Scroll Compressor Shaft Eccentric Lubrication Design
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Solution Overview
Problem
Scroll compressors experience vibration and noise due to the misalignment of the repulsive force and reaction force during refrigerant compression, and face challenges in oil supply efficiency, particularly in top and bottom compression types, leading to reduced bearing performance.
Innovation Solution
The design includes strategically positioned oil-feeding holes and slits on the eccentric portion of the rotational shaft, optimized to prevent high-pressure refrigerant from blocking the oil supply and ensure quick, smooth oil distribution to the bearing areas, thereby aligning the repulsive and reaction forces and enhancing bearing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the orbiting wrap and boss are spaced apart in the axial direction to allow the orbiting wrap to be formed on the entire disk surface, then the compression ratio is improved, but the repulsive force and reaction force are applied at different heights causing the orbiting scroll to incline, generating vibration and noise
Solution Approach 1:
The coupled portion is repositioned from a radial offset configuration to an axial alignment configuration. By moving the coupled portion to the axial centerline of the rotational shaft and positioning it at the same axial height as the orbiting wrap, the force application points are aligned in the axial dimension, eliminating the incline and vibration while preserving the compression ratio benefits of the full-disk wrap configuration
2Productivity
If the rotational shaft is inserted up to the height where it overlaps the orbiting wrap to increase compression ratio, then the compression ratio is improved, but the space for forming the orbiting wrap on the disk is reduced, requiring reduction of the bearing area of the coupled portion
Solution Approach 1:
The coupled portion is repositioned from a radial overlap configuration to an axial alignment configuration. By moving the coupled portion to the axial centerline and positioning it at the same axial height as the orbiting wrap, the bearing area is minimized while still providing the necessary force transmission, allowing the orbiting wrap to be formed on the full disk surface for maximum compression ratio
3Reliability
If oil-feeding holes are formed on the eccentric portion to supply oil to the bearing area, then bearing performance is improved, but high-pressure refrigerant may block the oil-feeding holes, reducing oil supply efficiency
Solution Approach 1:
An oil-feeding slit is introduced as an intermediary structure between the oil passage and the bearing area. The slit is positioned to receive oil from the oil passage and channel it directly to the bearing area, serving as a mediator that prevents high-pressure refrigerant from blocking the oil supply path while ensuring continuous and efficient oil delivery to maintain bearing performance
4Reliability
If the oil-feeding hole is formed through the outer circumferential surface of the eccentric portion, then oil supply to the bearing area is enabled, but the structure becomes more complex and the oil supply path is longer, reducing oil supply efficiency
Solution Approach 1:
The oil-feeding function is extracted from the complex outer circumferential hole structure and simplified into a direct oil-feeding slit formed on the axial surface of the eccentric portion. This extraction simplifies the structure by eliminating the need for outer circumferential drilling while maintaining effective oil supply to the bearing area through a more direct and shorter path
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 configuration reduces vibration and noise by aligning the forces and improves oil supply efficiency, leading to enhanced bearing performance and compressor reliability.
Implementation Method 1
a third oil-feeding hole 53a, and a third oil-feeding slit 53b formed on an outer circumferential surface of the eccentric portion 53, so as to supply oil to a bearing area
Implementation Method 2
a high pressure refrigerant, leaked from a compression chamber, may block (shield, close) the oil-feeding hole
Data Source
AI summary
A scroll compressor is provided that may prevent an oil-feeding hole from being blocked due to a high pressure refrigerant, which is compressed in compression chambers and introduced into the oil-feeding hole through an oil-feeding slit, by blocking one of both end portions of the oil-feeding slit, adjacent to the compression chambers, when the oil-feeding hole is formed through an outer circumferential surface of a bearing and the oil-feeding slit, which communicates with the oil-feeding hole, is formed on the outer circumferential surface. This may allow for smooth oil supply onto the outer circumferential surface of the bearing through the oil-feeding hole, thereby enhancing a bearing performance. Also, the oil-feeding hole or slit may be formed at a closest position to an oil feeding-required section, not within the section. This may allow for quick oil supply into the oil feeding-required section, resulting in further enhanced bearing performance.