E-bike Plug Connector Sealing and Locking Mechanism

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Solution Overview

Problem

Existing electrical connectors for electric bicycles, particularly those located in the bottom bracket area, face challenges with water exposure and lack of a secure, fixed connection, as they are often designed as flying plug connections with limited space and no direct separation option within the motor housing.

Innovation Solution

A plug connector with a circumferential sealing element and an outwardly projecting locking element that secures the connector in place, ensuring sealing and locking when plugged in, combined with a hotmelt material for additional sealing and stabilization of the cable harness, and alignment elements for correct polarity insertion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flying plug connection is used in the middle of a cable, then the electrical connection can be made at some distance from the motor housing, but the connection is exposed to spray water and has limited space for secure mounting

Engineering Contradiction:
Improveease of connectionVSAvoidwater exposure
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary sealing structure (O-ring seal) between the electrical connector and the environment. The seal acts as a mediator that blocks water spray from reaching the electrical contacts while allowing the connector to remain accessible for connection operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Volume of moving object

If the electrical plug connection is arranged away from the motor housing, then there is more space for cable routing, but the connection lacks secure fixed mounting and can detach unintentionally

Engineering Contradiction:
Improvespace for cable routingVSAvoidconnection stability
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The connector incorporates a dynamic locking mechanism with spring-loaded locking elements that automatically engage with corresponding recesses in the mating connector. This dynamic system provides secure fixation during normal operation while allowing intentional disconnection when needed.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a locking mechanism is added to prevent unintentional detachment, then the connection stability improves, but the device complexity increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into a single integrated connector body: the sealing function (O-ring), the locking function (spring-loaded elements with recesses), and the electrical contact function are all combined in one compact assembly. This reduces overall system complexity compared to separate components.

Inventive Principle:
Principle #5Merging (Combining)

4Object-affected harmful factors

If a circumferential sealing element is added around the plug contacts, then the water protection improves, but the manufacturing complexity increases

Engineering Contradiction:
Improvewater protectionVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The patent employs a flexible O-ring seal that can be easily molded and installed around the connector body. This thin-film sealing solution provides effective water protection without requiring complex manufacturing processes or assembly steps.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP2978077B1Plug connector for an electric bicycle
Publication Date: 2021.04.14 WERNER WIRTH GMBH
  • EP2978077B1 patent drawingFigure 1~2
  • EP2978077B1 patent drawingFigure 3~4a
  • EP2978077B1 patent drawingFigure 4b

AI summary

The invention relates to a connector (1) for an electrical connection of an electric bicycle (3), comprising a plurality of electrical plug contacts (10, 10') and a connector wall (11) that circumferentially surrounds the plug contacts (10, 10'), characterized in that an outer surface (12) of the connector wall (11) is provided with a circumferential sealing element (14) and that an outwardly projecting locking element (15) is arranged on the outer surface (12) of the connector wall (11). The sealing element (14) seals the plug contacts (10, 10') in a suitable socket. Furthermore, the locking element (15) secures the connector (11) against accidental disconnection. The connector is space-saving, allowing multiple connections to be accommodated in a confined space.