Poppet-to-Actuator Coupling Using a Deformed Ductile Sidewall
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Solution Overview
Problem
Existing electromechanical actuator systems face challenges in reliably attaching hard and brittle ceramic or carbide poppets to ductile steel or nickel alloy shafts, especially in harsh downhole environments, due to stress concentrations, loose threaded fasteners, and corrosion issues with brazing or soldering.
Innovation Solution
The system employs a recessed design on the poppet with a ductile material sidewall that is deformed to form a mechanical connection with the servo shaft, eliminating the need for threading, screws, or brazing, and incorporating a shock-absorbing and self-aligning member to enhance stability and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threading, screws, or pins are used to attach the poppet to the shaft, then the connection can be made, but stress concentrations occur and threaded fasteners can become loose in high vibration and temperature cycling environments
Solution Approach 1:
The ductile material coupling component merges the functions of connection and stress absorption into a single integrated element that bonds the poppet to the shaft, eliminating the need for separate fasteners and their associated stress concentration points
Solution Approach 2:
The solution uses a composite structure combining a ductile material coupling component (metal alloy) with the brittle poppet material (ceramic or carbide), where the ductile material absorbs stresses that would otherwise concentrate on the brittle poppet
2Strength
If brazing or soldering is used to attach the poppet to the shaft, then the connection can be made, but additional dissimilar metal is introduced that can cause anodic corrosion
Solution Approach 1:
The invention extracts the harmful intermediate layer (brazing or soldering material) from the attachment process, creating a direct bond between the poppet and shaft through the ductile material coupling component, thereby eliminating the source of anodic corrosion
Solution Approach 2:
The ductile material coupling component serves as a beneficial intermediary that directly bonds the poppet to the shaft without introducing corrosive dissimilar metals, replacing the harmful brazing/soldering intermediary with a corrosion-resistant metal alloy
3Ease of manufacture
If press fitting or clamping is used to attach the poppet to the shaft, then the connection can be made, but reliability is reduced due to low frictional coefficient and thermal expansion rate differences
Solution Approach 1:
The ductile material coupling component is pre-formed with bonding surfaces designed to create strong mechanical and chemical bonds with both the poppet and shaft, establishing a reliable connection before service conditions are applied
Solution Approach 2:
The solution changes the frictional interface parameters by using a ductile material with higher friction coefficient and matched thermal expansion properties, creating a more reliable press-fit-like connection without the limitations of traditional hard material interfaces
4Device complexity
If the poppet and shaft are made as a unitary structure out of hard and brittle material, then attachment complexity is reduced, but manufacturing difficulty increases and stress concentrations remain
Solution Approach 1:
The attachment assembly is segmented into distinct functional components: the brittle poppet, the ductile material coupling component, and the shaft, allowing each to be optimized for its specific function while simplifying the overall attachment process
Solution Approach 2:
The solution uses a composite structure combining a ductile material coupling component (metal alloy) with the brittle poppet material (ceramic or carbide), where the ductile material absorbs stresses that would otherwise concentrate on the brittle poppet
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 significantly increases the reliability and strength of the poppet-shaft connection, achieving a pull strength of over one thousand pounds, surpassing conventional methods which typically achieve only a few hundred pounds, while minimizing the risk of fracture and corrosion.
Implementation Method 1
a ductile material sidewall that is deformed to form a mechanical connection with the recess
Implementation Method 2
incorporating a shock-absorbing and self-aligning member to enhance stability and alignment
Data Source
AI summary
An assembly having a coupling component and a poppet is disclosed. The coupling component has a first end. The first end has an opening extending into the coupling component, such that the coupling component has a sidewall extending around and defining the opening, the sidewall at least partially constructed of a ductile material. The poppet is positioned within the opening. The poppet has a first end outside of the opening, a second end within the opening, and an outer surface extending between the first end and the second end. The poppet has a recess positioned between the first end and the second end, the recess being defined by at least one sidewall and a bottom. At least a portion of the ductile material of the sidewall is positioned within the recess to secure the poppet into the opening.