Ring Rotor Drive with Roller Support for Low-Inertia Rotation
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Solution Overview
Problem
Conventional rotation drive devices for weaving machines face issues with large and heavy rotors due to dedicated rolling bearings, leading to increased moment of inertia, complexity, and difficulty in installing in narrow spaces, which hinder cost reduction and energy efficiency.
Innovation Solution
A rotation drive device with a movable body portion featuring a ring-shaped rotor yoke and rotor magnet, supported by small, lightweight support rollers, and a fixed body portion with stator core portions and stator coils, eliminating large rolling bearings and allowing for a compact, versatile design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated rolling bearing with large diameter is used to support the rotor, then the rotor can be supported reliably, but the rotor becomes heavier and larger, increasing the moment of inertia and reducing high-speed response
Solution Approach 1:
The patent replaces the traditional rolling bearing support system with a magnetic field-based support system. The rotor is supported by magnetic attraction forces between the rotor magnet and stator core portions, eliminating the need for mechanical rolling bearings. This substitution reduces rotor weight and moment of inertia while maintaining support reliability through magnetic forces.
Solution Approach 2:
The patent changes the support mechanism from mechanical contact (rolling bearing) to magnetic field interaction. By adjusting magnetic field parameters such as flux density and pole arrangement, the system achieves reliable rotor support without the weight and inertia penalties of traditional mechanical bearings.
2Reliability
If a dedicated rolling bearing with large diameter is used to support the rotor, then the rotor can be supported reliably, but the overall device structure becomes more complex and the device thickness increases
Solution Approach 1:
The patent merges the rotor support function with the electromagnetic drive system itself. The stator core portions that generate the driving magnetic field also provide the support function, eliminating the need for separate bearing structures. This integration simplifies the overall device structure and reduces thickness while maintaining support reliability.
Solution Approach 2:
The stator core portions serve multiple functions: generating the driving magnetic field for rotor rotation and providing support forces to hold the rotor in position. This multi-functionality eliminates the need for dedicated support structures, reducing device complexity and thickness.
3Reliability
If a dedicated rolling bearing with large diameter is used to support the rotor, then the rotor can be supported reliably, but the cost increases and energy efficiency decreases
Solution Approach 1:
The patent replaces expensive mechanical rolling bearings with a magnetic field-based support system that uses the same electromagnetic components (stator coils and core portions) already required for drive operation. This substitution reduces component count, manufacturing complexity, and overall cost while maintaining support reliability.
Solution Approach 2:
The electromagnetic components perform dual functions of driving and supporting the rotor, eliminating the need for separate bearing components. This reduces material costs, assembly costs, and maintenance costs while improving energy efficiency by eliminating mechanical friction losses.
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 device significantly reduces weight and moment of inertia, enhances high-speed responsiveness, and improves cost efficiency and versatility, enabling installation in narrow spaces while reducing magnetic attraction forces and enhancing durability.
Implementation Method 1
a fixed body portion Mc having a stator 2 in which a plurality of stator core portions 2c are integrally provided and a stator coil 3 wound around the stator core portion 2c; and a movable body portion Mm having a rotor magnet 4 having a plurality of magnetic poles
Data Source
AI summary
A rotation drive device includes a movable body portion having a rotor yoke formed in a ring shape and a ring-shaped rotor magnet in which a plurality of magnetic poles are arranged along a circumferential direction of an outer peripheral portion of the rotor yoke; a fixed body portion in which a plurality of stator core portions, each of which faces an outer peripheral portion of the movable body portion, are arranged in an inner peripheral portion of a stator formed in a ring shape at predetermined intervals along the circumferential direction; and a movable body support portion formed of a plurality of support rollers rotatably supporting the movable body portion by being fixed in position with respect to the stator and bringing a roller peripheral surface into contact with the outer peripheral portion or an inner peripheral portion of the movable body portion.