Compressor Check Valve Hunting Suppression
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Solution Overview
Problem
Variable capacity-type compressors experience pulsation of refrigerant gas, leading to vibration and noise issues due to the hunting phenomenon of the valve element, which is difficult to suppress, especially at low flow rates.
Innovation Solution
A check valve design with a valve hole featuring a small-diameter and large-diameter portion, a biasing member, and a communicating window in the valve housing, where the communicating window's opening area increases with distance from the valve seat, allowing for a buffering state that stabilizes the valve element's operation and reduces vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the lift length of the valve element is reduced to suppress hunting phenomenon, then vibration and noise are reduced, but the flow rate of refrigerant becomes extremely low making it difficult to suppress hunting phenomenon
Solution Approach 1:
The valve hole is designed with different diameter portions (small-diameter and large-diameter portions) at different locations. The small-diameter portion is positioned where the valve element contacts to suppress hunting phenomenon, while the large-diameter portion is positioned downstream to ensure sufficient refrigerant flow, creating local quality variations that solve both problems simultaneously.
Solution Approach 2:
The valve hole is segmented into multiple portions with different diameters along the flow path. This segmentation allows each portion to serve a specific function: the small-diameter portion controls valve element stability, while the large-diameter portion maintains adequate flow rate, resolving the contradiction between suppressing hunting and maintaining flow.
2Object-generated harmful factors
If the opening area of the communicating port is reduced to suppress hunting phenomenon, then vibration is reduced, but pressure loss increases
Solution Approach 1:
Instead of simply reducing the opening area in one dimension, the invention introduces a communicating window in the circumferential wall that provides an additional flow path dimension. This allows the valve hole opening to be restricted for vibration suppression while the communicating window compensates for pressure loss by providing alternative refrigerant passage.
3Object-generated harmful factors
If the valve element is pressed by pulsating refrigerant gas, then the valve element vibrates and noise propagates, but reducing the lift length limits the flow rate
Solution Approach 1:
The valve hole structure creates local quality differences with small-diameter and large-diameter portions. The small-diameter portion at the valve element contact area suppresses vibration and noise, while the large-diameter portion downstream maintains adequate refrigerant flow for compressor productivity, allowing both noise reduction and capacity maintenance.
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 check valve effectively suppresses the hunting phenomenon and stabilizes the operation of the valve element, reducing noise and vibration, even at low flow rates, by utilizing the damper effect of the large-diameter portion and communicating window to manage pressure differences.
Implementation Method 1
a biasing member for biasing the valve element in a direction in which the valve element comes close to the valve seat
Implementation Method 2
The check valve has an open state, a fully closed state, and a buffering state. When the abutting surface separates from the large-diameter portion of the valve hole and the outer circumferential surface opens the communicating window, the open state is defined.
Data Source
AI summary
In a check valve for a compressor, a valve element includes an abutting surface and an outer circumferential surface. A valve hole includes a large-diameter portion and a small-diameter portion. A communicating window has such a shape that an opening area thereof gradually becomes larger with increasing distance from a valve seat. The check valve has an open state, a fully closed state, and a buffering state. When the abutting surface separates from the large-diameter portion and the outer circumferential surface opens the communicating window, the open state is defined. When the abutting surface closes the large-diameter portion and the outer circumferential surface interrupts communication through the communicating window, the fully closed state is defined. When the abutting surface separates from the large-diameter portion and the outer circumferential surface interrupts communication through the communicating window, the buffering state is defined. The hunting phenomenon is suppressed.