Flow regulating valve
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Solution Overview
Problem
The existing flow regulating valve suffers from coaxial errors and unreliable axial positioning due to machining and assembly errors, leading to potential sticking issues and increased material costs.
Innovation Solution
A flow regulating valve design featuring a valve seat and shell with a motor-driven screw rod and nut, where the nut is in clearance fit with a mounting groove and includes a position limiting component like a snap ring, allowing radial wobble and improved axial limiting, reducing coaxial errors and sticking risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the nut is rigidly fixed to the valve rod through thread cooperation with the rear component, then the axial position is limited, but machining and assembly errors cause coaxial misalignment leading to sticking
Solution Approach 1:
The connection between the nut and valve rod is segmented into two independent functions: the mounting groove provides radial positioning with clearance fit to accommodate coaxial errors, while the snap ring provides axial positioning. This segmentation allows each component to optimize its specific function without being constrained by the other, eliminating sticking caused by coaxial misalignment while maintaining reliable axial positioning.
Solution Approach 2:
The mounting groove acts as an intermediary structure between the nut and valve rod. Instead of direct rigid thread cooperation, the groove provides a clearance fit that mediates the connection, allowing radial wobble to compensate for machining and assembly errors in coaxial alignment, thereby preventing sticking while the snap ring maintains axial positioning.
2Reliability
If the discharge piston is fixed in the sleeve to prevent radial wobble, then sealing performance is maintained, but the driving shaft has large deflection and gets stuck
Solution Approach 1:
The nut is allowed to have dynamic radial wobble within the clearance fit of the mounting groove, transforming the rigid fixed structure into a flexible adaptive structure. This dynamic capability allows the system to automatically compensate for coaxial errors during operation, eliminating sticking while the snap ring maintains necessary axial positioning for sealing.
Solution Approach 2:
The radial clearance fit parameter is introduced to change the connection characteristics between the nut and valve rod. By allowing radial movement through the clearance gap while maintaining axial positioning through the snap ring, the system achieves both sealing performance and smooth operation without sticking.
3Manufacturing precision
If the nut is in clearance fit with the mounting groove allowing radial wobble, then coaxial errors are eliminated, but additional position limiting components are needed
Solution Approach 1:
The snap ring serves multiple functions simultaneously: it limits axial position of the nut, prevents radial displacement, and compensates for axial length variations. This multi-functionality reduces the need for additional separate components, offsetting the complexity introduced by the clearance fit mounting groove while achieving superior coaxial alignment tolerance.
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 eliminates coaxial errors and enhances the reliability of axial positioning, preventing sticking and reducing material costs by allowing radial movement and precise axial control of the nut.
Implementation Method 1
The screw rod is connected with a nut in a thread cooperation manner; and the nut is connected with a valve rod, and the valve rod is movable in an axial direction to regulate an opening degree of a valve port on the valve seat
Implementation Method 2
an internal wall of the mounting groove is provided with an annular position limiting groove, and a position limiting component that limits an axial position of the nut is provided in the annular position limiting groove
Data Source
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AI summary
Disclosed in the present invention is a flow regulating valve comprises a valve seat (1) and a casing (2). A motor (21) provided inside the casing (2) is connected to a screw rod (3) through the output shaft of the motor. The screw rod is connected to a screw nut (4) connecting with a valve rod (5) and the inner part of the valve rod (5) is provided with a mounting groove (51). The screw nut (4) is in clearance fit with the mounting groove (51) along the radical direction, and the inner wall of the mounting groove (51) is provided with an annular limiting groove (52). A limiting element (53) provided in the annular limiting groove (52) limits the position along the axial direction of the screw nut (4) and is in clearance fit with the outside of the screw nut. On one hand, the configuration design of the flow regulating valve is able to eliminate the coaxial degree error between the screw rod and the screw nut generated during the processing and assembling of components and parts, on the other hand, it is able to improve the reliability of the axial limitation of the screw nut.