Stepping Motor Cr-Diffusion Magnetic Path
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stepping motors for analog electronic timepieces face issues with high power consumption and instability due to magnetic flux loss and mechanical stress during manufacturing, leading to inaccurate rotor positioning and potential damage.
Innovation Solution
A stepping motor with a Cr-diffusion region formed in the magnetic path around the rotor accommodating through-hole, using an integrated Fe—Ni alloy stator, reduces permeability and magnetic flux consumption, enhancing the retaining force and stability while avoiding mechanical stress and misalignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If an integrated stator with a narrow portion is used to easily obtain magnetic leakage flux, then the rotor can be rotated, but power consumption increases due to magnetic flux loss in the narrow portion
Solution Approach 1:
The patent applies local quality by creating a non-magnetic region with reduced permeability at specific locations (around the rotor accommodating through-hole) while maintaining high permeability in other parts of the magnetic path. This is achieved by forming Cr-diffusion regions or introducing non-magnetic material into specific portions of the stator, allowing magnetic flux to be concentrated where needed rather than being consumed by narrow portions throughout the magnetic path.
Solution Approach 2:
The patent changes the magnetic permeability parameter locally by forming Cr-diffusion regions or inserting non-magnetic material into the stator. This creates regions with different magnetic properties (high permeability in most areas, low permeability in specific regions around the through-hole), which optimizes magnetic flux distribution and reduces power consumption by preventing flux consumption in non-critical areas.
2Loss of energy
If the stator is divided into two pieces by machining and welding to minimize cross-sectional area, then magnetic leakage flux can be obtained, but mechanical stress and distortion occur during welding
Solution Approach 1:
The patent merges the stator into a single integrated piece rather than dividing it into multiple parts. This eliminates the need for welding or joining operations, thereby avoiding mechanical stress, distortion, and misalignment issues. The integrated structure maintains structural integrity while still achieving the desired magnetic flux characteristics through localized permeability modifications.
Solution Approach 2:
The patent replaces mechanical joining methods (welding, bolting) with a unified integrated structure. Instead of mechanically assembling multiple stator parts, the invention uses a single-piece construction with locally modified magnetic properties, substituting mechanical connection systems with a monolithic structure that avoids stress concentration and alignment errors.
3Reliability
If the narrow portion is saturated with magnetic flux to divide the stator into two magnetic pole pieces, then the rotor can be driven, but the magnetic flux generated from the rotor itself is consumed by the narrow portion
Solution Approach 1:
The patent applies local quality by creating non-magnetic regions with reduced permeability in specific locations (around the rotor accommodating through-hole) while maintaining high permeability in the main magnetic path. This allows the magnetic flux generated by the rotor to be preserved and directed to where it is needed for driving the rotor, rather than being consumed by narrow portions in the magnetic path.
Solution Approach 2:
The patent converts the potentially harmful effect of magnetic flux consumption into a beneficial configuration by strategically placing non-magnetic regions. These regions prevent flux leakage and consumption in areas where it would be wasted, while ensuring that sufficient flux reaches the rotor for reliable driving. The Cr-diffusion regions or non-magnetic material insertions create a magnetic flux distribution pattern that benefits overall motor performance.
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 reduces power consumption, improves rotor stability, and increases driving frequencies by minimizing magnetic flux loss and mechanical stress, resulting in more efficient and reliable operation.
Implementation Method 1
A Cr-diffusion region having a molten-solidified portion of Cr is formed in a portion of a magnetic path disposed around a rotor accommodating through-hole so as to decrease permeability in the region
Implementation Method 2
A Cr-diffusion region having a molten-solidified portion of Cr is formed in a portion of a magnetic path
Implementation Method 3
a principle of driving the rotor is that the narrow portion is first saturated with the magnetic flux and the stator is magnetically divided into two magnetic pole pieces
Implementation Method 4
it becomes difficult to obtain a peak of magnetic potential, thereby degrading a retaining force for magnetically stopping and retaining the rotor
Data Source
AI summary
A stepping motor includes a one-piece stator integrally molded by using a Fe—Ni alloy plate through machining, a rotor accommodating through-hole, and in which a magnetic path is disposed around the rotor accommodating through-hole. A rotor is rotatably arranged inside the rotor accommodating through-hole. A magnetic core is connected to the stator, and a coil is wound on the magnetic core. A Cr-diffusion region having a molten-solidified portion of Cr is diffused in the Fe—Ni alloy stator in a portion of the magnetic path.