Charging Contact Positioning Arm for Fast, Low-Wear Bus Charging

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Solution Overview

Problem

Existing positioning units for electric vehicles require a fixed relative distance between the retracted and contact positions, which is not adjustable, leading to issues with maintaining contact force and efficiency during charging, especially with varying vehicle heights and loads, and result in slow extension, noise, and potential damage.

Innovation Solution

A positioning unit with an articulated arm device and drive mechanism that adjusts contact speed and force based on relative distance, using sensors and a control unit to ensure consistent contact force and rapid charging, employing a spring assembly for automatic retraction and a brushless electric motor for high cycle performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the charging contact is extended quickly to ensure rapid contact, then charging time is reduced, but the charging contact or charging contact surface may be damaged or wear out quickly

Engineering Contradiction:
Improvecharging timeVSAvoidcontact durability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies periodic action by using a two-phase extension process: first a rapid extension phase to cover most of the distance, then a deceleration phase near the contact point. This periodic variation in speed allows the system to achieve fast charging while preventing damage through controlled deceleration before contact.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements beforehand cushioning by introducing a deceleration phase before the actual contact between charging contact and charging contact surface. This pre-cushioning approach reduces impact forces and prevents damage while maintaining overall fast charging performance.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the charging contact is pressed with high contact force to establish reliable electrical connection, then connection reliability is improved, but the charging contact surface or contact may wear out faster

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidcontact lifespan
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the contact force parameter. Instead of maintaining constant high force, the system varies the contact force to be sufficient for reliable electrical connection while avoiding excessive force that would cause premature wear, thereby extending contact lifespan.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the positioning unit is designed for a defined contact height, then contact force can be maintained, but the design must be regularly adjusted when vehicle types or heights change

Engineering Contradiction:
Improvecontact force consistencyVSAvoidvehicle type adaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by making the positioning unit adjustable in its retracted position. This dynamic adjustment capability allows the system to adapt to different vehicle heights and types while maintaining consistent contact force during charging, eliminating the need for regular design modifications.

Inventive Principle:
Principle #15Dynamics

4Reliability

If the charging contact extends slowly to prevent damage and noise, then contact durability is improved, but charging time increases

Engineering Contradiction:
Improvecontact durabilityVSAvoidcharging time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent resolves this contradiction through periodic action with distinct speed phases: a fast extension phase for most of the travel distance, followed by a deceleration phase near the contact point. This allows the system to achieve both fast charging (through the fast phase) and contact durability (through the deceleration phase).

Inventive Principle:
Principle #19Periodic action

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

Enables faster and more reliable charging by maintaining consistent contact force and reducing noise, extending charging time at stops, and minimizing mechanical wear and noise, with extended maintenance intervals and adaptability to varying vehicle heights.

Implementation Method 1

the drive device has a spring assembly that mechanically interacts with the adjustment drive, wherein the positioning unit comprises a holding device for attaching the positioning unit above a vehicle to a mast or underpass, wherein the spring assembly comprises at least one return spring for generating a return force on the articulated arm device

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

employing a spring assembly for automatic retraction and a brushless electric motor for high cycle performance

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3544843B1Positioning unit and contacting-making method
Publication Date: 2026.02.25 SCHUNK TRANSIT SYST GMBH
  • EP3544843B1 patent drawingFigure 1~2
  • EP3544843B1 patent drawingFigure 3~4
  • EP3544843B1 patent drawingFigure 5~6

AI summary

The invention relates to a positioning unit (10) and also to a method for establishing an electrically conductive connection between a stationary charging station and a vehicle, in particular an electric bus or the like, wherein an electrical charging contact of the positioning unit can be moved relative to a charging contact face (11) and can make contact with said charging contact face by means of the positioning unit, wherein the positioning unit has an articulated arm apparatus (12) and a drive apparatus for driving the articulated arm apparatus, wherein the charging contact can be positioned between a contact position (37) for transmitting power and a retracted position for interrupting power by means of the articulated arm apparatus, wherein the drive apparatus has an adjusting drive (13) for forming an adjusting force which acts on the articulated arm apparatus, wherein the drive apparatus has a control device by means of which the adjusting drive can be actuated, wherein the drive apparatus has a sensor device (62) by means of which the charging contact face can be detected, wherein the sensor device is coupled to the control device, wherein a speed of the charging contact during a movement of the charging contact from the retracted position to the contact position can be controlled depending on a relative distance of the charging contact and charging contact face from the control device.