Combined Threaded-Splined Valve Stem for Compact Choke Valves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art choke valves require a significant overall size, weight, and cost due to the axial length of the valve stem, which includes separate threaded and splined sections, necessitating a larger bonnet to accommodate these components.
Innovation Solution
A valve stem with a combination threaded and splined section, where the threaded section includes axial segments radially spaced around the perimeter, and an anti-rotation ring with tabs to prevent rotational movement while allowing translational movement, reducing the axial length needed and thus the overall size and weight of the valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate threaded and splined sections are used on the valve stem, then the valve stem can engage both the drive nut and anti-rotation ring, but the axial length of the valve stem increases, requiring a larger bonnet and increasing overall valve size and weight
Solution Approach 1:
The patent combines the threaded section and splined section into a single integrated section on the valve stem. The combination threaded-splined section allows the valve stem to engage both the drive nut (via threads) and the anti-rotation ring (via splines) simultaneously or in sequence, eliminating the need for separate threaded and splined sections. This merging reduces the axial length of the valve stem while maintaining all necessary engagement functions.
Solution Approach 2:
The patent utilizes radial spacing of thread segments around the perimeter of the valve stem to create a compact configuration. By arranging multiple axial thread segments radially around the stem perimeter rather than stacking them axially, the design achieves the same engagement capability with reduced axial length, effectively using the radial dimension to solve the axial space problem.
2Reliability
If separate threaded and splined sections are used on the valve stem, then the valve can function properly, but the overall size, weight, and cost of the valve increase
Solution Approach 1:
The integration of threaded and splined features into a single combination section reduces the overall valve stem length, which in turn allows for a more compact bonnet design. This merging of functions into a single structural element reduces the total material required and the overall weight of the valve assembly.
Solution Approach 2:
The combination threaded-splined section serves multiple functions simultaneously: it provides threaded engagement with the drive nut for actuation, provides splined engagement with the anti-rotation ring for preventing rotation, and maintains structural integrity. This multi-functionality in a single section eliminates the need for multiple separate components, reducing overall valve weight.
3Reliability
If separate threaded and splined sections are used on the valve stem, then the valve can engage drive and anti-rotation components, but the bonnet size and manufacturing cost increase
Solution Approach 1:
The combination threaded-splined section can be manufactured as a single integrated feature on the valve stem, either through conventional machining or additive manufacturing. This merging of features reduces the number of separate machining operations, minimizes the bonnet size required, and simplifies assembly procedures, thereby reducing overall manufacturing cost despite maintaining full engagement functionality.
Data Source
AI summary
One illustrative embodiment of a valve disclosed herein comprises a body (12), a valve stem (22) that comprises a combination threaded-splined section (22X) and an unthreaded section (22Y) wherein the combination threaded-splined section (22X) comprises at least one spline (22S) and a thread (22Z). The valve (10) also comprises an anti-rotation ring (26) that includes at least one tab (26T) positioned in the at least one spline (22S) of the combination threaded-splined section (22X) and a threaded drive nut (24) that is adapted to engage the thread (22Z) of the combination threaded-splined section (22X).