Stepped Rotor Motor Layout for Compact High-Torque Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a demand for motors that can achieve size reduction while maintaining high torque and performance.
Innovation Solution
The motor design includes an axial member, a tubular rotating body with a magnet, a stator inside the rotating body, and two bearings supporting the rotating body. The stator is fixed to the axial member, and the radial dimension of the stator is smaller than or equal to the radial dimension of the bearing, allowing for size reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the motor size is reduced, then the compactness is improved, but the torque output deteriorates
Solution Approach 1:
The stator is positioned inside the rotating body, creating a nested configuration where the stator core and coils are contained within the rotor structure. This allows the motor to achieve compact dimensions while maintaining the necessary functional components for torque generation, effectively nesting critical torque-producing elements within the limited radial space.
Solution Approach 2:
The patent utilizes the axial dimension by extending the stator and rotating body in the axial direction rather than increasing radial dimensions. The stepped configuration of the rotating body with different radial dimensions at opposite ends allows optimization of the magnetic path and torque generation in the axial direction, achieving high torque output without proportionally increasing overall motor volume.
2Volume of moving object
If the radial dimension of the stator is reduced, then the motor size is reduced, but the magnetic field strength deteriorates
Solution Approach 1:
The rotating body has different radial dimensions at opposite ends, creating local variations in the magnetic path length and flux distribution. This stepped configuration allows the magnetic field to be optimized locally in different axial regions, maintaining sufficient magnetic field strength despite reduced overall radial dimensions of the stator.
Solution Approach 2:
The stator is pre-positioned inside the rotating body during assembly, with the stator core and coils configured to generate the magnetic field before the rotating body is set into motion. This preliminary configuration ensures that the magnetic field is established within the constrained radial space, maintaining field strength despite the reduced stator radial dimension.
3Ease of manufacture
If a single-member tubular structure is used, then the manufacturing complexity is reduced, but the structural strength deteriorates
Solution Approach 1:
The single-member tubular structure is designed with segmented functional zones along its axial length, including different radial dimensions at opposite ends. This segmentation allows the structure to perform multiple functions (support, magnetic path, mechanical strength) within a single manufactured component, achieving both manufacturing simplicity and structural adequacy through careful geometric design rather than assembly of multiple parts.
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 achieves size reduction while maintaining high torque and performance, with the radial dimension of the stator being smaller than or equal to the radial dimension of the bearing, and the motor is capable of achieving high precision stabilization and high torque output.
Implementation Method 1
a bearing supporting the rotating body with respect to the axial member
Implementation Method 2
a magnet
Implementation Method 3
a magnet... a stator inside the rotating body
Data Source
AI summary
To provide a motor capable of meeting a demand for size reduction. The motor includes an axial member, a tubular rotating body rotatable in relation to the axial member, a bearing supporting the rotating body with respect to the axial member, and a stator inside the rotating body. The rotating body preferably includes a tubular member formed of a single member, and a magnet.