Electric Valve Shaft Holder Geometry for Low-Friction Alignment
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Solution Overview
Problem
The existing electric valves in refrigeration cycles suffer from increased contact resistance and positional misalignment due to large flat surfaces in contact, leading to rotor stoppages and axial misalignment of the valve shaft, especially when formed as molded resin products with weld lines or parting lines degrading sliding performance.
Innovation Solution
The electric valve incorporates a convex portion on the valve shaft holder's surface, reducing contact area with the fixed member, and aligning notches with weld or parting lines to minimize contact resistance and improve flatness, thus enhancing sliding performance and preventing misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If large flat surfaces are used for contact between valve shaft holder and fixed member, then stability of connection is improved, but contact resistance increases and sliding performance deteriorates
Solution Approach 1:
The invention replaces the large flat contact surface with a convex portion having a curved surface. This curvature reduces the contact area between the valve shaft holder and fixed member, thereby decreasing contact resistance and improving sliding performance while maintaining connection stability through the localized contact point.
Solution Approach 2:
The invention applies local quality by concentrating the contact function in a specific localized region (the convex portion) rather than distributing it over a large flat surface. This localized contact area provides both the necessary connection stability and reduced friction for reliable sliding operation.
2Ease of manufacture
If valve shaft holder is formed as molded resin product, then ease of manufacture is improved, but weld lines and parting lines degrade sliding performance and cause misalignment
Solution Approach 1:
The convex portion with its curved surface is particularly suitable for molded resin products because the curvature can be easily formed during molding without creating flat surfaces that are sensitive to weld lines and parting lines. This maintains both manufacturing ease and sliding surface quality.
Solution Approach 2:
By concentrating the contact function in the convex portion, the invention isolates the critical sliding surface from the areas where weld lines and parting lines typically occur in molded products. This localizes the high-precision requirement to a small area that can be controlled during molding.
3Strength
If contact area between valve shaft holder and fixed member is large, then structural stability is improved, but rotor positional misalignment and stoppages occur due to increased contact resistance
Solution Approach 1:
The convex portion's curved surface creates a localized contact area that reduces contact resistance enough to prevent rotor stoppages and misalignment, while the overall structural design maintains sufficient stability through the connection geometry and supporting structures.
Solution Approach 2:
The invention separates the functions of structural support and sliding contact by concentrating the contact function in the convex portion while maintaining overall structural stability through the valve shaft holder's design, allowing both strength and low friction to coexist.
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 design reduces contact resistance, prevents rotor misalignment, and maintains responsiveness by decreasing the contact area between the valve shaft holder and the fixed member, effectively suppressing axial misalignment and ensuring reliable operation.
Implementation Method 1
energization excitation to the stator coil is performed. Accordingly, the rotor rotates
Implementation Method 2
the valve shaft holder moves up by a screw feeding mechanism
Implementation Method 3
the valve closing spring which is interposed between the valve shaft holder and the valve shaft is compressed so that the valve body is pressed against the valve seat
Implementation Method 4
a part of a facing surface near the fixed member in the valve shaft holder is provided with a convex portion brought into contact with the fixed member... the contact resistance (the rotation sliding resistance) generated when the valve shaft holder comes into contact with the fixed member decreases
Data Source
Figure 1
Figure 2
Figure 3(A)~3(B)
AI summary
To provide an electric valve capable of preventing degradation in responsiveness and suppressing an axial misalignment of a valve shaft by improving a sliding performance between a valve shaft holder and a fixed member to prevent a positional misalignment (loss of synchronization) or a stop of a rotor. A convex portion 35 which is brought into contact with a fixed member 70 is provided in a part of a facing surface near the fixed member 70 in a valve shaft holder 30. A notch 36 is provided in a part of the convex portion 35.