Motor-Driven Compressor Check Valve Layout for Refrigerant Isolation
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Solution Overview
Problem
Motor-driven compressors face insulation deterioration due to liquid refrigerant accumulation, which increases in size requirements and complicates mounting, and leads to excessive pressure and higher torque demands during startup.
Innovation Solution
Incorporating check valves in the suction and discharge passages that open during operation and close during shutdown to prevent liquid refrigerant from entering the compressor housing, thereby maintaining insulation and reducing refrigerant accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an extra length part is provided to extend the insulation distance between the wiring connection part and the housing, then the insulation resistance is improved, but the size of the motor-driven compressor increases
Solution Approach 1:
The patent transitions from extending the insulation distance in one dimension (length) to utilizing spatial arrangement in three dimensions. The wiring connection part is repositioned to a location on the housing that provides adequate insulation distance through spatial configuration rather than linear extension, thereby maintaining insulation resistance without increasing overall compressor size.
Solution Approach 2:
Instead of extending the insulation distance by adding length to the wiring connection part, the patent inverts the approach by strategically positioning the wiring connection part at a specific location on the housing that naturally provides sufficient insulation distance. This reverses the conventional thinking of adding more material to achieve insulation.
2Temperature
If liquid refrigerant accumulates in the housing during stop, then the refrigerant is cooled and liquefied, but the insulation between conductive part and housing deteriorates
Solution Approach 1:
The patent introduces an intermediary spatial relationship between the conductive part and the housing. By positioning the wiring connection part at a specific location on the housing, it creates a buffer zone or intermediary space that prevents direct contact between liquid refrigerant and conductive parts, thereby maintaining insulation quality even when refrigerant accumulates during stop.
3Productivity
If liquid refrigerant is vaporized in the housing at start-up, then the pressure in the housing increases excessively, but a larger torque is required
Solution Approach 1:
The patent implements preliminary positioning of the wiring connection part during the design and assembly phase. This preliminary action ensures that the conductive part is placed in a location that maintains proper insulation distance before liquid refrigerant accumulation or vaporization occurs, preventing insulation deterioration and associated startup issues.
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
Prevents liquid refrigerant accumulation, reduces pressure increases during startup, and enhances mounting flexibility by maintaining insulation and minimizing power consumption.
Implementation Method 1
a check valve that is provided in at least one of the suction passage and the discharge passage, opened while the compressor is in operation and closed while the compressor is at a stop
Data Source
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AI summary
A motor-driven compressor (10) includes an electric motor (12), a compression mechanism (11) driven by the electric motor (12) so as to compress refrigerant gas, a metal housing (13) accommodating the electric motor (12) and the compression mechanism (11), a suction passage (S)communicable with interior of the housing (13) wherein refrigerant gas flows through the suction passage (S), a discharge passage (D) communicable with the interior of the housing (13) wherein refrigerant gas discharged from the compression mechanism (11) flows through the discharge passage (D) and a check valve (51;52) that is provided in at least one of the suction passage (S) and the discharge passage (D), opened while the compressor is in operation and closed while the compressor is at a stop.