Modular Crankshaft Assembly for Adjustable Compressor Eccentricity

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Solution Overview

Problem

Existing crankshaft manufacturing processes for reciprocating compressors require complex molds and high production costs due to low standardization and poor versatility, as they need to accommodate different eccentricities and shaft diameters, leading to increased manufacturing expenses and environmental impact.

Innovation Solution

A crankshaft design featuring independent first and second shafts connected by a crank arm with oil passages that allow for adjustable eccentricity, enabling modular assembly and forging processes to simplify production, reduce costs, and enhance versatility, while ensuring effective lubrication through varying wall thickness and centrifugal force optimization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If crankshafts are molded by casting with different eccentricities and shaft diameters to meet displacement requirements, then the crankshafts can be customized for different compressors, but re-molding is required for each configuration, leading to low standardization and poor versatility of molds

Engineering Contradiction:
Improvecrankshaft adaptability to different displacement requirementsVSAvoidmold complexity and versatility
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The crankshaft is divided into separate modular components: a first shaft with a first crank arm, and a second shaft with a second crank arm. These modules can be independently manufactured using standardized molds and then assembled in different configurations to achieve various eccentricities and shaft diameters, eliminating the need for complex customized molds for each crankshaft variant.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first shaft and first crank arm form a universal module that can be combined with different second shafts to create crankshafts with different eccentricities and shaft diameters. This modular design allows a single set of standardized molds to produce multiple crankshaft configurations, improving mold versatility and standardization while maintaining adaptability to different compressor displacement requirements.

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

2Ease of manufacture

If separate shafts are used with oil passages formed in each shaft and connected through the crank arm, then lubrication can be improved and modular assembly enabled, but the structural complexity increases

Engineering Contradiction:
Improvemodular assembly and processing simplicityVSAvoidcrankshaft structural complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The crankshaft is segmented into a first shaft and a second shaft that are independently manufactured and then assembled. Each shaft can have its oil passages formed separately during manufacturing, and the crank arm serves as the connecting element. This segmentation simplifies manufacturing processes and enables modular assembly while the oil passages are integrated into each module during production.

Inventive Principle:
Principle #1Segmentation

3Productivity

If traditional casting methods are used for crankshaft manufacturing, then production can be standardized, but the molds have poor versatility and manufacturing costs increase

Engineering Contradiction:
Improvecrankshaft production efficiencyVSAvoidmanufacturing cost and mold versatility
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The crankshaft manufacturing process is segmented into producing standardized first shaft-first crank arm modules and second shaft-second crank arm modules using conventional casting molds. These modules are then assembled to create the final crankshaft. This approach allows existing standardized molds to be used efficiently, improving productivity while reducing the need for expensive customized molds for each crankshaft variant.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The modular design enables universal first shaft-first crank arm modules to be combined with different second shafts, allowing a single set of standardized molds to produce multiple crankshaft types. This increases mold versatility and reduces manufacturing costs while maintaining high productivity through standardized production processes.

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

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 the versatility and production efficiency of crankshafts, reduces manufacturing costs, and minimizes environmental impact by allowing crankshafts with different eccentricities to be processed using a single set of forging molds, while maintaining structural strength and lubrication effectiveness.

Implementation Method 1

In any one of cross sections of the first shaft, the first oil passage does not have a constant wall thickness, so that different centrifugal forces are generated to apply lubricating oil into the first oil passage

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4001649B1Crankshaft, compressor, and refrigeration device
Publication Date: 2024.03.27 ANHUI MEIZHI COMPRESSOR CO LTD
  • EP4001649B1 patent drawingFigure 1~2
  • EP4001649B1 patent drawingFigure 3~4
  • EP4001649B1 patent drawingFigure 5~6

AI summary

A crankshaft (100), comprising a first shaft (110), a second shaft (130), and a first crank arm (120). A first oil passage (111) is formed in the first shaft (110) along an axis direction thereof; a second oil passage (131) is formed in the second shaft (130) along an axis direction thereof; the first crank arm (120) is configured to be connected between the first shaft (110) and the second shaft (130), the first crank arm (120) is provided with a third oil passage (121), and the third oil passage (121) is configured to communicate the first oil passage (111) and the second oil passage (131); the second shaft (130) is eccentrically provided relative to the axis of the first shaft (110). According to actual displacement requirements of a compressor, the relative position of the second shaft (130) and the first shaft (110) can be adjusted to adjust the eccentricity, so that the crankshaft can adapt to displacement requirements of different compressors, and the crankshaft is easy to process and manufacture. Also disclosed are the compressor comprising the crankshaft, and a refrigeration device comprising the compressor.