Variable Capacity Compressor Release Valve for Leak-Safe Mid-Stroke Control
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Solution Overview
Problem
Existing variable displacement compressors face challenges in preventing valve element movement inhibition by foreign substances and refrigerant leakage into the suction chamber, leading to deteriorated performance at mid-stroke due to the need for multiple passages and tight clearance control.
Innovation Solution
A release control valve that adjusts the degree of opening between the control pressure chamber and a branch passage based on differential pressure, using a movable valve element with a flange that abuts against a shoulder for sealing, and a sub-valve element to manage internal passage closure, reducing the need for multiple passages and enhancing sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the passage cross-sectional area of the orifice passage is large, then the refrigerant gas can flow out smoothly from the control pressure chamber, but the amount of refrigerant gas required to be led into the control pressure chamber increases, deteriorating mid-stroke performance
Solution Approach 1:
The patent divides the single orifice passage into multiple passages with smaller cross-sectional areas. This segmentation allows the refrigerant to flow smoothly (maintaining reliability) while reducing the total amount of refrigerant required to be led into the control pressure chamber (improving mid-stroke performance).
Solution Approach 2:
The patent creates local quality differences by providing multiple passages with different characteristics. The combined effect of multiple smaller passages achieves both smooth flow and reduced refrigerant quantity requirements, optimizing both reliability and productivity.
2Productivity
If the passage cross-sectional area of the orifice passage is small, then the refrigerant flow requirement is reduced, but blow-by gas accumulates in the control pressure chamber, preventing full piston stroke
Solution Approach 1:
By segmenting the flow path into multiple passages, the patent enables effective blow-by gas removal while maintaining controlled refrigerant flow. The multiple passages collectively provide sufficient flow capacity to prevent gas accumulation without requiring excessive refrigerant supply.
3Productivity
If multiple passages are formed to communicate with the control pressure chamber, then refrigerant flow control is improved, but the device complexity and housing space requirements increase
Solution Approach 1:
The patent merges multiple passages into a integrated structure within the housing. By combining the multiple passages and their associated components into a unified assembly, the patent achieves improved refrigerant flow control while minimizing the increase in device complexity and housing space requirements.
4Reliability
If tight clearance control is implemented between valve element and housing, then sealing is improved, but foreign substances can inhibit valve element movement
Solution Approach 1:
The patent introduces an intermediary mechanism (the flange-shoulder abutment structure) that provides sealing without requiring tight clearance between the valve element and housing. This intermediary approach maintains sealing effectiveness while preventing foreign substance accumulation that would inhibit valve element movement.
5Ease of operation
If the flange is positioned away from the shoulder, then valve element movement is maintained, but refrigerant leakage into the suction chamber occurs
Solution Approach 1:
The patent creates a dynamic sealing system where the flange can move relative to the shoulder. The flange is positioned to abut the shoulder during critical operations to provide sealing, while maintaining the capability to move away when movement is required. This dynamic positioning resolves the contradiction between valve element mobility and sealing performance.
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 prevents valve element inhibition by foreign substances and reduces refrigerant leakage, improving control performance at mid-stroke by integrating passages and maintaining effective sealing with sufficient clearance, thus enhancing the compressor's start-up and operational efficiency.
Implementation Method 1
a release control valve which moves in response to differential pressure between a pressure of a downstream side of the supply control valve and a pressure of the control pressure chamber
Implementation Method 2
the valve element includes a valve body which seals the communication between the supply passage and the control pressure chamber by abutting a flange against a shoulder
Data Source
Figure 1
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AI summary
A branch passage which branches off from a portion of a supply passage on the downstream side of a supply control valve and communicates with a suction chamber is provided, and when providing a release control valve which, while allowing working fluid to flow, moves in response to the differential pressure between the downstream side pressure of the supply control valve and the pressure of a control pressure chamber on the supply passage, while preventing the movement of a valve element from being inhibited by a foreign substance in refrigerant, a leakage of the refrigerant into a suction chamber is suppressed when supplying the refrigerant from a discharge chamber to the control pressure chamber via the supply passage, enhancing control performance. A release control valve 51 has a valve element 60 including a valve body 62 which, being disposed, in a valve housing space 50 provided on a supply passage 40, so as to be movable in an axial direction of the valve housing space 50, varies the degree of opening of the communication between a control pressure chamber 4 and a branch passage 43, and a flange 63 which is abutted, in an axial direction of the valve housing space, against a shoulder 52 formed on the inner peripheral wall of the valve housing space 50, thereby sealing between the valve body 62 and the inner peripheral wall of the valve housing space 50, wherein a configuration is such that the branch passage 43 is covered by the valve body 62 in a state in which the flange 63 is abutted against the shoulder 52.