Coreless Motor Coil Pitch Layout for Torque-Speed Tuning
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Solution Overview
Problem
Existing coreless motors face limitations in design flexibility when changing properties such as output torque or rotation speed, often leading to increased motor length or reduced stiffness.
Innovation Solution
A coreless motor design where the angle interval between conductive wire portions in a single winding is set differently from the magnetic pole interval, allowing for adjustable properties without altering the motor's overall size or strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the dimension of the parallel portion of the coil is increased to increase output torque, then the output torque is improved, but the overall length of the motor increases
Solution Approach 1:
The patent applies parameter changes by decoupling the coil pitch angle β from the magnetic pole pitch angle α. By setting β ≠ α, the design can optimize the parallel portion length for torque generation without being constrained by the magnetic pole configuration, thereby increasing torque output without proportionally increasing the overall motor length.
2Speed
If the number of turns of the coil is decreased to increase rotation speed, then the rotation speed is improved, but the stiffness of the coil is reduced
Solution Approach 1:
The patent utilizes parameter changes by introducing the angle interval β as an independent design variable. This allows optimization of the coil geometry (parallel portion dimension and oblique portion angle) to maintain structural stiffness even when the number of turns is reduced for higher rotation speed applications.
3Ease of manufacture
If the angle interval of the coil element is set equal to the magnetic pole pitch, then the manufacturing process is simplified, but the degree of freedom in designing the motor is reduced
Solution Approach 1:
The patent applies parameter changes by explicitly setting the coil pitch angle β to be different from the magnetic pole pitch angle α. This breaks the conventional constraint that limited design freedom, allowing independent optimization of coil geometry for various motor properties while maintaining manufacturing feasibility through the defined geometric relationships.
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
Enables changing motor properties like torque and speed without compromising design freedom, by optimizing the coil pitch relative to the magnetic pole pitch.
Implementation Method 1
a coil 60 that is formed by winding a conductive wire into a cylindrical shape, the coil being configured to rotate together with the rotating shaft; and a cylindrical magnet that is disposed inside or outside the cylindrical coil
Implementation Method 2
a cylindrical magnet that is disposed inside or outside the cylindrical coil
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
To change properties of a motor without lowering the degree of freedom in designing the motor, a coreless motor (100) includes a rotating shaft (20); a coil (60) that is formed by winding a conductive wire (61) into a cylindrical shape, the coil being configured to rotate together with the rotating shaft (20); and a cylindrical magnet (30) that is disposed inside or outside the cylindrical coil (60). An angle interval (β) about an axis (center C) of the rotating shaft (20) between conductive wire portions (as one example, between two parallel portions (62), (62)) in a single winding in the coil (60) is set to be different from an angle interval (a) about the axis (center C) of the rotating shaft (20) between magnetic poles (30N, 30S) of the magnet (30).