Watertight ECU Assembly for Vehicle Window Regulator
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Solution Overview
Problem
Existing watertight assemblies for connecting the electronic control unit (ECU) to the drive unit of a vehicle's window regulator face challenges in ensuring a proper seal due to the limited space within the vehicle door, leading to potential humidity ingress and poor sealing performance, especially when using seals with multiple lips that can become bent or twisted during assembly.
Innovation Solution
A watertight assembly design featuring an L-shaped support and housing with a specific L-shaped opening configuration, utilizing a seal with a U-shaped first sealing part and a second sealing part that are compressed in orthogonal planes during assembly, eliminating the need for multiple lips and ensuring a secure seal without gaps, even in radially oriented parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seals with multiple lips are used to seal the L-shaped opening, then the sealing coverage is improved, but the lips get bent or twisted during assembly leaving gaps for humidity to enter
Solution Approach 1:
The seal is divided into two separate sealing parts: a first sealing part for sealing the first opening and a second sealing part for sealing the second opening. This segmentation allows each sealing part to be independently positioned and compressed, eliminating the orientation problems that occur with multi-lip seals in L-shaped configurations.
Solution Approach 2:
Different sealing solutions are applied to different parts of the L-shaped opening. The first sealing part uses a compression seal compressed by a first sealing element, while the second sealing part uses a different compression mechanism. This allows each sealing location to have the optimal sealing configuration for its specific orientation and assembly direction.
2Adaptability or versatility
If the ECU is assembled into the housing in an L-shaped configuration, then the motor connector can be orthogonal to the motor shaft, but the vehicle connector must be placed parallel to the shaft which complicates the support structure
Solution Approach 1:
The connector arrangements are moved to different dimensional planes. The motor connector is positioned in a first plane while the vehicle connector is positioned in a second plane orthogonal to the first plane. This dimensional separation allows both connectors to have optimal orientations without requiring complex L-shaped support structures.
3Reliability
If the connection pins are over-molded with elastomeric material to guarantee watertight connection, then the sealing is improved, but the assembly process becomes more complex requiring welding of PCB to pins
Solution Approach 1:
The connection pins are extracted from the over-molded elastomeric material and positioned separately in connection pin holes that pass through the elastomeric material. This allows the pins to be independently accessible for PCB welding while the elastomeric material provides sealing without requiring the pins to be embedded in the mold.
Data Source
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AI summary
The assembly comprises a drive unit (1) and an ECU (4) connectable to the drive unit (1) in an assembly direction Y, transversal to a rotary shaft of the motor (3). The ECU (4) comprises an L shaped support (5) comprising a first part (51) parallel to the assembly direction Y and a second part (52) transversal to the first part Y and couplable in a sealing manner to an L shaped opening (31) of the housing (3) of the drive unit (1). The assembly comprises a seal (10) with a second sealing part (12) which, when the ECU (4) is coupled to the housing (3), is compressed in the assembly direction Y between the second part (52) of the support (5) and a second perimeter edge (322) of a second opening (312) of the housing (3) and a first sealing part (11) which, when the ECU (4) is coupled to the housing (3), is housed in a gap defined between the first part (51) and a first perimeter edge (321) of a first opening (311) of the housing (3), the gap and the first sealing part (11) being comprised in a plane parallel to the assembly direction Y. The first sealing (11) comprises two longitudinal branches (111) and a transversal branch (112) such that the longitudinal branches (111) are compressed in a direction transversal to the assembly direction Y whilst the transversal branch (112) is compressed in the assembly direction Y.