Blind Sealing Plug Tapered Stem for Axial Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blind sealing plugs face challenges in maintaining controlled radial expansion and axial stability during setting, leading to potential axial movement and leakage under high pressures, especially in applications like hydraulic fluid sealing.
Innovation Solution
A sealing plug design featuring a cylindrical hollow sleeve and a stem with a tapered central portion and an inclined annular shoulder, which engages frictionally to prevent axial movement and enhance radial flow control, ensuring a secure and fluid-tight seal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional sealing plug design is used, then the plug can be installed in a blind hole, but the sleeve may move axially within the hole during setting and may be ejected under high pressure
Solution Approach 1:
The stem is divided into three distinct portions with different diameters: a proximal cylindrical projection, a central portion, and a distal head. This segmentation allows each portion to serve a specific function - the central portion with larger diameter provides frictional engagement for axial retention, while the distal head provides the breaking point for setting
Solution Approach 2:
Different portions of the stem have different outer diameters to create localized functional zones. The central portion has a larger diameter than both the proximal projection and distal head, creating a localized expansion that provides frictional engagement with the sleeve inner surface for axial retention during installation and operation
2Strength
If the sleeve material is forced against the hole surface during setting, then high pressure resistance is achieved, but uncontrolled radial expansion and axial movement may occur
Solution Approach 1:
The stem central portion is designed with a larger diameter than the sleeve inner diameter, creating a preliminary interference fit. This preliminary action ensures that the sleeve is forced against the hole surface in a controlled manner during installation, achieving both high pressure resistance and controlled radial expansion
Solution Approach 2:
The outer diameter of the stem central portion is specifically designed to be greater than the outer diameter of the proximal cylindrical projection, creating a parameter change that generates frictional engagement. This parameter change controls the radial expansion of the sleeve while preventing axial movement
3Stability of the object's composition
If the stem is retained within the sleeve by frictional engagement, then axial stability is improved, but the stem may not be adequately retained under high load
Solution Approach 1:
The stem is segmented into portions with different diameters, with the central portion having a larger diameter to create a frictional engagement zone. This segmentation concentrates the retention force in the central portion while the distal head provides a controlled breaking point for setting
Solution Approach 2:
The central portion of the stem has a locally increased diameter that creates a frictional engagement zone with the sleeve. This local quality change provides both axial stability and adequate retention force through friction, while the smaller distal head provides the breaking point
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
The design achieves controlled progressive hole-filling and maintains the stem within the sleeve during setting, effectively resisting high pressures without axial movement or leakage, providing a reliable fluid-tight seal.
Implementation Method 1
the stem central portion, when within the sleeve, is arranged to be held therewithin by frictional engagement between an outer part of the stem central portion and an inner part of the sleeve
Implementation Method 2
Blind sealing plugs generally operate on the principle of radial expansion of material within the blind hole. The radial expansion of the plug blocks the hole thereby to prevent fluid flow past the sealed plug
Implementation Method 3
The head carries an annular projection for penetration into the sleeve material on setting of the plug within a blind hole. The annular projection, once set within the sleeve, provides a fluid-tight seal between the head and the sleeve of the plug
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A sealing plug comprises the combination of a stem (200) and sleeve (12), in which the stem is designed to have an external taper (50) such that, on installation of the plug by a setting tool, sleeve material flows into a gap (52) between the sleeve (12) and taper (50) to assist with locking the sleeve and stem together. Furthermore, the tool nose piece (30) has a conical taper designed to cause sleeve (12) material to flow, initially on installation, radially outward to effect locking of the plug into a blind hole (34) into which it is being installed.