Electric Drive Connector Sleeve Sealing Against Capillary Moisture
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Solution Overview
Problem
Existing electromotor designs for engine cooling fans and ABS/ESP systems in motor vehicles face issues with moisture penetration through capillaries between electric conductor strands, leading to potential short circuits and corrosion, especially when the electric lines are damaged.
Innovation Solution
The design incorporates a sleeve-like element connected fluid-tight to the exposed conductor section, with a seal bearing against the sleeve-like element and the conductor sheath, preventing liquid ingress by filling gaps with solder and using a mat seal or other sealing methods to ensure a fluid-tight connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a seal bearing against the insulation of the electric conductor is used, then the sealing structure is simple, but moisture can penetrate into the housing interior via capillaries between individual strands of the electric conductor
Solution Approach 1:
A sleeve-like element is introduced as an intermediary component between the electric conductor and the seal. This sleeve has an outer diameter that is smaller than the inner diameter of the sheath, creating a stepped configuration. The seal now bears against both the sheath and the sleeve-like element, preventing moisture from penetrating along the electric conductor into the housing interior through capillary action between individual strands
Solution Approach 2:
The sealing function is segmented into two distinct sealing surfaces: one where the seal bears against the sheath of the electric conductor, and another where the seal bears against the sleeve-like element. This segmentation creates multiple barriers to moisture penetration, with the sleeve-like element specifically addressing the capillary effect problem that the single seal configuration could not prevent
2Reliability
If the electric connection is designed to be fluid-tight in the direction of extent, then moisture penetration is prevented, but the sealing mechanism requires additional components and space
Solution Approach 1:
The sleeve-like element serves multiple functions simultaneously: it acts as a sealing surface for the seal to prevent moisture penetration, provides structural support for the electric connection, and creates the stepped configuration necessary for the seal to bear against both the sheath and the sleeve. This multi-functionality reduces the need for additional dedicated sealing components
Solution Approach 2:
The sleeve-like element is positioned within the sheath of the electric conductor, creating a nested configuration where the sleeve is contained within the sheath structure. This nesting approach allows the sealing mechanism to be integrated within the existing electric connection geometry rather than requiring external sealing components that would increase overall device complexity
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 solution effectively prevents moisture from entering the housing, enhancing the electromotor's lifespan by eliminating capillary-based liquid ingress and providing a space-saving, cost-effective, and corrosion-resistant sealing mechanism.
Implementation Method 1
undesired penetration of moisture into the housing interior can occur via the capillaries arranged between the individual strands of an electric conductor
Data Source
AI summary
The invention relates to an electric drive (10), in particular an electric motor of an engine-cooling fan or of an ABS/ESP of a motor vehicle, comprising an electric connector (22) and a housing (12), in the interior (14) of which a drive assembly (16) is arranged. The electric connector (22) has at least one electric line (41) contacting the drive assembly (16), an opening (20) is formed on the housing (12) for guiding through the electric line (41), and a seal (24) is arranged in the region of the housing opening (20). The electric line (41) has a first portion (50) and a second portion (52), the first portion (50) having a conductor (44) mid a sheath (48) encasing the conductor (44), and the second portion (52) being formed as an exposed conductor (44), the electric connector (22) having a sleeve-like element (42) in which the second portion (52) is arranged at least in part. According to the invention, the sleeve-like element (42) is connected in a fluid-tight manner to the second portion (52) and the seal (24) bears at least partially against the sleeve-like element (42), and the electric conductor (22) in the direction of its extent (54) is fluid-tight with respect to the housing interior (14) in the region of the sleeve-like element (42).