Canned Pump Stator Two-Component Injection Molding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing motor stators in canned pumps require high precision, significant material usage, extensive assembly work, and long production cycles, making it challenging to achieve a small air gap between the rotor and stator efficiently.
Innovation Solution
A two- or multi-component injection molding or transfer molding process is used, where a thermoset plastic forms the stator overmolding for mechanical strength and electrical insulation, and an elastomeric or thermoplastic plastic forms the thin-walled can for minimal electromagnetic losses and sealing, eliminating the need for additional mechanical processing and assembly steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If separate manufacturing and assembly of stator and can are used, then manufacturing flexibility is maintained, but manufacturing precision and air gap control deteriorate
Solution Approach 1:
The patent combines the separate manufacturing of stator and can into a single integrated injection molding process. The first amount of plastic forms the stator with embedded windings, while the second amount of plastic forms the can in a multi-component molding operation, eliminating separate assembly steps and achieving precise air gap control through inherent process integration.
Solution Approach 2:
The stator is pre-formed with embedded windings and insulation in the first injection molding step before the can is formed around it. This preliminary formation of the stator structure with precise dimensional control enables the subsequent can to be molded with accurate positioning, achieving small air gaps without requiring post-assembly adjustments.
2Loss of energy
If thicker can wall is used, then mechanical strength is improved, but electromagnetic losses increase and efficiency decreases
Solution Approach 1:
The patent employs a two-component plastic system where the first amount uses thermoset plastic for the stator providing mechanical strength and electrical insulation, while the second amount uses elastomeric or thermoplastic plastic for the can minimizing electromagnetic losses. This material differentiation allows the can wall thickness to be reduced to 0.1-0.2 mm while maintaining adequate mechanical strength through the composite structure.
Solution Approach 2:
The patent changes the material parameters by selecting different plastic types for different components. The can is formed from elastomeric or thermoplastic plastic with optimized flow properties and electrical characteristics, allowing thin wall construction (0.1-0.2 mm) that minimizes electromagnetic losses while the thermoset stator provides the necessary structural support.
3Productivity
If traditional separate manufacturing process is used, then material selection flexibility is maintained, but production time and assembly effort increase
Solution Approach 1:
The patent segments the molding process into two distinct injection steps with different materials - first forming the stator from thermoset plastic with embedded windings, then forming the can from elastomeric or thermoplastic plastic. This segmented multi-component approach maintains material selection flexibility for each component while integrating them into a single production cycle, reducing overall assembly effort and time.
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 approach reduces material usage, assembly effort, and production time while achieving refined mechanical tolerances and a smaller air gap, enhancing efficiency by allowing a can wall thickness of 0.1 to 0.2 mm and eliminating external sealing requirements.
Implementation Method 1
a first amount of plastic is first introduced into the mold, in particular injected, in this case the first amount of plastic surrounds the insert parts located in the mold, in particular metal parts and windings of the stator
Implementation Method 2
an elastomeric or thermoplastic plastic is used for the second amount of plastic
Data Source
Figure 1~3
AI summary
The invention relates to a method for manufacturing the motor stator of a canned tube pump by injection molding or transfer pressing, wherein in a two- or multi-component injection molding or transfer pressing process, a first quantity of plastic is first introduced into the mold, in particular by injection, the first quantity of plastic surrounding the insert parts located in the mold, in particular metal parts and windings of the stator, and leaving the space, in particular cylindrical, for the canned tube or the canned pot, and that afterwards the second quantity of plastic forming the canned tube/canned pot is introduced into the space left open.