Coaxial Segmented Motor Layout for Deeper Material Cutting

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Solution Overview

Problem

Conventional material cutting devices face limitations in cutting depth and efficiency due to the need for torque transmission systems, which increase complexity and cost, and the use of conventional electric motors that are too large for direct drive, reducing the effective cutting depth.

Innovation Solution

A material cutting device with a direct drive system using a segmented electric motor where the stator extends over an angle of less than 360°, eliminating the need for torque transmission and allowing the motor to be mounted coaxially with the tool holder, using a synchronous reluctance machine with a segmented stator to achieve higher efficiency and deeper cutting depth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional electric motor is used for direct drive, then the motor can be mounted on the cutting shaft, but the motor housing diameter becomes larger than the tool holder diameter, reducing cutting depth

Engineering Contradiction:
Improveelimination of torque transmission systemVSAvoidcutting depth
Core Design Contradiction:
Device complexityVSLength of moving object

Solution Approach 1:

The stator is divided into multiple segments arranged around the rotor, with each segment covering a specific angular range. This segmentation allows the motor housing to be compact enough to fit within the tool holder diameter while still providing sufficient torque for direct drive operation, thereby enabling both elimination of torque transmission and maintenance of cutting depth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The motor design transitions from a conventional radial configuration to a configuration where the stator segments are arranged to extend primarily in the axial direction rather than radially outward. This dimensional change allows the motor to generate adequate torque without increasing the radial footprint beyond the tool holder diameter, preserving cutting depth while enabling direct drive.

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

2Power

If a belt drive system is used, then torque transmission is achieved, but structural complexity increases and overall efficiency decreases

Engineering Contradiction:
Improvetorque transmissionVSAvoidstructural effort and cost
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The motor shaft is directly coupled to the cutting shaft, merging the drive function and the cutting function into a single rotational axis. This eliminates the need for separate torque transmission components such as belt drives, pulleys, and intermediate shafts, thereby reducing structural complexity and improving overall efficiency while maintaining full torque transmission capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The torque transmission system (belt drive, pulleys, intermediate components) is extracted and removed from the design. The motor is designed to provide direct drive, taking out the unnecessary intermediate torque transmission stages and leaving only the essential cutting function, which simplifies the structure and reduces costs.

Inventive Principle:
Principle #2Taking out (Extraction)

3Area of stationary object

If the motor is offset behind the cutting shaft, then space is saved, but the motor mass cannot fully counteract the cutting disc's upward movement

Engineering Contradiction:
Improvespace utilizationVSAvoidcounterforce against cutting disc
Core Design Contradiction:
Area of stationary objectVSForce

Solution Approach 1:

The motor is repositioned from an offset axial arrangement to a coaxial arrangement, changing the spatial dimension of motor placement. This allows the motor mass to be positioned directly above the cutting shaft, maximizing its leverage to counteract the upward movement of the cutting disc through gravitational force, while the segmented stator design ensures the motor housing does not protrude beyond the tool holder diameter.

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

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 enhances cutting depth by eliminating the need for torque transmission, reduces construction costs, and improves overall efficiency by utilizing the motor's weight to counteract upward cutting forces, ensuring the cutting tool penetrates deeply into the material without reducing the usable cutting depth.

Implementation Method 1

The drive comprises an electric motor with a rotor and a stator. The rotational axis of the rotor of the electric motor and the rotational axis of the tool holder are arranged coaxially with each other

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Only a portion of the motor's mass acts as a cutting load, thus counteracting the cutting disc's upward movement

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP4212274B1Material cutting device
Publication Date: 2025.10.15 WACKER NEUSON PRODUKTION GMBH & CO KG
  • EP4212274B1 patent drawingFigure 1~2
  • EP4212274B1 patent drawingFigure 3~4
  • EP4212274B1 patent drawingFigure 5~6

AI summary

A material cutting device is specified, comprising a rotatably mounted tool holder (11) designed to carry a cutting tool (10) and a drive for rotating the tool holder (11), wherein the drive comprises an electric motor (12) with a rotor (13) and a stator (14), wherein the axis of rotation of the rotor (13) of the electric motor (12) and the axis of rotation of the tool holder (11) are arranged coaxially, and wherein the stator (14) surrounds the rotor (13) over an angle of less than 360 degrees.