Conical Viscosity Pump Axial Impeller Flow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Viscosity pumps used in additive manufacturing systems face issues with clogging and inconsistent flow rates, especially when handling low-viscosity materials, leading to degradation in printed part quality due to residual material oozing and accumulation of slag at the extrusion outlet.
Innovation Solution
A viscosity pump assembly with a rotatable and axially positionable impeller that adjusts the gap between the impeller tip and the outlet orifice to control the flow rate, using sensors and actuators to monitor and adjust the impeller position based on material level, temperature, and viscosity, ensuring precise flow control and preventing clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a typical viscosity pump is used to extrude flowable material, then the pump can move material from inlet to outlet, but the flow rate cannot be precisely controlled and clogging occurs at the extrusion outlet
Solution Approach 1:
The impeller is made axially adjustable relative to the outlet orifice, allowing dynamic modification of the gap between the impeller tip and orifice. This dynamic adjustment enables precise control of flow rate and prevents clogging by optimizing the clearance based on material properties and operating conditions.
Solution Approach 2:
The patent changes the geometric parameter of the pump by adjusting the axial position of the impeller, which modifies the gap size between the impeller tip and outlet orifice. This parameter change directly controls the flow rate and prevents clogging by optimizing the clearance for different material viscosities and flow requirements.
2Adaptability or versatility
If the impeller is stationary in a fixed position, then the pump structure is simple, but the flow rate cannot be adjusted in response to material level, temperature, or viscosity changes
Solution Approach 1:
The impeller is designed with axial adjustability, transforming it from a static component to a dynamic one that can respond to changing operating conditions. This allows the pump to adapt flow rate to material level, temperature, and viscosity variations while maintaining a relatively simple single-degree-of-freedom adjustment mechanism.
Solution Approach 2:
The system incorporates sensors that monitor material level, temperature, and viscosity, providing feedback to the control system. Based on this feedback, the axial position of the impeller is automatically adjusted to maintain optimal flow rate, creating a closed-loop control system that enhances adaptability.
3Reliability
If the outlet gap is large to prevent clogging, then material flow is smooth, but residual material oozes from the outlet after impeller stops
Solution Approach 1:
The axial position of the impeller can be dynamically adjusted based on operational phase. During extrusion, a larger gap prevents clogging; after stopping, the impeller moves closer to seal the outlet, preventing oozing. This dynamic repositioning resolves the contradiction between preventing clogging and preventing oozing.
Solution Approach 2:
The system proactively adjusts the impeller position in advance of potential problems. Before stopping extrusion, the impeller is positioned to reduce the gap, creating a seal that prevents residual material from oozing out after the process stops, thereby preemptively eliminating the harmful effect.
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 solution effectively prevents clogging, maintains consistent flow rates, and improves the quality of printed parts by allowing precise control over the extrusion process, even with low-viscosity materials, and reduces the need for frequent component replacements.
Implementation Method 1
a rotatable impeller which is linearly positionable parallel to an axis of rotation within the viscosity pump
Implementation Method 2
The impeller distal tip-end is configured in one embodiment to have a complementary outer surface with the outlet such that a seal is formed to prevent flow from the outlet
Data Source
AI summary
A pump assembly for use in an additive manufacturing system includes a viscosity pump having a first end and a second end wherein the first end has a cross sectional area greater than a cross sectional area of the second end. The viscosity pump has a conical shaped inner surface defining a pump chamber, an inlet proximate the first end and an outlet proximate the second end. The viscosity pump includes an impeller having an axis of rotation, where the impeller has a shaft positioned through the first end of the first housing and into the pump chamber. The impeller includes a distal tip-end at a distal end of the shaft wherein the impeller is configured to be axially displaced within the pump chamber of the viscosity pump parallel to the axis of rotation. An actuator is coupled to a proximal end of the impeller, wherein the actuator is configured to move the impeller parallel to the axis of rotation.