Conical Electrical Feed-Through Unit for Compact Motor Housing
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Solution Overview
Problem
Conventional glass-to-metal feed-through units for hermetically sealed electric motors require additional space for assembly, are sensitive to mechanical stress, and have large housing apertures that weaken the structure, making them unsuitable for compact and high-pressure applications.
Innovation Solution
A wedge-shaped electrical feed-through unit with a conductive pin and insulating sheath, allowing for self-centering and compact design, which can be assembled independently of the stator, using materials like copper for improved conductivity and Duromer for enhanced insulation and mechanical robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional glass-to-metal feed-through units are used, then hermetic sealing is achieved, but additional space for assembly is required and structural strength is reduced due to large housing apertures
Solution Approach 1:
The feed-through unit is divided into separate components: a pin with conical contact surface, an insulating sheath, and a sealing element. These segmented parts can be assembled independently into a smaller aperture in the housing, reducing the overall aperture area required while maintaining hermetic sealing capability.
Solution Approach 2:
The pin is inserted into the insulating sheath, which in turn is positioned within the housing aperture. The sealing element is nested within the assembly, creating a compact multi-layer structure that achieves hermetic sealing through concentric nesting rather than requiring a large single aperture.
2Reliability
If conventional glass-to-metal feed-through units are used, then hermetic sealing is achieved, but the units are sensitive to mechanical stress
Solution Approach 1:
The feed-through unit combines different materials with complementary properties: a conductive pin (metal), an insulating sheath (polymer or ceramic), and a sealing element (elastomer). This composite structure distributes mechanical stress across materials with different mechanical properties, preventing the stress concentration that plagues conventional glass-to-metal units.
Solution Approach 2:
The conical contact surface geometry changes the stress distribution parameters compared to cylindrical interfaces. The tapered shape allows for gradual load distribution and self-centering during assembly, reducing peak stress concentrations that would otherwise occur at sharp edges or misaligned interfaces.
3Reliability
If conventional glass-to-metal feed-through units are used, then electrical conduction is achieved, but assembly complexity increases
Solution Approach 1:
The pin is pre-positioned with its conical contact surface oriented to receive the sealing element and insulating sheath in a predetermined sequence. The conical geometry provides self-alignment features that guide subsequent components into place during assembly, eliminating the need for complex alignment procedures required by conventional feed-through units.
Solution Approach 2:
The conical contact surface and matching conical borehole create a self-centering mechanism during assembly. As components are pressed together, the conical geometry automatically aligns the pin with the housing aperture center, providing self-service alignment that simplifies the assembly process and reduces the skill level required for installation.
4Reliability
If conventional glass-to-metal feed-through units are used, then electrical insulation is achieved, but the units require additional sealing components
Solution Approach 1:
The insulating sheath simultaneously provides electrical insulation around the conductive pin and serves as the primary sealing interface with the housing aperture. By merging the insulation function and sealing function into a single integrated component, the design eliminates the need for separate sealing elements that would otherwise be required with conventional GTMS units.
Data Source
AI summary
The invention relates to an electrical feed-through unit for penetration of electrical contacts through the wall of a housing of an electric motor. It has a pin made of an electrically conducting material, which is surrounded by an electrically insulating material. The pin possesses an at least partially wedge-shaped contact surface for the area of a penetration through the wall of the housing and is able to be arranged with the sheath surrounding it in an at least partially wedge-shaped borehole penetrating through the wall of the housing. In addition, the invention relates to a housing of an electric motor, which contains at least one such electrical feed-through unit as well as an electric motor which has such a housing.What is advantageous with the design of an electric motor proposed here, is that, through savings in assembly time and assembly expense, as well as parts costs, it is possible to assemble the motor components in the motor housing very simply and favorably, and additionally a number of advantages are offered as compared to use of conventional glass-to-metal feed-through (GTMS). The openings in the motor housing required for the electrical feed-through units are small, resulting in improved pressure resistance and stiffness of the motor housing. The cross-sectional surface to be sealed is also small, and as a consequence, the rates of leakage and permeation are low.