Asymmetrical Vane Rotary Compressor Roller Reaction Force Cancellation
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Solution Overview
Problem
In rotary compressors of the hinge vane type, the roller reaction force is not canceled, leading to increased side pressure and side wear between the vane and the vane slot, which reduces compressor efficiency and reliability.
Innovation Solution
The vane slot is disposed such that its second center line corresponds to the maximum roller reaction force direction, and the vane is asymmetrical with respect to this line, allowing the roller reaction force to be canceled by adjusting the direction of the vane or vane slot, and a wear-avoiding surface is provided to prevent interference between the vane and the roller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vane is hinge-coupled to the roller in a hinge vane type rotary compressor, then the vane behavior becomes stable and axial leakage is reduced, but the roller reaction force is not canceled and is transmitted to the vane, causing increased side pressure and side wear between the vane and vane slot
Solution Approach 1:
The vane is designed with an asymmetrical shape where the first length (from hinge center to front end) is different from the second length (from hinge center to rear end). This asymmetry allows the vane to effectively counterbalance the roller reaction force while maintaining stable behavior and reducing axial leakage, thereby resolving the contradiction between reliability and harmful side effects.
2Object-affected harmful factors
If the vane is detachably coupled to the roller in a rolling piston type, then the roller reaction force is canceled as the roller rotates, but the vane cannot be closely attached to the roller and axial leakage increases
Solution Approach 1:
The asymmetrical vane design enables the vane to maintain close attachment to the roller while incorporating structural features that allow for reaction force cancellation. The different lengths on either side of the hinge center create a mechanical advantage that addresses both the force cancellation and leakage control requirements.
3Ease of manufacture
If the vane slot is disposed with its center line passing through the axial center of the rotary shaft, then the structure is simplified and easier to manufacture, but the roller reaction force cannot be effectively canceled and side wear increases
Solution Approach 1:
The vane's asymmetrical geometry compensates for the simplified symmetrical vane slot positioning. By having different lengths from the hinge center to the front and rear ends, the vane can effectively counterbalance the roller reaction force even when the vane slot center line passes through the axial center, thus reducing side wear while maintaining ease of manufacture.
4Object-affected harmful factors
If the vane is made asymmetrical with respect to the second center line, then the roller reaction force can be canceled and side wear is reduced, but the processing and manufacturing of the vane becomes more complex
Solution Approach 1:
The asymmetrical vane design directly implements the principle to cancel roller reaction force and reduce side wear. The manufacturing complexity is managed by defining the asymmetry in terms of two simple length parameters (first and second lengths) from the hinge center, which can be controlled through standard machining processes.
Data Source
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Figure 3(a)~3(f)
AI summary
A rotary compressor according to the present disclosure may include a rotary shaft; a plurality of bearings supporting the rotary shaft; a cylinder provided between the plurality of bearings to define a compression space, and provided with a vane slot; a roller slidably coupled to the rotary shaft to be provided inside the cylinder, and disposed with a hinge groove on an outer circumferential surface thereof; and a vane, one end which is slidably coupled to the vane slot of the cylinder, and the other end of which is rotatably coupled to the hinge groove of the roller, wherein when an imaginary line passing through an axial center of the rotary shaft and a hinge center of the vane is referred to as a first center line, and a radial center line of the vane slot passing through the hinge center of the vane is referred to as a second center line, the vane slot is disposed such that the second center line is intersected by a preset tilting angle with respect to the first center line. Through this, a roller reaction force is canceled to suppress an increase in side pressure or side wear between a vane and a vane slot into which the vane is inserted.