Segment Motor Drive for Rail Wheel Machining

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Solution Overview

Problem

Existing machining centers for large and heavy components, such as rail vehicle wheels, face high mechanical loads and reduced service life due to gear drives, and segment motors require specific adaptations and complex assembly, limiting their applicability to specific products.

Innovation Solution

A radially segmented segment motor with a stator and rotor bell design, featuring permanent magnets and adjustable stator segments, is used to drive the chuck of the rail vehicle wheel, allowing for precise rotary position changes with reduced wear and simplified assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If gear drives operated by an electric motor are used to change the position of the work table, then the work table can be moved to different positions, but high mechanical loads occur during acceleration and braking phases causing increased wear and reduced service life

Engineering Contradiction:
Improvepositioning speedVSAvoidservice life of drive assemblies
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent replaces the mechanical gear drive system with a direct-drive motor system. The motor is directly coupled to the work table without intermediate gear mechanisms, eliminating mechanical loads during acceleration and braking phases. This substitution removes the wear-prone gear assemblies while maintaining positioning capability, thereby extending service life and reducing maintenance requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If segment motors are used to drive the work table, then wear on drive assemblies is reduced and acceleration and braking times are shortened, but the axial gap between primary and secondary elements must be kept constant requiring special axial bearings or hydrostatic solutions

Engineering Contradiction:
Improvewear resistance of drive assembliesVSAvoidcomplexity of bearing system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a dynamically adjustable axial gap in the segment motor design. The distance between the primary and secondary elements can be modified based on operational requirements and workpiece mass, eliminating the need for constant gap maintenance. This dynamic adjustment capability removes the requirement for complex special axial bearings or hydrostatic solutions while preserving the wear-resistant benefits of segment motor direct drive.

Inventive Principle:
Principle #15Dynamics

3Manufacturing precision

If segment motors are adapted for specific components like rail vehicle wheels, then high-precision coordinate drilling can be achieved, but the assembly of segment motors causes difficulties due to large magnetic forces affecting correct positioning of individual segments

Engineering Contradiction:
Improvecoordinate drilling precisionVSAvoidease of segment motor assembly
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies preliminary positioning measures during segment motor assembly. Individual segments are pre-positioned and temporarily fixed before final assembly, allowing correct alignment to be established before the large magnetic forces engage. This preliminary action ensures that segments are correctly positioned during assembly, eliminating positioning difficulties caused by magnetic forces while maintaining the high manufacturing precision required for coordinate drilling operations.

Inventive Principle:
Principle #10Preliminary 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

This design enables high-precision coordinate drilling and extended service life for machining centers, specifically suitable for rail vehicle wheels, with reduced maintenance efforts and adaptable to various applications.

Implementation Method 1

a rotor which is designed as a rotor bell with rotor segments designed as permanent magnets

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Correct positioning of the individual segments, which are not yet finally fixed in position, is problematic as a result of the large magnetic forces

Methodology Applied
Scientific EffectMagnetic force: Magnetic Field

Data Source

PatentEP3549247B1Bearbeitungszentrum zur bearbeitung von schienenfahrzeugrädern und verfahren zur herstellung eines segmentmotors für ein derartiges bearbeitungszentrum
Publication Date: 2021.05.26 NILES SIMMONS INDUSTRIEANLAGEN GMBH
  • EP3549247B1 patent drawingFigure 1~2

AI summary

The invention relates to a machining center for machining rail vehicle wheels, wherein the machining centre comprises a machine frame which consists of a base and a stand mounted on the base. The aim of the invention is to provide a segment motor which can be used as a drive for rotational position changes of a wheel for a rail vehicle, which is to be machined on the machining centre. The aim is achieved in that the drive of a chuck (10) for the rail vehicle wheel is designed as a workpiece (11) produced by a segment motor which is arranged below the workpiece (11), which is radially segmented and its constructional height can be modified, the segment motor comprises between two and five separate stator segments (2) with a respectively identical height of between 200 - 350mm. The invention also relates to a method for mounting a segment motor configured in said way.