Scroll Compressor Oil-Groove Bushing for Wear and Leakage Control
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Solution Overview
Problem
Existing scroll compressors face issues with increased wear and reduced lubrication due to gaps between the shaft and concentric bushing, leading to friction loss and efficiency deterioration, as well as limitations in bearing size and compression space.
Innovation Solution
A scroll compressor design incorporating a concentric bushing structure that supports the fixed scroll and includes oil grooves and oil supply mechanisms to form an oil film, reducing surface pressure and enhancing lubrication, while maintaining a sufficient compression space and sealing refrigerant leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a gap is provided between the shaft and concentric bushing for assembly, then assembly ease is improved, but lubrication is reduced causing increased wear
Solution Approach 1:
An oil groove is introduced as an intermediary structure between the shaft and concentric bushing. The oil groove receives and stores lubricating oil, then supplies it to the compression part through the bushing. This mediator structure allows the gap to exist for assembly purposes while ensuring continuous lubrication by compensating for oil loss through the gap.
Solution Approach 2:
The invention changes the oil supply mechanism by introducing an oil groove with specific dimensions (depth and width) that can store and regulate oil flow. This parameter change transforms the passive gap into an active lubrication system where oil is supplied on demand, maintaining reliability despite the assembly gap.
2Reliability
If the bearing of the fixed scroll is expanded to reduce surface pressure, then reliability is improved, but compression space is reduced
Solution Approach 1:
The concentric bushing acts as an intermediary component between the shaft and fixed scroll bearing. By introducing this bushing with an oil groove, the system achieves improved lubrication and reduced surface pressure without needing to expand the bearing dimensions, thus preserving compression space while enhancing reliability.
Solution Approach 2:
The invention uses hydraulic principles by introducing lubricating oil through the oil groove to create a fluid film between the shaft and bushing. This hydraulic lubrication system reduces friction and surface pressure without requiring larger bearing surfaces, maintaining compression space while improving bearing reliability.
3Reliability
If lubrication is improved by increasing oil supply, then wear is reduced, but refrigerant leakage increases
Solution Approach 1:
The oil groove is designed with specific local dimensions (depth and width) to provide lubrication only where needed in the compression part. This localized oil supply achieves wear protection at the critical shaft-bushing interface while minimizing overall oil quantity, thereby preventing refrigerant leakage through excessive oil.
Solution Approach 2:
The system uses controlled hydraulic lubrication where oil is supplied through the oil groove and bushing in regulated amounts. This controlled fluid delivery provides adequate lubrication for wear prevention while the regulated flow prevents excessive oil from causing refrigerant leakage, balancing both requirements.
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 friction loss, internal leakage, and wear by improving lubrication and sealing, thereby enhancing the reliability and efficiency of the compressor.
Implementation Method 1
When refrigerant enters or exits a compression part through this gap, a differential pressure oil supply function is reduced or does not work
Implementation Method 2
an oil groove formed in an outer circumference of the rotation shaft or in an inner circumference of the bushing, oil flowing into the oil groove forms an oil film
Data Source
AI summary
A scroll compressor, including a casing that forms an outer appearance thereof and having an oil storage space; an electromotive part installed inside of the casing to generate a drive force; a rotational shaft rotatably installed in the electromotive part; a compression part having an orbiting scroll installed to be capable of orbital rotation around the rotational shaft and a fixed scroll coupled to and engaged with the orbiting scroll to form a compression chamber between the orbiting scroll and the fixed scroll; and a bushing disposed between the fixed scroll and the rotational shaft and coupled to an outer circumference of the rotational shaft so as to rotate with the rotational shaft. The bushing is supported by one surface provided inside of the fixed scroll.