Variable Displacement Compressor Release Valve for Leak-Safe Control
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Solution Overview
Problem
The existing variable displacement compressor configurations face challenges in preventing foreign substances from inhibiting valve movement and enhancing control performance at mid-stroke, particularly due to refrigerant leakage issues when supplying refrigerant to the control pressure chamber from the discharge chamber via a supply passage.
Innovation Solution
A variable displacement compressor design that incorporates a release control valve with a valve element and flange configuration, allowing the control pressure chamber and branch passage to communicate via the supply passage, which adjusts based on differential pressure, ensuring efficient refrigerant flow and minimizing leakage, even with larger clearance settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the passage cross-sectional area of the orifice passage is increased to improve refrigerant flow, then the amount of refrigerant gas flowing out increases, but it requires increasing the amount of refrigerant gas to be led into the control pressure chamber, deteriorating mid-stroke performance
Solution Approach 1:
The patent divides the single orifice passage into two separate passages: a first passage (supply passage) that leads refrigerant from the discharge chamber to the control pressure chamber, and a second passage (release passage) that releases refrigerant from the control pressure chamber to the suction chamber. This segmentation allows independent optimization of each passage's cross-sectional area, enabling the release passage to have a larger area for improved refrigerant flow without negatively impacting mid-stroke performance through excessive refrigerant circulation.
2Manufacturing precision
If the passage cross-sectional area of the orifice passage is decreased to improve mid-stroke control, then blow-by gas accumulates in the control pressure chamber, but the piston cannot be fully stroked
Solution Approach 1:
By segmenting the orifice passage into separate supply and release passages, the patent allows the release passage to have a sufficiently large cross-sectional area to effectively discharge blow-by gas from the control pressure chamber, preventing gas accumulation that would restrict piston stroke, while the supply passage can be optimized for precise discharge displacement control.
Solution Approach 2:
The patent introduces a control valve as an intermediary device on the supply passage that can adjust the degree of opening to control the amount of refrigerant flowing into the control pressure chamber. This allows precise control of the balance between refrigerant supply and release, enabling full piston stroke while maintaining accurate discharge displacement control.
3Ease of operation
If the clearance between the valve element and the inner peripheral wall is increased to prevent foreign substance interference, then valve movement freedom improves, but refrigerant leakage increases
Solution Approach 1:
The patent replaces the traditional mechanical seal contact system with a magnetic field-based control system. The control valve uses magnetic attraction between a magnet and a ferromagnetic material to actuate the valve element, eliminating the need for tight mechanical clearance and contact friction. This allows larger clearance between the valve element and inner peripheral wall, preventing foreign substance interference while minimizing refrigerant leakage through magnetic field control.
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 enhances start-up performance and control precision by preventing valve element immobilization and reducing refrigerant leakage, thus improving the compressor's mid-stroke performance and overall control efficiency.
Implementation Method 1
a release control valve which moves in response to a difference between the pressure of the downstream side of the supply control valve and the pressure of the control pressure chamber is provided on the supply passage
Implementation Method 2
the flange which seals between the valve body and the inner peripheral wall of the valve housing space by being abutted, in the axial direction of the valve housing space, against a shoulder formed on the inner peripheral wall
Implementation Method 3
the branch passage is covered by the valve body in a state in which the flange is abutted against the shoulder
Data Source
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.