hole is used for the second suction passage, then suction efficiency is improved, but device complexity increases due to processing requirements

Engineering Contradiction:
Improvesuction lossVSAvoidprocessing complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The complex inclined passage is segmented into two simple axial holes, each of which can be drilled independently along the axial direction. This segmentation eliminates the need for complex inclined drilling operations while maintaining the flow efficiency benefits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of creating a single inclined hole to achieve the desired flow path, the invention inverts the approach by using two axial holes positioned at different radial locations. This inverted methodology achieves the same flow efficiency goal through a simpler manufacturing process.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of manufacture

If axial holes are used for suction passages, then manufacturability is improved, but suction efficiency deteriorates due to increased suction losses

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidsuction loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention applies local quality by positioning the first and second suction holes at different radial locations relative to the rotating shaft center. This radial offset creates a localized flow path that reduces suction losses while maintaining the simplicity of axial hole drilling throughout the structure.

Inventive Principle:
Principle #3Local quality

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 design improves manufacturability and efficiency by reducing suction channel losses, enabling high-performance and high-quality rotary compressors with lower production costs, even when using high-pressure working fluids like carbon dioxide.

Implementation Method 1

At least one of an opening edge of the first suction hole which is adjacent to the partition plate and an opening edge of the second suction hole which is adjacent to the first cylinder is provided with a chamfer

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP3557066B1Rotary compressor and refrigeration cycle device
Publication Date: 2021.06.30 TOSHIBA CARRIER CORP
  • EP3557066B1 patent drawingFigure 1
  • EP3557066B1 patent drawingFigure 2
  • EP3557066B1 patent drawingFigure 3

AI summary

A rotary compressor includes a rotating shaft, a first cylinder, a second cylinder, and a partition plate. The first cylinder includes a first suction passage. At least the first cylinder and the partition plate includes a second suction passage branching off from the first suction passage. The first cylinder includes a first suction hole provided in an axial direction of the rotating shaft. The first suction hole forms a part of the second suction passage. The partition plate includeds a second suction hole provided in the axial direction. The second suction hole forms another part of the second suction passage. The center of the first suction hole is located outside in a radial direction of the rotating shaft with respect to the center of the second suction hole.