Polymeric Electrical Machine Housing with Metallic Reinforcement

Solution Overview

Problem

Existing electrical machines, particularly those used in industrial settings, face challenges in withstanding washdown procedures without corrosion or contamination, often requiring expensive stainless steel housings, and existing polymeric materials lack the necessary mechanical strength and chemical resistance for harsh industrial environments.

Innovation Solution

The development of polymeric industrial electrical machines with a unique manufacturing method that incorporates a polymeric housing made from thermoplastic materials, enhanced with metallic structures and surface treatments, and a method for overmolding components to create a robust and chemically resistant single-piece housing that can withstand industrial washdown processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If stainless steel housings are used to withstand washdown procedures without corrosion or contamination, then chemical resistance and reliability are improved, but cost and weight increase

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent employs composite materials by integrating metallic structures (providing mechanical strength and stiffness) with polymeric materials (providing chemical resistance and corrosion protection). This combination allows the housing to achieve both the durability of metal and the corrosion resistance of polymers, eliminating the need for heavy stainless steel while maintaining reliability during washdown procedures

Inventive Principle:

Principle #40Composite materials

2Reliability

If stainless steel housings are used to withstand washdown procedures without corrosion or contamination, then chemical resistance and reliability are improved, but cost increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The composite construction using polymeric materials with metallic reinforcements provides both chemical resistance and structural integrity at a lower cost than stainless steel, reducing manufacturing expenses while maintaining the ability to withstand corrosive washdown environments

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies material parameters by selecting specific polymeric materials with enhanced chemical resistance properties and optimizing their composition and structure to achieve the required performance for industrial washdown conditions, providing a cost-effective alternative to stainless steel

Inventive Principle:

Principle #35Parameter changes

3Weight of stationary object

If polymeric materials are used to reduce cost and weight, then manufacturing cost and weight are improved, but mechanical strength and chemical resistance deteriorate

Engineering Contradiction:

Core Design Contradiction:

Weight of stationary objectVSStrength

Solution Approach 1:

The patent resolves this contradiction by creating a composite structure where metallic components (such as bearing sleeves, end plates, or reinforcement ribs) are integrated within or alongside polymeric housing sections. The metallic elements provide the necessary mechanical strength and structural support, while the polymeric portions maintain the advantages of reduced weight and cost, achieving an optimal balance between these competing requirements

Inventive Principle:

Principle #40Composite materials

4Weight of stationary object

If polymeric materials are used to reduce cost and weight, then manufacturing cost and weight are improved, but resistance to corrosion and contamination deteriorates

Engineering Contradiction:

Core Design Contradiction:

Weight of stationary objectVSReliability

Solution Approach 1:

The composite design leverages the complementary properties of different materials: polymeric sections provide inherent corrosion resistance and chemical inertness, while metallic sections are protected or positioned to minimize exposure to corrosive environments. This synergistic combination maintains reliability during washdown procedures while achieving weight reduction

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS11502588B2Manufacture of a polymeric electrical machine

Publication Date: 2022.11.15

AI summary

A method for manufacturing a polymeric electrical machine includes manufacturing a stator including a laminated stator core and a plurality of windings including winding overhangs; applying a surface treatment to the stator core constructed to reduce defects at an interface between a polymeric material and the stator core and enhance adherence between the polymeric material and the stator core; mounting the stator onto a mandrel; inserting the stator into an electrical machine housing mold; molding an electrical machine housing including a stator band with an integral non-drive end endplate, including overmolding the stator and winding overhangs within the stator band; molding a drive end endplate, including forming polymeric ribs in the drive end endplate and overmolding a metallic structure into the endplate, the metallic structure enhancing mechanical stiffness of the endplate; installing a rotor assembly into the electrical machine housing; and installing the endplate onto the electrical machine housing.