Spindle Motor Shaft Segmentation for Rigidity and Accuracy
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Solution Overview
Problem
Existing spindle motor designs face challenges in achieving shape accuracy and structural rigidity due to complex shapes, which hinder the miniaturization of disk drive apparatuses and affect manufacturing costs.
Innovation Solution
The design incorporates a shaft component with an inner and outer cylindrical shape, featuring lubricating oil in thrust and radial gaps, and dynamic pressure generating grooves, along with upper and lower seal portions to enhance structural rigidity and shape accuracy, allowing for easier manufacturing and miniaturization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the shaft and the first bearing component are manufactured as a single component, then the manufacturing process is simplified, but sufficient shape accuracy of the outer circumferential surface of the shaft cannot be obtained due to the complicated shape
Solution Approach 1:
The shaft is divided into two separate components: the shaft body and the outer circumferential surface portion. This segmentation allows each component to be manufactured independently with optimized processes - the shaft body can be manufactured with simpler processes while the outer circumferential surface portion is separately manufactured to achieve high shape accuracy, then assembled together.
2Strength
If the motor is designed with sufficient axial length to accommodate radial gap and fastening range, then structural integrity is ensured, but the motor cannot be made thinner
Solution Approach 1:
The fastening mechanism transitions from axial fastening to radial fastening. The outer circumferential surface portion of the shaft is inserted into the bearing component in the radial direction, allowing the fastening range to be established in the radial dimension rather than requiring additional axial length. This enables the motor to maintain structural integrity while reducing its axial 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 improves the structural rigidity and shape accuracy of the shaft component, enabling the motor to be made thinner while maintaining structural integrity and reducing manufacturing costs, thus enhancing the motor's performance and lifespan.
Implementation Method 1
a radial dynamic pressure generating groove array is provided on at least one of an inner circumferential surface of the sleeve portion and an outer circumferential surface of the outer shaft portion
Implementation Method 2
In the lower thrust gap, a lower thrust dynamic pressure generating groove array is provided on at least one of a lower surface of the sleeve portion and an upper surface of the lower plate portion
Implementation Method 3
The interface of the lubricating oil is located in the upper seal portion... The interface of the lubricating oil is located in the lower seal portion
Data Source
AI summary
A stationary portion of a motor includes a shaft component, an upper plate portion, and a lower plate portion. A rotating portion includes a sleeve portion which is disposed between the upper plate portion and the lower plate portion. The shaft component includes an inner shaft upper portion, an inner shaft lower portion which is located in a lower side of the inner shaft upper portion, and an outer shaft portion. The outer shaft portion is located on an outer circumferential surface of the inner shaft upper portion and an outer circumferential surface of the inner shaft lower portion. The inner shaft upper portion and the upper plate portion are preferably defined by a single monolithic member, and the inner shaft lower portion and the lower plate portion are preferably defined by a single monolithic member.