Rail Impact Wrench Handle Decoupling for Vibration Damping

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Solution Overview

Problem

Operating an electrically operated impact wrench for tightening and loosening nuts and bolts on a track is extremely strenuous due to high torques and forces involved, leading to operator fatigue and discomfort.

Innovation Solution

A vibration decoupling device is integrated to separate the handle from the impact wrench, using elastomeric materials around the axis of rotation of the electric drive motor, with the accumulator acting as a counterweight on the operating side, ensuring that forces and vibrations are heavily damped, and the control device is positioned to avoid undamped forces, allowing only electrical lines to pass through the decoupling plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the impact wrench mechanism is directly connected to the handle, then the structure is simple, but the operator experiences high vibrations and forces leading to fatigue

Engineering Contradiction:
Improveoperator comfortVSAvoidstructure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The impact wrench is divided into two separate sides by a decoupling plane: the working side containing the impact wrench mechanism and electric drive motor, and the operating side containing the handle and control device. This segmentation isolates the vibration source from the operator's hand, reducing vibration exposure while maintaining structural simplicity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A vibration decoupling device is introduced as an intermediary element between the working side and operating side. This decoupling device allows mechanical connection for power transmission while blocking vibration transmission to the handle, effectively mediating between the high-vibration impact mechanism and the operator's hand.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the electric drive motor is located on the operating side with the handle, then vibrations are reduced, but the mechanical connection becomes complex requiring drive shafts through the decoupling plane

Engineering Contradiction:
Improvevibration reductionVSAvoidmechanical connection complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of placing the electric drive motor on the operating side with the handle (conventional arrangement), the invention inverts this by locating the motor on the working side with the impact wrench mechanism. This inversion simplifies the mechanical connection by eliminating the need for drive shafts penetrating the decoupling plane, while the vibration decoupling device still effectively protects the operator.

Inventive Principle:
Principle #13The other way round (Inversion)

3Ease of operation

If vibration dampening materials are added around the motor axis, then vibration transmission is reduced, but the device complexity increases

Engineering Contradiction:
Improvevibration dampingVSAvoidcomponent quantity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Vibration dampening materials are applied locally and selectively around specific components (such as the motor axis or mounting points) rather than throughout the entire device. This targeted approach provides effective vibration damping at critical locations while minimizing the addition of components and maintaining overall structural simplicity.

Inventive Principle:
Principle #3Local quality

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 solution significantly reduces operator fatigue by providing a high level of operating comfort and reliability, allowing for efficient operation with reduced vibration transmission, enabling easier handling and maintenance of the impact wrench.

Implementation Method 1

The vibration decoupling device decouples the at least one handle from the impact wrench mechanism in a vibration-damping manner

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

The at least one vibration damper is elastically designed to achieve vibration decoupling or damping. Preferably, the at least one vibration damper comprises an elastomeric material, in particular a rubber material.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

Because the accumulator is arranged on the operating side, it forms a counterweight to the impact wrench mechanism and, optionally, to the electric drive motor, so that the accumulator effectively dampens or decouples vibrations at the at least one handle.

Methodology Applied
Scientific EffectCounterweight effect: Gravitation

Data Source

PatentEP3749806B1Impact wrench for tightening and loosening nuts and screws of a rail
Publication Date: 2022.09.21 ROBEL BAHNBAUMASCHINEN GMBH
  • EP3749806B1 patent drawingFigure 1
  • EP3749806B1 patent drawingFigure 2

AI summary

The invention relates to an impact wrench for tightening and loosening nuts and screws of a rail, having a vibration decoupling device (7) which serves for vibration decoupling of at least one handle (10, 11, 13) of an electrically operated impact wrench.