Electromechanical Actuator Play-Free Drive Bearing for Rail Couplers

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Solution Overview

Problem

Existing digital automatic couplings (DAK) for rail vehicles, particularly in freight transport, face challenges with inefficient and time-consuming screw clutches, which require significant personnel and effort. Additionally, the size of electromechanical actuators is not suitable for the narrow construction space of the coupling, leading to suboptimal attachment and increased maintenance needs.

Innovation Solution

The implementation of an electromechanical actuator with a spring pressure brake as a connecting device, which replaces the intermediate flange and provides a play-free drive deposit. This solution allows for a standardized, cost-effective, and robust attachment of the electric motor, effectively managing radial loads and reducing the risk of early failure due to bending moments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If an electromechanical actuator is used in the coupling, then the automation and efficiency of the coupling process is improved, but the size of the actuator is not suitable for the narrow construction space of the coupling

Engineering Contradiction:
Improveautomation of coupling processVSAvoidsize of actuator
Core Design Contradiction:
Extent of automationVSVolume of moving object

Solution Approach 1:

The electric motor is integrated into the actuator housing in a nested arrangement, with the motor positioned within the available space of the coupling mechanism. This nesting approach allows the electromechanical actuator to fit within the narrow construction space while maintaining full automation capabilities.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The motor brake is designed as a spring-loaded dynamic component that automatically engages and disengages based on operational requirements. This dynamic design allows the brake to provide necessary holding force during coupling while minimizing space requirements when not in use.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If a conventional connecting device with intermediate flange is used, then the attachment of the electric motor is simplified, but the radial loads and bending moments increase leading to early failure

Engineering Contradiction:
Improveattachment simplicityVSAvoidconnection durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connecting device is merged with the actuator housing, eliminating the separate intermediate flange as an independent component. The housing itself is designed to directly receive and secure the electric motor, thereby reducing the number of connection points subjected to radial loads and bending moments while maintaining manufacturing simplicity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The actuator housing serves multiple functions: it encloses the electromechanical components, provides structural support, and acts as the mounting structure for the electric motor. This multi-functionality eliminates the need for a separate intermediate flange while improving reliability by distributing loads throughout the housing structure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If the electric motor is attached to the housing with intermediate flange, then the assembly is easier to construct, but the radial loads cause bending moments that increase the risk of early failure

Engineering Contradiction:
Improveassembly easeVSAvoidconnection strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The connecting device features are merged directly into the actuator housing structure, eliminating the intermediate flange. The housing is designed with integrated mounting surfaces and securing mechanisms that directly attach the electric motor, thereby maintaining assembly ease while eliminating the weak connection points that would experience damaging bending moments.

Inventive Principle:
Principle #5Merging (Combining)

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

The use of a spring pressure brake in the electromechanical actuator enhances the robustness and reliability of the middle buffer coupling by absorbing radial loads and reducing bending moments, thereby extending the lifespan of the connection and simplifying maintenance. This solution also standardizes components, saves costs by eliminating the intermediate flange, and improves the overall efficiency of the coupling process.

Implementation Method 1

The use of a spring pressure brake in the electromechanical actuator enhances the robustness and reliability of the middle buffer coupling by absorbing radial loads and reducing bending moments

Methodology Applied
Scientific EffectSpring pressure: Spring

Implementation Method 2

The connecting device comprises the motor brake as a spring-loaded brake

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4545375A1Digital automatic clutch (DAK) with electromechanical actuator with play-free drive bearing for a rail vehicle, and rail vehicle having such a clutch
Publication Date: 2025.04.30 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP4545375A1 patent drawingFigure 1
  • EP4545375A1 patent drawingFigure 2
  • EP4545375A1 patent drawingFigure 3

AI summary

A central buffer coupler (1) of a rail vehicle, comprising a housing (1a), a hook disc (2) with a pivot axis (2a), and an actuator (6) with an actuating element (7), wherein the actuating element (7) interacts with the hook disc, wherein the actuator (6) is designed as an electromechanical actuator (6) with at least one electric motor (10) and a motor brake (11), wherein the electric motor (10) of the electromechanical actuator (6) is connected to a housing (15) of the electromechanical actuator (6) by means of a connecting device (100), the connecting device (100) having a connecting flange (15a). The connecting device (100) includes the motor brake as a spring-applied brake (24). A rail vehicle with such a central buffer coupler (1) is provided.