Linear Vibration Drives for Track-Tamping Machine Flexibility

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Solution Overview

Problem

Existing tamping units for track maintenance face limitations in flexibility and operational speed due to space constraints and eccentric shaft drives, leading to reduced service life and uneven stress distribution on components.

Innovation Solution

The use of linear vibration drives arranged approximately parallel to the tamping unit's longitudinal axis, allowing all tamping picks to pivot independently and maintaining uniform transmission ratios, eliminating the need for shortened drives and enhancing modular design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If linear vibration drives are arranged in the direction of the tamping unit's longitudinal axis, then the tamping unit can be compact, but the rocker arms have different lever arm lengths resulting in uneven stress distribution and reduced component life

Engineering Contradiction:
Improvetamping unit compactnessVSAvoidcomponent service life
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent applies asymmetry by deliberately designing the rocker arms with different lever arm lengths to accommodate the linear vibration drive arrangement along the longitudinal axis. This asymmetric configuration allows the system to maintain compactness while managing the uneven stress distribution through careful geometric design of the rocker arm connections and pivot points.

Inventive Principle:
Principle #4Asymmetry

2Productivity

If multiple tamping units are arranged in series along the track, then more sleepers can be tamped per cycle increasing productivity, but space constraints in the intermediate section limit the available working space

Engineering Contradiction:
Improvesleepers tamped per cycleVSAvoidintermediate section working space
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent resolves the space constraint problem by arranging the linear vibration drives in a plane extending transversely to the tamping unit longitudinal axis, rather than solely along the longitudinal direction. This dimensional reorganization allows multiple tamping units to be positioned in series along the track while maintaining adequate working space in the intermediate sections, as the drive mechanisms occupy a different spatial dimension.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent segments the tamping machine into multiple independent tamping units that can be arranged in series. Each tamping unit is designed as a modular component with its own linear vibration drives arranged in the transverse plane, allowing the system to increase productivity by adding more units without creating interference between adjacent units in the intermediate sections.

Inventive Principle:
Principle #1Segmentation

3Area of stationary object

If auxiliary cylinders with short strokes are used in the intermediate section, then space constraints are met, but stress on piston seals and cylinder bores increases significantly reducing service life

Engineering Contradiction:
Improveintermediate section spaceVSAvoidauxiliary cylinder service life
Core Design Contradiction:
Area of stationary objectVSDuration of action of stationary object

Solution Approach 1:

The patent utilizes hydraulic linear vibration drives instead of traditional auxiliary cylinders with short strokes. By arranging these hydraulic drives in the transverse plane and optimizing their positioning, the system achieves the required force transmission while maintaining longer effective stroke lengths, thereby reducing stress on seals and cylinder components and extending service life.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

This configuration ensures all tamping picks can pivot freely, increasing machine flexibility and performance, extending component life, and reducing stress on parts, while enabling symmetrical and cost-effective operation.

Implementation Method 1

Track-tamping machine with tamping units (W1) comprising linear vibration drives (2), each tamping unit with two pairs of tamping tools (7, 8) arranged as rocker arms (13) on a support (4) guided in a height-adjustable manner within a tamping unit frame (17), the lower tamping pick ends (10) of which, intended for immersion in a ballast bed, can be driven in the opposite direction to the linear vibration drives (2)

Methodology Applied
Scientific EffectLinear vibration: Vibration

Implementation Method 2

the lower tamping pick ends (10) of which, intended for immersion in a ballast bed, can be driven in the opposite direction to the linear vibration drives (2) and can be hydraulically adjusted relative to each other

Methodology Applied
Scientific EffectHydraulic adjustment: Hydraulic Press

Data Source

PatentEP4237619B1Track-tamping machine with tamping units
Publication Date: 2025.12.03 HP3 REAL GMBH
  • EP4237619B1 patent drawingFigure 1
  • EP4237619B1 patent drawingFigure 2
  • EP4237619B1 patent drawingFigure 3

AI summary

The invention relates to a tamping unit (W1) for a track-tamping machine (A), the tamping unit comprising tamping tool pairs (7, 8), which are disposed on a carrier (4) height-adjustably guided in a tamping unit frame and are in the form of oscillating levers (13) and the lower tamping tine ends (10) of which are driven in opposite directions by means of a linear oscillatory drive (2) and can be hydraulically fed toward each other, which tamping tine ends are intended to be plunged into a ballast bed. According to the invention, in order to provide advantageous tamping conditions, for each tamping unit (W1) two planes (1), which are mutually spaced at a track sleeper distance and are arranged on both sides of an associated carrier (4) perpendicularly to the tamping-unit longitudinal axis (L), span a working space (R), in which the oscillating levers (13) and tamping tool pairs (7, 8) describe movement paths by means of the tamping tine ends (10) during an oscillating feed movement (14), the envelope of which movement paths lies exclusively in the working space (R), and the linear oscillatory drives (2) of a tamping unit (W1) are disposed one over the other in an oscillation plane running perpendicularly to the planes (1) and are inclined with respect to the tamping-unit longitudinal axis (L) at least approximately in parallel with each other.