Variable Stator Winding Volume for Thin Spindle Motors
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Solution Overview
Problem
Reducing the height of spindle motors in disc drives while maintaining adequate electromagnetic performance is challenging, as it often results in increased current requirements to produce the same torque, compromising the small form factor and storage media density.
Innovation Solution
The design incorporates a stator lamination with different winding volumes on different stator teeth, where the portion not overlapping with the actuator arm travel area has increased winding volume, enhancing electromagnetic performance without increasing overall thickness, and allowing for a thinner profile where it overlaps with the actuator arm.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the winding volume on stator teeth is reduced to decrease motor height, then the form factor is improved, but the electromagnetic performance deteriorates
Solution Approach 1:
The patent applies local quality by differentiating the winding configuration across different stator teeth. Specifically, stator teeth in the first region (overlapping with actuator arm travel area) have reduced winding volume with fewer turns, while stator teeth in the second region (non-overlapping area) have increased winding volume with more turns. This localized differentiation allows the motor to achieve a thinner profile in the critical overlap region while maintaining adequate electromagnetic performance in non-critical regions.
2Power
If the winding volume is increased in non-overlapping regions, then the electromagnetic performance is improved, but the device complexity increases
Solution Approach 1:
The patent segments the stator teeth into distinct groups based on their spatial relationship with the actuator arm travel area. The stator is divided into a first region where teeth have reduced windings and a second region where teeth have increased windings. This segmentation strategy manages complexity by creating clear, region-based categories rather than requiring individual customization of each tooth, thereby balancing performance enhancement with manufacturing feasibility.
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 approach improves electromagnetic performance and reduces the disc drive thickness while maintaining desired performance levels, balancing form factor reduction with electromagnetic efficiency.
Implementation Method 1
The electric coils are supplied with current to produce a rotating magnetic field. The inside rotor with poles to capture torque from the rotating field and output the torque
Data Source
AI summary
A device includes a stator lamination of a stator for a motor with a first set of stator teeth and a second set of stator teeth, a first set of windings with wire having a first diameter on the first set of stator teeth and a second set of wire windings with wire having a second diameter. The second diameter is greater than the first diameter. The first and seconds sets of stator teeth are divided among at least two phases of the motor. Each phase includes an equal number of stator teeth from the first set of stator teeth and an equal number of stator teeth from the second set of stator teeth.