BLDC Vibrational Motor Axial Coil Relocation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional BLDC vibrational motors face challenges in reducing size and thickness while maintaining vibrational force, due to limitations in the design of the rotor, stator, and operating IC package, which restricts the miniaturization of components like the weight and magnet, leading to reduced vibrational power.
Innovation Solution
The design moves the coil closer to the central axis, eliminates the bearing support in the back yoke, and uses an iron-series oil-less bearing to shield magnetic fields, allowing for a larger weight volume and reduced magnet size, enabling stronger vibrational force without size constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the volume of the motor is reduced to make it thinner and smaller, then the size and thickness of the motor are reduced, but the vibrational force is reduced due to smaller weight volume
Solution Approach 1:
The patent relocates the coil from a radial position to an axial position (closer to the central axis), changing the spatial dimension of the magnetic field interaction. This dimensional change allows the weight to be positioned more effectively for generating vibrational force while accommodating a smaller overall motor volume.
Solution Approach 2:
The patent changes the positional parameter of the coil relative to the magnet, moving it closer to the central axis. This parameter change optimizes the magnetic field distribution and allows for increased weight volume within the same motor envelope, thereby maintaining vibrational force while reducing motor size.
2Force
If the coil is positioned farther from the central axis to maximize magnetic field interaction, then the magnetic force is improved, but the motor size increases
Solution Approach 1:
The patent transitions the coil positioning from a radial arrangement to an axial arrangement near the central axis. This dimensional repositioning maintains effective magnetic field interaction between the coil and magnet while significantly reducing the motor's radial dimensions and overall volume.
Solution Approach 2:
The patent concentrates the magnetic field interaction in a specific local region near the central axis where the coil and magnet are positioned close to each other. This localized optimization of magnetic interaction efficiency allows for reduced motor size while maintaining sufficient magnetic force for vibration generation.
3Stability of the object's composition
If a bearing support is provided in the back yoke to support the bearing, then the structural stability is improved, but the magnet size cannot be reduced due to space occupation
Solution Approach 1:
The patent extracts the bearing support function from the back yoke structure. By removing the dedicated bearing support component, space is freed up allowing for magnet size reduction, while the bearing is supported directly by the back yoke's cylindrical inner surface.
Solution Approach 2:
The back yoke is designed to serve multiple functions: it provides structural support for the bearing through its cylindrical inner surface, shields the magnetic field, and maintains rotor integrity. This multi-functionality eliminates the need for a separate bearing support component, freeing up space for magnet size reduction.
4Force
If the weight volume is increased to enhance vibrational force, then the vibrational power is improved, but the motor thickness increases
Solution Approach 1:
The patent repositions the coil axially near the central axis, which changes the spatial distribution of the magnetic field. This allows the weight to be positioned optimally for generating vibrational force without increasing the motor's axial thickness, as the magnetic interaction occurs in a different spatial configuration.
Solution Approach 2:
By changing the coil position parameter to be closer to the central axis, the patent optimizes the magnetic field distribution to work more efficiently with the weight. This parameter change allows for increased weight volume and enhanced vibrational power while maintaining the same motor thickness.
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 configuration results in a 20% increase in vibrational force without volume limitations, allowing for easier adjustment of vibration intensity by varying the weight's mass, and facilitates a more compact, efficient motor design.
Implementation Method 1
an iron-series oil-less bearing press-fitted in the inside of the permanent magnet to be engaged directly... having a function of shielding magnetic fields generated by the permanent magnet
Implementation Method 2
a doughnut-shaped permanent magnet... interacting with magnetic fields generated by the plurality of coils, and generating a rotational torque
Implementation Method 3
Each of the coils (28) flowing current forms a magnetic field, and interacts with the magnetic field of the rotor magnet (22), generating attracting and repelling forces
Implementation Method 4
Each of the coils (28) flowing current forms a magnetic field, and interacts with the magnetic field of the rotor magnet (22), generating attracting and repelling forces
Implementation Method 5
Outside or on the top of the magnet (22) is attached the weight (20) made of material having a high density such as tungsten, making the center of mass of the rotor eccentric... the rotor shakes and rotates, thus generating vibrations
Data Source
AI summary
A BLDC vibrational motor is provided, which is improved so as to generate a larger vibrational force per same volume compared to prior arts. A cylindrical bearing is fixed to a doughnut-shaped permanent magnet directly so that the magnet can be disposed as close as possible to the center of rotation, and thus coils can have a reduced volume and be disposed as close as possible to the center of rotation. The external space of the coils can be secured larger as much as the movement of position of the coils, and the weight takes up the space for rotation, so that volume of the weight can be enlarged. Thus, the weight can be extended and disposed to the external space of the coils, it is possible for a vibration motor with a small volume to generate a large vibrational force, which facilitates slim designs of the vibrational motor.