Scroll Compressor Shaft Guide Holes for Oil Lubrication
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Solution Overview
Problem
Conventional scroll compressors experience increased friction loss and noise due to eccentric loads on the rotational shaft, leading to reduced compression efficiency and poor oil supply performance, especially at low operation speeds and initial start-up with gaseous refrigerant presence.
Innovation Solution
The design includes a rotational shaft with a guide hole and recesses to reduce eccentric loads, branching the oil supply to decompression pins and bearings, and using a jaw to prevent oil discharge upward, ensuring efficient lubrication and oil distribution to the scroll wraps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the rotational shaft is supported by the main frame at a position higher than the action point, then the rotational shaft is subjected to a large eccentric load, but this configuration is simple to manufacture
Solution Approach 1:
The patent introduces a guide hole that penetrates from the inner circumferential surface toward the outer circumferential surface of the rotational shaft, creating a new dimensional pathway for oil flow. This allows oil to be supplied to the bearing from the outer surface, changing the traditional oil supply dimension and enabling the bearing to be positioned at the optimal support point rather than being constrained by the shaft insertion position.
Solution Approach 2:
The guide hole acts as an intermediary structure that facilitates oil flow from the oil passage through the rotational shaft to the bearing. By providing this intermediate pathway, the system can separate the oil supply route from the mechanical support structure, allowing the bearing to be positioned for optimal load support while still receiving adequate lubrication.
2Productivity
If oil is supplied using centrifugal force at high operation speeds, then the amount of supplied oil is large, but at low operation speeds the amount of supplied oil is small and friction increases
Solution Approach 1:
The guide hole is pre-formed in the rotational shaft structure, establishing an oil supply pathway before the compressor operates. This preliminary structural arrangement ensures that oil can flow to the bearing regardless of operating speed, eliminating the dependency on centrifugal force generated during operation.
Solution Approach 2:
The patent utilizes hydraulic principles by establishing a dedicated oil passage system with guide holes that enable liquid oil flow to the bearing. This hydraulic approach replaces reliance on centrifugal force with a structured fluid delivery system that maintains consistent lubrication across varying operating conditions.
3Device complexity
If the rotational shaft is inserted into the boss part with the supporting point higher than the action point, then the structure is simple, but compression efficiency is reduced due to friction loss
Solution Approach 1:
The guide hole creates a new dimensional pathway for oil supply that is independent of the vertical positioning of the support point. This allows the bearing to be optimally positioned for compression efficiency while maintaining the simple structural arrangement of the shaft insertion into the boss part.
4Reliability
If oil is supplied to the bearing through the rotational shaft, then lubrication is provided, but oil may be discharged upward through the open space between the rotational shaft and bearing
Solution Approach 1:
The guide hole extracts the oil supply function from the general rotational shaft structure and creates a dedicated, controlled pathway for oil delivery to the bearing. This separation ensures oil is delivered precisely where needed through a defined route, preventing unintended oil discharge through other spaces.
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 friction loss, improves compression efficiency, and enhances oil supply performance by minimizing eccentric loads and facilitating effective lubrication and refrigerant discharge, resulting in improved reliability and performance.
Implementation Method 1
a guide hole that penetrates from the inner circumferential surface portion toward the outer circumferential surface portion
Implementation Method 2
A first recess part or recess formed in the inner circumferential surface portion is further included. A second recess part or recess formed in the outer circumferential surface portion is further included. The guide hole extends from the first recess part toward the second recess part
Data Source
AI summary
A scroll compressor may include a rotational shaft, the rotational shaft including a first frame support having an inner circumferential surface, into which a boss of a first scroll is inserted, and an outer circumferential surface that forms an outer surface of the rotational shaft; and at least one guide hole that extends from the inner circumferential surface to the outer circumferential surface.