Knife Edge Pivot Seal for High-Pressure Displacement Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional displacement level sensors face challenges in maintaining accuracy and integrity under high-pressure conditions, where instrumentation must withstand numerous performance cycles and prolonged exposure to high pressures in fluid separation applications.
Innovation Solution
The design incorporates a pivot and seal assembly with a cylindrical pivot base and pivot body, featuring V-shaped grooves and knife edges for frictionless pivoting, and an annular seal for a fluid-tight seal, allowing the sensor to operate reliably in high-pressure environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional displacement level sensors are used in high-pressure applications, then the sensor can detect fluid level changes, but the sensor experiences deformation and loss of accuracy under high pressure
Solution Approach 1:
The sensor is divided into separate functional components: a process connection assembly, a sensor body, and a displacer assembly. Each component is optimized independently to withstand high pressure while maintaining measurement accuracy. The process connection assembly handles pressure isolation, while the sensor body contains the measurement mechanism.
Solution Approach 2:
A pivot assembly with knife edges acts as an intermediary mechanism between the displacer and the magnetic coupling system. This pivot assembly provides a low-friction, high-pressure-resistant connection point that allows the displacer to move freely in response to fluid level changes without being directly subjected to the full force of high pressure.
2Reliability
If the sensor components are tightly sealed to maintain fluid-tight integrity under high pressure, then pressure containment is improved, but the pivot mechanism loses ability to pivot freely
Solution Approach 1:
The seal is extracted from the pivot mechanism itself and placed in a separate location within the process connection assembly. This allows the pivot mechanism to remain mechanically free while the seal handles the fluid-tight containment function independently. The seal is positioned to contain pressure without interfering with the pivot's rotational movement.
Solution Approach 2:
The pivot assembly with knife edges serves as an intermediary that decouples the sealing function from the movement function. The knife edges provide a precise, low-friction pivot point that maintains mechanical freedom, while separate sealing elements in the process connection assembly maintain fluid-tight integrity under high pressure.
3Measurement precision
If the pivot mechanism uses traditional bearing surfaces, then the structure is simple, but friction prevents accurate and repeatable pivoting under high pressure
Solution Approach 1:
The pivot assembly uses knife edges with curved surfaces that roll against each other during pivoting motion. This curved contact geometry transforms sliding friction into rolling friction, dramatically reducing the friction force and enabling accurate, repeatable pivoting even under high-pressure conditions. The curved surfaces maintain continuous contact while minimizing resistance to movement.
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 ensures accurate and repeatable functionality, minimizes the risk of deformation under high pressure, and maintains a consistent seal, enhancing the sensor's durability and performance in high-pressure applications.
Implementation Method 1
an annular seal member carried within a through-bore of the cylindrical base member of the pivot base
Implementation Method 2
The first and second pivot body arms include first and second knife edges, respectively, that extend along the transverse axis of the pivot base and in line contact with the first and second grooves, respectively
Implementation Method 3
displacement level sensors can conventionally be used to detect changes in the level of fluid in a storage tank
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A seal and pivot assembly for a displacement level assembly includes a pivot base, an annular seal and a pivot body. The pivot base includes a cylindrical base member with an axial end surface defining first and second V-shaped grooves. The pivot body includes a cylindrical body member with first and second pivot body arms extending radially outward from opposite sides of the cylindrical body member. The first and second pivot body arms include first and second knife edges, respectively, that re in line contact with the first and second grooves, respectively, of the pivot base such that the pivot body can pivot relative to the pivot base, as well as uniformly distribute unbalanced forces applied to the pivot body across the entirety of the knife edges.